Abstract
Homogeneous charge compression ignition is promising a new combustion system reducing NOx and PM simultaneously without any penalty of fuel consumption. However, the operational range of the combustion system is limited because of some issues such as poor control of ignition timing and the excessive rate of pressure rise. In this study, a new combustion system based on the HCCI combustion process have been proposed. The combustion chamber of the engine is divided into two part, one is in the cylinder head, small chamber, another is in cylinder, large chamber. On the combustion system, at first compression ignition takes place in the small chamber, then, the burned gas ejected into the large chamber ignite the mixture in the chamber. The combustion process in the large chamber is aimed to go on same manner of the HCCI combustion process. This paper presents performance, exhaust emission and combustion characteristics of the combustion system. Test results show indicated thermal efficiency was almost same as or slightly higher than diesel engine. However, NOx emission was higher than ordinary HCCI engines.
