KR20230061000A - High temperature superconducting magnet cooling system equipped with liquid nitrogen bath for current lead cooling in helium heat exchanger - Google Patents

Abstract

The present invention relates to a helium gas heat exchange high temperature superconducting magnet cooling system equipped with a liquid nitrogen tank for current lead cooling, and more specifically, to a high temperature superconductor cooling system provided with a liquid nitrogen tank within a cryogenic vessel to reduce a load on a high temperature superconductor by cooling the current lead within the cryogenic vessel. According to an embodiment of the present invention, provided is the helium gas heat exchange high temperature superconducting magnet cooling system equipped with a liquid nitrogen tank for current lead cooling, comprising: a high temperature superconductor; a cryogenic vessel; a first heat exchanger; a cryo fan; a liquid hydrogen tank; a liquid nitrogen pre-cooler; a first helium piping; a second helium piping; a second heat exchanger; a hydrogen piping; a third heat exchanger; a nitrogen piping; a current lead; a liquid nitrogen tank; a liquid nitrogen supply piping; a liquid nitrogen level meter; and a nitrogen discharge pipe.

Description

High temperature superconducting magnet cooling system equipped with liquid nitrogen bath for current lead cooling in helium heat exchanger}

The present invention relates to a helium gas heat exchange high-temperature superconducting magnet cooling system having a liquid nitrogen bath for cooling a current lead, and more particularly, to a cooling system for a high-temperature superconducting magnet by cooling a current lead in a cryogenic container to reduce a load of a high-temperature superconducting magnet. It relates to a high-temperature superconducting magnet cooling system having a nitrogen bath.

A superconductor is a material with zero electrical resistance. A material with a current resistance close to 0 near 4K, the temperature of liquid helium, is called a low temperature superconductor (LTS), and a material with a liquid nitrogen temperature higher than liquid helium, 77K. Materials that exhibit superconductivity in the vicinity are called high temperature superconductors (HTS). Since superconductors exhibit high critical temperatures, critical current densities, and critical magnetic fields, they are manufactured in the form of superconducting coils and applied to many fields.

The superconductor (superconducting coil) as described above constitutes a cooling system because normal performance can be maintained only when the temperature of the superconductor (superconducting coil) is lowered below the critical temperature of the superconductor by continuously removing radiant heat from the cryogenic container for the superconducting coil and heat intrusion due to conduction from the upper flange. It is very important to do

In particular, since the current lead accommodated in the cryogenic container for the superconducting magnet is a normal conductor with resistance, a lot of Joule heat is generated in the process of passing current to the superconducting coil, and when all heat such as radiation heat, heat penetration, and Joule heat are combined, a superconductor is formed. The load on the cooling heat exchanger can increase significantly. When designing a heat exchanger, all of the above variables must be considered, and accordingly, an increase in load/capacity of the heat exchanger is inevitable.

Japanese Patent Laid-Open No. 1988-292610 (November 29, 1988) discloses a "current supply lead for a superconducting device", and in this patent document, the temperature of the current lead is lowered by penetrating the current lead into a liquid nitrogen tank. On the other hand, Japanese Patent Publication No. 1996-069719 (Mar. 12, 1996) discloses a "current lead for superconducting device", and in order to solve the limitations of the aforementioned Japanese Patent Publication No. 1988-292610, a unique shape of the current lead is provided. are proposing

However, in the configuration in which the current lead passes directly into the liquid nitrogen tank as described above, as the current lead and the liquid nitrogen are in direct contact (convective heat transfer), as described in Japanese Patent Laid-Open No. 1996-069719, heat shrinks in a part of the current lead. Since the difference is large, there is a high possibility of leakage of nitrogen gas due to breakage of the current lead and leakage. There are limitations in design and maintenance.

The problem to be solved by the present invention is to improve the limitations of the conventional current lead cooling device (liquid nitrogen tank) for superconductors as described above, constructing a liquid nitrogen tank with a plate of a metal material (stainless steel) having high thermal conductivity, Attach a current lead to the outside of the liquid nitrogen tank (not the type that penetrates the liquid nitrogen), but indirectly by liquid nitrogen by attaching a material that is electrically insulated and thermally conductive between the current lead and the outside of the liquid nitrogen tank. To provide a helium gas heat exchange high-temperature superconducting magnet cooling system equipped with a liquid nitrogen bath for cooling a current lead that generates cooling.

