Design method of ground excitation coil system and related product

Abstract

The application discloses a design method of a ground excitation coil system and related products. Among them, the method comprises: for the air cooling structure, the comprehensive model including the air cooling structure model and the ground suspension coil model is simulated, and the low-speed eddy current area with the temperature rise greater than the preset temperature rise is determined as the target area; according to the target area, the air cooling structure is topologically optimized, the target position on the air cooling structure is determined, and the spoiler fin is added at the target position; for the water cooling structure, the longitudinal edge design domain of the ground traction coil is topologically optimized to obtain the flow channel parameters of the water cooling structure, and / or, the vertical edge design domain of the ground traction coil is topologically optimized to obtain the cross-section parameters of the transition area in the water cooling structure. By optimizing each component in the ground excitation coil cooling structure, the cooling capacity of the ground excitation coil cooling structure is improved.

Description

Technical Field

[0001] This application relates to the field of superconducting magnet technology, and in particular to a design method for a ground excitation coil system and related products. Background Technology

[0002] Superconducting magnets need to operate for extended periods in environments with extreme low temperatures, strong magnetic fields, high current densities, and complex vibrations. Therefore, it is necessary to build a ground-based fatigue durability test bench for superconducting magnets to conduct fatigue tests on ground-based excitation coils.

[0003] Constructing a ground-based fatigue durability test rig for superconducting magnets places high demands on the cooling capacity of the ground-based excitation coil cooling structure. However, existing ground-based excitation coil cooling structures have certain deficiencies, resulting in insufficient cooling capacity and thus hindering the construction of such a test rig. Summary of the Invention

[0004] Based on the above problems, this application provides a design method and related products for a ground excitation coil system, which improves the cooling structure of the ground excitation coil and addresses the insufficient cooling capacity of the ground excitation coil cooling structure.

[0005] The embodiments of this application disclose the following technical solutions: In a first aspect, embodiments of this application provide a design method for a cooling structure of a ground-based excitation coil. The ground-based excitation coil system includes a ground-based suspension coil, a ground-based traction coil, and a ground-based excitation coil cooling structure. The ground-based excitation coil cooling structure includes an air-cooled structure and a water-cooled structure. The ground-based suspension coil is cooled by the air-cooled structure, and the ground-based traction coil is cooled by the water-cooled structure. The method includes: For the air-cooled structure, a comprehensive model including the air-cooled structure model and the ground-suspended coil model is created; the comprehensive model is simulated to determine the low-speed vortex region in the air-cooled structure where the temperature rise is greater than the preset temperature rise as the target region; the air-cooled structure is topologically optimized based on the target region to determine the target location on the air-cooled structure; and turbulence fins are added at the target location. For the water-cooled structure, with the goal of uniformly distributing the coolant to each flat tube in the water-cooled structure, topology optimization is performed on the longitudinal side design domain of the ground traction coil to obtain the flow channel parameters of the water-cooled structure, and / or, with the goal of uniformly distributing the coolant to each flat tube in the water-cooled structure, topology optimization is performed on the vertical side design domain of the ground traction coil to obtain the cross-sectional parameters of the transition zone in the water-cooled structure.

[0006] In one possible implementation, creating an air-cooled structural model includes the following steps: Given the inlet and outlet air volumes of the air-cooled structure, the vent size, vent location, and number of vents are modeled using Latin squares to obtain a parametric surrogate model. Determine the set of trade-off solutions for the parameterized surrogate model, and determine the target solution that minimizes the temperature rise of the ground suspension coil within the set of trade-off solutions; Based on the target solution, determine the target air outlet size parameters, target air outlet location parameters, and target air outlet quantity parameters; Create an air-cooled structure model based on the target air outlet size parameters, target air outlet location parameters, and target air outlet quantity parameters.

[0007] In one possible implementation, the ground excitation coil system further includes: a support structure; wherein the support structure is used to support the ground suspension coil, the ground traction coil, and the ground excitation coil cooling structure; For the load-bearing structure, shape optimization is performed on the load-bearing structure while avoiding the operating frequency of the ground excitation coil system, and / or topology optimization is performed on the load-bearing structure while keeping the stiffness and frequency characteristics of the load-bearing structure unchanged, to obtain the frame parameters of the load-bearing architecture.

[0008] In one possible implementation, topology optimization of the air-cooled structure is performed based on the target region, including: Determine the first constraint and the first objective function; under the first constraint, perform topology optimization on the air-cooled structure based on the first objective function and the target region; The first constraint condition includes that the ratio of the resulting material volume to the initial material volume of the air-cooled structure is less than or equal to a ratio threshold. First objective function Φ 1min for: ; Where ΔP1 represents the system pressure drop, ΔP0 represents the reference pressure drop, Q1 represents the fluid flow rate, Q0 represents the reference flow rate, and α represents the weight of the flow resistance term in the air-cooled structure.

[0009] In one possible implementation, topology optimization is performed on the longitudinal side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, including: Determine the second constraint and the second objective function; under the second constraint, with the objective of uniformly distributing the coolant to each flat tube in the water-cooled structure, perform topology optimization on the longitudinal side design domain of the ground traction coil according to the second objective function; The second constraint condition includes that the ratio of the resulting material volume to the initial material volume of the water-cooled structure is less than or equal to a ratio threshold. Second objective function Φ 2min for: ; Where ΔP2 represents the voltage drop in the longitudinal edge design domain, and ΔP0 represents the reference voltage drop. β represents the standard deviation of flow rate, and β represents the weight of the flow resistance term in the water-cooled structure.

