| The front pool and water inlet pool of the pump station are important water inlet components of the pumping station.Their main function is to adjust the water flow into the pump to ensure that the water flow velocity distribution into the pump is uniform and stable.Reasonable arrangement of water inlet components can provide good water inlet conditions for the inlet of the pump,which can not only ensure the energy performance and cavitation performance of the pump,but also effectively reduce the vibration of the pump unit and improve the reliability and durability of the pump operation.The function of the outlet pipe is to ensure the smooth and stable water flow into the outlet pool while greatly reducing the hydraulic loss.Some pumping stations are limited by land use and other conditions,and it is difficult for the design of the water inlet structure and water outlet pipeline to comply with the requirements of the specification,and it is impossible to ensure that the water flows smoothly and evenly through the pumping station.Therefore,it is necessary to add rectification measures to solve the problem of water flow.In this paper,aiming at the flow regime problems existing in the front pool and the inlet pool of the pumping station with large diffusion angle,the corresponding rectification measures are used to improve the flow regime,and on this basis,the straight-pipe outlet pipe of the original scheme is optimized.The effect of each rectification scheme is calculated and verified through numerical simulation technology,so as to obtain the optimal scheme combination to improve the flow state of the inflow and outflow water of the pump station.Through on-site investigation,it is found that when the gate station studied in this paper is in diversion operation,there is a large recirculation zone at the side pier wall of the fore-pool water pump and a vortex is generated.Therefore,it is necessary to carry out flow regulation to ensure the safe operation of the pumping station.First,a three-dimensional model is established,and the influent flow state is calculated by using the three-dimensional turbulent numerical simulation method.The calculation results are basically consistent with the actual operation results,indicating that the calculation method is accurate.Then,adding diversion piers of different sizes or improving the type of side piers in the fore pool to achieve the purpose of improving the flow state of the fore pool.After determining the optimal rectification scheme of the front pool,rectifying the inlet pool,and adding columns of different sizes at different positions to solve the flow state problem of the inlet pool of the pump station.The scheme of improving the fore-pool side pier to reduce the diffusion angle is the best for improving the flow-state of the fore-pool.At this time,compared with the original scheme,the flow velocity uniformity of section 2-2 is increased by 49.8%.On the basis of the optimal rectification scheme of the front pool,the scheme of adding four 0.25m wide columns before the inlet pool can improve the flow state of the inlet pool the best.At this time,compared with the original scheme,the uniformity of the flow velocity of the inlet section a-a of the flow channel 1 is improved.13.89%,the weighted average angle is increased by 1.14°,the flow velocity uniformity at the pump inlet a-1 is reduced by 0.67%,and the weighted average angle is increased by 1.41°;With an increase of 0.65 °,the uniformity of the flow velocity at the pump inlet b-1 is reduced by 0.50%,and the weighted average angle is increased by 1.10°.Finally,the outlet pipe of the pumping station is optimized,and the straight-pipe outlet pipe is changed to a 90° elbow outlet pipe,and the hydraulic loss between the inlet and outlet sections of the outlet pipe is used as the control index.Compared with the original scheme,the hydraulic loss of the outlet pipe is reduced by 0.458m,which effectively improves the flow state of the outlet pipe and improves the efficiency of the device. |
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