甲醇-汽油双燃料火花点火发动机试验研究

Experimental Study of the Methanol-Gasoline Dual-Fuel Spark Ignition(DFSI)Combustion

基于一台由缸内直喷汽油机改装而成的高压缩比双燃料汽油机,研究了甲醇-汽油双燃料喷射方式(M-G,是指进气道喷射甲醇,缸内直喷汽油)和汽油-甲醇双燃料喷射方式(G-M,是指进气道喷汽油,缸内直接喷甲醇)两种双燃料双喷方式对火花点火发动机燃烧排放特性、热效率和爆震抑制的影响。在试验过程中甲醇的喷射比例范围为0~100%。试验结果表明:相比于汽油单燃料发动机,两种双燃料喷射方式(M-G和G-M)都能够显著提高经济性、抑制爆震同时降低微粒排放;G-M双燃料喷射方式相比M-G双燃料喷射方式在抑制爆震、降低微粒排放上效果更加显著。

An experimental study on methanol-gasoline and gasoline-methanol dual-fuel spark ignition （DFSI） combustions for knock suppression and higher engine efficiency was conducted with a high compression ratio gasoline engine. The methanol-gasoline DFSI was organized using a port fuel injection （PFI） of methanol and a direct injection （DI） of gasoline, while the gasoline-methanol DFSI was organized by gasoline PFI and methanol DI. The tested engine was naturally aspirated and operated at stoichiometric condition. In the test, the amount of methanol injection was varied from 0 to 100%. The effects of these two injection modes on knock-limit extension, fuel economy, and PM reduction were investigated. The test results show that both the methanol-gasoline DFSI and gasoline-methanol DFSI are promising approaches of using alternative alcohol fuels in practical gasoline engines with significant improvement in engine efficiency and knock suppression. The gasoline-methanol DFSI exhibits better in anti-knock performance and PM reduction than the methanol-gasoline DFSI.