[0010] In one possible implementation, topology optimization is performed on the vertical side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, including: The third constraint and the third objective function are determined. Under the third constraint, with the goal of uniformly distributing the coolant to each flat tube in the water-cooled structure, the vertical edge design domain of the ground traction coil is optimized according to the third objective function. The third constraint condition includes that the ratio of the resulting material volume of the water-cooled structure to the initial material volume is less than or equal to a ratio threshold. Third objective function Φ 3min for: ; Where ΔP3 represents the pressure drop in the vertical design domain, ΔP0 represents the reference pressure drop, ΔP4 represents the inlet pressure drop, and ΔP5 represents the outlet pressure drop. ava This represents the average pressure drop.

[0011] In one possible implementation, the shape of the load-bearing structure is optimized, including: Determine the fourth objective function and the fourth constraint condition; under the fourth constraint condition, optimize the shape of the load-bearing structure according to the fourth objective function; The fourth constraint condition includes that the maximum deformation of the load-bearing structure is less than the deformation threshold and the stress of the load-bearing structure is less than the stress threshold. Fourth objective function Φ 4min for: ; in, This represents the i-th operating frequency of the ground excitation coil system. This represents the weight corresponding to the i-th running frequency. This represents the frequency of the load-bearing structure in the i-th iteration. Indicates the tolerance band.

[0012] Secondly, embodiments of this application provide a design apparatus for a ground excitation coil system, characterized in that the ground excitation coil system includes a ground suspension coil, a ground traction coil, and a ground excitation coil cooling structure. The ground excitation coil cooling structure includes an air-cooled structure and a water-cooled structure. The ground suspension coil is cooled by the air-cooled structure, and the ground traction coil is cooled by the water-cooled structure. The apparatus includes: The air-cooled structure design module is configured to create a comprehensive model that includes an air-cooled structure model and a ground-based suspended coil model; simulate the comprehensive model to identify the low-speed vortex region in the air-cooled structure where the temperature rise exceeds the preset temperature rise as the target region; perform topology optimization on the air-cooled structure based on the target region to determine the target location on the air-cooled structure; and add turbulence fins at the target location. The water-cooled structure design module is configured to perform topology optimization on the longitudinal side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, thereby obtaining the flow channel parameters of the water-cooled structure, and / or to perform topology optimization on the vertical side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, thereby obtaining the cross-sectional parameters of the transition zone in the water-cooled structure.

[0013] Thirdly, embodiments of this application provide a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the design method of the ground excitation coil system as described in any embodiment of the first aspect.

[0014] Fourthly, embodiments of this application provide a computer-readable storage medium storing instructions that, when executed on a terminal device, cause the terminal device to perform the design method for a ground excitation coil system as described in any embodiment of the first aspect.

[0015] In order to improve the cooling structure of the ground excitation coil and enhance its cooling capacity, this application provides a design method for a ground excitation coil system. The ground-based excitation coil system includes a ground-based suspension coil, a ground-based traction coil, and a ground-based excitation coil cooling structure. The ground-based excitation coil cooling structure includes an air-cooled structure and a water-cooled structure. The ground-based suspension coil is cooled by the air-cooled structure, and the ground-based traction coil is cooled by the water-cooled structure. The method includes: for the air-cooled structure, creating a comprehensive model including a model of the air-cooled structure and a model of the ground-based suspension coil; simulating the comprehensive model to determine the low-speed vortex region in the air-cooled structure where the temperature rise is greater than a preset temperature rise as the target region; performing topology optimization on the air-cooled structure based on the target region to determine the target position on the air-cooled structure; adding turbulence fins at the target position; for the water-cooled structure, with the goal of uniformly distributing the coolant to each flat tube in the water-cooled structure, performing topology optimization on the longitudinal side design domain of the ground-based traction coil to obtain the flow channel parameters of the water-cooled structure, and / or, with the goal of uniformly distributing the coolant to each flat tube in the water-cooled structure, performing topology optimization on the vertical side design domain of the ground-based traction coil to obtain the cross-sectional parameters of the transition region in the water-cooled structure.

[0016] In this embodiment, topology optimization of the air-cooled structure, specifically by adding turbulence fins, reduces flow resistance and improves heat dissipation. Similarly, topology optimization of the water-cooled structure ensures even distribution of coolant to each flat tube, further reducing flow resistance. Therefore, by optimizing the air-cooled and water-cooled structures in the ground-based excitation coil cooling structure, the cooling capacity of the ground-based excitation coil cooling structure can be improved, thereby enabling the construction of a ground-based fatigue durability test rig for superconducting magnets. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a design method for a ground excitation coil system provided in this application embodiment; Figure 2 A flowchart illustrating an air-cooled structure model provided in this application embodiment; Figure 3 This is a schematic diagram of a design device for a ground excitation coil system according to an embodiment of this application. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0020] The terms "first" and "second," etc., used in the specification and claims of this application are used to distinguish different objects, not to describe a specific order of objects. For example, "first operation instruction" and "second operation instruction," etc., are used to distinguish different operation instructions, not to describe a specific order of operation instructions.

[0021] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0022] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0023] To facilitate understanding of this solution, the technical terms involved in the embodiments of this application will be introduced before the solution is described.

[0024] A superconducting magnet is an electromagnet that uses a superconductor with a specific transition temperature rise and a particularly high critical magnetic field to make a coil at low temperatures. Its main characteristics are that there is no electrical loss caused by the resistance of the wires, nor is there any magnetic loss caused by the presence of an iron core.

[0025] A superconducting coil is a coil made of coils of superconducting tape wound together. There is no resistance or Joule energy loss in a superconducting coil, so once a current is superimposed, the current can exist indefinitely, and the magnetic field it generates can also be maintained at a constant speed without external work.

