JPH08159633A - Cryogenic device - Google Patents

Abstract

PURPOSE: To eliminate a restriction of a fixing position of a multi-stage type freezer and further to enable refrigerant gasified in a cryogenic tank to be efficiently cooled and liquified by a method wherein the cryogenic refrigerant gas evaporated within the cryogenic refrigerant tank is fed to a heating stage in the multi-stage type freezer and returned back again to the cryogenic refrigerant tank. CONSTITUTION: Helium gas evaporated within a helium tank 2 is fed to a heat exchanger 22 fixed to a third stage heating stage 12 by a refrigerant supplying pipe 23 and a blower 21, liquified again there and returned back to the helium tank 2 through the refrigerant supplying pipe 24, resulting in that a fixing location of the three-stage type freezer 20 can be freely selected with arrangement and configuration of the refrigerant supplying pipes 23, 24 and the fixing location of the three-stage freezer 20 may not be placed at another location where it is not thermally connected to a position having upper gaseous phase in the helium tank 2. Accordingly, since the fixing position of the three-stage type freezer 20 is placed at a waist height of a worker, a maintenance work such as a removing or a fixing of the internal component parts may be facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryogenic device for containing a superconducting magnet or the like for cooling.

[0002]

2. Description of the Related Art A conventional cryogenic device is disclosed in Japanese Unexamined Patent Publication No.
This is disclosed in Japanese Patent No. 275231 as a structure of a superconducting magnet. FIG. 13 is a cross-sectional view showing the structure of a conventional cryogenic device formed in a cylindrical shape (shown when cut in the axial direction of the cylinder). In the figure, 1 is a superconducting coil which is an object to be cooled, 2 is a helium tank which is a cryogenic refrigerant tank filled with liquid helium 3 which is an cryogenic refrigerant, 4 is a vacuum tank, 5 is a first radiation shield, 6 Is the second radiation shield,
7 is a leg of the cryogenic apparatus main body, 8 is a supporting member, 10 is a first stage heat stage, 11 is a second stage heat stage, 12 is a third stage heat stage, 15 is a flexible conductor, and 20 is a three-stage refrigeration system. It is a machine.

Next, the operation will be described. It should be noted that a case of a superconducting magnet used in a magnetic resonance imaging apparatus (hereinafter referred to as an MRI apparatus) using liquid helium as a cryogenic refrigerant will be described here. The superconducting coil 1 is housed inside a helium tank 2 and liquid helium 3
It is cooled to the superconducting state by. The helium tank 2 is surrounded by a first radiation shield 5 and a second radiation shield 6, which are cooled to a specified temperature, which will be described later, to reduce the amount of radiant heat that enters from the room temperature portion. The plurality of support members 8 are the helium tank 2, the first radiation shield 5 and the second
The radiation shield 6 and the like are supported adiabatically, and the vacuum chamber 4 maintains a high vacuum in the space between the vacuum chamber 4 and the helium chamber 2. Further, the three-stage refrigerator 20 attached to the upper end surface of the vacuum chamber 4 includes a first-stage heat stage 10, a second-stage heat stage 11, and a third-stage heat stage 12, each of which is provided with a flexible conductor 15. The first radiation shield 5, the second radiation shield 6, and the first radiation shield 5 are thermally connected to the upper part of the helium tank 2 where the liquid helium 3 is gasified.
Is cooled to about 80K and the temperature of the second radiation shield 6 is cooled to about 20K, and the helium gas to be evaporated from the helium tank 2 is reliquefied.

The vacuum chamber 4 of a general superconducting magnet of the conventional cryogenic device constructed as described above has an outer diameter of about 2 meters, and when it is installed on the floor, the legs 7 are used.
The height of the upper end of the vacuum chamber 4 is about 2.5 meters, and the height of the mounting position of the three-stage refrigerator 20 is about 2 meters.

On the other hand, although the three-stage refrigerator 20 is continuously operated, the operation is periodically stopped to replace consumable parts and clean the inside, and maintenance work is performed by removing the internal parts. is necessary.

[0006]

Since the conventional cryogenic device is constructed as described above, the first radiation shield 5 and the second radiation shield 6 are cooled by the conductive heat by the flexible conductors 15, respectively. However, there has been a problem that the temperature at a place away from the thermal connection point rises considerably, and the amount of heat entering the helium tank 2 increases.

Further, when the three-stage refrigerator is stopped, the temperature of the radiation shield rises rapidly because the heat conduction through the cylinder and the heat capacity of the object to be cooled are small, and the helium tank 2
However, there is a problem that the amount of heat invading into the space increases rapidly.

Further, since the mounting position of the three-stage refrigerator 20 is as high as 2 meters, it is necessary to perform maintenance work such as removal and mounting of internal parts on a step and a scaffold, and for these works. There was a problem that the workability was not good and the space was large.

The present invention has been made to solve the above-mentioned problems, and eliminates the restriction on the mounting position of the multistage refrigerator, and efficiently cools the gasified refrigerant in the cryogenic refrigerant tank. The purpose is to obtain a cryogenic device that can be liquefied.

A further object of the present invention is to obtain a cryogenic device capable of improving workability when performing maintenance work on a multistage refrigerator by eliminating restrictions on the mounting position of the multistage refrigerator. To do.

Another object of the present invention is to obtain a cryogenic device capable of uniformizing the cooling of the radiation shield and suppressing an increase in the amount of heat entering the cryogenic refrigerant tank.

Another object of the present invention is to obtain a cryogenic device capable of performing maintenance work such as removal and installation of internal parts of a refrigerator at room temperature.

Further, according to the present invention, the temperature of the multistage refrigerator is gradually raised to normal temperature when the multistage refrigerator is stopped, and maintenance work such as parts replacement of the multistage refrigerator is easily performed at room temperature. The purpose is to obtain a cryogenic device that can be used.

Still another object of the present invention is to obtain a cryogenic device capable of slowing the temperature rise of the radiation shield when the multistage refrigerator is stopped.

It is another object of the present invention to provide a cryogenic device capable of simplifying the refrigerant circulation mechanism and suppressing the amount of heat entering from the refrigerant circulation mechanism when a plurality of refrigerant circulation mechanisms are provided.

Further, according to the present invention, there is obtained a cryogenic device capable of suppressing electric power consumption for driving the refrigerant circulation mechanism, uniformizing the cooling of the radiation shield, and suppressing an increase in the amount of heat entering the cryogenic refrigerant tank. The purpose is to

[0017]

A cryogenic apparatus according to the invention of claim 1 uses a cryogenic refrigerant gas evaporated in a cryogenic refrigerant tank as a heat stage of a multi-stage refrigerator via a refrigerant supply pipe. It is provided with a refrigerant circulating mechanism arranged in a vacuum tank for liquefying and liquefying, and then recirculating to the cryogenic refrigerant tank via the refrigerant supply pipe.

In the cryogenic apparatus according to the invention of claim 2, a multistage refrigerator is installed substantially horizontally at a height position of 1 m or less on the floor surface where the cryogenic apparatus body is installed.

In the cryogenic apparatus according to the third aspect of the present invention, a multistage refrigerator is installed substantially vertically at a height position of 1 m or less on the floor surface where the cryogenic apparatus body is installed.

In the cryogenic apparatus according to the invention of claim 4, the second refrigerant cooled in the heat stage of the multistage refrigerator is passed through the condensation heat exchanger and the refrigerant circulation pipe laid in the cryogenic refrigerant tank. And a refrigerant circulation mechanism that circulates and reliquefies the gasified cryogenic refrigerant.

In the cryogenic apparatus according to the fifth aspect of the present invention, the condensing heat exchanger is provided inside the cryogenic refrigerant tank.

In the cryogenic apparatus according to the invention of claim 6, the condensing heat exchanger is arranged on the outer peripheral surface of the cryogenic refrigerant tank.

