Thermal simulation analysis method and device for superconducting power equipment body, medium and program product

Abstract

The invention relates to a thermal simulation analysis method, device, medium and program product for a superconductive power equipment body, which accurately discovers potential thermal problems and weak links by analyzing the heat exchange difference of different areas of a coil and the temperature and flow condition of liquid nitrogen. The simulation analysis method comprises the following steps: removing a framework and a connecting piece, simplifying a winding coil and a liquid nitrogen inlet and outlet structure, constructing a basic model, and dividing grids; the heat leakage equivalent heat flow boundary is added to the wall surface according to the Dewar and sleeve heat transfer conditions, and the alternating current loss is determined according to the equipment characteristics and is applied to the coil winding; setting liquid nitrogen inlet and outlet boundary types, selecting a turbulence model and algorithm, considering gravity and carrying out simulation operation in a steady state; and comprehensively analyzing the characteristics and association, and evaluating the thermal simulation condition. Compared with the prior art, the thermal simulation analysis method for the superconducting power equipment body is more accurate, comprehensive and systematic, the blank of the prior art is filled, and further development of the superconducting power equipment manufacturing technology is promoted.

Description

Technical Field

[0001] The present invention relates to the manufacturing technology of superconducting power equipment such as superconducting reactors, and in particular to a thermal simulation analysis method, device, medium, and program product for the superconducting power equipment body. Background Art

[0002] As a newly proposed superconducting power equipment, the superconducting reactor applies the second-generation high-temperature superconducting tape operating in the liquid nitrogen temperature range to the working winding of a conventional reactor. During operation, its working performance is closely related to temperature. With the development of superconducting technology, the precise control of the operating temperature of superconducting reactors has become an important problem to be solved urgently.

[0003] Traditional research on the temperature control of superconducting power equipment mostly focuses on the simple correlation between the self-characteristics of superconducting materials and external cooling systems, lacking in-depth and systematic analysis of the complex heat exchange process inside superconducting power equipment. For example, previous research often ignores the influence of structures such as coil windings inside superconducting power equipment on heat conduction, as well as the fine flow field and temperature field distribution characteristics during the flow and heat exchange of liquid nitrogen in the dewar.

[0004] In addition, there are many deficiencies in the existing thermal simulation analysis methods. Either the model construction is too rough to accurately reflect the true structure and thermal behavior of superconducting power equipment; or the boundary conditions are set unreasonably, without fully considering key factors such as heat leakage changes and AC losses in actual working conditions; or the definition of material properties is inaccurate, resulting in a large deviation between the thermal simulation results and the actual situation. Therefore, there is an urgent need for a more accurate, comprehensive, and systematic thermal simulation analysis method for the superconducting power equipment body to fill the gaps in the existing technology and promote the further development of superconducting power equipment manufacturing technology. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a thermal simulation analysis method, device, medium, and program product for the superconducting power equipment body, providing a more accurate, comprehensive, and systematic thermal simulation analysis method for the superconducting power equipment body, filling the gaps in the existing technology and promoting the further development of superconducting power equipment manufacturing technology.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The first aspect of the present invention provides a thermal simulation analysis method for the superconducting power equipment body, including the following steps:

[0008] S1. Model construction and mesh generation: Remove the skeleton and connectors of the superconducting power equipment, simplify the winding coils into corresponding geometric shapes, select the liquid nitrogen region, and simplify the liquid nitrogen inlet and outlet structures to construct a basic model;

[0009] S2. Boundary condition setting: Considering comprehensively the heat transfer conditions of the Dewar and the casing during actual operation, the heat leakage is equivalent to a heat flux boundary applied to the wall surface. At the same time, the AC loss is determined according to the operating characteristics of the superconducting power equipment and applied to the coil winding.

[0010] S3. Material property setting: Select appropriate materials to replace the superconducting tape for property setting.

