JP2941558B2 - Stirling refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirling refrigerating apparatus used as, for example, a refrigerator, an air conditioner and the like.

[0002]

2. Description of the Related Art In a refrigerating cycle device represented by a refrigerating machine, an air conditioner or the like, a steam type refrigerating cycle is employed. In such a steam-type refrigeration cycle, chlorofluorocarbon is used as a refrigerant as a working fluid, and a required cooling performance is obtained by utilizing the condensation and evaporation of chlorofluorocarbon.
However, it has been pointed out that CFCs used as a refrigerant have extremely high chemical stability, and when released into the atmosphere, reach the stratosphere and destroy the ozone layer. For this reason, in recent years, the use and production of CFCs for specific CFCs have been regulated. Therefore, as a substitute for the refrigeration cycle apparatus, a refrigeration apparatus using a reverse Stirling cycle, that is, a so-called stirling refrigeration apparatus has been receiving attention.

A stirling refrigeration system uses a gas that does not affect the global environment, such as helium gas, hydrogen gas, nitrogen gas, or the like, as a working fluid, and uses a reverse stirling cycle (the working gas is supplied by power input). A low temperature is obtained by a closed cycle in which heat is absorbed and radiated by compression and expansion.

[0004] To explain the principle, the configuration is as follows:
A display provided in a cylindrical expansion space
The reciprocating mechanism that reciprocates the support piston and the power piston provided in the compression space formed in a cylindrical shape by a predetermined phase difference, and communicates the expansion space and the compression space via the regenerator to close the circuit. And the working fluid of the closed circuit is filled with the working fluid.

[0005] In addition, the power piston is moved by a power through a reciprocating mechanism to compress and radiate the working fluid in the compression space, and then expand the working fluid through the regenerator. Send to space. Then, the display
The working fluid is expanded in the expansion space by the movement of the piston, thereby absorbing heat. By this heat absorption, a low temperature is obtained, and a role of a refrigerator is achieved.

[0006]

By the way, unlike the steam type refrigeration cycle, such a reverse staring cycle cannot utilize the latent heat of the working fluid for the refrigeration capacity, so that it is easy to obtain an extremely low temperature. However, there is a problem that the refrigeration capacity cannot be obtained efficiently.

Therefore, in the Stirling refrigerating apparatus, the heat transfer area on the cylinder chamber surface is increased in order to enhance the heat transfer between the working fluid and the wall surfaces of the expansion space and the compression space which are the walls of the working space. It is thought that.
However, simply increasing the heat transfer area increases the number of ineffective containers (spaces that do not contribute to a change in volume) and lowers the compression ratio. In this case, the input must be increased in order to compensate for the lowering of the refrigeration capacity due to the decrease in the compression ratio, and the coefficient of performance indicating the efficiency of the refrigeration capacity is not good. Therefore, there is a strong demand for a technology capable of improving the refrigeration capacity including these points.

The present invention has been made in view of such circumstances, and an object of the present invention is to improve the heat transfer between the working fluid and the piston wall while preventing the generation of an ineffective volume. It is an object of the present invention to provide a stirling refrigerating apparatus which can be used.

[0009]

According to a first aspect of the present invention, there is provided a Stirling refrigerating apparatus, comprising: an expansion space provided with a displacer piston or a compression space provided with a power piston; A fin portion is provided on an end surface on the top dead center side constituting both spaces, and the piston is top dead on the head of the displacer piston, the power piston, or both pistons facing the fin portion. A point is provided in which a housing portion for housing the fin portion when displaced to the point is provided.

[0010] The Stirling refrigerating apparatus according to the first aspect of the present invention provides a Stirling refrigerating apparatus having an expansion space in which a displacer piston is provided, a compression space in which a power piston is provided, or both of them. A first fin group is provided on the end surface, and the first piston is displaced to the top dead center at the head of the displacer piston or the power piston or both pistons facing the fin portion. And a second fin group that meshes with the other fin group.

[0011]

According to the stirling refrigerating apparatus of the present invention, when the power piston and the displacer piston are driven by power, each piston reciprocates in the expansion space and the compression space according to a predetermined phase difference. I do.

