JP3878924B2 - Stirling refrigerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a Stirling refrigerator, and more particularly to a free piston type Stirling refrigerator.
[0002]
[Prior art]
Conventionally, a Stirling cooling device using a Stirling refrigerator is known, and an example of the Stirling cooling device is described in, for example, Japanese Patent Application Laid-Open No. 11-223404.
[0003]
The Stirling cooling device described in the above document includes a Stirling refrigerator that encloses a working gas and has a cooling head and a heat exchanger for heat dissipation, a cold refrigerant pipe through which a cold refrigerant cooled in the cooling head flows, A refrigerant inlet plug provided at one end of the refrigerant pipe and an outlet plug provided at the other end are provided. Then, by connecting the outlet plug and the inlet plug of the refrigeration refrigerant to the refrigeration refrigerant pipe of the refrigeration equipment, the refrigeration refrigerant circulation pipe is formed between the Stirling cooling device and the refrigeration equipment to use the chill. Convey cold heat to equipment.
[0004]
A heat exchange channel is formed in the cooling head, and a cold refrigerant flows through the heat exchange channel. The cold refrigerant is cooled by the cooling head and then sent to the cold energy utilization device, and performs refrigeration or cooling in the cold energy utilization device.
[0005]
[Patent Document 1]
JP 11-223404 A
[0006]
[Problems to be solved by the invention]
In the Stirling cooling apparatus described in the above document, the working gas flows into the low temperature chamber (expansion space) after being cooled by the regenerator. Then, the working gas expands in the low temperature chamber to generate cold heat, and the cold heat is taken out through the cooling head. Therefore, there has been a problem that the efficiency of taking out the cold heat from the low temperature chamber is lowered.
[0007]
This invention was made in order to solve said subject, and it aims at providing the Stirling refrigerator which can take out the cold heat which generate | occur | produces in expansion space outside efficiently.
[0008]
[Means for Solving the Problems]
In one aspect, the Stirling refrigerator according to the present invention includes a cylinder assembled in a pressure vessel enclosing a working medium, a piston that reciprocates within the cylinder, and a reciprocating motion with a phase difference with respect to the piston within the cylinder. Displacer and reciprocating motion of piston and displacer In the pressure vessel so that the pressure fluctuates A compression space and an expansion space formed; A cylindrical communication path that communicates the compression space and the expansion space and is disposed outside the cylinder, a regenerator disposed in the communication path, and an expansion space that is disposed on the expansion space side of the regenerator in the pressure vessel. An internal heat exchanger that takes in the cold generated inside, a cap member that closes the end of the pressure vessel on the expansion space side and extends to the outside of the internal heat exchanger, and is located outside the internal heat exchanger Provided in the cap member, Remove cold heat Outside A heat exchanger.
[0009]
By installing a heat exchanger in the pressure vessel and taking out the cold heat directly in this way, it is possible to avoid exposing the surface of the heat exchanger to the external space located outside the pressure vessel. Can do. Thereby, the amount of heat exchange between the heat exchanger and the external space can be reduced, and the cold energy from the working medium can be efficiently transmitted to the heat exchanger.
[0010]
In another aspect, the Stirling refrigerator according to the present invention includes the above-described cylinder, piston, displacer, compression space, and expansion space, a regenerator disposed in a communication path that connects the compression space and the expansion space, and a pressure. An internal heat exchanger that is disposed in the expansion space side of the regenerator and takes in the cold generated in the expansion space, and is placed in contact with the internal heat exchanger in the pressure vessel and takes out the cold heat to the outside. An external heat exchanger.
[0011]
By installing the external heat exchanger in contact with the internal heat exchanger in the pressure vessel as in this aspect, the cold heat from the internal heat exchanger can be directly transmitted to the external heat exchanger. Therefore, the cold heat from the working medium can be efficiently transmitted to the external heat exchanger via the internal heat exchanger.
[0012]
The internal heat exchanger and the external heat exchanger are preferably integrated. For example, it is conceivable to attach or press-fit one to the other, or connect using some member. In this case, both can be adhered and heat transfer efficiency can be further improved. Also, it can be easily assembled to a Stirling refrigerator.
