JPS60169064A - Magnetic refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic refrigeration device capable of improving refrigeration efficiency.

['PJl''Jll technology of the invention and its problems] Conventionally, a magnetic refrigeration system that utilizes the magnetocaloric effect of a magnetic material has been known. This system is designed to remove heat from the air, and has the advantage of having a higher refrigerating capacity per unit unit than a normal gas refrigeration system.

By the way, in the case of magnetic refrigeration equipment, a magnetic material such as gadolinium gallium garnet, that is, a working material, is rapidly placed in a magnetic field to adiabatic magnetize it, and the heat generated in the working material at this time is released to the outside. There are two types of heat exchange: the heat exhaustion process and the endothermic process, in which the working material located within the magnetic field is rapidly introduced outside the magnetic field to adiabatic demagnetization, and the object to be cooled is cooled by the endothermic action of the working material at this time. It is necessary to perform the processes alternately. That is, it is necessary to position the work material within the magnetic field or outside the magnetic field.

For this reason, in conventional devices, the work material is fixed and a magnetic field generator made of a superconducting coil is fixed around the work material, and during adiabatic magnetization, the magnetic field generator t is energized and heat is exhausted. The system is operated, and during adiabatic demagnetization, the energization of the magnetic field generator is stopped and the operation of the heat exhaust system is also stopped, and this control is performed alternately.

With this configuration, the freezing cycle can be executed only by electrical control, making it possible to reduce the overall size, and since the work material is stationary, it is possible to improve the (M-axis) property of the heat exhaust process. There are advantages such as being able to

However, on the other hand, since the magnetic field generator, that is, the superconducting coil, is energized in pulses, there is a problem in that the loss in the superconducting coil is large and the refrigeration efficiency is significantly low.

Therefore, in order to solve this problem, the magnetic field generator is energized, and instead, the work material is mechanically moved to alternately enter and exit the magnetic field generated by the magnetic field generator. It is possible to position it. However, with this configuration, heat must be removed from the moving work, and the question becomes how to configure the casting heat system.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to employ a method of constantly energizing the magnetic field generation length fFi and mechanically moving the work material. It is an object of the present invention to provide a magnetic refrigeration device that can effectively exhaust heat from a working material during adiabatic magnetization, thereby improving refrigeration efficiency.

[Summary of the invention]

The present invention is characterized in that a magnetic field generator is constantly monitored and a workpiece η is mechanically moved alternately into and out of the magnetic field generated by the magnetic field generator, in which the workpiece is inside the magnetic field. a highly thermally conductive member that contacts or is in close proximity to the work material when the work material is located;
The feature is that a means is provided for discharging the heat generated by the work material to the outside of the seedlings where the work material is located via the good heat conductive portion 1.

〔Effect of the invention〕

When removing heat from a moving work material and discharging it, moving the thread for discharging heat together with the work material can avoid complicating the structure. There is no way to avoid heat invading the area.

However, as in the device of the present invention, a highly thermally conductive member is provided that comes into contact with or sufficiently close to the working material only when the working material is located within a magnetic field, and the structure is such that heat is exhausted through this part 1. Therefore, it is not necessary to move the above-mentioned good heat conductive member, that is, the entire heat exhaust system together with the work material. therefore,
Good heat exhaustion can be achieved without complicating the structure. Furthermore, during adiabatic demagnetization, the work material and the highly thermally conductive member can be separated from each other. Therefore, it is possible to prevent heat from entering the work material through the highly thermally conductive member during adiabatic demagnetization. Therefore, the percentage characteristics of the method for moving the working material while suppressing the complexity of the structure and heat penetration,
In other words, the inherent high refrigeration efficiency of this method can be maximized.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example in which the present invention is applied to a magnetic refrigeration device for helium liquefaction.

That is, in the figure, 1 indicates the outer tank, and 2 indicates the outer tank 1.
It shows the inner tank housed inside.

