Transformer ascending flanged base structure failure calculation method and related equipment

Abstract

The invention discloses a transformer ascending flanged base structure failure calculation method and related equipment, belongs to the technical field of power systems, and aims to accurately simulate oil pressure change, structural deformation and failure mechanism of extra-high voltage oil charge equipment under arc fault impact. According to the method, through a finite element-smoothed particle fluid dynamic coupling technology, in combination with a fault bubble pulsation behavior and a multi-physics field coupling action mechanism, the limitation of a traditional finite element method in processing large deformation and fracture problems is overcome, mass, momentum and energy conservation in the calculation process is ensured, and the calculation efficiency is improved. Therefore, the simulation precision of the failure behavior of the oil-filled equipment under the extreme fault condition is improved. By analyzing the stress and strain distribution of the key area of the equipment and the material failure behavior, the weak link of the equipment structure is accurately identified, and a theoretical basis and technical support are provided for optimizing the design of the transformer ascending flanged base.

Description

Technical Field

[0001] The invention belongs to the technical field of power systems, and in particular relates to a transformer riser structure failure calculation method and related equipment. Background Art

[0002] Transformers are an important part of the UHV transmission system. With the continuous increase in the installed capacity of the power grid and the scale of power generation, the voltage level and single-unit capacity of the transformer are also increasing. Once an internal short-circuit fault occurs, the sudden increase in pressure will cause the oil-filled equipment such as the riser to explode, seriously threatening the safe and stable operation of the power system. In recent years, there have been a series of explosions and fires in transformer risers, which have greatly threatened the safe and stable operation of the power grid, causing serious economic losses and adverse social impacts. Therefore, it is very important to prevent the explosion of the transformer riser under arc faults.

[0003] However, the structural failure mechanism of the transformer riser under fault impact has not been fully understood, and the relevant numerical calculation methods are not yet mature. Specifically, the existing theoretical models are mostly based on the static linear assumptions of gas generation rate and arc energy, and fail to effectively capture the dynamic pulsation behavior of fault bubbles, resulting in a large difference between the simulation and the actual test results. In addition, in the study of structural limit deformation and rupture behavior, the conventional finite element method relies on deleting units to simulate structural failure behavior. This processing method will lead to a significant reduction in calculation accuracy and is difficult to meet the reliability requirements of engineering analysis. Summary of the invention

[0004] The present invention provides a transformer riser structural failure calculation method and related equipment, which solves the problem that in the study of structural limit deformation and rupture behavior, the conventional finite element method relies on deleting units to simulate structural failure behavior. This processing method will lead to a significant reduction in calculation accuracy and it is difficult to meet the reliability requirements of engineering analysis.

[0005] To achieve the above object, the present invention provides the following technical solutions: A method for calculating failure of a transformer riser structure, comprising: Establish the solid domain geometry model and fluid domain geometry model of the transformer riser; Import the solid domain geometry model and fluid domain geometry model of the transformer riser into ANSYS software, perform meshing, obtain the solid domain mesh model and fluid domain mesh model of the transformer riser, and set the material properties of the solid domain mesh model and fluid domain mesh model of the transformer riser; Configure the solver and solution model of the fluid domain grid model, and calculate the flow field of the fluid domain grid model based on the fluid domain grid model; The solid domain mesh model is processed, and the finite element-smoothed particle fluid dynamics coupling method is used to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model to complete the failure calculation of the transformer riser structure.

[0006] Preferably, the steps of calculating the flow field of the fluid domain grid model are specifically: The Reynolds average equation model is used to describe the flow field changes, and the gas production process when an arc fault occurs in the fluid domain grid model is described according to the bubble dynamics equation. Then, the mesh quality of the fluid domain grid model is improved, and the standard The turbulence model describes the turbulence effects in the fluid domain mesh model based on the Reynolds averaged equation model, bubble dynamics equations and standard The flow field of the fluid domain grid model is obtained by coupling calculation of the turbulence model.