[0026] Electromagnetic force, taking superconducting maglev trains as an example, can generate a strong electromagnetic repulsion force through the interaction between superconducting magnets and ground coil magnets, suspending the superconducting maglev train above the track.

[0027] Topology optimization is a mathematical method that optimizes the distribution of materials within a given region based on given load conditions, constraints, and performance indicators. It is a type of structural optimization.

[0028] Elastic strain energy refers to the energy stored in a solid as the work done by external forces is converted into energy during deformation. The energy stored in a solid due to deformation under the action of external forces is called deformation energy or strain energy.

[0029] Volume fraction, for example, applying a 30% volume fraction, means that the volume of the optimal design must be less than or equal to 30% of the original volume.

[0030] Shape optimization, a subclass of structural optimization design, aims to improve the mechanical properties (such as stiffness, strength, and stability) or economic indicators (such as weight and cost) of a structure by adjusting its geometry, while meeting constraints (such as stress limits, displacement limits, and manufacturing feasibility).

[0031] Parameter optimization, a broader category of optimization problems, aims to optimize one or more performance metrics (such as minimizing error, maximizing efficiency, or minimizing cost) by adjusting the controllable parameters of a system, algorithm, or process.

[0032] Air-cooled structures are heat dissipation systems that use air as a cooling medium, carrying away heat through airflow. They are widely used in electronic equipment, mechanical devices, and engineering fields. Their core principle is to transfer heat from heat-generating components to the environment by increasing the heat dissipation area and accelerating airflow (natural or forced convection).

[0033] Water-cooled structures are heat dissipation systems that use liquids (such as water or ethylene glycol coolant) as the cooling medium, carrying away heat through a circulation system. They are commonly found in high-heat-generating equipment and scenarios requiring efficient heat dissipation. Their core principle is to absorb heat through the high heat capacity of the liquid and then release it into the environment through a radiator.

[0034] Latin square modeling, an experimental design method belonging to the branch of factorial design in statistics, aims to more accurately assess the impact of the main treatment factor (such as drug, process parameters) on the response variable (such as yield, efficacy) by controlling for the interference of two additional variables (row factors and column factors).

[0035] Turbulence is a complex state of fluid (gas or liquid) flow, as opposed to laminar flow. Its core characteristic is that the fluid motion exhibits a highly irregular and disordered chaotic state, accompanied by the generation, stretching, breaking up, and energy transfer of eddies.

[0036] In this embodiment, the ground excitation coil cooling structure includes a ground suspension coil, a ground traction coil, a load-bearing structure, an air-cooled structure, and a water-cooled structure. The ground suspension coil is cooled by the air-cooled structure, and the ground traction coil is cooled by the water-cooled structure.

[0037] In the central region of the ground-based levitation coil, the heat flux density is moderate, and the ambient temperature rise can be controlled within 40°C. With a well-designed air-cooling structure (efficient heatsinks, sufficient airflow, and a reasonable airflow path), the temperature rise range (ΔT) is 30K-50K. Within this temperature range, the cooling capacity of the air-cooling structure can be improved by appropriately increasing the heatsink area, increasing fan pressure and airflow, and optimizing airflow organization. It should be noted that 50K is a realistic upper limit for air-cooling structures in compact spaces.

[0038] In particular, the back area of ​​the ground traction coil, with its high heat flux density or limited space, is unfavorable for air cooling. The cooling water inlet temperature rise can be controlled within 30°C (±1°C). With a reasonable water-cooling structure design (flow channel design ensuring good heat exchange and sufficient water flow), its temperature rise range (ΔT) is 50K-80K. It should be noted that the water-cooling structure can theoretically handle higher temperature rises (e.g., 100K+, hotspots 130°C+), but this requires a more stringent design (higher flow rate, greater pressure drop, and better heat exchange) and ensures material compatibility.

[0039] The technical solution of this application will be described below with reference to the accompanying drawings.

[0040] See Figure 1 The figure is a flowchart of a design method for a ground excitation coil system provided in an embodiment of this application.

[0041] like Figure 1 As shown, the method includes the following steps: S1000: For the air-cooled structure, create a comprehensive model including the air-cooled structure model and the ground-suspended coil model; simulate the comprehensive model to determine the low-speed vortex region in the air-cooled structure where the temperature rise is greater than the preset temperature rise as the target region; perform topology optimization on the air-cooled structure based on the target region to determine the target position on the air-cooled structure; add turbulence fins at the target position.

[0042] In this embodiment, the turbulence fins can be any one of a 45° inclined flow guiding structure, a corrugated wall, and a locally protruding turbulence column.

[0043] In this embodiment, the specific method for creating the integrated model including the air-cooled structural model and the ground-based suspended coil model is not limited. The following embodiment will create the air-cooled structural model through the following steps: S1100: Given the inlet and outlet air volumes of the air-cooled structure, the size, location, and number of air outlets are modeled using a Latin square to obtain a parametric surrogate model.

[0044] In this embodiment, the given inlet air volume and outlet air volume are not specifically limited. For example, when the given inlet air volume is 200 CFM, the temperature rise of the hottest spot of the ground suspension coil is less than or equal to 45 K.

[0045] First, a simplified model (including heat dissipation teeth) and air duct of the ground-based levitation coil are established in computational fluid dynamics software (e.g., ANSYS Fluent). For the parameterized design variables of this model, the embodiments of this application specify the number of air vents N (3-8), the vent size W×H (width 20-50mm × height 5-15mm), and the vent positions P (distributed along the length of the ground-based levitation coil, with variable spacing). The constraints are that the vent spacing ≥ 30mm to avoid airflow interference, and the total airflow is constant (200 CFM evenly distributed to each vent).

