点火正时对电控稀燃天然气发动机性能的影响

The Influence of Ignition Timing on Electrically Controlled Lean-burn CNG Engine Performance

试验研究了点火正时对电控稀燃多点喷射天然气发动机燃烧及排放性能的影响规律。对该发动机转速为1 450 r/min,1 750 r/min,2 050 r/min,负荷为25%,50%,75%,100%的12个工况点进行了试验研究。研究结果表明,在其他燃烧边界条件不变的情况下,点火正时对该发动机输出扭矩及CH4排放影响不大,但是在2 050 r/min,100%负荷工况下,随着点火正时的进一步后移,出现扭矩下降及CH4排放增加的现象。点火正时对NOx排放有显著的影响,同一工况下,随着点火正时的推移,NOx排放明显降低。

The effects of ignition timing on combustion performance and emission behavior were studied through an electrically controlled lean-burn CNG engine. The experiment was carried out at twelve operating conditions which were 1 450 r/min, 1 750 r/min and 2 050 r/min which respectively corresponded to 25%, 50%, 75% and 100% four load points. Test results show that the ignition timing has little effect on output torque and CH4 emission under other combustion boundary conditions unchanged. Under the conditions of 2 050 r/min speed and 100% load, the torque is decreased and the CH4 emission is increased with the delay of ignition timing. The ignition timing has obvious effects on NOx emission, that is to say, NOx emissions are reduced with the delay of ignition timing under same conditions.