龙江水电站4号机组瓦温异常分析及处理

Analysis and Treatment of Abnormal Bearing Temperature in the No.4 Unit in Longjiang Hydropower Station

龙江水电站4号机组在安装完成后首次启动试验时,发现机组下导瓦温急剧升高,下导摆度超标,发现这一现象后,立即停机进行全面检查,从设备制造,安装工艺,冷却系统,电磁力不平衡等因数进行了详细分析,并对机组进行了系统全面的检查和实验,最终确定水轮发电机组冷却系统存在安装缺陷,下导瓦间隙调整不当、机械力不平衡导致机组摆度和振动过大,引起导轴承温度异常,通过对水轮发电机组下导瓦进行了修复、调整和增加配转子重的方法,使机组摆度和振动恢复正常,瓦温基本平稳,并满足相关规范要求。

In the first start-up test of the No.4 unit in Longjiang Hydropower Station,a sharp rising of the bearing temperature and excessive swinging of the lower guide bearing are observed.A systematic and thorough examination is then carried out immediately after the shut-down of the unit.Possible reasons of this fault are analyzed from different aspects including the unit manufacturing,unit installation,cooling system and electromagnetic force unbalance.It is found that the fault is caused by multiple factors.The installation of the unit cooling system is of certain defects.The clearance of the lower guide bearing is inappropriate.The unbalanced mechanical force causes the excessive swinging and vibration of the unit,and thus the abnormal bearing temperature rising.Then,the low guide bearing is repaired.The swinging and vibration of the unit is solved by adjusting the counterweight of the rotor.After the treatment,the bearing temperature is now stable and in accordance to the specification requirements.