Sealing interface leakage analysis method and system of flared pipe joint, medium and equipment

Abstract

The invention discloses a sealing interface leakage analysis method and system of a flared pipe joint, a medium and equipment, and belongs to the technical field of pipeline safety detection.The method comprises the steps that a finite element model of the flared pipe joint is established, and pressure distribution of a sealing surface is obtained through statics simulation; measuring the microstructure of the sealing surface of the flaring type pipe joint, and carrying out noise reduction treatment based on wavelet transform to obtain an equivalent contact surface; based on a boundary element microcosmic contact algorithm, solving microcosmic contact deformation of the equivalent contact surface by taking pressure distribution of the sealing surface as a boundary condition to obtain deformation quantity of microcosmic contact of the sealing surface, and obtaining node coordinates after contact deformation based on the deformation quantity; and constructing a local leakage channel of the sealing surface of the flaring type pipe joint based on the node coordinates, and solving a three-dimensional steady-state flow field and a leakage rate of the leakage channel by establishing a fluid simulation model of the leakage channel. According to the method, the accuracy of leakage analysis is remarkably improved on the basis of actual measurement surface microstructure reconstruction and a microcosmic contact boundary element algorithm.

Description

Technical Field

[0001] This invention belongs to the technical field of pipeline safety inspection, specifically relating to a method, system, medium, and equipment for analyzing leakage at the sealing interface of a flared pipe joint. Background Technology

[0002] Flared pipe fittings, as an important connecting element widely used in liquid and gas pipeline systems, have advantages such as simple structure, convenient installation, and wide applicability, and have been widely used in mechanical industries such as aerospace, shipbuilding, and weaponry. In the structure of a flared pipe fitting, the tightening of the outer nut provides a preload to compress the sealing cone surface, thereby preventing internal liquid or gas leakage. Its sealing reliability directly affects the safety and service life of the entire system.

[0003] Traditional methods for calculating the leakage rate of pipe joints involve establishing a rough surface mesh model, simulating the contact deformation, and then calculating the leakage rate by extracting the leakage channels. However, rough surface meshes are typically on the micrometer scale, and the number of meshes in the contact surface model is enormous, resulting in low computational efficiency and difficulty in convergence. Moreover, in actual processing and assembly, various parameters such as surface morphology have typical uncertainties, leading to poor calculation accuracy.

[0004] For example, Chinese patent CN202210691545.6 discloses a method for detecting the leading edge of a hydraulic conduit joint seal, including the following steps: Step 1: Assemble the conduit to be tested and fill it with a fluorescent solution; Step 2: Pressurize the conduit for 10-15 minutes; Step 3: Unload the pressure and drain the fluorescent solution; Disassemble the conduit after drying; Step 4: Obtain the fluorescence distribution of the sealing surface under ultraviolet light irradiation, and classify the leakage type according to the size of the fluorescence distribution area on the sealing surface; By filling the conduit connection assembly with a fluorescent solution, the liquid entry of the sealing surface under working conditions can be observed intuitively. In the absence of leakage, the sealing status and remaining sealing life of the conduit can be compared and analyzed. Summary of the Invention

[0005] The purpose of this invention is to provide a method, system, medium, and equipment for analyzing leakage at the sealing interface of flared pipe joints, in order to solve the above-mentioned problems.

[0006] This invention is mainly achieved through the following technical solutions: A method for analyzing leakage at the sealing interface of a flared pipe joint includes the following steps: Step S1: Establish a finite element model of the flared pipe joint and use static simulation to obtain the pressure distribution on the sealing surface; Step S2: Measure the microstructure of the sealing surface of the flared pipe joint and perform noise reduction based on wavelet transform to obtain the equivalent contact surface; Step S3: Based on the boundary element micro-contact algorithm, the pressure distribution of the sealing surface is used as the boundary condition to solve the micro-contact deformation of the equivalent contact surface, obtain the deformation of the micro-contact of the sealing surface, and obtain the node coordinates after contact deformation based on the deformation. Step S4: Construct a local leakage channel on the sealing surface of the flared pipe joint based on the node coordinates, and solve the three-dimensional steady-state flow field and leakage rate of the leakage channel by establishing a fluid simulation model of the leakage channel.

