A high-temperature superconducting coil cooling structure

Abstract

This invention discloses a high-temperature superconducting coil cooling structure, belonging to the field of high-temperature superconducting technology. It includes: a cold shield plate assembly, a guide rail platform, a cryogenic pipeline, a high-temperature superconducting coil, and one or more identical single-stage and two-stage refrigerators. The cold shield plate assembly is fixed to the four sides of a cold shield frame. The guide rail platform is fixed to the upper cold shield plate of the cold shield plate assembly. The cryogenic pipeline is C-shaped, including a cryogenic inlet, a cryogenic straight pipe, and a cryogenic groove connected in sequence. The cryogenic straight pipe is tightly fitted to the upper surface of the upper cold shield plate, then transitions into a thin tube extending vertically downwards to the cryogenic groove. The cryogenic groove is fixed to the upper surface of the guide rail platform. The high-temperature superconducting coil is disposed in multiple slots within the cryogenic groove. The single-stage and two-stage refrigerators are respectively fixed at different positions on the lower cold shield plate of the cold shield plate assembly. This invention can reduce the consumption of cryogenic liquid working fluid, significantly shorten the cooling time of the refrigerator, improve cooling efficiency, provide uniform heat conduction, and make the cooling process more stable.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature superconducting technology, specifically relating to a high-temperature superconducting coil cooling structure. Background Technology

[0002] High-temperature superconducting coils possess characteristics such as high current density, low loss, and excellent magnetic field properties, and have broad application prospects in fields such as superconducting motors, superconducting magnetic energy storage, and nuclear magnetic resonance imaging. As one of the common coil structure forms, high-temperature superconducting coils are composed of multiple superconducting discs stacked along the axial direction. They need to be maintained in a low-temperature environment to ensure superconducting properties during operation. Therefore, the design of the cooling structure directly affects the coil's operating stability, cooling efficiency, and overall performance.

[0003] Currently, the main cooling methods for high-temperature superconducting coils include immersion cooling and conduction cooling. Immersion cooling typically involves directly submerging the coil in cryogenic working fluids such as liquid helium or liquid nitrogen, resulting in high cooling efficiency. However, it suffers from high consumption of cryogenic working fluids (especially significant evaporation losses during liquid transfer in large devices) and complex system structure, limiting its application in miniaturized and mobile applications. Conduction cooling achieves heat transfer through a thermally conductive structure between the cooling medium and the coil, requiring no large amount of cryogenic working fluid and exhibiting a relatively simple system structure. This has become a research hotspot in high-temperature superconducting coil cooling technology. However, conduction cooling takes longer than immersion cooling and is prone to uneven heat conduction, high contact thermal resistance, and unreliable structural fixation under certain operating conditions.

[0004] Therefore, it is of great significance to design a conductive cooling structure that provides rapid and uniform heat conduction and good operating stability in order to improve the cooling efficiency and performance of high-temperature superconducting coils. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A high-temperature superconducting coil cooling structure includes: a cold shield plate assembly, a guide rail platform, a low-temperature pipe, a high-temperature superconducting coil, one or more single-stage refrigerators with the same structure, and one or more two-stage refrigerators with the same structure.

[0007] The cold screen panel assembly consists of four panels, top, bottom, front, and back, which are fixed to the four sides of the cold screen frame.

[0008] The guide rail platform is fixed at both ends to the upper cold screen plate of the cold screen plate assembly;

[0009] The cryogenic pipeline is C-shaped and includes a cryogenic inlet, a cryogenic straight pipe, and a cryogenic groove connected in sequence. The cryogenic straight pipe is a rectangular box that fits tightly against the upper surface of the upper cold shield plate, and then transitions into a thin pipe that extends vertically downward to the cryogenic groove. The cryogenic groove is a rectangular box with multiple through slots and is fixed to the upper surface of the guide rail platform. The cryogenic pipeline can be removed.

[0010] The high-temperature superconducting coil is set in multiple through slots of the low-temperature groove, and is closely attached to the inner surface of the multiple through slots and the upper surface of the guide rail platform. The current lead is led out from inside the guide rail platform.

[0011] The single-stage refrigeration unit and the two-stage refrigeration unit are fixed at different positions on the lower cold screen plate of the cold screen plate assembly.

[0012] The present invention has the following beneficial effects:

[0013] This invention pre-cools the cold screen, current leads, and high-temperature superconducting coil by circulating liquid through a low-temperature pipeline, which can significantly reduce the cooling time of the refrigerator and improve the cooling efficiency.

