Performance Study And Optimization Design Of Centrifugal Pump Based On Solid-Liquid Two-Phase Flow

The solid-liquid two-phase centrifugal pump is used for conveying medium of two-phase flow. Compared with the clarified water pump, the flow field and the performance of the pump are quite different. Because of the existence of solid, the pump has low head, low efficiency,serious abrasion, which result in reduced efficiency, shortened life. Therefore, it is very important and of far-reaching significance to optimize the design of two-phase flow pump and improve its performance. In this paper, the commercial ANSYS software is utilized and using CFD numerical simulation to simulate the solid-liquid two-phase centrifugal pump and optimization of the impeller and numerical simulation. The main work of this paper is as follows:Firstly, the whole flow passage of solid-liquid two-phase centrifugal pump is modeled and meshed. The numerical simulation of the boundary condition of the centrifugal pump is carried out, and the flow field characteristics of the centrifugal pump under different particle volume fraction are studied. The results show that: with the increase of solid phase volume fraction, the head of the centrifugal pump increases first and then decreases, and the efficiency decreases continuously; the pressure of blade increases gradually, and the pressure of surface rises more fiercely than that of suction surface.Secondly, study on the abrasion and cavitation performance of two-phase pump under single diameter particles and Multi-diameter particles. The research results show that the particle diameter and solid volume fraction are the main parameters affecting the abrasion and cavitation performance of the two-phase pump. The attrition rate of the pump under the condition of Multi-diameter particles is deeper, mainly concentrated in the impeller hub and blade pressure, but the abrasion law under the condition of single diameter particles is the opposite; the solid particle has a certain influence on the pump cavitation, which mainly concentrated in the head of the impeller inlet.Then, the impeller of the centrifugal pump is designed to change the blade angle of impeller inlet and the wrapping angle of the blade, the two of them are changed according to the 0 curve,and the numerical simulation is carried out for the five schemes before and after modification.The results show that: when the ratio of the blade angle of impeller inlet and the wrapping angle of the blade is too large or too small, there are no optimization effects; when the ratio is slightly less than the original scheme, the pump efficiency reaches the highest efficiency, it is the efficient optimal solution; when the ratio is slightly higher than that of the original scheme, the range of maximum efficiency is largest, it is high efficient optimal solution.Finally, carry out the unsteady numerical simulation of the whole flow passage on the basis of the steady calculation of the three impeller model, and study impeller pressure pulsation and frequency characteristic under different impellers. The research results show that the blade setting angle and the blade packing angle can determine the width of the impeller flow path, the width of the impeller channel affects the pressure pulsation and vibration amplitude of import and export, when the ratio of the two angles slightly smaller, fluid pressure pulsation amplitude is larger, while it is the original scheme or the slightly larger ratio scheme, the pressure fluctuation amplitude and frequency are more uniform. The study provides a basis for the study of the influence of the width of runner on the pressure fluctuation.