JPH0530135U - Regenerator material for regenerator - Google Patents

Abstract

(57) [Abstract] [Purpose] When using a rare earth compound magnetic material as a regenerator material, it is possible to avoid contamination in the refrigerator, improve refrigerating capacity, and improve the quality variation. To provide. [Structure] The magnetic substance 12 is coated into a wire to form a mesh or a coil, and the powder is filled in the regenerator. The powdery rare earth compound magnetic substance 12 is coated with the coating material 11. At the same time, the whole is made into a wire rod.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a regenerator material for a regenerator, and more particularly to a regenerator material for a regenerator that can improve the performance of the regenerator used in various regenerator type refrigeration systems.

[0002]

[Prior Art]

 At present, the technology of generating a low temperature of 80K or less is indispensable in both the fields of science and technology. However, liquefied gases such as liquid helium and liquid nitrogen used to generate such low temperatures tend to have large storage facilities and the liquefied gas itself is expensive.

In this respect, refrigerators to which various refrigeration cycles are applied, in particular, cold storage refrigerators are small in size and can easily obtain a low temperature of 80 K or less.

The operating principle of the cold storage refrigerator is basically the same in any refrigeration cycle, and a schematic structure of this refrigerator will be described with reference to FIG.

As shown in FIG. 10, the refrigerator 1 includes a helium gas compressor 2, a regenerator 3, and an expander 4.

The refrigerator 1 is a closed system, and the helium gas compressed by the compressor 2 is passed through the regenerator 3 and then expanded in the expander 4 to generate freezing.

Refrigeration is generated when the helium gas that reciprocates between the compressor 2 and the expander 4 expands. Therefore, if this helium gas is returned to the compressor 2 as it is, the generated refrigeration will also be compressed. It will be returned to 2.

Therefore, heat is exchanged with the helium gas in the regenerator 3 interposed between the compressor 2 and the expander 4, so to speak, refrigeration is stored in the regenerator 3.

By doing so, the helium gas fed next is first cooled by exchanging heat with the regenerator 3, and then further expanded in the expander 4 to be further cooled.

A regenerator material 5 is housed in the regenerator 3 in order to store such refrigeration.

The regenerator 3 preferably has a large heat capacity in terms of storing heat. However, since the volume of the regenerator 3 occupies the entire refrigerator 1 is limited, it is desirable that the regenerator material 5 constituting the regenerator 3 has a large specific heat.

The conventional regenerator 3 is made of a stainless steel or resin cylinder filled with a mesh of copper, brass or the like as the regenerator material 5, or a lead ball.

However, in recent years, a rare earth compound magnetic material (hereinafter referred to as “magnetic material”) having a relatively high specific heat at a low temperature has been developed as a cold storage material.

[0014] The _{magnetic, DyNi 2, ErCo 2, Er} (Ni 0.58 Co 0.42) 2, E r (Ni 0.85 Co 0.15) 2, ErNi 2, Er 3 Ni, Er 0.5 Dy 0.5 Ni 2, Gd Rh , Gd _0.5 Er _0.5 Rh, ErRh, etc., all of which cause a magnetic phase transition in a temperature range of about 10 K, and as a result, they have a large specific heat as compared with lead which is a conventional regenerator material. is doing.

By the way, at present, the use of spherical or sand-like magnetic material as a regenerator material for the Gifode-McMahon refrigerator is reported at academic societies and the like, and it is possible to generate a superfluid helium of 2.09K. ing.

However, the use of the regenerator material made of a magnetic material has the following problems. That is, both the spherical particles and the sandy particles of the magnetic material have an angle of several μm to several tens μm on the surface.

When the refrigerator 1 is filled with the regenerator material 5 having the corners and the refrigerator 1 is operated, the corners are broken and become fine powder, which contaminates the inside of the refrigerator 1.

As a result, in the expander 4 part, it causes abnormal friction of the seal between the displacer inside and the cylinder.

Further, it also enters the compressor 2 and causes damage to the compressor 2. Finally, there is a problem that the life of the refrigerator 1 itself is shortened.

If a large number of particles are packed in order to increase the heat capacity of the regenerator 3, pressure resistance against helium gas is generated and pressure loss becomes a problem.

Alternatively, if particles having a small particle size are packed in order to increase the heat transfer surface area, pressure resistance is similarly generated, which causes a problem of pressure loss and, on the contrary, a problem that the refrigerating capacity is deteriorated.

Further, the time during which the surface of the magnetic material is exposed to air from the production of the magnetic material to the completion of the refrigerator 1 cannot be neglected, and as a result, the magnetic material is oxidized and transformed by contact with air. However, there is also a problem that the thermal conductivity is lowered, and further the heat exchange rate is lowered.

Furthermore, it is difficult to pack the magnetic materials in the same way, and there is a problem that the minimum attainable temperature of the assembled refrigerator / freezer 1 and the amount of generated refrigeration are large and the quality is not stable. ..