[0046] Then, N sets of sample points are extracted in the 6-dimensional design space (N, W, H, P1, P2, P3) using Latin hypercube sampling (LHS). Fluid-thermal coupling simulation is performed on each set of sample points to extract the target response Y1 (temperature rise ΔT_max at the hottest spot of the ground-based levitation coil) and the constraint response Y2 (pressure drop ΔP in the flow channel). It should be noted that in this embodiment, P1, P2, and P3 are distributed along the length of the ground-based levitation coil, and the specific values ​​of P1, P2, and P3 are not limited in this embodiment.

[0047] Finally, a parametric surrogate model is established based on the 6-dimensional design space (N, W, H, P1, P2, P3), the target response Y1, and the constraint response Y2.

[0048] In addition, this application embodiment can also use 10% of the samples as a test set to verify the accuracy of the parameterized surrogate model. Specifically, if the coefficient of determination R² (a core indicator measuring the degree of fit between the predicted value and the simulated real value of the parameterized surrogate model) is greater than a preset threshold (e.g., the preset threshold is equal to 0.92), it indicates that the accuracy of the parameterized surrogate model is reliable.

[0049] S1200: Determine the set of trade-off solutions for the parameterized surrogate model, and determine the objective solution that minimizes the temperature rise of the ground suspension coil in the set of trade-off solutions.

[0050] For example, based on the constructed parameterized surrogate model (R²>0.92), the NSGA-II multi-objective genetic algorithm is used to carry out dual-objective optimization of the hottest spot temperature rise ΔT_max and the flow channel pressure drop ΔP. The parameter settings of population size 100 and number of iterations 50 are strictly followed. Finally, the Pareto trade-off solution set is obtained, and the Pareto objective solution with the minimum ΔTmax is selected. The actual ΔTmax is verified by computational fluid dynamics software simulation to be 42.1K (error <2%), which meets the engineering requirement of ΔTmax≤45K.

[0051] For ease of understanding, the initial uniform distribution scheme and the optimized scheme are compared in Table 1 below: Table 1

[0052] In this embodiment of the application, the hottest spot temperature rise ΔT_max and the flow channel pressure drop ΔP in the trade-off solution set are in one-to-one correspondence, and the trade-off solution set corresponding to the minimum hottest spot temperature rise ΔT_max is the objective solution.

[0053] S1300: Based on the target solution, determine the target air outlet size parameters, target air outlet location parameters, and target air outlet quantity parameters.

[0054] Taking Table 1 above as an example, the maximum temperature rise ΔT_max of the hottest spot corresponding to the target solution is 42.1, the pressure drop ΔP in the flow channel is 142, the target air outlet size parameter is 38×12, the target air outlet quantity parameter is 6, and the target air outlet location parameter is non-uniformly distributed.

[0055] S1400: Create an air-cooled structure model based on the target air outlet size parameters, target air outlet location parameters, and target air outlet quantity parameters.

[0056] In this embodiment, the method of creating the air-cooled structure model is not specifically limited. For example, the air-cooled structure model can be created using ANSYS Workbench, STAR-CCM+, or COMSOL Multiphysics.

[0057] Simulations were performed on the combined model of the air-cooled structure and the ground-based levitation coil to identify the target area (e.g., the area with a temperature rise greater than the preset temperature rise) in the low-speed vortex region (flow velocity <0.5m / s in the 90-120mm area between air outlets (ideally >2m / s)) of the air-cooled structure model. For the above target area (e.g., selecting the hot spot area as an 80×40×30mm cube as the design space), local topology optimization analysis was performed on the air-cooled structure to optimize it with the goal of reducing flow resistance and improving heat dissipation performance.

[0058] In one possible implementation, topology optimization of the air-cooled structure is performed based on the target region, including: determining a first constraint and a first objective function; and, under the first constraint, performing topology optimization of the air-cooled structure based on the first objective function and the target region.

[0059] The first constraint condition is that the ratio of the resulting material volume to the initial material volume of the air-cooled structure is less than or equal to a ratio threshold.

[0060] First objective function Φ 1min for: ; Where ΔP1 represents the system pressure drop, ΔP0 represents the reference pressure drop, Q1 represents the fluid flow rate, Q0 represents the reference flow rate, and α represents the weight of the flow resistance term in the air-cooled structure.

[0061] In this embodiment of the application, topology optimization is performed on the target area of ​​the air-cooled structure. The optimization results include the target location where turbulence fins need to be added so that turbulence fins can be added at the target location to increase local turbulence and remove heat from the location where air cooling cannot be better due to design domain limitations.

[0062] S2000: For water-cooled structures, with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, topology optimization is performed on the longitudinal side design domain of the ground traction coil to obtain the flow channel parameters of the water-cooled structure, and / or, with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, topology optimization is performed on the vertical side design domain of the ground traction coil to obtain the cross-sectional parameters of the transition zone in the water-cooled structure.

[0063] For example, this application embodiment uses a ground traction coil with basic dimensions of 400mm (length) × 200mm (width) × 50mm (height). It designs water-cooled drainage channels in two independent two-dimensional topology optimization domains: a design domain containing only the longitudinal side (XZ plane) of the ground traction coil and a design domain containing only the vertical side (YZ plane) of the coil. Following the conditions of 8 parallel flat pipes, a total flow rate of 10L / min, and a target pressure drop of <30kPa, a topology optimization strategy is implemented using customized objective functions (a second objective function and a third objective function). This determines the water channel layout, cross-sectional shape, and flow guiding structure for the two types of design domains, ultimately achieving the design goal of uniform coolant distribution and minimized flow resistance. The structures of the two optimization domains can be seamlessly connected to form a complete water-cooled drainage distribution system.

