摘要
为了明确高频交流电场对火焰燃烧的影响机理,分别选取了初始压力为0.1、0.3、0.5 MPa的CH4/空气和初始压力为0.1 MPa的CH4/O2/Ar预混稀燃气,通过在定容燃烧弹内的网状电极上加载幅值为5 kV、频率为15 kHz的高频交流电场,对比分析了在高频交流电场下两种预混气火焰传播特性的异同,以及不同初始压力下CH4/空气火焰传播特性的异同。结果表明:加载高频交流电场后,随着初始压力的增大,电场对CH4/空气火焰面发展的影响程度逐渐减小,平均火焰传播速度增大率逐渐减小;随着过量空气系数的增大,加载电场后对CH4/空气火焰的拉伸作用逐渐减小,对CH4/O2/Ar火焰的拉伸作用逐渐增大,CH4/空气的平均火焰传播速度增大率逐渐减小,CH4/O2/Ar的平均火焰传播速度增大率逐渐增大,电场对两种混合气火焰传播的影响趋向相同。这说明在CH4/空气预混稀燃气中,高频交流电场影响火焰燃烧的电化学效应中电子与燃烧产物分子的振动碰撞及其后续的链式反应占据主导。在不同初始压力下,平均火焰传播速度增大率随着简化场的增大呈线性增大,说明利用简化场来衡量高频交流电场电化学效应的强弱是可行的。
In order to clarify the affecting mechanism of high frequency AC electric field on flame combustion,two premixed lean gases including CH4/Air with the initial pressures of 0.1,0.3,0.5 MPa and CH4/O2/Ar with the initial pressures of 0.1 MPa were selected as the research object.The high-frequency AC electric field with the amplitude of 5 kV and the frequency of 15 kHz was applied on the mesh electrodes within the combustion bomb.The flame propagation characteristics of the two premixed gases under the high-frequency AC electric field and the flame propagation characteristics of CH4/Air at different initial pressures were analyzed.The results show that the degree of influence of the electric field on the development of the CH4/Air flame surface gradually decreases,and the increase rate of average flame propagation velocity gradually decreases with the initial pressure increasing under high-frequency AC electric field.With the increase of the excess air coefficient,the tensile effect on the CH4/Air flame gradually decreases but that on the CH4/O2/Ar flame gradually increases under the electric field.The increase rate of the average flame propagation velocity of CH4/Air gradually decreases,and that of CH4/O2/Ar gradually increases under the electric field.The influences of the electric field on the flame propagation of the two mixtures tend to be the same.This shows that in the premixed CH4/Air lean gas,the vibrational collision between electrons and combustion product molecules,as well as subsequent chain reactions,dominates the electrochemical effect in high-frequency AC electric fields affecting combustion.The increase rate of the average flame propagation velocity changes linearly with the increase of the simplified field E/N under different initial pressures.It shows that it is feasible to use the simplified field E/N to measure the strength of the electrochemical effect of high-frequency AC electric field.
作者
卢矍然
高忠权
潘俊宇
LU Jueran;GAO Zhongquan;Pan Junyu(School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;School of Material Science and Engineering, Shenyang University of Technology, Shenyang 110870, China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2020年第5期9-16,94,共9页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51306143)
中央高校基本科研业务费专项资金资助项目(xjj2018174)
西安市科技计划资助项目(2017040CG/CG014/成果转化-10)。
关键词
高频交流电场
稀燃火焰
平均火焰传播速度
电化学效应
high-frequency AC electric field
lean burn flame
average flame propagation velocity
electrochemical effect
