JPH02110280A - Cryogenic cooling device - Google Patents

Abstract

PURPOSE:To control the movement of heat between a high-temperature end and a low-temperature end to cool and/or heat a heat exchanger in a short period of time and prevent the inside of the vacuum tank of a cooling device from being contaminated by gas leak and the like by a method wherein the high-temperature end of the cryogenic heat exchanger is conducted to the low-temperature end of the same by heat conductors through a thermal switch. CONSTITUTION:The high-temperature end of a heat exchanger 10 in a cryogenic area is conducted to the low-temperature end of the same by heat conductors 16, 17 through a thermal switch 15 while the switching of the thermal switch 15 is effected by a handle 19 and a rod 20 in room temperature side through an elastic body 18. When the high-temperature end of the heat exchanger 10 is cooler than the low-temperature end of the same, a thermal switch 15 is put ON and heat is moved from a pipeline 25 to the pipeline 21 through the heat conductors 16, 17 whereby the low-temperature end is cooled in a short period of time from the outside of the heat exchanger. The thermal switch 15 moves heat by contact and, therefore, the thermal switch will never contaminate a vacuum space wherein the thermal switch is arranged. On the other hand, the low-temperature end may be heated also in a short period of time by the thermal switch in the same manner even when the heat exchanger is being heated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cryogenic cooling device, and particularly to a cryogenic cooling device suitable for cooling from normal temperature and heating from a very low temperature in a short time. Regarding.

[Conventional technology]

A conventional device is described in Japanese Patent Application Laid-open No. 109751/1983.

[Problem to be solved by the invention]

In the above conventional technology, in order to cool the object to be cooled from room temperature in a short time, in a cryogenic heat exchanger whose temperature is lower than the temperature reached by the rotating or reciprocating type cold generator of the cooling device, the high temperature end side is The high-pressure piping and the low-pressure piping on the cold end side are communicated via a bypass piping via a needle valve, and the needle valve is opened and closed. When cooling down the device, the extremely low temperature heat exchanger is cooled in a short time by bypassing the high-pressure refrigerant on the warm end side, which has a lower temperature than the cold end side.

However, if a leak occurs due to dirt getting caught between the inlet and outlet of the needle valve, the refrigerant on the hot end will cool down through the bypass piping instead of passing through the heat transfer part of the heat exchanger even when the needle valve is closed. There were problems such as the refrigerant leaking into the end side and not reducing the temperature of the cryogenic part, and the necessity of providing bypass piping, which caused the possibility that the refrigerant might leak out of the piping from the connecting part of the piping.

The purpose of the present invention is to prevent leakage of refrigerant between hot and cold ends of a heat exchanger,
To provide a cryogenic cooling device that cools an object to be cooled in a short time without causing refrigerant leakage to the outside of a heat exchanger.

[Means to solve the problem]

The above object is achieved by providing electrical continuity between the hot end and the cold end of the cryogenic heat exchanger using a heat transfer conductor via a thermal switch.

[Effect]

During cool-down, the heat switch of the cooling device is closed to establish thermal continuity between the cold end side of the cryogenic heat exchanger and the uncooled cold end side.

Thereby, the heat is transmitted through the heat conductor without passing through the inside of the heat exchanger, and the cold end side which has not been completely cooled can be cooled, so that the cooling device can be cooled in a short time.

When the thermal switch is opened, the thermal resistance between the two increases, almost stopping the transfer of heat, and the cold end cools to the desired temperature. Also, since the heat moves within the heat conductor, there is no need to move the refrigerant, eliminating the possibility of refrigerant leaks.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The working fluid 1, for example, gas helium, pressurized by the first compressor 2 and the second compressor 3 undergoes adiabatic expansion in the expander 1, and is then transferred to stages of two temperature levels, the first cold generation means 4, and the second cold generation means 5. Generates cold.

A first cold heat exchanger 6 and a second cold heat exchanger 7 are arranged in each stage, and the heat exchanger 6 is connected to the first heat exchanger 8.
and the second heat exchanger 9 , and the heat exchanger 7 is arranged between the second heat exchanger 9 and the third heat exchanger 10 .

