JPS59157452A - Cold storage instrument of cryogenic 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 (Object of the Invention and Field of Application of the Invention) The present invention relates to a regenerator used in ultra-low-quality refrigerators such as Sterling or Gifford-McMahon.

(Prior Art) A regenerator used in a Stirling or Gifford-McMahon cryogenic refrigerator receives heat from the refrigerant when the relatively high pressure refrigerant leaves in the initial direction, and stores the heat in a short period of time. However, heat is imparted to the refrigerant as the refrigerant flows in the opposite direction at a relatively low pressure.

Now, explanation will be given by taking the Stirling refrigerator shown in FIG. 1 as an example. It is compressed by the refrigerant full compression piston 1 in the compression cylinder 12' and at the same time removes heat by the high humidity flange 3 which is thermally connected to the hot bath. Cool storage device 4
When the relatively high pressure refrigerant passes through the system, it receives heat from the refrigeration system and stores it inside. The sous refrigerant entering the expansion cylinder 6 is expanded by the expansion cylinder 7,
At the same time, heat is absorbed by the low temperature 7 lunge 5 which is thermally coupled to the low temperature chamber. The regenerator 4 provides heat to the refrigerant when the refrigerant, which has reached a relatively low pressure, passes in the opposite direction. Figure 2 shows the ideal cycle of a Stirling refrigerator on the temperature-entropy diagram. In the process from point 8 to point 9 above, when the expansion piston 7 is at the uppermost position, the compression piston 1 moves downward, completely compressing the refrigerant. Hot forging Q1%7 flattened flange 3 that occurs at that time? It is then discharged to a high-temperature bath at a temperature of T. Next, point 9 on the cycle
In the process from point 10 to point 10, the compression piston 1 and the expansion piston 7 move downward simultaneously, and the refrigerant passes through the regenerator 4 and moves from the compression cylinder 2 to the expansion cylinder 6. When the refrigerator reaches a steady state, the humidity at the upper and lower ends of the regenerator Φ is T1+T2, respectively. , Therefore, the temperature of the refrigerant drops to 1, and the regenerator 4 receives the amount of heat Qn from the refrigerant. In the process from point 10 to point 1 on the cycle, the compression piston 1 is at the lowest position, the expansion piston 7 moves to the lowest position fff, and the refrigerant expands. At that time, the temperature '1 is passed through the low temperature 7 lunge 5.
It absorbs Q2 amount of heat from the cryostat '2. Finally, in the process from points 1 to 12 on the cycle, the expansion piston 7 and the compression piston 1 simultaneously move upward, passing through the regenerator 4 and moving from the expansion cylinder 6 to the compression cylinder. . At this time, the temperature of the refrigerant increases from 1° to Tl, and the regenerator Φ gives the refrigerant an amount of heat Qb% - 0. The heat tQa exchanged with the refrigerant by the regenerator 4 is
Qb corresponds to the enthalpy change of the refrigerant when the temperature of the refrigerant decreases from T2 to T2, and Qb corresponds to the enthalpy change of the refrigerant when the temperature of the refrigerant increases from T2 to T1. When the regenerator 4 and the refrigerant exchange heat, the heat capacity 12 of the regenerator is the temperature Tl at the upper and lower ends,
It must be large enough so that T2 changes little. Moreover, since the heat exchange between the regenerator 4 and the refrigerant is repeated in short cycles, the heat diffusion in the lateral direction of the regenerator 4 needs to be sufficiently large. Further, in the vertical direction of the regenerator 4, there is a steady temperature distribution in which the upper end is at a temperature T1 and the lower end is at a temperature T2. In order to suppress heat intrusion from the top end to the bottom end, the thermal resistance in the vertical direction must be sufficiently large. In the case of an ultra-low temperature refrigerator with an endothermic flow rate T2 of 20 or less using helium in cold rolling and 17, lead is usually used as the main heat quantity H (body (hereinafter referred to as a regenerator)) of the regenerator. Yes.8th floor
The total heat capacity per unit volume of lead 102 at low temperatures below 4 and 20 is shown. As the heat capacity decreases rapidly as the temperature decreases, at temperatures below IOK, there are almost no cases in which the specified temperature is not reached, let alone the output. A similar phenomenon is observed in solid materials other than lead-based materials. Figure 8 shows pressure 1.0at.
r+f7) 100 helium and 1 helium at a pressure of 1 atm
All heat capacities per unit volume of 01 are also listed. Helium exhibits high IIl\ at temperatures below lOK, and elements such as hydrogen and nitrogen also exhibit similar characteristics. For this reason, attempts have been made to use heritsum as a regenerator.

