Numerical Simulation Of Flow Field In Large Flow Centrifugal Slurry Pump

Slurry pump is widely used in coal washing,nonferrous metallurgy,chemical industry,power generation and other industries.The internal flow state of slurry pump is complicated,which is difficult to display intuitively,and it is difficult to use theoretical analysis method to carry out structural optimization design.In this paper,the numerical simulation method is used to analyze the internal flow state of slurry pump and the influence of structural parameters on pump performance,which has certain reference significance for the optimization design of slurry pump structure,improve efficiency and operational reliability.In this paper,the 300ZJ-I-A100 large-flow centrifugal slurry pump commonly used in production practice is taken as the research object,and the pressure distribution,velocity distribution and turbulent kinetic energy distribution of the flow field inside the slurry pump are analyzed.On this basis,the structural optimization suggestions are proposed.Meanwhile,the solid-liquid two-phase flow state inside the pump is analyzed.The effects of particle size,density and volume fraction on pump performance were studied.The results show that: under the rated flow rate and speed,the head increases gradually with the increase of the number of blades.The theoretical efficiency also increases with the increase of the number of blades,but the actual slurry pump efficiency increases first and then decreases due to the increase of inlet pressure and the aggravation of cavitation effect.When increasing from 4 tablets to 6 tablets,the efficiency increased from 82.15% to 85.95%.When the number of blades increased from 6 to 8,the efficiency decreased from 85.95% to 81.17%.When the number of blades is 4,the shaft power is296 k W;when the number of blades is 6,the shaft power is 340 k W;when there are more than 6 blades,the rear shaft power exceeds 355 k W.By comparing the performance characteristics of slurry pump with various blade quantities,it is found that 6 blades is a better scheme,which takes into account the efficiency and head,and the distribution of internal flow field is relatively stable.Through the analysis of solid-liquid two-phase flow state in the slurry pump,it is found that the solid phase velocity on the working surface is lower than that on the back,but the volume fraction is higher than that on the back.The area with high solid content is mainly concentrated in the back of the blade near the junction of the outlet and the front cover plate,and tends to expand towards the outlet of the blade.The region with high solid content at the blade inlet increases with the increase of particle diameter,and expands around the blade inlet.The velocity of solid phase at blade tail is the largest,and the volume fraction of solid phase at blade head is the largest.With the increase of particle diameter,the head decreases and the efficiency decreases.The research shows that the particle size,density and volume fraction have great influence on the pump head and efficiency,and special attention should be paid to the design.Through the analysis of the flow field inside the slurry pump,the influences of the number of blades,the size of solid particles,the density,the volume fraction and other factors on the performance of the slurry pump are obtained,and the structure optimization design scheme is proposed.The related work has certain reference significance and engineering value for improving the design level and efficiency of the slurry pump.