Energy efficiency optimization of water pump based on heuristic algorithm and computational fluid dynamics

To reduce the energy consumption of large centrifugal pumps, modified heuristic intelligent algorithms are used to directly optimize the diffuser of centrifugal pumps. Considering the hydraulic efficiency under the design condition as the optimization target, in this study, 14 geometric parameters such as the inlet diameter, outlet diameter, and leading and trailing vane angles of the diffuser are selected as design variables, and the modified particle swam optimization and gravitational search algorithm are used to directly search for optimization in the design space. The performance and loss of internal entropy production of the different models before and after optimization are compared and analyzed in detail. The results show that the global optimization ability of the modified algorithm is improved. The diffuser model changes from cylindrical to twisted, the vane wrap angle increases, and the thickness of the leading edge decreases. Under the design condition, the efficiency of modified particle swarm optimization algorithm solution is increased by 2.75% and modified gravitational search algorithm solution by 2.21%, while the power remains unchanged. Furthermore, the optimization solution has the largest lift efficiency improvement under part-load conditions. After optimization, the unstable flow in the model is improved and internal entropy production loss is reduced significantly. The interior of the diffuser is dominated by turbulent entropy production and direct entropy production under different operating conditions, and the wall entropy production accounts for the smallest proportion.