JP2008309452A - Coldness storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coldness storage device capable of preventing a flow of a coldness storing material, reducing a dead space in the coldness storage device, and improving refrigerating performance. <P>SOLUTION: In this coldness storage device 1, an internal space where a working medium is circulated through passages 4, 13 is filled with granular coldness storage materials 9a, 9b. An internal space is incorporated with distributors 6, 10 including a plurality of branch passages 5, 12 for distributing the working medium, and retainers 8a, 8c which are disposed between the distributors 6, 10 and coldness storage materials 9a, 9b to retain the coldness storage materials 9a, 9b and pass the working medium. The distributors 6, 10 are incorporated with a plurality of small coiled springs 7, 11 which energize the retainers 8a, 8c toward the coldness storage materials 9a, 9b, and the small coiled springs 7, 11 are housed at least in part of the plurality of branch passages 5, 12 in the distributors 6, 10, and dispersed and disposed on a surface orthogonal to the circulating direction of the working medium and the axial direction of the coldness storage device 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a regenerator, and more particularly, to a regenerator filled with a granular regenerator material, and more particularly to a regenerator that is suitably applied to a regenerative cryogenic refrigerator.

  Patent Document 1 proposes a regenerator in which a plurality of filters are provided in the regenerator in order to prevent particles of the regenerator material filled in the regenerator from flowing out of the regenerator. . In general, among the regenerator materials used in the cryogenic refrigerator, granular lead or rare earth alloy regenerator materials having a particle size of about 0.2 mm are used in a temperature range of about 60 K or less. Such a regenerator material receives pressure by the high-pressure working gas flowing in the regenerator, and further wears and breaks due to contact between particles, thereby generating fine powder. According to the invention of Patent Document 1, this phenomenon is suppressed by a plurality of filters installed in the regenerator.

  In the regenerator of Patent Document 2, a retainer and an elastic body (spring) for pressing the regenerator material are provided at the low temperature end and the high temperature end in the regenerator filled with the same regenerator material as in Patent Document 1, respectively. The state in which the cold storage material is pressurized is maintained to prevent the cold storage material from flowing out of the regenerator. Specifically, the regenerator of Patent Document 2 includes a plurality of box-shaped retainers and springs that bias the retainers, and the plurality of retainers are filled with a regenerator material. Further, this regenerator does not have a distributor for bringing the working gas into uniform contact with the regenerator material.

Japanese Patent Laid-Open No. 5-296687 JP-A-7-269966

  According to the regenerator of Patent Document 1, the gap between the regenerator particles expands due to wear or breakage of the regenerator material, so that the regenerator material easily moves along with the gas flow. As a result, according to the regenerator of Patent Document 1, the relatively thin filter (several mm in the embodiment) is inclined, so that the regenerator material leaks from the periphery of the filter and may flow out of the regenerator. There is.

  According to the regenerator of Patent Document 2, the problem of Patent Document 1 is solved by filling the box-shaped retainer with the regenerator material, and further, by applying a pressure to the regenerator material via the retainer with a spring. The gap between grains due to wear and breakage of the regenerator particles is suppressed. However, there is a problem that the installation of the spring for applying pressure increases the dead space on the low temperature side and the high temperature side in the internal space of the regenerator, thereby reducing the refrigeration performance. In addition, since the regenerator of Patent Document 2 does not have a distributor, there is a problem that the working gas is difficult to be supplied uniformly to the regenerator material, particularly in the direction perpendicular to the flow direction of the working gas.

  An object of the present invention is to provide a regenerator in which the flow of the regenerator material is prevented, the dead space in the regenerator is reduced, and the refrigeration performance is improved.

  In a first aspect, the present invention is a regenerator in which an internal space in which a working gas flows is filled with a granular regenerator material, and a plurality of branch channels for distributing the working gas to the internal space And a distributor that is disposed at least between the distributor and the granular regenerator material and that holds the regenerator material and allows the working gas to pass therethrough. A regenerator having a plurality of elastic members dispersed and arranged so as to be urged toward a regenerator material is provided.

  According to the present invention, by providing the distributor that distributes the working gas to the cold storage material, the working gas is uniformly supplied to the cold storage material, and the refrigeration performance is improved. Furthermore, according to the present invention, the elastic member that pressurizes the regenerator material is distributed and arranged in the distributor, so that the space for installing the spring that becomes the dead space of the regenerator can be greatly reduced. Decrease in refrigeration performance due to increase in the amount can be reduced. Furthermore, according to the present invention, a plurality of elastic members are distributed and arranged on the surface of the regenerator, so that the load (surface pressure) applied to the surface of the retainer urged from the elastic member is distributed, compared to the conventional case. The retainer surface can be made thinner, and the dead space in the regenerator can be further reduced. Moreover, according to this invention, while being able to simplify the structure of a retainer, since an equal load is added to a retainer, the durability of a retainer and also a regenerator is improved.

