不同孔密度多孔介质燃烧器内低浓度瓦斯燃烧特性研究

Study on combustion characteristics of low concentration gas in porous media burners with different pore densities

为了解决我国煤矿瓦斯抽采中大量低浓度瓦斯无法直接利用的问题,通过搭建多孔介质燃烧器内低浓度瓦斯燃烧试验系统,探究了5种不同孔密度多孔介质燃烧器内低浓度瓦斯燃烧温度分布及污染物排放规律。研究结果表明:多孔介质燃烧器孔密度对低浓度瓦斯燃烧温度的影响并非线性函数关系,在孔密度由10孔增加到20孔时,多孔介质燃烧器内燃烧温度成上升趋势;在孔密度由20孔增加到40孔时,多孔介质燃烧器内燃烧温度出现先降低后升高的趋势。孔密度为20孔的多孔介质内整体换热效果较好。相同流速燃烧工况下,不同孔密度多孔介质内的CO排放浓度均随当量比的增加而降低,NO的排放浓度随当量比的增加而升高。孔密度为20孔的多孔介质对应的CO排放浓度在所测当量比范围内普遍偏低,NO的排放浓度相对较高;孔密度为10孔的多孔介质对应的CO排放浓度偏高,NO的排放浓度偏低。

In order to solve the problem that a large number of low concentration gas can not be directly used in the gas extraction of coal mines in China,by building a low concentration gas combustion test system in porous media,the combustion temperature distribution and pollutant emission law of low concentration gas in five kinds of porous media burners with different hole density were studied.The results show that the influence of the hole density of the porous media burner on the combustion temperature of the low concentration gas is non-linear function relationship,when the hole density increases from 10 holes to 20 holes,the combustion temperature in the porous media burner tends to increase;when the hole density increases from 20 holes to 40 holes,the combustion temperature in the porous media burner tends to decrease first and then increase.The porous medium with 20 holes has better overall heat transfer effect.Under the same flow rate combustion condition,the CO emission concentration in porous media with different pore density decreases with the increase of equivalence ratio,and the NO emission concentration increases with the increase of equivalence ratio.The CO emission concentration of porous media with a pore density of 20 holes is generally low within the range of measured equivalence ratio,and the NO emission concentration is relatively high;the CO emission concentration of porous media with a pore density of 10 holes is relatively high,and the NO emission concentration is low.