Aspen培训资料03

©2002AspenTech.AllRightsReserved.UnitOperationsAspenPlus®11UpdateforVersion10Users©2002AspenTech.AllRightsReserved.LessonObjectives•ReviewupdatestoColumns,Heatexchangers,andReactors;plusnewManipulatorblocks©2002AspenTech.AllRightsReserved.ColumnBlocksNewAspenPlus11.1columnfeaturesinclude:•Sizingof4-passtraysforallcolumntypes–Version10.2supportedonlytwopassesoneachtray•ThermaltrayefficienciesforthePetroFracblockaccountsforthermaldeviationsfromequilibrium•ColumnTargetingtoolprovidesdebottleneckingcapabilitiesforallcolumntypes©2002AspenTech.AllRightsReserved.ThermalTrayEfficienciesinPetroFrac(1)•Thermaltrayefficienciesareusedtomodelthethermalnon-equilibriumeffectsfoundinlargerefinerycolumns,suchascrudecolumns,catalyticcrackers,andcokermainfractionators.•Thermaltrayefficiencyallowsthevaporandliquidtemperaturestobedifferent(notatequilibrium),thusallowingforthecalculationofbothacompositionalandathermaldeviationfromequilibrium.Incontrast,Murphreetrayefficienciesassumethermalequilibriumbetweenthevaporandliquidphases.•Thermalefficienciesaredefinedfrom0.0to1.0,with1.0correspondingtoanidealstageatthermalequilibrium.©2002AspenTech.AllRightsReserved.ThermalTrayEfficienciesinPetroFrac(2)•Recommendations–Vaporthermaltrayefficienciesshouldbeusedwherehighand/orsuperheatedvaporflowsdominatethecolumnprofile.–Liquidthermaltrayefficienciesshouldbeusedintheoppositesituationwherehighand/orsubcooledliquidflowsdominatethecolumnprofile.–Onlyoneofthesetwotypesofthermalefficiencycanbeusedonanygivensectionofthecolumn.ThesedataareinputontheBlocksColumnEfficienciesThermalsheet.©2002AspenTech.AllRightsReserved.ColumnTargeting(1)•TheColumnTargetingtoolofferscapabilitiesforthermalandhydraulicanalysisofdistillationcolumns.Duringdesignorretrofitanalysisofaprocess,thesecapabilitiescanbeexploitedtoidentifythetargetsforappropriatecolumnmodificationsinorderto:–Reduceutilitiescost–Improveenergyefficiency–Reducecapitalinvestment(byimproveddrivingforces)–Facilitatecolumndebottlenecking•ThesecapabilitiesareavailablefortheRadFrac,MultiFrac,andPetroFraccolumnmodels.©2002AspenTech.AllRightsReserved.ColumnTargeting(2)•Thethermalanalysiscapabilityisbasedontheconceptofminimumthermodynamicconditionforadistillationcolumn.Theminimumthermodynamicconditionpertainstothermodynamicallyreversiblecolumnoperation.–Inthiscondition,adistillationcolumnwouldoperateatminimumreflux,withaninfinitenumberofstages,andwithheatersandcoolersplacedateachstagewithappropriateheatloadsfortheoperatingandequilibriumlinestocoincide.–Inotherwords,thereboilingandcondensingloadsaredistributedoverthetemperaturerangeofoperationofthecolumn.©2002AspenTech.AllRightsReserved.ColumnTargetingPlots(1)•Stage-Enthalpy(Stage-H)orTemperature-Enthalpy(T-H)profilesforsuchacolumnthereforerepresentthetheoreticalminimumheatingandcoolingrequirementsinthetemperaturerangeofseparation.TheseprofilesarecalledtheColumnGrandCompositeCurves(CGCCs).•ActivateontheColumnReportPropertyOptionssheet.©2002AspenTech.AllRightsReserved.ColumnTargetingPlots(2)•ThePlotWizardoffersfournewplottypes:–CGCC(T-H):TemperatureversusEnthalpy–CGCC(S-H):StageversusEnthalpy–HydraulicsAnalysis:ThermodynamicIdealMinimumFlow,HydraulicMaximumFlowandActualFlowforeachStage–ExergyLossProfile:StageorTemperatureversusExergyLoss©2002AspenTech.AllRightsReserved.UsetheSRKPropertyMethod15stagesFeedstage3TopstageP=200kPaDistillaterate=400kmol/hrRefluxratio=7.5ColumnTargetingExampleFlow=1000kmol/hrTemperature=100°CPressure=2.4bar0.2Molefractionofeach:HeptaneOctaneNonaneDecanePentadecaneCOLUMNFEEDOVHDBTMS•Examinetheconfigurationofthiscolumnanddeterminepossibilitiesfordesignmodification:©2002AspenTech.AllRightsReserved.•Resultsdependstronglyontheselectionoflightkeyandheavykeycomponents.Theycanbebasedon:–User-defined–Componentsplitfractions–K-values(default)–Columncompositionprofiles•SpecifyontheColumnReportTargetingOptionssheet.•UsetheColumnReportTargetingSpecificationssheettospecifyparametersfortheselectedmethod(optional;exceptforwhenyouselectUser-defined).ComponentSelection©2002AspenTech.AllRightsReserved.ColumnTargetingApplications•ColumnGrandCompositeCurveshelpdeterminepossiblecolumnmodifications,including:–Feedlocation–Refluxratiomodifications–Sidecondensingorreboiling–Feedconditioning(heatingorcooling)•TheHydraulicsAnalysisandExergyLossprofileswillhelpconfirmtheneedforimprovementstocolumndesignandoperation.©2002AspenTech.AllRightsReserved.DeterminingtheFeedLocation•Stage-HCGCCplotscanidentifydistortionsduetoinappropriatefeedplacement.Theyareapparentassignificantprojectionsatthefeedlocation(pinchpoint),duetoaneedforextralocalrefluxtocompensatefortheinappropriatefeedplacement.–Acorrectlyplacedfeedatstage7removesthedistortionsintheStage-HCGCCplot.©2002AspenTech.AllRightsReserved.ModifyingtheRefluxRatio•ThehorizontalgapbetweentheT-HCGCCpinchpointandtheordinaterepresentsthescopeforareductioninrefluxratio.Astherefluxratioisreduced(whileincreasingthenumberofstagestopreservetheseparation),theCGCCwillmovetowardstheordinate,thusreducingboththereboilerandconden