Superconducting electromagnet device

Abstract

A superconducting magnet device has a superconducting coil (2), a refrigerant container (3), a refrigerator (8), a heat exchanger (11), and a cooling cylinder (13). The refrigerant container (3) houses a refrigerant that cools the superconducting coil (2). The refrigerator (8) has a refrigeration stage. The heat exchanger (11) is disposed inside the refrigerant container (3) and is connected to the refrigeration stage to cool the gasified refrigerant. The cooling cylinder (13) has a bottom (14) and a peripheral wall portion (15) that is vertically disposed from an outer edge of the bottom (14) and surrounds the heat exchanger (11) inside the refrigerant container (3). The cooling cylinder (13) has an opening (16) in the peripheral wall portion (15) through which the gasified refrigerant flows, and stores the liquid refrigerant condensed by the heat exchanger (11) on the bottom (14).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a superconducting magnet device. BACKGROUND

[0002] As prior art documents disclosing the structure of a superconducting magnet, there are Japanese Patent Application Publication No. 2013-53824 (Patent Document 1). The superconducting magnet described in Patent Document 1 includes a superconducting coil, a vacuum container, a refrigerator, and a heat exchanger. The heat exchanger has a mechanism for discharging a liquid refrigerant.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-53824 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In a superconducting magnet device, a liquid refrigerant gasifies due to heat from the outside intruding into a refrigerant container, thereby generating a refrigerant gas. In order to prevent a pressure rise in the refrigerant container caused by the refrigerant gas, the refrigerant gas is recondensed by continuously operating a refrigerator while the superconducting magnet device is operating. In order to ensure the amount of liquid refrigerant required for cooling a superconducting coil while reducing the power consumption of the refrigerator, it is required to increase the amount of recondensation of the refrigerant per unit time.

[0008] The present disclosure was made in order to solve the above problem, and aims to provide a superconducting magnet device capable of increasing the amount of recondensation of the refrigerant per unit time.

[0009] MEANS FOR SOLVING THE PROBLEM

[0010] The superconducting magnet device according to the present disclosure includes a superconducting coil, a refrigerant container, a refrigerator, a heat exchanger, and a cooling cylinder. The refrigerant container houses a refrigerant that cools the superconducting coil. The refrigerator has a refrigeration stage. The heat exchanger is disposed inside the refrigerant container and connected to the refrigeration stage, and cools the refrigerant after gasification. The cooling cylinder has a bottom and a peripheral wall portion that is vertically disposed from an outer edge of the bottom, and surrounds the heat exchanger inside the refrigerant container. The cooling cylinder has an opening in the peripheral wall portion through which the refrigerant after gasification flows, and stores the liquid refrigerant after recondensation by the heat exchanger on the bottom.

[0011] EFFECTS OF THE INVENTION

[0012] According to the present disclosure, the latent heat of the liquid refrigerant stored in the bottom portion of the cooling cylinder can be used to reduce the temperature of the cooling cylinder. By reducing the temperature of the cooling cylinder, the refrigerant gas located around the cooling cylinder can be cooled. The low-temperature refrigerant gas is supplied to the heat exchanger through the opening of the cooling cylinder. Thus, the condensation heat transfer coefficient in the heat exchanger can be improved, and the amount of recondensed refrigerant per unit time can be increased. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a front view showing a superconducting magnet apparatus of Embodiment 1.

[0014] Figure 2 is a side view of the superconducting magnet apparatus as viewed from the arrow II direction. Figure 1

[0015] Figure 3 is a cross-sectional view of the superconducting magnet apparatus as viewed from the arrow direction of the III-III line. Figure 1

[0016] Figure 4 is a perspective view showing a cooling cylinder provided in the superconducting magnet apparatus of Embodiment 1.

[0017] Figure 5 is a cross-sectional view in which the cooling cylinder provided in the superconducting magnet apparatus of Embodiment 1 is enlarged and the flow of refrigerant is shown.

[0018] Figure 6 is a cross-sectional view showing the structure of a superconducting magnet apparatus of Embodiment 2.

[0019] Figure 7 is a perspective view showing a cooling cylinder provided in the superconducting magnet apparatus of Embodiment 2.