[0007] Preferably, the Reynolds average equation model is:

[0008] in, and is the spatial coordinate, and For different directions, is the fluid density, For time, and is the Reynolds mean velocity component, Reynolds mean velocity component The partial derivative with respect to time, is the Reynolds mean velocity component exist Direction The velocity gradient in the direction, represents the pressure field, Indicates the pressure field The direction of the component, represents the Reynolds stress tensor, represents the divergence of the Reynolds stress tensor, is the dynamic viscosity of the fluid.

[0009] Preferably, the bubble dynamics equation is:

[0010] in, , , represent the bubble radius, bubble expansion speed and bubble expansion acceleration respectively, is the initial radius of the bubble, is the specific heat ratio, is the fluid density, is the fluid dynamic viscosity, and is the maximum and minimum time value, For and Integrate within the range, is the arc energy conversion coefficient, is the arc energy, is the pressure at the fluid boundary, represents the bubble surface tension term, is the surface tension coefficient of the gas-liquid interface, is the internal energy of the bubble at the moment of its generation, is the surface tension coefficient of the fluid, is the integral symbol, represents the integration variable.

[0011] Preferably, the standard The turbulence model is: Turbulent Kinetic Energy It describes the generation, diffusion and dissipation of turbulent energy and is expressed as:

[0012] in, represents the velocity components of the fluid in all directions, Indicated in Direction partial derivative, Indicated in Direction partial derivative, represents the fluid dynamic viscosity, represents the viscosity coefficient of the turbulence model, is the turbulent Prandtl number of the turbulent kinetic energy, , is the turbulent kinetic energy generated by shear stress and velocity gradient, is the turbulence frequency; Turbulence frequency Describes the change in turbulence scale and is expressed as:

[0013] in, , , is the dissipation term of the turbulence frequency, , k is the turbulent kinetic energy.

[0014] Preferably, the steps of processing the solid domain network model are specifically as follows: Based on the BWH failure criterion and the solid domain of the transformer riser, the plastic deformation and failure of the geometric model of the solid domain of the transformer riser are obtained. According to the plastic deformation and failure of the geometric model of the solid domain of the transformer riser, the failure unit is obtained and the failure unit is converted into a smooth particle, and virtual particles are obtained based on the smooth particle. The basic form of the BWH failure criterion is:

[0015] in, represents the first principal stress at the failure point, and They represent the strength coefficient and hardening index of the material respectively, is the necking strain measured by the single-phase tensile test, Represents the ratio of the two principal strain rates of a planar element.

[0016] Preferably, the finite element-smoothed particle fluid dynamics coupling method is used to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model, and the steps for completing the transformer riser structure failure calculation are specifically as follows: The oil pressure load transfer under the arc fault inside the transformer riser is realized through the coupling interface, and then the smooth particle fluid dynamics equation is obtained based on the flow field, smooth particles and virtual particles of the fluid domain mesh model. The failure behavior of the transformer riser structure is simulated according to the smooth particle fluid dynamics equation. The equation for smooth particle hydrodynamics is:

[0017]

[0018]

[0019] in, Represents particles The density of Represents particles The square of the density, Represents particles The square of the density, Represents particles Quality, Represents particles The number of real particles in the influence domain, Represents particles The number of virtual particles in the affected domain, and Represents particles and particles exist The velocity component in the direction, =1,2,3 correspond to direction, is the kernel function, Represents the kernel function Particle Coordinates The partial derivative of Represents particles exist The acceleration in the direction, and Represents particles and particles The stress tensor components of is the symbol of the Kronecker function, when = 1 if yes, 0 otherwise. Represents particles The rate of change of internal energy with time, Represents particles and particles exist The speed difference in direction, is an artificial viscosity term.

[0020] A transformer riser structure failure calculation system, comprising: Modeling module: used to establish the solid domain geometry model and fluid domain geometry model of the transformer riser; Partition module: used to import the solid domain geometry model and fluid domain geometry model of the transformer riser into ANSYS software, perform mesh division, obtain the solid domain mesh model and fluid domain mesh model of the transformer riser, and set the material properties of the solid domain mesh model and fluid domain mesh model of the transformer riser; Solving module: used to configure the solver and solving model of the fluid domain grid model, and calculate the flow field of the fluid domain grid model based on the fluid domain grid model; Simulation module: used to process the solid domain mesh model, and use the finite element-smoothed particle fluid dynamics coupling method to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model to complete the transformer riser structure failure calculation.

