喷射参数对二甲醚PPCCI发动机燃烧与排放特性的影响  

Influences of Injection Parameters on Combustion and Emission Characteristics in a Dimethyl Ether PPCCI Engine

作　　者：杨武林 王春海[1] 黄震[1] 

机构地区：[1]上海交通大学动力机械与工程教育部重点实验室,上海200240

出　　处：《内燃机工程》2017年第5期22-27,共6页Chinese Internal Combustion Engine Engineering

基　　金：国家"八六三"高技术研究发展计划项目(2012AA111721)~~

摘　　要：在一台6缸增压电控共轨二甲醚发动机上进行试验,研究了预喷时刻、预喷燃料量、喷射压力、主喷时刻等喷射参数对二甲醚部分预混合充量压缩燃烧(PPCCI)发动机燃烧与排放特性的影响。试验结果表明:随预喷时刻提前,缸内压力峰值降低,二甲醚发动机缸内燃烧由两阶段放热转变为PPCCI三阶段放热,氮氧化物(NOx)排放显著降低,HC和CO排放升高;随预喷射燃料量增加,缸内压力峰值及预混合燃烧的冷焰反应和热焰反应速率明显增大,NOx排放逐渐降低,HC和CO排放显著升高;随喷射压力降低,预混合燃烧热焰反应速率增加,主喷扩散燃烧始点推迟,扩散燃烧放热率峰值和NOx排放明显降低,HC和CO排放升高;随主喷时刻推迟,预喷预混合燃烧几乎没有变化,主喷扩散燃烧延后,缸内压力峰值和放热率峰值降低,NOx排放显著降低,HC和CO排放升高。The effects of pilot injection timing, pilot injection quantity, injection pressure and main injection timing on thepartial premixed charge compression ignition （PPCCI） combustion and emissions of a six cylinders, electronically controlled common rail dimethyl ether （DME） engine were investigated. Results show that, with the advance of the pilot injection timing, the peak cylinder pressure is reduced, and the combustion heat release is changed from the two-stage mode to the three-stage mode of PPCCI; in addition, NO^ emission is reduced, and HC and CO emissions are increased. With the increase of pilot injection quantity, the peak cylinder pressure and the reaction rates of cool flame and thermal flame of the PCCI are increased, HC and CO emissions are also increased, while NO^ emission is decreased. With the decrease of injection pressure, the peak value of heat release rate of the PCCI is increased and the start of the main injection diffusion combustion is delayed, the peak heat release rate of the main injection diffusion is significantly reduced; furthermore, NO^ emission is significantly decreased while HC and CO emissions are increased dramatically. With the delay of the main injection timing, there is little change in the PCCI, the start of the main injection diffusion combustion is delayed significantly, the peak pressure and the peak heat release rate are decreased; moreover, NOx emission is significantly decreased while HC and CO emissions are increased.

关 键 词：二甲醚发动机 喷射参数 部分预混合充量压缩燃烧 燃烧 排放 

分 类 号：TK46[动力工程及工程热物理—动力机械及工程]