WO2024004422A1

WO2024004422A1 - Cryogenic refrigerator

Info

Publication number: WO2024004422A1
Application number: PCT/JP2023/018540
Authority: WO
Inventors: 孝明森江
Original assignee: 住友重機械工業株式会社
Priority date: 2022-07-01
Filing date: 2023-05-18
Publication date: 2024-01-04
Also published as: JP2024006360A

Abstract

A cryogenic refrigerator (100) includes: a cold head (104) that can be mounted on a vacuum container (20); a cold head mount (106) that is configured to couple the cold head (104) with the vacuum container (20) so as to allow movement of the cold head (104) with respect to the vacuum container (20); a flexible line (108) that is connected to the cold head 104 outside the vacuum container (20); and a flexible line holder (110) that is configured to hold the flexible line (108) in a fixed manner with respect to the vacuum container (20).

Description

cryogenic refrigerator

The present invention relates to a cryogenic refrigerator.

Cryogenic refrigerators, such as the Gifford-McMahon (GM) refrigerator, provide cryogenic cooling for a variety of cooling purposes, such as cooling superconducting equipment and condensing cryogenic liquids such as liquid helium. It is often used for this purpose. Conventionally, such a cryogenic refrigerator was installed in a cryostat via a bellows, and the vertical movement of the cryogenic refrigerator accompanied by the expansion and contraction of the bellows was used to thermally connect the cryogenic refrigerator to the object to be cooled inside the cryostat. Or it is known to realize a disconnecting thermal switch.

Japanese Patent Application Publication No. 2016-211803

When a thermal switch of the type described above is on (i.e. when the cryocooler is thermally connected to the object to be cooled), the cryocooler can be rigidly fixed to the cryostat, whereas when the thermal switch is off (i.e., the cryocooler is temporarily disconnected from the object to be cooled), the cryocooler may be supported by the cryostat with low stiffness, for example due to the flexibility of the bellows. It tends to happen.

When operating a cryogenic refrigerator on site, various piping and wiring, such as flexible hoses for supplying and discharging working gas and cables for power supply, are connected to the cryogenic refrigerator. extends around. One of the risks that can be assumed in a typical setup of such a cryocooler is that a worker passing by the cryocooler may trip over these pipes. There are concerns that unexpected large external forces may be applied to the machine from the piping. These unexpected external forces can cause problems, especially when the thermal switch is off. External forces may disturb the position and orientation of the cryogenic refrigerator, causing interference or collision with surrounding structures, and in the worst case scenario, the cryogenic refrigerator or its supporting structure may be damaged.

One exemplary objective of certain embodiments of the present invention is to protect cryogenic refrigerators from unexpected external forces.

According to an aspect of the invention, a cryogenic refrigerator includes a cold head mountable in a vacuum vessel and a cold head configured to couple the cold head to the vacuum vessel to allow movement of the cold head relative to the vacuum vessel. The apparatus includes a head mount, a flexible line connected to the cold head outside the vacuum vessel, and a flexible line holder configured to hold the flexible line fixedly with respect to the vacuum vessel.

According to the present invention, a cryogenic refrigerator can be protected from unexpected external forces.

FIG. 1 is a diagram schematically showing a cryogenic device according to an embodiment. FIG. 3 is a diagram schematically showing a working gas line of a cryogenic refrigerator according to a comparative example. 2 schematically illustrates exemplary electrical connections applicable to the cryogenic refrigerator shown in FIG. 1; FIG. 2 is a diagram schematically illustrating an exemplary drive source that may be applied to the cryogenic refrigerator shown in FIG. 1; FIG.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and overlapping explanations will be omitted as appropriate. The scale and shape of each part shown in the drawings are set for convenience to facilitate explanation, and should not be interpreted in a limited manner unless otherwise stated. The embodiments are merely illustrative and do not limit the scope of the present invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

FIG. 1 is a diagram schematically showing a cryogenic device 10 according to an embodiment. In this embodiment, cryogenic device 10 may be utilized as a cryogenic liquid storage device. Therefore, the cryogenic apparatus 10 includes a vacuum container 20 for storing, for example, liquid hydrogen or other cryogenic liquid 12, and a vacuum container 20 for storing liquid hydrogen or other cryogenic liquid 12, and the cryogenic liquid 12 to be stored at its liquefaction temperature (in the case of liquid hydrogen, about -253°C). 20K)) or lower.