A cryogenic apparatus according to a seventh aspect of the present invention passes through a condensing heat exchanger laid in a cryogenic refrigerant tank, a refrigerant circulating pipe, the condensing heat exchanger and the refrigerant circulating pipe. In a cryogenic device including a refrigerant circulation mechanism that circulates a second refrigerant cooled in a heat stage of a multistage refrigerator and reliquefies the gasified cryogenic refrigerant, the multistage refrigerator is a polar The installation of the low temperature device body is to be installed substantially horizontally at a height position of 1 m or less above the floor surface.

According to the eighth aspect of the present invention, there is provided a cryogenic device which includes a condensation heat exchanger laid in a cryogenic refrigerant tank, a refrigerant circulation pipe, the condensation heat exchanger and the refrigerant circulation pipe. A cryogenic device including a refrigerant circulation mechanism that circulates a second refrigerant cooled in a heat stage of a multi-stage refrigerator and reliquefies the gasified cryogenic refrigerant in a cryogenic device main body installation floor A multi-stage refrigerator is mounted substantially vertically at a height of 1 meter or less on the surface.

The cryogenic apparatus according to the invention of claim 9 is the second
For the second refrigerant by means of a third refrigerant circulation mechanism having a refrigerant supply pipe and a radiation shield cooling tube for cooling the radiation shield, the third refrigerant passing through a heat stage of a multistage refrigerator. By circulating a supply pipe and the radiation shield cooling pipe, an intermediate portion of the radiation shield and the support member is cooled.

In the cryogenic apparatus according to the tenth aspect of the present invention, the refrigerant supply pipe is made of a material having a small thermal conductivity.

The cryogenic apparatus according to the invention of claim 11 comprises a shutoff valve for evacuating the interior of the refrigerant circulation pipe, the second refrigerant supply pipe or the radiation shield cooling pipe during maintenance. .

The cryogenic apparatus according to the twelfth aspect of the present invention is provided with a separate refrigerator for cooling only the third refrigerant different from the refrigerator for reliquefying the gasified cryogenic refrigerant. is there.

In the cryogenic apparatus according to the thirteenth aspect of the present invention, the cryogenic refrigerant is helium gas at approximately atmospheric pressure, hydrogen gas, neon gas, or a mixture thereof, and the second refrigerant is helium at approximately atmospheric pressure. Gas, hydrogen gas, neon gas or a mixed gas thereof, and the third refrigerant is helium gas, hydrogen gas, neon gas or a mixed gas thereof pressurized to atmospheric pressure or higher.

According to the fourteenth aspect of the invention, the cryogenic device is provided with a refrigerant circulation mechanism in which the blowers are driven by a common drive shaft.

A cryogenic apparatus according to a fifteenth aspect of the present invention is a cryogenic storage tank mounted on a heat stage of a multi-stage refrigerator, a check valve and a discharge valve mounted on a second refrigerant supply pipe. When the multistage refrigerator is stopped, the third refrigerant is released to the atmosphere via the release valve.

A cryogenic apparatus according to a sixteenth aspect of the present invention is a cryogenic tank installed at an arbitrary place capable of being in thermal contact with a multistage refrigerator or a second refrigerant supply pipe or a radiation shield cooling pipe; The third refrigerant supply pipe provided in parallel with the second refrigerant supply pipe, the fourth radiation shield cooling pipe for the fourth refrigerant, and the discharge valve are provided, and when the multi-stage refrigerator is stopped, the inside of the refrigerant tank The fourth refrigerant gas is discharged to the atmosphere via the third refrigerant supply pipe, the fourth radiation shield cooling pipe for the fourth refrigerant, and the discharge valve.

In the cryogenic apparatus according to the seventeenth aspect of the present invention, the fourth refrigerant is oxygen gas or nitrogen gas pressurized to atmospheric pressure or higher, or dry air.

In the cryogenic apparatus according to the eighteenth aspect of the present invention, a magnetic material that causes a magnetic transition phenomenon at a temperature of 80K or more and 100K or less is thermally treated with a multistage refrigerator, a third refrigerant supply pipe or a radiation shield cooling pipe. It is installed in any place that can be contacted with.

In the cryogenic apparatus according to the invention of claim 19, the radiation shield cooling pipe is composed of a plurality of parallel flow paths, and
A flow control valve is provided near the outlet of each flow path.

In the cryogenic apparatus according to the invention of claim 20, when the radiation shield cooling pipe is composed of a plurality of parallel flow paths,
The flow rate control valve provided near the outlet of each flow path of the parallel flow path is such that the opening degree of the flow path control valve changes according to the temperature change of the refrigerant flowing inside the flow path.

[0037]

In the refrigerant circulating mechanism arranged in the vacuum tank of the cryogenic apparatus according to the first aspect of the invention, the cryogenic refrigerant gas evaporated in the cryogenic refrigerant tank is supplied to the multi-stage refrigerator via the refrigerant supply pipe. Liquefied by circulating it to the heat stage, and then returned to the cryogenic refrigerant tank again via the refrigerant supply pipe, eliminating the restriction on the installation location of the multi-stage refrigerator, and flexibly installing the multi-stage refrigerator. This makes it possible to select and also to efficiently liquefy the gasified refrigerant in the cryogenic refrigerant tank.

The multistage refrigerator of the cryogenic apparatus according to the second aspect of the present invention is provided on the floor 1 on which the cryogenic apparatus main body is installed.
Since it is attached to the cryogenic device main body at a height position of less than or equal to a meter substantially horizontally, the worker can perform maintenance work such as maintenance of the multi-stage refrigerator at a waist height position and perform maintenance work. Workability when performing is improved.

In the multistage refrigerator of the cryogenic device according to the invention of claim 3, the cryogenic device main body is installed on the floor 1
Since it is installed almost vertically to the cryogenic device body at a height position of less than a meter, the worker should perform work such as maintenance of the multistage refrigerator at a waist height position and work from above. The workability when performing maintenance work is improved.

According to a fourth aspect of the invention, the cryogenic device cools the heat stage of the multistage refrigerator via the condenser heat exchanger and the refrigerant circulation pipe laid in the cryogenic tank by the refrigerant circulation mechanism. The second refrigerant is circulated, and the cryogenic refrigerant gasified by the condensation heat exchanger laid in the cryogenic refrigerant tank is indirectly cooled and reliquefied to flexibly select the installation location of the multistage refrigerator. It is possible to efficiently liquefy the gasified refrigerant in the cryogenic refrigerant tank.

The cryogenic apparatus of the fifth aspect of the present invention is a heat stage of a multistage refrigerator, wherein the refrigerant circulation mechanism passes through a condensation heat exchanger and a refrigerant circulation pipe provided in the cryogenic refrigerant tank. The cooling second refrigerant is circulated, and the cryogenic refrigerant gasified by the condensation heat exchanger provided in the cryogenic refrigerant tank is indirectly cooled and reliquefied, and the multistage refrigerator is installed at the location. And the gasified refrigerant in the cryogenic refrigerant tank is efficiently liquefied.

According to the sixth aspect of the present invention, in the cryogenic device, the heat of the multistage refrigerator is passed through the condensing heat exchanger and the refrigerant circulation pipe arranged on the outer peripheral surface of the cryogenic refrigerant tank by the refrigerant circulation mechanism. The second refrigerant cooled in the stage is circulated, and the cryogenic refrigerant gasified by the condensation heat exchanger arranged on the outer peripheral surface of the cryogenic refrigerant tank is indirectly cooled and reliquefied, and the multistage freezing is performed. It enables flexible selection of machine installation location and efficiently liquefies the gasified refrigerant in the cryogenic refrigerant tank.

