Cold conduction device for superconducting magnet

Abstract

The invention relates to the technical field of superconducting magnets, in particular to a cold conduction device for a superconducting magnet, which comprises a cold conduction chamber and a refrigerator mounted on the cold conduction chamber, and the cold conduction chamber comprises an upper end plate, a corrugated pipe section and a lower end plate; a first cold conducting piece is arranged in the middle of the corrugated pipe section; the upper end plate is fixed on a normal temperature layer of the superconducting magnet; the lower end plate is fixed on a low-temperature layer of the superconducting magnet; the refrigerating machine comprises a first-stage cold head and a second-stage cold head, a first cold conduction plate is arranged on the first-stage cold head, and the first cold conduction plate is connected with the cold shield layer of the superconducting magnet through a first cold conduction piece and a first cold conduction belt to achieve heat conduction between the first cold conduction plate and the cold shield layer. And a second cold conduction plate is fixed on the secondary cold head and is connected with the low-temperature layer of the superconducting magnet through a second cold conduction piece and a second cold conduction belt. The first-stage cold head and the second-stage cold head of the cold conduction device do not bear pressure from the cold conduction piece, and good thermal contact and heat conduction exist between the cold heads and the cold conduction piece; the refrigerator has the advantages of long service life, high heat conduction efficiency and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting magnets, and particularly to a conduction cooling device for a superconducting magnet. Background Art

[0002] A conduction-cooled superconducting magnet is a magnet that does not use liquid helium and keeps the superconducting wire in a superconducting environment through a large number of excellent conduction materials. At present, the research and development and production of conduction-cooled superconducting magnets are increasing. The service life of a superconducting magnet is generally 10 years, which is much longer than that of a refrigerator. Therefore, during the entire life cycle of the superconducting magnet, the refrigerator needs to be maintained and replaced multiple times. In a conduction-cooled superconducting magnet, to prevent the vacuum environment in the normal temperature layer from being damaged during its maintenance and replacement, the refrigerator is installed in a vacuum container to reduce its heat conduction to the outside. At the same time, the vacuum container should be separated from the normal temperature layer and the cold screen layer to prevent the vacuum environment between the normal temperature layer and the cold screen layer from being damaged during the repair and replacement of the refrigerator.

[0003] In the existing conduction cooling devices, such as those disclosed in Chinese patents with publication numbers CN117079920A and CN118299142A, the cold head of the refrigerator is mainly pressed against the conduction cooling component by means of an elastic component or gas pressure to achieve thermal contact. Since the thermal contact between the cold head and the conduction cooling component is achieved through an elastic component or gas pressure, the contact condition is poor, there is a large thermal resistance between the two, and the thermal conductivity is not good. At the same time, in order to increase the pressure of the thermal contact between the cold head and the conduction cooling component, a very large upward pressure is applied to the cold head of the refrigerator in these assembly methods, which causes certain damage to the cold head of the refrigerator.

[0004] Therefore, designing a conduction cooling device for a superconducting magnet has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a conduction cooling device for a superconducting magnet aiming at the above deficiencies. During the use of the refrigerator in this conduction cooling device, neither the primary cold head nor the secondary cold head of the refrigerator bears the pressure from the conduction cooling component; both the primary cold head and the secondary cold head of the refrigerator are fixedly connected to the first conduction cooling component and the second conduction cooling component respectively through fasteners, ensuring good thermal contact and heat conduction; it has the advantages of simple structure, long service life of the refrigerator, high heat conduction efficiency, etc.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows: A conduction cooling device for a superconducting magnet, comprising a conduction cooling chamber with openings at both ends and a refrigerator installed on the conduction cooling chamber. The conduction cooling chamber includes an upper end plate, a corrugated pipe section, and a lower end plate connected in sequence from top to bottom; a first conduction cooling member is provided in the middle of the corrugated pipe section; the upper end plate is fixed on the normal temperature layer of the superconducting magnet, and the lower end plate is fixedly installed on the low temperature layer of the superconducting magnet; the refrigerator includes a first stage cold head, and a first conduction cooling plate is fixedly installed on the first stage cold head. The first conduction cooling plate is fixedly connected to the first conduction cooling member; the first conduction cooling member is connected to the cold shield layer of the superconducting magnet through a first conduction cooling belt and realizes heat conduction between the two.