Regarding conventional regenerators using helium,
This will be explained with reference to FIGS. 4 and 5. The connecting pipe 21 connects the regenerator and the expansion cylinder or the compression cylinder, and serves as a flow path through which the refrigerant passes. 7 The outer wall of the regenerator is formed by the flange 22 and the outer tubes 2 and 3. The porous heat conductive plates 24° and the heat insulating plates 25 are alternately laminated, and are connected to the inner fill of the inner circumferential heat insulating plate 258 by the shaded line 1 and the coolant flow path through the pores 26b of the porous heat conductive plates. . , the regenerator is supplied by following the supply pipe 27 L7, and the heat diffusion in the lateral direction of the regenerator is caused by the porous heat conduction plate 24.
The thermal resistance in the vertical direction is determined by the thermal insulation plate 25.
Secured by 7L.

In the conventional regenerators shown in FIGS. 4 and 5, aluminum is used as the material for the porous heat conduction plate 24, and FRP covered with resin such as porcelain is used as the material for the heat insulating plate 25. 150℃ in air during bonding
Due to the high temperature of 0.degree. C., it was not possible to use a material with higher thermal conductivity as the material for the porous heat conductive plate 241 due to the problem of deterioration of adhesiveness due to surface oxidation.

In addition, it is generally difficult to obtain airtightness for gases with small mass numbers such as helium and hydrogen, and in the structures shown in Figures 4 and 5, there are usually 500 to 1000 adhesive points.
It is extremely important to achieve airtightness in all areas. Moreover, even if airtightness is obtained initially, the airtightness may often be lost during use because it is subjected to heat cycles from room temperature to 4. Therefore, the boundary wall between the refrigerant and the regenerator, which is formed by the inner heat insulating plate 25fi and the porous heat transfer plate 24-, communicates with each other without losing airtightness, and the pressure of the regenerator can be set to a high level relative to the refrigerant. Not only is it impossible to increase the heat capacity per unit volume of the regenerator, but the storage container of the regenerator becomes a dead space.
The specified compression ratio could not be ensured, resulting in frequent unusable conditions.

Furthermore, since the porous heat conductive plate 2 has no protrusions such as fins, the heat transfer area is small, and heat transfer with the cold body II or the regenerator is not sufficient.

(Technical Problem) Therefore, the present invention aims to easily achieve reliable airtightness at the boundary between the refrigerant and the regenerator, and also to provide the present invention G, j.
The present invention also aims to increase the heat transfer area of the refrigerant or regenerator, and furthermore, the present invention aims to use a material such as copper, which has higher thermal conductivity than aluminum, for the heat conductive member between the refrigerant and the regenerator. ;21! This is the subject.

(Technical measures) The technical measures taken to solve the above technical issues are:
To explain this, refer to Figure 4, δ, and 5th Mf, jFf.
The inner 1731 penetrates vertically and is connected to an expansion cylinder or a compression cylinder, through which the refrigerant passes.
AF becomes the road. The outer tube 34 and the seven flange 35 form the outer wall of the regenerator. An inner mesh 83n1 is laminated on the inside of the inner pipe 81, and an outer mesh 33b is laminated on the outside of the inner pipe 81.
1 and the mensch 33 are joined. Inner mesh 88fl
is fixed by a stopper 82. The regenerator is supplied through the supply pipe 864, but it can be sealed off by sealing it off at high pressure at room temperature, or it can be sealed off by pouring liquefied gas into it to shorten the pre-cooling time, or the temperature can be lowered from an external 5-part tank. Various methods can be considered, such as ways to control the pressure depending on the situation (effects of technical means).The effects of the above technical means are as follows. In other words, in the regenerator having such a configuration, since the inner tube 81 penetrates vertically 7, it is inevitable that heat will infiltrate from the high-temperature part at the upper end to the low-temperature part at the lower end. For this reason, the inner pipe 8
It is important to achieve the desired material quality. FIG. 8 shows the thermal conductivity of each glazed metal barb at a low temperature of 20 K or less, which is 7.

If the inner tube 81 is made of a material with low thermal conductivity such as 5US304 end and 200°, the heat intrusion Gj from the upper end to the lower end can be completely suppressed, but there is a large resistance to lateral heat diffusion. becomes. In general, if a material with high thermal conductivity such as tough pitch copper (C1100) 201 is used for the inner tube 3], will the lateral heat diffusion be very good? Too loud. In the present invention, a phase material having an intermediate thermal conductivity, such as phosphor If deoxidized copper (C1220) 202 and industrially pure titanium (H4600) 203 are used for the inner tube 31, the structure is long and thin in the vertical direction, and the lateral heat diffusion is sufficiently good. It has been found that heat intrusion into the lower end can also be sufficiently suppressed.

