JPH05126426A - Cryogenic refrigerator - Google Patents

Abstract

PURPOSE:To increase the heat-releasing efficiency of a gaseous refrigerant and improve the refrigerating capacity by a method wherein gaseous refrigerant discharged from a compressor is sent into a vortex tube through a tube of small diameter and in a tangential direction and into a cold heat accumulator as it spirals along the inner wall of the vortex tube. CONSTITUTION:A precooling heat exchange device 11 is connected to the outlet side of a compressor 8 and to the outlet side of the precooling heat exchange device a cold heat accumulator 13 in part designed to act as a precooling heat exchanger 12, a cold-end heat exchanger 15. and a pulse tube 16 are connected. After releasing compression heat from a high temperature end part 17 in the function of a heat-releasing heat exchanger, the apparatus conveys heat to a buffer tank 18 through an orifice valve 19. In such a cryogenic refrigerator the precooling heat exchange device 11 is provided with a vortex tube 20 in which the main tube 21 has a first tube 22 of small diameter projecting in a direction tangential to the circumferential wall of the main tube and has it connected to the compressor 8; on the other hand, the precooling heat exchange device 11 is provided with a vortex tube 20 from which a second tube 23 of small diameter projects through an end of the main tube 21 and is connected to the cold heat accumulator 13; gaseous refrigerant is conveyed into the cold heat accumulator 13 as it spirals so that the heat-releasing effect of the gaseous refrigerant relative to the vortex tube 20 can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a low temperature end heat exchanger using a pulse tube at 100 to 20K (-173 to 25K).
The present invention relates to a cryogenic refrigerator that generates a cryogenic temperature (3 ° C.) and uses the cryogenic temperature for cooling various infrared sensors and high temperature superconducting devices.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 1-116767 prior to the present invention
In the conventional cryogenic refrigerator described in Japanese Patent No. 0, as shown in FIG. 3, the compressor 1 is sequentially arranged in the precooling heat exchanger 2, the regenerator 3, the low temperature end heat exchanger 4, the pulse tube 5,
Pipe connection to the orifice valve 6 and the buffer tank 7,
During the compression process, the gaseous refrigerant compressed by the compressor 1 is cooled while passing through the pre-cooling heat exchanger 2 and the regenerator 3 and flows into the pulse tube 5 to compress the residual refrigerant in the pulse tube 5 and compress it. Radiates heat at the high temperature end 5a,
Further, while passing through the orifice valve 6, it is cooled by adiabatic expansion and flows into the buffer tank 7, and then the compressor 1 is sucked in the expansion process to return and move the gaseous refrigerant in the buffer tank 7 to the pulse tube 5. Adiabatic expansion is performed in the interior to further lower the temperature, the low temperature end heat exchanger 4 and the regenerator 3 are cooled and returned to the compressor 1, and the reciprocating cycle is repeated to obtain an extremely low temperature in the low temperature end heat exchanger 4. There is.

However, in this type of conventional cryogenic refrigerator, the high temperature end portion 5a and the precooling heat exchanger 2 are simply cooled with water, and the heat dissipation function is insufficient, so that the refrigerating capacity is sufficient. There are drawbacks such as not being able to upgrade.

[0004]

The present invention solves the above-mentioned drawbacks and provides a cryogenic refrigerator having a high refrigerating capacity.

[0005]

According to the present invention, a compressor is sequentially connected to a pre-cooling heat exchange device, a regenerator, a low temperature end heat exchanger, a pulse tube and a buffer tank by piping to connect the buffer tank and the compressor. In between, by moving the gaseous refrigerant back and forth, the low temperature end heat exchanger is cooled to an extremely low temperature, the pre-cooling heat exchange device is equipped with a vortex tube, the peripheral wall of this vortex tube The first thin tube projecting in the tangential direction is communicated with the compressor, and the second thin tube projecting in the center of the end of the vortex tube is communicated with the regenerator.

[0006]

According to the present invention, since the gaseous refrigerant compressed by the compressor flows tangentially from the first thin tube into the vortex tube, it is rotated by the centrifugal force along the peripheral wall of the tube and the heat of compression is sufficiently supplied during the rotation. After radiating heat to the peripheral wall, it reaches the central part of this tube and is then sent from the second thin tube to the regenerator. Therefore, the heat dissipation efficiency of the gaseous refrigerant to the vortex tube is improved, and the pulse is correspondingly increased. The freezing capacity of the tube refrigerator is increased.

[0007]

Next, an embodiment of the present invention will be described.

Reference numeral 8 is a compressor, and a reciprocating piston 10 is housed inside a cylinder 9. Reference numeral 11 is a heat exchanger for pre-cooling which is connected to the compressor 8 by piping, the details of which will be described later. Reference numeral 12 is a pre-cooling heat exchanger pipe-connected to the pre-cooling heat exchanger 11, 13 is a regenerator having a pre-cooling heat exchanger 12 as a part thereof, and is a regenerator material 1 made of lead, copper or the like.
Holds 4. Reference numeral 15 is a low temperature end heat exchanger pipe-connected to the regenerator 14, 16 is a stainless steel pulse tube connected to the low temperature end heat exchanger 15, and the compression heat generated in the compression process is used as a heat radiating heat exchanger. Heat is radiated from the high temperature end portion 17. Reference numeral 18 denotes a buffer tank which adiabatically expands the gaseous refrigerant extruded from the pulse tube 16 during the compression process by the orifice valve 19 to further cool and inflow.

