JP2015117778A - Vacuum heat insulation pipe and vacuum heat insulation transfer tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent vacuum heat insulation performance from being reduced and provide superior vacuum heat insulation performance of a cryogenic refrigerant transfer pipe even in the case that a refrigerant transfer pipe is mechanically contacted with an outer pipe of a normal temperature heat insulation pipe due to a thermal deformation of cryogenic refrigerant transfer pipe or the like at a vacuum heat insulation transfer tube and in the case that releasing of residual gas from a stacked heat insulation material wound around the refrigerant transfer pipe causes vacuum in a refrigerant transfer pipe installing space to be reduced.SOLUTION: A heat insulation pipe constituting the outermost layer of a vacuum heat insulation transfer tube is constituted by a double vacuum hermetic sealed heat insulation pipe storing vacuum space in hermetic sealed state, connecting bayonets are arranged at both ends of the vacuum hermetic sealed heat insulation pipe so as to enable several vacuum hermetic sealed heat insulation pipes to be connected in series. Even in the case that a cryogenic temperature refrigerant transfer tube is contacted with an inside part of the vacuum hermetic sealed heat insulation pipe or vacuum in a transfer tube installing space is reduced, it is heat insulated by the vacuum hermetic sealed space between the inner tube and the outer tube of the vacuum hermetic sealed heat insulation pipe against a normal temperature part so as to reduce an amount of heat intrusion for the transfer tube.

Description

The present invention relates to a vacuum-insulated transfer tube, and in particular, a heat-insulating container containing a body to be cooled, and a cooling device having a built-in cold generating means for supplying, supplying, and recovering a refrigerant for cooling the body to be cooled. In a low-temperature cooling device that communicates with a transfer tube that transfers the refrigerant, the amount of heat intrusion from the atmosphere is reduced and, for example, a low-temperature refrigerant such as a low-temperature liquefied gas or high-pressure or low-temperature helium gas is transferred. It is suitable as a vacuum heat insulating transfer tube excellent in vacuum heat insulating performance that can cool a cooling body to a low temperature.

In conventional superconducting accelerators with large superconducting accelerator cavities, the cavity to be cooled is cooled with liquid helium, and the heat shield is cooled with liquid nitrogen to suppress the penetration of radiant heat into the liquid helium tank containing the cavity. The board is installed and the structure is disclosed by patent publication 2000-294399 (patent document 1).

Refrigerants such as liquid nitrogen, liquid helium, and high-pressure low-temperature helium gas are supplied and recovered from a liquefier or storage tank installed away from the superconducting accelerator by a transfer tube that is insulated from the vacuum. Is disclosed in Patent Publication No. 2003-004350 (Patent Document 2), and the structure of a transfer tube is disclosed in Patent Publication No. 2007-321875 (Patent Document 3).

In the superconducting biomagnetic measuring device, the superconducting SQUID element for measurement, which is the object to be cooled, is cooled at the liquid helium temperature, and the liquid helium produced by the helium liquefaction refrigerator installed remotely is used as the cooling system. JP-A-1999-063697 (Patent Document 4) discloses a system for recovering helium gas that has been transferred to a biomagnetic measuring section by a vacuum-insulated flexible transfer tube and evaporated.

Patent Publication 2000-294399 Patent Publication No. 2003-004350 Patent publication 2007-321875 Patent Publication No. 1999-063697

However, in the transfer tubes of Patent Document 2, Patent Document 3 and Patent Document 4, a vacuum heat insulating space in which a cryogenic inner tube for transferring liquid helium, liquid nitrogen, low-temperature high-pressure helium gas or the like as a refrigerant is disposed, and the atmosphere The outer tube is made up of a single metal straight tube or metal bellows tube. When the cryogenic inner tube comes into contact with the outer tube due to heat shrinkage, etc. A large amount of heat enters from the tube, and the liquid helium and liquid nitrogen transferred in the inner tube evaporate in the inner tube, and the temperature of the low-temperature high-pressure helium gas rises, so that the object to be cooled is improved. There was a problem that could not be cooled.

Also, when a disaster such as an earthquake occurs, if the inner tube or transfer tube connection cracks and the vacuum in the vacuum space where the inner tube is located is broken, the amount of heat penetration increases rapidly and the cooling target There was a problem that the cooling function of the body stopped and a dangerous state occurred.

