Abstract: Applying optimized kinetic process technology the waste thermal energy in the coolant and exhaust gases for intake air heating was used to realize HCCI combustion in a multicylinder gasoline engine. The effects of spark assisted HCCI on combustion and emissions were investigated. The results show that utilization of spark assisted HCCI is found to increase indicated mean effective pressure (IMEP), pmax, (dp/dθ)max and reduce cyclebycycle variation so as to improve the stability of HCCI combustion. Spark assisted HCCI can achieve a twostage combustion. When increasing the spark advance angle, the heat release rate peak value will increase. The introduction of spark significantly advances the combustion to top dead center (TDC) and lowers the NOx and HC emissions.

Key words: spark assisted, multicylinder gasoline engine, homogeneous charge compression ignition (HCCI) combustion, emissions characteristic