E22乙醇汽油发动机的早燃特性试验研究及优化

张宗澜^1,2，陈泓²，赖开昌²，李钰怀²，昝磊²，李云龙²

1.广州汽车集团股份有限公司，广东 广州  511434；

2.广东省汽车清洁动力与能源应用技术重点实验室，广东 广州  511434

摘要：针对某排量为1.5 L、增压、进气道喷射发动机，制备乙醇体积分数为22%的乙醇汽油（记为E22），通过试验研究E22发动机的早燃特性，并进一步分析低钙机油、喷油器优化、过量空气系数对E22发动机早燃的影响。结果表明：在低速大负荷工况，E22发动机的早燃频次是纯汽油（记为E0）发动机的1～3倍；使用低钙机油可降低发动机早燃频次，转矩为240 N·m时的E22发动机早燃频次较常规机油降低了65%；将喷油器喷孔数由4孔增加至8孔且位置前移，转矩为240 N·m时E22发动机早燃频次较优化前降低了61%；减小过量空气系数，早燃频率逐步降低。采用低钙机油结合喷油器优化的措施，E22发动机早燃频次显著降低，通过了早燃测试，转速为1 750～4 000 r/min时转矩提高到240 N·m，转速为5 500 r/min时达到最大功率（120 kW）。

关键词：E22；早燃；低钙机油；喷油器优化；过量空气系数

Experimental study on pre-ignition characteristics of an E22 ethanol gasoline engine and its optimization

ZHANG Zonglan^1,2, CHEN Hong², LAI Kaicang², LI Yuhuai², ZAN Lei², LI Yunlong²

1.GAC Group Co., Ltd., Guangzhou 511434, China;

2.Guangdong Provincial Key Laboratory of Clean Automotive Propulsion and Energy Application Technology, Guangzhou 511434, China

Abstract: An ethanol gasoline (E22) with a volume fraction of 22% ethanol is prepared for a 1.5-liter turbocharged and port fuel injection engine. The pre-ignition characteristics of the E22 engine are studied through experiments. And the effects of low calcium engine oil, injector optimization, and excess air coefficient on the pre-ignition characteristics of the E22 engine are further analyzed. The results show that under low-speed and high load conditions, the pre-ignition frequency of the E22 ethanol gasoline is 1-3 times that of pure gasoline (E0). The use of low calcium engine oil can reduce the frequency of pre-ignition. When the torque is 240 N·m, the pre-ignition frequency of the E22 engine is reduced by 65% compared to conventional engine oil. Increasing the number of fuel injector holes from 4 to 8 and shifting the injection, the pre-ignition frequency of the E22 engine is decreased by 61% compared to before optimization when the torque is 240 N·m. Reducing the excess air coefficient can gradually decrease the frequency of pre-ignition. By using low calcium engine oil combined with optimized fuel injection, the pre-ignition frequency of the E22 engine is significantly reduced, and it passed the pre-ignition test standard. The engine produces a peak torgue of 240 N·m within the speed range of 1 750-4 000 r/min, and achieves a maximum power of 120 kW at 5 500 r/min.

Keywords: E22; pre-ignition; low-calcium engine oil; injector optimization; excess air ratio