At present,many planned pumping and storage projects have installed new wide anti-rotation piers at the entrance of circular weir vertical shafts of the spillway tunnels to eliminate adverse flow patterns such as choking caused by uncontrollable swirling flow at the throat.The water and air characteristics in the circular weir vertical shafts with wide anti-rotation pier are significantly different from the previous vertical shafts using starting rotation piers and narrow anti-rotation piers.The vertical shaft of the spillway tunnel in the lower reservoir of the Shitai Pumped Storage Power Station was taken as the research object,and hydraulic evaluation indicators such as flow state,flow velocity,pressure,and energy dissipation rate were used to conduct research using a combination of physical model experiments and numerical simulations.The research results showed that the wide anti-ro-tation pier guided the water flow smoothly into the vertical shaft to form a detached flow,and a smooth ventilation channel could be formed at the tail.Air can fully enter the vertical shaft through this channel to maintain the stability of the flow state and pressure inside the well.The over current capacity of the vertical shaft met the requirements,the flow velocity and pressure distribution in various parts were normal,and the total energy dissipation rate of the vertical shaft was over 85%.The wide anti-rotation pier can eliminate the choking phenomenon caused by uncontrollable swirling flow and guide the water flow to form a detached flow state in the vertical shaft,preventing the wall surface of the vertical shaft from being damaged by cavitation.When the ventilation capacity at the end of the pier was sufficient,the traditional design of the ventilation pipe and the sudden expansion shape at the junction of the circular weir and the vertical shaft can be canceled,simplifying the engineering layout.This experience can be a reference for the similar projects.
关键词
宽式防旋墩/环形堰竖井/脱壁流/水力特性/消能率/石台抽水蓄能电站
Key words
wide anti-rotation pier/circular weir vertical shaft/shedding wall flow/hydraulic characteristics/energy dissi-pation rate/Shitai Pumped Storage Power Station
维普
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