[0020] Figure 8 is a cross-sectional view of the cooling cylinder as viewed from the arrow direction of the VIII-VIII line. Figure 7

[0021] Figure 9 is a cross-sectional view in which the cooling cylinder provided in the superconducting magnet apparatus of Embodiment 2 is enlarged and the flow of refrigerant is shown.

[0022] Figure 10 is a cross-sectional view showing the structure of a superconducting magnet apparatus of Embodiment 3.

[0023] Figure 11 is a cross-sectional view in which the cooling cylinder provided in the superconducting magnet apparatus of Embodiment 3 is enlarged and the flow of refrigerant is shown.

[0024] Figure 12 is a cross-sectional view showing the structure of a superconducting magnet apparatus of Embodiment 4.​​​

[0025] Figure 13 Observe from the direction of the arrow on line XIII-XIII Figure 12 A cross-sectional view of the fins of the heat exchanger.

[0026] Figure 14 This is a perspective view showing the cooling cylinder included in the superconducting magnet device of Embodiment 4. Detailed Implementation

[0027] Hereinafter, superconducting magnet devices according to various embodiments will be described with reference to the accompanying drawings. In the following description of the embodiments, the same or equivalent parts in the drawings will be labeled with the same reference numerals, and their descriptions will not be repeated. In the following embodiments, a cylindrical superconducting magnet device will be described, but it is not necessarily limited to a cylindrical superconducting magnet device.

[0028] Implementation Method 1

[0029] Figure 1 This is a front view showing the superconducting magnet device of Embodiment 1. Figure 2 Viewed from the direction of arrow II Figure 1 A side view of a superconducting magnet device. Figure 3 Observe from the direction of the arrow on line III-III Figure 1 A cross-sectional view of a superconducting magnet device.

[0030] like Figures 1 to 3 As shown, the superconducting magnet device 100 includes a superconducting coil 2, a refrigerant container 3, a refrigerator 8, a heat exchanger 11, and a cooling cylinder 13. The superconducting magnet device 100 also includes a radiation shield 4, a vacuum container 5, a refrigerator housing tube 6, and a heat anchor 7.

[0031] The superconducting coil 2 is cooled below its critical temperature by the sensible or latent heat of the liquid refrigerant 1 through direct or indirect contact with it. Figure 3 As shown, in this embodiment, the superconducting coil 2 is immersed in liquid refrigerant 1 and is cooled by direct contact with liquid refrigerant 1. However, the superconducting coil 2 can also be cooled by indirect contact with liquid refrigerant 1 through contact with a pipe connected to the refrigerant container 3 containing liquid refrigerant 1.

[0032] The refrigerant container 3 contains the refrigerant 1 used to cool the superconducting coil 2. The refrigerant 1 is a material with a boiling point lower than the critical temperature at which the superconducting coil 2 becomes superconducting, such as helium, hydrogen, or nitrogen. The refrigerant container 3 is made of a non-magnetic metal, such as stainless steel.

[0033] The radiation shield 4 is disposed at a distance from the refrigerant container 3 and surrounds the refrigerant container 3. The radiation shield 4 reduces thermal radiation from the vacuum container 5 to the refrigerant container 3. The radiation shield 4 is preferably made of a material with high light reflectivity and thermal conductivity, such as aluminum.

[0034] Vacuum container 5 houses refrigerant container 3 and radiation shielding component 4. The interior of vacuum container 5 is depressurized to a high vacuum to improve the insulation of refrigerant container 3. More specifically, the space from the inside of vacuum container 5 to the outside of refrigerant container 3 is a high vacuum. Vacuum container 5 is, for example, made of stainless steel.

[0035] The refrigeration unit housing pipe 6 connects to the refrigerant container 3 from the outside of the vacuum container 5. The refrigeration unit housing pipe 6 is connected to the refrigerant container 3. A thermal anchor 7 is disposed at the center of the refrigeration unit housing pipe 6 along its length. The thermal anchor 7 is a block-shaped component made of a material with high thermal conductivity, such as copper or aluminum, and is connected to the radiation shielding component 4 via a flexible conductor (not shown).

