JPH0556005B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device using a superconducting magnet, and particularly to a superconducting device suitable for using a refrigerator for cooling a superconducting magnet in a horizontal state.

[Conventional technology]

A conventional device, as described in U.S. Pat. No. 3,894,403, installs a refrigerator vertically and seals a fluid between the first and second stages of the refrigerator and a container containing the refrigerator. The cold heat from the first and second stages of the refrigerator is transferred to the refrigerator container.

[Problem to be solved by the invention]

In the above conventional technology, when the refrigerator and the refrigerator storage container are operated in a horizontal state, the gap between the refrigerator and the refrigerator storage container is large. Creates convection in the horizontal direction. In particular, in a refrigerator having two stages, the refrigerating capacity of the second stage (low temperature side) is impaired by horizontal convection.

An object of the present invention is to sufficiently transmit the refrigerating capacity of a refrigerator to a storage container of the refrigerator.

[Means to solve the problem]

The above object is achieved by inserting a pair of thermally conductive members into the gap formed between the refrigerator and the storage container of the refrigerator.

The superconducting device of the present invention is constructed by filling a gaseous medium into the gap formed by the cooling section of a horizontally mounted refrigerator and a container into which the cooling section of the refrigerator is inserted. It is characterized by the installation of obstacles with low thermal conductivity.

Preferably, the refrigerator has two cold heads, and the obstacle is installed between the two cold heads.

[Effect]

The gap between the horizontal refrigerator and the storage container of the refrigerator is narrowed by embedding an obstacle with low thermal conductivity. As a result, horizontal convection is less likely to occur in the gas medium interposed in the gap between the refrigerator and the storage container of the refrigerator. Therefore, heat can be sufficiently transferred from the refrigerator to the storage container of the refrigerator.

Furthermore, by using a material with low thermal conductivity for the obstruction in the gap between the containers of the refrigerator, the amount of heat conducted from the components is reduced.

〔Example〕

Hereinafter, one embodiment of the present invention will be described using FIGS. 1 to 4.

1 in FIG. 1 is a superconducting coil, and 2 is a cryogen for cooling the superconducting coil 1. The cryogen 2 is 3
It is stored in a cryogen container. In addition, cryogen 2 is
The cryogen gas injected from injection pipe 4 and evaporated is 5
released into the atmosphere from gas pipes. Reference numeral 6 indicates a second shield, and reference numeral 7 indicates a first shield, each of which shields radiant heat. 9 is a vacuum container for vacuum insulating the inside. 10 is a Keihod McMahon cycle compact refrigerator having two cooling sections. 11 is the first stage of the small refrigerator, 12 is the second stage, each with 65W (80K
) Has a refrigeration capacity of 6W (at 20K). 13
is a refrigerator storage container that houses a refrigerator. 14
is a pipe for injecting the gas medium 15 into the gap between the cooling parts 11 and 12 of the refrigerator and the refrigerator storage container.
The gaseous medium is preferably a gas with high thermal conductivity, such as helium. 16 is a valve, and by closing this valve, the gas medium is sealed in the gap between the refrigerator storage container 13 and the cooling section (first stage 11 and second stage 12) of the refrigerator 10. Reference numeral 17 denotes a first connector attached to the refrigerator storage container 13 in the vicinity of the first stage 11 of the refrigerator 10. Similarly, 18 is a second connector attached to the refrigerator storage container 13 at a position near the second stage 12 of the refrigerator 10. Further, the connectors 17 and 18 are thermally connected to the first and second shields 7 and 6. The first and second connectors 17 and 18 are made of a material that conducts heat well, such as copper or aluminum. 21 is an O-ring. 22 is the first
This is an obstacle inserted between the connecting body 23 connecting the stage 11 and the second stage 12 and the refrigerator storage container 13.

FIG. 2 is a sectional view taken along line A-A. 19 in Figure 2
is a bolt for tightening the second connector to improve the thermal connection between the refrigerator storage container 13 and the connector 18. In addition, the same reference numerals as in FIG. 1 indicate the same parts. FIG. 3 is a sectional view taken along line BB in FIG. 1. Numeral 19 is a bolt for tightening the connector 17 to improve the thermal connection between the connector 17 and the refrigerator container 13 in the same manner as shown in FIG. Other symbols in FIG. 2 and the same symbols as in FIG. 1 indicate the same items. Figure 4 is Figure 1C-
FIG.

The operation of the embodiment will be explained below. gaseous medium 15
is the refrigerator storage container 13 and the cooling part of the refrigerator 10 (first and second stages 11, 12, connecting body 23, etc.)
It is enclosed in the gap formed by. Since the outer diameter of the second stage 12 is larger than the diameter of the coupling body 23, the inner diameter of the refrigerator storage container 13 around the coupling body 23 is The size is larger than the outer diameter of the second stage 12. Therefore, the gap between the connecting body 23 and the surrounding refrigerator container 13 becomes large. If no obstruction 22 is inserted, the gaseous medium enclosed in this gap will tend to flow freely. In particular, when the refrigerator 10 is operated, the first stage 11
and the temperatures of the second stage 12 are 20K and 80K, respectively.
Therefore, the gas medium 15 around the connecting body 23 creates a large convection vortex within the gap formed between the refrigerator storage container 13 and the connecting body 23. This convection vortex is
Since heat is exchanged between the first stage and the second stage, the refrigeration capacity transmitted from the second stage to the second connector is reduced. In this patent, an obstacle 22 is inserted into the gap between the refrigerator storage container 13 and the connecting body 23 in order to prevent the convection of the gaseous medium. This obstacle 22 is an object that can fill the gap as much as possible,
Moreover, it is better to use a material with low thermal conductivity. for example,
It is preferable to use materials that are relatively elastic, have limited voids to the extent that convection is suppressed, and have low thermal conductivity, such as felt fibers, glass fiber cloth, or mat.

If the thermal conductivity is high, heat will be transferred from the first stage 11 to the second stage 12 via the obstacle 23, reducing the cooling performance at the second connector. The obstruction 22 prevents convection of the gaseous medium 15,
The refrigeration capacity of the first stage is connected to the first connector,
Since the refrigeration capacity of the second stage can be transmitted to the second connector, both the first and second shields are cooled well, resulting in a superconducting device with a small amount of cryogen evaporation.

Note that the obstacle 22 may also be inserted into a gap formed between the first stage 11 and the flange 24 at room temperature.

Further, even if the refrigerator has only one cooling stage, the spirit of the present invention can be implemented.

〔Effect of the invention〕

According to the present invention, the gas medium in the gap between the cooling part of the refrigerator and the container housing the cooling part of the refrigerator is in a state where convection is difficult to occur because the gap is narrowed due to obstacles, so the refrigerator is It has the same effect of transmitting the cooling capacity of the refrigerator to the object to be cooled as when it is used vertically.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1, and FIG. FIG. 2 is a sectional view taken along line CC in FIG. 1; 10... Refrigerator, 11... First stage, 12
...Second stage, 13...Freezer storage container, 1
5... Gas medium, 17... First connector, 18
...Second connector, 23...Connection body.

Claims (1)

[Claims] 1. In a superconducting device in which a gaseous medium is sealed in a gap formed by a horizontally mounted cooling unit of a refrigerator and a container into which the cooling unit of the refrigerator is inserted, an obstacle with low thermal conductivity is placed in the gap. A superconducting device characterized by being attached.