A large high-temperature superconducting magnet structure with conduction cooling

Abstract

The present invention provides a large-scale high-temperature superconducting magnet structure with conduction cooling, including a coil frame, a high-temperature superconducting coil group and a cooling channel assembly; the high-temperature superconducting coil group is provided with an electrical connection assembly, and the electrical connection assembly is used to excite the high-temperature superconducting coil group; a second insulating layer made of heat-conductive material is provided between the cooling channel assembly and the high-temperature superconducting coil group, which is used to prevent the cooling channel assembly from being charged as a whole; the two sides of the second insulating layer are in thermal contact with the high-temperature superconducting coil group and the cooling channel assembly respectively; the cooling channel assembly is provided with an air inlet for inputting low-temperature helium and an air outlet for discharging the low-temperature helium. The structure is simple and easy to process, and is suitable for conduction cooling of large-scale high-temperature superconducting magnets; the large-scale high-temperature superconducting magnet adopting the structure of the present invention has better temperature uniformity during operation, which is conducive to improving the cooling effect and reducing the refrigeration cost.

Description

Technical Field

[0001] The invention belongs to the technical field of superconducting magnets, and in particular relates to a large-scale high-temperature superconducting magnet structure with conduction cooling. Background Art

[0002] This section is intended to provide a background or context to embodiments of the invention recited in the claims. Nothing herein should be admitted to be prior art by virtue of its inclusion in this section.

[0003] Strong magnetic field technology is widely used in industry, medicine, national defense and scientific research. The magnetic field strength of magnets wound with ordinary wires is limited due to the limitation of Joule heat generated by the running current. Magnets wound with superconducting wires (strips) do not generate Joule heat when the running current is used, and the magnetic field strength can be greatly improved. Superconducting magnets have broad application prospects in the field of high-intensity magnetic fields. During the operation of superconducting magnets, it is necessary to ensure that the operating temperature of the superconducting magnets is below the critical temperature of the superconducting wires (strips). The higher the operating temperature of the superconducting magnet, the lower the refrigeration cost required to maintain the low-temperature environment of the superconducting magnet. Therefore, increasing the operating temperature of the superconducting magnet and finding superconducting wires (strips) with high critical temperatures are important technical directions for the development of superconducting magnets.

[0004] At present, the critical temperature of high-temperature superconducting wires (strips) with practical engineering value has reached above the liquid nitrogen temperature zone (77K). Although the theoretical operating temperature of high-temperature superconducting magnets can reach above 77K, in order to provide operating current and improve the stability of magnet operation, most high-temperature superconducting magnets are designed to operate at a temperature of about 30K, so they need to be cooled by a cryogenic refrigerator. Due to the high price of helium, the high-temperature superconducting magnet using a conductive cooling method without liquid helium is the main technology at present. The existing conductive cooling superconducting magnet structure is generally from the inside to the outside: inner skeleton, superconducting coil, binding wire or clamp. Among them, the inner skeleton and binding wire support and fix the superconducting coil. The general method of conductive cooling is to set a flexible conductive cooling belt on the cold head of the cryogenic refrigerator to conduct the cold energy of the cryogenic refrigerator to the high-temperature superconducting magnet. This general method cannot guarantee the uniformity of the overall temperature of the high-temperature superconducting magnet when the size of the high-temperature superconducting magnet is large.

[0005] Therefore, there is a great need to study a large-scale high-temperature superconducting magnet structure with conduction cooling, which can be suitable for conduction cooling and achieve overall temperature uniformity of large-scale high-temperature superconducting magnets, so as to further promote the in-depth development and wide application of superconducting magnet technology. Summary of the invention

[0006] The present invention is to solve all or part of the problems of the above-mentioned prior art. The present invention provides a large-scale high-temperature superconducting magnet structure with conduction cooling, which is suitable for cooling by conduction cooling.

