Optimized Design of a Multistage Centrifugal Pump Based on Volumetric Loss Reduction by Auxiliary Blades

Abstract

Throat ring leakage is a major factor deteriorating the performance of multistage centrifugal pumps. This paper focuses on the optimization of multistage centrifugal pumps by incorporating the principle of the Tesla valve and adding an auxiliary set of blades to the impeller body. By changing the direction and magnitude of the leaking fluid’s flow, the leakage volume of the impeller throat ring is reduced. The study results demonstrate that the experimental error in head calculation with numerical simulation at the optimal working condition was 0.65%, verifying the accuracy of the numerical simulation method. The leakage volume of the throat ring decreased by up to approximately 28.99% compared to the original structure, which significantly increased the pump’s head and overall efficiency. Near the optimal operating point, the pump’s head and overall efficiency increased by approximately 8.1% and 8.7%, respectively. The larger the flow rate, the greater the improvement in the pump’s head and total efficiency. Near high-flow operating conditions, the pump’s head and overall efficiency increased by approximately 116.45% and 110.84%, respectively. The auxiliary blade structure introduces a non-contact seal which, compared to traditional seal structures, improves seal life and reduces seal costs. Additionally, the auxiliary blades can shift the optimal operating point of the multistage centrifugal pump towards a higher flow rate, improving the pump’s delivery capability.