JP3271346B2 - Refrigerator regenerator and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerator (regenerative heat exchanger) used in a refrigerator and a method for producing the same, and more particularly to a regenerator material.

[0002]

2. Description of the Related Art Conventionally, a compressor for compressing a refrigerant gas and a compressor for compressing the refrigerant gas have been used as a cryogenic refrigerator for expanding a high-pressure refrigerant gas such as helium gas to generate cryogenic cooling. A GM refrigerator that combines an expander that expands a refrigerant gas, reciprocates a displacer in a cylinder of the expander, and adiabatically expands the refrigerant gas in the expansion space to generate cold. There is known a Stirling refrigerator in which a displacer of an expander is reciprocated by pulsating gas discharged from a linear motor compressor to generate cold by expansion of a refrigerant gas in an expansion space. The expander of such a cryogenic refrigerator has a built-in regenerative heat exchanger called a regenerator. This regenerator is usually filled in a case as a displacer through which gas can flow. A matrix made of a large number of granular lead, that is, a type having a regenerator material, and performing heat storage and heating of the gas refrigerant by exchanging heat with a gas refrigerant passing through the regenerator material is generally adopted. .

However, in the above-mentioned regenerator, as shown in FIG. 4, gas refrigerant circulation holes (94, 95) are formed at the center of caps (92, 93) attached to both ends of the case (91). While being formed, the cold storage material (9
6) Since the porosity is uniformly formed as a whole, the flow rate V1 of the gas refrigerant flowing in the center is fast, the flow rate V2 of the gas refrigerant flowing outside is slow, and heat exchange is excessive in the center. There was a problem that the capacity was insufficient, and conversely, the heat exchange was small on the outside and the capacity was excessive, and the heat exchange was unbalanced as a whole. Therefore, conventionally, Japanese Patent Application Laid-Open
As shown in the publication, a cylindrical partition wall is provided in the case, and the inside and outside of the partition wall are filled with a cold storage material having a different porosity so that the gas refrigerant is entirely inside the case. It has been proposed to provide a uniform flow and prevent heat exchange imbalance.

[0004]

However, in the above-described regenerator, since the partition wall is provided, there is a problem that heat conduction loss occurs. That is, since a temperature difference of about 200 ° C. occurs at both ends of the cold storage material, even if the partition wall is formed thin, heat conduction loss occurs, and there is a problem that the regenerator efficiency is reduced.

The present invention has been made in view of the above points, and a first object of the present invention is to prevent a heat conduction loss due to a partition wall and to prevent an imbalance in heat exchange, thereby improving a regenerator efficiency. It is in. A second object of the present invention is to realize a method for manufacturing the regenerator.

[0006]

Means for Solving the Problems In order to achieve the above object, the means taken by the present invention is such that a plurality of cold storage material layers having different porosity are formed so as to be in direct contact with each other. That is, as shown in FIGS. 2 and 3, the means according to the first aspect of the present invention firstly uses the gas refrigerant supplied to and discharged from the expansion space (20, 21) to achieve the first object. It is assumed that the regenerator of the refrigerator is configured to store heat and heat the gas refrigerant by heat exchange with the regenerator. The gas refrigerant circulation holes (38, 3) are formed at both open ends of the cylindrical case (32).
A cap (36, 37) having 9) is attached. Further, inside the case (32), a columnar cold storage material layer (34) located on the center of the case (32) and one or more cylindrical cold storage material layers located outside the columnar cold storage material layer (34). Cool storage material layer (35) and case (3
It is filled by laminating in the radial direction of 2). In addition, each of the cold storage material layers (34, 35) is separated from the columnar cold storage material layer (34) by the case (3).
2) The configuration is such that the porosity increases as it goes to the cylindrical cold storage material layer (35) located inside and outside.

Further, in order to achieve the second object, the means adopted by the invention according to claim 2 is a method for manufacturing a regenerator for a cryogenic refrigerator according to claim 1, which first comprises the steps of: A columnar cold storage material layer (34) located on the center;
4) and one or more cylindrical cold storage material layers (35) located outside the case (32) from the columnar cold storage material layer (34). As the porosity is increased as it goes, the inner peripheral surface of the case (32) is longer than the effective filling length of the case (32) and the cylindrical cold storage material layer (35).
And between the respective cold storage material layers (34, 35). Subsequently, with the cap (37) attached to one end of the case (32), each of the cold storage material layers (34, 35) is inserted from the open end of the other end. Thereafter, at the opening end of the case (32), the gap between the inner peripheral surface of the case (32) and the cylindrical cold storage material layer (35) and between the respective cold storage material layers (34, 35) are closely contacted. Each cold storage material layer (34, 35) is compressed in the longitudinal direction, a cap 36 is attached, and the case (32) is filled with each cold storage material layer (34, 35).