In short, the regenerator material, which is a key point in the next-generation refrigerator, is now ideally spherical particles from the viewpoints of pulverization, pressure loss, and filling method, and development by each manufacturer is proceeding. However, the poor yield of the regenerator material and the high cost in the production of spherical particles are a bottleneck.

[0025]

[Problems to be solved by the device]

 The present invention has been made in consideration of the above problems, and solves the problems described above, avoids contamination in the refrigerator, improves the refrigerating capacity, and disperses the quality. It is an object of the present invention to provide a regenerator material for a regenerator that can improve the above.

[0026]

[Means for Solving the Problems]

 That is, the present invention focuses on filling the inside of the regenerator with a mesh or coil by coating a magnetic material into a wire, and coating the powdery rare earth compound magnetic material with the coating material. In addition, it is a regenerator material for a regenerator characterized by being made into a wire rod as a whole.

[0027]

[Action]

 In the regenerator material for a regenerator according to the present invention, a rare earth compound magnetic material having a relatively large specific heat at low temperature is adopted as a material for the regenerator material, and the magnetic material is covered with a covering material and formed into a wire to form a mesh or a coil. Since it can be processed into any shape such as a shape and can be filled in the regenerator after that, it is not necessary to fill the magnetic material in the form of fine powder, which stabilizes the quality of the regenerator and prolongs its service life. It can be planned.

[0028]

【Example】

 A regenerator material 10 for a regenerator according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 9. However, the same parts as those in FIG. 10 are designated by the same reference numerals, and the detailed description thereof will be omitted.

FIG. 1 is a cross-sectional view of a regenerator material 10 for a regenerator. The regenerator material 10 for a regenerator is composed of a covering material 11 and a magnetic body 12, and is made into a wire rod as a whole. ..

The covering material 11 is preferably made of a material having good thermal conductivity and excellent spreadability. For example, pure metal such as copper or lead is used as the sheath material.

The magnetic body 12 is generally in the form of powder, and any one is selected from the rare earth compound magnetic bodies.

As shown in FIG. 2, a regenerator material 20 for a regenerator having an elliptical cross section other than a circular cross section can be used.

By doing so, it is possible to prevent the deterioration of the magnetic body 12 due to oxidation and the like, and to prevent the inside of the refrigerator 1 from being contaminated due to the fine corners of the magnetic body 12 and to prolong the life of the regenerator 3. ..

Further, powder is not handled at the time of assembling the regenerator 3, and it is not necessary to newly prepare the powder in a special place even in the working environment, and the conventional method may be used.

The regenerator material 10 for regenerator or the regenerator material 20 for regenerator thus formed is used to form a mesh-shaped regenerator material 21 or a coil-shaped regenerator material 22 as shown in FIGS. 3 and 4.

FIG. 5 is a cross-sectional perspective view taken along line VV of FIG. As shown in the figure, if the regenerator material 20 for the regenerator having an elliptical cross section is used, the projected cross-sectional area can be reduced to reduce the air resistance and improve the passage of helium gas.

In the case of the mesh-shaped cold storage material 21, the ease of manufacture can be taken into consideration, and in the case of the coil-shaped cold storage material 22, pressure loss can be taken into consideration.

The mesh-shaped material has been used as the regenerator material 5 in the past, and the way of handling and packing has been established, and it is expected that the performance of the refrigerator 1 is unlikely to vary from individual to individual.

As shown in FIG. 6, a regenerator 24 is formed by stacking a mesh-shaped regenerator material 21 or a coil-shaped regenerator material 22 and packing them in a cylinder 23 of stainless steel or resin.

In such a regenerator 24, the disc-shaped mesh-shaped regenerator material 21 and the coil-shaped regenerator material 22 are stacked, so that the heat conduction from the high temperature side to the low temperature side is poor and the heat is difficult to be transmitted to the low temperature side. ..

Further, since the mesh-shaped cool storage material 21 and the coil-shaped cool storage material 22 are aligned in the same direction and stacked, the cool storage material 24 is uniformly packed over the whole of the cool storage material 24, and the cool storage material 24 of the cool storage material 24 is packed rather than packed with grains. The pressure difference between the entrance and the exit is unlikely to occur.

The amount of the cold storage material to be packed can be freely changed depending on the mesh roughness of the mesh-shaped cold storage material 21 and the coil-shaped cold storage material 22 depending on the number of windings.

When manufacturing the cold accumulating materials 10 and 20 for the regenerator, as shown in FIG. 7, the covering material 11 and the magnetic material 12 are passed between the guide rolls 25 and 26 to form a wire rod. Can take action.

Therefore, even if the magnetic body 12 itself is fragile and it is difficult to make it into a wire, it is possible to form a wire having a predetermined diameter and length while covering the magnetic body 12 by processing it together with the covering material 11.

When such a wire rod is cut at a predetermined position, as shown in FIG. 8, the cut surface of the covering material 11 bends, and only a slight gap 27 remains, so that the inner magnetic body 12 is exposed to the outside. Never spill.

