空燃比选择对稀燃汽油机指示效率影响模拟分析  

Simulation of AFR Influence on the Indicated Efficiency of Lean Burn Engines

作　　者：李志军[1] 杨阳[1] 刘磊[1] 张洪洋[1] 刘臣富[2] 石传龙[2] 王银山[2] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]天津职业技术师范大学汽车与交通学院,天津300222

出　　处：《燃烧科学与技术》2014年第5期388-392,共5页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(50276042;51276128);国家高技术研究发展计划(863计划)资助项目(2008AA06Z322);天津市自然科学基金资助项目(11JCZDJC23200)

摘　　要：搭建汽油机数值模型,按照汽油机燃烧效率随空燃比增大而升高、缓慢下降及大幅下降等现象,将空燃比划分为3个阶段,分析了不同阶段内工质绝热指数、压缩比、燃烧持续时间及传热损失对指示效率的影响规律.结果表明,随空燃比升高,绝热指数对指示效率的影响变小,提高压缩比使得末端气体温度升高,加长燃烧持续时间,导致热量转化为功的能力下降.综合分析可知,在第2阶段实现汽油机稀燃其指示效率增幅较大.In this paper,the simulation model of the engine was established and the AFR（air fuel ratio） was divided into 3 phases,in which the gasoline engine combustion efficiency presents different trends with the increase of AFR,namely increase,slow decrease,and sharp decrease. The influence of adiabatic exponent,compress ratio,combustion duration and heat transfer on the indicated efficiency of engine was analyzed. The result shows that with the increase of AFR,the influence of adiabatic exponent on the indicated efficiency becomes smaller,that with increase of the temperature of the gas,and the combustion duration,the growth of irreversibility declines. Applying the lean burn technology in the second phase can guarantee the best efficiency benefits.

关 键 词：稀燃 空燃比 指示效率 

分 类 号：TK411.5[动力工程及工程热物理—动力机械及工程]