JPH0268460A - Cryogenic refrigerating device - Google Patents

Abstract

PURPOSE:To enable the formation of a stabilized system which will not lose a temperature balance with ease against disturbances, such as drastic thermal load by placing a piping of circulation circuit into thermal contact with a radiation heat shield plate or fixing the piping with the shield plate and placing the circuit into thermal contact with the shield plate and a refrigerator. CONSTITUTION:When disturbances, such as drastic thermal load enter a circulation circuit system, and hence the temperature of refrigerant of the same system rises, a radiation heat shield plate 19 whose heat connection part 20 is in thermal contact with the circulation system, is subject to a rise in temperature. At the same time, the temperature of a refrigerator 12 rises as well since it is heat-exchanged by heat exchangers 15 and 16. However, when the temperature of refrigeration gas is lowered afterward, the temperature is immediately transmitted to a radiation heat plate 19 by way of the heat connection part 20. In this manner, the piping of circulation circuit is placed into thermal contact or fixed with the radiation heat plate. it is, therefore, possible to form a stabilized thermal system which will not lose a temperature balance against disturbances, such as drastic thermal load by bringing both the circulation circuit and the refrigerator into a closer and mutual connection by placing the circulation circuit into thermal contact with the refrigerator by way of the radiation heat shield and a low temperature end.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a cryogenic refrigeration device, and relates to a Josephson element,
It is used for purposes such as maintaining skid elements etc. at extremely low temperatures at all times, or cooling or maintaining superconducting magnets cooled with liquid helium to the temperature of liquid helium.

(Prior art) Conventionally, as this type of cryogenic refrigeration equipment, the
There is one shown in Publication No. 186.

This cryogenic refrigeration apparatus includes a refrigerant gas circulation circuit having a plurality of heat exchangers, and at least one low temperature end, which is in thermal contact with the refrigerant gas flowing through the circulation circuit. The refrigerator includes at least one refrigerator that cools refrigerant gas, and a radiant heat shield plate that shields radiant heat to the circulation circuit and the refrigerator.

(Problems to be Solved by the Invention) In the conventional cryogenic refrigeration equipment described above, the radiant heat shield plate is cooled by liquid nitrogen or conduction by contact with the refrigerator 1, for example, by being fixed to the flange of the cylinder of the refrigerator. The refrigerant gas in the circulation circuit is cooled at the low temperature end of the refrigerator. Therefore, the thermal relationship between the circulation circuit system and the radiant heat shield plate is not close, and for example, if a disturbance such as a heat load suddenly enters the circulation circuit system, the temperature balance will be immediately lost. An unstable situation could occur in which the problem occurred only in the circulation circuit system and did not affect the refrigerator or the radiant heat shield plate. In other words, when a disturbance such as a heat load suddenly occurs in the circulation circuit system and the temperature of the refrigerant gas in the same system rises, the temperature of the refrigerator that is in thermal contact with the refrigerant gas also rises by 1, and along with that, the radiant heat increases. The temperature of the shield plate also increases. Even if the temperature of the refrigerant gas in the circulation circuit system subsequently decreases, the temperature of the radiant heat shield plate does not decrease quickly, and the time required to cool the refrigeration system increases. Further, there is a problem in that the thermal response of the circulation circuit system and the radiation heat shield plate is also poor, making it difficult to control.

Therefore, the present invention aims to create a stable system that does not easily lose its temperature balance even in the face of disturbances such as sudden heat loads by creating a close thermal relationship between the circulation circuit system and the refrigerator.
This is a technical issue.

[Structure of the invention]

(Means for solving the problem) The technical means taken to solve the above-mentioned technical problem are a refrigerant gas circulation circuit having a plurality of heat exchangers,
A regenerator having at least one low-temperature end, a compression space that thermally contacts and cools the refrigerant gas flowing through the circulation circuit at the low-temperature end, an aftercooler, and one or more stages. and an expansion space, and a radiant heat shield plate that shields the circulation circuit and the radiant heat to the refrigerator, wherein the cryogenic refrigerator is provided at a low temperature end of the first stage of the refrigerator. The piping of the circulation circuit connected to the heat exchanger is in contact with or fixed to the radiant heat shield plate on its upstream side.

(Function) According to this, by thermally contacting or fixing the piping of the circulation circuit to the radiant heat shield plate, and by bringing the circulation circuit into thermal contact with the refrigerator via the radiant heat shield plate and the low temperature end, By creating a close thermal relationship between the circulation circuit, the refrigerator, and the radiant heat shield plate, it is possible to form a thermally stable system that maintains temperature balance against disturbances such as sudden heat loads. .

(Example) Hereinafter, an example of a cryogenic refrigeration apparatus according to the present invention will be described based on the drawings.