[0011] S4. Simulation operation: According to the principles of fluid mechanics and heat transfer, for the liquid nitrogen inlet, set the boundary types related to velocity and temperature, and for the outlet, set the corresponding boundary types. Select the turbulence model and algorithm, and at the same time consider the gravity factor and limit it to the steady state to carry out the simulation operation.

[0012] S5: During the simulation process, collect the data of the superconducting power equipment according to the set wall and coil heat conditions, including the coil temperature distribution, surface heat flux density, liquid nitrogen temperature and flow velocity distribution. Comprehensively analyze the characteristics and correlations of the collected data of the superconducting power equipment to evaluate the thermal simulation status of the superconducting power equipment body.

[0013] Further, in the S1 model construction step, the winding coil is simplified into regular geometric bodies such as racetrack-shaped cakes and coaxial cylinders.

[0014] Further, in the S1 model construction step, the coil is simplified into regular geometric bodies such as racetrack-shaped cakes and coaxial cylinders.

[0015] Further, in the S1 model construction step, the liquid nitrogen inlet and outlet of the bellows structure are simplified into straight pipes.

[0016] Further, in the S3 boundary condition setting step, the heat flux boundary value equivalent to the heat leakage of the Dewar and the casing is higher than the theoretically calculated heat leakage value and a certain margin is reserved.

[0017] Further, in the S4 material property setting step, since the base Hastelloy accounts for most of the thickness of the high-temperature superconducting tape and its thermal properties are similar to those of stainless steel, stainless steel is used to replace the superconducting tape.

[0018] Further, in the S5 simulation operation step, a constant flow velocity and temperature are set at the liquid nitrogen inlet, the outlet is set as the outflow boundary, and the SST k-omega turbulence model and the Coupled algorithm are used.

[0019] Further, in the process of comprehensively analyzing the characteristics and correlations of the collected data of the superconducting power equipment in S5, the thermal simulation status is evaluated by analyzing the difference in heat transfer characteristics between the edge area and the flat area of the coil and the temperature uniformity and flow mixing of the liquid nitrogen in the Dewar except for the upper inlet area.

[0020] In the second aspect of the present invention, an electronic device is provided, including a memory and a processor, and the processor is configured to execute a program in the memory to implement the superconducting power device body thermal simulation analysis method as described above.

[0021] In the third aspect of the present invention, a storage medium containing computer-executable instructions is provided. When the computer-executable instructions in the storage medium are executed by a computer processor, they are used to execute the superconducting power device body thermal simulation analysis method as described above.

[0022] In the fourth aspect of the present invention, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, it implements the superconducting power device body thermal simulation analysis method as described above.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) Through reasonable simplification of the superconducting power device model, such as simplification of winding coils, liquid nitrogen inlet and outlet structures, etc., the model complexity is reduced on the premise of ensuring the simulation of key thermal characteristics, effectively reducing the simulation calculation amount and time cost, and significantly improving the simulation efficiency. At the same time, by accurately setting boundary conditions, equivalent leakage heat and margin reservation, and accurate application of AC losses, the actual operating thermal environment of the device can be more realistically simulated, making the simulation results more reliable and accurate, providing strong data support and theoretical basis for the design optimization, performance evaluation and safe operation of superconducting power devices.

[0025] 2) Using appropriate materials to replace superconducting tapes for property settings, scientifically selecting turbulence models, algorithms and reasonably setting boundary types not only improves the operability of the simulation process, but also can deeply analyze the heat transfer and flow characteristics inside the device. For example, by analyzing the heat transfer differences in different regions of the coil and the temperature and flow conditions of liquid nitrogen, it helps to accurately discover potential thermal problems and weak links, thus providing a targeted direction for the research and improvement of superconducting power devices, strongly promoting the development and application of superconducting power device technology, reducing research and operation and maintenance costs, and improving economic benefits. Description of the Drawings

[0026] Figure 1 It is a sample diagram of the simulation simplified model;

[0027] Figure 2 It is a sample diagram of the simulation mesh division;

[0028] Figure 3 In it: (a) Sample diagram of the temperature distribution of the coil and liquid nitrogen, (b) Sample diagram of the heat flux density distribution on the coil surface;

[0029] Figure 4 In it: (a) Liquid nitrogen flow velocity distribution in the dewar, (b) Liquid nitrogen velocity vector distribution in the dewar. Detailed implementation mode

[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. For the component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution, they are regarded as common technical features disclosed in the prior art.