The present invention is a high-temperature superconductor; a cryogenic container having a predetermined inner space sealed against the outside and accommodating the high-temperature superconductor; a first heat exchanger coupled to the high-temperature superconductor to cool the high-temperature superconductor; a cryo fan connected to the first heat exchanger to circulate helium; a liquid hydrogen tank for cooling the helium supplied to the first heat exchanger; a liquid nitrogen pre-cooler for pre-cooling hydrogen supplied to the liquid hydrogen tank; a first helium pipe for transporting helium discharged from the first heat exchanger to a liquid hydrogen tank; a second helium pipe for transporting helium supplied to the first heat exchanger from the liquid hydrogen tank; a second heat exchanger connected between the first helium pipe and the second helium pipe and accommodated in the liquid hydrogen tank to generate heat exchange between liquid hydrogen and helium; a hydrogen pipe for transporting hydrogen to the liquid hydrogen tank; a third heat exchanger connected to the hydrogen pipe and accommodated in the liquid nitrogen pre-cooler to generate heat exchange between liquid nitrogen and liquid hydrogen; a nitrogen pipe supplying nitrogen to the liquid nitrogen pre-cooler; a current lead connected to the high-temperature superconductor; a liquid nitrogen bath accommodated in the cryogenic container and provided to cool the current lead; A liquid nitrogen supply pipe connected to one side of the liquid nitrogen tank; a liquid nitrogen level meter provided in the liquid nitrogen tank; and a nitrogen discharge pipe provided at one side of the cryogenic container, including a current lead for maintaining the amount of liquid nitrogen in the liquid nitrogen tank within a predetermined range and discharging nitrogen vaporized in the cryogenic container to the outside of the cryogenic container. Provided is a helium gas heat exchange high-temperature superconducting magnet cooling system equipped with a liquid nitrogen bath for cooling.

In addition, the liquid nitrogen tank is formed to be surrounded by a plate of a metal material, and a predetermined insulator may be provided at a junction between the liquid nitrogen tank and the current lead to insulate the plurality of current leads from each other.

In addition, a helium tank for storing helium to be supplied to the first heat exchanger; a third helium pipe connected from the helium tank to the first heat exchanger; a vacuum pump connected to one side of the third helium pipe; And an on-off valve provided on the other side of the third helium pipe (between the first heat exchanger and one side of the third helium pipe to which the vacuum pump is connected); further including, new helium from the helium tank in the first heat exchanger. or may be controlled to remove some of the helium in the first heat exchanger.

In addition, it is provided outside the liquid hydrogen tank, a predetermined partition is formed to block heat transfer between the liquid hydrogen tank and the outside air, and the liquid nitrogen shield is accommodated inside the partition wall; may further include.

According to an embodiment of the present invention, by making a heat exchanger in a form in which a long metal tube (copper tube) is spirally wound and inserted into a metal plate (copper plate), the solder portion can be minimized compared to conventional heat exchangers used in cryogenic / high pressure environments. can According to this structure, since the pressure of the gas flowing in the metal tube acts perpendicularly to the tube surface, the proof load is much stronger. (In contrast, in the case of U-Band storage, the mechanical strength is weak because the shear stress that receives the pressure of the gas in the horizontal direction of the tube acts.)

In addition, since most of the vertical stress due to gas pressure is handled by the metal pipe, sufficient strength can be obtained by soldering alone without using silver solder having excellent mechanical strength for joining the metal plate and the metal pipe. Through this, cracks in the heat exchanger can be prevented, and silver solder, which is difficult and expensive to process, can be replaced with a simple and low-cost soldering process.

In addition, it is possible to reduce the required amount of refrigerant, which is difficult to increase the amount of helium indefinitely, through a multi-stage heat exchange system.

In addition, by soldering between the metal plate and the metal tube, the gap between the metal plate and the metal tube is filled, thereby maximizing heat transfer efficiency from the refrigerant to the metal tube to the metal plate to the superconductor.

