Thermal Performance of EV and HEV Battery Modules

CENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalPerformanceofEVandHEVBatteryModulesandPacksThermalPerformanceofEVandHEVBatteryModulesandPacksAhmadA.Pesaran,Ph.D.AhmadA.Pesaran,Ph.D.AndreasVlahinos,Ph.D.AndreasVlahinos,Ph.D.StevenD.BurchStevenD.BurchNationalRenewableEnergyLaboratoryNationalRenewableEnergyLaboratory14thInternationalElectricVehicleSymposium14thInternationalElectricVehicleSymposiumOrlando,FloridaOrlando,FloridaDecember16,1997December16,1997CENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSAcknowledgmentAcknowledgmentThisworkwassponsoredbytheU.S.DOEaspartofthecost-sharedHybridVehiclePropulsionSystemsProgramCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSPresentationOutline➤➤ImportanceofthermalmanagementImportanceofthermalmanagement➤➤ThermalmanagementandanalysisThermalmanagementandanalysis➤➤TypicalresultsTypicalresults➤➤ThermalimagingThermalimaging➤➤MeasuringheatgenerationMeasuringheatgeneration➤➤SummarySummaryCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSImportanceofThermalManagement➤➤HEV/EVperformanceandlife-cyclecostisHEV/EVperformanceandlife-cyclecostisinfluencedbybatterypackinfluencedbybatterypack➤➤Temperatureaffectsbatterymodule/packTemperatureaffectsbatterymodule/packperformanceandlifeperformanceandlifeCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSImportanceofThermalManagement➤➤UneventemperaturedistributioninapackUneventemperaturedistributioninapackleadstounbalancedmodulesandreducedleadstounbalancedmodulesandreducedperformanceperformance➤➤Packthermalmanagementisrequired,Packthermalmanagementisrequired,particularlyforhighpowerbatteriesinparticularlyforhighpowerbatteriesinHEVsHEVsCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalManagementSystem➤➤DesiredattributesDesiredattributes◆◆SmalltemperatureSmalltemperaturevariationwithinamodulevariationwithinamoduleandwithinapackandwithinapack◆◆OptimumtemperatureOptimumtemperaturerangeforallmodulesrangeforallmodules➤➤RequirementsRequirements◆◆Compact,lightweight,andCompact,lightweight,andeasytopackageeasytopackage◆◆ReliableandserviceableReliableandserviceable◆◆Low-costandlowLow-costandlowparasiticpowerparasiticpowerCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalAnalysisforThermalManagement➤➤Module/packthermalanalysisaidsinModule/packthermalanalysisaidsindesigningbetterthermalmanagementdesigningbetterthermalmanagementsystemssystems➤➤WeusedfiniteelementanalysisandheatWeusedfiniteelementanalysisandheattransferprinciplestoobtainthermaltransferprinciplestoobtainthermalperformanceperformance➤➤2-Dor3-D2-Dor3-D➤➤Steady-stateortransientSteady-stateortransientCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalAnalysisofaBatteryPack30Modules30ModulesAircoolingflowrate:0.08kg/sAircoolingflowrate:0.08kg/s1/3flowforeachcolumn1/3flowforeachcolumn25ºCinletair25ºCinletair35W/module35W/moduleAircirculatedequallyaroundeachmoduleAirsideheattransfercoefficientof35W/m2KCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSSteady-State,2-DPackResultsTemperaturedistributionwithairflowrateTemperaturedistributionwithairflowrateTmaxTmax,core=58ºC,,core=58ºC,TminTmin,core=40ºC,core=40ºCAirenteringat25ºCUniformheatgenerationof35W/moduleAirleavingat38ºCCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSSteady-StateClosedPackResultsTemperaturedistributionwithnoairflowTemperaturedistributionwithnoairflowAssumingsomeheatlossfromthesidesAssumingsomeheatlossfromthesidesTmax=144ºC,Tmin=40ºCTmax=144ºC,Tmin=40ºCUniformheatgenerationof35W/moduleCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSSteady-State,2-DPackResultsOpen,withairflowOpen,withairflowTmax=144ºCTmax=144ºCTmin=40ºCTmin=40ºCClosed,noflowClosed,noflowTmax=58ºCTmax=58ºCTmin=40ºCTmin=40ºCUniformheatgenerationof35W/moduleAirenteringat25ºCCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSAnalyzinganHEVModule➤➤Spiral-woundSpiral-wound➤➤LeadacidLeadacid➤➤HighpowerHighpower➤➤12cells,24V12cells,24V➤➤Analyzed1/4ofAnalyzed1/4ofmoduleduetomoduleduetosymmetrysymmetry➤➤Aircooledat25ºCAircooledat25ºCCellcoreCellcorePlasticPlasticcasecaseAirgapAirgapCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalPerformanceoftheHEVModuleSteadyState,2-DSteadyState,2-DTmax=53ºCTmax=53ºCDeltaTcore=13ºCDeltaTcore=13ºCCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalPerformanceofModulewithCoolingHolesSteadyStateSteadyStateTmax=44ºCTmax=44ºCDeltaTcore=9ºCDeltaTcore=9ºCCoolingholeswereadded.Coolingholeswereadded.Everythingelseremainedthesame.Everythingelseremainedthesame.CENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalImprovementbyAddingCoolingHolesNoHolesNoHolesWithHolesWithHolesTmax=44ºCDeltaTcore=9ºCTmax=53ºCDeltaTcore=13ºCCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSOptimaHEVModulesUseCoolingHolesCENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSThermalImagingUsefulmethodstoobtaininformationonthermalbehaviorofbatterymodulesandpacksformodelvalidationanddiagnostics➤➤InfraredInfraredThermographyThermography➤➤LiquidCrystalLiquidCrystalThermographyThermography(temperature-sensitivepaint)(temperature-sensitivepaint)CENTERFORTRANSPORTATIONTECHNOLOGIESANDSYSTEMSInfraredThermalImagin