A method for calculating radiation heat transfer of a temperature field of a power device and related equipment

Abstract

The application provides a kind of radiation heat transfer calculation method of power equipment temperature field and related equipment, belong to the field of power equipment simulation calculation, the method includes the following steps: obtaining the grid surface unit of power equipment model, the occlusion surface between the grid surface unit is removed to obtain radiation surface;Calculate the angle coefficient between the radiation surface, the heat exchange between the radiation surface is calculated according to the angle coefficient;According to the heat exchange between the radiation surface, establish the radiation heat transfer balance equation of microelement body, solve the radiation heat transfer balance equation, obtain the power equipment temperature field, realize radiation heat transfer calculation.The application can solve the problem of low numerical calculation precision caused by ignoring internal thermal radiation of power equipment in prior art.

Description

Technical Field

[0001] This invention belongs to the field of power equipment simulation calculation, specifically relating to a method for calculating radiative heat transfer in the temperature field of power equipment and related equipment. Background Technology

[0002] Thermal radiation is a crucial mode of heat transfer in electrical equipment, and its study is of great significance for accurately solving the temperature field of such equipment. In actual power equipment operation scenarios, the heat radiation emitting and receiving parts are mostly complex shapes, with their surfaces often being irregular planes or even curved surfaces. Previous methods for calculating thermal radiation often relied on simulation software for simplified calculations, resulting in low accuracy and slow computation.

[0003] Furthermore, current calculations of the temperature field of power equipment largely rely on commercial software. Commercial software typically ignores internal thermal radiation when solving the temperature field of power equipment, only considering external radiation, heat conduction, and heat convection. While this approach can improve the efficiency of temperature field calculations, it reduces the accuracy of the temperature field calculations. Summary of the Invention

[0004] The purpose of this invention is to provide a method and related equipment for calculating the radiative heat transfer of the temperature field of power equipment, so as to solve the problem that the existing technology ignores the internal thermal radiation of power equipment, resulting in low accuracy of temperature field numerical calculation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] Firstly, a method for calculating radiative heat transfer in the temperature field of electrical equipment includes the following steps:

[0007] Obtain the mesh surface elements of the power equipment model, and remove the occlusion surfaces between the mesh surface elements to obtain the radiation surface;

[0008] Calculate the angle coefficient between the radiating surfaces, and calculate the heat transfer between the radiating surfaces based on the angle coefficient;

[0009] Based on the heat exchange between the radiating surfaces, a radiative heat transfer balance equation for a micro-element is established. By solving the radiative heat transfer balance equation, the temperature field of the power equipment is obtained, and radiative heat transfer calculation is realized.

[0010] In some embodiments, the step of removing the obstructing surfaces between the mesh surface units to obtain the radiating surface specifically includes:

[0011] The center point and unit normal vector of the mesh surface element are solved by coordinate calculation. It is then determined whether the dot product of the unit normal vectors between the mesh surface elements is less than 0. If it is less than 0, there is a radiation relationship between the current mesh surface elements; otherwise, there is no radiation relationship.

[0012] Based on the center point, establish the equation for the line connecting the center points of the grid surface elements that have a radial relationship. Determine whether the line segment represented by the equation passes through other grid surface elements. If the line segment passes through other grid surface elements, then there is an occlusion surface between the grid surface elements that have a radial relationship; otherwise, there is no occlusion surface.

[0013] By removing the occlusion surfaces between the grid surface units that have a radiation relationship, the radiation surface is obtained.

[0014] In some embodiments, the transmittance of the radiating surface is 0, and the absorptivity of the radiating surface is equal to its emissivity.

[0015] In some embodiments, the radiative heat transfer balance equation of the micro-element is the following equation (18):

[0016] (18)

[0017] in, As a heat source, For convective heat transfer, For radiative heat exchange, Thermal conductivity, For material density, For the heat capacity of the material, For temperature, For time.

[0018] In some implementations, the step of obtaining the mesh surface elements of the power equipment model specifically includes:

[0019] The power equipment model was divided using the finite element method to obtain mesh surface elements.

