Abstract:During partload operation, recirculation was inevitably developed at pump impeller inlet. Based on standard k-ε turbulent model, the 3D steady turbulent flow in a centrifugal pump was simulated under different conditions to analyze the velocity distribution of the recirculation flow field and the vortex morphology.To solve recirculation, a control strategy of injecting high pressure water into impeller inlet was proposed. The control effects, the recirculation vortex morphology and the pump head and efficiency with different injection pressure were analyzed and compared through numerical simulation. The result indicates that high pressure water injection can effectively control inlet recirculation and improve the velocity distribution in inlet flow field with decreased recirculation vortex strength and recirculation onset critical flow rate, but also with decreased pump head and efficiency. Based on the experiment results, the optimum injection pressure in the proposed control stratgy is 0.10 MPa.