直喷天然气发动机稀薄燃烧特性的仿真试验  

Simulation study of lean combustion characteristic of direct injection CNG engine

作　　者：黄丫[1] 林学东[1] 李德刚[1] 顾静静[1] 侯玉晶[1] 

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130022

出　　处：《吉林大学学报（工学版）》2015年第3期797-805,共9页Journal of Jilin University:Engineering and Technology Edition

基　　金：吉林省青年基金项目(201202052);中国博士后基金项目(2013M541295)

摘　　要：在缸内直喷压缩天然气(Compressed natural gas,CNG)试验样机进行火焰传播特性可视化研究的基础上,仿真计算分析了不同喷射方式和不同点火方式对缸内浓度场、温度场等微观物理场的影响,以及这种微观物理场对NO生成规律的影响。结果表明:缸内浓度场的分布特性直接影响火焰传播速度和温度场,是控制稀薄燃烧过程的关键,可通过喷射方式来控制;点火方式主要改变温度场由此影响NO的生成规律;浓度梯度越大,火焰传播速度越快,稀薄燃烧稳定性越好;通过双点点火方式可以有效控制火焰传播速度。This paper is focused on the effects of different injection and spark modes on the in-cylinder equivalence ratio, temperature field as well as the NO formation. The simulation process is based on the experiment on a direct injection Compressed Natural Gas （CNG） engine, which was observed with optical device. Results show that the in-cylinder equivalence ratio distribution, which can be controlled by the injection mode, is the key factor for lean combustion control. Moreover, the equivalence ratio distribution directly impacts the flame propagation and temperature field. The spark mode mainly influences the in-cylinder temperature filed, so that influences the NO formation. The higher the gradient of equivalence ratio distribution, the faster the flame propagation and the more stable the lean combustion. The double spark mode can effectively control the flame propagation speed.

关 键 词：动力机械工程 直喷压缩天然气发动机 稀薄燃烧 喷射方式 点火方式 火焰传播机 理 NOx生成规律 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]