Yungjin Kim

Effects of Injection Strategies on the Partial Premixed Charge Combustion and Emission Characteristics in a Diesel Engine

Abstract : Recently, PCCI (premixed charge compression ignition) combustion is studied to reduce both NOx and PM because of homogeneous mixture formation and lower combustion temperature. It has also merit of increasing thermal efficiency owing to better air-fuel mixure. However, it is well known that PCCI combustion has a weakness in fuel economy because PCCI combustion tends to start before TDC. Therefore, it is necessary to find an optimal conditions for PCCI combustion which maintains reduction of NOx, PM and increase of thermal efficiency. In this study, pPCCI combustion was realized by adding early injection strategy to a conventional diesel engine. In addition, the charac-teristics of pPCCI combustion was analized by comparing conventional diesel injection strategy. The results show that NOx and PM per power in pPCCI combution were reduced compared to a conventional diesel combustion. Key words : pPCCI(부분 예혼합 압축착화), Pilot injection(파일럿 분사), Early injection(조기 분사), Common-rail diesel engine(커먼레일 디젤 엔진)