JPH0648122B2 - Refrigeration equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus, and more particularly to a refrigerating apparatus suitable for using a part of a refrigerant gas used for cold generation for cooling circulation.

[Background of the Invention]

A conventional device is described in U.S. Pat. No. 4,484,458, i.e., as shown schematically in FIG.
When the object to be cooled is cooled by the cold obtained in the cold generating part of the reciprocating expander 1, the high pressure pipe 11 at the inlet of the expander 2 is introduced as the refrigerant for transferring the cold of the cold generator.
The high-pressure helium gas branched into 2 was used, and after the cold transfer, the return pipe 17 was returned to the low-pressure pipe 18 at the outlet of the expander 2. However, since the high-pressure helium gas, which is a refrigerant for transferring cold, is circulated to the low-pressure side after being circulated, no consideration has been given to improving cold-generation efficiency in the expander.

Thus, when the high-pressure helium gas used to cool the cooled object is returned to the low-pressure pipe 18 at the outlet of the expander 2, the high-pressure helium gas supplied from the compressor 1 is directly supplied to the expander 2. Since only high pressure helium gas contributes to the generation of cold, and the high-pressure helium gas used for cooling the object to be cooled is not related to the generation of cold in the expander 2, it is necessary to have a large discharge amount in the compressor 1. For example, the discharge rate of the compressor 1 is 2g /
If 0.5 g / s of gas is required to cool the object to be cooled with s, the amount of gas that can be supplied to the expander 2 is 1.5 g / s, and the amount of cold generation is the discharge of the compressor 1 to the expander 2. The amount is reduced to 3/4 compared to the case where the entire amount is supplied. In other words, in order to make the amount of cold generation in the expander 2 100%, the discharge amount is 2.5g
A / s compressor is required.

[Object of the Invention]

The object of the present invention is to discharge the refrigerant gas of the compressor by returning the refrigerant gas to the branched pipe after guiding the refrigerant gas to the object to be cooled by branching a part of the refrigerant gas on the discharge side or the suction side of the compressor. It is intended to provide a refrigerating apparatus which can be miniaturized by introducing the entire amount of the above into the expander and efficiently using the refrigerant gas to reduce the size of the compressor.

[Outline of Invention]

The present invention provides a compressor for compressing and circulating a refrigerant gas, a cold generating means for adiabatically expanding the refrigerant gas pressurized by the compressor to generate cold, and a part of the refrigerant gas exchanges heat with the cold generating means. By using the cold refrigerant gas generated by, in a refrigerating device with a cooled object cooled by the cold refrigerant gas, a part of the refrigerant gas from the discharge side of the compressor, or from the suction side. A cooling circuit is provided, which is branched and guided to the object to be cooled and then returned to the discharge side or the suction side of the compressor, wherein one of the refrigerant gas is discharged on the discharge side or the suction side of the compressor. By returning the refrigerant gas to the pipe where the refrigerant gas is branched after branching the part to the object to be cooled, the entire amount of the refrigerant gas discharged from the compressor is introduced into the expander, and the refrigerant gas is efficiently flowed to the compressor. Small It is those that can Kusuru.

Example of Invention

 An embodiment of the present invention will be described below with reference to FIG.

