001_thermal management for reduction of emissions

ThermalmanagementforthereductionofemissionsandfuelconsumptionintrucksHeatup.Cooldown.TechnicalPressDay2010TechnicalPressDay20102Contents341018IntroductionEnergyefficientcommercialvehicleenginecoolingsystemsforEuroVIVisco®fansandwaterpumpdrivestoreducefuelconsumptionincommercialvehiclesWasteheatrecovery:thenextchallengefortruckenginedevelopmentThermalmanagementforthereductionofemissionsandfuelconsumptionintrucks3Introduction2009wasadifficultyearforthecommercialvehicleindustry.Alongsidetheeconomiccycleandthefinancialcrisis,therewerealsostructuralcausesforthemarketscollapsing.Sincethebeginningof2010themarkethasbeenrecovering.Ingeneralweexpectslightincreasesoverthenextfewyearsbutwithmajorshiftsbetweenregions.Despitethesecycles,thetruckmarketremainsimportanttoBehrandBehrisimportanttothetruckbusinesstoo.Asignificantfactorinthisarethenewproductsoutlinedbelow.EuroVIcontinuestobetheNo.1drivingforceinthetruckbusiness.Inthiscontextthermalmanagementisbecomingincreasinglyimportant,asEuroVIcannotbeimplementedeffectivelywithoutexhaustgasrecirculation,i.e.onlywithSCR.Inpracticethismeansthatinthefuture,coolingsystemswillhavetodissipatemoreheat,notless.Forthis,largerandmoreefficientradiatorsandmorepowerfulfansareneeded,whichinturnrequirenewdrives.Anotherdriverforthetruckbusinessisreducingfuelconsumptioneitherbecauseofstatutoryregulationsinthefutureoreconomicnecessity.Howcanwemeetthesechallenges?ElectronicallycontrolledVisco®fandrivesnowdominatetheEuropeanmarket.Thecontrolsystem,whichrespondstodemand,canbetransferredtootherapplicationssuchasthewaterpump,thusreducingparasiticpowerlosses.Hybridsolutionswillnotplaythesameroleintheclassictruckapplicationsastheydoforlightvehicles.Challengesariseherefromtheextracostsofsuchasystem,thespecificoperatingmodesofthetrucks,whichforexamplemakeitdifficulttoeffectivelyrecoverthebrakingenergy,andtheasyetinsufficientpowerandstoragedensityofcurrentLi-ionbatteries.Soanotherpotentialsolutionistousethethermalenergyremainingintheexhaustgas.Forexample,itcanbeconverteddirectlyintomechanicalenergybymeansofaRankineprocessandmadeavailabletothepowertrain.Initialresearchbyourdevelopmentengineersshowsthatthistechnologyhasconsiderablepotential.Asyoucansee,thetruckbusinessremainsexcitingandtechnologicallychallenging,achallengethatwearehappytoembrace,forwhichwehavetherightapproachandaredevelopingtherightsolutions.Inthefollowingpageswewillbeshowingyousomespecificapproachesforimplementingthermalmanagement,ensuringthattruckswillcontinuetofulfillemissionsandfuelconsumptiondirectivesinthefuture.Wehopeyou’llfindthefollowingpagestobeaninterestingread.4EnergyefficientcommercialvehicleenginecoolingsystemsforEuroVIFrom2013,commercialvehicleenginesinEuropemustmeettheEuroVIemissionslimitvalues.SimilarlystrictregulationsarealreadyinforcetodayinJapan,whilestandardsintheUSareevenstricter.Othercountrieswillfollowsuitinduecourse.AsopposedtotheemissionsstandardsEuroIIItoV,itisunlikelythatthemuchlowerEuroVIlimitvaluescanbeachievedwithoutincreasingfuelconsumption.Inordertokeepthisadditionalfuelconsumptiontoaminimum,Behrhasmadethecommercialvehicleenginecoolingsystemgenerallymoreenergyefficient,throughtheuseofnewandoptimisedcomponentsandbyimprovingtheinteractionbetweenthesecomponents.Thisoptimizedcoolingsystemisalsoakeytotheimplementationoffurthertechnologiestocutemissionsandfuelconsumption.EberhardPantow,Manager,AdvancedEngineering,Systems,ModulesandFans,TrucksAnoptimizedcoolingsystemisalsoakeytotheimplementationoffurthertechnologiestocutemissionsandfuelconsumption.ExhaustgasrecirculationwillbeintroducedacrosstheboardThepredictionsthatBehrmadeatthe2008PressDayaboutforthcomingexhaustgasrecirculationtechnologiesforEuroVIhavebecomereality:forexample,theoverwhelmingmajorityofapplicationswillfeatureacombinationofcooledexhaustgasrecirculationwithselectivecatalyticreduction,Fig.1.Withthiscombination,neitherofthetwosystemsneedstobeoperatedatthelimitsofwhatistechnicallyfeasible,where,inthemajorityofcases,operatingandsystemcostsmaybeunacceptable.Inaddition,irrespectiveofthereductioninnitrogenoxides,Behranticipatesthatallsystemswillfeatureaparticulatefilter.WhatisimportantforBehristhat,followingtheUSandJapan,exhaustgasrecirculationisnowbecomingamoreorlessacrosstheboardtechnologyinEuropeaswell.Figure1|PossibletechnologiestoachieveEuroVIlimitvalues00AllsystemswithDieselparticulatefilter(DPF)NOx[g/kWh]1EuroVIEuroVDPFSCR(85%)2DPF3456780,01PM[g/kWh]0,020,030,05MaindevelopmentpathforEuroVIDPFSCRonlyHighlevelofcomplexityforSCRsystemDPFSCR(75%)SCRfocus•Simpleengine•HighlevelofcomplexityforSCRsystemEGRfocus•Highlevelofenginecomplexity•SimpleSCRsystemEGRonly•HighlevelofenginecomplexitySCR(90%)TechnicalPressDay20105Eventhoughreducingengineemissionsgenerallyleadstoincreasedfuelconsumption,itwaspossible,attheEuroIIItoVstandards,tocompensateforthisdrawbackthroughtechnicaladvances.InthecaseofEuroVI,thisisnolongerentirelyfeasible,whichmakesthecontributionofthecoolingsystemtovehiclefuelconsumptionallthemoreim-portant.TheoptimizationstepstakenbyBehrtominimizethisadditio