[0031] Embodiment 1

[0032] This embodiment provides a thermal simulation analysis method for a superconducting power equipment body, including the following steps:

[0033] S1. Model construction and mesh generation: Remove the skeleton and connectors of the superconducting power equipment, simplify the winding coils into corresponding geometric shapes, select the liquid nitrogen area and simplify the liquid nitrogen inlet and outlet structures to construct a basic model;

[0034] The winding coils are simplified into regular geometric bodies such as racetrack-shaped cakes and coaxial cylinders. In the S1 model construction step, the coils are simplified into regular geometric bodies such as racetrack-shaped cakes and coaxial cylinders. The liquid nitrogen inlet and outlet with a bellows structure are simplified into straight pipes.

[0035] During model construction and mesh generation, remove the complex skeletons and connectors in the superconducting power equipment that have relatively minor impacts on the overall thermal simulation to reduce the model complexity. For the winding coils, based on their shape characteristics and thermal simulation requirements, they are simplified into regular geometric bodies such as racetrack-shaped cakes and coaxial cylinders. This simplification method facilitates subsequent thermal characteristic analysis and mesh generation operations for the coils. For the liquid nitrogen inlet and outlet structure, since the bellows structure may introduce unnecessary complex geometric factors in thermal simulation, it is simplified into a straight pipe, which not only retains the basic functions of liquid nitrogen inlet and outlet and the simulation elements of heat exchange characteristics, but also greatly simplifies the model structure, making the constructed basic model easier to perform mesh generation processing while effectively reflecting the key thermal behaviors of the superconducting power equipment.

[0036] S2. Boundary condition setting: Considering the heat transfer conditions of the cryostat and the bushing during actual operation, the heat leakage is equivalently regarded as a heat flux boundary applied to the wall surface, and at the same time, the AC loss is determined according to the operating characteristics of the superconducting power equipment and applied to the coil windings.

[0037] S3. Material property setting: Select appropriate materials to replace the superconducting tape for property setting;

[0038] In the S3 boundary condition setting step, the heat flux boundary value equivalent to the heat leakage of the cryostat and the bushing is higher than the theoretically calculated heat leakage value and a certain margin is reserved.

[0039] Due to the special physical properties of superconducting tapes and their relatively complex structural composition, stainless steel with similar thermal properties to the Hastelloy substrate of superconducting tapes is selected to replace the superconducting tapes for property settings during thermal simulation. This can simplify the difficulty and complexity of material property settings while ensuring a certain degree of accuracy in simulating the heat transfer process, making the simulation calculation easier to implement. At the same time, when considering the boundary condition settings for heat leakage from the dewar and the casing, when it is equivalent to a heat flux boundary, the set value is higher than the theoretically calculated heat leakage value and a certain margin is reserved. This is because in the actual operating environment, there are many uncertain factors, such as external environmental fluctuations and heat transfer changes caused by equipment aging. Reserving a margin can ensure that the thermal simulation boundary conditions cover a wider range of actual possible situations.

[0040] S4. Simulation operation: Based on the principles of fluid mechanics and heat transfer, set the boundary types related to velocity and temperature for the liquid nitrogen inlet, set the corresponding boundary types for the outlet, select the turbulence model and algorithm, and at the same time consider the gravity factor and limit it to the steady-state situation to carry out the simulation operation;

[0041] In the material property setting step of S4, since the Hastelloy substrate accounts for most of the thickness of the high-temperature superconducting tape and its thermal properties are similar to those of stainless steel, stainless steel is used to replace the superconducting tape.

