JP2731142B1 - Regenerator - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To improve heat exchange efficiency with a refrigerant gas and to set an appropriate flow path characteristic such as a penetration area and a penetration path length of a refrigerant gas passing through a regenerator by omitting an extra step. The present invention provides a useful technology capable of realizing a regenerator having a high degree of freedom in designing a plate and a casing. SOLUTION: In a regenerative heat exchanger in which a plate laminate is mounted inside a casing and heat is exchanged between the plate laminate and a gas passing through the casing, a square plate constituting the plate laminate 23 is provided. Reference numeral 30 denotes a thin-walled portion 3 in which a predetermined pattern of pores 31 is formed in a polygonal stainless steel thin plate, and a plate thickness is reduced on the outer peripheral edge.
2 are provided. When filling the casing 22a, the pattern of the pores 31 of the square plate 30 is visually grasped, the outer shape is confirmed, and the casing is inserted at a predetermined rotation angle, so that desired flow path characteristics can be easily set. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerator (also called a regenerative heat exchanger or regenerator) used in a cryogenic refrigerator such as an inverse Stirling refrigerator, a GM refrigerator or a pulse tube refrigerator.

[0002]

2. Description of the Related Art FIG. 6 is a diagram showing an example of use of a regenerator.
Although not particularly limited, it is a schematic configuration diagram of a reverse Stirling refrigerator (hereinafter abbreviated as “refrigerator”). This refrigerator generally comprises two cylinder devices 1 and 2 and a pipe 3 connecting between the two cylinder devices. The cylinder device 1 on the right side of the drawing is called a “compression cylinder”, and the cylinder device 2 on the left side of the drawing is called an “expansion cylinder”.

The interior of the compression cylinder 1 is divided into two chambers by a piston (hereinafter, "compression piston") 4 reciprocating at a predetermined cycle, and when the compression piston 4 is at a top dead center position (position shown). Chamber with minimum volume (hereinafter "compression chamber") 5
Is connected to the pipe 3. Reference numeral 6 denotes a seal member for ensuring airtightness. The expansion cylinder 2 is a piston that reciprocates at a predetermined cycle (hereinafter, “expansion piston”).
7, the regenerator 8 provided inside the expansion piston 7, and the expansion piston 7 at the top dead center position (the position shown is the middle position).
A chamber (hereinafter referred to as an “expansion chamber”) 9 having a minimum volume at the time of
A cooling unit 11 which also serves as a chamber wall of the expansion chamber 9 and is in contact with the cooled object 10. Reference numerals 12 to 14 are seal members for ensuring airtightness.

The regenerator 8 is formed by filling a large number (for example, 1000 or more) of circular mesh plates called a matrix as a regenerator material in a cylindrical casing open at both ends. The communication between the compression chamber 5 and the expansion chamber 9 is via the pipe 3, the side hole 7 a of the expansion piston 7, the inside of the regenerator 8, and the end surface hole 7 b of the expansion piston 7. , High pressure refrigerant gas such as helium, hydrogen or nitrogen.

The refrigerating machine having such a configuration has a reverse Stirling cycle, that is, a cycle including four strokes of an "isothermal compression stroke", an "isothermal radiation stroke", an "isothermal expansion stroke", and an "isothermal heat absorption stroke". Is repeatedly executed. FIG. 7 is a piston locus diagram of the refrigerator. A solid sine curve A indicates a reciprocating locus of the expansion piston 2, and a dashed sine curve B indicates a reciprocating locus of the compression piston 1. In addition, a black circle (●) indicates a top dead center, a black triangle (▲) indicates a middle point, and a white circle (O) indicates a bottom dead center. As can be understood from this trajectory diagram, the reciprocating motion cycle of the compression piston 1 and the expansion piston 2 matches, and the cycle of the compression piston 1 is 1
/ 4 cycle (90 degrees in phase angle).

The operation of each process will be described below. (1) In the isothermal compression process, the refrigerant gas in the compression chamber 5 is compressed, and the heat generated by this compression is released from the pipe 3 to the outside, and the isothermal process is performed. Become. (2) In the equal volume heat radiation process, the compressed refrigerant gas is transferred to the expansion chamber 9 without changing its volume, but the regenerator 8 in the transfer path is cooled by the equal volume heat absorption process in the previous cycle. Therefore, heat exchange is performed by the regenerator 8,
A sufficiently cooled refrigerant gas is transferred to the expansion chamber 9. (3) In the isothermal expansion process, as the volume of the expansion chamber 9 increases,
The refrigerant gas in the same room 9 is the surrounding heat (mainly the heat of the cooling unit 11).
While isothermally expanding. (4) In the equal volume heat absorption process, the refrigerant gas that has expanded isothermally is transferred to the compression chamber 5 without changing its volume, but the regenerator 8 in the transfer path stores heat in the previous equal volume heat radiation process. Therefore, heat exchange is performed between the low-temperature refrigerant gas and the high-temperature regenerator 8, the regenerator 8 is cooled, the temperature of the refrigerant gas rises, and one cycle is completed.