The vacuum container 20 includes an outer tank 22 and an inner tank 24. A vacuum insulation layer 26 is formed between the outer tank 22 and the inner tank 24. The outer chamber 22 is configured to separate the vacuum insulation layer 26 from the surrounding environment of the cryogenic device 10 (eg, a room temperature, atmospheric pressure environment). Additionally, the inner tank 24 is configured to separate its internal volume from the vacuum insulation layer 26. Cryogenic liquid 12 is contained in inner tank 24 . The outer tank 22 and the inner tank 24 are formed of a metallic material, such as stainless steel, or other suitable high-strength material to withstand pressure differences between the inside and outside.

A heat insulating structure 28 including a heat insulating support 28a and a heat insulating layer 28b may be arranged on the vacuum heat insulating layer 26. The heat insulating support 28a is made of a hard material with heat insulating properties, such as fiber-reinforced plastic, and is configured to support the inner tank 24 on the outer tank 22. The insulation layer 28b may include multilayer insulation (MLI). In addition to or in place of the insulation layer 28b, the insulation structure 28 may include granular or other forms of insulation (eg, granular perlite) filled into the vacuum insulation layer 26.

The inner tank 24 includes a recondensing section 30 provided on the tank wall. The recondensing section 30 is cooled from outside the inner tank 24 by the cryogenic refrigerator 100. The recondensing section 30 has a heat transfer surface 30a that is exposed outside the inner tank 24 and comes into contact with the cryogenic refrigerator 100. The recondensing section 30 may have fin-like protrusions or irregularities inside the inner tank 24 to increase the surface area that comes into contact with the cryogenic liquid 12 or the vaporized cryogenic liquid 12 . The recondensing section 30 is formed of, for example, pure copper (eg, oxygen-free copper, tough pitch copper, etc.) or other high heat conductive metal.

The cryogenic refrigerator 100 includes a compressor 102, a cold head 104 that can be mounted on a vacuum vessel 20, and a cold head 104 coupled to the vacuum vessel 20 to allow movement of the cold head 104 with respect to the vacuum vessel 20. and a cold head mount 106 configured.

The compressor 102 is configured to recover the working gas of the cryogenic refrigerator 100 from the cold head 104, increase the pressure of the recovered working gas, and supply the working gas to the cold head 104 again. Cold head 104 is also referred to as an expander or a refrigerator. Compressor 102 and cold head 104 constitute a refrigeration cycle for cryogenic refrigerator 100, whereby cryogenic refrigerator 100 provides cryogenic cooling. The working gas, also referred to as refrigerant gas, is typically helium gas, although other suitable gases may be used.

In this embodiment, the cryogenic refrigerator 100 is a single-stage GM refrigerator. Therefore, the cold head 104 includes a cooling stage 104a, a cylinder 104b, a drive section 104c, and a cold head flange 104d. The cooling stage 104a is formed of, for example, pure copper (eg, oxygen-free copper, tough pitch copper, etc.) or other high heat conductive metal. During operation of the cryogenic refrigerator 100, the cooling stage 104a is cooled to a desired cryogenic temperature, such as a temperature range below the liquefaction temperature of the cryogenic liquid 12. When the cryogenic liquid 12 is liquid hydrogen, the cooling stage 104a is, for example, at a cooling temperature within the temperature range of 10K to 30K (for example, cooling around 20K, such as 20K±1K, 20K±2K, or 20K±5K). temperature).

Cylinder 104b connects cooling stage 104a to cold head flange 104d. A displacer (not shown) for controlling the volume of the working gas expansion space adjacent to the cooling stage 104a is disposed within the cylinder 104b so as to be movable in the axial direction of the cylinder 104b (in the vertical direction in FIG. 1). ing. Cylinder 104b and cold head flange 104d are typically formed of a suitable metallic material, such as stainless steel. The drive portion 104c is attached to the cold head flange 104d on the opposite side from the cylinder 104b. The drive unit 104c includes a cold head drive motor 104e, such as an electric motor, for driving the displacer in the cylinder 104b, and a pressure control, such as a rotary valve, for controlling the working gas pressure in the expansion space in the cylinder 104b. A mechanism (not shown) is provided.

