抽水蓄能电站厂房板梁柱体系抗振性能研究

Anti-vibration Performances of the Plate-beam-column System in Pumped Storage Power Plant

为研究抽水蓄能电站厂房板梁柱体系的抗振性能,结合某实际工程建立了三维有限元模型,对板梁、厚板和厚板+边梁三种楼板结构的自振特性和流道脉动压力作用下的动力响应开展了研究。研究发现,在厂房四周边界条件相同的情况下,三种楼板结构型式和楼板厚度、立柱截面尺寸的小幅调整对他们的自振特性影响有限;但从减小楼板强迫振动响应峰值的角度分析,当蜗壳流道内激振频率分别在35~45、50~60、65~75 Hz时,相对较优的结构型式分别为厚板+边梁、板梁、纯厚板,且增加板厚可以减小振动响应。另外,当厂房内激振频率与立柱自振频率相近时,增加立柱截面尺寸对降低立柱振动响应具有较明显的效果。考虑到抽水蓄能电站厂房内振源复杂,建议以转轮叶片数频率及其两倍频率为主要目标,通过动力有限元方法开展抽水蓄能电站厂房结构的抗振优化设计。

A three-dimensional finite element model based on an actual project is established to study anti-vibration performances of the plate-beam-column system in a pumped storage power plant.This paper studies the natural vibration characteristics of plate beams,thick plates,thick plates,side beams and the dynamic response under the pulsating pressure in the flow passage.It is found that when the boundary conditions around the plant are the same,three floor structure types,floor thickness and the small adjustment of the column section size have limited influence on their natural vibration characteristics.However,from the perspective of reducing the peak value of floor forced vibration response,when the excitation frequency in the spiral case channel is 35~45 Hz,the relatively preferred structural type is thick plate and side beam.When it is 50~60 Hz,the slab beam is better.When it is 65~75 Hz,the pure thick plate performs better,and increasing the plate thickness can reduce the vibration response.In addition,when the excitation frequency in the plant is close to the natural vibration frequency of the column,increasing the section size of the column has an obvious effect on reducing the vibration response of the column.Considering the complex vibration sources in the powerhouse of pumped storage power station,it is suggested that the anti-vibration optimization design of the powerhouse structure of pumped storage power station should be carried out by dynamic finite element method with the main objective of the number frequency of runner blades and its double frequency.