沙角A电厂5号锅炉再热器管泄漏原因分析及处理

Analysis and solution of reheater tube leakage in boiler No.5 in Shajiao A Power Plant

针对沙角A电厂5号炉在每次机组大、小修后进行水压试验期间,末级再热器管和屏式再热器管在与顶棚密封板的焊接焊缝处都会发生泄漏的问题,经多年的运行观察及对泄漏管子进行分析,认为顶棚密封的刚性结构、再热器管子材料金属机械性能相对较差,再热器管子与顶棚密封的焊接质量较差等是造成再热器管发生泄漏的主要原因。在该炉大修期间采用改装定位密封板、加装套管、更换再热器管材等相应措施对再热器顶棚密封结构进行了相应改造,改造后未出现泄漏情况,达到了预期的目的。

There was leakage at the welded seam connecting final reheater tubes and platen reheater tubes with the sealing plate of ceiling during hydraulic test after both current repair and overhaul on boiler No.5 every time. By many years' observations on the leaking tubes, it was concluded that the rigid framework of the sealing, poor mechanical performance of reheater tube material and bad welding quality were the main reasons of leakage. In an overhaul, the settling plates of the sealing were reformed, sleeves were added and the material of reheater tubes was changed. Then, no more leakage appears.