二甲醚均质充量压燃发动机排放特性的试验研究

Experimental Investigation of DME HCCI Engine Emissions

试验研究了压缩比为10 7的二甲醚均质充量压缩点燃燃烧发动机的排放特性。试验结果表明,采用DMEHCCI燃烧方式可以有效控制发动机的氮氧化合物排放,使其接近于零,实现无烟燃烧。在一定的负荷范围内,发动机的碳氢和一氧化碳排放与柴油机相当;低负荷时混合气过稀,则碳氢和一氧化碳排放偏高,而高负荷混合气过浓时,又有可能导致敲缸。发动机稳定运转的条件是一定的空燃比必须对应一定的发动机转速和负荷。

The emission characteristics of a DME fueled HCCI engine with compression ratio of 10.7 was studied experimentally.The test results showed that DME HCCI engine presented almost zero NO_x emission and smokeless behavior.Within a narrow range of A/F ratio,the emissions of CO and HC of the DME HCCI engine gave the same level as that of CI diesel engine.Under the low load conditions,leaner mixture would result in higher CO and HC emissions.While under high load cases,knock would occur due to the richer mixture.DME HCCI engine could only work within a limited range of speed and load under a limited air fuel ratio.