【摘要】 以国内某电厂采用多次引射分级燃烧技术的600 MW超临界W火焰锅炉为研究对象,在拱上燃烧器采用集中布置的基础上,利用Fluent14.5软件计算了拱上燃烧器与竖直方向夹角分别为0°、5°、10°、15°和20°时炉内速度场、温度场和烟气组分浓度场的分布情况。数值模拟结果与试验测试结果吻合性良好。计算结果表明:当拱上燃烧器角度从0°逐渐增大到20°,炉内速度场对称性良好,温度场的对称性会逐渐变差;前后墙拱上气流的下冲深度逐渐变短,炉膛火焰中心明显上移,一次风和二次风对前后墙水冷壁的冲刷作用逐渐变强;炉膛出口烟气的氧量值不断降低,这在一定程度上会减少排烟热损失;但炉膛出口处NOx值由889.1 mg/m3增大为1220.6 mg/m3(6%O2)。更多还原

【Abstract】 Taking a domestic power plant 600 MW supercritical down-fired boiler with multi-injection multi-stage combustion technology as the research object, on the basis of centralized arrangement of the burner on arch, Fluent14.5 software was used to calculate when the burner and the vertical angle of the arch were 0°, 5°, 10°, 15°and 20°, the distribution of velocity field, temperature field and flue gas component concentration field in the furnace. The simulated results were in good agreement with the measured results. The simulated results showed that with the arch burners angle gradually increased from 0°to 20°, the symmetry of velocity field was well, the symmetry of temperature field would gradually deteriorate. The air flow punch depth around the arch of the front and back wall gradually became shorter, the center of the furnace flame significantly moved upward, the scour action of primary air and secondary air against the front and back wall gradually enhanced. The oxygen values of furnace exit flue gas continued to decrease, which would reduce heat losses; but the NOx value at the furnace exit increased from 889.1mg/m3 to 1220.6mg/m3(6%O2).更多还原