【摘要】 以660 MW褐煤锅炉为对象,研究了含水量升高对褐煤燃烧特性及锅炉性能的影响。模拟中采用一种特殊的方法来考虑褐煤中水分的存在,计算准确性高。研究结果表明:水分较高的褐煤炉膛温度相对较低,炉内受热面吸热量减少,但气体发射率变大使得屏区的辐射传热差异相比水冷壁减小。水分含量升高对炉内气化反应有促进作用,但总体影响小于温度降低带来的抑制作用。高含水率煤的未燃尽碳浓度升高,煤粉燃尽变差,锅炉整体效率降低。因此,实际锅炉运行时不宜燃用超过设计燃料水分太大的褐煤。更多还原

【Abstract】 The influences of elevated water content and on coal combustion was studied based on a 660 MW lignite-fired boiler. A special method is adopted to consider the existence of water in lignite, who has high accuracy. Results show that the furnace temperature is lower when consuming higher moisture lignite. The decrease in the temperature makes heat transfer get worse, however, the increase in the gas emissivity reduces the decline of radiation heat transfer in the panel. The increase of moisture content decreases the intensity of gasification reaction because the positive effect of moisture is less than the negative influence of decline of temperature. The concentration of unburned char particles increases when consuming higher moisture coal, making the overall efficiency of the boiler decreases. It is not suitable burn the lignite whose moisture exceeds the design value in actual operation.更多还原