摘要
在一台两缸二甲醚发动机上开展了不同废气再循环(EGR)率下发动机的性能和排放特性研究,测量了不同工况下发动机的油耗,HC、CO和NOx的排放.研究表明:二甲醚发动机可承受的最大EGR率接近60%,但在高负荷时,过大的EGR率会导致发动机燃油消耗率显著升高;EGR率对发动机的NOx排放量影响很大,随着EGR率的增加,发动机的NOx排放量大幅度下降,高负荷时下降幅度更大;EGR率增大,HC和CO排放增加,高负荷时增加的幅度更大,特别是当EGR率超过一定范围时,EGR率的增大会引起HC和CO排放的急剧增加;低负荷时,最佳EGR率应保持在30%左右,而高负荷时,应采用较小的EGR率.
To study the influences of the exhaust gas recirculation（EGR）rate on the emissions and performance of dimethyl ether （DME） engines, an experimental investigation was conducted on a 2-cylinder DME engine with EGR. Under the various operating conditions, the fuel consumption and emissions of HC, CO, and NOx were measured. The results show that the maximum EGR rate of the DME engine can reach 60% approximately, however, under high load conditions, too large EGR rate will result in obvious deterioration in the engine brake specific fuel consumption. EGR has significant effects on NOx emissions. NOx emissions decrease clearly with the increase in the EGR rate, especially under high load conditions. HC and CO emissions increase with the increase in the EGR rate, particularly under high load conditions. When the EGR rate is over a certain value, the increase of the EGR rate will lead to a quick increase in HC and CO emissions. It is suggested that the optimal EGR rate should be near 30% under low load conditions while the engine should run with low EGR rates under high load conditions.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2009年第11期27-31,共5页
Journal of Xi'an Jiaotong University
关键词
二甲醚发动机
废气再循环
性能
排放特性
dimethyl ether engine
exhaust gas recirculation
performance
emission characteristics
