Low-temperature system of high-temperature superconducting magnet

Abstract

The invention discloses a high-temperature superconducting magnet low-temperature system, and belongs to the technical field of superconducting magnet low-temperature systems. Comprising an outer Dewar, an inner Dewar, a pluggable refrigerating machine, a cold head support, a plurality of double-cone main supporting columns, Dewar supporting columns, a cold conduction copper plate, a cold conduction copper strip, a helium conveying pipe, a liquid nitrogen conveying pipe and a gas return pipe. The outer Dewar is sleeved outside the inner Dewar, and the high-temperature superconducting magnet module is mounted in the inner Dewar; the pluggable refrigerating machine is inserted into the outer Dewar and is connected with the cold conduction copper strip; the double-cone main supporting columns are installed on the front side and the rear side outside the inner dewar. The Dewar support column is connected with the front and rear side walls of the outer The cold conduction copper plate wraps the outer wall of the inner Dewar; the other end of the helium conveying pipe is connected with the upper wall of the outer Dewar; and the other ends of the liquid nitrogen conveying pipe and the air return pipe are connected with the upper wall of the outer Dewar. Three cooling modes of refrigerating machine conduction cooling, cold helium circulation cooling and nitrogen fixation heat preservation cooling can be adopted, and the application range of the system is widened.

Description

Technical Field

[0001] The present invention belongs to the technical field of cryogenic systems for superconducting magnets, and particularly relates to a cryogenic system for high-temperature superconducting magnets. Background Art

[0002] Since the discovery of the superconducting phenomenon in 1911, superconductors have been widely used to manufacture superconducting magnets to generate strong magnetic fields due to their zero-resistance effect. Different from traditional resistive magnets that require megawatt-level power supplies and water-cooling systems to maintain operation, superconducting magnets, due to their zero-resistance characteristics, hardly generate heat even when passing a huge current, thus avoiding high operating costs.

[0003] Superconducting magnets need to operate below their critical temperature to reduce their resistance to almost zero, which requires superconducting magnets to be equipped with complex and large cryogenic systems to maintain their low-temperature environment. In recent years, the breakthrough of high-temperature superconducting technology has increased the operating temperature of superconducting magnets from below 4.2K to 20 - 77K, making the cooling methods of superconducting magnets more diverse.

[0004] Currently, the cooling methods of cryogenic systems for high-temperature superconducting magnets mainly include conduction cooling, cold helium gas circulation cooling, and solid nitrogen heat preservation. These cooling methods all have their respective applicable scenarios. However, the above cooling methods usually cannot be achieved in the same cryogenic system, which means that each superconducting magnet needs to build a cryogenic system matching its operating conditions after being built, greatly increasing the construction time and cost. Summary of the Invention

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A cryogenic system for a high-temperature superconducting magnet, comprising: an outer dewar, an inner dewar, a pluggable refrigerator, a cold head bracket, a plurality of double-cone main support columns, dewar support columns, a heat conduction copper plate, a heat conduction copper strip, a helium gas transmission pipe, a liquid nitrogen infusion pipe, and a return gas pipe; the outer dewar is sleeved outside the inner dewar, and the inside of the outer dewar is in a vacuum environment, and a high-temperature superconducting magnet module is installed inside the inner dewar; the pluggable refrigerator is inserted into the outer dewar, connected to one end of the heat conduction copper strip, and fixed by the cold head bracket; the double-cone main support columns are installed on the front and rear sides outside the inner dewar, one end of each double-cone main support column is connected to the outer wall of the inner dewar, and the other end is connected to the inner wall of the outer dewar; the dewar support columns are connected to the front and rear side walls of the outer dewar and do not fit with the inner dewar, and are used to support the outer dewar to prevent it from deforming; the heat conduction copper plate wraps the outer wall of the inner dewar, and both ends of the heat conduction copper strip are respectively connected to the pluggable refrigerator and the side wall of the inner dewar and the high-temperature superconducting magnet module; one end of the helium gas transmission pipe is connected to the bottom of the inner dewar, and the other end is connected to the upper wall of the outer dewar; both the liquid nitrogen infusion pipe and the return gas pipe are connected to the upper wall of the inner dewar at one end and the upper wall of the outer dewar at the other end; support beams are respectively arranged on the inner surfaces of the outer dewar and the inner dewar.

