300 MW机组锅炉空气分级燃烧改造

Staging combustion retrofitting for a 300MW unit coal-fired boiler

对湘潭电厂1 025t/h电站煤粉锅炉燃烧系统进行了的深度空气分级燃烧技术改造。将原二次风部分喷嘴封堵,增设炉内还原区,在还原区上部角水冷壁管屏处装设分离式燃尽风(SOFA)喷口。对不同煤种、不同机组负荷下投入SOFA与不投入SOFA时的锅炉热效率与NOx生成特性进行了试验研究。结果表明,对于高热值、低灰分煤种,投入SOFA后,炉内形成了良好的空气分级燃烧工况,NOx排放浓度最高降低了41%,减排效果显著。

Air staged combustion technology transformation was conducted on combustion system of the 1 025 t/h coal-fired boiler in Xiangtan Power Plant. A part of nozzles for the original sec- ondary air were blocked to increase the reduction zone area. The separated over fire air （SOFA） nozzle was installed at water wall tubes at upper part of the reduction zone. The boiler efficiencies and NO~ emission characteristics were experimentally investigated, with the SOFA putting into service and not, under conditions of different kinds of coal and different unit loads. The results show that,for the coal with high heating value and low ash content,when the SOFA was put into service,well air staged combustion condition is formed in furnace,resulting in drop of the NO~ e- mission by 41% ,which is significant.