WO2017141656A1

WO2017141656A1 - Stirling refrigerator

Info

Publication number: WO2017141656A1
Application number: PCT/JP2017/002659
Authority: WO
Inventors: 中野　恭介; 善勝平塚; 健太湯本
Original assignee: 住友重機械工業株式会社
Priority date: 2016-02-18
Filing date: 2017-01-26
Publication date: 2017-08-24
Also published as: JP2017146036A

Abstract

This Stirling refrigerator comprises: a first assembly comprising a cylinder 56, a regenerator 38 that is disposed adjacent to the radial outer side of the cylinder 56, and a first regenerator support member 37 that is fixed to the base end of the cylinder 56; a second assembly comprising a regenerator vessel 54 and a second regenerator support member 39 that is fixed to the base end of the vessel, the second assembly being detachably attached to the first assembly so that the regenerator 38 is disposed adjacent to the radial inner side of the regenerator vessel 54 and is interposed between the first regenerator support member 37 and the second regenerator support member 39 in the axial direction; and a annular seal member 64 that is interposed between the leading end of the cylinder 56 and the second regenerator support member 39.

Description

Stirling refrigerator

The present invention relates to a Stirling refrigerator.

A plurality of laminated metal meshes may be used as a cold storage material for a cryogenic refrigerator such as a Stirling refrigerator. Such cold storage material is packed in a container and attached to a refrigerator.

JP-A-8-14684

Due to manufacturing tolerances, a slight gap can occur between the regenerator and the container. The gap can serve as a working gas passage. When the working gas bypasses the cold storage material and flows through the gap, heat exchange between the working gas and the cold storage material is not effectively performed. For this reason, the efficiency of the regenerator is reduced.

Such leakage of the working gas can be eliminated by joining the container member and the adjacent structural member by an appropriate method such as brazing and closing the entrance of the gap. However, advanced techniques may be required to join these members without undesired deformation. This is especially true when high dimensional accuracy is required. In addition, it takes time to assemble and disassemble the regenerator.

The present invention has been made in view of such circumstances, and one of the exemplary purposes of an embodiment of the present invention is a Stirling refrigerator having a seal structure that blocks a working gas flow through a gap between a cold storage material and a container. Is to provide.

According to an aspect of the present invention, a Stirling refrigerator includes a cylinder base end and a cylinder front end, a cylinder extending in an axial direction from the cylinder base end to the cylinder front end, and a radially outer side of the cylinder. And a first regenerator support member fixed to the cylinder base end, a container base end and a container front end, and a shaft extending from the container base end to the container front end. A regenerator container extending in a direction and a second regenerator support member fixed to the container base end, wherein the regenerator is radially inward of the regenerator container A second assembly that is disposed adjacently and removably attached to the first assembly so as to be axially sandwiched between the first regenerator support member and the second regenerator support member; Cylinder tip And a annular seal member which is sandwiched between the second regenerator supporting member.

It should be noted that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention that are mutually replaced between methods, apparatuses, systems, etc. are also effective as an aspect of the present invention.

According to the present invention, it is possible to provide a Stirling refrigerator having a seal structure that blocks the working gas flow passing through the gap between the cold storage material and the container.

It is a figure which shows roughly the whole structure of the Stirling refrigerator which concerns on a certain embodiment. It is a figure which shows schematically the expander of the Stirling refrigerator which concerns on a certain embodiment. It is an exploded view of an expander of a Stirling refrigerator according to an embodiment. It is a figure which shows roughly the regenerator of a certain Stirling refrigerator. It is a figure which shows schematically the expander of the Stirling refrigerator which concerns on other embodiment. It is a figure which shows schematically the expander of the Stirling refrigerator which concerns on other embodiment. It is a figure which shows schematically the expander of the Stirling refrigerator which concerns on other embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Moreover, the structure described below is an illustration and does not limit the scope of the present invention at all.