[0007] To better realize the present invention, in step S1, during the meshing process of the finite element model, all structures are meshed using hexahedral meshes, and the mesh size of the sealing surface and threaded surface of the pipe joint is smaller than the mesh size of the other structures.

[0008] To better realize the present invention, further, in step S1, during the static simulation, the contact interface is divided into the contact surface and the target surface, and the mesh is generated using CONTA173 elements and TARGE170 elements respectively. The friction coefficient of all contact interfaces is set to 0.15. The boundary conditions are defined as follows: the bottom end face of the pipe joint is fixedly constrained. During the assembly simulation, a rotation angle around the Z-axis is applied to the outer cylindrical surface of the outer sleeve nut. The simulation process is quasi-static.

[0009] To better realize the present invention, step S2 further includes the following steps: Step S21: Use an optical 3D surface profilometer to measure the sealing surface of the flared pipe joint and obtain point cloud data of the rough surface; Step S22: Reconstruct the three-dimensional surface micro-morphology based on point cloud data to obtain the micro-morphology; Step S23: Based on the wavelet multi-scale contour decomposition method, the micro-morphology is decomposed into eight layers, each layer representing a signal at a different wavelength scale. High-frequency noise signals are then removed from the signals at different wavelength scales. Finally, the remaining signals are reconstructed by wavelet to obtain the equivalent contact surface.

[0010] To better realize the present invention, step S3 further includes the following steps: Step S31: According to Johnson's assumption, the microscopic contact of the equivalent contact surface is equivalent to the contact between an equivalent rough surface and a smooth rigid plane; when the two contact surfaces are pressed against each other, according to the minimum potential energy theory, the contact problem of the equivalent rough surface is transformed into the problem of calculating the minimum complementary potential energy: (3) (4) in: Total residual potential energy; The internal residual potential energy of the entity below the surface; For a fixed surface displacement; This represents the magnitude of the surface force on the elastic body; This refers to the force-bearing range on the surface of the elastic body. For surface contact pressure distribution; This represents the normal deformation of the equivalent rough surface. The initial contact gap distribution; For the displacement of a rigid plane; Step S32: Formula (4) contains only one independent variable. Furthermore, there exists a unique contact surface pressure distribution that minimizes the system's residual potential energy. The contact deformation of the rough surface is solved using the conjugate gradient-fast Fourier transform method. Step S33: Based on the solution of the contact deformation of the rough surface, obtain the deformation of the rough surface of the flared pipe joint after being subjected to surface contact pressure.

[0011] To better realize the present invention, step S4 further includes the following steps: Step S41: Mesh the rough surface after contact deformation based on node coordinates. For the discretized rough surface after compression deformation, connect adjacent nodes in the X and Y directions in sequence, and generate a quadrilateral network model of the rough surface based on the connection between nodes. Step S42: Match the quadrilateral mesh model of the rough surface with the quadrilateral mesh nodes of the rigid plane to generate a three-dimensional mesh, and remove the meshes with zero height due to the contact between the rough surface and the rigid plane to obtain the three-dimensional mesh model of the leakage channel. Step S43: Use the fluid dynamics calculation software Fluent to solve for the three-dimensional steady-state flow field and leakage rate of the incompressible unidirectional flow in the sealing surface leakage channel.

[0012] This invention is mainly achieved through the following technical solutions: A leakage analysis system for the sealing interface of a flared pipe joint, based on the aforementioned leakage analysis method for the sealing interface of a flared pipe joint, includes: Model building module: used to build a finite element model of the flared pipe joint, and to obtain the pressure distribution on the sealing surface by static simulation based on the finite element model; Microscopic morphology measurement module: used to measure the microscopic morphology of the sealing surface of the flared pipe joint using a surface profilometer, and to perform noise reduction processing on the microscopic morphology using wavelet transform to obtain the equivalent contact surface; Contact Deformation Calculation Module: Based on the boundary element micro-contact algorithm, using the pressure distribution of the sealing surface as the boundary condition, it solves the micro-contact deformation of the equivalent contact surface, obtains the deformation of the micro-contact of the sealing surface, and obtains the node coordinates after contact deformation based on the deformation. Leakage rate calculation module: used to construct local microscopic leakage channels on the sealing surface of flared pipe joints based on node coordinates, and solve the three-dimensional steady-state flow field and leakage rate of the leakage channels by establishing a fluid simulation model of the leakage channels.

