JP2000018742A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize coldness and to improve cooling efficiency by providing a body to be cooled being thermally in contact between the high-temperature and low-temperature ends of a pulse pipe. SOLUTION: This cooling device is composed of a body 20 to be cooled that is in thermal contact continuously between a high-temperature end 18a and a low- temperature end 18b of a part for generating coldness of a pulse tube 18 of a pulse tube refrigerating machine A1 and a third body 32 to be cooled in thermal contact with the low-temperature end 16b of cold storage equipment 16 that communicates with the low-temperature end 18b of the pulse tube 18. The discharge side of a compression means 1 of a pressure vibration source communicates with high-pressure switching valves 2 and 3 via high-pressure pipes 6 and 7 and the suction side of the compression means 1 communicates with low-pressure switching valves 4 and 5 via low-pressure pipes 8 and 9. The high-pressure switching valves 2 and 3 and the low-pressure switching valves 4 and 5 are connected to such drive part 19 as a pulse motor, and the high-pressure switching valves 2 and 3 and the low-pressure switching valves 4 and 5 are switched at a certain timing, thus enabling the body 20 to be cooled to absorb heat over a wide continuous range between the high-temperature end 18a and the low-temperature end 18b of the pulse tube 18 and hence improving cooling efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for cooling a body to be cooled by obtaining cold by a pulse tube refrigerator.

[0002]

2. Description of the Related Art As a cooling device using a regenerative refrigerator according to the present invention, for example, Japanese Patent Publication No. 45-27 shown in FIG.
The configuration is as disclosed in Japanese Patent Application Laid-Open No. 634/634.
The cooling device in FIG. 19 includes a refrigerator 101 of a (reverse) Stirling cycle refrigerator and a cooling circuit 120 that conveys cold to the cooled object 110.

A refrigerator 101 includes a cylinder 100, a piston 102 reciprocating in the cylinder 100, a displacer 103 reciprocating from the piston 102 with a certain phase difference, a piston 102 and a displacer 10.
3, a cooler 108 disposed between the displacer 103 and the upper end of the cylinder, and a cool storage disposed between the cooler 106 and the expansion chamber 105. And a vessel 107.

[0004] A cooling circuit 120 includes a compressor 121 and a plurality of cold transfer heat exchangers 12 in thermal contact with the refrigerator 108.
5 and a conduit system 124 in which a plurality of cooling heat exchangers 126 for cooling the object to be cooled 110 are alternately arranged in series, and a counter-flow heat exchange interposed between the conduit system 124 and the compressor 121. And a vessel 123.

[0005] In the cooling device, in the refrigerator 101, first, heat is generated in the compression chamber 104 by the compression operation (isothermal compression) of the piston 102, and then the displacer 10 is pressed.
By moving the piston 3 toward the piston 102, the working medium passes through the regenerator 107 while being cooled (constant volume cooling). The heat is absorbed from the working medium flowing in the cold transfer heat exchanger 125 that has come into thermal contact with the cooling medium. Further, due to the shift of the displacer 103 to the top dead center, the working medium cools the regenerator 107 while compressing the compression chamber 10.
Return to 4 (fixed volume heating).

Accordingly, in the cooling circuit 120, the working medium flowing in the cold transfer heat exchanger 125 absorbs heat, so that the cold is transferred to each cooling heat exchanger 126,
The object to be cooled 110 is cooled. The countercurrent heat exchanger 123 is
Each working medium is cooled by a low-pressure working medium returning to the compressor 121.

[0007]

However, in the conventional apparatus, the cold of a specific temperature generated in the expansion chamber 105 of the refrigerator 101 is cooled in the refrigerator 108 by the cold transfer heat exchanger 1.
Since it is transmitted to the working medium flowing in the inside 25, there is a disadvantage that the cooling efficiency is low. Such a drawback is that only the cold of a specific temperature generated in the expansion chamber 105 formed by the reciprocating operation of the displacer 103 is used.

Therefore, an object of the present invention is to improve the cooling efficiency by effectively utilizing the cold obtained by the entire refrigerator by cooling the object to be cooled in a wide temperature range of the pulse tube.

