某核电厂1000MW级汽轮机振动异常分析与处理

Analyze and Treatment of The 1000MW Steam Turbine Vibration in A Nuclear Power Station

某核电厂3号机组商运前进行调试,试验期间连续出现了3次振动异常问题,其中2次由于振动超手动停机打闸值导致汽轮机被迫打闸停机。经分析确认,汽轮机振动异常根本原因为高中压缸径向通流间隙多级偏下限,容易发生动静碰磨,促成原因为汽水分离再热器二级再热调节阀动作逻辑异常,导致中压缸排汽温度下降过快。发生振动异常情况后,电厂技术人员及时制定方案,避免了再次冲转并网过程中二级再热调节阀动作逻辑异常,并计划后续机组大修时调整汽轮机高中压缸径向通流间隙至标准的中上限,彻底消除由于径向通流间隙过小导致的动静碰摩风险。

The steam turbine has 3 times unusual vibration during the commissioning, two of the three vibrations has to shut off the steam turbine. The reason of vibrations is found out that the radial passage clearances of high and intermediate pressure cylinder pressure of steam turbine are too closed to the minimum limited value, that the rubbing movement between rotor and stator is easily happen. Because of the MSR 2nd reheat valve acts abnormal, that makes the intermediate pressure cylinder exhaust air temperature decreased too fast. The treatment of this accident is deal with and avoid the risk of rubbing movement caused by the radial passage clearances are too small.