In addition, it is possible to reduce the risk while using hydrogen, which is a combustible gas, for cooling.

In addition, by attaching the current lead to the liquid nitrogen bath, heat from room temperature can be blocked and the temperature can be lowered to near 77K, which is the liquid nitrogen temperature, reducing the cooling load of the helium gas-cooled heat exchanger. Joule heat generated in the lid can be removed through a metal plate attached to the liquid nitrogen bath. Therefore, by minimizing the heat load in the cryogenic container for the superconducting coil, the load of the heat exchanger (first heat exchanger) directly contacting (attached) to the superconductor can be significantly reduced.

In addition, by configuring the current lead so that the refrigerant (liquid nitrogen) does not come into direct contact with each other, problems such as leakage and breakage caused by difference in thermal contraction of a part of the current lead can be prevented.

In addition, while heat is transferred by liquid nitrogen, it may be configured so that current does not flow in the liquid nitrogen tank container.

In addition, by adding a high-temperature superconducting current lead to a section between the current lead passing through the liquid nitrogen bath and connecting to the superconducting magnet, the amount of heat penetration can be reduced both when current is not flowing to the superconducting magnet and when current is flowing.

1 is a diagram of a high-temperature superconductor cooling system according to an embodiment of the present invention.
2 is a view showing a heat exchanger according to the prior art.
3 is a view showing a heat exchanger for cooling a superconductor according to an embodiment of the present invention.
4 is a view showing the main parts of a helium gas heat exchange high-temperature superconducting magnet cooling system equipped with a liquid nitrogen bath for cooling a current lead according to an embodiment of the present invention.

Hereinafter, various embodiments of this document will be described with reference to the accompanying drawings. However, this is not intended to limit the technology described in this document to specific embodiments, and should be understood to include various modifications, equivalents, and/or alternatives of the embodiments of this document. . In connection with the description of the drawings, like reference numerals may be used for like elements.

In this document, expressions such as "has," "may have," "includes," or "may include" indicate the existence of a corresponding feature (eg, numerical value, function, operation, or component such as a part). , which does not preclude the existence of additional features.

Expressions such as "first," "second," "first," or "second," as used in this document may modify various elements, regardless of order and/or importance, and refer to one element as It is used only to distinguish it from other components and does not limit the corresponding components. For example, a first user device and a second user device may represent different user devices regardless of order or importance. For example, without departing from the scope of rights described in this document, a first element may be called a second element, and similarly, the second element may also be renamed to the first element.

A component (e.g., a first component) is "(operatively or communicatively) coupled with/to" or "connected" to another component (e.g., a second component). When referred to as "connected to", it should be understood that the certain component may be directly connected to the other component or connected through another component (eg, a third component).

Terms used in this document are only used to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by a person of ordinary skill in the technical field described in this document. Among the terms used in this document, terms defined in a general dictionary may be interpreted as having the same or similar meaning as the meaning in the context of the related art, and unless explicitly defined in this document, an ideal or excessively formal meaning. not be interpreted as In some cases, even terms defined in this document cannot be interpreted to exclude the embodiments of this document.

Of course, various modifications can be made by those skilled in the art without departing from the gist of the present invention claimed in the claims of the present invention, and these modifications are the technical spirit of the present invention or It should not be understood individually from the perspective.

The superconductor described in the description of the present invention may mean a low-temperature superconductor, a high-temperature superconductor, or a high-temperature superconducting magnet.

Terms such as 'high temperature', 'low temperature', and 'cryogenic temperature' described in the description of the present invention refer to high temperature, low temperature and extremely low temperature as terms commonly used in the field of superconductors. For example, near 4K, the temperature of liquid helium, is understood as the 'low temperature' or 'cryogenic' range, and near 77K, the temperature of liquid nitrogen, which is higher than liquid helium, or 30K to 40K, the target temperature of high-temperature superconductors, is understood as the 'high temperature' range. It can be. Since these temperature ranges are obvious to those skilled in the art, the description of the temperature ranges for each word/composition to be described later will be omitted.

On the other hand, if there is no explicit description of 'liquid' or 'gas' in helium, hydrogen and nitrogen to be described later, any of liquid, gas or mixed state within the range that can be designed by a person skilled in the art with reference to the description of the present invention. can be understood as one.