Next, a cylinder device in which a regenerator is housed,
In particular, details of the expansion cylinder will be described with reference to FIG. 8, reference numeral 20 denotes an expansion cylinder (corresponding to the expansion cylinder 2 in FIG. 6). The expansion cylinder 20 has a piston 22 that reciprocates at a predetermined cycle (see a sine curve A in FIG. 12) inside a cylinder main body 21. The piston 22 includes a cylindrical casing 22a and a cylindrical casing 22a. A circular plate laminate 23 mounted on the casing 22a as a cold storage material, a solid portion 22b for closing an opening at a lower end side of the casing 22a, an opening 22c formed at an upper end of the casing 22a, The regenerator 24 includes a communication passage 22d formed between the upper end and the side surface of the real part 22b.

An opening 22c formed in the upper end of the casing 22a and a communication passage 22d formed between the upper end and the side surface of the solid portion 22b serve as an inlet and outlet for a refrigerant gas (gas) passing through the regenerator 24. . As shown in FIG. 9, the plate stack 23 mounted on such a regenerator 24 is formed by punching a circular mesh plate 25 punched out of a mesh screen from one end of a casing 22a to a regenerator material filling portion 22e. They were inserted sequentially, and 1000 or more sheets were laminated. By applying the circular mesh plate 25 as the cold storage material in this way, it is possible to secure a good flow path of the refrigerant gas passing through the inside of the casing 22a. That is, the cold storage material filling portion 22e of the casing 22a
Since is formed by cutting using a machine tool, a circular cross section has the advantage that dimensional accuracy can be easily increased. On the other hand, although the dimensional accuracy of the mesh plate 25 punched from the mesh screen is extremely low, when the mesh plate 25 is inserted into the cold storage material filling portion 22e, the outer edge of the circular mesh plate 25 becomes uniform as shown in FIG. In the state where it is pressed, it comes into close contact with the inner wall of the cold storage material filling portion 22e. Therefore, the inner wall of the cold storage material filling portion 22e and the mesh plate 25a
It is possible to prevent the generation of a gap formed with the outer end portion, and the refrigerant gas passing through the casing 22a has an original flow path in contact with the plate laminate 23 to improve heat exchange efficiency. be able to.

[0009]

However, in the regenerator 24 described above, the mesh plate 25
Also has a specific problem associated with the circular outer shape. That is, since a large number of mesh plates are punched and manufactured from one mesh screen, the shape variation of each mesh plate is large, and the degree of overlap between the plates when laminating is different each time. For example, FIG. As shown in FIG.
10 (a) and (b), the reference direction (indicated by an arrow in the figure) of each circular mesh plate 25 is shifted by α degrees, and α, α × 2, α × 3 are set. ...
It is extremely difficult to accurately grasp and set the rotation angle in the reference direction. In FIG. 10, the reference direction is indicated by an arrow for the sake of clarity of the description of the rotation angle of the mesh plate 25.

[0010] Since the outer diameter of the mesh plate 25 and the inner diameter of the cold storage material filling portion 22e of the casing 22a substantially match, the mesh plate 25 must be inserted and filled with an appropriate pressing force. The pressing force must be finely adjusted so that the plate 25 is not deformed. In consideration of the ease of filling the mesh plate 25 and the heat exchange efficiency, the shape of the casing 22a cannot be made other than the cylindrical shape, so there is no design freedom.

As a remedy for solving such inconveniences, as shown in FIG. 11A, a rectangular mesh plate 27 (hereinafter, referred to as a rectangular mesh plate) is used to form each square mesh plate. It is conceivable that the reference direction of the plate 27 is grasped from the outer shape (sides and corners), and the rotation angle at the time of insertion into the casing 22a is sequentially shifted to set a predetermined flow path characteristic. According to such a rectangular mesh plate 27, for example, the reference direction can be rotated by 90 degrees in the case of a square mesh plate and 60 degrees in the case of a hexagonal mesh plate, as shown in FIG. The predetermined gas flow path 26 can be easily set. In addition, since there is no restriction on the shape of the mesh plate, the degree of freedom in designing the casing 22a can be improved. In FIG. 11, the reference line is indicated by an arrow for the sake of convenience in order to represent the rotation angle of the mesh plate 27 as in FIG.

