Numerical optimization and experimental analysis of the internal cavity in double-suction pump

Abstract

【Objective】 The cavity chamber is a crucial component in double-suction pumps, and its design directly impacts pump performance. This study investigates the influence of key design parameters of the chamber on the efficiency of double-suction centrifugal pumps, aiming to optimize its design to enhance hydraulic performance of the pumps. 【Method】 Based on the principle of minimizing hydraulic loss, we designed the shapes of the chamber and the internal flow passages in the volute. We then examined the evolution of the cross-sectional area of the flow passages. Computational fluid dynamics (CFD) was used to compare the flow and performance characteristics of the pump before and after the optimization. The improved performance of the optimized design was evaluated against experimental results obtained from physical models. 【Result】 Compared to the original design without optimization, the optimized design increased efficiency of the pump at rated operating conditions by 3.36%. Within the range of 0.7 QBEP (design condition) to 1.2 QBEP, the optimized design improved overall pump efficiency compared to that without optimization. The optimization reduced the hydraulic losses across the volute significantly, with the reduction exceeding 20% under most operating conditions. At 1.3 QBEP, the reduction was 6.18%. For the chamber, the hydraulic losses in the optimized model were lower than those in the original model without optimization when flow rate exceeded 0.98 QBEP. 【Conclusion】 The optimized design of the suction chamber and the internal flow passages in the volute significantly improves flow stability in the suction chamber, eliminates vortices near the impeller outlet, reduces hydraulic losses, and enhances the hydraulic efficiency of the double-suction pumps.

Keywords

• double-suction pump
• efficiency improvement
• flow passage reshaping
• computational fluid dynamics (cfd)