According to an embodiment of the present invention, a high-temperature superconductor (1); a cryogenic vessel (2) having a predetermined inner space sealed against the outside and accommodating the high-temperature superconductor (1); A first heat exchanger (3) coupled to the high-temperature superconductor (1) to cool the high-temperature superconductor (1); a cryo fan 4 connected to the first heat exchanger 3 to circulate helium (cryo fan; cryogenic pump; cryogenic blower); a liquid hydrogen tank (5) cooling the helium supplied to the first heat exchanger (3); a liquid nitrogen pre-cooler (6) for pre-cooling the hydrogen supplied to the liquid hydrogen tank (5); A first helium pipe (7) for transferring the helium discharged from the first heat exchanger (3) to the liquid hydrogen tank (5); a second helium pipe 8 for transporting helium supplied to the first heat exchanger 3 from the liquid hydrogen tank 5; A second heat exchanger (9) connected between the first helium pipe (7) and the second helium pipe (8) and accommodated in the liquid hydrogen tank (5) to generate heat exchange between liquid hydrogen and helium; a hydrogen pipe 10 for transporting hydrogen to the liquid hydrogen tank 5; a third heat exchanger 11 connected to the hydrogen pipe 10 and accommodated inside the liquid nitrogen pre-cooler 6 to generate heat exchange between liquid nitrogen and liquid hydrogen; and a nitrogen pipe 12 supplying nitrogen to the liquid nitrogen pre-cooler 6; a current lead 16 connected to the high-temperature superconductor 1; a liquid nitrogen bath 17 accommodated in the cryogenic vessel 2 and provided to cool the current lead 16; A liquid nitrogen supply pipe 26 connected to one side of the liquid nitrogen tank 17; a liquid nitrogen level meter provided in the liquid nitrogen tank 17; and a nitrogen discharge pipe 27 provided at one side of the cryogenic container 2, to maintain the amount of liquid nitrogen in the liquid nitrogen tank 17 within a predetermined range, and to vaporize the liquid nitrogen in the cryogenic container 2. The nitrogen is discharged to the outside of the cryogenic container 2, and the first heat exchanger 3 is: a metal plate 13 having a predetermined spiral groove 14 formed on one surface and having the high-temperature superconductor 1 attached to the other surface. ); And a metal tube 15 coupled to the spiral groove 14 formed in the metal plate 13; it provides a high-temperature superconductor cooling system comprising a.

According to this configuration, since the upper part of the high-temperature superconducting current lead (the section between the liquid nitrogen bath 17 and the high-temperature superconductor 1) passes through the liquid nitrogen bath, it is lower than the critical temperature of high-temperature superconducting, so that the superconducting state can be maintained. .

The cryogenic vessel 2, the liquid hydrogen tank 5, and the liquid nitrogen pre-cooler 6 are preferably configured to be insulated from outside air. Meanwhile, the cryogenic container 2, the liquid hydrogen tank 5, and the liquid nitrogen pre-cooler 6 may each be provided with a discharge pipe capable of discharging gas to the outside, and the internal pressure is reduced to a predetermined level due to the vaporized gas. If it exceeds the value of , it can be transferred to the outside or to a separate gas tank (nitrogen tank, hydrogen tank, etc.) provided outside.

The control target temperature of the high-temperature superconductor 1 is between 30K and 40K, and for this purpose, it is preferable to control the temperature of the helium gas circulating inside the first heat exchanger 3 to be between 20K and 30K. The pressure of the helium gas can be controlled between 9 and 10 atm, and the heat transfer rate from the high-temperature superconductor 1 can be maximized by flowing the cryogenic/high-pressure gas into the cryopan 4.

The helium gas absorbs heat from the high-temperature superconductor 1 in the first heat exchanger 3 and releases heat to liquid hydrogen in the second heat exchanger 9. Helium gas cooled by liquid hydrogen may be cooled to a temperature between 20K and 30K by liquid hydrogen (boiling point of about 20K).

