JPH04324073A - Cryogenic refrigerating plant - Google Patents

Abstract

PURPOSE:To make the mounting of a replaced pulse tube unnecessary and develope the maximum refrigerating capacity even when a compressor, having a different output, is mounted on a cryogenic refrigerating plant for the replacement of the compressor. CONSTITUTION:A compressor 8 is communicated with a cold heat accumulator 13, a low-temperature end heat exchanger 15, a pulse tube 16, an orifice valve 18, a baffer tank 19 and the like sequentially while gaseous refrigerant is moved reciprocally between the baffer tank 19 and said compressor 8. Said pulse tube 16 is constituted so that the length of the same is adjustable.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention uses a pulse tube to
The present invention relates to a cryogenic refrigeration system that obtains a cryogenic temperature of 50 to 20 K (-123 to -253° C.) and is used for cooling various infrared sensors, high-temperature superconducting devices, and the like.

0002

2. Description of the Related Art In a conventional cryogenic refrigeration system filed by the present applicant in Japanese Patent Application No. 1-335564, as shown in FIG. , the pulse tube 4, the orifice valve 5, the buffer tank 6, etc., and by reciprocating the gaseous refrigerant between the buffer tank 6 and the compressor 1, the high temperature end 7 of the pulse tube 4 Heat is radiated and a cryogenic temperature is generated in the low temperature end heat exchanger 3.

However, in this kind of conventional cryogenic refrigeration equipment, the length of the pulse tube 4 cannot be adjusted, so it cannot be used with cryogenic refrigeration equipment with different refrigerating capacities. This has the disadvantage that the pulse tube 4 must be replaced with one of a different length. That is, in the cryogenic refrigeration system, if the pulse tube 4 is too long compared to the output of the compressor 1, not only will the shape become large, but the high-low pressure ratio of the gaseous refrigerant will not be maintained, resulting in a reduction in the refrigerating capacity. On the other hand, if the pulse tube 4 is too short, it will not be possible to maintain a large temperature difference between the high temperature end and the low temperature end, resulting in a reduction in refrigerating capacity. However, in order to maximize the performance of the compressor 1, the pulse tube 4 has to be replaced with one of the optimum length.

0004

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks and achieves maximum refrigeration capacity by eliminating the need to replace pulse tubes even when compressors with different outputs are installed in cryogenic refrigeration equipment. It is something that allows you to demonstrate your abilities.

[0005]

[Means for Solving the Problems] The present invention sequentially connects a compressor to
It communicates with a regenerator, a low-temperature end heat exchanger, a pulse tube, an orifice valve, a buffer tank, etc., and moves a gaseous refrigerant back and forth between the buffer tank and the compressor, and the pulse The pipe is constructed so that its length can be adjusted freely.

[0006]

[Function] According to the present invention, even when compressors with different outputs are replaced and installed, the cryogenic refrigeration system can exhibit the maximum refrigerating capacity simply by adjusting the length of the pulse tube.

[0007]

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

Reference numeral 8 denotes a compressor connected to the main body of the cryogenic refrigeration system through a pipe 9. A piston 11 is housed in a cylinder 10, and the piston 11 is reciprocated by a drive device (not shown) to compress the gaseous refrigerant. Or inflate by suction. 12 is a pre-cooling heat exchanger connected to the compressor 8 and is water-cooled or air-cooled. A regenerator 13 communicates with the precooling heat exchanger 12 and stores a regenerator material 14 . A low-temperature end heat exchanger 15 is connected to the regenerator 13 and is integrally formed on the refrigerant introduction side of the pulse tube 16 made of stainless steel. 17 is pulse tube 1
A high temperature end heat exchanger integrally formed at the other end of pulse tube 1
The compression heat generated in the high temperature end heat exchanger 17 is radiated by water cooling or air cooling. 18 is a high temperature end heat exchanger 17
19 is a buffer tank that communicates with the orifice valve 18.

In the cryogenic refrigeration system configured as described above, the gaseous refrigerant compressed by the piston 11 of the compressor 8 is cooled while passing through the precooling heat exchanger 12 and the regenerator 13, and then flows into the pulse tube 16. The residual refrigerant in the pulse tube 16 is compressed and the heat of compression is radiated in the high temperature end heat exchanger 17, cooled by adiabatic expansion while passing through the orifice valve 18, and flows into the buffer tank 19, after which the piston 11 is pulled up. When the gaseous refrigerant moves back and expands adiabatically within the pulse tube 16, the temperature is further lowered, cools the low-temperature end heat exchanger 15 and the regenerator 13, and returns to the compressor 8, completing such a reciprocating cycle. By repeating this, 150 to 2
A cryogenic temperature of 0K (-123 to -253°C) is obtained.

The pulse tube 16 is constructed such that its length can be adjusted freely. As shown in FIG. 2, the length adjustment mechanism 20 of the pulse tube 16 includes a metal bellows portion 2.
1, and means 22, 22 for adjusting the expansion/contraction length of the bellows portion 21.
It is composed of. The expansion/contraction length adjusting means 22, 22 are as follows:
Specifically, it consists of length adjustment bolts, etc., and these length adjustment bolts 22, 22 are connected to a pair of hard pulse tube parts 23, 2.
By screwing into the flanges 23a, 24a of No. 4 and rotating them, the relative gap X between the pulse tube sections 23, 24 can be adjusted, and the length of expansion and contraction of the bellows section 21 can be adjusted. The length adjustment bolts 22, 22 are configured so that they are screwed into only one hard pulse tube section 23, and are simply locked into the insertion hole with an axial stopper for the other hard pulse tube section 24. Various embodiments may be implemented, such as one in which only the hard pulse tube section 23 is adjusted and moved.

[0011] In the cryogenic refrigeration system, even when compressors 8 with different outputs are replaced, this can be easily handled by simply operating the length adjustment mechanism 20 of the pulse tube 16.
Conversely, the pulse tube 16 may be too long compared to the output of the compressor 8, making it impossible to maintain the high-low pressure ratio of the gaseous refrigerant.
It is also possible to prevent the temperature difference between the high temperature end and the low temperature end of the compressor 6 from being too short and the temperature difference between the high temperature end and the low temperature end thereof cannot be maintained, so that the compressor 8 and the cryogenic refrigeration equipment can demonstrate their capabilities to the maximum.

0012

[Effects of the Invention] Since the present invention is configured as described above, the cryogenic refrigeration system can achieve maximum refrigeration capacity by simply adjusting the length of the pulse tube even when replacing and installing compressors with different outputs. It becomes like this.

[Brief explanation of drawings]

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

FIG. 2 is a sectional view of essential parts of an embodiment of the present invention.

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

[Explanation of symbols]

8 Compressor 13　Regenerator 15 Low temperature end heat exchanger 16 Pulse tube 18 Orifice valve 19 Buffer tank 21 Bellows part 22 Adjustment means

Claims (2)

[Claims] Claim 1: A compressor is sequentially connected to a regenerator, a low-temperature end heat exchanger, a pulse tube, an orifice valve, a buffer tank, etc., and between the buffer tank and the compressor,
1. A cryogenic refrigeration device that is constructed by reciprocating a gaseous refrigerant, and is characterized in that the pulse tube is configured to be freely adjustable in terms of tube length. 2. The cryogenic refrigeration apparatus according to claim 1, wherein the pulse tube includes a bellows portion and means for adjusting an expansion/contraction length of the bellows portion.