[0021] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of a method for calculating the structural failure of a transformer riser are implemented.

[0022] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of a method for calculating the failure of a transformer riser structure are implemented.

[0023] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides a method for calculating the structural failure of a transformer riser. Through the finite element-smoothed particle fluid dynamics coupling technology, the oil pressure change and structural deformation of the transformer riser under an arc fault can be accurately simulated, and the internal structural failure mechanism of the oil filling equipment under the action of the arc is revealed. The present invention takes into account the dynamic pulsation behavior of the fault bubbles and the multi-physical field coupling mechanism, and can accurately obtain the weak areas of the transformer riser structure and its rupture behavior under arc faults at different positions and energies, and reproduce its structural failure behavior.

[0024] The present invention effectively overcomes the limitations of the traditional finite element method when dealing with large deformations or even rupture problems. The traditional finite element method usually simulates the destructive behavior of the structure by deleting the failed unit. However, this processing method inevitably causes the non-conservation of the system's mass, momentum and energy, resulting in a significant decrease in calculation accuracy and difficulty in obtaining accurate results. In contrast, the finite element-smoothed particle fluid dynamics coupling method of the present invention converts the unit into a smooth particle after the unit fails, inherits the physical properties of the failed unit, and ensures the conservation of mass, momentum and energy during the calculation process, thereby significantly improving the simulation accuracy and reliability of the failure behavior of complex structures under extreme conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a model diagram of an oil-immersed transformer riser according to an embodiment of the present invention, wherein Figure a is a geometric model diagram and Figure b is a mesh division diagram.

[0026] Figure 2 The present invention provides a calculation flow chart of a transformer riser structure failure calculation method according to an embodiment of the present invention.

[0027] Figure 3 This is a curve diagram of oil pressure variation under an arc fault inside the riser of an embodiment of the present invention.

[0028] Figure 4 The strain distribution of the lifting seat structure at different time points after a fault occurs in the embodiment of the present invention, wherein Figure a is When hour.

[0029] Figure 5 The present invention is a block diagram of a transformer riser structure failure calculation system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] See also Figure 1 The oil-immersed transformer riser with a diameter of 600 mm and a height of 1000 mm was used as the research object. The wall material of the riser was structural steel with a density of 7850 kg / m 3 , the shear modulus is 7.3×10 10 Pa, Young's modulus is 2.1×10 11 Pa, Poisson's ratio is 0.3, and yield strength is 339MPa.

[0035] like Figure 2 As shown, the present invention provides a method for calculating the failure of a transformer riser structure, comprising the following steps: (1) Establish the solid domain geometry model and fluid domain geometry model of the transformer riser; (2) Import the solid domain geometry model and fluid domain geometry model of the transformer riser into ANSYS software, perform meshing, obtain the solid domain mesh model and fluid domain mesh model of the transformer riser, and set the material properties of the solid domain mesh model and fluid domain mesh model of the transformer riser; (3) configuring the solver and solution model of the fluid domain mesh model, and calculating the flow field of the fluid domain mesh model based on the fluid domain mesh model; (4) The solid domain mesh model is processed, and the finite element-smoothed particle fluid dynamics coupling method is used to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model to complete the failure calculation of the transformer riser structure.

[0036] Furthermore, the step (1) is specifically as follows: The solid domain geometric model and fluid domain geometric model of the 1:1 transformer riser are established using Spacecliam software. Note that in order to reduce the amount of calculation while meeting the requirements of simulation calculation accuracy, the original physical model is reasonably simplified to a certain extent.

[0037] Furthermore, the step (2) includes the following steps: Import the established solid domain geometry model and fluid domain geometry model of the transformer riser into ANSYS software, mesh the solid domain geometry model and fluid domain geometry model of the transformer riser, encrypt the mesh in key areas, and check and adjust the mesh quality; Set the material properties of the solid and fluid domains of the transformer riser to structural steel with a density of 7850 kg / m 3 , the shear modulus is 7.3×10 10 Pa, Young's modulus is 2.1×10 11 Pa, Poisson's ratio is 0.3, and yield strength is 339MPa.