As shown in FIG. 1, the outer tank 22 of the vacuum container 20 is provided with a mounting port 32 for mounting the cold head 104 onto the vacuum container 20. During mounting, the cold head 104 is inserted into the vacuum vessel 20 through the mounting port 32 and is removably attached to the mounting port 32 via the cold head mount 106 . The cold head 104 is attached to the vacuum vessel 20 such that the cooling stage 104a is placed on the vacuum insulation layer 26 inside the vacuum vessel 20, and the drive unit 104c is placed outside the vacuum vessel 20.

As an example, the mounting port 32 is formed on the top plate or upper part of the vacuum container 20. The cold head 104 is installed in the vacuum container 20 so that its central axis coincides with the vertical direction. However, the position of the mounting port 32 and the mounting posture of the cold head 104 are not limited to this. For example, the mounting port 32 may be formed in the bottom plate or lower part of the vacuum container 20. The cold head 104 can be installed in any desired posture, and may be installed in the vacuum vessel 20 with its central axis aligned diagonally or horizontally.

The cold head mount 106 includes a mounting flange 106a that can be attached to the vacuum vessel 20, and an expandable and contractible airtight partition wall 106b that connects the cold head 104 to the mounting flange 106a. The mounting flange 106a is fixed to the mounting port 32 of the vacuum container 20 using a fastening member such as a bolt, or by other suitable fixing means. Note that the mounting flange 106a may be fixed to the vacuum vessel 20 via a connecting member instead of being directly fixed to the vacuum vessel 20 as illustrated. A retractable airtight bulkhead 106b, for example a bellows, connects the cold head flange 104d to the mounting flange 106a. Therefore, the mounting port 32 is closed by the mounting flange 106a, the airtight partition wall 106b, and the cold head flange 104d, and the airtightness of the vacuum container 20 is maintained.

The mounting flange 106a has an opening in the center, and the expandable and retractable airtight partition wall 106b is formed in a cylindrical shape. The cylinder 104b of the cold head 104 extends from the cold head flange 104d into the vacuum vessel 20 through an expandable airtight bulkhead 106b and an opening in the mounting flange 106a.

The cold head mount 106 also includes a drive source 106c that is mounted on the cold head mount 106 and configured to move the cold head 104 relative to the vacuum vessel 20. The drive source 106c may be configured to move the cold head 104 using appropriate power such as pneumatics, hydraulic pressure, an electric motor, or an electromagnet, or may be operable to move the cold head 104 manually. There may be.

The drive source 106c is installed on the mounting flange 106a, and is connected to the cold head flange 104d so as to move the cold head flange 104d in the direction of expansion and contraction of the airtight partition wall 106b. Therefore, by operating the drive source 106c, the cold head flange 104d can be moved relative to the mounting flange 106a while expanding and contracting the airtight partition wall 106b. In the example shown in FIG. 1, the drive source 106c can move the cold head flange 104d up and down with respect to the mounting flange 106a (that is, the cold head 104 with respect to the vacuum vessel 20).

In this manner, the cold head mount 106 can act as a thermal switch that thermally connects or disconnects the cold head 104 to the inner vessel 24 of the vacuum vessel 20, which is a storage tank for the cryogenic liquid 12. In FIG. 1, a solid line indicates a state in which the thermal switch is on, and a broken line indicates a state in which the thermal switch is off. When the thermal switch is on, the cooling stage 104a of the cold head 104 contacts the heat transfer surface 30a of the recondensing section 30 of the inner tank 24. Thereby, the cooling stage 104a can cool the recondensing section 30 to the liquefaction temperature of the cryogenic liquid 12, retain the cryogenic liquid 12 in the inner tank 24, and recondense the vaporized cryogenic liquid 12. be able to. On the other hand, when the cold head 104 is lifted by the operation of the drive source 106c, the cooling stage 104a separates from the heat transfer surface 30a of the recondensing section 30. Since the cooling stage 104a is disposed on the vacuum insulation layer 26, thermal contact between the cooling stage 104a and the recondensing section 30 is broken. At this time, the cold head 104 does not cool the inner tank 24.