[0042] Based on the principles of fluid mechanics and heat transfer, set the boundary types related to velocity and temperature for the liquid nitrogen inlet, such as specific flow velocity and temperature values, to simulate the initial conditions of the actual liquid nitrogen inflow. Set the corresponding boundary types for the outlet to ensure the integrity and rationality of the fluid domain calculation. Select turbulence models such as SST k-omega to accurately characterize the turbulent flow characteristics of liquid nitrogen in superconducting power equipment. Use the Coupled algorithm to realize the coupled calculation of the flow field and the temperature field, fully consider the influence of the gravity factor on the natural convection of liquid nitrogen, and limit it to the steady-state situation to simplify the calculation complexity and focus on the thermal characteristic analysis under the stable operating state. In terms of material property settings, since the Hastelloy substrate accounts for a large proportion in the high-temperature superconducting tape and its thermal properties are similar to those of stainless steel, stainless steel is used to replace the superconducting tape. This can not only effectively characterize the key thermal properties such as heat conduction of the superconducting tape in thermal simulation, but also facilitate the unified material property setting and calculation in the entire simulation system.

[0043] S5: During the simulation process, collect the data of the superconducting power equipment according to the set wall and coil thermal conditions, including the coil temperature distribution, surface heat flux density, liquid nitrogen temperature and flow velocity distribution. Comprehensively analyze the characteristics and correlations of the collected data of the superconducting power equipment to evaluate the thermal simulation status of the superconducting power equipment body.

[0044] In the S5 simulation running step, a constant flow rate and temperature are set at the liquid nitrogen inlet, and the outlet is set as the outflow boundary. The SST k-omega turbulence model and the Coupled algorithm are adopted. In the process of comprehensively analyzing the characteristics and correlations of the data collected from the superconducting power equipment, the thermal simulation status is evaluated by analyzing the differences in heat transfer characteristics between the coil edge region and the flat region, as well as the temperature uniformity and flow mixing of the liquid nitrogen in the dewar except for the upper inlet region.

[0045] During the simulation running, a constant flow rate and temperature are set at the liquid nitrogen inlet, such as specific flow rate and temperature values, and the outlet is set as the outflow boundary, which can accurately simulate the flow state of the liquid nitrogen in the superconducting power equipment. The SST k-omega turbulence model can accurately describe the details of the turbulent flow of the liquid nitrogen, and the Coupled algorithm realizes the efficient coupled calculation of the flow field and the temperature field. In the data acquisition stage, according to the pre-set wall heat flux boundary and coil heat source conditions, key data such as the coil temperature distribution, surface heat flux density, liquid nitrogen temperature and flow rate distribution are comprehensively obtained. When analyzing the data characteristics and correlations, the differences in heat transfer characteristics caused by the special structure of the coil edge region are deeply explored, as well as the heat exchange balance reflected by the temperature uniformity of the liquid nitrogen in the dewar except for the upper inlet region and the influence of the hydrodynamic characteristics reflected by the flow mixing on heat transfer. By comprehensively considering these factors, the thermal simulation status of the superconducting power equipment body is evaluated from multiple dimensions, and the fitness of the simulation model and the actual equipment thermal behavior is accurately judged, providing strong technical support and decision-making basis for further optimizing the model parameters, improving the equipment design and ensuring its stable operation.

[0046] Embodiment 2

[0047] In this embodiment, an electronic device is provided, including a memory and a processor. The processor is used to execute the program in the memory to implement the thermal simulation analysis method of the superconducting power equipment body as described above. In this electronic device, the memory stores program codes, data, model information, etc. related to the thermal simulation analysis method of the superconducting power equipment body. As the core computing unit, the processor reads and executes the program in the memory, and according to the steps set by the thermal simulation analysis method of the superconducting power equipment body, such as model construction and mesh generation, boundary condition setting, material property setting, simulation running, and data acquisition and analysis evaluation, etc., converts each step into a computer-processable instruction sequence, so as to use the computing power of the electronic device to achieve the accurate simulation and analysis of the thermal simulation of the superconducting power equipment, providing data support and decision-making basis for the research, optimization and operation and maintenance of the superconducting power equipment.

