JPH05133630A - Cryogenic refrigerating device - Google Patents

Abstract

PURPOSE:To make the device compact by tuning back a pulse tube 180 deg. in an arc and arranging the pulse tube, a high temperature end heat exchanger, an orifice valve, and a buffer tank in a line parallel to an arrangement of a compressor, a heat exchanger for preliminary cooling, a cold heat accumulator, and a low temperature end heat exchanger. CONSTITUTION:A pulse tube 15 is turned back 180' at the end connected with a low temperature end heat exchanger 14 so that the pulse tube 15, a high temperature end heat exchanger 16, an orifice valve 18, and a buffer tank 17 are arranged in a line parallel to an arrangement of a compressor 8, a heat exchanger for preliminary cooling 11, a cold heat accumulator 12, and a low temperature end heat exchanger 14. For this structure, the total length X can be reduced to roughly a half compared with a conventional structure and, unlike an elbow-shaped bend, the bend is formed in an arc. With no sharp turning in the passageway for refrigerant, a cryogenic refrigerating device having the pressure loss minimized, being compact in structure, and having a high refrigerating capacity can be produced.

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 150K to 20K (-123 ° C to
The present invention relates to a cryogenic refrigerating apparatus which generates a cryogenic temperature of −253 ° 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 refrigeration system disclosed in Japanese Patent Publication No.
As shown in, the compressor 1 is sequentially connected to the pre-cooling heat exchanger 2, the regenerator 3, the low temperature end heat exchanger 4, the pulse tube 5, 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 the conventional cryogenic refrigerating apparatus of this kind, the pulse tube 5 is used for the purpose of increasing the refrigerating capacity.
When extended, the entire length of the cryogenic refrigeration system becomes large, making it difficult to handle and making the mechanism complicated.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks and provides a compact cryogenic refrigerating apparatus having a high refrigerating capacity.

[0005]

DISCLOSURE OF THE INVENTION In the present invention, a compressor is sequentially provided with a precooling heat exchanger, a regenerator, a low temperature end heat exchanger,
The low temperature end heat exchanger is cooled to an extremely low temperature by communicating with the pulse tube, the high temperature end heat exchanger, the orifice valve and the buffer tank, and moving the gaseous refrigerant back and forth between the buffer tank and the compressor. The pulse tube is formed into an arc shape of about 180
By being bent, the pulse tube, the high temperature end heat exchanger, the orifice valve and the buffer tank are substantially parallel to the compressor, the precooling heat exchanger, the regenerator and the low temperature end heat exchanger. It has been arranged.

[0006]

According to the present invention, the pulse tube is set to approximately 180 °.
By bending, the pulse tube can be extended without increasing the total length of the cryogenic refrigerator, the refrigerating capacity of the cryogenic refrigerator can be improved, and the bending mode of the pulse tube can be arcuate. By this, it is possible to prevent the sudden change of the refrigerant flow and the generation of vortex accompanying it, and it is possible to suppress the pressure loss in the pulse tube to the minimum. The device can be provided.

[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. A heat exchanger 11 for pre-cooling is connected to the compressor 8 by piping and is water-cooled or air-cooled. Reference numeral 12 is a regenerator having a pre-cooling heat exchanger 11 as a part thereof, and stores a regenerator material 13 made of lead, copper or the like. Reference numeral 14 is a low temperature end heat exchanger connected to the regenerator 12, and 15 is a stainless steel pulse tube whose one end is connected to the low temperature end heat exchanger 14. The compression heat generated in the compression process is heated to the high temperature at the other end. Heat is radiated from the end heat exchanger 16.
Reference numeral 17 is a buffer tank, which uses an orifice valve 18 to pass the gaseous refrigerant extruded from the pulse tube 15 during the compression process.
At adiabatic expansion, it is further cooled and made to flow in.

Thus, the pulse tube 15 has an arc-shaped shape near the connection end 15a of the low temperature end heat exchanger 14 in an arc shape.
It is bent by 80 ° and its total length X is extended as compared with the conventional example. The bent pulse tube 15 includes a pulse tube 15, a high temperature end heat exchanger 16, an orifice valve 18 and a buffer tank 17, which are connected to a compressor 8, a precooling heat exchanger 11, a regenerator 12 and a low temperature end heat exchanger 14. By arranging them in parallel with each other, the total length X of the cryogenic refrigeration system is about 1/2 of that of the conventional example.
Shorten to. In addition, the pulse tube 15 has an arcuate bending mode, so that unlike the elbow-type bending pulse tube 19 as shown in FIG. 2, even when the refrigerant flow is suddenly changed, the vortex flow 20 associated therewith is changed. It also becomes possible to prevent the occurrence of pressure and to minimize the pressure loss in the pulse tube 15.

