Semi-open impeller structural parameters optimization on hydraulic performance for a sanitary centrifugal pump

Sanitary centrifugal pumps, which are widely used in industrial production and account for a significant share of global electric motor energy, suffer from reduced efficiency and stability due to hydraulic losses caused by the tip clearance with semi-open impeller. Improving the performance of these pumps is therefore of great importance. This study optimizes the structural parameters of semi-open impellers for a sanitary centrifugal pump to enhance pump efficiency and reduce energy losses. Five key impeller structural parameters are evaluated and a sample database is generated using the Optimal Latin Hypercube Sampling method. The performance improvement is carried out using a Response Surface Methodology approximation model combined with the Non-dominated Sorting Genetic Algorithm II. Analysis of the optimized pump reveals a 2.04% increase in efficiency and a 1.81 m improvement in head compared to the original model. In the optimized scheme, a noticeable reduction in the areas affected by flow separation and vortex formation is identified and the high-entropy production rate area in flow channel is significantly reduced with smaller high-vorticity regions. Furthermore, a novel front cover structure is developed, revealing optimal performance at a 1/5 coverage ratio, resulting in a 6.2% efficiency gain and a 1.87 m head improvement. These findings offer valuable insights and effective strategies for enhancing the performance of sanitary centrifugal pumps while minimizing energy losses.