运行参数对甲醇 HCCI 燃烧稳定性和循环变动的影响

摘要

为研究进气温度、过量空气系数和发动机转速对甲醇HCCI燃烧循环变动和燃烧稳定性的影响，在1台改造的试验发动机上进行相关的试验。试验结果表明：随着进气温度的升高，循环变动变大，最高燃烧压力的分布较为集中；循环变动系数对过量空气系数较为敏感，随着过量空气系数的增大，循环变动变大，最高燃烧压力的分布较为分散；随着转速的增大，循环变动变小，最高燃烧压力的平均值变大，最高燃烧压力分布集中，对于甲醇而言，进气温度为160℃，过量空气系数为2时，n＝1300 r/min是较优的转速。%In order to study the influences of intake temperature ,excess air coefficient and engine speed on methanol HCCI combustion stability and cycle-to-cycle variation ,the relevant tests were carried out on a retrofit engine .The results show that the cycle-to-cycle variation increases and the distribution of maximum combustion pressure concentrates with the increase of in-take temperature .The excess air coefficient is more sensitive to the coefficient of cycle-to-cycle variation .With the increase of excess air coefficient , the cycle-to-cycle variation decreases and the distribution of maximum combustion pressure scatters . With the increase of engine speed ,the cycle-to-cycle variation decreases ,the mean value of maximum combustion pressure in-creases and its distribution concentrates .For the methanol fuel ,1 300 r/min is the optimal speed at 160 ℃ of intake tempera-ture and when the excess air coefficient is 2 .