[0007] The present invention has the following beneficial effects:

[0008] (1) In the cryogenic system of the high-temperature superconducting magnet of the present invention, by arranging a variety of cooling medium delivery pipelines, the system can adopt three cooling methods: refrigerator conduction cooling, cold helium gas circulation cooling, and solid nitrogen heat preservation cooling, which broadens the applicable scenarios of the system.

[0009] (2) In the cryogenic system of the high-temperature superconducting magnet of the present invention, a pluggable refrigerator is adopted, which greatly reduces the heat leakage during the cold helium gas circulation cooling and solid nitrogen heat preservation cooling processes of the system, enabling the magnet to operate at a lower temperature and have a longer heat preservation time.

[0010] (3) In the cryogenic system of the high-temperature superconducting magnet of the present invention, a double-cone main support column is used as the support, which greatly improves the shock resistance of the system and is suitable for dynamic working conditions such as vehicle-mounted. Brief Description of the Drawings

[0011] Figure 1 It is a schematic structural diagram of the cryogenic system of the high-temperature superconducting magnet of the present invention. Among them, 1 - outer dewar, 2 - inner dewar, 3 - pluggable refrigerator, 4 - cold head support, 5 - double-cone main support column, 6 - dewar support column, 7 - heat conduction copper plate, 8 - heat conduction copper strip, 9 - helium delivery pipe, 10 - liquid nitrogen delivery pipe, 11 - return gas pipe;

[0012] Figure 2 It is a schematic structural diagram of the high-temperature superconducting magnet module of the present invention. Among them, 201 - magnet cooling copper plate, 202 - magnet end plate, 203 - insulating partition, 204 - magnet support column, 205 - high-temperature superconducting magnet;

[0013] Figure 3 It is a schematic structural diagram of the double-cone main support column of the present invention. Among them, 301 - double-cone support structure, 302 - inner dewar connection flange, 303 - outer dewar connection flange;

[0014] Figure 4 It is a schematic structural diagram of the pluggable refrigerator of the present invention. Among them, 1 - outer dewar, 401 - cryogenic refrigerator, 402 - pressing structure, 403 - bellows, 404 - cold head connector;

[0015] Figure 5 It is the temperature change curve during the temperature reduction process of the refrigerator conduction cooling of the present invention;

[0016] Figure 6 It is the temperature change curve during the process of combining refrigerator conduction cooling and cold helium gas circulation cooling with solid nitrogen heat preservation;

[0017] Figure 7 It is the shock response curve of the present invention;

[0018] Figure 8 These are the frequency response curves of the present invention before and after the impact test. Specific embodiments

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present 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 only used to explain the present invention and are not used to limit the present invention.

[0020] In the drawings, components with the same structure are denoted by the same reference numerals, and components with similar structures or functions everywhere are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of some components is appropriately exaggerated in the drawings.

[0021] The present invention provides a cryogenic system for high-temperature superconducting magnets (hereinafter referred to as the cryogenic system), which can cool high-temperature superconducting magnets of various structures. As shown in the attached... Figure 1-3 As shown, in a typical embodiment of the cryogenic system for high-temperature superconducting magnets of the present invention, when using the present invention to cool high-temperature superconducting magnets of other structures, only the size of the inner dewar shown in the drawings needs to be adjusted to a size matching the structure of the high-temperature superconducting magnet.

[0022] Figure 1 This is a schematic structural diagram of the cryogenic system for high-temperature superconducting magnets (hereinafter referred to as the cryogenic system) of the present invention, including: an outer dewar 1, an inner dewar 2, a pluggable refrigerator 3, a cold head support 4, a plurality of double-cone main support columns 5, a dewar support column 6, a heat conduction copper plate 7, a heat conduction copper strip 8, a helium inlet pipe 9, a liquid nitrogen inlet pipe 10, and a return gas pipe 11.

