The Flow Pattern Optimization Of Pump Station Intake Sump Based On PIV Experiment And Numerical Simulation

The poor distribution of the flow state for sewage pumping station will cause backflow,partial flow and partial vortex in the pumping pool.On the one hand,it will cause sediment deposition in local areas,and on the other hand,the water inflow condition of the pump will deteriorate and pump efficiency is also reduced.As an important inlet structure of the pumping station,the pump pool is of great significance to optimize its influent flow state.Through the PIV experiment,the flow state of each section for slope protection and elimination vortex board under the design condition of the DK pumping station in foreign countries was analyzed.And these results verified that installing slope protection and elimination vortex board have effect for improvement of flow regime.The PIV experiments were carried out to compare the flow patterns of the three pumps and two pumps during operation.The flow velocity distribution uniformity and the speed weighted average angle were used as the objective functions,and the inlet flow patterns of the pumps were improved when the two pumps were running.However,in both cases,a small vortex is formed under the L-shaped baffle,and the flow distribution is asymmetrical under the suction port of the pump.Due to the particularly disordered flow pattern in the L-shaped baffle area,the V3 V three-dimensional flow field was measured on the area above the rightmost square hole in the L-shaped baffle.After correct calibration and image processing,discovered that there is a significant vortex in the upper region of the L-shaped flap corresponding to the running pump when two pumps are operated.The numerical simulation results of the k-? turbulence model of Standard,RNG and Realizable in partial section were compared with the experimental results.The calculation results of the Standard k-? model are most consistent with the experimental results in terms of numerical values and trends.According to the results of PIV experiment,three optimization schemes for improving the flow regime of pumping pool were proposed.The Standard k-? model was used to simulate the three schemes and 13 optimization conditions,and the velocity distribution uniformity and velocity weighted average angle are used as the optimized objective function to get the following results:(1)When the height of the L-shaped eliminator from the bottom of the interception tank is 1400 mm,the flow pattern in the area below the eliminator is best.(2)When the bottom clearance of submersible pump maintains the original design,the flow pattern at the bottom of the pump pool is the most uniform,and the inflow direction is also good.(3)When the 1# and 2# pump units are running,the flow pattern of the pump pool is the best.The paper combined PIV,V3 V measurement technology and numerical simulation to study the flow patterns of various sections and regions in the pumping station,and proposes effective measures to improve flow.