The liquid hydrogen may be supplied by a liquid hydrogen tank (not shown), and by cooling the vaporized hydrogen gas with the liquid nitrogen pre-cooler 6 and supplying it into the liquid hydrogen tank 5, a plurality of hydrogen for cooling session can be used.

When liquid hydrogen in contact with helium that has absorbed the heat of the high-temperature superconductor 1 is vaporized by endotherm, the vaporized hydrogen gas can be transported to the outside or to a hydrogen gas tank. The heated hydrogen gas may be put into the liquid nitrogen pre-cooler 6 again and put back into the liquid hydrogen tank 5 in a cooled state by liquid nitrogen.

The liquid nitrogen temperature in the liquid nitrogen pre-cooler 6 may be maintained within a range of 77K to 80K.

A heat exchange process according to an embodiment of the present invention will be described again as follows. The circulating helium gas is cooled by the second heat exchanger 9 in the liquid hydrogen tank 5. The cooled helium gas is transferred to the first heat exchanger (3, copper plate heat exchanger) equipped with a superconducting magnet (high-temperature superconductor) by a circulation pump (cryopan). The cooled helium gas absorbs heat of the high-temperature superconductor 1 through the copper plate, and the temperature of the helium gas rises. The helium gas whose temperature has risen is transferred to the second heat exchanger 9 of the liquid hydrogen tank 5 again. While repeating this process, the first heat exchanger 3 attached to the superconducting magnet can lower the temperature through liquid hydrogen. In this process, liquid hydrogen evaporates, and the evaporated hydrogen gas is recondensed by a cryogenic refrigerator.

In addition, since the temperature of the lower part of the high-temperature superconducting current lead reaches around 30 K by the first heat exchanger 3 using helium gas, the superconducting state is maintained while current flows through the superconducting magnet 1, and thus Joule heat is generated. there is no

Since the high-temperature superconducting current lead has a very small cross section compared to the copper current lead, it has the advantage of being able to keep the amount of heat penetration to a minimum. Therefore, the amount of heat penetration can be reduced both when current is not flowing to the superconducting magnet and when current is flowing.

In addition, the predetermined groove formed in the metal plate 13 is formed in a spiral shape, and the metal pipe 15 is: at least a portion coupled to the metal plate 13 is integrally formed, and the metal plate 13 is formed in a spiral shape. It is configured by being bent into a shape corresponding to the groove 14, and a predetermined slag 18 is soldered to the joint between the metal plate 13 and the metal pipe 15.

2 shows the structure of a conventional heat exchanger. Holes are drilled in the copper plate, U-Bands connecting each hole are joined between the holes, and then the copper plate and U-Band are joined using the brazing method.

In the bonding according to the brazing method as described above, physical bonding is performed as the liquid slag and the solid copper plate (hole) are bonded, and in the example of FIG. 2, 10 points (the remaining 2 The elbow will be brazed even in the hole of the dog, but brazing is performed on the elbow (omitted for simplicity of description).

In this structure, when cryogenic/high-pressure helium is flowed, stress may be concentrated at brazed points, and accordingly, the probability of occurrence of cracks is very high.

According to the embodiment of the present invention, there is no need to use brazing as a means for extending the length of the metal tube 15 in which heat exchange occurs, and a single (integral) metal tube 15 that is not joined by a physical bonding method such as brazing By bending it spirally, it is possible to increase the surface area for heat exchange.

The smelting material (brazing) in the prior art should directly withstand the pressure of the refrigerant, but the smelting material 18 used according to the embodiment of the present invention does not have to support the pressure of the refrigerant, ① the metal pipe 15 is the metal plate 13 ), and performs only functions of heat transfer between the metal tube 15 and the metal plate 13.

According to the configuration as described above, the stress caused by the cryogenic/high pressure helium is generated only at both ends of the metal pipe 15, and accordingly, even if a strong bonding method is employed only at both ends of the metal pipe 15, the first heat exchanger (3 ) and connection pipes (such as the first helium pipe 7, the second helium pipe 8, and the second heat exchanger 9), cracks or leaks can be prevented from occurring.

As shown in FIG. 1, the second heat exchanger 9 and the third heat exchanger 11 spirally (or coiled) pipes to increase the contact area (heat exchange area) with liquid hydrogen and liquid nitrogen. It can be formed into a twisted shape.