  In a preferred embodiment of the present invention, a distributor having a plurality of holes (a plurality of branch flow paths) is arranged in the high-pressure working gas inflow / outflow portion of the regenerator, and a plurality of distributors are disposed on the inner end face of the regenerator. Provide spot facings, place small coil springs (elastic members) to apply pressure to the regenerator, and distribute them, or distribute multiple coil springs in multiple branch channels, A retainer formed of a porous material or a wire mesh is provided between the distributor and the cold storage material. Preferably, the counterbore is part of the branch channel. Preferably, the retainer is provided with a guide portion that is formed so as to be in contact with the inner surface of the tubular regenerator without a gap and whose axial length of the tubular regenerator is several mm or more.

  In a preferred embodiment of the present invention, the plurality of elastic members are arranged in a distributed manner on a plane orthogonal to the flow direction of the working gas or the axial direction of the regenerator. As a result, the load applied to the retainer urged by the elastic member is dispersed, the retainer can be thinned, and the dead space in the regenerator can be further reduced.

  In a preferred embodiment of the present invention, in the distributor, the plurality of elastic members are respectively accommodated and arranged in at least a part of the plurality of branch flow paths. This further reduces dead space.

  In a preferred embodiment of the present invention, the plurality of elastic members are housed in a plurality of spot facings formed in the main body of the distributor.

  In a preferred embodiment of the present invention, a flow path for introducing the working gas into the internal space of the regenerator is expanded toward the distributor. Thereby, working gas is uniformly distributed with respect to a cool storage material, and refrigerating performance is improved.

  In a preferred embodiment of the present invention, the distributor is made of stainless steel or the like that can hold a plurality of small coil springs.

  In a preferred embodiment of the present invention, a plurality of elastic members arranged in the distributor, for example, a plurality of small coil springs, are arranged axisymmetrically so that the regenerator material can be evenly pressurized in the regenerator surface.

  According to a preferred embodiment of the present invention, the retainer includes a porous end surface through which the working gas passes and a guide portion that is in sliding contact with the inner surface of the regenerator.

  An embodiment of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing the structure of a regenerator according to Embodiment 1 of the present invention.

  Referring to FIG. 1, a cylindrical cold storage in which an internal space in which a working gas (for example, He gas) flows through flow paths 4 and 13 is filled with granular cold storage materials 9 a and 9 b (for example, a diameter of about 0.2 m). The container 1 is disposed in the internal space between the distributors 6 and 10 having a plurality of branch passages 5 and 12 for distributing the working gas, and between the distributors 6 and 10 and the regenerator materials 9a and 9b. Retainers 8a and 8c that hold the materials 9a and 9b and allow the working gas to pass therethrough are incorporated. Further, a retainer 8b is sandwiched between the cold storage materials 9a and 9b. The retainers 8a, 8b, and 8c are formed of a porous material that allows the working gas to pass therethrough, and include guide portions 14 that are in sliding contact with the inner peripheral surface of the regenerator 1 without any gaps. The retainers 8a, 8b, and 8c can be formed of a porous material or a wire mesh through which the working gas passes.

  Distributors 6 and 10 respectively disposed in the working gas inflow / outflow portions of the regenerator 1 incorporate therein a plurality of small coil springs 7 and 11 that urge at least the retainers 8a and 8c toward the regenerator materials 9a and 9b, respectively.

  The small coil springs 7 and 11 are accommodated in at least a part of the plurality of branch flow paths 5 and 12 in the distributors 6 and 10, respectively, on a plane perpendicular to the working gas flow direction or the axial direction of the regenerator 1. It is distributed and serves to hold down the cold storage materials 9a and 9b by applying a load to at least the retainers 8a and 8c. The plurality of branch channels 5 and 12 communicate with the distributors 6 and 10 in the axial direction.

  The flow paths 4 and 13 for introducing the working gas into the internal space of the regenerator 1 are respectively expanded toward the distributors 6 and 10 so that the working gas distribution capability is improved, and a plurality of branch flow paths 5 are provided. , 12 are introduced into the working gas, respectively.

  The operation of the regenerator according to the first embodiment of the present invention described above will be described. In the following description, the upper part in FIG. 1 is the high temperature side 2 and the lower part is the low temperature side 3.

