JPH06323658A - Refrigerator - Google Patents

Abstract

PURPOSE:To prevent deterioration of cold storage capacity due to lube oil, etc., and deterioraion of heat exchanging performance. CONSTITUTION:A refrigerator communicates a compressing space 11 to be compressed by a compressing cylinder 12 with an expanding space to be expanded by an expending cylinder 15 via a channel via a cold accumulator 4, so connects a compressing piston 13 of the cylinder 12 and an expanding piston 16 of the cylinder 15 to a drive motor via a crank mechanism 9 as to drive to reciprocate them with a specific phase difference, and generates low temperature by a heat cycle having an expanding step of refrigerant gas to be guided from the space 11 to the expanding space. A filter for removing impurities from the gas is suitably disposed at a specific position of the channel of the refrigerator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus for realizing an ultra-low temperature by using a cold storage type refrigerator such as a Stirling refrigerator.

[0002]

2. Description of the Related Art In the field of advanced technology such as the field of biotechnology and the field of electronic devices, there is an urgent need to develop an ultralow temperature preservation technique for various samples and various materials. In particular, regenerative refrigerators such as Stirling refrigerators have been attracting attention as means for achieving the above-mentioned ultra-low temperatures, and are being widely used for various infrared sensors, freezers for cooling superconducting devices and the like, biomedical freezers, freezers and the like.

The operation principle of the two-piston Stirling refrigerator will be described with reference to FIG.

The Stirling refrigerator 1 has a gas flow path 5 in which a gas compressor 2 and an expander 3 are interposed, and a regenerator 4 is interposed therebetween.
The radiator 6 and the radiator 7 are arranged on the gas compressor 2 side of the gas flow path 5 on the gas compressor 2 side and the inlet side of the regenerator 4 on the other hand, and the freezing take-out portion 8 is formed on the upper part of the expander 3. Further, a crank mechanism portion 9 is arranged behind the gas compressor 2 and below the expander 3.

The gas compressor 2 is for compressing a refrigerant gas having a cryogenic boiling point such as helium according to a predetermined cycle and supplying the compressed refrigerant gas to the expander 3. In the gas compressor 2, a compression cylinder is used. A compression space 11 for compressing a refrigerant gas is formed inside the main body 10, a compression piston 13 is slidably fitted in a compression cylinder 12, and the compression piston 13 reciprocates by the action of a crank mechanism section 9 described later. It is like this.

The expander 3 expands the compressed refrigerant gas supplied from the gas compressor 2 via the regenerator 4. The expander 3 has an expansion cylinder 15 inside the expander body 14 in the vertical direction. The expansion piston 16 is fitted inside the expansion cylinder 15 so as to be slidable in the vertical direction, and a freezing generation portion 17 as an expansion space for generating a low temperature is formed inside the expander 3. .

The regenerator 4 is formed in a cylindrical shape between the inner circumference of the expander body 14 and the outer circumference of the expansion cylinder 15, and is a compressed refrigerant gas supplied to the expander 3 through the gas flow path 5. On the other hand, when the refrigerant gas expanded and cooled in the freezing generation section 17 is returned to the gas compressor 2 while cooling the refrigerant, the refrigerant is cooled and stores cold. Stainless steel, lead, and the like are used, and they are formed into a cylindrical shape having a large number of fine holes through which a refrigerant gas passes.

The gas flow path 5 is a pipe connecting the gas compressor 2 and the expander 3 so that the compressed refrigerant gas evenly passes through the regenerator 4 at the inlet side of the regenerator 4. The radiator 6 and the radiator 7 lower the compressed high temperature refrigerant gas to near room temperature. The radiator 6 has a large number of disc-shaped fins standing upright outside the body of the compression cylinder body 10 for heat radiation. Bowl 7
Has a large number of circular fins standing on the outside of the body of the expander body 14. The freezing take-out unit 8 includes the freezing generation unit 17
The cold heat generated in 1 is taken out to a low temperature tank (not shown) or the like, and is covered with a plate-like body such as stainless steel on the upper portion of the expander body 14.

The crank mechanism section 9 reciprocates by the action of a crank motion using a compression motor and a compression piston 13 as drive sources (not shown). The crank mechanism section 9 of the compression cylinder 12 is reciprocated. A crank chamber 22 having a guide portion 20 formed at the rear and a guide portion 21 below the expansion cylinder 15 is provided. Lubricating oil 23 is stored at the bottom of the crank chamber 22. A crank mechanism 24 is arranged inside.

