【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。更多还原

【Abstract】 To explore the influence of air classification combustion on NOxformation,some analysis and simulation to air flow,heat transfer,fuel combustion,NOxformation 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,species distribution of combustion product.The simulation result has indicated that the combusting mixture can be seen in most area of boiler and the separation of lower oxygen concentration in main combustion region and higher oxygen concentration in overfire air region has contributed 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-NOxsituation.With the enhancing of OFA ratio,the average temperature of boiler drops,however the NOx doesn’t decrease monotonically and it reaches the lowest emission values when OFA ratio come to 23%.更多还原