experimental investigation of the effects of AFR, spark advance and EGR on nanoparticle emissions in a PFI SI engine

Nanoparticle emissionscontinuetocatchtheattentionbecauseoftheiradversehealth effectsandtheirimpactontheenvironment.Internalcombustionenginesarethemajor source ofparticleemissionsinurbanareas.Thelegislationproposesastrongerrestriction for bothdieselandgasolineengines.Inparticular,theEuropeanparticlemeasurement program(PMP)hasintroducedparticlenumberregulationforbothdieselandgasoline engines.Greateffortsarethendevotedtothereductionoftheparticleemissions; nonetheless,themechanismsgoverningparticleformationarestillnotfullyunderstood, neitherfordieselnorforgasolineengines. The aimofthepaperistheexperimentalcharacterizationofparticlesemittedfroma Port FuelInjection(PFI)gasolineengineinsteadystateoperatingconditions.Inparticular, the impactofenginecontrolvariables(i.e.injectiontimeandsparkadvance)and emissionscontroltechnologies(i.e.exhaustgasrecirculation--EGR)onparticlesizeand numberwasdeeplyinvestigated.Moreover,theeffectofthedilutionconditionswasalso analyzed. Theinvestigationwascarriedoutattheexhaustofa1242ccPFIsparkignition (SI) engine.Theenginetestbenchwasequippedwithafull-passenginecontrolsystem dSPACEMicroAutoBox and a scannering mibility particle sizer (SMPS) for particle counting and sizing.