[0008]

According to the first aspect of the present invention,
The gas refrigerant supplied to and exhausted from the expansion spaces (20, 21) passes through the inside of the regenerator case (32), and the respective cold storage material layers (3, 3) in the case (32).
4, 35), heat storage and gas refrigerant heating. In this case (32), a plurality of cold storage material layers (34, 35) are laminated in the radial direction, and go from the columnar cold storage material layer (34) at the center to the outer cylindrical cold storage material layer (35). The gas refrigerant is formed so that the porosity increases according to
(38, 39) flowing into the case (32) toward the columnar cold storage material layer (34) .Since the porosity of the columnar cold storage material layer (34) is small, the outer cylindrical cold storage material layer ( 35). From this, the gas refrigerant is stored in each cold storage material layer (34,
35) will flow almost uniformly. As a result, heat exchange between each of the cold storage material layers (34, 35) and the gas refrigerant is performed almost uniformly, and the regenerator efficiency is improved.

According to the second aspect of the present invention, each of the cold storage material layers (34, 35) is formed to be slightly longer than the effective filling length of the case (32), and each of the cold storage material layers (34, 35) is formed in the case. (32), each cold storage material layer (34, 35) is compressed in the longitudinal direction and the case (3
2), each cold storage material layer (34, 35) swells slightly outward, and each cold storage material layer (34, 35) comes into close contact with each other,
Since the case (32) and the tubular cold storage material layer (35) are in close contact with each other, there is no gap between the cold storage material layers (34, 35) and the like, and blow-through of the gas refrigerant is prevented.

[0010]

Therefore, according to the first aspect of the present invention,
A plurality of cold storage material layers (34, 35) are laminated in the radial direction, and the porosity increases from the columnar cold storage material layer (34) at the center to the outer cylindrical cold storage material layer (35). In order to form the gas refrigerant, the outer cylindrical cold storage material layer (35)
Will also be distributed. As a result, each cold storage material layer (3
4, 35), the flow rate of the gas refrigerant can be made almost uniform, so that the heat exchange between each of the cold storage material layers (34, 35) and the gas refrigerant can be made almost uniform, Since the occurrence of a shortage portion and an excess portion of the exchange capacity can be reliably prevented, the regenerator efficiency can be improved. Furthermore, since each of the cold storage material layers (34, 35) is brought into close contact without providing a partition wall between each of the cold storage material layers (34, 35), heat conduction loss can be reduced. The efficiency of the regenerator can be improved.

According to the second aspect of the present invention, each regenerator material layer (34, 35) is formed to be slightly longer than the effective filling length of the case (32), and the regenerator material layer (34, 35) is formed. After inserting the cold storage material layers (34, 35) in the longitudinal direction,
In order to fill (32), each of the cold storage material layers (34, 3
The cold storage material layers (34, 35) can be brought into close contact with each other by the bulging of 5), and the case (32) and the cylindrical cold storage material layer (35)
Can be brought into close contact with each other. As a result, it is possible to reliably prevent a gap such as between the above-described regenerative material layers (34, 35), and prevent blow-by of the gas refrigerant.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a helium refrigerator having a GM cycle as a cryogenic refrigerator according to an embodiment of the present invention;
Is an expander that expands helium gas as a refrigerant gas compressed by a compressor (not shown), and the expander (1)
Are connected to the compressor by high-pressure and low-pressure gas pipes (both not shown) to form a closed circuit. The expander (1) has a high-pressure gas inlet (2) to which the high-pressure gas pipe is connected, and a low-pressure gas outlet to which the low-pressure gas pipe is connected.
A valve housing (4) having (3) and an upper large-diameter portion integrally airtightly joined to a lower portion of the valve housing (4).
(5a) and a two-stage cylinder consisting of the lower small-diameter part (5b)
(5), and inside the valve housing (4),
A motor chamber (6) communicating with the high-pressure gas inlet (2), a vertical through hole (7) communicating with the motor chamber (6), and an auxiliary orifice (8) at the low-pressure gas outlet (3). And a surge volume (9) communicating therewith.