[0013] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for analyzing leakage at the sealing interface of a flared pipe joint.

[0014] An electronic device includes a memory and a processor; the memory stores a computer program; the processor is configured to execute the computer program in the memory to implement the above-described method for analyzing leakage at the sealing interface of a flared pipe joint.

[0015] The beneficial effects of this invention are as follows: This invention combines finite element mechanics and fluid simulation, reconstruction of measured surface microstructure, and the micro-contact boundary element algorithm to solve for quantitative evaluation indicators of the sealing performance of flared pipe joints, laying the foundation for subsequent reliability analysis of pipe joint seals. Specifically, this invention uses wavelet transform to denoise the microstructure to obtain an equivalent contact surface; based on the boundary element micro-contact algorithm, using the pressure distribution on the sealing surface as the boundary condition, it solves for the micro-contact deformation of the equivalent contact surface; the contact surface model has a small mesh size and high computational efficiency. This invention, based on reconstruction of measured surface microstructure and the micro-contact boundary element algorithm, significantly improves the accuracy of leakage analysis. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the principle of the leakage analysis method for the sealing interface of the flared pipe joint of the present invention. Figure 2 This is a schematic diagram of a flared pipe fitting. Figure 3 A schematic diagram of the finite element model of a flared pipe fitting; Figure 4 This is a schematic diagram of the simulated boundary conditions; Figure 5 This is a schematic diagram of the sampling area for the flared catheter; Figure 6 A schematic diagram of the surface morphology of the equivalent contact surface obtained for noise reduction processing; Figure 7 A schematic diagram of the Johnson hypothesis for contact between elastic and rough surfaces; Figure 8 The image shows a comparison of the microstructure of the equivalent rough surface before and after contact. Figure 9 A flowchart illustrating the process of constructing a 3D mesh model of the leakage path; Figure 10 A simulation diagram of the three-dimensional steady-state flow field of the leakage channel. Figure 11 This is a schematic diagram of the sealing interface leakage analysis system for the flared pipe joint of the present invention; Figure 12 This is a schematic diagram of the electronic device.

[0017] Among them: 1-pipe fitting, 2-outer nut, 3-flat pipe nozzle, 4-flared conical tube, 5-sealing conical surface. Detailed Implementation

[0018] Example 1: A method for analyzing leakage at the sealing interface of a flared pipe fitting, such as Figure 1 As shown, it includes the following steps: Step S1: Establish a finite element model of the macroscopic structure of the flared pipe joint 1, and use static simulation to obtain the pressure distribution on the sealing surface; Step S2: Measure the microstructure of the sealing surface of the flared pipe joint 1 using a surface profilometer, and use wavelet transform to perform noise reduction processing on the microstructure to obtain the equivalent contact surface. Step S3: Based on the boundary element micro-contact algorithm, the pressure distribution of the sealing surface is used as the boundary condition to solve the micro-contact deformation of the equivalent contact surface, obtain the deformation of the micro-contact of the sealing surface, and obtain the node coordinates after contact deformation based on the deformation. Step S4: Construct a local microscopic leakage channel on the sealing surface of the flared pipe joint 1 based on the node coordinates, and then solve the three-dimensional steady-state flow field and leakage rate of the leakage channel by establishing a fluid simulation model of the leakage channel.

[0019] In this embodiment, as Figure 2 As shown, the flared pipe fitting 1 mainly consists of a pipe fitting 1, an outer nut 2, a flat nozzle 3, and a flared conduit 4. After the outer nut 2 is tightened, a preload is generated to compress the sealing cone surface 5, so as to achieve tight contact between the mating surfaces of the flared conduit 4 and the pipe fitting 1 and ensure sealing performance. According to the structural dimensions specified in relevant aviation standards, the diameter of the flared conduit 4 of the research object of this invention is 6mm, the thread specification is M14×1mm, and the thread tooth profile is MJ thread.