[0013]
In still another aspect of the Stirling refrigerator according to the present invention, the cylinder, the piston, the displacer, the compression space and the expansion space, and a cylindrical shape that communicates the compression space and the expansion space and is disposed outside the cylinder. A communication path, a regenerator disposed in the communication path, an internal heat exchanger disposed in the expansion space side of the regenerator in the pressure vessel and taking in the cold generated in the expansion space, and an internal heat exchanger And an external heat exchanger that takes out the cold heat to the outside.
[0014]
When the external heat exchanger is installed inside the internal heat exchanger as described above, the external heat exchanger can be brought into contact with or close to the internal heat exchanger. Also in this case, the cold heat from the working medium can be efficiently transmitted to the external heat exchanger via the internal heat exchanger.
[0017]
The Stirling refrigerator described above preferably includes a cap member (closing member) that closes an end of the pressure vessel on the expansion space side. In this case, the cap member is formed of a low thermal conductivity material. In addition, low thermal conductivity material Is This refers to stainless steel or a material having a thermal conductivity equal to or lower than that of stainless steel.
[0018]
Thus, by forming the cap member with a low thermal conductivity material, the amount of cold heat from the working medium transmitted to the external space located outside the pressure vessel via the cap member can be reduced. Therefore, the loss of cold heat can be reduced.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0026]
(Embodiment 1)
FIG. 1 is a cross-sectional view of a Stirling refrigerator in Embodiment 1 of the present invention. As shown in FIG. 1, the Stirling refrigerator 1 of the first embodiment includes a pressure vessel (casing) 11 having a vessel portion 10, a cylinder 2 assembled to the pressure vessel 11, and reciprocation within the cylinder 2. The moving piston 3 and the displacer 4, the cylindrical regenerator 5 disposed outside the cylinder 2 and in the communication passage 23 described later, the compression space (first working space) 6, and the expansion space (second space) Working space) 7, heat radiating part (worm head) 8, heat absorbing part (cold head) 9, linear motor 12 as piston driving means, piston spring 13, displacer spring 14, back pressure space 15, An internal heat exchanger 16 on the heat absorption part 9 side, an external heat exchanger 17 on the heat absorption part 9 side, a cap member (blocking member) 18, an internal heat exchanger 20 on the heat radiation part 8 side, and a heat radiation part 8 side It includes a section heat exchanger 21, the refrigerant pipe 19 and 22, and a communication passage 23 for communicating the compression space 6 and the expansion space 7.
[0027]
The pressure vessel 11 is a portion constituting the outer shell (outer wall) of the Stirling refrigerator 1, and various components including the cylinder 2 are assembled to the pressure vessel 11. In the example of FIG. 1, the pressure vessel 11 is not configured as a single vessel, but defines a back pressure space 15 and a vessel portion 10 that receives a linear motor 12, a heat radiating portion 8, a regenerator 5, and a heat absorbing portion 9. The outer wall portion surrounding the outer periphery and the cap member 18 are mainly configured. The inside of the pressure vessel 11 is filled with a working medium such as helium gas, hydrogen gas, or nitrogen gas.
[0028]
The cylinder 2 has a substantially cylindrical shape, and receives the piston 3 and the displacer 4 in a reciprocating manner. In the cylinder 2, the piston 3 and the displacer 4 are arranged coaxially with a space therebetween, and the piston 3 and the displacer 4 reciprocate in the cylinder 2. The displacer 4 reciprocates with a predetermined phase difference with respect to the piston 3 in the cylinder 2.
[0029]
The piston 3 and the displacer 4 divide the working space in the cylinder 2 into a compression space 6 and an expansion space 7. A regenerator 5 is disposed between the compression space 6 and the expansion space 7, and both spaces communicate with each other via the regenerator 5. Thereby, a closed circuit is formed in the Stirling refrigerator 1. The working medium sealed in the closed circuit flows in accordance with the operation of the piston 3 and the displacer 4, thereby realizing a reverse Stirling cycle.
[0030]
A linear motor 12 is disposed outside the cylinder 2. This linear motor 12 drives the piston 3 in the axial direction of the cylinder 2. One end of the piston 3 is connected to a piston spring 13 composed of a leaf spring or the like. The piston spring 13 functions as an elastic force applying means for applying an elastic force to the piston 3. The piston spring 13 and the linear motor 12 cause the piston 3 to reciprocate within the cylinder 2 with a desired amplitude and cycle. Is possible.
[0031]
A back pressure space 15 surrounded by the vessel portion 10 of the pressure vessel 11 is disposed on the side opposite to the displacer 4 with respect to the piston 3. There is also a working medium in the back pressure space 15.