A joint between the valve housing (4) and the cylinder (5) is provided with a valve stem (10) constituting an upper closed end of the cylinder (5). ) Includes a valve seat portion (10a) hermetically fitted in the through hole (7) of the valve housing (4), and a hanging portion (10b) hanging down at an upper portion in the cylinder large diameter portion (5a). And a through hole (7) above the valve seat portion (10a).
Is formed in a valve chamber (11) communicating with the high-pressure gas pipe through the motor chamber (6). The upper half of the valve stem (10) has two branch flow paths (12a, 12a).
And a first gas flow path (12) communicating with the valve chamber (11) and the cylinder (5), and a first gas flow path (27) having one end through a low pressure port (27) of a rotary valve (24) described later. Gas flow path (12)
And a second gas flow path (13) whose other end communicates with the low-pressure gas outlet (3) through a communication path (14) formed in the valve housing (4). The second gas flow path (13) is provided at the center of the upper surface of the valve stem (10).
The branch flow paths (12a, 12a) of the first gas flow path (12) are respectively opened on the upper surface of the valve stem (10) at symmetrical positions with respect to the opening of the second gas flow path (13).

On the other hand, the large-diameter portion (5
At the upper end in a), a substantially cup-shaped slack piston (16) that defines a driving space (15) in the upper part of the cylinder large-diameter portion (5a) has its upper end inner surface facing the valve stem (10). ) Is reciprocally fitted in an airtight sliding contact with the hanging part (10b) of the valve housing (15).
The surge volume (9) in (4) is always in communication with the orifice (17). The above slack piston (16) is the bottom wall
The bottom wall (16a) is formed with a center hole (16b) and a communication hole (16c) communicating the inside and outside of the piston (16). The cylinder (5) has a displacer (1
8) is fitted reciprocally. The displacer (1
The large diameter portion (18a), which slides in the lower half of the large diameter portion (5a) of the cylinder (5), and the lower end of the large diameter portion (18a) are formed integrally with the cylinder (5). (5) consists of a closed cylindrical small-diameter portion (18b) that slides in the small-diameter portion (5b) .The displacer (18) raises the space inside the cylinder (5) below the slack piston (16). , An intermediate space (19), a first-stage expansion space (20), and a second-stage expansion space (21).
The space in the large-diameter portion (18a) of the displacer (18) is always communicated with the first-stage expansion space (20) through the lower communication hole (18c), and the space in the small-diameter portion (18b) is also provided. The space is always in communication with both the first and second-stage expansion spaces (20, 21) via the upper communication hole (18d) and the lower communication hole (18e).

Further, the large diameter portion (1) of the displacer (18)
8a), the upper cap (3) of the regenerator (30)
6) is provided, and the upper cap (36) has a large-diameter portion (18a).
The upper circulation hole (3) that communicates the space inside the space with the intermediate space (19).
8) is drilled, and a tubular locking piece (22) is integrally provided. The locking piece (22) extends through the center hole (16b) of the slack piston bottom wall (16a) into the piston (16) by a predetermined size, and has a piston bottom wall (16
a) A flange-shaped locking portion (22a) that engages with (a) is integrally formed. When the slack piston (16) moves upward, the locking portion (22a) engages with the bottom wall (16a) when the piston (16) moves up by a predetermined stroke, and moves the displacer (18) to the piston (16). 16), the displacer (18) is moved to follow the piston (16) with a delay of a predetermined stroke.

In the valve chamber (11) of the valve housing (4), a valve motor (2) disposed in a motor chamber (6) is provided.
A rotary valve (24) rotationally driven by 3) is provided, and a switching operation of the rotary valve (24) causes a valve chamber (11) communicating with the high-pressure gas pipe, and a communication path ( 14) and the intermediate space (19) in the cylinder (5),
And the second-stage expansion space (20, 21). That is, the rotary valve (24)
Is non-rotatably and slidably connected to the output shaft (23a) of the valve motor (23). Further, a spring (25) is contracted between the upper surface of the valve (24) and the motor (23), and the spring force of the spring (25) and the high-pressure helium gas introduced into the valve chamber (11). Rotary valve by pressure
The lower surface of (24) is pressed against the upper surface of the valve stem (10) with a constant pressing force.