The entire outer wj1 is formed of a member with poor thermal conductivity. Further, only the upper wall 2a of the inner tank zH1 is made of a thick material with good thermal conductivity, and the remaining part is made of a material with poor thermal conductivity. A space 3 existing between the outer tank 1 and the inner tank 2 is evacuated and formed into a vacuum insulation layer.

At two places on the earthen wall 2 & of the inner tank 2, there are cylindrical portions 4m which communicate the upper and lower sides of the earthen wall 2a in the figure.

4b are provided to protrude downward in parallel and with the same dimensions. These cylindrical parts 4a and 4b are thickly formed from the same material as the material constituting the upper wall 2& or a material with better thermal conductivity, and extend a predetermined length from the lower end thereof. 5&.

The inner diameter of the portion 5b is smaller than that of the portion Iff.The upper and lower inner edges of the portions 5m and 5b are each tapered.

Therefore, there is a vacuum N+s1 between the inner tank 2 and the inner tank 2.
A helium tank 6 is accommodated through the % layer. The helium tank 6 is entirely made of a non-magnetic and heat-conductive material, and is specifically constructed as follows. That is,
The tank body 7, a partition wall 8 provided to vertically divide the inside of the tank body 7, and a partition wall 8 provided on the upper wall 9 of the tank body 7 to allow the cylindrical portions (m, 4b) to contact each other in a non-contact manner. Holes 10h and 10b to be inserted and 10m of these holes.

Cylindrical bodies 11* and llb that extend the edges of the cylindrical bodies 10b to the upper surface of the partition Ii8, respectively, and a flange 12* that protrudes in a two-stage configuration in the vertical direction from the outer peripheral surfaces of these cylindrical bodies 11a and llb,
li! b and 13m.

13b. And the cylinder body 111°11
Superconducting coils 14m, 14b constituting the main magnetic field generation length & are installed between the flanges 12 &, 12b and the upper wall 9 on the outer periphery of the cylinders 11a, llb, and the flanges 1
Between 3h and 13b and the partition wall 8, superconducting coils 15m and 15b constituting a magnetic field generating device are installed. Each jl ¥ (conducting coil 14th, l 4b and 15a.

15b uses liquid helium H accumulated at the bottom of the helium tank 6 as a cooling source, and is cooled to a required temperature via a helium fine structure. And superconducting coils 15a, ll
b generates a magnetic field in the opposite direction to the magnetic field generated by the superconducting coils 14a and 14b, thereby causing the superconducting coil 1
4a.

The lower intensity gradient of the magnetic field generated at 14b is made steeper.

Therefore, at a position facing the lower end surface of the cylindrical portion dm of the partition wall 8, 4b, there is a diameter larger than the inner diameter of the portions 5h, 5b.
And the holes 16m and 16b are smaller than the outer diameter of the cylindrical parts 4a and 4b.
is formed.

A cylindrical body 17a formed of a material with poor thermal conductivity is provided at the inner edge of the holes 16* and 16b.

The lower end side of J7b is connected, and these cylinders 17m,
The upper end side of 17b is airtightly connected to the cylindrical portions #m and 4b, respectively. In addition, the cylindrical portion 4a,
At a position facing 4b, holes lem and 18b having the same diameter as the inner diameter of the cylinders 17m and 17b are provided coaxially. The edges of the holes 18m and 18b and the upper edges of the cylindrical parts 4m and 4b are cylindrical bodies J9m and 19 formed of a black material with poor conductivity.
b is airtightly connected.

That is, the hole is 18m, the cylinder body 19a, and the cylinder part 4m.

The cylinder 17h and the hole 16m are coaxially connected to form a cylinder 20m that communicates the outside with the space in which liquid helium H is accommodated.
The aX cylindrical portion 4b, the cylindrical body 17b, and the hole 16b are coaxially connected to form a similar cylinder 20b.

Rods 21m and 21b are inserted into each of the cylinders 20m and 20b from the outside so as to be movable up and down.

The rods 21 and 21b are members with poor thermal conductivity, and are the aforementioned cylindrical portions 4a.