[0036] The refrigerator 8 is inserted into the refrigerator housing pipe 6. The refrigerator 8 has a first cooling stage 9 and a second cooling stage 10. As the refrigerator 8, a Gifford McMahon type refrigerator or a pulse tube refrigerator with such a two-stage cooling stage is used. The first cooling stage 9 cools the heat anchor 7.

[0037] The cooling capacity of the refrigerator 8 varies depending on the temperature of the first cooling station 9 and the second cooling station 10. When helium is used as the refrigerant 1, the temperature of the first cooling station 9 of the refrigerator 8 is, for example, above 30K and below 60K, and the cooling capacity of the first cooling station is, for example, above 20W and below 70W. The temperature of the second cooling station 10 is, for example, 4K, and the cooling capacity of the second cooling station 10 is, for example, 1W.

[0038] A heat exchanger 11 is disposed inside the refrigerant container 3 and connected to the second refrigeration stage 10 to cool the refrigerant gas 1G. The heat exchanger 11 is provided with fins 12 to increase the heat exchange area. Inside the refrigerant container 3, the heat exchanger 11 is disposed in the space where the refrigerant gas 1G is present.

[0039] The fins 12 extend toward the bottom of the cooling cylinder 13, which will be described later. Furthermore, in this embodiment, the fins 12 have a comb-like shape, but any shape that increases the heat exchange area is acceptable and is not limited to a comb-like shape. The fins 12 may also have a pin-like shape, for example. The refrigerant gas 1G surrounding the heat exchanger 11 recondenses on the surface of the heat exchanger 11, becoming a liquid refrigerant 1.

[0040] Figure 4This is a perspective view showing the cooling cylinder included in the superconducting magnet device of Embodiment 1. Figure 4 The cover of the cooling cylinder 13, described later, is not shown in the diagram. Figure 4 As shown, the cooling cylinder 13 has a bottom 14 and a peripheral wall portion 15 erected from the outer edge of the bottom 14. The cooling cylinder 13 is arranged inside the refrigerant container 3 in a manner that surrounds the heat exchanger 11. The cooling cylinder 13 has an opening 16 in the peripheral wall portion 15 for the vaporized refrigerant gas 1G to flow through, and stores the liquid refrigerant 1 after being recondensed by the heat exchanger 11 on the bottom 14. In this embodiment, the cooling cylinder 13 has a bottomed cylindrical shape, but it may also have a bottomed square cylindrical shape.

[0041] The cooling cylinder 13 is connected to the second cooling platform 10. In this embodiment, as... Figure 3 and Figure 5 As shown, the cooling cylinder 13 has a cover portion 15t extending inward from the upper end of the peripheral wall portion 15. The cover portion 15t of the cooling cylinder 13 is connected to the second cooling platform 10. The cover portion 15t is provided with a hole through which the second cooling platform 10 and the heat exchanger 11 can be inserted. After the second cooling platform 10 and the heat exchanger 11 are inserted into the hole, the cooling cylinder 13 is rotated in the circumferential direction, thereby... Figure 3 and Figure 5 As shown, the cover 15t is connected to the second cooling platform 10. Alternatively, the cooling cylinder 13 can be connected to the heat exchanger 11 instead of the second cooling platform 10. The cooling cylinder 13 is made of a material with high thermal conductivity, such as copper or aluminum.

[0042] In this embodiment, the opening 16 has a slit-like shape, but it can be any shape that allows the refrigerant 1 to flow through; it can also be a circular hole or a mesh. Preferably, at least a portion of the opening 16 is located at a position lower than the lower end of the heat exchanger 11, but the position of the opening 16 is not necessarily limited to the position described above.