On the other hand, on the lower surface of the rotary valve (24), a pair of high-pressure ports (26, 26) cut by a predetermined length from the radially opposed outer peripheral edge in the center direction,
The high pressure ports (26, 26) are arranged at an angular interval of about 90 ° in the rotation direction of the rotary valve (24), and the valve (2
4) A low-pressure port (27) is formed which is cut out in the diameter direction from the center of the lower surface toward the vicinity of the outer peripheral edge. When the rotary valve (24) is rotated by pressing the lower surface thereof against the upper surface of the valve stem (10) by the drive of the valve motor (23) to perform a switching operation, slack occurs in accordance with the switching operation of the rotary valve (24). Piston (16) and displacer (18)
Is reciprocated in the cylinder (5). And valve (24)
When the inner ends of the high pressure ports (26, 26) on the lower surface respectively match the first gas flow path (12), the valve chamber (11) is connected to the high pressure port.
(26, 26) and the first gas flow path (12), and communicate with the intermediate space (19) in the cylinder (5) and the first and second stage expansion spaces (20, 21). The slack piston (16) and the displacer (18) driven by the piston (16) by introducing and filling high-pressure helium gas into (19 to 21).
To rise. On the other hand, when the outer end of the low pressure port (27) constantly communicating with the second gas flow path (13) coincides with the first gas flow path (12), each space (19 to 21) in the cylinder (5) is turned on. ) To the first gas passage (12), the low pressure port (27), the second gas passage (13)
The helium gas filled in each space (19 to 21) is discharged to the low-pressure gas pipe by communicating with the low-pressure gas outlet (3) through the communication passage (14) and the slack piston.
(16) and the displacer (18) are lowered, and the expansion space (20,
Cold is generated by the expansion of helium gas in 21).

Further, the large diameter portion (1) of the displacer (18)
A first-stage regenerator (30) composed of a regenerative heat exchanger is provided in the space inside 8a), and a similar second-stage regenerator (31) is provided in the space inside the small diameter portion (18b). Each is fitted. As shown in FIG. 2, each of the regenerators (30, 31) has a case (32) filled with a cold storage material (33), and a gap in the cold storage material (33) serves as a gas passage. I have. When the displacer (18) is in the intake stroke rising in the cylinder (5), each regenerator (30,
The cold storage material (33) of (31) is brought into contact with room temperature helium gas flowing from the intermediate space (19) to the first or second stage expansion space (20, 21), and the gas is cooled to a very low temperature by heat exchange between the two. Cool to near level. On the other hand, when the displacer (18) is in the descending exhaust stroke, each helium gas whose temperature has dropped to a cryogenic level due to expansion in each expansion space (20, 21) is discharged to the outside of the cylinder (5) during the regeneration. The regenerator (3) is brought into contact with the cold storage material (33) of the
0, 31) is cooled again to near the cryogenic level.

As shown in FIG. 2, each of the regenerators (30, 31) includes a cold storage material layer (34) and a cylindrical cold storage material layer (35) in a cylindrical case (32). It is formed by filling a material (33). An upper cap (36) and a lower cap (37) are respectively attached to both open ends of the case (32), and the upper cap (36) has a flow hole (38) on the center.
Are formed over the upper and lower surfaces, and the lower cap (37) is formed with an inverted T-shaped flow hole (39) having an inner end on the center of the inner surface and an outer end opened on both sides. I have. The respective communication holes (38, 39) communicate the outside and the inside of the case (32),
As described above, the flow hole (39) of the lower cap (37) in the first stage regenerator (30) is connected to the lower flow hole (18c) in the large diameter portion (18a) of the displacer (18). The flow hole (38) of the upper cap (36) is an upper flow hole (38) in the large-diameter portion (18a) of the displacer (18), and the upper cap (36) is provided with the locking piece (22). Are formed. still,
In the second-stage regenerator (31), the locking piece (22) in the first-stage regenerator (30) is not formed, and the flow hole (38) of the upper cap (36) is connected to the displacer (18). As described above, the lower cap (37) has the communication hole (39) communicating with the upper communication hole (18d) in the small diameter portion (18b).
The lower flow hole (18e) in the small diameter portion (18b) of (8) is the same as the first stage regenerator (30) in other configurations.