[0064] In one possible implementation, topology optimization of the longitudinal edge design domain of the ground traction coil is performed with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure. This includes: determining a second constraint and a second objective function; and under the second constraint, with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, performing topology optimization of the longitudinal edge design domain of the ground traction coil according to the second objective function.

[0065] The second constraint condition includes that the ratio of the resulting material volume to the initial material volume of the water-cooled structure is less than or equal to a ratio threshold.

[0066] Second objective function Φ 2min for: ; Where ΔP2 represents the longitudinal domain voltage drop, and ΔP0 represents the reference voltage drop. β represents the standard deviation of flow rate, and β represents the weight of the flow resistance term in the water-cooled structure.

[0067] It is important to note that Q i Let i be the actual flow rate of the i-th exit. The average flow rate is σ_Q ∈ [0, 1] after normalization; the smaller the value, the more uniform the flow rate. n is the number of parallel flat tubes; therefore, in this embodiment, n can be 8.

[0068] In this embodiment, a fluid domain (porosity = 1) and a solid domain (porosity = 0) are defined. Fluid-structure interaction boundary conditions are applied, and topology optimization is performed using the gradient descent method iteratively 100 times. The optimization results indicate a gradually expanding flow channel, i.e., an inlet width of 8 mm and an outlet width of 15 mm for the water-cooled structure, with arc-shaped guides at 40 / 120 / 240 mm to form a graded buffer structure.

[0069] In one possible implementation, topology optimization is performed on the vertical edge design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure. This includes: determining a third constraint condition and a third objective function; and under the third constraint condition, with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, performing topology optimization on the vertical edge design domain of the ground traction coil according to the third objective function.

[0070] The third constraint condition includes that the ratio of the resulting material volume of the water-cooled structure to the initial material volume is less than or equal to a ratio threshold. Third objective function Φ 3min for: ; Wherein, ΔP3 represents the vertical pressure drop, ΔP0 represents the reference pressure drop, ΔP4 represents the inlet pressure drop, ΔP5 represents the outlet pressure drop, and ΔP ava This represents the average pressure drop.

[0071] In this embodiment, topology optimization is performed by iterating 100 times using the gradient descent method. The optimization results indicate a double streamlined contraction of the water-cooled structure's inlet diameter of 12mm → elliptical cross section (10×6mm) in the transition zone, as well as a vortex control wing with 45° inclined guide vanes.

[0072] In this embodiment of the application, by optimizing the topology of the water-cooling structure, the coolant can be evenly distributed to each flat tube, reducing flow resistance.

[0073] In this embodiment, topology optimization of the air-cooled structure is performed to determine the target location, and adding turbulence fins at the target location can reduce the flow resistance of the air-cooled structure and improve its heat dissipation performance. Optimizing the topology of the water-cooled structure allows for uniform distribution of coolant to each flat tube, reducing flow resistance. Therefore, in this embodiment, by optimizing the various components in the ground-based excitation coil cooling structure, the cooling capacity of the ground-based excitation coil cooling structure can be improved, thereby enabling the construction of a ground-based fatigue durability test bench for superconducting magnets.

[0074] The ground excitation coil system in this application embodiment also includes a support structure, wherein the support structure is used to support the ground suspension coil, the ground traction coil and the ground excitation coil cooling structure; For the load-bearing structure, shape optimization is performed on the load-bearing structure while avoiding the operating frequency of the ground excitation coil system, and / or topology optimization is performed on the load-bearing structure while keeping the stiffness and frequency characteristics of the load-bearing structure unchanged, to obtain the frame parameters of the load-bearing architecture.

[0075] While keeping the internal flow channel design domain of the water-cooled structure unchanged, shape and topology optimizations were performed on the main load-bearing structure of the ground coil. First, the shape of the load-bearing structure was optimized, with the optimization target set at a frequency range outside the main operating frequency of the test bench (test bench operating frequency: 25-40 Hz (this range must be avoided), and the first-order frequency of the ground traction coil structure is 37 Hz), to ensure that the structure does not resonate. Second, the topology of the load-bearing structure was optimized. While keeping the stiffness frequency unchanged, the weight reduction was further achieved by using the yield strength of the structural material as a constraint.

[0076] In one possible implementation, the shape of the load-bearing structure is optimized, including: determining a fourth objective function and a fourth constraint; and optimizing the shape of the load-bearing structure according to the fourth objective function under the fourth constraint.

[0077] The fourth constraint condition includes that the maximum deformation of the load-bearing structure is less than the deformation threshold, and the stress of the load-bearing structure is less than the stress threshold.

[0078] Fourth objective function Φ 4min for: ; Among them, among them, This represents the i-th operating frequency of the ground excitation coil system. This represents the weight corresponding to the i-th running frequency. This represents the frequency of the load-bearing structure in the i-th iteration. Indicates the tolerance band.

[0079] For example, operating frequency Including 55Hz, 120Hz and 185Hz, 55Hz 120Hz 185Hz; weight Including 0.7, 0.2, and 0.1, It is 0.7. It is 0.2. It is 0.1.

[0080] In this embodiment, shape optimization is performed by establishing a parameterized FE model, modal analysis (extracting the first 5 frequencies), sensitivity analysis (frequency derivative with respect to shape variable), and gradient optimization iteration (30 times), and the shape optimization result is obtained.

