JPH11337207A - Refrigerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerating device to suppress lowering of performance due to a friction heat generated at a seal part along with working. SOLUTION: A cold head 15 cooled by a cold heat generated through the working of a refrigerating device and a seal lock 18 are connected through a wire-form copper 31. A cold heat generated through the working of the refrigerating device is transmitted to a wire-form copper core 31 and seal parts 8 and 9 through the wire-form copper core 31 and a seal lock 18. By a transmitted cold heat, thermal deterioration of the seal parts 8 and 9 and lowering of viscosity of lubrication oil 10 at the peripheries of the seal parts 8 and 9 are suppressed. This constitution suppresses lowering of performance of the refrigerating device due to leakage of lubrication oil 10 and penetration of the lubrication oil through the seal parts 8 and 9 to a cold storage material 14 of lubrication oil 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system using a Stirling cycle engine or a Premier cycle engine, and more particularly to a refrigeration system using a gas expansion compressor.

[0002]

2. Description of the Related Art In recent years, in advanced technology fields such as the field of biotechnology and the field of electronic devices, the development of techniques for storing various samples and various materials at extremely low temperatures has been activated. In particular, Stirling refrigerating equipment, which is a refrigerating equipment using a working gas expansion compressor, is attracting attention as means for achieving extremely low temperatures, and is used for cooling various infrared sensors, superconducting devices, etc., for biomedical freezer, freezer, etc. It is going to be widely used.

The operation principle of the displacer type Stirling refrigerating apparatus will be described with reference to FIG. The expansion cylinder 2 provided inside the expander 21 main body container and the compression cylinder 3 provided inside the compressor 22 main body container are attached to the main body housing 1 at an angle difference of 90 °. Built-in displacer 6 and compression piston 7 built in compression cylinder 3
Are connected to a common crank mechanism 5 and
Reciprocating drive is performed with the phase shifted by 0 °.

[0004] The displacer 6 is filled with a cooling material 14 as a heat exchange material made of, for example, a sintered metal, and a working gas flowing from one opening of the displacer 6 passes through the cooling material 14. Then, in the process up to the outflow from the other opening, heat exchange with the animal cooling material 14 is performed.

The displacer 6 also has a function as a regenerative heat exchanger, and its heat exchange performance greatly affects the coefficient of performance of the refrigeration system. The expansion cylinder 2 and the compression cylinder 3 are separated from the crank chamber 12 by seal portions 8 and 9, respectively.
The base end and the compression space of the compression cylinder 3 are connected to each other by a working gas passage 4. Thereby, the compression space 13 formed in the compression cylinder 3 and the expansion cylinder 2
Is communicated with the expansion space 11 through the working gas passage 4 via the cooling material 14. On the other hand, oil 10 is injected into the crank chamber 12.

Next, the operation of the Stirling refrigerating apparatus having the above-described structure will be described with reference to FIG.
In FIG. 5, the horizontal axis represents time T, and the vertical axis represents stroke S.

In the Stirling refrigerator, the displacer 6 reciprocates as shown by curves B and C in FIG. 5 and the compression piston 7 reciprocates as shown by curve D in FIG. , FIG.
5, the volume of the compression space 13 of the compression cylinder 3 changes in the width region between the curves C and D in FIG.

As a result, in the process shown in FIG. 5, the working gas in the compression space 13 is compressed and flows into the expansion cylinder 2 through the working gas passage 4 (ideally, isothermal compression). This working gas passes through the storage material 14 in the displacer 6 in the process of FIG. 5 and exchanges heat with the storage material 14 to lower the temperature (constant volume cooling). The working gas that has passed through the cooling material 14 flows into the expansion space 11 of the expansion cylinder 2 in the stroke of FIG. 5, and then expands as the compression piston 7 descends (ideally, isothermal expansion). Next, in the process of FIG.
The working gas in the expansion space 11 passes through the cold storage material 14 with the rise of the displacer 6, exchanges heat with the cold storage material 14, rises in temperature, and is again introduced into the compression space 13 through the working gas passage 4. (Fixed volume heating).

As a result, the cold head 15 provided on the head of the expansion cylinder 2 is cooled.

