1000MW塔式直流锅炉炉膛水冷壁管壁温度和热负荷分布的试验研究

对2台1 000MW超超临界压力塔式直流锅炉炉膛水冷壁管壁温度和热负荷分布进行了测量和计算,并对不同负荷工况、不同磨煤机投运方式下的热负荷和管壁温度分布规律以及炉膛上部垂直水冷壁的热负荷分布进行了分析.结果表明:1 000MW塔式直流锅炉炉膛热负荷的分布规律与其他四角切圆燃烧锅炉炉膛热负荷的分布规律基本一致.由于在最上层的燃烧器上方布置了燃尽风,对炉内烟气的扰动加强,导致沿管长方向的热负荷在54m标高处波动较大;在燃尽风喷嘴中心线以上,因受到燃尽风进入炉膛的影响,水冷壁热负荷大幅度下降.为了避免炉膛大比热区传热恶化,可以将处于拟临界点附近的水冷壁布置在低热负荷区域.

Study on Water Wall Temperature and Heat Load Distribution in 1 000 MW Tower-type Once-through Boilers

By measuring the water wall temperature and calculating the heat load in furnace of 2×1 000 MW ultra-supercritical pressure tower-type once-through boilers,the tube wall temperature and heat load distribution were analyzed under different working conditions at different modes of coal mill operation,including the heat load distribution of vertical water wall on upper part of the furnace.Results show that the heat load distribution in 1 000 MW tower-type once-through boiler is basically the same as that of other tangential-firing boilers.The heat load distribution along tube length direction at 54 m elevation changes greatly due to enhanced flue gas disturbance by over-fire air(OFA) above the top layer burners.The heat load on water wall along OFA nozzle centerline reduces considerably due to the entrance of OFA into boiler furnace.To avoid heat-transfer deterioration in large specific heat region,it is suggested that the water wall neighboring pseudo-critical point be arranged in low heat load areas.