有序堆积床内预混气体燃烧特性实验研究

为研究预混气体在多孔介质燃烧器中的火焰燃烧特性,设计了一种新型多孔介质燃烧器,其中多孔介质区域由氧化铝圆柱体有序堆积而成。分别研究了当量比和入口速度对甲烷/空气预混气体在多孔介质燃烧器中的火焰温度分布、火焰最高温度以及火焰传播速度的影响。结果表明:在当量比0.162~0.324、入口速度0.287~0.860 m/s的实验工况下火焰均可以稳定向前传播,并且都发生了超绝热燃烧;当量比越大,入口速度越大,火焰最高温度越高;当入口速度为0.430 m/s时,贫可燃极限的当量比可以扩展到0.162;火焰传播速度随着入口速度的增加和当量比的减小而增大,其数量级为0.100 mm/s,属于一种十分典型的低速过滤燃烧。

Experimental study on premixed gases combustion characteristics in a structured packing bed

In order to understand the combustion characteristics of premixed gases in porous media, a new porous media burner was designed, in which the porous media region was formed by alumina cylinders regularly staggered. The effects of methane/air premixed gas with different equivalence ratios and inlet velocities on the flame temperature distribution, the maximum flame temperature and the flame propagation velocity were studied. The results show that the flame propagation is stable and super-adiabatic combustion phenomena are observed under the test conditions of the equivalence ratios in the range of 0.162-0.324 and inlet velocities in the range of 0.430-0.860 m/s. The higher equivalence ratio and the larger inlet velocity lead to higher maximum flame temperature. The lean flammability limit is extended to an equivalence ratio of 0.162 at the inlet velocity of 0.430 m/s. The flame propagation velocity is higher when the equivalence ratio is lower and the inlet velocity is higher. The order of magnitude of the combustion wave propagation velocity is 0.100 mm/s, which is typical for the low-velocity filtration combustion.