提高炉内燃烧稳定性的数值模拟

针对某电厂四角切圆锅炉由于燃用煤质下降,炉内出现燃烧不稳定以及过热、再热蒸汽温度偏低等问题,提出在主燃区内敷设一定数量卫燃带以稳定炉内燃烧并提高过热、再热蒸汽温度。数值计算结果表明,敷设卫燃带后,炉膛内整体温度水平有所升高,煤粉着火和燃烧较为稳定;较高的烟气温度也有利于提高过热、再热蒸汽温度;同时合理的卫燃带布置方式降低了炉内结渣的可能,有效地保证了锅炉的安全经济运行。

Numerical simulation on the improvement of combustion stability in boiler

For the combustion instability and lower temperature of superheated and reheated steam owing to the declining coal quality in a tangential firing boiler,the method of installing some refractory belts can optimize the combustion in furnace and improve the temperature of superheated and reheated steam.The numerical computation results show that after the refractory belt installed the temperature in furnace was increased,and the ignition and combustion process were stabilized.The higher flue gas temperature can reinforce the heat transfer between gas,reheaters and superheaters.The reasonable arrangement mode of refractory belt can reduce the possibility of slagging in furnace.The reconstruction can stabilize the combustion of pulverized coal and improve the steam temperature of reheater and superheater.It can ensure the safe and economical operation of boiler.