Chemcad 6 User Guide 2011 - [PDF Document] (2024)

CHEMCAD Version 6 User Guide

CHEMCADVersion6UserGuide i

CHEMCAD Version 6 User Guide

Table of Contents

Chapter1–IntroductiontoCHEMCAD .............................................................................................. 1 OverviewofCHEMCADandItsUses ................................................................................................ 1 CHEMCADProductsandFeatures ................................................................................................. 3

CC-STEADY STATE .......................................................................................................................................3 CC-DYNAMICS ...............................................................................................................................................3 CC-BATCH.......................................................................................................................................................3 CC-THERM.......................................................................................................................................................3 CC-SAFETY NET.............................................................................................................................................3 CC-FLASH........................................................................................................................................................3

CHEMCADFeaturesbyModule...................................................................................................... 4 UnitOpsbyModule............................................................................................................................ 5

Chapter2–GettingStartedwithCHEMCAD..................................................................................... 7 InstallingtheSoftware........................................................................................................................... 7 LicensingCHEMCAD ......................................................................................................................... 10 TypesofCHEMCADLicenses........................................................................................................ 10 LicenseSettings ................................................................................................................................. 11 UpdatingaLicense ........................................................................................................................... 13

GettingHelpwithCHEMCAD .......................................................................................................... 15 OnlineHelp ....................................................................................................................................... 15 CHEMCADCoach............................................................................................................................ 15 ProcedureDemos.............................................................................................................................. 16 TheChemstationsWebSite............................................................................................................. 16 ContactingChemstationsTechnicalSupport ............................................................................... 16

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Chapter3–TheCHEMCADInterface................................................................................................ 17 TheCHEMCADWindow ................................................................................................................... 17 TheWorkspace.................................................................................................................................. 18 TheCHEMCADExplorerPane ...................................................................................................... 18

The Recent Files Tab .......................................................................................................................................19 The Simulation Tab .........................................................................................................................................19 The Visual Basic Tab.......................................................................................................................................20

ThePalettePane................................................................................................................................ 20 Selecting a Palette............................................................................................................................................20 Customizing Palettes .......................................................................................................................................21

TheMessagesPane ........................................................................................................................... 22 The Errors and Warnings Tab..........................................................................................................................22 The Run Trace Tab ..........................................................................................................................................22 The Notes Tab .................................................................................................................................................23

TheMainMenu................................................................................................................................. 23 TheToolbar........................................................................................................................................ 23

CustomizingtheCHEMCADScreen................................................................................................. 24 ViewingandHidingScreenElements ........................................................................................... 24 ResizingandMovingItems............................................................................................................. 24

Resizing a Pane................................................................................................................................................24 Moving a Pane .................................................................................................................................................25

PinningandUnpinningPanes........................................................................................................ 25 OtherUsefulInterfaceHints............................................................................................................... 26 UndoandRedo ................................................................................................................................. 26 VisibleGrid........................................................................................................................................ 27 AdjustingYourViewoftheWorkspace........................................................................................ 27 TheCHEMCADCoachPane .......................................................................................................... 27

Chapter4–WorkingwithSimulationFiles ...................................................................................... 29 AboutCHEMCADSimulationFiles.................................................................................................. 29 UserComponentsinCHEMCAD .................................................................................................. 30 ExampleFiles..................................................................................................................................... 30

OpeninganExistingSimulation ........................................................................................................ 31 CreatingaNewSimulation................................................................................................................. 31 SavingaSimulation.............................................................................................................................. 32 SavingDifferentCasesfortheSameSimulation.......................................................................... 32

E‐mailingaSimulation ........................................................................................................................ 33 WorkingwithCHEMCADFilesfromPreviousVersions .............................................................. 34

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CHEMCADVersion6UserGuide iii

Chapter5‐BuildingandUsingaBasicSimulation......................................................................... 35 StartingaNewSimulation .................................................................................................................. 35 SelectingEngineeringUnits................................................................................................................ 36 DrawingtheFlowsheet........................................................................................................................ 36 AddingUnitOps ............................................................................................................................... 36

Selecting a Default Icon for a UnitOp .............................................................................................................37 Manipulating UnitOp Icons .............................................................................................................................38 UnitOp ID Numbers ........................................................................................................................................38

DrawingandConnectingaStream ................................................................................................ 39 Choosing a Stream Route ................................................................................................................................39 Rerouting a Stream ..........................................................................................................................................40 Stream ID Numbers .........................................................................................................................................40

OtherDrawingTools........................................................................................................................ 41 The Text Tool ..................................................................................................................................................41 Simple Drawing Tools: Rectangle, Ellipse, and Line......................................................................................41 Complex Drawing Tools: Multi-line and Polygon ..........................................................................................41

SelectingChemicalComponents........................................................................................................ 42 FindingaComponent ...................................................................................................................... 43 AddingaComponent....................................................................................................................... 44 ChangingtheOrderofSelectedComponents .............................................................................. 45 RemovingItemsfromtheSelectedComponentsList ................................................................. 45

SelectingK‐valueandEnthalpyOptions .......................................................................................... 46 UsingtheThermodynamicsWizard .............................................................................................. 46

Selecting Components to Ignore......................................................................................................................46 Specifying Process Conditions ........................................................................................................................46 How the Thermodynamics Wizard Makes Suggestions ..................................................................................46 Should the Thermodynamics Wizard be trusted to make design decisions? ...................................................47

ManuallySelectingThermodynamicsSettings ............................................................................ 47 DefiningStreams .................................................................................................................................. 48 ThermodynamicProperties............................................................................................................. 48 StreamComposition......................................................................................................................... 49 TotalFlowProperties ....................................................................................................................... 49

SpecifyingEquipmentParameters..................................................................................................... 49 RunningtheSimulation....................................................................................................................... 50 ReviewingtheResults.......................................................................................................................... 51

Chapter6‐UsingCHEMCADforHigh‐fidelityModeling ........................................................... 53 Whatishigh‐fidelitymodeling?......................................................................................................... 53 CriteriaforHigh‐fidelityModeling ................................................................................................... 54

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IntroductiontoEquipmentSizing ..................................................................................................... 54 High‐fidelityModelingandSizingforCommonUnitOps ............................................................ 55 Piping.................................................................................................................................................. 55

Low-fidelity .....................................................................................................................................................55 Sizing...............................................................................................................................................................55 High-fidelity ....................................................................................................................................................56

Pumps,Compressors,andExpanders ........................................................................................... 56 Low-fidelity .....................................................................................................................................................56 High-fidelity ....................................................................................................................................................56

VesselsandTanks............................................................................................................................. 56 Low-fidelity .....................................................................................................................................................56 Sizing...............................................................................................................................................................57 High-fidelity ....................................................................................................................................................57

Valves ................................................................................................................................................. 57 Low-fidelity .....................................................................................................................................................57 Sizing...............................................................................................................................................................58 High-fidelity ....................................................................................................................................................58

Columns ............................................................................................................................................. 58 Low-fidelity .....................................................................................................................................................58 Sizing...............................................................................................................................................................58 High-fidelity ....................................................................................................................................................60

HeatExchangers ............................................................................................................................... 60 Low-fidelity .....................................................................................................................................................60 Sizing...............................................................................................................................................................60 High-fidelity ....................................................................................................................................................60

ReliefDevices .................................................................................................................................... 61 Low-fidelity .....................................................................................................................................................61 High-fidelity ....................................................................................................................................................62

LicensingConsiderationsforHigh‐fidelityModeling.................................................................... 62 Chapter7–BuildingandUsingaDynamicSimulation ................................................................. 63 Whatdowemeanbydynamics? ....................................................................................................... 63 LicensingConsiderations .................................................................................................................... 63 AdditionalInputforDynamicOperation......................................................................................... 64 StrategiesforDynamicSimulations ............................................................................................... 65

SettingUpDynamicOperation .......................................................................................................... 65 SwitchingtoDynamics .................................................................................................................... 65 SettingtheRunTime........................................................................................................................ 66 SelectingStreamsandUnitOps ...................................................................................................... 68

RunningaDynamicSimulation ......................................................................................................... 69 RunfromInitialState ....................................................................................................................... 69

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RunfromCurrentState.................................................................................................................... 69 RunOneStepataTime ................................................................................................................... 70

OtherDynamicCommands ................................................................................................................ 70 ResettoInitialState .......................................................................................................................... 70 SaveAsInitialState .......................................................................................................................... 71

OutputfromDynamicSimulations ................................................................................................... 71 ReviewingtheFlowsheetSpecifications........................................................................................ 72 PlottingDynamicResults ................................................................................................................ 72 Text‐basedDynamicReports .......................................................................................................... 72

Chapter8–OutputandReports........................................................................................................... 75 TextReports .......................................................................................................................................... 75 ReportOutputSetup ........................................................................................................................ 75 Stream‐basedReports....................................................................................................................... 76

Stream Groups .................................................................................................................................................76 Stream Compositions.......................................................................................................................................78 Stream Properties.............................................................................................................................................79 Particle Size Distribution.................................................................................................................................80 Pseudocomponent Curves................................................................................................................................80

UnitOp‐basedReports...................................................................................................................... 80 UnitOp Groups ................................................................................................................................................80 Select UnitOps.................................................................................................................................................81 Spec Sheet........................................................................................................................................................82 Distillation .......................................................................................................................................................82

Flowsheet‐basedReports ................................................................................................................. 83 Topology..........................................................................................................................................................83 Thermodynamics .............................................................................................................................................83 Mass and Energy Balances ..............................................................................................................................83

DynamicsReports............................................................................................................................. 83 Batch Results ...................................................................................................................................................83 Dynamics .........................................................................................................................................................83

ConsolidatedReportsandtheCHEMCADReportWriter......................................................... 84 Choosing and Ordering Report Sections..........................................................................................................84 Selecting Flowsheet Elements .........................................................................................................................85 Formatting Report Sections .............................................................................................................................85 Naming the Report and Choosing a Destination..............................................................................................86

GraphicalReports................................................................................................................................. 87 ThermophysicalDataGraphs ......................................................................................................... 87

TPXY...............................................................................................................................................................87 Binary LLE......................................................................................................................................................87 Binodal Plot .....................................................................................................................................................87

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Binodal/Residue Curves ..................................................................................................................................87 Residue Curves ................................................................................................................................................88 Solid/Liquid Equilibrium.................................................................................................................................88

Flowsheet‐basedGraphs.................................................................................................................. 88 UnitOp‐basedPlots .......................................................................................................................... 88

Tower Profiles .................................................................................................................................................88 Heat Curves .....................................................................................................................................................88 Plug Flow Reactor Profile ...............................................................................................................................88 Pipe Profile ......................................................................................................................................................88 Controller Convergence...................................................................................................................................89

DynamicPlots ................................................................................................................................... 89 User‐specifiedFile ............................................................................................................................ 89

PrintingCHEMCADReports ............................................................................................................. 89 ProcessFlowDiagrams ....................................................................................................................... 90 FlowsheetDataboxes........................................................................................................................ 90

Stream Boxes...................................................................................................................................................90 UnitOp Boxes ..................................................................................................................................................91 TP Boxes .........................................................................................................................................................91 Excel Range Boxes ..........................................................................................................................................92

UsingtheLayersFeatureforSelectiveViewingandPrinting ................................................... 93 Scenarios for Using Layers..............................................................................................................................93 Creating a New layer .......................................................................................................................................94 Assigning Objects to a Layer...........................................................................................................................95 Hiding and Viewing Layers.............................................................................................................................95 Removing an Object from a Layer ..................................................................................................................96 Deleting an Entire Layer..................................................................................................................................96

PrintingaProcessFlowDiagram ................................................................................................... 96 Chapter9–CustomizingCHEMCAD ................................................................................................ 99 FlowsheetTemplates ........................................................................................................................... 99 CreatingaTemplate ....................................................................................................................... 100 ViewingaTemplate’sProperties.................................................................................................. 100 ApplyingaTemplate...................................................................................................................... 100 RenamingorDeletingaTemplate................................................................................................ 100

CreatingCustomComponents ......................................................................................................... 101 AddingaSingleComponent......................................................................................................... 101

Creating the Component ................................................................................................................................101 Regressing Data into the Component ............................................................................................................104

PseudocomponentRange .............................................................................................................. 105 ImportingaNeutralFile ................................................................................................................ 106

CreatingaCustomSymbol ............................................................................................................... 107

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CustomizedCostingCalculations.................................................................................................... 109 CreatingCustomUnitOps ................................................................................................................ 109 CreatingaCustomUnitOpDialogBox ....................................................................................... 110

CustomizingThermodynamics ........................................................................................................ 111 CreatingaCustomK‐valueorEnthalpyModel......................................................................... 111 CreatingaCustomMixingRule ................................................................................................... 112

VisualBasicApplications(VBA)...................................................................................................... 113 DefiningaReaction,MixingRule,orUnitOp ............................................................................ 113 UsingaVBA‐definedReaction ..................................................................................................... 113 UsingaVBA‐definedMixingRule............................................................................................... 114 UsingaVBA‐definedUnitOp ....................................................................................................... 115

Chapter10–DataInterfaces ............................................................................................................... 117 ExcelDataMapping........................................................................................................................... 118 CreatinganExcelDataMap.......................................................................................................... 118 DataMapExecutionRules ............................................................................................................ 121

CreatingExcelUnitOps ..................................................................................................................... 123 SpecificationSheets ............................................................................................................................ 124 UsingCHEMCADasanOPCServer .............................................................................................. 125 OPCApplications ........................................................................................................................... 125 OPCCompliance............................................................................................................................. 125 EnablingCHEMCADasanOPCServer ..................................................................................... 125 ReadingandWritingValuestoCHEMCADUsingOPC ......................................................... 126 OPCServerOperations.................................................................................................................. 126 CHEMCADOPCNamespace ....................................................................................................... 127

COMInterfaces ................................................................................................................................... 128 ConnectingExcelandCHEMCAD:ASimpleCOMInterface ................................................. 128

Using the VBClient Example ........................................................................................................................129 A Peek under the Hood..................................................................................................................................129

Chapter11–CHEMCADTutorials ................................................................................................... 131 CC‐STEADYSTATETutorial ........................................................................................................... 132 Overview.......................................................................................................................................... 132 StartingaNewSimulation ............................................................................................................ 133 SelectingEngineeringUnits .......................................................................................................... 133 DrawingtheFlowsheet .................................................................................................................. 133

Placing UnitOps.............................................................................................................................................133 Drawing Streams ...........................................................................................................................................136

SelectingComponents.................................................................................................................... 136

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SelectingThermodynamicOptions.............................................................................................. 138 DefiningtheFeedStreams............................................................................................................. 140 EnterUnitOpParameters .............................................................................................................. 142

First Heat Exchanger .....................................................................................................................................142 Second Heat Exchanger .................................................................................................................................143 Flash Drum ....................................................................................................................................................143 Valve..............................................................................................................................................................143 Stabilizer Tower ............................................................................................................................................144

RuntheSimulation ......................................................................................................................... 144 ReviewtheResultsandPrintasNeeded..................................................................................... 144

Checking the Cricondentherm Dewpoint.......................................................................................................144 Checking the Bottoms Stream Purity.............................................................................................................147 Re-running the Simulation.............................................................................................................................148 Producing a Text Report ................................................................................................................................149 Generating a Process Flow Diagram..............................................................................................................150

CC‐THERMTutorial .......................................................................................................................... 153 OverviewoftheHeatExchangerSizingProcess ....................................................................... 154 IdentifytheTube‐sideStream....................................................................................................... 154 GeneratetheHeatCurve ............................................................................................................... 155 DefineGeneralSpecifications ....................................................................................................... 156 SetTubeSpecifications................................................................................................................... 157 SetShellSpecifications ................................................................................................................... 157 SetBaffleSpecifications.................................................................................................................. 158

Baffle Spacing ...............................................................................................................................................158 Baffle Cut Percent .........................................................................................................................................158

SetNozzleSpecifications ............................................................................................................... 159 SetClearanceSpecifications .......................................................................................................... 159 SetMaterialSpecifications............................................................................................................. 160 SetMiscellaneousSpecifications................................................................................................... 160 RunSizingCalculations................................................................................................................. 161 ReviewResultsandCreatePlots .................................................................................................. 161

CC‐BATCHTutorial .......................................................................................................................... 164 DescriptionoftheProblem............................................................................................................ 164 OverviewoftheBatchDistillationProcess ................................................................................. 165 CreatingaNewSimulation ........................................................................................................... 166 SelectingEngineeringUnits .......................................................................................................... 166 DrawingtheFlowsheet .................................................................................................................. 166

Placing UnitOps.............................................................................................................................................166 Drawing Streams ...........................................................................................................................................167

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SelectingComponents.................................................................................................................... 168 SelectingThermodynamicOptions.............................................................................................. 168 SpecifyingPotCharge.................................................................................................................... 170 SpecifyingtheDistillationColumn.............................................................................................. 172 DefiningtheOperatingSteps........................................................................................................ 173

Operating Step 1 ............................................................................................................................................173 Operating Step 2 ............................................................................................................................................174 Operating Step 3 ............................................................................................................................................174 Operating Step 4 ............................................................................................................................................175 Operating Step 5 ............................................................................................................................................175 The Run Time Information Dialog Box.........................................................................................................175

RunningtheSimulation ................................................................................................................. 176 ReviewingandPrintingResults ................................................................................................... 177

Plotting the Results ........................................................................................................................................177 Generating Text Reports................................................................................................................................178 Generating a Full Report ...............................................................................................................................178

PipingTutorial .................................................................................................................................... 180 ControlValveSizingExample ...................................................................................................... 180

Problem Statement.........................................................................................................................................180 Rating Case....................................................................................................................................................181 Flow Rate as a Function of Pressure..............................................................................................................183

SimpleFlowExample..................................................................................................................... 186 Problem Statement.........................................................................................................................................186 Creating the Simulation .................................................................................................................................186 Using Controllers to Simplify the Problem ...................................................................................................188 Calculating NPSHa........................................................................................................................................189

BranchedFlowExample ................................................................................................................ 190 Problem Statement.........................................................................................................................................190 Creating the Simulation .................................................................................................................................190 Running the Simulation .................................................................................................................................193 Selecting a Pump ...........................................................................................................................................193

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CHEMCADVersion6UserGuide 1

Chapter 1

Introduction to CHEMCAD

WelcometoCHEMCADVersion6,apowerfulandeffectivesoftwaretoolforchemicalprocesssimulation.Whetheryou’reaneworexperiencedCHEMCADuser,you’llappreciatetheprogram’suser‐friendly,feature‐richinterface.CreatingflowsheetsandrunningsimulationsisfastandeasywithCHEMCAD,andtheprogramishighlycustomizabletofityourneedsandthewayyouwork.

ThismanualwillhelpyougetupandrunningwithCHEMCAD,frominstallationandlicensingtotutorialsthatwalkyouthroughreal‐worldexamples.

Overview of CHEMCAD and Its Uses Today’schemicalprocessingindustry(CPI)facesnumerouschallenges:risingfuelandfeedstockcosts,reducedengineeringstaff,shorterproductlifecycles,increasedglobalcompetition,andincreasedregulation.ThesechallengesrequirethatCPIcompaniesseekoutandusethebesttoolstoincreaseproductivityandimproveengineeringdecisions.

CHEMCADisapowerfulandflexiblechemicalprocesssimulationenvironment,builtaroundthreekeyvaluesofinnovation,integration,andopenarchitecture.ThesevaluescreateimportantadvantagesforCHEMCADusers:

• Thelatestchemicalengineeringtechniquesatyourfingertips

• Allfunctionalityunitedinasinglesoftwareenvironment

• Seamlessconnectiontothechemicalengineeringcomputingenvironment,withlinkstotoolssuchasMSExcelandWordandinterfacessuchasCOM,DCOM,OPC,CAPE‐OPEN,andXML

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2 CHEMCADVersion6UserGuide

CHEMCADcombinesastate‐of‐the‐artgraphicaluserinterface(GUI),anextensivechemicalcomponentdatabase,alargelibraryofthermodynamicdata,andalibraryofthemostcommonunitoperationstogiveuserstheabilitytoprovidesignificantandmeasurablereturnsontheirinvestment.Inaddition,theprogramiscustomizabletoallowcustomchemicals,thermodynamics,unitoperations,calculations,andreporting—allingredientsforapowerfuluserexperience.

CHEMCADiscapableofmodelingcontinuous,batch,andsemi‐batchprocesses,anditcansimulatebothsteady‐stateanddynamicsystems.Thisprogramisusedextensivelyaroundtheworldforthedesign,operation,andmaintenanceofchemicalprocessesinawidevarietyofindustries,includingoilandgasexploration,production,andrefining;gasprocessing;commodityandspecialtychemicals;pharmaceuticals;biofuels;andprocessequipmentmanufacturing.

Withinalloftheseindustries,chemicalengineersworkeverydaywithCHEMCADtoaddressavarietyofchallenges:

• Initialdesignofnewprocesses

• Optimizationorde‐bottleneckingofexistingprocesses

• Performancemonitoringofprocesses

• Designandratingofprocessequipmentsuchasvessels,columns,heatexchangers,piping,valves,andinstrumentation

• Evaluationofsafetyreliefdevices

• Heatexchangersizing

• Pressureandflowbalancingofcomplexpipingnetworks

• Reconciliationofplantdata

• Economiccomparisonsofprocessalternatives

• Advancedprocesscontrol(APC),includingmodelpredictivecontrol(MPC),real‐timeoptimization(RTO),andoperatortrainingsystems(OTS)

• Scale‐upofprocessesfromlab‐scaletopilot‐scale,andfrompilot‐scaletofull‐scale

• Binaryinteractionparameter(BIP)regressionfromprocessorlabdata

• Batchreactionrateregressionfromprocessorlabdata

Nomatterhowcomplexyourprocess,CHEMCADiscapableofdeliveringtheresultsyouneedtostaycompetitiveinanincreasinglyfastandfluidglobalmarket.Easytolearnandhighlycustomizable,CHEMCADcanputfuture‐proofsolutionswithineasyreachofyourengineeringstaff.

IntroductiontoCHEMCAD

CHEMCADVersion6UserGuide 3

CHEMCAD Products and Features TheCHEMCADsuiteconsistsofseveralmodulesthatservespecificpurposes.Dependingonyourparticularneeds,youmayhavepurchasedsomeorallofthesemodules.ThefollowingarebriefdescriptionsofthevariousCHEMCADmodulesandtheirmostcommonuses.

CC-STEADY STATE ThemainCHEMCADproduct,knownasCC‐STEADYSTATE,enablesyoutodesignnewprocesses,rateexistingprocesses,andoptimizeprocessesinsteadystate.

CC-DYNAMICS ThemoduleknownasCC‐DYNAMICSmakesitpossibletodesignandrateexistingprocessesusingadynamicsimulation.ThismoduleisfullyintegratedwithCHEMCADtomakeswitchingbetweensteadystateanddynamicseasyandintuitive.UsingCC‐DYNAMICS,youcaneasilysimulateeverythingfromsimplevesselaccumulationtocomplexcontrolsystemsoncolumns.Thismodulealsoprovidestoolsforsimulationofcontinuousstirred‐tankreactors(CSTRs),includingcomplexreactionrateandpressurecalculation.

CC-BATCH TheCC‐BATCHproductenablesyoutodesign,rate,oroptimizeabatchdistillationcolumn.CC‐BATCHincludesaschedulinginterfacetoallowan“operationstep”approachtosimulationofbatchcolumns.

CC-THERM TheCC‐THERMproductletsyoudesignasingleheatexchanger,orvetavendor’sheatexchangerdesign.Itisalsoidealforcustomerswhowanttorateexistingexchangersinnewservice,ortoperformcalculationsonhypotheticalsituations.CC‐THERMcansimulateshell‐and‐tube,air‐cooled,plate‐and‐frame,anddouble‐pipeexchangers.FullintegrationwithCHEMCADmakesitpossibletocalculateexitconditionsfromexchangergeometryforhigh‐fidelitysimulations.

CC-SAFETY NET TheCC‐SAFETYNETproductprovidesthecapabilitytodesignorratepipingnetworksandsafetyreliefdevicesandsystems,inbothsteady‐stateanddynamicsystems.Thesteady‐statefeaturesofCC‐SAFETYNETareincludedwithCC‐STEADYSTATE.Thisproductenablesuserstomakesimultaneousflow‐andpressure‐balancedsimulations—eveninreverse‐flowsituations—forsingle‐ormulti‐phaseflow.

CC-FLASH TheCC‐FLASHmoduleprovidesphysicalpropertyandphaseequilibriumdata,aswellaspropertypredictionandregression.CC‐FLASHisasubsetofCC‐STEADYSTATE,andismeantforcustomerswhodonotneedfullflowsheetsimulationtools.

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4 CHEMCADVersion6UserGuide

CHEMCAD Features by Module ThefollowingmatrixliststhefeaturesassociatedwitheachcomponentoftheCHEMCADsuite.Foramoredetailedexplanation,ortoinquireaboutaparticularcomponentorfeature,pleasecontactChemstationsoryourCHEMCADdistributor(seecompletecontactinformationatwww.chemstations.com/contact.htm).

CC-S

TEA

STA

CC-D

YNA

MIC

CC-B

ATC

CC-T

HER

CC-S

AFE

TY N

CC-F

LASH

VB/COM/OPC/Data Map

Sensitivity/optimization

Sizing (line/valve/orifice/vessel)

Run steady state

Run dynamics

Run recycles

Costing

Reconciliation

Sizing columns

Sizing heat exchangers

Economics

Reports (incl. Excel)

DIERS

CO2 solid

Hydrates

Depress

TOC/COD

Pure regression

BIP regression

Electrolyte regression

Rate regression

Units calculator

Execute parser

Environmental report

Simple calculator

Spec sheet

IntroductiontoCHEMCAD

CHEMCADVersion6UserGuide 5

UnitOps by Module Theavailabilityofcertainunitoperations,orUnitOps,inCHEMCADsimulationsisafunctionofwhichmodulesyouhavelicensed.ThefollowingmatrixlistsallavailableUnitOpsandtheCHEMCADmodulesassociatedwiththem.

CC-S

TEA

STA

CC-D

YNA

MIC

CC-B

ATC

CC-T

HER

CC-S

AFE

TY N

CC-F

LASH

Baghouse filter

Batch column

Batch reactor

Calculator

Centrifuge

Component separator

Compressor

Control valve

Controller

Crusher/grinder

Crystallizer

Cyclone

Divider

Dynamic vessel

Electrostatic precipitator

Equilibrium reactor

Excel unit

Expander

Fired heater

Flash

Gibbs reactor

Heat exchanger

Hydrocyclone

Kinetic reactor

Liquid/liquid extractor

LLV flash*

LNGH exchanger

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6 CHEMCADVersion6UserGuide

CC-S

TEA

STA

CC-D

YNA

MIC

CC-B

ATC

CC-T

HER

CC-S

AFE

TY N

CC-F

LASH

Loop

Mixer

Node

Phase generator*

PID controller

Pipe simulator

Polymer reactor

Pump

Ramp controller

Recorder*

Run subflowsheet META unit

SCDS distillation column

Screen

Sedimentator

Shortcut column

Solids dryer

Solids washer

Stoichiometric reactor

Stream reference

Tank

Time delay

Time switch

Tower distillation column

Tower plus distillation column

User-added module

Vacuum filter

Valve

Venturi scrubber

Vessel*

* These UnitOps will be phased out eventually.

CHEMCADVersion6UserGuide 7

Chapter 2

Getting Started with CHEMCAD

NowthatyouhaveCHEMCADinhand,youprobablywanttogetstartedrightaway.Let’sgetdirectlytothepoint,withstep‐by‐stepinstructionsforinstallingandlicensingtheprogram.

Installing the Software StartbyensuringthatyourPCmeetstheminimumsystemrequirements,aslistedbelow.It’salsoagoodideatofindoutbeforeyoubeginwhetheryourcopyofCHEMCADwillrelyonanetworklicense;ifitwill,makesuretoaskyournetwork

administratorforalltheinformationthatyou’llneedwheninstallationiscompleteandit’stimetosetuplicensing.

Onceyou’veestablishedthatyourcomputerisreadyforinstallation,inserttheCHEMCADinstallationdiscintoanavailableCDmediadriveandwatchfortheCHEMCADsplashscreentoappear.

CHEMCAD System Requirements Processor speed: 500 MHz or higher

Operating system: Windows 2000, XP, Vista, or 7 (all 32- and 64-bit versions) RAM: 256 MB Video card: 128 MB or higher video memory Display resolution: 1024 x 768 or higher Hard disk space: 500 MB (750 MB during installation) Productivity software: Some features require Microsoft Office®

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8 CHEMCADVersion6UserGuide

Note: IfyouinsertthediscandclosetheCDmediadrivedoor,butnothinghappenswithinoneminute,thenyoursystemisnotconfiguredtolaunchtheCDcontentautomatically.Tolaunchtheinstallationprogrammanually,gotoMyComputer,double‐clicktheiconforyourcomputer’sCDmediadrive,opentheCHEMCADfolder,andthendouble‐clickthefileendingin_Setup.exe.

ClickInstallCHEMCADtolaunchtheInstallShieldWizard.InstallShieldinspectsyourcomputerforsoftwarecomponentsthatCHEMCADwillneed,andpromptsyoutoinstallanyneededcomponentswithascreensimilartoFigure2‐01.

Figure 2-01: InstallShield Wizard screen listing software components to be installed

ClickInstalltocontinue.FollowthepromptsonallotherscreensuntilyouseetheCHEMCADSuite–InstallShieldWizardscreen,showninFigure2‐02.

Note:DependingonhowmanysoftwarecomponentsInstallShieldidentifies,theremaybequiteafewscreens,andtheprocedurecouldtakeseveralminutes.Oncethesecomponentsareinstalledonyourcomputer,however,youwillnotneedtoreinstallthemwithfutureCHEMCADupdates.

Figure 2-02: The CHEMCAD Suite – InstallShield Wizard screen

Getting Started with CHEMCAD

CHEMCAD Version 6 User Guide 9

ClickNexttobegintheinstallationprocess.TheLicenseAgreementscreenappears,listingtheCHEMCADstandardlicense.Onceyou’vereadandunderstoodthetermsofthelicense,you’llneedtoclicktheIacceptthetermsinthelicenseagreementbuttonbeforeyoucanclickNextagaintoproceed.Notethatyouhavetheoptiontoprintacopyofthelicenseagreementfromthisscreen.

Figure 2-03: The Standard License screen

FollowingthestandardCHEMCADlicenseagreement,asimilarscreenappearswiththelicensetermsoftheMicrosoftVisualStudiotools.Again,you’llneedtoclicktheIacceptthetermsinthelicenseagreementbuttonandthenclickNexttoproceed.

TheDestinationFolderscreenappearsnext,displayingthenameofthefolderintowhichtheCHEMCADfileswillbeinstalledbydefault.Normally,thisdestinationisC:\ProgramFiles\Chemstations\CHEMCAD,anditisrecommendedthatyouusethislocationunlessyouhaveaspecificneedtoinstalltheprogramelsewhere.ClicktheChangebuttonifyouwanttochangethefiledestination,orclickNexttoacceptthesuggesteddestinationandproceed.

TheSetupTypescreennowappears,offeringachoicebetweencompleteandcustominstallation.Eachtypeofinstallationisdescribedonthescreen.EitheracceptthedefaultsettingofCompleteorclickCustomtoselectspecificcomponentstoinstall,thenclickNexttoproceed.

TheReadytoInstalltheProgramscreennowappears.Notethatonthisscreen,andinfactonanyscreenintheinstallationprocess,youcanclickBacktoreturntoapreviousscreenandverifyorchangeyourinstallationsettings.Ifyouaresatisfiedwithyoursettingsastheyare,clickInstalltostarttheinstallation.

TheInstallingCHEMCADSuitescreenappears,showingtheprogressofyourinstallationwithagreenstatusbar.

Getting Started with CHEMCAD

10 CHEMCAD Version 6 User Guide

Figure 2-04: Status bar showing the progress of CHEMCAD installation

Wheninstallationiscomplete,you’llseeonefinalscreen,whichstatesthattheInstallShieldWizardhascompletedinstallationoftheCHEMCADSuite.IfyouwouldliketostartCHEMCADnow,checktheLaunchCHEMCADSuiteboxbeforeclickingFinish.

Licensing CHEMCAD BeforeyoucanuseCHEMCAD,you’llneedtosetupalicensingschemeofsometype.Dependingonyourparticularlicensingagreement,youwilluseoneofseveraltypesoflicensestorunCHEMCAD.

Types of CHEMCAD Licenses ThevarioustypesofCHEMCADlicensesaredesignedtofitdifferentusers’software,hardware,andnetworkingneeds.Mostlicensesrequiretheuseofahardwaredevice,commonlyknownasadongle,toruntheprogram.

ThedonglesimplyplugsintoeitheraUSBportoraparallelportonthecomputer,andmustbepluggedinanytimetheprogramruns.IfyouworkonanetworkwithotherCHEMCADusers,yourlicensemayrelyonadonglepluggedintoanetworkserverelsewhereinyourorganization,ratherthanonepluggeddirectlyintoyourcomputer.

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CHEMCAD Version 6 User Guide 11

Youoryourorganizationmayuseoneofthefollowingtypesofdongles:

• SuperProsingle‐userdongle(parallelorUSBconnection)

• SuperProNetdongle(parallelorUSBconnection)

Insomeinstances,softwarelicensingisaccomplishedwithouttheuseofahardwaredevice:

• RMSLicenseManagersoftware,whichrunsoveralocal‐orwide‐accessnetwork

• SystemAuthorization,amethodthatauthorizesasingle‐usermachineforalimitedtime(usedforsoftwareevaluation)

License Settings TorunCHEMCADforthefirsttime,makesurethatyourdongle(ifapplicable)ispluggedinproperly,andthenstarttheprogram.FromtheWindowsStartmenu,selectAllPrograms>Chemstations>CHEMCAD.

Theprogramopens,displayingaCHEMCADsplashscreen.Afterafewmoments,thatscreenisreplacedbytheCHEMCADLicenseMonitordialogbox,whichdisplaysinformationaboutthelicense(s)thatyourcomputerisusingtorunCHEMCAD.

Figure 2-05: The CHEMCAD License Monitor dialog box

Note:Insomecases,theCHEMCADscreenthatappearsmaydisplayaNoLicenseFoundmessage,whichindicatesthatCHEMCADhasnotyetdetectedavalidlicense.Ifyourcomputerisexperiencingslowcommunicationwiththelicenseserversystem,CHEMCADmaysimplyneedmoretimetodetectthelicense(s).Assoonasanyvalidlicenseisfound,CHEMCADwilldisplaytheCHEMCADLicenseMonitorscreen.

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12 CHEMCADVersion6UserGuide

Normally,thisdialogboxremainsinviewforonlyafewseconds,listingallproductlicensesthatCHEMCADhasobtained.Duringthattime,youcanclickanywhereinthedialogboxtokeepitopen.Ifyoudonotclickinthedialogbox,itdisappearsfromview,butyoucanbringitbackupatanytimebyselectingTools>Options>Licensing.

WhiletheCHEMCADLicenseMonitordialogboxisopen,youcanviewthevariousCHEMCADlicensesdetectedforyoursystemandseewhatmethod(andwhereapplicable,whichserver)isbeingusedtoobtainthoselicenses.IfyourorganizationusesRMSLicenseManageroraSuperProNethardwarekey,youcanalsoseewhichotheruserscurrentlyholdvariousproductlicenses.

Fornetworklicenses,youcanright‐clickaservernameunderaparticularproductandselectalicensingpreference(ondemand,always,ornever)asshownbelow.

Figure 2-06: Selecting a licensing preference

Youcanusethealwaysorneversettingtoturnlicensingforaproductabsolutelyonoroff,respectively.TheondemandsettingsecuresalicenseonlywhenyoubegintouseaspecificCHEMCADfeaturecontrolledbyacertainproduct.Thissettingisidealinmostsituations,asitleavesunneededlicensesavailableforotherusers.

ToclosetheCHEMCADLicenseMonitorscreen,clicktheContinuebutton,orclicktheXinthetoprightcornerofthescreen.

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CHEMCAD Version 6 User Guide 13

Updating a License CHEMCADdonglesrequirere‐programmingonaregularbasis,eitheronceayearormoreoftendependingonyourlicensingagreement.Thisisasecuritymeasuretoreducethelikelihoodthatyourdonglewillbestolenandmisused.

Thedonglethatyouuseisprogrammedtoworkonlythroughthelicensedtimeperiod,andwhenthattimehaselapsed,thedonglemustbeupdatedbeforeyoucancontinueusingCHEMCAD.

Updatingadongleisarelativelysimpleprocedure.Beforeyourlicenseexpiration,youoryoursoftwareadministratorshouldreceiveane‐mailfromChemstations,withwhat’sknownasaconfigurationfileincludedasanattachment.YoushouldsavethisfiletoyourWindowsdesktopassoonasyoureceiveit.

Note:Ifyou’veupdatedthesamedongleinthepast,thenewconfigurationfileshouldhavetheexactsamefilenameasthepreviousone.If,whilesavingthefiletoyourdesktop,youseeaWindowsmessageaboutanexistingfilewiththesamename,youshouldoverwritetheoldfile(whichinanycasecannotbeusedagain),replacingitwiththenewone.

It’simportanttoensurethatyourconfigurationfilematchesyourdongle.Theconfigurationfileshouldbea.DNGfilewhosenameincludesafour‐orfive‐digitcode;thiscodemustmatchthenumberstampedontoyourdongle.Ifthenumbersdon’tmatch,contactyoursoftwareadministratororChemstationssupporttoresolvetheissue.

Theupdatee‐mailalsospecifiesthedateonwhichyou’llneedtoupdateyourdongle.Beforethatdatearrives,followthisproceduretoperformtheupdate:

1. StarttheCHEMCADprogramandselectTools>Options>Licensing.ThisbringsuptheCHEMCADLicenseMonitordialogbox,whichdisplaysthestatusofallapplicableCHEMCADproductlicenses,alongwithyourdongletypeandnumber.

Figure 2-07: The CHEMCAD License Monitor dialog box

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14 CHEMCAD Version 6 User Guide

2. ClicktheSetupbuttontobringuptheLicenseSetupdialogbox,thenclickUpdatedongleasshownbelow.

Figure 2-08: Clicking Update dongle within the License Setup dialog box

3. Thedialogboxnowlistsalllicensingdonglesanddisplaysafieldforenteringthefullpathandfilenameforthedongleupdatefile.ClicktheBrowsebuttontonavigatetotheupdatefile.

Figure 2-09: Browsing for the dongle update file

4. IntheOpendialogbox,navigatetothelocationwhereyousavedthe.DNGconfigurationfile.Normally,thisistheWindowsdesktop;ifyousavedyourconfigurationfilethere,clickDesktoptotellCHEMCADwheretolookforthefile,thenclickOpen.

5. TheLicenseSetupdialogboxnowdisplaysthedirectorypathandfilenamefortheselected.DNGfile.ClickOKtoupdatethedongle.

Figure 2-10: Updating the dongle with the selected update file

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CHEMCADVersion6UserGuide 15

6. CHEMCADre‐programsthedongle,andthendisplaysapop‐upwindowstatingthattheupdateiscomplete.

Figure 2-11: Successful re-programming of a CHEMCAD dongle

7. ClickOKtoclosethepop‐upwindow.IftheCHEMCADLicenseMonitorscreenappears,clickContinuetocloseit.

YoushouldnowbeabletoproceednormallyinCHEMCAD.

Note:ForSuperProNetdonglesonly,thenetworkadministratormayneedtostopandrestarttheWindowsservicecalledSentinelProtectionServeronthelicensingserverafterauserupdatesadongle.

Getting Help with CHEMCAD IfyoufindthatyouhavequestionsthatarenotaddressedinthisUserGuide,youcanturntoseveralresourcesforCHEMCADhelp.

Online Help AtanytimewhilerunningCHEMCADinanactivewindow,youcanpressthe[F1]keytobringuptheCHEMCADHelpscreenthat’smostappropriatetothetaskyouarecurrentlyperformingorthedialogboxcurrentlydisplayed.

Insomesituations,pressing[F1]willbringupthemainCHEMCADHelpwindowinsteadofaparticularhelpscreen.Fromthere,youcanclicktheContents,Index,orSearchtabintheupperleftcorneroftheCHEMCADHelpwindow,andusethesetoolstofindtheinformationyouneed.

YoucanalsogodirectlytothemainCHEMCADHelpwindowbyselectingHelp>HelpTopicsfromtheCHEMCADmainmenu.RegardlessofhowyouopenCHEMCADHelp,italwaysopensinaseparatewindowthatdoesnotinterferewiththeoperationoftheCHEMCADprogram.

CHEMCAD Coach TheCHEMCADCoachpaneisatoolthatyoucanopenwithinCHEMCADtoviewconciseinstructionsforcommonprocedures.Toseealistofavailabletopics,selectHelp>CHEMCADCoach.ThenclickonanylinkintheCHEMCADCoachwindowtoviewtheinstructionsforaspecifictask.

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16 CHEMCAD Version 6 User Guide

Procedure Demos AnimateddemonstrationsofcommontasksareavailabletohelpyougetstartedusingtheCHEMCADprogram.ThedemofilesareinstalledalongwithCHEMCAD.Toaccessthesedemos,selectStart>AllPrograms>Chemstations>Demos,andthenbrowsethelistofavailabletopics.Whenyouselectademofromthemenu,itwillstartplayingautomatically.