FIG. 1 is a diagram schematically showing an overall configuration of a Stirling refrigerator 10 according to an embodiment. The Stirling refrigerator 10 includes a compressor 11, a connecting pipe 12, and an expander 13. The compressor 11 is arranged away from the expander 13. The connecting pipe 12 connects the working gas chamber of the compressor 11 to the working gas chamber of the expander 13. The connecting pipe 12 provides a gas flow path through which the working gas flows between the compressor 11 and the expander 13. The working gas is, for example, helium gas.

The Stirling refrigerator 10 is, for example, a split type Stirling refrigerator. In this case, the compressor 11 generates a pressure vibration of the working gas. This is transmitted to the expander 13 through the connection pipe 12. In the expander 13, pressure vibration having a phase difference from the vibration is generated at the same frequency as the pressure vibration of the compressor 11. A reverse Stirling cycle is formed between the compressor 11 and the expander 13. In this way, the expander 13 generates cold.

FIG. 2 is a diagram schematically showing the expander 13 shown in FIG. FIG. 2 shows an outline of the internal structure of the expander 13. FIG. 3 is an exploded view of a portion of the expander 13 shown in FIG.

The expander 13 includes a first assembly 13a and a second assembly 13b. The first assembly 13 a includes a cylinder 56, an annular seal member 64, a regenerator 38, and a first regenerator support member 37. The second assembly 13 b includes a regenerator container 54, a second regenerator support member 39, and a cooling stage 29.

The cylinder 56 includes a cylinder base end 56a, a cylinder front end 56b, and a cylinder inner peripheral surface 56c. The cylinder 56 extends in the axial direction from the cylinder base end 56a to the cylinder front end 56b. The cylinder 56 is made of metal or resin. The regenerator 38 is disposed adjacent to the outside of the cylinder 56 in the radial direction. The regenerator 38 includes a regenerative material laminate, for example, a laminated structure of a wire mesh. The first regenerator support member 37 is fixed to the cylinder base end 56a. The axial length of the cylinder 56 from the first regenerator support member 37 is longer than the axial height of the regenerator 38. Therefore, the cylinder tip 56b protrudes from the regenerator 38 in the axial direction.

The regenerator container 54 includes a container proximal end 54a and a container distal end 54b, and extends in the axial direction from the container proximal end 54a to the container distal end 54b. The regenerator container 54 is disposed coaxially with the cylinder 56, and forms an annular or donut-shaped accommodation space for the regenerator 38 with the cylinder 56. The second regenerator support member 39 is fixed to the container base end 54a. The cooling stage 29 is disposed on the opposite side to the regenerator 38 in the axial direction with respect to the second regenerator support member 39 and is fixed to the container base end 54a. The cooling stage 29 has a dome-shaped inner surface. A working gas expansion space 28 is formed between the dome-shaped inner surface of the cooling stage 29 and the second regenerator support member 39.

The second assembly 13b is detachably attached to the first assembly 13a. By attaching the first assembly 13a to the second assembly 13b, the regenerator 38 is disposed adjacent to the inside of the regenerator container 54 in the radial direction, and the first regenerator support member 37 and the second regenerator support member 39 are disposed. And are held in the axial direction.

The expander 13 includes an expander body 20, a displacer 22, and at least one support portion 40.

The expander body 20 is a pressure vessel configured to hold a high-pressure working gas in an airtight manner. This pressure vessel may be composed of a plurality of vessel parts connected to each other so as to keep the inside airtight. The displacer 22 is a movable member configured to reciprocate within the expander body 20. The support unit 40 supports the displacer 22 on the expander body 20 so that the displacer 22 can reciprocate.

The expander body 20 includes a first section 24 and a second section 26. The first compartment 24 includes a working gas expansion space 28 formed between the expander body 20 and the displacer 22. A portion of the expander body 20 adjacent to the expansion space 28 is provided with a cooling stage 29 for cooling the object. The second section 26 is configured to support the displacer 22 on the expander body 20 via the elastic member 30.

A part of the expander body 20 on the first section 24 side is accommodated in a vacuum container (not shown). The flange 47 separates the vacuum layer inside the vacuum vessel and the atmospheric layer outside the vacuum vessel.

