JPS61184373A - Cryostat with refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cryostat with a refrigerator, and more particularly to a cryostat with a refrigerator of a separate type in which the refrigerator and the cryostat are separated.

[Background of the invention]

For a separate type cryostat with a cryostat that separates the cryostat and the cryostat, for example, the Japan Railway Technology Association, 1 Research Report on Superconducting Magnets for Levitated Railway Vehicles (Research on Cooling Systems for Superconducting Magnets) a
(March 1972) is known.

However, in such a cryostat with a refrigerator, it is necessary to cool the pipes that supply and return the working fluid of the refrigerator between the refrigerator and the cryostat until the refrigerator reaches a low temperature steady state from a room temperature state. Therefore, there is a problem in that it takes a long time to cool down the refrigerator.

[Purpose of the invention]

An object of the present invention is to provide a cryostat with a refrigerator that can shorten the time required for cooling down the refrigerator by reducing the refrigeration load on the refrigerator during cooldown.
There it is.

[Summary of the invention]

The present invention is characterized in that the mechanism for transferring the working fluid of the refrigerator between the refrigerator and the cryostat is arranged so that it can be cooled by the cold of the refrigerant supplied from the refrigerant source to the cryostat. During or before cool-down of the refrigerator, the pipes that transfer the working fluid of the refrigerator between the refrigerator and the cryostat are cooled by the cold refrigerant supplied from the refrigerant source to the cryostat. This is an attempt to reduce the refrigeration load on the refrigerator when it is down.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, a refrigerator 10 and a cryostat 20 are placed at separate locations. A pipe that transfers the working fluid of the refrigerator 10 between the refrigerator 10 and the cryostat 20 can be cooled during or before cooling down the refrigerator 10 by means of a refrigerant number supplied to the cryostat 20 from a refrigerant source. ing.

At the 11th page, the cryostat 20 has a cryogenic container 2
1 is installed inside, and a cryogenic container 22 is provided corresponding to the cryogenic container 21.
is installed inside. The inside of the cryostat 20 is evacuated and insulated. The cryostat 20 is supplied with a refrigerant. That is, the cryogenic container 21 is supplied with a cryogenic refrigerant, for example, liquid helium (hereinafter abbreviated as LHe), and the cryogenic container 22 is supplied with a low-temperature refrigerant having a boiling point between the boiling point of LHe and room temperature, For example, liquid nitrogen (hereinafter referred to as L
N.

) is supplied. Inside the cryogenic container 21, a cooled body 30 is provided so as to be immersed in LHe. Cryogenic vessel 2111: A first supply pipe 40 supplying LHe is connected to the side wall of the cryogenic vessel 21, in this case substantially horizontally, in communication with the gas layer within the cryogenic vessel 21. There is.

The third supply pipe 41 supplies LN to the low temperature container 22,
It is connected to the side wall of the cryocontainer 22, in this case substantially horizontally, in communication with the gas layer within the cryocontainer 22.

A refrigerator cold storage tank 50 in which a low-temperature part of the refrigerator 10 is stored and a cryostat 20 are connected by a flexible tube 60. The inside of the refrigerator cold storage tank 50 and the inside of the tube 60 are evacuated and insulated similarly to the inside of the cryostat 20.

On the top wall of the refrigerator cold storage tank 50, nozzles 70 and 71 are provided with their lower ends projecting vertically into the refrigerator cold storage tank 50 to maintain airtightness.

The first supply pipe 40 is in the second cryostat 20, in the pipe 6
0 and is connected to the nozzle 70 within the refrigerator cold storage tank 50. The third supply pipe 41 passes through the cryostat 20 and the pipe 60, and is connected to the nozzle 711 within the refrigerator cold storage tank 50. A first condenser 80 is provided in the gas layer within the cryogenic container 21 . A second condenser 81 is provided in the gas layer within the low temperature container 22 . The first condenser 801 contains the working fluid that has been heated to a cryogenic temperature in the refrigerator 10.
That is, the second supply pipe 42 is connected to supply a working fluid at a temperature level slightly lower than the boiling point of LHe supplied into the cryogenic container 21. The helium gas (hereinafter abbreviated as GHe) evaporated and vaporized from the LHe supplied into the cryogenic container 21 due to the refrigeration load of the object to be cooled 30, etc., is transferred to the first condenser 80I to cool the supplied working fluid. From this, it is condensed and liquefied. The working fluid whose temperature has increased by condensing and liquefying GHe is returned to the refrigerator 10 via the first return pipe 43 connected to the first condenser 80 . Second condenser 81
1ζ is a fourth supply pipe 44 that supplies a working fluid that has undergone low temperature I in the refrigerator 10, that is, a working fluid that is slightly lower than the boiling point of LN supplied into the low-temperature container 22.
are connected. LN supplied into the low temperature container 22,
Nitrogen gas (hereinafter referred to as
GN, abbreviated) is the second condensation! ! The working fluid supplied to 81 is condensed and liquefied by cooling. The working fluid whose temperature has increased by condensing and liquefying the GN is transferred to the refrigerator 10 via the second return pipe 45 connected to the second condenser 81.
IC is returned. The first return pipe 43 and the second return pipe 45 pass through the cryostat 20 and the pipe 60, respectively, and are connected to the refrigerator 101ζ within the refrigerator cold storage tank 50. One end of a heat-insulated transfer pipe 90 is connected to the nozzle 70 lc, and the other end is connected to an LHe supply source 100. One end of a heat-insulated transfer pipe 91 is connected to the nozzle 71, and the other end is connected to the LN and supply source 101. The cryogenic container 21 has a tube 1 connected to the gas layer.
A pipe 111 is connected to the low temperature container 22 so as to communicate with the gas layer thereof. The open ends of the tubes 110, 111 are taken out of the cryostat 20, and each open end is provided with a valve 120, 121.