[0009]

According to the first aspect of the present invention, there is provided a pulse vibration source having a pressure vibration source for compressing and expanding a working medium, a regenerator communicating with the pressure vibration source, and a pulse tube communicating with the regenerator. The object to be cooled is cooled by a cooling device including a tube refrigerator and an object to be cooled that is in thermal contact between a high temperature end and a low temperature end of the pulse tube.

According to a second aspect of the present invention, there is provided a pulse tube refrigerator having a pressure vibration source for compressing and expanding a working medium, a regenerator communicating with the pressure vibration source, and a pulse tube communicating with the regenerator. The pulse tube is characterized by comprising a first cooled body thermally contacted between a high temperature end and a low temperature end of the pulse tube, and a second cooled body thermally contacted with a low temperature end portion of the pulse tube.

According to a third aspect of the present invention, the first object to be cooled is:
The pulse tube is a shield case in thermal contact between a high-temperature end and a low-temperature end.

According to a fourth aspect of the present invention, the first object to be cooled is:
The pulse tube is in thermal contact with a heat exchanger disposed between a high-temperature end and a low-temperature end.

According to a fifth aspect of the present invention, there is provided a cooling heat exchanger in thermal contact with the first cooled object, a cold transfer heat exchanger communicating with the cooling heat exchanger by refrigerant flow, The transfer heat exchanger is characterized by being in thermal contact between the hot end and the cold end of the pulse tube.

The invention according to claim 6 is characterized in that a radiator communicating with the high-temperature end is arranged at the high-temperature end of the pulse tube.

[0015]

According to the first aspect of the present invention, the object to be cooled is brought into thermal contact between the high-temperature end and the low-temperature end of the pulse tube of the pulse tube refrigerator. It is used for cooling the cooling body.

Considering the above-mentioned cooling principle from the viewpoint of Carnot efficiency, bringing the object to be cooled into thermal contact between the high-temperature end and the low-temperature end requires a higher temperature than the cooling using a specific temperature as a cold source. Therefore, the total amount of cooling is greater than when cooling is obtained only from a specific low temperature, and the cooling efficiency can be increased.

According to the second aspect of the present invention, the object to be cooled is brought into thermal contact with different temperatures of the pulse tube, so that cold can be obtained even from a higher temperature than cooling using a specific temperature as a cold source. In other words, the total cooling amount is larger than when cooling is obtained only from a specific temperature, and the cooling efficiency can be increased.

According to the third aspect of the present invention, the shield case is in thermal contact between the high-temperature end and the low-temperature end of the pulse tube.
Since the loss due to radiation from the cold source can be reduced, and the shield case also obtains cold, the total cooling amount is larger than when cold is obtained only from a specific temperature,
Cooling efficiency can be increased.

According to the fourth aspect of the present invention, by arranging the heat exchanger in the pulse tube, it is possible to efficiently obtain the cold that can be taken out from the pulse tube, and to further improve the cooling efficiency.

According to the fifth aspect of the present invention, the object to be cooled can be continuously cooled by installing the cold transfer heat exchanger in thermal contact between the high temperature end and the low temperature end of the pulse tube. The cooling efficiency can be increased for the same reason as in the first and second aspects.

According to the sixth aspect of the present invention, since the radiator communicating with the high-temperature end of the pulse tube is disposed, heat is radiated positively, so that the cooling efficiency of the first to fifth aspects is further improved. Can be. Further, since the temperature at the high-temperature end of the pulse tube decreases, the heat conduction loss transmitted from the high-temperature end to the low-temperature end of the pulse tube through the wall of the pulse tube can be reduced.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a cooling device according to the present invention will be described in detail with reference to specific examples.

First Embodiment FIG. 1 shows a first embodiment of the present invention, in which a high-temperature end 18a and a low-temperature end 18b of a portion of a pulse tube refrigerator A1 and a part of the pulse tube 18 of the pulse tube refrigerator A1 that generate cold are generated. The object to be cooled 20 that has been continuously in thermal contact with the low temperature end 18b of the pulse tube 18
And a third cooled body 32 that is in thermal contact with the low-temperature end 16b of the regenerator 16 that communicates with the cooling unit 16.

