| 房建峰,姚永玉,周辉,等.高电压下浓/稀天然气燃烧特性的对比研究[J].内燃机工程,2021,42(3):26-32. |
| 高电压下浓/稀天然气燃烧特性的对比研究 |
| Compare Study on Combustion Characteristics of Rich/Lean Nature Gas under Positive Electric Field |
| DOI：10.13949/j.cnki.nrjgc.2021.03.004 |
| 关键词:正电场 球形火焰 离子风 燃烧化学反应 火焰传播 燃烧压力 拉伸效应 |
| Key Words:positive electric field spherical flame ionic wind combustion chemical reaction flame propagation combustion pressure stretch effect |
| 基金项目: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(2016BZ08)；河南省科技攻关计划 项目 (182102210423) |
|
| 摘要点击次数: 2100 |
| 全文下载次数: 964 |
| 摘要:为了利用高压正电场促进天然气火焰的燃烧过程,并探讨电场作用下以自由电子为主的阴离子对混合气燃烧的作用,该文研究了正电场作用下浓/稀天然气火焰的燃烧特性。试验中的加载正电压为0、5和10 kV,浓/稀混合气的过量空气系数λ为0.8和1.4。加载正电压时,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火焰的平均传播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。高压正电场对球形膨胀火焰的作用可用火焰中的阴离子,尤其是O2-主导的离子风效应来说明。同时,正电场在一定程度上也促进了火焰燃烧化学反应的进行。 |
| Abstract:This paper researched the effects of positive electric fields on the outwardly expanding premixed methane-air flames in a constant chamber. 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 showed the flame propagation in the opposite direction of electric field was improved, and the flame develop velocity and the flame stretch rate were increased as the electric field become more intense and these behaviors were more pronounced for lean mixtures. For the mixtures of λ=0.8 and 1.4 at 10 kV, the mean flame speed was increased by 36.4% and 49.5%, respectively. The improvement of flame speed enhanced the combustion process, and this led to reducation of the initial period of combustion and advancement of the timing of peak pressure. Meanwhile, the stretch effect of the flame propagation was increased. The joint functions of the two respects made the peak pressure for lean mixture increase, while the value kept almost the same for rich mixtures.Two alternative mechanisms to explain the positive electric field enhanced effects were proposed: 1) ionic wind effect due to negative ion-neutral molecule collisions in the field direction; 2) direction action of positive electric field on chemical kinetics via excited nitrogen molecule due to collisions with electrons. |
|
查看全文 HTML
查看/发表评论 下载PDF阅读器 |
|
|
|