煤粉分级燃烧对炉内燃烧过程影响的试验研究

Experimental study on effects of pulverized coal staging on in-furnace combustion process

为了考察炉内燃烧过程的变化特性,研究了2.11 MW四角喷燃煤粉炉的煤粉分级燃烧效果.试验采用的锅炉燃料分级百分比为20%,二级燃烧区过量空气系数取0.95.一级燃烧区和燃尽区过量空气系数取1.10.结果表明,与未进行分级燃烧的基础工况相比,煤粉分级燃烧试验炉二级燃烧区和炉膛出口温度增高,锅炉NOx排放体积比降低45%.CO、CO2和SO2在应用分级燃烧后的炉内变化复杂,但其排放体积比未发生较大改变,甚至略有下降.分级燃烧使锅炉固体不完全燃烧损失(SICL)有一定程度增加,该煤粉分级燃烧是一种清洁燃烧技术.

To study the characteristics of in-furnace combustion process, the effects of pulverized coal staging in a 2.11 MW tangential-firing pulverized coal furnace were investigated. Twenty percent of the total fuel fired in the furnace was burned at high location to create a fuel-rich secondary combustion zone with excess air coefficient of 0.95. Both primary combustion zone and burnout zone took excess air coefficient of 1.10. The results show that compared with the value under baseline condition, the in-furnace temperatures of the secondary combustion zone and the furnace exit under staging condition increase, and that NOx emissions decrease by about 45%. Although the in-furnace characteristics of CO, CO2 and SO2 are complex, their emissions change little, even decrease slightly. The furnace solid incomplete combustion loss （SICL） increases by using pulverized coal staging. The proposed pulverized coal staging technology is a clean combustion technology.