660MW超临界循环流化床锅炉水冷壁磨损泄漏分析及预防措施

Analysis and Preventive Measures for Wear and Leakage of Water Wall in 660MW Supercritical Circulating Fluidized Bed Boiler

连续运行197天后,某电厂660 MW超临界CFB锅炉发生了水冷壁管突然泄漏事故。为揭示泄漏产生的本质原因,采用宏观形貌测量、光谱分析、金相组织检测和力学性能测试相结合的方法深入剖析泄漏位置。结果表明,水冷壁管泄漏的主要原因是材料磨损,造成壁管的有效厚度变薄,因不能承受内部的压力而泄漏。针对上述情况,提出可行的防范措施,以杜绝类似事故再次发生,从而保证机组安全稳定持续运行。目前,2台机组共运行500多天,无一例磨损造成水冷壁泄漏,证明预防措施有效。

After continuous operation for 197 days,a 660 MW supercritical CFB boiler in a power plant experienced a sudden leakage accident of its water-cooled wall tubes.To reveal the essential cause of the leakage,a combination of macroscopic morphology measurement,spectral analysis,metallographic structure testing,and mechanical property testing was used to deeply analyze the location of the leakage.The results indicate that the main cause of leakage in water-cooled wall tubes is material wear,resulting in a reduction in the effective thickness of the wall tubes,which cannot withstand internal pressure and leaks.In response to the above situation,feasible preventive measures are proposed to prevent similar accidents from happening again and ensure the safe,stable and continuous operation of the unit.At present,the two units have been operating for more than 500 days,and there has been no case of water wall leakage caused by wear and tear,proving the effectiveness of preventive measures.