[0023] The outer dewar 1 and the inner dewar 2 are both hollow cuboid structures (or other shapes), the outer dewar 1 is sleeved outside the inner dewar 2, and its interior is in a vacuum environment to reduce heat leakage. The inner dewar 2 is internally installed with a high-temperature superconducting magnet module, which serves to accommodate the high-temperature superconducting magnet module and cryogenic working fluid; the pluggable refrigerator 3 is inserted into the outer dewar 1, connected to one end of the cold conduction copper strip 8, and fixed by the cold head support 4, and is used to provide cooling capacity for the cryogenic system; the double-cone main support columns 5 are installed at the positions of four corners on the front and back sides outside the inner dewar 2 (the double-cone main support columns 5 are set to 4, and in a static environment, heat leakage can be reduced by removing 2 of the diagonally opposite ones; it can also be other quantities or positions, which can be set according to actual needs). One end of each double-cone main support column 5 is connected to the outer wall of the inner dewar 2, and the other end is connected to the inner wall of the outer dewar 1, and is used to transfer the electromagnetic force received by the superconducting magnet to the outside; the dewar support column 6 is connected to the front and back side walls of the outer dewar 1 and does not fit with the inner dewar 2, and is used to support the outer dewar 1 to prevent it from deforming; the cold conduction copper plate 7 is wrapped around the outer wall of the inner dewar 2, and the two ends of the cold conduction copper strip 8 are respectively connected to the pluggable refrigerator 3 and the side wall and the high-temperature superconducting magnet module of the inner dewar 2, and transfer the cooling capacity of the refrigerator to the inner dewar 2 and the high-temperature superconducting magnet module; one end of the helium gas transmission pipe 9 is connected to the bottom of the inner dewar 2, and the other end is connected to the upper wall of the outer dewar 1, and is used to input helium gas into the inner dewar 2 under the condition of cold helium gas circulation cooling; one end of both the liquid nitrogen infusion pipe 10 and the return gas pipe 11 is connected to the upper wall of the inner dewar 2, and the other end is connected to the upper wall of the outer dewar 1. The liquid nitrogen infusion pipe 10 is used to input liquid nitrogen into the inner dewar 2 under the condition of solid nitrogen cooling, and the return gas pipe 11 is used to return helium gas and nitrogen gas.

[0024] Support beams are respectively arranged on the inner surfaces of the outer dewar 1 and the inner dewar 2 to prevent the dewar from deforming due to atmospheric pressure in a vacuum state.

[0025] The cold head support 4 is made of epoxy resin material to ensure electrical insulation.

[0026] The high-temperature superconducting magnet cryogenic system adopts a symmetric support structure on the front and back sides. The double-cone main support columns 5 are installed on both the front and back walls of the inner dewar 2 to improve the anti-impact performance of the cryogenic system. The dewar support column 6 passes through the center of the inner dewar 2 and does not contact the central wall of the inner dewar 2 to reduce heat leakage of the cryogenic system.

[0027] The dewar support column 6 adopts a solid structure to improve strength. The double-cone main support column 5 adopts a hollow structure to reduce heat leakage of the cryogenic system.

[0028] The double-cone main support column 5 is designed as a detachable structure. Multiple double-cone main support columns 5 are provided. When the high-temperature superconducting magnet cryogenic system operates in a static environment, some of the double-cone main support columns 5 (such as 2 diagonal ones) can be removed to reduce the heat leakage of the cryogenic system.

[0029] The outer dewar 1, the inner dewar 2, the dewar support column 6, the helium transfer pipe 9, the liquid nitrogen transfer pipe 10, and the return gas pipe 11 are all made of stainless steel material to ensure the overall impact resistance of the cryogenic system.

[0030] The heat-conducting copper strip 8 is divided into two parts. One part passes through the side wall of the inner dewar 2 and enters the inside of the inner dewar 2, and is connected to the magnet cooling copper plate 201 on the high-temperature superconducting magnet module inside the inner dewar 2 for cooling the high-temperature superconducting magnet 205; the other part is connected to the heat-conducting copper plate 7 for realizing the overall cooling of the inner dewar 2.

[0031] The heat-conducting copper plate 7 and the heat-conducting copper strip 8 are made of oxygen-free copper material with high thermal conductivity to ensure the heat conduction performance. The heat-conducting copper plate 7 is made of hard copper plate, and the heat-conducting copper strip 8 is made of soft thick copper wire, and its end is welded with a copper nose as a terminal.

[0032] Studs are welded on the outer surface of the inner dewar 2. Through holes are provided at corresponding positions on the surface of the heat-conducting copper plate 7. The heat-conducting copper plate 7 and the inner dewar 2 are positioned through the through holes and studs; at the same time, the copper nose at the end of the heat-conducting copper strip 8 passes through the studs on the outer surface of the inner dewar 2 and is fixed by nuts.

