300MW锅炉引风机增容改造后叶片断裂原因分析及对策

The reason analysis and countermeasure to the blade failure after upgrading in one 300MW boiler induced draft fan

某电厂300MW锅炉在增容改造后运行不到6000h，接连发生引风机叶片断裂事故。经分析，其直接原因是振动引起疲劳失效，引风机长期在失速、喘振不稳定工作区运行是引起叶片振动疲劳破坏的主要原因。通过对叶片进行焊接加强环等措施，来有效防止类似事故的发生。

The blade failure accidents happens one after another within operating 6000h after upgrading in one 300MW boiler in one plant. Through analyzing, the direct reason is the fatigue failure caused by the vibration and the induced draft fan operates in the instability state with staU surge, which is the main reason of the blade vibration fatigue failure. Through welding stiffening ring to the blade, such accident can be well prevented efficiently.