The discharge side of the compression means 1 of the pressure vibration source communicates with the high-pressure switching valves 2 and 3 through high-pressure pipes 6 and 7, and the suction side of the compression means 1 through low-pressure pipes 8 and 9, respectively. It communicates with the low pressure switching valves 4 and 5.

The high-pressure switching valves 2 and 3 and the low-pressure switching valves 4 and 5 are connected to a drive unit 19 such as a pulse motor so that the high-pressure switching valves 2 and 3 and the low-pressure switching valves 4 and 5 open and close at a certain timing. It has become. The high-pressure switching valve 2 and the low-pressure switching valve 4 are connected to the high-temperature end 16 of the regenerator 16 via pipes 10 and 12, respectively.
a. The high-pressure switching valve 3 and the low-pressure switching valve 5 also communicate with one end of a throttle 14 that adjusts the flow rate through pipes 11 and 13, respectively. It communicates with the hot end 18a of the tube 18.

The low-temperature end 18b of the pulse tube 18 communicates with the low-temperature end 16b of the regenerator 16 via a pipe 17. The compression means 1, the high-pressure switching valves 2, 3, the low-pressure switching valves 4, 5, the radiator 31, and the drive unit 19 such as a pulse motor are arranged in a normal temperature atmosphere. Thus, the pulse tube refrigerator A1
Is configured.

The operation state of the pulse tube refrigerator A1 is determined by the high pressure switching valves 2, 3, which are driven by a drive unit such as a pulse motor.
Opening and closing as shown in FIG. 2 is repeated by the low pressure switching valves 4 and 5. The state of the internal working medium accompanying the operation is temporally divided into the following four processes a to d. Each step will be described in detail. Step a When the high-pressure switching valve 2 is open and the low-pressure switching valve 4 is closed, the compression means 1
Therefore, the compressed working medium flows into the regenerator 16 sequentially through the high-pressure pipe 6, the high-pressure switching valve 2, and the pipe 10. The working medium flowing into the regenerator 16 is cooled by the cold regenerative material in the regenerator 16 and flows into the pulse tube 18 through the pipe 17.

Step b When the low pressure switching valve 5 is open and the high pressure switching valve 3 is closed, the pulse tube 1
The working medium that has flowed into 8 performs a substantially isothermal expansion work by displacing the working medium having a continuous temperature in the axial direction of the pulse tube 18, and the working medium on the high-temperature side of the cold generating part in the pulse tube 18 sequentially After passing through the radiator 31, the pipe 15, the throttle 14, the low-pressure switching valve 5, and the low-pressure pipe 9, it flows into the suction side of the compression means 1. Move to hot side of tube. At this time, the pulse tube 1
Eight axially continuous refrigerations are produced.

Step c When the low pressure switching valve 4 is open and the high pressure switching valve 2 is closed, the pulse tube 1
The working medium on the low-temperature side of the cold generation section in
7, regenerator 16, pipe 12, low-pressure switching valve 4, low-pressure pipe 8
And returns to the suction side of the compression means 1.

Step d When the high-pressure switching valve 3 is open and the low-pressure switching valve 5 is closed,
Accordingly, the compressed working medium sequentially passes through the high-pressure pipe 7, the high-pressure switching valve 3, the pipe 11, the throttle 14, the pipe 15, and the radiator 31, and moves the working medium present in the pulse tube 18 toward the low-temperature end 18b. Move.

The above steps a to d are defined as one cycle, and by repeating this, cold is generated.

Here, the efficiency η of the Carnot refrigeration cycle
Can be expressed by the following equation, where Qe is the heat amount of the heat absorbing portion and Qc is the heat amount of the heat radiating portion.

[0033]

Η = Qe / (Qc−Qe) Assuming that the mass of the heat absorbing portion is Me and the specific heat is Cpe, the relationship between the heat quantity Qe of the heat absorbing portion and the temperature Te is as follows.

[0034]

## EQU2 ## Assuming that the mass of the radiator is Mc and the specific heat is Cpc, the relationship between the heat quantity Qc of the radiator and the temperature Tc is as follows.

[0035]

[Formula 3] Qc = Mc · Cpc · Tc Here, if Me = Mc and Cpe = Cpc, the efficiency η can be expressed by the following equation.

