稀燃天然气发动机燃烧循环变动影响因素研究  

Study on Influencing Factors of Cycle-to-cycle Combustion Variations in a Lean Burn Natural Gas Engine

作　　者：姚宝峰[1] 李国岫[1] 

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《内燃机工程》2007年第5期23-27,共5页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金资助项目(50406003)

摘　　要：通过对一台点燃式多点电喷稀燃天然气发动机进行试验,获得了不同工况下的平均指示压力循环变动系数,以此为基础研究了燃空当量比、节气门开度、转速及点火时刻对稀燃天然气发动机燃烧循环变动的影响趋势。结果表明:混合气燃空当量比越小,燃烧循环变动越明显,当燃空当量比降低到一定值时,平均指示压力循环变动系数的增长会突然加大;节气门开度越小燃烧循环变动越明显,节气门开度小于30%后,其对燃烧循环变动影响更加明显;燃烧循环变动量随转速上升有增加的趋势,在高转速工况下燃烧循环变动的加强尤其明显;在工况一定的条件下存在一个最优的点火时刻可使稀燃天然气发动机的燃烧循环变动最小。The investigation of cycle-to-cycle combustion variations was carried out with a spark ignition, multi-point port fuel injected, lean burn natural gas engine. Consecutive in-cylinder pressure data were recorded and indicated mean effective pressure of each cycle and coefficients of variations of indicated mean effective pressure under different operating conditions were calculated. Then influencing factors of cycle-to-cy-cle combustion variations in the lean burn natural gas engine, such as equivalent ratio, engine speed, throttle opening and ignition timing, were discussed. In lean burn conditions, the decrease of equivalent ratio can raise the level of cycle-to-cycle combustion variations; the level of cycle-to-cycle combustion variation increa- ses as throttle opening decreases, especially under conditions with throttle opening below 30%; at high speed condition cycle-to-cycle combustion variations obviously increases; there is an optimum ignition timing to make the smallest cycle-to-cycle combuStion variations for each operating condition.

关 键 词：内燃机 天然气 稀燃 循环变动 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]