[0020] In step S1, to ensure the computational efficiency and accuracy of the finite element model, such as... Figure 3As shown, during the mesh generation process, all structures in the model are meshed using hexahedral meshes, resulting in a reasonable sparse transition. Furthermore, the mesh size for the sealing and threaded surfaces of pipe joint 1 is smaller than that for the other structures. In addition, the parameters of the finite element model need to be defined. All hexahedral meshes use SOLID 185 elements; pipe joint 1 and outer nut 2 are made of 2A12 aluminum alloy, the flared conduit 4 is made of 5A02 aluminum alloy, and the flat nozzle 3 is made of 1Cr17Ni2 stainless steel.

[0021] like Figure 3 As shown, the finite element model contains four pairs of contact interfaces: the threaded contact surface between the pipe fitting 1 and the outer nut 2, the contact surface between the pipe fitting 1 and the flared conduit 4, the contact surface between the flared conduit 4 and the flat pipe nozzle 3, and the contact surface between the flat pipe nozzle 3 and the outer nut 2.

[0022] During the simulation, the contact interface was divided into a contact surface and a target surface. The contact surface and target surface were meshed using CONTA173 and TARGE170 elements, respectively. The friction coefficient of all contact interfaces was set to 0.15. Figure 4 As shown, the boundary conditions are defined as follows: the bottom end face of the pipe joint 1 is fixedly constrained, and a rotation angle about the Z-axis is applied to the outer cylindrical surface of the outer sleeve nut 2 during the assembly simulation. The simulation process is quasi-static.

[0023] In this embodiment, as Figure 3 As shown, in step S2, to obtain the true microstructure of the sealing surface of the flared pipe joint 1, an optical 3D surface profilometer is used to measure the point cloud data of the rough surface, where, for example... Figure 5 As shown, during the measurement, four sampling areas are selected for each flared tube 4, and the size of the sampling area and the measurement resolution are determined according to the length of the contact surface between the flared tube 4 and the connector 1. For example, the contact surface length between the flared tube 4 and the connector 1 is 2.675 mm, so the size of the sampling area is determined to be 1 mm × 2.675 mm, and the measurement resolution is 1 μm. A total of 1001 × 2676 sample points are obtained for each sampling area.

[0024] The micro-morphology of a three-dimensional surface is obtained by reconstructing the micro-morphology of the surface using point cloud data. By reconstructing the micro-morphology of the three-dimensional surface, real morphological information is provided for the subsequent numerical calculation of the contact behavior of the rough surface.

[0025] Due to the influence of the internal or external environment of the system, the surface morphology data collected during the experimental measurement process may contain noise interference and cannot be directly used for subsequent contact mechanics calculations. It is necessary to perform noise reduction processing on the original surface signal to eliminate high-frequency noise signals in the measurement signal. Wavelet transform, based on the localization idea of ​​short-time Fourier transform, can generate a "time-frequency" window whose size varies with frequency. Through scaling and translation transformation, the measured signal is gradually refined at multiple scales, processing the local details of the signal, achieving the effect of subdividing low-frequency frequency and high-frequency time, and adapting to the analysis requirements of signals with different time-frequency characteristics.

[0026] Specifically, such as Figure 6 As shown, based on the Bior 6.8 wavelet multi-scale contour decomposition method, the micro-morphology is decomposed into eight layers, each representing a signal at a different wavelength scale. High-frequency noise signals are then removed from the signals at different wavelength scales, and finally, the remaining signals are reconstructed by wavelet to obtain the equivalent contact surface.

[0027] In this embodiment, step S3 specifically includes: According to Johnson's hypothesis, the elastic contact between two rough surfaces can be equivalent to the contact between an equivalent rough surface and a smooth, rigid plane, such as... Figure 7 As shown, the surface morphology of the equivalent rough surface is: (1) In the formula, and These represent the height values ​​of the topographic data points on the upper and lower rough surfaces, respectively. The minimum value is 0, which is the elastic modulus of the equivalent rough surface. Compared to Poisson Satisfy the following expression: (2) In the formula, E1 and E2 are the elastic moduli of the two equivalent contact surfaces, and ν1 and ν2 are the Poisson's ratios of the two equivalent contact surfaces. This invention only considers axial load; the tangential stress and tangential displacement are both zero. Therefore, the Poisson's ratio of the equivalent rough surface is defined as 0, i.e. .