[0048] Embodiment 3

[0049] This embodiment provides a storage medium containing computer-executable instructions. When the computer-executable instructions stored in this storage medium are executed by a computer processor, they are used to execute the superconducting power equipment body thermal simulation analysis method as described above. The computer-executable instructions contained in the storage medium store the complete logic and process of the superconducting power equipment body thermal simulation analysis method in a specific coding form. When the computer processor accesses this storage medium and executes the instructions therein, the instructions are parsed line by line and drive the processor to perform corresponding operations, including constructing a simplified model of the superconducting power equipment, determining the material properties and boundary conditions of each component, performing simulation operations based on the principles of fluid mechanics and heat transfer, and processing and analyzing a large amount of data generated during the simulation process, such as information on coil temperature, liquid nitrogen state, etc. Thus, the storage medium becomes the carrier of the superconducting power equipment thermal simulation analysis method, spreads among different computer systems, and realizes the functions of this method, promoting the wide application and development of technologies related to superconducting power equipment.

[0050] Embodiment 4

[0051] The fourth aspect of the present invention provides a computer program product, including a computer program. When this computer program is executed by a processor, it realizes the superconducting power equipment body thermal simulation analysis method as described above. The computer program in the computer program product integrates all the algorithms and functional modules of the superconducting power equipment body thermal simulation analysis method. When executed by the processor, the program first initializes relevant variables and data structures, and then guides the processor to execute the model construction link in a predetermined order, reasonably simplifies and abstracts the complex structure of the superconducting power equipment, accurately assigns values and definitions during the material property and boundary condition setting stage, accurately calls the selected turbulence model and algorithm for complex numerical calculations during the simulation operation process, and finally deeply analyzes and correlates and mines various collected data to comprehensively evaluate the thermal simulation status of the superconducting power equipment body, providing an efficient, convenient and repeatable technical solution for the thermal characteristic research of superconducting power equipment in the form of software, and improving the efficiency and quality of the research and operation and maintenance of superconducting power equipment.

[0052] Application Example 1

[0053] During the research and development process of superconducting power equipment, such as in the design stage of superconducting reactors, the thermal simulation analysis method of the present invention can be applied. First, according to the model construction steps, the reactor coil is simplified into a racetrack-shaped cake, and the liquid nitrogen region and the simplified inlet and outlet structures are determined. The mesh is divided using Ansys Fluent, and a total of 672,068 units are divided. Figure 1 It is a sample diagram of the simplified simulation model; Figure 2 It is a sample diagram of the simulation mesh division.

[0054] Then, set the boundary conditions. Equivalent the heat leakage of the dewar and the casing to a 400W heat flux boundary applied to the wall surface, and set the AC loss of the reactor to 1000W applied to the coil. Use stainless steel to replace the superconducting tape to set the material properties. During the simulation operation, set the liquid nitrogen inlet velocity to 0.8m / s and the temperature to 75K as the velocity inlet, and the outlet as the outflow boundary. Apply the SST k-omega turbulence model and the Coupled algorithm and consider the steady state with gravity. Finally. Figure 3 Among them: (a) Sample diagram of the temperature distribution of the coil and liquid nitrogen, (b) Sample diagram of the heat flux density distribution on the coil surface; Figure 4 Among them: (a) Liquid nitrogen flow velocity distribution in the dewar, (b) Liquid nitrogen velocity vector distribution in the dewar.

[0055] It can be seen from the simulation results that the highest temperature of the coil is 78.3K, which is within the acceptable range and the temperature is relatively uniform, without obvious local high-temperature areas, and the heat transfer at the edge is stronger than that in the flat area; the temperature of liquid nitrogen is uniform in most areas and close to 77K except for the temperature gradient at the inlet. The flow velocity distribution shows that the coil has a positive effect on the distribution of liquid nitrogen flow, ensuring the heat transfer efficiency. This provides key data support for the structural optimization and performance improvement of the superconducting reactor, helping it to better meet the actual application requirements.