However, when such a rectangular mesh plate 27 is used as a cold storage material, a new problem occurs. That is, the cold storage material filling portion 22e of the casing 22a
Is formed by cutting with a machine tool as described above. Therefore, as shown in FIG. 12B, when it is attempted to form a polygonal hole so as to match the shape of the square mesh plate 27, A roundness (R) R2 of the cutting tool and the cutting locus is inevitably formed at the corner (B). Therefore, in order for the square mesh plate 27 to be filled to be in close contact with the radius R2 of the corner B of the cold storage material filling portion 22e with good consistency, it must have a predetermined dimensional accuracy, as described above. In a mesh plate, it is extremely difficult to achieve a desired dimension with high accuracy, so that the dimensional accuracy at a corner (A portion) is low. In the corner portions (A portion and B portion) in such a state, the casing 22
A gap 22f is formed between the corner B of the cold storage material filling portion 22e and the corner A of the square mesh plate 27, and passes through the gap 22f without passing through the plate laminate 23 that is the cold storage material. There is a problem that the amount of the refrigerant gas increases and sufficient heat exchange is not performed.

Accordingly, the present invention improves the heat exchange efficiency with the refrigerant gas and eliminates an extra step to properly adjust the flow path characteristics such as the penetration area and the penetration path length of the refrigerant gas passing through the regenerator as required. It is an object to provide a regenerator that can be set and has a high degree of freedom in designing a plate and a casing.

[0014]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 mounts a plate laminated body in which a plate having a large number of pores as a cold storage material is laminated inside a casing, In a regenerator that performs heat exchange between a plate laminate and a gas passing through a casing, a plate constituting the plate laminate has a polygonal shape, and an edge of the plate is subjected to external stress. And has high deformability.

In the present invention, since the outer shape (side or corner) of the square plate can be visually grasped and the rotation angle at the time of inserting each plate can be sequentially shifted, a desired gas flow path can be formed. It can be easily set. In addition, since the edge of the square plate has high deformability (for example, a thin portion or a composite structure using a highly deformable material), the edge is easily deformed when inserted into the cold storage material filling portion. In addition, since the shape matches the shape of the cold storage material filling portion, fine adjustment of the plate insertion pressing force is not required, and the manufacturing process of the cold storage device is simplified. Furthermore, the shape of the square plate is not limited to a square and a hexagon, but may be an octagon, a parallelogram, a rhombus, or any other rotationally symmetric shape. Therefore, the degree of freedom in designing the plate and the casing can be improved.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing one embodiment of a square plate applied to the regenerator according to the present invention.
1A and 2A, the square plate 30
For example, a predetermined pattern of pores 31 is formed in a stainless steel thin plate, and a thin portion 32 having a reduced plate thickness is provided on the outer peripheral edge. This thin part 32
Are formed to such an extent that they are sufficiently deformed. Here, the square plate 30 has a polygonal shape, for example, a square, and in the embodiment of FIG. 1, matches the side dimension of the cold storage material filling portion 22e of the casing 22a. The corner R of the square plate 30 is formed with a radius R1 like the square mesh plate 27 of the related art (FIG. 12). 22e
Is formed to be smaller than the radius R2 of the corner B portion. On the other hand, in the embodiment of FIG. 2, the side dimensions of the square plate 30 are set to be larger than the side dimensions of the cold storage material filling portion 22e, and as in the embodiment of FIG.
Of the corner A of the cold storage material filling portion 22e is smaller than the radius R2 of the corner B of the cold storage material filling portion 22e.

In the manufacturing process of a regenerator using such a rectangular plate 30 as a cold storage material, as shown in FIG. 3A, the reference direction of the rectangular plate 30 is grasped by the external shape (sides and corners). It is possible to set a predetermined flow path characteristic by sequentially shifting the rotation angle at the time of insertion into the cold storage material filling section 22e. For example, if the square plate is a square, by inserting it at an angle every 90 degrees,
A spiral gas flow path similar to that shown in FIG. 11B can be set.
In FIG. 3A, the reference line is indicated by an arrow for the sake of convenience to indicate the rotation angle of the square plate 30 as in FIGS.