In FIG. 2, the first supply pipe 40, the second supply pipe 42 and the first
The return pipe 43 is arranged so as to be able to exchange heat, and the third supply pipe 41, the fourth supply pipe 44, and the second return pipe 45 are arranged so as to be able to exchange heat. That is, the first supply pipe 4
0, the second supply pipe 42, and the first return pipe 43 are brought into thermal contact in the longitudinal direction with metal foil 130 such as copper foil, and in this case, inside the pipe 60, that is, in a vacuum atmosphere. It is located in Such a first supply pipe 40. A pipe 61 is provided inside the pipe 60 outside the second supply pipe 42 and the first return pipe 43.
A tube 62 is disposed outside the tube 61 and inside the tube 60. The space 140 formed by the tubes 61 and 62 is
It is airtightly separated from the inside of the tube 60. The third supply pipe 41, the fourth supply pipe 44 and the second return pipe 4 in the pipe 60
5 is included in the space 140 and is connected to the third supply pipe 41
A fourth supply pipe 44 and a 227th) return pipe 45 are arranged on both sides of the pipe. The space 140 is filled with a fluid having high thermal conductivity, such as GHe.

First, in FIG. 2, LHe is started to be supplied from the LHe supply source 100 to the cryogenic container 21 via the transfer pipe 90, the nozzle 70, and the first supply pipe 40. This supplied LHe is initially emitted and vaporized by cooling the cryogenic container 21 and the object to be cooled 30, and this GHe is released to the outside of the cryostat 20 through the pipe 110 by opening the valve 120. .

Further, LN is started to be supplied from the supply source 101 to the low temperature container 22 via the transfer pipe 91, the nozzle 71, and the third supply pipe 41. This supplied LN is initially evaporated and vaporized by cooling the low temperature container 22, and this GN is released to the outside of the cryostat 20 through the pipe 111 by opening the valve 121. On the other hand, at this point, the refrigerator 10
cool-down operation begins. During this cool-down, the second supply pipe 42 and the first return pipe 43 are cooled by the cold LHe flowing through the first supply pipe 40,
As a result, the temperature of the working fluid flowing through the second supply pipe 42 and the first return pipe 43 is lowered. The temperature of this working fluid is also lowered by the cooling of LHe in the first condenser 80. On the other hand, at the same time, the fourth supply pipe 44 and the second return pipe 45 are cooled by using the cold LN flowing through the third supply pipe 41 and the heat conduction of GHe. Fourth supply pipe 44, second return pipe 4
The working fluid flowing through 5 is reduced in temperature. Also,
This working fluid is also reduced in temperature by refrigeration of LN in the second condenser 81. The working fluid whose temperature has been reduced in this manner is returned to the refrigerator 10, thereby cooling the refrigerator 10. After a predetermined amount of LHe is stored in the cryogenic container 21 and a predetermined amount of LN is stored in the cryogenic container 22,
The supply amount of LHe and LN from the LHe supply source 100 and the supply amount of LN from the supply source 101 are reduced, and the liquid level of LHe in the cryogenic container 21 and the liquid level of LN in the cryogenic container 22 are as follows. Each is maintained at a constant level. After the refrigerator 10 reaches a steady temperature state by the cool-down operation, the I
P120.121 is closed and LHe source 10
Supply of LHe from 0 and LN, LN from supply source 101
, the supply will be stopped. Moreover, the refrigerator 10 is made to shift from cool-down operation to steady operation. After that, GHe evaporated and vaporized from LHe in the cryogenic container 21,
Chilling of the cryogenic working fluid flowing through the first condenser 80 1
This condenses and liquefies the LHe, and as a result, the liquid level of LHe in the cryogenic container 21 is maintained at a partial level. In addition, LN and more evaporated and vaporized GN in the low-temperature container 22 are condensed by the cooling of the low-temperature working fluid flowing through the second condenser 81.
The LNs is liquefied, and as a result, the liquid level of LNs in the cryogenic container 22 is partially maintained.

In this embodiment, the following effects can be obtained.

(1) Since the second supply pipe and the first return pipe can be cooled by the cold LHe flowing through the first supply pipe, the refrigeration load on the refrigerator during cool-down can be reduced, and the cooling load on the refrigerator can be reduced. The time required can be shortened.

(2) Since the first supply pipe is connected approximately parallel to the side wall of the cryostat and the third supply pipe is connected approximately parallel to the side wall Iζ of the cryostat, the height of the first supply pipe is lower than the height of the cryostat. The height of the supply pipe and the third supply pipe can be reduced, which is extremely effective when installing a cryostat in a restricted space.

In addition, in addition to this embodiment, the first supply pipe, the second supply pipe, and the first return pipe are arranged in a fluid atmosphere with high thermal conductivity, and the third supply pipe is connected to the fourth supply pipe. and the second return pipe may be arranged in thermal contact with each other.

〔Effect of the invention〕

As explained above, the present invention can reduce the refrigeration load during cool-down of the refrigerator, and therefore has the effect of shortening the time required for cool-down of the refrigerator.

[Brief explanation of the drawing]

FIG. 1 is a device configuration diagram showing an embodiment of a cryostat with a refrigerator according to the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. 1.

Claims (1)

[Claims] 1. A cryostat with a refrigerant machine, characterized in that a pipe for transferring the working fluid of the refrigerator between the refrigerator and the cryostat is arranged so that it can be cooled by the cold of the refrigerant supplied from the refrigerant source to the cryostat. .