The Equal Strength Formula Design Of 180 Degree Tube Wall Thickness And Optimization Of Process Parameters Of Hot Forming Horn Mandrel

Bend pipe is an important component of pipeline transportation network.The fluid flows through the pipe,the pipe flange pipe wall to form a larger impact,but in the concave side bend the formation of reduced pressure zone,to make the convex and concave side bend pipe wall uneven force.The limitations of the processing technology,easy to cause in the pipe flange thickness,flange in bending and prone to wrinkling phenomenon,double factors lead to pipe cracking,explosions and other serious consequences.It is often seen.Therefore,in view of the above problems,this paper uses FLUENT software,through numerical simulation method to analyze the different flow parameters of crude oil and the influence of the variation of the pipe geometry parameters on the internal pressure of the pipe wall,and establish the corresponding calculation model.The axial,circumferential and radial stresses are analyzed,and the formula for calculating the thickness of the wall with variable wall thickness is derived by using the third strength theory.Using DEFORM-3D CAE application software of the simulation of plastic forming process analysis of the influence of hot horn mandrel,the distribution of different process parameters on wall thickness of the workpiece deformation,predict the forming process and defects,for optimal or feasible design to provide theoretical guidance and reference,it has important engineering significance.Specific contents are as follows:(1)FLUENT software was used to analyze the distribution of internal pressure P of elbow with the variation of outlet pressure P0,inlet velocity v,fluid density ? and the degree of curvature k=R/D during the flow of crude oil in 180 degree bend pipe,to establish 135 kinds of working condition of internal pressure P distribution database.According to the distributionlaw of the pressure of the inner wall of the elbow under different parameters(P0?v???k),calculation formula of the internal pressure distribution of the pipe is analyzed and fitted by1 stOpt software.Through the numerical simulation results of 135 kinds of working condition of FLUENT,the calculation precision of the formula was verified(Maximum relative errord ??0.045%).It provides basis for design of bend pipe and safety evaluation of pipeline in high pressure,high flow rate and long distance petroleum pipeline.(2)The circumferential stress and axial stress and radial stress analysis,and through the third strength theory of pipe wall thickness design,wall thickness design formula is derived,the wall thickness of the bend convex concave edge is always greater than the wall thickness,wall thickness from the concave convex edge to increase with the change of the circumferential angle.And through the condition verification,comparison under internal pressure pressure distribution,has a certain consistency,can explain the feasibility of variable thickness tube wall thickness,the effectiveness of the design,the wall thickness distribution can meet the engineering requirements.(3)Design and optimization of the process parameters of the horn mandrel.In order to keep the proportional relation between the forming process of the tube,the mandrel of the horn mandrel should be a curve with variable curvature.That is,the bending deformation and the expansion deformation should be gradually increased,and should be continuous smooth.The use of DEFORM-3D plastic forming process of CAE application software simulation of variable wall thickness strength bending,analysis the influence of different process parameters on the wall thickness of the bend,and the processing parameters were optimized,the optimum combination of process parameters.