"W"火焰锅炉低负荷再热汽温提效研究

Research on Improving Reheat Steam Temperature of "W" Flame Boiler under Low Load

随着机组年利用小时数不断降低,中低负荷再热汽温偏低严重影响机组运行经济性。烟气再循环技术具有改变各受热面吸热量分配比例特点,可有效提高再热蒸汽温度。通过锅炉热力计算和数值模拟相结合的方法研究烟气再循环对"W"型火焰燃烧锅炉燃烧、经济性的影响,制定了从省煤器出口引出烟气送入SOFA+贴壁风喷口的烟气再循环改造方案。改造后再热汽温可提高至541℃,机组煤耗可降低0.73 g/(kW·h),年节约标煤量1084 t,为同类型机组开展再热汽温提效改造提供参考。

As the annual utilization hours of the unit decreasing, the low reheat steam temperature of medium and low load seriously affects the operation economy of the unit. Flue gas recirculation technology changes the heat absorption and distribution ratio of each heating surface, which can effectively improve the reheat steam temperature. In this paper,the influence of flue gas recirculation on the combustion and economy of "W" flame combustion boiler is studied by means of the combination of boiler thermal calculation and numerical simulation, and the transformation scheme of flue gas recirculation from the outlet of economizer to the inlet of SOFA+T is proposed. After transformation, reheat steam temperature can be increased to 541 ℃, the coal consumption of the unit can be reduced by 0.73 g/(kW·h), and the annual standard coal consumption is about 1084 t. It can provide reference for the same type of unit to carry out the transformation of reheat steam temperature lifting efficiency.