600MW亚临界锅炉后屏水塞爆管原因分析及措施

Study on Causes and Countermeasures of Water Plug Burst in Rear Platen of a 600MW Subcritical Boiler

某电厂锅炉后屏过热器因焊接工艺原因,发生焊口爆裂,随后锅炉紧急停运。在机组再次启动过程中,再次发生锅炉后屏过热器爆管,通过对炉管爆管特征和历史曲线调阅分析,认为机组停运、启动期间操作不当,后屏过热器形成水塞,加之受热面温度测点布置不合理,综合造成短期超温爆管。通过优化壁温测点、明确水塞形成判断方法、制定防止水塞相关措施,在后续机组启动时未发生水塞爆管现象。

The welding joints of the rear platen superheater of a power plant burst due to the welding process failure and then the boiler had to be shut down emergently. When the unit was started up again,the boiler rear platen superheater burst again. Based on an analysis of the characteristics and historical curve of the furnace tube burst,it is concluded that several reasons combine to cause short-term overtemperature tube burst,including the improper operation during the shutdown and start-up of the unit,the formation of water plug in the rear platen superheater,and the unreasonable arrangement of temperature measurement points on the heating surface. By optimizing the measurement points of wall temperature,clarifying the judgment method of water plug formation,and formulating relevant measures to prevent water plug,no water plug burst occurred during subsequent unit start-up.