Fracture Mechanism And Structural Optimization Of The Pump Apron Of The Fracturing Pump

Fracturing pump is the core equipment in fracturing acidizing treatment system.Due to the solid particles in the transmission medium and the reciprocating working principle of the pump valve,the valve rubber is easy to wear by solid particles and affected by impact loading,which causes the destruction of the valve rubber.The failure of the valve rubber not only influences the efficiency of fracturing acidizing treatment,but also leads to pump valve's failures in advance.So it is significant to master the mechanism and the law of wear failure of valve rubber in the fracturing fluid.What's more,the rubber structure optimization study is also important.This thesis took the 70 MPa fracturing pump valve rubber as the research object,and studied the failure mechanism and structure optimization of the pump valve rubber.The detailed analysis and research methods are as follows:(1)Based on the actual structure and working principle of fracturing pump,taking the fracturing fluid compressibility and movement inertia force of pump valve into consideration,this thesis used the AMESim simulation to study the motion law of the fracturing pump valve.The simulation results is good agreement with the numerical calculation results of traditional theory and method,which verifies the validity of the simulation model.Then the movement law of pump valve was analyzed under different influencing factors.The results can be used as the data base of the pump valve gap flow field analysis.(2)Under different lift distance,valve speed,valve angle and the concentration of solid phase,the pump valve gap flow field was simulated by the Fluent.The solid-liquid two-phase flow velocity distribution near the rubber was obtained.The results reveal the reasons of the honeycomb peeling in the rubber bottom.The simulation results also confirmed the solid particles movement speed near wall of the rubber,which provided the data base for the rubber material erosion wear research.(3)Under different particle shape,particle diameter,impact velocity and impact Angle,Abaqus was used to simulate the valve rubber material erosion process,which obtained the change rule of stress and strain and energy of the rubber material in the erosion process.The results reveal the loss essence of erosion wear of the valve rubber material from the micro perspective.Then using this model analyzes the erosion characteristics of different shapes particles based on energy wear theory,the results showed the different shape particles(the blunt particles and sharp particles)erosion failure mechanism of the target material.(4)MDW-100 friction and wear test machine was used to complete the friction and wear test of valve rubber in the sand fracturing fluid.Then the abrasive wear mechanism and rule of the rubber were discussed,under different concentrating of sand,impact loading and sliding speed between the valve body and valve seat.The results showed the abrasive wear failure mechanism of the valve rubber in sand fracturing fluid.(5)The finite element model of the valve body and rubber impacting the valve seat was built.The results showed that the maximize stress appears in the rubber bottom which is tend to fatigue failure.The failure part is consistent with the block peeling morphology in the valve rubber bottom.Finally,on the basis of the finite element model,the method of orthogonal experiment was applied on the structure optimization of the valve rubber,which got the optimal structure parameters of valve rubber.