Next, FIG. 3B shows a state in which the square plate 30 of the present embodiment is laminated in the casing 22a.
Since the thin portion 32 formed on the edge portion of the square plate 30 is formed to be larger than the side dimension of the cold storage material filling portion 22e, the thin portion is deformed like the portion C and the cold storage material filling portion 22e is formed.
e Filled closely to the inner wall. As described above, when filling the rectangular plate 30 into the casing 22a, the pattern of the pores 31 of the rectangular plate 30 is visually grasped, the outer shape (side or corner) is confirmed, and the casing 22a is inserted at a predetermined rotation angle. Therefore, desired flow path characteristics can be easily set. Further, since the thin portion 32 formed at the edge of the rectangular plate 30 is in close contact with the inner wall of the cold storage material filling portion 22e, the generation of the gap 22f as shown in FIG. The formation of the gas flow path passing through the gap can be suppressed, and the plate laminate 2 which is the original gas flow path
3 and the refrigerant gas are in good contact, and the heat exchange efficiency can be improved. Furthermore, since the shape of the square plate 30 can be set to any polygonal shape, the degree of freedom in designing the casing can be improved. Moreover, since it is not necessary to finely adjust the pressing force of inserting the rectangular plate 30 into the cold storage material filling portion 22e, the manufacturing process of the cool storage device 24 is simplified, and the adaptability to the liberalization of the manufacturing process is improved. be able to.

Next, a manufacturing process of the above-described square plate 30 will be described with reference to FIG. In the method of manufacturing the square plate 30 according to the present embodiment, a photo-etching technique applied to a semiconductor manufacturing process or the like can be effectively used. In addition, a stainless steel material generally used as a cold storage material for exchanging heat with a refrigerant gas is made of a square plate 30.
And its manufacturing method will be described.

First, as shown in FIG. 4A, after a photoresist 41 is formed on the entire surface of a stainless steel substrate 40,
As shown in FIG. 4B, patterning is performed using a photomask (not shown) so as to remove the photoresist 41 at a position where a thin portion at the edge of the rectangular plate is formed. Next, as shown in FIG. 4C, the edge of the rectangular plate is etched using the patterned photoresist 41 to form a thin portion 40a. After removing the photoresist 41, as shown in FIG. 4D, a photoresist 42 is formed again on the entire surface of the stainless steel plate 40 and the thin portion 40a, and a thin film penetrating the stainless steel plate 40 by a photomask (not shown). The photoresist 42 at the position where the hole is to be formed is patterned to form the opening 4.
Form 3 Next, etching is performed using the patterned photoresist 42 to form pores 44 at predetermined positions as shown in FIG. By such a series of manufacturing steps, for example, the external dimension opening 30 to 8 m
m, thin part width 4 to 1 mm, pore forming part plate thickness 0.1
~ 0.02mm, thin part plate thickness 0.01 ~ 0.00
A 5 mm square plate 30 is obtained. Here, the radius of the corner of the square plate 30 is formed smaller than the radius of the corner of the cold storage material filling portion 22e to be inserted.

In this way, a rectangular plate 30 having a thin portion 32 formed on the edge as shown in FIG. 3 is obtained, and the thin portion 32 is deformed by insertion and filling into the cold storage material filling portion 22e. (Deflection), and aligns and adheres to the sides and corners of the cold storage material filling portion 22e. Therefore, the square plate 30
The formation of a gap between the outer periphery (all sides and full widths) and the inner wall of the cold storage material filling portion 22e is prevented. Here, since the radius of the corner of the rectangular plate is smaller than the radius of the corner of the cold storage material filling portion, the thin portion 32 is deformed (bent) when inserted into the cold storage material filling portion 22e. The radius is aligned with and adhered to the inner wall of the larger cold storage material filling portion 22e. On the other hand, if the corner radius of the square plate 30 is larger than the radius of the corner of the cold storage material filling portion 22e, even if the corner portion of the square plate 30 is deformed, the inner wall of the cold storage material filling portion 22e will remain. There is no contact in alignment, a gap is formed, refrigerant gas escapes, and heat exchange efficiency deteriorates.

Next, an embodiment showing another form of the square plate 30 applied as a cold storage material will be described with reference to FIG. FIGS. 5A and 5B show an example of a square plate made of a stainless steel plate having a square outer shape, similarly to the above-described embodiment. In the present embodiment, unlike the above-described pattern such as the shape and arrangement of the pores of the rectangular plate, substantially L-shaped pores 3 are formed in parallel and continuously on two adjacent sides.
It has one group. The continuity of the pores 31 between the rectangular plates 30 is improved by inserting and filling the rectangular plate 30 having the group of the pores 31 having such a pattern in the regenerator material filling portion 22e by rotating it 90 degrees at a time. Thus, a gas flow path with reduced pressure loss can be set.

