某660MW超临界机组试运期间发电机振动故障诊断及处理

Fault Diagnosis and Treatment of the Generator Vibration of a 660MW Unit During Trial Operation Period

某660 MW超临界机组在试运过程中,在带负荷阶段出现发电机轴振及瓦振异常升高的故障。通过跟踪对比发电机轴瓦振动的变化,制定了试验方案并实施,在分析运行及试验数据的基础上,对发电机轴瓦振动大故障进行了诊断。诊断结果表明,发电机轴瓦振动大的原因为发电机转子线圈不对称膨胀引起热不平衡。根据诊断结果,结合现场实际运行情况,在2号低压转子和发电机的连接对轮上加配重块,进行现场高速动平衡。动平衡结果表明,发电机轴瓦振动得到了有效降低,汽轮机轴瓦振动也处在优良范围内。

During the trial operation of a 660 MW supereritieal unit, the generator shaft and hearing vibrations rise abnormally during the loading stage. By tracking the changes in the generator bearing vibrations, a testing scheme is formulated and implemented. Based on the analysis on the operation and test data, the fault diagnosis on the generator bearing vibrations is conducted, which eoneludes that the thermal unbalance from the generator rotor coil asymmetic expansion causes the abnormal vihrations. According to the diagnostic result and by taking the site situation into account, counterweights are added to the low pressure Rotor 2 and the generator connecting wheel to carry out high speed dynamic balancing. The dynamic balancing resuhs show that the generator bearing vibration is then effectively reduced with the turbine bearing vibration also kept in favorable range.