预喷持续期对预燃室式天然气发动机性能的影响

李晓东，邰鲁建，史艳军，游凯

潍柴动力股份有限公司大缸径发动机研究院，山东 潍坊  261061

摘要：为改善天然气发动机的性能，对某预燃室式天然气发动机进行试验，分析增加预喷持续期对预燃室进气量、预燃室气管温度、预燃室和主燃室的着火时刻、预燃室和主燃室缸压、主燃室平均有效压力波动率、燃气消耗率和气体排放的影响。结果表明：预喷持续期增加，预燃室进气量线性增加，预燃室气管温度降低；预喷持续期曲轴转角小于100°时，预喷持续期增加，预燃室及主燃室的着火时刻提前，预燃室及主燃室缸压增大，平均有效压力波动及燃气消耗率降低，NOx排放增加，CH4、HC、CO排放降低；预喷持续期曲轴转角大于100°时，预喷持续期增加，预燃室及主燃室的着火时刻缓慢推迟，预燃室缸压缓慢增加，主燃室缸压减小且趋于平稳，平均有效压力波动及燃气消耗率缓慢增加，NOx排放降低，CH4、HC、CO排放增加。

关键词：预燃室式;预喷持续期;天然气发动机

Effects of pilot injection duration on the performance of pilot combustion chamber natural gas engine

LI Xiaodong, TAI Lujian, SHI Yanjun, YOU Kai

R&D Center,Weichai Power Co., Ltd., Weifang 261061，China

Abstract：In order to improve the performance of natural gas engine,a natural gas engine with a pilot combustion chamber is tested. The effects of increasing the duration of pilot injection on the intake air volume of the pilot combustion chamber, the gas pipe temperature of the pilot combustion chamber, the ignition time and the cylinder pressure of the pilot combustion chamber and the main combustion chamber,the fluctuation rate of the average effective pressure of the main combustion chamber, the fuel consumption rate and the gas emission are analyzed.The results show that with the increase of pilot injection duration,the intake air volume of the pilot chamber increases linearly,and the gas pipe temperature of the pilot chamber decreases;during the duration of pilot injection, when the crankshaft angle is less than 100°,the duration of pilot injection increases, the ignition time of the pilot combustion chamber and the main combustion chamber advances, the cylinder pressure of the pilot combustion chamber and the main combustion chamber increases, the average effective pressure fluctuation and the gas consumption rate decrease, NOx emissions increase, and CH₄,HC,CO emissions decrease; during the duration of pilot injection, when the crankshaft angle is greater than 100°,the duration of pilot injection increases,the ignition time of the pilot combustion chamber and the main combustion chamber decreases slowly, the cylinder pressure of the pilot combustion chamber increases slowly, the cylinder pilotssure of the main combustion chamber decreases slightly and tends to be stable,the average effective pressure fluctuation and the gas consumption rate increase slowly,NO_x emissions decrease,and CH₄, HC, CO emissions increase.

Keywords:pilot combustion chamber type; pilot injection duration; natural gas engine