[0020] In some embodiments, the step of establishing the radiative heat transfer balance equation of the micro-element based on the heat exchange between the radiating surfaces specifically includes:

[0021] Based on the heat transfer between the radiating surfaces, a heat transfer equation between the radiating surfaces is established, and the radiative heat transfer of any micro-element surface is obtained through the heat transfer equation between the radiating surfaces.

[0022] The radiative heat transfer equilibrium equation of the micro-element is established based on the radiative heat transfer of any micro-element surface.

[0023] The heat transfer equations between the radiating surfaces include the following equations (16) and (17):

[0024] (16)

[0025] (17)

[0026] in, and These represent the heat exchange capacity of different radiating surfaces. Representing a micro-element surface For micro-element surfaces angular coefficient, Representing a micro-element surface For micro-element surfaces angular coefficient, Let be the blackbody radiation constant. Let the emissivity of the infinitesimal surface be . p The reflectivity of an object For micro-element surfaces temperature, For micro-element surfaces The temperature.

[0027] Secondly, a radiative heat transfer calculation system for the temperature field of electrical equipment includes:

[0028] The occlusion removal module is used to obtain the mesh surface units of the power equipment model and remove the occlusion surfaces between the mesh surface units to obtain the radiation surface;

[0029] The radiant surface heat transfer calculation module is used to calculate the angle coefficient between the radiant surfaces and calculate the heat transfer between the radiant surfaces based on the angle coefficient.

[0030] The micro-element radiation heat transfer calculation module is used to establish the micro-element radiation heat transfer balance equation based on the heat exchange between the radiation surfaces, solve the radiation heat transfer balance equation, obtain the temperature field of the power equipment, and realize radiation heat transfer calculation.

[0031] Thirdly, a computer device includes a memory, a processor, and a computer program stored in the memory and executable in the processor, wherein the processor executes the computer program to implement the steps of the method for calculating the radiative heat transfer of the temperature field of an electrical device.

[0032] Fourthly, a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method for calculating the radiative heat transfer of a temperature field in an electrical device.

[0033] Fifthly, a computer program product, the computer product comprising a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the method for calculating the radiative heat transfer of the temperature field of an electrical device.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] This invention provides a method for calculating the radiative heat transfer of the temperature field in power equipment. After eliminating the obstructing surfaces between grid elements to obtain the radiating surfaces, the angle coefficients between these surfaces are calculated, and the heat transfer between them is calculated based on these angle coefficients. A micro-element radiative heat transfer equilibrium equation is established based on the heat transfer between the radiating surfaces, and solving this equation yields a precise temperature field inside the power equipment. This method solves the problem of low accuracy in temperature field calculations caused by neglecting internal thermal radiation in existing technologies. Furthermore, the radiative heat transfer equilibrium equation of this invention is based on the heat transfer between the radiating surfaces, rather than directly on the complex geometry of the entire power equipment, thus simplifying the calculation process.

[0036] Furthermore, this invention uses coordinate solving and center point connection equations to determine whether there is an occlusion relationship between mesh surface elements, avoiding complex geometric calculations and improving computational efficiency. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating a specific method for calculating the radiative heat transfer of a power equipment temperature field, as provided in this embodiment.

[0038] Figure 2 This is a vector relationship diagram between mesh surface elements that have a radiative relationship in this embodiment;

[0039] Figure 3 This is a schematic diagram of the shielding surface involved in this embodiment;

[0040] Figure 4 This is a schematic diagram illustrating the solution of the surface angle coefficient of the micro-element involved in this embodiment;

[0041] Figure 5 This is a schematic diagram of the absorption, reflection, and transmission of radiant energy involved in this embodiment;

[0042] Figure 6 This is a schematic diagram of the radiation surface involved in this embodiment;

[0043] Figure 7 This is a flowchart of a method for calculating radiative heat transfer in the temperature field of power equipment provided by the present invention.

[0044] Figure 8 This is a structural diagram of a radiation heat transfer calculation system for the temperature field of power equipment provided by the present invention. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. The content described herein is for explanation rather than limitation of the present invention.

