论文部分内容阅读
使用快速压缩装置研究了燃油喷射正时对直喷式天然气发动机性能的影响。研究结果表明 ,提早喷射(喷射正时 6 0 ms)会降低燃烧初期放热速率而增加后期放热速率 ;推迟喷射 (喷射正时 75 ms)会增加燃烧初期放热速率而降低后期放热速率 ;在喷射持续期结束时 (喷射正时 80 ms)点火放热持续期最短 ;提早喷射增加火焰发展期而推迟喷射会增加后燃期 ;在当量比相同且大于 0 .8的条件下 ,提早喷射会产生相对量低的CO,而推迟喷射会产生相对量高的 CO;在当量比为 0 .6～ 0 .8时 ,不同喷射正时条件下 NOx 均较高 ,喷射推迟 NOx 降低 ;在当量比为 0 .5～ 0 .8时 ,燃烧效率较高 ,当量比小于 0 .5或大于 0 .8时燃烧效率都会降低
The effect of fuel injection timing on the performance of direct injection natural gas engines was studied using a rapid compression device. The results show that the early injection (injection timing 60 ms) will reduce the early combustion exothermic rate and increase the late heat release rate; delayed injection (injection timing 75 ms) will increase the initial combustion rate of heat release and reduce the late heat release rate ; At the end of the injection duration (injection timing 80 ms) the shortest duration of the ignition exotherm; early injection increases the flame development and postponed injection increases after-combustion; at the equivalence ratio greater than 0.8, The injection will produce a relatively low amount of CO, and delaying the injection will produce a relatively high amount of CO; equivalent ratio of 0.6 ~ 0.8, the different injection timing conditions, NOx are higher, postpone NOx reduction; When the equivalence ratio is 0.5 ~ 0.8, the combustion efficiency is higher, and the combustion efficiency will decrease when the equivalence ratio is less than 0.5 or greater than 0.8