Research of Tubular Pumping Systems on Dual-Directional Operation

The tubular pumping system on dual-directional operation is used extensively for drainage and feedwater pumping stations of the cities and towns. The performance of the dual-directional operation of pumping systems is different with that of simple-way operation. The article described the three-dimensional fluid flow and the predicted performance of the numerical investigation inside a tubular pumping station on dual-directional operation, based on the Reynolds time-averaged Navier-Stokes equations and the realizable k-ε turbulent flow model, applied the law-of-wall and sliding mesh technique, and comparing with the experiment data. The main phenomena existing in pressure contours, velocity contours, velocity vectors and flow lines is showed. The disturbance of fluid flow from the pump outlet to pumping station channel is researched. The axial-whirling flow, circulation-vortex flow is discovered inside discharge diffuser of tubular pumping station on feed-directional operation. The axial-whirling flow is strengthened as a result of diffuse flow. The circulation-vortex flow of the impeller outlet is enhanced in the radius and reduced in the middle of discharge diffuser without guide vanes. There is more loss of head in discharge diffuser of the channel, comparing with that of the suction reducer. It was a close predicted performance of numerical simulation with that of the experiment in the best efficiency point. There was a more difference between the predicted performances with that of the experiment data on the feedwater-directional operation, comparing that of the drainagewater -directional operation.