[0043] Figure 5 This is an enlarged cross-sectional view showing the flow of refrigerant in the cooling cylinder of the superconducting magnet device of Embodiment 1. Since the superconducting magnet device 100 is placed in a room temperature environment, heat enters from the vacuum container 5 into the radiation shield 4, and then from the radiation shield 4 into the refrigerant container 3. The heat entering the refrigerant container 3 causes the liquid refrigerant 1 inside the refrigerant container 3 to vaporize, producing refrigerant gas 1G. Figure 3 and Figure 5As shown, refrigerant gas 1G accumulates in the upper part of refrigerant container 3 due to buoyancy. If refrigerant gas 1G continues to be generated inside refrigerant container 3, the internal pressure of refrigerant container 3 will rise. Therefore, the refrigerant gas 1G is cooled and recondensed by heat exchanger 11 connected to the second refrigeration stage 10 of refrigeration machine 8, thereby keeping the internal pressure of refrigerant container 3 constant.

[0044] The cooling cylinder 13 is cooled to a temperature near the boiling point of the refrigerant 1 by the latent heat of the liquid refrigerant 1 stored in the bottom 14 and the second cooling stage 10. The temperature of the refrigerant gas 1G is near the boiling point of the refrigerant 1 near the gas-liquid interface between the liquid refrigerant 1 and the refrigerant gas 1G. For example, when the refrigerant 1 is helium, the temperature of the refrigerant gas 1G near the gas-liquid interface is about 4.2K, but the density of the refrigerant gas 1G decreases towards the upper part of the refrigerant container 3, and the temperature of the refrigerant gas 1G becomes higher than the boiling point of the refrigerant 1. As a result, the temperature of the cooling cylinder 13 located at the top of the refrigerant container 3 is lower than that of the refrigerant gas 1G present around the cooling cylinder 13, and therefore, the refrigerant gas 1G can be cooled by the cooling cylinder 13.

[0045] As shown by the dashed arrow F1, the refrigerant gas 1G cooled by the cooling cylinder 13 flows through the opening 16 in the cooling cylinder 13 and into the heat exchanger 11. It is then cooled and condensed by the heat exchanger 11, becoming a liquid refrigerant 1. The liquid refrigerant 1 flows down the surface of the heat exchanger 11 and the fins 12, and is stored on the bottom 14 of the cooling cylinder 13.

[0046] In Embodiment 1, when the amount of refrigerant 1 stored on the bottom 14 increases and the liquid level of refrigerant 1 reaches the opening 16, as shown by the solid arrow F2, the liquid refrigerant 1 is discharged from the opening 16 and flows to the lower part of the refrigerant container 3.

[0047] Typically, in a space containing a single-component gas, when a heat transfer surface exists with a temperature lower than the gas's boiling point, the gas condenses on the surface of the heat transfer surface, forming a liquid film. In this case, the condensation thermal resistance around the heat transfer surface is the sum of the convective thermal resistance required to lower the gas's temperature to its boiling point and the liquid film thermal resistance of the condensed liquid film. The smaller the condensation thermal resistance, the greater the amount of recondensation per unit time.

[0048] The smaller the temperature difference between the gas surrounding the heat transfer surface and the heat transfer surface, the lower the convective thermal resistance. The thinner the liquid film formed on the heat transfer surface, and the lower the latent heat of the refrigerant, the lower the liquid film thermal resistance. The refrigerant 1 used in the superconducting magnet device 100, with its extremely low boiling point, has a low latent heat, thus resulting in low liquid film thermal resistance. Therefore, the influence of convective thermal resistance on the condensation thermal resistance becomes greater.

[0049] In the superconducting magnet device 100 of this embodiment, by providing a cooling cylinder 13 surrounding the heat exchanger 11 inside the refrigerant container 3, the temperature of the cooling cylinder 13 can be reduced by utilizing the latent heat of the liquid refrigerant 1 stored at the bottom 14 of the cooling cylinder 13. The temperature reduction of the cooling cylinder 13 cools the refrigerant gas 1G surrounding it. The low-temperature refrigerant gas 1G is supplied to the heat exchanger 11 through the opening 16 of the cooling cylinder 13. As a result, the temperature difference between the refrigerant gas 1G surrounding the heat exchanger 11 and the temperature of the heat exchanger 11 decreases, reducing convective and condensation thermal resistance. This improves the condensation heat transfer coefficient in the heat exchanger 11 and increases the recondensation rate of the refrigerant 1 per unit time.

