利用OH发射谱进行的高温低浓度甲烷着火研究

采用激波管进行低浓度甲烷和空气混合气的着火实验,通过测量压力和OH发射光谱,得到不同工况下的着火延迟,并与甲烷的详细反应机理计算结果作比较。结果表明:不同浓度下甲烷着火延迟的对数与温度倒数呈线性关系,着火延迟随甲烷浓度的降低而减少;贫燃条件下,采用详细动力学机理计算的表观活化能与实验数据拟合较好。

Research on methane ignition in lean-fuel and high temperature condition through OH emission measurements

Ignition characteristics in lean-burn conditions are significant to methane oxidation mechanism. Low equivalence ratio methane/air mixture was ignited in a shock tube. Ignition delay was obtained through transient pressure signal and OH emission measurement. The experiment results were compared with the caculation based on detailed methane oxidation mechanism. It is indicated that there is a linear relationship between ogarithm of ignition delay and recipracol of temperature. Ignition delay decrease with the reducion of methane concentration. Temperature has more significant influence than methane concentration on ignition delay time. Detailed mechanism can be used as reference in lean-burn conditions. The apparent activation energy of experiment results agree well with the simulation of detailed mechanism.