The columnar cold storage material layer (34) and the cylindrical cold storage material layer (3)
5) is a feature of the present invention, wherein the case (32)
The first stage regenerator (30) is formed of a fiber mesh such as copper fiber, and is formed in the second stage regenerator (30).
(31) is formed of a fiber mesh such as lead fiber. The columnar cold storage material layer (34) is formed in a columnar shape with a smaller diameter than the case (32) and is provided on the center of the case (32),
The cylindrical cold storage material layer (35) has an outer diameter on the inner diameter of the case (32),
The inner surface of the case (32) and the columnar cold storage material layer are formed in a cylindrical shape whose inner diameter corresponds to the outer diameter of the columnar cold storage material layer (34), respectively.
(34), the tubular cold storage material layer
The outer peripheral surface of (35) is in close contact with the inner peripheral surface of the case (32), and the inner peripheral surface of the tubular cold storage material layer (35) is in close contact with the outer peripheral surface of the columnar cold storage material layer (34). Further, the columnar cold storage material layer (34) and the cylindrical cold storage material layer (3
5) is formed such that the porosity of the columnar cold storage material layer (34) in the center is smaller than the porosity of the outer cylindrical cold storage material layer (35) .Specifically, for example, the columnar cold storage material The porosity of the layer (34) is 8
The porosity of the tubular regenerative material layer (35) is set to 85%.

Next, a method of manufacturing the regenerators (30, 31) will be described. First, the columnar regenerative material layer (34) and the cylindrical regenerative material layer (35) are formed into a columnar shape and a cylindrical shape, respectively, using a fiber mesh such as a copper fiber or a lead fiber. At this time, the lengths X1 and X2 of the columnar cold storage material layer (34) and the tubular cold storage material layer (35) are formed to be slightly longer than the effective filling length X of the case (32), and the columnar shape at the center is formed. The length X1 of the cold storage material layer (34) is
5) The same length as the length X2 or the columnar cold storage material layer (34)
Is formed slightly longer (X <X2 ≦ X1). Further, the outer diameter of the cylindrical cold storage material layer (35) is slightly smaller than the inner diameter of the case (32), and the outer diameter of the columnar cold storage material layer (34) is changed to the cylindrical cold storage material layer (35).
Each of them is formed to have a diameter slightly smaller than the inner diameter of the cylindrical cold storage material layer (35), and the cylindrical cold storage material layer (35) is simply inserted into the case (32), and the columnar cold storage material layer (34) is formed into the cylindrical cold storage material layer (35). In the inserted state,
The column-shaped cold storage material layer has a diameter between the case (32) and the cylindrical cold storage material layer (35), and a small gap between the cylindrical cold storage material layer (35) and the columnar cold storage material layer (34). (34) and a tubular cold storage material layer (35) are formed.

Thereafter, one of the caps (36, 37) is attached to one end of the case (32), and for example, the lower cap (3
7) is attached, and the cylindrical cold storage material layer (35) and the columnar cold storage material layer (34) are inserted from the open end of the other end of the case (32). In this state, as described above, between the case (32) and the tubular cold storage material layer (35), the tubular cold storage material layer (35) and the columnar cold storage material layer (34)
And a small gap is formed between Subsequently, the cold storage material layers (34, 35) are compressed in the longitudinal direction, and an upper cap (36) is attached to the open end of the case (32). This top cap (36)
Each cold storage material layer (34, 35) swells in the radial direction due to the mounting of the case, the inner peripheral surface of the case (32) and the outer peripheral surface of the cylindrical cold storage material layer (35), and the cylindrical cold storage material layer ( 35) Inner peripheral surface and columnar cold storage material layer (34)
Each cold storage material layer is placed in the case (32) in close contact with the outer peripheral surface of
(34, 35) are filled, and the production of the regenerator (30, 31) is completed.

Next, the operation of the above embodiment will be described. The operation of the refrigerator is basically performed in the same manner as a normal refrigerator. That is, first, the cylinder (5) in the expander (1)
When the internal pressure is low and the slack piston (16) and the displacer (18) are at the lower end position, the rotation of the rotary valve (24) driven by the valve motor (23) causes the high pressure port ( 26, 26) but the valve stem (10)
Rotary valve (24) matching the first gas flow path (12) on the upper surface
Opens to the high pressure side. Along with this, normal-temperature high-pressure helium gas supplied from the compressor to the valve chamber (11) via the high-pressure gas pipe and the motor chamber (6) of the expander (1) is supplied to the high-pressure helium gas of the rotary valve (24). Ports (26, 26) and the first gas flow path (1
It is introduced into the intermediate space (19) via 2). Further, the helium gas is sequentially filled from the intermediate space (19) through the regenerators (30, 31) of the displacer (18) into the respective expansion spaces (20, 21), and the regenerators (30, 31) are filled. During the passage, it is cooled to near the cryogenic level by heat exchange with the regenerator (30, 31) cooled in the previous exhaust stroke. Further, the piston (16) rises due to a pressure difference between the drive space (15) above the piston (16) and the lower intermediate space (19). And this piston (16)
When the ascent stroke of the piston reaches a predetermined value, the piston (16)
The bottom wall (16a) of the displacer (18) and the locking piece (22) at the upper end of the displacer (18) are engaged, and the displacer (18) is pulled up by the piston (16) with a delay with respect to a change in pressure. 18), the expansion space (20,
21) is further filled with high-pressure gas (intake stroke).

