旋流燃烧器配燃尽风对氮氧化物排放和燃尽率的影响

Effect of Over Fire Air in a Swirling Burner on NO_x Emission and Burnout Rate

为减少电站锅炉氮氧化物的有害排放,采用1MW热态煤粉燃烧试验锅炉进行热态模化试验,使用两台双调风旋流燃烧器进行对冲燃烧。该试验过程在主燃烧器的上方不同位置,布置了分级燃烧的燃尽风装置。通过截面渐变一次风管与相邻的碰撞环结合以使空气和煤粉混合气流在一次风管内,将煤粉与空气的混合气体中的煤粉颗粒沿径向分离为内淡外浓的环状气流,实现了燃料在燃烧器喷口处沿径向的浓淡分布。通过对特性差异较大的神华煤、河津煤和长治煤的热态模拟实验,结果表明:燃尽风布置的相对位置变化影响氮氧化物的生成与排放,燃尽率受燃尽风布置相对位置的影响,氮氧化物的生成与排放和燃尽率之间呈正相关,燃尽风布置为锅炉燃烧稳定性和经济性的主要影响因素。

The study aims to reduce the emission of harmful nitrogen oxides from power plant boilers.1 MW hot pulverized coal combustion test boilers were used in the thermal model test,and two double-regulated Swirling Burners were used for opposed firing.The exhaust air device for staged combustion was arranged at different positions above the main burner in the test process.The pulverized coal particles in the mixture of pulverized coal and air were separated radially into annular gas flow with inner light and outer dense by combining the primary air duct with the adjacent collision ring.The radial denselean distribution of fuel at the burner nozzle was realized.The thermal simulation experiments on Shenhua coal,Hejin coal and Changzhi coal with different characteristics show that the change of the relative position of exhaust air device affects the production and emission of nitrogen oxides and influences the burnout rate,that the production of nitrogen oxides is positively correlated with the emission and burnout rate,and that the arrangement of exhaust air is the main factor influencing the combustion stability and economy of boilers.