[0007] The present invention provides a conduction-cooled large-scale high-temperature superconducting magnet structure, comprising a coil frame, a high-temperature superconducting coil group and a cooling channel assembly; a first insulating layer is arranged between the coil frame and the high-temperature superconducting coil group to prevent the coil frame from being charged; the high-temperature superconducting coil group is provided with an electrical connection assembly, and the electrical connection assembly is used to excite the high-temperature superconducting coil group; a second insulating layer made of a heat-conductive material is arranged between the cooling channel assembly and the high-temperature superconducting coil group to prevent the cooling channel assembly from being charged as a whole; the two sides of the second insulating layer are in thermal contact with the high-temperature superconducting coil group and the cooling channel assembly respectively; the cooling channel assembly is provided with an air inlet for inputting low-temperature helium and an air outlet for discharging the low-temperature helium. The cooling channel assembly and the high-temperature superconducting coil group are cooled by heat exchange through heat conduction connection, which solves the limitation of the traditional structure that relies on the flexible conductive cooling belt set at the cold head of the low-temperature refrigerator for cooling, is not limited by the size of the flexible conductive cooling belt and the cooling area range of the flexible conductive cooling belt, can be applied to the cooling of large-scale high-temperature superconducting magnets, and has better temperature uniformity during the operation of large-scale high-temperature superconducting magnets.

[0008] In general, the cooling channel assembly includes a cooling unit and a cooling pipe; the outer wall of the cooling pipe is in thermal contact with the cooling unit; the openings at both ends of the cooling pipe are the air inlet and the air outlet respectively; the cooling unit is in thermal contact with the second insulating layer.

[0009] There are multiple cooling units, which are arranged in series on the cooling pipe. The cooling channel assembly is formed by connecting multiple cooling units in series to form a segmented structure. The segmented structure increases the overall flexibility of the cooling channel assembly, reduces the surface processing requirements for the cooling channel assembly, and is conducive to a larger heat conduction area between the cooling channel assembly and the high-temperature superconducting coil assembly.

[0010] The cooling pipe is a flexible pipe.

[0011] The cooling unit comprises a cooling block, a through hole is provided inside the cooling block, the outer wall of the cooling tube is tightly connected with the inner wall of the through hole to form thermal contact; the second insulating layer is arranged on the outer surface of the cooling block.

[0012] The outer wall of the cooling pipe and the inner wall of the through hole are fixedly connected by vacuum brazing.

[0013] The cooling unit further comprises a limiting structure, which fixes the cooling block on the outer surface of the high temperature superconducting coil assembly. The setting of the limiting structure can maintain continuous and stable heat conduction between the high temperature superconducting coil assembly and the cooling block.

[0014] Preferably, a cooling plate is further included; a third insulating layer made of a heat-conducting material is provided between the cooling plate and the high-temperature superconducting coil assembly to prevent the cooling plate from being charged; and both sides of the third insulating layer are in thermal contact with the cooling plate and the high-temperature superconducting coil assembly respectively. The high-temperature superconducting coil assembly is cooled by the cooling plate and the cooling channel assembly together, and the cooling effect is better, so that the operating temperature of the refrigerator cold head can be appropriately increased, thereby reducing the operating cost of the refrigerator, which is conducive to saving refrigeration costs.

[0015] The cooling plates are respectively arranged on the upper and lower sides of the high temperature superconducting coil assembly.

[0016] The cooling plate is made of copper material.

[0017] There are a plurality of high temperature superconducting coil groups, and adjacent high temperature superconducting coil groups are electrically connected via the electrical connection assembly.

[0018] Compared with the prior art, the main beneficial effects of the present invention are:

[0019] A large high-temperature superconducting magnet structure with conduction cooling of the present invention has a simple structure and is suitable for conduction cooling of a large high-temperature superconducting magnet including one or more high-temperature superconducting coil groups; it includes the cooling channel assembly, which is insulated and heat-conducting from the high-temperature superconducting coil group, and the two can make the large high-temperature superconducting magnet have better temperature uniformity during operation through heat exchange; the cooling plate and the cooling pipe assembly jointly cool the high-temperature superconducting coil group, and the cooling effect is better at the same operating temperature of the refrigerator cold head, so the operating temperature of the refrigerator cold head can be appropriately increased, thereby reducing the operating cost of the refrigerator. The cooling channel assembly adopts a segmented structure of multiple cooling units, which improves the flexibility of the cooling channel assembly and reduces the machining accuracy requirements of the cooling channel. At the same time, the heat conduction area between the high-temperature superconducting coil group and the high-temperature superconducting coil group is larger, which is conducive to improving the cooling effect of the high-temperature superconducting coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a large high-temperature superconducting magnet according to Embodiment 1 of the present invention.