[0056] The above description of the embodiments is to facilitate the understanding and use of the invention by those of ordinary skill in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for thermal simulation analysis of a superconducting power device, characterized in that: The following steps are involved: S1. Model construction and meshing: Remove the skeleton and connectors of the superconducting power equipment, simplify the winding coil into the corresponding geometric shape, select the liquid nitrogen area and simplify the liquid nitrogen inlet and outlet structure to build the basic model; S2. Boundary condition setting: Comprehensively consider the heat transfer conditions of the dewar and the casing in actual operation, apply the heat leakage equivalent to the heat flow boundary to the wall, and determine the AC loss based on the operating characteristics of the superconducting power equipment and apply it to the coil winding; S3. Material property setting: Select appropriate materials to replace superconducting tapes for property setting; S4. Simulation operation: Based on the principles of fluid mechanics and heat transfer, set the boundary type related to velocity and temperature for the liquid nitrogen inlet, set the corresponding boundary type for the outlet, select the turbulence model and algorithm, consider the gravity factor and limit the simulation operation to the steady state; S5: During the simulation process, the superconducting power equipment data is collected according to the set wall and coil thermal conditions, including coil temperature distribution, surface heat flux density, liquid nitrogen temperature and flow rate distribution. The characteristics and correlations of the collected superconducting power equipment data are comprehensively analyzed to evaluate the thermal simulation status of the superconducting power equipment itself.

2. The method for thermal simulation analysis of a superconducting power device according to claim 1, characterized in that: In the model building step in S1, the winding coil is simplified into a regular geometry.

3. The method for thermal simulation analysis of a superconducting power device according to claim 1, characterized in that: In the S1 model building step, the coil is simplified into regular geometric shapes such as racetrack-shaped pancakes and coaxial cylinders; In the model building step in S1, the liquid nitrogen inlet and outlet of the bellows structure were simplified into straight pipes.

4. The method for thermal simulation analysis of a superconducting power device according to claim 1, characterized in that: In the boundary condition setting step in S3, the heat flux boundary value of the heat leakage equivalent of the dewar and the casing is higher than the theoretically calculated heat leakage value and a preset margin is reserved.

5. The method for thermal simulation analysis of a superconducting power device according to claim 1, characterized in that: In the material property setting step in S4, stainless steel is used to replace the superconducting tape based on the fact that the base Hastelloy alloy occupies most of the thickness of the high-temperature superconducting tape and has similar thermophysical properties to stainless steel.

6. The method for thermal simulation analysis of a superconducting power device body according to claim 1, characterized in that: In the simulation running step in S5, the liquid nitrogen inlet is set to a constant flow rate and temperature, the outlet is set to an outflow boundary, and the SST k-omega turbulence model and the Coupled algorithm are used.

7. The method for thermal simulation analysis of a superconducting power device body according to claim 1, characterized in that: In the process of comprehensively analyzing the characteristics and correlations of the collected superconducting power equipment data in S5, the thermal simulation conditions were evaluated by analyzing the differences in heat transfer characteristics between the coil edge area and the flat area, as well as the temperature uniformity and flow mixing of liquid nitrogen in the Dewar except the upper inlet area.

8. An electronic device, comprising a memory and a processor, characterized in that: The processor is used to execute the program in the memory, so as to implement the thermal simulation analysis method of the superconducting power device body as claimed in any one of claims 1 to 7.

9. A storage medium containing computer executable instructions, characterized in that: The storage medium of the computer executable instructions is used to execute the thermal simulation analysis method of the superconducting power device body as claimed in any one of claims 1 to 7 when executed by a computer processor.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for thermal simulation analysis of a superconducting power device body as claimed in any one of claims 1 to 7 is implemented.

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