Thus, in the working space, the working fluid in the compression space is compressed and radiated, then sent to the expansion space, and then the working fluid is expanded in the expansion space to absorb heat, thereby performing a reverse staring cycle. Composed and exerts refrigeration capacity. At this time, on the heat radiating side, the heat of the working fluid in the compression space is transferred to the wall surface of the compression space and then transferred to the outside to release the heat. On the heat-absorbing side, heat is absorbed through a path in which external heat is transmitted to the wall surface of the expansion space, and further this heat is transmitted from the wall surface of the expansion space to the working fluid in the expansion space. Here, the heat transfer area on the wall surface of the working space is increased by the fin portion. Since the heat transfer of the working fluid is promoted (heat transfer property: large), the refrigerating capacity is improved.

At the same time, when the piston reaches the top dead center during the reverse staring cycle operation, the fin portion is accommodated in the accommodating portion of the piston, so that the generation of the dead volume due to the fin portion is minimized. Will be. However, the refrigeration capacity can be increased without increasing the input as in the related art.

According to the stirling refrigerating apparatus of the second aspect, the heat transfer area on the wall surface of the working space is increased by the first fin group, as in the first aspect. In addition, since the second fin group is also provided on the piston side, heat transfer from the piston side can be expected. By this, the heat transfer of the working fluid is promoted (heat transfer: large),
The refrigeration capacity is improved.

At the same time, when the piston reaches the top dead center during the reverse staring cycle operation, the first fin group and the second fin group engage with each other. It will be kept to a minimum. However, as in the case of the first aspect, the refrigeration capacity can be increased without increasing the input.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to FIGS.
A description will be given based on the embodiment.

FIG. 1 shows, for example, a two-cylinder stirling refrigerating apparatus to which the present invention is applied, wherein 1 is an expansion cylinder in which a displacer piston 2 is slidably provided, and 3 is a power inside. This is a compression cylinder in which the piston 4 is slidably provided. The expansion cylinder 1 and the compression cylinder 3 are substantially V-shaped so as to make a predetermined phase difference.
It is mounted on the crankcase 5 in a letter shape. A portion partitioned by the displacer piston 2 is defined as an expansion space 6, and a portion partitioned by the power piston 4 is defined as a compression space 7.

The expansion space 6 and the compression space 7 are interconnected by a low-temperature heat exchanger 8, a regenerator 9, and a high-temperature heat exchanger 1.
The communication connection is established via the “0”. The working space formed by these connections is filled with a working fluid such as helium gas, hydrogen gas, or nitrogen gas.

Each of the displacer piston 2 and the power piston 4 is connected via connecting rods 11 and 12 to each other.
The crankcase 5 is rotatably connected to a crankshaft 13 provided on the crankcase 5.

The crank shaft 13 is connected to a power source, for example, an output of a motor 14, and reciprocates the displacer piston 2 and the power piston 4 in the expansion space 6 and the compression space 7 with a predetermined phase difference. I try to move it. The displacer piston 2 and the power piston 4
, A reverse staring cycle is formed to obtain a low temperature.

On the other hand, a fin group 15 (corresponding to the first fin group of the present application) is provided on the end surface on the top dead center side of the expansion space 6, that is, on the inner surface of the head of the expansion cylinder 1 serving as the head portion. . As shown in FIGS. 2 and 3, the fin group 15 is configured by, for example, providing a plurality of circular fin portions 16 having different large and small diameters concentrically around the axis of the expansion cylinder 1. The expansion space 6 is formed by these fin portions 16.
The heat transfer area of the expansion cylinder 1 is increased.

A fin group 17 is also provided on the head of the displacer piston 2 corresponding to the fin group 15. The fin group 17 has a circular groove 18 corresponding to the outer shape of the fin 16 in a portion facing the fin 16.
(Corresponding to the accommodating portion of the present application) in a childlike shape. In other words, the ridges formed inside and outside the groove 18 become the fins 18a.

Each of the grooves 18 has a corresponding fin 16
Is set so as to be removably received via a minimum gap, and when the displacer piston 2 reaches the top dead center, the fin group 15 and the fin group 17 come into mesh with each other. I have. As a result, the displacer piston 2 and the head of the expansion cylinder 1 are closely opposed to each other at the top dead center as in the case where there is no conventional fin portion. Next, the operation of the thus configured stirling refrigerating apparatus will be described.

