积木型多孔介质燃烧器的辐射输出效率及CO排放

Radiation Output Efficiency and CO Emissions in Modular Porous Media Burner

为加大对以CO为主要可燃成分的超低热值气体的利用,设计开发了同心套筒多孔介质燃烧系统,研究了以CO和N_(2)配制而成的超低热值燃气燃烧强度、热值和当量比对燃烧室出口表面温度、辐射输出效率和CO排放的影响.结果表明,只改变单一变量时,增大燃气热值或燃烧强度可以提高燃烧室出口表面温度、降低CO排放,但辐射输出效率随燃气热值或燃烧强度的增大而降低.燃烧强度为193.28 kW/m^(2)、当量比为0.9时,热值为2.0~3.0 MJ/m^(3)的超低热值燃气在积木型多孔介质燃烧器中燃烧的CO排放最低,燃烧室出口表面温度和辐射输出效率最高;当量比低于0.9时,当量比越小,燃烧室出口表面温度和辐射输出效率越低,CO排放越高.以CO为可燃成分的超低热值气体在多孔介质中的燃烧特性对多孔介质结构有很强的敏感性.

To increase the utilization of ultra-low calorific gas with CO as main combustible component,a dual-tube porous medium combustion system was designed and developed.The ultra-low calorific gas was made from CO and N_(2).The effects of firing rate,calorific value of gas and equivalence ratio on surface temperature of burner outlet,radiation output efficiency and CO emissions were studied.The results show that,with a single variable changed,as the calorific value of gas or firing rate increased,the surface temperature of burner outlet increased and CO emissions decreased,while the radiation output efficiency decreased.At the equivalence ratio of 0.9 and the firing rate of 193.28 kW/m^(2),the lowest CO emissions were achieved and the highest surface temperature of burner outlet and radiation output efficiency were reached for the ultra-low calorific gas of 2.0-3.0MJ/m^(3)in a modular porous media burner.When the equivalence ratio was lower than 0.9,both the surface temperature of burner outlet and radiation output efficiency decreased and the CO emissions increased with the decrease of equiva-lence ratio.The combustion characteristics of ultra-low calorific gas with CO as main combustible component in porous media are highly sensitive to the structure of porous media.