In the multistage refrigerator of the cryogenic device according to the invention of claim 7, the cryogenic device is mounted substantially horizontally on the cryogenic device body at a height of 1 meter or less from the floor on which the cryogenic device body is installed. Therefore, the worker can perform work such as maintenance of the multi-stage refrigerator at a waist height position, and workability at the time of performing maintenance work is improved.

According to the eighth aspect of the present invention, in the multistage refrigerator of a cryogenic device, the cryogenic device is mounted substantially vertically to the cryogenic device body at a height of 1 meter or less from the floor on which the cryogenic device body is installed. Therefore, the worker can perform work such as maintenance of the multi-stage refrigerator at a waist height position, and workability at the time of performing maintenance work is improved.

In the cryogenic apparatus according to the invention of claim 9, the second refrigerant circulating mechanism circulates the third refrigerant through the second refrigerant supply pipe and the radiation shield cooling pipe, and the intermediate of the radiation shield and the support member. The part is cooled to prevent an increase in the amount of heat entering the cryogenic refrigerant tank.

The cryogenic device according to the invention of claim 10 is
The refrigerant supply pipe is made of a material having a small thermal conductivity,
Disconnect the thermal coupling between the refrigerator and the low temperature part via the refrigerant supply pipe, facilitate the temperature rise of the stopped refrigerator, and perform maintenance work such as removal and installation of refrigerator parts at room temperature. It is possible to carry out.

The cryogenic device according to the invention of claim 11 is
By vacuuming the refrigerant circulation pipe, the second refrigerant supply pipe, or the radiation shield cooling pipe from outside during maintenance via a shutoff valve, the inside of the refrigerant circulation pipe or the second refrigerant supply pipe or The inside of the radiation shield cooling pipe is evacuated, and refrigeration is performed via the refrigerant circulation pipe and the second refrigerant supply pipe when the multistage refrigerator is stopped, or the gas convection in the radiation shield cooling pipe. Break the thermal coupling between the machine and the low temperature part,
This makes it possible to easily raise the temperature of the stopped refrigerator and perform maintenance work such as removal and installation of the refrigerator parts at room temperature.

The cryogenic device according to the invention of claim 12 is
In addition to the refrigerator for reliquefying the gasified cryogenic refrigerant, a refrigerator for cooling only the third refrigerant is provided, and the cryogenic refrigerant and the third refrigerant are cooled by separate refrigerators. ,
Efficiently liquefy the gasified refrigerant in the cryogenic refrigerant tank.

The cryogenic device according to the invention of claim 13 is
Helium gas, hydrogen gas, neon gas or a mixed gas thereof having substantially atmospheric pressure is used as the cryogenic refrigerant and the second refrigerant, and helium gas or hydrogen gas pressurized to above the atmospheric pressure is used as the third refrigerant. Alternatively, neon gas or a mixed gas thereof is used to efficiently liquefy the gasified refrigerant in the cryogenic refrigerant tank.

The cryogenic device according to the invention of claim 14 is
When a plurality of refrigerant circulation mechanisms configured by blowers are provided, the drive shaft of each blower is a common drive shaft,
The drive mechanism of the refrigerant circulation mechanism is simplified, and the amount of heat penetration from the drive shaft is suppressed.

The cryogenic device according to the invention of claim 15 is
When the multistage refrigerator is stopped, it is possible to release the third refrigerant in the refrigerant storage tank to the atmosphere via the release valve. Therefore, the release valve releases the third refrigerant to the atmosphere. It is possible to moderate the degree of increase in the temperature rise of the radiation shield when the multistage refrigerator is stopped.

The cryogenic apparatus according to the invention of claim 16 is
When the multistage refrigerator is stopped, the fourth refrigerant gas in the fourth refrigerant tank installed in an arbitrary place where it can be in thermal contact with the multistage refrigerator, the second refrigerant supply pipe, or the radiation shield cooling pipe is supplied. Since it is possible to discharge to the atmosphere via the third refrigerant supply pipe provided in parallel with the second refrigerant supply pipe, the fourth radiation shield cooling pipe for the fourth refrigerant, and the discharge valve, The release of the fourth refrigerant gas from the release valve to the atmosphere makes it possible to moderate the increase in the temperature rise of the radiation shield when the multistage refrigerator is stopped.

The cryogenic device according to the invention of claim 17 is
Since oxygen gas, nitrogen gas, or dry air pressurized to atmospheric pressure or higher is used as the fourth refrigerant, the radiation shield when the multistage refrigerator is stopped by discharging the fourth refrigerant to the atmosphere from the discharge valve. It is possible to moderate the degree of temperature rise. .

The cryogenic apparatus according to the invention of claim 18 is
It is installed in any place that can be in thermal contact with the multistage refrigerator or the second refrigerant supply pipe or the radiation shield cooling pipe, and the magnetic transition phenomenon occurs at a temperature of 80K or more and 100K or less to increase the specific heat. The buffer action of the material moderates the temperature rise of the radiation shield when the multistage refrigerator is stopped.

The cryogenic device according to the invention of claim 19 is
The radiation shield cooling pipe is configured by a plurality of parallel flow passages, and the flow passage resistance in the radiation shield cooling pipe is reduced to suppress power consumption for driving the refrigerant circulation mechanism.

The cryogenic device according to the invention of claim 20 is
A radiation control valve provided in the vicinity of the outlet of each flow path of the radiation shield cooling pipe configured with parallel flow paths changes the valve opening according to the temperature change of the refrigerant flowing inside the flow path, and the radiation of each parallel flow path is increased. The temperature difference between the shield cooling pipes is reduced to make the radiation shield more uniform and cool.

[0057]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of the cryogenic device of the first embodiment. In FIG. 1, the same parts as those in FIG. 13 are designated by the same reference numerals and the description thereof is omitted. In this embodiment, a cryogenic device for cooling a superconducting magnet for an MRI device will be described as an example. This cryogenic device has a configuration in which a three-stage refrigerator is installed horizontally below the end surface of the cryogenic device body. In the figure, 21 is a blower (refrigerant circulation mechanism) for circulating gasified liquid helium (cryogenic refrigerant), and 22 is heat attached to the third heat stage (heat stage) 12 in thermal contact therewith. An exchanger, 23 is a refrigerant supply pipe for sending the evaporated helium gas directly to the heat exchanger 22, and 24 is for returning the helium cooled in the heat exchanger 22 directly to the helium tank (cryogenic refrigerant tank) 2. 3 is a refrigerant supply pipe. The refrigerant supply pipes 23 and 24 are opened at the place where the upper gas phase of the helium tank 2 is located. The refrigerant supply pipes 23 and 24 are arranged along the circumference of the cylinder.

Next, the operation of this embodiment will be described. The superconducting coil (object to be cooled) 1 is housed inside a helium tank 2 and cooled to a superconducting state by liquid helium (cryogenic refrigerant) 3. The helium tank 2 is surrounded by the first radiation shield 5 and the second radiation shield 6, which are cooled to the specified temperatures, respectively, and the amount of radiant heat entering from the room temperature portion is small. The plurality of supporting members 8 adiabatically support the helium tank 2, the first radiation shield (radiation shield) 5, the second radiation shield (radiation shield) 6 and the like, and the vacuum tank 4 is provided between the helium tank 2 and the helium tank 2. The space is maintained at high vacuum.

In the three-stage refrigerator (multistage cooler) 20 attached to the lower part of the end surface of the vacuum chamber 4, the first heat stage (heat stage) 10 is the first due to the flexible conductor 15.
The second heat stage (heat stage) 11 is thermally connected to the second radiation shield 6 on the radiation shield 5, and the temperature of the first radiation shield 5 is about 80K and the temperature of the second radiation shield 6 is about 20K. Cool to. Further, since the heat exchanger 22 attached to the third heat stage 12 is cooled to a helium liquefaction temperature of about 4K or less, the vaporized gas of liquid helium in the helium tank 2 is supplied by the blower 21 to the refrigerant supply pipe 23, After passing through 24 and the heat exchanger 22 attached to the third heat stage 12, it becomes liquid and circulates back to the helium tank 2.

