甲醇汽油机怠速稀燃特性的试验研究

为改善传统汽油机怠速稀燃的燃烧与排放特性,在1台加装了电控甲醇喷射系统的汽油机上对燃用汽油(M0)、50%质量比例甲醇汽油(M50)和纯甲醇(M100)3种燃料的发动机的怠速稀燃特性进行了试验研究。试验先后在过量空气系数a=1.1和a=1.3两组稀燃工况下进行,怠速转速稳定在800r/min左右。试验结果表明:添加甲醇后,两组稀燃工况下指示热效率均有所提升;发动机的火焰发展期、快速燃烧期和平均指示压力的循环变动系数随着甲醇比例的增加而降低;甲醇能够显著降低发动机怠速稀燃工况下的HC和NOx排放,CO2排放随着甲醇含量的增加也略有降低。

Experimental Study on Lean Burn Characteristics of Methanol-gasoline Engine at Idle Condition

To improve the combustion and emission performance of traditional gasoline engine at idle ,the effects of pure gaso-line (M0) ,50% mass content gasoline-methanol blend (M50) and pure methanol (M100) on the lean burn characteristics at i-dle were experimentally investigated on a gasoline engine equipped with an electronically controlled methanol injection system . The experiments were conducted under the lean burn conditions of excess air coefficientΦa =1 .1 andΦa =1 .3 at 800 r/min re-spectively .The results show that the indicated thermal efficiencies under both lean burn conditions increase slightly .Both the flame development and propagation periods shorten and the cyclic variation coefficient of indicated mean effective pressure de-creases with the increase of methanol fraction .The HC and NOx emissions decrease effectively and the CO2 emission decreases slightly after mixing methanol .