12 Improving Heavy Truck Fuel Economy

©SouthWestResearchInstitute®2009RSouthwestResearchInstitute®美国西南研究院AdvancedU.S.TechnologyCo-hostedbyChinaInternalCombustionEngineIndustryAssociation(CICEIA)ChinaAssociationofAutomobileManufacturers(CAAM)SouthwestResearchInstitute13-14November20091©SouthWestResearchInstitute®2009RSouthwestResearchInstitute®美国西南研究院ImprovingHeavyTruckFuelEconomyTomReinhartProgramManager–EngineDesign&Development2©SouthWestResearchInstitute®2009RIntroductionƒScope:heavyduty,longhaultrucks¾Classiccombination6X4tractorwith53foot(16.2m)boxvantrailer¾Mostlyhighwaydutycycle¾EvaluaterangeofpotentialtechnologiesandpackagesƒResultsmaybeusedtohelpguidedevelopmentofpotentialgovernmentfueleconomyregulationsƒAllimprovementsarelistedin%fuelsaved¾Recommendedmetric:fuelconsumptionperunitwork(litersper100ton-km)¾Thisisthesameasthe%reductioninGreenHouseGas(GHG)3©SouthWestResearchInstitute®2009RProjectDutyCycle0102030405060708001000200030004000500060007000Time(sec)Speed,MPHAveragecruisespeed105–110km/h(65–70MPH)(muchhigherthantypicalinChina)4©SouthWestResearchInstitute®2009RProjectDutyCycle-4-3-2-101234020406080100120Distance(miles)Grade,(%)Simulatedhillsinthesecondandthirdsteadyspeedcruisesegment5©SouthWestResearchInstitute®2009RTechnologyPackage#1ƒBaselineengine/vehiclepackage¾KenworthT600truck•Meanttorepresentaverageof2007USAon-the-roadfleet•Mildaeropackage:bumperfairing,partiallyaerodynamicmirrors,partialfueltankfairing,integratedrooffairing,exhaustsystemoutoftheairflow,andcabsideextenders•TotalmeasuredvehicleCd:0.63(coastdowntestresults)•Eaton/Fuller10speedmanualtransmission•CoefficientofrollingresistanceCrr=0.0068,typicalofcurrentstandardtires6©SouthWestResearchInstitute®2009RTechnologyPackage#17©SouthWestResearchInstitute®2009RTechnologyPackage1¾VolvoD13engine•NotactuallysoldintheKenworthtruck,butsimilarinperformanceandisavailableinsimilartrucks•SwRIHDDBenchmarkingprogramdatawasusedtocalibratetheGT-Powercyclesimulationenginemodel•HighpressureloopcooledEGR,electronicveryhighpressurefuelinjection(unitinjectors),VGturbo•DPF-equippedfor2007;extrapolatedtoSCR+DPFfor2010•SwRIassumption:2010fuelconsumptionwithSCRand0.2g/HP-hrNOxisthesameas2007•Actual2010fuelconsumptionisstillunderdevelopment–maybeequaltoorslightlybetterthan20078©SouthWestResearchInstitute®2009RTechnologyPackage1Package1:FuelEconomyvsGVW55.566.577.588.596500070000750008000085000GVW(lbs)FuelEconomy(mpg)0510152025303540PercentFuelSavedFuelEconomy(mpg)PercentFuelSaved29.5ton36.3ton9©SouthWestResearchInstitute®2009RTechnologyPackage1ƒBaselinevehiclefuelconsumptionis43.6L/100kmonthelinehauldrivecycle(at36.3ton)¾39.5L/100kmat29.5tonGVWƒWeightreductionprovidesanimprovementofabout1.3%per1000kgGVWreduction¾Tractorandtrailerweightreductionwillhelp,buthaveonlyaminoroverallbenefitforcubed-outvehicles¾Grossed-outvehicleswillgain4.8%per1000kgduetohigherfreightcapacity¾Reductioninfreightloadimprovesvehiclefuelconsumption,butwillactuallyincreaseloadspecificconsumption(liters/100ton-km)10©SouthWestResearchInstitute®2009RTechnologyPackage#2ƒBaseline+EPASmartWaypackage+WideBaseSingleTires(SuperSingles)¾AerodevicesassumedinadditiontoPackage#1:•Tractor:fullfueltankfairings,fullyaerodynamicmirrors•Trailer:sidefairing,andoneof(boattail,splitterplate,orgapfairing)•Overallaerobenefitassumption:5%fueleconomyimprovementfromtrailerpackage,2%improvementfromtractorpackage¾Rollingresistanceimprovements:•LowrollingresistanceWideBasetires,Crr=0.005511©SouthWestResearchInstitute®2009RTech.Package#2CdSweepPackage2:CdSweep:Crr=0.0055,GVW=80klbs55.566.577.588.590.350.40.450.50.550.60.65CoefficientofDrag(-)FuelEconomy(mpg)0510152025303540PercentFuelSavedFuelEconomy(mpg)PercentFuelSavedvsPackage112©SouthWestResearchInstitute®2009RPackage2ConclusionsƒCrrreductionfrom0.0068to0.0055providesa6%improvementƒCdreductionfrom0.6298to0.5providesan8%improvementƒThefullPackage2providesa14%improvementat80,000lbs.GVWƒNote:Chineseroadspeedsaretypicallylower,sotheeffectofaerodynamicimprovementwillbeless13©SouthWestResearchInstitute®2009RTechnologyPackage#3ƒBaseline+advancedSmartwaypackage(2017)¾Aerodevicesunderconsideration:•AssumedCd=0.40•Cd=0.40wouldrequirecompleteredesignofthetractor/trailersystem•SomeoperationalchangesmayberequiredtoallowCdthislow¾Rollingresistanceimprovementprediction:•Crr=0.0045selectedwithEPAandindustryinputfor2017¾ActuallymodeledasasweepofCdandCrr¾Weightpenalty:225kg14©SouthWestResearchInstitute®2009RTech.Package#3:CdSweepPackage3:CdSweepwithCrr=0.0045,GVW=80klbs55.566.577.588.590.30.350.40.450.50.550.60.65CoefficientofDrag(-)FuelEconomy(mpg)0510152025303540PercentFuelSavedFuelEconomy(mpg)PercentFuelSavedvsPackage115©SouthWestResearchInstitute®2009RPackage3ConclusionsƒCrrreductionfrom0.0068to0.0045providesa10.6%fuelconsumptionreductionƒCdreductionfrom0.6298to0.4providesanadditional14.1%fuelconsumptionreductionƒManytechnicalandpracticalchallengesremaintoachieveeven0.4CdƒThefullPackage3providesa24.7%fuelconsumptionandGHGreductionat80,000lbs.GVW16©SouthWestResearchInstitute®2009RPackage4:ParallelHybridƒParallelhy