[0028] When the two contact surfaces are pressed against each other, the entire system approaches the state of minimum total residual potential energy. Therefore, according to the minimum potential energy theory, the contact problem of the equivalent rough surface can be transformed into the problem of calculating the minimum residual potential energy. (3) In the formula, For the total remaining potential energy, The internal residual potential energy of the subsurface entity. For a fixed surface displacement, The magnitude of the surface force on the elastic body. This refers to the force-bearing range on the surface of the elastic body. Approximating the equivalent rough surface as a frictionless linear semi-wireless elastic body, the intrinsic residual potential energy of the subsurface solid is... Numerical and elastic strain energy Equal, and The surface potential energy can be calculated from the surface contact pressure and the surface contact normal deformation; the surface displacement between the equivalent rough surface and the rigid plane can be calculated from the initial contact gap and the rigid plane displacement. Therefore, the total residual potential energy of the system can be further expressed as: (4) In the formula, Indicates the surface contact pressure distribution. This represents the normal deformation of the equivalent rough surface. This represents the initial contact gap distribution. This represents the displacement of a rigid plane. According to Boussinesq's theory, the normal deformation of an equivalent rough surface is related to the surface contact pressure distribution. Therefore, (5) In the formula, This represents the influence coefficient of a normal load on a point on a contact surface on the normal displacement of other points on the surface. The influence coefficient is related to the elastic modulus and Poisson's ratio of the equivalent rough surface. (6) At this point, there is only one independent variable in formula (4). Furthermore, there exists a unique contact surface pressure distribution that minimizes the system's residual potential energy. The process of solving for the contact deformation of the rough surface is transformed into finding the conditional extremum of a quadratic functional, and this process can be solved using the conjugate gradient-fast Fourier transform (CG-FFT) method, such as... Figure 8 As shown, the final surface morphology after contact is calculated based on the boundary element method.

[0029] Based on the solution of the contact deformation of the rough surface, the deformation of the rough surface of the flared pipe joint 1 after being subjected to surface contact pressure is obtained, and then the nodal coordinates of the rough surface after deformation are obtained.

[0030] In this embodiment, step S4 specifically includes: Mesh the rough surface after contact deformation based on node coordinates. For the discretized rough surface after compression deformation, connect adjacent nodes in the X and Y directions in sequence, and generate a quadrilateral network model of the rough surface based on the connection between nodes. By corresponding the quadrilateral mesh nodes of the rough surface to the quadrilateral mesh nodes of the rigid plane, a three-dimensional mesh is generated. Mesh with zero height due to the contact between the rough surface and the rigid plane is removed, thus completing the construction of the three-dimensional mesh model of the leakage channel.

[0031] Specifically, such as Figure 9 As shown, mesh generation is performed by first selecting the ANSYS parametric design language, such as... Figure 9 As shown in (a), the height data points of the discretized rough surface after compression deformation are imported into the finite element analysis software ANSYS 19.2, and adjacent nodes in the x and y directions are connected sequentially, as shown in (a). Figure 9 As shown in (b), a rough surface quadrilateral mesh model is then generated based on the connections between nodes; as shown in (b). Figure 9 As shown in (c), the quadrilateral mesh model of the rough surface is imported into the simulation analysis software Hypermesh 12.0 and matched with the quadrilateral mesh nodes of the rigid plane to generate a three-dimensional mesh, as follows. Figure 9 As shown in (d), the mesh with a height of 0 due to the contact between the rough surface and the plane is finally removed, and the three-dimensional mesh model of the leakage channel is constructed.

[0032] In this embodiment, for the fluid between the sealing surfaces, the gap between the contact interfaces of the static sealing structure is usually less than 10 μm. The liquid flow is mainly manifested as molecular flow and viscous flow. Viscous flow is affected by the fluid cohesion and the adhesion force between the fluid and the solid surface. Inertial force plays a secondary role in the flow process. When the viscous force dominates the flow, the adjacent streamlines are parallel to each other, and the flow is approximately laminar. Therefore, the fluid dynamics calculation software Fluent can be used to solve the three-dimensional steady-state flow field and leakage rate of the incompressible unidirectional flow in the leakage channel of the sealing interface.

