Structural Optimization Design And Performance Analysis Of Large Flow Low Temperature Submersible Pump

Natural gas as a clean energy,takes more and more proportion in the primary energy industry application.The transmission of the liquef Ied natural gas needs to be achieved with the help of low-temperature submersible pump.and the performance of the pump directly affects the efficiency of the entire transport system.Therefore,this paper takes the 460-square-meter high-flow low-temperature submersible pump designed by a research institute in Beijing as the research object,and uses the combination of numerical simulation and experimental test to study the structure of the cryogenic submersible pump to solve the problem that the existing cryogenic submersible pump has too high a head and the efficiency cannot meet the user’s requirements.Firstly,the internal flow field of the cryogenic submersible pump was analyzed by numerical simulation method,and it was found that there was a vortex in the pump impeller and the flow in the guide vane was uneven,and the above factors were analyzed as the reasons affecting the efficiency.Then,in view of the problem that the pump lift is too high,the impeller cutting amount is simulated,and a set of cutting laws applicable to this low-temperature submersible pump are obtained;the flow field and performance curve of the impeller outlet angle and the number of blades are analyzed,and it is found that the existence of an optimal outlet angle can improve the efficiency of the pump,and the reduction of the number of blades can improve the efficiency and reduce the head.Secondly,the matching of the angle of the guide vane,the thickness of the blade and the number of blades between the impeller and the impeller are studied,and the flow field,performance curve and hydraulic loss in the guide vane and the vortex shell are analyzed,and the flow field in the guide vane and vortex shell is the best,the highest efficiency and the lowest hydraulic loss are obtained when the angle of the guide vane is 80°,the thickness of the tail edge of the blade is 14 mm,and the number of blades of the impeller and the guide vane is 5 and 10.Finally,according to the structural parameters of the optimal performance,the impeller and guide vane models were designed and assembled into the original pump for performance testing,and it was found that the pump head dropped to 324.09 m,and the efficiency increased by 3.38%,indicating that the low-temperature submersible pump achieved an optimized effect.In summary,the impeller and guide vane structure parameters of the cryogenic submersible pump are numerically analyzed,and the impeller and guide vane structure parameters under optimal performance are obtained,and the pump head is 324.09 m and the efficiency is 56.45%,which meets the user’s requirements.