FIG. 5C shows an example of a rectangular plate 30 having a hexagonal outer shape. In the square plate 30 of the present embodiment, since the gas flow path rotated by 60 degrees can be set at the time of insertion and filling into the cold storage material filling portion 22e, the continuity of the pores 31 between the square plates 30 is improved. The pressure loss can be further reduced, and the degree of freedom in setting the gas flow path can be further improved.

In any of the embodiments shown in FIG. 5, the outer shape of the square plate 30 is visually recognized,
At the time of insertion into the cold storage material filling portion 22e, a predetermined rotation angle can be visually grasped, so that the gas flow path can be set very easily, and the square plate 30 can be formed similarly to the above-described embodiment. The thin portion 32 and the inner wall of the cold storage material filling portion 22e are aligned and adhered without any gap, so that the refrigerant gas passes through the original plate laminate 23,
Heat exchange efficiency can be improved.

In the description of the above embodiment, the square plate 30 is a regular polygon (square, regular hexagon).
However, if the outer shape of the square plate applied to the regenerator of the present invention has a rotationally symmetric shape and a shape in which the rotation angle of the square plate 30 can be visually confirmed, For example, it may have a shape such as a parallelogram or a diamond. In the present invention, as a condition for improving the heat exchange efficiency, the cold storage material
Since the edge of the square plate 30 may be deformed and aligned with and tightly adhered to the inner wall of e, the shape is not limited to the shape having the thin-walled portion 32 as shown in the above-described embodiment. Any structure that is easily deformed by external stress can be suitably applied to the regenerator of the present invention. For example, a rectangular plate having a composite structure in which a material having high deformability is used at the edge may be used. Here, it is needless to say that the deformation of the edge portion is not limited to the type of plastic deformation or elastic deformation.

[0026]

According to the present invention, the outer shape (side or corner) of the rectangular plate is visually grasped, and the rotation angle of each plate is sequentially shifted when the plate is inserted into the cold storage material filling portion. Therefore, a desired gas flow path can be easily realized. In addition, high deformability (for example, a thin portion, a composite structure using a highly deformable material) on the edge of the square plate
In order to insert and fill the cold storage material filling section, this edge is easily deformed and conforms to the inner wall shape of the cold storage material filling section. Efficiency can be improved, and fine adjustment of the insertion pressing force of the square plate is not required, so that the manufacturing process of the regenerator can be simplified. Furthermore, the outer shape of the square plate is not limited to a square and a hexagon, but an octagon,
A rotationally symmetrical shape such as a parallelogram or a rhombus may be used, and the degree of freedom in designing the casing, which is limited by the conventional circular mesh plate, can be greatly improved.

[Brief description of the drawings]

FIG. 1 is an external view (part 1) of a square plate according to an embodiment.

FIG. 2 is an external view of a square plate according to one embodiment (part 2).

FIG. 3 is a manufacturing process diagram of a regenerator using a square plate according to one embodiment.

FIG. 4 is a manufacturing process diagram of the square plate of one embodiment.

FIG. 5 is an external view of a square plate according to another embodiment.

FIG. 6 is a schematic diagram of a reverse Stirling cycle refrigerator.

FIG. 7 is a piston trajectory diagram of the reverse Stirling cycle refrigerator.

FIG. 8 is a conceptual sectional view of a conventional cylinder device (expansion cylinder).

FIG. 9 is a manufacturing process diagram of a conventional mesh plate laminate.

FIG. 10 is a conceptual diagram of setting a flow path of a refrigerant gas in a conventional regenerator.

FIG. 11 is a conceptual diagram of setting a flow path of a refrigerant gas in a conventional regenerator improvement measure.

FIG. 12 is a conceptual explanatory diagram of a plate shape and heat exchange efficiency.

[Explanation of symbols]

 Reference Signs List 20: expansion cylinder 21: cylinder body 22: piston 22a: casing 22b: solid portion 22c: opening 22d: communication passage 22e: cold storage material filling portion 22f: gap 23: plate laminate 24: regenerator 25: circular mesh plate 25a: Mesh hole 26: Gas flow path 27: Square mesh plate 30: Square plate 31, 44: Pores 32, 40a: Thin portion 40: Stainless steel substrate 41, 42: Photoresist 43: Opening

Claims (1)

(57) [Claims] 1. A regenerator for mounting a plate laminate in which a plate having a large number of pores is laminated as a regenerator material inside a casing, and performing heat exchange between the plate laminate and a gas passing through the casing. 3. The regenerator according to claim 1, wherein the plates constituting the plate laminate have a polygonal shape, and the edges of the plates are formed to have high deformability against external stress.