When the crankshaft 13 is driven by the motor 14, the displacer piston 2 and the power piston 4 move through the connecting rods 11 and 12 with a predetermined phase difference into the expansion space 6 and the compression space 7, respectively. Reciprocate.

By this reciprocating motion, the working fluid in the compression space 7 is compressed and radiated, and then sent to the expansion space 6.
That the working fluid is expanded in the expansion space 6 to absorb heat.
A reverse Stirling cycle as shown in FIG. 4 is configured to exhibit a refrigeration capacity.

More specifically, the isothermal compression process is performed in the “A → B” stroke in which the power piston 4 rises. In this process, the working fluid in the compression cylinder 3 is compressed, and the heat generated at this time is radiated from the high-temperature side heat exchanger 10.

Next, an equal volume cooling process of "B → C" is performed. In this process, the displacer piston 2 descends, and the working fluid moves to the expansion cylinder 1 side through the regenerator 9. Then, at this time, the heat is accumulated by the cold stored in the heat storage device 9.

Subsequently, an isothermal expansion process of “C → D” is performed. In this process, the power piston 4 descends and expands the working fluid in the expansion cylinder 1. That is, a refrigeration action occurs.

When the isothermal expansion process is completed, "D →
The displacer piston 2 of "A" rises, and the working fluid whose temperature has dropped is led to the low-temperature side heat exchanger 8 and the regenerator 9. Thereby, the heat absorption by the isothermal expansion process and the heat release by the isothermal compression process are repeatedly performed, and the refrigeration ability is exhibited.

At this time, on the heat radiation side of the Stirling refrigerating apparatus, the heat of the working fluid in the compression space 7 is transferred to the wall surface of the compression cylinder 3 (working space) and then to the outside. Is performed.

On the heat-absorbing side, a path in which heat outside the expansion cylinder 1 is transmitted to the wall surface of the expansion space 6 and further this heat is transmitted from the wall surface of the expansion space 6 (working space) to the working fluid in the expansion space 6. Then, heat absorption is performed. At this time, the fin portion 16 is provided on the head portion of the expansion cylinder 1 to increase the heat transfer area on the wall surface of the expansion cylinder 1.

This means that the heat transfer between the working fluid on the heat absorbing side and the expansion cylinder 1 is promoted (heat transfer property: large), and the refrigerating capacity obtained by the operation of the reverse stirring cycle is correspondingly improved. Can be done.

In addition, since the fin portion 17 is also provided at the head of the display piston 2,
Heat transfer from the piston 2 to the expansion cylinder 1 can also be expected,
Further, the refrigeration capacity can be improved.

When the display piston 2 reaches the top dead center during the reverse stirling cycle operation, as shown in FIG.
However, since the fins 6 mesh with the fins 17 on the piston head, that is, the fins 6 are accommodated in the grooves 8, it is possible to minimize the generation of an ineffective volume due to an increase in the heat transfer area. it can. Therefore, the refrigeration capacity can be increased without increasing the input unlike the conventional case. A Stirling refrigerating apparatus that provides a high coefficient of performance can be provided. In the first embodiment, an example is described in which the heat transfer area is increased only on the heat absorption side. However, the same effect can be obtained even if the heat transfer area is increased only on the heat dissipation side.

That is, the expansion cylinder 1 and the display
Even if the fin groups 15 and 16 are provided not on the support piston 2 but on the compression cylinder 3 and the power cylinder 4, the endothermic effect of the reverse stirling cycle is promoted, so that the generation of the invalid volume is minimized. It is possible to improve the refrigeration capacity while suppressing the refrigeration.

However, in the structure in which the fin groups 15 and 16 are provided only in the "compression cylinder 3 and the power cylinder 4", the fin installation portion in FIG. 1 is merely moved from the expansion side to the compression side. Omitted.

Of course, as in the second embodiment shown in FIG. 5, "expansion cylinder 1 and displacer piston 2"
The fin groups 15 and 16 may be provided for each of the “compression cylinder 3 and the power cylinder 4”.
The refrigeration capacity can be further improved.

