高电压下浓/稀天然气燃烧特性的对比研究  

Comparative Study on Combustion Characteristics of Rich/Lean Natural Gas Under High Voltage

作　　者：房建峰 姚永玉 周辉 葛述卿 贾贵西 FANG Jianfeng;YAO Yongyu;ZHOU Hui;GE Shuqing;JIA Guixi(School of Machinery Engineering,Luoyang Institute of Science and Technology,Luoyang 471023,China)

机构地区：[1]洛阳理工学院机械工程学院,洛阳471023

出　　处：《内燃机工程》2021年第3期26-32,共7页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金联合基金重点项目(U1604141);洛阳理工学院博士启动基金项目(2016BZ08);河南省科技攻关计划项目(182102210423)。

摘　　要：利用定容燃烧装置研究了高电压作用下浓/稀天然气火焰的燃烧特性,并探讨了以自由电子为主的阴离子对火焰燃烧的作用机理。试验中加载电压为0 kV、5 kV和10 kV,浓/稀混合气的过量空气系数λ分别为0.8和1.4。在加载电场作用下,球形膨胀火焰在与电场相反方向上的火焰传播明显加快,火焰传播速度和火焰拉伸率随加载电压的增强而增大,稀燃混合气的火焰传播的增强程度最为明显。加载10 kV电压时,λ为0.8和1.4火焰的平均速度比没有电场作用时分别增加了36.4%和49.5%。火焰传播速度的增强,促进了燃烧过程的进行,使得混合气燃烧的滞燃期缩短,压力升高率增加,且压力峰值时间提前。稀燃混合气的燃烧压力峰值有较大提高,而浓燃混合气的压力峰值变化不大。试验中加载电场对球形膨胀火焰燃烧的作用机理可用火焰中的阴离子,尤其是O-2主导的离子风效应来说明。同时,电场在一定程度上也促进了火焰燃烧化学反应的进行。A constant-volume chamber was used to research the effects of electric fields on the combustion of rich/lean methane-air flames.The input voltages were 0 kV、5 kV and 10 kV,the excess air ratios(λ)of mixtures were 0.8 and 1.4,representing the two mixed gas states of rich combustion and lean combustion,respectively.The results show the flame propagation in the opposite direction of electric field is improved,and the flame developing velocity and the flame stretching rate are increased as the electric field becomes more intense and these behaviors are more pronounced for lean mixtures.For the mixtures ofλ=0.8 and 1.4 at 10 kV,the mean flame speed is increased by 36.4%and 49.5%,respectively.The improvement of flame speed enhances the combustion process,and this leads to reduction of the initial period of combustion and advancement of the timing of peak pressure.Meanwhile,the stretching effect of the flame propagation is increased.The joint functions of the two respects make the peak pressure for lean mixture increase,while the value keeps almost the same for rich mixtures.Two alternative mechanisms to explain the applied electric field enhanced effects are proposed:ionic wind effect due to negative ion-neutral molecule collisions in the field direction,especially for O-2,and direction action of positive electric field on chemical kinetics via excited nitrogen molecule due to collisions with electrons.

关 键 词：电场 离子风 燃烧化学反应 火焰传播 燃烧压力 拉伸效应 

分 类 号：TK431[动力工程及工程热物理—动力机械及工程]