Such a thermal switch is advantageous in improving the energy saving performance of the cryogenic device 10. As an exemplary operation of the cryogenic refrigerator 100, it is possible to stop the cooling operation of the cryogenic refrigerator 100 when the vacuum container 20 is sufficiently cooled. At this time, if the cold head 104 remains in contact with the inner tank 24 of the vacuum vessel 20, the cold head 104 becomes a heat transfer path from the surrounding environment of the cryogenic apparatus 10 to the inner tank 24, and transfers heat to the cryogenic liquid 12. Undesired heat intrusion can occur. On the other hand, such intruding heat can be cut off by separating the cold head 104 from the inner tank 24 using a thermal switch when stopping the cryogenic refrigerator 100.

For switching the thermal switch, the cryogenic device 10 may be provided with a sensor 34 that detects a physical quantity of the cryogenic liquid 12. The drive source 106c may be configured to receive an output signal from the sensor 34 indicative of the detected physical quantity of the cryogenic liquid 12 and move the cold head 104 based on the detected physical quantity of the cryogenic liquid 12. good.

For example, the sensor 34 may be arranged in the inner tank 24 of the vacuum container 20 and configured to measure the internal pressure of the inner tank 24. The vapor pressure of cryogenic liquid 12 in inner tank 24 is measured by sensor 34 . The drive source 106c compares the measured pressure with a pressure threshold, turns on the thermal switch when the measured pressure exceeds the pressure threshold, and turns off the thermal switch when the measured pressure is below the pressure threshold. It may work like this. In this way, the internal pressure of the inner tank 24 can be maintained at an appropriate pressure corresponding to the pressure threshold.

Alternatively, the sensor 34 may be configured to measure the temperature of the cryogenic liquid 12. In this case, the sensor 34 may be arranged within the inner tank 24 or installed in the recondensation section 30 of the inner tank 24 . The drive source 106c compares the measured temperature with a temperature threshold, turns on the thermal switch when the measured temperature exceeds the temperature threshold, and turns off the thermal switch when the measured temperature is below the temperature threshold. It may work like this. In this way, the cryogenic liquid 12 can be maintained at a suitable temperature corresponding to a temperature threshold.

The cryogenic refrigerator 100 also includes a flexible line 108 connected to the cold head 104 outside the vacuum container 20, and a flexible line holder configured to hold the flexible line 108 fixedly with respect to the vacuum container 20. 110. A flexible line 108 connects the drive portion 104c of the cold head 104 to an external element located outside the vacuum vessel 20 (eg, the compressor 102). A flexible line holder 110 is secured to the mounting flange 106a of the cold head mount 106 and holds the flexible line 108 on its way from the cold head 104 to an external element. In other words, the flexible line holder 110 corresponds to a relay point for fixing the flexible line 108 to the vacuum container 20.

Compressor 102 may be located remotely from coldhead 104 and vacuum vessel 20, such as in a separate room or compartment from the room or compartment in which coldhead 104 and vacuum vessel 20 are installed. , the length of the flexible line 108 may be, for example, 10 m or more. Since the flexible line holder 110 is fixed to the mounting flange 106a, the end of the flexible line 108 on the cold head 104 side (for example, the end of the flexible line 108 that is within 10% or 5% of the total length of the flexible line 108) 1) to hold the flexible line 108.

Flexible line 108 in this embodiment is a working gas line for supplying working gas to or exhausting working gas from cold head 104 , more specifically gas supply line 112 and gas recovery line 114 . Be prepared. The gas supply line 112 connects the working gas discharge port 102a of the compressor 102 to the high pressure port 116a of the cold head 104, and the gas recovery line 114 connects the working gas intake port 102b of the compressor 102 to the low pressure port 116b of the cold head 104. Connect to.

Therefore, the working gas of the cryogenic refrigerator 100 is supplied from the compressor 102 to the cold head 104 through the gas supply line 112, and is recovered from the cold head 104 to the compressor 102 through the gas recovery line 114. As is well known, the pressure of the working gas in the gas supply line 112 and the pressure of the working gas in the gas recovery line 114 are both significantly higher than atmospheric pressure and can be referred to as a first high pressure and a second high pressure, respectively. . For convenience of explanation, the first high pressure and the second high pressure are also simply referred to as high pressure and low pressure, respectively. Typically, the high pressure is for example 2-3 MPa. The low pressure is, for example, 0.5 to 1.5 MPa, for example about 0.8 MPa.