In all of the above embodiments, the present invention is applied to a two-cylinder type stirling refrigerating apparatus.
However, the present invention is not limited to this, and can be applied to other types of stirling refrigerating devices. FIG. 6 and FIG. 7 show a third embodiment of the present invention applied to a one-cylinder type stirling refrigerating apparatus.

In the third embodiment, two pistons, that is, a displacer piston 22 with a built-in regenerator 21 and a power piston 23 are slidably provided in one cylinder 20, and a cylinder head and Display piston 2
2, an expansion space 24 is formed, and a compression space 25 is formed between the displacer piston 22 and the power piston 23. The expansion space 24 is connected to the regenerator 2 via a passage 26 provided in the displacer piston 22.
It communicates with 1. The regenerator 21 communicates with the compression space 25 via a passage 27 provided in the displacer piston 22 and a high-temperature heat exchanger 28 provided on the outer peripheral side of the cylinder 20.

The displacer piston 22 and the power piston 23 are reciprocated at a predetermined phase difference via a reciprocating mechanism 29 (such as a combination of a cam mechanism).
It is connected to the output shaft of the motor 30 as a power source,
The motors 30 reciprocate the pistons 22 and 23.

As shown in FIG. 7, a fin group 15 is provided on the end surface on the top dead center side of the expansion space 24, that is, on the head portion of the cylinder 20, similarly to the first embodiment. The fin group 17 is provided on the head of the displacer piston 22, so that the same effect as in the first embodiment can be obtained.

In this type of staring refrigerating apparatus, when the displacer piston 22 reaches the top dead center, the working fluid in the expansion space 24 flows into the regenerator 21.
It moves to the compression space 25 through the high-temperature side heat exchanger 28.

In the above-described embodiments, the fin groups 15 and 17 having a large outer shape are provided to increase the heat transfer area. However, the present invention is not limited to this example. Fine fin groups 15 and 17 may be provided.

[0044]

As described above, according to the first and second aspects of the present invention, it is possible to enhance the heat transfer between the working fluid and the piston wall surface while preventing the generation of an ineffective volume. Therefore, it is possible to provide a stirling refrigerating apparatus that can increase the refrigerating capacity without unnecessarily increasing the input and provide a high coefficient of performance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a two-cylinder stirling refrigerating apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a head structure on an expansion side of the device.

FIG. 3 is an exploded cross-sectional view of the head of FIG. 2 into a piston side and a cylinder side.

FIG. 4 shows P- for explaining the reverse staring cycle.
V diagram.

FIG. 5 is a diagram showing a schematic configuration of a two-cylinder stirling refrigerating apparatus according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view showing the configuration of a one-cylinder stirling refrigerating apparatus according to a third embodiment of the present invention.

FIG. 7 is an exploded sectional view showing a structure around a fin on the cylinder head side of the device.

FIG. 8 is a view for explaining the periphery of a fin of a stirling refrigerating apparatus according to a fourth embodiment of the present invention.

[Description of Signs] 2 ... Displacer piston, 4 ... Power piston, 6
... expansion space, 7 ... compression space, 9 ... regenerator, 3 ... crankshaft, 15 ... fin group, 16 ... fin part, 17 ... fin group, 18 ... groove (housing part).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-12267 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F25B 9/14 510 F25B 9/14 520

Claims (2)

(57) [Claims] 1. A displacer piston provided in a cylindrical expansion space, and a power piston provided in a cylindrical compression space.
A reciprocating piston having a predetermined phase difference to form a reverse stirling cycle, wherein the expansion space or the compression space, or both spaces, A fin portion is provided on the end surface on the top dead center side to constitute, and when the piston is displaced to the top dead center on the head of the displacer piston or the power piston or both pistons facing the fin portion A stirling refrigerating apparatus, further comprising a housing for housing the fin. 2. A displacer piston provided in a cylindrical expansion space, and a power piston provided in a cylindrical compression space.
A reciprocating piston having a predetermined phase difference to form a reverse stirling cycle, wherein the expansion space or the compression space, or both spaces, A first fin group is provided on an end face on the top dead center side to be configured, and the piston is moved to the top dead center on the head of the displacer piston or the power piston or both pistons facing the fin portion. A stirling refrigerating apparatus comprising a second fin group that meshes with the fin group when displaced.