[0021] Figure 2 This is a schematic diagram of the composition of a large high-temperature superconducting magnet structure according to Embodiment 1 of the present invention.

[0022] Figure 3 It is a cross-sectional schematic diagram of a cooling channel assembly according to Embodiment 1 of the present invention.

[0023] Figure 4 This is a schematic diagram of the structure of a large high-temperature superconducting magnet according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0024] The technical solutions in the specific embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings. In the drawings, parts with the same structure or function are marked with the same reference numerals, and for the sake of clarity, not all parts shown are marked with the corresponding reference numerals in all drawings when necessary.

[0026] Embodiment 1

[0027] In the first embodiment of the present invention, Figure 1 and Figure 2 As shown, a large-scale high-temperature superconducting magnet structure with conduction cooling includes a coil frame 1, a single high-temperature superconducting coil group 2 wound on the coil frame 1, and a cooling channel assembly 3; a first insulating layer A is provided between the coil frame 1 and the high-temperature superconducting coil group 2 to prevent the coil frame from being charged; the high-temperature superconducting coil group 2 is provided with an electrical connection assembly 4, which is used to excite the high-temperature superconducting coil group 2; a second insulating layer B made of a heat-conductive material is provided between the cooling channel assembly 3 and the high-temperature superconducting coil group 2 to prevent the cooling channel assembly 3 from being charged as a whole; the two sides of the second insulating layer B are in thermal contact with the outer surface of the high-temperature superconducting coil group 2 away from the coil frame 1 and the surface of one side of the cooling channel assembly 3; the cooling channel assembly 3 is provided with an air inlet 5 for inputting low-temperature helium and an air outlet 6 for discharging the low-temperature helium. In this embodiment, the cooling channel assembly 3 includes a cooling unit 30 and a cooling pipe 31; the openings at both ends of the cooling pipe 31 are the air inlet 5 and the air outlet 6 respectively. In this embodiment, the cooling pipe 31 is a flexible pipe.

[0028] In this embodiment, Figure 3 As shown, the cooling unit 30 includes a cooling block 32, a through hole is provided inside the cooling block 32, and the outer wall of the cooling tube 31 is in thermal contact with the cooling unit 30. Specifically, the outer wall of the cooling tube 31 is tightly joined with the inner wall of the through hole to form thermal contact, and the outer wall of the cooling tube 31 is fixedly connected with the inner wall of the through hole by vacuum brazing. The second insulating layer B is arranged on the outer surface of the cooling block 32. The cooling unit 30 is heat-conducted with the high-temperature superconducting coil group 2 through the second insulating layer B. In this embodiment, there are multiple cooling units 30, which are arranged in series on the cooling tube 31. Nine cooling units 30 are shown in the drawings of this embodiment, but it is not limited, and there can be more or fewer cooling units 30 according to actual application conditions. The cooling channel assembly 3 is composed of multiple cooling units 30 connected in series to form a segmented structure.

[0029] In this embodiment, a cooling plate 7 is provided on the upper and lower sides of the high-temperature superconducting coil group 2. The cooling plate 7 is made of copper material. A third insulating layer C made of a heat-conducting material is provided between the cooling plate 7 and the high-temperature superconducting coil group 2 to prevent the cooling plate 7 from being charged. The two sides of the third insulating layer C are in thermal contact with the cooling plate 7 and the high-temperature superconducting coil group 2 respectively. The high-temperature superconducting coil group 3 is cooled by the cooling plate 7 and the cooling channel assembly 3, and the cooling effect is better, so that the operating temperature of the cold head of the refrigerator can be appropriately increased, thereby reducing the operating cost of the refrigerator, which is conducive to saving refrigeration costs. In some embodiments, only one side of the high-temperature superconducting coil group 2 is provided with a cooling plate 7 or there is no cooling plate 7, which is not limited.

[0030] In this embodiment, the cooling unit 30 also includes a limiting structure, and the limiting structure fixes the cooling block 32 on the outer surface of the high-temperature superconducting coil group 2. The setting of the limiting structure can maintain continuous and stable heat conduction between the high-temperature superconducting coil group 2 and the cooling block 32. The limiting structure in this embodiment is specifically composed of 4 clamping bolts T and a clamping side plate P. The clamping side plate P is fixed to the cooling plate 7 by bolts and the like, and the clamping bolts T are connected to the clamping side plate P through the screw holes on the clamping side plate P. Tightening the clamping bolts T pushes against the cooling block 32, and the cooling block 32 is pressed on the outer surface of the high-temperature superconducting coil group 2. In other specific cases, the limiting structure may also include other forms, such as binding the cooling block 32 to the outer surface of the high-temperature superconducting coil group 2 with a binding belt, etc., which is not limited. Similarly, the number of clamping bolts T and clamping side plates P is also set according to actual needs and is not limited.