  Still referring to FIG. 1, the working gas introduced from the flow path 4 on the high temperature side 2 is dispersed by the distributor 6 on the high temperature side 2 and enters a plurality of branch flow paths 5, and further passes through the retainer 8 a to store cold. Contact material 9a. Subsequently, the working gas passes through the retainer 8b, the regenerator material 9b, and the retainer 8c, and merges in the low-temperature side 3 flow path 13 through the plurality of branch flow paths 12 provided in the low-temperature side 3 distributor 10 to store the cold. Out of vessel 1 Further, the working gas from the low temperature side 3 flows in the opposite direction while being in contact with the cold storage materials 9b and 9a.

  The regenerative flow of the working gas moves the regenerator materials 9a and 9b, and the regenerator materials 9a and 9b come into contact with each other and wear to form a gap. At this time, since at least the retainers 8a and 8c are uniformly urged by the plurality of small coil springs 7 and 11, respectively, a load is applied to the cool storage materials 9a and 9b, and free movement of the cool storage materials 9a and 9b is restricted. .

  Further, since the plurality of small coil springs 7 and 11 are built in the distributors 6 and 10, a large space is not required for arrangement. For this reason, the dead space in the cool storage 1 which becomes a factor which reduces refrigeration performance can be reduced.

  In particular, according to the present embodiment, by installing a plurality of small coil springs 7 and 11 in the branch flow paths 6 and 10, the installation space of the spring and the flow path of the working gas are integrated, so that the dead space is further increased. It can suppress and the storage space of the cool storage materials 9a and 9b can further be expanded.

  Further, since the plurality of small coil springs 7 and 11 are dispersedly arranged with respect to the end surfaces of the retainers 8a and 8c, respectively, the load is evenly applied to the end surfaces, and the retainers 8a and 8c receiving the load can be made thin. it can. Thereby, retainer 8a, 8c can be reduced in size, and the dead space in the regenerator 1 can be reduced more.

  FIG. 2 is a schematic diagram showing an example of a distributed arrangement of the plurality of small coil springs 7 and 11 in the regenerator of FIG. 1, and shows an axial section of the distributors 6 and 10. In FIG. 2, black circles indicate the branch flow paths 5 and 12 in which the small coil springs 7 and 11 are disposed, and white circles indicate the branch flow paths 5 and 12 in which the small coil springs 7 and 11 are not disposed.

  Referring to FIG. 2, it is sufficient that the plurality of small coil springs 7 and 11 are distributed and arranged in a part of the plurality of branch flow paths 5 and 12 formed in the distributors 6 and 10, respectively.

  In the description of the regenerator according to the second embodiment of the present invention, the description of the first embodiment can be appropriately referred to for the same structure, operation and effect as the regenerator according to the first embodiment. Hereinafter, differences from the first embodiment will be mainly described.

  FIG. 3 is a cross-sectional view illustrating the structure of the regenerator according to the second embodiment of the present invention. Referring to FIG. 3, in the regenerator 1 according to the second embodiment, a plurality of countersunks 6 a and 10 a are provided on the inner end surface of the regenerator 1 of the distributors 6 and 10, separately from the plurality of branch channels 5 and 12. Each is formed. A plurality of small coil springs 7 and 11 are incorporated in the plurality of counterbore 6a and 10a, respectively, and are distributed on a plane orthogonal to the flow direction of the working gas or the axial direction of the regenerator 1.

  The regenerator according to the present invention can be applied not only to the fixed regenerator of Example 1 or 2, but also to a regenerator created inside a displacer that moves like a GM refrigerator or a Stirling refrigerator. it can. Examples thereof will be described below. FIG. 4 is a cross-sectional view illustrating an example in which the regenerator of the present invention is applied to a displacer according to the third embodiment of the present invention.

  In the description of the regenerator according to the third embodiment of the present invention, the description of the first embodiment may be referred to as appropriate for the same structure, operation, and effect as the regenerator according to the first embodiment. In the following, differences from the first embodiment will be mainly described.

  Referring to FIG. 4, the regenerator 1 shown in FIG. 1 is configured in the reciprocating displacer 15, and a plurality of high-temperature distributors 6 are provided in the displacer 15. A plurality of small coil springs 7 are respectively installed in a part of the branch flow path 5, and a plurality of small coil springs 11 are respectively installed in a part of the plurality of branch flow paths 12 included in the distributor 10 on the low temperature side. Moreover, the cool storage material 9c is also filled between the intermediate retainers 8b and 8b.