Reference numeral 1 is a compressor for compressing and circulating a refrigerant gas such as helium gas. Reference numeral 2 denotes an expander that adiabatically expands the refrigerant gas, and in this case, it comprises a first stage expander 3 and a second stage expander 4. Reference numeral 5 is a first heat exchanger, 7 is a second heat exchanger, 6 is a first cold station heat exchanger provided in the first stage expander, 9 is an object to be cooled, in this case, the first of the cryopump 26. The second cryoheat exchanger for cooling the second cryopanel 24, 10 for the first cryoheat exchanger for cooling the first cryopanel 25 of the cryopump 26, and 11 for connecting the discharge side of the compressor 1 and the expander 2 to each other. High pressure piping, 12 is branched from the high pressure piping 11, passes through the first heat exchanger 5, and is an introduction piping that is connected to the first cold station heat exchanger 6, and 13 is from the first cold station heat exchanger 6. Further, a second cryogenic pipe connected to the second cryo heat exchanger 9 through the second heat exchanger 7 and the second cold station heat exchanger 8. 14 is the first cryostation heat exchanger as it is from the first cold station heat exchanger 6.
The first cryogenic pipe connected to 10, the second cryogenic return pipe 15 joining the first cryogenic return pipe 16 from the second cryo heat exchanger 9 through the second heat exchanger 7, and 16 the first Cryo heat exchanger
The first low-temperature return pipe that joins 10 to the second low-temperature return pipe 15, and 17 from the junction of the first low-temperature return pipe 16 and the second low-temperature return pipe 15 to the high-pressure pipe 11 through the first heat exchanger. Return pipe for joining, 18 is low-pressure pipe returning from the expander 2 to the compressor 1, 19 is a pressure adjusting valve, 20 and 21 are flow adjusting valves, 22 is a cold insulation tank, 23 is a flexible piping cold insulation tank, and 27 is a cryopump. A partition wall that seals and isolates the pipe 26 and the pipe cold storage tank 23.

With the above configuration, the high-pressure helium gas compressed by the compressor 1 is supplied to the reciprocating expander 2 after passing through the high-pressure pipe 11 to slightly reduce the pressure with the pressure control valve 19. The high-pressure helium gas adiabatically expands in the first-stage expander 3 and the second-stage expander 4 in the expander 2 to generate cold, and becomes low-pressure helium gas to the compressor 1 through the low-pressure pipe 18. Return.

On the other hand, branch in front of the pressure adjusting valve 19, pass through the introduction pipe 12,
The helium gas that has passed through the flow rate adjusting valve 20 is transferred to the first heat exchanger 5
And through the first cold station heat exchanger 6 to the first
After being cooled by the stage expander 3, the first cryopanel 25 is cooled through the first cryogenic heat exchanger 10 through the first cryogenic pipe 14, and the first low temperature return pipe 16 and the first heat exchanger 5 are cooled. To return to the high pressure pipe 11 after the pressure regulating valve 19. Further, the helium gas branched from the introduction pipe 12 and entering the second cryogenic pipe 13 passes through the second heat exchanger 7 and the second cold station heat exchanger 8, and is cooled by the second stage expander 4. The second cryopanel 24 through the second cryogenic pipe 13 to the second cryopanel 24.
The second low temperature return pipe is cooled through the cryo heat exchanger 9.
15, the second heat exchanger 7, the flow rate adjusting valve 21
Join the low temperature return pipe 16. The partition 27 is a cryopump
The inside of the cold insulation tank 26 and the inside of the cold insulation tank 22 containing the low temperature part of the expander and the piping cold insulation tank 23 are vacuum-isolated. belongs to.

In this case, the pressure difference before and after the pressure control valve 19 is about 0.5 kgf / c.
Set to m ² . This is equal to the pressure loss until the helium gas supplied from the introduction pipe 12 cools the cryopanels 24 and 25, passes through the return pipe 17, and returns to the high pressure pipe 11 after the pressure regulating valve 19.

According to this embodiment, since the helium gas used for cooling the cryopanel can be supplied to the expander, the capacity of the compressor can be reduced. That is, the treated air volume m ₀ is 2 g / s,
Using a compressor with inlet and outlet pressures of 4,16 kgf / cm ² , the cooling medium helium gas m ′ required to cool the cryopump 26 is 0.5 g / s, which is distributed from the high-pressure pipe. Considering the case, in the conventional method, the helium gas after cooling the cryopump returns to the outlet side of the expander, so that the gas supply to the expander is insufficient, that is, the amount of cold generation decreases. In this embodiment, the helium gas after cooling the cryopump 26 returns to the inlet side of the expander 2, so that the expander 2 is entirely supplied and the amount of cold generation Q ₁ and the flow rate m _0.
Of pressure loss Δp, which in this case is 0.5 kgf / cm ² .

