CNG/汽油两用燃料发动机排放试验研究

汽油机燃用CNG燃料的排放状况是广受关注的问题。参照GB18352的试验运转循环工况的规定，在发动机台架上对汽油机燃用CNG的排放污染物进行测试，并利用燃烧分析仪对气缸内燃烧状况进行辅助监测。通过分析CNG发动机在各工况下排放规律表明：调整点火提前角对CO、THC和NOn排放的影响趋势是不同的；若过分注重燃料经济性的CNG稀薄燃烧工况，尽管发动机所排放的CO很低，但THC和NO排放极高。根据GB18352．1-2001中在2001年和2004年分别开始实施的排放限值对CO和HC＋NOx实行不同的削减比例，在开发CNG发动机电控系统时应重点从降低THC和NO排放的角度制定电控策略。

Study on Emission Tests of a CNG/Gasoline Dual-fuel Engine

The problem of emission of CNG-engine is widely concerned. Referring to GB18352 test operate-condition,in order to test the emission of CNG-engine,and combustion condition in the cylinder is inspected using combustion-analysis instruments. The exhausting rules obtained from the analysis of the CNG engine under various working conditions indicate that influence of the adjustment of the spark-advance angle on the emission of CO?THC and NO_X is different. Under the working condition in which the lean-mixture-combustion is used considering economic-performance,as CO emission is very low,the THC and NO exhaust are much higher. According to GB18352.1-2001,the emission value limit of CO and HC+NO_X is reduced in terms of different proportion in 2001 and 2004. So when constituting the control strategy of CNG electronic engine,reduction of THC and NO emission should be taken into consideration.