分级配风对切圆锅炉NO_x生成与燃烧经济性的影响  

Effects of air staging combustion for a tangential-fired boiler on NO_x emission and boiler efficiency

作　　者：姚瑶 吕当振[2] 邱应军[2] 

机构地区：[1]华电郑州机械设计研究院有限公司,河南郑州450015 [2]国网湖南省电力公司电力科学研究院,湖南长沙410007

出　　处：《湖南电力》2015年第6期27-31,共5页Hunan Electric Power

摘　　要：针对燃用劣质混煤的300 MW四角切圆燃烧锅炉,通过低氮燃烧系统改造与增设燃尽风(SOFA)相结合的方式,用于降低氮氧化物(NO_x)排放浓度。通过三种劣质混煤的实炉燃烧试验获得了SOFA风率,三次风投、退,缩腰配风方式对NO_x排放浓度与锅炉燃烧经济性的影响规律。试验结果表明,随着SOFA风率增加,锅炉热效率随之下降,而NO_x排放浓度呈现出先下降后上升的趋势;制粉系统三次风退出时,NOx排放浓度明显降低,而飞灰含碳量有所升高;此外通过优化缩腰配风,有助于提高锅炉热效率和降低NO_x生成浓度,从而实现低氮燃烧的同时,兼顾锅炉燃烧经济性。In order to reduce the NOxemission during the low-quality blended coal combustion,a novel technique combining an additional separated over fire air( SOFA) and boiler combustion system retrofit was carried out in a 300 MW tangential-fired boiler. Through three low-quality blended coals firing experiments,the impacts of SOFA,the tertiary-air and shrinked-middle wind on NOxemission and boiler efficiency were obtained. The results indicated that with the increase of air damper opening degree of SOFA,the NOxemission firstly decreased and then increased,while the boiler efficiency decreased. Meanwhile,by comparison with using the tertiary-air,the NOxemission reduced rapidly,but the unburned carbon slowly increased without the tertiary-air. Furthermore,the proper shrinked-middle wind could not only improve the coal combustion efficiency,but also reduce the NOxemission. Hence,air staging combustion adjustment should obtain a proper point for both the low NOxemission and the optimal boiler efficiency.

关 键 词：四角切圆锅炉 燃尽风 三次风 NOx排放 

分 类 号：TK227.1[动力工程及工程热物理—动力机械及工程]