燃烧室形状对天然气发动机燃烧过程影响的研究  

Effect of Combustion Chamber Geometry on Combustion Process in Spark Ignition Natural Gas Engine

作　　者：焦运景[1] 董宏[2] 张惠明[1] 杨志勇 张自立 司鹏鹍[1] 程辉 

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]天津大学内燃机研究所,天津300072 [3]东风南充汽车有限公司,南充637000

出　　处：《内燃机工程》2009年第4期28-33,共6页Chinese Internal Combustion Engine Engineering

基　　金：国家“八六三”高技术研究发展计划资助项目(2006AA11A1B2)

摘　　要：在对天然气发动机燃烧室进行优化的过程中,在一定压缩比下,开发设计了3种不同形状的燃烧室。应用CFD对不同形状燃烧室的缸内气体流动及燃烧过程进行了数值模拟,并在台架上进行了试验验证。模拟得出了缸内气体湍动能分布、温度场分布及燃烧持续期。针对不同形状燃烧室的缸内气体湍动能与温度场进行了详细分析后得出:增大挤气面积,则挤流强度增大,提高了缸内气体的流动速率,有利于提高火焰传播速度,改善天然气燃烧速度慢的特点;但挤气面积过大时,缸内燃烧速度过快,温度峰值增大,使NOx排放增加。最终将模拟结果与试验结果进行对比,综合考虑动力性经济性与排放性能,选取了最优形状燃烧室。In the process of optimizing CNG engine, three types of combustion chambers were designed with a constant compression ratio. By adopting CFD numerical simulation software, the combustion process and gas flow in three combustion chambers with different geometric shapes were simulated and the simulated results were verified on an engine. By 3D simulation, temperature fields, turbulence kinetic energy and combustion duration. In the cylinder of three combustion chambers were obtained and analyzed. The results show that the combustion chambers with different geometry have different squish area; the squish flow intensity becomes stronger with the increase of squish area; higher squish flow intensity is favorable to the flame propagation in the combustion chamber. If the squish area is too large, the temperature in cylinder will fast increase, which will result in increase of NOx emission. The best combustion chamber is determined by comparing numerical simulation results with experimental results.

关 键 词：内燃机 火花点火 天然气发动机 燃烧室形状 燃烧过程 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]