Frequency conversion condensate pump is easy to produce structural resonance because of insufficient support stiffness of vertical structure and increased working frequency range. According to the problem of excessive vibration in two resonance zones of a 350 MW vertical variable-frequency condensate pump

this paper introduces the principle and influencing factors of structural resonance

the judgment method of vibration fault and the treatment process. Theoretical calculation and actual treatment results show that

when there is unbalance on the shafting

dynamic balancing can effectively reduce the vibration amplitude in the resonance area of the condensate pump. However

when there are multiple resonance zones at the same time and the counterweight schemes corresponding to different resonance zones are contradictory

the dynamic balance mode cannot be considered at the same time. The angle of the counterweight determines the dynamic balance effect. Due to the limitation of the reserved counterweight angle

the rapid change of the vibration phase near the resonance point

inaccurate measurement and other factors

it is difficult to achieve on-site fine dynamic balance. Increasing the support to improve the system stiffness can change the natural frequency of the structure and reduce the vibration amplitude in the resonance area

which is an effective measure to solve the resonance problem. The vibration reduction effect of radial support is better than that of axial support.