In the cryogenic device constructed as described above,
The helium gas evaporated in the helium tank 2 is supplied to the third heat stage 1 by the refrigerant supply pipe 23 and the blower 21.
2 is liquefied again by being sent to the heat exchanger 22 attached to the heat exchanger 22, and returned to the helium tank 2 by the refrigerant supply pipe 24. Therefore, the three-stage refrigerator 20 is attached by the arrangement configuration of the refrigerant supply pipes 23 and 24. The location can be freely selected, and the installation location of the three-stage refrigerator 20 does not have to be the location in thermal contact with the location of the upper gas phase of the helium tank 2.

Therefore, in the cryogenic apparatus of this embodiment, the mounting position of the three-stage refrigerator 20 is about 60 cm in height from the floor, which is the waist of the worker. For this reason, it is not necessary to install a step or scaffold for maintenance work such as removal and installation of parts inside the three-stage refrigerator 20, and the cryogenic device does not require a large space for these works. .

Example 2. Second Embodiment FIG. 2 is a sectional view showing the structure of a cryogenic device according to a second embodiment of the present invention. In FIG. 2, FIG.
The same parts as those of are denoted by the same reference numerals, and the description thereof will be omitted.
In the cryogenic apparatus of this embodiment, the three-stage refrigerator 20 is installed vertically below the end surface of the cryogenic apparatus body. The operation and the like are the same as in the case where the three-stage refrigerator 20 is horizontally installed in the first embodiment, but the work such as the removal and installation of the parts inside the three-stage refrigerator can be performed in the vertical direction. Therefore, the maintenance work becomes easier.

Example 3. Third Embodiment FIG. 3 is a sectional view showing the structure of a cryogenic device according to a third embodiment of the present invention. In FIG.
The same parts as those of are denoted by the same reference numerals, and the description thereof will be omitted.
In the cryogenic apparatus of the present embodiment, the three-stage refrigerator 20 is installed horizontally below the end surface of the cryogenic apparatus main body, and the helium gas evaporated in the helium tank 2 is condensed in the helium tank 2. Is indirectly cooled by and returned to liquid again.

In the figure, reference numerals 26 and 27 are refrigerant supply pipes (refrigerant circulation pipes), 28 is a blower (refrigerant circulation mechanism), and 31 is condensation heat exchange provided at a place where the upper gas phase of the helium tank 2 is present. It is a vessel. Also, the blower 28
The heat exchanger 22, the refrigerant supply pipes 26 and 27, and the condensing heat exchanger 31 are closed flow paths interconnected with each other, and the inside of the helium has a pressure slightly lower than the pressure of the helium tank 2 at about atmospheric pressure. Gas is enclosed.

In this embodiment, the third stage heat stage 1
The heat exchanger 22 attached to No. 2 is cooled to a helium liquefaction temperature of about 4K or less, and is enclosed inside by the blower 28 via the refrigerant supply pipes 26 and 27 and the condensing heat exchanger 31. By circulating the helium gas, the vaporized gas in the helium tank 2 is returned to the liquid again.

Since the cryogenic apparatus of this embodiment is configured as described above, the helium gas sealed in the closed flow path is circulated to indirectly cool the helium gas evaporated in the helium tank 2. Since it is re-liquefied as compared with the case where the evaporated gas in the helium tank 2 is directly circulated, there is no fear that impurities such as dust are mixed in, and troubles such as clogging in the refrigerant supply pipes 26 and 27 do not occur and reliability is eliminated. Is improved and handling becomes easier.

In this embodiment, the case where the three-stage refrigerator 20 is installed horizontally below the end face of the cryogenic device main body is shown. However, the three-stage refrigerator 20 is perpendicular to the bottom end face of the cryogenic device main body. It may be installed in.

Example 4. Fourth Embodiment FIG. 4 is a sectional view showing the structure of a cryogenic device according to a fourth embodiment of the present invention. In FIG.
The same parts as those of are denoted by the same reference numerals, and the description thereof will be omitted.
In the cryogenic apparatus of the present embodiment, the three-stage refrigerator 20 is installed horizontally under the end surface of the cryogenic apparatus main body and the heat provided in the third heat stage 12 of the three-stage refrigerator 20. The helium tank 2 itself is indirectly cooled by the second refrigerant cooled by the exchanger 22, so that the helium gas evaporated in the helium tank 2 is returned to the liquid again in the helium tank 2.

In the figure, reference numeral 41 denotes a condensing heat exchanger arranged and attached on the outer peripheral surface of the helium tank 2.
The operation of the cryogenic apparatus of this embodiment is the same as that of the case where the condensation heat exchanger 31 is arranged inside the helium tank 2 in the third embodiment.

In this embodiment, the case where the three-stage refrigerator 20 is installed horizontally below the end face of the cryogenic device main body is shown. However, the three-stage refrigerator 20 is placed vertically below the end face of the cryogenic device main body. It may be installed in.

Example 5. FIG. 5 is a sectional view showing the structure of a cryogenic device according to a fifth embodiment of the present invention. In FIG.
The same parts as those of are denoted by the same reference numerals, and the description thereof will be omitted.
In the cryogenic apparatus of the present embodiment, the three-stage refrigerator 20 is installed horizontally below the end surface of the cryogenic apparatus main body, and the helium gas evaporated in the helium tank 2 is directly stored in the three-stage refrigerator 20. Heat exchanger 22 provided in the third heat stage
And is cooled to be returned to liquid helium and circulated in the helium tank 2.

In the figure, 51 is a second blower (second blower).
Refrigerant circulation mechanism), 52 is a third blower (second refrigerant circulation mechanism), 53 is a heat exchanger attached to the first heat stage (heat stage) 10, and 54 is a second heat exchanger.
A heat exchanger attached to the multi-stage heat stage (heat stage) 11, 55 is a first radiation shield refrigerant supply pipe (second refrigerant supply pipe) for circulating a refrigerant that cools the first radiation shield 5. , 56 is a second radiation shield refrigerant supply pipe (second refrigerant supply pipe) for circulating a refrigerant for cooling the second radiation shield 6, and 57 is arranged and attached on the outer peripheral surface of the first radiation shield 5. The first radiation shield cooling pipe (radiation shield cooling pipe),
Reference numeral 58 denotes a second radiation shield cooling pipe (radiation shield cooling pipe) arranged and attached on the outer peripheral surface of the second radiation shield 6.

The radiation shield cooling pipe 57 arranged and attached on the outer peripheral surface of the first radiation shield 5 is connected to the first radiation shield refrigerant supply pipe 55, the third blower 52, and the heat exchanger 53. A closed flow path is formed, and helium gas pressurized above atmospheric pressure is enclosed inside.
Similarly, the radiation shield cooling pipe 58 disposed and attached on the outer peripheral surface of the second radiation shield 6 includes a second radiation shield refrigerant supply pipe 56, a second blower 51, and a heat exchanger 54.
Are connected to each other to form a closed flow path, and helium gas pressurized above atmospheric pressure is sealed inside.

With the above construction, the temperature of the first radiation shield 5 over the entire area is the first heat stage 10 of the refrigerator.
The temperature can be maintained at 80K. In addition, the second radiation shield 6
Similarly, the second stage heat stage 1 of the refrigerator over the entire area
The temperature of 1 can be maintained at 20K. This has the effect of further suppressing the amount of heat entering the helium tank 2. The heat exchanger 22 attached to the third heat stage 12 has a temperature of 4K.
Since the helium liquefaction temperature is cooled to a certain level or lower, the evaporative gas in the helium tank 2 is circulated to the helium tank 2 as a liquid by the first blower 21 via the refrigerant supply pipes 23 and 24.

