Research On The Pass Performance And Wear Of Solid-Liquid Two-Phase Centrifugal Pump

Centrifugal pump is the key power equipment in the solid-liquid two-phase conveying system,but in the conveying process,its flow wall will be worn,which will lead to the reliability of the centrifugal pump,and eventually lead to equipment damage and economic losses.The numerical calculation and experimental study of a centrifugal pump HCK100-80-250 are carried out in this paper.Based on the contrastive analysis of the existing models of wear and tear,based on E/CRC model is perfect,the secondary development function of EDEM software compiling,introducing modified wear model calculation,adopt the method of CFD-DEM coupling to complete different mass concentration,particle size,and internal rotation speed centrifugal pump in the cases of two phase flow and wall wear and tear is calculated.The experiment includes the external characteristic test under clean water and two phase condition and the wear test with 120 h duration.The main research results are as follows:1.The change of particle mass concentration,particle size and speed will have an impact on the flow field in the centrifugal pump.The speed has the greatest impact,followed by particle mass concentration,and the particle size has the least impact on the flow field.2.With the change of particle mass concentration,particle size and speed,the passage of solid particles in the centrifugal pump is also very different.With the increase of mass concentration,the particle transmissibility shows a linear decreasing trend.With the increase of rotational speed,the particle transmissibility increases.There is no linear relationship between particle size and particle transmissibility.3.No matter the particle mass concentration,particle size or rotational speed changes,the growth rate of particle velocity in the area near the wall of the blade pressure surface presents a trend of first increasing,then decreasing and then increasing,and the particle velocity in different areas of the volute reaches its peak in the area of0-1 or 1-2 section.4 centrifugal pump impeller,volute,wear before and after the wear degree is different.With the increase of particle mass concentration,particle size and rotational speed,the wear of the blade pressure surface especially the second half near the outlet is intensified,followed by the second half in front of the pressure,and the wear of the middle region of the pressure surface is relatively slow.According to the statistics of particle collision times in different areas of the pressure surface,it is found that the proportion of particle collision in the middle area of the pressure surface is smaller than that in the first and second half of the pressure surface.Combined with the result of the minimum wear degree there,it can be considered that the particle collision times are directly related to the wear degree.For the volute,with the increase of particle mass concentration and rotational speed,the wear degree of different sections of the volute intensifies.With the increase of particle size,the wear rate has a linear relationship with particle size before section 6,but after section 6,the wear rate fluctuates greatly under different particle size conditions and has no obvious relationship with particle size.No matter what kind of working conditions,the volute 7-8 section wear is the most serious.Similar to the cause of blade wear,the particle collision probability of section 7-8 is also the largest.Because of the particle velocity in the axial direction,the wear degree of the rear wear plate is greater than that of the front wear plate.5.Under the condition of mixed particle size,the large particles in the impeller basin tend to move closer to the pressure surface,and the distribution of small particles in the impeller passage is more uniform than that of large particles.In addition,by sectional analysis of the total and average particle energy loss on the pressure surface,it is found that the radial wear rate of the blade pressure surface is directly related to the particle energy loss.For the wear of the volute wall,the average collision times of particles in section 7-8 are the largest,and the accumulation movement of particles near the wall of the volute is slow,leading to serious wear.