介质阻挡放电边缘电场对甲烷燃烧强化的影响

Effects of Edge Electric Field in Dielectric Barrier Discharges on Methane Combustion Enhancement

燃烧强化是介质阻挡放电的一种新应用,是加速燃烧的化学动力学过程,从而提高燃料的点火性能、燃烧速度和稳定性等燃烧特性的一种新技术。为此,利用一种同轴介质阻挡放电结构对甲烷进行放电,然后将处理后的甲烷与空气混合、燃烧,研究放电对火焰形态的影响。实验现象表明经处理后燃料的燃烧火焰的整体位置向下移动,出现回火现象,通常认为这是由火焰的燃烧传播速度增加所引起的。但该文认为这种回火现象是由介质阻挡放电电极的边缘电场效应所引起的。边缘电场加速燃料等离子体与空气的混合过程,并最终引起回火。该文采用添加绝缘导管的方法考察边缘电场对燃料气体混合过程的影响,证实了带电粒子在边缘电场的作用下会改善燃料气体的混合过程。

Non-thermal plasma combustion enhancement is a new application of dielectric barrier discharge {DBD）. The chemical activity of plasmas, generated in the process of discharging in gaseous fuel or fuel/air mixtures, has an effect on the chemical equilibrium of combustion system so as to improve the ignitability of the fuel, the velocity of combustion and the stability of combustion. Therefore, we employed a coaxial cylindrical configuration to study the influence of DBD on the methane combustion. Methane gas flows out from discharge zone, mixes with air in the mixing zone and finally combusts in the open air. The experimental results show that the combustion can be influenced by the edge electric field of the electrodes of DBD. The mixing process of methane and air can be changed by this field because its transverse component exerts an electric force on the charge particles generated in DBD.