Hydraulic performance and design optimization of a multistage centrifugal pump for solar ejector refrigeration

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To meet the low-flow and high-pressure-difference requirements of solar ejector refrigeration systems, this study investigates the hydraulic performance and design optimization of a multistage centrifugal pump for R245fa. A closed-loop experimental system was established, and a combined experimental–numerical approach was used to evaluate turbulence models, blade number, and key impeller geometric parameters. The experimental results show that the pump head decreases monotonically with increasing flow rate, and reaches 183.7 m at the rated flow rate of 1.0 m 3 /h, whereas the optimized pump achieves a maximum head of 212 m over the investigated flow range. Four turbulence models were assessed under representative operating conditions, and the SST k–ω model, which showed the best agreement with experimental results at the rated condition, was adopted for subsequent optimization. The optimal blade number was determined to be 7. Three impeller parameters, namely blade exit width ( b 2 ), blade inlet angle ( β 1 ), and blade exit angle ( β 2 ), were optimized using an orthogonal design, and Scheme (c) was identified as the optimal solution. Under the design condition, the maximum hydraulic efficiency reaches 47.1 %, while the head over the full flow range increases by 5 %–7 %. Range analysis indicates that the influence of the three parameters follows the order b 2 > β 1 > β 2 , and Pearson correlation analysis further confirms the dominant role of b 2 in determining both head and efficiency. This study provides guidance for the design and numerical modeling of dedicated pumps for solar ejector refrigeration systems.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.