往复流多孔介质燃烧器的二维数值模拟与结构改进

对往复式惰性多孔介质燃烧器进行了二维数值模拟,模型的有效性通过实验数据进行验证.在燃烧器中分别填充4孔/cm泡沫陶瓷或小球,研究其内部的燃烧温度和压力损失.结果表明,由相同材料制成但结构不同的多孔介质对燃烧器内的高温区域和压力损失有显著的影响.孔隙率较大的泡沫陶瓷适合于布置在燃烧区,而孔隙率较小的小球适合于布置在热交换区域.改进燃烧器结构,即在燃烧器的中间布置泡沫陶瓷,而在两端布置小球.对于当量比为0.1的甲烷与空气混合气,得到了更为宽广的高温区域和适度的压力降.

2D Numerical Modeling and Structure Improvement of Porous Medium Burner with Reciprocating Flow

2D numerical modeling of a porous inert media burner with reciprocating flow was presented.The model was validated through comparison with experimental data.The combustion temperature and pressure loss were investigated inside the burner, which was packed with alumina spheres or 4 pores/cm ceramic foam respectively.Results show that porous media made of the same material but with different structurs have significant influence on both the high temperature zone and pressure loss in the burner,and that ceramic foam with high porosity was suitable for the combustion region whereas alumina spheres with low porosity should be placed in heat exchange region.According to this principle,an improved burner was proposed,the center of which was packed with ceramic foam while both ends of it with alumina spheres,and this leads to a wider high temperature profile and moderate pressure loss for extremely dilute CH4/air mixture with an equivalence ratio of 0.1.