In the cryogenic refrigeration system, when the compressor 8 is compressed during the compression process, the compressed refrigerant releases its compression heat in the precooling heat exchanger 11 and the regenerator 12 and flows into the pulse tube 15. Pulse tube 1
The residual refrigerant of No. 5 is compressed and this compression heat is transferred to the high temperature end heat exchanger 1
The heat is radiated from 6 and is further cooled through adiabatic expansion through the orifice valve 18 to flow into the buffer tank 17. Then, when the compressor 8 is suctioned in the expansion process, the gaseous refrigerant moves back from the buffer tank 17 at a high speed, adiabatically expands in the pulse tube 15 and further cools to a low temperature end heat exchanger 15 and a regenerator 13. Is cooled and returned to the compressor 8. By repeating such a reciprocating movement cycle, the low temperature end heat exchanger 14 has a temperature of 150K to 20K.
An extremely low temperature of K (-123 ° C to -253 ° C) can be obtained.

In the above cryogenic refrigerator, the pulse tube 15 can be extended by bending it by about 180 ° without increasing the total length X of the cryogenic refrigerator, and the pulse tube 15 can be extended. By doing so, the high temperature end heat exchanger 1 at both ends of the pulse tube 15
6, the temperature difference between the low temperature end heat exchanger 14 and the low temperature end heat exchanger 14 becomes large, the heat radiation of the high temperature end heat exchanger 16 is promoted, and the thermal adverse effect from the high temperature end heat exchanger 16 to the low temperature end heat exchanger 14 is also limited. The refrigerating capacity is improved. Furthermore, by making the bent form of the pulse tube 15 arcuate, it is possible to prevent a sudden change in the course of the refrigerant flow and the generation of a vortex accompanying it, and the pressure loss inside the pulse tube 15 is suppressed to a minimum. Freezing capacity is improved.

FIG. 3 shows another embodiment. The feature of this embodiment is that the pulse tube 21 is
That is, a plurality of bend tubes 22 bent into the same shape as the above are inserted. As shown in the bend tube 22, the bend tubes 22a, 22b, 2 having different diameters are used.
By holding 2c by a spacer 23, the central axis of the pulse tube 21 is aligned with that of the pulse tube 21.
Each of the bend tubes 22a, 22b, 22c functions to rectify the refrigerant flow that tends to be complicated in the pulse tube 21 because of the bent tube shape.

In the cryogenic refrigeration system of another embodiment, the gaseous compressed refrigerant flowing into the pulse tube 21 in the compression process becomes parallel to the central axis of the pulse tube 21 along each bend tube 22a, 22b, 22c. It is guided and smoothly sent to the high temperature end heat exchanger 16 so that internal heat diffusion to the outside in the radial direction during the pressurization is prevented, and as a result, the low temperature end heat exchanger 14 moves to the high temperature end heat exchanger. The heat gradient toward 16 increases, the temperature of the high temperature end heat exchanger 16 rises, the amount of heat radiation increases, and the refrigerating capacity is further improved by the increase.

Incidentally, in the other embodiments, the other parts are constructed in the same manner as in the above-mentioned embodiment and are given the same reference numerals, and their explanations are omitted.

[0015]

Since the present invention is constructed as described above, by bending the pulse tube by approximately 180 °, the pulse tube can be extended without increasing the total length of the cryogenic refrigerator, By improving the refrigerating capacity of the cryogenic refrigerating device, and by making the bent form of the pulse tube arcuate, it is possible to prevent a sudden change in the refrigerant flow path and to prevent the occurrence of vortex flow associated therewith, and Pressure loss can be minimized, therefore
It is possible to provide a cryogenic refrigeration system that is compact and has a high refrigeration capacity.

[Brief description of drawings]

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

FIG. 2 is an operation explanatory view shown in comparison with a conventional example of the same embodiment.

FIG. 3 is a configuration diagram of another embodiment of the present invention.

4 is a cross-sectional view taken along the line AA in FIG.

FIG. 5 is a configuration diagram of a conventional example.

[Explanation of symbols]

 8 Compressor 11 Pre-cooling heat exchanger 12 Regenerator 14 Low temperature end heat exchanger 15 Pulse tube 16 High temperature end heat exchanger 17 Buffer tank 18 Orifice valve 22 Bend tube

Front page continuation (72) Inventor Michihiro Kurokawa 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A compressor is sequentially connected to a pre-cooling heat exchanger, a regenerator, a low temperature end heat exchanger, a pulse tube, a high temperature end heat exchanger, an orifice valve and a buffer tank, and the buffer tank and the compressor are connected to each other. In between, the low temperature end heat exchanger is cooled to an extremely low temperature by reciprocating the gaseous refrigerant, and the pulse tube is bent in an arc shape by about 180 °, The high temperature end heat exchanger, the orifice valve and the buffer tank are arranged substantially parallel to the compressor, the precooling heat exchanger, the regenerator and the low temperature end heat exchanger. Cryogenic refrigerator. 2. The cryogenic refrigerator according to claim 1, wherein the pulse tube is formed by inserting a plurality of bend tubes bent into the same shape as the pulse tube.