某型航空活塞式发动机气缸内沉积物生成机理-《内燃机学报》

文章信息/Info

Title:: Formation Mechanism of Deposits in Cylinder at an Aero Piston En-gine

作者:: 孟现召; 冯岩鹏; 1. 中国民用航空飞行学院洛阳北郊机场，河南洛阳 471000； 2. 中国民航科学技术研究院航空安全研究所，北京 100028

Author(s):: Meng Xianzhao; Feng Yanpeng; 1. Luoyang Beijiao Airport，Civil Aviation Flight University of China，Luoyang 471000，China；2. Laboratory of Aviation Safety Technology，China Academy of Civil Aviation Science and Technology，Beijing 100028，China

Keywords:: aero piston engine; leaded gasoline; in-cylinder gas compressibility; deposit in cylinder; gas temperature in cylinder; air idle

摘要:: 针对某型航空活塞式发动机存在由气缸内沉积物诱发气缸压缩性衰减的问题，以相同运行条件下未出现类似故障的不同型号的发动机作为对比，通过对故障发动机气缸内沉积物的微观形貌及成分分析，结合该型发动机的结构设计和运行数据，分析这种气缸内沉积物的形成机理．结果表明：气缸内燃气温度过低是形成气缸内沉积物的充分条件，而该型发动机燃油系统设计特性造成空中慢车时气缸内混合气过富油是其缸内燃气温度过低的主要原因．由此提出，以提高小功率状态下缸内燃气温度为目的的控制排气温度不低于427℃的测试方案，经实践验证有效．

Abstract:: In order to solve the reduction issue of in-cylinder gas compressibility on an aero piston engine caused by the de-posits in the cylinder，another type of engine without the issue under the same leaded gasoline conditions was tak-en as comparison study. Through the analysis of the micro-morphology and composition of the deposits in the cyl-inder of the fault engine，combined with the structural design and operation data of the engine，the formation mechanism of the deposits in cylinder was analyzed. Research results show that low temperature of the gas in the cylinder is the sufficient condition for the deposits formation，and the excessive rich mixture related to the charac-teristics of engine design is the main cause for the low temperature of the gas in the cylinder when the engine runs in air idle condition. Based on the result，a test scheme of leaning the mixture to keep the exhaust gas temperature no less than 427℃ was proposed in order to increase the gas temperature in the cylinder in low power operating conditions. This proposal was proved to be effective by engine testing.