[0046] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification and claims of this invention are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, systems, products, or devices.

[0047] like Figure 1 and Figure 7 As shown, this embodiment provides a method for calculating radiative heat transfer in the temperature field of power equipment, specifically including the following steps:

[0048] S1. Using commercial software, the power equipment model is meshed using finite element methods. By numbering all mesh surface elements, the positional and geometric relationships between each mesh surface element are determined, and the center point and unit normal vector of each mesh surface element are solved using coordinates.

[0049] After determining the index relationship of each mesh element, the radiation relationship between each mesh element is found using the unit normal vector of the mesh element. Specifically, for example... Figure 2 As shown, when two mesh elements have a radiating relationship, the dot product of the normal vectors of the two radiating mesh elements is less than zero. Using this as a criterion, by iterating through all mesh elements, all possible mesh elements with radiating relationships can be obtained for any given mesh element. For complex models such as power equipment, there may be other shading surfaces between mesh elements with radiating relationships, such as... Figure 3 As shown, surface a is the radiating element, surface b is the element that may have a radiative relationship with surface a, and surface c is the obstructing surface between surfaces a and b, preventing radiation from occurring between them. Therefore, the obstructed radiating surfaces need to be removed to obtain the mesh elements that actually have a radiative relationship.

[0050] To eliminate occlusion surfaces, all potentially radiating mesh elements need to be processed. Using the coordinates of the center points, the equations connecting the center points of all potentially radiating mesh elements are calculated. Then, it is verified whether the line segment represented by this equation passes through other mesh elements. If a line segment passes through a mesh element, it means there is an occlusion surface between these two mesh elements, and this occlusion surface can be eliminated. By processing all potentially radiating mesh elements using this method, all occlusion surfaces can be eliminated, revealing the mesh elements that truly exhibit radiating relationships, i.e., the radiating surfaces.

[0051] S2, after obtaining the radiating surface, solve for the angle coefficients between the infinitesimal elements. For example... Figure 4 As shown, two infinitesimal surfaces separated by a distance R have surface areas of respectively... and Their normals are n1 and n2, respectively, and the angles between the normals and the lines connecting the midpoints of the two infinitesimal surfaces are respectively... and According to Lambeth's specific law, we can obtain Towards The emitted radiant energy is

[0052] (1)

[0053] In the above formula, I n The normal radiation intensity, and has For a gray body, in addition to its own radiation, there is also reflected radiation. In the case of diffuse reflection, By the definition of solid angle, For solid angles, For the energy of radiation, there is

[0054] (2)

[0055] so,

[0056] (3)

[0057] Similarly,

[0058] (4)

[0059] (5)

[0060] So there is.

[0061] (6)

[0062] or

[0063] (7)

[0064] like and If all are finite gray body surfaces, then:

[0065] (8)

[0066] set up For micro-element surfaces For micro-element surfaces From the angle coefficient, we can deduce:

[0067] (9)

[0068] From this, the angle coefficients between all radiating surfaces can be obtained, so the heat transfer between two infinitesimal surfaces is:

[0069] (10)

[0070] The radiative force of the radiating surface is defined by the Stefan-Boltzmann law:

[0071] (11)

[0072] Let be the blackbody radiation constant, with a value of . , Let be the emissivity of the infinitesimal surface. From this, the heat transfer between two infinitesimal surfaces can be calculated. .

[0073] After calculating the heat exchange between all radiating surfaces, it is necessary to establish the radiation energy equation for each infinitesimal element. For example... Figure 5 As shown, the surface of an object responds to radiant energy There are three functions: absorption, reflection, and transmission, therefore,

[0074] (12)

[0075] in The absorptivity of the object to incident radiation is denoted as . ; The reflectivity of the object to incident radiation is denoted as . ; The transmittance of the object to incident radiation is denoted as . .

[0076] (13)

[0077] For the internal radiating surface of power equipment, transmittance When the absorptivity is 0, the emissivity equals the absorptivity, that is: = .