The Chemstations Web Site TofindthemostrecentupdatesoftheCHEMCADsoftware,manuals,andvarioustrainingtools,gotowww.chemstations.com.Thereyou’llfindthefollowingitemsavailablefordownload:

• ThelatestreleaseofCHEMCAD

• Alistofupdatesimplementedinthemostrecentrelease

• CHEMCADdocumentationanddemos

• ProgrammingguidesforinterfacingwithCHEMCAD

Contacting Chemstations Technical Support Ifyouareunabletosolveaproblemorfindtheanswertoaquestionusingthismanualortheothertoolslistedhere,youcancontactChemstations’technicalsupportstaffforassistance.

Ourtechnicalsupportengineersareavailableviae‐mail,orbyphoneMondaythroughFriday,7:00AMthrough6:00PMCentralStandardTime.

OutsideoftheUnitedStates,pleaseseewww.chemstations.comforregionalcontactinformation.

Phone: 713.978.7700

Toll-free (U.S. and Canada): 800.243.6223

FAX: 713.978.7727

E-mail: [emailprotected]

CHEMCADVersion6UserGuide 17

Chapter 3

The CHEMCAD Interface

ThischaptertakesyouonatouroftheCHEMCADscreen,includingthemenusandtoolbars,themainareasofthescreen,andtheflowsheetdrawingtools.Italsoshowsyousomewaysthatyoucancustomizethescreenlayoutsothatitbestsuitsyourownwayofworking.

Note:WiththereleaseofVersion6.0,theCHEMCADinterfaceunderwentamajortransformation.Forthisreason,usersupgradingfromCHEMCAD5willbenefitfromareviewoftheprogram’sscreenlayoutandthelocationofimportantfeatures.

The CHEMCAD Window WhenyoulaunchtheCHEMCADprogramforthefirsttime,you’llseeascreenwithalargewhiteareainthemiddleandvariouspanes,orspecializedareas,attheedgesofthescreen.

Workspace CHEMCAD Explorer pane Palette pane Messages pane

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The Workspace Theareainthemiddleofthescreenisknownastheworkspace.ThisisthemainfocusoftheCHEMCADwindow,theplacewhereyou’llbuildandeditflowsheets,viewgraphs,andrunandtweakprocesssimulations.

WhenyoufirstlaunchCHEMCAD,theworkspaceissolidwhite.Whenyoustarttobuildaflowsheetoropenanexistingsimulation,theflowsheetdisplaysintheworkspace.

TheworkspaceusestabstoenableyoutoswitchbetweenyouropensimulationandanyopenExcelDataMapsand/ordataplots.Atthebottomoftheworkspacearea,you’llseeoneormoretabswheneverasimulationisopen.EachtabincludesabuttonmarkedwithanX;tocloseanytab,firstclickthetabandthenclicktheXbutton.

Figure 3-01: The bottom of the workspace area, showing several tabs and their X buttons

Notethatanytimeyou’veclosedasimulationandhaven’tyetopenedanotherone,theworkspacedisplaysasablankgrayspace.

The CHEMCAD Explorer Pane AlongtheleftedgeoftheCHEMCADwindow,you’llseeanareawithatitlebaratthetopthatreadsCHEMCADExplorer.AtthebottomoftheCHEMCADExplorerpanearethreetabscalledRecentFiles,Simulation,andVisualBasic.Toviewthecontentsofatab,simplyclickitsname.

Figure 3-02: CHEMCAD Explorer tabs

TheCHEMCADExplorertabsarepresentedinwhat’sknownasatreeformat,withitemsorganizedintoamulti‐levelhierarchy.Thedefaultviewshowsonlytop‐levelitems,butyoucanexpandeachitemtoviewsecond‐levelitems,third‐levelitems,andsoforth.

Attheleftofeachtop‐levelitemisasmallboxwithaplussign.Toexpandanitem,clicktheplussign.Twothingshappensimultaneouslywhenyouclick:thetreeexpandstoshowthatitem’scontents,andtheplussignbecomesaminussign.Youcanhide(orcollapse)thelower‐levelitemsagainbyclickingtheminussign,whichthenturnsbackintoaplussign.Figure3‐03showsanexampleofaCHEMCADExploreritemincollapsedandexpandedview.

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Figure 3-03: Clicking the plus sign to expand an item (left); the resulting view (right)

ExpandingandcollapsingitemsintheCHEMCADExplorertabsisonewaythatyoucanmakethebestuseofyourscreenspacewhenworkinginCHEMCAD.

The Recent Files Tab TheRecentFilestabisselectedbydefaultwhenyoufirstlaunchCHEMCAD.Thistablistsallofthesimulationfilesthatyouhaveopenedlately,startingwiththemostrecent.WhenyoufirstinstallCHEMCAD,thelistisempty,butwitheverysimulationthatyouopen—newfilesorexistingonessuchasbuilt‐inexamples—thelistwillgrow,providingconvenientaccesstofilesthatyouusefrequently.

ToopenasimulationfromtheRecentFileslist,simplydouble‐clickonthefilenameinthelist.

The Simulation Tab TheSimulationtabdisplaysbydefaultanytimeasimulationisopen.Itprovidesaseriesofshortcutstocommoncommandsandsettings,including:

• Components:Includesone‐clickaccesstocomponent,electrolyte,andsolidsselection,aswellasdistillationcurves

• Thermodynamics:Providesquickaccesstothermodynamicsettingsandtransportproperties

• Flowsheet:AllowsquickeditingofUnitOpandstreamdata

• SensitivityStudies:Providesaconvenientwaytocreate,edit,andrunsensitivitystudies

• DataMaps:EnablesyoutocreateorsetexecutionrulesforaDataMapwithoutusingthemenu

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• SavedCharts:Providesquickaccesstopreviously‐savedchartsforthissimulation

• Groups:ProvidesaneasywaytocategorizeUnitOps,streams,andcomponents

• Layers:Allowsselectedpartsoftheflowsheettobedisplayedorhiddenforviewingandprinting

• Templates:StoresandorganizesstreamandUnitOpspecificationsthatyoucan“clone”forre‐use

Expandanyoftheseitemstoseeandusespecificfeatures,whicharedescribedinfurtherdetailintheappropriatechaptersofthisuserguide.

The Visual Basic Tab IfyouuseVisualBasictocustomizeCHEMCAD,thistabprovidesquickandeasyaccesstoyourVisualBasiccode.YoucanexpandtheReactions,Properties,orUnitOpsitemtoviewavailablesubroutinesforthatcategory.ClickingthenameofasubroutineopensaVisualBasiceditorinaseparatewindow.

The Palette Pane AlongtherightsideoftheCHEMCADwindowisapanetitledPalette,whichisarepositoryforthevariousunitoperationiconsandothertoolsneededtodrawflowsheets.

Selecting a Palette TheseUnitOpiconsandtoolsaregroupedintopalettesaccordingtofunctionorequipmenttype.ThedefaultpaletteiscalledAllUnitOps,anditincludeseveryavailableUnitOpiconanddrawingtool.Toselectadifferentpalette,simplyclickitstitlebar.Theselectedpaletteexpandsinplace,asshowninFigure3‐04.

Figure 3-04: The expanded Piping and Flow palette

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Customizing Palettes AtthetopofthePalettepaneisafieldcalledSearchforUnitOp(s).TypeasearchtermhereandthenclickGo!tolocatealloftheUnitOpiconsassociatedwiththatterm.TheresultsfromthesearchappearinanewpaletteatthebottomofthePalettepane.Figure3‐05showsthesearchresultsforthewordvessel.

Figure 3-05: Search results showing all vessel UnitOps

PerformingaUnitOpsearchcreateswhatisknownasauser‐addedpalette.Thistypeofpaletteisdesignatedwithaspecialiconattheleftendofthepaletteheading.

ThepalettecontainingyoursearchresultsremainsavailableuntilyoucloseCHEMCAD.Youcanmakeyouruser‐addedpaletteavailablepermanentlybyright‐clickingthenewpalette’stitlebarandselectingSave.

Figure 3-06: Saving search results for future use

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Youcandothefollowingwithuser‐addedpalettes:

• Renameanyuser‐addedpalettebyright‐clickingitstitlebarandselectingRename.Intheresultingdialogbox,typethenameyouwantandthenclickOK.

• Deleteauser‐addedpaletteatanytimebyright‐clickingandselectingRemove.

• AddindividualUnitOpsortoolstoanexistinguser‐addedpalette.Simplyright‐clicktheiconfortheitemyouwanttoadd,selectInsertintoPalette,andthenclickthenameoftheuser‐addedpalette.

• Removeanitemfromauser‐addedpalettebyright‐clickingtheiconandselectingRemovefromPalette.

• Createauser‐addedpalettewithoutasearch.Right‐clickthefirsticonthatyou’dliketoincludeonanewpaletteandselectInsertintoPalette>NewPalette.TypeanameintheresultingdialogboxandclickOK.Thenaddasmanyothericonsasyou’dlikeusingthemethoddescribedjustabove.

Youcannotchangethenameoriconselectionforabuilt‐inpalette,asyoucanwithauser‐addedpalette.Youcan,however,makeacopyofabuilt‐inpalette,renamethecopy,andthenaddanddeleteiconsuntilthepalettehasjustwhatyouwant.

Tocopyanypalette(whetherbuilt‐inoruser‐added),simplyright‐clickthepaletteheadingandselectSaveCopyAs.TypeanameforthenewpaletteandclickOK.

The Messages Pane TheMessagespaneislocatedatthebottomedgeoftheCHEMCADworkspace.Atthebottomofthispanearethreetabs:ErrorsandWarnings,RunTrace,andNotes.

The Errors and Warnings Tab Thistabdisplaysarunninglistoferrorandwarningmessagesthathavebeengeneratedwhilethecurrentsimulationfilehasbeenopen.Theoldestmessagesdisplayatthetopofthelist.Whentherearetoomanycumulativemessagestodisplayinthepane,themostrecentmessagesdisplayandtheoldermessagesscrolloffthetopedgeofthepane.Ifneeded,youcanusetheverticalscrollbarontherightsideofthepanetoscrollupandreviewearliermessages.

The Run Trace Tab ThistabdisplaysdiagnosticmessagesfromeachUnitOpeachtimeasimulationisrun.Thisinformationishelpfulintroubleshootingasimulationthatisnotworkingproperly.

ThetextontheRunTracetabisnotsavedwiththesimulation,butrefresheswitheachrunandclearswhenyouclosethesimulation.

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The Notes Tab Thistabprovidesahandyplacetostoreadditionalinformation,intextform,aboutthesimulation.Youcanuseittolistanydetailsaboutthesimulation,suchasitsoriginandanyassumptionsthatarebeingmade.

Anynotesthatyouaddorchangearesavedaspartofthesimulation.Todeletetextfromanote,simplyclickanddragtoselectthetextandthenpress[DELETE]onyourkeyboard.

The Main Menu ThemainCHEMCADmenuislocatedjustunderthetitlebaratthetopoftheprogramwindow.SomeitemsonthemainmenuarecommontonearlyallWindowsprograms—namelyFile,Edit,Format,andHelp—whileothermenuitemssuchasThermophysicalandSizingaremorespecifictochemicalprocesssimulation.

Touseamenucommand,clicktherelevantmainmenuitemandthenclickthecommandinthedrop‐downlistthatappears.

Toexecutemenucommandswithoutusingthemouse,youcanholddownthe[ALT]keyonyourkeyboardasyoupresstheletterkeythatcorrespondstotheunderlinedletterinthedesiredmenuitem,forexample[ALT‐F]fortheFilemenu.Youcanthenusetheupanddownarrowkeystoselectanitemonthemenuandpress[ENTER]toexecutetheselectedcommand.

The Toolbar TheCHEMCADtoolbarprovidesbuttonsthatarecommontomostWindowsapplications,suchasNew,Open,Save,andPrint,alongwithbuttonsthatarespecifictochemicalprocesssimulation.

Todiscovertheuseofaparticularbutton,simplypointyourmousecursoratthebuttonandwatchforthetooltiptoappear,asshowninFigure3‐07.

Figure 3-07: Viewing a button’s tooltip

Toolbarbuttonsprovidequick,one‐clickaccesstofrequently‐usedcommandsthatarealsoavailableviatheCHEMCADmenus.

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Customizing the CHEMCAD Screen WhenyoufirstinstallCHEMCAD,thescreenislaidoutwiththeCHEMCADExplorerpaneontheleft,thePalettepaneontheright,andtheMessagespanebelowtheworkspace.

Ifhavingalloftheseitemsvisibleleavesyoulessworkspacethanyouwouldprefer,orifthelocationofoneormorepanesislessthanoptimalforthewaythatyouwork,youcanhideormovepanestocustomizeyourCHEMCADscreen.

Viewing and Hiding Screen Elements YoucanvieworhideanyoftheCHEMCADscreen’spanes,aswellasgroupsoftoolbarbuttons,tomakeoptimaluseofyourscreenspace.

Totoggleapaneonoroff,selecttheViewmenuandthenchooseCHEMCADExplorer,Palette,orMessages.Itemswithacheckmarkarecurrentlydisplayed,whileitemswithnocheckmarkarecurrentlyhidden.YoucanalsochoosetovieworhidethestatusbaratthebottomoftheCHEMCADwindow.

Toselectivelyvieworhidegroupsoftoolbarbuttons,selectView>Toolbars.IntheToolbarsdialogbox,eachgroupofbuttonsislistedunderadescriptivename;initially,allofthesegroupshavecheckmarks,indicatingthattheyarecurrentlydisplayed.Tohideanygroupofbuttons,clicktoremovethecheckmarkandthenclickClosetoreturntothemainCHEMCADwindow.

Resizing and Moving Items Nowthatyouhavedeterminedwhichpanesandtoolbarbuttongroupstodisplay,youcanfurthercustomizeyourCHEMCADwindowtodetermineexactlywhereeachoftheseitemswillappear.

Resizing a Pane Thesimplestwaytoaltertheappearanceofapaneistoresizeit.YoucanmaketheCHEMCADExplorerandPalettepaneswiderornarrower,ormaketheMessagespaneshorterortaller,bymovingtheinsideedge,orwall,ofthepanetowardorawayfromtheedgeofthemainwindow.

Toresizeapane,startbypositioningyourmousecursorattheinsidewallofthepane—thatis,therightedgeoftheCHEMCADExplorerpane,theleftedgeofthePalettepane,orthetopedgeoftheMessagespane.Whenthecursorisinthecorrectpositionforresizing,thenormalpointerwillbereplacedwithatwo‐headedarrowasshowninFigure3‐08.

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CHEMCADVersion6UserGuide 25

Figure 3-08: The two-headed arrow cursor used for resizing panes

Whenyouseethetwo‐headedarrow,clickanddraginthedirectionyouwanttomovethepanewall.Athickgraylineshowsapreviewofthenewpanesize;whenyoureleasethemousebutton,theresizedpaneappears.

Moving a Pane Inadditiontoresizing,youcanalsomoveanyofthepanesintheCHEMCADwindow,eithertoadifferentedgeofthescreenortothemiddleofthescreen.Youcanalsomovegroupsofbuttonsfromtheirdefaultpositionsonthetoolbar.

Initially,allofthepanesandbuttongroupsaredocked,meaningthattheyare“snappedinto”anedgeofthescreenorthetoolbararea.Whenyouundockanitem,youcanputitinthelocationofyourchoosing,awayfromthescreenedge.

Toundockapane,clickanddragthepane’stitlebar,thatis,thebluebaratthetopofthepanethatshowsthepanename.Toundockabuttongroup,you’llneedtoclickanddragtherowoffourdotsrunningalongtheleftedgeoftheleftmostbuttoninthegroup.

Note:InthecaseoftheMessagespane,thetitlebarrunsalongtheleftedgeofthepane,andthenameisnotvisiblewhenthepaneisdocked.

Ifyoudragthepaneorbuttongroupintotheworkspacearea,you’llseeagrayboxrepresentingthepositiontheitemwilloccupywhenyoureleasethemousebutton.Ifyoudon’tlikethenewposition,youcanclicktheitem’stitlebaranddragitelsewhere,includingitsoriginalposition.

Youcanalsodockapanetoadifferentedgeofthescreen,ormovebuttongroupsaroundwithinthetoolbararea,insteadofundockingtheseitems.

Pinning and Unpinning Panes Inadditiontomovingandresizingthevariouspanes,there’sanotherwaythatyoucancustomizeyourCHEMCADscreen:pinningandunpinningtheCHEMCADExplorerandPalettepanes.

Thesetwopanescantakeupafairamountofhorizontalscreenspace,andmakingthemverynarrowisn’tanidealwaytowork.Pinningandunpinningprovideawaytoviewfull‐widthCHEMCADExplorerandPalettepaneswhenyouneedthesetools,whilealsofreeingupspacewhenyouaren’tusingthem.

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Whenevereitherofthesepanesisdockedatanedgeofthescreen,itisinoneoftwostates:

• Pinned,meaningthatthepaneisalwaysvisible

• Unpinned,meaningthatthepaneismostlyhiddenfromview,andappearsonlyondemand

Bydefault,allCHEMCADpanesareinitiallypinnedinplace.Youcanchoosetounpinapaneifyouprefertohavesomeextraspaceonthescreen.Tounpinapane,findthetinypushpiniconinthepane’stitlebar,nexttotheXiconthatenablesyoutoclosethepane.Ifthepaneisstationary,you’llseethatthepinisuprightwithitspointdown.

Figure 3-09: The icon indicating a pinned, or stationary, pane

Ifyouclickthepinicon,thepanesuddenlydisappearsfromview—butitisn’tgone.Instead,asmallgraytabbearingthenameofthepaletteappearsattheedgeofthescreenwherethepaneisdocked.Toseethepanereappear,youonlyhavetorollyourmouseoverthattab.Whenthepaneappears,you’llnoticethatthepushpiniconisnowpointedtotheside.UsethetoolsontheCHEMCADExplorerorPalettenormally;then,whenyounolongerneedthepane,justmovethemousepointerelsewhere.Thepanewillautomaticallyhideitselfuntilthenexttimeyourollthemouseoverthetab.

Figure 3-10: An unpinned pane in use; note the sideways pin icon

Tore‐pinanunpinnedpane,pointtothetabtomakethepaneappearandthenclickthepinicon.Thepinturnssothatitisonceagainupright,andthepaneisonceagainapermanentfixtureontheCHEMCADscreen.

Other Useful Interface Hints ThefollowingarehelpfulitemsthatcanhelptomakeyourCHEMCADexperienceeasierandmoreefficient.

Undo and Redo AswithmostWindows‐basedprograms,CHEMCADallowsyouto“backout”ofactionsyouhavejusttakenwhileworkingwithafile.YoucanusetheUndo

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commandtoreversethelastchangeyoumade;simplyselectEdit>Undo,orusethekeycombination[CTRL‐Z].

YoucanusetheUndocommandtoretractuptothelast99actionsthatyouperformedsincethelasttimeyouopenedthecurrentsimulationfile.

Visible Grid Youcanturnonaworkspacegridtouseasaguidewhilecreatingyourflowsheet.SelectView>GridVisibletotogglethisfeatureonoroff.

OthergridoptionsincludeView>SnaptoGrid,whichhelpswithalignmentofobjectsontheflowsheet,andView>ChangeGridSize,whichenablesyoutocustomizethehorizontalandverticalspacingofgridlines.

Adjusting Your View of the Workspace TheView>ZoomOptionsmenuoffersawholeseriesofoptionsformovingandresizingyourviewoftheCHEMCADworkspace.

• SelectIntoviewtheworkspacefromcloserin,orOuttoviewfromfartheraway.

• SelecteitherInataPointorOutataPoint,andthenclickapointontheworkspace,tozoominoroutwiththatpointasafocus.

• SelectZoomRectangle,andthenclickanddragontheworkspace,todesignateaspecificareathatyouwanttoview.

• SelectZoomPercentagetochooseaspecificdisplaysizefortheworkspace.

• SelectZoomtoFittoviewatthelargestsizethatstillpermitsalloftheexistingflowsheetelementstoremaininthevisibleworkspace.

Ifyourcomputermouseisequippedwithascrollwheelbetweentheleftandrightmousebuttons,youcanzoominandoutontheCHEMCADworkspacewithatouchofyourfinger.Tozoomin,rollthewheelup—thatis,pushyourfingertipaway,towardthetopedgeofthemouse.Tozoomout,rollthewheeldowntowardthebottomofyourmouse,pullingyourfingertiptowardyourpalm.Whenyouzoominandoutthisway,thefocalpointforthezoomisthelocationofthemousepointer.

Note:Youcanalsoclickandholdthemousewheeltopanacrosstheworkspace.

The CHEMCAD Coach Pane TheCHEMCADCoachpaneisnotdisplayedbydefault,butyoucanaccessitatanytimebyselectingHelp>CHEMCADCoach.ThepurposeofCHEMCADCoachistoprovideconciseinstructionsforcommonprocedures.Ifyou’velearnedhowtoperformacommonprocedureinCHEMCADbuthaveforgottentheexactmenucommandtouse,CHEMCADCoachcanhelpjogyourmemoryandputyouontherighttrack.

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YoucandragtheCHEMCADCoachwindowtoanylocationonthescreen,simplybyclickinganddraggingthetitlebaratthetopofthewindow.

IfyouhavefinishedusingtheCHEMCADCoachtoolandwanttocloseit,justclicktheClosebutton(theredX)intheupperrightcorneroftheCHEMCADCoachwindow.NotethatifthemainCHEMCADwindowwasmaximizedbeforeyouopenedtheCHEMCADCoachtool,youmayneedtomaximizetheCHEMCADwindowagaintorestoreittofull‐screensize.

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Chapter 4

Working with Simulation Files

AlloftheworkthatyoudowithCHEMCADisstoredinsimulationfiles.BeginningwithCHEMCAD6,eachdiscretesimulationispackagedintoasinglefilethatisportableandeasytohandle.Allthedetailsofthesimulation—fromUnitOpspecificationstostreamcompositiontothermodynamics—areincludedinthisfile.ThischapterdescribesthevariouswaysthatyoucanaccessandmanageCHEMCADsimulationfiles.

About CHEMCAD Simulation Files SimulationscreatedinCHEMCAD6usethefileextension.CC6,whichdistinguishesthemfromotherfilesonyourcomputer,includingsimulationfilescreatedusingearlierversionsofCHEMCAD.

Oneofthemostnotabledifferencesbetween.CC6filesandpredecessorssuchas.CCXfilesistheirportability.A.CC6simulationfileisaseasytoworkwith,transport,andshareasanMSWorddocumentoranExcelspreadsheet.WhereasCHEMCADsimulationsoncerequiredextrastepsbeforetheycouldbee‐mailedormoved,simulationscreatedwithCHEMCAD6canbehandledasstand‐alonefiles.

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Figure 4-01: Stand-alone CHEMCAD 6 files in the My Simulations directory

User Components in CHEMCAD AnotherdeparturefrompreviousversionsofCHEMCADisthatsimulationsareself‐containedwithrespecttothedataneededtorunthem.Customcomponentsthatyoucreatecanbestoredinacommondatabasesothatyoucanusetheminmanydifferentsimulations.Usercomponentsarealsostoredwithinthesimulationsthatusethem,soyounolongerhavetoworryaboutlosingusercomponentswhenmovingasimulationfromplacetoplace.

Eachtimeyouopenasimulation,CHEMCADcomparesanyusercomponentsinthesimulationwiththecopiesofthosesamecomponentsinthedatabase.Ifthetwocopiesdonotmatch,youwillbeofferedachoice:youcankeepusingthelocalcopystoredinthesimulation,orusetheupdatedcopyfromthedatabase.

YourcopyofCHEMCADcannowhavemultipleuserdatabases,andevensharethemonnetworkswithotherusers.Tolearnmoreaboutusercomponentsandbestpracticesformanagingandsecuringusercomponentdatabases,seeChapter10,CustomizingCHEMCAD.

Example Files Especiallyifyou’renewtoCHEMCAD,it’sagoodideatoopenandpracticeworkingwithsomeexamplefilesbeforecreatingyourownsimulations.Forthispurpose,we’vecreatednumerousexamplesofsimulationsfortypicalchemicalprocesses.Youcanopen,view,andeditanyexamplefile,andevensaveacopyinanotherlocationtojump‐startasimulationofyourown.

TheCHEMCADexamplefilesareautomaticallycopiedtoyourcomputerwithacompleteCHEMCADinstallation.Theexamplesareorganizedbyprocesstypeandlocatedinthe\MyDocuments\MySimulations\Examplesdirectory.

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Opening an Existing Simulation SelectFile>OpentobringuptheOpendialogbox.Navigatetothefolderwherethesimulationislocated,selecttheappropriate.CC6file,andclickOpen.

IfyouuseCHEMCADonanetworkandsharefileswithotherusers,it’spossiblethatyoucouldtrytoopenasimulationthatisalreadyopenforeditingbyanotheruser.Ifyoushouldattempttoopenasimulationthatisunavailableforediting,amessageboxwillappear.Youcanchoosetosavethesimulationwithanewnameand/orlocation,openaread‐onlycopyofthesimulation,orcanceltheopenoperation.

Figure 4-02: Notification that a simulation is already in use

Ifyoushouldhavetroublelocatingaparticularsimulation,youcansearchyourharddriveornetworkforallfileswitha.CC6fileextension.

Creating a New Simulation WhenyoufirstopenCHEMCAD,you’llseeablanksimulationwindowand[Untitled]inthetitlebar.

Youcanbeginbuildingyoursimulationrightaway,butit’srecommendedthatyousaveandnamethesimulationbeforeyouproceedveryfar.Thelongeryouwaittosavethesimulation,themoreyourisklosingyourworkifanunforeseencomputerornetworkproblemshouldoccur.

Ifyoualreadyhaveasimulationfileopenandwanttostartanewsimulation,firstsaveyourworkifapplicable.ThenselectFile>NeworclicktheNewtoolbarbutton,toclosethecurrentfileandbringupanewblanksimulationscreen.Notethatifyouhaveunsavedchangesinyourexistingfile,CHEMCADwillaskyoutosaveordiscardyourchangesbeforeopeningthenewsimulation.

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Saving a Simulation Tosaveallchangesinasimulationthatyouhavealreadynamed,selectFile>SaveorclicktheSavebuttononthetoolbar.

Note:Insomecases,suchasthebuilt‐inCHEMCADexamplefiles,existingfilesmaybesetasread‐onlytopreventaccidentaloverwriting.Youcansaveacopyofaread‐onlyfileusingadifferentfilenameand/orfilelocation.

Tosaveanewsimulationthatyouhaven’tyetnamed,selectFile>SaveAs.TheSaveAsdialogboxappears,withCHEMCAD6(*.cc6)asthedefaultfiletype.Leavethefiletypeasitis,givethefileauniquename,andifnecessarynavigatetoanewfilelocation.ClickSavetoclosethedialogboxandreturntothesavedsimulation.

Figure 4-03: Giving a new simulation a unique name

Note:UnlikepreviousversionsofCHEMCAD,thechangesyoumaketoasimulationarenotsaveduntilyouusetheSaveorSaveAscommand.Thisoffersyougreaterflexibilityinchoosingwhichchangestosaveordiscard.

Savingandstoringallofyoursimulationsinthesamedirectoryhelpspreventthelosttimeandfrustrationthatcanresultwhenfilesarescatteredindifferentlocations.ItisrecommendedthatyoustoreyoursimulationsintheMySimulationsfolder,whichiscreatedautomaticallywithintheMyDocumentsfolderatinstallation.

Saving Different Cases for the Same Simulation Incertainsituations,youmayneedtocreateagroupofsimulationsthatarenearlyidenticaltooneanother;previousversionsofCHEMCADreferredtosuchgroupsofsimilarsimulationsascases.InCHEMCAD6,eachsimulationisafree‐standingfile,butyoucanstilleasily“clone”simulationsandmakeminorchangesforcomparisoncases.

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Todothis,simplycreateasimulation,saveit,andthenselectFile>SaveAstorenamethenextcase.Maketheneededchangesforthatcase,saveit,andcontinueinthatveintocreateasmanyclonesofyouroriginalsimulationasneeded,withwhateverdifferencesyourequire.

E-mailing a Simulation WithCHEMCAD6,e‐mailingasimulationisasimplematterofaddingafileattachment.Justopenyourpreferrede‐mailprogram,createanewmessage,chooseyourrecipientsandaddyourtext,thenusetheprogram’scommandforattachingafile.Navigatetothefolderwherethesimulationislocated,selecttheappropriate.CC6file,andaddthefileasanattachment.

Figure 4-04: Adding a .CC6 file as an attachment in MS Outlook

Beforeyoue‐mailasimulation,youshouldensurethatyouhavesavedanyrecentchanges.Also,it’sagoodideatocheckthesizeofthefilebeforeaddingtheattachment,assimulationfilescaninsomecasesbequitelarge.

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Working with CHEMCAD Files from Previous Versions YoucanuseCHEMCAD6toopensimulationsthatwereoriginallycreatedwithCHEMCAD5.Whenyoudothis,CHEMCADcreatesacopyoftheoriginalsimulation,andmakesthatcopycompatiblewithallCHEMCAD6functionality.Theflowsheetandsimulationdatainthecopyarenotalteredinanyway,andtheoriginalfileisleftintact.

TobringanexistingsimulationuptodatewithCHEMCAD6,selectFile>Open,selectthesimulation,andclickOpen.Amessagewillappear,notifyingyouthatthesimulationwillbecopied.

Figure 4-05: Converting a CHEMCAD 5 file to the .CC6 format

ClickSavetobringuptheSaveAsdialogbox,whereyoucaneitherkeeporchangethefile’snameandselectalocationfortheCHEMCAD6copy.ClickSavetocreateandopenthenewfile.

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Chapter 5

Building and Using a Basic Simulation

AlthoughthetypesofsimulationsyoucancreateusingCHEMCADaremanyandvaried,thebasicprocedureforcreatingasimulationcanbebrokendownintothefollowingcommonsteps:

1. Startanewsimulation.

2. Selectengineeringunitsforthesimulation.

3. Createaflowsheetwiththeappropriatestreamsandunitoperations.

4. Selectchemicalcomponentsfortheprocess.

5. SelectK‐valueandenthalpyoptionsfortheprocess.

6. Definethefeedstreamsusedintheprocess.

7. Enterspecificationsfortheunitoperations.

8. Runthesimulation.

9. Reviewtheresultsofthesimulation.

Starting a New Simulation LaunchCHEMCADandthenselectFile>SaveAs.IntheSaveAsdialogbox,specifyanameandlocationforthesimulationfile.

WhenyoufirstinstallCHEMCAD,thedefaultlocationforsavingnewsimulationsisafoldercalledMySimulations,locatedwithinyourcomputer’sMyDocumentsfolder.Youcansaveyournewsimulationtothatfolder,ortoanyaccessibledirectoryonyourcomputerornetwork.Asyou’llnoticeintheSaveAsdialogbox,thefileextensionforCHEMCADsimulationfilesis.CC6.

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Selecting Engineering Units Tospecifyengineeringunitsforthissimulation,selectFormat>EngineeringUnits.ThisbringsuptheEngineeringUnitSelectiondialogbox,whereyoucanselecttheunitstobeusedforeverythingfromtimeandtemperaturetosurfacetension.ThemajorityoftheoptionsinthisdialogboxarelocatedontheUnitsselectiontab,butyoucanclickasecondtabcalledOptionsandreferencesformoreoptions.

ThebuttonsalongthebottomoftheUnitsselectiontabenableyoutosetalloftheunitstoEnglish,alternativeSI,SI,ormetric.Ifyourdesiredunitsdonotfitneatlyintooneofthesecategories,youcanchoosetheclosestoneandthenmanuallyselectdifferentunitsforanyitemsyoulike.

Ifyoudofindyourselfcustomizingyourlistofunits,youcansaveyourselectionsasaset,orprofile,thatyoucanquicklyduplicateforfuturesimulations.Todothis,firstsetalloftheunitsthewayyouwantthem,thentypeanameforthisprofileandclicktheSaveProfilebutton.

YoumaynotnoticeanythinghappeningwhenyouclickSaveProfile,butyoucanverifythatyournewprofilehasbeensavedbyclickingtheLoadProfilebutton.Thisisthebuttonthatyouwilluseforfuturesimulations,toapplyyourcustomunitsprofilewithasingleclick.YoushouldseeaSelectItemscreenthatshowsthenameyougavetheprofile.IfyouclicktheprofilenameandthenclickOK,you’llloadyourcustomunitsprofile.

BackontheEngineeringUnitSelectiondialogbox,clickOKtoapplyyourengineeringunitselectionsandcontinuecreatingyoursimulation.

Drawing the Flowsheet Tocreatetheflowsheetforyoursimulation,you’llneedtoaddtheappropriateunitoperationiconstoyourworkspaceandconnectthoseUnitOpstooneanotherwithstreams.ThisconnectedgroupofstreamsandUnitOpsformsthebasisforthesimulation.

ThetoolsfordrawingaflowsheetarelocatedinthePalettepane,whichbydefaultdisplaysontherightmarginoftheCHEMCADwindow.ThePalettepaneisdividedintoUnitOpcategories,oryoucanviewalloftheavailableUnitOpiconsatonceusingtheAllUnitOpsview.

Adding UnitOps ToplaceaUnitOpicononyourflowsheet,followthesesteps:

1. OntheAllUnitOpspalette,findtheappropriateUnitOpiconfortheequipmentyouwanttorepresent.Whenyoupointtotheiconwiththemouse,theboxaroundtheiconlightsup.ClicktheicontoselecttheUnitOp.

2. Moveyourmousecursortotheworkspacearea,notingthatthepointerdisplaysanoutlineoftheUnitOpiconyou’veselected.Pointtothelocation

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ontheworkspacewhereyouwanttoplacetheselectedUnitOp,andthenclickandreleasetheleftmousebutton.TheiconfortheselectedUnitOpappearswhereyouclicked.

3. Right‐clicktodeselecttheUnitOpdrawingtoolandreturntoanormalpointer.YoucannowclickintheworkspaceareawithoutdrawingduplicateUnitOps.

Selecting a Default Icon for a UnitOp ForcertainUnitOps,youcanselectadefaulticontocustomizethewaythattypeofequipmentlooksonyourflowsheet.

Note:Iconsthatarealreadyinplaceontheflowsheetwillnotbeaffectedwhenyouselectanewdefaulticon.

YoucanseewhichiconsofferthisfeaturebymovingyourcursorovertheAllUnitOpspalette,notingtheboxesthatlightuparoundtheicons.AUnitOpthatoffersachoiceofdefaulticonswillhaveablacktriangleinthelowerrightcornerwhenyoupointtoitsbox.

Figure 5-01: Black triangle showing that the Divider UnitOp offers a choice of icons

ToselectanewdefaulticonforaUnitOp,clicktheblacktriangletoseeapop‐upselectionboxwithallavailableicons.Clicktheiconyouwanttouse;thaticonreplacesthepreviouslydisplayedicononthepalette.YoucanchangethedefaulticonforaUnitOpasoftenasyoulike.

Figure 5-02: Selecting a new default Divider UnitOp icon

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Manipulating UnitOp Icons AfterdrawingaUnitOpicononaflowsheet,youcanmove,resize,ordeletetheiconasneeded.

1. Verifythatthemousepointercurrentlydisplayedisanormalarrow.IfthepointerdisplaysasaUnitOpiconoutline,right‐clicktoturnoffUnitOpdrawing.

2. ClicktheUnitOpiconsothatit*foursizinghandles(blackboxesateachcorner)appear.

3. ManipulatetheUnitOpiconasneeded:

• TomovetheUnitOp,clicktheiconanddragtoitsnewlocation.

• ToresizetheUnitOp,clickanysizinghandleanddraginwardoroutwardtoachievethedesiredsize.

• TodeletetheUnitOp,right‐clickandselectDelete,orsimplypressthe[DELETE]keyonyourkeyboard.

UnitOp ID Numbers WhenyouplaceUnitOpsonyourflowsheet,CHEMCADassignseachoneaUnitOpIDnumberthatisuniquewithinthesimulation.TheUnitOpIDnumberisanimportantidentifierfortheunit,andisusedinvariousreportsandchartsasyouworkwiththesimulation.Bydefault,yourUnitOpswillbenumbered,startingat1,intheorderinwhichyoucreatethem;alltypesofequipmentsharethesamepoolofIDnumbers.

IfyouwanttogroupyourUnitOpsnumericallybyequipmenttype,youcanusetheStartingIDsfeaturetoaccomplishthis.

SelectFormat>StartingIDs,whichbringsuptheStreamandUnitOpStartingIDsdialogbox.Hereyou’llseeeachtypeofUnitOpavailableinCHEMCAD,eachwithadefaultsettingof1.ThismeansthatanynewUnitOpwillbeassignedanIDfromthesamenumberpool—thenextnumber(1orgreater)thathasnotbeenusedyetinthissimulation.

Tosetupseparaterangesofnumbersfordifferentequipmenttypes,youcaneditthevaluesintheStreamandUnitOpStartingIDsscreen.Forexample,youcouldsettheHeatExchangervalueto200,thePumpvalueto300,thePipevalueto400,andsoon,usinganystartingvaluesthataremeaningfultoyou.AnyUnitOptypeyoudon’tassignastartingvaluewillpullIDnumbersfromthepoolstartingwith1,skippinganynumbersthatarealreadyassigned.

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Drawing and Connecting a Stream Beforeyoucanaddastreamtoaflowsheet,youmustalreadyhavedrawntheUnitOpsthatthestreamwillconnect.Followthesestepstoaddastream:

1. ClicktheStreamtoolintheupperrightcorneroftheAllUnitOpspalette.

2. Movethecursorontotheworkspace,notingthatthepointernowappearsasasmallplussign.FindtheiconfortheUnitOpwherethestreamwillstart,andpointattheiconsothattheblueinletdotsandredoutletdotsarevisible.IfthisUnitOpoffersmorethanoneoutletlocation,decidewhichoneyouwilluse.

3. Pointattheredoutletdotsothatthepointerturnsintoasmallblackarrow.Clickandreleasetheleftmousebuttontostartdrawingthestream.

4. MovethecursortowardtheUnitOpwherethestreamwillend.AsyouapproachtheUnitOpicon,theinletandoutletdotsonthaticonwillbecomevisible.Ifmorethanoneinletlocationisavailable,decidewhichoneyouwilluse.

5. Whenyoureachtheblueinletdot,clickthemouseagaintocompletethestream.

Afteryoudrawastream,theStreamtoolremainsactivesothatyoucandrawanotherstreamrightawayifdesired.Toturnoffstreamdrawing,simplyclickonanyblankareaoftheworkspace;thisreturnsyourpointertothenormalwhitearrow,whichyoucanusetoselectandmanipulateitemsontheflowsheet.

Choosing a Stream Route IfyoudrawastreambyclickingonlyattheUnitOpoutletandinlet,CHEMCADchoosestheshortestandmostdirectpathforthestream.Insomesituations—whenaUnitOpisinthedirectpathofthestream,forexample—youwillneedtochooseadeliberaterouteforyourstream.

Todothis,clickthemouseasyoumovefromoutlettoinlet,whereveryouwantthestreamtomakeaturn.Eachtimeyouclick,thestreamfreezesinplace,andfromthereyoucanmakea90°turntoeithertheleftortheright.YoucanaddasmanydetoursasyouliketoastreambeforebringingitintoaUnitOpinlet.

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Figure 5-03: Stream 2 with automatic routing (above) and deliberate routing (below)

Rerouting a Stream Evenafteryou’vecompletedyourflowsheetandaddeddetailedinformationaboutyourstreams,youcanstillrerouteastreamifneeded.Todothis,clickthestreamtoselectit,thenright‐clickandselectReroutestream.Theoldstreamdisappears,replacedbythebeginningofanewstreamoriginatingatthesameoutlet.

Youcannowclicktocreate90°turns,thesamewayyouwouldwithanewstream,toroutethestreamexactlywhereyouwantit.Yourlastclickmustcompletethestreamatthesameinletyouusedbefore.Afterastreamisrerouted,itretainsallofthestreamdetailthatyouhadpreviouslyentered.

Stream ID Numbers Whenyoudrawstreamsinyourflowsheet,CHEMCADassignseachoneastreamIDnumberthatisuniquewithinthesimulation.Thestreamnumberisanimportantidentifierforthestream,andisusedinvariousreportsandchartsasyouworkwiththesimulation.Bydefault,yourstreamswillbenumbered,startingat1,intheorderinwhichyoucreatethem.

IfyouwanttocreateaseriesofstreamswithaseparaterangeofIDnumbersfromtherestofyoursimulation,youcanusetheStartingIDsfeaturetoaccomplishthis.

SelectFormat>StartingIDs,whichbringsuptheStreamandUnitOpStartingIDsdialogbox.ThenscrolldowntotheStreamoptionandclicktheadjacentnumbercolumn.EnterthenumberthatwillbethestartofyourseparatestreamIDpool,and

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clickOK.IfyoulaterneedtodrawmorestreamswithIDnumbersinthenormalrange,youcanreturntothisdialogboxandreloadthedefaultsetting.

Forexample,todrawaseriesofutilitystreamswithIDnumbersstartingat300,youwouldsetthestreamstartingIDoptionto300anddrawthestreamsinquestion.Thosestreamswouldbenumbered300,301,302,andsoforth.Afterdrawingallofyourutilitystreams,youwouldthensettheStreamIDoptionbackto1,sothatthenextnewstreaminthemainflowsheetwouldbeassignedthenextavailablestreamIDfromtheregularpoolofnumbers.Youcanresetthestreamoptionnumberasmanytimesasneededwhileyoucreateandedityoursimulation.

Other Drawing Tools InadditiontotheStreamtoolandthevariousUnitOpicons,thePalettepaneoffersatexttool,aswellastoolsfordrawingrectangles,ellipses,lines,multi‐partlines,andpolygons.