In the cryogenic refrigeration system shown in Fig. 1, 10 is a gas compressor that compresses refrigerant gas (helium, etc. or other refrigerant) in the circulation circuit, and ICl3 exchanges heat of the gas with the refrigerant gas in the circulation circuit. A countercurrent heat exchanger 14 is a cooled part such as a superconducting magnet housed in a liquid helium tank or the like.

Reference numeral 12 denotes a refrigerator having two low-temperature ends 12a and 12b, and the first low-temperature end 12a is in thermal contact with the refrigerant gas heat-exchanged on the primary side 11a of the heat exchanger 11. At least a heat exchanger 15 for cooling is provided, and the second
At the low temperature end 12b of the stage, there is a heat exchanger 16 that cools the refrigerant gas cooled by the heat exchanger 15 by bringing it into thermal contact with the refrigerant gas heat exchanged on the primary side 13a of the heat exchanger 13.
is provided.

Reference numeral 17 denotes a flow rate regulating valve that is interposed in the circulation circuit from the heat exchanger 16 to the cooled section 14 and adjusts the flow rate of refrigerant gas flowing through the circuit, and 18 is a low-pressure gas holder that stores the refrigerant gas.

In this embodiment, the heat exchangers 13, 15, 16, each low temperature end 12a, 12b of the refrigerator 12, and the cooled part 14 are surrounded by a radiant heat shield plate 19, and these members are formed inside. It is located in a low temperature chamber 19a. Further, from the primary side 11 of the heat exchanger 11 to the heat exchanger 1
The piping of the circulation circuit leading to No. 5 is in contact with or fixed to the radiant heat shield plate 19 at the thermal connection portion 20.

The operation of this embodiment having the above configuration will be explained.

When steady refrigeration operation is being performed, the gas compressor 10
The high-pressure refrigerant gas supplied through the high-pressure refrigerant gas pipe 21 from the
On the way through a, it is precooled by the first stage heat exchanger 15 of the refrigerator 12, further cooled by the heat exchanger 16, expanded by the flow rate adjustment valve 17, and supplied to the liquid helium tank etc. of the part to be cooled 14. Ru. When the refrigerating capacity of the circulation circuit and the refrigerating load of the object to be cooled are balanced, the same amount of low-temperature, low-pressure refrigerant gas as the high-pressure gas refrigerant gas supplied from the gas compressor 10 is delivered to the object to be cooled 14 at a low pressure. It returns to the secondary sides 11b, 13b of each heat exchanger 11.13 via the side refrigerant gas pipe 22, and reaches almost room temperature while exchanging heat with the high-pressure refrigerant gas on the primary side 11a, 13a of each heat exchanger. The gas is sucked into the gas compressor 10.

Then, it is pressurized again by the gas compressor 10 to become a high-pressure refrigerant gas, and thereafter the same cycle is repeated to perform the refrigeration operation.

However, in this embodiment, the primary side 1 of the heat exchanger 11
The piping of the circulation circuit from 1a to the heat exchanger 15 is in contact with or fixed to the radiant heat shield plate 19 at the thermal connection part 20. As a result, when a disturbance such as a heat load suddenly occurs in the circulation circuit system and the temperature of the refrigerant gas in the same system rises, the temperature of the radiant heat shield plate 19 that is in thermal contact with the thermal connection part 20 rises, and , the temperature of the refrigerator 12 rises as a result of heat exchange by each heat exchanger 15, 16, but when the temperature of the refrigerant gas decreases thereafter, that temperature is easily transmitted to the radiant heat shield plate 19 via the thermal connection part 20. . in this way,
In this embodiment, the piping of the circulation circuit is brought into thermal contact with or fixed to the radiant heat shield plate, and the circulation circuit is brought into thermal contact with the refrigerator via the radiant heat shield plate and the low-temperature end. 7. Maintain a close thermal relationship with the refrigerator to prevent disturbances such as sudden heat loads.
), it is possible to form a thermally stable system that does not easily upset the temperature balance. In addition, thermal response can be further improved,
By controlling the refrigerator, the circulation system can also be easily controlled. Furthermore, since the radiant heat shield plate is configured to be cooled by piping, cooling can be done anywhere on the radiant heat shield plate by routing the piping. Unlike cooling by contact, the heat transfer area can be secured freely, and the temperature of the radiant heat shield plate can be easily set.

FIG. 2 shows a second embodiment of the present invention, in which a refrigerator 112A having a single stage low temperature end 112A+ is used.
and a refrigerator 112B having two stages of low-temperature ends 112B+ and 112B2,
0. The refrigerant gas from the primary side 111a of the heat exchanger 111 is first cooled to 70 to 50K in the heat exchanger 115a installed at the low temperature end 112A+ of the refrigerator 12A.
Furthermore, the refrigerator 112B is cooled down to 50 to 30K in the heat exchanger 115b provided at the low temperature end 112B+ of the first stage, and then heat exchanged in the primary side 113a of the heat exchanger 113, and then the refrigerator 112B second stage low temperature end 112
30 to IO at the heat exchanger 116 provided in B2
It is designed to be cooled down to K, and cooling efficiency is improved by cooling in an orderly manner. The other structures and functions are the same as those of the embodiment shown in FIG. 1, and the same structures are given the same numbers as those used in FIG. 1 plus 100, and their explanations will be omitted here.

