Abstract
A physical model with a scale of 1:20 was used to study the hydraulic characteristics of the flow in the forebay area of the pump station in Tian Wan Nuclear Power Plant Project Unit 5&6. The original layout scheme of the pump station forebay is limited by space, the turning radius of the intake gallery is small and the straight line section is short, the uniformity of water distribution is poor after seawater enters the forebay, the flow in the forebay cannot fully diffuse, the mainstream is concentrated, the flow distribution in the inlet section of each channel of the pump station is uneven, and the flow pattern is poor. Firstly, the distribution of water flow and uniformity of water distribution in the pump station forebay under different turning radius of tunnel are compared, and the turning radius of intake corridor is determined by calculating the head loss in different parts of tunnel. A variety of rectification facilities are arranged in the pumping station forebay, including modifying the grid type, setting diversion wall, diversion plate, energy dissipation beam, rectification bottom sill, etc. The recommended scheme is determined by hydraulic model test. The scheme can satisfy the requirement of uniformity of water distribution in the forebay, and the flow pattern along each section of the channel is also good.
