N2＋H2O稀释氢/空气混合气层流燃烧特性

摘要

Hydrogen fuel engine exhaust gas recirculationis mainly composed of N2 and H2O,and thus exploring the laminar combustion characteristic of hydrogen and air under N2 and H2O dilution is of great theoretical and practi-cal importance.Based on the constant volume combustion test systems,the laminar combustion characteristic of hy-drogen and air under dilution was studied experimentally by the method of the partial pressure matching mixture com-position.Results showed that the dilution has a significant effect on the flame propagation of hydrogen and air mixture.Temperature in burned zone,unstretched flame propagation speed and the laminar burning velocity of hy-drogen and air decrease significantly with the increase dilution rate.At the same time,with increasing dilution rate, the flame stretch rate and the Markstein length decrease slightly,and the flame stability declines.%氢内燃机废气再循环的主要成分是N2和H2O，探索N2＋H2O稀释条件下的氢/空气混合气层流燃烧特性具有重要理论和实际应用。基于定容燃烧测试系统，采用分压法匹配混合气成分，试验研究了稀释条件下的氢/空气混合气层流燃烧特性。结果表明，稀释对于氢/空气混合气的火焰传播有显著的影响：已燃区温度、无拉伸火焰传播速率和氢/空气混合气层流燃烧速度随着稀释率的增加而显著下降；同时，随着稀释率的增大，火焰拉伸率和马克斯坦长度略微减小，火焰的稳定性有所下降。