The Text Tool Toplacetextonaflowsheet,selecttheTexttool(whichdisplaysalargeletterT)ontheAllUnitOpspalette.Whenyoumoveyourcursorovertheworkspace,you’llnowseethatyourpointerhasbecomeaverticalline.Clickthemousetoplaceablinkingcursorontheflowsheet.

Starttypingthetextthatyouwanttoadd.Youwillseethetextappearwhereveryouclickedthemouse.Whenyoufinish,clickanywhereintheworkspacetoturnofftheTexttool.

Youcannowclickanddragyournewblockoftextaroundtheworkspace.YoucanalsoselectFormat>ColororFormat>Fonttoaccessvariousstandardtextandobjectformattingtools.

Simple Drawing Tools: Rectangle, Ellipse, and Line Youcandrawvariousshapesasneededonaflowsheet.Thesimplestoftheseshapestodrawarerectangles,ellipses,andlines.

Toaddanyoftheseshapestoaflowsheet,simplyclickthecorrespondingtoolintheAllUnitOpspalette.Then,thenclickanddragintheworkspacetodrawtheshape,releasingthemousebuttonwhenyouhaveachievedthedesiredsizeandshape.

Notethattomakeaperfectsquareorcircle,youcanholddownthe[SHIFT]keyasyoudrawwiththeRectangleorEllipsetool,respectively.

Complex Drawing Tools: Multi-line and Polygon Inadditiontothesestraightforward,click‐and‐dragshapes,youcanalsocreatemorecomplexshapesandlinesonaflowsheet.

Tocreateanyopenfigurewithanirregularshape,selecttheMulti‐linetoolintheAllUnitOpspalette.Moveyourcursortotheworkspaceandclickintheareawhere

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youwanttostartdrawing.Thenmovethecursorandclickagaintocreatetheshape’sfirstline.Keepclickingandmovingthemouseuntilyou’vecreatedtheshapeyouwant,andthendouble‐clicktocompletetheshapeandturnofftheMulti‐linetool.

Tocreateanirregularclosedpolygon,selectthePolygontoolandthenmoveyourcursortotheworkspace.Clickwhereyouwanttostartdrawing,andthenclickasecondtimetocreatethefirstsideofyourpolygon.Afterthesecondclick,you’llbegintoseetheopenareabeingcreated.Continuemovingthecursorandclickinguntilyouarereadytoplaceyourlastpoint,andthendouble‐clicktocompletetheshapeandturnoffthePolygontool.

Notethatyoucanholddownthe[SHIFT]keywhileusingthePolygontooltocreatearighttriangle.

Selecting Chemical Components Youcanselectchemicalcomponentsforyoursimulationatanypointwhilecreatingtheflowsheet,oryoucanwaituntilyou’vedrawntheentireflowsheetbeforeaddingcomponents.Beforeyoucanrunthesimulation,youwillneedtolisteverycomponentinvolvedinyourchemicalprocesssothatCHEMCADcanworkwiththosecomponents’properties.

ThesechemicalcomponentsarepulledfromCHEMCAD’scomponentdatabase,amasterlistofthousandsofchemicalswiththeirassociatedproperties.Whenyou’rereadytolistcomponentsforyoursimulation,selectThermophysical>SelectComponentstoopentheSelectComponentsdialogbox.NotethatyoucanalsoopenthisdialogboxbyclickingtheSelectcomponentsbuttononthetoolbar.

Figure 5-04: The Select components button

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Figure 5-05: The Select Components dialog box

TheAvailableComponentscolumnliststhecontentsoftheCHEMCADcomponentdatabase,whiletheSelectedComponentscolumnliststhecomponentscurrentlyincludedinthissimulation.Foranewsimulation,theSelectedComponentslistisemptyatfirst.

Everychemicalthatwillbepartoftheprocess,whetherit’safeedstream,product,orutility,mustbelistedonthissimulation’scomponentlist.

Finding a Component BecauseofthelargenumberofcomponentsintheCHEMCADcomponentdatabase,scrollingupanddownthelistofavailablecomponentscanbetime‐consuming.Tofindaspecificcomponentquickly,usetheSearchfieldatthebottomoftheSelectComponentsdialogbox.

TypethenameofthechemicalyouwanttofindintheSearchfield.Witheachletterthatyoutype,CHEMCADsuggestspossiblematchesintheAvailableComponentslist.Inthefollowingexample,typingtheletterswaintheSearchfieldhashighlightedtheWatercomponent.

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Figure 5-06: Using the Search field to locate the Water component

Notethatinsomesituations,thefirstresultmaynotbetheoneyouwant.Forexample,typingethaneintheSearchfieldbringsuptheMethanecomponentatfirst.Toseethenextmatchforyourtext,clickNext;continueclickingthisbuttonasneededuntilyoufindthedesiredcomponent.

TheSearchfieldacceptsbothtextandnumericentries.Bydefault,CHEMCADwillsearchforyourentryamongallchemicalnames,chemicalformulas,andCHEMCADdatabaseIDs;ifyoulike,youcanalsosearchbyCASnumber.Toturnanyofthesesearchoptionsonoroff,clicktheOptionsbuttonbelowtheSearchfield.ThisbringsuptheSearchOptionsdialogbox,whereyoucanspecifywhichdatatoincludeinyourcomponentsearches.

Figure 5-07: Selecting which data to include in component searches

Note:YoucanaddyourowncustomcomponentstotheCHEMCADcomponentdatabase.Formoredetailsaboutthisfeature,seeChapter10ofthismanual.

Adding a Component Onceyou’velocatedthecomponentyouwantintheAvailableComponentslist,simplydouble‐clickthecomponenttoaddittotheSelectedComponentslistforyoursimulation.

YoucanalsoselectmultiplecomponentsintheAvailableComponentslistandthenclicktherightarrowbutton,locatedbetweenthetwocolumns,toaddthe

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componentstoyoursimulation.Toselectmultiplecomponents,useWindows’standardselectionmethodsofholdingdown[SHIFT]toselectcontiguousitemsorholdingdown[CTRL]toselectnon‐contiguousitems.

Figure 5-08: Adding multiple components using the right arrow button

Ifyouwouldliketoduplicatethecomponentlistfromanexistingsimulation,clickCopyFromAnotherSimulation.IntheresultingOpendialogbox,navigatetothedesiredsimulation,selectthatsimulation,andclickOpen.TheSelectedComponentslistisnowpopulatedwiththecomponentsusedinthesimulationyouselected;youcanaddordeleteitemstocustomizethelist.

Changing the Order of Selected Components WhenyourSelectedComponentslistforasimulationisparticularlylong,youmayfindithelpfultoplacecertaincomponentsateitherthetoporthebottomofthelist.Youcanaddcomponentsinanyorder,andthenmovethemaroundinthelistasneeded.

TomoveacomponenttoanewpositionintheSelectedComponentslist,clickthecomponenttoselectitandthen:

• ClickToptomoveittothefirstpositiononthelist.

• ClickUptomoveituponeposition.

• ClickDowntomoveitdownoneposition.

• ClickBottomtomoveittothelastpositiononthelist.

Removing Items from the Selected Components List ToremoveasinglecomponentfromtheSelectedComponentslist,clickthecomponenttoselectitandthenclickDeleteinthebottomrightareaoftheSelectComponentsdialogbox.

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ToremoveallcomponentsfromtheSelectedComponentslistandbeginagain,clickClear,justtotherightofDelete.Ifyouhavechangedyourmindaboutaddingcomponentsatthistime,youcansimplyclickCanceltobackoutofcomponentselection.

Selecting K-value and Enthalpy Options ThefirsttimeyoucompletetheComponentSelectiondialogbox,you’llbetakentotheThermodynamicsWizarddialogbox.Atthispoint,youcaneitherclickCanceltoskipthewizardandenterthermodynamicsmanually,orenterparametersinthedialogboxandclickOKtoseewhichmethodsthewizardsuggests.

Using the Thermodynamics Wizard Properselectionofthermodynamicsisgenerallythemostimportantstepinaprocesssimulation.Apoorthermodynamicsselectionmayleadtounrealisticsimulationresults.

TheThermodynamicsWizardmakesgeneralsuggestions,basedonyourcomponentlistandthespecifiedrangesfortemperatureandpressure.

Selecting Components to Ignore Intheupperportionofthewizardscreen,usethedrop‐downboxestoindicateanycomponentsthattheThermodynamicsWizardshouldnotconsider.Thismayaffecttheresultsformodelsuggestion.Forexample,ifyouareusingwaterasacoolantandyourothercomponentsarealkanes,theThermodynamicsWizardwillchooseUNIFAC.Ifyouspecifythatwatershouldbeignored,thewizardwillignorethewaterandselectSRK.

Specifying Process Conditions Inthelowerportionofthewizardscreen,specifytheapproximatetemperatureandpressurerangesforthisprocess.EnteringaccurateinformationinthesefieldswillhelptheThermodynamicsWizardreturnamoreusefulrecommendation.

IntheBIPDataThresholdfield,entertheminimumpercentageofpossiblebinaryinteractionparameters(BIPs)whichmustbepresentinaBIPactivitycoefficientmodel(NRTL,Wilson,etc).WithoutBIPs,activitycoefficientmodelssimplifytoRaoult’slaw.

How the Thermodynamics Wizard Makes Suggestions CHEMCAD’sThermodynamicsWizardfollowsalogictreetochooseamodel.Thelogictreeassumesthatallyourcomponentsaremixedinavessel,withconditionsfallingintothespecifiedtemperatureandpressureranges.

• Ifallcomponentsarehydrocarbons,thewizardwilllikelysuggestanequationofstate.

• Ifwaterispresent,thewizardwilllikelyselectanactivitycoefficientmethod.

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• Ifwaterandhydrocarbonsarepresent,thewizardwilllikelyselectUNIFAC.

• Ifwaterandstrongelectrolytes(HCl,NaOH,etc.)aredetected,thewizardwillsuggestelectrolytemodels.

Temperatureandpressurerangewillaffecttheselectionofmodel.Ifpressureishigh,CHEMCADismorelikelytosuggestanequationofstate.Ifpressureisatmosphericandtemperatureisbelowthenormalboilingpointofallcomponents,CHEMCADmaychoosealiquidactivitymodeloridealvaporpressure.

Should the Thermodynamics Wizard be trusted to make design decisions? Usethewizardasastartingpointforyourdecision.Properselectionofthermodynamicsistheengineer’sresponsibility.YoursimulationmaycallfortheuseofadifferentthermodynamicmodelthanwhattheThermodynamicsWizardsuggests.

Manually Selecting Thermodynamics Settings Tosetupthermodynamicsforyoursimulationmanually,followthesesteps:

1. SelectThermophysical>ThermodynamicSettings,orclickthebuttonbythesamenameonthetoolbar.

Figure 5-09: The Thermodynamic Settings button on the toolbar

2. ThisopenstheThermodynamicSettingsdialogbox.Startbydetermining,basedonyourprocessknowledge,whetheryoursystemhastwoliquidphasesorasingleliquidphase.IntheGlobalKValueModelfield,selectamethodthatcancalculatethephasebehaviorrelevanttoyoursystem.

3. Basedonthespecificcirc*mstancesofyourprocess,makeanyneededalterationstotheoptionsdisplayedontheK‐valueModelstab.NotethattheoptionsappropriatetoyourselectedK‐valuemethodaredisplayedinblack,whileirrelevantoptionsaredisplayedingray.

4. ClicktheEnthalpyModelstab,selectthemostappropriatemodelintheGlobalEnthalpyModelfield,andmakeanyotherchangestotheoptionsonthistabasneededforyourprocess.

5. ClicktheTransportPropertiestabandverifythatthesettingsthereareappropriateforthissimulation.ChangeanysettingsasneededandthenclickOKtoclosetheThermodynamicSettingsdialogbox.

6. Ifyou’vemadeanychanges,amessageboxappears:Allstreamsshouldbereinitialized.Proceedwithreinitialization?ClickYestoreinitializeallstreamsnow,orNoifyou’dprefertowaitandreinitializethestreamslater.

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Defining Streams Thestreamsthatyouhavedrawnonyourflowsheetarestilljustlineswithnodatabehindthem,sothenextstepistoeditthesestreams,populatingthemwithcompositiondataandotherproperties.

Note:Inmostsituations,thestreamsyou’llneedtodefinewillbethefeedstreamsinyourprocess.Othertypesofstreams,suchasrecyclecutstreams,mayalsorequiredefinition.

Youcaneditasinglefeedstreamusingeitherofthesemethods:

• Double‐clickthestream.

• OntheSimulationtabintheCHEMCADExplorer,expandFlowsheetandthenStreams,right‐clickthestreaminquestion,andselectEditStream.

Youcaneditallfeedstreamsintheflowsheetatonceusingeitherofthesemethods:

• SelectSpecifications>FeedStreams.

• ClicktheEditFeedStreamstoolbarbutton(justtotheleftofthegreenRunAllbutton).

Whichevermethodyouchoose,you’llseetheEditStreamsdialogbox,witheitherasinglecolumnofdataoracolumnforeachfeedstreamintheflowsheet.Inthisdialogbox,specifypropertiesforeachfeedstreamlisted.

Thermodynamic Properties Youmustspecifyexactlytwoofthefollowingthreevariables:

• Temperature

• Pressure

• Vaporfraction

CHEMCADwillcalculatethethirdvariableandenthalpy,basedonthetwovariablesyouspecifyandthethermodynamicsmethodyou’veselected.

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Stream Composition Todefinethestreamcomposition,you’llneedtospecifyacompositionunitandtheamountofeachcomponentthatispresentinthestream.

SelectaunitfromtheCompunitdrop‐downlist,andthenbasedonthatselection,populatethefieldforeachcomponentwiththeappropriateamount,percentage,orfraction.

Forstreamcompositionsexpressedasapercentageorfraction,youcanentervaluesthatdonottotal100%.Inthiscase,CHEMCADwillnormalizethecompositiontofractionalvaluesthattotal1.TopreviewthenormalizedvaluesthatCHEMCADassignstothecomponents,clickFlash.

Total Flow Properties Ifthecomponentflowengineeringunitusedforastreamisdimensionless(i.e.,molefraction,weightfraction,orvolumefraction),youmustspecifythefollowingflowproperties:

• Totalflow

• Totalflowunit

Ifyouenteryourcomponentamountsasfractions,thenyoumustalsoenteratotalflowrate.Ifyouentercompositionamountsusingquantitativeflowunits,CHEMCADcalculatesthetotalflowrateforyou.

Specifying Equipment Parameters Onceyouhavespecifiedthenecessarystreampropertiesforyoursimulation,thenextstepistoenterspecificationsfortheUnitOps.YoucaneditthepropertiesofaUnitOpusinganyofthefollowingmethods:

• Double‐clicktheUnitOpiconontheflowsheet.

• ClicktheUnitOpiconandthenselectSpecifications>EditUnitOps>SelectUnitOps.

• OntheSimulationtabintheCHEMCADExplorer,expandFlowsheetandthenUnitOps,right‐clicktheUnitOpinquestion,andselectEditUnitOpData.

ThedialogboxthatdisplayswhenyougotoeditaUnitOp’spropertieswilldependonthetypeofUnitOp.TheStreamMixerUnitOp,forexample,hasonlyonespecificationthatyoucanset,whiletheSCDSDistillationColumnUnitOphasfivetabbedpagesofdetailedsettings.

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Figure 5-10: Two different UnitOps that require very different amounts of input

ThedetailedinformationaboutthespecificationsforeachtypeofUnitOpiscontainedintheCHEMCADHelpsystem,whichyoucanaccessfromanyCHEMCADscreenbypressingthe[F1]key.

Thesespecificationscreensdo,however,havecertainrulesincommon:

• Itemswithgreentextlabelsarerequiredentries.

• Allotherentriesareoptional.

• ClickingOKsavesyourspecificationchanges;clickingCanceldiscardsthem.

AfteryouclickOK,CHEMCADchecksyourdataforinternalconsistencyandthenreturnserrorsorwarningsaswarranted.TheseitemsdisplayintheMessagespaneintheCHEMCADwindow.

Running the Simulation Nowthatyou’vedrawntheflowsheetandaddeddetailtothestreamsandUnitOpsthatmakeuptheflowsheet,youcanrunthesimulation.YoucaneitherselectRun>Run>RunAllorsimplyclickthegreenRunAllbuttononthetoolbar.

Whenyourunasimulation,CHEMCADcalculatesmaterialandenergybalancesthroughouttheentireflowsheetandreturnsanyerrorsorwarningsdiscoveredintheflowsheet.Iftheruncompletessuccessfully,aRunfinishedmessageappearsatthefarleftofthestatusbar,attheverybottomoftheCHEMCADwindow.

Note:ForpreliminarychecksofindividualUnitOpsorgroupsofUnitOps,youcanselectRun>Run>RunSelectedUnitOps,orright‐clickanyUnitOpontheflowsheetandselectRunthisUnitOp.

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Reviewing the Results Afterasimulationhasrun,youcancallupanynumberofindividualtext‐basedreportsorgraphicalplots,eitherforon‐screenviewingorforprinting.ReportscanprovidedataonanysinglestreamorUnitOp,oranygroupofstreamsorUnitOps,inasteady‐stateordynamicsimulation.YoucanalsorequestaconsolidatedreportthatprovidescomprehensivedataonthestreamsandUnitOpsyouselect.

Note:CHEMCADreports,plotting,andplotprintingarecoveredindetailinChapter8,OutputandReports.

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Chapter 6

Using CHEMCAD for High-fidelity Modeling

UnitoperationspecificationsinCHEMCADvarygreatlyindetail,fromvagueandconceptualtoextremelyspecificandrealistic.Dependingonthedemandsofyourprocessandwhatyou’retryingtoachievewithyoursimulation,youmayworkwithwhatwecalllow‐fidelitymodeling,high‐fidelitymodeling,orboth.

ThischapteraddressesCHEMCAD’scapacityforhigh‐fidelitymodelingandhowtoachieveahighlevelofrealismwithyourUnitOps.

What is high-fidelity modeling? Withlow‐fidelitymodeling,youspecifywhatyouwant,orwhatyouhaveobserved,andCHEMCADmakesitscalculationsbasedontheassumptionthatyoucanachievewhatyou’vespecified.It’scommontospecifyobservedpropertiessuchastemperatureand/orpressurecomingoutofaUnitOp,orcomponentpuritycomingoutofaseparationunit.Specifyingtemperaturecomingoutofaheatexchangerisanexampleoflow‐fidelitymodeling.

High‐fidelitymodeling,ontheotherhand,requiresthatyouenternumerousextensivevariables.CHEMCADcalculatestheresultingconditionsbasedonthesedetailedentries.Withhigh‐fidelitymodeling,you’reoftenrequiredtospecifygeometry‐relatedvariablesforaUnitOpsothatCHEMCADcancalculatepreciseconditionsattheequipment’soutlet.

Here’sthekeydistinctionbetweenlow‐fidelityandhigh‐fidelitymodelinginCHEMCAD:

• Low‐fidelity:YouspecifythedesiredresultsandCHEMCADassumesthatyoucanachievethoseresultswiththeequipmentyouhave.

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• High‐fidelity:YouspecifyenergyandequipmentparametersandCHEMCADcalculatestheactualresults.

Criteria for High-fidelity Modeling TotakeadvantageofCHEMCAD’shigh‐fidelitymodelingcapabilities,youmustprovidedetailedspecificationsforyourequipment.Todothis,mostUnitOpsrequirethatyouselectacalculationmodethatallowsforentryofhigh‐fidelity‐caliberdetail.

Forexample,ifyouhaveapumpthatissettothedefaultmodeofSpecifyoutletpressure,you’llgetalow‐fidelityresultfromthispump—thatis,thesimulationwillusetheoutletpressurethatyouspecify,butwithoutconsiderationforthesizeofthepump,theamountoffluidenteringthepump,orinletpressure.

IfyouswitchthepumptoSpecifyperformancecurve,ahigh‐fidelitymode,you’llneedtoenterdatapointsfromthepump’sperformancecurve,eitherforasinglespeedlineorformultiplespeedlines.Usingthismode,CHEMCADwillcalculatethechangeofpressureheadbasedontheperformancedataandtheinletvolumetricflowrate.Thisprovidesarealisticpressureincreasefortheactualpumpthatyourprocessuses.

NoteverytypeofCHEMCADUnitOplendsitselftohigh‐fidelitymodeling.ThefollowingsectionsdiscussvarioustypesofUnitOpsthatdoofferhigh‐fidelitycalculationmodes,andprovidesomebasicinformationabouthowtousethosemodes.

Introduction to Equipment Sizing EquipmentsizinginCHEMCADisoptional.ItentailsusingtheSizingmenuoptions,generallyafterrunningasimulation,tocalculateapproximatesizesforpipes,vessels,valves,orifices,andotherequipment.

Figure 6-01: The Sizing menu, showing heat exchanger sizing options

Equipmentsizingcancomplementlow‐fidelityresults,andoftenprovidesanexcellentstartingpointforhigh‐fidelitymodeling.Youcanusecertainsizingresultsasinputforhigh‐fidelitymodelsofUnitOpsinyoursimulation.SpecifyinggeometricparametersforUnitOpscanhelpyouobtainmorerealisticresults.

Notethatforlow‐fidelitymodeling,sizingdoesnotchangeconvergedflowsheetresults.Also,forsomeUnitOps,certaingeometryparametersmustbeenteredregardlessoftheselectedcalculationmode.

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High-fidelity Modeling and Sizing for Common UnitOps High‐fidelitymodelingdoesnotapplytoallCHEMCADUnitOps.ThissectionsummarizesthoseUnitOpsforwhichyoucanusehigh‐fidelitymodeling,andcomparesthatapproachforeachUnitOptypetolow‐fidelitymodeling.Whereapplicable,UnitOpsizingisalsodiscussedasitrelatestolow‐fidelityversushigh‐fidelitymodelingoftheseUnitOptypes.

Piping Youcanuseeitherlow‐orhigh‐fidelitymodelingforpipinginyoursimulation.Pipelinesizingisdonebasedonthecompositionofaselectedstream.

Low-fidelity Forlow‐fidelitymodelingofpiping,youarerequiredtospecifypipediameterandlengthinmostmodes;designmodesthatcalculatediameteraretheobviousexceptiontothis.Thepressuredropthroughthepipeiscalculatedbasedondiameter,length,andflowratethroughthepipe.

Sizing Toperformsizingcalculations,selectSizing>Piping.Selectoneormorestreams,theninthePipeSizingdialogbox,selectasizingoptionandclickOKforlinesizingresults.Youcanusetheseresults,suchassuggestedpipethicknessanddiameter,tospecifygeometryforaPipeUnitOp,orsimplyreviewthemfortheinformationyouneed.

Figure 6-02: Line sizing results from the Pipe Sizing dialog box

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High-fidelity Inhigh‐fidelitypipingmodels,PipeUnitOpsinteractwithNodeUnitOpstobalancepressureandflowrateshydraulicallyamongconnectedpiecesofflow‐basedequipment.NodesmustbeplacedonbothsidesofallPipeUnitOpstobeincludedinhydraulicbalance;pressureandflowconstraintsaresetatthenodes,notinthepipes.

Ahigh‐fidelitypipingmodelcanshowchangesinflowratebasedonbackpressurewheretwopipesmix,whereasalow‐fidelitymodelwouldsimplyassigntheloweroftwospecifiedpressurestotheoutletwithoutconsiderationforbackpressure.

Pumps, Compressors, and Expanders Youcancreatepump,compressor,andexpanderUnitOpsusingeitherlow‐fidelityorhigh‐fidelitymodeling.

Low-fidelity Fortheseequipmenttypes,CHEMCADcalculatespowerusageandthermaleffectsonthefluid,basedonspecifiedoutputpressureorpressureincrease.Otherparameters,suchasefficiency,areoptionalbutdoaffectresults.

High-fidelity Toproduceahigh‐fidelitymodelfortheseequipmenttypes,youmustselecttheoperationmodeinwhichyouspecifyperformancecurves—thatis,pressurechangeasafunctionofvolumetricflowrate.Thisperformanceinformationisgenerallyavailablefromtheequipmentvendor.BasedonthevolumetricflowenteringtheUnitOp,CHEMCADcalculatesoutletpressure.

Aswithpiping,high‐fidelitymodelingforpumps,compressors,andexpanderscanbeusedwithnodesaspartofahydraulicflowbalancednetwork.

Vessels and Tanks Youcanaddvesselsandtankstoyoursimulationsusinghigh‐fidelitymodeling,orperformlimitedapproximationoftheseequipmenttypeswithlowfidelityinsteadystate.Sizingisavailableforcertaintypesofvessels.

Low-fidelity Withlow‐fidelitymodelingofavesselortank,astreamenterstheFlashUnitOpandseparatesintovaporandliquid;CHEMCADdoesnotconsiderhold‐uporliquidlevelinthetank.Ifyouwanttotakeasteady‐statesnapshotofthevessel,youcanmanuallyadjusttheflowrateand/orthermalconditionstomakevolumetricflowratesmatchthevolumeofthevessel.

Note:TheTankUnitOpisspecificallyintendedforusewiththeBatchColumnUnitOp.Itdoesnotrepresentastandardstoragetankforgeneralpurposes.

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Sizing Tocalculatesizingforavessel,selectaFlashUnitOpandthenselectSizing>Vessel.ChooseeitherLVVessel(liquid‐vaporvessel)orLLVVessel(liquid‐liquid‐vaporvessel),dependingonyourneeds.Intheresultingdialogboxes,entertheappropriatevaluesforyourvesselandclickOK.

Figure 6-03: Sizing a vessel in CHEMCAD

TheresultsthatCHEMCADreturnsincludebasicvesselgeometrysuchasheightanddiameter.

Youcanalsoperformvesselsizingonaconvergeddistillationcolumntocalculategeometryforarefluxdrumorsimilarpieceofequipment.

High-fidelity Youcanperformhigh‐fidelitymodelingonlyonbatchreactorsanddynamicvessels,andonlywithaCC‐DYNAMICSlicense(fordynamicvessels,aCC‐SAFETYNETlicensewillsuffice).IfyouspecifythegeometryofyourvesselanduseCHEMCAD’sdynamicsmode,youcanstudywhathappensinthevesselovertimeasmaterialisaddedorwithdrawn.

Unlikesimpleflashvessels,batchreactorsanddynamicvesselsdoconsiderhold‐up,liquidlevel,andvariablepressureovertime.

Valves ValvemodelinginCHEMCADcanbeeitherlow‐fidelityorhigh‐fidelity.Youcansizeacontrolvalvebasedonanyflowsheetstream.

Low-fidelity TheVALVUnitOpisusedforlow‐fidelitymodelingofavalve.ForthistypeofUnitOp,youspecifyoutletpressureorpressuredecreasethroughthevalve.

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Sizing SelectSizing>ControlValve,thenselectastream.IntheControlValveSizingdialogbox,specifytheoutletpressureforthetheoreticalvalve,andenterotherspecificationsasappropriate.WhenyouclickOK,CHEMCADreturnsinformationsuchascapacitycoefficient(Cv)andvalvesize.

Figure 6-04: The Control Valve Sizing dialog box

High-fidelity TheCVALUnitOpisusedforhigh‐fidelityvalvemodeling.DecidewhichvaluesyouwillprovideandwhichvaluesCHEMCADwillcalculate,andselecttheappropriateoperatingmodeintheControlValvedialogbox.Providethevalve’sCvvalue,andanyotherspecificationsasneeded.

Controlvalvescanbeusedwithnodesaspartofahydraulicflowbalancednetwork.

Columns ColumnsinCHEMCADcanbemodeledaseitherlow‐fidelityorhigh‐fidelity.Youcanperformsizingonanyconvergedcolumn.

Low-fidelity Forlow‐fidelitymodelingofcolumns,usetheTower,TowerPlus,orSCDSUnitOps.Specifyidealstagesandtheconditionsatthereboilerandcondenser,asapplicable.Alow‐fidelitycolumnmodeldoesnotconsidermasstransfereffectsorcolumninternals.

Differentcolumnspecificationscanprovidemorerealismwithouttakinggeometryintoaccount.Specifyingtoppurityisaverylow‐fidelitymodel,whilespecifyingrefluxratioorcondenserdutycanbringyourresultsclosertoreality.

Sizing Afterrunningyoursimulation,clicktheUnitOprepresentingthedistillationcolumnandselectSizing>Distillation;chooseeitherTraysorPacking,basedonthetypeofcolumn.

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Theresultingdialogboxespromptyoutoenterinformationaboutyourtraysorpackingandthecalculationmethodsyouwanttouseforcolumnsizing.Youwillgenerallyneedtoentersomegeometryandhydraulicparameterstocompletecolumnsizing.

Figure 6-05: Specifying high-level tray data for distillation column sizing

Figure 6-06: Specifying detailed tray data

Basedonflowsheetvaluesandyoursizinginput,CHEMCADreturnscolumngeometryinformationsuchasheightanddiameter.Italsoprovideshydraulicperformanceinformationsuchaspredictedamountofflooding.

Note:Theresultsofcolumnsizingcalculationsdonotinteractivelychangetheresultsoftheflowsheetsimulation.

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High-fidelity Toperformhigh‐fidelitymodelingofadistillationcolumninsteadystate,usetheSCDSUnitOpandselecteitherofthemass‐transfersimulationmodelsforthecolumn.

Youwillneedtospecifygeometryforthecolumnandchooseacalculationmethodfortheselectedmass‐transfermodel.CHEMCADcalculatescolumnperformancebasedonyourpackingortrayspecifications.

Forcolumns,mass‐transfer‐basedmodelingperformsrigorousnon‐equilibriummixingofvaporandliquid,whereaslow‐fidelitymodelingassumesidealmixing.

Toperformhigh‐fidelitymodelingofadistillationcolumnindynamics,specifythegeometryofthecolumnanddetailsaboutthecontrolsystem.Thisdynamicdistillationcanconsidercolumnhold‐upandtheeffectofvariableschangingovertime.

Note:TheShortcutColumnUnitOpisnotarigorouscalculationmodel.Unlessyoursystemsatisfiestheconstantmolarunderflowassumption,youshouldconsiderusingadifferenttypeofdistillationcolumn.

Heat Exchangers Whenspecifyingaheatexchangerinasimulation,youcanuseeitherlow‐orhigh‐fidelitymodelingaswellassizing,dependingonthetypeofheatexchangerinvolved.

Low-fidelity Whencreatingasimulation,youcanusealow‐fidelityapproachbysimplyspecifyingthethermalconditionscomingoutoftheexchanger.Specifyingheatdutyinsteadofmerelyanoutlettemperaturebringsyourresultsclosertoreality,butthisapproachstilldoesn’tconsidergeometry.

Sizing YoucanusetheCC‐THERMmoduleforrigorouscalculationofheattransfercoefficient(U)basedonheatexchangergeometry.Inratingmode,CC‐THERMdetermineswhethertheuser‐specifiedheatexchangeriscapableoftheflowsheetheatexchangerperformance.Indesignmode,CC‐THERMcalculatesanexchangerdesignthatiscapableoftheflowsheetperformance.

High-fidelity Forsomeexchangercategories—specificallyshell‐and‐tubeanddouble‐pipe—youcanusetherigorousCC‐THERMmodeltocalculateheatexchangerperformance.TheflowsheetresultsarebasedonrigorouslycalculatedUvalueandthespecifiedexchangergeometry.Youcanalsodetermineapproximatefoulingofaunitifactualoutlettemperaturesareknown.

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Figure 6-07: Heat exchanger summary report generated as an Excel worksheet

Relief Devices Forreliefdevices,sizingisnotnecessarilydistinctfromlow‐fidelitymodeling.Tomodeldynamicreliefofavessel,youcaninsteadusehigh‐fidelitymodeling.

Low-fidelity Tomodelasteady‐statesnapshotofareliefdevice,selectSizing>ReliefDevice,specifyratingordesignmode,andselecttheappropriateoptionsforyourreliefscenario.WhenyouclickOK,CHEMCADreturnsareliefdevicecalculationsummary.

IfyouselecttheRigorousintegralanalysisdesignmethodwhensizingareliefdevice,youwillobtainamoredynamicresult.

Figure 6-08: Selecting the rigorous integral analysis method for relief device design

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High-fidelity Youcanperformhigh‐fidelityreliefdevicemodelingfortheBatchReactorandDynamicVesselUnitOps.Youcanspecifythereliefdevicenozzlearea,aswellasotherspecificationsforyourreliefscenario.Thisenablesyoutostudythedynamicreliefofthevessel.

Licensing Considerations for High-fidelity Modeling Tousetheheatexchangersizingfunctionality,youmustcurrentlyhaveavalidlicensefortheCC‐THERMmoduleofCHEMCAD.Tousebatchreactors,you’llneedavalidlicensefortheCC‐DYNAMICSmodule.Fordynamicvessels,alicenseforeitherCC‐DYNAMICSorCC‐SAFETYNETisrequired.

Eachofthesemodulesislicensedindependently.Tovieworchangethedispositionofyourvariousproductlicenses,seetheCHEMCADLicenseMonitorscreen(Tools>Options>Licensingwhenasimulationisopen,orLicense>Licensingwhennosimulationisopen).

Ifyoudon’tcurrentlyhaveaccesstotheheatexchangersizingordynamicsfeaturesandwanttoaddanyofthesemodulestoyourcopyofCHEMCAD,contactthepersonwithinyourorganizationwhohandlessoftwarelicensing,orifappropriate,youcancontactChemstationsoraCHEMCADdistributordirectly.ForacompletelistofChemstationscontactsforallpartsoftheglobe,seeourwebsite(www.chemstations.com).

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Chapter 7

Building and Using a Dynamic Simulation

Whilesteady‐statemodelingcanprovidealloftheinformationyouneedformanypurposes,it’softeninformativetolookcloselyatthechangesovertimethataffectyourstreamsandequipment.CHEMCAD’sCC‐DYNAMICSmodulemakesitpossibletosimulateaprocessovertime.

What do we mean by dynamics? Weusethetermdynamicstodescribemodelingachemicalprocessoverasetperiodoftime.Duringthecourseofareal‐worldchemicalprocess,factorssuchasutilitytemperature,feedcomposition,andliquidlevelstendtochange.Modelingtheresponseofyourprocesstothesechangescanhelpyouunderstandandpredictwhatmighthappenwithyourprocessovertime.

Givenaflowsheet,alengthoftimetorun,andthecalculationintervaltouse,CHEMCADcanreturndetailedresultsthattakeintoaccountthesetypesofchanges.Theprogramcanconsiderthematerialholdupwithinprocessequipmentsuchastanks,reactors,andpipes.ItalsoenablesyoutomodelcontrolsystemssuchasPIDcontrollers.

Licensing Considerations Tousethefunctionalitydescribedinthischapter,youmusthaveavalidlicensefortheCC‐DYNAMICSmoduleofCHEMCAD.TovieworchangethedispositionofyourCC‐DYNAMICSproductlicense,seetheCHEMCADLicenseMonitorscreen(Tools>Options>Licensingwhenasimulationisopen,orLicense>Licensingwhennosimulationisopen).

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Ifyoudon’tcurrentlyhaveaccesstothedynamicsfeaturesandwanttoaddCC‐DYNAMICStoyourcopyofCHEMCAD,contactthepersonwithinyourorganizationwhohandlessoftwarelicensing,orifappropriate,youcancontactChemstationsoraCHEMCADdistributordirectly.ForacompletelistofChemstationscontactsandCHEMCADdistributorsforallpartsoftheglobe,seeourwebsite(www.chemstations.com/contact.htm).

Additional Input for Dynamic Operation Beforeyoucreateadynamicsimulation,you’llneedtogathertherelevantinformationaboutyourUnitOpsandstreams,asyouwouldwithanysimulation.Inaddition,youneedtobeabletoanswerthefollowingdynamics‐specificquestions:

• Howlongwillthesimulationrun?

• Whatwillbetheinterval(deltatime/stepsize)betweencalculations?

• Whatisthechangethatyouwanttostudyovertime?

• Ifapplicable,whatistheinitialcompositionandchargeofanydynamicvesselsorbatchreactors?

Thebasicstepsforadynamicsimulationarelargelythesameasthoseforasteady‐statesimulation,withafewvitaldifferences:

1. Createanewsimulation.

2. Selectengineeringunits.

3. Drawtheflowsheet.

4. Selectcomponents.

5. Selectthermodynamicsoptions.

6. Specifyfeedstreamsandinitialstreamconditions.

7. SetspecificationsforUnitOps.

8. Runthesimulationinsteadystatetoobtaintime‐zerovalues.

9. Switchthesimulationtodynamics.

10. Specifydynamicssettings,suchasruntimeandinitialcharge(s).

11. Runthesimulationindynamics.

12. Reviewtheresults.

13. Re‐runorextendthesimulationasneeded.

14. Generateplotsandreportsasneeded.

Beforeyoustartworkingonadynamicsimulation,it’simportanttohaveasmuchinformationaboutyourprocessaspossible,aclearideaofwhatyouwanttofindout,andastrategyforproducingtheresultsyouneed.

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Strategies for Dynamic Simulations Whenyoustartplanningadynamicsimulation,it’svitalthatyouknowwhatquestionorquestionsyouaretryingtoanswer.Togetuseful,informativeresults,youshouldstartwithasimplequestionandthenrefinethesimulationandrunitagain.

Forexample,todiscoverhowheataffectsavessel’stemperatureovertime,youmightstartbyapplyingconstantheattothevesselforthedurationofyourdynamicsimulation.Youcanthensaveacopyofthatsimulation,changeittousevariableheat,andreviewtheresultstoseehowtheydifferfromtheoriginal.Basedonthatsecondsimulation,youcanmakeanothercopy,andthistimetryvariableheatwithacontrolsystemtoattempttomaintainaconsistenttemperature.Eachofthesedynamicsimulationswouldbringyouclosertowhatyouactuallywanttodiscover.Eachsubsequentsimulationrequiresmoreinformationfromyoutorunandreturntheresultsyouwant.

Whilethereisnorequirementthatyouapproachdynamicsproblemsthisway,it’sasoundpracticethatwillsaveyoutimeandfrustrationinthelongrun.

Setting Up Dynamic Operation Beforeyoucanrunadynamicsimulation,youneedtoprovideparameterssuchasruntimeandstepsize.First,however,youmustactivateCHEMCAD’sdynamicsmode.

Switching to Dynamics Followthesestepstoswitchasimulationfromsteady‐statetodynamicoperation:

1. OpenthesimulationandselectRun>Convergence.ThisbringsuptheConvergenceParametersdialogbox.

2. Inthelowerrightportionofthedialogbox,clickintheSteadyState/DynamicsfieldandselectDynamics.

Figure 7-01: Switching to dynamics

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3. ClickOKtosavethechangesandclosethedialogbox.

Afteryouswitchtodynamics,you’llnoticethatafewthingshavechangedontheCHEMCADscreen:

• ThestatusbaratthebottomofthemainCHEMCADwindowchanges.Afewinchesfromtherightedgeofthescreen,insteadofthewordsSteadyState,you’llnowseeDTimeandatimecounterdisplayingthenumberofminutesyoursimulationhasrun.Beforeyourunthesimulation,theDTimesettingdisplays0:00min.

• Thesteady‐stateRunAllbuttononthetoolbarisdisabled,andthedynamicsbuttonsarenowactivated.Thesebuttons,showninFigure7‐02,are(lefttoright)SetRunTime,ResettoInitialState,RunDynamicSimulation,PlotDynStreams,andPlotDynUnitOps.

Figure 7-02: Toolbar buttons for dynamics

• YoucannowselectRun>DynamicstobringuptheDynamicsMenu.Thiswindowprovidesconvenientaccesstoalldynamicssettingsandcommands.

Figure 7-03: The Dynamics Menu

Setting the Run Time Thenextstepistosettheruntimeforthesimulation.Firstdecidewhetheryourrunwillrequireasinglestepormultiplesteps.

AstepinthiscasereferstoatimeperiodduringwhichCHEMCADwillcapturedatafromthesimulationatuniformintervals.Forexample,youmightsetupasingle‐stepdynamicrunof60minutes,withastepsizeofoneminute,foratotalof60datapointsfortherun.Ifthisisallthatyouneedtodo,yourruncanbeaccomplishedinasinglestep.

If,ontheotherhand,youneedtorunyourprocessfor60minutescapturingdataatone‐minuteintervals,andthenswitchtocapturingdataevery30secondsforthenext20minutes,you’llneedtousetwosteps.Ifyouwanttorecorddataeveryfiveminutesforthefirsthour,everyminuteforthesecondhour,andevery30secondsforthethirdhour,you’llneedtousethreesteps.

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Thestepsizethatyouselectwillhaveanimpactontheaccuracyoftheresultsandthespeedofthecalculation.Smallertimestepsproducemorepreciseresults,butalsorequiremoretimetomaketherun.Smallerisn’talwaysbetter,however,asextremelysmalltimestepscanleadtosignificantround‐offerror.

Onceyouknowhowmanystepsyouneedtouseandwhatyourdata‐captureintervalwillbeforeachstep,followthesestepstosettheruntimeparameters:

1. ClickSetRunTimeontheDynamicsMenu,orclicktheSetRunTimebuttononthetoolbar.ThisbringsuptheDynamicRunTimeScheduledialogbox.

Figure 7-04: The General tab on the Dynamic Run Time Schedule dialog box

2. OntheGeneraltab,setthenumberofoperationstepsyouplantouse,orleavethedefaultsettingof1.Themaximumnumberofstepsthatyoucanspecifyis10.

Note:Whenyouinitiallysetupdynamicsforasimulation,theCurrenttimedisplayfieldonthistabwillbeempty.Afterthesimulationhasrun,thisfielddisplaysthetotaltimeofacompletedrunorthecurrenttimeofaninterruptedrun.