The flexible line holder 110 may include a working gas line holder that holds such a working gas line. The flexible line holder 110 may have a first holder that holds the gas supply line 112 and a second holder that holds the gas recovery line 114, and these two holders may be fixed to the mounting flange 106a. The flexible line holder 110 may be rigidly secured to the mounting flange 106a, for example, by screwing, welding, or other suitable securing means.

The two holders may be arranged side by side on the mounting flange 106a, may be arranged on the mounting flange 106a so as to sandwich the drive portion 104c, or may be arranged at any other arbitrary location on the mounting flange 106a. It's okay. In the example shown in FIG. 1, the flexible line holder 110 is attached to the upper surface of the mounting flange 106a, but it may be attached to the lower surface of the mounting flange 106a or other parts.

The gas supply line 112 includes a first portion 112a extending from the high pressure port 116a of the cold head 104 and a second portion 112b extending from the working gas discharge port 102a of the compressor 102. The flexible line holder 110 may be configured as an intermediate joint with an internal flow path through which the working gas of the cryogenic refrigerator 100 can flow. For example, the first holder may be a first intermediate joint having a first internal flow path. In this case, the first portion 112a of the gas supply line 112 is connected at one end to the first holder and at the other end to the high pressure port 116a. The second portion 112b of the gas supply line 112 is connected at one end to the first holder and at the other end to the working gas discharge port 102a. In this way, the high-pressure working gas discharged from the working gas discharge port 102a flows into the cold head 104 through the second portion 112b, the first holder, and the first portion 112a.

Similarly, gas recovery line 114 includes a first portion 114a extending from low pressure port 116b of cold head 104 and a second portion 114b extending from working gas intake port 102b of compressor 102. The flexible line holder 110 may be configured as an intermediate joint with an internal flow path through which the working gas of the cryogenic refrigerator 100 can flow. For example, the second holder may be a second intermediate joint having a second internal flow path. In this case, the first portion 114a of the gas recovery line 114 is connected at one end to the second holder and at the other end to the low pressure port 116b. The second portion 114b of the gas recovery line 114 is connected at one end to the second holder and at the other end to the working gas intake port 102b. Thus, the low-pressure working gas flowing out from the low-pressure port 116b of the cold head 104 is recovered to the compressor 102 through the first portion 114a, the second holder, and the second portion 114b.

The gas supply line 112 and the gas recovery line 114 may be flexible piping such as flexible hoses. Gas supply line 112 and gas recovery line 114 may also be removable from compressor 102, cold head 104, and flexible line 108, for convenient replacement due to wear and tear, for example.

FIG. 2 is a diagram schematically showing a working gas line of a cryogenic refrigerator according to a comparative example. As shown, cryogenic refrigerator 200 includes a compressor 202 and a cold head 204. Compressor 202 and cold head 204 are connected by flexible hose 206. The cold head 204 is mounted on the vacuum container 20 so that it can move (elevate and lower) relative to the vacuum container 20. The cold head 204 can operate as a thermal switch that thermally connects or disconnects the cold head 204 from the object to be cooled 208 by raising and lowering the cold head 204 . FIG. 2 shows a state in which the thermal switch is off, that is, the cold head 204 is separated from the object 208 to be cooled.

A worker passing near the cryogenic refrigerator 200 may get his or her foot 210 caught on the flexible hose 206 and trip. In this case, the flexible hose 206 is instantly pulled strongly by the hooked leg 210, and a strong lateral load 212 may be applied to the cold head 204. Since the cold head 204 is supported by the vacuum vessel 20 by a support structure with low rigidity such as a bellows when the thermal switch is off, the lateral load 212 is applied to the cryogenic refrigerator as shown by the black arrow 214 and the dashed line in FIG. This may disturb the position and attitude of the cryogenic refrigerator 200, and in some cases may cause the cryogenic refrigerator 200 to collide with surrounding structures such as the vacuum container 20 and the object to be cooled 208. As a result, the cryogenic refrigerator 200 and surrounding structures may be damaged.

On the other hand, according to the embodiment, the flexible line 108 is fixedly held with respect to the vacuum vessel 20 by the flexible line holder 110. Regarding the second portions of the flexible line 108 (for example, 112b, 114b) on the side far from the cold head 104, there may still be a risk that a worker may trip over them. However, even if such a situation occurs, the tensile force acting on the second portion is only received by the mounting flange 106a to which the flexible line holder 110 is fixed and the vacuum vessel 20. This tensile force is not directly transmitted to the cold head 104, and it is expected that the position and posture of the cold head 104 can be maintained even when the heat switch is off. In this way, cryogenic refrigerator 100 can be protected from unexpected external forces.

FIG. 3 is a diagram schematically illustrating exemplary electrical connections that may be applied to the cryogenic refrigerator 100 shown in FIG. 1. The flexible line 108 may be a power supply cable for supplying power to the cold head 104. A power supply cable connects a power source 118 located outside the vacuum vessel 20 to a drive portion 104c of the coldhead 104 (eg, the coldhead drive motor 104e shown in FIG. 1). In an exemplary configuration, compressor 102 may be used as power source 118.

The flexible line holder 110 may be a cable holder that is fixed to the mounting flange 106a and holds the power supply cable. In the illustrated example, flexible line holder 110 is attached to attachment flange 106a so as to pass through attachment flange 106a. Thereby, the power supply cable can be guided from one surface (for example, the top surface) of the mounting flange 106a to the opposite surface (for example, the bottom surface). The degree of freedom in arranging the power supply cable can be increased compared to the case where the power supply cable is routed only on the upper surface side of the mounting flange 106a.

Even in this case, the cryogenic refrigerator 100 can be protected from unexpected external forces in the same way as the embodiment described with reference to FIGS. 1 and 2. That is, even if an unexpected external force acts on the second portion of the flexible line 108 extending from the flexible line holder 110 to the power source 118, this external force will not be received by the mounting flange 106a to which the flexible line holder 110 is fixed and the vacuum vessel 20. Can be done. The negative influence on the cold head 104 due to external force can be reduced.

Note that the flexible line holder 110 of the type that passes through the mounting flange 106a as described above may be used as the holder for the working gas line described with reference to FIG. 1.

FIG. 4 is a diagram schematically showing an exemplary drive source that can be applied to the cryogenic refrigerator 100 shown in FIG. 1. The drive source 106c is attached to a plate-shaped support 120 placed above the cold head 104. The drive source 106c includes a movable piston 122 that penetrates the support body 120 and projects downward. A plurality of (for example, four) guide rods 124 are erected on the mounting flange 106a so as to surround the cold head 104, and a support 120 is fixed to the tips of the guide rods 124. The guide rod 124 passes through the cold head flange 104d in the vertical direction, and the cold head flange 104d is movable in the vertical direction along the guide rod 124.

Furthermore, a movable frame 126 including a support column 126a and a movable plate 126b is installed on the cold head flange 104d. The support column 126a is erected on the cold head flange 104d, and a movable plate 126b is fixed to the support column 126a so as to bridge the ends of the support column 126a. The lower end of the movable piston 122 is fixed to the movable plate 126b.

Therefore, when the movable piston 122 moves up and down by the operation of the drive source 106c, the cold head flange 104d can also move up and down via the movable frame 126. At this time, the cold head flange 104d moves up and down along the guide rod 124 while the airtight partition wall 106b expands and contracts. In this manner, drive source 106c can provide movement of cold head 104 relative to vacuum vessel 20.

The cryogenic refrigerator 100 includes another flexible line 128 connected to the drive source 106c, and another flexible line holder 130 configured to fixedly hold the other flexible line 128 with respect to the vacuum container 20. , may be provided. The drive source 106c may be, for example, an air cylinder, and in that case, the flexible line 128 may be a compressed air line for supplying and discharging compressed air to the drive source 106c. The flexible line holder 130 may be a holder that is fixed to the mounting flange 106a and holds a compressed air line.

Even in this way, the cryogenic refrigerator 100 can be protected from unexpected external forces. That is, even if an unexpected external force acts on the second portion of the flexible line 128 extending from the flexible line holder 130 to the compressed air source 132, the mounting flange 106a to which the flexible line holder 130 is fixed and the vacuum vessel 20 absorb this external force. Can receive. The negative influence on the cold head 104 due to external force can be reduced.

The present invention has been described above based on examples. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that various design changes and modifications are possible, and that such modifications also fall within the scope of the present invention. By the way. Various features described in connection with one embodiment are also applicable to other embodiments. A new embodiment resulting from a combination has the effects of each of the combined embodiments.

Although the above-described embodiments have been described using an example in which the working gas line holder is an intermediate joint, other configurations are also possible. For example, the working gas line holder may be a suitable fixture such as a hose clamp for holding the working gas line, and such a fixture may be secured to the mounting flange 106a. In this case, the working gas line does not need to be divided by the holder (the working gas line does not need to be divided into a first part and a second part, and may be a single flexible hose).

Although the above-described embodiment has been described as an example in which the flexible line holder 110 is fixed to the mounting flange 106a of the cold head mount 106, other configurations are also possible. For example, flexible line holder 110 may be directly fixed to vacuum vessel 20. For example, the flexible line holder 110 may be fixed to the wall surface of the vacuum container 20 to which the mounting flange 106a is attached (that is, to which the mounting port 32 is provided) or to other parts of the vacuum container 20.

Although the above-described embodiment has been described as an example in which the cryogenic refrigerator 100 is a single-stage GM refrigerator, other configurations are also possible. For example, the cryogenic refrigerator 100 may be a two-stage GM refrigerator. In this case, cryogenic refrigerator 100 may provide cryogenic cooling of about 4K or less, and cryogenic liquid 12 may be liquid helium. Alternatively, cryogenic refrigerator 100 may be a pulse tube refrigerator, a Stirling refrigerator, or other type of cryogenic refrigerator.

Although the above-described embodiment has been described with reference to the case where the cryogenic device 10 is a storage device for the cryogenic liquid 12, other configurations are also possible. For example, cryogenic device 10 may be a superconducting device, and cryogenic refrigerator 100 may be used to cool a superconducting coil placed within vacuum vessel 20.

Although the present invention has been described using specific words based on the embodiments, the embodiments merely illustrate one aspect of the principles and applications of the present invention, and the embodiments do not include the claims. Many modifications and changes in arrangement are possible without departing from the spirit of the invention as defined in scope.

The present invention can be used in the field of cryogenic refrigerators.

20 vacuum containers, 100 polar low and hot freezers, 104 cold heads, 106 cold head mounts, 106A mounting flanges, 106B airtight sore walls, 106C driving sources, 108 flexible lines, 110 flexible line holder.

Claims

A cold head that can be mounted on a vacuum container,
a cold head mount configured to couple the cold head to the vacuum vessel to allow movement of the cold head relative to the vacuum vessel;
a flexible line connected to the cold head outside the vacuum vessel;
A cryogenic refrigerator comprising: a flexible line holder configured to fixedly hold the flexible line with respect to the vacuum container.
The cryogenic refrigerator according to claim 1, wherein the flexible line holder holds the flexible line at an end of the flexible line on the cold head side.
The flexible line includes a working gas line for supplying working gas to or discharging working gas from the cold head,
The cryogenic refrigerator according to claim 1 or 2, wherein the flexible line holder includes a working gas line holder that holds the working gas line.
The working gas line holder includes an intermediate joint having an internal flow path through which the working gas can flow;
4. The cryogenic refrigerator according to claim 3, wherein the working gas line includes a first portion connecting the cold head to the intermediate joint, and a second portion connecting the intermediate joint.
The cold head mount includes a mounting flange attachable to the vacuum vessel and an expandable airtight bulkhead connecting the cold head to the mounting flange,
The cryogenic refrigerator according to claim 3, wherein the working gas line holder is fixed to the mounting flange.
The flexible line includes a power supply cable for power supply to the cold head,
The cryogenic refrigerator according to claim 1 or 2, wherein the flexible line holder includes a cable holder that holds the power supply cable.
The cold head mount includes a mounting flange attachable to the vacuum vessel and an expandable airtight bulkhead connecting the cold head to the mounting flange,
The cryogenic refrigerator according to claim 6, wherein the cable holder is fixed to the mounting flange.
a drive source mounted on the cold head mount and configured to move the cold head relative to the vacuum vessel;
another flexible line connected to the drive source;
8. The cryogenic method according to claim 1, further comprising another flexible line holder configured to fixedly hold the other flexible line with respect to the vacuum container. refrigerator.
The cold head mount includes a mounting flange attachable to the vacuum vessel and an expandable airtight bulkhead connecting the cold head to the mounting flange,
The cryogenic refrigerator according to claim 8, wherein the other flexible line holder is fixed to the mounting flange.