[0038] Furthermore, the step (3) includes the following steps: Set the solver of the fluid domain mesh model to a transient solver; The Reynolds averaged equations model (RANS) is used to describe the flow field changes of the fluid domain grid model: (1) in, and is the spatial coordinate, and For different directions, ρ is the fluid density, For time, and is the Reynolds mean velocity component, Reynolds mean velocity component The partial derivative with respect to time, is the Reynolds mean velocity component exist Direction The velocity gradient in the direction, represents the pressure field, Indicates the pressure field i The direction component, represents the Reynolds stress tensor, represents the divergence of the Reynolds stress tensor.

[0039] Furthermore, the gas generation process when an arc fault occurs in the fluid domain grid model is described according to the bubble dynamics equation. The bubble dynamics equation is:

[0040] in, , , represent the bubble radius, bubble expansion speed and bubble expansion acceleration respectively, is the initial radius of the bubble, is the specific heat ratio, is the fluid density, is the fluid dynamic viscosity, and is the maximum and minimum time value, For , is the arc energy conversion coefficient, is the arc energy, is the pressure at the fluid boundary, represents the bubble surface tension term, is the surface tension coefficient of the gas-liquid interface, is the internal energy of the bubble at the moment of its generation, is the surface tension coefficient of the fluid, is the integral symbol, represents the integration variable.

[0041] Furthermore, in order to determine the quality of all meshes and re-divide the meshes with lower quality when the boundary of the target area changes, the mesh diffusion smoothing model is used to determine the motion displacement of the mesh nodes, which is specifically expressed as: (3) In the formula, is the vector differential operator, is the grid movement speed, is the diffusion coefficient, expressed as: (4) In the formula, d is the distance between the regularized grid node and the boundary, a Set the diffusion parameter in the panel for scattered light, with a value range of 0~2.

[0042] After solving the mesh motion velocity, the position of the mesh node at the next time step is expressed as: (5) In the formula, and are the positions of the grid nodes in the next time step and this time step respectively, It is the time difference between the next time and the current time of the grid node.

[0043] Furthermore, based on the Reynolds average equation model, bubble dynamics equation and standard The coupling calculation of the turbulence model obtains the flow field of the fluid domain grid model; standard The turbulence model is: Turbulent Kinetic Energy k It describes the generation, diffusion and dissipation of turbulent energy and is expressed as: (6) in, Indicated in Direction partial derivative, Indicated in Direction partial derivative, represents the fluid dynamic viscosity, represents the viscosity coefficient of the turbulence model, is the turbulent Prandtl number of the turbulent kinetic energy, , is the turbulent kinetic energy generated by shear stress and velocity gradient, is the turbulence frequency, Obtained from the RANS equations (inside the fluid) and the bubble dynamics equations (fluid boundary).

[0044] Turbulence frequency Describes the change in turbulence scale and is expressed as:

[0045] in, , , is the dissipation term of the turbulence frequency, , k is the turbulent kinetic energy.

[0046] Furthermore, the step (4) comprises the following steps: Based on the BWH failure criterion and the solid domain mesh model, the plastic deformation and failure of the solid domain mesh model are obtained. The failure unit is converted into a smooth particle based on the plastic deformation and failure of the solid domain mesh model. The virtual particle is obtained based on the smooth particle. The core idea is that the failure of the material depends not only on a single stress component (such as the maximum principal stress or the maximum shear stress), but is related to the comprehensive stress state under the multi-axial stress state. This criterion introduces the concept of equivalent stress to convert the complex multi-axial stress state into an equivalent uniaxial stress state, so as to determine whether the material will fail. Its basic form is: (8) In the formula, represents the first principal stress at the failure point, and They represent the strength coefficient and hardening index of the material respectively, The necking strain measured by the single-phase tensile test is usually taken as It represents the ratio of the two principal strain rates of the plane element, that is: .

