HCCI发动机介绍

PresentationatWindsorWorkshop2000TransportationFuelsATFEngineManagementSystemsSessionToronto,ONJune6,2000Jan-RogerLinna,RichardStobart,RobertP.WilsonArthurD.Little,Inc.HomogeneousChargeHomogeneousChargeCompressionIgnitionCompressionIgnitionTheHolyGrailofInternalCombustionEngines...butCanweTametheBeast?1HCCI-CanweTametheBeast?22ObjectiveandApproachObjectiveandApproach33HCCISystemsControlModelHCCISystemsControlModel4411IntroductionandBackgroundIntroductionandBackground77SummarySummaryModelScreeningofSelectedLoadControlStrategiesforSteadyStateModelScreeningofSelectedLoadControlStrategiesforSteadyState66TakingitForwardTakingitForward55EngineTestingforModelValidationEngineTestingforModelValidation2HCCI-CanweTametheBeast?2ObjectiveandApproach3HCCISystemsControlModel411IntroductionandBackgroundIntroductionandBackground7SummaryModelScreeningofSelectedLoadControlStrategiesforSteadyState6TakingitForward5EngineTestingforModelValidation3Evenifmanmadecarbondioxideemissionsworldwideareestimatedtocontributeonly3to5percenttothetotalglobalCO2emissions,thereareconcernsthatthisadditionalfractionmayadverselyaffectthenaturalCO2equilibriumandthusglobalclimate.COCO22ReleasedtoAtmosphereinGt/yrReleasedtoAtmosphereinGt/yrNatural95-97%02004006008001,000Manmade3-5%600-1,000Gt/yrReferenceReferenceYear1996Year1996VegetationVegetation29%29%OceansOceans43%43%SoilSoil28%28%25-30Gt/yrContributiontoCOContributiontoCO22EmissionsEmissionsfromFossilFuelBurningfromFossilFuelBurningIntroductionandBackgroundSource:EmissionsandAirQuality;Lenz,HansPeter,andCozzarini,Christian-SAE1999North-North-AmericaAmerica28%28%Europe30%EuropeEurope30%30%AsiaandOceania36%AsiaandAsiaandOceaniaOceania36%36%AfricaAfrica3%3%CentralandCentralandSouthAmericaSouthAmerica3%3%114Thetransportationsector,representingonefifthofallmanmadeCO2emissions,consequentlycanexpecttofacemountingpressuretoraisefuelefficiencyinthewakeoftheKyotoagreementtocutemissionsofgreenhousegasesbackto1990levelsby2008–2012.IntroductionandBackgroundSource:EmissionsandAirQuality;Lenz,HansPeter,andCozzarini,Christian-SAE1999Trucks(6%)Trucks(6%)IndustryIndustry19%19%ResidentialBurners23%ResidentialBurners23%PowerStations25%PowerStations25%BiomassBiomassBurningBurning19%19%PassengerCars(5.5%)PassengerCars(5.5%)AirTraffic(3%)AirTraffic(3%)SeaTraffic(1.5%)SeaTraffic(1.5%)OtherTraffic(2%)OtherTraffic(2%)Traffic18%Traffic18%115Inaddition,therecentlyproposed2007Federalheavy-dutyemissionsstandardspresentacriticalchallengefordieselenginemanufacturersinNorthAmericaqTheproposed2007mandatesrepresentanorderofmagnitudereductionofemissions.qTheproposedstandardsarebeyondreachofeventhemostadvanceddieseltechnologies.qTheindustryisnowlookingfornewtechnologybreakthroughs.0.00.20.40.60.81.01.2024681012NOx[g/kWh]Particulates[g/kWh]US1990US2004US2007US1994AdvancedElectronicControlTurbo-chargedTurbo-chargedandAftercooledEU1992EU200011IntroductionandBackground6Controversyoverthehealtheffectsofparticulatematteremissionsandtoxicityofdieselexhaustposeadditionalchallengestodieselengines.IdentifiedParticulateMatterfromdieselfueledenginesasaToxicAirContaminant(8/98).qReviewedbytheCleanAirScientificAdvisoryCommittee(CASAC)andreturnedforrevisionqDevelopingariskmanagementplanqFocusoncontrolmeasuresthatmaybeneededtoreduceparticulateemissionsandotherpotentiallyharmfulpollutantsfromdieselfueledenginesqPossiblestrategiesincludeadditionalvehicleemissionstandards,improvementsindieselfuel,andincentiveprogramstoaccelerateturn-overofin-useequipment,butnotexplicitbanningofdieselfuelordieselenginesDieselemissionsidentifiedasa“probable”humancarcinogen(1998Draft)IntroductionandBackground117HomogeneousChargeCompressionIgnition(HCCI)enginesareattractingsignificantattentionasacleanandefficientpowersourceHCCIenginesprovidehighefficiencieswithdramaticallyimprovedemissions.qThermalefficiencyreported:50%qNOx10ppm(comparedto500ppmfordieselengines)qPMdetectionlimit(comparabletogasolineengines)Ifthecontrolissuesaresuccessfullyaddressed,HCCIcouldcombinefueleconomiescomparabletothebestdieselengines,withexhaustemissionscomparabletothebestspark-ignitionengines.Withconventionalcontroltechnologies,misfireandknocklimitstheloadfollowingcapabilitiesofHCCIenginestolessthanhalfofthatrequired.11IntroductionandBackground8TheseemissionscharacteristicscouldallowthetechnologytooperatewithoutNOxreductionexhaustaftertreatment.OxidationcatalystswouldberequiredhoweverasbothCOandHCcanexceed10,000ppm.HCCIhasbeenproposedastheultimateleanburnconceptbecauseofthepotentialforhighthermalefficiencyandnear-zeroNOxemissions.qAsinDieselengines,thefuelisexposedtoasufficientlyhightemperatureforauto-ignitiontooccur(compressionignition).qHowever,incontrasttoDieselenginesahomogeneousfuel/airmixtureisused.qAnimportantdifferencebetweensparkignitionandHCCIenginesisthelackofflamepropagationinHCCIcombustionandhenceincreasedleanburntolerance.AdvantagesAdvantages•Highthermalefficiency(somestudieshavereportedover50%)associatedwithunthrottled,ultra-leanoperation:­Increasedratioofspecificheatsduringex