在多入口燃烧器内加入多孔介质,以甲烷/空气为燃料,采用非预混燃烧的数值模拟方法,探究多入口燃烧器的燃烧情况.对比多孔介质燃烧与空间自由燃烧,分析了"超焓燃烧"现象;在多孔介质燃烧基础上,探究不同当量比对燃烧温度的影响;在多孔介质燃烧和不同当量比的基础上探究污染物CO和CO_2的排放情况.结果表明:多孔介质燃烧可以实现"超焓燃烧"特性,燃烧火焰温度高于自由空间燃烧温度;当量比对燃烧温度影响很大,随着当量比的增大,燃烧器内最高燃烧温度升高,但燃烧过程存在一个最佳当量比0.6,超过该当量比后最高温度将不再变化;多入口多孔介质燃烧有助于减少CO和CO_2的生成量.
Numerical investigation on combustion characteristics of methane and air in a multi-nozzle porous medium combustor with non-premixed combustion model has been conducted.Comparison between porous medium combustion and tradition combustion has been made to investigate "excess enthalpy combustion".When combustion in porous medium was conducted,effects of equivalence ratio on the combustion temperature and emissions of CO and CO_2 were explored.The results showed that combustion in porous medium could realize the "excess enthalpy combustion".The maximum combustion temperature was obviously higher than that of tradition combustion.And it increased with the rising of equivalent ratio.However,there existed an optimum equivalence ratio of 0.6in this study.Beyond this value,the maximum combustion temperature kept constant.The multi-nozzle porous medium burner could reduce the production of CO and CO_2.