预燃室式火花塞在大缸径气体机上的试验研究

徐清祥^1,2，孙永亮^1,2，孔龙^1,2，许有豹^1,2

1.内燃机可靠性国家重点实验室,山东 潍坊  261061；

2.潍柴动力股份有限公司，山东 潍坊  261061

摘要：为解决大缸径气体机燃烧不稳定问题，在大缸径气体机上进行普通火花塞、预燃室式火花塞性能对比试验，及3种预燃室式火花塞对气体机性能影响的对比试验。结果表明：采用预燃室式火花塞可以拓展气体机稀燃极限，大幅提高发动机燃烧稳定性，平均指示压力波动率和最大缸内爆发压力波动率降低约45%，缸内燃烧速度加快，热效率提高约0.5%，涡前排气温度降低约15 ℃；预燃室式火花塞喷孔直径和数量对气体机燃烧的滞燃期影响较大，较小的喷孔直径更有利于缩短滞燃期，增大喷孔直径导致失火率上升，喷孔数量对失火率影响较小，喷孔直径和数量对燃烧持续期、燃气消耗率和NO_x排放影响较小。

关键词：大缸径气体机；预燃室式火花塞；稀薄燃烧

Experimental study on pre-chamber spark plug for large bore gas engine

XU Qingxiang^1,2, SUN Yongliang^1,2, KONG Long^1,2, XU Youbao^1,2

1. State Key Laboratory of Internal Combustion Engine Reliability, Weifang 261061，China;

2. Weichai Power Co., Ltd., Weifang 261061, China

Abstract：To solve the problem of unstable combustion in large gas engines, performance comparison tests are conducted with ordinary spark plugs and prechamber spark plugs. Three types of pre-chamber spark plugs are also tested. The results show that the use of prechamber spark plugs could expand the lean burn limit of gas engines, significantly improve engine combustion stability, reduce the average indicated pressure fluctuation rate and maximum cylinder burst pressure fluctuation rate by about 45%, accelerate cylinder combustion speed, increase thermal efficiency by about 0.5%, and reduce the exhaust temperature before the turbine by about 15 ℃. The diameter and number of nozzle holes for prechamber spark plugs show a significant impact on the ignition delay period of gas engine combustion. A smaller nozzle diameter is more conducive to shortening the ignition delay period, and increasing the nozzle diameter led to an increase in misfire rate. The number of nozzle holes has a smaller impact on misfire rate, while the diameter and number of nozzle holes has a smaller impact on combustion duration, gas consumption rate, and NO_x emissions.

Keywords:large bore gas engine; pre-chamber spark plug; lean burn