[0081] The shape optimization results are shown in Table 2 below: Table 2

[0082] As shown in Table 2 above, regarding the stiffener thickness, the value before optimization was 15mm, and the value after optimization was 18.7mm; regarding the flange angle, the value before optimization was 45°, and the value after optimization was 52.3°; regarding the web curvature, the value before optimization was 1.2m. - ¹, After optimization, its value is 2.11.2m - ¹; For the first-order frequency, the value before optimization is 37Hz, and the value after optimization is 58Hz.

[0083] In one possible implementation, topology optimization of the load-bearing structure includes: determining a fifth objective function and a fifth constraint; and, under the fifth constraint, performing topology optimization of the load-bearing structure according to the fifth objective function.

[0084] The fifth constraint includes |f1|≥55Hz, |δ_max|≤0.15mm, |σ_VM|≤350MPa and ρ e ∈[0.2, 1], symmetric constraint (XY plane) and minimum member size of 8mm.

[0085] The fifth objective function Φ5min is: ; Among them, ρ(ρ1,ρ2,…,ρ N ) is the design variable vector, representing the relative density of the material in each element, v e The volume of an element is represented by N, which represents the total number of elements in the design domain when the element is made entirely of solid material.

[0086] The constraints indicate that |f1|≥55Hz, |δ_max|≤0.15mm, |σ_VM|≤350MPa and ρ e Given the constraints ∈ [0.2, 1], symmetric constraints (XY plane), and a minimum member size of 8mm, topology optimization is performed on the load-bearing structure. The topology optimization results indicate that the main frame opening ratio is 42%, and the critical path thickness is 18mm → 12mm. Here, f1 represents the lower limit of the first-order frequency, δ_max represents the maximum deformation limit, σ_VM represents the upper limit of the von Mises equivalent stress, and ρ... e This indicates the range of material density design variables.

[0087] The topology optimization results are shown in Table 3 below: Table 3

[0088] As shown in Table 3 above, for the mass of the load-bearing structure, the value before optimization was 48 kg, after shape optimization it was 51, and after topology optimization it was 36.5; for the first-order frequency, the value before optimization was 37, after shape optimization it was 58, and after topology optimization it was 58; for the maximum stress, the value before optimization was 412, after shape optimization it was 338, and after topology optimization it was 326; for the stiffness, the value before optimization was 42, after shape optimization it was 66, and after topology optimization it was 78; for the power-to-mass ratio, the value before optimization was 0.83, after shape optimization it was 0.78, and after topology optimization it was 1.09.

[0089] In this embodiment of the application, shape optimization and topology optimization of the load-bearing structure can be performed with the yield strength of the structural material as a constraint to reduce the weight of the load-bearing structure.

[0090] It should be noted that the design requirements specify the following: for thermal management, the maximum temperature rise of the coil must be ≤45K (ambient temperature 25℃); for flow resistance, the ΔP of the air-cooled structure must be ≤200Pa, and the ΔP of the water-cooled structure must be ≤30kPa; for structural safety, σ must be ≤350MPa, and deformation must be ≤0.2mm; for dynamic characteristics, the first-order frequency must be ≥55Hz.

[0091] Therefore, after completing the above optimizations, it is necessary to verify the optimization effects of the air-cooled structure (6 air outlets + turbulence fin structure), the water-cooled structure (staged water channels + conformal cross-section), and the load-bearing structure (mass of the load-bearing structure). The optimization effects of the air-cooled structure (6 air outlets + turbulence fin structure), the water-cooled structure (staged water channels + conformal cross-section), and the load-bearing structure (mass of the load-bearing structure) are shown in Table 4 below: Table 4

[0092] As shown in Table 4 above, for the air-cooled structure, the temperature rise ΔT_max of the hottest spot decreased from 52K before optimization to 43.1K after optimization, with an improvement rate of 17.1%; for the water-cooled structure, the pressure drop ΔP in the flow channel decreased from 42.7kPa before optimization to 27.3kPa after optimization, with an improvement rate of 36%; for the load-bearing structure, its mass decreased from 48kg before optimization to 36.5kg after optimization, with an improvement rate of 24%, and the first-order frequency f1 increased from 37Hz before optimization to 58.3Hz after optimization.

[0093] As can be seen, in this embodiment of the application, by optimizing the air-cooled structure, water-cooled structure and load-bearing structure, the ground excitation coil cooling structure meets the design requirements, thereby building a ground fatigue durability test bench for superconducting magnets.

[0094] Based on the design method of the ground excitation coil cooling structure mentioned in the foregoing embodiments, this application also provides a design device for a ground excitation coil system. The ground excitation coil system includes a ground suspension coil, a ground traction coil, and a ground excitation coil cooling structure. The ground excitation coil cooling structure includes an air-cooled structure and a water-cooled structure. The ground suspension coil is cooled by the air-cooled structure, and the ground traction coil is cooled by the water-cooled structure.

[0095] like Figure 3 As shown, the device includes an air-cooled structure design module 1000 and a water-cooled structure design module 2000. The air-cooled structure design module 1000 is configured to create a comprehensive model including an air-cooled structure model and a ground-based suspended coil model; simulate the comprehensive model to identify the low-speed vortex region in the air-cooled structure where the temperature rise exceeds the preset temperature rise as the target region; perform topology optimization on the air-cooled structure based on the target region to determine the target location on the air-cooled structure; and add turbulence fins at the target location. The water-cooled structure design module 2000 is configured to perform topology optimization on the longitudinal side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, thereby obtaining flow channel parameters for the water-cooled structure, and / or to perform topology optimization on the vertical side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, thereby obtaining cross-sectional parameters for the transition zone in the water-cooled structure.

