多孔介质燃烧器的辐射输出效率和污染物

使用双温度体积平均模型、详细化学反应机理GRI3．0，对甲烷，空气预混气在多孔介质燃烧器内的预混火焰进行模拟．分析不同当量比和质量流量下的预热效率、辐射输出效率以及污染物排放情况，并对辐射输出效率随多孔介质热物性参数的变化进行敏感性分析．结果表明，增大相间对流换热系数或减小当量比、质量流量及固相消光系数都可以提高辐射输出效率，减小当量比或质量流量可以减少污染物排放．在所有的影响因素中，当量比的影响最大，发展超贫燃燃烧技术是获得高效低污染多孔介质燃烧器的关键．

Radiation Output Efficiency and Emissions in a Porous Burner

Combustion of CH4/Air premixed gases in a porous burner was simulated using the two-equation model and the detailed reaction mechanism GRI 3.0. Preheat efficiency, radiation output efficiency and emission output were analyzed under different equivalence ratios and mass fluxes. Sensibility analysis of radiation output efficiency with thermophysical properties was also studied. The results show that radiation output efficiency increases with the increase of interphase heat exchange coefficient or the decrease of extinction coefficient, equivalence ratio or mass flux, and that emission output decreases with the decrease of equivalence ratio or mass flux. Of all the influencing factors , equivalence ratio is of the greatest importance. So developing ultra-lean combustion is the key to improving efficiency and decreasing emission of the porous burner.