[0047] Assuming that the yield function is consistent with the plastic flow potential, the relationship between strain rate and stress can be expressed as: (9) in, represents the plastic strain rate, represents the stress tensor, represents the plasticity multiplier, f represents the yield function, represents the yield function f Stress tensor The partial derivative of .

[0048] Strain rate and principal stress and The relationship is expressed as: (10) in, represents the ratio of the principal stresses, Represents the ratio of the two principal strain rates of a planar element.

[0049] Furthermore, the finite element-smoothed particle fluid dynamics coupling method is used to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model to complete the failure calculation of the transformer riser structure.

[0050] The oil pressure load transfer under arc fault in the solid domain mesh model is realized through the coupling interface. When the finite element unit meets the failure criterion, the failed unit is transformed into a smooth particle through the conversion algorithm and continues to participate in the calculation. These particles will inherit the mass, velocity, position, stress tensor and other information of the failed unit to ensure the conservation of mass, momentum and energy during the calculation process.

[0051] Use the following formula to determine whether it is considered a virtual particle: (11) In the formula, The center of gravity of the finite element to the smooth particle The distance between the centers, is the expansion coefficient, is the radius of influence of the smooth particle, and ,in, For particles If the smooth length satisfies equation (11), the finite element is regarded as a virtual particle.

[0052] After the virtual particles are generated, the mass and density Satisfy the following formula: (12) Among them, the subscript and denote the virtual particle and finite element numbers, respectively. and Represent the virtual particles and finite element unit numbers respectively.

[0053] The stress of virtual particles is the same as that of finite element units and is expressed as: (13) Among them, the superscript represents the components of the stress tensor along different directions. and denote the virtual particle and finite element numbers, respectively. and Represent the virtual particles and finite element unit numbers respectively.

[0054] After taking into account virtual particles, the equation of smooth particle hydrodynamics can be transformed into: (14) (15) (16) Where, for the density update equation (14), Represents particles The density of Represents particles The square of the density, Represents particles The square of the density, Represents particles Quality, Represents particles The number of real particles in the influence domain, Represents particles The number of virtual particles in the affected domain, and Represents particles and particles exist The velocity component in the direction ( =1,2,3 correspond to direction), kernel function To describe particles and particles The interaction between Represents the kernel function Particle Coordinates The partial derivative of .

[0055] For the momentum update equation (15), Represents particles exist Acceleration in the direction ( =1,2,3 correspond to direction), and Represents particles and particles The stress tensor components of is the symbol of Kronecker delta (Kronecker function), when = 1 if yes, 0 otherwise. is an artificial viscosity term.

[0056] For the energy update equation (16), Represents particles The rate of change of internal energy with time, Represents particles and particles exist a Speed ​​difference in direction.

[0057] Replace the nodal loads in the finite element equations of motion with nodal contact forces: (18) in, is the finite element contact force matrix, K, C , M denote the stiffness matrix, damping matrix and mass matrix respectively, express Moment displacement.

[0058] The present invention successfully simulates the oil pressure change and structural failure process inside the equipment when an arc fault occurs in the transformer riser through finite element-smoothed particle fluid dynamics coupling technology and simulation calculation. This method reproduces the impact of the sudden increase in oil pressure caused by the arc fault on the oil-filled equipment structure, and deeply reveals the weak areas and structural damage mechanism of the equipment under high-energy fault impact. This technology provides accurate mechanical analysis and dynamic response data support for the explosion-proof design of the transformer riser, and can effectively quantify the pressure change and equipment failure risk under fault conditions.