[0014] This invention uses a refrigeration unit to cool the cold shield, current leads, and high-temperature superconducting coil, which greatly reduces the consumption of cryogenic liquid working fluid and makes it more adaptable.

[0015] This invention achieves uniform cooling of the cold screen, current leads, and high-temperature superconducting coil by sequentially cooling the cold pipe and the refrigeration mechanism. This reduces uneven heat conduction paths in conductive cooling, solves the problem of large temperature gradients in different areas of the superconducting coil, which can easily lead to local overheating, and makes the overall cooling process more stable. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the high-temperature superconducting coil cooling structure in this invention, wherein 1-pull rod, 2-low temperature pipe, 3-high-temperature superconducting coil, 4-guide rail platform, 5-current lead, 6-cooling block, 7-single-stage refrigerator cold chain, 8-single-stage refrigerator, 9-secondary refrigerator, 10-secondary refrigerator primary cold chain, 11-secondary refrigerator secondary cold chain, 12-cold shield plate assembly, 13-cold shield frame.

[0017] Figure 2 This is a schematic diagram of the structure of the cryogenic pipeline of the present invention, wherein 3-high temperature superconducting coil, 5-current lead, 12-cold shield plate assembly, 14-cryogenic pipe port, and 15-cryogenic straight pipe;

[0018] Figure 3This is a schematic diagram of the structure of the refrigeration machine of the present invention, wherein 4-guide rail platform, 6-cooling block, 7-single-stage refrigeration machine cold chain, 8-single-stage refrigeration machine, 9-second-stage refrigeration machine, 10-second-stage refrigeration machine first-stage cold chain, 11-second-stage refrigeration machine second-stage cold chain, 12-cold shield plate assembly, 16-second-stage refrigeration machine first-stage cold head, 17-second-stage refrigeration machine second-stage cold head;

[0019] Figure 4 This is a schematic diagram of the coil placement and pull rod fixing structure of the present invention, wherein 1-pull rod, 2-low temperature pipe, 3-high temperature superconducting coil, 4-guide rail platform, 13-cold screen frame, 18-low temperature groove;

[0020] Figure 5 This is a cross-sectional view of the cooling structure of a high-temperature superconducting coil, where 1-pull rod, 2-low-temperature pipe, 3-high-temperature superconducting coil, 4-guide rail platform, 6-cooling block, 7-single-stage refrigerator cold chain, 8-single-stage refrigerator, 9-second-stage refrigerator, 10-second-stage refrigerator first-stage cold chain, 11-second-stage refrigerator second-stage cold chain, 13-cold shield frame, and 15-low-temperature straight pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] The purpose of this invention is to address the shortcomings of existing technologies by providing a high-temperature superconducting coil cooling structure. This invention solves the problems of high consumption of cryogenic liquid working fluid, long cooling time, and uneven and unreliable heat conduction during the cooling process of high-temperature superconducting coils.

[0023] like Figure 1 , Figure 5 As shown, the high-temperature superconducting coil cooling structure includes: a cold shield plate assembly 12, a guide rail platform 4, a low-temperature pipe 2, a high-temperature superconducting coil 3, one or more single-stage refrigerators 8 with the same structure, and one or more two-stage refrigerators 9 with the same structure.

[0024] The cold screen panel assembly 12 includes four panels: upper cold screen panel, lower cold screen panel, front cold screen panel, and rear cold screen panel, which are fixed to the upper, lower, front, and rear panels of the cold screen frame 13 (rectangular bracket) by bolts.

[0025] The guide rail platform 4 is fixed to the upper cold screen plate at both ends by two tie rods 1 (there is a gap between the guide rail platform 4 and the lower cold screen plate in the vertical direction).

[0026] The cryogenic pipeline 2 is C-shaped and includes a cryogenic inlet 14, a cryogenic straight pipe 15, and a cryogenic groove 18 connected in sequence. The cryogenic straight pipe 15 of the cryogenic pipeline 2 is a rectangular box that fits tightly against the upper surface of the upper cold shield plate, and then transitions into a thin pipe that extends vertically downward to the cryogenic groove 18; the cryogenic groove 18 is a rectangular box with multiple through slots and is fixed to the upper surface of the guide rail platform 4.

[0027] The high-temperature superconducting coil 3 is disposed in multiple through slots of the low-temperature groove 18 and is in close contact with the inner surface of the multiple through slots of the low-temperature groove 18 and the upper surface of the guide rail platform 4.

[0028] The current lead 5 of the high-temperature superconducting coil 3 is led out from the guide rail platform 4, coiled on the inner surface of the front cooling plate, and then connected to the front cooling plate.