Next, in order to improve the lateral heat diffusion' (l-, the mesh 88 is made of tough pitch tin @ (Cl, ], OO) 20
Since the materials are stacked vertically, heat may enter from the top to the bottom. When the meshes 33 are laminated, the contact area is very small, and therefore the amount of heat penetration is also small, so there is no problem in normal situations.

However, if the mesh 33 is made of a material with very high thermal conductivity, such as high-purity enzyme-free material, or if the output of the refrigerator is very small, this heat infiltration also becomes a problem. In the present invention, between the meshes 83 of high thermal conductivity material, there are meshes of low thermal conductivity material of 200 mm, such as 5 us 304, with appropriate intervals between them. It has been found that by inserting it, it is possible to sufficiently suppress heat intrusion through the stacked mensch 88 in the vertical direction.

For reference, industrial pure aluminum <Anoo-.

) 204 temperature (thermal conductivity to Kl (2) A・K)
is shown in Figure 8.

Furthermore, in the structures of FIGS. 6 and 7, the inner tube 3 is generally
It is very difficult to join 1 and mesh 88 [7. In the present invention, a vacuum furnace (J!" 1 (J' Torr)
Inner tube; 31 and mesh 38 at high g, (embryo 1800
The bonding method using the atomic diffusion phenomenon, so-called diffusion bonding, was used to achieve bonding between the two.

In the embodiments shown in FIGS. 6 and 7, in which the materials of the inner tube 81 and the mesh 88 are selected and the two are joined as described above, the inner tube 4': 31 penetrates vertically, and the refrigerant flow path Since the storage parts of the cooler and cooler are completely separated, airtightness between the two can be easily achieved, and the airtightness will not be compromised by thermal cycles that occur during operation and shutdown.

For example, the mesh 8B is 100 meshes (wire diameter ""'+ k-7chi0-29nn).
50 mesh 7 (g diameter 0.0 busy, pitch sail 10++y
m) can be easily obtained, and moreover, the heat transfer area can be several times larger than that of conventional porous heat transfer plates.

Furthermore, since there is no problem with surface oxidation, the material for mesh 38 could be tough pinch copper, which has high thermal conductivity. Heat intrusion from the upper end of the mesh 8 to the lower guar j, which has good lateral heat diffusion, can also be sufficiently suppressed due to the compatibility of the inner M' d 1 /l-mesh 38.

(Specific Effects Achieved by the Present Invention) Invention 61: The following effects of F4t'I are explained. In other words, since the inner tube penetrates from the top and bottom, highly reliable airtightness can be easily achieved at the boundary between the refrigerant and the regenerator.Moreover, if the materials of the inner tube and mesh are selected appropriately, the inner tube can be passed from the upper end to the lower end. It is possible to sufficiently suppress heat infiltration.

In addition, because the mesh is layered on the inside and outside of the inner tube and the mesh is connected to the inner tube, the heat transfer area of the refrigerant or regenerator can be increased.

Furthermore, since there is no problem of surface oxidation, all materials such as copper, which has a higher thermal conductivity than aluminum, can be used for the mesh.

(Actual example) A specific example of the above technical means is as described above.

Therefore, a second embodiment of the present invention will be described below with reference to Group 9 and FIG. 10. Contact Mf tube 41 G
This is a canal through which the refrigerant passes between the cold type and the 1f C tension cylinder or compression cylinder 〇rfii. Supply M'42
8 inner pipes 45 that supply the regenerator through the pipes penetrate vertically,
Separate the inner (1ii1) regenerator and the outer (lull) refrigerant.Inner 7 langes 43Q, outer 7 langes 48b.

The outer wall of the regenerator is shaped by the outer tube Φ6.

FIG. 10 is a cross-sectional view taken along the line X-X in FIG. 9. The inner mesh ←i is laminated on the inside of the inner tube 45, and the outer mesh 44b is laminated on the outside tL, and the inner tube 45 and mesh 44 are joined. be done. In the second embodiment configured in this way, the first
To achieve the effect explained in the example above, the refrigerant flow path is placed outside,
Since the regenerator is distributed all over the inside of the regenerator, the boundary area between the refrigerant and the regenerator can be increased, and as a result, the heat transfer area can be increased.

