介质阻挡放电对甲烷离解及燃烧火焰的影响

Effect of Dielectric Barrier Discharge on Methane Dissociation and Combustion

介质阻挡放电(dielectric barrier discharge,DBD)燃烧强化是等离子体技术领域发展起来的新的应用途径。在未燃烧的气体燃料或者可燃混合气体中进行DBD,利用放电产生的活性自由基,影响燃烧系统的化学平衡,进而达到改善燃料燃烧特性的目的。采用光谱仪分别对放电间隙和燃烧火焰进行光谱测量,并对燃烧的火焰形态进行记录。实验结果表明,甲烷放电后离解生成了CH基和H基,放电电压增加,CH基对应的光谱强度相应增加;放电处理后的甲烷燃烧火焰主要组成成分发生变化;在一定放电条件下,火焰产生回火现象。利用Fluent仿真软件研究了CH基和H基对甲烷燃烧的影响,仿真结果与实验结果吻合。研究认为甲烷燃烧特性的改善是DBD使甲烷离解生成的CH基和H基造成的。

Dielectric barrier discharge（DBD） enhanced combustion is a new application in plasma technology field.The active species in fuel or fuel air mixtures plasmas generated by DBD can influence the chemical kinetics of combustion and improve combustion properties considerably.In this paper,the emission spectrum of discharge area and flame was measured,and the flame structure was recorded.The experiment results showed that the radical of CH and H were produced by DBD in methane,and the optical emission spectrum line intensities of radical CH in the flame increased with voltage.Flash-back phenomenon was observed under some certain conditions.CFD software Fluent was used to investigate the effect of radicals of CH and H on methane combustion.And the simulation results agreed well with experiment results.It is concluded that the improvement of combustion property is contributed to radicals of CH and H produced by DBD in methane.