Hydrodynamic Efficiency Improvement of High-Specific-Speed Centrifugal Pump Impeller

Abstract

The high-specific-speed centrifugal pumps are very common in industrial factory for transporting fluids all day long. However, oversized pumps with low performance still could meet the purpose of fluid transporting. The aim of this study was to reduce the existed commercial impeller energy consumption by optimizing the performance of impeller through CAE processes. The impeller model was first generated by BladeGen software and analyzed by CFX in Turbo-mode. The optimized model then exported to machine center to cut the precise aluminum mold. A regular sand die casting processes were used to manufacture the impeller. The original pump which only impeller was replaced with the new one was tested with performance measurement system again. The results show that when the mass flow rate between 40-90kg/s the CFD software predicted very well pump heads and efficiencies with experimental data, which was called optimized impeller. But around the minimum and maximum flow rate region, the recirculation flow between blades and frictional loss model used still need further investigation to shrink the difference. Compare to the original impeller, the optimized one had increased efficiency 6% at the mass flow rate of 80kg/s. Also the high efficiency region (nearby of BEP) of the new impeller had broadened 50%. And the maximum mass flow rate increased 13% than the original one.