煤粉粒径分布对电站锅炉低氮燃烧器性能的影响

Influence of Particle Size Distribution of Pulverized Coal on the Performance of a Low-NO_x Burner in Power Plant Boiler

通过对WR型低氮燃烧器的分离器进行分析计算,研究了煤粉在分离器内的运动过程以及影响分离器效率的因素。结合某300 MW煤粉锅炉的变工况试验结果表明:WR型低氮燃烧器的合理运行区间应高于75%额定负荷;当锅炉负荷低于75%额定负荷时,由于煤粉粒径的重新分布,将使WR型低氮燃烧器的分离器效率有所下降,进而引起浓淡燃烧效果下降、NOx排放量升高。

Based on analysis and calculation of the separator in a WR dense-dilute burner,a study was conducted on the movement trajectory of pulverized coal in the separator and on the factors influencing the separation efficiency.In addition,off-design tests were carried out on a 300 MW coal-fired boiler.Results show that the reasonable operation range of the WR low-NOx burner is above 75%rated load.When the boiler load is lower than 75%rated load,due to the redistribution of pulverized-coal particle sizes,the separation efficiency of the WR burner reduces,resulting in decreased dense-dilute combustion efficiency and increased NOx emission.