Experimental Study On Hydraulic Characteristics Of Side Inlet And Outlet In Pumped Storage Power Station

The inlet and outlet is throat of a pumped storage power station and an important hydraulic structure connecting the reservoir area and the power station units.It has the characteristics of two-way overflow.The inlet and outlet shape design has a great influence on the safe operation and economic benefits of the pumped storage power station.This paper takes the inlet and outlet of the lower reservoir of Yixian pumped storage power station in Hebei province as the research object and carries out systematic experimental research on the hydraulic characteristics of the lateral inlet and outlet.The research contents include:the flow ratio of each inlet channel and the non-uniformity coefficient of flow velocity,the vortex flow state and its occurrence conditions on the upper part of the anti-vortex beam,and the head loss coefficient of each inlet section.The main research results are as follows:(1)The relative positions of the three shunt piers at the head of the diffusion section of the four-channel inlet are important factors to control the shunt ratio and velocity inhomogeneity of each channel.In this paper,the reasonable value range of the configuration parameters of the shunt pier is proposed,and the design scheme is modified accordingly.The test shows that the shunt ratio and the velocity non-uniformity coefficient of each channel meet the design requirements under the condition of positive and negative flow.(2)By means of underwater photography and increasing the flow rate,the underwater vortex form on the upper part of the anti-vortex beam was systematically observed under pumping conditions.It is found that the vortex flow pattern at the inlet is affected by the upper working piers.In the open water on the upper part of the anti-vortex beam,the vortex intensity is low,but the square cavity flow is easy to form between the working piers,and finally harmful vortex is formed.By adding transverse structural beams near the dead water level,the vortex can be effectively prevented from entering the area between the working piers.At the same time,when the water level rises,the depth increases and the intensity of the vortex weakens,ensuring that no harmful vortex occurs within the range of the normal operating water level.(3)For head loss coefficient,the influence of water flow viscosity cannot be ignored.The method of increasing the flow rate has been adopted in this paper.It was found that only when the inlet Re number was greater than 3×104,the test results were in good agreement with the prototype.The test results show that the head loss coefficient of the inlet and outlet of Yixian Pumped storage power station is 0.28 and 0.11 respectively under the inflow condition.The head loss coefficient of the inlet and outlet(pumping)is 0,19 under discharge conditions,and the head loss coefficient of sluice chamber section is about 0.11.The above results can provide reference for the design and research of similar ProjectsFigure[46],table[10],reference[85]...