Moreover, in the transfer tube of patent document 2, patent document 3, and patent document 4, an outer tube and a cryogenic inner tube are manufactured integrally, and piping, a liquefaction refrigeration apparatus, and a storage tank on the cooled object side are provided at both ends of the transfer tube. If there is a malfunction such as a vacuum leak or contact due to deformation during cooling operation on the outer tube or part of the inner tube of the transfer tube, remove the entire transfer tube and disassemble the entire tube. There was a problem that had to be repaired, requiring a long time to repair, and increasing the repair cost.

Moreover, in the transfer tube of patent document 2, patent document 3, and patent document 4, the laminated heat insulating material for radiation heat prevention which vapor-deposited aluminum etc. on the plastic thin film is wound around a cryogenic inner tube, and heat penetration amount is reduced. The structure is general, but in this case, the residual gas is released from the laminated heat insulating material into the vacuum layer during long-term operation, the vacuum deteriorates, the vacuum heat insulating performance is reduced, and the cryogenic inner tube is cooled to room temperature. A large amount of heat enters from the outer tube, and liquid helium and liquid nitrogen transferred through the inner tube evaporate in the inner tube. Also, the temperature of the low-temperature high-pressure helium gas rises, and the object to be cooled is improved. There was a problem that could not be cooled.

If laminated insulation is not used to prevent emitted gas, the heat insulation performance is reduced due to the increased amount of radiant heat penetration, and a large amount of heat enters the cryogenic inner tube from the outer tube at room temperature, and the inner tube is transferred. Liquid helium or liquid nitrogen evaporates in the inner tube, and the temperature of the low-temperature high-pressure helium gas rises, so that there is a problem that it becomes impossible to cool the object to be cooled at the transfer destination.

The object of the present invention is that when a normal temperature outer tube and a cryogenic inner tube are in mechanical contact due to thermal deformation or the like of the cryogenic inner tube, residual gas discharge or liquid from a laminated heat insulating material wound around the inner tube Even when the vacuum in the inner tube installation vacuum space deteriorates due to the leakage of refrigerant such as helium, preventing the vacuum insulation performance from deteriorating provides excellent vacuum insulation performance and further reduces transfer tube repair costs. It is to provide a safer vacuum insulated transfer tube when it occurs.

In order to achieve the above-mentioned object, the present invention comprises an outer tube constituted by a vacuum sealed heat insulating tube that seals and incorporates a vacuum space, and in the case of a long length, a plurality of vacuum sealed heat insulating tubes are connected to form a vacuum heat insulating transfer tube. It is composed.

In order to solve the above-mentioned problems, the vacuum heat insulating tube and the vacuum heat insulating transfer tube according to claim 1 are made of a metal room-temperature outside straight tube in which a vacuum sealed heat insulating tube containing a vacuum space is hermetically placed outside. A pipe and a metal inner inner pipe placed inside are concentrically arranged in double, and a bayonet for connection is provided at both ends, and the temperature between the normal temperature outer straight pipe and the inner inner pipe is high. After the vacuum baking, the vacuum exhaust port is vacuum-sealed by a sealing means.

According to the present vacuum heat insulating transfer tube, even if a cryogenic inner tube arranged in the inner inner tube contacts the inner inner tube wall, the inner inner tube and the room temperature outer straight tube are vacuum insulated in a sealed vacuum space. Therefore, the amount of heat penetration from the normal temperature outer straight pipe into the cryogenic inner pipe is small, and it is possible to provide a vacuum heat insulating transfer tube that prevents a decrease in heat insulating performance due to contact. In addition, since a long vacuum heat insulation transfer tube can be configured by connecting multiple vacuum sealed heat insulation tubes, conversely it is easy to disassemble and even if there is a problem with the cryogenic inner tube, it can be easily done in a short period of time. In addition, there is an effect that repair is possible at low cost.

The vacuum heat-insulating transfer tube according to claim 2, wherein a vacuum-sealed heat-insulating tube having a vacuum space sealed therein is connected to an outside metal room temperature outside straight tube and at least partly connected by a deformation-absorbing metal bellows tube. It is composed of a tube, provided with a connecting bionet at both ends, and baked at a high temperature between the normal temperature outer straight tube and the inner inner tube, and then the vacuum exhaust port is sealed with a sealing means.