The connecting rod 25 extending from the crank mechanism 24 is connected to the guide receiver 2 of the guide portion 20.
0a has a cross guide 26 slidably fitted therein, and a piston rod 27 communicating with the cross guide 26 penetrates the through hole 20b of the guide portion 20 to be connected to the rear portion of the compression piston 13 and also from the crank mechanism 24. The extending connecting rod 28 is slidably fitted to the guide receiver 21a of the guide portion 21, and the piston rod 30 communicating with the cross guide 29 is connected to the rear portion of the expansion piston 16.

Reference numeral 31 is a piston seal for disconnecting the compression space 11 and the space 32 behind the compression piston 13,
Reference numeral 3 denotes an oil seal that prevents the lubricating oil 23 in the crank chamber 22 from entering the space 32. Further, 34 is a piston seal that disconnects the space 35 behind the freezing generator 17 and the expansion piston 16, and 36 is an oil seal that prevents the lubricating oil 23 in the crank chamber 22 from entering the space 35.

First, when the crank mechanism 24 of the crank mechanism portion 9 is driven by the rotation of a drive motor (not shown), the compression piston 13 in the compression cylinder 12 of the gas compressor 2 moves to the compression space 11 side and the compression space 11 Refrigerant gas, such as helium or nitrogen, which is difficult to liquefy, is compressed. The compressed refrigerant gas is radiated to the outside by the radiator 6 provided on the outer periphery of the compression cylinder body 10 and cooled to near room temperature, passes through the gas flow path 5, and further the radiator 7
It is cooled by and flows into the regenerator 4.

The refrigerant gas flowing into the regenerator 4 is cooled by a material having a large specific heat, for example, a regenerator material made of copper or lead wire mesh or spheres, and the cooled refrigerant gas is frozen by the freezing generation section 17 of the expander 3. And the freezing generation unit 17 is in a high pressure state.

Thereafter, the expansion piston 16 in the expansion cylinder 15 of the expander 3 descends with a phase difference of about 90 ° with the compression piston 13. Thereby, the freezing generation part 17 as an expansion space is expanded, and the high-pressure refrigerant gas flowing from the regenerator 4 into the freezing generation part 17 is suddenly expanded,
Since the pressure of the refrigerant gas in the freezing generation unit 17 suddenly drops, the refrigerant gas has a low temperature.

When the expansion piston 16 starts to rise and the compression piston 13 retreats, the low temperature refrigerant gas returns to the compression space 11 through the regenerator 4 and the gas flow path 5. At this time, in the regenerator 4, the regenerator material is cooled and cold heat is stored in the regenerator 4.

One thermal cycle is completed by the steps described above, and this step is repeated by the reciprocating movement of the crank mechanism 24 of the crank mechanism section 9. As a result, the temperature of the freezing generator 17 and the temperature of the regenerator 4 gradually drop,
The refrigerant gas in the freezing generation unit 17 is set to a low temperature. In this state, in the freezing take-out section 8, the cold heat of the freezing generation section 17 is exchanged with an external low temperature tank or the like as a heat utilization section (not shown) to bring the cooling load of the external low temperature tank to the freezing temperature.

[0017]

However, in the conventional Stirling refrigerator 1 described with reference to FIG. 3, the lubricating oil 23 of the crank chamber 22 extends from the sealing portions of the guide portions 20 and 21 to the gas compressor as an operating space. 2 and expander 3
However, there is a problem that the refrigerating capacity is deteriorated by being mixed in with.

Conventionally, in the gas compressor 2, the crank mechanism 2 is used.
The connecting rod 25 extending from
No. 0 guide receiver 20a is slidably fitted to the cross guide 26, and the piston rod 27 of the cross guide 26 penetrates through the through hole 20b. The piston rod 27 is provided with an oil seal 33, and the compression piston 13 It is attached to the rear of the.

With this structure, the crank motion of the crank mechanism 24 is converted into the reciprocating motion of the compression piston 13, and
The lubricating oil 23 in the crank chamber 22 is prevented from entering the space 32 behind the compression piston 13.