3. NowclicktheStep1tabandspecifytheparametersforthisportionofthedynamicrun.EnterthetotaltimeforthisdynamicstepintheRuntimefield,andtheintervalinminutesintheStepsizefield.

Figure 7-05: The Step 1 tab on the Dynamic Run Time Schedule dialog box

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4. Ifyouhaveotherstepstospecify,clickeachtabinturnandentertheRuntimeandStepsizeinformation.

5. Whenyouhavespecifiedallsteps,clickOKtoreturntothemainCHEMCADwindow.

TheDynamicRunTimeScheduledialogboxalsoallowsforconditionsotherthantimetodeterminethedurationofadynamicoperationstep.IfyouselectStreamorEquipmentinsteadofthedefaultTimeoption,youcanspecifyastreamorUnitOpparameterthatwilltriggertheendofthisstep,ifthatparameterisreachedbeforethestep’sruntimeisup.

Selecting Streams and UnitOps Nowthatyouhavespecifiedhowlongyourdynamicprocesswillrun,youneedtotellCHEMCADwhatstreamandUnitOpdatatorecordduringtherun.

1. IftheDynamicsMenuisnotalreadyopen,selectRun>Dynamicstoopenit,thenclicktheRecordStreamsbutton.

2. IntheRecordStreamsdialogbox,dooneofthefollowing:

• ChecktheSelectstreamsfromflowsheetbox,clickOK,andthenusethemousetoaddstreamstotheSelectStreamsdialogbox.

• TypethenamesofstreamsyouwanttorecordintheIDboxes.

Figure 7-06: The Record Streams dialog box

3. Whenyouhaveselectedallthestreamsyouwanttorecord,clickOKtoreturntotheDynamicsMenu.

4. NowclicktheRecordUnitOpsbutton.IntheRecordUnitOpsdialogbox,selectUnitOpsinthesamewaythatyouselectedstreamsinstep2.

5. ClickOKtoreturntotheDynamicsMenu.

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Note:InboththeRecordStreamsandRecordUnitOpsdialogboxes,youcanusetheRunTimePlotcheckboxestoincludeselecteditemsinareal‐timeplot.Selectingitemsforruntimeplottingleadstoanotherdialogbox(eitherDynamicStreamPlotOptionsorDynamicEquipmentPlotOptions),whereyoucanselectplotspecificsforeachstreamorUnitOp.Itisrecommendedthatyouuseruntimeplottinginmoderation,astoomanystreamsandUnitOpscanbecomevisuallyconfusingandslowdowncalculationsconsiderably.

Running a Dynamic Simulation Nowthatyouhavesettheruntimeandrecordingparameters,youcanrunthesimulation.WhenyourunadynamicsimulationinCHEMCAD,acalculationoftheentireflowsheetrunsforeachstepinthetimerangethatyouselect.

Indynamicsmode,youhavethreeoptionsforrunningasimulation:runfromthesimulation’sinitialstate,runfromthesimulation’scurrentstate,oradvancethesimulationonetimeintervalatatimemanually.

Note:Atanypointduringadynamicrun,youcanpressthe[ESC]keyonyourkeyboardtostoptherunafterthecurrentcalculation.Whenyoudothis,youwillseeaPrograminterruptedmessage.ClickOKtoclosethemessagebox,andtheneitherinspectyourrunresultsorselectaruncommandtocontinue.

Run from Initial State Thisoptionresetstheflowsheettoitsinitialconditionsandbeginsthedynamicsimulation.Whenyourunasimulationthisway,allresultsfromprevioussimulationsarediscarded.

Tousethisoption,useeithertheRunfromInitialStatebuttonontheDynamicsMenuortheRunDynamicSimulationbuttonontheCHEMCADtoolbar.

Run from Current State Whenyouusethisoption,thedynamicrunbeginsfromthecurrentconditions.Thoseconditionsmightbetheinitialstateoftheflowsheet,theendofapreviousrun,orthemiddleofaninterruptedrun.Selectingthisoptioncontinuesthesimulationfromthecurrentstate,i.e.,fromthelastcalculatedresult.

Youcanusethisoptiononlywhensomecalculationsremaintoberun.Thismeansthatunlessyouhaveinterruptedtherunusing[ESC]orthestep‐by‐stepmethoddescribedinthenextsection,youmustscheduleoneormoreadditionalstepsusingtheDynamicRunTimeSchedulebeforecontinuing.

UsetheRunfromCurrentStatebuttonontheDynamicsMenutorunthesimulationstartingfromcurrentconditions.

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Run One Step at a Time Ifyouwanttogetadetailedviewofyourdynamicrunasitunfolds,youcanchoosetorunoneintervalatatime.Withthisoption,thedynamicrunwillstopaftereachdiscretetimestep.Torunthenexttimestep,youwillneedtousetheRunDynamicSimulationtoolbarbuttonortheRunfromCurrentStatebuttonontheDynamicsMenu.

Tousethisframe‐by‐frameapproachtodynamics,selectRun>ConvergenceandthenchecktheboxcalledRunonetimestepfordynamicsimulation.ClickOKtoconfirmthischange.Toturnoffthisfeature,returntotheConvergenceParametersdialogboxtoclearthischeckbox.

Figure 7-07: Convergence Parameters setting to run one step at a time

Other Dynamic Commands Inadditiontotheoptionsfordynamicrunsetupanddynamiccommands,theDynamicsMenuofferstwootheritems:ResettoInitialStateandSaveasInitialState.

Reset to Initial State Inadynamicsimulation,youcanchangestreamandUnitOpspecificationsonlywhenthedynamictimeissettozero.Duringorafterarun,ifyouattempttoeditthespecificationdialogboxforaUnitOp,youwillfindtheOKbuttondisabledandamessageinstructingyoutorestorethesimulationtoitsinitialstate.

Figure 7-08: A UnitOp specification dialog box during a dynamic run

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Toreturnthesimulationtoitsinitialstate—alsoknownastimezero—clicktheResettoInitialStatebuttonontheDynamicsMenu,orusetheResettoInitialStatebuttononthemainCHEMCADtoolbar.

Note:Anadvancedfeaturetoallowspecificationeditingatanytimeisavailable,butshouldbeusedwithextremecautiontoavoidconfusionandunintendedresults.ThisfeatureiscontrolledbyacheckboxontheConvergenceParametersdialogbox.

Save As Initial State TheSaveasInitialStatecommandsetsthecurrentconditionsofthedynamicrunasthenewinitialstate.Itdiscardsallparametersfromthepreviousinitialstate,andmakesitimpossibletorecoverthepreviousinitialstatedata.

Anexampleofadynamicruncanillustratetheusefulnessofthiscommand.Supposethatyourunasimulationforfiveminutesandthetemperatureinavesselincreasesfrom50°Cto70°C.Youdecidethat70°Cisabetterstartingpointforthisvessel,andyouwanttocapturealloftheothervaluesthatcorrespondtothattemperatureinthisvessel.Youcanachievethisbysavingthecurrentconditionsastheinitialstate.

Todothis,clicktheSaveasInitialStatebuttonontheDynamicsMenu.Youwillseeamessagewarningyouthatyouwilllosetheoriginalstateconditionsifyoucontinue.Ifyouarepreparedtodothis,clickYes.Forourexample,thiswouldmeanlosingthefirstfiveminutesofyourpreviousrun,alongwiththe50°Cstartingtemperatureforthevessel.

Afteryousaveanewinitialstate,theRunfromInitialStateandResettoInitialStatecommandsbothreferenceyournewinitialstatesettings.

Output from Dynamic Simulations Theresultsfromdynamicsimulationsaremarkedlydifferentfromthoseproducedbysteady‐statesimulations,primarilyinthattheyrecorddatatrendsovertimeinsteadofastaticsnapshotofafixedprocess.Withdynamicsimulations,comparisonsofslightlydifferentprocessspecifications,andofthesameprocessatdifferentpointsduringarun,canbeveryuseful.

Forthisreason,youmayfindthatgraphicalreportsprovidethemostusefulinformationwhenyou’reworkingwithdynamicsimulations.CHEMCADprovidesaseriesofdynamicsplottingoptionstomeetthisneed;youcanalsogeneratevarioustext‐basedreports,andviewcalculatedflowsheetvaluesatanypointduringadynamicrunorafteraruniscomplete.

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Reviewing the Flowsheet Specifications Asnapshotofflowsheetvaluesfromadynamicrundoesn’tprovideasmuchvalueasitwouldforasteady‐staterun,butitcancomeinhandyinmanysituations.

Afterrunningadynamicsimulation,youcanviewthedatabehindanyflowsheetstreamorUnitOptoseetheeffectsoftheruncalculations.Double‐clickanystreamorUnitOpontheflowsheettoreviewitsend‐of‐runvalues.

Youcanalsostoptoreviewflowsheetdatainthemiddleofarun,eitherbyusingtheRunonetimestepfordynamicsimulationoptionorbypressing[ESC]topausearun.Oncetherunhasstopped,youcandouble‐clickanystreamorUnitOptoreviewitscurrentvalues.

Plotting Dynamic Results YoucanplottheresultsofdynamicsimulationsusingeitherthePlotmenuorthedynamicsbuttonsonthemainCHEMCADtoolbar.

Dynamicplotsdisplayselectedvaluesovertime.Thefollowingdynamicplotsareavailable:

• BatchReactor/DVSLHistory:Thisplotdisplaysselectedvaluesforabatchreactorordynamicvessel,includingcompositionofthevesselcontentsovertime.Thedialogboxusedtogeneratethisplotisuser‐friendlyandfocusesonthemostcommonlyusedvariablesforthesetypesofequipment.

• DynamicColumnHistory:Thisplotdisplaysselectedvaluesforadynamiccolumn,includingcompositionoftrays,distillate,andbottoms.

• DynamicUnitOpHistory:ThisplotdisplaysselectedUnitOpparametersfromanyrecordedUnitOp.YoucanalsogeneratethisreportusingthePlotDynUnitOpstoolbarbutton.

• StreamHistory:Thisplotdisplaysselectedstreampropertiesfromanyrecordedstream.YoucanalsogeneratethisreportusingthePlotDynStreamstoolbarbutton.

Note:FortheStreamHistoryandDynamicUnitOpHistoryplots,besuretorecordthestreamsandUnitOpsthatyouwanttostudy.YoucanonlyrequesttheseplotsforrecordedstreamsorUnitOps.

Text-based Dynamic Reports Basedonthegraphicalresultsofyourdynamicsimulationrun,youmaydecidetomakechangestoyourprocess,runparameters,orboth,andthenre‐runthesimulation.Whenyouhavefine‐tunedyoursimulationandobtainedsatisfactoryresults,youcanviewthoseresultsintextformaswellasgraphicalform,foramoredetailedlookatexactvalues.

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Toaccesstext‐baseddynamicreports,selectReport>Dynamicsandthenselectoneofthefollowingreports:

• DynamicColumnHistory:Thisreportprovidesdynamiccolumnresultsforaselectedcolumn.ThePrintReportOptionsdialogboxoffersthemostrelevantitemsfordynamiccolumnreporting.

• DynamicStreamHistory:Thisreportprovidesstreamhistoriesforaspecificstreamthatyouselect,basedontheintervalthatyouspecifyandincludingthecompositions,components,andstreampropertiesthatyouselect.

• DynamicUnitOpHistory:ThisreportprovidesdetailedinformationaboutadynamicUnitOpinthesimulation,basedontheintervalthatyouspecifyandincludingtheUnitOpparametersthatyouselect.

Note:FortheDynamicStreamHistoryandDynamicUnitOpHistoryreports,besuretorecordthestreamsandUnitOpsthatyouwanttostudy.YoucanonlyrequestthesereportsforrecordedstreamsorUnitOps.

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Chapter 8

Output and Reports

OneofCHEMCAD’sgreateststrengthsisitscapacitytoprovidedetailed,customizedinformationaboutequipment,streams,andprocesses.Youcancreatecustomreportsfromsimulations,specsheetsforUnitOps,anddataboxesforprocessflowdiagrams,andyoucanplotorprintanyoftheseitemsinthemostappropriateformat.

Text Reports CHEMCADcanproduceawidearrayofcustomizabletext‐basedsimulationreports,basedonstreamdata,UnitOpdata,flowsheetdata,ordynamics.YoucanalsouseCHEMCAD’spowerfulReportWriterfeaturetoproducecustomizedconsolidatedreportsincorporatinganycombinationofavailabletextreports.

Report Output Setup Beforeyourun,view,orprintreports,youshouldcheckthesettingsthatdeterminewhichprogramsCHEMCADwillusetodisplayandprintyourreports.

Forindividualtextreports,youcanuseCHEMCAD’sdefaultinternalreportviewer,orelecttodisplayreportsusingMSWordPadorExcel.Toswitchtooneoftheseoptionalprogramsforreportviewing,selectTools>Options>Preferences,thenclickReportViewerinthePreferencesdialogbox.

Here,youcandesignateapathtoMSWord(usedbytheinternalreportviewer)orWordPad,andspecifythedefaultreportdestination.ClickOKtoreturntothemainCHEMCADworkspace.

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Inadditiontoindividualreports,youcancreateconsolidatedreports,whicharecustomizablecombinationsofdifferentindividualreports.Foranygivenconsolidatedreport,youcanusethedestinationoptionyou’vesetupinthePreferencesdialogbox,orchangetoanyviableoutputformat:CHEMCAD’sinternalreportviewer,MSWord,WordPad,orExcel.

Tochooseadefaultprogramforconsolidatedreportoutput,selectReport>FormatConsolidatedReport.OntheFormattab,chooseanoptionintheDestinationdrop‐downlist.ClickOKtoapplyyourchange.Notethatyouwillhavetheoptiontooverridethisdefaultdestinationforanygivenconsolidatedreportthatyoucreate.

Stream-based Reports AnumberofCHEMCADreportsareavailabletoanalyzestreamdatafromasimulation.Toaccessanyofthefollowingreports,selecttheappropriateitemfromtheReportmenu.TheresultswilldisplayaccordingtothewayyouhaveconfiguredCHEMCADtohandletextreports.

Note:Bydefault,thesereportswillusetheengineeringunitsyouselectedwhenbuildingthesimulation.Youcan,however,usedifferentflowrateunitswhenrunningreports.Tochangeflowrateunitsforreporting,selectReport>SetFlowUnits.IntheViewFlowRateUnitdialogbox,selecttheunitsyouwanttouseandthenclickOK.Thenexttimeyourunstreamcompositionorpropertyreports,theunitsthatyou’veselectedherewillbethedefaultsetting;youcanchangetheflowrateunitsasoftenasneeded.

Stream Groups Forstreamcompositionandpropertyreports,youcancreatecustomstreamgroupswithinasimulationtostreamlineyourreportrequests.

Forexample,ifyouhaveaprocessthatinvolvestendifferentfeedstreams,andyoufrequentlyrunreportsonthisgroupofstreams,youcansetupagroupconsistingofjustthosestreams.Then,wheneveryouwanttoobtaincompositionorpropertydataforthosestreams,you’rejustafewclicksawayanytimethesimulationisopen.

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ThequickestwaytosetupanygroupistousetheCHEMCADExplorer.Followthesestepstocreateastreamgroup:

1. IntheCHEMCADExplorerpane,findthetop‐levelitemcalledGroups.ClicktheplussignnexttoGroupstoexpandthisitem.

Figure 8-01: Expanding the Groups item in CHEMCAD Explorer

2. NowclicktheStreamsitemunderGroups,tobringuptheNewGroupdialogbox.Replacethedefaultname(suchasGroup1)withadescriptivenameforyourgroup,thenclickOK.

Figure 8-02: Naming the new stream group

3. IntheEditStreamGroupdialogbox,selectthestreamsforthisgroup,eitherbytypinginthestreamnumbers(oneperline)orbyclickingonstreamsintheflowsheet.ClickOKtoclosethedialogbox.

4. Assoonasyoufinishcreatingthegroup,itsnameappearsunderStreamsintheCHEMCADExplorer.Fromhere,youcanright‐clickthegroupnameandselectanyofthefollowing:

• View/Edit:OpentheEditStreamGroupdialogbox,whereyoucanaddordeletestreamnumberstoincludeinthegroup.

• Rename:OpentheRenameGroupdialogbox,whereyoucantypeanewnameforthestreamgroup.

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• Copy:OpentheCopyGroupdialogbox,whereyoucantypeanewgroupnametomakeanexactcopyofthestreamgroup.AfteryouclickOK,youcantheneditthenewcopyofthegrouptofityourneeds.

• Delete:Removethisstreamgroupfromthesimulation.Ifyou’resureaboutdeletingthegroup,clickYesinthedialogboxthatappears.

• Composition:Runaninstantstreamcompositionreportforthestreamsinthegroup.

• Properties:Runaninstantstreampropertiesreportforthestreamsinthegroup.

Figure 8-03: Right-click menu options for custom stream group

Note:Thecommandstocreate,edit,andremovestreamgroupsarealsoofferedontheReportmenu,underbothStreamCompositionsandStreamProperties.

Stream Compositions Youcanrunastreamcompositionreportbasedonallstreams,oryoucanspecifywhichstreamstoinclude.Torunastreamcompositionreport,selectReport>StreamCompositionsandthenselectfromthefollowingoptions:

• SelectStreams:ChoosethestreamsyouwanttoincludeintheSelectStreamsdialogbox,eitherbytypinginthestreamnumbers(oneperline)orbyclickingonstreamsintheflowsheet.ClickOKtoclosethedialogboxanddisplaythereport.

• AllStreams:Thisreportdisplaysallstreamcompositiondatafortheentireflowsheet.

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• FeedStreams:ThisreportdisplaysstreamcompositiondataonlyforstreamsissuingfromaFeediconontheflowsheet.

• ProductStreams:ThisreportdisplaysstreamcompositiondataonlyforstreamsterminatinginaProducticonontheflowsheet.

• UnitStreams:ThisreportdisplaysallinletandoutletstreamcompositiondataforaspecifiedUnitOpontheflowsheet.IfnoUnitOpiconisselectedwhenyourunthereport,you’llseetheSelectUnitOpsdialogbox;typetheUnitOpIDorclicktheUnitOpontheflowsheetandthenclickOKtodisplaythedata.IfyouselectaUnitOpiconbeforerunningthereport,thedatawilldisplaywithoutfurtherinput.

Youcanquicklydisplaystreamcompositionforasinglestreamatanytime,simplybyright‐clickingthestreamintheflowsheetandselectingViewComposition.

Stream Properties Beforerunningreportsonstreamproperties,you’llneedtospecifywhichpropertiestoinclude.Todothis,selectReport>StreamProperties>SelectProperties.ThisopenstheViewPropertyOptionsdialogbox,whereyoucanreviewwhichpropertiesarecurrentlyselected.

Ifyouwanttoaddanyproperties,checktheappropriateboxes;toremoveproperties,clickoncheckedboxestoclearthem.BesuretoclickthePage2tabandmakeanyappropriatechangesthereaswell.Whenyouarefinished,clickOKtoreturntothemainCHEMCADwindow.

Torunastreampropertiesreportforthepropertiesyou’vespecified,selectReport>StreamPropertiesandthenselectfromthefollowingoptions:

• AllStreams:Thisreportdisplaysallstreampropertydatafortheentireflowsheet.

• FeedStreams:ThisreportdisplaysstreampropertydataonlyforstreamsissuingfromaFeediconontheflowsheet.

• ProductStreams:ThisreportdisplaysstreampropertydataonlyforstreamsterminatinginaProducticonontheflowsheet.

• UnitStreams:ThisreportdisplaysallinletandoutletstreampropertydataforaspecifiedUnitOpontheflowsheet.IfnoUnitOpiconisselectedwhenyourunthereport,you’llseetheSelectUnitOpsdialogbox;typetheUnitOpIDorclicktheUnitOpontheflowsheetandthenclickOKtodisplaythe

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data.IfyouselectaUnitOpiconbeforerunningthereport,thedatawilldisplaywithoutfurtherinput.

Youcanquicklydisplaystreampropertiesforasinglestreamatanytime,simplybyright‐clickingthestreamintheflowsheetandselectingViewProperties.

Particle Size Distribution Foraparticlesizedistributionreport,selectReport>ParticleSizeDistribution.IntheSelectStreamsdialogbox,chooseoneormorestreamsforwhichaparticlesizedistributionexists(oneperline),eitherbytypinginstreamnumbers(oneperline)orbyclickingonstreamsintheflowsheet.ClickOKtodisplaythereport.

Pseudocomponent Curves Foratextreportonpseudocomponentcurves(alsoknownasdistillationcurves),selectReport>PseudocomponentCurves.Selectoneormorestreamscontaininghydrocarbons,eitherbytypinginstreamnumbers(oneperline)orbyclickingonstreamsintheflowsheet.ClickOKtodisplaythereport.

UnitOp-based Reports CHEMCADcanalsorunreportstoanalyzeUnitOpdata.Toaccessthesereports,selecttheappropriateitemfromtheReportmenu.TheresultswilldisplayineitherWordPadorExcel,dependingonhowyou’veconfiguredCHEMCADtohandletextreports.

UnitOp Groups FortheUnitOpsreport,youcancreatecustomUnitOpgroupswithinasimulation.Muchliketheirstream‐basedcounterparts,UnitOpgroupscansaveyoutimeandeffortwhenrequestingreports;inaddition,youcanusethesegroupswhenrunningyoursimulation,toisolateandrunonlyselectedUnitOpsfordiagnosticorotherreasons.

Note:BecauseofthisotherfunctionalityofUnitOpgroups,theorderinwhichyoulistUnitOpIDswhensettingupthesegroupsisimportant.

ThequickestwaytosetupanygroupistousetheCHEMCADExplorer.FollowthesestepstocreateaUnitOpgroup:

1. IntheCHEMCADExplorerpane,underGroups,clicktheUnitOpsitem.ThisbringsuptheNewGroupdialogbox.

2. Replacethedefaultname(suchasGroup1)withadescriptivenameforyourUnitOpgroupandthenclickOK.

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Figure 8-04: Naming the new UnitOp group

3. IntheEditUnitOpSequenceGroupdialogbox,selecttheUnitOpsforthisgroup,eitherbytypingintheUnitOpIDs(oneperline)orbyclickingonUnitOpiconsintheflowsheet.AddUnitOpsintheordertheyruninthesimulation.ClickOKtoclosethedialogbox.

Assoonasyoufinishcreatingthegroup,itsnameappearsunderUnitOpsintheCHEMCADExplorer.Fromhere,youcanright‐clickthegroupnameandselectanyofthefollowing:

• View/Edit:OpentheEditUnitOpSequenceGroupdialogbox,whereyoucanaddordeleteUnitOpsorreordertheexistinglist.

• Rename:OpentheRenameGroupdialogbox,whereyoucantypeanewnameforthegroup.

• Copy:OpentheCopyGroupdialogbox,whereyoucantypeanewgroupnametomakeanexactcopyoftheUnitOpgroup.AfteryouclickOK,youcantheneditthenewcopyofthegrouptofityourneeds.

• Delete:RemovethisUnitOpgroupfromthesimulation.Ifyou’resureaboutdeletingthegroup,clickYesinthedialogboxthatappears.

• Run:RunthesimulationonlyforthoseUnitOpsincludedinthisgroup.

• View:DisplayasummaryreportoftheUnitOpsincludedinthisgroup.

• Specifications:BringuptheUnitOpspecificationdialogboxesforeachitemintheUnitOpgroup,startingwiththefirstUnitOplisted.

Note:Thecommandstoadd,edit,andremoveUnitOpgroupsarealsoofferedontheReportmenuunderUnitOps.

Select UnitOps TorunareportthatcoversjusttheUnitOpsyouspecify,selectReport>UnitOps>SelectUnitOps.IntheSelectUnitOpsdialogbox,specifytheUnitOpsyouwanttoincludeinthereport,eitherbytypingintheUnitOpIDs(oneperline)orbyclickingonUnitOpsintheflowsheet.ClickOKtoclosethedialogboxanddisplaythereport.

IfyouselectaUnitOpiconbeforerunningthereport,thedatawilldisplaywithoutfurtherinput.

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Spec Sheet TheSpecSheetcommandexportsdetailedinformationaboutaUnitOpintoapreformattedExcelworksheet.Thisreportisusefulfortaskssuchassolicitingamanufacturingquoteforapieceofequipment.

• TocreateaspecsheetforallUnitOpsontheflowsheet,selectReport>SpecSheet>AllUnits.

• TocreateaspecsheetonlyforspecificUnitOps,selectReport>SpecSheet>SelectUnit.ChoosetheUnitOpsyouwanttoincludeintheSelectUnitOpsdialogbox,eitherbytypingintheUnitOpIDs(oneperline)orbyclickingonUnitOpiconsintheflowsheet.ClickOKtoclosethedialogboxanddisplaythespecsheet.

• ForasingleUnitOpspecsheet,youcanselecttheUnitOpiconbeforerunningthereport;Excelwillopenandthedatawilldisplaywithoutfurtherinput.

Note:ForspecsheetsthatincludemultipleUnitOps,CHEMCADcreatesaseparateworksheetforeachUnitOp’sdatawithintheExcelfilethatCHEMCADcreates.

Distillation Torunadistillationreport,selectReport>Distillationandthenselectoneofthefollowing:

• TowerProfiles:Generatesareportdetailingtemperature,pressure,andflowrateforadistillationcolumn

• TrayCompositions:Createsareportthatshowsthevaporflowrate,liquidflowrate,andK‐valueofeachcomponentoneachstageofadistillationcolumn

• TrayProperties:Reportsoncurrentlyselectedstreampropertiesforeachstageofadistillationcolumn

• TowerMassTransfer:ForanSCDSdistillationcolumnthatusesamasstransfermodel,providesmasstransfercoefficients,heightoftransferunits,andestimatedheightoftheoreticalplates(HETP)

• DynamicColumnHistory:Providesdatafromasingledynamicrunofacolumn(describedindetailinChapter7,BuildingandUsingaDynamicSimulation)

• ColumnDiagnosis:Forcolumnsthathavenotsuccessfullyconverged,providesrecommendationsforchangingcolumnsettingstoachieveconvergence

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Flowsheet-based Reports InadditiontoreportsthatfocusonparticularUnitOpsandstreams,CHEMCADofferstextreportsthatprovideinformationaboutthesimulationasawhole.Toaccessanyofthesereports,selecttheappropriateitemfromtheReportmenu.

Topology ThisreportprovidesalistingofallUnitOpsintheflowsheet,aswellasallstreamoriginsanddestinations.

Thermodynamics Thisreportlistsallcomponentsusedinthesimulationandprovidesvitalinformationaboutthethermodynamicsmethodsused.

Mass and Energy Balances Inadditiontomassandenergybalances,thisreportgivestheorderinwhichUnitOpsarecalculated,calculationmodesused,andinformationaboutrecycleloops,cutstreams,andconvergence.

Dynamics Reports TheReportmenuprovidesaccesstotheBatchResultsandDynamicscommands,whichprovidereportsaboutnon‐steady‐stateprocesses.

Batch Results Thisreportsummarizestheresultsofabatchdistillationcolumnsimulationattheendofeachoperatingstep.

Dynamics YoucanaccessthreedifferentreportsbyselectingReport>Dynamics:DynamicColumnHistory,DynamicStreamHistory,andDynamicUnitOpHistory.ThesereportsaredescribedindetailinChapter7,BuildingandUsingaDynamicSimulation.

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Consolidated Reports and the CHEMCAD Report Writer Youcanrunanycombinationofthetext‐basedreportsdescribedaboveasasingleoperation,byselectingReport>ConsolidatedReport.ThisbringsuptheReportWriterdialogbox.

Figure 8-05: The CHEMCAD Report Writer

Fromhere,youcanclickGeneratetobringupadefaultconsolidatedreportthatincludestopology,convergence,massandenergybalances,andtheotherreportslistedinthedialogbox’sleftcolumn.Ifthisreportisadequatetoyourneeds,simplyclickCancelaftergeneratingtheconsolidatedreport,toclosetheReportWriterdialogbox.

Ifyouwantsomethingotherthanthedefaultconsolidatedreport,youcanalsousetheReportWritertocustomizewhichindividualreportstoinclude,whatordertoputthemin,whichflowsheetelementstoinclude,andmuchmore.Youcanfine‐tuneyourreportsettingswithoutclosingthisdialogbox,andthensaveyourreportconfigurationwithanewnamesothatyoucanrunitagaininthefuture.

Choosing and Ordering Report Sections TocustomizeyourConsolidatedReport,firstdecidewhichreportsectionsyouwanttoinclude.TheCurrentReportSectionsarealistsitemsintheordertheywillappearwhenyouruntheConsolidatedReport.

IfyourwishlistofreportsectionslookslargelylikethedefaultlistshowninFigure8‐05,youcanbeginwiththatlistandmakesomechanges;ifnot,youcanstartwithablankslateandbuildyourConsolidatedReportonereportsectionatatime.

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Youcandoanyofthefollowingtoaltertheexistingsectionlist:

• Addasectionbydouble‐clickinganyitemintheAddNewReportSectionareaoftheFormattab.Thenewitemappearsattheendofthereportlist.

• RemoveasectionbyselectingitintheCurrentReportSectionslistandthenclickingDelete.

• MoveasectiontoadifferentpositionwithintheConsolidatedReportbyselectingitintheCurrentReportSectionslistandthenclickingtheUporDownbuttonasneeded.

Ifyouprefertobuildthesectionlistyourself,youshouldaccesstheReportWriterbyselectingReport>NewfromtheCHEMCADtoolbar.ThisbringsuptheReportWriterscreenwithablankleftcolumn,readyforyoutoaddjustthereportsectionsthatyouwantinwhateverorderyouchoose.

Selecting Flowsheet Elements ToselectflowsheetelementsforinclusioninaConsolidatedReport,clicktheSelectStreams&UnitOpstabwithintheReportWriter.Thistab,liketheFormattab,isvisibleonlywhenConsolidatedReportisselectedintheleftcolumnoftheReportWriterscreen.

Initially,theSelectStreamsandSelectUnitOpscheckboxesonthistabareempty,andtheAllStreamsandAllUnitOpscheckboxesarecheckedanddisabled.

ToexcludestreamsorUnitOpsfromyourreport,checktheappropriateboxatthetopofthetab;thisenablestheotheroptions.YoucanclickSelectFromFlowsheettoselectstreamsorUnitOpsusingyourmouse,orcleartheAllStreamsorAllUnitOpsboxtoaccessoptionsforselectingflowsheetitemsbytypesoruser‐createdgroups.

Formatting Report Sections CertainreportsectionsthatyoucanincludeinaConsolidatedReporthaveformattingoptionsthatyoucanchangebeforerunningthereport.Theseoptionsinclude:

• ForUnitOps,asection‐specificUnitOpsselectiontabandtheoptiontolimitthenumberofcolumnsforExcelreportoutput

• ForStreamProperties,asection‐specificstreamselectiontabandtheoptiontochangethedefaultlistofstreampropertiestoincludeinthereport

• ForStreamComposition,asection‐specificstreamselectiontab,theoptiontochangethedefaultflowoptions,andalternativesettingsforcompositiondataformatandprecision

• ForParticleSizeDistribution,asection‐specificstreamselectiontab

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• ForTrayProfile,asection‐specificUnitOpselectiontabandanoptiontochangethedefaultflowunits

• ForHeatCurves,asection‐specificUnitOpselectiontabandtheoptiontochooseacuttingmethodandnumberofcutpoints

Naming the Report and Choosing a Destination WhenyoufinishcustomizingaConsolidatedReport—particularlyifyou’vedoneasignificantamountofcustomization,orifyoususpectyou’llwanttorunthesamereportparametersagain—youshouldconsidersavingthereportforfutureuse.

Todothis,firstgivethereportadistinctivenameusingtheReportNamefield.ThisfieldisvisibleintherightportionoftheReportWriterdialogboxwhenyouclickthetop‐levelitemunderCurrentReportSections.

NotethatConsolidatedReportisthedefaultreportname;whenyoutypeanewnameasinFigure8‐06,boththetop‐levelitemontheleftandthetitleovertherightportionofthedialogboxchangetoreflectthereportname.

Figure 8-06: Results of typing a new name into the Report Name field

Onceyouhavenamedthereport,youcanclickSavetosavethereportlocally(thatis,onlyforthissimulation),orclickSaveAstosavethereportunderMySimulations\MyReports\GlobalReports.SavingintheGlobalReportsdirectorymakesthereportavailabletoanysimulationyoumayopeninthefuture.

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Togenerateareportthatyouhavesavedlocally,selectReport>SimulationReports;selectthereportbynameandclickGenerateReport.OtheroptionshereareEdittoopenthereportintheReportWriter,Exporttocopyittoagloballocation,orDeletetoremoveitfromthemenu.

Figure 8-07: Generating a report that has been saved locally

Notethattogenerateoraccessaglobally‐savedreport,youcanselectReport>Global/PoolReports.

Graphical Reports Inadditiontotext‐basedreports,CHEMCADoffersawidevarietyofgraphicalplotsthatyoucanviewonscreenorprintforreview.

Thermophysical Data Graphs CHEMCADoffersanumberofgraphicalreportsthatrelatespecificallytotheselectedcomponentsandthermodynamicsoptions.Toaccessanyoftheseplots,selecttheappropriateitemfromthePlotmenu.

TPXY Thisselectiongeneratesvapor‐liquidequilibriumcurvesbetweenanytwocomponents,withanoptionalthirdcomponent.YoucanincludeTPXY,TXY,activitycoefficient,andfugacitycoefficientcurves.

Binary LLE Thisselectiongeneratesliquid‐liquidequilibriumcurvesbetweenanytwocomponents.

Binodal Plot Thisselectiongeneratesaternaryphasediagramshowingthedistributionofthreeselectedcomponentsintwoliquidphases,includingtielinesandplaitpoint.

Binodal/Residue Curves Thisselectioncreatesaplotthatcombinesthecurvesfromabinodalplotandaresiduecurveplot.Thisisusefulwhenworkingwithheterogeneousazeotropicdistillation.

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Residue Curves Thisselectiongeneratesandplotsagraphicaldisplayofdistillationzones,azeotropes,andresiduecurvesassociatedwithauser‐specifiedternarymixture.

Solid/Liquid Equilibrium Thisselectiongeneratessolid‐liquidequilibriumcurvesbetweenanytwocomponents.

Flowsheet-based Graphs Toviewgraphicalreportsthatreflectyouroverallsimulation,selectoneofthefollowingfromthePlotmenu:

• StreamProperties:Plotsoneselectedstreampropertyforaselectedstreamintheflowsheet

• PhaseEnvelopes:Plotsaphaseenvelopeforagivenstream,highlightingthecriticalpointofthemixture;canincludeplotsatvaporfractionsotherthan0(bubblepointcurve)and1(dewpointcurve)

• CompositeCurves:Plotscompositeheatcurvesfortheentireflowsheet,aswellasoptionalheatcurvesforindividualUnitOps

• PseudocomponentCurves:Displaysaplotofoneormoredistillationcurvesforastream

UnitOp-based Plots CHEMCADoffersseveralplotsthatdisplaydataforasingleUnitOp.Toaccessanyoftheseplots,selectPlot>UnitOpPlotsandthenselectoneofthefollowingoptions.

Tower Profiles Thisselectionplotscompositions,temperature,andflowprofilesfordistillationcolumns.

Heat Curves Thisselectionplotsheatingandcoolingcurvesforaselectedheatexchanger.

Plug Flow Reactor Profile Thisselectionplotsthetemperatureorcompositionprofilesalongtheaxiallengthofakineticplugflowreactor.

Pipe Profile ThisselectionplotsfluidpropertiesforpipeUnitOpsalongtheaxiallengthofthepipe.Thisplotrequiresthatthepipecontainmultiplesegments.

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Controller Convergence Forcontrollersthathavenotconverged,thisplotenablesyoutodiagnosethecontrollerbehaviorthatispreventingconvergence.Theplotshowshowthecontrollererrorfunctionchangeswithiteration.

Dynamic Plots CHEMCADoffersaseriesofplotsforusewithdynamicoperations.SelectPlot>DynamicPlotstoaccessanyofsixgraphicaldynamicsreports.

TheseplotsaredescribedindetailinChapter7,BuildingandUsingaDynamicSimulation.

User-specified File IfyouhavecustomizedCHEMCADusingVBA,C++,orotherprogramminglanguages,youcansaveplotdataintoatextfileandusethisfeaturetodisplaythatdataasacurve.

SelectPlot>UserSpecifiedFiletobringupamessageboxthatprovidesinstructionsonhowtoformatthetextfile.ClickOKtocontinuetoanOpendialogbox,whereyoucanselectthetextfileyouwanttouse.WhenyouclickOpen,thecurveisplottedanddisplayed.

Printing CHEMCAD Reports YoucanprintanytextreportfromwithinCHEMCAD’sinternalreportviewer,orfromwithinanotherprogramthatyouhaveselectedtoviewreports.

IfareportisdisplayedinaCHEMCADtab,youcanselectFile>PrinttobringupthestandardPrintdialogbox,whereyoucanchooseadifferentprinter,selectapagerange,orspecifythenumberofcopiestoprint.ForashortcuttothePrintdialogbox,clickthePrintbuttoninthetoolbar.

Ifyou’vesetupanotherprogramasyourreportdestination,simplybringupthePrintdialogboxinWord,WordPad,orExcelbyselectingFile>Print.EachoftheseprogramsalsooffersaPrintbuttononthetoolbarforyourconvenience.

Forgraphicalreports,youcanprintdirectlyfromCHEMCAD,justasyouwouldprintatextreport.Plotsaresetuptoprintinlandscape(horizontal)orientation,asthisisthebestfitforthehorizontalplotlayout.

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Process Flow Diagrams CHEMCADprovideseasy‐to‐usetoolsforcreatingprintedprocessflowdiagrams.Youcanaddvarioustypesofdataboxestoaccompanyyourflowsheet,andthenselectivelyviewandprintgroupsofitems,includingdataboxes.

Flowsheet Databoxes CHEMCADoffersfourtypesofdataboxes:

• StreamBox:Liststhestreamsthatyouselectinasingletable,alongwiththestreampropertiesthatyouchoosetoinclude

• UnitOpBox:GeneratesaseparatedataboxforeachselectedUnitOp

• TPBox:Generatesseparatesummarydataboxesforselectedstreams

• ExcelRangeBox:ReferencesarangeofcellsfromanExcelworksheet

Stream Boxes Tocreateastreamdatabox,startbyselectingFormat>AddStreamBox.FromtheSelectStreamsdialogbox,followthesesteps:

1. Determinewhichstreamstoincludeinthedatabox,usingoneofthreemethods:

• ChecktheAllstreamsboxtoincludeallstreamsonyourflowsheet,thenclickOK.

• Typethenumbersofthestreamsyouwanttoincludeintotheboxesprovided(onenumberperline),thenclickOK.

• Choosethestreamsyouwanttoincludebyclickingtheactualstreamlineswithyourprimarymousebutton.StreamnumbersthatyouselectwillappearintheSelectStreamsdialogbox;totoggleaselectedstreamoff,justclickitagain.Whenyou’veselectedallthestreamsyouwant,clickOKtocontinue.

2. AnyoftheseselectionmethodswillbringyoutotheDataboxPropertyOptionsdialogbox.Here,youcanselectwhichstreampropertiesyouwanttoincludeonthestreamdatabox.Youcankeepthedefaultsettings,orturnanycheckboxonorofftocustomizeyourdatabox.

Note:Theselectionsyoumakeherewillbethedefaultselectionsthenexttimeyoucreateastreamdataboxforthissimulation.

InadditiontothemainGeneraltab,notetheCrude/Solidtab,whichyoucanclicktoselectcrudeoilstreampropertiesorsolidstreamproperties.Whenyou’veselectedthestreampropertiesyouwant,clickOKtocontinue.

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3. IntheDataboxSettingsdialogbox,youcanchoosewhethertoincludehorizontallinesorhorizontalsectiondividersinthedatabox.ClickOKtoplacethedataboxonyourworkspace.

Aswithflowsheetelements,youcanmove,stretch,orresizeadataboxusingyourmouse.

UnitOp Boxes TheprocedureforcreatingUnitOpdataboxesissimilartothatusedtocreatestreamdataboxes,withthechiefdifferencebeingthatthereisnoselectionofUnitOpproperties.

BeginbyselectingFormat>AddUnitOpBox,andtheneithertypeinUnitOpIDsorclickUnitOpsontheflowsheet.Notethatyoudon’thavetheoptionofautomaticallyincludingallUnitOps,asyoudidwithstreams;toincludeallUnitOpsinthedatabox,clickablankareaoftheflowsheetandthenpress[CTRL‐A]toaddallUnitOpIDstothelist.

WhenyoucompleteyourselectionsandclickOK,theDataboxSettingsdialogboxappears,withthesameformattingoptionsthatareavailableforstreamdataboxes.Changeanysettingsyouwanthere,andthenclickOKtoplacetherequesteddataboxesonyourworkspace.

Unlikeastreamdatabox,whichdisplaysdataformultipleitemsinasinglebox,aUnitOpdataboxdisplaysdataonlyforasingleUnitOp.IfyouselectedthreeUnitOpsintheUnitOpIDsdialogbox,you’llseethreeseparatedataboxesappearwhenyouclickOK.Ifyouseeonlyonedataboxatfirst,trymovingthatboxtoanotherpartofthescreentoseeiftheothersarehiddenbehindit.

TP Boxes CHEMCADcancreatedataboxes,calledTPboxes,whichdisplayanycombinationoftemperature,pressure,andflowrateforallstreamsorselectedstreamsonaflowsheet.