[0031] Embodiment 2

[0032] like Figure 4 As shown, the difference between the second embodiment and the first embodiment is that the conduction-cooled large-scale high-temperature superconducting magnet structure in the present embodiment includes six high-temperature superconducting coil groups 2, cooling plates 7 are provided between adjacent high-temperature superconducting coil groups 2, and adjacent high-temperature superconducting coil groups 2 are electrically connected through electrical connection components 4. The six stacked high-temperature superconducting coil groups 2 are a preferred exemplary description of the present embodiment in combination with the accompanying drawings. In practical applications, the number of high-temperature superconducting coil groups 2 is not limited to six, and there may be more or less, without limitation.

[0033] Some commonly used English nouns or letters used in the present invention for the convenience of narration are only used for exemplary reference rather than restrictive interpretation or specific usage, and the protection scope of the present invention should not be limited by their possible Chinese translation or specific letters. It should also be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment.

[0034] The present invention is described in detail above. The structure and working principle of the present invention are described in detail using specific examples herein. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, the present invention can also be improved and modified without departing from the principle of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A large high-temperature superconducting magnet structure with conduction cooling, characterized in that: It includes a coil frame, a high-temperature superconducting coil group and a cooling channel assembly; a first insulating layer is arranged between the coil frame and the high-temperature superconducting coil group to prevent the coil frame from being electrified; the high-temperature superconducting coil group is provided with an electrical connection assembly, and the electrical connection assembly is used to excite the high-temperature superconducting coil group; a second insulating layer made of heat-conducting material is arranged between the cooling channel assembly and the high-temperature superconducting coil group to prevent the cooling channel assembly from being electrified as a whole; both sides of the second insulating layer are in thermal contact with the high-temperature superconducting coil group and the cooling channel assembly respectively; the cooling channel assembly is provided with An air inlet for inputting low-temperature helium and an air outlet for discharging the low-temperature helium; the cooling channel assembly includes a cooling unit and a cooling tube; the outer wall of the cooling tube is in thermal contact with the cooling unit; the openings at both ends of the cooling tube are the air inlet and the air outlet respectively; the cooling unit is in thermal contact with the second insulating layer; there are multiple cooling units, which are arranged in series on the cooling tube; the cooling unit includes a cooling block, a through hole is opened inside the cooling block, and the outer wall of the cooling tube is tightly joined with the inner wall of the through hole to form thermal contact; the second insulating layer is arranged on the outer surface of the cooling block.

2. A conduction-cooled large-scale high-temperature superconducting magnet structure according to claim 1, characterized in that: The cooling unit further includes a limiting structure, which fixes the cooling block on the outer surface of the high-temperature superconducting coil assembly.

3. A conduction-cooled large-scale high-temperature superconducting magnet structure according to claim 1, characterized in that: The cooling pipe is a flexible pipe.

4. A conduction-cooled large-scale high-temperature superconducting magnet structure according to claim 1, characterized in that: It also includes a cooling plate; a third insulating layer made of heat-conducting material is arranged between the cooling plate and the high-temperature superconducting coil group to prevent the cooling plate from being charged; both sides of the third insulating layer are in thermal contact with the cooling plate and the high-temperature superconducting coil group respectively.

5. A conduction-cooled large-scale high-temperature superconducting magnet structure according to claim 4, characterized in that: The cooling plate is made of copper material.

6. A conduction-cooled large-scale high-temperature superconducting magnet structure according to claim 4, characterized in that: The cooling plates are respectively arranged on the upper and lower sides of the high temperature superconducting coil assembly.

7. A conduction-cooled large-scale high-temperature superconducting magnet structure according to any one of claims 1 to 6, characterized in that: There are a plurality of high temperature superconducting coil groups, and adjacent high temperature superconducting coil groups are electrically connected via the electrical connection assembly.

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