Design of Tandem Guide Vanes and Analysis of Internal Flow Field Characteristics for Well Submersible Pumps

This study focuses on the 130QJ25–33 multi-stage submersible well pump to resolve low efficiency and flow instability under low-flow conditions by redesigning tandem space guide vanes. CFD simulations and physical experiments are carried out for validation. A grid independence analysis is completed to determine the optimal grid scheme with 9.413 million cells. The relative error of hydraulic performance between numerical simulation and the experiment is less than 10%, which verifies the accuracy of the numerical model. An orthogonal experiment is adopted to optimize three key geometric parameters: wrap angle, installation angle and axial position. Under the operating range of 0.6 Qd–1.1 Qd, the optimized tandem guide vane structure raises the pump head by 12.4% and improves efficiency by up to 8.7%. These data are derived from the comparative external characteristic tests of the original model and the optimized model. The optimized structure effectively suppresses flow separation and vortices, homogenizes flow and pressure distribution, reduces hydraulic loss, balances blade loading, and improves operational stability. The results provide theoretical and engineering guidance for high-efficiency guide vane design of well submersible pumps. The structure can effectively reduce the hydraulic loss in the pump, improve the flow efficiency, and significantly improve the hydraulic matching performance of the guide vane.