600MWe超临界循环流化床锅炉的炉膛水冷壁传热

Heat transfer in a 600 MWe supercritical circulating fluidized bed boiler with water cooled wall panels

对带隔墙的600MWe超临界循环流化床锅炉的炉膛水冷壁传热及热流密度分布进行了研究。基于构建的循环流化床锅炉传热模型,得到了锅炉最大连续工况、75%及50%汽轮机热耗验收工况下炉膛局部物料浓度、热流密度及传热系数的分布情况。结果表明,炉膛局部物料浓度、热流密度及传热系数沿高度的增加均逐渐降低,并在一定高度上逐渐均匀,随着负荷的降低,趋于均匀的高度有所下降。侧墙与隔墙局部物料浓度等参数沿周向的分布呈现角部高、中心低的分布趋势。由于隔墙的存在,前墙与侧墙的热流密度分布不同。整体上,炉膛出口处热流密度偏差最大;随负荷降低,传热系数周向偏差减小。

The water wall heat transfer and heat flux distribution in a 600 MWe supercritical circulating fluidized bed furnace were investigated. The solid suspension density, the heat flux, and the heat transfer coefficient distribution in the furnace were predicted at the maximum boiler continuous rating and at 75% and 50% of the turbine heat acceptance. The results show that the heat flux, the heat transfer coefficient, and suspension density all decrease with increasing distance to the distributor up to a critical height while deereases with decreasing load. The horizontal heat flux distribution is related to the horizontal position on the water wall and the boiler load with the highest heat fluxes is in the corner. The heat flux distribution on the front wall is quite different from that on the side wall. The heat flux is highest at the top of the tube.