乙烷着火化学反应动力学机理研究

Study on the Chemical Kinetic Mechanisms of Ethane Ignition

本文利用激波管测量了乙烷在不同压力、温度和当量比下的着火延迟期,并利用CHEMKIN软件结合GRI-Mech3.0机理对预混合气着火过程进行了模拟计算和化学反应动力学分析。结果表明,GRI-Mech 3.0机理不能很好地预测乙烷的着火延迟期。通过对着火过程进行敏感性分析,得出反应C_2H_5+O_2=C_2H_4+HO_2和C_2H_4+H+M=C_2H_5+M对着火延迟期的影响较大,并对其反应速率常数进行了修正。修正后的机理能够较好地改善对乙烷着火延迟期的预测,并同时保持了对层流燃烧速度的准确预测。

Ignition delay times of ethane were measured behind reflected shock waves under different pressures,temperatures,and equivalence ratios.Simulations and chemical kinetic analysis on the ignition process of the mixtures were carried out using CHEMKIN II package with GRIMech 3.0mechanismThe simulation results showed large scatters with the experimental data especially at lean mixtures.Reaction C2H5＋O2=C2H4＋HO2 and reaction C2H4＋H＋M=C2H5＋Mwere found to havesignificantinfluenceon the ignition process of ethane,and their rate constants were modified in order to give more accurate prediction.The optimized mechanism can give better prediction of ignition delay times of ethane and maintains its good prediction onthe laminar flame speed.