The second section 26 is adjacent to the first section 24 in the reciprocating direction of the displacer 22 (indicated by an arrow C in the figure). A seal portion 25 is provided between the second compartment 26 and the first compartment 24, whereby the second compartment 26 is partitioned from the first compartment 24. Therefore, the pressure fluctuation of the working gas in the first section 24 is not transmitted to the second section 26 or does not significantly affect the pressure of the working gas in the second section 26. The second compartment 26 is filled with the same type of gas as the working gas so as to have a pressure equivalent to the average pressure of the working gas sent from the compressor 11.

The displacer 22 extends in the cylinder 56 in the axial direction. The displacer 22 is disposed so as to reciprocate in the axial direction along the cylinder 56. The displacer 22 includes a first displacer outer peripheral surface 32a, a second displacer outer peripheral surface 32b, and a displacer step portion 32c.

The displacer 22 includes a displacer head 32 accommodated in the first section 24 and a displacer rod 34. The displacer rod 34 is a shaft portion thinner than the displacer head 32. The displacer 22 has a central axis (indicated by the alternate long and short dash line A in the figure) parallel to the reciprocating direction of the displacer, and the displacer head 32 and the displacer rod 34 are provided coaxially with the central axis of the displacer 22. The displacer 22 has an internal space and is filled with the same kind of gas as the working gas.

The displacer rod 34 extends from the displacer head 32 through the seal portion 25 to the second section 26. The displacer rod 34 is supported by the expander body 20 in the second section 26 so that the displacer 22 can reciprocate. For example, the seal portion 25 described above may be a rod seal formed between the displacer rod 34 and the expander body 20. The displacer rod 34 also has an internal space like the displacer 22. The displacer rod 34 is connected to the displacer head 32 and communicates with the internal space of the displacer 22.

The expander 13 supports the displacer 22 on the expander body 20 so that the displacer 22 can reciprocate at a plurality of different positions in the reciprocating direction of the displacer 22. For this purpose, the expander 13 is provided with two support portions 40. These two support portions 40 are provided in the second section 26. In this way, tilting of the displacer 22 with respect to the central axis can be suppressed.

The elastic member 30 provided in the support portion 40 is disposed between the displacer rod 34 and the expander body 20 so that an elastic restoring force acts on the displacer 22 when the displacer 22 is displaced from the neutral position. ing. Thereby, the displacer 22 reciprocates at a natural frequency determined from the spring constant of the elastic member 30, the spring constant caused by the pressure of the working gas, the weight of the displacer 22, and the like. For example, the gas spring action according to the cross-sectional area of the displacer rod 34 also affects the natural frequency.

The elastic member 30 includes, for example, a spring mechanism including at least one leaf spring. The leaf spring is a spring called a flexure bearing, and is flexible in the reciprocating direction of the displacer 22 and rigid in the direction perpendicular to the reciprocating direction. Therefore, the displacer 22 is allowed to move in the direction along the central axis by the elastic member 30, but the movement in the direction orthogonal to the displacer 22 is restricted. The displacer rod 34 is fixed to the elastic member 30 via the elastic member mounting portion 51.

Thus, a vibration system composed of the displacer 22 and the elastic member 30 is configured. This vibration system is configured such that the displacer 22 vibrates at the same frequency as the vibration of the movable member of the compressor 11 and has a phase difference with the vibration. The displacer 22 is driven by the pulsation of the working gas pressure generated by the vibration of the movable member of the compressor 11. A reciprocating motion of the displacer 22 and the movable member of the compressor 11 forms a reverse Stirling cycle between the expansion space 28 and the working gas chamber of the compressor 11. Thus, the cooling stage adjacent to the expansion space 28 is cooled, and the Stirling refrigerator 10 can cool the object.

The expansion space 28 is formed between the distal end surface of the displacer head 32 and the cooling stage 29. The expansion space 28 is formed on the opposite side in the axial direction from the joint between the displacer head 32 and the displacer rod 34. A gas space 36 connected to the connection pipe 12 is formed between the joint portion and the seal portion 25. The working gas can be circulated between the expansion space 28 and the gas space 36 through a regenerator 38.

