Research On Contact Analysis And Optimization Design Of Single Screw Pump With Equal Wall Thickness

With the development and deepening of the oil production industry in China,compared with the failure conditions of the traditional oil production system,such as sealing failure,sucker rod falling off,rod tube partial grinding and so on,the submersible direct drive screw pump oil extraction system with integrated advantages of downhole driving and rod free pumping has been paid more and more attention.On the basis of the structural design and parameter calculation of the oil extraction system of the submerged oil direct drive screw pump,the contact analysis and optimization design of the wall thickness single screw pump for the key components are studied.The specific research methods and results are as follows:(1)Using the Creo3.0 software,the 3D solid modeling of the oil submersible direct drive screw pump oil extraction system is carried out by adopting the top-down design method,and the seamless connection between Mathcad and Creo is carried out to realize the transmission and sharing of the structure size and design parameters of the oil production system,and the automatic updating and correction of the structural model are realized,and the design efficiency is improved.(2)Based on the tensile test of the stator rubber material,the contact analysis of the equal wall thickness single screw pump under the 4 conditions of uniform pressure,pressure difference,temperature and friction coefficient are carried out,and the change laws of the contact analysis results are evaluated comprehensively.The results show that the effect of different working conditions on the contact performance of the screw pump are different.The contact analysis of 3 structural parameters,such as interference volume,eccentricity and thickness of stator rubber,are carried out by the P2P single screw pump.Through the analysis,it is found that the influence of interference on the contact sealing of pump is greatest,the thickness of stator is second,and the influence of eccentricity is smallest.(3)The multi-objective optimization technology and response surface method are combined to optimize the multi-objective structure parameters of the response surface for a wall thickness single screw pump.Three groups of quadratic polynomial response surface fitting models with the maximum total deformation of stator,the maximum contact pressure and the maximum equivalent stress as the target variables are set up.And the accuracy of all regression analysis of the fitting model are above 90%,which has better fitting and predictability.Sensitivity analysis and 3D response surface analysis are carried out for the design variables and optimization objectives of the PW single screw pump.The analysis results are consistent with the finite element contact analysis results.Through the multiobjective optimization design of response surface,3 groups of optimal solution of structural parameters of the single screw pump with equal wall thickness are obtained.The 3 sets of optimal solutions reduce the total deformation amount and the equivalent stress value of the pump stator,and the maximum contact pressure is greater than the pump pressure difference.The optimization results have improved the contact seal performance of the equal wall thickness single screw pump and reduced the volume and quality of the pump.The research results provide a theoretical guidance for the optimization design of the ISO wall thick single screw pump,which has certain engineering application value.(4)Based on the Pump Linx software,the fluid mechanical properties of the four groups of wall thickness before and after the optimization model of single screw Pump are analyzed.And the analysis results show that the optimized thickness of single screw pump such as cavity pressure difference to ascend,Pump lifting capacity increased;In addition,the flow velocity of the fluid decreased slightly,the impact force of the stator decreased,and the stability of the fluid flow at the meshing increased.