冷起动和怠速时火花点火发动机缸内未燃碳氢生成过程的研究  

Study on Formation Process of In Cylinder Unburned Hydrocarbons During Cold Start and Idling Periods in SI Engines

作　　者：黄佐华[1] 庞俊国[1] 潘克煜[1] 蒋德明[1] 周龙保[1] 杨中乐[1] 

机构地区：[1]西安交通大学

出　　处：《燃烧科学与技术》1997年第4期406-411,共6页Journal of Combustion Science and Technology

基　　金：国家自然科学基金;攀登计划;福特-中国研究与发展基金

摘　　要：为了更好地弄清起动和怠速时发动机缸内未燃碳氢生成过程以及顶岸间隙和油膜对缸内未燃碳氢的影响，测量了起动和怠速过程活塞顶岸壁面和缸套壁面温度。根据测量结果，预测了起动过程顶岸间隙和壁面油膜处未燃碳氢生成量，发现顶岸和缸套壁温在发动机起动后（１５０～２００）ｓ时达到其稳定状态。起动后顶岸间隙和油膜处生成的碳氢量分别降低至其初始值的２／５和３／４。研究认为：热容量小的活塞能迅速减小顶岸容积和提高其内混合气温度，从而可减少起动期间缸内生成的总未燃碳氢量。In order to understand better the process of hydrocarbon formation and the effect of the top land crevice and the oil layer of the cylinder liner on unburned hydrocarbons during cold start and idling period,the temperature of piston top land and liner has been measured.Based on the measured results,the amount of unburned hydrocarbons from the crevice and liner was predicted.It was found that the temperature of piston top land and cylinder liner takes about 150s～200s to reach its equilibrium state as the engine started up.The concentration of hydrocarbons from top land crevice will reduce to its two fifths and that from oil layer will reduce to its three quarters of their initial values respectively.It is considered that reduction in piston thermal capacity can reduce the total unburned hydrocarbons during this transient period due to the quick minimization of top land crevice volume and rapid increase of mixture temperature in the crevice region.

关 键 词：温度 碳氢排放 冷起动 火花点火发动机 怠速 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]