300MW等级W火焰锅炉低氮燃烧改造技术的介绍

Introduction to Low No_x Retrofit Technology for 300MW Class Downshot Coal Fired Boiler

以某B&WB-1025/17.2-M型锅炉为研究对象,考察低氮旋流燃烧器及分级燃烧技术在300 MW等级W火焰锅炉中的应用情况。针对该炉因燃用未设计煤种引起的炉内燃烧恶化,排烟温度上升及NO_x排放量过高等问题,通过优化一次风喷口,提高火焰稳定性;改造调风器,实现火炬径向分层;设置乏气挡板,控制乏气风量,调节一次风速;加装分离式火上风及在下炉膛底部增设分级风,建立炉内分级配风制度。采用上述技术措施改造后,在锅炉50%、75%及100%负荷下进行全面性能考核试验。结果表明,锅炉燃烧效率提高约0.81%,排烟温度恢复至设计水平,NO_x排放量降低15.5%。改造后,节能减排效果显著。

In order to improve the NOx emissions level in a down-shot coal fired boiler with RSFC burner based on graded combustion technology, the 300 MW class boiler of B＆WB-1025/17.2-M was investigated as research object. Due to a great deviation from the contract coal, a series of problem such as deteriorated combustion in furnace, higher exhaust temperature and increased NOx emissions. In view of that, some technical measures were applied to improve the boiler performance, which include coal nozzle retrofitted to enhance the flame stability, swirler modified to realize radial stratification in fireball, vent damper installed to control the vent air flow and primary air flow, and SOFA burner as well as staged air installed to classify the air distribution. After retrofitted, a comprehensive performance test was performed to evaluate the reconstruction effect under the load of 50%, 75% and 100%. The test results show that the combustion efficiency could be increased by around 0.81%, exhaust temperature could be reduced to design level, and the NOx emissions could be 15.5% lower. The reduction effect should be remarkable.