600MW亚临界“W”火焰锅炉机组劣质煤燃烧特性

The practice and analysis of inferior coal combustion characteristic in 600 MW W-Flame subcritical boiler

介绍了贵州黔东电力有限公司600MW亚临界"W"火焰锅炉机组燃烧系统的特点。鉴于600MW机组"W"火焰锅炉在以往调试和生产中存在燃烧不稳、管壁超温、燃尽差等难题,有针对性开展劣质高硫煤燃烧实践,确定了适宜的一次风速与乏气风速、各负荷阶段风门开度、不同煤质下高负荷时各风门开度,以及最佳氧质量分数和煤粉细度等,分析了双旋风煤粉燃烧器前后墙"W"燃烧方式的运行特性,包括风粉均匀性、烟气、蒸汽温度偏差、炉膛结焦等。调试期间,1号机组累计消耗燃油2488.9t,锅炉燃烧稳定,未发生管壁超温现象,左右侧主、再热汽温偏差控制在5℃以内,飞灰含碳质量分数小于5%,燃烧效率保持较高水平,锅炉无明显结焦。

The feature of combustion system of 600 MW W-flame subcritical boiler in Guizhou Qiandong power plant was introduced in this paper. Unsteady combustion, over-temperature of the tube-wall and low burnout rate are the difficult problems in this kind of boiler. Based on the research and practice of inferior high-S coal, the techniques hereinafter were adopted： determining appropriate primary air speed and exhausting air speed; defining the draft damper opening under different high load and when burning different coal, especially burning the anthracite coal, fixing on the optimal oxygen mass fraction and pulverized coal fineness; analyzing the ＂W＂ combustion method characteristics at the front and rear walls of the twin-cyclone pulverized-coal burners, which including the flow uniformity of primary air and particles, the temperature deviation of gas and steam, furnace slagging, and so on. In the period of commissioning, the oil accumulative total cost was 2488.9 t, the comhustion of the boiler was stable, the tube-wall was not over-temperature, the temperature deviation of main and reheat steam was bellow 5℃, unburned carbon in flue dust was bellow 5%, the combustion efficiency kept in a high level, the heating surface have not obviously slagging.