冷EGR对DME PCCI-DI发动机燃烧和排放特性影响的试验研究  

Investigation on Effects of Cold EGR on Combustion and Emission Characteristics in a DME PCCI-DI Engine

作　　者：汪映[1] 周杰[1] 何利[1] 郭振祥[1] 周龙保[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《内燃机工程》2010年第4期17-20,共4页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金资助项目(50706038)

摘　　要：PCCI-DI是一种部分预混充量压缩着火和燃料直接喷射燃烧的组合工作方式,可有效降低发动机的NOx排放,但其在高负荷工作时易受到爆震影响,导致发动机功率下降,排放恶化。为此,开展了冷EGR对DME PCCI-DI发动机燃烧和排放特性影响的试验研究。结果表明:随着EGR率的增加,缸内最高燃烧压力下降,主燃烧期推迟并略有延长,NOx排放下降,但较大的EGR率会导致PCCI-DI发动机HC和CO排放迅速升高。采用冷EGR在一定程度上可以改善PCCI-DI发动机的燃烧过程,拓宽发动机的工作范围。Part charge compression ignition and direct injection （PCCI-DI） combustion can effectively reduce NOx emissions, however the PCCI-DI operation is liable to be effected by knocking at high load region, which would lead to engine power lowered and emissions deteriorated. In view of the fact, the experimental investigation into the effects of cold EGR on performance and emissions of DME PCCI-DI engine was carried out. Results show that for PCCI-DI engine, with EGR rate increasing the peak cylinder pressure lowers and main combustion duration delays and extends slightly, NO, emissions reduce. However, high EGR rate may result in engine HC and CO emissions rapid rise. It is concluded, in the DME PCCI-DI engine intro- ducing the cold EGR may improve combustion process and widen operation range to a certain extent.

关 键 词：内燃机 废气再循环 部分预混充量压缩着火 直喷 二甲醚 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]