The first regenerator support member 37 is disposed between the regenerator 38 and the gas space 36, that is, in the normal temperature part of the Stirling refrigerator 10. Similar to the regenerator 38, the first regenerator support member 37 has an annular or donut shape. The first regenerator support member 37 extends outward in the radial direction from the cylinder base end 56a. The first regenerator support member 37 has a working gas flow path, and the working gas flows between the gas space 36 and the regenerator 38 through the first regenerator support member 37.

The first regenerator support member 37 includes a first heat exchanger 37a. The first heat exchanger 37a may be, for example, a water-cooled heat exchanger or a heat exchanger that uses a coolant or a refrigerant. The first heat exchanger 37 a cools the working gas supplied from the compressor 11 and realizes heat exchange for releasing the heat to the outside of the expander 13. The first regenerator support member 37 may be formed integrally with the first heat exchanger 37a.

The second regenerator support member 39 is arranged between the regenerator 38 and the cooling stage 29, that is, in the low temperature part of the Stirling refrigerator 10. Similar to the regenerator 38, the second regenerator support member 39 has an annular or donut shape. The second regenerator support member 39 extends radially inward from the container base end 54a. The second regenerator support member 39 has a working gas flow path, and the working gas flows between the expansion space 28 and the regenerator 38 through the second regenerator support member 39. The second regenerator support member 39 may be a low temperature heat exchanger. The second regenerator support member 39 is made of metal (for example, oxygen-free copper).

The first regenerator support member 37 and the second regenerator support member 39 are provided as a pair of holders for the regenerator 38. The pair of holders sandwich the cold storage material laminate from both axial ends so as to compress and hold the cold storage material laminate in the axial direction. The reason for compressing and holding the regenerator material in this way is to prevent a change in the position of the regenerator material due to the flow of the working gas. In this way, a large number of cool storage material members forming the cool storage material laminate are fixed between the pair of holders.

The second regenerator support member 39 includes an annular groove 39a and a support member inner peripheral surface 39b. The annular groove 39a is formed at a position corresponding to the cylinder tip 56b. The cylinder inner peripheral surface 56c has a first inner diameter D1, and the support member inner peripheral surface 39b has a second inner diameter D2 that is smaller than the first inner diameter D1.

The first displacer outer peripheral surface 32a faces the cylinder inner peripheral surface 56c and has a first outer diameter d1. The second displacer outer peripheral surface 32b faces the support member inner peripheral surface 39b and has a second outer diameter d2 that is smaller than the first outer diameter d1. The displacer step portion 32c is formed between the first displacer outer peripheral surface 32a and the second displacer outer peripheral surface 32b. The displacer step portion 32 c helps to reduce the leakage of the working gas that passes through the gap between the displacer head 32 and the cylinder 56.

The annular seal member 64 is sandwiched between the cylinder tip 56b and the second regenerator support member 39. Specifically, the cylinder front end 56 b includes an annular seal member 64, and the cylinder front end 56 b is fitted into the annular groove 39 a together with the annular seal member 64. The annular seal member 64 is attached to the cylinder tip 56b so as to cover the inner surface and the outer surface of the cylinder tip 56b. As shown by the arrows in FIG. 3, the first assembly 13a is inserted into the second assembly 13b, and both are combined. The cylinder tip 56b and the second regenerator support member 39 are not joined by brazing.

The annular seal member 64 is made of a resin material. For example, the annular seal member 64 is made of a fluorine resin (for example, polytetrafluoroethylene, PTFE) or polyamide resin sleeve, a polyimide film adhesive tape (for example, Kapton (registered trademark) tape), a heat shrinkable tube, A slipper seal or an O-ring may be used. The annular seal member 64 may be an elastic body.

FIG. 4 schematically shows a regenerator 138 of a Stirling refrigerator. In FIG. 4, the displacer is not shown, and its central axis is indicated by a one-dot chain line. The regenerator 138 is disposed coaxially with the center axis of the displacer.

