裂解气对稀燃甲醇发动机性能影响的仿真研究

王向阳; 刘宇; 解方喜

车用发动机 ›› 2023, Vol. 0 ›› Issue (5) : 51-56.

栏目

裂解气对稀燃甲醇发动机性能影响的仿真研究

王向阳^1,2，刘宇^1,2，解方喜^1,2

作者信息 +

Influences of Dissociated Gas on Lean-burned Methanol Engine Performance

WANG Xiangyang^1,2,LIU Yu^1,2,XIE Fangxi^1,2

Author information +

文章历史 +

摘要

基于甲醇发动机三维模型，通过CONVERGE仿真软件计算分析了EGR稀释和空气稀释下进气道喷射裂解气对甲醇发动机燃烧特性和排放特性的影响。结果表明：掺烧甲醇裂解气后，缸内混合气分布趋于均匀；同一稀释比下，甲醇裂解气掺烧对空气稀释下燃烧速率的提高要大于EGR稀释；相同裂解气掺烧比下，EGR稀释的CO排放和HC排放明显高于空气稀释，NO_x排放明显低于空气稀释，甲醇裂解气掺烧在空气稀释下对CO和NO_x排放的降低相对于EGR稀释更为明显，HC排放则相反；随着甲醇裂解气掺烧比的增大，EGR稀释下的最高综合指示热效率逐渐逼近空气稀释，在裂解气掺烧比达到30%时，两种稀释方式的最高综合指示热效率只相差2.6%。

Abstract

Based on the threedimensional model of methanol engine, the effects of inlet dissociated gas injection under EGR dilution and air dilution on the combustion characteristics and emission characteristics were calculated and analyzed by CONVERGE simulation software. The results show that the mixture distribution tends to be uniform after methanol dissociated gas is mixed. For the same dilution ratio, the combustion rate of methanol dissociated gas in air dilution increases more than that in EGR dilution. At the same time, CO and HC emissions in EGR dilution are significantly higher than those in air dilution, while NO_x emission is significantly lower than that in air dilution. The reduction of CO and NO_x emissions of methanol dissociated gas blending in air dilution is more obvious than that in EGR dilution, while the HC emission shows the opposite trend. With the increase of methanol dissociated gas mixing ratio, the maximum comprehensive indicated thermal efficiency under EGR dilution gradually approaches that of air dilution, and the difference between them is only 2.6% when the dissociated gas mixing ratio reaches 30%.