[0029] For the single-stage refrigeration unit 8: one end of the single-stage refrigeration unit cold chain 7 is fixed to the cold head of the single-stage refrigeration unit 8, and the other end is fixed to the lower surface of the lower cold shield plate. The single-stage refrigeration unit 8 is used to cool the cold shield plate assembly 12.

[0030] For the secondary chiller 9: one end of the primary cold chain 10 of the secondary chiller is fixedly connected to the cooling block 6 at the primary cold head 16 of the secondary chiller, and the other end is fixed to the lower surface of the lower cold screen plate; one end of the secondary cold chain 11 of the secondary chiller is fixedly connected to the secondary cold head 17 of the secondary chiller, and the other end passes through the lower cold screen plate and is fixed on the guide rail platform 4. The primary cold chain 10 of the secondary chiller is used to cool the cold screen plate assembly 12, and the secondary cold chain 11 of the secondary chiller is used to cool the guide rail platform 4, thereby (through conduction) cooling the cold screen frame 13, the current lead 5, and the high-temperature superconducting coil 3.

[0031] like Figure 2 As shown, the cryogenic liquid working fluid is injected from the cryogenic port 14 of the cryogenic pipe 2, enters the cryogenic groove 18 through the cryogenic straight pipe 15, and fills the entire cryogenic pipe 2. The cryogenic straight pipe 15 of the cryogenic pipe 2 is in full contact with the upper cold shield plate, and the cryogenic groove 18 of the cryogenic pipe 2 is in full contact with the high-temperature superconducting coil 3. The current lead 5 led out from the high-temperature superconducting coil 3 is coiled on the front cold shield plate, and the two are in full contact. Before the single-stage refrigerator 8 and the two-stage refrigerator 9 start cooling, the cold shield plate assembly 12, the cold shield frame 13, the high-temperature superconducting coil 3, and the current lead 5 are pre-cooled through the cryogenic pipe 2.

[0032] like Figure 3 As shown, the single-stage refrigeration unit 8 is tightly connected to the lower cold shield plate through the single-stage refrigeration unit cold chain 7. The two secondary refrigeration units 9 have the same structure and are respectively set at different positions on the lower surface of the lower cold shield plate.

[0033] The primary cold head 16 of the secondary refrigeration unit is fitted into the cooling block 6. The secondary refrigeration unit 9 is tightly connected to the lower surface of the lower cold screen plate through the primary cold chain 10, and the secondary refrigeration unit 9 is tightly connected to the guide rail platform 4 through the secondary cold chain 11.

[0034] After the cold shield assembly 12, cold shield frame 13, high-temperature superconducting coil 3 and current lead 5 are pre-cooled by the low-temperature pipeline 2, the cold shield assembly 12, cold shield frame 13, current lead 5 and high-temperature superconducting coil 3 are cooled by the single-stage refrigerator cold chain 7, the second-stage refrigerator first-stage cold chain 10 and the second-stage refrigerator second-stage cold chain 11 respectively.

[0035] like Figure 4 As shown, the high-temperature superconducting coil 3 is in contact with the inner surface of the through groove of the low-temperature groove 18 of the low-temperature pipe 2. Both are placed on the upper surface of the guide rail platform 4. Each through groove of the low-temperature groove 18 is respectively equipped with a high-temperature superconducting coil 3. The current lead 5 of the high-temperature superconducting coil 3 is led out from the guide rail platform 4. The inner wall of the low-temperature groove 18 is tightly fitted with the outer edge of the coil of the high-temperature superconducting coil 3, so that each high-temperature superconducting coil 3 is uniformly cooled. The cold screen is composed of a cold screen frame 13 and a cold screen plate assembly 12. Four tie rods 1 fix the low-temperature pipe 2 (through the guide rail platform 4) on the cold screen.

[0036] The current lead 5, the cooling block 6, the single-stage refrigeration unit cold chain 7, the two-stage refrigeration unit first-stage cold chain 10, and the two-stage refrigeration unit second-stage cold chain 11 are all made of oxygen-free copper. Specifically, the single-stage refrigeration unit cold chain 7, the two-stage refrigeration unit first-stage cold chain 10, and the two-stage refrigeration unit second-stage cold chain 11 are all composed of oxygen-free copper blocks and braided copper wire bundles, with the oxygen-free copper blocks located at both ends and the braided copper wire bundles connecting the two ends. The guide rail platform 4, the cold shield plate assembly 12, and the cold shield frame 13 are all made of aluminum alloy, and the tie rod 1 is made of G10 (epoxy resin) material.