[0050] In the superconducting magnet device 100 of this embodiment, the cooling cylinder 13 is connected to either the second cooling stage 10 or the heat exchanger 11. Thus, the cooling cylinder 13 can be effectively cooled by either the second cooling stage 10 or the heat exchanger 11, together with the liquid refrigerant 1 stored in the bottom 14.

[0051] Implementation Method 2

[0052] The superconducting magnet device of Embodiment 2 will be described below. The superconducting magnet device of Embodiment 2 differs from that of Embodiment 1 only in the structure of the cooling cylinder; therefore, other structural details will not be repeated.

[0053] Figure 6 This is a cross-sectional view showing the structure of the superconducting magnet device according to Embodiment 2. Figure 6 In, with Figure 3 The same cross-section is used for illustration. For example... Figure 6 As shown, in Embodiment 2, the cooling cylinder 13A disposed around the heat exchanger 11 is disposed inside the refrigerant container 3 and connected to the refrigerant container 3.

[0054] Figure 7 This is a perspective view showing the cooling cylinder included in the superconducting magnet device of Embodiment 2. Figure 8 Observe from the direction of the arrow on line VIII-VIII Figure 7 A cross-sectional view of the cooling cylinder. Figure 7 The flange portion of the cooling cylinder 13A, which will be described later, is not shown in the figure.

[0055] like Figure 7 and Figure 8As shown, the cooling cylinder 13A has a bottom 14 and a peripheral wall portion 15 erected from the outer edge of the bottom 14. The cooling cylinder 13A is arranged inside the refrigerant container 3 in a manner that surrounds the heat exchanger 11. The cooling cylinder 13A has an opening 16 in the peripheral wall portion 15 for the passage of vaporized refrigerant gas 1G, and stores the liquid refrigerant 1 after being recondensed by the heat exchanger 11 on the bottom 14.

[0056] A drain pipe 16A is provided at the bottom 14, extending through the bottom 14. The drain pipe 16A protrudes into the cooling cylinder 13A within a range that does not interfere with the fins 12. The upper end 17 of the drain pipe 16A is lower than the lower end of the opening 16. In this embodiment, the cross-sectional shape of the drain pipe 16A is circular, but it can be any shape that allows the refrigerant 1 to flow in the drain pipe 16A, or it can be a rectangle or other polygon.

[0057] Cooling cylinder 13A is connected to refrigerant container 3. For example... Figure 8 and Figure 9 As shown, the cooling cylinder 13A has a flange portion 15f extending outward from the upper end of the peripheral wall portion 15. The upper surface of the flange portion 15f of the cooling cylinder 13A is connected to the inner surface of the refrigerant container 3.

[0058] Figure 9 This is an enlarged cross-sectional view showing the flow of refrigerant in the cooling cylinder of the superconducting magnet device of Embodiment 2. (e.g.) Figure 9 As shown, in Embodiment 2, when the amount of refrigerant 1 stored on the bottom 14 increases and the liquid level of refrigerant 1 reaches the upper end 17 of the drain pipe 16A, as indicated by the solid arrow F2, the liquid refrigerant 1 is discharged from the drain pipe 16A and flows to the lower part of the refrigerant container 3.

[0059] In the superconducting magnet device of this embodiment, by having a cooling cylinder 13A surrounding the heat exchanger 11 inside the refrigerant container 3, the condensation heat transfer coefficient in the heat exchanger 11 can be improved, and the amount of refrigerant 1 recondensed per unit time can be increased.

[0060] In the superconducting magnet device of this embodiment, the cooling cylinder 13A is connected to the refrigerant container 3. As a result, the structure connecting to the second cooling stage 10 can be reduced, and therefore, the connection structure of the refrigerator 8 can be simplified compared to the superconducting magnet device 100 of Embodiment 1.

[0061] Implementation Method 3

[0062] The superconducting magnet device of Embodiment 3 will be described below. Furthermore, the superconducting magnet device of Embodiment 3 differs from that of Embodiment 2 mainly in the structure of the refrigerator, the refrigerator housing tube, and the cooling cylinder; therefore, structures identical to those in the superconducting magnet device of Embodiment 2 will not be described again.