[0078] like Figure 6 As shown, for any set of radiating surfaces, the radiation emitted from either surface includes its own radiation and the reflection of radiation from the other surface:

[0079] (14)

[0080] (15)

[0081] Solving the system of equations simultaneously, we get:

[0082] (16)

[0083] (17)

[0084] From this, the radiative heat transfer of any infinitesimal surface can be solved, and thus the radiative heat transfer balance equation for any infinitesimal element of a power equipment can be obtained:

[0085] (18)

[0086] in, As a heat source, For convective heat transfer, For radiative heat exchange, Thermal conductivity, for, for, for, for.

[0087] Solving the above equation yields the accurate temperature field of the power equipment.

[0088] In summary, this embodiment utilizes the finite element method, combining triangulation of complex surfaces with Gaussian integration. The power equipment is divided into micro-mesh, and the radiative relationships between mesh elements are determined using the index relationships between meshes. The angular coefficients between different mesh elements are solved, transforming the radiative heat transfer between surfaces within the power equipment into radiative heat transfer between surfaces of micro-mesh elements. The radiative heat transfer equilibrium equation for the micro-element is established using the radiative heat transfer conditions between mesh elements, thereby accurately solving for the temperature field of the power equipment.

[0089] like Figure 8 As shown, this embodiment provides a radiative heat transfer calculation system for the temperature field of power equipment, including:

[0090] The occlusion removal module is used to obtain the mesh surface units of the power equipment model and remove the occlusion surfaces between the mesh surface units to obtain the radiation surface;

[0091] The occlusion removal module is specifically used to solve for the center point and unit normal vector of the mesh surface unit by coordinate calculation, and to determine whether the dot product of the unit normal vectors between the mesh surface units is less than 0. If it is less than 0, then there is a radiation relationship between the current mesh surface units; otherwise, there is no radiation relationship. Based on the center point, an equation is established for the line connecting the center points of the mesh surface units with radiation relationship. It is then determined whether the line segment represented by the equation of the line connecting the center points passes through other mesh surface units. If the line segment passes through other mesh surface units, then there is an occlusion surface between the mesh surface units with radiation relationship; otherwise, there is no occlusion surface. The occlusion surface between the mesh surface units with radiation relationship is removed to obtain the radiation surface.

[0092] The radiant surface heat transfer calculation module is used to calculate the angle coefficient between the radiant surfaces and calculate the heat transfer between the radiant surfaces based on the angle coefficient.

[0093] The micro-element radiation heat transfer calculation module is used to establish the micro-element radiation heat transfer balance equation based on the heat exchange between the radiation surfaces, solve the radiation heat transfer balance equation, obtain the temperature field of the power equipment, and realize radiation heat transfer calculation.

[0094] The micro-element radiation heat transfer calculation module is specifically used to establish a heat transfer equation between the radiation surfaces based on the heat transfer between the radiation surfaces, obtain the radiation heat transfer of any micro-element surface through the heat transfer equation between the radiation surfaces, and establish a micro-element radiation heat transfer balance equation based on the radiation heat transfer of any micro-element surface.

[0095] The module division in this embodiment of the invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0096] This embodiment also provides a computer device, which includes a processor and a memory. The memory is used to store a computer program (in this embodiment, the computer program includes a calculation component and an iterative component, capable of model calculation and model updating). The computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to realize the corresponding method flow or corresponding function. The processor described in this embodiment can be used to operate a method for calculating the radiative heat transfer of the temperature field of power equipment.

[0097] This embodiment also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the radiative heat transfer calculation method for the temperature field of a power device in the above embodiment.

[0098] This embodiment also provides a computer program product, which includes a computer program that, when executed by a processor, implements the corresponding steps of the radiative heat transfer calculation method for the temperature field of power equipment in the above embodiment.