Thereafter, when the rotary valve (24) is closed, the displacer (18) further rises due to the inertial force, and accordingly, the intermediate space (1) above the displacer (18).
9) Helium gas in the first and second stage expansion space (20, 21)
Go to Then, after the displacer (18) reaches the rising end position, the low pressure port (27) of the rotary valve (24) matches the first gas flow path (12) and the valve (24) opens to the low pressure side, With the opening of the valve, the helium gas in each of the expansion spaces (20, 21) below the displacer (18) expands adiabatically, and the expansion of the helium gas causes cooling (expansion stroke).

The helium gas in the extremely low temperature state is as follows:
Contrary to the above-mentioned gas introduction, it returns to the above-mentioned intermediate space (19) through the regenerator (30, 31) in the displacer (18), and in the meantime, each cold storage material layer in the regenerator (30, 31). While (34, 35) is cooled to a cryogenic level, it warms itself to room temperature. Then, the helium gas at room temperature is further expanded with the helium gas in the intermediate space (19) through the first gas flow path (12), the low pressure port (27) of the valve (24), and the communication path (14). (1) It is discharged outside and sucked into the compressor through low-pressure gas piping. With this gas discharge, the gas pressure in the intermediate space (19) decreases, and the slack piston (16) descends due to the pressure difference with the driving space (15), and the bottom wall (16a ) Contacts the upper surface of the displacer (18)
(18) is pressed and descends, and the downward movement of the displacer (18) causes the gas refrigerant in the expansion space (20, 21) to expand.
(1) It is further discharged outside (exhaust stroke). Next, the rotary valve (24) is closed, and thereafter the displacer (18)
Descends to the lower end position, the helium gas in the expansion space (20, 21) is discharged, and returns to the initial state. Thus, one cycle of the operation of the expander (1) is completed, and thereafter, the same operation as described above is repeated.

In this embodiment, each regenerator (30, 31), which is a feature of the present invention, includes a columnar cold storage material layer (34) in a case (32).
And the cylindrical cold storage material layer (35) are laminated in the radial direction, the porosity of the columnar cold storage material layer (34) at the center is small, and the porosity of the outer cylindrical cold storage material layer (35) is large. Helium gas flows into the case (32) from one of the circulation holes (38, 39) toward the columnar cold storage material layer (34).
Since the porosity of 4) is small, the outer cylindrical cold storage material layer (35)
Will also be distributed. From this, the helium gas flows almost uniformly in each cold storage material layer (34, 35). As a result, heat exchange between each of the cold storage material layers (34, 35) and the helium gas is performed almost uniformly. Also,
The length X1, X2 of each of the cold storage material layers (34, 35) is formed slightly longer than the effective filling length X of the case (32), and the respective cold storage material layers (34, 3) are formed.
5) is inserted into the case (32), and each regenerator material layer (34, 35) is compressed in the longitudinal direction to fill the case (32), and each regenerator (30, 3)
1), the respective cold storage material layers (34, 35) swell slightly outward, and the respective cold storage material layers (34, 35) are connected to each other and to the case (3).
2) and the tubular cold storage material layer (35) are in close contact with each other without any gap.

