进气道喷水对汽油机爆震和缸内燃烧过程影响的仿真分析  

Simulation Analysis of the Effects of Inlet Water Injection on Knock and Combustion Process of A Gasoline Engine

作　　者：尤岳林 高莹[1] 寇亚林 张博[2] 卢强 YOU Yuelin;GAO Ying;KOU Yalin;ZHANG Bo;LU Qiang(State Key Laboratory of Automobile Simulation and Control,Jilin University,Changchun 130025,China;China Automotive Technology Research Center Co.,Ltd.,Tianjin 300300,China;Beijing CATARC Science and Technology Center Co.,Ltd.,Beijing 100071,China)

机构地区：[1]吉林大学汽车仿真与控制国家重点实验室,长春130025 [2]中国汽车技术研究中心有限公司,天津300300 [3]北京卡达克科技中心有限公司,北京100071

出　　处：《内燃机工程》2022年第5期68-77,共10页Chinese Internal Combustion Engine Engineering

基　　金：国家重点研发计划项目(2019YFE0101900)。

摘　　要：以一台1.5 L气道喷射汽油机为研究对象,根据汽油机台架试验结果与喷水器喷雾特性,利用AVL FIRE软件建立了进气道喷水汽油机三维模型,仿真分析了水雾的发展过程与分布状态,研究了4组喷水量对汽油机爆震和缸内燃烧过程的影响规律。结果表明,水雾发展至气门附近即被蒸发,仅有少量水雾以液态形式进入缸内。随喷水量增加,爆震指数降低,降幅达33.70%,缸内温度与压力曲线逐渐向后、向下移动。喷水量为13.186 mg时缸温峰值与不喷水相比下降20.27 K,缸压峰值降低0.48 MPa。缸内进水量低于喷油量的5%时,水雾对爆震和缸内燃烧过程影响微弱。喷水对速燃期影响效果更显著。随喷水量增加,火焰传播速度降低,速燃期延长,累积放热率曲线后移,总燃烧持续期共延长2.5°曲轴转角。Taking a 1.5 L port fuel injection system gasoline engine as the research object,based on the test results of gasoline engine and the spray characteristics of the water injector,a three-dimensional model of the inlet port water injection gasoline engine was established by using AVL FIRE software.The development process and distribution state of the water spray were simulated and analyzed.The effects of 4 sets of water spray quality on the gasoline engine knock and combustion process were studied.The results show that the water mist is evaporated when it develops near the valve,and only a small amount of water mist enters the cylinder in liquid form.With the increase of water injection quality,the knock index(KI)decreases by 33.70%and the temperature and pressure curve in the cylinder gradually moves backward and downward.Compared with no water injection,when the water injection quality is 13.186 mg,the peak value of cylinder temperature decreases by 20.27 K and the peak value of cylinder pressure decreases by 0.48 MPa.When the water inflow in the cylinder is less than 5%of the fuel injection,the water mist has little effect on the knock and combustion process in the cylinder.The effect of water spray on the rapid combustion period is more significant.With the increase of water injection quality,the flame propagation speed decreases,the rapid combustion period is prolonged,the cumulative heat release rate curve moves backward,and the total combustion duration is prolonged by 2.5°crank angle.

关 键 词：汽油机 进气道喷水 爆震 燃烧过程 喷雾特性 

分 类 号：TK411.22[动力工程及工程热物理—动力机械及工程]