端部导流板对多孔介质内低浓度瓦斯燃烧特性的影响

摘要

The combustion of low concentration coal mine methane in porous media was numerically simulated through a two-dimensional model and reasonable setting by using software Fluent 6.3. The gas velocity and temperature distributions and the N0x formation in the porous media combustor with or without baffle in its front end were investigated. The results showed that the velocity distribution of the combustor with baffle was more uniform than that of the combustor without baffle; the combustor with baffle could prevent backfiring and improve safety and heat transfer efficiency; and the formation of NOX in the combustor without baffle was less at low velocity of methane, but when the velocity of methane increased to some extent, the formation of NO, with baffle was less. The baffle should be considered according to the velocity of methane in the design of combustor.%利用模拟软件Fluent 6.3建立二维模型并进行合理设置,对多孔介质中的煤矿低浓度瓦斯燃烧进行数值模拟,研究了燃烧器端部设置导流板和没有导流板时的速率分布、温度分布和NOx生成情况.结果表明,有导流板的多孔介质燃烧器的速率分布比无导流板的燃烧器更加均匀;加导流板时,可防止回火,提高燃烧器的安全性,一定程度上有利于换热效率的提高;瓦斯流速较小时,无导流板燃烧器中生成的NOx较少,而流速增大一定量后,有导流板的NOx产生量较少,燃烧器设计时,应根据实际燃气速率的情况考虑导流板的设置.