However, it is difficult to completely seal the lubricating oil 23 with only the oil seal 33, and the lubricating oil 23 enters the space 32 at the rear. Therefore, there is a problem that the invading lubricating oil 23 mixes with the refrigerant gas to reduce the refrigerating capacity, and mixes with the regenerator material of the regenerator 4 to deteriorate the regenerator capacity.

The above is the compression piston 1 of the expander 3.
The same applies to 3 and the guide portion 21.

Therefore, it is an object of the present invention to provide a refrigerating apparatus which avoids a reduction in refrigerating capacity even if lubricating oil is mixed in the working space.

[0023]

According to the present invention, a compression space compressed by a compression cylinder and an expansion space expanded by an expansion cylinder communicate with each other by a flow path through a regenerator, and a compression piston of the compression cylinder. And an expansion piston of the expansion cylinder are connected to a drive motor through a crank mechanism so as to be reciprocally driven with a predetermined phase difference, and the expansion process of the refrigerant gas guided from the compression space to the expansion space is performed. In a refrigeration system that generates a low temperature by a heat cycle that includes a filter, a filter that removes impurities from a refrigerant gas is appropriately arranged at a required position in a flow path.

[0024]

With the above structure, impurities are removed from the refrigerant gas containing impurities such as lubricating oil and iron powder mixed in the working space by the filter arranged at the required position in the flow path. Therefore, it is possible to prevent the deterioration of the refrigerating capacity by preventing the deterioration of the stock cooling capacity and the deterioration of the heat exchange performance.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a Stirling refrigerator showing a first embodiment of the present invention, and the same reference numerals as those in FIG. 3 showing a conventional example indicate the same or corresponding portions. The Stirling refrigerator 1 connects the gas compressor 2 and the expander 3 with each other through a gas passage 5 having a regenerator 4 interposed therebetween, and a radiator 6 is provided on the gas compressor 5 side of the gas passage 5. A radiator 7 is arranged on the inlet side of the regenerator 4, a refrigeration take-out portion 8 is formed on the upper part of the expander 3, and a crank is arranged behind the gas compressor 2 and below the expander 3. The mechanical section 9 is provided.

The gas compressor 2 is for compressing a refrigerant gas having a cryogenic boiling point such as helium according to a predetermined cycle and supplying the compressed refrigerant gas to the expander 3, and the refrigerant is provided inside the compression cylinder body 10. Compression space 11 for compressing gas
The compression piston 13 is slidably fitted into the compression cylinder 12, and the compression piston 13 reciprocates by the action of the crank mechanism portion 9.

The expander 3 expands the compressed gas supplied from the gas compressor 2 via the regenerator 4. The expander 3 has an expansion cylinder 15 vertically arranged inside the expander body 14. The expansion piston 16 is installed inside the expansion cylinder 15 so as to be slidable in the vertical direction.
As the expansion space where low temperature is generated inside the
Are formed.

Further, in the expander 3, the expansion cylinder 15
The gas line filter 37c is filled in a part of an annular flow path formed on the outer side of and the inner side of the freezing take-out portion 8. In the gas compressor 2, the gas line filter 37a is filled in a part of an annular flow path formed outside the compression cylinder 12 and inside the compression cylinder body 10. As the gas line filter 37a, for example,
Fluorine-based resin with low pressure loss and high porosity is used, and when the refrigerant gas containing impurities such as lubricating oil passes through the filter, impurities are attached to the filter and removed. Gas line filters 37b to 3
The same applies to 7h.

The regenerator 4 is formed in a cylindrical shape between the inner circumference of the expander body 14 and the outer circumference of the expansion cylinder 15, and is a compressed refrigerant gas supplied to the expander 3 through the gas flow path 5. On the other hand, when the refrigerant gas expanded and cooled in the freezing generation section 17 is returned to the gas compressor 2 while cooling the refrigerant, the refrigerant is cooled and stores cold. Stainless steel, lead, and the like are used, and they are formed into a cylindrical shape having a large number of fine holes through which a refrigerant gas passes.

A gas line filter 37b is filled in a part of the flow passage formed between the outside of the expansion cylinder 15 on the inlet side of the regenerator 4 and the inside of the expander main body 14, and further,
A gas line filter 37d is filled in a part of a flow path formed outside the expansion cylinder 15 on the outlet side of the regenerator 4 and inside the expander body 14.