A Joule-Thomson valve 11 is installed at the high pressure side outlet of the heat exchanger 10.
is provided, and a heat exchanger 12 is disposed downstream thereof. The heat exchanger 12 and the sample stand 13 are brought into thermal contact, and the object to be cooled 14 is attached to the sample stand 13.

The high-temperature end and low-temperature end of the heat exchanger 10 in the cryogenic region are connected via a thermal switch 15 with good thermal conductors 16 and 17, and switching of the thermal switch 15 is performed via an elastic body 18 with a handle on the room temperature side. 19 and rod 20, thermal switch 15
is fixed to the high-temperature side low-pressure pipe 21 of the heat exchanger 10 with a screw 22 using a good thermal conductor 16, and its adhesive surface has a sufficiently low thermal resistance. Arm 23 supported by a part of the heat switch body
A bearing 24 is fixed to the rod 20, and the rotation of the rod 20 is maintained by the bearing 24. On the other hand, heat switch 15
The other end is a flexible thermal conductor 17 made of copper W4, for example.
It is fixed to the low temperature side low pressure piping 25 of the heat exchanger 10 via a rigid thermal conductor 26. 27 and 28 are a high-pressure pipe on the high-temperature side and a low-pressure pipe on the low-temperature side of the heat exchanger 10.

A cross section of the thermal switch is shown in FIG.

A good thermal conductor 16a that turns heat transfer ON and OFF with a side plate 29 made of a poor conductor, for example, an epoxy resin.

16b is fixed at both ends with screws 22. good thermal conductor 16a,
When transferring heat between the heat conductors 16b and 16b, the rotor 30 is positioned as shown in FIG. thermally integrated via To stop the heat transfer, the rod 20 is rotated 90° around the axis of the rod 20 from the position of the rotor 30 shown in FIG. 4 to thermally isolate the two. This operation can be easily performed by rotating the rod 20.

In other words, according to this embodiment, when the high temperature end of the heat exchanger 10 is desired to be cooler than the low temperature end, the heat switch 15 is turned on, and heat is transferred from the pipe 25 to the pipe 21 through the heat conductors 16 and 17, and the temperature is lowered. The end can be cooled in a shorter time than outside the heat exchanger. Also.

Since the thermal switch 15 transfers heat through contact, the vacuum space in which the thermal switch is placed will not be contaminated.

Also, when heating the heat exchanger, the low temperature end side can be heated within a short time by using the heat switch.

In this embodiment, a rotary type thermal contact mechanism has been described as a thermal switch, but a reciprocating type thermal contact mechanism also produces similar effects.

【Effect of the invention〕

According to the present invention, heat transfer between the high-temperature end and the low-temperature end of the heat exchanger can be controlled using a solid heat conductor through a heat switch placed outside the heat exchanger, so cooling and heating of the heat exchanger can be controlled. It can be carried out in a short time and has the effect of not contaminating the inside of the vacuum chamber of the cooling device due to gas leakage or the like.

[Brief explanation of drawings]

Figure 1 is a system diagram showing the flow of a cryogenic cooling device according to an embodiment of the present invention, Figure 2 is a configuration diagram around a heat exchanger, Figure 3 is a side view of a heat switch, and Figure 4 is a It is a sectional view taken along the line IV-IV of the heat switch shown in the figure. 10... Heat exchanger, 15... Heat switch, 16.1
7... Good thermal conductor, 18... Elastic body, 20... Rod, 21... High temperature end low pressure piping, 25... Low temperature end low pressure piping, 30... Rotor, 31... Arc surface , 32...
Coil spring, 33... arc body. No. 10-Heat exchanger 15--°Heat temperature 7 pieces/hook;7-Heat temperature level

Claims (1)

[Claims] 1. A first cold generation means, a second cold generation means that generates cold at a lower temperature than the first cold generation means, and a refrigerant cooled by the cold of both cold generation means, and a temperature difference between the two cold generation means and the second cold generation means. In a cryogenic cooling device having a heat exchanger arranged in the heat exchanger, a part of the hot end side of the heat exchanger and a part of the low temperature end side are connected by a heat conductor via a heat transfer control means. A cryogenic cooling device featuring: