潮州发电厂1000MW超超临界压力锅炉水冷壁超温原因及控制策略分析

Reasons and Control Strategy Analysis on Water Wall Overheat in 1000MW Ultra Supercritical Pressure Boiler of Chaozhou Power Plant

潮州发电厂3、4号锅炉在调试期间出现低负荷阶段水冷壁超温的现象,严重时达到500℃以上。通过分析水冷壁热负荷分布和燃烧器投运原则,认为水冷壁管节流孔圈直径偏小导致通流量减小、燃烧器投入顺序不合理造成锅炉下部水冷壁吸热量增大是产生水冷壁超温的主要原因。为防止水冷壁超温,提出优化制粉系统投运方式、调整燃烧方式、合理控制煤水比、加强节流孔圈检查等措施。潮州发电厂采取温度控制措施后,水冷壁超温次数大大较少。

The water wall overheat,which exceeds 500℃ in severe cases,occurs in low load conditons during the commissioning of No.3 and No.4 boilers in Chaozhou power plant.By analysis of heat load distribution of water wall and commissioning principle of burner,it is believed that the decreased water flow caused by smaller throttle orifice diameter and increased heat absorption capacity of water wall by unreasonable burner input sequence are major reasons for water wall overheat.For preventing water wall overheat,optimization of pulverizing system commissioning test,adjustment of combustion method,reasonable proportion control of coal and water,strengthening inspection on throttle orifice and other measures are proposed.The overheat frequency of the water wall becomes drastically lower after the adoption of temperature control measures in Chaozhou power plant.