[0033] Preferably, during the solution process, a three-dimensional double-precision solver is selected, and a laminar flow model is selected as the solution model, such as... Figure 10 As shown, the boundary conditions for the fluid simulation of the leakage channel are as follows: the gray area represents the leakage channel region where fluid flows; the white area represents the actual contact area, through which fluid cannot flow. Pressure types are selected for both the inlet and outlet, with the outlet pressure set to 0 Pa and the inlet pressure set to the actual fluid pressure. The sealing surface is set to a no-slip boundary condition. The fluid medium parameters between the sealing surfaces include fluid density and viscosity, and the solid medium parameter is set to the metal density of the rough surface.

[0034] Example 2: A leak analysis system for the sealing interface of a flared pipe fitting, such as Figure 11 As shown, it includes: Model building module: used to build a finite element model of the macroscopic dimensional error of the flared pipe joint 1, and to obtain the pressure distribution of the sealing surface by static simulation based on the finite element model; Microscopic morphology measurement module: used to measure the microscopic morphology of the sealing surface of the flared pipe joint 1 using a surface profilometer, and to perform noise reduction processing on the microscopic morphology using wavelet transform to obtain the equivalent contact surface; Contact Deformation Calculation Module: Based on the boundary element micro-contact algorithm, using the pressure distribution of the sealing surface as the boundary condition, it solves the micro-contact deformation of the equivalent contact surface, obtains the deformation of the micro-contact of the sealing surface, and obtains the node coordinates after contact deformation based on the deformation. Leakage rate calculation module: used to construct local microscopic leakage channels on the sealing surface of the flared pipe joint 1 based on node coordinates, and then solve the three-dimensional steady-state flow field and leakage rate of the leakage channel by establishing a fluid simulation model of the leakage channel.

[0035] Preferably, such as Figure 12 As shown in the figure, this embodiment of the invention also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. Memory, used to store computer programs; When a processor executes a program stored in memory, it implements the above-mentioned method for analyzing leakage at the sealing interface of a flared pipe joint.

[0036] This invention combines finite element mechanics and fluid simulation, measured surface micromorphology reconstruction, and micro-contact boundary element algorithm to propose a method for solving the leakage rate of flared pipe joint 1. This method serves as a quantitative evaluation index for the sealing performance of flared pipe joint 1, laying the foundation for subsequent sealing reliability analysis of pipe joint 1.

[0037] Preferably, the communication bus mentioned in the above-mentioned electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the figure, but this does not indicate that there is only one bus or one type of bus.

[0038] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0039] Preferably, the memory may include random access memory (RAM), or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0040] Preferably, the processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0041] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for analyzing leakage at the sealing interface of a flared pipe joint, characterized in that, Includes the following steps: Step S1: Establish a finite element model of the flared pipe joint and use static simulation to obtain the pressure distribution on the sealing surface; Step S2: Measure the microstructure of the sealing surface of the flared pipe joint and perform noise reduction based on wavelet transform to obtain the equivalent contact surface; Step S3: Based on the boundary element micro-contact algorithm, the pressure distribution of the sealing surface is used as the boundary condition to solve the micro-contact deformation of the equivalent contact surface, obtain the deformation of the micro-contact of the sealing surface, and obtain the node coordinates after contact deformation based on the deformation. Step S4: Construct a local leakage channel on the sealing surface of the flared pipe joint based on the node coordinates, and solve the three-dimensional steady-state flow field and leakage rate of the leakage channel by establishing a fluid simulation model of the leakage channel.

2. The method for analyzing leakage at the sealing interface of a flared pipe joint according to claim 1, characterized in that, In step S1, during the mesh generation process of the finite element model, all structures are meshed using hexahedral meshes, and the mesh size of the sealing surface and threaded surface of the pipe joint is smaller than the mesh size of the other structures.

3. The method for analyzing leakage at the sealing interface of a flared pipe joint according to claim 2, characterized in that, In step S1, during the static simulation, the contact interface is divided into the contact surface and the target surface. CONTA173 and TARGE170 elements are used for meshing, respectively. The friction coefficient of all contact interfaces is set to 0.

15. The boundary conditions are defined as follows: the bottom end face of the pipe joint is fixed and constrained. During the assembly simulation, a rotation angle around the Z-axis is applied to the outer cylindrical surface of the outer sleeve nut. The simulation process is quasi-static.