[0032]
In the first embodiment, an external heat exchanger 17 that takes out cold heat generated in the expansion space 7 to the outside is installed in the pressure vessel 11. Thereby, it can be avoided that the surface of the external heat exchanger 17 is exposed to the external space located outside the pressure vessel 11. Therefore, the amount of heat exchange between the external heat exchanger 17 and the external space can be reduced, and the cold heat from the working medium can be directly transmitted to the external heat exchanger 17. As a result, it is possible to efficiently extract the cold generated in the expansion space 7 to the outside.
[0033]
Here, the external heat exchanger 17 is demonstrated using FIG. 5 and FIG. As shown in FIG. 5, the external heat exchanger 17 typically has an annular shape and is made of a material having high thermal conductivity such as copper or aluminum. A set of openings 17 a is provided on the upper surface of the external heat exchanger 17. The opening 17a functions as a cold refrigerant supply port or an outlet. A refrigerant pipe 19 (to be described later) that functions as a supply pipe or an extraction pipe is connected to the supply port or the outlet.
[0034]
As shown in FIG. 6, the external heat exchanger 17 main body has a hollow structure and has an internal space 17b. Cold refrigerant is enclosed in the internal space 17b. As a cold refrigerant usable in the external heat exchanger 17, carbon dioxide (CO ₂ ), Ethyl alcohol, ether-based fluorine compound (HFE), perfluorocarbon (PFC), nitrogen, helium, and the like.
[0035]
Here, referring again to FIG. 1, in the first embodiment, an external heat exchanger 17 is arranged in the expansion space 7. Thereby, the cold heat from the working medium can be transmitted directly from the periphery of the external heat exchanger 17 to the external heat exchanger 17. Therefore, the cold heat from the working medium can be efficiently transmitted to the external heat exchanger 17.
[0036]
Further, as shown in FIG. 1, an internal heat exchanger 16 on the heat absorption unit 9 side is installed in the pressure vessel 11 and on the expansion space 7 side of the regenerator 5. Thus, by installing the internal heat exchanger 16 in the flow path of the working medium in the pressure vessel 11, the cold heat from the working medium cooled by the regenerator 5 is efficiently transmitted to the internal heat exchanger 16. Can do. Further, cold heat from the working medium cooled in the expansion space 7 is also transmitted to the internal heat exchanger 16.
[0037]
The internal heat exchanger 16 is preferably made of a metal material having excellent thermal conductivity such as copper or aluminum. Note that the internal heat exchanger 16 may be formed of a material other than a metal material as long as the material has excellent thermal conductivity.
[0038]
Here, a structural example of the internal heat exchanger 16 will be described with reference to FIG. As shown in FIG. 7, the internal heat exchanger 16 includes a cylindrical outer shell portion, and corrugated fins 16 a and a ring member 16 b that are housed in the outer shell portion.
[0039]
The corrugated fins 16a are inserted inside the outer shell (the pressure vessel 11 in the first embodiment), and have a structure in which a metal plate is folded into a corrugated shape and overlapped. As shown in FIG. 7, the corrugated fin 16 a is installed along the inner peripheral surface of the outer shell portion, and the corrugated fin 16 a forms an annular flow path through which the working medium passes inside the outer shell portion. The cold heat generated when the working medium cooled by the regenerator 5 passes through the annular flow path and the cold heat from the working medium cooled in the expansion space 7 are generated by the internal heat exchanger 16 such as the corrugated fins 16a. It is transmitted to each element.
[0040]
The ring member 16b is press-fitted inside the corrugated fin 16a. Since the corrugated fin 16a has flexibility in the radial direction of the outer shell portion, the ring member 16b is deformed so as to be expanded to the outer shell portion side by being press-fitted inside the corrugated fin 16a, Crimped to the inner peripheral surface of the outer shell.
[0041]
Here, referring again to FIG. 1, the external heat exchanger 17 is installed in the pressure vessel 11 in close contact with the inner periphery of the internal heat exchanger 16. Thereby, the cold heat from the internal heat exchanger 16 can be directly transmitted to the external heat exchanger 17. Therefore, the cold heat from the working medium can be efficiently transmitted to the external heat exchanger 17 via the internal heat exchanger 16.
[0042]
At this time, if the outer periphery of the external heat exchanger 17 is formed in a tapered shape, and this external heat exchanger is press-fitted directly into the corrugated fins 16a, the ring member 16b can be eliminated, which is preferable.