[0007] As an improvement, the refrigerator further includes a second stage cold head, and a second conduction cooling plate is fixedly installed on the second stage cold head. The second conduction cooling plate is fixedly connected to the second conduction cooling member; the second conduction cooling member is connected to the low temperature layer of the superconducting magnet through a second conduction cooling belt and realizes heat conduction between the two.

[0008] As an improvement, both the first conduction cooling belt and the second conduction cooling belt are flexible conduction cooling belts, and the flexible conduction cooling belts enable soft connections between the first conduction cooling member and the cold shield layer, and between the second conduction cooling member and the low temperature layer.

[0009] As an improvement, a detachable fixing plate is fixedly installed on the upper end plate of the conduction cooling chamber, and the refrigerator is fixedly installed on the fixing plate.

[0010] As an improvement, the first conduction cooling plate and the first conduction cooling member are detachably fixedly connected through a plurality of first fasteners; a plurality of first through holes are provided on the fixing plate; the first fasteners are located directly below the first through holes to facilitate the disassembly, assembly, and fixation between the first conduction cooling plate and the first conduction cooling member.

[0011] As an improvement, the second conduction cooling plate and the second conduction cooling member are detachably fixedly connected through a plurality of second fasteners; a plurality of second through holes are provided on the first conduction cooling plate; the second fasteners are located directly below the second through holes, and the second through holes are located directly below the first through holes to facilitate the disassembly, assembly, and fixation between the second conduction cooling plate and the second conduction cooling member.

[0012] As an improvement, an annular cover plate is provided on the fixing plate, and the cover plate is used to cover the plurality of first through holes.

[0013] As an improvement, the corrugated pipe section includes a first corrugated pipe and a second corrugated pipe located below the first corrugated pipe, and the first conduction cooling member is fixed between the first corrugated pipe and the second corrugated pipe.

[0014] The present invention adopts the above technical solutions and has the following advantages compared with the prior art: 1. The above structural design enables that during the operation of the refrigerator, neither the first-stage cold head nor the second-stage cold head of the refrigerator bears the pressure from the heat conduction member; the first-stage cold head and the second-stage cold head of the refrigerator are respectively fixedly connected to the first heat conduction member and the second heat conduction member through fasteners, ensuring good thermal contact and heat conduction; and the refrigerator has a long service life and high heat conduction efficiency.

[0015] 2. In the heat conduction device of the present invention, during the operation, the cryogenic container of the superconducting magnet is not connected to the heat conduction device, and they are independent chambers respectively. When replacing or maintaining the refrigerator, this structure can reduce the heat conduction amount from the external environment to the inside of the magnet.

[0016] 3. The arrangements of the first through hole and the second through hole facilitate the disassembly and assembly during the maintenance and replacement of the refrigerator.

[0017] The present invention will be described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of a heat conduction device for a superconducting magnet according to the present invention; Figure 2 is Figure 1 a schematic structural diagram of the heat conduction chamber in Figure 3 is Figure 1 a schematic structural diagram of the cold head in Figure 4 is Figure 3 a schematic structural diagram of the fixing plate in Figure 5 is Figure 3 a schematic structural diagram of the first heat conduction plate in Figure 6 is Figure 3 a schematic structural diagram of the second heat conduction plate in Wherein: 1 - normal temperature layer, 2 - cold shield layer, 3 - low temperature layer, 4 - heat conduction chamber, 5 - refrigerator, 6 - upper end plate, 7 - first bellows, 8 - first heat conduction member, 9 - second bellows, 10 - lower end plate, 11 - first heat conduction band, 12 - second heat conduction band, 13 - second heat conduction member, 14 - bellows section, 15 - first-stage cold head, 16 - second-stage cold head, 17 - first heat conduction plate, 18 - second heat conduction plate, 19 - fixing plate, 20 - first through hole, 21 - second through hole, 22 - first fastener, 23 - second fastener, 24 - cover plate, 25 - first sealing ring, 26 - second sealing ring, 27 - third sealing ring, 28 - first screw hole, 29 - first light hole, 30 - second screw hole, 31 - second light hole. Detailed Embodiments

