Impeller Optimization And Injection Molding Process Analysis Of Carbon Fiber Composite Magnetic Pump

Magnetic pumps deliver toxic and corrosive media with no leakage,while metallic magnetic pumps suffer from some disadvantages such as low efficiency and easy corrosion.Taking a carbon fiber composite magnetic pump as the research object,which was optimized by hydraulic design and injection molding process through a combination of numerical simulation and experimental verification,in order to explore the internal flow laws of the pump,The impeller injection molding process of thick filament carbon fiber/polyetheretherketone(hereafter referred to as CF/PEEK)composites was obtained to develop a high efficiency and reliability magnetic pump for carbon fiber composites.The main research content and results are as follows:1.In this paper,the key components of the carbon fiber composite magnetic pump impeller,the volute shell are designed,and a three-dimensional full flow domain model is constructed,the simulation software CFX is used to simulate the pump full flow field with the outside characteristics simulation and obtain the pump simulated outside characteristics performance curve with the cavitation performance curve.2.Taking closed impeller as injection moulding object,Moldflow is used to simulate and analyze it.Injection moulding material uses innovative filament CF/PEEK composite material(including 30%filament carbon fiber,70%PEEK)to create a reasonable injection moulding program.An orthogonal experiment of L₁₆(4⁴)type was designed by taking volume shrinkage and warpage deformation as the criteria for evaluating the quality of plastic parts.The simulation results show that the process parameters influencing the degree of warpage deformation and volume shrinkage are as follows:melt temperature>holding time>cooling time>mold temperature.A group of better parameter combination is obtained by comparing the two schemes.The volume shrinkage and warpage distortion simulated by this combination parameter are both the smallest,which provides a certain reference for the injection-molded impeller of this material.3.Innovative use of Hastelloy and CF/PEEK composite material to prepare double-layer structure isolation sleeve.The prototype test shows that the hydraulic performance test and cavitation test of carbon fiber composite magnetic pump are in good agreement with the simulation results.The mechanical test report and test results show that the isolation sleeve has good pressure resistance and small magnetic eddy loss.The impeller has the advantages of light weight,wear resistance and good stability.The comprehensive performance of filament CF/PEEK composite injection magnetic pump developed in this project is higher than that of similar products,with good social and economic benefits.4.In order to improve the hydraulic efficiency of the carbon fiber composite impeller,the blades were optimized and designed based on the loading curve,a series of impeller schemes were obtained to explore the effect of the front loading point(NC),rear loading point(ND),and slope of the loading curve(SL)on the pump performance through numerical simulation.The results of the trial showed that:(1)The position ranges of front and rear loading points are(0.1?0.5)and(0.5?0.9)of relative streamline length(m)of blades respectively.As the front loading point moves back and the high efficiency zone moves forward,the peak efficiency increases slightly and the head curve decreases.When the current loading point is at m=0.5,the efficiency drops sharply and the head rises sharply.The rear loading point moves back and the high efficiency zone moves forward,but the peak efficiency decreases slightly and the head decreases under the rated operating conditions.Therefore,with efficiency as the optimization objective,the front loading point should be moved back as far as possible and the rear loading point should be moved forward as far as possible,but not exceeding m=0.5.(2)When load curve slope SL<0(front loading mode),the efficiency of magnetic pump is the lowest and the head is the highest.As the slope increases,the pump head curve and efficiency curve both increase.When the slope is increased to SL=0(middle loading mode),there is a sudden increase in efficiency and a sudden drop in head.Negative pressure occurs at the back of the blade inlet,which affects the anti-cavitation performance of the magnetic pump.When SL>0(rear loading mode),the efficiency zone moves forward and the efficiency value near the rated operating condition continues to rise,but excessive SL will cause excessive wrapping angle of blades,which in turn will lead to a decrease in efficiency.SL has the most significant effect on the performance of pump external characteristics.(3)The impeller 11 with the highest efficiency in the optimization scheme is compared with the original pump before optimization.The research shows that the hydraulic efficiency of the optimized pump flow field is 5.05%higher than that of the original pump under the rated conditions.The efficiency of impeller designed based on load curve of blade increases slightly under off-design conditions and remarkably near rated conditions.5.Select the load curve slope(SL),which has the greatest influence on the pump performance,as the dependent variable to explore the influence of SL on the pressure pulsation and radial force in the pump.The unsteady simulation results show that the radial force distribution is in the order of front loading mode>back loading mode>middle loading mode at rated flow rate;The pressure fluctuation amplitude near the volute tongue is the largest,and the order is:front loading mode>middle loading mode>back loading mode.The results show that the fluctuation amplitude and radial force of impeller 11 are smaller than that of the original pump impeller under small flow rate;The pulsation amplitude and radial force of impeller 11 are larger than that of the original pump at large flow rate.