[0043]
In the example of FIG. 1, the inner peripheral surface of the internal heat exchanger 16 and the outer peripheral surface of the external heat exchanger 17 are brought into contact with each other, but the internal heat exchanger 16 and the external heat exchanger 17 can be brought into contact with each other. As long as it is a thing, you may make the surface part of the internal heat exchanger 16 other than the above and the surface part of the external heat exchanger 17 contact. It is also conceivable that both are brought into contact with each other by being assembled to the internal heat exchanger 16.
[0044]
It is also conceivable to integrate the internal heat exchanger 16 and the external heat exchanger 17. Although any method can be considered as the integration method, for example, mounting, press-fitting, or integration using a fixture can be employed. By fixing the internal heat exchanger 16 and the external heat exchanger 17 in this manner, the internal heat exchanger 16 and the external heat exchanger 17 can be brought into close contact with each other, and the internal heat exchanger 16 to the external heat exchanger 17 can be brought into close contact with each other. The heat transfer efficiency can be improved.
[0045]
When integrating the internal heat exchanger 16 and the external heat exchanger 17, it is preferable to integrate both so that the contact area between the internal heat exchanger 16 and the external heat exchanger 17 becomes large. Thereby, the heat transfer efficiency from the internal heat exchanger 16 to the external heat exchanger 17 can be further improved.
[0046]
In the example of FIG. 1, the external heat exchanger 17 is disposed inside the internal heat exchanger 16. Thereby, the outer peripheral surface of the external heat exchanger 17 can be brought into contact with or close to the inner peripheral surface of the internal heat exchanger 16. Since the area of the outer peripheral surface of the external heat exchanger 17 is larger than the area of the inner peripheral surface of the external heat exchanger 17, the outer peripheral surface of the external heat exchanger 17 is brought into contact with the inner peripheral surface of the internal heat exchanger 16. In this case, the contact area between the external heat exchanger 17 and the internal heat exchanger 16 can be increased, and the cold heat from the working medium is efficiently transmitted to the external heat exchanger 17 via the internal heat exchanger 16. be able to.
[0047]
In the example of FIG. 1, the external heat exchanger 17 is press-fitted and fixed inside the internal heat exchanger 16. In this case, both can be made to adhere easily and heat transfer efficiency can also be improved. It is also conceivable to install a material having high thermal conductivity between the external heat exchanger 17 and the internal heat exchanger 16 so as to fill a gap between them.
[0048]
Further, in the example of FIG. 1, the cap member 18 that closes the end portion of the pressure vessel 11 on the expansion space 7 side is formed of a concave plate. More specifically, the cap member 18 is press-fitted and fixed inside the outer wall of the pressure vessel 11, and the central portion of the cap member 18 is recessed toward the displacer 4.
[0049]
The cap member 18 is preferably formed of a low thermal conductivity material. A specific example is stainless steel.
[0050]
By forming the cap member 18 with a low thermal conductivity material in this way, the amount of cold heat from the working medium released to the external space located outside the pressure vessel 11 via the cap member 18 can be reduced. Therefore, the loss of cold heat can be reduced.
[0051]
As shown in FIG. 1, a set of refrigerant pipes 19 is connected to the external heat exchanger 17. One refrigerant pipe 19 serves as a supply pipe that supplies a cold medium for taking out cold heat from the external heat exchanger 17 to the external heat exchanger 17, and the other refrigerant pipe 19 takes out the above-mentioned cold medium from the external heat exchanger 17. It becomes a take-out pipe.
[0052]
This set of refrigerant pipes 19 preferably extends outward from the end face of the pressure vessel 11 on the expansion space 7 side. A set of refrigerant pipes 19 in the example of FIG. 1 extends through the cap member 18 in the axial direction of the cylinder 2, that is, in the direction in which the piston 3 and the displacer 4 move.
[0053]
With the above-described configuration, a set of refrigerant pipes 19 mounted in advance on the external heat exchanger 17 are inserted into the refrigerant pipe insertion holes of the cap member 18, and the cap member 18 is attached to the end of the pressure vessel 11. The outer circumference of the cap member 18 is welded to the pressure vessel 11 and the refrigerant pipe 19 and the refrigerant pipe insertion hole of the cap member 18 are welded to complete the attachment. Therefore, it is possible to easily attach the refrigerant pipe 19.