According to this vacuum heat insulating transfer tube, when the inner inner tube is cooled by thermal contact with the cryogenic inner tube, etc., heat deformation in the longitudinal direction is absorbed by the metal bellows displacement absorption function, and heat shrink deformation Thus, it is possible to provide a vacuum heat insulating transfer tube that prevents the vacuum in the sealed vacuum space from being deteriorated due to the leakage of the refrigerant due to mechanical breakage of the inner inner tube wall due to the above, thereby preventing the heat insulating performance from being deteriorated.

The vacuum heat insulating transfer tube according to claim 3 is configured such that a vacuum sealed heat insulating tube that seals and contains a vacuum space is composed of an outer metal bellows outer tube and an inner metal bellows inner tube at room temperature, and both ends are connected. A bayonet is provided, and a spacer made of a fine wire bundle of glass or the like that emits almost no outgas is spirally wound around the outer periphery of the metal bellows inner tube, and a high temperature is generated between the metal bellows outer tube and the metal bellows inner tube. The vacuum exhaust port is sealed with a sealing means after being baked in the vacuum insulation transfer tube according to claim 4, wherein a bayonet is disposed at both ends of the vacuum seal insulation tube. The vacuum heat insulating transfer tube is characterized in that partition walls are provided at both ends of the vacuum heat insulating transfer tube and the isolation space is a vacuum heat insulating space.

According to the present vacuum heat insulating transfer tube, the vacuum sealed heat insulating tube can be constituted by a bellows tube having excellent flexibility, so that the cryogenic inner tube is made of a metal bellows when the transfer tube is curved three-dimensionally. Even when contacting the inner tube wall, it is possible to provide a long and safe vacuum heat insulating transfer tube by reducing the contact pressure to prevent a decrease in heat insulating performance.

According to the present invention, since the cryogenic inner tube can be disposed inside the inner tube of the room temperature vacuum sealed insulation tube that seals the vacuum space, the cryogenic inner tube is in mechanical contact with the vacuum sealed insulation tube due to thermal deformation or the like. Vacuum insulation even when the residual gas is released from the laminated insulation wrapped around the cryogenic inner tube, when the cryogenic inner tube is repaired, or when the cryogenic inner tube breaks due to an earthquake, etc. It is possible to provide a safe vacuum insulation transfer tube that prevents deterioration in performance, has excellent vacuum insulation performance, and can reduce repair costs.

It is a block diagram which shows the cooling system using the vacuum heat insulation transfer tube of 1st Example of this invention. It is sectional drawing of the vacuum-sealed heat insulation pipe | tube which comprises the vacuum heat insulation transfer tube of FIG. It is sectional drawing of the vacuum heat insulation transfer tube of the connection part of the vacuum heat insulation transfer tubes of FIG. It is XX sectional drawing of FIG. It is sectional drawing of the vacuum-sealed heat insulation pipe | tube which has flexibility in the vacuum heat insulation transfer tube of 2nd Example of this invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.

[Example 1]

The vacuum heat insulating transfer tube according to the first embodiment of the present invention will be described more specifically with reference to FIGS. FIG. 1 is a block diagram of a cooling system using a vacuum heat insulating transfer tube according to a first embodiment of the present invention, and FIG. 2 is a cross section of a vacuum sealed heat insulating tube which is a component of the vacuum heat insulating transfer tube constituting the cooling system of FIG. FIG. 3 is a cross-sectional view of the connecting portion between the vacuum heat-insulating transfer tubes, and FIG. 4 is a cross-sectional view of the vacuum heat-insulating transfer tube as viewed from the direction of arrows XX in FIG.

The cooling system 1 using the vacuum heat-insulating transfer tube of the present embodiment is used as a cooling system for an object to be cooled 2 such as a superconducting cavity or a superconducting magnet. This cooling system is intended to improve the heat insulation performance of the apparatus, reduce the cost of repair and repair, while solving the problems of the prior art, and includes the following components.

As shown in FIG. 1, a cooling device 3 that cools the object to be cooled 2 includes a liquid helium container 4 made of, for example, stainless steel that contains the object to be cooled 2, and stainless steel that prevents heat from entering the liquid helium container 4. In order to prevent heat intrusion due to radiant heat from the steel vacuum vessel 5, the heat shield plate 7 made of copper or aluminum having a high thermal conductivity installed in the vacuum space 6 and the vacuum vessel 5 are evacuated. The vacuum pump 8, the vacuum pipe 9, the vacuum valve 10, the heat exchanger 11 for cooling the heat shield plate 7 with liquid nitrogen, the liquid nitrogen supply pipe 12 for supplying liquid nitrogen, for example, and the nitrogen gas after cooling Nitrogen gas exhaust pipe 13 for exhausting to the atmosphere, liquid helium 14 for cooling and holding the object 2 to be cooled, liquid helium supply pipe 15 for supplying liquid helium, for example, stainless steel, evaporated helium And helium gas recovery pipe 16 made of stainless steel, for example to collect the scan, and a connecting flange 17 of the transfer tube.

As shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, the vacuum heat insulating transfer tube 18 includes a vacuum sealed heat insulating tube 19 and an outside metal room temperature outer outer tube 20 and a part made of, for example, stainless steel. It is composed of an inner inner tube 22 to which a metal bellows tube 21 is connected, and a male bayonet 23 and a female bayonet 24 made of stainless steel, for example, are provided at both ends, and the joint is metallurgically integrated to the outside at room temperature. A sealed vacuum space 25 sealed after the outer tube 20 and the inner inner tube 22 are baked at a high temperature, a mounting flange 26, a connecting flange 27 that connects the two vacuum-sealed heat-insulating tubes 19 to each other, and the connection portion is an atmosphere. And an O-ring 28 for isolating.

A liquid helium supply pipe 15, a helium gas recovery pipe 16 and a liquid nitrogen supply pipe 12 are arranged inside the inner inner pipe 22 of the vacuum sealed heat insulation pipe 19, and the internal space 29 is formed in the vacuum space 6 of the vacuum vessel 5. The connection flange 27 is connected to the vacuum pump 8 through a vacuum valve 31 by a vacuum pipe 30 to evacuate the space 29 in parallel with the vacuum space 6, and the space 29 is thermally insulated.

The vacuum sealed heat insulation pipe 19 is connected to the connection flange 33 of the refrigerant supply device 32, and the liquid helium supply pipe 15, the helium gas recovery pipe 16, and the liquid nitrogen supply pipe 12 are disposed in the refrigerant supply apparatus 32 with vacuum insulation. It is connected to a liquid helium tank (not shown), a liquid helium liquefier, or a liquid nitrogen tank (not shown), which is a cold generating means, and a good supply of liquid helium and liquid nitrogen and recovery of evaporated helium gas, It is the structure which performs reliquefaction.

When the structure of the vacuum-sealed heat insulating tube 19 is shown in more detail in FIG. 2, the inner inner tube 22 is supported in a state in which the inner inner tube 22 is slidable in the axial direction at the connecting portion of the inner inner tube 22 connected to the metal bellows tubes 21 at both ends. A support tube 34 is provided, and an end portion of the support tube 34 is metallurgically integrated with the connection flange 26 in a metallurgical manner.

A vacuum exhaust nozzle 35 communicating with the sealed vacuum space 25 is integrated in a metallurgical and airtight manner on the outer peripheral portion of the normal temperature outer outer tube 20, and the mechula flange 36 is heated at a temperature of, for example, a high temperature vacuum baking apparatus (not shown). In a vacuum state at the end of the vacuum baking performed at 400 to 1000 ° C., in a vacuum state, it is sealed with a structure that is metallurgically sealed with a metallurgical bonding material 37 such as a silver-based precious metal brazing material for vacuum, which is a vacuum sealing means, A sealed vacuum space 25 is formed. A gas adsorbent 38 made of ceramic such as zeolite is attached to the sealed vacuum space 25, and a minute outgas in the sealed vacuum space is adsorbed over a long period of time to prevent vacuum deterioration and ensure heat insulation performance.

The connection flange 26 has a bolt hole 39 and an O-ring groove 40, and the vacuum-sealed heat insulating tube 19 can be hermetically connected by an O-ring 28. The length of the vacuum-sealed heat insulating tube 19 is, for example, 10 m long per piece.

On the other hand, the liquid helium supply pipe 15, the helium gas recovery pipe 16, and the liquid nitrogen supply pipe 12 disposed in the vacuum sealed heat insulation pipe 19 connected by the connection flange 27 and the fastening bolt 41 via the O-ring 28 have both ends. It is composed of a metal bellows tube that is metallurgically and airtightly integrated with the flange 42 of the part, and the bellows part absorbs thermal deformation caused by the temperature of the refrigerant in which each refrigerant flows.