In addition, the liquid nitrogen tank 17 is formed to be surrounded by a plate made of a metal material, and a plurality of current leads 16 are insulated from each other at a junction between the liquid nitrogen tank 17 and the current lead 16. The insulator 19 of may be provided.

By adjusting the contact area (contact length) of the current lead 16 to the side plate and bottom plate constituting the liquid nitrogen tank 17, the current lead 16 can be configured to be sufficiently cooled. For example, if the current lead 16 is bent in a spiral shape similar to the city tube metal tube 15 in FIG. 3 and attached to the liquid nitrogen tank 17, the current lead 16 can be sufficiently cooled, and the current Differences in heat shrinkage by position of the lead 16 can also be compensated for.

In order to prevent the two strands of current lead 16 (signal line; SC Coil Current Lead) connected to the high-temperature superconductor 1 from being short-circuited, an insulator ( 19) is preferably provided.

Further, the metal pipe 15 is formed at a predetermined angle with respect to the metal plate 13 based on the boundary surface 20 between a portion coupled to the spiral groove 14 formed in the metal plate 13 and a portion not coupled thereto. It may be bent to have, and both ends 21 may be configured to be coupled with a VCR fitting (Vacuum Coupling Radiation fitting), brazing, or a high-pressure fitting.

As described above, even if only the ends 21 of the metal tubes are perfectly joined (connected/combined), the occurrence of cracks/leakage can be fundamentally blocked, so the heat exchanger/cooling system (device) production yield due to the reduction in the number of junction points increase, etc.

3 shows an example in which the metal tube 15 is bent at an angle of 90 degrees with respect to the metal plate 13 based on the boundary surface 20 .

In addition, a helium tank 22 for storing helium to be supplied to the first heat exchanger 3; a third helium pipe 23 connected from the helium tank 22 to the first heat exchanger 3; a vacuum pump 24 connected to one side of the third helium pipe 23; And an on-off valve 25 provided on the other side of the third helium pipe 23 (between the first heat exchanger 3 and one side of the third helium pipe 23 to which the vacuum pump 24 is connected); Including further, it may be controlled to supply new helium from the helium tank 22 to the first heat exchanger 3 or to remove a part of the helium from the first heat exchanger 3.

In the "control to supply new helium from the helium tank 22 to the first heat exchanger 3 or to remove a part of the helium in the first heat exchanger 3", the first heat exchanger 3 is It may mean including the first to third helium pipes 7, 8, and 23 and the second heat exchanger 9 (removing/injecting some/all of helium in the connected heat exchange system).

In addition, a liquid nitrogen shield provided outside the liquid hydrogen tank 5, having a predetermined barrier rib formed to block heat transfer between the liquid hydrogen tank 5 and the outside air, and containing liquid nitrogen inside the barrier rib; may further include.

1 shows an embodiment including the liquid nitrogen shield. The liquid hydrogen tank 5 may be formed in a double structure having an outer wall and an inner wall, and the liquid nitrogen shield may be provided between the outer wall and the inner wall. By configuring a predetermined space to be provided outside and inside the liquid nitrogen shield, heat transfer can be remarkably reduced by separating the outer wall and the inner wall from the liquid nitrogen shield.

The liquid hydrogen tank 5, the liquid nitrogen pre-cooler 6, the liquid nitrogen tank 17, and the liquid nitrogen shield each have a level meter, a liquid tank (hydrogen tank/nitrogen tank), a supply device, a connection pipe, and a gas discharge pipe. may be provided.

According to an embodiment of the present invention, in the method of manufacturing a heat exchanger for cooling a superconductor, a metal plate 13 having a predetermined flat surface formed on one surface and a predetermined spiral groove 14 formed on the other surface so as to be attached to the superconductor is used. A metal plate manufacturing step to manufacture; A metal joint bending step of bending the metal pipe 15 into a shape corresponding to the spiral groove 14 formed in the metal plate 13; A fastening step of inserting the bent metal pipe 15 into the spiral groove 14 of the metal plate 13; and a soldering step of filling the empty space by soldering the space between the spiral groove 14 of the metal plate 13 and the metal tube 15.

