Technology for Actualizing HCCI in Gasoline Engines

The homogenous charge compression ignition (HCCI) is a new combustion concept, which incorporates the best features and discards the disadvantages of both traditional spark ignition (SI) gasoline engine and compression ignition (CI) diesel engine. In this article, feasibility of gasoline engines that implement HCCI technology is analyzed; the problems facing the practicability of HCCI engine are introduced; an eclectic scheme of dual-combustion-mode engine is presented, in which HCCI is operated in low-to-medium load but the normal mode comes back in high load operation and cold-start operation. Schemes of variable compression ratio (VCR), variable exhaust gas recirculation (EGR), variable exhaust valve timing, and EGR with stratification by tumble charge flow are recommended. The technology trend is indicated for applying HCCI to gasoline engines as soon as possible.