Since the cryogenic apparatus of this embodiment is constructed as described above, it is possible to freely select the mounting location of the three-stage refrigerator 20 for the first radiation shield 5 and the second radiation shield 6. The degree of freedom of the mounting location of the three-stage refrigerator 20 is further expanded as compared with the case of the first embodiment. For this reason 3
It is not necessary to install a step or scaffold for maintenance work such as removal and installation of internal parts of the multi-stage refrigerator 20.
Also, it does not require a large space for these tasks,
It becomes a cryogenic device with a small amount of heat penetration.

In this embodiment, the case where the three-stage refrigerator 20 is installed horizontally below the end surface of the cryogenic device main body is shown, but the three-stage refrigerator 20 is perpendicular to the lower end face of the cryogenic device main body. It may be installed in.

Further, the refrigerant supply pipes 23 and 24, the first radiation shield refrigerant supply pipe 55, and the second radiation shield refrigerant supply pipe 56 are made of a material having a small thermal conductivity, so that the three-stage refrigerator is provided. Even when 20 is stopped, the three-stage refrigerator 2
It is possible to reduce the conduction heat through the 0 cylinder. As a result, when performing maintenance work such as removal and installation of parts inside the three-stage refrigerator 20,
When the multistage refrigerator 20 is stopped, the temperature of the three-stage refrigerator 20 easily rises to room temperature, and the entire temperature including the cylinder can be carried out at room temperature, which facilitates the work.

Example 6. 6 is a sectional view showing the structure of a cryogenic device according to a sixth embodiment of the present invention. In FIG.
The same parts as those of are denoted by the same reference numerals, and the description thereof will be omitted.
In the cryogenic apparatus of this embodiment, the condensation heat exchanger is installed in the upper gas phase portion in the helium tank 2. Although not shown, the operation and effects are the same even when the condensation heat exchanger is installed on the outer peripheral surface of the helium tank 2.

In the figure, 62 is a shutoff valve provided in a pipe branched from the refrigerant supply pipe 24, 63 is a shutoff valve provided in a pipe branched from the first radiation shield refrigerant supply pipe 55, and 64 is a second shutoff valve. Radiation Shield Refrigerant Supply Pipe 56
It is a shutoff valve provided in a pipe branched from.

In this embodiment, during maintenance work, the refrigerant supply pipe 23, the first radiation shield refrigerant supply pipe 55, and the second radiation shield refrigerant supply are supplied through the shutoff valves 62, 63, 64. The inside of the pipe 56 can be evacuated. As a result, there is no heat transfer due to the gas in the pipe, and the temperature of the cylinder portion of the three-stage refrigerator 20 can be easily raised to room temperature.

Further, maintenance work such as removal and installation of internal parts of the three-stage refrigerator can be performed on the three-stage refrigerator at room temperature, and a space for these operations is not required so much. It becomes a low temperature device. Also,
The helium gas to be circulated is enclosed, and unlike the evaporative gas in the helium tank 2, there is no fear of inclusion of impurities such as dust, and the handling becomes easier.

Example 7. 7 is a sectional view showing the structure of a cryogenic device according to a seventh embodiment of the present invention. In FIG.
The same parts as those of are denoted by the same reference numerals, and the description thereof will be omitted.
In the cryogenic device of the present embodiment, the two-stage refrigerator and the three-stage refrigerator are horizontally provided below the end surface of the cryogenic device body.

In the figure, 71 is a two-stage refrigerator (multistage refrigerator) provided below the end surface of the cryogenic apparatus main body, and 72.
Is a heat exchanger attached to the first heat stage of the two-stage refrigerator 71, and 73 is a heat exchanger attached to the second heat stage of the two-stage refrigerator 71.

In this embodiment, the first of the two-stage refrigerator 71 is used.
The heat exchanger 72 attached to the multi-stage heat stage is the first
The radiation shield 5 is cooled, and the heat exchanger 73 attached to the second heat stage cools the second radiation shield 6. In addition, the third heat stage 1 of the three-stage refrigerator 20
The heat exchanger 22 attached to 2 reliquefies the helium gas evaporated in the helium tank 2.

As described above, the degree of freedom of the places where the three-stage refrigerator 20 and the two-stage refrigerator 71 are respectively attached is further expanded, and in the present embodiment, the three-stage refrigerator 20 and the two-stage refrigerator 71 are kept at an extremely low temperature. It was installed horizontally at the bottom of the end of the device,
They may be attached to different places, for example, on opposite sides of each other, where it is easier to perform maintenance work. It may also be mounted vertically. Therefore, maintenance work such as removal and installation of internal parts of the three-stage refrigerator 20 does not require a step or scaffolding, and does not require a large space for these works, and the amount of heat penetration is small. It becomes a low temperature device.

Example 8. Further, in the embodiments described above, liquid helium is used as the cryogenic refrigerant, helium tank is used as the cryogenic refrigerant tank, and helium gas is used as the second and third refrigerants, but depending on the operating temperature of the superconducting magnet,
It is also possible to use hydrogen gas or neon gas or a mixed gas thereof.

Example 9. FIG. 8 is a cross-sectional view of a superconducting magnet for a linear motor, which is an embodiment when the cryogenic device of the present invention is applied to the superconducting linear motor. Reference numeral 81 is a racetrack-shaped superconducting coil, 82 is a helium tank, 85 is a first radiation shield, 86 and 87 are refrigerant supply pipes, 88 is a two-stage refrigerator, and 89 is heat attached to the first heat stage. An exchanger, 90 is a heat exchanger attached to the second heat stage, 91 is a first radiation shield cooling blower provided in a refrigerant supply pipe 93 for cooling the first radiation shield, and 92 is a refrigerant A blower that is provided in the supply pipe 86 and sends the helium gas evaporated in the helium tank 82 to the heat exchanger 90, 94 is a first radiation shield cooling pipe for cooling the first radiation shield, and 95 is a support member. The configuration is slightly different, but functions similarly to the cryogenic device of the fifth embodiment.

Example 10. FIG. 9 shows a tenth embodiment of the present invention.
FIG. 3 is a partial cross-sectional view showing the configuration near the three-stage refrigerator 20 of the cryogenic device. 10, the same parts as those in FIGS. 5, 6 and 7 are designated by the same reference numerals and the description thereof will be omitted. In the cryogenic apparatus of the present embodiment, the three-stage refrigerator 20 is provided horizontally below the end surface of the cryogenic apparatus main body, and the first blower 21,
The second blower 51 and the third blower 52 are also provided horizontally below the end surface of the cryogenic device body.

In the figure, 101 is the first blower 2
1, a common drive shaft (drive shaft) for the second blower 51 and the third blower 52, and a drive shaft motor 102. Since the three first blower 21, the second blower 51, and the third blower 52 are driven by the common drive shaft 101, the heat that enters from the outside via this common drive shaft is sequentially absorbed by the blower, In the first blower 21 in the temperature section, the amount of heat that penetrates is small.

Example 11. FIG. 10 is a first embodiment of the present invention.
It is sectional drawing which shows the structure of the 1st cryogenic apparatus, and expand | deploys the 1st heat stage and the 1st radiation shield 5 of the 3-stage refrigerator 20, and shows it typically. In the figure, 111 is a refrigerant storage tank containing helium gas pressurized to atmospheric pressure or higher. Reference numeral 112 denotes a magnetic material attached to the first radiation shield 5, and when it is cooled to 80 K by the radiation shield cooling pipe 113, the specific heat increases due to magnetic transition. 114 is a discharge valve, 115 is a check valve, 11
6 is a blower for circulating the helium gas, 1
Reference numeral 17 is a refrigerant supply pipe (second refrigerant supply pipe).