[0010]

It is important to improve the coefficient of performance of the above-mentioned refrigerating apparatus, that is, to suppress the loss of the working gas as the refrigerant in order to cool the cold head 15 efficiently. It is important that the parts 8 and 9 increase the airtightness of the expansion cylinder 2 and the compression cylinder 3.

When the diameter and stroke of the compression piston 7 are reduced in order to reduce the size of the refrigeration system, the displacer 6 and the compression piston 7 must be driven at high speed. It is necessary to drive the force transmitting rod at high speed.

According to the above-described method, the expansion cylinder 2 and the compression cylinder 3 are brought into contact with the rod and
The seal portions 8 and 9 held in an airtight state are thermally degraded due to frictional heat generated by driving the rod, causing a decrease in airtightness, or a seal portion having reduced viscosity due to the generated frictional heat. Lubricating oil near 8 and 9 intrudes into the expansion cylinder 2 or the compression cylinder 3.

That is, the following two problems mainly occur due to frictional heat generated in the seal portion.

First, the seal portions 8 and 9 are deteriorated due to frictional heat and the airtightness is reduced, so that the working gas as a refrigerant leaks. For this reason, the amount of working gas that contributes to the cold heat generation cycle is reduced, the efficiency of cold heat generation is reduced, and the coefficient of performance is reduced.

Further, lubricating oil near the seal portions 8 and 9 whose viscosity has decreased due to frictional heat enters from the seal portions 8 and 9. The penetrated lubricating oil moves in the moving space of the working gas together with the working gas, and a part of the lubricating oil permeates the cooling material to form a film of the lubricating oil on the cooling material surface. Since this coating hinders heat exchange between the working gas and the cold storage material, the cold storage performance of the cold decreases, and the coefficient of performance decreases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress the heat of friction generated in a seal portion during operation to prevent thermal deterioration of the seal portion and intrusion of lubricating oil. An object of the present invention is to provide a refrigeration apparatus in which a decrease in coefficient of performance is suppressed.

[0017]

According to a first aspect of the present invention, there is provided a refrigeration apparatus which performs heat exchange by contacting a refrigerant moving between a compression space in a compression cylinder and an expansion space in an expansion cylinder. The heat exchange member removes the heat of the refrigerant moving from the compression space to the expansion space by the heat exchange member, and applies heat to the refrigerant moving from the expansion space to the compression space to generate cold heat in the expansion space. Refrigeration equipment.

The invention according to claim 1 is characterized in that it includes a seal cooling means for cooling a seal portion that partitions a refrigerant storage space in which a refrigerant is stored and a crank chamber.

Thus, the seal portion that generates heat due to friction can be cooled. According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the seal cooling means cools the seal portion by utilizing cold generated by operation.

Thus, the sealing portion can be forcibly cooled without newly providing a cold heat generating device.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the compression cylinder and the expansion cylinder are arranged in parallel.

As a result, the two seal portions are also arranged in parallel and are in a state as close as possible. The invention described in claim 4 is
In addition to the configuration of the invention according to any one of claims 1 to 3,
The seal cooling means cools the seal portion via a fixing member for fixing the seal portion.

Thus, the fixing member is used for both fixing the seal portion and cooling the seal portion. According to a fifth aspect of the present invention, in addition to the configuration of the first aspect, the seal cooling means extends from at least one of the outside of the cylinder to the seal portion. A heat conductive member is brought into contact with the portion, and the seal portion is cooled by utilizing heat conduction of the heat conductive member.

Thus, the seal portion can be cooled by the seal portion cooling means without providing a driving source.

According to a sixth aspect of the present invention, in addition to the configuration of any one of the first to fourth aspects, the seal cooling means has a cooling fluid circulating path facing the seal portion. The present invention is characterized in that the seal portion is cooled by a cooling fluid circulated to the seal portion.

Thus, the cooling of the seal portion can be performed more effectively. According to a seventh aspect of the present invention, in addition to the configuration of the first aspect of the present invention, one of the two seals is preferentially cooled, and the other seal is preferentially cooled. It is characterized by including cooling order switching means capable of switching to a state in which cooling is performed.

[0027] Thus, the two seal portions that generate different amounts of heat are effectively cooled, and the temperature difference between the seal portions can be suppressed.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. The same components as those of the above-described conventional example are indicated by the same reference numerals, and a detailed description of these portions will be omitted.