[0099] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0100] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0101] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0102] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for calculating radiative heat transfer in the temperature field of power equipment, characterized in that, Includes the following steps: Obtain the mesh surface elements of the power equipment model, and remove the occlusion surfaces between the mesh surface elements to obtain the radiation surface; Calculate the angle coefficient between the radiating surfaces, and calculate the heat transfer between the radiating surfaces based on the angle coefficient; Based on the heat exchange between the radiating surfaces, a radiative heat transfer balance equation for a micro-element is established. By solving the radiative heat transfer balance equation, the temperature field of the power equipment is obtained, and radiative heat transfer calculation is realized. The heat transfer equilibrium equation for the infinitesimal element is as follows (18): （18） in, As a heat source, For convective heat transfer, For radiative heat exchange, Thermal conductivity, For material density, For the heat capacity of the material, For temperature, For time; The step of establishing the radiative heat transfer balance equation of the micro-element based on the heat exchange between the radiating surfaces specifically includes: Based on the heat transfer between the radiating surfaces, a heat transfer equation between the radiating surfaces is established, and the radiative heat transfer of any micro-element surface is obtained through the heat transfer equation between the radiating surfaces. The radiative heat transfer equilibrium equation of the micro-element is established based on the radiative heat transfer of any micro-element surface. The heat transfer equations between the radiating surfaces include the following equations (16) and (17): （16） （17） in, and These represent the heat exchange capacity of different radiating surfaces. Representing a micro-element surface For micro-element surfaces angular coefficient, Representing a micro-element surface For micro-element surfaces angular coefficient, Let be the blackbody radiation constant. Let the emissivity of the infinitesimal surface be . p The reflectivity of an object For micro-element surfaces temperature, For micro-element surfaces The temperature.

2. The method for calculating radiative heat transfer in the temperature field of power equipment according to claim 1, characterized in that, The step of removing the obstructing surfaces between the mesh surface units to obtain the radiating surface specifically includes: The center point and unit normal vector of the mesh surface element are solved by coordinate calculation. It is then determined whether the dot product of the unit normal vectors between the mesh surface elements is less than 0. If it is less than 0, there is a radiation relationship between the current mesh surface elements; otherwise, there is no radiation relationship. Based on the center point, establish the equation for the connection between the center points of the grid surface units that have a radial relationship. Determine whether the line segment represented by the equation for the connection between the center points passes through other grid surface units. If the line segment passes through other grid surface units, then there is an occlusion surface between the grid surface units that have a radial relationship; otherwise, there is no occlusion surface. By removing the occlusion surfaces between the grid surface units that have a radiation relationship, the radiation surface is obtained.

3. The method for calculating radiative heat transfer in the temperature field of power equipment according to claim 1, characterized in that, The transmittance of the radiating surface is 0, and the absorptivity of the radiating surface is equal to its emissivity.

4. The method for calculating radiative heat transfer in the temperature field of power equipment according to claim 1, characterized in that, The step of obtaining the mesh surface elements of the power equipment model specifically includes: The power equipment model was divided using the finite element method to obtain mesh surface elements.

5. A system for calculating radiative heat transfer in the temperature field of electrical equipment, characterized in that, A method for calculating radiative heat transfer in the temperature field of power equipment according to claims 1-4 includes: The occlusion removal module is used to obtain the mesh surface units of the power equipment model and remove the occlusion surfaces between the mesh surface units to obtain the radiation surface; The radiant surface heat transfer calculation module is used to calculate the angle coefficient between the radiant surfaces and calculate the heat transfer between the radiant surfaces based on the angle coefficient. The micro-element radiation heat transfer calculation module is used to establish the micro-element radiation heat transfer balance equation based on the heat exchange between the radiation surfaces, solve the radiation heat transfer balance equation, obtain the temperature field of the power equipment, and realize radiation heat transfer calculation.

6. A computer device, characterized in that, The device includes a memory, a processor, and a computer program stored in the memory and executable in the processor. When the processor executes the computer program, it implements the steps of the radiative heat transfer calculation method for the temperature field of an electrical device as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the radiative heat transfer calculation method for the temperature field of an electrical device as described in any one of claims 1 to 4.

8. A computer program product, said computer product comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the radiative heat transfer calculation method for the temperature field of power equipment as described in any one of claims 1 to 4.

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