火花点火发动机燃烧室沉积物未燃碳氢排放的理论与实验研究

Theoretical and Experimental Study on Unburned Hydrocarbon Emissions from Combustion Chamber Deposits in Spark Ignition Engines

本文从实验和理论两个方面来系统地研究火花点火式发动机燃烧室沉积物处未燃碳氢排放浓度随冷却水温、发动机转速、节气门开度和点火提前角等运转参数的变化规律。对发动机缸内沉积物处未燃碳氢的生成过程和缸内、排气系统中未燃碳氢的氧化过程进行了模拟，对缸内沉积物未燃碳氢生成过程进行了详细的研究，找出了影响燃烧室沉积物处未燃碳氢生成量的关键因素。

In this paper, the relations of operating parameters such as coolant temperature, engine speed, throttle valve opening and spark advance angle with unburned hydrocarbon emissions due to the presence of combustion chamber deposits in spark ignition engine are investigated both theoretically and experimentally. The simulation is carried out in formation process of unburned hydrocarbons in combustion chamber deposits and oxidation process of unburned hydrocarbons in cylinder and exhaust system. The formation process of unburned hydrocarbon in combustion chamber deposits is studied extensively. The key factors that influence the amount of unburned hydrocarbons in combustion chamber deposits are found out. In addition, the effect of combustion chamber deposits on engine performances is analyzed.