A cooling device for superconducting magnets

Abstract

The present invention relates to the technical field of superconducting magnets, and in particular to a cooling device for superconducting magnets, comprising a cooling chamber and a refrigerator mounted on the cooling chamber. The cooling chamber comprises an upper end plate, a bellows section, and a lower end plate. A first cooling member is provided in the middle of the bellows section. The upper end plate is fixed to the normal temperature layer of the superconducting magnet. The lower end plate is fixed to the low temperature layer of the superconducting magnet. The refrigerator comprises a primary cold head and a secondary cold head. The primary cold head is provided with a first cooling plate, which is connected to the cold shield layer of the superconducting magnet via the first cooling member and a first cooling tape, thereby achieving heat conduction between the two. A second cooling plate is fixed to the secondary cold head, which is connected to the low temperature layer of the superconducting magnet via a second cooling member and a second cooling tape. Neither the primary nor the secondary cold heads of the cooling device bear pressure from the cooling member, and good thermal contact and heat conduction are achieved between the cold heads and the cooling member. The device has the advantages of a long service life of the refrigerator and high heat conduction efficiency.

Description

Technical Field

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

[0002] Conduction-cooled superconducting magnets avoid the use of liquid helium and instead maintain the superconducting wire in a superconducting environment through the use of a large amount of high-quality conductive material. Currently, the research, development, and production of conduction-cooled superconducting magnets are increasing. The lifespan of a superconducting magnet is typically 10 years, far exceeding the lifespan of the refrigerator. Therefore, the refrigerator requires frequent maintenance and replacement throughout the lifespan of a superconducting magnet. In conduction-cooled superconducting magnets, to prevent the vacuum environment within the room-temperature layer from being disrupted during maintenance and replacement, the refrigerator is housed in a vacuum vessel, minimizing its exposure to the outside world. Furthermore, the vacuum vessel should be separated from the room-temperature layer and the cold shield layer to prevent damage to the vacuum environment between the two layers during refrigerator maintenance and replacement.

[0003] The cooling devices in the prior art, such as those disclosed in Chinese patents with publication numbers CN117079920A and CN118299142A, mainly use elastic components or gas pressure to press the cold head of the refrigerator and the cooling conductor together to achieve thermal contact. Since the thermal contact between the cold head and the cooling conductor is achieved through elastic components or gas pressure, the contact conditions are poor, there is a large thermal resistance between the two, and the thermal conductivity is poor. At the same time, in order to increase the pressure of the thermal contact between the cold head and the cooling conductor, these assembly methods will apply a huge, upward pressure to the cold head of the refrigerator, causing certain damage to the cold head of the refrigerator.

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

[0005] The technical problem that the present invention intends to solve is to address the above shortcomings and provide a cooling device for superconducting magnets. During the use of the refrigerator of the cooling device, the first-level cold head and the second-level cold head of the refrigerator are not subjected to pressure from the cooling member; the first-level cold head and the second-level cold head of the refrigerator are fixedly connected to the first cooling member and the second cooling member respectively through fasteners to ensure that they have good thermal contact and heat conduction; it has the advantages of simple structure, long service life of the refrigerator, and high heat conduction efficiency.

[0006] In order to solve the above problems, the technical solutions adopted by the present invention are as follows:

[0007] A cooling device for a superconducting magnet comprises a cooling chamber with openings at both ends and a refrigerator mounted on the cooling chamber, wherein the cooling chamber comprises an upper end plate, a bellows section and a lower end plate connected in sequence from top to bottom; a first cooling member is provided in the middle of the bellows section; the upper end plate is fixed on the normal temperature layer of the superconducting magnet, and the lower end plate is fixed on the low temperature layer of the superconducting magnet; the refrigerator comprises a first-stage cold head, on which a first cooling plate is fixedly mounted, and the first cooling plate is fixedly connected to the first cooling member; the first cooling member is connected to the cold shield layer of the superconducting magnet via a first cooling belt to achieve heat conduction between the two.

[0008] As an improvement, the refrigerator also includes a secondary cold head, on which a second cold conduction plate is fixedly mounted, and the second cold conduction plate is fixedly connected to a second cold conduction member; the second cold conduction member is connected to the low-temperature layer of the superconducting magnet through a second cold conduction belt to achieve heat conduction between the two.

[0009] As an improvement, the first cooling belt and the second cooling belt are both soft cooling belts, which enable soft connections between the first cooling member and the cold shield layer, and between the second cooling member and the low-temperature layer.

[0010] As an improvement, a detachable fixing plate is fixedly mounted on the upper end plate of the cooling chamber, and the refrigerator is fixedly mounted on the fixing plate.

[0011] As an improvement, the first cooling plate and the first cooling member are detachably fixedly connected by 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 disassembly and fixation between the first cooling plate and the first cooling member.

[0012] As an improvement, the second cooling plate and the second cooling member are detachably fixedly connected by multiple second fasteners; multiple second through holes are provided on the first 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, so as to facilitate the disassembly and fixation between the second cooling plate and the second cooling member.