The portion 5m in 4b is formed into a cylindrical shape with an outer diameter several hundred μ smaller than the inner diameter of 5b. At the lower end of each rod 21m, 21b, working materials 22a, 2 are formed by processing a magnetic material such as gadolinium gallium garnet into a columnar shape with an outer diameter equal to the outer diameter of the rods 21m, 21b.
2b is inserted in series.

Support members 23g, 23b are attached to the ends of the rods 21m, 21b located outside wjl, and racks 241L, 24b are fixed to the tips of these support members 23g, 23b in a relationship facing each other. . At a central position between the rack 24m and the rank 24b, a shaft 25 extending in a direction perpendicular to the plane of the paper is rotatably supported by a bearing (not shown). Rack 24&
and the rack 24b.
A pinion 26 that commonly meshes with 4 & 24b is fixed. In addition, the binion 26 and each rack 24a, 24b
They have a close relationship with each other. That is, the working material 22 inserted into the lower end portions of the rods 21m and 21b.
The top dead center is when a and 22b are located exactly within the portion 5a (5b) of the front 4m (4b) like the work material 22* in Figure A1, and the partition is defined as the work material 22b. wall 8
and the liquid level of liquid helium H is considered bottom dead center, and when either working material is located at top dead center, the other working material is located at bottom dead center. They fit together to form a structure. Another pinion (not shown) is fixed to the outer periphery of the shaft 25, and this pinion meshes with a rack (not shown). The rack is connected to a reciprocating drive source (not shown).

Thus, a thick wall portion 31 is formed at the peripheral edge of the upper wall 2a of the sandalwood 2, and a cylindrical recess 32 with an opening facing laterally is formed in the thick wall portion 31. . A hole 33 having a larger diameter than the recess 32 is formed in the side wall of the outer tank 1 at a position where the recess 32 is carved, and a flange 34 projecting outward is airtightly connected to the peripheral edge of the hole 33. ing. One side of a heat transfer rod 35 made of a material with good thermal conductivity is fitted into the recess 32 through the flange 34 . A flange portion 36 is provided on the outer periphery of the heat transfer rod 35, and this flange portion 36 is fastened and fixed to the flange 34 via a sealing material. The other end of the heat transfer rod 35 is thermally connected to a cooler 37 such as a small refrigerator. In addition, 38m and 38b in FIG. 1 indicate sealing members.

Next, the operation of the magnetic refrigeration system configured as described above will be explained.

First, superconducting coils 14a, 14b and 15h, 15
It is assumed that a persistent current that can generate the magnetic field in the relationship described above is flowing through b. Further, it is assumed that the cooler 37 is in an operating state.

When the cooler 37 operates, heat is removed from the earth wall 2a via the heat transfer rod 35. Therefore, the cylindrical portions 4m and 4b are also kept at a sufficiently low temperature.

When the reciprocating drive source is operated in this state, the pinion 26 reciprocates and rotates as shown by the actual arrow P in FIG. As a result, the rods 21a and 21b move up and down as shown by solid line arrows Q+ and Q* in Figure i1. In other words, the rods 21a and 21b move upward and downward in such a manner that when the rod 21a begins to descend at G11, the rod 21b begins to rise. For this reason, the working materials 22*, 22b move 18 times between the top dead center and the bottom dead center.
It will move up and down with a phase difference of 0 degrees. When located at the top dead center, the working material 22m in FIG. 1 is completely located within the magnetic field generated by the superconducting coil. Therefore, an adiabatic magnetization state is established. On the other hand, when K is located at the bottom dead center, it is located outside the magnetic field, as seen in the work material 22b in FIG. Therefore, FBr
It becomes thermally demagnetized. In the adiabatic demagnetization state, the working material 22b
(22m) absorbs heat.

Helium gas floating on the sump liquid surface condenses on the surface of the work material 22b (22a).

The droplets formed by this condensation fall naturally and liquefy the helium.

Therefore, when the workpiece 'j (Z J a (x z b )) becomes in the adiabatic magnetized state as described above, it generates heat. This heat is led to the outside as follows. That is, the workpiece 'j (Z J a (x z b )) Power: Located at Kamiyumi point.