The freezing take-out section 8 takes out the cold heat generated in the freezing generation section 17 as an expansion space to a low temperature tank or the like (not shown). The crank mechanism portion 9 has a guide portion 20 formed behind the compression cylinder 12 and a guide portion 21 formed below the expansion cylinder 15 and the crank chamber 2
2, the bottom of the crank chamber 22 is filled with lubricating oil 23, and the crank mechanism 2 is provided inside the crank chamber 22.
4 are arranged.

First, when a drive motor (not shown) of the crank mechanism portion 9 starts to rotate, the crank mechanism 24 rotates, and a connecting rod 25 extending from the crank mechanism 24 is fitted to the guide portion 20. Guide 26
Is slid in the direction of the compression space 11. The piston rod 27 connected to the cross guide 26 pushes the rear portion of the compression piston 13 so that the portion of the piston seal 31 of the compression piston 13 resists the inside of the compression cylinder 12 and moves the compression piston 13 forward. A reciprocating motion is made. At this time, the lubricating oil 23 in the crank chamber 22 enters the guide receiver 20a as the cross guide 26 fitted in the guide receiver 20a of the guide portion 20 reciprocates, and the lubricating oil 23
May pass through the oil seal 33 and enter the rear space 32. Then, the lubricating oil 23 mixes into the refrigerant gas in the compression space 11 through the slight gap of the piston seal 31.

The refrigerant gas mixed with the lubricating oil 23 is compressed by the action of the compression piston 13, and is first filled in a part of an annular flow path formed outside the compression cylinder 12 and inside the compression cylinder body 10. Gas line filter 37
Pass a. As a result, the first stage removal of the lubricating oil 23 is performed by the gas line filter 37a from the refrigerant gas mixed with the lubricating oil 23, and the radiator 6 cools the gas passage 5
Is flowed into.

The refrigerant gas flowing into the gas passage 5 is further cooled by the radiator 7 and flows into the regenerator 4. At this time, the second stage of the lubricating oil 23 from the refrigerant gas by the gas line filter 37b filled in a part of the flow passage formed by the outside of the expansion cylinder 15 on the inlet side of the gas flow passage 5 and the expander main body 14 Is removed. As a result, the refrigerant gas from which the lubricating oil 23 has been almost completely removed from the refrigerant gas passes through the regenerator 4.

The refrigerant gas flowing into the regenerator 4 is cooled by a material having a large specific heat, for example, a regenerator material made of copper or lead wire mesh or spheres, and the cooled refrigerant gas is frozen by the freezing generation section 17 of the expander 3. And the freezing generation part 17 is in a high pressure state.

Thereafter, the expansion piston 16 in the expansion cylinder 15 descends with a phase difference of about 90 ° with the compression piston 13. As a result, the high-pressure refrigerant gas that has expanded from the regenerator 4 to the freezing generation portion 17 by expanding the freezing generation portion 17 as an expansion space is suddenly expanded, and the pressure of the refrigerant gas in the freezing generation portion 17 drops sharply. Therefore, the refrigerant gas has a low temperature.

When the expansion piston 16 starts to rise and the compression piston 13 retreats, the low temperature refrigerant gas returns to the compression space 11 through the regenerator 4 and the gas flow path 5. At this time, in the same manner as described for the gas compressor 2, the cross guide 29 fitted to the guide receiver 20a of the guide portion 21.
The lubricating oil 23 of the crank chamber 22 enters the guide bridge 21a with the reciprocating movement of the part, and a part of the lubricating oil 23 breaks through the oil seal 36 and enters the freezing generating part 17 through the space 35 at the rear and mixes with the refrigerant gas. I have something to do.

The low-temperature refrigerant gas mixed with the lubricating oil 23 is
With the rise of the expansion piston 16, first, the first stage of the lubricating oil 23 from the refrigerant gas by the gas line filter 37c filled in the annular flow path formed outside the expansion cylinder 15 and inside the freezing generation portion 17 Is removed.

Further, the gas line filter 37d provided at the end of the regenerator 4 removes the lubricating oil 23 from the second stage refrigerant gas. As a result, the lubricating oil 23 mixed from the crank chamber 22 to the expander 3 side is almost completely removed.