[0036]

Η = Te / (Tc−Te) From this, it can be seen that when the cooling amount in the heat absorbing portion increases, the temperature Te of the heat absorbing portion increases, and the efficiency η improves.

In the first embodiment, as shown in the detailed view of FIG. 3, the object to be cooled 20 can absorb heat over a continuous wide range between the high-temperature end 18a and the low-temperature end 18b of the pulse tube 18. The cooling amount increases, and the cooling efficiency improves accordingly.

FIG. 4 shows a modification of the first embodiment, in which a pulse tube 1 is shown.
8 is a specific example in which a body to be cooled 20 is in thermal contact with a part of the circumference of FIG.

FIG. 5 shows a modification of the first embodiment, in which a pulse tube 1 is used.
This is a specific example in which a cooled body 20 is attached to the inside of an inner portion 8.

Second Embodiment FIG. 6 shows a second embodiment in which the pulse tube refrigerator A1 according to the first embodiment is connected to the first tube which is in thermal contact between the high temperature end 18a and the low temperature end 18b of the pulse tube 18. The cooling body 21, the second cooled body 22 that is in thermal contact with the low temperature end 18 b of the pulse tube 18, and the third cooled body 32 that is in thermal contact with the low temperature end 16 b of the regenerator 16.
Consists of That is, the low temperature end 18b of the pulse tube 18;
In the middle of the high temperature end 18a and the low temperature end 18b of the pulse tube 18,
By bringing the first cooled object 21 and the second cooled object 22 into thermal contact with each other, the cooling efficiency can be increased for the same reason as in the first embodiment.

FIG. 7 shows a modification of the second embodiment.
The low temperature end 18b of the second cooling object 22 is in thermal contact with the
In the middle of the high temperature end 18a and the low temperature end 18b of the pulse tube 18,
The shield case 21a is in thermal contact. With this shield case 21a, the second cooled object 22 and the third cooled object 3
2 can prevent radiation loss.
Since 1a also absorbs heat from the pulse tube 18, the cooling efficiency can be increased as in the second embodiment.

Third Embodiment FIG. 8 shows a third embodiment, in which a pulse tube 1 of a pulse tube refrigerator A1 is used.
As shown in FIG. 9, the first cooling member 2 is moved to a position where the working medium in the middle of the high-temperature end 18a and the low-temperature end 18b reciprocates.
1 is provided with a heat exchanger 23 which is in thermal contact with the heat exchanger 1 so as to positively improve the heat transfer with the reciprocating working medium. Therefore, the cooling efficiency can be increased as compared with the case of the second embodiment.

FIG. 10 is a cross-sectional view of the heat exchanger 23 according to the third embodiment.
This is a specific example in which the first cooled object 21 is brought into thermal contact with the heat exchanger 23 in which the heat exchanger 23 is opened.

FIG. 11 shows a modification of the third embodiment, in which a heat exchanger 23a in which a wire mesh 30 for promoting heat transfer is in thermal contact with a hole 29 through which the working medium flows, Are specific examples of thermal contact.

Fourth Embodiment FIG. 12 shows a fourth embodiment in which the compression means 2 for compressing the working medium is used.
A cooling heat exchanger 26 and a cooling heat exchanger 28 are sequentially connected to the discharge port 5, and the cooling body 20 is in thermal contact with the cooling heat exchanger 28. As shown in FIG. 13, the cold transfer heat exchanger 26 is connected to the pulse tube 18 of the pulse tube refrigerator A1.
Is in thermal contact between the high-temperature end 18a and the low-temperature end 18b, and the refrigerant flows in the cold transfer heat exchanger 26. The refrigerant is cooled by a working medium that reciprocates in the pulse tube 18 from room temperature to low temperature, and is cooled through the cooling heat exchanger 28.
To cool. The refrigerant passes through the cold transfer heat exchanger 26,
Since cooling is performed by the working medium that reciprocates in the pulse tube 18 continuously from normal temperature to low temperature, the cooling efficiency is improved as in the case of the first embodiment.

FIG. 14 shows a modification of the fourth embodiment, which is a specific example in which a number of pulse tubes 18 are provided in a cold transfer heat exchanger 26.