173
I am doing ahti. The inner diameter of the portions 5a and 5b is 22 m, ? , l slightly larger than the outer diameter of b by 1
It is set to about. For this reason, the working material 22a.

When 22b is located within the portion 5&, Sb, the circular surface of the portion 5a (5b) and the work material 22m (22b) are in direct contact, as shown by the double dotted line in Fig. 2. The gap between the two...The condition t (which is always formed) makes the workpiece 5 very small.
The heat generated in 122a and 22b is transferred to the cylindrical portion 4a,
4b, and the heat is quickly exhausted to the outside via the upper wall 2a. Therefore, the working substance,? ,? a, 2
．． ? The helium bath 6 does not become unstable (temperature-wise) due to the heating in step b, and a good cold face is achieved here.

In this way, the working material 22m-, 22b force xuan-sho + AI!
These fi: karma substances 22 only when they are in a magnetized state.
A conductive member 122b is provided with a conductive member ladle sufficiently close to contact with the conductive member 122b, and heat is discharged to the outside via this thermally conductive member. Therefore, unlike a system in which the exhaust heat system is moved together with the working materials, the overall structure can be simplified.

Furthermore, during adiabatic demagnetization, a long adiabatic distance can be ensured between the thermally conductive member and the work material. Therefore, during adiabatic demagnetization, there is no heat intrusion through the thermally conductive member, and the above-mentioned effects can be obtained after all.

Note that, as in the embodiment, the portions 5*, 5 of the cylindrical portions 4a, 4b
By setting the inner diameter of b to be slightly larger than the outer diameter of rods 21m and 21b, the rod in portion /i a t 5b;
It is also possible to perform the function of a guide body for guiding the jl&, 21b. With the configuration of the embodiment, the rod 21 &.

Since 21b is longer, this rod 21a.

Some kind of guide body is required to move 21b up and down smoothly. Part 5 & as in the example.

If the inner diameter of 5b is set to the above relationship, parts 5h, 5
Since the part b can also function as a guide body, the number of parts can be reduced accordingly. Further, when the rods 21m and 21b move up and down inside the portions 5a and Sb, heat is generated due to sliding friction, but since the portions 51L and 5b are cooled, the influence of heat generation can be avoided.

However, if a main magnetic field generator and an auxiliary magnetic field generator are provided as in the embodiment, and the auxiliary magnetic field generator is used to steepen the intensity gradient at the edges of the magnetic field, it is possible to increase the amount of energy necessary for the work material to exit the magnetic field. The travel stroke can be made smaller. Therefore, it can contribute to miniaturization of the entire device. In addition, as in the embodiment, two working materials can be moved using one driving source l/'1 and #l
(If you use a method of raising and lowering the workpiece, when one workpiece tries to leave the magnetic field, the other workpiece approaches the magnetic field. As a result, the magnetic attraction generated between the magnetic field and the work material can be reduced. Furthermore, the present invention is not limited to those that employ the elevating method as in the above-mentioned embodiments, but can also be applied to those that employ the rotating method.

FIG. 3 schematically shows only the main parts of an example in which the present invention is applied to a rotating type helium liquefaction magnetic refrigeration system, and FIG. 4 shows a cross section of the main parts. That is, in these figures, 41 is a helium tank that stores liquid helium H therein. A slit-shaped hole 42 is provided in the upper wall 411L of the helium tank 41, and a rotary ring 43 is disposed through this hole 42 such that a portion thereof is always located inside the helium tank 41. The rotating ring 43 is fixed to the outer periphery of a horizontally arranged shaft 44. The shaft 44 has a bearing 45
It is rotatably supported by etc. And the shaft 44
One end side is connected to a rotational drive source (not shown) via an intermediate shaft 46.

The rotating ring 43 is formed of a portion 1 that is non-magnetic and has poor thermal conductivity. A hole 47 parallel to the axis line is provided at the peripheral edge.
A plurality of cylindrical working materials 48 are formed in the holes 47 in a circumferential direction, and the working material 48 formed in the cylindrical shape in these holes 47 is in such a relationship that only its both end surfaces are exposed, and both end surfaces are flush with the end surface of the rotating ring 43. It is installed.