In this embodiment, the low temperature end 112A of the refrigerator 112A is
+ The circulation system piping between the first stage low temperature end 112B1 of the refrigerator 112B is connected to the radiant heat shield plate 119 at the thermal connection part
0, which creates a close thermal relationship between the circulation circuit and the refrigerator, creating a stable system that does not easily upset the temperature balance in the face of sudden heat loads or other disturbances. .

FIG. 3 shows a third embodiment of the present invention, in which there are three stages of cold ends 212a, 212b.

A first radiant heat shield plate 219A forming a first chamber 219a containing a first-stage low-temperature end 212a, and a second-stage and third-stage low-temperature end 212b 212C in the first chamber 219a. Second chamber 2 that accommodates
The second radiant heat shield plate 219B forming the second radiant heat shield plate 19b is provided with two radiant heat shield plates arranged in two layers.

In this embodiment, the heat exchanger 2 is connected to the gas compressor m210.
The piping of the circulation system that passes through the primary side 211a of 11 and reaches the heat exchanger 215 provided at the low temperature end 212a of the first stage of the refrigerator 212 contacts or is fixed to the first radiant heat shield plate 219A, and the first The radiant heat shield plate 219A is cooled to about 70°C, and the heat exchanger 215 provided at the low temperature end 212a of the first stage of the refrigerator 212
The piping of the circulation system that passes through the primary side 213a of 13 and reaches the heat exchanger 216 provided at the low temperature end 212b of the second stage of the refrigerator 212 is in contact with or fixed to the second radiant heat shield plate 219B, and the second radiant heat is The shield plate 219B is designed to be cooled to about 20°C, and the circulation circuit and the refrigerator are closely interconnected thermally. The refrigerant gas in the circulation system that has undergone heat exchange with the heat exchanger 216 then passes through the primary side 223a of the heat exchanger 223 and the heat exchanger 224 provided at the third stage low temperature end 212C of the refrigerator 212 to adjust its flow rate. The valve 217 and the cooled part 214 are reached. In this embodiment, the other configurations and operations are almost the same as those in the embodiment shown in FIG. is omitted here.

〔Effect of the invention〕

According to the present invention, by thermally contacting or fixing the piping of the circulation circuit to the radiant heat shield plate, and by bringing the circulation circuit into thermal contact with the refrigerator via the radiant heat shield plate and the low temperature end, the circulation circuit It is possible to form a thermally stable system that does not easily upset the temperature balance even in the face of disturbances such as sudden heat loads by closely interconnecting the thermal relationship between the refrigerator and the refrigerator. Furthermore, the thermal responsiveness is further improved, and the circulation system can be easily controlled by controlling the refrigerator.

Further, according to the present invention, since the radiant heat shield plate is cooled by the piping, the radiant heat shield plate can be cooled anywhere freely, making it easy to configure. In contrast, the heat transfer area can be freely secured, and the temperature of the radiant heat shield plate can be easily set.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a first embodiment of the present invention, Fig. 2 is a block diagram showing a second embodiment of the present invention, and Fig. 3 is a block diagram showing a third embodiment of the present invention.
FIG. 2 is a configuration diagram showing an example. 10... Gas compressor, 11, 13, 15.16...
Heat exchanger, 12... Refrigerator, 12a12b... Low temperature end, 14... Cooled part, 17... Flow rate control valve, 19
...Radiation heat shield plate, 20...Thermal contact part.

Claims (3)

[Claims] (1) A refrigerant gas circulation circuit having a plurality of heat exchangers and at least one stage of low-temperature end, which thermally contacts the refrigerant gas flowing through the circulation circuit at the low-temperature end to cool the refrigerant gas. at least one refrigerator comprising a compression space, an aftercooler, a regenerator having one or more stages, and an expansion space, and a radiant heat shield plate that blocks radiant heat to the circulation circuit and the refrigerator. In the cryogenic refrigeration system, the piping of the circulation circuit connected to the heat exchanger provided at the low temperature end of the first stage of the refrigerator is in contact with or fixed to the radiant heat shield plate on its upstream side. Features cryogenic freezing equipment. (2) Two of the refrigerators are arranged, and the heat exchangers provided at the low temperature end of the first stage of each refrigerator are connected to each other via the circulation circuit, and the circulation circuit is connected to each of the refrigerators. The cryogenic refrigeration apparatus according to claim 1, wherein the radiant heat shield plate is in contact with or fixed to the radiant heat shield plate between each low temperature end thereof. (3) Claim (1) or (2) characterized in that the radiant heat shield plates are arranged in multiple layers for each temperature level.
The cryogenic refrigeration device described in .