Experimental Research on Heat-Work Conversion of Fuel Pre-Combustion Process in Gasoline HCCI Engines
The effects of in-cylinder fuel pre-combustion (FPC) process on Homogeneous charge compression ignition (HCCI) combustion were studied in a gasoline direct injection (GDI) engine with negative valve overlap (NVO).The in-cylinder fuel pre-combustion process was obtained by a pre-injection into the high temperature exhaust gas during the NVO period and used to increase the mixture temperature for HCCI auto ignition. The influences of the pre-injection timing, pre-injection amount and oxygen concentration during NVO period on FPC process were analyzed. The result showed that, like the main combustion process, the fuel injected into the high temperature exhaust gas during the NVO period would partly combust and form a special energy conversion process. Part of the released heat is converted to effective work and part of the heat is remained in the mixture to raise the temperature and pressure helping reduce the pumping loss. The amount of released heat during fuel pre-combustion is determined by the oxygen concentration and influenced by the fuel injection timing and amount. The effects of FPC on main combustion timing are the main reasons for the thermal efficiency variation.
Dong-bo Yang Zhi Wang Fan Xu Jian-Xin Wang
State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China
国际会议
天津
英文
1-8
2009-08-19（万方平台首次上网日期，不代表论文的发表时间）