In this embodiment, the refrigerant storage tank 111 containing the helium gas pressurized to atmospheric pressure or higher is cooled by the first heat stage of the three-stage refrigerator 20. Three
When the multistage refrigerator 20 is stopped, the refrigerant storage tank 111
The internal pressure rises, and the helium gas in the refrigerant storage tank 111 is released to the atmosphere from the release valve 114 via the radiation shield cooling pipe 113 by the action of the check valve 115.

The magnetic material 112 attached to the first radiation shield 5 is a substance that causes a magnetic transition phenomenon at a temperature of 80 K or more and 100 K or less, such as GdMn2, and is cooled to 80 K by the radiation shield cooling pipe 113 and magnetic. The specific heat is increasing due to the transition. When the three-stage refrigerator 20 is stopped, the temperature of the first radiation shield 5 gradually rises due to the buffer action of the magnetic material 112 having a large heat capacity.

Example 12. FIG. 11 is a first embodiment of the present invention.
FIG. 11 is a cross-sectional view showing the configuration of the cryogenic device of No. 2, and schematically shows the first heat stage and the first radiation shield 5 of the three-stage refrigerator 20 as in the case of FIG. 10. In the figure, 120 is a magnetic material, and when it is cooled to 80 K, the specific heat increases due to magnetic transition. 121
Is a blower and is provided in the radiation shield cooling pipe 124. 122 is a heat exchanger attached to the heat stage of the three-stage refrigerator 20 and a radiation shield cooling pipe (4th
The radiation shield cooling pipe 125 for the refrigerant is installed together with the radiation shield cooling pipe 124. Reference numeral 126 is a release valve provided in the radiation shield cooling pipe 125, 127 is a refrigerant tank containing oxygen gas, 128 is a refrigerant supply pipe (second refrigerant supply pipe) 129 and a refrigerant supply pipe (first) 3 is a refrigerant supply pipe).

In this embodiment, the refrigerant tank 127 containing the oxygen gas pressurized to atmospheric pressure or above is the three-stage refrigerator 20.
The internal oxygen gas is in a liquid state because it is cooled in the first heat stage. When the three-stage refrigerator 20 is stopped, the temperature of oxygen gas in the refrigerant tank 127 rises and is released to the atmosphere via the refrigerant supply pipe 128, the radiation shield cooling pipe 125, and the discharge valve 126. At this time, the latent heat from the liquid state to the gasification can also be utilized, so that the temperature rise of the first radiation shield 5 becomes gentle. The refrigerant tank 12
The oxygen gas is injected into 7 through a discharge valve 126 from a discharge hole (not shown) communicating with the atmosphere during operation of the three-stage refrigerator.

Although the case where oxygen gas is injected into the refrigerant tank 127 has been described in this embodiment, the same effect can be obtained with nitrogen gas or dry air. In addition, the temperature increase of the radiation shield when the three-stage refrigerator 20 is stopped is further moderated by using the magnetic material 120 having a large heat capacity together with the buffer action.

Example 13 FIG. 12 is a first embodiment of the present invention.
3 is a schematic view showing the configuration of a cryogenic device of No. 3, which is an axial cross section of a superconducting magnet for an MRI device, and shows a first heat stage and a first radiation shield 5 of a three-stage refrigerator 20.
And are schematically expanded and shown. In FIG. 12, FIG.
The same parts as those of are denoted by the same reference numerals, and the description thereof will be omitted.
In this embodiment, the radiation shield cooling pipe is composed of a plurality of parallel flow passage radiation shield cooling pipes 132, and a flow rate control valve 133 is provided near the outlet of each flow passage.

Parallel Flow Path Since the plurality of radiation shield cooling pipes 132 are provided as parallel flow paths of the radiation shield cooling pipe, the inner diameter of the radiation shield cooling pipe is substantially increased, so that the overall flow passage resistance is reduced and the blower is reduced. The power supplied to the drive motor is small, and the temperature distribution of the first radiation shield 5 becomes more uniform. Further, since the flow control valve 133 changes its valve opening degree according to the temperature change of the refrigerant flowing inside,
The temperature difference between the parallel flow path radiation shield cooling pipes 132 is eliminated.

In the above description, the case of a superconducting magnet for an MRI apparatus has been described, but it goes without saying that it can also be used for a cryogenic device using a superconducting magnet, for example, a superconducting linear motor, a superconducting electromagnetism propulsion ship, or the like.

[0099]

As described above, according to the invention of claim 1, since the cryogenic refrigerant tank and the multistage refrigerator are connected by the refrigerant supply pipe, the evaporation in the cryogenic refrigerant tank is achieved. Since the cryogenic refrigerant gas is liquefied by being circulated to the heat stage of the multi-stage refrigerator via the refrigerant supply pipe and returned to the cryogenic refrigerant tank, the installation location of the multi-stage refrigerator can be flexibly selected, The cryogenic refrigerant gas evaporated in the cryogenic refrigerant tank is directly cooled in the heat stage of the multi-stage refrigerator via the refrigerant supply pipe, and the cryogenic refrigerant tank can efficiently liquefy the gasified refrigerant. There is an effect that a low temperature device can be obtained.

According to the second aspect of the invention, since the multistage refrigerator is configured to be mounted substantially horizontally at a height of 1 m or less above the floor where the cryogenic device body is installed, maintenance work and the like can be performed. Since the multistage refrigerator is attached to a position lower than the waist height of the worker who performs the operation, there is an effect that a cryogenic device with improved workability when performing maintenance work of the multistage refrigerator can be obtained.

According to the third aspect of the present invention, the multi-stage refrigerator is configured to be installed substantially vertically at a height position of 1 m or less above the floor where the cryogenic device body is installed. The multi-stage refrigerator will be installed vertically at a position lower than the waist height of the worker who performs it, and the cryogenic device with improved workability when performing maintenance work of the multi-stage refrigerator will be obtained. is there.

According to the invention of claim 4, the condensing heat exchanger laid in the cryogenic refrigerant tank and the multistage refrigerator are connected by the refrigerant circulation pipe, and the multistage refrigerator is constituted by the refrigerant circulation mechanism. No. 2 sent to the heat stage of
Since the cryogenic refrigerant gas evaporated in the cryogenic refrigerant tank is indirectly cooled and liquefied by the refrigerant, it is possible to flexibly select the installation location of the multi-stage refrigerator, and in the cryogenic refrigerant tank There is an effect that a cryogenic device capable of efficiently liquefying the vaporized cryogenic refrigerant gas can be obtained.

According to the fifth aspect of the present invention, the second cooling is performed in the heat stage of the multi-stage refrigerator via the condensation heat exchanger and the second refrigerant circulation pipe provided in the cryogenic refrigerant tank. Since it is configured to have a refrigerant circulation mechanism that circulates the refrigerant and cools the gasified cryogenic refrigerant with the condensation heat exchanger in the cryogenic refrigerant tank to reliquefy, the installation location of the multi-stage refrigerator Can be flexibly selected, and a cryogenic device can be obtained in which the cryogenic refrigerant gas evaporated in the cryogenic refrigerant tank can be efficiently liquefied in the cryogenic refrigerant tank.

According to the sixth aspect of the present invention, the second stage is cooled by the heat stage of the multistage refrigerator via the condensation heat exchanger and the refrigerant circulation pipe arranged on the outer peripheral surface of the cryogenic refrigerant tank. Since it is configured to have a refrigerant circulation mechanism that circulates the refrigerant and cools and reliquefyes the gasified cryogenic refrigerant, the installation location of the multi-stage refrigerator can be flexibly selected, and the cryogenic refrigerant tank There is an effect of obtaining a cryogenic device capable of efficiently cooling and liquefying the cryogenic refrigerant gas evaporated inside from the outer peripheral surface of the cryogenic refrigerant tank.