An eighth embodiment of the present invention will be described with reference to FIGS. 11' and 12. In Figure 1.1, the connecting pipe 51 passes between the regenerator and the expansion cylinder or compression cylinder. ? This is the iF path. The inner pipe 58 penetrates vertically to separate the regenerator on the inside and the refrigerant on the outside.
liii L, the outer sheath 54 is also passed through vertically to separate the inner cooling chamber and the outer sheath 1. 7 langes 52 and outer tube 5
7 forms the outside of the regenerator 4. The cold storage is supplied to the outside storage part of the outside 01 (1 inner pipe 5Φ) through the entire supply 57, and is further supplied to the inside storage part of the inner inner pipe 53 through the communication pipe 584. Xll in Figure 11
This is a cross-sectional view taken along line -
The intermediate mesh 56b is located between the inner and outer tubes 54 and 54.
An outer mesh 560 is laminated on the outside of the inner tube 58.
Alternatively, the outer inner tube 54 and the mesh 56 are joined.

In the third example 71i configured in this way, in addition to the effects described in the first example, a triple pipe structure is used for the refrigerant flow path. Since the cold storage n is arranged inside and outside the middle r#t+ section, the boundary area between the refrigerant and the cold storage device can be increased, and as a result, the heat transfer area can be increased.

Furthermore, the average distance between the refrigerant and the regenerator can be reduced, and thermal resistance can be reduced.

Regarding the rS4 embodiment of the present invention, i 1181;? l
And the 14th! This will be explained with reference to the figures. ? , ] In Figure 8, two inner pipes 61 penetrate vertically to separate the inner refrigerant flow path and the outer regenerator storage. outside·
64 and 7 langes 65 form the outer wall of the regenerator. The regenerator 4 is supplied through the supply pipe 66. 14th. The figure is a sectional view taken along the line -XIv in FIG.
11. Inner medulo 3+t is laminated on the inside of ■ and outer medulo 3b is laminated on the outside. The inner tube 61 and the mating tube 81+ are joined together. . / In addition to the effects described in the first embodiment, the fourth embodiment having configuration 1 as described above has a plurality of refrigerant flow paths, so the boundary area between the refrigerant and the regenerator can be increased, and the As a result, the heat transfer area can be increased.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but may include the following without changing the gist thereof:
Of course, it can be implemented with various modifications.

[Brief explanation of drawings]

