某型百万千瓦核电汽轮机振动高原因分析

Cause analysis on high vibration of turbine steam and drain pipe in nuclear power station

针对某核电机组调试期间出现的汽轮机高压缸瓦振值高问题,借助频谱分析、锤击测试等手段确认是由主蒸汽管道振动激励诱发轴承座局部共振所致。进一步调查发现主蒸汽管道振动规律与机组负荷、主调阀开度具有高度关联性,通过对大量测试数据的分析,最终确认主蒸汽管道振动高原因为进汽调节阀在机组低功率阶段存在严重的节流现象,不稳定的汽流在管道内产生高频激振。

Aiming at the problem of high bearing vibration value of high pressure cylinder bush of steam turbine during commissioning of a nuclear power unit,it is confirmed by means of spectrum analysis and hammering test that the vibration excitation of main steam pipeline induces local resonance of bearing seat.Further investigation shows that the vibration law of main steam pipeline is highly correlated with unit load and the opening of main regulating valve.Through analysis of a large number of test data,it is finally confirmed that the vibration plateau of main steam pipeline exists serious throttling phenomenon at the low power stage of the unit due to the intake regulating valve,and unstable steam flow occurs high frequency vibration in the pipeline.