煤粉锅炉气体再燃及SNCR联合脱硝的实验研究  

Experimental Study on Joint Denitration by Gas Reburning and SNCR in PC-boiler

作　　者：岳朴杰[1] 张忠孝[1] 毕德贵[1] 付振华 

机构地区：[1]上海理工大学环境与建筑学院,上海200093

出　　处：《热能动力工程》2017年第9期57-62,共6页Journal of Engineering for Thermal Energy and Power

摘　　要：对某厂一台240 t/h煤粉锅炉采用空气分级、化工合成气再燃及以氨气为还原剂的SNCR(选择性非催化还原)等技术进行联合脱硝改造。实验结果表明:气体再燃比在0~20%时,随着再燃量增大脱硝效率增加,高、低负荷工况时脱硝效率可达39.1%、43.1%;SNCR喷射点位置沿炉膛纵深存在温度梯度,水冷壁附近温度梯度较大,靠近炉膛中心处温度梯度降低;在空气分级基础上,高、低负荷工况时SNCR可分别提高35.1%、42.4%脱硝效率,氨气的使用不会造成锅炉效率的降低;满负荷工况采用气体再燃及SNCR技术联合脱硝时,在尾部氨逃逸小于12 mg/m3时,可达到80.2%的整体脱硝效率。Joint denitration transform for a 240 t/h pulverized coal fired boiler was carried out by adopting gas reburning with chemical syngas as the fuel and SNCR(selective catalytic reduction) with gas-state ammonia as reducing agent based on air classification,and the transformed denitration effect was tested. Results showed that as the gas amount ranges from 0 to 20%,the denitration efficiency increases with the increase of reburning fuel. The denitration efficiency under high and low load conditions can reach 39. 1% and 43. 1%,respectively. Along the depth of the furnace,the temperature for SNCR injection point has a gradient. The temperature gradient is larger near the water wall and it declines near the center of the furnace. The SNCR denitration efficiency can reach 39. 1% and 43. 1%,respectively,under high and low load conditions. Moreover,the use of ammonia gas does not reduce the efficiency of the boiler. Under the full load operation condition,the denitration efficiency can reach 80. 2% using gas reburning combined with SNCR technology,while ammonia escape is less than 12 mg/m^3 at the rear of the boiler.

关 键 词：气体再燃 温度梯度 氨气 SNCR 脱硝效率 

分 类 号：TK39[动力工程及工程热物理—热能工程] TM621[电气工程—电力系统及自动化]