In addition, a heat exchanger for cooling a superconductor manufactured according to the method for manufacturing a heat exchanger for cooling a superconductor as described above is provided.

By applying the superconductor cooling heat exchanger as described above to the superconductor cooling system described above, the technical spirit of the present invention can be implemented.

1: high-temperature superconductor 2: cryogenic container
3: first heat exchanger 4: cryopan
5: liquid hydrogen tank 6: liquid nitrogen pre-cooler
7: first helium pipe 8: second helium pipe
9: second heat exchanger 10: hydrogen pipe
11: third heat exchanger 12: nitrogen pipe
13: metal plate 14: spiral groove
15: metal tube 16: current lead
17: liquid nitrogen tank 18: solvent
19: insulator 20: interface
21: metal pipe end 22: helium tank
23: third helium pipe 24: vacuum pump
25: on-off valve 26: liquid nitrogen supply pipe
27: nitrogen discharge pipe

Claims (4)

high-temperature superconductors;
a cryogenic container having a predetermined inner space sealed against the outside and accommodating the high-temperature superconductor;
a first heat exchanger coupled to the high-temperature superconductor to cool the high-temperature superconductor;
a cryo fan connected to the first heat exchanger to circulate helium;
a liquid hydrogen tank for cooling the helium supplied to the first heat exchanger;
a liquid nitrogen pre-cooler for pre-cooling hydrogen supplied to the liquid hydrogen tank;
a first helium pipe for transporting helium discharged from the first heat exchanger to a liquid hydrogen tank;
a second helium pipe for transporting helium supplied to the first heat exchanger from the liquid hydrogen tank;
a second heat exchanger connected between the first helium pipe and the second helium pipe and accommodated in the liquid hydrogen tank to generate heat exchange between liquid hydrogen and helium;
a hydrogen pipe for transporting hydrogen to the liquid hydrogen tank;
a third heat exchanger connected to the hydrogen pipe and accommodated in the liquid nitrogen pre-cooler to generate heat exchange between liquid nitrogen and liquid hydrogen;
a nitrogen pipe supplying nitrogen to the liquid nitrogen pre-cooler;
a current lead connected to the high-temperature superconductor;
a liquid nitrogen bath accommodated in the cryogenic container and provided to cool the current lead;
A liquid nitrogen supply pipe connected to one side of the liquid nitrogen tank;
a liquid nitrogen level meter provided in the liquid nitrogen tank; and
Including; nitrogen discharge pipe provided on one side of the cryogenic container,
A helium gas heat exchange high-temperature superconducting magnet cooling system equipped with a liquid nitrogen tank for cooling a current lead, which maintains the amount of liquid nitrogen in the liquid nitrogen tank within a predetermined range and discharges nitrogen vaporized in the cryogenic container to the outside of the cryogenic container. The method of claim 1,
The liquid nitrogen tank is formed to be surrounded by a plate of metal material,
A helium gas heat exchange high-temperature superconducting magnet cooling system equipped with a liquid nitrogen bath for cooling a current lead, in which a predetermined insulator is provided at the junction between the liquid nitrogen bath and the current lead to insulate a plurality of current leads from each other. According to any one of claims 1 to 3,
a helium tank storing helium to be supplied to the first heat exchanger;
a third helium pipe connected from the helium tank to the first heat exchanger;
a vacuum pump connected to one side of the third helium pipe; and
An on-off valve provided on the other side of the third helium pipe (between the first heat exchanger and one side of the third helium pipe to which the vacuum pump is connected); further comprising,
New helium is supplied from the helium tank in the first heat exchanger,
A helium gas heat exchange high-temperature superconducting magnet cooling system having a liquid nitrogen bath for cooling a current lead, which is controlled to remove a part of helium in the first heat exchanger. According to any one of claims 1 to 3,
A liquid nitrogen shield provided outside the liquid hydrogen tank, having a predetermined barrier rib formed thereon to block heat transfer between the liquid hydrogen tank and the outside air, and accommodating liquid nitrogen inside the barrier rib; further comprising a liquid for cooling the current lead. Helium gas heat exchange high-temperature superconducting magnet cooling system equipped with a nitrogen bath

Images