ToaddTPdataboxes,selectFormat>AddTPBox.IntheTPBoxSettingsdialogbox,firstselectanoptionatthetop,todeterminewhethertoaddTPboxesforallstreamsoronlyforthestreamsyouselect.

IntheDisplaycolumn,selectitemsfromthedrop‐downlistineachfieldtodeterminewhichstreampropertiestodisplayandinwhatorder.UseNoselectionasappropriateifyouwanttodisplayfewerthanfourproperties.

IntheNumberformatcolumn,makeaselectionineachfieldtodeterminehownumberswilldisplayintheTPboxes.IntheDigitscolumn,typethenumberofdigitstodisplayafterthedecimalpoint.YoucanalsochoosewhethertodisplaystreamIDsandengineeringunits.

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ThePreviewboxdisplaysadynamicsampleofhowtheitemsyou’veselectedwillappearintheTPboxes.

WhenyoufinishmakingyourselectionsintheTPBoxSettingsdialogbox,clickOK.Ifyou’vechosentomakeTPboxesforallstreams,theTPboxeswillappearontheflowsheetrightaway.Ifyou’veoptedtoselectthestreamsfromtheflowsheet,you’llseeaSelectStreamsdialogbox;typethestreamnumbers(oneperline)orclickonthestreamlinesintheflowsheettoselectstreams,andthenclickOKtocreatetheTPboxes.

Figure 8-08: TP boxes added to a simple flowsheet

Excel Range Boxes AnExcelrangeboxdisplaysdynamicdatafromaspecifiedcellrangeinaspecifiedExcelworksheet.TocreateanExcelrangebox,followthesesteps:

1. StartbyselectingFormat>AddExcelRange.ThisbringsuptheExcelDataboxSettingsdialogbox.

2. ClickBrowsetonavigatetothefolderwheretheExcelworkbookresides,thenhighlightthenameoftheworkbookyouwantandclickOpen.

3. IntheWorksheetnamefield,typethenameoftherelevantworksheetwithintheworkbookthatyou’veindicated.

4. Inthecenterportionofthedialogbox,specifythestartingandendingcolumnandrowcoordinatesthatyouwanttoreferencewithintheselectedworksheet.

5. Inthelowerportionofthedialogbox,changeanyformattingsettingsasdesiredandthenclickOKtocreatethedatabox.

AnExcelrangeboxisadynamiclinkbetweenCHEMCADandtheExcelworksheet.Asdataisupdatedandsavedintheselectedcellrange,therangeboxcanautomaticallyupdatetoreflectthosechanges.Toviewthemostup‐to‐datedatainyourExcelrangeboxesatanytime,selectView>RefreshDataBoxes.

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Using the Layers Feature for Selective Viewing and Printing WhenyoucreateasimulationinCHEMCAD,youcanbuildyourflowsheetacrossahugeworkspace,zoominginandoutasneededtoworkwithspecificareasoftheflowsheet.Youcanalso,asdescribedabove,addanynumberofdataboxestoprovideaquickvisualreferenceforthedatabehindyourflowsheetobjects.Youcanaddtextlabels,drawcirclesarounditemsthatyouneedtoworkonfurther—inshort,there’spracticallynoendtothevisualclutterthatcouldenduponyourprocessflowdiagram.Butalloftheseelementsareusefultosomeone,andyoucertainlydon’twanttospendyourtimerepeatedlyaddingorremovingvisualelementsbeforeprintingorsharingaPFD.

CHEMCAD’ssolutiontovisual‐elementoverloadisafeaturecalledLayers.Alayerisagroupofobjectsinasimulationfile—anycombinationofdataboxes,drawnshapes,textlabels,streams,andUnitOps—thatyoucanvieworhidewithasingleclick.Youdefineexactlywhichobjectsbelongtoalayer,andthentoggleeachlayereitheron(visible)oroff(hidden)usingtheCHEMCADExplorerpane.

Note:Turningoffalayerdoesnothingbeyondhidingtheassociatedobjectsfromview.Havingalayerhidden—evenifthatlayerincludesstreamsandUnitOps—doesnotinanywayaffectthewaythesimulationrunsoranystreamorUnitOpproperties.

Scenarios for Using Layers Thefollowingareexamplesofsituationsinwhichyoucanuselayerstoenhanceyourprocessflowdiagrams:

• Severaldifferentdepartmentsneedtoreviewyourprocessflowdiagram,buteachdepartmentwantstoseedifferentdatahighlightedindataboxes.YoucancreateonesetofTPboxeslistingonlyflowrates,forexample,andthenassignthemalltoalayer;thenhidethatlayerandcreateanewsetofTPboxeslistingtemperatureandpressureonly.Assignthesedataboxestotheirownlayer,hideit,andcontinuewithstreamboxes,UnitOpboxes,orwhateverotheritemsyouneed.Createasmanydifferentlayersasyoulike,andeachtimeyougotoprintthediagram,viewonlythelayersthatyouwanttoprint.

• Youneedtoe‐mailasimulationtodifferentrecipientswhowanttoviewdifferentdataboxes.Createsetsofdataboxesassignedtomultiplelayers,andthenviewjustthelayersthatyouwantyourfirstrecipienttoseeuponopeningthefile.Saveandclosethesimulationbeforeattachingittoane‐mailmessage.Openthesimulationagainforthenextrecipient,selectthelayersyouwantthatpersontosee,savethefile,andattachittoanothere‐mailmessage.

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• Youhaveaverylargeflowsheetthatencompassesanumberofdiscreteprocesses.Youcancreateseparatelayersforvariousportionsoftheoverallflowsheet,andviewonlytheportionsyou’reworkingwithatagiventime.Youcanalsohideunneededportionsoftheflowsheetforprinting.

• Ifyouaretroubleshootingaprocess,orforwhateverreasonneedto“markup”aprocessflowdiagram,youcandrawshapessuchasellipsesorrectanglesaroundcertainUnitOpsorgroupsofUnitOps,usingtextorbrightcolorstodrawextraattention.Thenassignallofthesemark‐upitemstoasinglelayersothatyoucanchoosetovieweitherthemarked‐upversionorthe“clean”versionoftheflowsheetatanytime.

Creating a New layer Bydefault,allobjectsareassignedtoamasterlayer,whichisalwaysvisible.Beforeyoucanassignobjectstoanotherlayer,youmustfirstcreateanewlayertouse.ThemostconvenientwaytocreatealayeriswithintheCHEMCADExplorerpane.

IntheCHEMCADExplorer,findthetop‐levelitemcalledLayers,right‐clickit,andselectNew.

Figure 8-09: Creating a new layer

IntheNewLayerdialogbox,replacethedefaultlayernamewithadescriptivenameofyourownandthenclickOK.

Figure 8-10: Naming the new layer

ThenewlayernowappearsundertheLayersiteminCHEMCADExplorer.Ifnecessary,clicktheplussignnexttoLayerstoviewthelayername.Youcanaddasmanylayersasyoulikeandviewthecompletelisthere.

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Whenalayerisfirstcreated,itisvisiblebydefault.Alayer’sstatusasvisibleorhiddenisindicatedinCHEMCADExplorerbytheiconthatdisplaysnexttoitsname.Avisiblelayershowsagreencheckmark,whileahiddenlayerisgrayincolor.

Figure 8-11: Visible and hidden layers as they appear in CHEMCAD Explorer

Assigning Objects to a Layer Nowthatyouhavelayers,youcanassignitemstothem.Startbyclickinganobjecttohighlightit;thismightbeanythingfromastreamIDlabeltoaUnitOptoaTPbox.Whatevertypeofobjectitis,whenyouhighlightityou’llseethefourblackboxesthatdefineitsouteredges.Withtheobjectselected,right‐clickthenameofthedesiredlayerintheCHEMCADExplorerandchooseAddSelected.

Tosavetime,youcanaddmultipleobjectstoalayeratonce.Justholddownthe[SHIFT]keyasyouclickeachobjectinturn,thenright‐clickthelayernameandchooseAddSelected.

Note:Ifyoulike,youcanassignoneormoreobjectstoalayeratthesametimeyoucreatethelayer.Todothis,simplyclickthedesiredobject(usethe[SHIFT]‐clickmethodformultipleobjects),thenright‐clickLayers,selectNew,andassignthelayeraname.Theselectedobjectsareautomaticallyassignedtothenewlayer.

Hiding and Viewing Layers Assoonasyou’veaddedatleastoneobjecttoalayer,youcantestthelayerbyhidingitandwatchingwhathappens.Tohidealayer,simplyclickthelayer’sname,orthegreencheck‐markediconnexttoitsname;theiconshouldchangetograyandallitemsassignedtothelayershoulddisappearfromview.

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Atanytime,youcanhideorvieweachlayerinyoursimulationindependently.TheiconsnexttothelayernamesintheCHEMCADExplorerprovideaconstantreminderofwhichlayers,ifany,arecurrentlyhiddenfromview.

Eachtimeyouopenasimulationfile,CHEMCADdisplaysorhidesitslayersaccordingtothewaytheyweresetthelasttimeyousavedthesimulation.

Note:Itispossibleforanobjecttobeassignedtomorethanonelayer.Ifanobjectisassignedtotwoormorelayers,however,itwillbedisplayedunlessallofitsassociatedlayersarehidden.

Removing an Object from a Layer Ifyounolongerwantaspecificobjectorgroupofobjectstobeassignedtoagivenlayer,youcanremovetheassignmentaseasilyasyoucreatedit.

Firstensurethatthelayerinquestionisvisible.Thenselectalltheobjectsthatyouwanttoremovefromthelayer,right‐clickthelayernameinCHEMCADExplorer,andchooseRemoveSelected.Nowwhenyouhidethelayer,theobjectorobjectsyouremovedshouldremaininview.

Deleting an Entire Layer Ifforanyreasonyouwanttoremovealayerfromyourlist,simplyright‐clickthelayer’snameinCHEMCADExplorerandselectDelete.Thelayerdisappearsfromthelist,andifthelayerwashiddenwhenyoudeletedit,theitemsassignedtoitnowreappear.

Printing a Process Flow Diagram WhenyouusethePrintcommandonthemainCHEMCADscreen,theresultisaverbatimreproductionofyourvisibleworkspace.

Ifyou’rezoomedcloseintooneportionofyourflowsheetwhenyouprint,you’llgetaclose‐upprintoutthatdoesnotincludetherestoftheflowsheet.Ifyou’vehiddenallofyourdataboxestokeepthemoutofyourwaywhileyoufixaproblem,thosedataboxeswillnotappearontheprintout.IfthePalettepaneiscoveringuptheproductstreamscomingfromoneofyourUnitOps,thoseproductstreamswon’tbeontheprintouteither.

Forthisreason,thefirstthingyoushoulddowhenyou’rereadytoprintaprocessflowdiagramistodecidewhatneedstobeincludedontheprintout.Ifyouneedtheentireflowsheettoappearontheprinteddiagram,selectView>ZoomOptions>ZoomtoFit,orzoommanuallyifyouprefer.Youmaywanttohideorunpinoneormorepanesaswell,togiveyourselfmoreworkspacewhileyoupreparetoprint.

Next,considerwhetheryourprocessflowdiagramshoulddisplayajobbox,UnitOporstreamdataboxes,textnotes,orotheritemsinadditiontotheflowsheet

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itself.Ifyouhavealreadycreatedtheneededitems,makesurethattheyarecurrentlyvisibleandplacedwhereyouwantthem.

Whenalloftheitemsyouwanttoprintarevisible,checkoncemoretoensurethateverythingfallswithintheCHEMCADworkspace.ThenselectFile>Print,orclickthePrintbuttononthetoolbar.ThisbringsupthePrintSetupdialogbox,whereyoucanselectprintingoptionsorsimplyclickOKtoprinttheprocessflowdiagram.

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Chapter 9

Customizing CHEMCAD

AsyoubecomemorefamiliarwiththewaythatCHEMCADworksandthevariousoptionsandtoolsthatareavailable,youmayfindyourselfwishingthatyoucouldmakeyourownadditions—eitherforspecializeditemsorforthoseyouusefrequently.YoucaninfactcustomizeCHEMCADinseveralwaysthatsaveyoutimebystreamliningandsimplifyingyourworkflow.Theseinclude:

• CreatingstreamandUnitOptemplates

• AddingcustomcomponentstoCHEMCAD’scomponentdatabase

• MakingyourownsymbolsandaddingthemtotheUnitOpspalette

• BuildingcustomUnitOps

• CreatingcustomdialogboxesforUnitOpsettings

• Definingcustomthermophysicalrules

Thischapterdiscussesallofthesetypesofcustomization,startingwiththesimplestproceduresandthenmovingontomorecomplexcustomizationsthatrequiresomeprogrammingexperience.

Flowsheet Templates OneofthemosteffectivewaystosavetimewhencreatingCHEMCADsimulationsistomakeuseofstreamandUnitOptemplates.Atemplateissimplyasetofcharacteristics,whichyouassignanameandsaveforlateruse.WhenyousetupstreamorUnitOpspecificationsthatyouknowyou’llneedtorecreateinthefuture,youcancreateatemplateofthatstreamorUnitOp.Youcanthenduplicatethatitemwithinthesamesimulation—orinanyothersimulation—withjustafewmouseclicks.

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Creating a Template Tocreateastreamtemplate,firstcreatethestreamyouwanttocloneandgiveitallofthecharacteristicsyouwanttoincludeinthetemplate.

ThenfindthisstreamontheCHEMCADExplorer’sSimulationtab.ExpandtheFlowsheetitem,thenexpandtheStreamitem,andfinallydouble‐clicktheapplicablestreamID.ThisbringsupanitemcalledSave.Double‐clickthewordSavetobringuptheEnterTemplateNamedialogbox,thentypeanameforyournewstreamtemplateandclickOK.ThenewstreamnameisnowlistedbeneaththeSaveitem.

TocreateaUnitOptemplate,selecttheappropriateUnitOpIDinCHEMCADExplorer,andthenfollowthesameprocedureusedtocreateastreamtemplate.

Viewing a Template’s Properties Toseewhatspecificationsanexistingtemplateincludes,lookitupintheCHEMCADExplorer.ExpandtheTemplatesitem,thenexpandtheUnitOpsitem,andfinallyexpandthenameoftherelevantUnitOptype.Forexample,ifyou’relookingupatemplatethatyoucreatedforatypeofpumpthatyoufrequentlyuse,expandthePumpitemintheCHEMCADExplorer.

Whenyoufindyourtemplate,simplyclickthetemplatenametoopenitsspecificationsdialogbox.

Applying a Template Toapplyastreamtemplate,firstexpandtheCHEMCADExploreritemforthestreaminquestion,eitherbyclickingtheplussigntoitsleftorbydouble‐clickingthestreamname.

Whenthestreamitemisexpanded,you’llseetheSaveitembelowit,followedbythenamesofallthestreamtemplatesthatyouhavecreated.Double‐clickthenameofthetemplateyouwanttouse,thenclickOKtoconfirmthatyouwanttoapplythisstreamtemplate.

Renaming or Deleting a Template Torenameatemplate,simplyfinditunderTemplatesinCHEMCADExplorer,right‐clickthetemplatename,andselectRename.TypethenewnameandclickOK.ThischangesthetemplatenamethroughoutCHEMCADExplorer.

Theprocedurefordeletingatemplateissimilartorenamingatemplate.Again,findthetemplateyouwantunderTemplates,right‐clickitsname,andselectDelete.ClickOKtoconfirmthatyouwanttodeletethistemplate.ThetemplatenamedisappearsfromCHEMCADExplorer,butstreamsorUnitOpsthatwerespecifiedusingthetemplatearenotaffectedinanyway.

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Note:AnystreamorUnitOptemplatethatyoucreateisavailableforusewithallothersimulationsonthesameinstallationofCHEMCAD,untilandunlessyoudeletethetemplate.

Creating Custom Components TheCHEMCADcomponentdatabaseplacesdetailedinformationaboutthousandsofchemicalsatyourfingertips.IfforanyreasonyoufindthatyouneedtouseachemicalcomponentthatdoesnotmatchanyitemcurrentlyintheCHEMCADdatabase,youcancreateyourowncomponentforusewithyoursimulations.

Youcancreateasinglecomponent,definearangeofpseudocomponents,orimportacomponent’sphysicalpropertiesfromanexternalsource.Theseprocedureshavesimilaraims,butdiffersignificantlyfromoneanother.

Adding a Single Component CreatingapurecomponentintheCHEMCADcomponentdatabaseisatwo‐parttask.Youmustfirstcreatethecomponentandthenregressdataintothecomponent.

Creating the Component Tocreateanewcustomcomponent,youcanuseanyoffivedifferentestimationmethods:

• Createahydrocarbonpseudocomponent.Thisistreatedlikeapurecomponentinthatcertainaspectsofhowitbehavesorreactsareknown.

• UsetheJoback/Lydersenmethod.Withthismethodyouindicatebasiccharacteristics,andselectmoleculargroups(knownasJobackgroups,calledGroupAssignmentsinCHEMCAD)fromalist,toindicatehowmanyofeachmoleculargrouparepresentinthecomponent.

• UsetheUNIFACmethod.ThismethodissimilartoJoback/Lydersen,exceptthatthegrouplistismorespecializedtowardorganiccomponents.

• Createacombustionsolid.Thismethodisusedtosimulatesolidcomponentsforwhichanelementalanalysisandheatingvalueareknown,e.g.,coal.

• Createanelectrolytecomponent.Thismethodcreatesacomponentthatyoucansubsequentlyuseinanelectrolytesimulation.

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Theprocedureforcreatingapurecomponentisasfollows:

1. SelectThermophysical>ComponentDatabase>CreateNewComponent.ThisbringsuptheNewComponentdialogbox.

Figure 9-01: The New Component dialog box

2. Givethenewcomponentadescriptivename;itisstronglyrecommendedthatyoumakethisnameunique.Allothercharacteristicshereareoptional,exceptfornormalboilingpoint,whichisrequiredforthepseudocomponentmethod.

3. SelectaCorrelationoptiontoindicatewhichoftheabovemethodsyouwilluse,andclickOKtocontinue.

4. ThedialogboxthatappearsnextdependsontheCorrelationthatyouselected:

• PseudocomponentbringsuptheHydrocarbonCorrelationdialogbox.

• Groupcontribution–JobackbringsuptheGroupAssignmentsdialogbox.

• Groupcontribution–UNIFACbringsuptheNewComponentUNIFACGroupsdialogbox.

• CombustionsolidbringsuptheCombustionSoliddialogbox.

• ElectrolytebringsuptheElectrolyteDatadialogbox.

Selecttheappropriateoptionsforyournewcomponentandspecifyasmanycharacteristicsasyoulike,asaccuratelyaspossible.ClickOKtocontinue.

5. IntheSelectDestinationDatabasedialogbox,youwillseenodatabaseslistedifthisisyourfirsttimetoaddacomponent.Ifthisisthecase,clickNewtobringuptheManageComponentDatabasesdialogbox.

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Figure 9-02: The Manage Component Databases dialog box

6. Normally,you’llneedtoclickCreate,whichbringsuptheSaveAsdialogbox.Navigatetothelocationyouwantforyourcustomcomponentdatabase,givethedatabaseaname,andclickSave.Ifyouwanttoaddadatabasethatsomeoneelsehascreated(generallyinanetworklocation),youcanclickConnect,whichbringsupanOpendialogbox;navigatetothatdatabase’slocation,highlightthedatabase,andclickOpen.

7. TheManageComponentDatabasesdialogboxnowliststhedatabasethatyoucreatedorselected.ClickOKtocontinue.

8. IntheSelectDestinationDatabasedialogbox,thenewdatabaseyouhavejustnamedisnowlisted;highlightitandclickOK.

9. TheView/EditComponentDatamenunowappears.Clickanyitemonthemenutoaccessadialogboxwithoptionsfordefiningyournewcomponent.Afterdefiningasmanycharacteristicsaspossible,clickExittoclosethemenu.

Thenewcomponentisnowavailabletoaddtoyourcurrentsimulationandallfuturesimulations.Toreturnatanytimetomakechangestoauser‐definedcomponent,dooneofthefollowing:

• SelectThermophysical>ComponentDatabase>View/EditDatabaseComponenttobringuptheSelectSingleComponentdialogbox,whichlistsallavailablecomponents.HighlightthecomponentyouwantinthelistandclickOKtobringuptheView/EditComponentDatamenu.

• ClickComponentListonthetoolbar(orselectThermophysical>ComponentDatabase>View/EditSimulationComponent)tobringupthelistofcomponentsinthecurrentsimulation.Double‐clickthecomponentyouwantinthelisttobringuptheView/EditComponentDatamenu.

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Regressing Data into the Component Dataregressionistheprocessoffittingexperimentaldatapointstoapolynomialequationform,sothattheindividualerrorofeachdatapointisminimized.

Dataregressionisonlyrelevanttotemperature‐dependentpropertiessuchasheatcapacity,density,andvaporpressure.CHEMCADusesthesepolynomialequationfitstocalculatethepropertiesofacomponentatanygiventemperature.

Toregressdataintoacomponentthatyouhavecreated,followthesesteps:

1. SelectThermophysical>ComponentDatabase>ComponentPropertyRegression.ThisbringsuptheSelectRegressionDataSetdialogbox.

Figure 9-03: The Select Regression Data Set dialog box

2. Selecttheuser‐addedcomponentthatyouwanttoregressandclickNew.ThisbringsuptheEditRegressionSetdialogbox.

Figure 9-04: The Edit Regression Set dialog box

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3. Selectaregressiontypeandprovideadescriptivenameforthedataregression,thenclickOK.Thisbringsupadialogboxthatdisplaysparametersfortheselectedregressiontype.

4. Verifythedataonthisdialogbox,makingadditionsorchangesasnecessary,andthenclickOK.Thisbringsupadialogboxfordataentry.

5. Enteryourexperientialdatapointsinthecellsprovided.YoucanenteravalueintheWeight_factorcolumntoweighttheregressiontowardoneormoredatapoints.Whenyouhaveenteredallofyourdatapoints,clickOK.

Note:YoucanpasteacontiguousrangeofcellsfromanExcelworksheetintothecellsinthisdialogbox.

6. TheregressiondataisdisplayedinatabinthemainCHEMCADwindow.Anothertabdisplaystheregressionresultsingraphicalformat.Reviewthedataandplot,anddecidewhethertheregressionadequatelyrepresentsyourexperimentaldata.

7. Adialogboxappears,askinghowyouwouldlikethechangestobeappliedtoexistingsimulations.ChooseanoptionandthenclickOK.

8. Repeatthisprocedureasneededtoregressotherpropertiesforyourcomponent.

Pseudocomponent Range Usingapseudocomponentcurve—anothertermforthedistillationcurveportionofanassay—youcancutahydrocarbonstreamintopseudocomponents,orfractions.Apseudocomponentrepresentsagroupofcomponentsthatboilwithinanarrowtemperaturerange.PseudocomponentrangesareusedinCHEMCADtomodelhydrocarbons.

Whenyoudefineapseudocomponentrangeforastream,CHEMCADcreatesentriesinthecomponentdatabaseforeachhydrocarboncut,andassignsthesecomponents’compositionstothestream.

Note:Beforeyoudefineapseudocomponentrange,makesurethatyouhavespecifiedinyourcomponentlist,asappropriate,waterandanylightendsthatexistintheassay.

1. SelectThermophysical>PseudocomponentCurves.

2. IntheDistCurveCharacterizationdialogbox,enterstreamnumber(s)andclickOK.

3. IntheHydrocarbonCorrelationdialogbox,selecttheappropriatecorrelationsforyourcurve,orusethedefaultselectionsandclickOK.

4. ThisbringsuptheCurveTemperatureCutRangesdialogbox.Foreachcutrangethatyouwanttodefine,provideabeginningandendingtemperature,

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andenterthenumberofpointsthatyouwanttodefineasdiscretepseudocomponentswithinthatrange.ClickOKtocontinue.

5. IntheBulkPropertiesdialogbox,specifyadistillationcurvetypeandenteratotalflowrateandbulkgravityforthestream.Youcanmakeotherentrieshereasneeded,butonlythesethreeitemsarerequired.Notethatifyouhaveviscositydatathatyouwanttouse,youmustchecktheViscosityboxhere.ClickOKtocontinue.

6. Intheresultingdialogbox,enterthedistillationcurvefromyourassay,specifyingthevolumepercentageandboilingtemperatureforatleastfivedatapoints.ClickOKtocontinue.

7. Thenextdialogboxisoptional.Enteragravitycurvefromyourassay,listingthevolumepercentageandspecificgravityforatleastfivedatapoints.ClickOKtocontinue.

8. Thenextdialogboxisalsooptional.Ifyouhavelightendsandwaterdefinedinyourassay,entervolumepercentagedatahereforallrelevantcomponents.ClickOKtocontinue.

9. IfyoucheckedtheViscosityboxontheBulkPropertiesdialog,youwillnowseetheViscosityDatadialogbox.EnteryourviscositydataandclickOK.

10. ThisbringsuptheEditDistillationCurvesmenu,showninFigure9‐05.

Figure 9-05: The Edit Distillation Curves menu

11. ClickSaveandExit.ThepseudocomponentpropertiesnowdisplayinatabinthemainCHEMCADwindow.Youcanreviewandprinttheseresults,andleavethetabopenaslongasyoulike.Toreturntothemainworkspaceandyourflowsheet,simplyclickthefarlefttab,whichdisplaysthenameofyoursimulation.

12. Toseethelistofpseudocomponentsthatyouhavecreated,editthepropertiesforthestreamyouselected.Thepseudocomponentswillbelistedafterpurecomponents,withnamesthatbeginwithNBP.

Importing a Neutral File Youcanalsoaddacomponenttothedatabasebyimportingitsphysicalpropertiesfromanexternaldatasource.Thisprocedureisknownasneutralfileimport.

Fordetailedinformationaboutimportingandusinganeutralfile,seetheCHEMCADHelpsystem.

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Creating a Custom Symbol YoucancreateacustomsymbolinCHEMCAD,forusewitheitherabuilt‐inUnitOporauser‐definedUnitOp.ThetoolusedtocreatesymbolsiscalledtheCHEMCADSymbolEditor.

YoucanlaunchtheSymbolEditorineitheroftwoways:

• WithinCHEMCAD,selectEdit>EditUnitOpSymbols.

• FromWindows,selectStart>AllPrograms>Chemstations>Utilities>SymbolEditor.

Oncetheeditorisopen,you’llseeagriddedworkspaceandasmall,free‐floatingtoolpalette.

Figure 9-06: The Symbol Editor’s workspace and palette

Youcanbuildasymbolfromthegroundup,butthebestwaytolearntousethistoolistoeditanexistingCHEMCADUnitOpsymbol.Todothat,followthesesteps:

1. SelectFile>OpenfromtheSymbolEditormenu.IntheOpendialogbox,selectafilefromSymbolsdirectoryandclickOpen.TheselectedsymbolopensintheSymbolEditorworkspace,asshowninFigure9‐07.

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Figure 9-07: The pump_1.sym file open in the Symbol Editor workspace

2. SelectFile>SaveAsandsavethefileinadifferentdirectory,usingadistinctivenametoavoidconfusionwiththeoriginalsymbol.

3. UsethetoolsavailableinSymbolEditortochangethesymbolasneeded:

• Toremoveoralteranyexistingpartofthesymbol,selectStructure>Ungrouptobreakthesymbolintoitsindividualcomponents.

• Toaddgraphicalcomponentstothesymbol,usethedrawingtoolsonthetoolpalette,suchasRectangleandEllipse.

• Toaddatextlabeltothesymbol,usetheTexttool.

• Toaddaninletoroutlet,clicktheappropriateitemonthetoolpaletteandthenclicktoplacetheinletoroutletonthesymbol.

• Tobackoutofachangethatyou’vemade,selectEdit>Undoorpress[CTRL‐Z].

4. Whenyou’rereadytosavethesymbol,makesurethatyouhavedeletedanyunwanteditemsontheworkspace.SelectEdit>SelectAllorpress[CTRL‐A],andthenselectStructure>Group.

5. SelectFile>Savetosavethechangestoyournewsymbol.

Tocreateatotallynewsymbol,simplystartfromablankworkspace,namethefile,andusethevariousdrawingtoolstocreatethedesiredcombinationofshapesandtext.Addinletsandoutletsasneeded,thengroupthesymbol’scomponentsandsavethefile.

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Onceyou’vecreatedyournewsymbol,youneedtoassociateitwithaUnitOptypeandthenadditintotheappropriateUnitOpsubpalette.

1. WithintheSymbolEditorprogram,selectFile>EditUnitOpType.TheSelectUnitOperationTypedialogboxappears.

Figure 9-08: The Select Unit Operation Type dialog box

2. SelecttheappropriateUnitOptypeandclickOK.

3. ToassignthenewsymboltoaUnitOppalette,selectFile>AddtoCHEMCADPalette.

4. CloseandrestartCHEMCADtoseeyournewsymbolappearonthespecifiedsubpalette.

Customized Costing Calculations CHEMCADincludessomeverybasiccostingroutinestohelpdeterminethecapitalcostofequipment.UsingasimplifiedformofCknownastheParserlanguage,youmaymodifytheseroutinestobettersuityourneeds.DetailsofthisprocedurearefoundintheCHEMCADCalculator/ParserModuleguide,availableontheChemstationswebsite.

Creating Custom UnitOps IfyouneedaUnitOpthatfallsoutsidetherangeofoptionsofferedontheAllUnitOpspalette,youcancreateacustomUnitOp.ThegoalofcreatingacustomUnitOpistohaveaunitwhereyoucanenteryourownequationstocalculateheatandmassbalances.Overtheyears,CHEMCADusershavecreatedcustomUnitOpsforpurposesasdiverseasmembraneseparationunits,fuelcells,specializedsolidshandlingunits,andcrystallizersfortheseparationofxylenes.

FouritemsontheAllUnitOpspalettearededicatedtouser‐definedUnitOps.YoucancreateacustomUnitOpusinganyofthefollowingfourways:

• ExcelUnitOp:CreatedthroughacombinationoftheCOMinterfaceandtheDataMapinterface

See Also

Where wind power is harnessed

• Calculator:CreatedusinganinlineCprogram

• User‐addedmodule:CreatedusingVisualStudiooranotherC++compiler

• VBAUnitOp:CreatedthroughtheVBAEditor,whichispartofCHEMCAD

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ThebasicproceduresforcreatingcustomExcelUnitOpsarecoveredinChapter10,DataInterfaces.CalculatorUnitOpsaredefinedbyaprogramminglanguagecalledParser,thesyntaxforwhichisdocumentedintheCHEMCADCalculator/ParserModuleguide,availableontheChemstationswebsite.

C++user‐addedmodulesaredevelopedusingMicrosoft’sVisualC++developmenttool,thesametoolsthatwereusedinthecreationofCHEMCAD’sownUnitOps.TheproceduresforcreatingC++user‐addedmodulesforusewithCHEMCADaredetailedintheUser‐addedModulesGuide,whichisalsoavailableontheChemstationswebsite.

VBAUnitOpsaredefinedbyVBAsubroutines,andaredescribedlaterinthischapter.

ThemethodyouchooseisanimportantfirststeptowardcreatingaUnitOp,butthechoiceisalmostentirelyuptoyou.CalculatorUnitOpscanbequickandeasytosetup,buttheycan’tdoeverythingtheothermethodscan.TheExcel/VisualBasicapproachisverypowerfulandusesthefamiliarVisualBasiclanguagefordevelopment.AdrawbacktothismethodisthatcalculationcansometimesbeslowduetotheuseofMicrosoftExceltodothecalculations.ThemostpowerfulandfastestcalculatingmethodistheC++user‐addedmodulemethod,butifyouarenewtoC++,itmaybechallengingtouse.VBAUnitOpsareaspowerfulasthosecreatedusingC++,andaremucheasiertobuild.

WhichevermethodyouusetoprogramthecalculationsofyourUnitOp,youwilllikelyneedtocreateadialogboxtoprovideauserinterface.AdialogboxenablesuserstosendinformationintoyourUnitOp,forexamplethenumberofstagesforadistillationUnitOp.NomatterwhatmethodyouusetoprogramyourUnitOp,youwillusetheDialogEditorprogramtocreatetheuserinterface.

Creating a Custom UnitOp Dialog Box CHEMCADusesdialogboxestosetvariablesforalltypesofUnitOps.UsingtheDialogEditorprogram,youcancreateacustomdialogboxforusewithanytypeofuser‐addedunits.

YoucanalsoeditanexistingUnitOp’sspecificationdialogbox—forexampletoaddtextnotes,totranslatefromEnglishtoanotherlanguage,ortolimittheUnitOp’sfunctionality—althoughthisisnotcommonlydone.

TheDialogEditorprogramenablesyoutocreateandmodifydialogboxes,whicharecontrolledbyfileswiththe.MYextension.Thesefiles,alongwith.MAPfilesand.LABfiles,definedialogboxesforuseinCHEMCAD.

TousetheDialogEditorprogram,you’llneedagoodunderstandingofWindows,alongwithabasicknowledgeofVisualProgrammingconceptssuchasobjectsandproperties.YoushouldalsohaveafirmunderstandingofsimulationinCHEMCADbeforeventuringintoDialogEditor.

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TheDialogEditorprogramisseparatefromCHEMCAD.Tolaunchit,selectStart>AllPrograms>Chemstations>Utilities>DialogEditor.

Figure 9-09: The Dialog Editor window showing an open dialog

AdetaileddescriptionofhowtousetheDialogEditorisavailableontheChemstationswebsite,aswellasontheCHEMCADinstallationCD‐ROM.

Customizing Thermodynamics Occasionally,youmayfindthatnoneofthethermodynamicmodelsbuiltintoCHEMCADserveyourneedsforaparticularsimulation.Ifthisshouldhappen,youcantakeoneoftwoapproachestohandlingthermodynamicsforthesimulation:eithercreateyourownK‐valueorenthalpymodelorcreateyourownmixingrule.

Creating a Custom K-value or Enthalpy Model TheK‐valueforanycomponentisaratiothatreflectstheamountofthatcomponentpresentinvaporandliquidphasesundergivenconditions.CHEMCADusesK‐valuestocalculatevapor‐liquidequilibriuminstreamsandinUnitOps.

Anenthalpymodelcalculatestheheatcontentofasystemundergivenconditions.EnthalpymodelsareusedtocalculatetheheatbalanceinCHEMCADsimulations.

IfyouhaveaK‐valueorenthalpymethodthatyou’dliketouse,youcanwriteC++codetointroduceyourmodelintotheCHEMCADsystem.AdetaileddescriptionofhowtocreatecustomK‐valuesandenthalpymodelsisavailableintheUser‐addedModulesGuide,whichisavailableontheChemstationswebsiteandontheCHEMCADinstallationCD‐ROM.

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Whenyou’vesuccessfullyaddedacustomK‐valuemethod,youcanselectitontheK‐valueModelstaboftheThermodynamicSettingsdialogbox,byusingtheGlobalK‐valueOptionsettingcalledADDK.

Figure 9-10: Selecting the ADDK K-value option

Afteraddingacustomenthalpymodel,youcanselectitontheEnthalpyModelstaboftheThermodynamicSettingsdialogbox,byusingtheGlobalEnthalpyOptionsettingcalledADDH.

Figure 9-11: Selecting the ADDH enthalpy model

Creating a Custom Mixing Rule AmixingruledetermineshowCHEMCADcalculatesthepropertiesofamixer,basedonthepropertiesofitspurecomponents.YoucancreatecustommixingrulesforanyoftheselectionslistedontheTransportPropertiestab,eitherusingVBAasdescribedinthefollowingsectionorusingC++.

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Visual Basic Applications (VBA) YoucancustomizeCHEMCADusingVisualBasicApplications,orVBA.TheCHEMCADExplorer’sVisualBasictabprovidesaccesstothefollowingtypesofcustomizableitems:

• Reactions

• Properties

• UnitOps

IfyouhavewrittencodeinVBAthatyouwouldliketomakeavailableinCHEMCAD,youcaninsertthatcodeintooneofthetemplatesthatCHEMCADprovides,oruseanyofthesetemplatesasastartingpointandlaunchaVBAeditorfromwithinCHEMCAD.

Defining a Reaction, Mixing Rule, or UnitOp Todefineacustomreaction,mixingrule,orUnitOpusingVBA,followthesesteps:

1. ClicktheVisualBasictabinCHEMCADExplorerandexpandtherelevantitem:Reactions,Properties,orUnitOps.

2. Double‐clicktherelevanttemplateitemtoopentheVBAeditor.

3. Copytheexistingsubroutineandpastethecodebelowtheexampleinthecodewindow.Renamethenewsubroutinecopy.

4. Editthenewsubroutineasneededtoachievetheresultthatyouwant.

5. ReturntoCHEMCADbyeitheroftwomethods:

• Use[ALT‐TAB]ortheWindowstaskbar,leavingtheVBAeditorwindowopen.

• ClicktheViewCHEMCADbuttonatthefarleftendoftheVBAeditor’stoolbartoclosetheeditorwindow.

Note:Youcanalsousethe[ALT–F11]keycombinationtotogglebetweenCHEMCADandtheVBAeditor.

6. SavethecurrentCHEMCADsimulation,thenexpandtherelevantCHEMCADExploreritemagaintoseeyournewlydefinediteminthelist.

Using a VBA-defined Reaction Onceyouhavedefinedanewreaction,youcanuseitforakineticorbatchreactor:

1. SelecttheBatchReactororKineticReactortoolandplaceareactoriconontheflowsheet.AddandspecifystreamsforthisUnitOpasappropriate.

2. Double‐clicktheicontodefinereactorspecifications.MakethefollowingselectiontouseyourVBA‐definedreaction.

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• Batchreactor:Afterspecifyingthereactor’sinitialcharge,you’llseetheBatchReactorGeneralInformationdialogbox.OntheGeneraltab,selectthekineticrateexpressionoptioncalledDefineeachreaction.

• Kineticreactor:OntheGeneralSpecificationstaboftheKineticReactordialogbox,selectthekineticrateexpressionoptioncalledDefineeachreaction.

3. Foreachreactionthatyoudefine,you’llenterdataintoaKineticDatadialogbox.ChoosetheKineticRateExpressionoptioncalledUser–VBA.Thisbringsupadrop‐downlisttotherightoftheKineticRateExpressionfield,whereyoucanchooseauser‐definedreaction.SelecttheappropriateoptionforeachreactionthatyoudefineforthisUnitOp,andthenclickOKtocontinuetothenextreaction.

Figure 9-12: Selecting a VBA-defined reaction in the Kinetic Data dialog box

4. Whenyouhavedefinedthelastreaction,clickOKtoreturntothemainCHEMCADwindow.

Using a VBA-defined Mixing Rule Onceyouhavedefinedanewmixingrule,youcanincludeitinyourCHEMCADsimulations:

1. SelectThermophysical>ThermodynamicSettings.

2. IntheThermodynamicSettingsdialogbox,dropdownthelistofoptionsforthemixingrulethatyouusedasatemplateforyournewrule.Selectyourrulefromthelist.

3. ClickOKtoreturntothemainCHEMCADwindow.

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Using a VBA-defined UnitOp OnceyouhavedefinedanewVBAUnitOp,youcanincludeitinyourCHEMCADsimulations:

1. SelecttheVisualBasicUnitOptoolandplaceaniconontheflowsheet.AddstreamsintoandoutoftheUnitOpasyounormallywould.

2. Double‐clicktheicontodefinetheUnitOp’sspecifications.

3. IntheVisualBasicUnitOpdialogbox,dropdowntheFunctionlisttoseetheavailableVBAUnitOps.SelecttheoneyouwanttouseandclickOK.

Figure 9-13: Selecting a VBA UnitOp

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Chapter 10

Data Interfaces

CHEMCADenablesyoutoexchangedatawithotherprogramsthroughavarietyofmethods.Thissavestime,effort,andthepotentialforkeystrokeerroranddataomissions.Insomecases,thesedatainterfacescanenableCHEMCADtolinkdirectlyintoyourplantinformationsystemstorunsimulationswithouthumanintervention.

ThedatainterfacesthatCHEMCADusesareasfollows:

• TheExcelDataMapinterface,whichcanlinkanyvalueinaCHEMCADsimulationtoanycellinanExcelworksheet,orviceversa(notethatrunningCHEMCADsimulationsfromExcelrequiresaCOMinterface,describedbelow)

• TheVisualBasicApplicationinterface,whichenablesyoutobuildcustomreactions,mixingrules,andUnitOps

• TheOPCinterface,whichpermitsanyOPCClientapplicationtoaccessvaluesinaCHEMCADsimulation

• COMinterfaces,whichallowanyCOM‐enabledprogram(suchasMATLAB)toaccessandcontrolaCHEMCADsimulation

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Excel Data Mapping TheExcelDataMappingfeatureallowsyoutolink,retrieve,andinsertdatafromanExcelspreadsheetintoaCHEMCADsimulation.ItalsoletsyouinsertdatafromaCHEMCADsimulationintoanExcelspreadsheetwithjustafewclicks.TheintegrationofCHEMCADandExcelisapowerfulandeasy‐to‐usetoolthatsavesyoutimeandwork.

WithExcelDataMapping,youcanquicklyandeasilygetthemostofCHEMCAD/Excelintegration,evenifyouhavenoexperiencewithVisualBasicorExcelprogramming.Infact,youcanuseandbenefitfromthisfeatureevenwithverylittleknowledgeoftheExcelprogram.

TouseExcelDataMapping,youmustfirstcreateoneormoreDataMaps,andthensetuprulesfortheexecutionofeachDataMapinuse.

