600MW煤粉锅炉低NO_x排放模拟及墙式高位燃尽风途径NO_x生成机理探究  

Research on Reduced-NO_x Simulation and Wall-type OFA-NO_x Formation Mechanism of a 600MW Pulverized Coal Boiler

作　　者：王立睿 缪正清[1] 李江涛[1] 黄文静[1] 彭彬彬[1] 

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《锅炉技术》2014年第5期49-52,共4页Boiler Technology

摘　　要：为探究空气分级燃烧对NOx生成的影响,针对某台600MW超临界锅炉,基于ANSYS-Fluent软件对其流动、传热、燃烧及NOx生成进行了多组工况数值模拟,得到了炉膛内烟气速度场、温度场和燃烧产物组分浓度分布等。结果表明,炉膛充满度良好,燃尽风工况中主燃区氧浓度较低,CO浓度高,有利于降低氮氧化物的生成。主燃区燃烧在缺氧环境下进行,合理优化墙式高位燃尽风与主燃区氧量配比是关键。随着高位燃尽风风率提高,炉膛平均温度有所下降,但出口NOx并不随风率单调下降,而是在23%时达到最低排放值。To explore the influence of air classification combustion on NOx formation, some analysis and simulation to air flow, heat transfer, fuel combustion, NOx formation of a 600 MW pulverized coal boiler have been carried out based on Fluent business software. Various simulation conditions were set up to obtain the result of temperature and velocity field, spe- cies distribution of combustion product. The simulation result has indicated that the combust- ing mixture can be seen in most area of boiler and the separation of lower oxygen concentra- tion in main combustion region and higher oxygen concentration in overfire air region has con- tributed a lot to reduce NOx. To keep the reduction atmosphere in main combustion zone and maintain the appropriate oxygen ratio are the key to optimize the OFA reduced-NOx situation. With the enhancing of OFA ratio, the average temperature of boiler drops, however the NO, doesn＇t decrease monotonically and it reaches the lowest emission values when OFA ratio come to 23 %.

关 键 词：热能工程 空气分级 墙式高位燃尽风 燃尽风风率 数值模拟 氮氧化物排放 

分 类 号：TK229.6[动力工程及工程热物理—动力机械及工程]