Development-Progress-of-the-Toyota-Fuel-Cell-Hybri

Fig.1.EstimatesofconventionaloildemandandsupplyABSTRACTSince1992,ToyotaMotorCorporation(TMC)hasbeenworkingonthedevelopmentoffuelcellsystemtechnology.TMCisdesigningprincipalcomponentsin-house,includingfuelcellstacks,high-pressurehydrogenstoragetanksystems,andhybridsystems.TMCdevelopedthe’02modelTOYOTAFCHV,theworld-firstmarket-readyfuelcellvehicle,andstartedlimitedleaseofthevehiclesin2002.In2005,TMCdevelopedanewmodelofTOYOTAFCHVwhichobtainedvehicletypecertificationinJapan,andiscurrentlyavailableforleasing.TMChasimprovedthecruisingrangeandcoldstart/drivecapabilityoftheTOYOTAFCHV,andconductedpublicroadteststoevaluatetheperformance.TheimprovedTOYOTAFCHVsuccessfullytraveledfromOsakatoTokyo(approximately560km,350miles)onasinglefuelingofhydrogen.Inaddition,thecoldweathertestscarriedoutinHokkaidoandNorthAmericahaveverifieditsstarting/drivingcapabilityatsubfreezingtemperaturesincluding-37°C.Althoughmanyobstaclesremaintowardscommercializationoffuelcellvehicles,TMCiscommittedtoovercometheobstacles.ThispaperdescribesTMC'sapproachestowardsolvingthechallengesofcruisingrangeandcoldstart/drivecapability.INTRODUCTIONSeveralissuesmustbesolvedbeforesustainablemobilitycanbeachieved.Especially,theissuesofenergysupplyanddemandandthecarbondioxide(CO2)emissionsarecrucial.Consideringthatmostofthecurrentvehiclesrelyonoil,TMCismakingeffortstodevelopvarioustechnologiestosolvetheissues.Fuelcelltechnologyisoneofthemostpromisingavenuestoachievesustainablemobility.Afuelcellgenerateselectricalpowerwithhydrogenandoxygen,withoutemittinggasessuchasCO2,NOX,orPMindriving,andisthereforeregardedastheultimateincleanpowergeneration.Furthermore,afuelcellfeatureshighenergyefficiencyandisenvisionedasanext-generationpowertrain.Whiletherearestillmanyissuescurrentlyimpedingthecommercializationoffuelcellvehicles,theprospectsofsolvingthetechnicalchallengesofcruisingrangeandcoldstart/drivecapabilityareimproving.TMCisconductingpublicroadtestswithtestvehiclestoverifythesolutions.ThispaperfirstdiscussesTMC'sapproachtowardsachievingsustainablemobility.ThenitdescribesthepresentstateandchallengesoftheTOYOTAFCHV,andfinallydescribestheeffortsandresultsofimprovedcruisingrangeandcoldstart/drivecapability.CHALLENGESFORACHIEVINGSUSTAINABLEMOBILITYENERGYSUPPLYANDDEMANDTrendsofconventionaloilconsumptionanddiscoveryareshowninFig.1.Since1980,consumptionhasexceededtherateofdiscoveryanditisnotpredictedthattheamountoffuturediscoverywillrapidlyincrease.Consequently,itisexpectedthatoilsupplywillpeakinthenearfuture,andthusitmaybedifficulttocontinueusingconventionaloil-dependenttransportation.2030199020101970605040302010019301950YearSource:©2008SAEInternationalSAEInt.J.Engines|Volume1|Issue1296DownloadedfromSAEInternationalbyJilinUniversity,Thursday,December22,2016Fig.5Toyota'sapproachFig.6Toyota'sfuelcelltechnologyREDUCTIONOFCO2EMISSIONSFig.2showsthechangesinatmosphericCO2concentrationoverthelast10,000years.ThisgraphillustratesanabruptriseofCO2concentrationsincethe19thcentury–thebeginningoftheIndustrialRevolution.ScientificconsensusestimatesthattheprincipalcauseisduetoCO2emissionsbyusingfossilfuel.AsFig.3shows,thetransportationsectoraccountsforapproximately20%ofCO2emissions.Fig.4isaprojectionoflong-termenvironmentaleffectsofCO2emissions.Thediagramshowsthattheriseinsealevelwouldcontinueforapproximately1000yearsevenifCO2emissionsweretobesubstantiallyreducedimmediately.ThisisbecauseitwilltakeasignificantamountoftimebeforetheconcentrationofCO2stabilizes.Therefore,immediateandlong-termmeasurestoreduceCO2emissionsarerequired.EFFORTSBYTOYOTAMOTORCORPORATIONFig.5showsTMC’sapproachestotackletheissuesofenergysupply/demandandCO2emissions.Forthenextfewdecades,itwouldbedifficulttorelyononlyoneenergysource,andtherefore,technologiestomeetdiversifiedenergysourcesarerequired.TMCismakingeffortstodeveloppowertrainscompatiblewithdiversifiedenergysourcesincludingbio-fuels,syntheticfuels,electricityandhydrogenaswellastoimproveconventionalgasolineanddieselengines.Inaddition,improvementofefficiencyisimportanttoreduceCO2emissions.TMCbelievesthathybridtechnology,whichcanimproveefficiencyofalltypesofpowertrains,isacoretechnologyandthusisintegratedwiththefuelcellsystem.TOYOTAFUELCELLTECHNOLOGYAhydrogen-poweredfuelcellisoneofthemostimportantsolutionstoachievesustainablemobility.39.9%20.8%17.3%13.8%8.2%PowersectorTransportIndustryResidence&servicesOthersSource:IEA/WEO200439.9%20.8%17.3%13.8%8.2%PowersectorTransportIndustryResidence&servicesOthersSource:IEA/WEO2004Fig.3EnergyrelatedCO2emissions(2002)Timetakentoreachequilibrium1,000years100yearsTodaySource:IPCCThirdAssessmentReport2001CO2emissionspeak0to100yearsMagnitudeofresponseSealevelriseduetoicemelting:severalmillenniaSealevelriseduetothermalexpansion:centuriestomillenniaTemperaturestabilization:afewcenturiesCO