The elongation when the pressure of the refrigerant transferred through the metal bellows pipe is high is restrained by a flexible metal blade 43 that is metallurgically or mechanically integrated with the flanges 42 at both ends of the metal bellows pipe. And no major deformation occurs. A laminated heat insulating material 44 is wound around the outer peripheral portion of the metal blade 43 to prevent intrusion of radiant heat. A plastic spacer 45 is spirally wound around the outer peripheral portion of the laminated heat insulating material 44.

A connecting straight pipe 46 is metallurgically and integrally integrated with the flange 42, and a connecting male joint 47 that is metallurgically and airtightly integrated with the connecting straight pipe 46 at a connecting portion thereof, and a female joint 49 via a seal piece 48. It is tightened and hermetically integrated and connected and fastened. The connecting straight pipe 46 that is airtightly fastened is supported by plastic spacers 50 at both ends inside the male bayonet 23. The spacer 50 is provided with a vent hole 51.

In the vacuum heat insulating transfer tube 18 of the present embodiment, an inner space 29 configured by hermetically connecting a vacuum sealed heat insulating tube 19 having a heat sealed vacuum space is evacuated by a vacuum pump 8 to form a heat insulating vacuum space. Due to the structure in which the liquid helium supply pipe 15, the helium gas recovery pipe 16 and the liquid nitrogen supply pipe 12 for transporting the refrigerant into the space are arranged, the cryogenic liquid helium supply pipe 15, the helium gas recovery pipe 16 and the liquid nitrogen supply pipe 12 are provided. Is strongly in contact with the inner inner tube 22 of the vacuum sealed heat insulating tube 19 due to thermal deformation or the like, the inner inner tube 22 and the normal temperature outer outer tube 20 are insulated by the sealed vacuum space 25 and the inner inner tube 22. Is made of, for example, stainless steel or titanium steel having a low thermal conductivity, so that even if the contact portion is cooled to a low temperature, the temperature difference from the outside outer tube 20 at room temperature is large. No longer, amount of inserted heat by conduction than is suppressed to a small amount, born effect of preventing the deterioration of the insulating performance of the vacuum heat insulating transfer tube 18.

Further, in the vacuum heat insulating transfer tube 18 of the present embodiment, in the precooling stage of the entire apparatus after the supply of the refrigerant is started, there is a process in which the vacuum pressure in the apparatus is high and the vacuum heat insulating performance of the vacuum space 6 and the vacuum space 29 is lowered. As a result, when the apparatus is enlarged, the precooling period may take several days. However, since the vacuum heat insulating transfer tube 18 has a vacuum sealed heat insulating tube 19, it is vacuum insulated from the room temperature outer outer tube 20. The cryogenic liquid helium supply pipe 15, the helium gas recovery pipe 16 and the liquid nitrogen supply pipe 12 can be prevented from evaporating, and the heat insulation performance of the vacuum heat insulation transfer tube 18 can be prevented from being deteriorated. It is possible to supply efficiently and the effect that the pre-cooling of the cooling device 3 can be completed in a short time is produced.

Further, in the vacuum heat insulating transfer tube 18 of the present embodiment, the cryogenic liquid helium supply pipe 15, helium gas recovery pipe 16 and liquid nitrogen supply pipe 12 are first connected to the male joint 47 and the female piece through the seal piece 48. 49, and using a vacuum leak detector (not shown) to confirm that there is no leak in the connection portion, insert a vacuum-sealed heat insulating tube 19 and connect it with the connecting flange 27 to make a long vacuum insulation. Since the transfer tube 18 can be manufactured and installed, it is not necessary to connect the connecting parts of the cryogenic liquid helium supply pipe 15, the helium gas recovery pipe 16 and the liquid nitrogen supply pipe 12 by metallurgy integrally by welding or the like. The vacuum heat insulating transfer tube 18 can be provided at a low cost. Further, when troubles such as refrigerant leakage occur in the connection part after production, The so repaired by replacement of the connection portion of the sealing piece 48 and the female joint 49 easily in the process, there is an effect of reducing the repair cost.

Further, in the case of an abnormal state such as an earthquake occurrence, cracks occur in the walls of the cryogenic liquid helium supply pipe 15, the helium gas recovery pipe 16 and the liquid nitrogen supply pipe 12 themselves, which are thin-walled and weak in strength. Alternatively, even when the joint of the connecting portion is loosened and the refrigerant leaks from the connecting portion, the plurality of connected vacuum sealed heat insulating pipes 19 can secure a sealed vacuum space that can be insulated independently, so that a large amount of the leaked refrigerant There is an effect that it is possible to provide a safe vacuum insulation transfer tube 18 that can prevent sudden evaporation and prevent the vacuum insulation transfer tube 18 from bursting.