[0037] The ends of the single-stage refrigeration cold chain 7, the first-stage refrigeration cold chain 10, and the second-stage refrigeration cold chain 11 are fixed to other components with bolts. Similarly, the cold shield frame 13 and the cold shield plate assembly 12, as well as the tie rod 1 and the cold shield plate assembly 12, are also fixed with bolts. The oxygen-free copper surface is polished to make it smooth. Gaps between various components, including between the cold shield plate assembly 12 and the single-stage refrigeration cold chain 7 and the first-stage refrigeration cold chain 10, and between the guide rail platform 4 and the second-stage refrigeration cold chain 11, are filled with indium foil or thermal grease to ensure more efficient heat transfer. The current lead 5 is tightly coiled and attached to the front cold shield plate to cool the cold shield when current flows through it. The single-stage refrigeration unit 8 and the two-stage refrigeration unit 9 are connected to the cold shield or guide rail platform 4 via a single-stage refrigeration unit cold chain 7, a two-stage refrigeration unit primary cold chain 10, and a two-stage refrigeration unit secondary cold chain 11. This increases the contact area between the single-stage refrigeration unit 8 and the two-stage refrigeration unit 9 and the cold shield plate assembly 12 and the guide rail platform 4 during heat conduction, thereby improving the heat conduction capacity. The single-stage refrigeration unit cold chain 7, the two-stage refrigeration unit primary cold chain 10, and the two-stage refrigeration unit secondary cold chain 11 are made of braided copper wire bundles to reduce the impact of vibration on the single-stage refrigeration unit 8 and the two-stage refrigeration unit 9 and to improve the heat conduction capacity of the single-stage refrigeration unit 8, the two-stage refrigeration unit primary cold chain 10, and the two-stage refrigeration unit secondary cold chain 11.

[0038] like Figure 4 As shown, key cooling components such as the cold shield (cold shield plate assembly 12, cold shield frame 13), current leads 5, and high-temperature superconducting coil 3 are pre-cooled uniformly by circulating liquid through the cryogenic pipe 2. After pre-cooling, a single-stage refrigerator 8 and a two-stage refrigerator 9 are used for further cooling, which reduces the loss of the cryogenic liquid working fluid. The pre-cooled high-temperature superconducting coil 3 is then cooled by conduction cooling through the single-stage refrigerator 8 and the two-stage refrigerator 9. At this point, the cryogenic pipe 2 can be removed, facilitating the use of the high-temperature superconducting coil cooling structure in a vacuum Dewar, enabling its subsequent application in miniaturized and mobile equipment.

[0039] This invention uses a cryogenic pipeline 2 to pass liquid for cooling. Specifically, a cryogenic liquid working medium is introduced from the cryogenic pipe port 14 to pre-cool the cold shield plate assembly 12, the cold shield frame 13, the high-temperature superconducting coil 3, and the current lead 5. Once the temperature drops to a stable range, the single-stage refrigerator 8 and the two-stage refrigerator 9 are started for refrigeration. This can significantly reduce the cooling time of the refrigerator and improve the cooling efficiency.

[0040] This invention uses a single-stage refrigeration unit 8 and a two-stage refrigeration unit 9 for cooling and temperature reduction. Specifically, the cold shield and low-temperature pipeline 2 are cooled by a single-stage refrigeration unit cold chain 7, a two-stage refrigeration unit first-stage cold chain 10, and a two-stage refrigeration unit second-stage cold chain 11. This can significantly reduce the consumption of low-temperature liquid working fluid and make the cooling application more adaptable.

[0041] This invention achieves uniform cooling of the cold screen, current lead 5, and high-temperature superconducting coil 3 by using a low-temperature pipe 2 for liquid cooling and a refrigerator for cooling in sequence. This reduces uneven heat conduction paths in conductive cooling, solves the problem of large temperature gradients in different areas of the superconducting coil, which can easily lead to local overheating, and makes the conductive cooling process more stable and reliable.

[0042] The overall device of this invention is suitable for small high-temperature superconducting coil magnets. The entire device is about 1400mm long, about 1000mm high, and about 500mm wide.