[0054]
On the other hand, the internal heat exchanger 20 and the external heat exchanger 21 are installed in the pressure vessel 11 also on the heat radiating unit 8 side. The internal heat exchanger 20 and the external heat exchanger 21 have basically the same configuration as the internal heat exchanger 16 and the external heat exchanger 17 on the side of the heat absorption part 9 described above.
[0055]
The internal heat exchanger 20 on the heat radiating unit 8 side is installed in the pressure vessel 11 and on the compression space 6 side of the regenerator 5 disposed in the communication path 23. An external heat exchanger 21 on the side of the heat radiating unit 8 is installed outside the internal heat exchanger 20. More specifically, the external heat exchanger 21 is fitted on the internal heat exchanger 20 so that the outer peripheral surface of the internal heat exchanger 20 and the inner peripheral surface of the external heat exchanger 21 are in contact with each other.
[0056]
A set of refrigerant pipes 22 is also connected to the external heat exchanger 21. One of the set of refrigerant pipes 22 functions as a supply pipe for supplying the refrigerant to the external heat exchanger 21, and the other refrigerant pipe 22 functions as an extraction pipe for taking out the refrigerant from the external heat exchanger 21.
[0057]
In the example of FIG. 1, the outer wall of the pressure vessel 11 extends so as to cover the external heat exchanger 21. One set of refrigerant pipes 22 is inserted into the outer wall to connect the one set of refrigerant pipes 22 to the external heat exchanger. 21 is connected.
[0058]
Next, operation | movement of the Stirling refrigerator 1 in this Embodiment 1 is demonstrated.
[0059]
First, the linear motor 12 is operated to drive the piston 3. The piston 3 driven by the linear motor 12 approaches the displacer 4 and compresses the working medium (working gas) in the compression space 6.
[0060]
When the piston 3 approaches the displacer 4, the temperature of the working medium in the compression space 6 rises, but the heat generated in the compression space 6 is released to the outside by the heat radiating unit 8. At this time, the heat generated in the compression space 6 is efficiently released to the outside through the internal heat exchanger 20 and the external heat exchanger 21. Therefore, the temperature of the working medium in the compression space 6 is maintained almost isothermal. This process corresponds to an isothermal compression process in a reverse Stirling cycle.
[0061]
After the piston 3 approaches the displacer 4, the displacer 4 moves to the heat absorbing portion 9 side. The working medium compressed in the compression space 6 by the piston 3 flows into the regenerator 5 and further flows into the expansion space 7. At that time, the heat of the working medium is stored in the regenerator 5. This process corresponds to an isovolumetric cooling process in a reverse Stirling cycle.
[0062]
The high-pressure working medium that has flowed into the expansion space 7 expands when the displacer 4 moves to the piston 3 side. Thereby, the temperature of the working medium in the expansion space 7 falls. The cold heat from the working medium can be efficiently taken out to the outside through the internal heat exchanger 16 and the external heat exchanger 17. In addition, since external heat is transferred into the expansion space 7 by the heat absorption part 9, the inside of the expansion space 7 is kept substantially isothermal. This process corresponds to the isothermal expansion process of the reverse Stirling cycle.
[0063]
Thereafter, the displacer 4 starts to move away from the piston 3. Thereby, the working medium in the expansion space 7 passes through the regenerator 5 and returns to the compression space 6 side again. At that time, since the heat stored in the regenerator 5 is given to the working medium, the working medium is heated. This process corresponds to an equal volume heating process in a reverse Stirling cycle.
[0064]
By repeating the above series of processes (isothermal compression process-isovolume cooling process-isothermal expansion process-isothermal heating process), an inverse Stirling cycle is configured. As a result, the endothermic portion 9 gradually becomes low temperature and has a very low temperature.
[0065]
(Embodiment 2)
Next, Embodiment 2 of the present invention will be described with reference to FIG. In the second embodiment, an external heat exchanger that takes out the cold generated in the expansion space to the outside is installed inside the pressure vessel and outside the internal heat exchanger on the heat absorption part side. Accordingly, as in the case of the first embodiment, it is possible to avoid the surface of the external heat exchanger from being exposed to the external space located outside the pressure vessel, and efficiently cool the heat from the working medium to the outside. Can be transferred to a heat exchanger.