4. The method for analyzing leakage at the sealing interface of a flared pipe joint according to claim 1, characterized in that, Step S2 includes the following steps: Step S21: Use an optical 3D surface profilometer to measure the sealing surface of the flared pipe joint and obtain point cloud data of the rough surface; Step S22: Reconstruct the three-dimensional surface micro-morphology based on point cloud data to obtain the micro-morphology; Step S23: Based on the wavelet multi-scale contour decomposition method, the micro-morphology is decomposed into eight layers, each layer representing a signal at a different wavelength scale. High-frequency noise signals are then removed from the signals at different wavelength scales. Finally, the remaining signals are reconstructed by wavelet to obtain the equivalent contact surface.

5. The method for analyzing leakage at the sealing interface of a flared pipe joint according to claim 1, characterized in that, Step S3 includes the following steps: Step S31: According to Johnson's assumption, the microscopic contact of the equivalent contact surface is equivalent to the contact between an equivalent rough surface and a smooth rigid plane; when the two contact surfaces are pressed against each other, according to the minimum potential energy theory, the contact problem of the equivalent rough surface is transformed into the problem of calculating the minimum complementary potential energy: （3） （4） in: Total residual potential energy; The internal residual potential energy of the entity below the surface; For a fixed surface displacement; This represents the magnitude of the surface force on the elastic body; This refers to the force-bearing range on the surface of the elastic body. For surface contact pressure distribution; This represents the normal deformation of the equivalent rough surface. The initial contact gap distribution; For the displacement of a rigid plane; Step S32: Formula (4) contains only one independent variable. Furthermore, there exists a unique contact surface pressure distribution that minimizes the system's residual potential energy. The contact deformation of the rough surface is solved using the conjugate gradient-fast Fourier transform method. Step S33: Based on the solution of the contact deformation of the rough surface, obtain the deformation of the rough surface of the flared pipe joint after being subjected to surface contact pressure.

6. A method for analyzing leakage at the sealing interface of a flared pipe joint according to claim 1 or 5, characterized in that, Step S4 includes the following steps: Step S41: Mesh the rough surface after contact deformation based on node coordinates. For the discretized rough surface after compression deformation, connect adjacent nodes in the X and Y directions in sequence, and generate a quadrilateral network model of the rough surface based on the connection between nodes. Step S42: Match the quadrilateral mesh model of the rough surface with the quadrilateral mesh nodes of the rigid plane to generate a three-dimensional mesh, and remove the meshes with zero height due to the contact between the rough surface and the rigid plane to obtain the three-dimensional mesh model of the leakage channel. Step S43: Use the fluid dynamics calculation software Fluent to solve for the three-dimensional steady-state flow field and leakage rate of the incompressible unidirectional flow in the sealing surface leakage channel.

7. A leakage analysis system for the sealing interface of a flared pipe joint, based on the leakage analysis method for the sealing interface of a flared pipe joint according to any one of claims 1-6, characterized in that, include: Model building module: used to build a finite element model of the flared pipe joint, and to obtain the pressure distribution on the sealing surface by static simulation based on the finite element model; Microscopic morphology measurement module: used to measure the microscopic morphology of the sealing surface of the flared pipe joint using a surface profilometer, and to perform noise reduction processing on the microscopic morphology using wavelet transform to obtain the equivalent contact surface; Contact Deformation Calculation Module: Based on the boundary element micro-contact algorithm, using the pressure distribution of the sealing surface as the boundary condition, it solves the micro-contact deformation of the equivalent contact surface, obtains the deformation of the micro-contact of the sealing surface, and obtains the node coordinates after contact deformation based on the deformation. Leakage rate calculation module: used to construct local microscopic leakage channels on the sealing surface of flared pipe joints based on node coordinates, and solve the three-dimensional steady-state flow field and leakage rate of the leakage channels by establishing a fluid simulation model of the leakage channels.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements a method for analyzing leakage at the sealing interface of a flared pipe joint as described in any one of claims 1-6.

9. An electronic device, characterized in that, It includes a memory and a processor; the memory stores a computer program; the processor is used to execute the computer program in the memory to implement the method for analyzing leakage at the sealing interface of a flared pipe joint as described in any one of claims 1-6.

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