Leakage Mechanism And Structural Parameter Optimization Of All Metal Single Screw Pump

All metal single screw pump is a kind of heavy oil production equipment rising in recent years.It solves the problems encountered in the production of traditional rubber single screw pump.The analysis and Research on the operating conditions and specific structure of the single screw pump and the matching relationship between them are of great significance to the subsequent hydrodynamic simulation research on the stability of the internal flow field and the optimization of structural parameters of the single screw pump,so as to ensure the safe and efficient operation of the single screw pump.Based on the hydrodynamic simulation analysis,considering the influence of parameters such as pressure,medium viscosity and speed,and aiming at high pump efficiency and low loss,this paper studies the optimization of structural parameters of all metal single screw pump.The main research work is as follows:(1)Summarize the flow field calculation model and structural parameter optimization theory of all metal single screw pump,so as to provide a feasible reference for the research of this paper.(2)The basic structure composition and leakage mechanism of screw and stator bushing of all metal single screw pump are studied;The derivation of the three-dimensional equation of the pump stator and the numerical analysis of the single screw seal line provide the theoretical basis for the establishment of the three-dimensional equation of the pump stator;Analyze the basic parameters affecting the performance of all metal single screw pump,such as medium viscosity,clearance value,speed,etc.,and calculate the volumetric flow,leakage and volumetric efficiency of the pump.(3)The three-dimensional flow field numerical calculation model of single screw pump is established,the fluid domain is extracted for grid division,the fluid calculation model,materials and inlet and outlet boundary conditions are set,and the pretreatment of hydrodynamic numerical simulation is completed;By simplifying the leakage model,the two clearance leakage modes of single screw pump are analyzed,and the leakage between chambers is calculated.(4)The influence laws of different operating parameters and structural parameters on the flow field in the pump are analyzed.On this basis,different fluid simulation models are set up respectively,and the pressure field,shear stress field,kinetic energy field and velocity field models are established to study the influence of various parameters on the stability of the flow field in the pump,and analyze the influence of these parameters on the performance of single screw pump,such as displacement,power and volumetric efficiency.(5)In order to improve the volumetric efficiency of all metal single screw pump,the structural parameters such as eccentricity,lead and clearance value are regarded as independent variables,and the influence of each parameter on the pump performance is analyzed.The structural parameters are optimized by orthogonal experiment and range analysis to obtain the parameters that optimize the pump efficiency,and two structural improvement schemes suitable for cold production and hot production are put forward.