[0019] Explanation of Related Terms The cold head is a part of the refrigerator. When the refrigerator works, heat conduction occurs between the cold head and the cooling material to the outside world to achieve the purpose of refrigeration.

[0020] Embodiment

[0021] As Figure 1 and Figure 2 As commonly shown in [relevant figures], the superconducting magnet includes a normal temperature layer 1, a cold screen layer 2, and a low temperature layer 3 that are sleeved in sequence from the outside to the inside; a sealed vacuum chamber is formed between the normal temperature layer 1 and the low temperature layer 3 for heat preservation of the superconducting magnet. The normal temperature layer 1 is provided with mounting holes for installing a heat conduction device; the cold screen layer 2 is provided with avoidance holes for installing the heat conduction device.

[0022] As Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As commonly shown in [relevant figures], a heat conduction device for a superconducting magnet includes a heat conduction chamber 4 with openings at both ends and a refrigerator 5 installed on the heat conduction chamber 4. The heat conduction chamber 4 includes an upper end plate 6, a corrugated pipe section 14, and a lower end plate 10 that are connected in sequence from top to bottom. A first heat conduction member 8 is provided in the middle of the corrugated pipe section 14. Preferably, the corrugated pipe section 14 includes a first corrugated pipe 7 and a second corrugated pipe 9 located below the first corrugated pipe 7, and the first heat conduction member 8 is fixed between the first corrugated pipe 7 and the second corrugated pipe 9. The inner diameter of the first corrugated pipe 7 is larger than the outer diameter of the first heat conduction member 8, and the outer diameter of the second corrugated pipe 9 is smaller than the inner diameter of the first corrugated pipe 7. Each component of the heat conduction chamber 4 is welded into a whole.

[0023] A detachable fixing plate 19 is fixedly installed on the upper end plate 6 of the heat conduction chamber 4, and the fixing plate 19 is disc-shaped. The refrigerator 5 is detachably fixedly installed on the fixing plate 19 through fasteners. A first sealing ring 25 is provided between the upper end plate 6 and the fixing plate 19, and a second sealing ring 26 is provided between the refrigerator 5 and the fixing plate 19.

[0024] The upper end plate 6 is fixed on the mounting hole of the normal temperature layer 1 of the superconducting magnet; the lower end plate 10 is fixedly installed on the low temperature layer 3 of the superconducting magnet. The sealed vacuum chamber formed between the normal temperature layer 1 and the low temperature layer 3 is not connected to the heat conduction chamber 4, and they are independent chambers.

[0025] The first heat conduction member 8 is connected to the cold screen layer 2 of the superconducting magnet through a first heat conduction belt 11 to achieve heat conduction between the two. In this embodiment, preferably, the first heat conduction belt 11 includes multiple groups of copper braids. One end of each group of copper braids is fixed on the first heat conduction member 8, and the other end is fixed on the cold screen layer 2 of the superconducting magnet. The copper braids are fixed to the first heat conduction member 8 and the cold screen layer 2 by welding to ensure the heat conduction efficiency between the two.

