废气再循环对米勒循环汽油机性能及颗粒物排放特性的影响

Effects of Exhaust Gas Recirculation on Performance and Particulate Emission Characteristics of Miller Cycle Gasoline Engine

为了更好地探究废气再循环技术对汽油机性能及颗粒物排放的影响,在一台单缸热力学汽油机上,通过控制EGR率及EGR废气温度,进行了发动机性能和排放试验研究。研究表明,随着EGR率的提高,燃油消耗率降低,发动机热效率提高,发动机点火时刻提前,爆震倾向减小;但大负荷工况,低EGR率会增大发动机的爆震倾向,导致燃油消耗率升高。试验所选负荷工况,当EGR率提高至17%时,燃油消耗率降低约5.6%。小负荷工况,随着EGR率的提高,颗粒物数量排放峰值升高。大负荷工况,随着EGR率的提高,核膜态颗粒物排放峰值降低,积聚态颗粒物排放峰值升高。各工况下,EGR废气温度对颗粒物数量排放的影响相对不明显。

In order to better explore the effects of exhaust gas recirculation technology on gasoline engine performance and particulate matter emission,the engine performance and emission tests were carried out on a single cylinder thermodynamic gasoline engine by controlling EGR rate and EGR exhaust gas temperature.The results show that with the increase of EGR rate,the fuel consumption rate is reduced,the engine thermal efficiency is improved,the engine ignition time is advanced,and the knock tendency is reduced.However,under heavy load conditions,low EGR rate will increase the knock tendency of the engine,resulting in increased fuel consumption.Under the selected load conditions,when the EGR rate increases to 17%,the fuel consumption rate decreases by 5.6%.Under small load condition,with the increase of EGR rate,the emission peak of particulate matter increased.Under heavy load conditions,with the increase of EGR rate,the peak value of nuclear membrane particulate emissions decreased,while the peak value of aggregated particulate emissions increased.The influence of EGR exhaust gas temperature on the quantity of particulate matter emission is relatively insignificant.