[0059] Figure 3 and Figure 4 The simulation calculation results based on the finite element-smoothed particle fluid dynamics coupling method in the specific embodiment of the present invention reveal the oil pressure change and structural strain distribution of the transformer riser under the impact of an arc fault. Figure 3 The curves showing the change of oil pressure over time at measuring point 1 (located in the middle of the bushing) and measuring point 2 (located in the geometric center of the hand hole of the transformer riser). Figure 3 It shows that the oil pressure at measuring point 2 rises rapidly after the fault and reaches a peak value of nearly 1.7MPa at about 10ms, while the oil pressure at measuring point 1 rises slowly and has a lower peak value, indicating that the transformer riser area has been subjected to a greater pressure shock. This difference also reflects the uneven pressure distribution in different structural areas under arc faults. Figure 4 The figure shows the strain distribution of the transformer riser structure at different time points after the fault occurs. t =5ms, the strain of the structure is concentrated in the middle area of ​​the transformer riser, and the strain value is relatively low. t =11.9ms, the strain in the transformer riser area increased significantly, and large-scale plastic deformation and rupture occurred, indicating that the transformer riser structure had failed under high voltage. The above quantitative analysis results not only verify the effectiveness of the finite element-smoothed particle fluid dynamics coupling method in simulating structural failure behavior under arc faults, but also provide a reliable numerical basis for evaluating the safety of key parts of the transformer riser and improving the design.

[0060] like Figure 5 As shown, the present invention provides a transformer riser structure failure calculation system, comprising: Modeling module: used to establish the solid domain geometry model and fluid domain geometry model of the transformer riser; Partition module: used to import the solid domain geometry model and fluid domain geometry model of the transformer riser into ANSYS software, perform mesh division, obtain the solid domain mesh model and fluid domain mesh model of the transformer riser, and set the material properties of the solid domain mesh model and fluid domain mesh model of the transformer riser; Solving module: used to configure the solver and solving model of the fluid domain grid model, and calculate the flow field of the fluid domain grid model based on the fluid domain grid model; Simulation module: used to process the solid domain mesh model, and use the finite element-smoothed particle fluid dynamics coupling method to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model to complete the transformer riser structure failure calculation.

[0061] A terminal device is provided in one embodiment of the present invention. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0062] The computer program may be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to accomplish the present invention.

[0063] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0064] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0065] The memory may be used to store the computer programs and / or modules, and the processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory.

[0066] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0067] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields, and the above-mentioned specific embodiments are only illustrative and instructive, rather than restrictive. Under the guidance of the specification, a person skilled in the art can also make many forms without departing from the scope of protection of the claims of the present invention, all of which belong to the scope of protection of the present invention.

Claims

1. A method for calculating the failure of a transformer riser structure, characterized in that: include: Establish the solid domain geometry model and fluid domain geometry model of the transformer riser; Import the solid domain geometry model and fluid domain geometry model of the transformer riser into ANSYS software, perform meshing, obtain the solid domain mesh model and fluid domain mesh model of the transformer riser, and set the material properties of the solid domain mesh model and fluid domain mesh model of the transformer riser; Configure the solver and solution model of the fluid domain grid model, and calculate the flow field of the fluid domain grid model based on the fluid domain grid model; The solid domain mesh model is processed, and the finite element-smoothed particle fluid dynamics coupling method is used to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model to complete the failure calculation of the transformer riser structure.

2. A transformer riser structure failure calculation method according to claim 1, characterized in that: The steps for calculating the flow field of the fluid domain mesh model are as follows: The Reynolds average equation model is used to describe the flow field changes, and the gas production process when an arc fault occurs in the fluid domain grid model is described according to the bubble dynamics equation. Then, the mesh quality of the fluid domain grid model is improved, and the standard The turbulence model describes the turbulence effects in the fluid domain mesh model based on the Reynolds averaged equation model, bubble dynamics equations and standard The flow field of the fluid domain mesh model is obtained by coupling calculation of the turbulence model.

3. A transformer riser structure failure calculation method according to claim 2, characterized in that: The Reynolds average equation model is: in, and is the spatial coordinate, and For different directions, is the fluid density, For time, and is the Reynolds mean velocity component, Reynolds mean velocity component The partial derivative with respect to time, is the Reynolds mean velocity component exist Direction The velocity gradient in the direction, represents the pressure field, Indicates the pressure field The direction component, represents the Reynolds stress tensor, represents the divergence of the Reynolds stress tensor, is the dynamic viscosity of the fluid.