Creating an Excel Data Map ThetoolusedtocreateandeditDataMapsinCHEMCADistheExcelDataMapEditor.ThistooldisplayswithintheCHEMCADworkspace,andresemblesanExcelspreadsheet.IthasallyouneedtolinkstreamandUnitOpparameterstooneormoreExcelspreadsheets.OneachExcelDataMap,youcanlinkupto500parametersinasinglespreadsheet,andyoucanhaveuptotenDataMapspersimulation.

TolinkyoursimulationtoanExcelspreadsheet,firstcreatethetargetExcelworkbook,makinganoteofthefile’sname,itslocation,andthenameofthespecificworksheettowhichyouwanttolink.Thenfollowthesestepstocreateanewdatamap:

1. OntheCHEMCADExplorer,expandtheDataMapsitemandthenclickNewDataMap.AspreadsheetwillopenwithintheCHEMCADworkspace.

Figure 10-01: The Excel Data Map Editor

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2. ClicktheBrowsebuttonandlocatethetargetworkbook.SelecttheworkbookfileandclickOpen.

3. InthecellnexttoExcelWorksheetName,typethenameoftheworksheettowhichyouwanttolinkyoursimulation.

Note:Ifyouneedtoverifythenameoftheworksheet,youcanclicktheOpenbuttontolaunchExcelandviewtheworkbook.

4. Double‐clickthecellbelowMapRuletoseeadrop‐downlistofmappingoptions:

• ToWorksheetOnlyenablesyoutosenddatafromstreamsorUnitOpsinCHEMCADtotheselectedworksheet.

• ToCCOnlyenablesyoutosenddatafromanycellontheworksheettotheselectedstreamorUnitOpparameterinyoursimulation.

• FordatareconciliationenablesyoutomanipulatethedatausingCHEMCAD’sDataReconciliationfeature.

Figure 10-02: Selecting a Map Rule option in the Excel Data Map Editor

5. Double‐clickthecellbelowCCObjTypetoseeadrop‐downlistofmappingoptions:

• StreamenablesyoutolinkanExcelcellorcellrangetoastreamontheflowsheet.

• UnitOpenablesyoutolinkanExcelcellorcellrangetoaUnitOpontheflowsheet.

• Miscenablesyoutochangedynamicflowsheetsettings.

6. ClickthecellbelowCCObjID.TypetheIDnumberofthestreamorUnitOptowhichyouwanttolink.

7. Double‐clickthecellbelowParIDtoseeadrop‐downlistofparametersfortheselectedUnitOporstream.Scrolldownandselectanoptionfromthelist.

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Note:WhenyouareimportingcelldataintoCHEMCAD,thelistofparameteroptionsislimited,asmanyvaluesinaCHEMCADsimulationarecalculatedbasedonothervalues.

8. Ifyouchoseaparameterthatisrelatedtoaspecificcomponent(e.g.,CompMolefraction,oranyitemmarkedwithanarrow),youwillneedtospecifythecomponent.Double‐clickthecellbelowComponenttoseeadrop‐downlistofavailablecomponents.Selectacomponentfromthelist.

Figure 10-03: Component-specific parameters marked with arrows on the Par ID list

9. ClickthecellbelowWrkShtCell/Range.Typethecelladdressorcellrangetowhichyouwanttolink.Celladdressesshouldbeformattedwiththecolumnletterandrownumber,e.g.,A1orD17.Cellrangesshouldbeformattedastwosuchaddresses(representingtherange’sfirstandlastvalues)separatedbyacolon,e.g.,A1:A12orB5:E20.

10. Ifyouareperformingadatareconciliation,youcanusetheWeightcolumntogivecertainitemsinthereconciliationmoreimportancethanothers.

11. Repeattheprocedureuntilyouhavespecifiedallofthecellsorcellrangesthatwilllinktoyoursimulation.

12. SavetheDataMapbyselectingFile>SaveAs.TypeanameforyourDataMapandthenclickOK.ThenewlycreatedDataMapnowappearsontheCHEMCADExplorerundertheDataMapsitem.

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Figure 10-04: List of available Data Maps in CHEMCAD Explorer

13. ToleavetheDataMapopenandreturntoyoursimulation,usethetabsatthebottomofthemainCHEMCADworkspace.ToclosetheDataMap,selectFile>Close,orclicktheredXbuttonontheDataMap’stab.

Data Map Execution Rules AfterconfiguringoneormoreExcelDataMapsforasimulation,youmustsetupexecutionrulestousethem.YoucanconfigureuptotenDataMapfilespersimulation.

TosetupDataMapexecutionrules,followthesesteps:

1. OntheCHEMCADExplorer,expandtheDataMapsitemandthenclickExecutionRules.TheDataMapExecutionRulesdialogboxappears.

Figure 10-05: The dialog box for configuring execution rules

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2. ClickthesquarebuttonnexttothefirstfieldintheSelectDataMapscolumntobringuptheSelectDataMapdialogbox.

Figure 10-06: Selecting a Data Map from the list

3. SelectthenameoftheDataMapforwhichyouwanttosetrules,andclickOKtoreturntotheDataMapExecutionRulesdialogbox.RepeatthisstepforallotherDataMapswhoserulesyouwanttosetupatthistime.

4. IntheBeforeSimulationRunsfieldnexttoeachselectedDataMap,clickthedrop‐downlisttochooseanactionforthatDataMaptoperformbeforecalculationsbegin:

• DoNothingperformsnoactionbeforethesimulationisrun.YoumightusethisoptiontodisableaDataMaptemporarily.

• ToWorkbooksendstherequesteddatatoExcelbeforerunningthesimulation.YoumightusethisoptionwhenyouwanttopulldatafrominletstreamsorUnitOpspecifications.

• ToCHEMCADsendstherequesteddatainExceltoCHEMCADbeforerunningthesimulation.YoumightusethisoptionwhenyouwanttofeeddatatoinletstreamsorUnitOpswithdatafromtheExcelworksheet.

5. IntheAfterSimulationRunsfieldnexttoeachselectedDataMap,clickthedrop‐downlisttochooseanactionforthatDataMaptoperformaftercalculationsarecomplete:

• DoNothingperformsnoactionafteryoursimulationhasrun.YoumightusethisoptiontodisableaDataMaptemporarily.

• ToWorkbooksendstherequesteddatatoExcelafterrunningthesimulation.YoumightusethisoptionwhenyouwanttosenddatafromstreamsorcalculatedparametersofUnitOpstotheworkbookinExcel.

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Figure 10-07: Three different Data Maps with rules set up

6. WhenyouhaveconfiguredalloftheDataMapsthatyouwanttouse,clickOKtosaveyourrulesandclosetheDataMapExecutionRulesdialogbox.

Youcannowrunthesimulation.IfyouopentheExcelfilesthatarelinkedtothesimulation,youwillbeabletoseetheparametersofstreamsandUnitOpsrelatedtotheExcelDataMap.YoucanalsoperformyourowncalculationsintheworkbookbasedonthedatalinkedtoCHEMCAD.

Creating Excel UnitOps YoucanbuildanExcelspreadsheetthatfunctionsasaUnitOpwithinCHEMCAD.ThisisusefulforextremelysimpleUnitOpssuchasmixersanddividers,orforsimpleseparations.

1. StartbycreatingacustomdialogboxforyournewUnitOp,asdescribedinChapter9,CustomizingCHEMCAD.

2. Next,createanExcelspreadsheetcontainingyourdesiredcalculationsforthenewUnitOp.

3. Openasimulation,selecttheExcelUnitOptoolontheAllUnitOpspalette,andplaceaUnitOpiconontheworkspace.

4. DrawtheappropriatestreamsintoandoutoftheExcelUnitOp.

5. Double‐clicktheUnitOpicontoopentheExcelWorkBookUnitdialogbox.

6. OntheFilePathstab,usethetopBrowsebuttontospecifythelocationandfilenameofthecustomdialogboxthatyoucreated.UsethesecondBrowsebuttontospecifythelocationandfilenameoftheExcelworkbook.

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7. NowyouneedtospecifyhowthisspreadsheetwilllinktoCHEMCAD.ClicktheDataMapstabtolinkthespreadsheetusingoneormoreDataMaps,orclicktheExcelMacrostabtolinkthespreadsheetusingtheCOMinterface.

• OntheDataMapstab,specifytheexecutionrulesasdescribedearlierinthischapter.

• OntheExcelMacrostab,specifythenamesoftheExcelmacrosthatyouhaveprogrammedtousetheCOMinterface,intheorderthatyouwantthemtobecalculated.

8. ClickOKtoreturntothemainCHEMCADwindow.

Specification Sheets UsingtheinterfacewithMicrosoftExcel,CHEMCADallowsyoutooutputsimulationdatatoanExcelspreadsheetresemblingavendorspecificationsheet,asdiscussedinChapter8,OutputandReports.Customizingthesespecsheetssavesyoutimebyoutputtingdataintheformatrequiredbyyourcompanyorvendor.

TocustomizethespecsheetforaspecificUnitOptype,editthecorrespondingExcelspreadsheetinthefollowingdirectory:

C:\ProgramFiles\Chemstations\CHEMCAD\Program\templates

IftheUnitOptypeyouwantisnotrepresentedbytheExcelfilesinthisdirectory,youcancopythegenericspecsheet.xlsfileanduseitasatemplateforanewUnitOpspreadsheet.

Placethecopyinthesamedirectory,andmakeitsfilenamethestandardfour‐characterabbreviationfortheUnitOptypeinquestion.Forexample,tocreateaspecsheettemplatefortheFlashUnitOp,youwouldneedtonamethefilecopyflas.xls.SeetheCHEMCADHelpinformationaboutyourspecificUnitOpifyouneedtolookupthisabbreviation.

Beforeyoucontinue,youwillneedtoturnofftheRead‐onlyattributeforthenewspreadsheetfile.Thequickestwaytodothisistoright‐clickthefilewithintheWindowsExplorer,selectProperties,andthencleartheRead‐onlycheckboxinthePropertiesdialogbox.

OncethecopyisrenamedandtheRead‐onlyattributeisturnedoff,youcanopenthespreadsheetandedititasneeded.

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Using CHEMCAD as an OPC Server CHEMCADiscapableofsettingupanOPCserverwhichallowsdirectdatatransferbetweenanyCHEMCADsimulationandanyOPCclientapplication.

OPCstandsforOLEforProcessControl.OPCprovidesastandardmethodfordifferentdevicesandapplicationstosharedata.UsingOPC,youcansharedatabetweenCHEMCADsimulationsandSCADAsystems,datahistorians,distributedcontrolsystems(DCS),andhuman‐machineinterfaces(HMIs).

Infact,theacronymOPCisnowconsideredbymanytomeanOpenness,Productivity,Connectivity,becausethistechnologyformsthebasisforsharingandmanipulatingplantdata.

OPC‐enabledsystemsareclassifiedaseitherOPCserversorOPCclients.OPCserversareeitherapplicationsordevicesthatprovidedata.OPCclientsareinterfacesthatuseandmanipulatethisdata.OPCclientscanconnecttomultipleOPCserversatanytimeandreadandwritedatatoallofthem.

OPC Applications OPCcanbeappliedasfollows:

• Inferentialsensors:Sometimescalledsoftsensors,inferentialsensorsuseoneormoremeasuredvariablestoestimateanothervariable.UsingCHEMCADsimulationsanddatafromyourplant’sDCS,youcanembedsimulationstoprovidedatasuchasconcentrations,heatduty,andfoulingfactor,whichwouldnotnormallybeavailable.

• Operatortraining:YoucancoupleanoperatorHMItoadynamicsimulationtocreateatrainingsimulatorthatcanhelptrainoperatorsinasafeandeffectiveway.

OPC Compliance ChemstationsisaMemberoftheOPCFoundation,anorganizationdevotedtomaintainingtheOPCstandards.CHEMCADhasbeencertifiedfor,andinteroptestedfor,OPCDAstandard2.05a.

Enabling CHEMCAD as an OPC Server ToenableOPCwithinCHEMCAD,selectTools>Options>Misc.Settings,thenchecktheEnableOPCServerboxandclickOK.Whenyoudothis,CHEMCADregistersanOPCservernamedCHEMCAD.SimulationServer.1onyourmachine.

Onceyouloadasimulation,allofthatsimulation’sstreampropertiesandUnitOpsettingsandvariablesareautomaticallypublishedastagstotheOPCserver’snamespace.

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Everyvaluetaghasaunitstagassociatedwithit,whichshowstheengineeringunitsusedtoreportthevalue.Tochangetheengineeringunits,selectFormat>EngineeringUnitswithinaCHEMCADsimulation.

WhentheOPCserverfeatureisenabled,CHEMCADautomaticallyregistersitselfasanOPCserver.IfyouwanttounregisterCHEMCADandremoveitfromthelistofOPCservers,youcanselectStart>Runandtypethefollowingcommand:

{program directory}\CC6.Exe –unregister

Forexample,ifyourprogramdirectorywereC:\ProgramFiles\Chemstations\CHEMCAD\Program(thedefaultdirectory),youwouldtypethefollowing:

C:\Program Files\Chemstations\CHEMCAD\Program\CC6.exe -unregister

Reading and Writing Values to CHEMCAD Using OPC YoucanuseOPCtohavevaluesreadfromorwrittentoasimulation,andtorunthesimulation.Bothsteady‐stateanddynamicsimulationscanberuninthisway.

ValuesareupdatedtotheOPCserverwheneverCHEMCADcompletesasteady‐staterunoradynamictimestep.Valuescanalsoberead;inthecaseofadynamicsimulation,readingvaluesbetweentimestepswillcausetheprogramtoextrapolatefromthelastconvergedresults.

Valuescanbewrittenatanytime.IfCHEMCADisintheprocessofexecutingatimesteporasteady‐statesimulation,thevaluesareheldinabufferuntilthesimulationisconverged,atwhichtimethevaluesarewrittentoCHEMCAD.

WhenvaluesarewrittentoaCHEMCADstream,thestreamisimmediatelyreflashed,andallOPCtagsforthatstreamareupdated.

OPC Server Operations InadditiontoreadingandwritingprocessdatatoCHEMCAD,itisusefultobeabletosendcommandstoCHEMCAD,forexampletotellCHEMCADtostartorstoprunningasimulation.

ThisisdonewithaseriesofflagsintheCHEMCADgroupoftheOPCserver.Touseanyoftheseflags,writea1toflag.CHEMCADwillexecutethedesiredcommandandreturnavalueindicatingsuccessorfailure.Areturnof0indicatesthatthecommandhascompletedsuccessfully,whileanegativereturnindicatesaproblemofsomekind.

Theavailablecommandsareasfollows:

• RefreshServertellsCHEMCADtorefreshalldatasenttotheOPCserver.

• RunSteadyStaterunsasteady‐statesimulation.Whenthesimulationfinishes,theflagwillbereseteitherto0(runconverged)ortoanegativenumberindicatingthenumberoferrorsthatoccurredduringtherun.To

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viewtheerrormessagetext,youmustopentheCHEMCADinterfacedirectly.

• Restoretoinitialstatereturnsadynamicsimulationtotimezero.Areturnof0indicatessuccess;avalueof‐1indicatesfailure.

• RunDynamicstartsadynamicsimulation.Areturnof0indicatessuccess;avalueof‐1indicatesfailure.

• RunDynamicOneSteprunsasingletimestepofadynamicsimulation.Areturnof0indicatessuccess;avalueof‐1indicatesfailure.

• SetInitialStatesetsthecurrentprocessconditionsasthetime‐zeroconditions,overwritingtheprevioustime‐zeroconditions.Areturnof0indicatessuccess;avalueof‐1indicatesfailure.

• StopSimulationstopsadynamicsimulation.Areturnof0indicatessuccess;avalueof‐1indicatesfailure.

CHEMCAD OPC Namespace AnOPCnamespacedefinesandorganizesalltheavailablecommandsanddata.OPCnamespacesaredividedintogroups,eachofwhichcontainsitems.Itemsaresometimesreferredtoastags.

Note:Mostofthedataitemsinasimulationhaveengineeringunitsassociatedwiththem.Inthesecases,weusuallydefinetwoseparatetags,onecontainingthedatavalueandtheothercontainingtheunitsstring.AllunitsstringsarereadonlyfromOPC.Theunitsstringsaregovernedbythesettingsinsidethesimulation.

ThegroupsinCHEMCAD’sOPCnamespaceareorganizedasfollows:

• CHEMCAD.SimulationServer:ThisistheOPCservername.Byconvention,thisnameisfollowedbyaversionnumber,e.g.,CHEMCAD.SimulationServer.1,toindicatetheOPCServerversion.ThisistheservernametowhichOPCclientswillconnect.

• CHEMCADGroup:ThisgroupcontainsanyinformationthatisnotdependentonastreamorUnitOp,andallcommandsusedtorunCHEMCAD.

• StreamsGroup:Thisgroupcontainsaseriesofsubgroups,oneforeachstreamontheflowsheetnumberedbystreamIDnumber.

• UnitOperationsGroup:Thisgroupcontainsaseriesofsubgroups,oneforeachunitoperationontheflowsheet,numberedbyUnitOpIDnumber.

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COM Interfaces ComponentObjectModel(COM)isaMicrosoft‐standardplatformthatenablesprogramstosharecontentsuchasdataandcalculationroutines.ThisinterfacemakesitpossibleforotherprogramstocontrolaCHEMCADsimulation.

CHEMCADactsasaCOMserver,soanyprogramthatcanactasaCOMclientcanbemadetointerfacewithCHEMCADinthisway.Ifyouaren’tcertainwhetheryourapplicationcanactasaCOMclient,checkwiththesoftwarevendor.

Note:UsingtheCOMinterfacetoCHEMCADisacomplicatedprocedurethatrequiressomeexperienceinprogramming.Ifyourorganizationlacksin‐houseexpertiseinprogramming,considerbringinginathird‐partyresourcetoassistyouwiththeprocedure.

Thefollowingsectionisabriefwalk‐throughofasimpleCOMinterfacebetweenExcelandCHEMCAD.

Connecting Excel and CHEMCAD: A Simple COM Interface WhileyoucanexportorimportdatavaluesusingExcelDataMap,morecomplicatedinteractions—suchasrunningasimulationfromanotherprogram—requiretheextracontrolaffordedbytheCOMinterface.

ThefollowingisasimplifieddescriptionoftheprocedureforconnectingthesetwoprogramsandenablingExceltoloadasimulation,changeavalue,runthesimulationagain,readthesamevalue,andthenclosethesimulation.

Inthisprocedure,you’lluseExceltodothefollowing:

• OpenCHEMCAD

• ReadinvaluesfromCHEMCADintoanExcelworkbook

• Changeavalueinthesimulation

• Runthesimulation

• ReadtherevisedvaluesbackintoExcel

Normally,usingCOMinterfacesinvolvessomeprogramming.WehavecreatedanexamplecalledVBCLient.xlstohelpyouovercomethathurdle;youdon’tneedtowriteanycodeatalltousethistool.Evenifyouneedtowriteyourownprogram,thecodeinthemacrosofVBClientwillcomeinhandyasaguide.

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Using the VBClient Example FollowthesestepstousetheVBClientexample:

1. OpenExcelandloadtheworkbookcalledVBClient.xls.Thisworkbookhasthreeworksheets:

• CommandcontainsbuttonsforcontrollingaCHEMCADsimulation.

• Streamsdisplaysallstreamdatainthesimulation.ThissheetcanbeusedforbothinputandoutputofstreamvariablestotheCHEMCADsimulation.

• UnitOpsdisplaysallUnitOp‐relateddataforthesimulation.ThissheetcanbeusedforbothinputandoutputofUnitOpvariablestotheCHEMCADsimulation.

2. OntheCommandsheet,youwillseeaseriesofbuttonstoloadCHEMCAD,loadasimulation,readdatafromthesimulation,writedatabacktothesimulation,andrunthesimulation.ClickLoadCHEMCADtostartaninstanceofCHEMCAD.

ClickLoadSimulationtoloadasimulationintoCHEMCAD.

MakeachangetothedatashownontheStreamsandUnitOpssheets.

Note:Somevaluesareread‐only.Forexample,VBClientdoesnotallowyoutochangeastream’stotalflowratedirectly;youmustinsteadchangethecomponentflowratestomakeachangetothetotalflowrate.

3. ClickSaveDatatopushyourchangestotheCHEMCADsimulation.

4. ClickRunAlltorunthesimulation.

5. NotethechangestothedataontheStreamsandUnitOpssheets.

A Peek under the Hood Right‐clickLoadCHEMCAD,selectAssignMacro,andthenclickEdit.TheVisualBasiceditorinExcelopenstodisplaythecodebehindthebutton:

Sub LoadCC5() ' initialize global variables selJobName = "" selCaseName = "" selUpdateStrUopData = False selOK = False Set CC5 = Nothing

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' load CHEMCAD Set CC6 = CreateObject("CHEMCAD.VBServer") If CC6 Is Nothing Then Dim msg As String msg = "Can not load CHEMCAD." MsgBox msg End If End Sub

Themostimportantlineinthatwholesubroutineis:

Set CC6 = CreateObject("CHEMCAD.VBServer")

Inthatsingleline,ExcelloadsCHEMCADintomemory.

Loadingasimulationisaccomplishedwiththissimpleline:

retFlag = CC6.LoadJob(casePath)

Runningasimulationcanbeassimpleasthis:

retFlag = CC6.SSRunAllUnits

TheCOMInterfaceReferencesectionoftheCHEMCADHelpfile(listedundertheheadingCustomization)providesafullreferenceofthecommandsavailablethroughCOM.

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Chapter 11

CHEMCAD Tutorials

AlthoughthesimulationsstoredinyourExamplesdirectoryareusefulformanyscenarios,thebestwaytolearntouseCHEMCADistocreateandrunsimulationsyourself.Thetutorialsinthischapterwalkyouthroughbasicsimulationbuildingstepbystep,usingarealisticexampleproblemthatwillhelpprepareyouforyourownsimulations.

Thefirsttutorialisforasimplesteady‐statesimulation,whichisthenusedasthebasisforthesecondtutorial,inwhichyou’lllearntousetheCC‐THERMmoduletorateaheatexchanger.ThethirdtutorialwalksyouthroughabatchdistillationproblemusingCC‐BATCH,andthefinaltutorialcoversvariousscenariosforpipingsystems.

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CC-STEADY STATE Tutorial Thistutorialcreatesabasicsteady‐statesimulationforacondensatestabilizerplant.Inthisplant,gasentersthesystemwiththefeedconditionsshowninthefollowingdiagram:

Figure 11-01: Condenser stabilizer problem diagram

Yourjobistodeterminenewoperatingconditionsforthisexistingplant,alongwithanynecessarymodifications.Thedesignrequirementsareasfollows:

• Thecricondenthermdewpointoftheproductgasmustbe20°Forless.Acricondenthermdewpointisthehighesttemperaturefortwo‐phasecoexistenceofamixture.Aslongasthestreamtemperaturestaysabovethecricondenthermdewpoint,thestreamcontentswillnotcondense.

• Thestabilizedcondensatemusthavemaximumpropanecontentof1%.

Overview RunningaflowsheetsimulationinCHEMCADisessentiallyanine‐stepprocedure:

1. Startanewsimulation.

2. Selectengineeringunits.

3. Createaflowsheet.

4. Selectcomponents.

5. Selectthermodynamicsoptions.

6. Definethefeedstreams.

7. EnterUnitOpparameters.

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8. Runthesimulation.

9. Reviewtheresultsandprintasneeded.

Thestepsdonothavetobeperformedinthisorder,nordoallofthemhavetobedoneforeachflowsheet,butyoushouldconsiderallstepsforeachproblem.

Starting a New Simulation Startbycreatinganewsimulationandgivingitaname.

Todothis,launchCHEMCADandthenSelectFile>SavetoopentheSaveAsdialogbox.Navigatetothedirectorywhereyouwanttostorethesimulation(tryMySimulations,locatedunderMyDocuments)andgiveyoursimulationaname,leavingthetypeasCHEMCAD6(*.cc6).ThenclickSavetocreatethefileandreturntothemainCHEMCADwindow.

Note:Insteadofsavingallchangesinstantly,CHEMCADnowsavesyoursimulationonlywhenyouusetheSavecommand.Thisprovidesyouwithgreaterflexibilityandgivesyoumorecontroloveryoursimulations,butitalsomeansthatyoushouldsaveyourworkfrequently.Thisisasoundpracticeforworkinginanysoftwareapplication,asitcanhelpyouavoidlosingworkintheeventofapowerproblemorcomputerglitch.

Selecting Engineering Units SelectFormat>EngineeringUnitstoopentheEngineeringUnitSelectiondialogbox.

TheEnglishunitsoptionisthedefaultandiscurrentlyhighlighted.Tochangetheengineeringunitssystem,youwouldclicktheAltSI,SI,orMetricbutton;youcouldthenchangeanyoftheindividualunitsaswell.Forthistutorial,youwilluseEnglishunits,soclickCanceltoexitthisdialogboxwithoutmakingchanges.

Drawing the Flowsheet AsdescribedinChapter5,creatingaflowsheetisamatterofplacingUnitOpiconsonthescreen,connectingthemwithstreams,andthenaddingvariousgraphicalobjectstoenhancethedrawing.

Placing UnitOps 1. Startyourflowsheetbyaddinganicontorepresenttheinitialfeedstream.In

theAllUnitOpspalette,findtheFeedicon,whichisanarrowpointingtotheright.ClicktheFeedicon,thenclickintheworkspacewhereyouwanttoplacethefeedstream.Whenthefeedstreamarrowappears,goaheadandturnofftheFeeddrawingtoolbyright‐clickinganyblankareaoftheworkspace.

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Note:AtanytimeafterdrawingafeedstreamoranyUnitOpicon,youcanclicktheicontodisplaytheblacksizinghandlesateachcorner.Withtheiconselectedthisway,youcanclicktheiconanddragittoanewlocation,orclickanysizinghandleanddragitoutwardorinwardtoresizetheicon.

2. Nowplacethetwoheatexchangersontheflowsheet.OntheAllUnitOpspalette,pointtotheHeatExchangericonuntilitspop‐uplabelappears(seeFigure11‐02).

Figure 11-02: The pop-up label that identifies the UnitOp icon

3. ClickthelowerrightcorneroftheHeatExchangericon,ontheblacktriangle,toopenthesub‐palette.Selectthetwo‐sidedheatexchangericonasshowninFigure11‐03.Theiconthatyouclickedinthesub‐palettenowappearsonthemainAllUnitOpspalettetorepresenttheHeatExchangerUnitOp.

Figure 11-03: Selecting the two-sided heat exchanger icon

4. Pointthemousecursoraboutaninchtotherightofthefeediconandclick.Atwo‐sidedheatexchangericonappearsontheflowsheetwhereyouclicked.

Note:TheUnitOpIDlabelof1shouldappearinacirclenexttotheheatexchangericon.ForeachsubsequentUnitOpthatyoudraw,CHEMCADwillassignanordinalnumberinthisway,touniquelyidentifyeachpieceofequipmentontheflowsheet.

5. ReturntotheAllUnitOpspalette,andagainclicktheHeatExchangericon’sblacktriangle.Toswitchfromthetwo‐sidedmodeltoasingle‐sidedmodel,you’llneedtoselecttheappropriateicon(seeFigure11‐04)fromtheHeatExchangersub‐palette.

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Figure 11-04: Switching to the single-sided heat exchanger icon

6. Againmovethecursortotheworkspace,thistimeaboutaninchtotherightofthefirstheatexchanger,andclickthemouse.Asingle‐sidedheatexchangericonappearsontheflowsheetwhereyouclicked.YourflowsheetsofarshouldlooksomethinglikeFigure11‐05.

Figure 11-05: The flowsheet so far

7. AddtheFlashandValveUnitOpiconstoyourflowsheet,usingthestandardicons.

8. Forthecondensatestabilizer,useadistillationcolumn.MultipledistillationUnitOpsareavailable,butfornow,assumethatthemoduleyouwanttouseistherigorousdistillationmodelcalledTower.You’llneedaTowericonwithtraysandareboilerbutnocondenser;thisisdifferentfromthedefaultTowerUnitOpicon.ClickthelowerrightcorneroftheTowericon’sboxtoviewthesub‐palette,thenselecttheiconshowninFigure11‐06.

Figure 11-06: Selecting the appropriate Tower UnitOp icon

9. NowthatyouhaveselectedtheappropriateTowericon,addthisUnitOptotheflowsheet.

10. PlacethreeProducticonsontheflowsheet,oneforeachproductstream.Youcanquicklyplacethreeidenticalicons,simplybyclickingrepeatedlyina

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slightlydifferentlocation.Whenyou’veclickedtocreatethethirdProducticon,right‐clicktoturnofftheProductdrawingtool.

Drawing Streams NowthatalloftheUnitOpsareinplace,selecttheStreamtoolandconnectthevariousUnitOpsasappropriate.RememberthateachstreammuststartataredoutletpointontheupstreamUnitOp,andendatablueinletpointonthedownstreamUnitOp.

Toavoidhavingtore‐selecttheStreamtooleachtime,makesurethatassoonasyouclicktocompleteonestream,youmovethecursortothenextlocationandclicktostartthenextstream.

Drawstreamstoconnectthefollowing:

• Feedstreamtofirstheatexchanger’sleft‐sideinlet

• Firstheatexchanger’sright‐sideoutlettosecondheatexchanger’sleft‐sideinlet

• Secondheatexchanger’sright‐sideoutlettoflashinletofyourchoice

• Flashtopoutlettofirstheatexchanger’stopinlet

• Firstheatexchanger’sbottomoutlettonearestproducticon

• Flashbottomoutlettovalveinlet

• Valveoutlettotowerinletofyourchoice

• Towertopoutlettonearestproducticon

• Towerbottomreboileroutlettonearestproducticon

Asyoudrawstreams,CHEMCADassignsstreamIDs,justasitassignedUnitOpIDswhenyoucreatedthoseitems.ThelabelsforstreamIDsaredisplayedinsquares,todistinguishthemfromtheUnitOpIDsdisplayedincircles.

Selecting Components Nowyouneedtoidentifythecomponentstobeusedinthissimulation.StartbyselectingThermophysical>SelectComponents.ThisbringsuptheSelectComponentsdialogbox,showninFigure11‐07.

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Figure 11-07: The Select Components dialog box

Forthisexample,you’llchoosecomponentsfromthestandardCHEMCADdatabase.IntheSelectComponentsdialogbox,findandaddeachneededcomponent,beginningwithnitrogen:

1. IntheSearchbox,starttypingthewordnitrogen.

2. Assoonasyou’vetypedni,youshouldsee46–Nitrogen–N2highlightedintheAvailableComponentsarea.Clicktherightarrowbuttontoaddnitrogentoyoursimulation.

3. UsethescrollbarintheAvailableComponentsareatoreturntothetopofthecomponentlist.

4. Holddownthe[CTRL]keyonyourkeyboardasyouclickeachofthefollowingcomponentsinturn:

• 2 Methane

• 3 Ethane

• 4 Propane

• 5 I‐Butane

• 6 N‐Butane

5. Clicktherightarrowbutton,locatedtotherightoftheAvailableComponentsarea,toaddalloftheselectedcomponentstoyoursimulation.

6. Nowaddthefollowingcomponentsbydouble‐clickingeachoneinturn:

• 7 I‐Pentane

• 8 N‐Pentane

• 10 N‐Hexane

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Figure 11-08: The completed Select Components dialog box

7. SaveyourcomponentselectionsbyclickingOK.

Selecting Thermodynamic Options Assoonasyouhavefinishedcomponentselection,theThermodynamicsWizardappears.Thistoolcansuggestthermodynamicsoptionstousewiththissimulation.

CHEMCAD’sThermodynamicsWizardworkslikethis:

1. First,itlooksatthecomponentlistanddecideswhatgeneraltypeofmodelisrequired,i.e.,equation‐of‐state,activitymodel,etc.

2. Second,itlooksattemperatureandpressurerangesthatyouprovideanddecideswhichequationwithinagivencategoryisbestatthelimitsofthoseranges.

3. Ifthemethodisanactivitymodel,theprogramthenlooksattheBIPdatabasetoseewhichmodelhasthemostdatasetsforthecurrentproblem.ItthencalculatesthefractionalcompletenessoftheBIPmatrix.IfthatfractionisgreaterthantheBIPthresholdparameter,itusesthechosenactivitymethod;ifnot,itusesUNIFAC.

TheThermodynamicsWizardisnoreplacementforengineeringjudgment.Thistoolusesanalgorithmbasedongeneralrules,andisthereforefallible.Thesuggestedmodelmightnotalwaysbethebestmodelforthesystem.

Selectingthermodynamicoptionsbasicallymeansselectingamodelormethodforcalculatingvapor‐liquid(orvapor‐liquid‐liquid)phaseequilibrium(calledtheK‐valuemodel)andselectingamethodormodelforcalculatingtheheatbalance(calledtheenthalpymodel).ThecommandsfortheseselectionsarelocatedontheThermophysicalmenu.

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thePeng‐RobinsonmethodforboththeK‐valueandenthalpycalculations.Followthesestepstoselectyourthermophysicaloptions:

1. AcceptthedefaulttemperatureandpressurerangesintheThermodynamicsWizardandclickOK.

2. ClickOKagaintoacceptthewizard’ssuggestedmethodofSRK.

3. WhentheThermodynamicSettingsdialogboxopens,findtheGlobalK‐ValueModelselection,intheupperleftcorneroftheK‐ValueModelstab.ThecurrentsettingisSRK,butforthepurposesofthetutorial,you’llneedtoselectthePeng‐Robinsonmodel.ClickthedownarrowattherightendoftheselectionboxtoviewalonglistofK‐valuechoices,thenclickPeng‐Robinson.

Figure 11-09: The new K-value selection in the Thermodynamic Settings dialog box

4. NowclicktheEnthalpyModelstab.ThePeng‐RobinsonmethodhasalreadybeenenteredastheGlobalEnthalpyModelselection;thiswasdoneautomaticallybecauseyouchosePeng‐RobinsonasyourK‐valuemethod.Whileyoudohavetheoptiontooverridethischoice,inthiscaseyou’llneedtokeepthePeng‐Robinsonmodel;leaveallsettingsastheyareandclickOKtoreturntothemainCHEMCADworkspace.

Forthepurposeofthistutorial,thethermodynamicselectionsarenowcomplete.

Note:WhileyouarenotrequiredtousetheThermodynamicsWizard,youshouldknowhowtouseit,ifonlyasastartingpointforyoursimulations.YoucanrevisitthewizardatanytimebyselectingThermophysical>ThermodynamicsWizard.

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Defining the Feed Streams Nowit’stimetodefineyoursimulation’sfeedstream.Thereareseveralwaysthatyoucandothis,butthequickestandmostefficientwaytodefineasinglestreamistodouble‐clickthestreamline.

Note:Beforeyouproceed,verifythatyourengineeringunitsaresettoEnglishintheEngineeringUnitSelectiondialogbox,asdescribedearlierinthistutorial.

Double‐clickthelineforstream1,yourfeedstream,tobringuptheEditStreamsdialogbox.

Figure 11-10: The Edit Streams dialog box

Youwillspecifythefeedstreamaccordingtothefollowingrules:

• TheStreamNamefieldcandisplayastreamlabelofupto16alphanumericcharacters.Thisfieldisoptional,andyoucanuseanylabelyoulike.

• Thenextfourfields—TempF,Prespsia,VaporFraction,andEnthalpyMMBtu/h—arethethermodynamicpropertiesofthestream.AccordingtotheGibbsPhaseRule,onceamixture’scompositionisgiven,specifyinganytwoofthesefourthermodynamicpropertieswilldefinetheothertwo.Assuch,definingthecomposition,temperature,andpressureforamixtureuniquelydefinesitsvaporfractionandenthalpy.Alternatively,definingthecomposition,pressure,andenthalpywilluniquelydefinethemixture’stemperatureandvaporfraction.

Sinceenthalpiesarecalculatedrelativetoadatum,thecalculationofanygivenstreamenthalpyisaninvolvedprocesswhichispronetoerrors.Forthisreason,CHEMCADdoesnotpermityoutoenterstreamenthalpyasaconstraint.

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Inadditiontodefiningthestream’scomposition,youmustdefineexactlytwoofthefollowingproperties:temperature,pressure,andvaporfraction.Thetwovariablesthatyouspecifywilldisplayasredtext,whilethethirdvariableandthevalueenthalpywillbedisplayedinblackwhenyouflashthestream.

Anexceptiontothisconventionallowsyoutoaddheatdutywithanemptystream.Ifyouspecifyatotalcomponentflowrateofzero,youmayspecifyatemperature,pressure,andenthalpyrate.Astreamdefinedthiswayistreatedasaheatduty,andisaddedtotheheatbalanceoftheunit.Thetemperatureandpressurearearbitraryforthissituation.

• TheTotalflowunitandCompunitfieldsworktogethertoprovideavarietyofwaystodefinestreamcompositions.Iftheselectedcompunitismole,mass,orvolumefraction(eithergloballyorlocally),thentheTotalflowunitselectionisavailable.Iftheselectedcompunitisafloworamountoption,thenthetotalflowratebecomesthesumofthecomponentflowrates,andtheTotalflowunitselectionisnotavailable.

• IftheCompunitfieldselectionisanamountflowunit(asopposedtoafractionalunit),thenthecomponentflowratevaluesareautomaticallyaddedasyouenterthem.ThecurrentsumisdisplayedintheTotalflowfield.

• YoucanclicktheFlashbuttonatanytimetoperformaflashcalculationusingthecurrentlyspecifiedcompositionandthermodynamicproperties.Thisenablesyoutoobtainflashcalculationsquicklyandwithoutleavingthedialogbox.

• Fractionsthatdonotaddupto1.0areautomaticallynormalizedwhenyoueitherclickFlashorexitthedialogbox.

Withtheserulesandbehaviorsinmind,enterthedataforyourfeedstream.

1. Beginwiththestreamtemperature.ClicktheTempFlabel,thenclicktheemptyfieldtoitsright.Type75andthenpressthedownarrowkeyonyourkeyboardtocontinue.

2. Type200inthePrespsiafield,thenpressthedownarrowkeyseveraltimesuntilyouarriveattheNitrogenfield.

Note:Beforeyoucontinue,verifythattheCompunitfieldissettolbmol/h.

3. Type100.19intheNitrogenfield,andtheninsimilarfashion,typethefollowingnumbersinthecorrespondingfields:

• Methane:4505.48

• Ethane:514

• Propane:214

• I‐Butane:19.2

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• N‐Butane:18.18

• I‐Pentane:26.4

• N‐Pentane:14

• N‐Hexane:14

4. ClickOKtosavethisstreaminformationandreturntothemainCHEMCADworkspace.

Enter UnitOp Parameters Nowthatyou’vespecifiedyourfeedstreamproperties,it’stimetospecifythecharacteristicsofyourUnitOps.ThefollowingsectionsaddresseachUnitOpinturn.

Note:Aswithstreams,youcanenterUnitOpparametersinvariousways,butforthepurposesofthistutorial,we’llusethequickestandsimplestmethod,double‐clickingeachUnitOptoaccessitsspecificationdialogbox.

First Heat Exchanger 1. Double‐clicktheflowsheeticonforthefirstheatexchanger.TheHeat

Exchangerdialogboxwillappear,asshowninFigure11‐11.

Figure 11-11: The Heat Exchanger dialog box

2. AswithmanytypesofUnitOps,thedialogboxforspecifyingaheatexchangerconsistsofmultipletabbedpages.YoucanbrowsethroughtheSpecifications,Misc.Settings,andCostEstimationstabsbyclickingeachtabinturn.

3. Thepressuredroponbothsidesofthisexchangeris5psi.OntheSpecificationstab,findthePressureDropsarea,andenter5inboththeStream1andStream4fields.

4. Thefirststreamoutletmustbeatit*dewpoint,soyou’llneedtospecifyanoutletvaporpressureof1.InthefieldnexttoVaporfractionstream2,enter1.

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5. ClickOKtosavethespecificationsforthisUnitOpandclosethedialogbox.

Second Heat Exchanger 1. Double‐clicktheflowsheeticonforthesecondheatexchanger.TheSimple

HeatExchangerdialogboxwillappear.

2. Theoutlettemperaturefromthisheatexchangerwilldeterminehowmuchoftheliquidisremovedintheflashdrum.This,inturn,willdeterminethecricondenthermdewpointoftheproductgas.Therefore,thisspecificationisoneofthekeyparametersofthisprocess.Asafirstattempt,useanoutlettemperatureof‐5°F.Enter5inthePressuredropfieldand–5intheTemperatureofstream3field.

Figure 11-12: Setting up the second heat exchanger

3. ClickOKtosavethespecificationsforthisUnitOpandclosethedialogbox.

Flash Drum Inthissimulation,theflashdrumisavapor‐liquidseparatorandrequiresnospecification.

Valve 1. Double‐clickthevalveflowsheeticontobringuptheValvedialogbox.

2. Theoutletpressureforthisunitis125psia,soenter125intheOutletpressurefield.

3. ClickOKtosavethespecificationsforthisUnitOpandclosethedialogbox.

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Stabilizer Tower 1. Double‐clickthetowericontoopentheTOWRDistillationColumndialog

box.NotethatthesettingsforthisUnitOparedividedintofivetabs.

2. OntheGeneraltab,enterthefollowing:

• Colmpressdrop:5

• No.ofstages:12

• Feedtrayforstream:1

3. ClicktheSpecificationstabtomakespecificationsforthecolumn.Thiscolumnhasnocondenserorsidestreams,soyouwillonlybemakingspecificationsforthereboiler.DropdownthelistofoptionsforSelectreboilermode,andselectthemodecalled4Bottommoleflowrate.

