进气温度对汽油/正庚烷HCCI燃烧与排放特性的影响

Effects of Intake Temperature on the Gasoline/N-Heptane HCCI Combustion and Emissions in Gasoline Engine

采用双燃料喷射系统在进气道分别喷入汽油和正庚烷,结合优化动力技术手段,实现了四缸汽油机的均质混合气压燃(HCCI)燃烧,研究不同进气温度对发动机燃烧特性与排放特性的影响。试验结果表明:在其他边界条件一定时,随着进气温度的升高,燃烧相位提前,燃烧持续期缩短;缸内最大爆发增大,最大放热率提高,压力升高率提高,其最大值到达的时间提前;HC、CO排放呈现降低的趋势;IMEP整体呈现先升高后降低的趋势,但是之间出现两个峰值。

Stable homogeneous charge compression ignition （HCCI） combustion on a commercial gasoline en- gine was realized through dual fuel （gasoline/n -heptane） port injection system as well as the optimized ki- netic process technology. The effects of intake temperature on HCCI combustion and emissions were explored. The test result shows that increasing the intake temperature leads to earlier combustion timing, shorter combus- tion duration ; the peak value of pressure, heat release rate and rate of pressure rise increase, and come earli- er; HC and CO emissions are lower; IMEP appears in the trend of firstly increased then decreased including two peaks.