According to the invention of claim 7, a multistage refrigerator having a heat stage for cooling the second refrigerant circulated by the refrigerant circulation mechanism is provided on the floor surface on which the cryogenic device body is installed. Since it is configured to be installed substantially horizontally at a height position of 1 meter or less, the multistage refrigerator will be installed at a position lower than the waist height of the worker who performs maintenance work, etc., and maintenance of the multistage refrigerator There is an effect that a cryogenic device with improved workability when performing work is obtained.

According to the eighth aspect of the present invention, a multistage refrigerator having a heat stage for cooling the second refrigerant circulated by the refrigerant circulation mechanism is provided on the floor on which the cryogenic apparatus main body is installed. Since it is configured to be installed substantially vertically at a height position of 1 meter or less, the multi-stage refrigerator will be installed vertically at a position lower than the waist height of a worker who performs maintenance work, etc. There is an effect that a cryogenic device with improved workability when performing the maintenance work of is obtained.

According to the invention of claim 9, the third refrigerant passing through the heat stage of the multi-stage refrigerator is circulated through the second refrigerant supply pipe and the radiation shield cooling pipe by the second refrigerant circulation mechanism. By doing so, the radiation shield and the intermediate part of the support member are configured to be cooled, so that the radiation shield can be uniformly cooled, and a cryogenic device capable of suppressing an increase in the amount of heat entering the cryogenic refrigerant tank can be obtained. It is effective.

According to the tenth aspect of the present invention, the second refrigerant supply in which the third refrigerant passing through the heat stage of the multi-stage refrigerator is made of a material having a small thermal conductivity by the second refrigerant circulation mechanism. Since the pipe and the radiation shield cooling pipe are circulated to cool the radiation shield and the intermediate portion of the support member, heat entering through the second refrigerant supply pipe and the radiation shield cooling pipe is suppressed. It is possible to efficiently cool the radiation shield and the intermediate portion of the support member, and the temperature of the multi-stage refrigerator can easily rise to room temperature when the multi-stage refrigerator is stopped. It is possible to obtain a cryogenic device capable of performing maintenance work such as removal and installation of internal components at room temperature.

According to the eleventh aspect of the present invention, the refrigerant circulation pipe and the second refrigerant supply pipe or the radiation shield cooling pipe are provided with a shut-off valve for evacuating the inside of the multi-stage. There is an effect that a cryogenic device can be obtained that can easily raise the temperature of the multi-stage refrigerator to normal temperature when the refrigerator is stopped.

According to the twelfth aspect of the present invention, the refrigerator for cooling only the third refrigerant is provided separately from the refrigerator for reliquefying the cryogenic refrigerant gasified in the cryogenic tank. Since it is configured, it is possible to flexibly select the mounting position of each refrigerator, and since the cryogenic refrigerant gas evaporated in the cryogenic refrigerant tank is cooled by a dedicated refrigerator, the gasified refrigerant in the cryogenic refrigerant tank is cooled. There is an effect that a cryogenic device capable of efficiently liquefying is obtained.

According to the thirteenth aspect of the present invention, helium gas, hydrogen gas, neon gas, or a mixed gas thereof having a substantially atmospheric pressure is used as the cryogenic refrigerant,
Further, as the second refrigerant, helium gas, hydrogen gas, neon gas, or a mixture thereof of approximately atmospheric pressure is used, and as the third refrigerant, helium gas, hydrogen gas, neon gas, or a gas pressurized to atmospheric pressure or more is used. Since the mixed gas is used, there is an effect of obtaining a cryogenic device capable of efficiently cooling the gasified refrigerant in the cryogenic refrigerant tank.

According to the fourteenth aspect of the invention, when the refrigerant circulation mechanism is constituted by the blower, each of the blowers is driven by the common drive shaft, so that the refrigerant circulation mechanism can be simplified, There is an effect that a cryogenic device capable of suppressing the amount of heat entering from the refrigerant circulation mechanism can be obtained.

According to the fifteenth aspect of the present invention, when the multistage refrigerator is stopped, the third refrigerant in the refrigerant storage tank attached to the heat stage of the multistage refrigerator is connected to the second refrigerant supply pipe. Since it is configured such that it can be released to the atmosphere via the attached release valve, there is an effect that a cryogenic device can be obtained which can moderate the temperature rise of the radiation shield when the multistage refrigerator is stopped.

According to the sixteenth aspect of the present invention, when the multistage refrigerator is stopped, the refrigerant installed in any place that can be in thermal contact with the multistage refrigerator, the second refrigerant supply pipe, or the radiation shield cooling pipe. The fourth refrigerant gas in the tank is released to the atmosphere via the third refrigerant supply pipe provided in parallel with the second refrigerant supply pipe, the fourth refrigerant radiation shield cooling pipe, and the discharge valve. Since it is configured to release the gas, there is an effect that a cryogenic device can be obtained which can moderate the degree of temperature rise of the radiation shield when the multistage refrigerator is stopped.

According to the seventeenth aspect of the present invention, since oxygen gas or nitrogen gas pressurized to atmospheric pressure or dry air or dry air is used as the fourth refrigerant, radiation occurs when the multistage refrigerator is stopped. There is an effect that a cryogenic device capable of moderately increasing the temperature rise of the shield can be obtained.

According to the eighteenth invention, the temperature is 80K.
Since the magnetic material that causes the magnetic transition phenomenon at 100 K or less is installed in any place that can be in thermal contact with the multistage refrigerator, the second refrigerant supply pipe, or the radiation shield cooling pipe, the multistage refrigeration There is an effect that a cryogenic device can be obtained which can further moderate the temperature rise of the radiation shield when the machine is stopped.

According to the nineteenth aspect of the invention, since the flow control valve is provided near the outlet of each of the plurality of parallel flow passages of the second refrigerant supply pipe and the radiation shield cooling pipe, The road resistance is reduced, and the cryogenic device capable of suppressing the power consumption for driving the refrigerant circulation mechanism can be obtained.

According to the twentieth aspect of the invention, in the vicinity of the outlet of each flow path of the plurality of parallel flow paths of the second refrigerant supply pipe and the radiation shield cooling pipe, the third refrigerant flowing inside the flow path is provided. Since it is equipped with a flow control valve whose opening changes according to the temperature change, it suppresses the power consumption for driving the refrigerant circulation mechanism and evens out the cooling of the radiation shield to heat the cryogenic refrigerant tank. There is an effect that a cryogenic device capable of suppressing an increase in the amount of penetration can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the configuration of a cryogenic device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a cryogenic device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the configuration of a cryogenic device according to Example 3 of the present invention.

FIG. 4 is a cross-sectional view showing the configuration of a cryogenic device according to a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional view showing the structure of a cryogenic device according to a fifth embodiment of the present invention.

FIG. 6 is a cross-sectional view showing the structure of a cryogenic device according to Example 6 of the present invention.

FIG. 7 is a cross-sectional view showing the configuration of a cryogenic device of Example 7 of the present invention.

FIG. 8 is a sectional view showing the structure of a cryogenic device according to Example 9 of the present invention.

FIG. 9 is a partial cross-sectional view showing the structure around a three-stage refrigerator of a cryogenic device of Embodiment 10 of the present invention.

FIG. 10 is a sectional view showing the structure of a cryogenic device according to Example 11 of the present invention.

FIG. 11 is a cross-sectional view showing the structure of a cryogenic device of Example 12 of the present invention.

FIG. 12 is a cross-sectional view showing the structure of a cryogenic device of Example 13 of the present invention.

FIG. 13 is a cross-sectional view showing the configuration of a conventional cryogenic device.

