Hydro-vibration resonance analysis of ultra high head pump turbine submerged in water

Le résumé fourni par la source

The stability and safety of the pump turbine runner are crucial to the long-term operation of pumped storage power stations. Strong pressure pulsations caused by stator rotor interaction (SRI) can lead to strong vibrations or even resonance of the pump turbine runner, especially with ultra-high heads, which can cause severe structural fatigue damage. Therefore, it becomes particularly important to investigate the modal behavior and hydro-vibration resonance of the pump turbine runners at the design stage. In this paper, the modal behavior analysis of a 300MW pump turbine with a maximum head of 500m is carried out the modal behavior analysis considering the effects of the near-wall boundary, small gaps of the labyrinth seals, and the water added mass of the pump turbine runner. The results show that the critical vibration mode of the runner is the 4 node diameters (ND), and the difference between the natural frequency for 4 ND and the SRI induced pressure excitation frequency is only about 2%. Therefore, the runner will be subjected to strong vibration as it is almost in a hydrodynamic vibration resonance state. The countermeasures are provided to redesign the runner and change the number of guide vanes so that the hydro-vibration resonance can be avoided. The research methodology can be used for the optimal design of pump turbines, turbines, and pumps of other power stations and pumping stations.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.