Research on the influence of start-up combinations on the flow pattern in forebay of side-inlet pumping station on sandy river

Abstract

For the purpose of probing into the influence of start-up combinations on the flow pattern in forebay of side-inlet and multi-unit pumping station on sandy river, the side-inlet forebay of #3 Pump Station of Total Trunk Line (Phase I), Gansu Jingtaichuan Irrigation District was taken as the research object, field sampling was used to analyze the sediment content in the forebay, field measurement was carried out on the flow field in the forebay by using the ultrasonic doppler flow velocity flowmeter, and meanwhile, reverse engineering technology was introduced to construct the three-dimensional geometric model of the forebay under the condition of deposition (hereinafter referred to as in-situ forebay). The FLUENT software was used to numerically calculate the water flow pattern of the in-situ forebay on the basis of Realizable k-ε turbulence model and Mixture multiphase flow model, the numerical simulation results and the actual flow measurement results were compared to verify the accuracy of the numerical calculation process. On that basis, the numerical simulation analysis of the water flow pattern in the forebay without siltation (hereinafter referred to as prototype forebay) under 10 different start-up combinations was carried out. The results show that the backflow areas and sedimentation is mainly distributed at the end of the forebay and the outer side wall. The numerical simulation results of flow pattern in the in-situ forebay based on reverse engineering are consistent with the field flow measurement results. The main flow diffusion effect in the prototype forebay is not good, and the flow pattern in the forebay is better when the pump station unit is opened symmetrically, at the same time the units at both ends are avoided to stop, especially the terminal unit. The research idea proposed in this paper has certain application value for the research of numerical simulation about the flow pattern in the forebay of pump station, and the research results will provide reference for the optimizing design and operating of similar pumping station projects.