Geothermal Energy and Emission Control Lab.

New Combustion Technology of gasoline engine such as CAI(controlled Auto-ignition) engine, SCCI(Stratified Charged Compression Ignition) engine, HCCI(Homogeneous Charged Compression Ignition)engine. Stratified charge compression ignition (SCCI) combustion, which is developed to extend the HCCI (homogeneous charge compression ignition) operating range, has a good potential to improve fuel economy and to reduce emissions. In this study, SCCI combustion and emission characteristics were investigated in a single-cylinder gasoline engine with a direct-injection system. From the experimental results, we elucidated the effects of air-fuel ratio, intake temperature and injection timing including early and late injection on the attainable SCCI combustion region. CAI combustion was realized using a single cylinder gasoline DI engine. In this study, the camshafts were modified in order to restrict the gas exchange process. We investigated the effects of air-fuel ratio, residual EGR rate and injection timing on the CAI combustion area. In addition, the effect of injection timing on combustion factors such as the start of combustion, its duration and its heat release rate was also investigated.