气道喷射汽油机缸内燃烧过程的可视化研究

Visualization of Combustion Process in the Port Fuel Injection Gasoline Engine

利用光学单缸机和高速摄像系统,研究了喷油正时对气道喷射汽油机暖机工况缸内燃烧过程的影响,并从不同喷油正时对缸内混合气形成影响过程出发,解释了出现的缸内燃烧现象。研究结果表明,气道喷射汽油机在暖机工况缸内燃烧过程会出现较多的扩散燃烧现象;不同喷油正时对应的雾化和燃油进入缸内的机理不同,所形成的混合气质量也有较大差异,导致出现不同的燃烧现象;在排气行程晚期、进气行程早期和压缩行程中期进行燃油喷射,缸内混合气燃烧过程中出现扩散燃烧现象较少。

In this paper, the influence of fuel injection timing on combustion process in the PFI gasoline engine was studied by using optical single cylinder and high speed camera, which was explained by the process of the mix formation at different fuel injection timing. The results showed that the port injection gasoline engine will create more diffusion combustion phenomena in the warming operating condition; because the different mechanism of atomization and fuel entering the cylinder at different injection timing, the formation of mixed gas quality are quite different, which was the reason of different combustion processes; the fuel injection which happened in the exhaust stroke, the early intake stroke or the middle compression stroke resulted less diffusion combustion phenomena in the combustion process.