The Research On Outflow Characteristic Of Flank Inlet-Outlet In Pumped Storage Station

Inlet-outlet is one of the important part of pumped storage power station. On the condition that the design of inlet-outlet structure is not appropriate, in the process of diffusion, the outflow will separate from the wall of inlet-outlet, and occur back flow phenomenon and so on, so it will affect on the hydraulic characteristics such as the velocity and discharge distribution in each passage and the water head loss, it will brings the power station's efficiency descend, and affect the station running in security and stably. Take care of the same inlet-outlet, the outflow is more complicated, more difficult to adjust and the water head loss is lager than inflow,so, for the sake of making sure the flow diffusing smoothly and safety of power station and working efficiently, it is necessity to study the hydraulic characteristics of the outflow, and to optimize the body form of the flank inlet-outlet.The paper, first of all, study hydraulics characteristics of inlet-outlet and flow distribution in reservoir. Then by means of theories analysis and 3D numerical simulation which is validated by physical model experiment, the effects of the main factor which include horizontal angle, the length of the diffusion part, vertical plane angle, the location of the guide piers and pipe slope etc on the outflow characteristics are analyzed, and the result can be provided as the gist for optimizing the flank inlet-outlet structure. The main contents are as follows:(1) Contraposing the single body physical model experiment of the inlet-outlet of the head reservoir of the hongping pumped storage power station, the paper analyze the flow characteristic at different operation condition, including velocity distribution at the trash racks section, the loss of water head and discharge distribution in each passage and so on, then, on this foundation, the physical model experiment of optimizational scheme of the inlet-outlet are carried on,and the effection of the body form is analyzed.(2) Estabilishing the 3-D numerical model of inlet-outlet outflow and compared with the datum of physical model experiment,the result indicate that the numerical model of the paper can simulate flank inlet-outlet flow very well and the result is reasonable and reliable, and can regard as the reference for optimizing the flank inlet-outlet structure;(3) Through numerical simulation and single factor comparation, the paper studies the effects of the main factor on the outflow characteristics. It indicates that as long as the design of the inlet-outlet body form is logical,the outflow hydraulics characteristics will be fine. In the paper, the propositional range of the size of the main inlet-outlet geometrical parameters has been given;(4) By studying the conduit slope's effect on hydraulics characteristics of the flank inlet-outlet such as the vertical position of the maximum velocity and velocity distribution at the trash racks section the loss of water head and discharge distribution in each passage at different conduit Reynolds number, the result indicates that if the design of the conduit slope is proper,the outflow characteristic can be improved.