某百万千瓦核电厂发电机在线动平衡研究

Research on On-line Rotor Balance of A 1000 MWe Nuclear Power Plant Generator

某百万千瓦核电厂汽轮发电机组自调试以来一直存在发电机冷态过临界振动大问题,发电机冷态过临界振动最高达271μm。在104大修汽轮发电机冲转期间,发电机7瓦轴瓦温度瞬间上升到144℃,经分析,发电机过临界振动大可能导致轴瓦碰磨引起轴瓦温度上升,在2020年春节小修期间,对发电机7瓦轴瓦进行了解体检查,确认轴瓦发生了较为严重的碰磨。通过分析,确定发电机冷态过临界振动大为发电机转子冷态不平衡所致,根据经验确定机械滞后角和配重位置,在105大修期间实施发电机在线动平衡,在105汽轮发电机冲转期间,发电机过临界振动降到161μm,达到同类型机组发电机过临界振动优秀水平,成功解决了机组的重大隐患。

The commissioning of A 1000 MWe nuclear power plant generator has problem,which the highest cold critical vibration reaches to 271μm.The generator No.7 bearing temperature increases to 144℃during 104 overhauling turbine generator speeding up.According to analysis,the cold critical vibration of generator causes the collision between shaft and bearing,which results the bearing temperature increasing.During small overhauling of 2020 spring festival,serious collisions of the generator No.7 bearing are examined after disassembly.The mechanical lagging angle and adding weight place are determined empirically during 105 overhauling,and generator on line rotor balance is carried.The cold critical vibration of generator decreases to 161μm during 105 overhauling turbine generator speeding up,which reaches to excellent level among same type units and the high cold vibration risk is eliminated.