壁面反应对微小通道内燃烧影响的数值模拟  

Effects of Surface Reactions on Hydrogen/Air Premixed Flames in Micro-Channels

作　　者：张立志[1,2] 赵黛青[1] 冯耀勋[1,2] 杨浩林[1] 

机构地区：[1]中国科学院广州能源研究所可再生能源与天然气水合物院重点实验室,广东广州510640 [2]中国科学院研究生院,北京100049

出　　处：《工程热物理学报》2011年第11期1973-1978,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50776090);中日NFSC-JST重大国际合作资助项目(No.50721140651)

摘　　要：对微小通道内氢气/空气预混火焰进行了数值模拟。通过对比考虑壁面反应和不考虑壁面反应的微通道内燃烧特性的差异,考察了壁面反应对微通道内燃烧状况的影响,揭示了壁面附近自由基行为和壁面反应、气相反应的相互关系,并探讨了不同尺度下壁面反应效应的程度。结果表明,壁面反应改变了微火焰结构,近壁面附近的自由基被吸附,在径向上出现了明显的指向壁面的扩散流,使得气相中的自由基浓度降低,以H基尤为显著。壁面反应不但能够引起着火延迟,还能引起熄火点提前,从而降低了微火焰稳燃极限。在更小的燃烧尺度下,壁面反应降低微火焰可燃极限范围将更加明显。A numerical simulation of hydrogen/air premixed flames in micro-channels is performed. To gain a understanding of flame-radical-wall interaction on millimeter and submillimeter scale combustion, the effects of surface reactions including 5 adsorption reactions and 7 desorption reactions on hydrogen/air premixed flames are investigated by comparing differences of flame structures with surface reactions or not. The results shows that surface reactions have a significant influence on flame structures and radical profiles near wails and induce decreases of radicals such as H, O, and OH radical. Decreases of radicals not only cause ignition delay but also narrow flame stability limits. In addition, it is found that flame stability limits become smaller with decreases of combustion scale.

关 键 词：壁面反应 微尺度燃烧 自由基失活 化学熄火 

分 类 号：TK16[动力工程及工程热物理—热能工程]