[0063] Figure 10 This is a cross-sectional view showing the structure of the superconducting magnet device according to Embodiment 3. Figure 10 In, with Figure 6 The same cross-section is used for illustration. For example... Figure 10 As shown, in embodiment 3, the refrigerator 8 is inserted into the interior of the vacuum container 5. The first cooling stage 9 is located outside the radiation shield 4. The first cooling stage 9 and the radiation shield 4 are interconnected via a flexible conductor (not shown) and a thermal anchor 7, etc.

[0064] Figure 11 This is an enlarged cross-sectional view showing the flow of refrigerant in the cooling cylinder of the superconducting magnet device of Embodiment 3. (e.g.) Figure 11 As shown, in embodiment 3, the heat exchanger 11 is inserted into the interior of the refrigerant container 3 through the insertion port 19 provided therein. The heat exchanger 11 and the insertion port 19 are sealed by a sealing material 20 such as indium or an O-ring, so that the refrigerant gas 1G does not flow out of the refrigerant container 3.

[0065] In embodiment 3, the second cooling stage 10 is located outside the refrigerant container 3. The heat exchanger 11 and the second cooling stage 10 are interconnected via a connecting conductor 18. The connecting conductor 18 is preferably flexible. The connecting conductor 18 is made of a material with high thermal conductivity, such as copper.

[0066] In embodiment 3, the configuration structure is not limited to the above-described configuration as long as the heat exchanger 11 and the second cooling station 10 are connected by the connecting conductor 18 and the fins 12 provided in the heat exchanger 11 are arranged inside the refrigerant container 3.

[0067] Cooling cylinder 13B is connected to refrigerant container 3. No drain pipe 16A is installed on cooling cylinder 13B. Figure 11 As shown, in embodiment 3, when the amount of refrigerant 1 stored on the bottom 14 increases and the liquid level of refrigerant 1 reaches the opening 16, as indicated by the solid arrow F2, the liquid refrigerant 1 is discharged from the opening 16 and flows to the lower part of the refrigerant container 3.

[0068] In the superconducting magnet device of this embodiment, by having a cooling cylinder 13B surrounding the heat exchanger 11 inside the refrigerant container 3, the condensation heat transfer coefficient in the heat exchanger 11 can be improved, and the recondensation amount of refrigerant 1 per unit time can be increased.

[0069] In the superconducting magnet device of this embodiment, the second cooling stage 10 is located outside the refrigerant container 3, and the heat exchanger 11 and the second cooling stage 10 are connected to each other by the connecting conductor 18, so that the refrigeration housing tube 6 does not need to be set up. Therefore, the connection structure of the refrigerant container 3, the radiation shield 4 and the vacuum container 5 can be made easier.

[0070] Implementation Method 4

[0071] The superconducting magnet device of Embodiment 4 will be described below. Furthermore, the superconducting magnet device of Embodiment 4 differs from that of Embodiment 1 only in the structure of the cooling cylinder and the heat exchanger; therefore, other structural details will not be repeated.

[0072] Figure 12 This is a cross-sectional view showing the structure of the superconducting magnet device according to Embodiment 4. Figure 12 In, with Figure 3 The same cross-section is used for illustration. For example... Figure 12 As shown, in embodiment 4, the cooling cylinder 13C arranged around the heat exchanger 11 is disposed inside the refrigerant container 3 and connected to the second cooling platform 10. The heat exchanger 11 is provided with fins 12 to increase the heat exchange area.

[0073] Figure 13 Observe from the direction of the arrow on line XIII-XIII Figure 12 A cross-sectional view of the fins installed in the heat exchanger. (e.g.) Figure 13 As shown, a plurality of grooves 22 are provided on the surface of the fin 12. The plurality of grooves 22 extend from the surface of the fin 12 toward the bottom 14 of the cooling cylinder 13C. In this embodiment, the cross-sectional shape of each of the plurality of grooves 22 is triangular, but it can also be semi-circular or rectangular. The extending direction of each of the plurality of grooves 22 does not necessarily have to be toward the bottom 14.

