关键词: 出口扩散段；喇叭管；导水锥；双向流道泵；水力性能

Abstract: To improve the hydraulic performance of large low-lift bidirectional flow channel pump devices, based on the elliptical profile design of the outlet diffuser section of the flow channel and combined with the SST k-ω turbulence model, this paper explores the influence of the diameter of the outlet diffuser section on the hydraulic performance of the bidirectional flow channel pump device. By adjusting the maximum diameter D1​ of the outlet trumpet tube of the flow channel, the maximum diameter D2​ of the guide cone, and adjusting both simultaneously, the distribution laws of indicators such as the velocity uniformity, hydraulic loss, and kinetic energy recovery rate of the outlet flow channel under different diameter schemes were compared. Combined with the entropy production theory, the influence law of the overall diameter of the outlet diffuser section on the hydraulic performance of the bidirectional flow channel pump device was revealed. The research results show that when only the maximum diameter D1​ of the trumpet tube is increased, the maximum efficiency of the pump device first increases and then decreases. When D1​=2.09D0​ (D0​ is the impeller diameter), the pump device has the highest efficiency, and the hydraulic loss of the outlet flow channel is reduced by 1 cm compared with the initial scheme. When only the maximum diameter D2​ of the guide cone is increased, the hydraulic loss of the outlet flow channel first decreases and then increases, and the minimum hydraulic loss of the outlet flow channel occurs when D2​=2.09D0​. When the maximum diameters D1​ and D2​ of the trumpet tube and the guide cone are increased simultaneously, the maximum efficiency of the pump device gradually increases. When the maximum overall diameters D1​ and D2​ are both 2.28D, the highest efficiency value is obtained, and the hydraulic loss of the outlet flow channel is reduced by 1.8 cm compared with the initial scheme. The research results can provide a reference for the optimized design of bidirectional flow channel pump devices

Key words: outlet diffusion section； horn tube； water guide cone； bidirectional flow channel； hydraulic performance