A cover member 49 made of a material with good thermal conductivity is disposed around the portion of the rotating ring 43 located outside the helium tank 41 so as to cover the portion. Holes 50m and 50b, which are periodically coaxial with the work material 48, are formed at positions of the cover member 49 facing both end surfaces of the work material 48 described above. Inside the holes 50m and 50b are pressure welding parts 1 made of a good heat conductive material and periodically in contact with the end surface of the work material 48.
51&, 51b are accommodated. The outer openings of the holes 50a and 50b are closed by closing plates 52a and 52b, and between these closing plates 52h and 52b and the corresponding pressing members 51a and 51b, there are pressing members ' 51 m.

Spring 53g for pressing 51b against the side surface of rotation k143 and the end surface of work material 48.

53b is installed respectively. And handling parts 49
is thermally connected to a small refrigerator 54. Furthermore, a superconducting coil 55 is disposed around the core member 49 to place the working material 48 located outside the helium tank 4 within the magnetic field.

Note that 56 in the figure indicates a heat insulating tank.

With this configuration, as the rotary wheel 430 rotates, each work material 48 is placed inside the magnetic field when it is located outside the helium tank 4, and outside the magnetic field when it is located inside the helium TFL 4J. Located in Therefore, when each work material 48 is located in the helium tank 41, it is in an adiabatic demagnetized state. Therefore, the helium gas floating in the helium tank 41 condenses on the end surface of the work material 48, and this K
Therefore, helium will be liquefied. on the other hand,
When each working substance 48 is located outside the helium tank 1 and 4, it is in an adiabatic magnetized state. Therefore, each work material 48 generates heat. However, when each work material 48 rotates, the pressure contact members 51h and 51b always come into contact with the end surfaces thereof. The pressing members 51h and 51b are core members 4 made of a material with good thermal conductivity.
Since the cover member 49 is cooled by the refrigerator 54, the pressure contact member 51
The heat of the work material 48 is immediately dissipated upon contact with the material 48. Therefore, the same effects as in the embodiment described above can be obtained.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of a magnetic refrigeration device according to an embodiment of the present invention, Fig. 2 is a sectional view showing only the main parts of the magnetic refrigeration device, and Fig. 11ca is a longitudinal sectional view of a magnetic refrigeration device according to another embodiment of the present invention. FIG. 4 is a schematic perspective view showing a main part of the magnetic refrigeration device in a cutaway manner, and FIG. 4 is a longitudinal cross-sectional view of the main part. 1... Outer tank, 2... Inner tank, 6.41... Helium tank, 4*, 4b... Cylindrical part formed of good heat conductive material, 1
4*, 14b, 15a, 15b"・Chocolate cobble for magnetic field generation electrical production, 20m, 20b...Cylinder, 21
m, 21b-・orad, 22m. 2 J b--Working substance, 24a, 24b... Rack, 26... Binion, 43... Rotating wheel.

Claims (1)

[Claims] (1) A magnetic field generator that constantly generates a magnetic field, and a drive means that mechanically moves the work material alternately into and out of the magnetic field when located within the magnetic field generated by the magnetic field generator. a highly thermally conductive member that contacts or is in close proximity to the working material when the working material is located within the magnetic field; 1. A magnetic refrigeration device characterized by comprising means for discharging heat to the outside between walls in which it is located. Q) The magnetic refrigeration apparatus according to claim 1, wherein the good heat conductive member also serves as a guide member for guiding the movement of the working material. 0) The magnetic refrigeration device according to claim 1, wherein the magnetic field generator includes an auxiliary magnetic field generator that steepens the intensity gradient at the end of the magnetic field. 0) At least one pair of elements consisting of the magnetic field generating device, the working substance, and the well-thermal conductive member is provided, and the working substance of each pair is within the magnetic field generated by each magnetic field generating device by one driving means. 2. The magnetic refrigeration device according to claim 1, wherein the magnetic refrigeration device is exclusively controlled to move outside the magnetic field.