[0074] Figure 14 This is a perspective view showing the cooling cylinder included in the superconducting magnet device of Embodiment 4. Figure 14 As shown, in the cooling cylinder 13C, fins 21 for increasing the heat exchange area with the refrigerant gas 1G are provided on the outer peripheral surface of the peripheral wall portion 15. In this embodiment, fins 21 extending toward the bottom 14 of the cooling cylinder 13C are provided in the circumferential direction of the peripheral wall portion 15 between the openings 16. The fins 21 have a flat plate shape, but they can also be corrugated or other shapes that can increase the heat exchange area with the refrigerant gas 1G. In addition, protrusions that guide the refrigerant gas 1G to flow through the openings 16 can also be provided on the fins 21.

[0075] In the superconducting magnet device of this embodiment, the refrigerant 1, after being recondensed by the heat exchanger 11, concentrates in the grooves 22 of the fins 12 due to surface tension. As a result, the liquid film of the refrigerant 1 becomes thinner in areas other than the grooves 22 of the fins 12, reducing liquid film thermal resistance. This reduces condensation thermal resistance in the heat exchanger 11 and increases the recondensation rate of the refrigerant gas 1G per unit time.

[0076] Furthermore, by providing fins 21 on the outer peripheral surface of the peripheral wall portion 15 of the cooling cylinder 13C, the heat exchange area between the refrigerant gas 1G surrounding the heat exchanger 11 and the cooling cylinder 13C can be increased. As a result, the convective thermal resistance in the heat exchanger 11 can be reduced. Consequently, the condensation thermal resistance in the heat exchanger 11 can also be reduced, and the recondensation rate of the refrigerant gas 1G per unit time can be increased.

[0077] Furthermore, the embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of this disclosure is not limited to the above embodiments. Additionally, all modifications within the meaning and scope equivalent to the claims are included. In the description of the above embodiments, structures that can be combined may also be combined with each other.

[0078] Explanation of reference numerals in the attached figures

[0079] 1. Refrigerant; 1G Refrigerant Gas; 2. Superconducting Coil; 3. Refrigerant Container; 4. Radiation Shielding Component; 5. Vacuum Container; 6. Refrigeration Unit Housing Pipe; 7. Thermal Anchor; 8. Refrigeration Unit; 9. First Refrigeration Platform; 10. Second Refrigeration Platform; 11. Heat Exchanger; 12, 21. Fins; 13, 13A, 13B, 13C. Cooling Cylinder; 14. Bottom; 15. Peripheral Wall; 15f. Flange; 15t. Cover; 16. Opening; 16A. Drain Pipe; 17. Upper End; 18. Connecting Conductor; 19. Insertion Port; 20. Sealing Material; 22. Groove; 100. Superconducting Magnet Device.

Claims

1. A superconducting magnet device, wherein, have: Superconducting coils; A refrigerant container for holding the refrigerant used to cool the superconducting coil; A refrigeration unit, which has a refrigeration platform; A heat exchanger, which is disposed inside the refrigerant container and connected to the refrigeration platform, cools the vaporized refrigerant; as well as A cooling cylinder having a bottom and a peripheral wall portion erected from the outer edge of the bottom, surrounds the heat exchanger inside the refrigerant container. The cooling cylinder has an opening in its peripheral wall to allow the vaporized refrigerant to flow through, and stores the liquid refrigerant, which has been recondensed by the heat exchanger, at the bottom.

2. The superconducting magnet device according to claim 1, wherein, The cooling cylinder is connected to either the refrigeration platform or the heat exchanger.

3. The superconducting magnet device according to claim 1, wherein, The cooling cylinder is connected to the refrigerant container.

4. The superconducting magnet device according to claim 3, wherein, The refrigeration platform is located outside the refrigerant container. The heat exchanger and the cooling platform are connected to each other via connecting conductors.

5. The superconducting magnet device according to any one of claims 1 to 4, wherein, The heat exchanger has fins extending toward the bottom. Multiple grooves are provided on the surface of the fin.

6. The superconducting magnet device according to any one of claims 1 to 4, wherein, The cooling cylinder has fins disposed on the outer peripheral surface of the peripheral wall portion.

7. The superconducting magnet device according to claim 5, wherein, The cooling cylinder has fins disposed on the outer peripheral surface of the peripheral wall portion.

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