Multi-operating condition design of centrifugal pump with medium specific speed

In order to allow the hydraulic performance of type TS65-40-125 centrifugal pump with a medium specific speed to satisfy multi-operating-condition simultaneously, its impeller was redesigned three times by means of the enlarged design flow rate method. A structure grid was generated in Ansys Workbench 12 and the grid size-independence was analyzed. The pressure, turbulence kinetic energy, velocity distributions in those impellers and the overall performance curves were obtained with the commercial software CFX. Finally, one optimal impeller was identified and experiments were made against it. It can be concluded that the properly selected geometry parameters of the impeller can effectively improve head and efficiency of the centrifugal pump with medium specific speed and expand the high efficiency zone by using the enlarge design flow rate method. The head of the redesigned pump was improved as high as 5 m compared with the original one at the design point and the efficiency at five operating points basically met the specifications in the related national pump standard of China. Some references are provided for the multi-operating-condition design of centrifugal pump with medium specific speed.