4. Nowyouneedtospecifythenumericvalueofthereboilerflowrate.IntheSpecificationfieldimmediatelytotherightofyourreboilermodeselection,enteravalueof30.

5. ClickOKtosavethespecificationsforthisUnitOpandreturntothemainCHEMCADworkspace.

Allofthedataentryfortheflowsheetisnowcomplete.Beforeyoucontinue,youshouldsaveyoursimulation.Asnotedearlier,it’sagoodideatodothisperiodicallyasyoubuildthesimulation,butcompletionofyourUnitOpspecificationsisaparticularlygoodtimetostopandsave.

Run the Simulation Torunthesimulation,clicktheRunAllbuttononthetoolbar.

TheprogramfirstrechecksthedataandlistsanyerrorsandwarningsintheMessagespane.Inthiscase,youshouldhavenoerrors,althoughyouwillhavewarningsaboutestimatesyouhavenotgiven.YoucanignorethesewarningsandproceedbyclickingYes.Thecalculationwillthenproceed.

Whentherunfinishes,amessageboxappears:Recyclecalculationhasconverged.Toclosethisdialogboxandclearthescreen,clickOK.

Review the Results and Print as Needed Beforerunningandprintingreportsandplots,youshouldreviewthesimulationtoverifywhetheritmeetsthedesigncriteriasetoutforthisproblem.

Checking the Cricondentherm Dewpoint Ifyouhavechosentheproperoutlettemperatureforthesecondheatexchanger,thecricondenthermdewpointfortheproductgasstream(stream5)willbe20°Forless.Thecricondenthermdewpoint,youwillrecall,isthehighestdewpointtemperatureamixturewilleverseeatanypressure.Thesimplestwaytoidentifythehighest

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dewpointtemperatureoftheproductgasistoplotallofthedewpointtemperaturesoftheproductgas,i.e.,toplotaphaseenvelope.

1. StartwiththePlotmenu,whichprovidesaccesstoalltypesofgraphicalreports.SelectPlot>PhaseEnvelopes.IntheSelectStreamsdialogbox,specifystream5,thenclickOKtobringupthePhaseEnvelopedialogbox.

2. Noentriesarerequiredonthisscreensinceyouonlyneedtolookatthedewpointline,buttomaketheplotmoreinteresting,displaythe0.25andthe0.5vaporfractionlinesinadditiontothenormalphaseenvelopeboundaries.CompletethedialogboxasshowninFigure11‐13.

Figure 11-13: Plotting vapor fraction lines along with the cricondentherm dewpoint

3. ClickOKtocontinue.CHEMCADperformtherequiredflashcalculationstogeneratethespecifiedphaseenvelope.Phaseenveloperesultsareproducedintwoformats:

• Anumericaltabulation(table)ofthetemperature,pressure,vaporfraction,vaporcompressibilityfactor,andtheliquidcompressibilityfactor

• Agraphicalplotoftemperatureandpressureforeachvaporfractionlinerequested

Thetabularresultswillappearfirst;sinceyou’reinterestedinthegraphicalresults,closethewindowdisplayingthetable.ThescreenwillnowlooksimilartoFigure11‐14.NotethatthemainCHEMCADbuttontoolbarislargelyunavailablenow,andthemenuitemshavechanged.

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Figure 11-14: Phase envelope plot results

4. Todeterminewhetherthecricondenthermdewpointofstream5is20°Forless,zoominonthefarrightportionofthedewpointcurve.Todothis,clickanddragwithyourmousetohighlightthatportionofthegraph—approximately400to1000psiand0to30°F.Whenyoureleasethemousebutton,theselectedareawillfilltheentireplotwindow,givingyouaclose‐upviewofspecificdatapoints.

Figure 11-15: Zoomed-in plot results

5. Asthisviewshows,thehighestdewpointofthismixtureisalittlelessthan20°F,sothecricondenthermdewpointisindeedwithinthetargetproductgasspecification.Right‐clickthemouseanywhereintheplotwindowtoreturntothefullplotview.

6. Toprintthephaseenvelopeplot,clickthePrintbuttonandthenfollowanypromptsfromyourprinter.

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7. YoucanalsotrythefollowingtopracticeworkingwithplotsinCHEMCAD:

• Editthetextoftheplottitle(inthiscase,PhaseEnvelopeforStream5)orthegraphaxislabelsbyselectingChart>EditTitles.IntheChartTitlesdialogbox,makeanydesiredchangesandthenclickOKtoviewtheupdatedchart.

• SelectChart>EdittoopentheChartExplorer,whichprovidesaccesstosettingsforcolor,size,layout,andvariousotheraspectsoftheplotpresentation.

8. Returntothemainsimulationwindowbyclickingthecharttab’sredxbutton,orleavethechartwindowopenandclickthemainsimulationtabatthebottomleftoftheCHEMCADworkspace.

Checking the Bottoms Stream Purity Thisproblemalsorequiresthatthepercentofpropaneinstream9be1%.Youcanchecktoseeifyou’veachievedthisspecificationbycheckingthestreamcompositionreportavailableontheReportmenu.First,though,you’llneedtosettheflowunitsforthestreamcomposition.

1. SelectReport>SetFlowUnitstobringuptheViewFlowRateUnitdialogbox.ClicktheMole%buttonandthenclickOKtoapplythisselectionandclosethedialogbox.

2. NowselectReport>StreamCompositions>SelectStreams.IntheSelectStreamsdialogbox,type9andthenclickOKtocontinue.

3. Theresultingtabulardatawindowshowsthatpropaneisgreaterthanthe1%specification(seeFigure11‐16).Thismeansthattheinitialdesignistooconservative.Tocorrectthis,youcangobackandre‐specifythecolumntoproduceprecisely1%propaneinthebottom.

Figure 11-16: Stream Composition report for stream 9

4. Returntothemainsimulationwindowbyclickingthereporttab’sredxbutton.

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Re-running the Simulation Youcannowre‐runthestabilizer,specifyingthatyouwant1%propaneinthebottom.

1. Double‐clicktheTowerUnitOptobringuptheTOWRDistillationColumndialogboxforthestabilizer.

2. ClicktheSpecificationstab.Youneedtochangethereboilermodefrom4Bottommoleflowratetoapurityspecification.ClicktheSelectreboilersmodedrop‐downlistandselect6Bottomcomponentmolefraction.

3. Withthischangeofmode,youneedtospecifythedesiredpurityandthecomponentforwhichitisbeingspecified.IntheSpecificationfield,enter.01.IntheComponentdrop‐downlist,select4Propane.

4. ClickOKtosaveyourchangesandreturntothemainCHEMCADworkspace.

5. Youcannowre‐runthecalculationsforthecondensatestabilizer.WhileyoucouldaccomplishthisusingtheRunAllcommand,it’smoreefficienttore‐runonlytheUnitOpthatyouhavechanged.Thequickestwaytodothisistoright‐clicktheUnitOpiconontheflowsheetandselectRunthisUnitOp.RuntheTowerUnitOpusingthismethod.

AssoonasyouseetheRunfinishedmessageinthebottomleftcorneroftheCHEMCADwindow,youcancheckonthepropanecontentofthebottomstream.You’vealreadyseenhowtogetadetailedStreamCompositionreport;youcanalsousetheFlowsheetQuickviewfeaturetogetinstantstreaminformationwithoutevenclickingthemouse.

FindtheFlowsheetQuickviewbuttonatthefarrightendoftheCHEMCADtoolbar.Ifthisbuttonisnotcurrentlyactivated(withathinoutlineandawhitebuttonbackground),clickthebuttontoturnonthisfeature.

Figure 11-17: Turning on the Flowsheet Quickview feature

WithFlowsheetQuickviewturnedon,pointyourmousecursoratstream9ontheflowsheet.Afteramoment,apop‐upinformationwindowappears,listingstreampropertiesincludingcomposition.Thevalueforpropaneshouldbe1orverycloseto1,asshowninFigure11‐18.

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Figure 11-18: Checking the propane content of stream 9

Nowthatyouhaveachievedtheresultsthatyousetouttoproduce,savethesimulation,usingeitherFile>SaveortheSavebuttononthetoolbar.

Producing a Text Report TheReportmenuoffersabroadarrayoftextreports,asdescribedinChapter8,OutputandReports.Forthepurposeofthistutorial,assumethatyouwanttoviewandprintoutareportwiththefollowinginformation:

• ForStreams1,5,8,and9,thestreamcompositioninmassflowratesandmolefractions,aswellasthedefaultstreamproperties

• Theequipmentsummariesforeverypieceofequipmentintheflowsheet

• Towertrayprofilesforthecondensatestabilizer

Becauseyouwantareportwithabroadrangeofinformationaboutyoursimulation,usetheConsolidatedReportoption.

1. SelectReport>ConsolidatedReporttobringuptheReportWriterdialogbox.Fromhere,youcanspecifyexactlywhatyouwanttoincludeinyourreport.

2. Startbyspecifyingwhichstreamsyouwanttoinclude.ClicktheSelectStreams&UnitOpstabandchecktheSelectStreams(OverrideDefaults)box.Thisprovidesaccesstotheotherstreamselectionsettings.

3. ClicktheSelectFromFlowsheetbutton,whichbringsuptheSelectStreamsdialogbox.Eithertypeinthenumbers1,5,8,and9orclickthecorrespondingstreamsontheflowsheettoaddthenumbers.ClickOKtoreturntotheSelectStreams&UnitOpstab.

4. TheAllUnitOpsoptionisselectedbydefault.Inthiscase,youdowanttoincludeallUnitOpsinthereport,soleavethesettingsontherightsideofthetabastheyare.

5. ClickStreamPropertiesintheleftcolumntoviewthestreampropertiesoptions.ThenclickthePropertiestab,whichlistsacollapsedlistofallavailablestreamproperties.YoucanchecktheStreamProperties(Override

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Defaults)boxtoexplorethevariouspropertiesandseewhichonesareselected,butforthepurposeofthistutorial,usethedefaultsettingsonthistab.

6. ClickStreamCompositionintheleftcolumntoviewthestreamcompositionoptions.ThenclicktheStreamCompositionstab,whichlistsavailableandselectedflowoptions.ClicktheStreamComposition(OverrideDefaults)boxtogainaccesstotheseoptions.KeeptheMassFlowRateoption,anddouble‐clickMoleFractionsintheleftcolumntoaddthisoptiontothelistofselectedflowoptionsatright.

7. Finally,verifythattheTrayprofilereportsectionisincludedintheConsolidatedReport.Youcanalsodeleteanyreportsectionsthatyoudon’tneed,andre‐orderthedesiredsectionstosuityourneeds.

8. ClickGeneratetorunanddisplaythereport.Youcannowreviewtheresults,re‐runifdesired,savethereportforlateruse,andprintthereportasneeded.

9. Whenyoufinishreviewingandworkingwiththereport,clickCanceltoclosetheReportWriterdialogboxandreturntothemainCHEMCADworkspace.

Generating a Process Flow Diagram Asyouknow,thestreamsandUnitOpsonaflowsheetonlytellpartofthestoryofyourprocess.Fortunately,CHEMCADprovidesmanyfeaturestohelpyouaddtheextracontentneededtoturnaplainflowsheetintoafull‐fledgedprocessflowdiagram(PFD)forotherstoreviewanduse.

ToprepareyourfinishedsimulationtobeprintedasaPFD,you’lladdastreamdataboxcontainingtheheatandmaterialbalancefortheentireflowsheet.You’llplacethatdataboxunderneaththeflowsheetdiagramandthenaddatitletotheareaabovetheflowsheet.Finally,youwillcreateanewlayerinthissimulationandassignthePFD‐specificitemstothatlayer,sothatyoucanhidethemfromviewwhenworkinganddisplaythemagainquicklyforprinting.

FollowthesestepstoprepareandprintthePFD:

1. Startbyzoomingouttogiveyourselfmoreworkspace.Ifyouuseamousethatisequippedwithascrollwheelbetweenthemousebuttons,youcanpointatthecenterofyourflowsheetandrollthescrollwheeldownafewclickstozoomout.Ifyoudon’thaveascrollwheel,youcanselectView>ZoomOptions>Out.

2. Nowplacethedataboxcontainingtheheatandmaterialbalanceforthisflowsheet.SelectFormat>AddStreamBoxtobringuptheSelectStreamsdialogbox.Becauseyouwanttoincludeallstreams,leavethesettingsthewaytheyareandclickOKtocontinue.

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3. IntheDataboxPropertyOptionsdialogbox,reviewthedefaultselections,indicatedbycheckedboxes.Forthepurposesofthistutorial,leavetheselectionsastheyareandclickOKtocontinue.

4. IntheDataboxSettingsdialogbox,youcanindicatewhethertousedividinglineswithinthebox.AcceptthedefaultsettingshereandclickOK.

5. ThestreamdataboxappearsintheupperleftcorneroftheCHEMCADworkspace,butyouwanttoplaceitbelowtheflowsheet.Thedataboxisalreadyselected,sopointyourmousecursoranywhereinsidetheboxandthenclickanddragtorepositionit.Movethedataboxuntilitiscenteredbelowtheflowsheetdiagram.

Note:Youcanalsoresizeadataboxbyselectingtheboxandthenclickinganddragginganyofthesizinghandlesatthecorners.Dragintomakethedataboxsmaller,orouttomakeitlarger;noticethatthetextadjustsinsizetofitthebox.

6. NowplaceatitleonthePFDtodescribetheprocess.IntheAllUnitOpsorDrawingSymbolspalette,findandselecttheTexttool.

7. Movethecursortoapointsomewhereabovetheflowsheetandclicktheprimarymousebutton.Averticalinsertionpointlinebeginstoblinkwhereyouhaveclicked.TypethewordsCondensateStabilizerPFDandthenclickanyblankspotontheCHEMCADworkspace.

8. Tomakethistextlarger,selectFormat>Font.IntheFontdialogbox,changetheSizesettingto18andthenclickOK.

9. Clickanddragthenewheadingtocenteritabovetheflowsheetdiagram.

10. Finally,setupalayerforyourstreamdataboxandtitlesothatyoucandisplayorhidetheseitemsasasingleunit.AtthebottomoftheCHEMCADExplorerpane,clicktheSimulationtab,thenright‐clicktheLayersitemandselectNew.

Figure 11-19: Creating a new layer using the CHEMCAD Explorer

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11. IntheNewLayerdialogbox,typeanameforthenewlayer.Forthisexample,namethelayerPFDElements,thenclickOKtocreatethelayer.

12. NowaddthetwoPFDelementstothelayer.Clickthetitlethatyouplacedabovetheflowsheet,thenholddownthe[SHIFT]keyandclickinsidethestreamdataboxthatyouplacedbelowtheflowsheet.Bothitemsshouldnowbeselected,withsmallblackboxesvisibleineachcorner.

13. IntheCHEMCADExplorerpane,double‐clicktheLayersitemtoexpandit,thenright‐clickonyournewlycreatedPFDElementslayerandclickAddSelected.

Figure 11-20: Adding selected items to your new layer

14. ThetitleandstreamdataboxarenowpartofthePFDElementslayer.Thislayerisvisible,asindicatedbythegreencheckmarkonitsicon.ClickthisiconorthenamePFDElementstotogglethelayeroff,causingthetitleandstreamdataboxtodisappear;thenclickagaintomakethemvisible.

15. WiththePFDelementsvisible,selectView>ZoomOptions>ZoomtoFit.Thiscustom‐fitstheentirePFDtotheavailableworkspaceforoptimalprinting.Toprint,youcaneitherselectFile>PrintorclickthePrintbuttononthemainCHEMCADtoolbar.Followthepromptsforyourprintertocompletetheprintingprocess.

16. TocloseCHEMCAD,selectFile>Close,orclicktheClosebuttonintheupperrightcorneroftheCHEMCADwindow.ClickYesatthemessageaskingwhetheryouwanttoexitCHEMCAD,thenclickYesagaintosavechangestothesimulation.

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CC-THERM Tutorial Thistutorialwalksyouthroughtheratingofaheatexchanger.Theexampleyou’llworkwithisthecondensatestabilizerexampledescribedintheCC‐STEADYSTATEtutorial,whichlookslikethis:

Whileit’srecommendedthatanewCHEMCADuserbuildthissimulationfrom

thegrounduptogainproficiencywiththesoftware,aready‐madeexamplecalledCHEMCADTutorial.CC6isalsoavailable.ThisfileislocatedbydefaultinthedirectorycalledMyDocuments\MySimulations\Examples\Tutorials.

Yourobjectiveistoratethefirstheatexchangerinthisflowsheet.Theequipmentyou’reworkingwithisacountercurrentgas/gasheatexchangerwiththefollowinggeometryanddimensions:

• TEMAclass=R

• TEMAtype=BEM

• Foulingfactors=0.001bothsides

• Shellinsidediameter=27”

• Numberoftubes=646

• Tubeoutsidediameter=0.75”

• Tubewallthickness=0.065”

• Tubelength=20’

• Tubepattern=rotatedtriangular(60°)

• Tubepitch=0.9375”

• Baffles:10,equallyspaced

• Baffletype=singlesegmental

• Bafflecut=35%(diameter)

• Impingementplatepresent

• Shell‐sidenozzles=one,12”

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• Tube‐sidenozzles=one,12”

• BaffletoshellI.D.clearance=0.3125”(diameter)

• ShellI.D.toOTLclearance=0.35433”(diameter)

• Tubetobaffleholeclearance=0.035”(diameter)

• Spaceattopofbundle=2.8”

• Carbonsteeltubes;allothermaterialsA‐285‐C

• 5rowspersealingstrip

Overview of the Heat Exchanger Sizing Process TheCC‐THERMmoduleenablesyoutogenerateheatcurvesandspecifyheatexchangers.Thisprocessinvolvesthefollowingsteps:

1. Identifythetube‐sidestream.

2. Generateandfinalizetheheatcurveandpropertiesonbothsidesoftheexchanger.

3. Definegeneralinformationabouttheexchanger.

4. Specifyanydesiredtubedata.

5. Specifyanydesiredshelldata.

6. Specifyanydesiredbaffledata.

7. Specifyanydesirednozzledata.

8. Specifyanydesiredspecificclearances.

9. Specifythematerialsusedintheconstructionoftheheatexchanger.

10. Specifyanydesiredmiscellaneousdata.

11. Runthesizingcalculations.

12. Reviewresultsandcreateplotsasneeded.

Identify the Tube-side Stream OncethesimulationiscompleteinCC‐STEADYSTATE,youcanstartsizingthefirstheatexchangerbyidentifyingthetube‐sidestream:

1. ClickonthefirstheatexchangericonandthenselectSizing>HeatExchangers>Shell&Tube.

2. Amessageboxpromptsyoutoselectastreamenteringtheexchanger’stubeside.ClickOKtocontinue.

3. AttheSelectStreamsdialogbox,eithertype1orclickstream1ontheflowsheet,thenclickOK.

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4. CC‐THERMdisplaysdataforallfourstreamsaroundtheexchangerinaseparatereportwindow.Revieworprintthedataasneededandthenclosethereportwindow.

Generate the Heat Curve Oncethetube‐sidestreamisidentified,CC‐THERMpromptsyouthroughthesetupoftheheatcurve.TheHeatCurveParametersdialogboxdisplaysassoonasyouclosethereportfromthepreviousstep.

Figure 11-21: The Heat Curve Parameters dialog box

Toaccountforthechangeinphysicalpropertiesacrosstheheatexchanger,CC‐THERMdividestheanalysisintozones.Thesezonesarethermodynamicsegmentsbasedonequaltemperaturechangesorequalenthalpyincrements.Therearetwooptionstochoosefrom:

• Equalenthalpy:Incrementsofequalenthalpychange

• Bubble‐dewpoint:Incrementsofequalenthalpychangebetweenthedewandbubblepoints,withseparatezonesforsuperheatingandsubcoolingifpresent

Thedefaultsettingisthebubble‐dewpointoption.Foreithersegmentationmethod,youcanalsodecidehowmanyzonestocalculatefortheexchanger.Themorezonesyouspecify,themoreaccuratethecalculationswillbe,butcalculationswillalsobeslower.Theindustrystandardis10zones(11points),whichisthedefaultentryhere,butyoucanselectanynumberbymakinganentryintheNumberofcuttingpointsfield.Bearinmindthatthenumberofpointsequalsthenumberofzonesplusone.

Forthistutorial,leaveallthedefaultsettingsandclickOKtocontinue.CC‐THERMcalculatesthe11pointsneededfortheheatcurveanddisplaysaplotliketheoneshowninFigure11‐22.

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Figure 11-22: Heat curve plot for first heat exchanger

Thisplotenablesyoutoinspectthecalculatedheatcurveforanyobviousproblemsinthesetupoftheanalysis.ClickOKtoclosethiswindowandcontinue.

Define General Specifications ThenextdialogboxtoappeariscalledGeneralSpecifications.Here,youcanprovidebasicinformationgoverningheatexchangercalculations,suchasprocesstype,allowablepressuredrop,foulingfactor,TEMAclassandtype,andsoforth.

Thisdialogboxhastwotabs,andmostofthefieldsonbothtabshavedefaultsettings.ThetabthatinitiallydisplaysiscalledGeneralInformation,anditincludesthefollowingsettings:

• Calculationmode:Thisentrydetermineswhetheryouaredesigningorratingaheatexchanger.UsethedefaultsettingofRating.

• TEMAclass/standard:Thisentryspecifiestheexchanger’sTEMAclass,whichisprimarilyafunctionofitsmechanicaldetails.UsethedefaultsettingofTEMAR.

• Orientation:Thisentryspecifieswhethertheexchangerismountedhorizontallyorvertically.UsethedefaultsettingofHorizontal.

• TEMAfrontendhead,TEMAshelltype,andTEMArearendhead:Toestablishthebasicconfigurationoftheexchanger,youmustdefinethesecharacteristicsoftheexchangeraccordingtoTEMAdesignations.Thesimplestandmostcommonkindofexchangerisafixedtubesheet,orBEM,TEMAtype.SelectB‐Bonnetforthefronthead,E‐OnePassfortheshelltype,andM‐FixedTubesheet(Bhead)fortherearhead.

• Processtype:Insomecases,youmustidentifytheprocesstype,forexampleinthecaseofpoolboilingorfalling‐filmcondensation.Inthiscase,usethe

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defaultselectionofSensibleFlowforbothtubesideandshellside,asthereisnophasechangeoneithersideoftheexchanger.

• Foulingfactor‐Toallowforfoulingontheinsideandoutsideofthetube,youcanenterfoulingfactors.Usethedefaultsettingof0.001(Englishunits)onbothsides.

OntheModelingMethodstab,youcanselecttheformulastobeusedincertainaspectsoftheheatexchangercalculations.Forthepurposesofthistutorial,usetheprogram’sdefaultselections.ClickOKtocontinue.

Set Tube Specifications TheTubeSpecificationsdialogboxnowappears,populatedwithdefaultentriesinallfields.

Figure 11-23: The Tube Specifications dialog box

Enter646intheNumberoftubesfieldandclickOKtocontinue.

Set Shell Specifications ThenextdialogboxtoappeariscalledShellSpecifications.

Figure 11-24: The Shell Specifications dialog box

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Theonlyvaluethatyouneedtospecifyhereistheshelldiameter.CC‐THERMassumesthatthevalueenteredhereistheactualshellinsidediameter.Type2.25(theequivalentinfeetto27”)intheShelldiameterfieldandthenclickOKtocontinue.

Note: TheCHEMCADsuitehasahandybuilt‐inconversionfeaturethatcanhelpwheninputfieldsrequireadifferentunitofmeasurethanthedatayouhave.Placeyourcursorinanynumericdataentryfield,andthenpress[F6]tobringupadialogboxthatoffersconversionunitsrelevanttotheselectedfield.Typethevalueyouhaveintheappropriatefieldandpress[ENTER]toconverttootherunits.VerifytheresultsoftheconversionandthenclickOK.CHEMCADautomaticallyselectstheappropriateunitsforthefieldandentersthatconvertedvalue.

Set Baffle Specifications TheBaffleSpecificationsdialogboxdisplaysnext.

Figure 11-25: The Baffle Specifications dialog box

Mostofthedefaultentrieshereareappropriateforthisexample;youdo,however,needtospecifythebafflespacingandbafflecut.

Baffle Spacing Allthatyouknowforthepurposesofbafflespacingisthatthereare10bafflesequallyspaced.Eraseanydefaultvaluesforspacingandenter10intheNumberofbafflesfield.CC‐THERMwillcalculateequalspacingforthebaffles.

Baffle Cut Percent Thebafflecutpercentcanbebasedeitherondiameteroronarea.TheBasisofcutfieldidentifiesthebasisforthespecifiedcut;usethedefaultsettingofDiameter,andenter35intheBafflecutpercentfield.ClickOKtocontinue.

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Set Nozzle Specifications TheNozzleSpecificationsdialogboxnowappears.

Figure 11-26: The Nozzle Specifications dialog box

Thedefaultentriesareacceptableforthisexample,soyouonlyneedtoentertheinsidediameterfortheinletandoutletnozzlesonboththetubeandshellsides.Allofthesenozzleshave1’internaldiameters.

Enter1ineachofthefourfieldsatthetopofthedialogbox,thenclickOKtocontinue.

Set Clearance Specifications YouwillnowseetheClearanceSpecificationsdialogbox.

Figure 11-27: The Clearance Specifications dialog box

CC‐THERMalwaysdefaultstoTEMAclearances,sonormallynoentryisrequiredinthisdialogbox.Inthiscase,theclearancesareknown,soyoushouldenterthemintheeventtheydonotconformexactlytoTEMA.Youcanusethe[F6]featurenotedearlierinthistutorialtoconvertthegivenclearancesfrominchestofeet.

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Also,becausethereisanimpingementplate,youneedtoenterthespaceatthetopofthebundle.Type0.233333intheSpaceatTopofBundlefieldandthenclickOKtocontinue.

Set Material Specifications ThenextdialogboxtoappeariscalledMaterialSpecifications.

Figure 11-28: The Material Specifications dialog box

Here,youcanspecifythematerialsofconstructionfortheheatexchanger.Forthisexample,usethedefaultentries:carbonsteelforthetubesandA‐285‐Cforallothermaterials.ClickOKtocontinue

Set Miscellaneous Specifications ThelastdialogboxtoappeariscalledMiscellaneousSpecifications.

Figure 11-29: The Miscellaneous Specifications dialog box

TheonlyfieldthatisimportanttothisexampleisRowsperSealingStrip.Thedefaultentryof5iswhattheexamplecallsfor,soleavethedialogboxasitisandclickOKtocontinue.

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Run Sizing Calculations Nowthatyouhavespecifiedheatexchangerdatainalloftherequireddialogboxes,theShellandTubeExchangermenuappears.Notethatthismenuiswhatyouwillseeifyoureturntoshellandtubesizingforthisexchangeratanytimeafterthisinitialspecification.

Figure 11-30: The Shell and Tube Exchanger menu

ClicktheCalculatebuttononthemenu.Thecalculationwillrunveryfast,showingruntimemessagesonthestatusbarandthenreturningyoutotheShellandTubeExchangermenu.

Review Results and Create Plots Nowthatcalculationsarecomplete,youcanclicktheViewResultsbuttontoseetheresultoftheheatexchangercalculations.TheViewResultsmenuwillappear.

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Figure 11-31: The View Results menu

Clickanyofthesebuttonstoviewvariousreportsoneverythingfrombaffleparameterstovibrationanalysis.Whenyouselectareport,thedatadisplaysinaseparatewindow,whichyoucanrevieworprintandthenclose.ToreturntotheShellandTubeExchangermenuatanytime,clicktheExitbutton.

YoucanalsodisplayresultsgraphicallybyclickingPlot.ThisopensthePlotmenu,fromwhichyoucanselectavarietyofzone‐by‐zonegraphs.

Figure 11-32: The Plot menu

Theseplotsopeninaplotwindow,justliketheheatcurveplotthatyouwesawatthebeginningofthistutorial.WhenyouclickOKtocloseanyplot,youwillreturntotheShellandTubeExchangermenu.

Youcanalsoprinttabulated,hard‐copyreportsusingtheSelectReportsandGenerateReportsoptionsontheShellandTubeExchangermenu.First,clickSelectReportstobringuptheReportSelectiondialogbox.

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Figure 11-33: The Report Selection dialog box

Selectareportviewer,andchecktheboxesforthereportsthatyouwanttogenerate.ClickOKtoreturntotheShellandTubeExchangermenu,thenclickGenerateReports.Allofthereportsthatyouselectedwillbegeneratedanddisplayedusingtheviewerthatyouchose.

ClickExittoclosetheShellandTubeExchangermenu,thenclickYeswhenaskedwhetheryouwanttosaveyourchanges.Youcannowrevieworprintthereport.

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CC-BATCH Tutorial ThistutorialwalksyouthroughtheprocessofusingCC‐BATCHtosimulateabatchdistillationcolumn.

Description of the Problem Thesimulationyouwillcreateisafive‐stepbatchdistillationcampaign,asillustratedinFigure11‐34.Theobjectiveistoseparate100lb•molofmixedpropane,butane,pentane,andhexaneintothreeseparatetanks,producing99%purebutane.

Figure 11-34: The batch distillation flowsheet

Thefollowingaredetailedspecificationsforthisproblem:

ThermodynamicSelections• K-value:Peng‐Robinson• Enthalpy:Peng‐Robinson

ColumnSpecifications• No.ofinternalstages:8• No.ofoperations:5• Internalstageholdup:0.01ft3• Condenserholdup:0.1ft3• Condenserpressure:14.7psia• Columnpressuredrop:2psia

InitialChargeConditions• Temperature:Calculated• Pressure:16.7psia• VaporFraction:0atbubblepoint• Totalamountofcharge:

100lb•mol

InitialChargeComposition(molefrac)• Propane: 0.1 • N-Butane: 0.3 • N-Pentane: 0.1 • N-Hexane: 0.5

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OperatingStep1• Purpose:Propaneremoval• Refluxratio:5• Distillatemolarflowrate:2• Stopwhen:Distillatemole

fractionofN‐Butaneis0.2• Materialstobeaddedatstart:

None

OperatingStep2• Purpose:Propaneremoval• Refluxratio:20• Distillatemolarflowrate:2• Stopwhen:Distillatemolefractionof

N‐Butaneis0.985• Materialstobeaddedatstart:None

OperatingStep3• Purpose:Butaneproduction• Refluxratio:25• Distillatemolarflowrate:2• Stopwhen:Accumulatormole

fractionofN‐Butaneis0.99• Materialstobeaddedatstart:20

lb•molofmolefraction40%N‐Butane/60%N‐Hexane,atit*bubblepointat16.7psia

OperatingStep4• Purpose:Pentaneremoval• Refluxratio:15• Distillatemolarflowrate:2• Stopwhen:Distillatemolefractionof

N‐Hexaneis0.2• Materialstobeaddedatstart:None

OperatingStep5• Purpose:Pentaneremoval• Refluxratio:25• Distillatemolarflowrate:2• Stopwhen:Bottommolefraction

ofN‐Hexaneis0.9998• Materialstobeaddedatstart:

None

Overview of the Batch Distillation Process Theprocessofbuildingtheflowsheetandsimulatingthebatchdistillationinvolvesthefollowingsteps:

1. Createanewsimulation.

2. Selectengineeringunits.

3. Drawtheflowsheet.

4. Selectthecomponents.

5. Selectthermodynamicoptions.

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6. Specifypotcharge.

7. Specifythedistillationcolumn.

8. Defineoperatingsteps.

9. Runthesimulation.

10. Reviewtheresultsandprintasneeded.

Creating a New Simulation Startbycreatinganewsimulationandgivingitaname.

Selecting Engineering Units SelectFormat>EngineeringUnitstoopentheEngineeringUnitSelectiondialogbox.

Drawing the Flowsheet AsdescribedinChapter5,creatingaflowsheetisamatterofplacingUnitOpiconsonthescreen,connectingthemwithstreams,andthenaddingvariousgraphicalobjectstoenhancethedrawing.

Placing UnitOps BeginbyplacingtheBatchColumnunitonthescreen.

1. OntheAllUnitOpspalette,clicktheBatchcolumntool(seeFigure11‐35)andthenclickinthemainCHEMCADworkspace.Thebatchcolumniconappearswhereyouclicked.

Figure 11-35: The icon representing a batch column

2. ClicktheTanktool(seeFigure11‐36).Ontheworkspace,clicktotherightofthebatchcolumntoplaceatankicon.Thenclickjustbelowthefirsttank,and

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clickagainbelowthesecondtank.Whenyouhaveplacedallthreetanksontheflowsheet,right‐clicktodeactivatetheTanktool.

Figure 11-36: The tank icon

3. ClicktheProducttool(seeFigure11‐37)andinsimilarfashion,placethreeproductarrowsontheflowsheet,eachonebelowandtotherightofatankicon.Right‐clicktodeactivatetheProducttool.

Figure 11-37: The product icon

Drawing Streams NowthatalloftheUnitOpsareinplace,selecttheStreamtoolandconnecteachtank’soutlettothenearestproductarrow.Thesearetheonlystreamsthatyouneedforthistutorial.

Note:Inthissimulation,thebatchdistillationcolumntransfersproductstothetanksbaseduponbatchoperationparametersthatyouprovide.Streamconnectionsbetweenthecolumnandthetanksarenotnecessary,andareambiguousgiventhedynamicnatureofsuchstreams.

RememberthateachstreammuststartataredoutletpointontheupstreamUnitOp,andendatablueinletpointonthedownstreamUnitOp.Toavoidhavingtore‐selecttheStreamtooleachtime,makesurethatassoonasyouclicktocompleteonestream,youmovethecursortothenextlocationandclicktostartthenextstream.

Asyoudrawstreams,CHEMCADassignsstreamIDs,justasitassignedUnitOpIDswhenyoucreatedthoseitems.ThelabelsforstreamIDsaredisplayedinsquares,todistinguishthemfromtheUnitOpIDsdisplayedincircles.

Atthispoint,theflowsheetshouldlooksimilartoFigure11‐34.

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Selecting Components Nowyouneedtoidentifythecomponentstobeusedinthissimulation.StartbyselectingThermophysical>SelectComponents.

Forthisexample,you’llchoosecomponentsfromthestandardCHEMCADdatabase.IntheSelectComponentsdialogbox,findandaddeachneededcomponent.

1. Holddownthe[CTRL]keyonyourkeyboardasyouclickeachofthefollowingcomponentsinturn:

• 4 Propane

• 6 N‐Butane

• 8 N‐Pentane

• 10 N‐Hexane

2. Clicktherightarrowbutton,locatedtotherightoftheAvailableComponentsarea,toaddalloftheselectedcomponentstoyoursimulation.TheSelectComponentsdialogboxshouldnowlooklikeFigure11‐38.

Figure 11-38: The completed Select Components dialog box

3. SaveyourcomponentselectionsbyclickingOK.

Selecting Thermodynamic Options Assoonasyouhavefinishedcomponentselection,theThermodynamicsWizardappears.Thistoolcansuggestthermodynamicsoptionstousewiththissimulation.

CHEMCAD’sThermodynamicsWizardworkslikethis:

1. First,itlooksatthecomponentlistanddecideswhatgeneraltypeofmodelisrequired,i.e.,equation‐of‐state,activitymodel,etc.

2. Second,itlooksattemperatureandpressurerangesthatyouprovideanddecideswhichequationwithinagivencategoryisbestatthelimitsofthoseranges.

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TheThermodynamicsWizardisnoreplacementforengineeringjudgment.Thistoolusesanalgorithmbasedongeneralrules,andisthereforefallible.Thesuggestedmodelmightnotalwaysbethebestmodelforthesystem.

CHEMCADhasalibraryofdozensofK‐valuemodelswithavarietyofoptionsandabout12enthalpymodels.Makingtheproperselectionfromtheselibrariescansometimesbedifficult.Forthepurposesofthistutorial,assumethatyouwanttousethePeng‐RobinsonmethodforboththeK‐valueandenthalpycalculations.Followthesestepstoselectyourthermophysicaloptions:

1. AcceptthedefaulttemperatureandpressurerangesintheThermodynamicsWizardandclickOK.

2. ClickOKagaintoacceptthewizard’ssuggestedmethodofSRK.

Figure 11-39: The new K-value selection in the Thermodynamic Settings dialog box

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Forthepurposeofthistutorial,thethermodynamicselectionsarenowcomplete.

Note:WhileyouarenotrequiredtousetheThermodynamicsWizard,youshouldknowhowtouseit,ifonlyasastartingpointforyoursimulations.YoucanrevisitthewizardatanytimebyselectingThermophysical>ThermodynamicsWizard.

Specifying Pot Charge Nowthatyouhavethermodynamicsandcomponentsdefinedforthissimulation,andyouhaveabatchcolumnintheflowsheet,youcandefinethepotchargeforthecolumn.

Youwillspecifythepotchargeaccordingtothefollowingrules:

• TheTempF,Prespsia,VaporFraction,andEnthalpyMMBtu/hfieldsarethethermodynamicpropertiesofthecharge.AccordingtotheGibbsPhaseRule,onceamixture’scompositionisgiven,specifyinganytwoofthesefourthermodynamicpropertieswilldefinetheothertwo.Assuch,definingthecomposition,temperature,andpressureforamixtureuniquelydefinesitsvaporfractionandenthalpy.Alternatively,definingthecomposition,pressure,andenthalpywilluniquelydefinethemixture’stemperatureandvaporfraction.

Sinceenthalpiesarecalculatedrelativetoadatum,thecalculationofanygivenenthalpyisaninvolvedprocesswhichispronetoerrors.Forthisreason,CHEMCADdoesnotpermityoutoenterenthalpyasaconstraint.

Inadditiontodefiningthepotcomposition,youmustdefineexactlytwoofthefollowingproperties:temperature,pressure,andvaporfraction.Thetwovariablesthatyouspecifywilldisplayasredtext,whilethethirdvariableandthevalueenthalpywillbedisplayedinblackwhenyouflashthecharge.

• TheTotalflowunitandCompunitfieldsworktogethertoprovideavarietyofwaystodefinechargecomposition.Iftheselectedcompunitismole,mass,orvolumefraction(eithergloballyorlocally),thentheTotalflowunitselectionisavailable.Iftheselectedcompunitisanamountoption,thenthetotalchargebecomesthesumofthecomponentquantities,andtheTotalflowunitselectionisnotavailable.

• IftheCompunitfieldselectionisanamountunit(asopposedtoafractionalunit),thenthecomponentchargevaluesareautomaticallyaddedasyouenterthem.ThecurrentsumisdisplayedintheTotalflowfield.

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• Fractionsthatdonotaddupto1.0areautomaticallynormalizedwhenyoueitherclickFlashorexitthedialogbox.

Withtheserulesandbehaviorsinmind,enterthedataforyourpotcharge:

1. Double‐clickthebatchcolumntoopentheEditBatchChargedialogbox.

Figure 11-40: The Edit Batch Charge dialog box

2. InthePrespsiafield,type16.7,thenpress[TAB]andtype0intheVaporFractionfield.

Note:It’simportantthatyouactuallytypea0overtheexisting0entryintheVaporFractionfield.ThistellsCC‐BATCHthatyouarechoosingtospecifyavaporfraction.

3. IntheCompunitfield,selectmolefrac.Youcannowtypeavalueof100intheTotalflowfield.

4. Type0.1inthePropanefield,andtheninsimilarfashion,typethefollowingnumbersinthecorrespondingfields:

• N‐Butane:0.3

• N‐Pentane:0.1

• N‐Hexane:0.5

5. ClickOKtosavethischargeinformationandcontinue.

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Specifying the Distillation Column Whenyouhavespecifiedthepotcharge,CC‐BATCHdisplaystheBatchDistillationColumndialogbox.

Figure 11-41: The Batch Distillation Column dialog box

MakethefollowingentriesontheGeneraltabofthisdialogbox:

• Numberofstages:8

• Numberofoperationsteps:5

• Stageholdup:.01

• Condenserholdup:1

• Condpressure:14.7

• Colmpresdrop:2

Whenyouhaveenteredtheseparameters,clickOKtosavethedataandcontinue.

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Defining the Operating Steps Whenyouhavecompletedtheinitialcolumnspecification,theBatchOperationParametersdialogboxappears.

Figure 11-42: The Batch Operation Parameters dialog box

Inthisdialogbox,you’lldefinetheparametersforeachoperatingstepofthebatchcampaign.Beforeyoubegin,youneedtounderstandhowCC‐BATCHhandlestankassignments.

TheProductassignmentfieldsidentifytheaccumulatortowhichaproductordecantstreamwillbesent.Youcanusethisoptionevenifyoudonotplacetanksontheflowsheet;simplydesignatingaUnitOpIDnumberissufficient.Inthiscase,it’simportantthatyoudesignateaUnitOpIDthatisnotalreadyinuse.

SinceCC‐BATCHpermitsvapor‐liquid‐liquiddistillation,theremaybetwoliquidphasesinthecondenser,possiblygivingrisetodecantingofonephaseortheother.TheDistillateTank#fieldentryrepresentsthetankthataccumulatesthedistillate.TheDecanterTank#fieldentryrepresentsthetankthataccumulatesthedecantedliquid,ifany.

Operating Step 1 Foroperatingstep1,makethefollowingentriesintheBatchOperationParametersdialogbox:

• ChangetheStartupoptionfieldto1Startwithtotalreflux.

• IntheProductassignmentarea,enter2intheDistillatetank#field.

• IntheFirstspecvaluefield,enter5asthevalueoftherefluxratio.

• IntheSecondspecvaluefield,enter2.

