核电厂汽轮发电机组轴承振动高分析与处理

Analysis and Treatment on High Shaft Vibration of a Turbo-Generator Set in Nuclear Power Station

针对某核电厂2号汽轮发电机组大修后开机过程中11号轴承振动高接近打闸值,通过全面振动故障诊断分析,提出振动最可能的原因为励磁机套装靠背轮松动。检查发现套装靠背轮有一定瓢偏且连接螺栓紧力不均匀,针对这两种异常现象可能引起振动的机理进行了深入的分析和计算,最终得出靠背轮松动是根本原因;更换励磁机转子,重新开机后振动恢复正常。

To solve the problem of high vibration that approaches the trip value encountered by shaft 11 in No.2 turbo-generator set of a nuclear power plant during startup after overhaul,fault diagnosis was conducted,based on which,the most possible cause was believed to be the loosened shrunk coupling.Two abnormities were found in the subsequent examinations,such as the deflected coupling and the unevenly tightened connection bolts,and the root cause of the failure was determined to be the loosened shrunk coupling by means of further analysis and calculation on the vibration mechanism that may be resulted from the two abnormities.The problem was finally solved by replacing the exciter rotor.