Therefore, according to the present embodiment, the columnar cold storage material layer (34) and the cylindrical cold storage material layer (35) are laminated in the radial direction and formed at the center. The helium gas is also dispersed in the outer cylindrical cold storage material layer (35) in order that the porosity of the outer cylindrical cold storage material layer (35) is small and the porosity of the outer cylindrical cold storage material layer (35) is large. Will be. As a result, the flow rate of the helium gas flowing through each of the cold storage material layers (34, 35) can be made substantially uniform, so that heat exchange between each of the cold storage material layers (34, 35) and the helium gas can be substantially performed. Can be performed uniformly,
Since it is possible to reliably prevent the generation of the insufficient portion and the excess portion of the heat exchange capacity, it is possible to improve the regenerator efficiency. Furthermore, each cold storage material layer (3) is provided without providing a partition wall between the columnar cold storage material layer (34) and the cylindrical cold storage material layer (35).
4, 35) are closely arranged, so that heat conduction loss can be reduced and regenerator efficiency can be improved. According to the method for manufacturing the regenerator (30, 31), each regenerator material layer (34, 35) is formed to be slightly longer than the effective filling length X of the case (32), and the regenerator material layer (34) is formed. After inserting the cold storage material layers (34, 35) into the case (32), the respective cold storage material layers (34, 35) are compressed in the longitudinal direction to fill the case (32). Three
Each of the cold storage material layers (34, 35) can be brought into close contact with each other by the expansion of the cold storage material layer (4, 35), and the case (32) and the cylindrical cold storage material layer
(35) can be brought into close contact with each other. As a result, it is possible to reliably prevent a gap such as between the respective regenerative material layers (34, 35), thereby preventing helium gas from flowing through.

In this embodiment, the cold storage material (33)
Is formed by two layers of the columnar cold storage material layer (34) and the cylindrical cold storage material layer (35), but in the present invention, the cold storage material (33) may be formed in three or more layers. At that time, the porosity is formed to be larger toward the outermost cylindrical cold storage material layer. Further, the present invention is not limited to the helium refrigerator having the GM cycle as in the above embodiment, but uses a regenerator in a heat pump device such as a Stirling refrigerator or a Billmeyer heat pump device, and further uses a refrigerant gas other than helium gas. It is needless to say that the present invention can also be applied to those that do.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing the entire configuration of a cryogenic refrigerator.

FIG. 2 is an enlarged sectional view showing a regenerator.

FIG. 3 is a perspective view of a main part of the regenerator showing a state in which each cold storage material layer is inserted into a case.

FIG. 4 is an enlarged sectional view showing a conventional regenerator.

[Explanation of symbols]

 1 Expander 5 Cylinder 18 Displacer 20,21 Expansion space 30,31 Regenerator 32 Case 34 Column cold storage material layer 35 Cylindrical cold storage material layer 36,37 Cap 38,39 Flow hole

Continuation of the front page (56) References JP-A-3-129257 (JP, A) JP-A-2-93663 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 9 / 00

Claims (2)

(57) [Claims] A regenerator of a refrigerator configured to store heat and heat a gas refrigerant by exchanging heat with a gas refrigerant supplied to and discharged from an expansion space (20, 21). Caps (36, 37) having gas refrigerant flow holes (38, 39) are attached to both open ends of the (32), while the case (32) has a columnar shape located at the center of the case (32). A cold storage material layer (34) and one or more cylindrical cold storage material layers (35) located outside the columnar cold storage material layer (34) are stacked and filled in the radial direction of the case (32), Each of the cold storage material layers (34, 35) is formed such that the porosity increases as going from the columnar cold storage material layer (34) to the cylindrical cold storage material layer (35) located outside the case (32). A regenerator for a refrigerator, which is characterized in that: 2. The method for manufacturing a regenerator for a refrigerator according to claim 1, wherein a columnar cold storage material layer (34) located on the center of the case (32) and an outer side of the columnar cold storage material layer (34). And one or more cylindrical cold storage material layers (35) located in the case (32) from the columnar cold storage material layer (34).
It is formed so that the porosity increases toward the cylindrical cold storage material layer (35) located inside and outside, and the case (3
The outer shape is longer than the effective filling length of 2) and has a small gap between the inner peripheral surface of the case (32) and the cylindrical cold storage material layer (35) and between each cold storage material layer (34, 35). With the cap (37) attached to one end of the case (32), insert each of the cold storage material layers (34, 35) through the open end of the other end, and then open the open end of the case (32). In the part, between the inner peripheral surface of the case (32) and the cylindrical cold storage material layer (35) and each cold storage material layer (34, 35)
The cold storage material layers (34, 35) are compressed in the longitudinal direction so that the space between them is close to each other, a cap (36) is attached, and the case (32) is filled with each cold storage material layer (34, 35). A method for producing a regenerator for a refrigerator.