浅谈循环流化床锅炉对氮氧化物的影响

Influence of Nitrogen Oxides in Circulating Fluidized Bed Boiler

通过对NO_x生成机理及NO_x排放影响因素的分析探讨,结合循环流化床锅炉自身的特点可知,在循环流化床锅炉中,燃料型NO_x在氮氧化物排放中占主导地位,循环流化床锅炉控制NO_x的排放浓度应从入炉燃料的自身特性、炉膛内燃烧温度、炉膛内过量空气系数、配风方式、物料的循环倍率等方面着手;在燃料一定,炉膛内的燃烧温度控制在850～900℃,配风采用分级配风形式时,选择合理的脱硫剂及还原剂的品质、粒径及喷入量,可有效地控制NO_x的排放浓度。

By analyzing and discussing the mechanism of NOx formation and influencing factors of NOx emission,combined with the characteristics of CFB boilers, it is known that fuel-type NOx playsa dominant role in NOxemission of CFB boilers. The control of NOx emission concentration in CFB boilers should start with the characteristicsof fuel entering the furnace, combustion temperature in the furnace, excess air coefficient in the furnace, air distributionmode and circulation ratio of materials. When the fuel is certain, the combustion temperature in furnace is controlled at850~900 ℃, the emission concentration of NOx can be effectively controlled by choosing reasonable desulfurizer, andthe quality, particle size and injection amount of reductant.