[0033] Due to the low density of helium gas, the helium transfer pipe 9 is connected to the bottom of the inner dewar 2 to ensure that the inside of the inner dewar 2 is fully cooled and reduce the conduction heat leakage at the same time.

[0034] A part of the helium transfer pipe 9, the liquid nitrogen transfer pipe 10, and the return gas pipe 11 is set as a corrugated pipe structure, which can ensure that the device has a certain amount of expansion and contraction to facilitate positioning and installation.

[0035] The high-temperature superconducting magnet cryogenic system adopts a cold shield-free structure design to reduce the overall weight of the cryogenic system, and the working temperature is set between 25 and 40 K.

[0036] The cryogenic system of the high-temperature superconducting magnet can adopt three cooling methods: conduction cooling, cold helium gas circulation cooling, and solid nitrogen heat preservation. Among them, the solid nitrogen heat preservation method needs to be combined with any one of the first two cooling methods to achieve temperature reduction. The helium gas transmission pipe 9, the liquid nitrogen transmission pipe 10, and the return air pipe 11 can be designed as plug-and-play structures. When the cryogenic system uses conduction cooling for temperature reduction, they can be removed to reduce heat leakage of the cryogenic system. When the cryogenic system uses cold helium gas circulation cooling for temperature reduction, the plug-and-play refrigerator 3 can be detached to reduce heat leakage of the cryogenic system. In the case of rapid temperature reduction or an extremely low-temperature working environment, the above three cooling methods can be used in combination to reduce the temperature of the superconducting magnet and improve the temperature distribution uniformity of the cryogenic system.

[0037] As Figure 2 shown, the high-temperature superconducting magnet module of the present invention includes two magnet cooling copper plates 201, two magnet end plates 202, two insulating partitions 203, several magnet support columns 204, and a high-temperature superconducting magnet 205. The high-temperature superconducting magnet module is generally in a racetrack shape (it can also be in a circular shape, etc.). Each component is in a racetrack shape and is arranged in layers, in the following order: the first magnet end plate 202 - the first magnet cooling copper plate 201 - the first insulating partition 203 - the high-temperature superconducting magnet 205 - the second insulating partition 203 - the second magnet cooling copper plate 201 - the second magnet end plate 202. Among them, the surface areas of the two magnet cooling copper plates 201 are slightly larger than those of other components, and the surface areas of other components are the same. The high-temperature superconducting magnet 205 is located at the center of the high-temperature superconducting magnet module. Its front and rear side walls are respectively in close contact with the insulating partitions 203, and the other side of the insulating partitions 203 is in close contact with the magnet cooling copper plates 201, playing an insulating role. One side of the magnet cooling copper plate 201 is in close contact with the insulating partition 203, and the other side is in close contact with the magnet end plate 202. The outer edge of the magnet cooling copper plate 201 is connected to the heat-conducting copper strip 8, playing a role in heat conduction and improving temperature uniformity. The magnet end plate 202 is used to press and fix each component of the high-temperature superconducting magnet module. The magnet support column 204 is installed on the magnet end plate 202 and is connected to the inner dewar 2, playing a role in positioning and supporting the high-temperature superconducting magnet module; specifically, one end of the magnet support column 204 is welded to the round hole on the surface of the outer side of the magnet end plate 202 (the side not in contact with the magnet cooling copper plate 201), and the other side is welded to the inner wall of the inner dewar 2. A number of holes are reserved in the front and rear interiors of the inner dewar 2, and these holes are welded to the other end of the support column 204, playing a role in positioning and supporting the magnet module.

[0038] The surface area of the magnet cooling copper plate 201 is slightly larger than that of the magnet end plate 202 to facilitate connection with the heat-conducting copper strip 8.

[0039] The magnet cooling copper plate 201 is made of oxygen-free copper material with high thermal conductivity to ensure heat conduction performance.

[0040] A number of grooves are provided on the surface of the magnet end plate 202 to reduce the weight of the high-temperature superconducting magnet module.

[0041] The magnet end plate 202 and the magnet support column 204 are made of stainless steel material to enhance their structural strength.

[0042] The insulating partition 203 is made of epoxy resin or aluminum alloy material. When the insulating partition 203 is made of aluminum alloy material, a layer of polytetrafluoroethylene film needs to be sprayed on its surface to ensure its insulation performance.