[0066]
As shown in FIG. 2, the external heat exchanger 17 on the heat absorption unit 9 side is installed in the pressure vessel 11 and is disposed outside the internal heat exchanger 16 on the heat absorption unit 9 side. More specifically, the external heat exchanger 17 is fitted on the internal heat exchanger 16 so that the inner peripheral surface of the external heat exchanger 17 and the outer peripheral surface of the internal heat exchanger 16 are in contact with each other.
[0067]
In the example of FIG. 2, the external heat exchanger 17 on the heat absorbing unit 9 side and the external heat exchanger 21 on the heat radiating unit 8 side have substantially the same structure. Accordingly, a refrigerant pipe 19 connected to the external heat exchanger 17 is inserted into the cylindrical portion of the pressure vessel 11 and extends in the radial direction of the cylinder 2. Other configurations are the same as those in the first embodiment.
[0068]
(Embodiment 3)
Next, Embodiment 3 of the present invention will be described with reference to FIG. In the third embodiment, a plurality of internal heat exchangers are arranged in the pressure vessel and on the expansion space side of the regenerator, and external heat that extracts the cold generated in the expansion space to the outside is provided between the internal heat exchangers. Install the exchanger.
[0069]
By arranging the external heat exchanger between the internal heat exchangers in this way, the cold heat from the working medium can be transmitted to the external heat exchanger from both sides of the external heat exchanger via the internal heat exchanger. . Thereby, the cold heat from a working medium can be efficiently transmitted to an external heat exchanger via an internal heat exchanger.
[0070]
In particular, by contacting the internal heat exchanger and the external heat exchanger, a plurality of contact surfaces can be provided between the internal heat exchanger and the external heat exchanger, and the internal heat exchanger and the external heat exchanger can be provided. The contact area between the two can be increased. Thereby, the cold heat from a working medium can be more efficiently transmitted to an external heat exchanger via an internal heat exchanger.
[0071]
In the example of FIG. 3, a plurality of internal heat exchangers 160 and 161 are arranged at intervals in the radial direction of the cylinder 2, and the external heat exchanger 17 is installed between the internal heat exchangers 160 and 161. The inner peripheral surface of the external heat exchanger 17 is in contact with the outer peripheral surface of the internal heat exchanger 160, and the outer peripheral surface of the external heat exchanger 17 is in contact with the inner peripheral surface of the internal heat exchanger 161. The other configuration is almost the same as that in the first embodiment.
[0072]
(Embodiment 4)
Next, Embodiment 4 of the present invention will be described with reference to FIG. In the fourth embodiment, the cap member (closing member) that closes the end of the pressure vessel on the side of the expansion space is brought into contact with the internal heat exchanger, and the cold heat generated in the expansion space is extracted to the outside inside the cap member. A heat exchanger is provided. At this time, unlike the above-described embodiment, the cap member is formed of a material having high thermal conductivity such as copper or aluminum.
[0073]
By bringing the cap member and the internal heat exchanger into contact with each other as described above, cold heat can be directly transmitted from the internal heat exchanger to the cap member. Thereby, cold heat can be efficiently transmitted from the internal heat exchanger to the cap member.
[0074]
Since the external heat exchanger is provided inside the cap member, the cold heat transmitted to the cap member can be efficiently transmitted to the external heat exchanger. Therefore, the cold heat from the working medium can be efficiently transmitted to the external heat exchanger via the internal heat exchanger.
[0075]
Further, the cap member may be extended to the outside of the internal heat exchanger, and the external heat exchanger may be provided inside the cap member positioned outside the internal heat exchanger. In this case, the external heat exchanger can be brought into contact with or close to the internal heat exchanger, and the cold heat from the working medium can be efficiently transmitted to the external heat exchanger via the internal heat exchanger. .
[0076]
In the example of FIG. 4, the peripheral edge of the cap member 18 is bent, and the cap member 18 is externally fitted to the internal heat exchanger 16. And the external heat exchanger 17 is provided in the cap member 18 by providing the refrigerant path through which a cold refrigerant circulates in the bent peripheral part of the cap member 18.
[0077]
The external heat exchanger 17 is not necessarily provided inside the cap member 18. A groove is provided in the outer peripheral portion of the cap member 18, and a cover separate from the cap member 18 is covered and welded to the groove. You may form integrally.
[0078]
In addition, the internal heat exchanger 16 is provided integrally with the cap member 18 on the surface of the cap member 18 facing the displacer 4, and the external heat exchanger 17 is positioned at a position facing the internal heat exchanger 16 of the cap member 18 or You may make it arrange | position to the periphery.