[0043] The above description is merely an embodiment of the present invention and does not limit the scope of the invention. Any equivalent structural or procedural transformations made based on the description and drawings of this invention, or direct or indirect applications in other related system fields, are similarly included within the protection scope of this invention. Contents not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A high-temperature superconducting coil cooling structure, characterized in that, include: Cold shield panel assembly, guide rail platform, low temperature pipeline, high temperature superconducting coil, one or more single-stage refrigerators with the same structure and one or more two-stage refrigerators with the same structure; The cold screen panel assembly consists of four panels, top, bottom, front, and back, which are fixed to the four sides of the cold screen frame. The guide rail platform is fixed at both ends to the upper cold screen plate of the cold screen plate assembly; The cryogenic pipeline is C-shaped and includes a cryogenic inlet, a cryogenic straight pipe, and a cryogenic groove connected in sequence. The cryogenic straight pipe is a rectangular box that fits tightly against the upper surface of the upper cold shield plate, and then transitions into a thin pipe that extends vertically downward to the cryogenic groove. The cryogenic groove is a rectangular box with multiple through slots and is fixed to the upper surface of the guide rail platform. The cryogenic pipeline can be removed. The high-temperature superconducting coil is set in multiple through slots of the low-temperature groove, and is closely attached to the inner surface of the multiple through slots and the upper surface of the guide rail platform. The current lead is led out from inside the guide rail platform. The single-stage refrigeration unit and the two-stage refrigeration unit are fixed at different positions on the lower cold screen plate of the cold screen plate assembly.

2. The high-temperature superconducting coil cooling structure according to claim 1, characterized in that, The configuration of one or more identical single-stage chillers is as follows: one end of the cold chain of the single-stage chiller is fixed to the cold head of the single-stage chiller, and the other end is fixed to the lower surface of the lower cold shield plate; the single-stage chiller is used to cool the cold shield plate assembly. One or more identical secondary chillers are configured as follows: one end of the primary cold chain of the secondary chiller is fixedly connected to the cooling block at the primary cold head of the secondary chiller, and the other end is fixed to the lower surface of the lower cold shield plate; one end of the secondary cold chain of the secondary chiller is fixedly connected to the secondary cold head of the secondary chiller, and the other end passes through the lower cold shield plate and is fixed to the guide rail platform; the primary cold chain of the secondary chiller is used to cool the cold shield plate assembly, and the secondary cold chain of the secondary chiller is used to cool the guide rail platform, thereby cooling the cold shield frame, current leads and high-temperature superconducting coil.

3. The high-temperature superconducting coil cooling structure according to claim 1, characterized in that, The cold screen panel assembly includes: upper cold screen panel, lower cold screen panel, front cold screen panel, and rear cold screen panel, which are fixed to the upper, lower, front, and rear surfaces of the cold screen frame by bolts.

4. The high-temperature superconducting coil cooling structure according to claim 2, characterized in that, The guide rail platform is fixed to the upper cooling screen plate at both ends by two tie rods.

5. The high-temperature superconducting coil cooling structure according to claim 1, characterized in that, The current lead of the high-temperature superconducting coil is led out from the guide rail platform, coiled on the inner surface of the front cooling plate, and then exited from the front cooling plate.

6. The high-temperature superconducting coil cooling structure according to claim 2, characterized in that, Oxygen-free copper is used for current leads, cooling blocks, single-stage refrigeration cold chain, two-stage refrigeration first-stage cold chain, and two-stage refrigeration second-stage cold chain.

7. The high-temperature superconducting coil cooling structure according to claim 2, characterized in that, The single-stage refrigeration unit cold chain, the two-stage refrigeration unit first-stage cold chain, and the two-stage refrigeration unit second-stage cold chain are all composed of oxygen-free copper blocks and braided copper wire bundles. The oxygen-free copper blocks are located at both ends, and the braided copper wire bundles are connected between the two ends.

8. The high-temperature superconducting coil cooling structure according to claim 4, characterized in that, The guide rail platform, cold screen plate assembly, and cold screen frame are all made of aluminum alloy, while the tie rods are made of epoxy resin.

9. The high-temperature superconducting coil cooling structure according to claim 4, characterized in that, The cold chain of a single-stage refrigeration unit, the first-stage cold chain of a two-stage refrigeration unit, and the second-stage cold chain of a two-stage refrigeration unit are fixed to other components by bolts. The cold shield frame is fixed to the cold shield panel assembly, and the tie rod is fixed to the cold shield panel assembly by bolts.

10. The high-temperature superconducting coil cooling structure according to claim 6, characterized in that, The surface of oxygen-free copper is polished to make it smooth; the gaps between the cold shield plate assembly and the cold chain of the single-stage refrigeration unit, the first-stage cold chain of the second-stage refrigeration unit, and the connection between the guide rail platform and the second-stage cold chain of the second-stage refrigeration unit are filled with indium sheets or thermal grease.

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