600 MW发电机轴承振动故障诊断及处理

Fault Diagnosis and Handling of the Bearing Vibration of a 60o MW Generator

某600 MW发电机运行过程中出现其本体与基础共振问题,导致励磁滑环和碳刷磨损加剧,危及发电机的安全运行。从发电机本身出发,通过现场测试和结果分析,得出其振动原因为发电机支撑刚度下降,发电机组转子振动诱发发电机两侧轴承振动,最终形成了基础共振问题。结合诊断意见,现场采取轴承配重、调整地脚螺栓紧力和改善端盖轴承各结合面的接触状况等方案,提高了轴承的结构动刚度,并且在此基础上,通过转子动平衡,降低转子激振力,最终解决了机组运行中的振动问题。

A resonance problem between the generator and its foundation occurred in the operation of the 600 MW unit,which led to increased wear of the excitation slip ring and the carbon brush,endangering its safe operation.After the vibration theory analysis of the generator,this paper introduces the field test and result analysis of the fault and concludes that the foundation resonance occurred because of the vibration of the bearings on both sides of the generator induced by the vibration of the rotor of the generator together with the reduction of the support stiffness of the generator.According to the diagnostic suggestions,the structural dynamic stffness of the bearings were improved by means of the counterweight of the bearings,the adjustments of the tightening force of the anchor bolt and the improvement of the contact conditions of the joint surfaces of the end cover.On this basis,a dynamic balance of the rotor was executed to reduce its exciting force,which solved the vibration problem during the operation of the unit.