The regenerator 138 includes a regenerator container 152 having a container outer cylinder 154 and a container inner cylinder 156. The container inner cylinder 156 functions as a cylinder for guiding the displacer. A cold storage material laminate 158 is accommodated between the container outer cylinder 154 and the container inner cylinder 156. The cold storage material laminate 158 is formed of a number of wire mesh members 160 laminated in the axial direction. Each wire mesh member 160 extends along a plane perpendicular to the axial direction. A pair of holders 162 is provided at both axial ends of the regenerator material stack 158. The metal mesh member 160 has an annular or donut shape. Similarly, the holder 162 has an annular or donut shape.

Generally, the wire mesh member 160 is dimensioned so that the space in the cool storage material container 152 is completely filled and no gap is generated between the cool storage material container 152 and the cool storage material laminate 158. However, actually, as shown in the drawing, a slight gap may occur between the cold storage material laminate 158 and the cold storage material container 152. An outer gap 164a may be formed between the container outer cylinder 154 and the cool storage material laminate 158, and an inner gap 164b may be generated between the container inner cylinder 156 and the cool storage material stack 158. Such gaps are caused by manufacturing tolerances of the wire mesh member 160. The gap can serve as a working gas passage. When the working gas flows through the gap, heat exchange between the working gas and the cold storage material is not effectively performed. Therefore, the efficiency of the regenerator 138 will fall. Even with a slight gap, the performance of the regenerator 138 can be significantly reduced.

On the other hand, the Stirling refrigerator 10 according to the embodiment is provided with an annular seal member 64, and a gap that may be generated between the second regenerator support member 39 and the cylinder 56 is closed. Even if a gap is generated between the regenerator 38 and the cylinder 56, the annular seal member 64 can block the working gas flow there. Therefore, the efficiency reduction of the regenerator 38 can be prevented or alleviated.

Further, the annular seal member 64 closes a gap that may be generated between the second regenerator support member 39 that is a low-temperature heat exchanger and the cylinder 56. Therefore, the heat exchange efficiency of the low-temperature heat exchanger can be improved.

The annular seal member 64 may be provided in the cylinder 56 to prevent the regenerator 38 from coming off. Before the first assembly 13a is attached to the second assembly 13b, the regenerator 38 can be prevented from falling when the first assembly 13a is turned upside down. Assembling workability can be improved.

FIG. 5 is a diagram schematically showing an expander 13 according to another embodiment. As shown in FIG. 5, the annular seal member 64 may be attached to the cylinder tip 56b so as to cover only the outer surface of the cylinder tip 56b. The annular seal member 64 is sandwiched between the cylinder front end 56 b and the second regenerator support member 39. Even in this case, the annular seal member 64 can block the working gas flow in the gap between the regenerator 38 and the cylinder 56.

FIG. 6 is a diagram schematically showing an expander 13 according to another embodiment. As shown, the annular seal member 64 is similar to the embodiment of FIGS. However, the second regenerator support member 39 includes an inner peripheral portion 39c that contacts the annular seal member 64 and an outer peripheral portion 39d that is fixed to the container base end 54a. The inner peripheral portion 39c protrudes in the axial direction toward the cooling stage 29 in the expansion space 28 with respect to the outer peripheral portion 39d. Such a shape of the second regenerator support member 39 serves to direct the working gas flow 66 between the second regenerator support member 39 and the expansion space 28 toward the cooling stage 29.

FIG. 7 is a diagram schematically showing an expander 13 according to another embodiment. The first heat exchanger 37a may be provided as a first regenerator support member. As illustrated, the first heat exchanger 37a may directly support the regenerator 38. Thus, the 1st regenerator support member 37 shown by FIG. 2 etc. may be abbreviate | omitted.

The second regenerator support member 39 includes a second heat exchanger 41 (for example, the low-temperature heat exchanger described above), and a regenerator presser member 42 sandwiched between the second heat exchanger 41 and the regenerator 38. May be. As described above, the second regenerator support member 39 may be configured by a heat exchanger and a pressing member that are separate from each other, similarly to the first regenerator support member 37 illustrated in FIG. 2.