[0013] As an improvement, an annular cover plate is provided on the fixing plate, and the cover plate is used to cover the multiple first through holes.

[0014] As an improvement, the bellows section includes a first bellows and a second bellows located below the first bellows, and the first cooling member is fixed between the first bellows and the second bellows.

[0015] The present invention adopts the above technical solution and has the following advantages compared with the prior art:

[0016] 1. The above structural design ensures that during the use of the refrigerator, the first-level cold head and the second-level cold head of the refrigerator are not subjected to pressure from the cooling member; the first-level cold head and the second-level cold head of the refrigerator are fixedly connected to the first cooling member and the second cooling member respectively through fasteners, ensuring that they have good thermal contact and heat conduction; and the refrigerator has a long service life and high heat conduction efficiency.

[0017] 2. The cooling device of the present invention is not connected to the low-temperature container of the superconducting magnet during use, and each is an independent chamber. When replacing or maintaining the refrigerator, this structure can reduce the amount of heat conducted from the external environment to the inside of the magnet.

[0018] 3. The arrangement of the first through hole and the second through hole can facilitate the disassembly and assembly of the refrigerator during maintenance and replacement.

[0019] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a cooling device for a superconducting magnet according to the present invention;

[0021] Figure 2 for Figure 1 Schematic diagram of the structure of the intermediate cooling chamber;

[0022] Figure 3 for Figure 1 Schematic diagram of the structure of the intercooler;

[0023] Figure 4 for Figure 3 Schematic diagram of the structure of the middle fixed plate;

[0024] Figure 5 for Figure 3 A schematic structural diagram of the first cooling plate;

[0025] Figure 6 for Figure 3 Structural schematic diagram of the second cooling plate;

[0026] Among them: 1-normal temperature layer, 2-cold shield layer, 3-low temperature layer, 4-cooling chamber, 5-refrigeration machine, 6-upper end plate, 7-first bellows, 8-first cooling part, 9-second bellows, 10-lower end plate, 11-first cooling belt, 12-second cooling belt, 13-second cooling part, 14-bellows section, 15-first stage cold head, 16-second stage cold head, 17-first cooling plate, 18-second cooling 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 DESCRIPTION

[0027] Explanation of relevant terms

[0028] The cold head is a part of the refrigerator. When the refrigerator is working, heat is transferred to the outside through the cold head and the cooling material to achieve the purpose of cooling.

[0029] Example

[0030] like Figure 1 and Figure 2 As shown, the superconducting magnet consists of a room-temperature layer 1, a cold shield layer 2, and a low-temperature layer 3, arranged in sequence from the outside in. A sealed vacuum chamber is formed between the room-temperature layer 1 and the low-temperature layer 3 to insulate the superconducting magnet. The room-temperature layer 1 has mounting holes for a cooling device, while the cold shield layer 2 has avoidance holes for installing the cooling device.

[0031] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown together, a cooling device for a superconducting magnet includes a cooling chamber 4 with openings at both ends and a refrigerator 5 installed on the cooling chamber 4. The cooling chamber 4 includes 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. Preferably, the bellows section 14 includes 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. The inner diameter of the first bellows 7 is larger than the outer diameter of the first cooling member 8, and the outer diameter of the second bellows 9 is smaller than the inner diameter of the first bellows 7. The various components of the cooling chamber 4 are welded into a whole.

[0032] A removable, disc-shaped fixing plate 19 is fixedly mounted on the upper end plate 6 of the cooling chamber 4. The refrigerator 5 is removably fixed to the fixing plate 19 via 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.

[0033] The upper end plate 6 is fixed to the mounting hole of the superconducting magnet's room-temperature layer 1, while the lower end plate 10 is fixed to the superconducting magnet's low-temperature layer 3. The sealed vacuum chamber formed between the room-temperature layer 1 and the low-temperature layer 3 is not connected to the cold conduction chamber 4, and each is an independent chamber.

[0034] The first cooling element 8 is connected to the superconducting magnet's cold shield layer 2 via a first cold conductive tape 11, enabling heat conduction between the two. In this embodiment, the first cold conductive tape 11 preferably comprises multiple copper braids, one end of which is secured to the first cooling element 8 and the other end to the superconducting magnet's cold shield layer 2. The copper braids are secured to both the first cooling element 8 and the cold shield layer 2 by welding to ensure efficient heat conduction between them.

[0035] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, the refrigerator 5 includes a primary cold head 15 and a secondary cold head 16, both of which are arranged inside the cold conduction chamber 4. A first cold conduction plate 17 is fixedly mounted on the primary cold head 15, the lower end surface of the first cold conduction plate 17 being flush with and in contact with the upper end surface of the first cold conduction member 8, and the first cold conduction plate 17 and the first cold conduction member 8 being detachably fixedly connected via fasteners. A second cold conduction plate 18 is fixedly mounted on the secondary cold head 16, the lower end surface of the second cold conduction plate 18 being flush with and in contact with the upper end surface of the second cold conduction member 13, and the second cold conduction plate 18 and the second cold conduction member 13 being detachably fixedly connected via fasteners. The outer diameters of the second cold conduction plate 18 and the second cold conduction member 13 are both smaller than the inner diameter of the second bellows 9. The second cold conduction member 13 is connected to the low-temperature layer 3 of the superconducting magnet via a second cold conduction belt 12 to achieve heat conduction between the two.

