Research on the hydraulic loss in the side inlet and outlet of a pumped storage power station

Abstract The side inlet and outlet play an important role in the hydraulic system of a pumped storage power station. The flow patterns within it are of great significance to the safe operation of the whole project. The aim of this study was to reveal the quantitative relationship between various flow patterns and hydraulic losses within the side inlet and outlet, the wall roughness theoretical model and the RNG k-ε turbulence model were combined to investigate the internal flow, vortex distribution, hydraulic loss, and other hydraulic characteristics within the side inlet and outlet for pumping and electric power generating cases, the results of the numerical model are in good agreement with the experimental results. In addition, a hydraulic losses model in the side inlet/outlet based on the energy conservation equation and the distribution of the various hydraulic losses were present. The results show that various types of vortices occurred in the reservoir area close to the inlet and outlet region when the inlet flow rate of the pumping case is higher than 1.67 Q * (Dimensionless flow rate Q *= Q actual flow/ Q rated flow of a unit), and the flow rate distribution is more nonuniform for the pumping case. The hydraulic loss is higher and mainly concentrated in the adjustment section, the anti-vortex beam section, and the side-and middle-channel diffusion section for the electric power generating case. The results of this paper can be used in the optimisation design in the related fields.