高压共轨柴油机燃烧与排放模型的研究

利用高速闪光摄影技术,对高压喷射喷雾体空间发展规律进行了试验分析,提出了一个计算高压喷射喷雾体发展的数学公式;在正确描述高压燃油喷雾的基础上,建立了一个能预测高压共轨柴油机性能和排放的准维燃烧模型,此模型改进了燃油喷射模型及碳烟的生成与氧化模型,考虑到燃烧区的区间传热和缸内工质的对流辐射传热,对一台高压共轨柴油机进行了仿真计算。计算与试验结果对比分析表明,改进后的燃烧与排放模型能较好地反映缸内各区的燃烧与排放情况。

Study on Combustion and Emission Model of Diesel Engine with High Pressure Common Rail System

High speed spark photography is applied to take pictures of high pressure injection fuel spraying, through experiment and analysis a new formula for calculating the spray tip development under the high injection pressure is developed. Based on exactly describing high pressure fuel injection spraying, a quasi-dimensional combustion model for forecasting performance and emission of high pressure common rail diesel engine is established. This model gives some improvements about fuel spray and atomization, soot formation and oxidation, heat transfer of substance in cylinder has been offered. The simulation shows that the model work well in predicting the combustion and pollutant formation of diesel engine, and it can be used to study the performance and emission of diesel engine with a high pressure common rail system.