[0079]
In addition, a set of through holes reaching the refrigerant passage is provided in the cap member 18, and a set of refrigerant pipes 19 are inserted through the through holes, respectively. Other configurations are basically the same as those in the first embodiment.
[0080]
Although the embodiments of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the features of the above-described embodiments.
[0081]
In addition, it should be considered that the embodiment disclosed this time is illustrative and not restrictive in all respects. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0082]
【The invention's effect】
According to the present invention, since the cold heat from the working medium can be efficiently transmitted to the external heat exchanger, the cold heat generated in the expansion space can be efficiently taken out to the outside.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a Stirling refrigerator in a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a Stirling refrigerator in a second embodiment of the present invention.
FIG. 3 is a cross-sectional view of a Stirling refrigerator in a third embodiment of the present invention.
FIG. 4 is a cross-sectional view of a Stirling refrigerator in a fourth embodiment of the present invention.
FIG. 5 is a perspective view of an example of an external heat exchanger that can be used in the Stirling refrigerator in the embodiment of the present invention.
6 is a cross-sectional view of the external heat exchanger shown in FIG.
FIG. 7 is a perspective view of an example of an internal heat exchanger that can be used in the Stirling refrigerator in the embodiment of the present invention.
[Explanation of symbols]
1 Stirling refrigerator, 2 cylinders, 3 pistons, 4 displacer, 5 regenerator, 6 compression space, 7 expansion space, 8 heat radiation part, 9 heat absorption part, 10 vessel part, 11 pressure vessel, 12 linear motor, 13 piston spring, 14 displacer spring, 15 back pressure space, 16, 20, 160, 161 internal heat exchanger, 16a corrugated fin, 16b ring member, 17, 21 external heat exchanger, 17a opening, 17b internal space, 18 cap member, 19 , 22 Refrigerant piping, 23 communication path.

Claims (4)

A cylinder assembled in a pressure vessel enclosing a working medium;
A piston that reciprocates within the cylinder;
A displacer that reciprocates with a phase difference with respect to the piston in the cylinder;
A compression space and an expansion space formed in the pressure vessel so that the pressure fluctuates by the reciprocating motion of the piston and the displacer;
A tubular communication passage that communicates the compression space and the expansion space and is disposed outside the cylinder;
A regenerator disposed in the communication path;
An internal heat exchanger that is disposed in the expansion space side of the regenerator in the pressure vessel and takes in the cold generated in the expansion space;
A cap member that closes the end of the pressure vessel on the expansion space side and extends to the outside of the internal heat exchanger;
Located outside of the internal heat exchanger provided in the cap member, and an external heat exchanger to take out the cold to the outside,
Stirling refrigerator equipped with. A cylinder assembled in a pressure vessel enclosing a working medium;
A piston that reciprocates within the cylinder;
A displacer that reciprocates with a phase difference with respect to the piston in the cylinder;
A compression space and an expansion space formed in the pressure vessel so that the pressure fluctuates by the reciprocating motion of the piston and the displacer;
A regenerator disposed in a communication path communicating the compression space and the expansion space;
An internal heat exchanger that is disposed in the expansion space side of the regenerator in the pressure vessel and takes in the cold generated in the expansion space;
An external heat exchanger installed in contact with the internal heat exchanger in the pressure vessel and taking out the cold heat to the outside;
Stirling refrigerator equipped with. A cylinder assembled in a pressure vessel enclosing a working medium;
A piston that reciprocates within the cylinder;
A displacer that reciprocates with a phase difference with respect to the piston in the cylinder;
A compression space and an expansion space formed in the pressure vessel so that the pressure fluctuates by the reciprocating motion of the piston and the displacer;
A cylindrical communication passage that communicates the compression space and the expansion space, and is disposed outside the cylinder;
A regenerator disposed in the communication path;
An internal heat exchanger that is disposed in the expansion space side of the regenerator in the pressure vessel and takes in the cold generated in the expansion space ;
An external heat exchanger that is installed inside the internal heat exchanger and extracts the cold generated in the expansion space to the outside;
Stirling refrigerator equipped with. A cap member for closing an end of the pressure vessel on the expansion space side;
The Stirling refrigerator according to claim 2 or 3, wherein the cap member is formed of a low thermal conductivity material.

Images