  An example in which the regenerator of the present invention is applied to a refrigeration unit of a pulse tube refrigerator will be described. FIG. 5 is a block diagram showing a system of a pulse tube refrigerator to which the regenerator according to the present invention is applied. Referring to FIG. 5, in this pulse tube refrigerator 19, the regenerator 1 according to the present invention is used as a low-temperature second-stage regenerator 1 having a temperature range of 80K or less.

  Specifically, the pulse tube refrigerator 19 is connected to the pressure vibration generating unit 20 and the pressure vibration generating unit 20 including the compressor 25 and the high-pressure side and low-pressure side switching valves 26 and 27 connected thereto. The freezing unit 24 is provided. The refrigeration unit 24 includes a first-stage and second-stage pulse tubes 22, 23, first-stage and second-stage pulse tubes 22, 23, and first-stage and second-stage regenerators 21, 1. ,have. The refrigeration unit 24 is connected to buffers 32 and 33 for generating substantial heat transport by shifting the phase of pressure fluctuation of the working gas and the position fluctuation of the working gas via the throttles 28 to 31. .

  The first-stage pulse tube 22 is connected between the first-stage and second-stage regenerators 21, 1, that is, the flow path 4 on the high temperature side of the regenerator 1 according to the present invention. The second-stage pulse tube 23 is connected to the flow path 13 on the low temperature side of the second-stage regenerator 1. For example, the high temperature side of the first stage regenerator 21 is about 300K (room temperature), the high temperature side flow path 4 of the second stage regenerator 1 is about 80-60K, and the low temperature side flow of the second stage regenerator 1 is. The path 13 is set to about 20-4K.

  According to the pulse tube type refrigerator 19, working gas is introduced from the pressure vibration generating unit 20 to the freezing unit 24, and pressure vibration is applied to the working gas in the pulse tubes 22 and 23, thereby cooling due to the thermoacoustic effect. This is transmitted to the regenerators 21, 1, and the working gas reciprocates in the regenerators 21, 1, so that the working gas is deprived of heat by the regenerator material in the regenerators 21, 1 and heat. The discharge operation is continuously performed. As a result, both sides of the regenerators 21 and 1 are maintained at the above-described temperature.

  The regenerator of the present invention is applied to a regenerative cryogenic refrigerator. The regenerator of the present invention is applied to a refrigerator having a fixed regenerator such as a pulse tube refrigerator. Alternatively, the regenerator of the present invention is configured in a movable displacer like a GM type refrigerator or a Stirling type refrigerator.

It is sectional drawing which shows the structure of the regenerator which concerns on Example 1 of this invention. FIG. 2 is a schematic diagram showing an example of a distributed arrangement of a plurality of small coil springs in the regenerator of FIG. 1. It is sectional drawing which shows the structure of the regenerator which concerns on Example 2 of this invention. It is sectional drawing which shows the structure of the regenerator which concerns on Example 3 of this invention. It is a block diagram showing a system of a pulse tube type refrigerator to which a regenerator according to the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Regenerator 2 High temperature side of regenerator 3 Low temperature side of regenerator 4, 13 Working gas flow path 5, 12 Branch flow path 6, 10 Distributor 6a, 10a Counterbore 7, 11 Small coil spring (elastic member)
8a, 8b, 8c Retainers 9a, 9b, 9c Regenerator 14 Guide part 15 Displacer 19 Pulse tube refrigerator 20 Pressure vibration generator 21, 1st stage and 2nd stage regenerator 22, 23 First stage and 2nd stage pulse Pipe 24 Refrigeration unit 25 Compressor 26, 27 High-pressure side and low-pressure side switching valve 28-31 Restriction 32, 33 Buffer

Claims (5)

A regenerator in which a granular regenerator material is filled in an internal space where working gas flows,
A distributor having a plurality of branch passages for distributing the working gas in the internal space, and at least disposed between the distributor and the granular regenerator, presses the regenerator, and allows the working gas to pass through. Built-in retainer,
The distributor includes a plurality of elastic members dispersedly arranged so as to urge the retainer toward the granular cool storage material.   The regenerator according to claim 1, wherein in the distributor, the plurality of elastic members are accommodated in at least a part of the plurality of branch flow paths.   2. The regenerator according to claim 1, wherein the plurality of elastic members are respectively incorporated in a plurality of counterbore formed in the main body of the distributor.   The regenerator according to any one of claims 1 to 3, wherein a flow path for introducing the working gas into the internal space of the regenerator is expanded toward the distributor.   5. The regenerator according to claim 1, wherein the plurality of elastic members are distributed on a surface orthogonal to a flow direction of the working gas or an axial direction of the regenerator.

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