Study on Vibration under the Water Pulsation of the High Head Pumped Storage Power Plant

The pump turbine of the pumped storage power station has the characteristics of high head, large capacity, high unit speed, two-way flow operation and frequent condition change, which leads to the prominent vibration problem. The rated head of a pumped storage power station is 710m, and the underground powerhouse is equipped with two kinds of pump turbines with different speeds (the rated speeds are 500r / min and 600r / min respectively). The rated head and the rated speed of 600r/min are the highest in domestic pumped storage power stations. In order to study the vibration characteristics of the power house structure under the action of water pressure pulsation of high head and high speed unit, the finite element dynamic time history method was used to study the vibration response of the power house under the assumption of harmonic load. The results show that the larger the amplitude of pressure pulsation is, the larger the vibration is. Under each working condition, the vibration response of stairs and turbine floor is relatively large, which is the weak part of the powerhouse structure. Under all working conditions, the vibration responses of the typical structures of 5# unit section do not exceed the allowable vibration standards of building structures specified in various codes. However, under case 1 and 4, the root mean square vibration accelerations of several parts of 5^# unit section are relatively large, which exceed the safety standard (1.0 m/s²), but will not cause structural damage (< 10 m/s²). Although the frequency weighting RMS acceleration does not exceed the limit, obvious vibration and noise may appear due to the high vibration frequency, which should be paid attention to.