The heat exchanger integrated first regenerator support member shown in FIG. 7 can be applied to any of the above-described embodiments. For example, when applied to the embodiment shown in FIG. 2, both the first regenerator support member 37 and the second regenerator support member 39 are configured as a heat exchanger integrated type. Moreover, the heat exchanger separated type second regenerator support member shown in FIG. 7 can be applied to any of the above-described embodiments. For example, when applied to the embodiment shown in FIG. 2, both the first regenerator support member 37 and the second regenerator support member 39 are configured as a heat exchanger separation type.

The present invention has been described above based on the embodiments. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, various modifications are possible, and such modifications are within the scope of the present invention. By the way.

The seal structure according to the embodiment may be applied to a Stirling refrigerator that does not include the displacer 22, for example, a Stirling pulse tube refrigerator. In this case, the cylinder 56 may be a pulse tube cylinder.

10 Stirling refrigerator, 13a first assembly, 13b second assembly, 22 displacer, 25 seal part, 28 expansion space, 29 cooling stage, 32a first displacer outer peripheral surface, 32b second displacer outer peripheral surface, 32c displacer step part 37, first regenerator support member, 37a first heat exchanger, 38 regenerator, 39 second regenerator support member, 39a annular groove, 39b support member inner peripheral surface, 39c inner peripheral portion, 39d outer peripheral portion, 40 support Part, 41, second heat exchanger, 54 regenerator container, 54a container proximal end, 54b container distal end, 56 cylinder, 56a cylinder proximal end, 56b cylinder distal end, 56c cylinder inner peripheral surface, 64 annular seal member.

The present invention can be used in the field of Stirling refrigerators.

Claims

A cylinder having a cylinder proximal end and a cylinder distal end and extending in the axial direction from the cylinder proximal end to the cylinder distal end; a regenerator disposed adjacent to a radially outer side of the cylinder; and fixed to the cylinder proximal end A first regenerator support member, and a first assembly comprising:
A second regenerator support member having a container proximal end and a container distal end and extending in the axial direction from the container proximal end to the container distal end; and a second regenerator support member fixed to the container proximal end. An assembly, wherein the regenerator is disposed adjacent to the radially inner side of the regenerator container and is held in the axial direction by the first regenerator support member and the second regenerator support member. A second assembly removably attached to the first assembly;
A Stirling refrigerator, comprising: an annular seal member sandwiched between the cylinder tip and the second regenerator support member.
The cylinder tip includes the annular seal member, the second regenerator support member has an annular groove, and the cylinder tip is fitted in the annular groove together with the annular seal member. Item 2. A Stirling refrigerator according to item 1.
The Stirling refrigerator according to claim 1 or 2, wherein the annular seal member is mounted on the tip of the cylinder so as to cover an inner surface and an outer surface of the tip of the cylinder.
The second assembly includes a cooling stage that is disposed on the opposite side of the regenerator in the axial direction with respect to the second regenerator support member and is fixed to the container base end. Formed between the stage and the second regenerator support member;
The second regenerator support member includes an inner peripheral portion that contacts the annular seal member and an outer peripheral portion fixed to the container base end, and the inner peripheral portion is in the expansion space with respect to the outer peripheral portion. The Stirling refrigerator according to claim 1, wherein the Stirling refrigerator projects in an axial direction toward the cooling stage.
A displacer extending in the axial direction in the cylinder, further comprising a displacer disposed so as to be capable of reciprocating in the axial direction along the cylinder;
The cylinder includes a cylinder inner peripheral surface having a first inner diameter, and the second regenerator support member includes a support member inner peripheral surface having a second inner diameter smaller than the first inner diameter,
The displacer has a first displacer outer peripheral surface facing the inner peripheral surface of the cylinder and having a first outer diameter, and a second outer surface facing the inner peripheral surface of the support member and having a second outer diameter smaller than the first outer diameter. The Stirling according to any one of claims 1 to 4, further comprising: a displacer outer peripheral surface, and a displacer step portion formed between the first displacer outer peripheral surface and the second displacer outer peripheral surface. refrigerator.
The Stirling refrigerator according to any one of claims 1 to 5, wherein the first regenerator support member includes a first heat exchanger.
The Stirling refrigerator according to any one of claims 1 to 6, wherein the second regenerator support member includes a second heat exchanger.