天然气发动机燃烧与排放特性数值模拟分析

Numerical Simiulation for Combustion and Emission Characteristic of CNG Engine

利用发动机建模软件建立了某型号天然气发动机的数学模型,通过变参数模拟分析,探讨了压缩比、空气过量系数、点火提前角对天然气发动机的燃烧特性和NOx排放特性的影响。模拟结果表明:当其他运行条件不变时,发动机最大爆压、缸内最高温度以及NOx排放量随压缩比、点火提前角的增大而增大,随发动机空气过量系数的增大而减小。

The article establishes a numerical model of CNG engine by using numerical simulation software. Through the simulation analysis of variable element, the article discusses the influence of compression ratio, air excessive coefficient and ignition advance angle on the combustion characteristic and the emission of NOx. The following results show that when the other conditions remain the same, the engine＇s maximum detonation pressure, the highest in cylinder temperature and the NOx emissions increase with the increase of the compression ratio and the ignition advance angle, but decrease with the increase of the air excessive air coefficient.