Abstract:

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.

Key words: supercritical unit, steam-flow exciting vibration, sequential valve operation mode