[0043] As Figure 3 shown, the double-cone main support column 5 of the present invention includes a double-cone support structure 301, an inner dewar connection flange 302, and an outer dewar connection flange 303. The double-cone support structure 301 is an integrated structure formed by connecting the tops of two conical cones relatively, and its interior is a hollow structure; the inner dewar connection flange 302 and the outer dewar connection flange 303 are respectively located at both ends of the double-cone support structure 301. The bottom of the inner dewar connection flange 302 is connected to the inner dewar 2, and the top of the outer dewar connection flange 303 is connected to the outer dewar 1, for connecting and fixing the double-cone support structure 301 between the inner dewar 1 and the outer dewar 2.

[0044] The surface of the double-cone support structure 301 is provided with through holes in the shape of a rounded rectangle (which can also be other shapes) to further reduce the heat leakage of the support device.

[0045] The wall thickness in the middle of the double-cone support structure 301 is greater than the wall thickness at both ends to enhance its structural strength.

[0046] The special structure of the double-cone support structure 301 has high structural strength in both the axial and transverse directions, and can enhance the shock resistance of the cryogenic system in all directions. At the same time, this structure extends the heat conduction path of the support device and further reduces the heat leakage of the cryogenic system.

[0047] The double-cone support structure 301 is made of high-strength non-metallic materials, including materials such as carbon fiber or fiberglass, to further reduce the heat leakage of the cryogenic system on the premise of ensuring the structural strength of the cryogenic system.

[0048] The radius of the inner dewar connection flange 302 is greater than the radius of the outer dewar connection flange 303.

[0049] The inner dewar connection flange 302 and the outer dewar connection flange 303 each include two parts, and threaded holes are provided around them. The first parts of the inner dewar connection flange 302 and the outer dewar connection flange 303 ( Figure 3The top and bottom (in the middle) are respectively welded and fixed to the inner Dewar 2 and the outer Dewar 1, and the second part is respectively connected to both ends of the double-cone support structure 301. The connection and fixation between the two parts are achieved by screws passing through the threaded holes, that is, passing through the two parts of the inner Dewar connection flange 302 or the outer Dewar connection flange 303. It can be seen that the two parts of the inner Dewar connection flange 302 and the outer Dewar connection flange 303 are detachably arranged. Therefore, the double-cone main support column 5 can be disassembled through the inner Dewar connection flange 302 and the outer Dewar connection flange 303.

[0050] The inner Dewar connection flange 302 and the outer Dewar connection flange 303 are made of stainless steel material to enhance their structural strength.

[0051] As Figure 4 shown, the pluggable refrigerator 3 of the present invention includes a cryogenic refrigerator 401, a pressing structure 402, a corrugated pipe 403, and a cold head connector 404. The corrugated pipe 403 is installed on the upper wall of the outer Dewar 1, and its interior is a hollow structure. The cryogenic refrigerator 401 as a whole is inserted into the vacuum interlayer of the outer Dewar 1 through the corrugated pipe 3; the pressing structure 402 is installed at the connection between the cryogenic refrigerator 401 and the corrugated pipe 403, and is used to apply pressure to adjust the longitudinal position of the cryogenic refrigerator 401; the cold head connector 404 is located at the bottom of the cryogenic refrigerator 401 and is used to transfer cold.

[0052] The pressing structure 402 and the corrugated pipe 403 are made of stainless steel material to improve their structural strength.

[0053] The cold head connector 404 is divided into two parts. One part is designed as a groove structure and is connected to the bottom of the cold head of the cryogenic refrigerator 401; the other part is designed as a frustum structure and is connected to the cold-conducting copper strip 8.

[0054] The cold head connector 404 is made of oxygen-free copper material with high thermal conductivity to ensure the heat conduction performance.

[0055] The pressing structure 402 adjusts the longitudinal position of the cryogenic refrigerator 401 by tightening the nut. In the untightened state, the cold head connector 404 is not in contact with the cold-conducting copper strip 8. When the low-temperature system needs to be cooled down, by adjusting the pressing structure 402, the cryogenic refrigerator 401 moves downward longitudinally to achieve the close fit between the cold head connector 404 and the cold-conducting copper strip 8. When the low-temperature system needs to be separated from the refrigerator, by adjusting the pressing structure 402, the corrugated pipe 403 returns to the normal state, so that the cold head connector 404 is separated from the cold-conducting copper strip 8, and the cryogenic refrigerator 401 is separated.