[0096] In this embodiment, topology optimization of the air-cooled structure is performed to determine the target location, and adding turbulence fins at the target location can reduce the flow resistance of the air-cooled structure and improve its heat dissipation performance. Optimizing the topology of the water-cooled structure allows for uniform distribution of coolant to each flat tube, reducing flow resistance. Therefore, in this embodiment, by optimizing the various components in the ground-based excitation coil cooling structure, the cooling capacity of the ground-based excitation coil cooling structure can be improved, thereby enabling the construction of a ground-based fatigue durability test bench for superconducting magnets.

[0097] In addition to the above, the device in the embodiments of this application also includes: a load-bearing structure design module.

[0098] By optimizing the shape of the load-bearing structure while avoiding the operating frequency of the ground excitation coil system, and / or by optimizing the topology of the load-bearing structure while keeping the stiffness and frequency characteristics of the load-bearing structure unchanged, the frame parameters of the load-bearing architecture are obtained.

[0099] In this embodiment of the application, shape optimization and topology optimization of the load-bearing structure can be performed with the yield strength of the structural material as a constraint to reduce the weight of the load-bearing structure.

[0100] In one possible implementation, the air-cooled structure design module is configured to, given the inlet and outlet air volumes of the air-cooled structure, perform Latin square modeling on the vent size, vent location, and number of vents to obtain a parametric surrogate model; determine the trade-off solution set for the parametric surrogate model, and determine the target solution corresponding to the minimum temperature rise of the ground suspension coil in the trade-off solution set; based on the target solution, determine the target vent size parameters, target vent location parameters, and target vent number parameters; and create the air-cooled structure model based on the target vent size parameters, target vent location parameters, and target vent number parameters.

[0101] In one possible implementation, the air-cooled structure design module is configured to determine a first constraint and a first objective function; under the first constraint, to perform topology optimization on the air-cooled structure based on the first objective function and the target region; The first constraint condition includes that the ratio of the resulting material volume to the initial material volume of the air-cooled structure is less than or equal to a ratio threshold. First objective function Φ 1min for: ; Where ΔP1 represents the system pressure drop, ΔP0 represents the reference pressure drop, Q1 represents the fluid flow rate, Q0 represents the reference flow rate, and α represents the weight of the flow resistance term in the air-cooled structure.

[0102] In one possible implementation, a second constraint and a second objective function are determined; under the second constraint, with the objective of uniformly distributing coolant to each flat tube in the water-cooled structure, topology optimization is performed on the longitudinal side design domain of the ground traction coil according to the second objective function; The second constraint condition includes that the ratio of the resulting material volume to the initial material volume of the water-cooled structure is less than or equal to a ratio threshold. Second objective function Φ 2min for: ; Where ΔP2 represents the voltage drop in the longitudinal edge design domain, and ΔP0 represents the reference voltage drop. β represents the standard deviation of flow rate, and β represents the weight of the flow resistance term in the water-cooled structure.

[0103] In one possible implementation, the water-cooled structure design module is configured to determine the third constraint and the third objective function; under the third constraint, with the objective of uniformly distributing the coolant to each flat tube in the water-cooled structure, the vertical edge design domain of the ground traction coil is topologically optimized according to the third objective function; The third constraint condition includes that the ratio of the resulting material volume of the water-cooled structure to the initial material volume is less than or equal to a ratio threshold. Third objective function Φ 3min for: ; Where ΔP3 represents the pressure drop in the vertical design domain, ΔP0 represents the reference pressure drop, ΔP4 represents the inlet pressure drop, and ΔP5 represents the outlet pressure drop. ava This represents the average pressure drop.

[0104] In one possible implementation, the load-bearing structure design module is configured to determine a fourth objective function and a fourth constraint condition; under the fourth constraint condition, the shape of the load-bearing structure is optimized according to the fourth objective function; The fourth constraint condition includes that the maximum deformation of the load-bearing structure is less than the deformation threshold and the stress of the load-bearing structure is less than the stress threshold. Fourth objective function Φ 4min for: ; in, This represents the i-th operating frequency of the ground excitation coil system. This represents the weight corresponding to the i-th running frequency. This represents the frequency of the load-bearing structure in the i-th iteration. Indicates the tolerance band.

[0105] In one possible implementation, the turbulence fins include a 45° inclined flow guide structure, a corrugated wall, or a locally protruding turbulence column.

[0106] In addition, embodiments of this application provide a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the design method of the ground excitation coil system as described in any of the foregoing embodiments.

[0107] In addition, embodiments of this application provide a computer-readable storage medium storing instructions that, when executed on a terminal device, cause the terminal device to perform the design method of the ground excitation coil system as described in any of the foregoing embodiments.

[0108] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components indicated as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0109] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A design method for a ground-based excitation coil system, characterized in that, The ground-based excitation coil system includes a ground-based suspension coil, a ground-based traction coil, and a cooling structure for the ground-based excitation coil. The cooling structure includes an air-cooling structure and a water-cooling structure. The ground-based suspension coil is cooled by the air-cooling structure, and the ground-based traction coil is cooled by the water-cooling structure. The method includes: For the aforementioned air-cooled structure, a comprehensive model including an air-cooled structure model and a ground-suspended coil model is created; the comprehensive model is simulated to determine the low-speed vortex region in the air-cooled structure where the temperature rise is greater than a preset temperature rise as the target region; the air-cooled structure is topologically optimized based on the target region to determine the target position on the air-cooled structure; and turbulence fins are added at the target position. For the water-cooled structure, with the goal of uniformly distributing the coolant to each flat tube in the water-cooled structure, topology optimization is performed on the longitudinal side design domain of the ground traction coil to obtain the flow channel parameters of the water-cooled structure, and / or, with the goal of uniformly distributing the coolant to each flat tube in the water-cooled structure, topology optimization is performed on the vertical side design domain of the ground traction coil to obtain the cross-sectional parameters of the transition zone in the water-cooled structure.

