The Texture Parameters Of The Plunger Seal Of The Fracturing Pump Are Optimized

During the development of oil and gas field,fracturing technology has been proved to be effective in improving the production of oil and gas wells and the recovery of oil and gas.However,under high pressure,cyclic loading and corrosive working conditions,the abrasive wear of plunger seal is the main factor of limit the performance and service life of fracturing pump.How to reduce the wear rate of plunger seal pair of fracturing pump has become an urgent problem to be solved to improve the comprehensive performance of the fracturing pump.A large number of research data show that bionic surface texture technology can effectively improve the tribological performance of relative sliding surfaces,but the choice of texture parameters directly determines the tribological performance of textures.Therefore,in this paper,the lubrication performance simulation and the unit tribology experiment of plunger seal under the simulated condition of the fracturing pump are carried out.In this paper,the main work is as follows:(1)Assume that the lubricating medium is a Newtonian fluid,the lubricating medium is in a laminar flow state,and the fluid body force,boundary slip,and inertia force are not considered,the lubrication theory model of single texture plunger seal is established by combining the geometrical structure of the plunger seal,the Reynolds equation and the texture geometry equation,as well as analysis of the influence of different parameters texture on lubrication performance of plunger seal.The influence of texture distribution Angle on hydrodynamic lubrication performance is related to texture symmetry and texture depth.Different texture aspect ratio has different influences on the hydrodynamic lubrication performance,and the optimization of texture aspect ratio is also related texture depth.The smaller the surface skewness of the texture unit and the greater the kurtosis value are,the better the hydrodynamic lubrication performance of the texture surface will be.The closer average depth of texture to the minimum oil film thickness is,the better the hydrodynamic lubrication performance of the texture surface will be.(2)Combined with the MDW-100 type vertical universal friction wear tester pin-disk friction pair of the geometrical size and the 3000-type fracturing pump of the actual conditions,the unit experimental scheme of the friction and wear of the woven plunger sealing pair is designed.By equivalent calculation,we have confirmed that the lubricating medium is L-CKD150 lube,the test load is 400N,the rotating speed is 332r/min and the experimental condition of ambient temperature as well.On the basis of studying the influence of different laser parameters on the texture geometry,the laser marking parameters(the laser scanning speed is 500 mm/s,the laser power is 8W and marking times is 2 times)was determined for the surface texture processing of the plunger unit specimen.(3)The influence of texture processing quality on texture surface lubrication and friction and wear performance was analyzed by numerical simulation and unit tribology experiments.If the process is insufficient within the texture,there will be discrepancy between the texture depth and the actual texture depth,which will affect the texture depth and then influence the dynamic pressure lubrication performance of the texture.The metal accumulation around the texture will increase the mutual scraping and furrow effect of the friction pair surface,and then have a certain negative effect on the texture lubrication antifriction performance.(4)The unit experimental Study of tribology under simulated working condition of fracturing pump reveals that:Only the reasonable parameter texture can effectively improve the tribological performance of the friction pair of the pin and disc specimen.When the elliptical texture is in different distribution angles,in order to obtain a better texture lubrication antifriction performance,the texture of the long axis should be as vertical velocity direction as possible,analogously,when the equilateral triangle texture is in different distribution angles,the optimum texture lubrication and antifriction performance can be obtained by any side of the equilateral triangle texture perpendicular to the velocity direction.Under the condition of different length-width ratio,the texture lubrication is more excellent when the axis of texture perpendicular to the velocity direction is greater than the length of parallel to the velocity direction.For the three kinds of textures of circle,ellipse and bar,the friction and wear properties of the circular texture friction pair are the best,followed by the strip texture surface,the ellipse texture surface to the worst.To sum up,in this paper,the numerical simulation of the hydrodynamic lubrication performance and the unit tribology experiment of the textured plunger seal under the simulated working conditions of the fracturing pump were carried out.The Influence law of parameters such as the distribution angle of the texture,the aspect ratio of the texture,the texture type and the texture cross-section on the tribological properties of the plunger seal was found,and mastered the basic methods for optimal design of the surface texture of the plunger seal of the fracturing pump.The research results of this paper have important significance for promoting the in-depth research and application of the bionic surface texture technology in the field of fracturing piston pumps.