[Explanation of symbols]

1 superconducting coil (cooled object), 2 helium tank (cryogenic refrigerant tank), 3 liquid helium (cryogenic refrigerant), 4 vacuum tank, 5 first radiation shield (radiation shield), 6 2nd radiation shield (radiation shield) ), 8 support members, 10
1st stage heat stage (heat stage), 11 2nd stage heat stage (heat stage), 12 3rd stage heat stage (heat stage), 20 3 stage type refrigerator (multistage refrigerator), 21 blower (refrigerant circulation) Mechanism), 23, 24 Refrigerant supply pipe, 26, 27 Refrigerant supply pipe (refrigerant circulation pipe), 28 Blower (refrigerant circulation mechanism), 31, 41 Condensation heat exchanger, 51 Second blower (second Refrigerant circulation mechanism), 52 Third blower (second refrigerant circulation mechanism), 55 First radiation shield refrigerant supply pipe (second refrigerant supply pipe), 56 Second radiation shield refrigerant supply pipe (second) Refrigerant supply pipe),
57 first radiation shield cooling pipe (radiation shield cooling pipe), 58 second radiation shield cooling pipe (radiation shield cooling pipe), 62, 63, 64 shutoff valve, 71 two-stage refrigerator (multistage refrigerator), 101 Common drive axis (drive axis),
111 Refrigerant storage tank, 112, 120 Magnetic material, 113, 124 Radiation shield cooling pipe, 114, 1
26 release valve, 115 check valve, 117 refrigerant supply pipe (second refrigerant supply pipe), 121 blower, 125
Radiation shield cooling pipe (radiation shield cooling pipe for fourth refrigerant) 127 refrigerant tank, 128 refrigerant supply pipe (third refrigerant supply pipe), 129 refrigerant supply pipe (second refrigerant supply pipe) 133 Flow control valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masashi Nagao 8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Corporation Central Research Laboratory

Claims (20)

[Claims] 1. A cryogenic refrigerant tank containing a cooled object and storing a cryogenic refrigerant for cooling the cooled object, a radiation shield surrounding the cryogenic refrigerant tank, the cryogenic refrigerant tank, and A vacuum tank surrounding the radiation shield, a support member for holding the cryogenic refrigerant tank, and a multistage refrigerator for cooling the radiation shield and reliquefying the gasified cryogenic refrigerant are provided. In the cryogenic device, the cryogenic refrigerant gas evaporated in the cryogenic refrigerant tank is sent to the heat stage of the multistage refrigerator via the refrigerant supply pipe to be liquefied, and again via the refrigerant supply pipe. A cryogenic device comprising a refrigerant circulation mechanism arranged in the vacuum tank for circulating the cryogenic refrigerant tank. 2. The cryogenic apparatus according to claim 1, wherein the multi-stage refrigerator is installed substantially horizontally at a height position of 1 m or less on a floor surface where the cryogenic apparatus body is installed. . 3. The cryogenic temperature according to claim 1, wherein the multi-stage refrigerator is installed substantially vertically at a height position of 1 m or less on the installation floor surface of the cryogenic device body. apparatus. 4. A cryogenic refrigerant tank containing a cooled object and storing a cryogenic refrigerant for cooling the cooled object, a radiation shield surrounding the cryogenic refrigerant tank, the cryogenic refrigerant tank, and A vacuum tank surrounding the radiation shield, a supporting member for holding the cryogenic refrigerant tank, and a multistage refrigerator for cooling the radiation shield and reliquefying the gasified cryogenic refrigerant. In the cryogenic device, the second refrigerant cooled in the heat stage of the multistage refrigerator is circulated through the condensation heat exchanger and the refrigerant circulation pipe laid in the cryogenic refrigerant tank to be gasified. A cryogenic device comprising a refrigerant circulation mechanism for reliquefying the cryogenic refrigerant. 5. The cryogenic apparatus according to claim 4, wherein the condensation heat exchanger is provided inside the cryogenic refrigerant tank. 6. The cryogenic apparatus according to claim 4, wherein the condensation heat exchanger is arranged on an outer peripheral surface of the cryogenic refrigerant tank. 7. The multistage refrigerator according to claim 4, wherein the multistage refrigerator is mounted substantially horizontally at a height of 1 m or less above the floor of the cryogenic device body. The cryogenic device according to item 1. 8. The multistage refrigerator is mounted substantially vertically at a height of 1 meter or less on the floor surface of the installation of the cryogenic device body, according to any one of claims 4 to 6. The cryogenic device according to item 1. 9. A third refrigerant having a second refrigerant supply pipe and a radiation shield cooling pipe for cooling the radiation shield, wherein the third refrigerant passing through the heat stage of the multistage refrigerator is the second refrigerant. The intermediate part of the said radiation shield and the said support member is cooled by circulating the said 2nd refrigerant | coolant supply pipe and the said radiation shield cooling pipe by a circulation mechanism. The cryogenic device according to any one of items. 10. The cryogenic apparatus according to claim 9, wherein the refrigerant supply pipe is made of a material having a low thermal conductivity. 11. A shutoff valve for vacuuming the inside of the refrigerant circulation pipe, the second refrigerant supply pipe, or the radiation shield cooling pipe during maintenance. Item 10. The cryogenic device according to any one of items 9. 12. A refrigerator for cooling only the third refrigerant,
10. The cooling machine for reliquefying the gasified cryogenic refrigerant is provided separately from the refrigerator.
The cryogenic device described in 0. 13. The cryogenic refrigerant is helium gas, hydrogen gas, neon gas, or a mixture thereof of approximately atmospheric pressure, and the second refrigerant is helium gas, hydrogen gas, neon gas, or a mixture thereof, which is approximately atmospheric pressure. 13. The gas according to claim 1, wherein the third refrigerant is helium gas, hydrogen gas, neon gas, or a mixed gas thereof, which is pressurized to atmospheric pressure or higher. The cryogenic device according to item 1. 14. The cryogenic apparatus according to claim 9, wherein the refrigerant circulation mechanism is configured by a blower, and each of the blowers is driven by a common drive shaft. 15. A multi-stage refrigerator having a refrigerant storage tank attached to a heat stage of the multi-stage refrigerator, and a check valve and a discharge valve attached to a second refrigerant supply pipe. 11. The cryogenic apparatus according to claim 9 or 10, wherein the third refrigerant is released to the atmosphere via the release valve when stopped. 16. A refrigerant tank installed at an arbitrary location where it can be in thermal contact with the multistage refrigerator, the second refrigerant supply pipe, or the radiation shield cooling pipe, and the third refrigerant supply pipe. A third refrigerant supply pipe, a fourth radiation shield cooling pipe for the fourth refrigerant, and a discharge valve provided side by side are provided, and when the multistage refrigerator is stopped, the fourth refrigerant gas in the refrigerant tank is 16. The air is discharged to the atmosphere via a third refrigerant supply pipe, the fourth radiation shield cooling pipe for the fourth refrigerant, and the discharge valve. Cryogenic device described in. 17. The cryogenic apparatus according to claim 16, wherein the fourth refrigerant is oxygen gas or nitrogen gas pressurized to atmospheric pressure or higher, or dry air. 18. A magnetic material that causes a magnetic transition phenomenon at a temperature of 80 K or more and 100 K or less is placed at any place where it can be thermally contacted with the multistage refrigerator, the second refrigerant supply pipe, or the radiation shield cooling pipe. The cryogenic apparatus according to any one of claims 9 to 17, which is installed. 19. The radiation shield cooling pipe is composed of a plurality of parallel flow passages, and a flow control valve is provided near the outlet of each flow passage. Cryogenic device according to item. 20. The cryogenic apparatus according to claim 19, wherein each of the flow rate control valves changes its opening degree according to a temperature change of the refrigerant flowing inside the flow passage.