某型机组低压转子油膜涡动的分析与处理

The Analysis and Dispose of Oil Film Whirl on a Certain Low-pressure Rotor

某型机组在高负荷时汽轮机低压转子发生了突发性振动现象,降低负荷振动缓慢降低,之后振动瞬间消失,振动持续了十几分钟;在中间负荷变润滑油温度试验过程中再次发生了类似突发性振动故障。振动频谱分析表明,故障轴承主频率是0.376×的低频分量,结合振动特性、机组结构特点、轴承钨金温度、油膜压力和降速过程轴心位置变化,诊断为油膜涡动。在轴承检查无异常的情况下,采取了增加轴承载荷的治理措施,消除了该机组的低频振动故障。

Sudden vibration phenomenon occur in steam turbine low pressure rotor at the high load condition. The vibration lasting for more than ten minutes disappeared instantly after the load was slowly decreased,but the similar sudden vibration phenomenon occur on the changing lubricating test at the middle load condition. The analysis of vibration spectrum shows that bearing main frequency is 0. 376 × low frequency component. Combining the with the characteristics of vibration characteristics,unit structure,bearing graphite metal temperature,oil film pressure and axis position change on the slow down the process,the oil film whirl was diagnosed. The low frequency vibration fault was eliminated after increasing the bearing load when the bearing was examined without exception.