【摘要】 在电控进气道喷射汽油机台架上,分别使用汽油、M10、M20和M30 4种燃油在常温条件下模拟了NEDC测试循环中的前2个市区工况循环(ECE),对冷起动过程中催化剂前后的常规排放和非常规排放以及燃烧特性进行了研究。研究结果表明:随着燃油中甲醇比例的增大,4种燃油的CO、NOx排放量逐步减少,而甲醇、甲醛等非常规排放量逐步增多。THC排放量在冷起动初期随着甲醇比例的增大而增加,在发动机温度上升后随着甲醇比例的增大而减少。但是在常规三效催化剂起燃以后,催化剂后的常规和非常规排放基本上均能得到有效控制。随着汽油燃料中甲醇添加比例的增大,在冷起动过程中发动机燃烧持续期缩短,缸内平均指示压力略有升高,对发动机缸内燃烧有一定的改善作用。更多还原

【Abstract】 In an electron-controlled port injection gasoline engine,separately operating on gasoline,M10,M20 and M30 blends under the ambient temperature,the combustion characteristics and cold-start emissions,including regulated and unregulated emissions,were researched by simulating the first two cycles of the urban conditions of new European driving cycle(NEDC).The results show that for the four kinds of fuel,as the methanol proportion increasing,CO and NOx emissions decrease,while methanol and formaldehyde unregulated emissions increase.The THC emissions increase in early period of cold-start as the methanol proportion increasing,and after the cylinder warmed up they decrease.But all the emissions from tailpipe come to a very low level once the three-way catalyst lights off.Addition of methanol in gasoline fuel can improve the combustion in cold-start stage to a certain extent,resulting in shortened combustion duration and higher cylinder indicated mean effective pressure.更多还原