Hydraulic Design Of A New-Type Deep Well Pump And Its Flow Simulation

Deep well pumps are widely used in rural areas. And many deep well pump factories are engaged in developing and manufacturing. So competition among them is intense. It is highly required to reduce the costs and to raise the quality of deep well pumps.A new-type deep well pump SJB has been developed by Lu Wei-gang et al. from 2004. Based on the research on SJB, a new hydraulic design—impeller head maximum approach and twisted return guide vane method was proposed. The front shroud was extended to the inner pump casing and the inclined impeller outlet was employed. The inlet of the return guide vane was designed to be twisted and the remaining part was cylindrical. The head was enlarged by 50% and the cost was reduced by 30% in the test of 100SJB8. The shortcut to develop high quality deep well pump was obtained.Improvement was made by powerful simulation of CFD during the hydraulic design. The flow calculation was performed on model 100SJB8 by commercial software Fluent6.0. The hydraulic performance was also calculated. By comparing with the test of model 100SJB8, it was proved that the calculation was able to forecast the performance and to guide the design.Discriminant of axial force was developed which was verified on the model 100SJB8. Self-balancing could be obtained with this discriminant. Numerical calculation of axial force was respectively performed on two seal conditions by Fluent 6.0. On the first condition, the seal was fully closed, and the force was toward the back shroud which would open the seal. On the second condition, there was a clearance of 0.5mm, the force was toward the impeller inlet which would close the seal. According to these two conditions, it indicated that the pump was able to keep self-balancing. According to Axial forces on other models, we found that the discriminant was not fully effective on all models and it remained to be improved.In order to master the mechanism of flow calculation, the grid generation based on BFC was performed. And flow calculation based on FVM and SIMPLE was also analyzed.