2. The method according to claim 1, characterized in that, Creating the air-cooled structure model includes the following steps: Given the air inlet and outlet air volume of the air-cooled structure, the air outlet size, air outlet location and air outlet number are modeled by Latin square to obtain a parametric surrogate model. Determine the set of trade-off solutions for the parameterized proxy model, and determine the target solution corresponding to the minimum temperature rise of the ground-based levitation coil in the set of trade-off solutions; Based on the target solution, the target air outlet size parameters, the target air outlet location parameters, and the target air outlet quantity parameters are determined; The air-cooled structure model is created based on the target air outlet size parameters, the target air outlet location parameters, and the target air outlet quantity parameters.

3. The method according to claim 1, characterized in that, The ground excitation coil system further includes: a support structure; wherein the support structure is used to support the ground suspension coil, the ground traction coil, and the ground excitation coil cooling structure; For the load-bearing structure, while avoiding the operating frequency of the ground excitation coil system, the shape of the load-bearing structure is optimized, and / or, while keeping the stiffness and frequency characteristics of the load-bearing structure unchanged, the topology of the load-bearing structure is optimized to obtain the frame parameters of the load-bearing architecture.

4. The method according to any one of claims 1-3, characterized in that, The topology optimization of the air-cooled structure based on the target region includes: Determine the first constraint and the first objective function; under the first constraint, perform topology optimization on the air-cooled structure according to the first objective function and the target region; The first constraint condition includes that the ratio of the resulting material volume of the air-cooled structure to the initial material volume is less than or equal to a ratio threshold. The first objective function Φ 1min for: ； Wherein, ΔP1 represents the system pressure drop, ΔP0 represents the reference pressure drop, Q1 represents the fluid flow rate, Q0 represents the reference flow rate, and α represents the weight of the flow resistance term in the air-cooled structure.

5. The method according to any one of claims 1-3, characterized in that, The topology optimization of the longitudinal side design domain of the ground traction coil, with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, includes: Determine the second constraint and the second objective function; under the second constraint, with the objective of uniformly distributing the coolant to each flat tube in the water-cooled structure, perform topology optimization on the longitudinal edge design domain of the ground traction coil according to the second objective function; The second constraint condition includes that the ratio of the resulting material volume of the water-cooled structure to the initial material volume is less than or equal to a ratio threshold. The second objective function Φ 2min for: ； Where ΔP2 represents the voltage drop in the longitudinal edge design domain, and ΔP0 represents the reference voltage drop. β represents the standard deviation of flow rate, and β represents the weight of the flow resistance term in the water-cooled structure.

6. The method according to any one of claims 1-3, characterized in that, The topology optimization of the vertical side design domain of the ground traction coil, with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, includes: The third constraint and the third objective function are determined; under the third constraint, with the objective of uniformly distributing the coolant to each flat tube in the water-cooled structure, the vertical side design domain of the ground traction coil is topologically optimized according to the third objective function. The third constraint condition includes that the ratio of the resulting material volume of the water-cooled structure to the initial material volume is less than or equal to a ratio threshold. The third objective function Φ 3min for: ； Where ΔP3 represents the pressure drop in the vertical design domain, ΔP0 represents the reference pressure drop, ΔP4 represents the inlet pressure drop, and ΔP5 represents the outlet pressure drop. ava This represents the average pressure drop.

7. The method according to claim 3, characterized in that, The shape optimization of the load-bearing structure includes: Determine the fourth objective function and the fourth constraint condition; under the fourth constraint condition, optimize the shape of the load-bearing structure according to the fourth objective function; The fourth constraint condition includes that the maximum deformation of the load-bearing structure is less than the deformation threshold and the stress of the load-bearing structure is less than the stress threshold. The fourth objective function Φ 4min for: ； in, This represents the i-th operating frequency of the ground excitation coil system. This represents the weight corresponding to the i-th operating frequency. This represents the frequency of the bearing structure in the i-th iteration. Indicates the tolerance band.

8. A design device for a ground excitation coil system, characterized in that, The ground-based excitation coil system includes a ground-based suspension coil, a ground-based traction coil, and a cooling structure for the ground-based excitation coil. The cooling structure includes both air-cooling and water-cooling components. The ground-based suspension coil is cooled by the air-cooling structure, and the ground-based traction coil is cooled by the water-cooling structure. The device includes: The air-cooled structure design module is configured to create a comprehensive model including an air-cooled structure model and a ground-suspended coil model; simulate the comprehensive model to determine the low-speed vortex region in the air-cooled structure where the temperature rise is greater than a preset temperature rise as the target region; perform topology optimization on the air-cooled structure based on the target region to determine the target position on the air-cooled structure; and add turbulence fins at the target position. The water-cooled structure design module is configured to perform topology optimization on the longitudinal side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, thereby obtaining flow channel parameters for the water-cooled structure, and / or to perform topology optimization on the vertical side design domain of the ground traction coil with the goal of uniformly distributing coolant to each flat tube in the water-cooled structure, thereby obtaining cross-sectional parameters for the transition zone in the water-cooled structure.

9. A computer device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the design method for a ground excitation coil system as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a terminal device, cause the terminal device to perform the design method for the ground excitation coil system as described in any one of claims 1-7.

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