FIG. 1 is a sectional view showing the structure of a Stirling refrigerating apparatus according to an embodiment of the present invention.
In this refrigerating apparatus, an expander 21 that generates cold heat and a compressor 22 that receives and compresses the working gas expanded in the expander 21 are provided in parallel. Also, an electric motor 40 as a drive source for driving the expander 21 and the compressor 22 and a crank chamber 12 including the crank 5
Are provided. Seal portions 8 and 9 that partition the expansion cylinder 2 and the compression cylinder 3 from the crank chamber 12 are provided fixedly by a seal stopper 18 that is integrally formed over the expander 21 and the compressor 22.

The seal stopper 18 is provided with one end of a copper core 31 in contact with it, and the other end of the copper core 31 is provided with contact with the cold head 15. As a result, heat is transferred between the cold head 15 and the seal stopper 18 via the copper core 31. The copper core 31 is coated with urethane foam,
The copper core 31 is configured to be thermally insulated from outside air.

Next, the operation of the refrigeration system will be described. The electric motor 40 is driven by a user operation,
The driving force is transmitted to the expander 21 and the compressor 22 via the crank 5. The rods 16 and 1 are transmitted by the transmitted driving force.
7 violently slides while contacting the seal portions 8 and 9 to drive the expander 21 and the compressor 22 to operate the refrigerating device.
By operating such a refrigerating apparatus, cold heat is generated based on the above-described heat cycle, and the cold head 15 is cooled.

During operation of the refrigeration system, the seal portions 8, 9 and the contact portions of the rods 16, 17 with the seal portions 8, 9 generate heat due to friction.

During operation of the refrigerating apparatus, a part of the generated cold heat is transmitted to the seal stopper 18 through the copper core 31. The cold heat transmitted to the seal stopper is transmitted to the seal portions 8 and 9, and heat generation at the contact portions of the seal portions 8 and 9 and the rods 16 and 17 with the seal portions 8 and 9 is suppressed.

That is, thermal deterioration of the seal portions 8 and 9 is suppressed, and the sealing property is maintained. Further, a decrease in the viscosity of the lubricating oil 10 existing in the vicinity of the seal portions 8 and 9 in the crank chamber 12 is also suppressed, and the intrusion of the lubricating oil 10 into the working gas storage space is suppressed.

FIG. 2 is a sectional view showing another configuration of a Stirling refrigerating apparatus which is an example of the embodiment according to the present invention. This refrigerating apparatus is provided with an expander 21 that generates cold heat similarly to the refrigerating apparatus described above, and a compressor 22 that receives the working gas expanded in the expander 21 and compresses and returns the expanded working gas. Motor 40 as a drive source for supplying a driving force to the compressor 21 and the compressor 22
And a crank chamber 12 including the crank 5 as a driving force transmitting means.

The periphery of the seal portion will be described with reference to FIGS. FIG. 3 is a sectional view taken along the line AA of FIG.
Seal portions 8 and 9 for partitioning the expansion cylinder 2 and the compression cylinder 3 from the crank chamber 12 are fixedly provided by a hollow seal stopper 18 integrally formed over the expander 21 and the compressor 22.

In the Stirling refrigerating apparatus shown in FIGS. 2 and 3, ethylene glycol as a cooling fluid is circulated between the cold head 15 and the seal stopper 18 so that the seal portions 8 and 9 are cooled. It is configured. To this end, a pump 33 as a drive source for circulating ethylene glycol and ethylene glycol sent from the pump 33 are supplied to the cold head 1.
5, a copper tube 32 for forming a circulation path returning to the pump 33 through the seal portions 8 and 9 is provided.

The copper tube 32 is in contact with the outer peripheral surface of the cold head 15, and the ethylene glycol flowing through the copper tube 32 at the contact portion is cooled. Further, the copper tube 32 and the seal stopper 18 are in contact with each other, and the copper tube 32
Next, the operation of the refrigeration system will be described. The electric motor 40 is driven by a user's operation, and the driving force is transmitted to the expander 21 and the compressor 22 via the crank 5. The rods 16 and 17 are violently slid while contacting the seal portions 8 and 9 by the transmitted driving force, so that the expander 21 and the compressor 22 are driven to operate the refrigerating apparatus. By operating such a refrigerating apparatus, cold heat is generated based on the above-described heat cycle, and the cold head 15 is cooled.

