Abatement potential analysis on CO2and size-resolved particle emissionsfrom a downsized LPG direct injection engine for passenger car

Özet

As global warming andfine dust problem became issues, the regulation for relevant exhaust emissions has beenstrengthened gradually. Thus, a major challenge of automotive engineers is reducing the CO2and particleemissions at the same time. Especially for gasoline direct injection (GDI) engines, which are widely used due toits higher fuel efficiency, an excessive particle emissions problem compared to port fuel injection system is thebig nuisance. The LPG fuel, which has great fuel properties for applying this direct injection scheme, could dealwith this. Also, downsized turbocharged system can reduce additional fuel consumption and CO2emissionssequentially. In this study, a GDI passenger car and the same vehicle equipped with a downsized turbochargedliquefied petroleum gas direct injection (T-LPDi) engine were evaluated under chassis dynamometer test toverify the exhaust emission abatement capability of T-LPDi vehicle. The T-LPDi engine was developed for re-search use, which has dedicated fuel supply and control strategy for LPG fuel. Comparing the T-LPDi and GDIvehicles, the CO2emissions were decreased by > 20% under the vehicle test condition, while particle numberand mass emissions were decreased by > 90% and > 50% from the T-LPDi vehicle respectively. These resultsshowed a potential of T-LPDi concept as a good alternative with the environmental competitiveness, thoughthere is room for further improvement of engine control and optimization of emission catalyst to meet morestringent future regulations.