220 MW汽轮机低压次末级叶片裂纹事故原因分析及处理

Causes analysis and treatment on a penultimate stage blades crack of 220 MW turbine in a power plant

文中对某发电厂6号汽轮机低压第4级多片叶片裂纹事故的原因作了分析,指出作为阻尼结构整圈连接叶片及作为不规则的网状连接叶片,它们的一阶带节径振动,节径数m=6落入共振是该机低压第4级叶片裂纹事故的主要原因,提出了挖补焊接裂纹叶片的处理方法并介绍了处理过程及结果。

Aims at a blades crack of the 4th stage blades in the low-pressure cylinder of the 6th turbine,the paper analyses the cause of the crack,and draws a conclusion that whether the damped structure round linking blades or the irregular mesh linking ones,when which effective diameter is 6,whose first mode vibration drops into the resonance vibration zone of the turbine is the primary reason of the blades crack.At last,an overlaying welding method has been put forward for fault treatment.