A novel EGR system to improve engine performance of a diesel engine

A recent focus on automotive researches is to reduce CO2 emission due to stringent regulation. Auto makers has been dealing such regulations with either applying novel combustion strategies or utilizing alternative fuels for IC engines. In addition, low emission vehicles such as HEV and FCEV have developed to reduce emission and fuel consumption. Of IC engines, diesel engine having a higher thermal efficiency compared to gasoline engine has an advantage of a low CO2 emission. In this study, various effects of cooled EGR on diesel engine performances, emission and combustion characteristics were investigated. A separate cooling circuit in combination with additional heat exchangers were installed to control temperatures of EGR gas and charged air independently. As the EGR gas temperature was decreased, PM and NOx emission and BSFC were substantially reduced. However, the cooled EGR was found to increase THC and CO emissions.