Figure 1 shows a partial section showing the main structure of a general Stirling refrigerator. 3rd MG: j l atm helium gas, I Q atnl helium gas and lead unit fJi
Figure 41 is a partially cross-sectional elevational view of a regenerator of a conventional ultra-low temperature refrigerator, Figure 5 is an enlarged cross-sectional view taken along line V-V in Figure 4, FIG. 6 is a -r elevational view showing the first embodiment of the regenerator for an ultra-low temperature refrigerator of the present invention, FIG. 7 is an enlarged cross-sectional view taken along the line Vll-Vll in FIG. 6, and FIG. Tough pitch copper, industrial pure aluminum,
A graph comparing the thermal conductivities of phosphorous-deoxidized copper, industrially pure titanium, and 5US804. FIG. 9 is a partially cross-sectional elevational view showing the second embodiment of the regenerator for an ultra-low temperature refrigerator of the present invention. FIG. Fig. 11 is an enlarged cross-sectional view taken along the line X-X in Fig. 9, Fig. 11 is a partial elevational view showing the eighth embodiment of the regenerator for the ultra-low temperature refrigerator of the present invention, and Fig. 12 is FIG. 11 is an enlarged cross-sectional view taken along the line Xll in FIG. 11, FIG.
The figure is a plan view of the decorative structure Pr along the line -11V in FIG. 13. Φ・・・Regenerator, 31, 45.53, 541, 61...
・Inner tube, 38, 4. Φ, 56.63... Metsch development permission lπf person Aisin Seiki Co., Ltd. Representative Rei Nakai Figure 2 Figure 3121 Warm! (to) 6.0i Figure 4 Figure 7 Figure 9 Figure 1011 Figure 14 10-10 Procedural amendment ■Kun 58 July 140 Commissioner of the Japan Patent Office 1, Indication of the case 1988 158 Patent application No. 03164552, Title of the invention: Ultra-low temperature refrigerator regenerator 3, Relationship to the person making the amendment case Patent applicant address: 2-1-4 Aikatsukashira Muriya Moe Old Town? iR positive target column and each column for a brief explanation of the drawing. 5. Contents of the amendment (1) As shown in the first appendix in the Scope of Claims column. - (2) The amendments and contents of each column of the detailed description of the invention and the brief description of the drawings are as shown in the second appendix. (First Attachment) Claims (1,1 In a regenerator for an ultra-low temperature refrigerator in which the refrigerant is -.lium and operates at a temperature of 2QK or less, A regenerator for an ultra-low temperature refrigerator, characterized in that the flow path and the regenerator storage part are separated by Mlt L, meshes are stacked in contact with both sides of the sidewall in a posture perpendicular to the flow direction of the refrigerant, and the sidewall and the wire mesh are joined. (2+ A regenerator for an ultra-low temperature refrigerator according to claim 1, wherein the side wall is a tube, the inside of the tube is a flow path for a refrigerant, and the outside of the tube is a storage section for a regenerator. (3) The side wall is a pipe, the outside of the pipe is a refrigerant flow path,
2. A regenerator for an ultra-low temperature refrigerator according to claim 1, wherein the inside of the tube serves as a regenerator. (4) The regenerator for an ultra-low temperature refrigerator according to claim 1, wherein the side wall is made of multiple tubes, and refrigerant flow paths and regenerator storage sections are provided alternately. (5) The side wall is made up of a plurality of pipes, the inside of the pipes is used as a flow path for a refrigerant, and the periphery of the pipes is used as a storage section for cold storage 1-! II. A regenerator for an ultra-low temperature refrigerator according to item 1. (6) A regenerator for an ultra-low temperature refrigerator according to claim 1, wherein the side wall and the mesh are joined by diffusion bonding. (7) The regenerator for an ultra-low temperature refrigerator according to claim 1, wherein Heliuno 1, hydrogen, neon, argon, oxygen, or a mixture thereof is used as the regenerator. (8) The material of the side wall is phosphorus-deoxidized copper or industrial wire, and the material of the mesh is oxygen-free copper, tough pitch copper,
The regenerator for an ultra-low temperature refrigerator according to claim 1, wherein high-purity aluminum, industrial pure aluminum, or silver is used. (9) Ultra-low temperature freezing according to claim 8, characterized in that meshes or plates made of stainless steel, high Mnt, titanium alloy, or ceramic are inserted at appropriate intervals between the meshes. Machine's reservoir. (Second Attachment) ・

Claims (1)

[Claims] (1) Cold tN″ff: In a regenerator for an ultra-low temperature refrigerator that uses helium and operates at a temperature below 20°C, the side wall penetrates in the direction of the refrigerant flow, and the refrigerant flow path and the regenerator An ultra-low-temperature refrigerator characterized in that the storage part of the machine is placed on the floor IL7, in contact with the sides of the side walls, and the mesh is stacked in a position perpendicular to the flow direction of the cold water, and the wire mesh is joined to the tsukuzai 1. (2) The above (11 tl wall is assumed to be large, the inside of the pipe is used as a flow path for refrigerating, and the outside of the pipe is used as a storage section for a full-grade refrigerant. 2) The left side is assumed to be a qe+ characteristic. A regenerator for an ultra-low temperature refrigerator according to Item 13 of Scope 1. (3) The side wall is a pipe and L7, and the pipe is used as a flow path for all the refrigerant outside the pipe, and the inside of the chopstick is used as a storage part of the regenerator. A regenerator for an ultra-low temperature refrigerator according to claim 18. (4) A regenerator for an ultra-low temperature refrigerator as set forth in claim 18. A regenerator for an ultra-low-temperature refrigerator according to item 1. (5) The regenerator is characterized in that the side wall is a fully dual-phase tube, the inside of the tube is a flow path for a refrigerant, and the periphery of the tube is a storage part of the regenerator. The ultra-low-temperature refrigerator according to the scope of the patent request, item 18.m The method of joining the side passage and the mesh is diffusion bonding. A regenerator for an ultra-low temperature refrigerator. (7) Is helium, hydrogen, neon, argon, or oxygen or a mixture thereof used as the regenerator? Ultra-low-temperature cooling 8P, machine regenerator as described. (8) The material of the side wall is made of deoxidized copper or industrial pure titanium, and the material of the mesh is plain copper, tough pitch steel,
A regenerator for an ultra-low temperature refrigerator according to claim 1, characterized in that the regenerator is made of high-purity aluminum, industrial pure aluminum, and is made of a tilted material. (9) The ultra-low temperature according to claim 8, characterized in that meshes or plates made of stainless steel, high Mr1@I4, titanium alloy, or ceramic are inserted at appropriate intervals between the meshes. Refrigerator heat storage device.