Study On Optimum Of LNG Submersible Pump

LNG submersible pump is the key equipment for transporting LNG.At present,China's liquefied natural gas related enterprises are using foreign equipment,high monopoly prices for a long time plagued domestic enterprises,the urgent need for research and development with independent intellectual property rights of LNG submersible pump.The hydraulic performance and cavitation performance of LNG submersible pump are the key indexes to evaluate its performance.In this paper,the numerical simulation method is used to study the hydraulic performance and cavitation performance of a single stage LNG submersible pump.The main work is as follows.Firstly,the principle and control equation of computational fluid dynamics are discussed.This paper introduces the setting up of 3D model,meshing and numerical calculation.Secondly,The hydraulic performance and cavitation performance of LNG submersible pump inducer with different inlet fillet and tip clearance were calculated.The effects of two kinds of inducer structure parameters on the hydraulic performance and cavitation performance of the inducer were discussed.The appropriate inlet angle and the tip clearance of the inducer were determined.Thirdly,The hydraulic performance and cavitation performance of LNG submersible pump impeller with different inlet diameter and offset angle of short blade are calculated.The effects of two kinds of impeller parameters on the hydraulic performance and cavitation performance of the impeller were studied.The proper inlet diameter and offset angle of the impeller blade are determined.Fourthly,The hydraulic performance of the volute with different radial clearance between the volute and impeller,the width of the volute inlet and the installation angle of the tongue are calculated.The influence mechanism of three kinds of volute structure parameters on the hydraulic performance of LNG submersible pump is analyzed.The values of the radial clearance of the volute and the impeller,the inlet width of the volute and the angle of the installation angle of the tongue of the LNG submersible pumpwere determined.Fifthly,The hydraulic performance and cavitation performance of the optimized LNG submersible pump are analyzed.Under the condition of unsteady state,the fluctuation of head and internal pressure of LNG submersible pump under is discussed.The rotational cavitation phenomenon of the inducer and impeller was analyzed.In conclusion,the results can provide some theoretical basis for the design and development of LNG submersible pump.