4. A transformer riser structure failure calculation method according to claim 2, characterized in that: The bubble dynamics equation is: in, , , represent the bubble radius, bubble expansion speed and bubble expansion acceleration respectively, is the initial radius of the bubble, is the specific heat ratio, is the fluid density, is the fluid dynamic viscosity, and is the maximum and minimum time value, For and Integrate within the range, is the arc energy conversion coefficient, is the arc energy, is the pressure at the fluid boundary, represents the bubble surface tension term, is the surface tension coefficient of the gas-liquid interface, is the internal energy of the bubble at the moment of its generation, is the surface tension coefficient of the fluid, is the integral symbol, represents the integration variable.

5. A transformer riser structure failure calculation method according to claim 2, characterized in that: standard The turbulence model is: Turbulent Kinetic Energy It describes the generation, diffusion and dissipation of turbulent energy and is expressed as: in, represents the velocity components of the fluid in all directions, Indicated in Direction partial derivative, Indicated in Direction partial derivative, represents the fluid dynamic viscosity, represents the viscosity coefficient of the turbulence model, is the turbulent Prandtl number of the turbulent kinetic energy, , is the turbulent kinetic energy generated by shear stress and velocity gradient, is the turbulence frequency; Turbulence frequency Describes the change in turbulence scale and is expressed as: in, , , is the dissipation term of the turbulence frequency, , k is the turbulent kinetic energy.

6. A transformer riser structure failure calculation method according to claim 1, characterized in that: The specific steps for processing the solid domain network model are: Based on the BWH failure criterion and the solid domain network model, the plastic deformation and failure of the solid domain network model are obtained, and the failure unit is obtained according to the plastic deformation and failure of the solid domain network model, and the failure unit is converted into a smooth particle, and a virtual particle is obtained based on the smooth particle; The basic form of the BWH failure criterion is: in, represents the first principal stress at the failure point, and Respectively represent the strength coefficient and hardening index of the material, is the necking strain measured by the single-phase tensile test, Represents the ratio of the two principal strain rates of a planar element.

7. A transformer riser structure failure calculation method according to claim 6, characterized in that: The finite element-smoothed particle fluid dynamics coupling method is used to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model. The steps to complete the failure calculation of the transformer riser structure are as follows: The oil pressure load transfer under arc fault in the solid domain mesh model is realized through the coupling interface, and the smooth particle fluid dynamics equation is obtained based on the flow field, smooth particles and virtual particles of the fluid domain mesh model. The failure behavior of the transformer riser structure is simulated according to the smooth particle fluid dynamics equation. The equation for smooth particle hydrodynamics is: in, Represents particles The density of Represents particles The square of the density, Represents particles The square of the density, Represents particles Quality, Represents particles The number of real particles in the influence domain, Represents particles The number of virtual particles in the affected domain, and Represents particles and particles exist The velocity component in the direction, =1,2,3 correspond to direction, is the kernel function, Represents the kernel function Particle Coordinates The partial derivative of Represents particles exist The acceleration in the direction, and Represents particles and particles The stress tensor components of is the symbol of the Kronecker function, when = 1 if yes, 0 otherwise. Represents particles The rate of change of internal energy with time, Represents particles and particles exist The speed difference in direction, is an artificial viscosity term.

8. A transformer riser structure failure calculation system, characterized in that: include: Modeling module: used to establish the solid domain geometry model and fluid domain geometry model of the transformer riser; Partition module: used to import the solid domain geometry model and fluid domain geometry model of the transformer riser into ANSYS software, perform mesh division, obtain the solid domain mesh model and fluid domain mesh model of the transformer riser, and set the material properties of the solid domain mesh model and fluid domain mesh model of the transformer riser; Solving module: used to configure the solver and solving model of the fluid domain grid model, and calculate the flow field of the fluid domain grid model based on the fluid domain grid model; Simulation module: used to process the solid domain mesh model, and use the finite element-smoothed particle fluid dynamics coupling method to couple the flow field of the fluid domain mesh model and the processed solid domain mesh model to complete the transformer riser structure failure calculation.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the transformer riser structure failure calculation method as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of a transformer riser structure failure calculation method as described in any one of claims 1 to 7 are implemented.

Images