Moreover, since there is a slight gap 27, it is possible to bleed air from the inside of the covering material 11 when the inside of the refrigerator 1 is evacuated when the refrigerator 1 is started, which is convenient in actual use.

The regenerator 24 stores refrigeration so that refrigeration generated in the expander 4 does not escape to the compressor 2 side, but the heat capacity is improved as compared with the conventional regenerator 3 using copper or lead. In addition, helium gas is easier to pass than that using magnetic particles.

Therefore, the ability to store refrigeration is improved as compared with the existing one, and as a result, the ability of the refrigerator 1 itself is expected to be improved.

Next, the heat capacity of the regenerator material was calculated. As a sample, a mesh as shown in FIG. 9 was constructed. That is, the wire diameter was 1 mm, the magnetic material part diameter was 0.5 mm, the wire interval was 2 mm, and the mesh thickness was 2 mm.

As a comparative sample regenerator material, lead particles were taken, the diameter was 0.2 mm, and the specific heat was C (J / cm ³ · K).

Er ₃ Ni is taken as the magnetic material of the regenerator material of the present invention, and its specific heat is 2C at around 10K. Lead was selected as the coating material.

In the case of conventional lead particles, the porosity when packed randomly is 0.38, so the total heat capacity is (1-0.38) CV = 0.62CV (J / K).

[0053] In cold storage dexterity regenerator material of the sample according to the present invention is, because the mesh 1 cm ³ per thickness 0.2 cm, volume per mesh 1 cm ³ becomes 0.2 cm ^3.

The volume of the magnetic material portion is π (0.05 / 2) ² × 1 × 25 = 0.0491 cm ³ .

The volume of the covering material portion is π (0.1 / 2) ² × 1 × 25-π (0.05 / 2) ² × 1 × 25 = 0.147 cm ³ .

When this is packed in the volume V, the magnetic material heat capacity is 0.0491 cm ³ ÷ (V / 0.2) × 2C = 0.491 CV (J / K), and the heat capacity of the coating material 11 is 0. 147 cm ³ ÷ (V / 0.2) × C = 0.735 CV (J / K) Since the total heat capacity of the mesh-shaped regenerator material is 1.226 CV (J / K), This is about twice that of conventional lead particles (0.62 CV (J / K)).

The regenerator material according to the present invention is applicable to regenerators such as the Gifode McMahon refrigerator, the Stirling refrigerator, the Solvay refrigerator, the pulse tube refrigerator in the experimental stage, which are currently in practical use. ..

Up to now, the refrigerator has been mainly used on the ground, but in the future, low temperature will be required even in outer space. Since the regenerator material according to the present invention leads to a high-performance and long-life refrigerator, it is considered that it can be applied to space science and space development in terms of low temperature generation in outer space.

[0059]

[Effect of the device]

 As described above, according to the present invention, when the magnetic material is made into a sheath wire, it does not become pulverized, so that stable refrigerator quality can be guaranteed, and a regenerator material using a magnetic material is practically used. Since it is possible, it is possible to reach a lower temperature range than before, it is possible to obtain a larger amount of refrigeration than before, and it is possible to obtain a refrigerator with high performance and long life.

[0060]

[Brief description of drawings]

FIG. 1 is a sectional view of a regenerator material 10 for a regenerator according to an embodiment of the present invention.

FIG. 2 is a sectional view of a regenerator material 20 for a regenerator according to another example of the present invention.

FIG. 3 is a plan view of a mesh-shaped regenerator material 21 manufactured by using the regenerator material 10 or 20 for the regenerator.

FIG. 4 is a plan view of a coil-shaped regenerator material 22 manufactured by using the regenerator material 10 or 20 for the regenerator.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a perspective view of the regenerator 24 of the same.

FIG. 7 is a schematic diagram of a manufacturing process of the regenerator material for a regenerator 10,20.

FIG. 8 is a cross-sectional view of a cut surface of the regenerator material for a regenerator 10, 20.

FIG. 9 is an enlarged perspective view of a mesh-shaped cool storage material 21.

FIG. 10 is a schematic configuration diagram of a general refrigerator 1.

[Explanation of symbols]

 1 Refrigerator 2 Compressor 3 Regenerator 4 Expander 5 Regenerator material 10 Regenerator material for regenerator 11 Coating material 12 Magnetic material (rare earth compound magnetic material) 20 Regenerator material for regenerator 21 Mesh-shaped regenerator material 22 Coil-shaped regenerator material 23 Stainless steel or resin cylinder 24 Regenerator 25 Guide roll 26 Guide roll 27 Slight gap

Claims (3)

[Scope of utility model registration request] 1. A regenerator material for a regenerator characterized in that a powdery rare earth compound magnetic material is coated with a coating material and the whole is made into a wire rod. 2. The regenerator material for a regenerator according to claim 1, wherein the regenerator material has a mesh shape. 3. The regenerator material for a regenerator according to claim 1, wherein the regenerator material has a coil shape.