During operation of the refrigerating apparatus, the seal portions 8, 9 and the contact portions of the rods 16, 17 with the seal portions 8, 9 generate heat due to friction.

During operation of the refrigerating apparatus, the generated cold heat is transmitted to the copper tube 32 in contact with the cold head 15. The transmitted cold heat is transmitted to the seal portions 8 and 9 via the ethylene glycol circulating in the copper tube 32 and the seal stopper 18, and
Seal portions 8, 9 and seal portions 8, 9 of rods 16, 17
The generation of heat at the contact portion with the contact is suppressed.

Further, the pump 3 controlled by the control unit 41
3, the circulation direction of ethylene glycol is changed, so that cold heat can be preferentially transmitted to the seal portion having a large amount of generated heat.

That is, thermal deterioration of the seal portions 8 and 9 is suppressed, and the sealing property is maintained. Further, a decrease in the viscosity of the lubricating oil existing near the seal portions 8 and 9 in the crank chamber is also suppressed, and the intrusion of the lubricating oil into the working gas storage space is suppressed. Since the seal portion that generates a large amount of heat can be preferentially cooled, the temperature difference between the two seal portions can be suppressed, and the bias of thermal deterioration of the seal portion can be suppressed.

Next, modifications and features of the above-described embodiment will be described below. As the seal portion cooling means, one end of the seal stopper having high thermal conductivity may be provided so as to be exposed in the main body housing.

Further, the seal stopper does not have to be integrally formed over both the expander and the compressor, and a seal cooling means may be provided around the seal stopper separately provided.

In the present embodiment, a wire-shaped copper core covered with urethane foam is used as the seal cooling means. However, the present invention is not limited to this. It is possible to substitute the one coated with.

Further, in the embodiment of the refrigerating apparatus using the wire-shaped copper core as the seal cooling means in the present embodiment, the seal cooling means has one path, but a plurality of paths may be provided. A plurality of seal cooling means may be provided so as to be detachable so that the number of paths and the amount of cold heat transfer can be changed according to the operation state.

On the other hand, in a refrigeration system using ethylene glycol circulated in a copper tube as a seal cooling means, the tube is made of a material having high thermal conductivity without being limited to the combination of copper tube and ethylene glycol. It is possible to substitute a cooling fluid capable of transmitting cold heat over a wide temperature range. By changing the cooling fluid in various ways, it is possible to transmit cold heat in accordance with the operation state of the refrigeration system. In addition, a temperature sensor is provided in the seal portion or the seal stopper, and a control unit including a microcomputer for controlling the circulation amount and the circulation direction of the cooling fluid based on an output signal from the temperature sensor is provided, so that the cooling heat transfer amount, the cooling priority, and the like are provided. , The thermal degradation of the seal portion is further suppressed, and the performance of the refrigeration system can be improved.

The embodiment disclosed this time is to be considered in all respects as illustrative and not restrictive.

The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0050]

Specific Examples of Means for Solving the Problems Seal cooling means for cooling the seal portion by the copper core 31, pump 33 and copper pipe 32 described above. Cooling priority switching means capable of switching from a state in which one of the two seals is preferentially cooled to a state in which the other seal is preferentially cooled by the control unit 41 and the pump. It is configured.

The copper core body 31 constitutes a heat conductive member extending from at least one of the outsides of the two cylinders to the seal portion and in contact with the seal portion.

[0052]

According to the first aspect of the present invention, the heat generation of the seal portion caused by the operation is suppressed, so that the heat deterioration of the seal portion is suppressed, and the lubricating oil is introduced into the cylinder by the lubricating oil. A decrease in reliability can be suppressed.

According to the second aspect of the present invention, the first aspect is provided.
In addition to the effects of the invention described in (1), it is possible to suppress the thermal deterioration of the seal portion and the decrease in the reliability of the refrigeration device due to the penetration of the lubricating oil into the cylinder without providing a new cold heat generating device. became.