[Example 2]

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view of a flexible vacuum sealed heat insulating tube in the vacuum heat insulating transfer tube of the second embodiment of the present invention.

In this second embodiment, a flexible vacuum-sealed heat insulating tube 60 that seals and incorporates a vacuum space includes a room temperature outer bellows outer tube 52 made of, for example, a stainless steel outer metal bellows tube, and an inner bellows inner tube 53 of a metal bellows tube. The second embodiment is different from the first embodiment in that a spacer 54 made of a material having high heat resistance and low thermal conductivity is disposed between both pipes. This is basically the same as the embodiment.

In FIG. 5, both ends of the normal temperature outer bellows outer pipe 52 are metallurgically and airtightly integrated with the flange 56 of the holding support pipe 55 and the flange 58 of the holding support pipe 57 that are metallurgically and airtightly integrated with the connection flange 26. The outer peripheral portion is provided with a blade 59 of a metal fiber made of, for example, stainless steel.

For example, both ends of the inner bellows inner pipe 53 of a metal bellows pipe made of stainless steel are metallurgically and airtightly integrated with the male bayonet 23 and the female bayonet 24 that are metallurgically and airtightly integrated with the connection flange 26. It has become.

A spacer 54 made of a bundle of ceramic thin wires such as glass having almost no outgas and having low thermal conductivity is wound around the outer periphery of the inner bellows inner tube 53 in a spiral shape.

A ring-shaped gas adsorbent 61 made of ceramic such as zeolite is attached to the sealed vacuum space 25, and a minute outgas in the sealed vacuum space is adsorbed over a long period of time to prevent vacuum deterioration and ensure heat insulation performance. ing.

In the vacuum heat insulating transfer tube 18 of FIG. 1 in which the flexible vacuum sealed heat insulating tube 60 of the second embodiment is used instead of the vacuum sealed heat insulating tube 19 of FIG. 2, the vacuum heat insulating transfer tube 18 is excellent in flexibility. When mechanical contact with the vacuum sealed heat insulating tube 19 occurs due to thermal deformation of the helium supply tube 15, helium gas recovery tube 16, and liquid nitrogen supply tube 12, the flexible vacuum sealed heat insulating tube 60 is easy for the contact reaction force. The contact pressure is reduced.

For this reason, the amount of heat intrusion due to heat conduction from the contact portion to the liquid helium supply pipe 15, helium gas recovery pipe 16 and liquid nitrogen supply pipe 12 is further reduced in the contact portion, and the heat insulation performance of the vacuum heat insulation transfer tube 18 is deteriorated. The effect which can prevent is born.

Furthermore, the heat heat transfer distance from the liquid helium supply pipe 15, the helium gas recovery pipe 16, the liquid nitrogen supply pipe 12, the outer / inner pipe 53 of the metal bellows pipe, and the heat contact portion to both ends at higher temperatures is the inner bellows. Since the tube 53 is a bellows tube, the tube 53 becomes longer, further reduces the amount of heat penetration, and produces an effect of further preventing deterioration of the heat insulation performance of the vacuum heat insulation transfer tube 18.

In the above embodiments, the case where the object to be cooled of the cooling system is a superconducting cavity or a superconducting magnet has been described. However, the object to be cooled is a superconducting bulk body, a SQUID element of a magnetic measuring device, an electronic element of a low temperature computer, a low temperature NMR. Similar actions and effects are produced even with a coil element for reception / irradiation and a superconducting wire of a superconducting power transmission line arranged in a long length in a refrigerant transfer pipe.

In the above embodiments, the case where a plurality of refrigerant transfer pipes are arranged in the same vacuum heat insulation transfer tube has been described. However, the refrigerant transport pipe is arranged in each vacuum heat insulation transfer tube to constitute a cooling system. However, the same effect occurs.

In the above-described embodiments, the case where the refrigerant is a liquefied gas has been described. However, the same operation and effect can be obtained when the refrigerant is a low-temperature high-pressure helium gas cooled by a refrigerator.

In the above embodiment, the case where the refrigerant transfer pipe is arranged in the vacuum-sealed heat insulating pipe 19 and the arrangement space 29 is communicated with the vacuum heat-insulating space 6 in the cooling device has been described. In this case, the arrangement space 29 is evacuated independently, a partition wall is provided that isolates the arrangement space 29 from the outside of the vacuum-sealed heat insulating tube, a refrigerant transfer pipe is passed through the partition wall, and the penetrating portion is hermetically integrated. Even in the case of a vacuum heat-insulating transfer tube that can be evacuated independently, even if the refrigerant leaks from the refrigerant transfer tube in an emergency such as an earthquake, the same action and effect are produced.

Further, in the above embodiment, the case where the male and female bayonets for heat insulation connection are arranged at both ends of the vacuum-sealed heat insulating tube has been described. However, the same male bayonet or the same female bionet is disposed at both ends. Even when the nets are arranged, since they are isolated from the vacuum space of the cooling device 3 and the refrigerant supply device 32, the same operation and effect that the heat insulating performance of the cooling device 3 and the refrigerant supply device 32 is not deteriorated are produced.

In the above embodiment, the case where the sealed vacuum space of the vacuum sealed insulation tube is formed after being baked at a high temperature and then sealed is described. However, after the vacuum is continuously evacuated for several months at a medium temperature of about 120 ° C., the sealed space is sealed. Even when a sealed vacuum space is formed, the same action and effect are produced.

Further, in the above-described embodiment, the structure in which the Mekura flange 36 is hermetically sealed with the metallurgical bonding material 37 as the vacuum sealing means has been described. Instead, a metal vacuum valve is used as the vacuum exhaust nozzle 35. The vacuum-sealed heat insulating tube 19 can be configured even in a structure that is mechanically closed and sealed in a high temperature state, and the same operation and effect are produced.

DESCRIPTION OF SYMBOLS 1 ... Cooling system, 2 ... Cooling object, 3 ... Cooling device, 4 ... Liquid helium container, 5 ... Vacuum container, 6 ... Vacuum space, 7 ... Heat shield board, 12 ... Liquid nitrogen supply pipe, 14 ... Liquid helium, DESCRIPTION OF SYMBOLS 15 ... Liquid helium supply pipe | tube, 19 ... Vacuum sealed heat insulation pipe | tube, 20 ... Room temperature outer side outer pipe, 21 ... Metal bellows pipe | tube, 22 ... Inner inner pipe | tube, 25 ... Sealed vacuum space, 32 ... Refrigerant supply apparatus, 35 ... Vacuum exhaust nozzle , 36 ... Mekura flange, 37 ... Metallurgical bonding material, 38 ... Gas adsorbent, 52 ... Normal temperature outer bellows outer pipe, 53 ... Inner bellows inner pipe, 54 ... Spacer, 60 ... Flexible vacuum sealed heat insulating pipe

Claims (5)

A first space in which a transfer pipe through which the refrigerant flows is disposed;
Having a vacuum tube isolated from the atmospheric space,
In a vacuum heat insulating transfer tube that forms and holds the first space in a negative pressure state inside the vacuum tube,
The vacuum tube comprises an outer tube and an inner tube having different diameters as a concentric double tube,
Forming the first space inside the inner tube;
A vacuum heat insulating tube and a vacuum heat insulating transfer tube, characterized in that a vacuum heat insulating tube is formed between the outer tube and the inner tube to form a negative pressure second space isolated from the first space. 2. The vacuum heat insulation tube and the vacuum heat insulation transfer tube according to claim 1, wherein at least a part of the inner tube is constituted by a metal bellows tube. 3. The vacuum heat insulating tube and the vacuum heat insulating transfer tube according to claim 1 and 2, wherein at least a part of the outer tube and the inner tube is formed of a metal bellows, and the second space is formed between the metal bellows. A vacuum heat insulating tube and a vacuum heat insulating transfer tube characterized by the above. The vacuum heat insulating tube and the vacuum heat insulating transfer tube according to claim 1, 2 and 3, wherein both ends of the vacuum heat insulating tube are constituted by a heat insulating connection bayonet, and Vacuum insulated transfer tube. The vacuum heat insulation tube and the vacuum heat insulation transfer tube according to claim 1, claim 2, claim 3, and claim 4, wherein the vacuum insulation heat transfer tube alone is used to isolate the first space from the atmospheric space. A vacuum heat insulating tube and a vacuum heat insulating transfer tube characterized by being a space.