[0026] AsFigure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 collectively show that the refrigerator 5 includes a first-stage cold head 15 and a second-stage cold head 16, and both the first-stage cold head 15 and the second-stage cold head 16 are disposed inside the heat conduction chamber 4. A first heat conduction plate 17 is fixedly installed on the first-stage cold head 15. The lower end surface of the first heat conduction plate 17 is flush with and in contact with the upper end surface of the first heat conduction member 8. The first heat conduction plate 17 and the first heat conduction member 8 are detachably fixedly connected by fasteners. A second heat conduction plate 18 is fixedly installed on the second-stage cold head 16. The lower end surface of the second heat conduction plate 18 is flush with and in contact with the upper end surface of the second heat conduction member 13. The second heat conduction plate 18 and the second heat conduction member 13 are detachably fixedly connected by fasteners. The outer diameters of both the second heat conduction plate 18 and the second heat conduction member 13 are smaller than the inner diameter of the second corrugated pipe 9. The second heat conduction member 13 is connected to the cryogenic layer 3 of the superconducting magnet through the second heat conduction belt 12 to achieve heat conduction therebetween.

[0027] As Figure 1 and Figure 2 collectively show, both the first heat conduction belt 11 and the second heat conduction belt 12 are flexible heat conduction belts. The flexible heat conduction belts provide a certain amount of movement allowance between the first heat conduction member 8 and the cold screen layer 2, and between the second heat conduction member 13 and the cryogenic layer 3, realizing flexible connection. Preferably in this embodiment, the second heat conduction belt 12 includes multiple groups of copper braids. One end of each group of copper braids is fixed on the second heat conduction member 13, and the other end is fixed on the cryogenic layer 3 of the superconducting magnet. The fixation between the copper braids and the second heat conduction member 13 and the cryogenic layer 3 is all achieved by welding to ensure the heat conduction efficiency therebetween.

[0028] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 collectively show that the first heat conduction plate 17 and the first heat conduction member 8 are detachably fixedly connected by a plurality of first fasteners 22. A plurality of first through holes 20 are provided on the fixing plate 19. The positions of the plurality of first fasteners 22 correspond to those of the plurality of first through holes 20 one by one. The first fasteners 22 are located directly below the first through holes 20 to facilitate the operation of the first fasteners 22 using tools when disassembling or fixing between the first heat conduction plate 17 and the first heat conduction member 8.

[0029] The second cold guide plate 18 and the second cold guiding member 13 are detachably and fixedly connected by a plurality of second fasteners 23; a plurality of second through holes 21 are provided on the first cold guide plate 17; the positions of the plurality of second fasteners 23 correspond to those of the plurality of first through holes 20 and the plurality of second through holes 21 one by one. The second fastener 23 is located directly below the second through hole 21, the second through hole 21 is located directly below the first through hole 20, and the aperture of the first through hole 20 is larger than that of the second through hole 21. The plurality of first through holes 20 and the plurality of second through holes 21 facilitate the use of tools to operate the second fastener 23 when disassembling, assembling and fixing between the second cold guide plate 18 and the second cold guiding member 13. An annular cover plate 24 is provided on the fixing plate 19, and the cover plate 24 is used to cover the plurality of first through holes 20. The fixing plate 19 and the cover plate 24 are used for sealing the upper end of the cold guide chamber 4. Preferably, two third sealing rings 27 are provided between the cover plate 24 and the fixing plate 19. The arrangement of the first through hole 20 and the second through hole 21 facilitates the disassembly and assembly of the refrigerator 5.

[0030] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 collectively shown, in this embodiment, preferably, both the first fastener 22 and the second fastener 23 are screws. First screw holes 28 are machined at positions corresponding to the first fastener 22 on the first cold guiding member 8, and first clearance holes 29 adapted to the first screw holes 28 are machined at positions corresponding to the first fastener 22 on the first cold guide plate 17. Second screw holes 30 are machined at positions corresponding to the second fastener 23 on the second cold guiding member 13, and second clearance holes 31 adapted to the second screw holes 30 are machined at positions corresponding to the second fastener 23 on the second cold guide plate 18.

[0031] The above structural design of the present invention is different from the prior art in which the cold head is press-connected to the cold guiding member by using an elastic component or gas pressure to achieve heat conduction. In the cold guiding device of the present invention, neither the primary cold head 15 nor the secondary cold head 16 of the refrigerator 5 bears the pressure from the cold guiding member or the pressure from the gas. The primary cold head 15 and the secondary cold head 16 of the refrigerator 5 are respectively fixedly connected to the first cold guiding member 8 and the second cold guiding member 13 through fasteners, ensuring good thermal contact and heat conduction; and the refrigerator 5 has a long service life and high heat conduction efficiency.

[0032] In summary, for the cold guiding device for a superconducting magnet of the present invention, during the use of the refrigerator, its cold head does not bear the pressure from the cold guiding member; the primary cold head and the secondary cold head of the refrigerator are respectively fixedly connected to the first cold guiding member and the second cold guiding member through fasteners, ensuring good thermal contact and heat conduction; and it has the advantages of simple structure, long service life of the refrigerator, high heat conduction efficiency, etc.

[0033] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A cooling device for a superconducting magnet, characterized in that: It comprises a cooling chamber (4) with openings at both ends and a refrigerator (5) mounted on the cooling chamber (4); the cooling chamber (4) comprises an upper end plate (6), a bellows section (14) and a lower end plate (10) connected in sequence from top to bottom; a first cooling member (8) is provided in the middle of the bellows section (14); The upper end plate (6) is fixed on the normal temperature layer (1) of the superconducting magnet, and the lower end plate (10) is fixedly mounted on the low temperature layer (3) of the superconducting magnet; The refrigerator (5) comprises a first-stage cold head (15), a first cold conduction plate (17) being fixedly mounted on the first-stage cold head (15), and the first cold conduction plate (17) being fixedly connected to a first cold conduction member (8); the first cold conduction member (8) is connected to a cold shield layer (2) of a superconducting magnet via a first cold conduction belt (11) to achieve heat conduction between the two.

2. The cooling device for superconducting magnets according to claim 1, characterized in that: The refrigerator (5) further comprises a secondary cold head (16), a second cold conduction plate (18) being fixedly mounted on the secondary cold head (16), the second cold conduction plate (18) being fixedly connected to a second cold conduction member (13); the second cold conduction member (13) is connected to a low-temperature layer (3) of the superconducting magnet via a second cold conduction belt (12) to achieve heat conduction between the two.

3. The cooling device for superconducting magnets according to claim 2, characterized in that: The first cooling belt (11) and the second cooling belt (12) are both soft cooling belts, which enable soft connections to be achieved between the first cooling component (8) and the cold shield layer (2), and between the second cooling component (13) and the low-temperature layer (3).

4. The cooling device for superconducting magnets according to claim 2, characterized in that: A detachable fixing plate (19) is fixedly mounted on the upper end plate (6) of the cooling chamber (4), and the refrigerator (5) is fixedly mounted on the fixing plate (19).

5. The cooling device for superconducting magnets according to claim 4, characterized in that: The first cooling plate (17) and the first cooling member (8) are detachably fixedly connected via a plurality of first fasteners (22); a plurality of first through holes (20) are provided on the fixing plate (19); and the first fasteners (22) are located directly below the first through holes (20) to facilitate assembly and disassembly of the first cooling plate (17) and the first cooling member (8).

6. The cooling device for superconducting magnets according to claim 5, characterized in that: The second cold conduction plate (18) and the second cold conduction member (13) are detachably fixedly connected via a plurality of second fasteners (23); a plurality of second through holes (21) are provided on the first cold conduction plate (17); the second fasteners (23) are located directly below the second through holes (21), and the second through holes (21) are located directly below the first through holes (20), so as to facilitate the disassembly, assembly and fixation between the second cold conduction plate (18) and the second cold conduction member (13).

7. The cooling device for superconducting magnets according to claim 5, characterized in that: An annular cover plate (24) is provided on the fixing plate (19), and the cover plate (24) is used to cover the plurality of first through holes (20).

8. The cooling device for superconducting magnets according to any one of claims 1 to 7, characterized in that: The bellows section (14) comprises a first bellows (7) and a second bellows (9) located below the first bellows (7), and the first cooling member (8) is fixed between the first bellows (7) and the second bellows (9).

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