The amount of cold generation Q [w] is the flow rate m [g / s] and the expansion pressure difference, that is, when the expander inlet pressure p _i and the outlet pressure p _o are (p
_i -p _o ) [kgf / cm ² ] and it is almost proportional to Therefore, cold generation is reduced by about 4%. However, in the case of the conventional method, the pressure drop of the supply gas to the expander, that is, the pressure loss Δp does not occur, but the supply flow rate m _o is significantly reduced. Comparing this with the case of full supply, As compared with the conventional method, the reduction rate of cold generation can be reduced to 1/6, and the cryopump can be cooled well in a short time. In other words, when the cooling time is the same, the discharge amount of the compressor can be made smaller and the compressor having a smaller capacity can be obtained, as compared with the conventional method, so that there is an effect that the entire refrigeration system can be downsized. .

Next, a second embodiment of the present invention will be described with reference to FIG.
In this figure, the same reference numerals as in FIG. 1 indicate the same members, and the difference of this figure from FIG. 1 is that the low-pressure pipe 1 on the outlet side of the expander 2
The introduction pipe 12 'is branched from 8', the point where the flow rate adjusting valve 20 'is provided, the return pipe 17' is joined to the low pressure pipe 18 ', and the pressure adjusting valve 19' is attached to the low pressure pipe 18 'before the joining part. That is the point.

According to this embodiment, the same effect as that of the above-mentioned one embodiment can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIG.
In this figure, the same reference numerals as those in FIG. 1 indicate the same members. The difference from this figure is that the cooling circuits for cooling the cryopanels 24, 25 of the cryopump 26 are separately branched and introduced from the high-pressure pipe 11. The first cryogenic pipe 14 'and the second cryogenic pipe 13' and the cryogenic pipes 13 'and 14' after branching from the high pressure pipe 11 are provided with flow control valves 20a and 20b, respectively. The point is that there are three heat exchange paths for the first heat exchanger 5 ', and that the first cold station heat exchanger is divided into 6a and 6b according to each pipe.

According to the present embodiment, in addition to the same effect as the one embodiment, the flow rate adjusting valves 20a, 20b are at room temperature and can be easily adjusted individually, so that the amount of gas adsorbed on the cryopanels 24, 25 can be adjusted. The effect is that adjustment, that is, the gas exhaust rate can be easily controlled.

〔The invention's effect〕

According to the present invention, the discharge side of the compressor, or by branching a part of the refrigerant gas on the suction side and guiding it to the object to be cooled and then returning the refrigerant gas to the pipe to discharge the refrigerant gas from the compressor. Since the entire amount of the above can be led to the expander and the refrigerant gas can be efficiently used, there is an effect that the compressor can be downsized and the refrigeration system can be downsized.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a refrigerating apparatus which is an embodiment of the present invention, FIGS. 2 and 3 are configuration diagrams showing another embodiment of the refrigerating apparatus of the present invention, and FIG. 4 is a conventional example. It is a block diagram. 1 ... Compressor, 2 ... Expander, 11 ... High-pressure piping, 12 ...
Introducing piping, 17 …… Return piping, 18 …… Low pressure piping, 26 …… Cryopump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Takada 794 Higashi-Toyoi, Shimomatsu City, Yamaguchi Prefecture Inside the Kasado Plant, Hitachi, Ltd. Kasado Plant, Hitachi, Ltd. (56) References JP-A-59-32758 (JP, A)

Claims (2)

[Claims] 1. A compressor for compressing and circulating a refrigerant gas, a cold generating means for adiabatically expanding the refrigerant gas pressurized by the compressor to generate cold, and a part of the refrigerant gas heats the cold generating means. Utilizing the cold refrigerant gas generated by exchanging, in a refrigerating device having a cooled object cooled by the cold refrigerant gas, a part of the refrigerant gas is branched from the discharge side of the compressor, A refrigerating device comprising a cooling circuit for returning to the discharge side of the compressor after being guided to the object to be cooled. 2. In the cooling circuit, after a part of the refrigerant gas is branched from the suction side of the compressor and guided to the object to be cooled,
The refrigerating apparatus according to claim 1, wherein the refrigerating apparatus is configured to return to the suction side of the compressor again.