[0036] like Figure 1 and Figure 2 As shown, both the first and second cooling belts 11, 12 are flexible. This allows for a certain degree of movement between the first cooling member 8 and the cold shield layer 2, and between the second cooling member 13 and the cryogenic layer 3, achieving a flexible connection. In this embodiment, the second cooling belt 12 preferably comprises multiple braided copper braids, one end of which is secured to the second cooling member 13 and the other end to the cryogenic layer 3 of the superconducting magnet. The copper braids are secured to the second cooling member 13 and the cryogenic layer 3 by welding to ensure efficient heat transfer between them.

[0037] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6As shown, 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 defined in the fixing plate 19. The plurality of first fasteners 22 correspond to the plurality of first through holes 20, and the first fasteners 22 are located directly below the first through holes 20, making it easier to manipulate the first fasteners 22 using tools when attaching or detaching the first cooling plate 17 and the first cooling member 8.

[0038] The second cold conduction plate 18 is detachably fixedly connected to the second cold conduction member 13 via a plurality of second fasteners 23. The first cold conduction plate 17 is provided with a plurality of second through holes 21. The plurality of second fasteners 23 correspond one-to-one with the positions of the plurality of first through holes 20 and the plurality of second through holes 21. 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. The aperture of the first through holes 20 is larger than the aperture of the second through holes 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 fasteners 23 when disassembling and fixing the second cold conduction plate 18 and the second cold conduction 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 to seal the upper end of the cold conduction chamber 4. Preferably, two third sealing rings 27 are provided between the cover plate 24 and the fixing plate 19. The provision of the first through hole 20 and the second through hole 21 can facilitate the assembly and disassembly of the refrigerator 5 .

[0039] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown together, in this embodiment, preferably, the first fastener 22 and the second fastener 23 are both screws. A first screw hole 28 is machined on the first cooling member 8 at a position corresponding to the first fastener 22, and a first aperture 29 is machined on the first cooling plate 17 at a position corresponding to the first fastener 22, which is compatible with the first screw hole 28. A second screw hole 30 is machined on the second cooling member 13 at a position corresponding to the second fastener 23, and a second aperture 31 is machined on the second cooling plate 18 at a position corresponding to the second fastener 23, which is compatible with the second screw hole 30.

[0040] The above structural design of the present invention is different from the prior art that uses elastic components or gas pressure to press the cold head and the cooling member to achieve heat conduction. In the cooling device of the present invention, the first-stage cold head 15 and the second-stage cold head 16 of the refrigerator 5 are not subjected to pressure from the cooling member, nor are they subjected to pressure from the gas. The first-stage cold head 15 and the second-stage cold head 16 of the refrigerator 5 are fixedly connected to the first cooling member 8 and the second cooling member 13 respectively by fasteners, ensuring that they have good thermal contact and heat conduction; and the refrigerator 5 has a long service life and high heat conduction efficiency.

[0041] To sum up, the present invention provides a cooling device for superconducting magnets. During the use of the refrigerator, its cold head does not bear the pressure from the cooling member. The first-level cold head and the second-level cold head of the refrigerator are fixedly connected to the first cooling member and the second cooling member respectively through fasteners to ensure that they have good thermal contact and heat conduction. It has the advantages of simple structure, long service life of the refrigerator, and high heat conduction efficiency.

[0042] Finally, it should be noted that the above descriptions are merely 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 aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A cooling device for a superconducting magnet, characterized in that: The invention 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) includes a first-stage cold head (15), a first cold plate (17) fixedly mounted on the first-stage cold head (15), and the first cold plate (17) is fixedly connected to a first cold member (8); the first cold member (8) is connected to a cold shield layer (2) of a superconducting magnet via a first cold belt (11) to achieve heat conduction between the two. 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); 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); the first fasteners (22) are located directly below the first through holes (20) to facilitate assembly and disassembly between the first cooling plate (17) and the first cooling member (8).

2. The cooling device for a superconducting magnet according to claim 1, wherein: 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), and the second cold conduction plate (18) being fixedly connected to the second cold conduction member (13); the second cold conduction member (13) is connected to the 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 a superconducting magnet according to claim 2, wherein: 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 a superconducting magnet according to claim 2, wherein: The second cooling plate (18) and the second cooling 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 cooling 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 and fixing between the second cooling plate (18) and the second cooling member (13).

5. The cooling device for a superconducting magnet according to claim 1, wherein: 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).

6. The cooling device for a superconducting magnet according to any one of claims 1 to 5, 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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