One heat cycle is completed by the above-mentioned steps, and this step is repeated by the crank movement of the crank mechanism 24 of the crank mechanism section 9. As a result, the temperature of the freezing generation unit 17 and the temperature of the regenerator 4 are gradually decreased, and the refrigerant gas of the freezing generation unit 17 is cooled to a low temperature. In this state, in the freezing take-out section 8, the freezing generation section 17
The cold heat of is exchanged with an external low temperature tank or the like (not shown) as a heat utilization unit, and the freezing load of the external low temperature tank is set to the freezing temperature.

Thus, the lubricating oil 23 in the crank chamber 22
Even if the gas enters the gas compressor 2 and the expander 3 and mixes with the refrigerant gas, the lubricating oil 23 can be removed by the gas line filter appropriately provided in the flow path. It is possible to avoid the reduction of the refrigerating capacity.

Impurities other than the lubricating oil 23, for example,
Although iron powder or the like may be mixed into the working space or the like when the Stirling refrigerator 1 is disassembled, even in such a case, it can be removed by the gas line filter appropriately filled in the flow path.

FIG. 2 is a schematic diagram of a Stirling refrigerator showing a second embodiment of the present invention, and the same reference numerals as those in FIG. 3 showing a conventional example indicate the same or corresponding portions.

The second embodiment is the compression space 1 of the gas compressor 2.
Outside of the compression cylinder 12 and the compression cylinder body 1
The gas line filter 37e is filled in almost the entire area of the annular flow path formed by the inside of 0, the gas flow path 5 is filled with the gas line filter 37f, and further, in the expander 3,
Gas line filters 37g and 37h are filled almost in the entire area of an annular flow path formed by the outside of the expansion cylinder 15 and the inside of the expander main body 14, excluding the regenerator 4.

In this structure, since the gas line filter is filled and arranged in almost the entire area where the gas compressor 2 and the expander 3 communicate with each other, the lubricating oil 23 and other impurities are surely removed. Therefore, deterioration of the cold storage capacity of the regenerator 4 and deterioration of the heat exchange performance of the heat exchange parts of the gas compressor 2 and the expander 3 as the working space are prevented.

[0047]

As described above, according to the present invention, impurities are removed from the refrigerant gas containing impurities such as lubricating oil and iron powder mixed in the working space by the filter. Therefore, it is possible to prevent the deterioration of the refrigerating capacity by preventing the deterioration of the stock cooling capacity and the deterioration of the heat exchange performance.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a Stirling refrigerator showing a first embodiment of the present invention.

FIG. 2 is a schematic view of a Stirling refrigerator showing a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a conventional Stirling refrigerator.

[Explanation of symbols]

 1 Stirling Refrigerator 2 Gas Compressor 3 Expander 4 Regenerator 5 Gas Flow Path 6 Radiator 7 Radiator 8 Refrigerator Extractor 9 Crank Mechanism 10 Compression Cylinder Body 11 Compression Space 12 Compression Cylinder 13 Compression Piston 15 Expansion Cylinder 16 Expansion Piston 17 Freezing generation part 37a-37h Gas line filter

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[Procedure amendment]

[Submission date] January 11, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023]

SUMMARY OF THE INVENTION According to the present invention, a compression space in a compression cylinder and an expansion space in an expansion cylinder are communicated with each other by a flow path through a regenerator, and a compression piston of the compression cylinder and the expansion cylinder. The expansion piston or the expansion displacer is connected to a drive motor through a crank mechanism so as to be reciprocally driven with a predetermined phase difference from each other, and includes an expansion process of a refrigerant gas guided from the compression space to the expansion space. In a refrigeration system that generates a low temperature by a heat cycle, a filter that removes impurities from a refrigerant gas is appropriately arranged at a required position in a flow path.

Claims (1)

[Claims] 1. A compression space compressed by a compression cylinder and an expansion space expanded by an expansion cylinder communicate with each other through a flow path through a regenerator, and the compression piston of the compression cylinder and the expansion piston of the expansion cylinder. Are connected to a drive motor through a crank mechanism so that they are reciprocally driven with a predetermined phase difference from each other, and generate a low temperature by a heat cycle including an expansion process of a refrigerant gas guided from the compression space to the expansion space. In the refrigeration system, a filter for removing impurities from the refrigerant gas is appropriately arranged at a required position in the flow path.