【摘要】 为了研究具有内嵌换热面的泡沫型多孔介质中的气体燃烧、传热特性,将换热面内嵌布置于双层泡沫型多孔介质下游碳化硅泡沫陶瓷中,试验研究甲烷/空气预混气体在其中的温度分布、稳燃范围、燃烧产物排放特性,分析燃烧器热效率和换热面在多孔介质内的传热过程.结果表明,在泡沫型多孔介质燃烧系统中内嵌换热面后可以降低燃烧器温度水平,具有较宽的稳燃范围;相较于无换热面情况,内嵌换热面后,燃烧器出口NOx排放量下降,试验工况范围内低于35mg/m3;燃烧器热效率随入口气流速度下降并保持在60%~80%;换热管外壁与多孔介质气固两相的传热相较于传统的气流横向冲刷管束,平均传热系数增幅可达75%.更多还原

【Abstract】 CH₄/air premixed combustion in SiC porous media with embedded heat exchangers were experimentally investigated in order to analyze the combustion and heat transfer behaviors in porous media with embedded heat exchangers.Temperature distribution,stability limits and pollutant emissions at varied equivalence ratios and cooling water flow rates were presented.Thermal efficiency of burner and the heat transfer between heat exchangers and the porous media were analyzed.The temperature level was lowered within heat exchangers embedded,and the flame can stabilize in a relatively wide range of the inlet velocity.The nitrogen oxide（NOx）emission of the burner with heat exchangers embedded was less than that of porous burner without heat exchangers,which was lower than 35 mg/m³ under all experiment conditions.The thermal efficiency of the burner decreaseds with the inlet air flow rate and was kept in the range of 60% ⁸0%.The average heat transfer coefficient between the porous media and the heat exchangers increaseds 75% compared with the conventional convection of flow across the tube banks.更多还原