背压汽轮机振动过大的分析与处理

Analysis and Treatment of Excessive Vibration of Back Pressure Steam Turbines

针对背压汽轮机单机试车时,多次因振动过大而跳车的问题进行检查,发现存在进汽端猫爪处膨胀余量不够、台座缺少定位锥销、轴端汽封出现偏磨等现象。分析认为,蒸汽管道顶缸及排汽管口冷气窜入等原因破坏了转子动平衡。经高速动平衡机上的复测结果显示,原转子动平衡确实遭到了破坏。在修复上述异常、更换备用转子后再次开车,机组振动恢复正常。

The Back Pressure Steam Turbine tripped many times due to excessive vibration during its test run.After inspection,it was found that this problem was a result of insufficient expansion allowance of the paw at the intake end,missing taper dowel pin on the pedestal and eccentric wear on the shaft end gland seal.Analysis revealed the root cause that the dynamic balance of the rotor was interrupted due to cylinder lifting by the steam pipe and coldness intrusion from the exhaust nozzle.Retest on a high-speed dynamic balancing machine proved that the rotor’s dynamic balance was indeed interrupted.The turbine resumed normal operation after the above abnormalities were addressed and the spare rotor was replaced.