According to the invention of claim 3, according to claim 1,
Or, in addition to the effect of the invention described in 2 above, since both seal portions are as close to each other as possible, it is possible to prevent inefficiency of cooling caused by distributed cooling, which cools seal portions provided separately, and collectively. The two seal portions provided at the locations can be efficiently cooled.

According to the invention described in claim 4, claim 1 is provided.
In addition to the effects of the invention described in any one of (1) to (3), since the fixing member is also configured to fix the seal portion and cool the seal portion, it is possible to reduce the number of parts by sharing the function.

According to the invention set forth in claim 5, according to claim 1,
In addition to the effects of the invention described in any one of (1) to (4), since the seal cooling means has a simple structure, the manufacturing cost is reduced.

According to the invention set forth in claim 6, according to claim 1,
In addition to the effects of the invention described in any one of the above-described embodiments, since the cooling of the seal portion can be performed more effectively, the refrigeration system by suppressing the thermal deterioration of the seal portion and invading the lubricating oil into the cylinder. Can be more effectively suppressed from lowering in reliability.

According to the invention of claim 7, according to claim 1,
In addition to the effects of the invention described in any one of Items 6 to 6, unevenness in thermal deterioration of the seal portion is suppressed, and the refrigeration apparatus can be operated for a long time in a high-performance state.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a refrigeration apparatus including a seal cooling unit, which is an example of an embodiment according to the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a refrigeration apparatus including a seal cooling unit, which is an example of an embodiment according to the present invention.

FIG. 3 is a sectional view taken on line AA of FIG. 2;

FIG. 4 is a sectional view showing the structure of a conventional Stirling refrigerating apparatus.

FIG. 5 is a diagram illustrating a heat cycle process in the Stirling refrigerating apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main body housing 2 Expansion cylinder 3 Compression cylinder 4 Working gas passage 5 Crank 6 Displacer 7 Compression piston 8 Seal part which separates an expander and a crank chamber 9 Seal part which separates a compressor and a crank chamber 10 Lubricating oil 11 Expansion space 12 Crank Room 13 Compression space 14 Cold storage material 15 Cold head 16 Rod (expander side) 17 Rod (compressor side) 18 Seal stop as a fixing member 21 Expander 22 Compressor 31 Wire-shaped copper core as an example of seal cooling means 32 Copper pipe as an example of a cooling fluid pipe 33 Pump as an example of a drive source for circulating a cooling fluid 40 Electric motor as an example of a drive source 41 Control unit

Claims (7)

[Claims] 1. A heat exchange member for exchanging heat by contacting a refrigerant moving between a compression space in a compression cylinder and an expansion space in an expansion cylinder. A refrigeration apparatus that removes heat of the refrigerant moving to the expansion space and applies heat to the refrigerant moving from the expansion space to the compression space to generate cold heat in the expansion space, wherein the refrigeration apparatus reciprocates a rotational motion of a drive source. A crank chamber for converting the motion into a motion; a seal section that partitions the inside of the compression cylinder from the crank chamber; a seal section that partitions the inside of the expansion cylinder from the crank chamber; and a seal cooling unit that cools both the seal sections. And a refrigeration apparatus. 2. The refrigeration apparatus according to claim 1, wherein said seal cooling means cools said seal portion by utilizing cold generated in said expansion space. 3. The refrigeration apparatus according to claim 1, wherein the compression cylinder and the expansion cylinder are arranged in parallel. 4. The refrigeration apparatus according to claim 1, wherein said seal cooling means cools said seal portion via a fixing member for fixing said seal portion. 5. The seal cooling means includes a heat conductive member extending from at least one of the outer sides of the two cylinders to the seal portion and contacting the seal portion. The refrigeration apparatus according to any one of claims 1 to 4, wherein the seal portion is cooled by using a cooling medium. 6. The seal cooling means according to claim 1, wherein said seal cooling means directs a circulation path of a cooling fluid toward said seal portion, and cools said seal portion with a cooling fluid circulated to said seal portion. The refrigeration apparatus according to any one of the above. 7. A cooling priority switching means capable of switching from a state in which one of the two seals is preferentially cooled to a state in which the other seal is preferentially cooled. The refrigeration apparatus according to any one of claims 1 to 6, comprising: