锅炉水冷壁大范围换管后连续爆管原因分析及防控

Cause Analysis and Treatment of Continuous Tube Burst After Large Scale Pipe Replacement of Boiler Water Wall

国内首批超超临界直流锅炉水冷壁易出现向火面横向裂纹缺陷,运行一定年限后需进行大范围换管,才能彻底解决长期运行隐患。但锅炉大范围换管,对换管工艺控制、异物堵塞防控措施有很高的要求,若处理不好极易发生修后多次过热爆管事件,造成机组连续多次非计划停运,对电网带来不良影响。以某厂2号锅炉为例,讲述水冷壁大范围换管后连续爆管事件分析及处理经验,研究建立了一套包含采购、施工、冲洗、监控、抢修等全过程的综合防控方法,为同类型机组相关工作提供参考。

The water wall of the first batch of ultra-supercritical direct-current boilers in China is prone to transverse cracks on the fire facing surface.After a certain number of years of operation,a large range of pipe replacement is needed to completely solve the long-term operation hidden trouble.However,due to the large-scale pipe changing of boilers,there are very high requirements for pipe changing process control and foreign body blockage prevention and control measures.If the treatment is not good,it is easy to occur multiple overheating and pipe burst incidents after repair,resulting in continuous outage of the unit for many times,which brings adverse effects on the power grid.Taking the boiler 2 as an example,this paper describes the analysis and treatment experience of continuous pipe burst incident after large-scale pipe replacement of water wall,studies and establishes a set of comprehensive prevention and control methods including procurement,construction,washing,monitoring and emergency repair,etc.,to provide reference for related work of the same type of units.