The heat exchanger 11 for precooling is equipped with a vortex tube 20. The vortex tube 20 is configured as shown in FIGS. 2 (a) and 2 (b) (b is a sectional view taken along the line bb of a), and the first thin tube 22 is formed on the peripheral wall of the main tube 21 so as to project in the tangential direction. Is communicated with the compressor 8, and a second thin tube 23 formed to project at the center of the end of the main tube 21 is communicated with the regenerator 13. According to this vortex tube 20, the gaseous refrigerant compressed by the compressor 8 flows into the vortex tube 20 from the first thin tube 22 in a tangential direction, so that it is rotated along the peripheral wall of the tube 20 by centrifugal force, and in the meantime. After the compression heat is sufficiently radiated to the peripheral wall, it reaches the central portion of the tube 20 and is sent to the regenerator 13 from the second thin tube 23 in the axial direction thereof. Therefore, the gaseous refrigerant to the vortex tube 20 is The heat dissipation efficiency of the pre-cooling heat exchange device 11 is increased by the amount of improved heat dissipation.

Further, the precooling heat exchange device 11 is provided with a refrigerant flow adjusting means 24. This refrigerant flow adjusting means 24
Connects the first thin tube 22 of the vortex tube 20 to the compressor 8 with a first connecting tube 25.
A second connecting pipe 26 is provided at an intermediate point of the connecting pipe 25 to connect the main pipe 21.
Is connected to the third thin pipe 27 at the end of the first pipe 28 and the precooling auxiliary heat exchanger 29 are sequentially connected to the second connecting pipe 26.
And the second valve body 30 is interposed. First valve body 28 and second
The valve body 30 is automatically opened / closed by an electric signal by a control device (not shown), and the first valve body 28 is closed and the second valve body 30 is opened in the compression process, whereby the compressor 8 is compressed. The refrigerant is introduced from the first thin tube 22 into the vortex tube 20, and a part of the refrigerant is pushed into the precooling auxiliary heat exchanger 29 through the opened second valve body 30 to radiate heat. Body 3
0 is closed and the first valve body 28 is opened, whereby the refrigerant after heat dissipation from the pre-cooling auxiliary heat exchanger 29 is sucked and expanded in the second connecting pipe 26 and cooled to cool the first connecting pipe 25. It returns to the compressor 8 by merging with the mainstream refrigerant.

In the cryogenic refrigerator, when the compressor 8 is compressed during the compression process, the compressed refrigerant radiates the compression heat by the pre-cooling heat exchange device 11, the heat radiation heat exchanger 12 and the regenerator 13. The refrigerant flowing in the pulse tube 16 is compressed, the residual refrigerant in the pulse tube 16 is compressed, and the heat of compression is radiated from the high temperature end portion 17 and further cooled by adiabatic expansion through the orifice valve 19 to flow into the buffer tank 18. After that, when the compressor 8 is sucked in the expansion process, the gaseous refrigerant is discharged into the buffer tank 1
Then, the low temperature end heat exchanger 15 and the regenerator 13 are cooled and returned to the compressor 8. By repeating such a reciprocating movement cycle, the low temperature end heat exchanger 15 is
An extremely low temperature of 00 to 20K (-173 to 253 ° C) can be obtained.

In the cryogenic refrigerator, the gaseous refrigerant compressed by the compressor 8 in the compression process flows from the first thin tube 22 into the vortex tube 20 in the tangential direction, so that the centrifugal force causes centrifugal force to the peripheral wall of the tube 20. It swirls along and the compression heat is sufficiently radiated to the peripheral wall in the meantime, and reaches the central portion of the tube 20 and is sent from the second thin tube 23 in the axial direction to the regenerator 13. Therefore, this vortex The heat dissipation efficiency of the gaseous refrigerant to the tube 20 can be improved, and the precooling heat exchanger 11 can also radiate heat in the precooling auxiliary heat exchanger 29 in addition to the vortex tube 20. As the heat dissipation capacity of the device 11 is increased, the refrigeration capacity of the pulse tube refrigerator is increased to ensure 6
The cryogenic temperature of 0 K or less can be generated in the low temperature end heat exchanger 15.

[0013]

Since the present invention is configured as described above, the gaseous refrigerant compressed by the compressor flows tangentially from the first thin tube into the vortex tube, so that it is swirled along the peripheral wall of the tube by centrifugal force. During that time, the compression heat is sufficiently radiated to the peripheral wall and then reaches the central portion of the tube to be sent to the regenerator from the second thin tube. Therefore, the heat dissipation efficiency of the gaseous refrigerant to the vortex tube is improved. The refrigerating capacity of the pulse tube refrigerator can be increased by that amount.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a main part of the embodiment.

FIG. 3 is a configuration diagram of a conventional example.

[Explanation of symbols]

 8 Compressor 11 Heat exchanger for pre-cooling 13 Regenerator 15 Low temperature end heat exchanger 16 Pulse tube 18 Buffer tank 20 Vortex tube 22 First thin tube 23 Second thin tube

Claims (1)

[Claims] 1. A compressor is sequentially connected to a pre-cooling heat exchanger, a regenerator, a low temperature end heat exchanger, a pulse tube and a buffer tank, and a gaseous refrigerant is reciprocated between the buffer tank and the compressor. By moving, the low-temperature end heat exchanger is cooled to an extremely low temperature, the pre-cooling heat exchange device comprises a vortex tube,
The first thin tube projecting in the tangential direction on the peripheral wall of the vortex tube communicates with the compressor, and the second thin tube projecting at the center of the end of the vortex tube.
A cryogenic refrigerator characterized in that the thin tube of (1) is communicated with the regenerator.