EGR和冷EGR对柴油机燃烧和排放的影响  

Effects of EGR and Cooled EGR on Combustion and Emission of a Diesel Engine

作　　者：朱瑞军[1] 王锡斌[1] 冉帆[1] 苗海燕[1] 黄佐华[1] 高兢[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《西安交通大学学报》2009年第9期23-26,55,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(50876086);国家自然科学基金创新群体资助项目(50521604)

摘　　要：设计了一种带冷却系统的柴油机废气再循环(EGR)装置,并进行了EGR及冷EGR对柴油机燃烧和排放性能影响的试验研究.结果表明,在各种工况下,EGR都可以显著降低NOx排放,当EGR率为15%时,中高负荷下NOx排放可以降低50%左右,当EGR率为30%时,高负荷下NOx排放可以降低75%左右.但是,EGR率的增加会给柴油机的动力性、燃油消耗率、烟度、CO和HC排放带来不同程度的负面影响,使柴油机的最大爆发压力及放热率峰值下降且出现的位置略微后移.使用冷EGR、中高负荷下,NOx排放可以减少15%左右,烟度排放略有降低.An EGR unit with a cooling system was developed for a diesel engine and the effects of cooled EGR and uncooled EGR on combustion and emission were investigated experimentally. The results show that EGR can reduce NOx emission of the diesel engine significantly under various operation conditions. NOx emission can decrease by about 75% at the EGR rate of 30% under high loads but the increase of the EGR rate has negative influence on torque output, brake specific fuel consumption, and emissions of smoke, CO and HC. Moreover, peak values of combustion pressure and heat release rate decrease. The cooled EGR system can reduce NOx and smoke emission more effectively compared with the uncooled EGR system under high and normal loads.

关 键 词：废气再循环 冷废气再循环 燃烧 排放 柴油机 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]