Coordinated improvement of energy performance and reliability in large centrifugal pumps: An interdisciplinary optimization approach

Large centrifugal pumps used in energy storage play a key role in renewable energy projects such as pumped-storage hydropower, where high efficiency and reliability are primary design objectives. Employing numerical simulation methods combined with experimental validation, this study first conducts a comprehensive analysis of the transient dynamic characteristics within the impeller, the primary component. Secondly, a multi-component collaborative optimization of the impeller and guide vanes is performed using the surrogate model method. The optimization objectives are pump efficiency and the maximum equivalent stress on the impeller, with nine geometric parameters of the impeller and guide vanes defined as design variables. The results indicate that the equivalent stress and total deformation distribution of the impeller at different time points are relatively consistent, with maximum values primarily concentrated near the outlet of the flow channel on the impeller shroud. Compared to the original model, the optimized model achieves a 2.96% increase in efficiency under the design condition and a 13.28% reduction in maximum equivalent stress on the impeller. These improvements effectively enhance the operational efficiency of the model pump and strengthen its operational reliability. Several factors significantly influence pump performance, including guide vanes design and the differentiated design of the outlet angle of the impeller blades.