350 MW超临界机组汽轮机汽流激振分析及处理

Analysis and Processing of the Steam-Flow Exciting Vibration in Steam Turbine of a 350 MW Supercritical Unit

转子振动问题一直是危及机组安全运行的重要因素。分析某350 MW超临界机组出现的振动突增的异常现象,认为发生了汽流激振。在单阀方式运行下,通过调整凝汽器真空、润滑油温度及轴封供汽压力,抑制发生汽流激振的频率。同时,试验研究几种典型因素对于机组振动的影响,分析该机组发生汽流激振的原因。基于试验分析结论,提出切换至顺序阀运行的处理方案,确定合理的阀门开启顺序,优化汽门配汽曲线。最终有效地解决了该机组的汽流激振问题,保障了机组的安全稳定运行。

Vibration has always been an important factor to endanger the operation of the unit. In this paper, the abnormal phenomenon of the vibration of a 350 MW supercritical unit was analyzed, in which the steam-flow exciting vibration happened. In the single valve operation mode, the frequency of vibration was suppressed by adjusting the condenser vacuum, lubricating oil temperature and shaft seal steam supply pressure. Then, the influence of several typical factors on the vibration was studied. Based on the conclusion of the test, this paper put forward the processing scheme to switch to the sequential valve operation mode, and determined the reasonable opening sequence of valves, and optimized the valve distribution curve. Finally, the steam-flow exciting vibration of the unit is solved effectively, the safety and stability operation of the unit is guaranteed.