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• IntheOperationstepstopoptionsarea,settheStopwhenoptiontoDistillate,settheMeasuredvariableoptiontoMolefraction,andenter0.2intheStopvaluefield.IntheComponentfieldthatnowappears,select2N‐Butane.

• IntheMin.runtimefield,enter0.5.

Whenyouhavemadetheseentries,clickOKtomoveontothenextoperatingstep.

Operating Step 2 Foroperatingstep2,makethefollowingentriesintheBatchOperationParametersdialogbox:

• Enter2intheDistillatetank#field.

• Enter20intheFirstspecvaluefieldand2intheSecondspecvaluefield.

• StoptheoperationwhenthemolefractionofN‐Butaneinthedistillateis0.985.

Whenyouhavemadetheseentries,clickOKtomoveontothenextoperatingstep.

Operating Step 3 Followthesestepsforoperatingstep3:

1. MakethefollowingentriesintheBatchOperationParametersdialogbox:

• Enter3intheDistillatetank#field.

• Enter25intheFirstspecvaluefieldand2intheSecondspecvaluefield.

• StoptheoperationwhenthemolefractionofN‐Butaneintheaccumulatoris0.99.

2. ClicktheAdditionalSettingstab.Hereyouwillspecifytheadditionof20molesofmixturetothepot,withacompositionof40%butaneand60%hexane.ChecktheAddmaterialtopotboxandthenclickOKtobringuptheEditBatchChargedialogbox.

3. InthePrespsiafield,type16.7,thenpress[TAB]andtype0intheVaporFractionfield.

4. Enterthefollowingcompositionsettings:

• SettheCompunitfieldtomolefrac.

• Enter0.4intheN‐Butanefield.

• Enter0.6intheN‐Hexanefield.

• Enter20intheTotalflowfield.

5. ClickOKtocontinuetothenextoperatingstep.

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Operating Step 4 Foroperatingstep4,makethefollowingentriesintheBatchOperationParametersdialogbox:

• Enter4intheDistillatetank#field.

• Enter15intheFirstspecvaluefieldand2intheSecondspecvaluefield.

• StoptheoperationwhenthemolefractionofN‐Hexaneinthedistillateis0.2.

• IntheMin.runtimefield,enter0.5.

Whenyouhavemadetheseentries,clickOKtomoveontothefinaloperatingstep.

Operating Step 5 Foroperatingstep5,makethefollowingentriesintheBatchOperationParametersdialogbox:

• Enter4intheDistillatetank#field.

• Enter25intheFirstspecvaluefieldand2intheSecondspecvaluefield.

• StoptheoperationwhenthemolefractionofN‐Hexaneintheresidualchargeatthebottomofthecolumnis0.9998.

• IntheMin.runtimefield,enter0.5.

Whenyouhavemadetheseentries,clickOKtocontinue.

The Run Time Information Dialog Box Atthecompletionofthelastoperatingstep,theRunTimeInformationdialogboxdisplays.Here,youcanchoosewhichvariableswillbeplottedwhenyourunthesimulation.

Figure 11-43: The Run Time Information dialog box

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Forthisexample,thedefaultdisplay—aplotofdistillatemolefractionsforallfourcomponents—iswhatyouwant,soclickOKtobringuptheBatchDistillationmenu.

Figure 11-44: The Batch Distillation menu

Thismenuprovidesaccesstotheentryscreensforalldefinedoperationsteps,aswellasoptionsforinserting,deleting,andcopyingoperationsteps.Youmightwanttoreviewtheoperatingstepsandverifyyourentriesbeforerunningthesimulation.Whenyouarefinished,clicktheExitbuttontoclosethemenu.

Running the Simulation Torunthesimulation,clicktheRunAlltoolbarbutton.CC‐BATCHfirstcheckstheinputdataforerrorsoromissions.Youmayseethefollowingtypesofmessages:

• Errormessagesmustbefixedbeforethesimulationcanproceed.Under‐specificationofthebatchcolumnwouldbeanexampleofthistypeoferror.

• Warningmessagesareusuallyinputomissions,whichmayormaynotcauseproblemsuponexecution.Thesearenon‐fatalerrorsthatdonotnecessarilyneedtobecorrectedpriortosimulation.

Assumingthatyoucorrectlyspecifiedthepotchargeandsubsequentoperationsteps,youshouldseenomessages;theprogramwillproceeddirectlytothecalculation.

Youwillseethedistillatemolefractionsplottedonthescreeninaplotwindow.Eachtimetheprogramproceedstothenextoperatingstep,anewplotwindowwillopen,alongwithanewtabatthebottomofthemainCHEMCADworkspace.Duringtherun,onlythecurrentstep’splotisvisible.Whenthesimulationisfinished,thedynamicplotwillquitscrollingandaRunfinishedmessagewillappearatthefarleftendoftheCHEMCADstatusbar.

Aftertherun,youcanviewtheplotforaparticularoperatingstepbyclickingthecorrespondingtabatthebottomoftheCHEMCADworkspace.Tocloseanyplot’stab,clicktheClosebutton(markedwithanx)onthetab.Toclosealloftheplottabsatthesametime,selectWindow>CloseAllCharts.

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Reviewing and Printing Results Oncethesimulationiscomplete,youcanreviewtheresultsinteractivelybeforeprintingahardcopy.ThecommandsneededtodothisarelocatedintheReportandPlotmenus.

Plotting the Results Forbatchcalculations,themostconvenientwaytoexaminetheoutputistoplottheresults.Todothis,clickyourbatchcolumnUnitOpandthenselectPlot>DynamicPlots>BatchColumnHistory.

ThisbringsuptheBatchColumnPlotsdialogbox.Fromhere,youcangenerateaplotthatencompassestheentirecampaign.Forexample,youcanfollowthesestepstoplotdistillatemolefractionsacrossalloperatingsteps:

1. InthePlotvariablefield,selectthe0Molefractionsoption.

2. IntheOfthefield,selectthe3Distillateoption.

3. IntheComponentstoplotarea,usethefirstfourfieldstoselectthefourcomponentsfoundinthedistillate.

Figure 11-45: The completed Batch Column Plots dialog box

4. ClickOKtoviewthecompositeplot,whichshouldresembleFigure11‐46.

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Figure 11-46: Composite plot showing composition of distillate over time

Revieworprinttheresultsasneeded,andthenclosetheplottabtoreturntothesimulation.

Generating Text Reports Youcanalsoviewcertainbatchresultsintabularformat.Todothis,selectReport>BatchResults.Asummaryoftheresultsofthissimulationdisplaysinaseparatewindow.Revieworprinttheresultsasneeded,andthenclosethereportwindowtoreturntothemainCHEMCADwindow.

Generating a Full Report TheReportmenuoffersabroadarrayoftextreports,asdescribedinChapter8,OutputandReports.Forthepurposeofthistutorial,assumethatyouwanttoviewandprintoutareportwiththefollowinginformation:

• Operatingstepresults

• Batchcolumnhistory

• Finalbatchcolumnholdup

Becauseyouwantareportwithabroadrangeofinformationaboutyoursimulation,usetheCHEMCADReportWritertool.

1. SelectReport>NewtobringuptheReportWriterdialogbox.

2. IntheAddNewReportSectionlist,thefirstthreeitemsareBatchDistillationResults,BatchHistory,andBatch/DynamicColumnHoldup.Double‐clickeachoftheseitemsinturntoaddthemtotheCurrentReportSectionslistatleft.

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Figure 11-47: Batch distillation items added to new report

3. ClickGeneratetocreatethereport.Youcanthenedit,save,andprintthereportasneeded.

4. Whenyoufinishreviewingandworkingwiththereport,clickCanceltoclosetheReportWriterdialogboxandreturntothemainCHEMCADworkspace.

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Piping Tutorial Apipingnetworkrepresentstheflowoffluidsthroughseveralpiecesofequipment.Ifsufficientvariables(flowrateandpressure)arespecifiedonthepipingnetwork,CHEMCADcalculatestheunknownvariables.

Forfluidflowthroughequipment,flowratemaybecalculatedasafunctionoftheinletandoutletpressure.Ifyouknowanytwoofthesethreevariables,CHEMCADcancalculatethethird.

Inthistutorial,youwillworkwithCHEMCAD’spipingfeatures.Youwillperformcontrolvalveandorificesizingandrating;simulatecomplexpipingnetworks;usefeedbackcontrollers;calculateNPSH;andmakeappropriateequipmentselections.

Control Valve Sizing Example Thisportionofthepipingtutorialcoverscontrolvalvesizing,controlvalves,andtheuseofnodes.

Problem Statement Forthispartofthetutorial,referencetheflowsheetshowninFigure11‐48.ThisexampleiscalledExample1,andit’slocatedintheMySimulations\Examples\Pipingfolder.

D-1-9F225 psig

D-2-1F15 psig

D-3-28F0.2 psig

Figure 11-48: Diagram of control valve sizing example

Youneedtosizecontrolvalvesforhandlingaflowof113,000lb/hrofliquidammoniaineachlinecomingfromvesselD‐1.Youmustselectproperly‐sizedvalvesandthendeterminethepercentopenforeachvalveattheratedservice.

Toperformtheinitialsizing,allyouneedarestreamswiththecorrectproperties(seeFigure11‐49).Itisnotnecessarytomodelthetanks.

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11 2

Figure 11-49: Streams for initial sizing

AllthreestreamsinFigure11‐49areattheinletconditionsof‐9°Fand225psig.Thedividersplitsthe226,000lb/hrflowintotwoequalflowsof113,000lb/hrofammonia.

Toperformtheinitialsizing,followthesesteps:

1. ClicktheRunAllbuttononthemainCHEMCADtoolbartocalculatetheflowinformationforstreams2and3.Bothstreamsshouldbeat‐9°F,225psig,and113,000lb/hrofammonia.

2. Clickstream2toselectit.Thestreamisselectedwhenitisshownbracketedbyblacksquares.SelectSizing>ControlValvetobringuptheControlValveSizingdialogbox.

Figure 11-50: The Control Valve Sizing dialog box

3. IntheDownstreampressurefield,enter15.ClickOKtodisplayacontrolvalvesizingreportinaseparatewindow.CHEMCADreportsthepropertiesofthestreamandthecalculatedparametersforthevalve.

4. Repeattheprocedureforstream3,usingadownstreampressureof0.2psig.

Rating Case Thenexttaskistoratethesevalvesinasimulation.Youneedtodeterminethevalvepositionforthesevalvesinthisserviceat113,000lb/hr.Sincethistaskmodelsthebehaviorofthecontrolvalves,youwillneedaslightlylargerflowsheet,asshowninFigure11‐51.

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Figure 11-51: Flowsheet for rating valves in a simulation

TheflashUnitOpsattheendarenotnecessary;theyareincludedtoillustratethevaporandliquidflowratesinseparatestreamsifflashingoccurs.

Thedividerisstillsetto113,000lb/hr,andtheflashtanksaresettothemodecalledSpecifyTandP;calculateV/FandHeat.FlashUnitOp#2issetto‐1°Fand15psig.FlashUnitOp#3issetto‐28°Fand0.2psig.

Followthesestepstoratethecontrolvalves:

1. Double‐clicktheiconforcontrolvalve#4toopentheControlValvedialogbox.

Figure 11-52: The Control Valve dialog box

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2. IntheValveflowcoefficient(Cv)field,enter36.IntheDownstreampressurefield,enter15.SelecttheOperatingmodeoptioncalledFixflowrate,adjustvalveposition.ClickOK.

3. Nowdouble‐clicktheiconforcontrolvalve#5.Forthisvalve,selectthesameoperatingmodethatyouusedforvalve#4.Specifyavalveflowcoefficientof54andadownstreampressureof0.2psig,andthenclickOK.

4. ClicktheRunAllbuttononthetoolbartorunthesimulation.

5. Toviewtheresults,firstclickablankareaoftheCHEMCADworkspacetoensurethatnoUnitOpsarecurrentlyselected.ThenselectReport>UnitOps>SelectUnitOps.

6. IntheSelectUnitOpsdialogbox,type4,press[RETURN],andthentype5.ClickOKtobringupareportforthesetwovalves.

Thereportshowsthatvalve#4isat72.5%open,andvalve#5isat53.3%open.

Toseehowmuchvaporizationoccursacrossvalve#5,right‐clickthevalveandselectViewStreamProperties.ThisvolumechangeiswhyCHEMCADchosealargervalveforthesecondstream.Withthevaporizationoccurringinthevalve,asmallertwo‐inchvalvebodywouldbeapproachingsonicvelocitythroughthevalvebody.

Flow Rate as a Function of Pressure IntypicalCHEMCADsimulations,informationflowsinonedirection:downstream.Upstreamconditionsdeterminethedownstreamconditions.Inmostsimulations,yousimplysettheflowratesandpressuresoffeedstreams.PressuredropsareeithercalculatedbasedonfloworspecifiedthroughUnitOps,andthedownstreampressures,flowrates,andsofortharecalculatedwhenyourunthesimulation.

Forpipingsimulations,flowrateandpressurearedependentoneachother.Thebackpressureonvalves,pipes,andotherUnitOpsaffectstheflowratethroughthevalve.Likewise,theflowratethroughavalve(orthroughapipeorapump)determinesthedownstreampressure.

Inflowmodelslikethecontrolvalvesizingmodel,itissometimesusefultoletflowratevaryasafunctionofthepressure.Forexample,supposeaprocessupsetinthesystemshowninFigure11‐53causedthepressureinvesselD‐2torisefrom15psigto30psig.Assumingtheupsetoccursfasterthanthevalvesreact,whatisthenewflowratefromD‐1?

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D-1-9 F225 psig

D-2-1 F30 psig (UPSET condition)

D-3-28F0.2 psig

Cv=3672.5 % open

Cv=5453.3% open

Figure 11-53: Vessel D-2 in an upset condition

Toanswerthisquestion,youneedaspecialUnitOpcalledanode.Anodeisapointinthesimulationthathasapressure,aflowcomingin,andaflowgoingout.Thenodeunitscreateanetwork,solvingforflowrateateachpointbasedonthefixedpressures.Nodesareplacedontheflowsheetimmediatelyupstreamanddownstreamfromeachcontrolvalve.Figure11‐54showsthesystemwithnodesinplace.

6 7

10 11

Figure 11-54: Nodes located upstream and downstream from control valves

Thefunctionofthedivider—tosplittheincomingflow—isnowhandledbynode#6.Thenodewillbalancetheflowratessothatallstreamsenteringandexitingthenodeareatthesamepressure.Nodesarealsoplacedbetweentheflashvesselsandthecontrolvalves.Atthenodesyoucanfixthepressures,andlettheflowratevaryasafunctionofvalvepositionandpressuredifference.

Toseehowthesenodesaresetup,youcandouble‐clicknode#6toopentheNodedialogbox.

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Figure 11-55: The Node dialog box

Thefixedpressureatthisnodeis225psig.TheinletflowmodeissettoFreeinletstream,andthetwooutletstreamsaresettoFlowsetbyUnitOp.Theflowintoeachcontrolvalvewillbedeterminedbythecontrolvalveopeningpositionandthepressuredifferenceacrossthevalve.

Fornode#9,thefixedpressureissetto30psig,andfornode#10,thepressureis0.2psig.FlowintoeachofthesenodesiscontrolledbythecontrolvalveusingtheFlowsetbyUnitOpmode;flowoutissettoFreeOutletstream.

Thecontrolvalvesneedtobechangedtofixthevalvepositionandcalculateflowrate.Todothis,settheOperatingmodeforeachvalvetoFixvalveposition,adjustflowrate.

Aftermakingthischange,clicktheRunAlltoolbarbuttontorunthesimulation.Afterrunning,youcanviewthestreamsaroundnode#6byright‐clickingthenodeandselectingViewstreamcomposition.Theresultingreport(Figure11‐56)showsthattheflowrateforstream11(upstreamfromD‐2)hasdroppedfrom113,000lb/hrto109,138lb/hr.Thisillustratestheeffectofbackpressureontheflowratesthroughthevalves.

Figure 11-56: Stream composition report for node #6

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Simple Flow Example Thisportionofthepipingtutorialcoverscontrolvalvesizing,feedbackcontrollers,NPSH,orificesizing/rating,pipesizing/rating,andthePipeUnitOp.

Problem Statement Thepipingsystemshownmustbedesignedtotransport120gpmofglacialaceticacidat70‐140°F.Thepressureattheinletisknownat20psia,andtheoutletmustbenolessthan20psia.Thepipingsystemanditsindividualelementsmustbesizedfordesignconditionsandthenratedatoperatingconditions.ThegoalistodeterminetheNPSHaandheadrequirementsforfuturepumpselection.

Figure 11-57: Piping isometric for this problem

ThisexampleiscalledExample2,andit’slocatedinthelocatedintheMySimulations\Examples\Pipingfolder.

Creating the Simulation Followthesestepstocreateandrunthissimulation:

1. ConvertthepipingisometricinFigure11‐57toaCHEMCADflowsheet.PipeUnitOpsareusedtorepresententiresectionsofpiping,includingfittings.

2. SelectSizing>PipingandselecttheapplicablestreamstobringupthePipeSizingdialogbox.

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Figure 11-58: The Pipe Sizing dialog box

3. SelecttheTypicalsizingforsinglephaseoptionandusestandardschedule40pipe.ClickOKtoviewalinesizingreportfortheselectedstream.

Note:Sincethefluidinthissystemissub‐cooledliquidandallflowsareconstant,thiscalculatedlinesizeshouldapplytoallpipinginthesystem.Theexceptionisthepumpsuctionpipe,whichasageneralruleshouldbeonesizelarger.

4. SelectSizing>Orificeandselectthestreamonthedischargesideofthepump.IntheOrificeSizingdialogbox,selectDandD/2pressuretaps,enter3asthepipeinsidediameter,andenter100asthewaterdifferentialpressure.ClickOKtobringupanorificesizingreportfortheselectedstream.

Note:Usingthecalculatedborehole,CHEMCADdeterminestheflowresistancefactoroftheorificeasshown:

)1(/( 4β−= dCC

21ββ

CKr −

≈

TheorificesizingreportgivestheKrvalue,whichyouwilluselaterinthePipeSizingandRatingdialogbox.

5. Tosizethecontrolvalve,selectstream#1andthenselectSizing>ControlValve.IntheDownstreampressurefield,enter15,andselecttheSingle‐seatoption.Sincestream#1isat20psia,youaresimplysizingacontrolvalvetoproduceapressuredropof5psi.ClickOKtoviewacontrolvalvesizingreportfortheselectedstream.

6. Double‐clickcontrolvalve#4toopentheControlValvedialogbox.Enterthevalveflowcoefficient(Cv)ofthevalvefromthesizingreport,setthevalvepositionto50%,andsettheoperatingmodetoFixflowandposition,calculatePout.ClickOKtosavethesesettingsandclosethedialogbox.

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7. Double‐clicktheheatexchangericontoopentheSimpleHeatExchangerdialogbox.Enterapressuredropof2psiandsettheoutlettemperatureto140°F.ClickOKtocontinue.

8. Tabulateandspecifythevalves,fittings,pipelengths,andelevationchangesofeachsectionofpipe.Forallofthesepipes,settheMethodfieldto2SinglePhaseflow,settheSizingoptionto0Rating,anduseflangedfittingsthroughout.

Pipe#11entrance,wellrounded2ballvalves4standardelbows,90‐degree1tee,flow‐throughbranch35feetofpiping‐8’elevationchange

Pipe#3(beforecontrolvalve)1swingcheckvalve,clearway2ballvalves2tee,flow‐throughrun1orificeplate(aspreviouslydetermined)14feetofpiping14’elevationchange

Pipe#5(aftercontrolvalve)2ballvalves2tee,flow‐throughrun3standardelbows,90‐degree1exitfrompipe24feetofpiping2’footelevationchange

Pipe#7(afterE‐1515)1ballvalve4standardelbows,90‐degree1tee,flow‐throughrun1wellroundedentrance1exitfrompipe157feetofpiping5’elevationchange

9. Specifythepumpoutletpressureatsomearbitraryvalue(try25psia)andmakeatrialrun.Checkthecalculatedoutletpressure.Youcantheniteratetofindtherequiredpumphead.

Using Controllers to Simplify the Problem Whilemanuallychangingthepumpoutletpressurewillgetyouwhereyouneedtobe,it’seasiertoletCHEMCADdothework.TheControllerUnitOpcanadjustthispressureforyou.

AfeedbackcontrollerinCHEMCADhasnothingtodowithprocesscontrolvalvesorPIDsettings.InaCHEMCADsteady‐statemodel,thetermfeedbackcontrolreferstoamathematicalcontroller.It’samathtoolusedtoadjustavariableonaflowsheetuntilatargetvaluereachesaspecifiedvalue.

Followthesestepstouseafeedbackcontrollertocalculatetherequiredoutletpressure:

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1. Right‐clickstream#8andselectInsertunit.ClickOKatthepop‐upmessageandthenclicktheControllertoolintheAllUnitOpspalette.

2. Clickneartheexistingstreamtoplaceacontrollericonontheflowsheet.Thestreamautomaticallyre‐routesthroughthisicon,asshowninFigure11‐59.

77 8

8 9

Figure 11-59: Insertion of feedback controller

3. IntheControllerdialogbox,specifythefollowingandthenclickOK:

• Controllermode:Feed‐backward

• Adjustthisvariable:UnitOp,IDnumber2,Variable2Outputpressure

• Untilthis:Stream,IDnumber8,Variable2Pressure

• Isequaltothistarget:Constant20,Units4Pressure

Whenyourunthesimulation,thecontrollerwillautomaticallychangethepumpoutletpressureuntilthepressureleavingthelastpipeunitisequalto20psia.Younowknowtheheadrequirementsforyourpump.

Calculating NPSHa Thenetpositivesuctionhead,betterknownasNPSH,isdefinedasthetotalpressureavailableatthepumpsuctionminusthepumpingfluid’svaporpressure.Itisalmostalwaysreportedinfeetofpumpedfluidorwater.

EverypumphasaspecifiedNPSHrequirement(NPSHr)atagivenoperatingspeed.Toensurereliableoperation,theavailableNPSH(NPSHa)mustbegreaterthantheNPSHr.Ifnot,cavitationandshortenedservicelifemayresult.

Toselecttheappropriatepump,youneedtocalculateNPSHa.InCHEMCAD,thisisaneasytask.SimplychecktheCalculateNPSHaboxinthePumpdialogbox,andthenrunthesimulation.NowwhenyoupullupthePumpdialogbox,thecalculatedNPSHaisdisplayed.

Note:ItisimportanttotheNPSHacalculationthattheinletpipingtothepumpbecorrectlyspecified.Ifthepipingspecificationsarenotcomplete,thepressureattheinletmaynotbeaccurate,leadingtoaninaccurateNPSHacalculation.

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Branched Flow Example ThisportionofthepipingtutorialcoverstheNodeUnitOp,pipenetworks,pumpselectioncriteria,andPumpUnitOpperformancecurves.

Problem Statement Thepreviouspipingsystemhasbeenchanged.Duetothebranchedflowtothetwoheatexchangers,theproblemisnolongerasimpleone.

Figure 11-60: Piping isometric showing branched flow

ThisexampleiscalledExample3,andit’slocatedinthelocatedintheMySimulations\Examples\Pipingfolder.

Thebranchedflowisadifficultproblemtosolveusingthecontrollerapproach.Bothexchangershavedifferentpipingandthereforedifferentflowrates.Youneedanapproachwhereyousplitandrecombineflows,andhavethesimulationcalculatethepressureandflowratesinaniterativemanner.TheNodeUnitOpgivesyouthisflexibility.

Rememberthatanodeisapointwherepressureisuniform.Theremaybemultipleinletsandoutlets.TheflowratesforeachstreamwillbebalancedbyCHEMCADtoreachasinglepressure.Youcanspecifythepressureorallowittovary.

Creating the Simulation ConvertthepipingisometrictoaCHEMCADflowsheet,asshowninFigure11‐61.

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Figure 11-61: The flowsheet representing this piping system

InCHEMCAD,PipeUnitOpsareusedtorepresententiresectionsofpiping,includingfittings.NodeUnitOpsareplacedwherepressureorflowrateareunknown.

Forthisexample,assumeapressuredropof2psiacrosseachheatexchanger.Tabulatethevalves,fittings,pipelengths,andelevationchangesofeachsectionofpipe.Useflangedfittingsthroughout.

Pipe#11entrance,wellrounded2ballvalves4standardelbows,90‐degree1tee,flowthroughbranch35feetofpiping

Pipe#2(beforecontrolvalve)1swingcheckvalve,clearway2ballvalves2tee,flowthroughrun1orificeplate(asdeterminedabove)14feetofpiping

Pipe#3(aftercontrolvalve)1ballvalve1tee,flowthroughrun2standardelbows,90‐degree10feetofpiping

Pipe#4(toE‐1514)1tee,flowthroughbranch1ballvalve1exitfrompipe3standardelbows,90‐degree26feetofpiping

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Pipe#5(fromE‐1514)1ballvalve1wellroundedentrance3standardelbows,90‐degree1tee,flow‐throughbranch30feetofpiping

Pipe#6(toE‐1515)1ballvalve1exitfrompipe1tee,flow‐throughrun1standardelbows,90‐degree14feetofpiping

Pipe#7(fromE‐1515)1standardelbow,90‐degree1ballvalve1wellroundedentrance1tee,flow‐throughrun10feetofpiping

Pipe#8(toV‐1522)3standardelbows,90‐degree1exitfrompipe147feetofpiping

Atthistimeyoudon’tknowthepumpspecifications,sosetthepumptoSpecify

OutletPressureandleavethepressurespecificationblank.TheNodeUnitOpwillsolveforthepressureincrease,andsetthepumpoutletpressureaccordingly.

Setupthenodeswiththefollowinginformation:

• Node3:Variablepressure,usecurrentstreamrateforinlet,flowsetbyUnitOpforoutlet,elevation=20feet

• Node5:Variablepressure,flowsetbyUnitOpforbothinletandoutlet,elevation=34feet

• Node7:Variablepressure,flowsetbyUnitOpforbothinletandoutlet,elevation=34feet

• Node9:Variablepressure,flowsetbyUnitOpforbothinletandoutlet,elevation=34feet

• Node12:Variablepressure,flowsetbyUnitOpforbothinletandoutlet,elevation=50feet

• Node16:Variablepressure,flowsetbyUnitOpforbothinletandoutlet,elevation=38feet

• Node18:Variablepressure,flowsetbyUnitOpforbothinletandoutlet,elevation=42feet

• Node20(lastnode):Fixedpressure,20psia,flowsetbyUnitOpforinlet,freeoutletstreamforoutlet,elevation=43feet

CHEMCADTutorials

CHEMCADVersion6UserGuide 193

Running the Simulation Torunthesimulation,clicktheRunAllbuttononthemainCHEMCADtoolbar.

Oncethesimulationhasrun,checkthePumpUnitOp’spressureincrease.Thistellsyoutheheadrequirementsofthepump.Usingthisinformationandtheflowrate(120gpm),youcanconsultapumphandbooktodeterminethecorrectpumpsize.

Selecting a Pump Thefollowingpumpcurvedataisrepresentativeofthetypeofequipmentthatwouldbeappropriateforthisapplication.

Pump Curve

1750 rpm

1450 rpm

1150 rpm

2030405060708090

0 40 80 120 160 200

Flow (gpm)

Hea

d (ft

)

1750 rpm1450 rpm

1150 rpm

0.3

0.35

0.4

0.45

0.5

0.55

0.6

0 40 80 120 160 200

Flow (gpm)

Effi

cien

Figure 11-62: Combined pump curves for a sample pump

Toenterthiscurveintoyourpump,openthePumpdialogboxandselectSpecifyPerformanceCurveforthepumpmode.Thissettingallowsyoutoentermultiplespeedlinesandanoperatingspeed.Forthepurposesofthistutorial,enter1

CHEMCADTutorials

194 CHEMCADVersion6UserGuide

forthenumberofspeedlinesandsetthepumpspeedto1750RPM.ClickOKtobringupthePerformanceCurvedialogbox.

Figure 11-63: The Performance Curve dialog box

Hereyoucanenterasmanypointsasyouwanttodefineyourcurve.CHEMCADwillfitaquadraticequationtothepoints,creatingasmoothcurvefitforyourdata.

Nowthatyouhaveenteredthepumpperformancecurve,youmustaddnodeUnitOpstothesuctionsideofthepumptoallowtheflowratetovary.Inthisway,youcancalculatethemaximumflowrateofyoursystem.

CHEMCADVersion6UserGuide 195

Index

.CC6files,29

Addingasinglecomponent,101

Addingcomponentstoasimulation,42

AllUnitOpspalette,37

Applyingatemplate,100

Assigningobjectstoalayer,95

Attachingasimulationfiletoane‐mail,33

BatchReactor/DVSLHistoryplot,72

BatchResultsreport,83

BinaryLLEplot,87

BinodalPlot,87

Binodal/ResidueCurvesplot,87

Buildingabasicsimulation,35

BulkPropertiesdialogbox,106

CallingChemstations,16

Cases,saving,32

CC‐BATCHtutorial,164

CC‐DYNAMICS,63

CC‐STEADYSTATEtutorial,132

CC‐THERMtutorial,153

CHEMCAD

Mainmenu,23

Toolbar,23

Tutorials,131

Gettinghelpwith,15

Installing,7

Interface,17

Licensing,10

Modules,3

Openingolderfiles,34

Overview,1

Productsandfeatures,3

Systemrequirements,7

Usercomponentsin,30

CHEMCADCoachpane,27

CHEMCADDialogEditor,110

CHEMCADExplorer,introduced,18

CHEMCADReportWriter,84

CHEMCADSymbolEditor,107

Index

196 CHEMCADVersion6UserGuide

CHEMCADtutorials

CC‐BATCH,164

CC‐STEADYSTATE,132

CC‐THERM,153

Piping,180

Chemicalcomponents,selecting,42

Chemstationswebsite,16

Coach,27

COMinterfaces,128

ComponentObjectModel(COM),128

Components

Adding,44

Finding,43

Removing,45

Selecting,42

CompositeCurvesplot,88

ConnectingstreamstoUnitOps,39

Consolidatedreporting,84

ControlValveSizingdialogbox,58

ControllerConvergenceplot,89

ConvergenceParametersdialogbox,65

Costingcalculations,customized,109

CreatingacustomUnitOpdialogbox,110

Creatingalayer,94

Creatinganewsimulation,31

Creatingatemplate,100

CreatinganExcelDataMap,118

Creatingcustomcomponents,101

CreatingExcelUnitOps,123

CreatingcustomUnitOps,109

CurveTemperatureCutRangesdialogbox,105

Customcomponents,101

Customenthalpymodel,111

CustomK‐valuemodel,111

Custommixingrule,creatingusingVBA,113

Customreaction,creatingusingVBA,113

CustomUnitOpicon

Creating,107

Addingtoasubpalette,109

CustomUnitOp,creatingusingVBA,113

CustomUnitOps,creating,109

Customizedcostingcalculations,109

CustomizingCHEMCAD,99

CustomizingtheCHEMCADscreen,24

Customizingthermodynamics,111

DatainterfacestoCHEMCAD,117

DataMapExecutionRulesdialogbox,121

DataMaps,creating,118

Databoxes,90

DefaulticonforUnitOp,37

Definingstreams,48

DefiningUnitOps,49

Deletingatemplate,100

Dialogbox,customizing,110

DialogEditorutility,110

DistCurveCharacterizationdialogbox,105

Distillationreport,82

Dongle

ForCHEMCADlicensing,10

Reprogramming,13

Drawingaflowsheet,36

Drawingstreamsonaflowsheet,39

Drawingtools,41

DynamicColumnHistoryplot,72

DynamicColumnHistoryreport,73

Dynamicoperation,settingup,65

Dynamicplots,89

DynamicRunTimeScheduledialogbox,67

Dynamicsimulation,running,69

Dynamicsimulations,strategiesfor,65

DynamicStreamHistoryplot,72

DynamicStreamHistoryreport,73

DynamicUnitOpHistoryreport,73

DynamicsMenu,66

Dynamicsreports,83

Dynamics

Additionalinputfor,64

Defined,63

Output,71

Plottingresults,72

RecordingstreamsandUnitOps,68

Runningonestepatatime,70

Text‐basedresults,72

Toolbarbuttonsfor,66

EditDistillationCurvesmenu,106

EditFeedStreamsbutton,48

EditStreamGroupdialogbox,77

EditStreamsdialogbox,48

Ellipsetool,41

E‐mailingasimulation,33

Index

CHEMCADVersion6UserGuide 197

EngineeringUnitSelectiondialogbox,36

Engineeringunits

Changingforreports,76

Selecting,36

Enthalpyoptions,selecting,46

Equipmentparameters,specifying,49

Equipmentsizing,introduction,54

ErrorsandWarningstab,onMessagespane,22

Examplefiles,30

ExcelDataMapEditor,118

ExcelDataMappingfeature,defined,118

ExcelDataboxSettingsdialogbox,92

Excelrangeboxes,92

ExcelUnitOps,creating,123

Flowsheetdataboxes,90

Flowsheettemplates,99

Flowsheets,drawing,36

Flowsheet‐basedgraphs,88

GlobalEnthalpyModel,47

GlobalKValueModel,47

Graphicalreports,87

Grid,27

Groups

Stream,76

UnitOp,80

HeatCurvesplot,88

Hidingalayer,95

High‐fidelitymodeling,defined,53

HydrocarbonCorrelationdialogbox,105

Icons,creating,107

InstallingCHEMCAD,7

Jobfiles,29

K‐valueoptions,selecting,46

Layers,93

Assigningobjectsto,95

Creating,94

Deleting,96

Hidingandviewing,95

Removingobjectsfrom,96

LicenseMonitorscreen,11

LicensingCHEMCAD,10

Licensing,fordynamics,63

Licensing,forhigh‐fidelitymodeling,62

Linesizing,55

Linetool,41

LockedforEditingdialogbox,31

Low‐fidelitymodeling,defined,53

Mainmenu,23

ManageComponentDatabasesdialogbox,102

MassandEnergyBalancesreport,83

Messagespane,22

Movingapane,25

MovingUnitOpicons,38

Multi‐linetool,41

MySimulationsdirectory,32

Neutralfileimport,106

NewComponentdialogbox,102

Newsimulation,creating,31

Notestab,onMessagespane,23

OlderCHEMCADfiles,34

OLEforProcessControl(OPC),125

OPC

Applications,125

Compliance,125

Namespace,127

Serveroperations,126

OPCserver,usingCHEMCADas,125

Opencommand,31

Openinganexistingsimulation,31

OpeninganolderCHEMCADfile,34

Palettepane,introduced,20

Palettes,customizing,21

ParticleSizeDistributionreport,80

PFDprinting,96

PFDs,90

PhaseEnvelopesplot,88

Pinningandunpinningpanes,25

PipeProfileplot,88

Pipingtutorial,180

PlotsinCHEMCAD,87

Plots,dynamic,89

Plottingdynamicresults,72

PlugFlowReactorProfileplot,88

Polygontool,41

Printingaprocessflowdiagram,96

PrintingCHEMCADreports,89

Processflowdiagrams,90

Properties,ofstreams,48

PseudocomponentCurvesplot,88

PseudocomponentCurvesreport,80

Index

198 CHEMCADVersion6UserGuide

Pseudocomponentrange,defining,105

RecordStreamsdialogbox,68

RecordingstreamsandUnitOpsfordynamics,68

Rectangletool,41

Redocommand,26

Regressingdataintoauser‐addedcomponent,104

Reliefdevicesizing,61

Removingcomponentsfromasimulation,45

Renamingatemplate,100

ReportWriter,84

Reportsfordynamicsimulations,71

Reports

CHEMCADReportWriter,84

Dynamics,83

Printing,89

Streamcompositions,78

Streamproperties,79

UnitOp‐based,80

Reprogrammingadongle,13

Reroutingastream,40

ResettoInitialStatebutton,70

ResidueCurvesplot,88

Resizingapane,24

ResizingUnitOpicons,38

Results,reviewing,51

Reviewingrunresults,51

Routingstreams,39

RunfromCurrentStatebutton,69

RunfromInitialStatebutton,69

Runtime,setting,66

RunTracetab,onMessagespane,22

Runningadynamicsimulation,69

Runningasimulation,50

SaveAscommand,32

SaveasInitialStatebutton,71

Savingasimulation,32

Savingdifferentcases,32

SearchforUnitOp(s)field,21

SearchOptionsdialogbox,44

SelectComponentsdialogbox,43

SelectDataMapdialogbox,122

SelectDestinationDatabasedialogbox,102

SelectRegressionDataSetdialogbox,104

SelectSingleComponentdialogbox,103

Selectingcomponents,42

Selectingengineeringunits,36

SelectingK‐valueandenthalpyoptions,46

Selectiveprinting,93

Settingruntimefordynamics,66

Simulationfiles

Introduced,29

Creating,31

E‐mailing,33

Opening,31

Overviewofbuilding,35

Saving,32

Simulation,running,50

Singlecomponent,adding,101

Sizing,introduction,54

Specsheetreport,82

Specsheets,outputtoExcel,124

SpecifyingUnitOps,49

Startinganewsimulation,31

Streamboxes,90

Streamcompositionreports,78

Streamcomposition,viewing,79

Streamgroups,creating,76

StreamPropertiesplot,88

Streampropertyreports,79

Streams

Drawingonaflowsheet,39

Defining,48

Rerouting,40

Switchingtodynamics,65

SymbolEditorutility,107

Symbols,creating,107

Technicalsupport,contacting,16

Templates

Applying,100

Creating,100

Defined,99

Deleting,100

Renaming,100

Textreports,75

Texttool,41

ThermodynamicSettingsdialogbox,47

Thermodynamicsreport,83

Thermodynamicssettings,manuallyselecting,47

ThermodynamicsWizard,46

Thermodynamics,customizing,111

Index

CHEMCADVersion6UserGuide 199

Thermophysicaldatagraphs,87

Toolbar,23

Topologyreport,83

TowerProfilesplot,88

TPboxes,91

TPXYplot,87

TraySizingdialogbox,59

Undocommand,26

UnitOpboxes,91

UnitOpdialogbox,customizing,110

UnitOpgroups,creating,80

UnitOpicons

Creatingcustomized,107

Manipulating,38

UnitOps

Addingtoaflowsheet,36

Selectingdefaulticonfor,37

Listingofallavailable,5

Specifying,49

UnitOp‐basedplots,88

UnitOp‐basedreports,80

UpdateSimulationFormatdialogbox,34

UpdatingaCHEMCADlicense,13

User‐specifiedfile,plotting,89

ValveTraydialogbox,59

VBA

Custommixingrules,113

Customreactions,113

CustomUnitOps,113

UsingtocustomizeCHEMCAD,113

VBA‐definedmixingrule,using,114

VBA‐definedreaction,using,113

VBA‐definedUnitOp,using,115

VesselSizingdialogbox,57

ViewPropertyOptionsdialogbox,79

View/EditComponentDatamenu,103

Viewingalayer,95

WebsiteforChemstations,16

ZoomOptionsmenu,27

Index

200 CHEMCADVersion6UserGuide

Chemcad 6 User Guide 2011 - [PDF Document] (2024)

FAQs

Is Chemcad software free? ›

Sign up for a free trial. Try CHEMCAD for free today and find out how easily you can simulate simple and complex chemical processes on one intuitive, graphical interface.

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What language is used in Chemcad? ›

Yes, CHEMCAD allows you to add a new unit operation as an Excel spreadsheet, as a user-programmed C++ .

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What is Chemcad software? ›

CHEMCAD is an integrated suite of intuitive chemical process simulation software that fits into the chemical engineering workflow and supercharges an engineer's efficiency.

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How to install Chemcad on PC? ›

How to install ChemCAD step-by-step

Download ChemCAD from the Box link above and note the license server name. ...
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Aug 6, 2021

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What is the difference between Chemcad and Aspen Hysys? ›

ChemCAD is simple ,basic and for beginners so it can be easily understand how to make use of simulation software. Aspen-HYSIS is effective for steady state simulation majorly petroleum product. But it is difficult as compare to previous one but have new version with DEtherm version that makes it easier.

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What are the benefits of Chemcad? ›

Using CHEMCAD for process engineering can offer a number of advantages. For example, it is highly flexible, as it can be used for a variety of applications and industries, and allows for customizing unit operations, components, thermodynamics, and properties.

How do I change Units in Solidworks simulation? ›

Unit systems can be changed in the Units settings under Tools > Options > Document Properties > Units. There are five default unit systems: MKS (metre, kilogram, second)

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Is chemical engineering difficult? ›

1) Chemical Engineering

Novik's list ranks chemical engineering as the hardest major in this field. This might be because chemical engineers' unique training involves concepts from across many other STEM disciplines, including chemistry, biology, math, and physics.

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Are chemical engineers in high demand? ›

High Demand

In fact, the US Bureau of Labor Statistics predicts that career possibilities for chemical engineers will increase by 9% between 2020 and 2030.

Who makes Chemcad? ›

Chemstations has served the chemical engineering community for 30 years, delivering adaptive process simulation technology called CHEMCAD. To this day, we remain committed to providing tools that help advance the field through a dynamic and novel approach.

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What is the free software for chemical reactions? ›

What is ChemReaX? ChemReaX™ is a free web app for modeling and simulating basic chemical reactions. The software is intended for chemistry students and their teachers at the undergraduate and high school (AP/IB) levels.

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Does ChemCAD work on Mac? ›

HOUSTON, TX (July 26, 2006) - Chemstations, Inc., makers of the CHEMCAD suite of chemical process simulation software, today announced that CHEMCAD can run on Intel-based Apple computers.

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What is the latest version of Chemcad? ›

Most recent release is Version 8.1. 1.17611 (July 31, 2023).

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