非平衡等离子体对甲烷点火和火焰传播影响的机理分析

Mechanism Analysis of Non-Equilibrium Plasma Effects on Ignition and Flame Propagation of Methane/Air Mixture

关键词:  非平衡等离子体  自由基  点火  火焰传播速度 

Key words:  Non-equilibrium plasma  Radicals  Ignition  Flame spreading velocity

摘要:

为了探讨非平衡等离子体对甲烷点火和火焰传播速度影响,采用化学动力学模型GRI-Mech3.0,利用零维、均质、完全混合模型和火焰传播速度模型,对甲烷点火过程和火焰传播过程进行数值模拟,计算得到了非平衡等离子体生成自由基(O自由基和NOX自由基)对甲烷点火延迟时间和火焰传播速度的影响规律。结果表明:当分别加入0.5% O和0.5% NOX活性基时,点火延迟时间减少了约94.7%,63.1%(加入NO)和94.2%(加入NO₂)。通过反应路径分析和敏感度分析,揭示了非平衡等离子体生成自由基影响甲烷点火和火焰传播速度的化学反应机理。 

Abstract:

In order to explore the physical mechanism of non-equilibrium plasma on ignition and flame propagation of methane/air mixture, based on GRI-Mech3.0, the ignition and flame propagation were carried out with the mode of the closed zero dimension homogeneous batch reactors and flame speed. The calculation revealed influencing rule of radicals (O and NOX) in non-equilibrium plasma on ignition delay time and flame spreading speed of methane/air mixture. The numerical results indicate that the ignition time is reduced by about 94.7%, 63.1%(adding NO) and 94.2%(adding NO₂) by adding radicals of the 0.5%O and 0.5%NOX. By using reaction path analysis and sensitivity analysis, the results have revealed the detailed kinetic mechanism for the effects of radicals resulted from non-thermal equilibrium plasma on the ignition and flame propagation of methane/air. 