[0056] Figure 5The figure shows the temperature change curve during the cooling process of the refrigerator conduction cooling of the present invention. The subfigure in the upper right corner is a partial enlarged view of the temperature change from 60 to 80 h. It can be seen that the cooling performance of the cryogenic system is good. The lowest temperature of the superconducting magnet drops to 31 K, and the temperature difference at both ends of the magnet is less than 0.5 K.

[0057] Figure 6 The figure shows the temperature change curve during the process of combining refrigerator conduction cooling and cold helium gas cycle cooling with solid nitrogen heat preservation. It can be seen that the cooling performance of the cryogenic system is good. The solid-solid phase transition of nitrogen has been successfully observed in both cooling methods. The temperature difference inside the inner dewar is less than 0.3 K, and the temperature uniformity is significantly improved. When using refrigerator conduction cooling combined with solid nitrogen heat preservation, the lowest temperature of the superconducting magnet drops to 35 K, and the cryogenic system is maintained below 40 K for 3 hours; when using cold helium gas cycle cooling combined with solid nitrogen heat preservation, the lowest temperature of the superconducting magnet drops to 28.7 K, and the cryogenic system is maintained below 40 K for 5.7 hours, and the solid nitrogen heat preservation time is significantly extended.

[0058] Figure 7 The figure shows the shock response curve of the present invention. The cryogenic system of the high-temperature superconducting magnet of the present invention was respectively subjected to half-sine shocks in the x, y, and z directions, with a pulse peak acceleration exceeding 10 g and a pulse width of 18 ms.

[0059] Figure 8 The figure shows the frequency response curves before and after the shock test of the present invention. It can be seen that there is no obvious change in the frequency response curves before and after the shock test of the cryogenic system, which proves that there is no damage inside the cryogenic system, and the cryogenic system has the characteristics of resisting high overload.

[0060] The above are only embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related cryogenic system fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A high temperature superconducting magnet cryogenic system, characterized in that: include: An outer dewar, an inner dewar, a pluggable refrigerator, a cold head bracket, several double-cone main support columns, a dewar support column, a cooling copper plate, a cooling copper belt, a helium gas pipe, a liquid nitrogen gas pipe, and a return gas pipe; the outer dewar is mounted on the outside of the inner dewar, the inside of the outer dewar is in a vacuum environment, and a high-temperature superconducting magnet module is installed inside the inner dewar; the pluggable refrigerator is inserted into the outer dewar, connected to one end of the cooling copper belt, and fixed by the cold head bracket; the double-cone main support columns are installed on the front and rear sides of the outer dewar, one end of each double-cone main support column is connected to the outer wall of the inner dewar, and the other end is connected to the inner wall of the outer dewar; the dewar support column is connected to the front and rear side walls of the outer dewar, and is not fitted with the inner dewar, and is used to support the outer dewar to prevent it from deformation; the cooling copper plate is wrapped around the outer wall of the inner dewar, and the two ends of the cooling copper belt are respectively connected to the pluggable refrigerator and the side wall of the inner dewar, and the high-temperature superconducting magnet module; One end of the helium delivery pipe is connected to the bottom of the inner Dewar, and the other end is connected to the upper wall of the outer Dewar; one end of the liquid nitrogen delivery pipe and the return gas pipe are connected to the upper wall of the inner Dewar, and the other end is connected to the upper wall of the outer Dewar; support beams are respectively arranged on the inner surfaces of the outer Dewar and the inner Dewar.

2. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: The cold head bracket is made of epoxy resin material; the outer dewar, inner dewar, dewar support column, helium gas pipe, liquid nitrogen gas pipe and return gas pipe are all made of stainless steel; the cooling copper plate and cooling copper belt are made of oxygen-free copper material with high thermal conductivity, among which the cooling copper plate is made of hard copper plate and the cooling copper belt is made of soft thick copper wire.

3. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: The high-temperature superconducting magnet cryogenic system adopts a front-to-back symmetrical support structure, and the front and rear walls of the inner dewar are both installed with double-cone main support columns with hollow structures; the dewar support columns adopt a solid structure, pass through the center of the inner dewar, and do not contact the center wall of the inner dewar; the double-cone main support columns are detachable structures. When the high-temperature superconducting magnet cryogenic system operates in a static environment, part of the double-cone main support columns are removed to reduce heat leakage of the cryogenic system.

4. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: The cooling copper belt is divided into two parts. One part passes through the side wall of the inner dewar and enters the inner dewar, and is connected to the magnet cooling copper plate on the high-temperature superconducting magnet module inside the inner dewar, and is used to cool the high-temperature superconducting magnet; the other part is connected to the cooling copper plate to achieve overall cooling of the inner dewar.

5. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: Studs are welded on the outer surface of the inner Dewar, and through holes are provided at corresponding positions on the surface of the cooling copper plate. The cooling copper plate and the inner Dewar are positioned through the through holes and studs. At the same time, the copper nose at the end of the cooling copper strip passes through the studs on the outer surface of the inner Dewar and is fixed by a nut.

6. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: A portion of the helium delivery pipe, the liquid nitrogen delivery pipe and the return air pipe is arranged as a bellows structure.

7. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: The high-temperature superconducting magnet module comprises two magnet cooling copper plates, two magnet end plates, two insulating partitions, a number of magnet support columns, and a high-temperature superconducting magnet; the high-temperature superconducting magnet module is runway-shaped or circular as a whole, and each component is runway-shaped or circular and arranged in layers, which are: a first magnet end plate, a first magnet cooling copper plate, a first insulating partition, a high-temperature superconducting magnet, a second insulating partition, a second magnet cooling copper plate, and a second magnet end plate, wherein the surface areas of the two magnet cooling copper plates are slightly larger than the surface areas of other components, and the surface areas of other components are the same; the high-temperature superconducting magnet is located at the center of the high-temperature superconducting magnet module, and its front and rear side walls are respectively close to the insulating partition, and the other side of the insulating partition is close to the magnet cooling copper plate; one side of the magnet cooling copper plate is close to the insulating partition, and the other side is close to the magnet end plate, and the outer edge of the magnet cooling copper plate is connected to the cooling copper belt; the magnet support column is installed on the magnet end plate and connected to the inner Dewar.

8. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: The magnet cooling copper plate is made of oxygen-free copper material with high thermal conductivity, and the magnet end plate and magnet supporting column are made of stainless steel material; the insulating partition is made of epoxy resin or aluminum alloy material. When the insulating partition is made of aluminum alloy material, a layer of polytetrafluoroethylene film is sprayed on its surface.

9. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: The double-cone main support column includes a double-cone support structure, an inner Dewar connecting flange, and an outer Dewar connecting flange; the double-cone support structure is an integrated structure formed by two cone tops connected relatively, and its interior is a hollow structure; the inner Dewar connecting flange and the outer Dewar connecting flange are respectively located at both ends of the double-cone support structure, the bottom of the inner Dewar connecting flange is connected to the inner Dewar, and the top of the outer Dewar connecting flange is connected to the outer Dewar; the radius of the inner Dewar connecting flange is greater than the radius of the outer Dewar connecting flange.

10. The high temperature superconducting magnet cryogenic system according to claim 9, characterized in that: The surface of the double-cone support structure is provided with through holes, the wall thickness in the middle is greater than the wall thickness at both ends, and it is made of high-strength non-metallic material; the inner Dewar connecting flange and the outer Dewar connecting flange are made of stainless steel material.

11. The high temperature superconducting magnet cryogenic system according to claim 9, characterized in that: The inner Dewar connecting flange and the outer Dewar connecting flange respectively include two parts, which are all surrounded by threaded holes; the first parts of the inner Dewar connecting flange and the outer Dewar connecting flange are respectively welded and fixed to the inner Dewar and the outer Dewar, and the second parts are respectively connected to the two ends of the double-cone support structure; the two parts of the inner Dewar connecting flange and the outer Dewar connecting flange are detachable; the double-cone main support column is disassembled through the inner Dewar connecting flange and the outer Dewar connecting flange.

12. The high temperature superconducting magnet cryogenic system according to claim 1, characterized in that: The pluggable refrigerator includes a low-temperature refrigerator, a compression structure, a bellows, and a cold head connector; the bellows is installed on the upper wall of the outer Dewar, and its interior is a hollow structure. The low-temperature refrigerator as a whole is inserted into the vacuum interlayer of the outer Dewar through the bellows; the compression structure is installed at the connection between the low-temperature refrigerator and the bellows; The cold head connector is located at the bottom of the cryogenic refrigerator; the cold head connector is divided into two parts, one part is a groove structure, connected to the bottom of the cold head of the cryogenic refrigerator; the other part is a frustum structure, connected to the cooling copper belt.

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