In this work, to further optimise the porous media combustion model and explore the combustion characteristics of low-concentration methane in porous media, a thermal non-equilibrium model of porous media combustion is established with modified effective thermal conductivity of the porous media based on the volume average method. The effects of foam ceramics pore density, inlet velocity and wall heat loss coefficient, as well as combinations of different pore density foam ceramics on flame stability were studied. Results show that the predicted temperature profile matched well compared with the experimental data. The temperature inside the burner can be divided into the following four zones: preheating zone, combustion zone, cooling zone dominated by wall heat loss and cooling zone dominated by heat radiation at the burner outlet. Moreover, it was found that the porous media combustion model with modified effective thermal conductivity of the porous media could simulate the flame front shape in different pore density foam ceramics. On the contrary, the flame front shape in the simulation with constant thermal conductivity does not change and remains a uniform radial disc. In addition, the flame is easier to stabilise at the interface of the foam ceramic with different pore densities.

本工作为进一步优化多孔介质燃烧模型，探索低浓度甲烷在多孔介质中的燃烧特性，基于多孔介质有效热导率，建立了多孔介质燃烧热非平衡模型。体积平均法。研究了泡沫陶瓷的孔密度、入口速度和壁面热损失系数以及不同孔密度泡沫陶瓷的组合对火焰稳定性的影响。结果表明，与实验数据相比，预测的温度曲线非常匹配。燃烧器内部的温度可分为以下四个区域：预热区、燃烧区、以壁面热损失为主的冷却区和以燃烧器出口处的热辐射为主的冷却区。而且，研究发现，修正多孔介质有效热导率的多孔介质燃烧模型可以模拟不同孔密度泡沫陶瓷中的火焰前锋形状。相反，在热导率恒定的模拟中，火焰前锋形状没有改变，仍然是一个均匀的径向圆盘。此外，不同孔密度的泡沫陶瓷界面处火焰更容易稳定。