FIG. 15 shows a modification of the fourth embodiment, which is a specific example in which a cold transfer heat exchanger 26 is provided in a pulse tube 18.

In this embodiment, all the pulse tube refrigerators A1
More than two steps may be used. In this embodiment, the compression means of the working medium of the pulse tube refrigerator A1 is of the GM type, but may be of the Stirling type.

In the above embodiment, the pressure vibration source on the room temperature side of the pulse tube 18 is a double-inlet four-valve system, but the orifice system using the buffer tank 33 in FIG. 16 and the double-inlet four-valve system in FIG. Any of a combination of a system and an orifice system, a basic system, and a phase shifter system may be used.

In the first embodiment, the object to be cooled 20 is continuously in thermal contact between the high-temperature end 18a and the low-temperature end 18b of the portion of the pulse tube 18 where cold is generated, as shown in FIG. As described above, the object to be cooled 20 may be discontinuous, and the pulse
Refrigeration can be obtained from any temperature.

[0051]

According to the present invention, in the pulse tube of the pulse tube refrigerator, the working medium performs substantially isothermal expansion work at a continuous temperature in the direction of the pulse tube, thereby producing a continuous temperature of cold. From the viewpoint of Carnot efficiency, the higher the temperature, the higher the cooling efficiency. Therefore, according to the present invention, since cold of a continuous temperature is generated and the object to be cooled is cooled using the cold, the cooling efficiency is improved as compared with a conventional refrigerator of this type.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a cooling device embodying a first embodiment.

FIG. 2 is a diagram showing the open / closed state of the switching valve of the pulse tube refrigerator in one cycle, which embodies the first embodiment.

FIG. 3 is a detailed view of a pulse tube section of the first embodiment.

FIG. 4 is a detailed view of a pulse tube unit embodying a modification of the first embodiment.

FIG. 5 is a detailed view of a pulse tube unit embodying a modification of the first embodiment.

FIG. 6 is a conceptual diagram of a cooling device embodying the second embodiment.

FIG. 7 is a conceptual diagram of a cooling device embodying a modification of the second embodiment.

FIG. 8 is a conceptual diagram of a cooling device embodying a third embodiment.

FIG. 9 is a detailed view of a pulse tube unit according to the third embodiment.

FIG. 10 is a detailed view of a heat exchanger section of the third embodiment.

FIG. 11 is a detailed view of a heat exchanger unit embodying a modification of the third embodiment.

FIG. 12 is a conceptual diagram of a cooling device embodying a fourth embodiment.

FIG. 13 is a detailed view of a pulse tube unit according to a fourth embodiment.

FIG. 14 is a detailed view of a cold transfer heat exchanger embodying a modification of the fourth embodiment.

FIG. 15 is a detailed view of a cold transfer heat exchanger embodying a modification of the fourth embodiment.

FIG. 16 is a conceptual diagram of a pressure vibration source of a pulse tube refrigerator embodying a modification of the present embodiment.

FIG. 17 is a conceptual diagram of a pressure vibration source of a pulse tube refrigerator embodying a modification of the present embodiment.

FIG. 18 is a detailed view of an object to be cooled, embodying a modification of the first embodiment.

FIG. 19 is an explanatory view showing a conventional cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Compression means 16 ... Regenerator 18 ... Pulse tube 20 ... Cooled body 21 ... First cooled body 22 ... Second cooled body 23 ... Heat exchanger 26 ... Cold transfer heat exchanger 28 ... Cooling heat exchange Vessel 31 ... radiator

Claims (6)

[Claims] 1. A pressure vibration source for compressing and expanding a working medium, a regenerator communicating with the pressure vibration source, a pulse tube refrigerator having a pulse tube communicating with the regenerator, and a high-temperature end of the pulse tube. And a cooled object thermally contacted between the low-temperature end. 2. A pressure vibration source for compressing and expanding a working medium, a regenerator communicating with the pressure vibration source, a pulse tube refrigerator having a pulse tube communicating with the regenerator, and a high-temperature end of the pulse tube. And the first in thermal contact between the cold end
A cooling device comprising: a cooled object; and a second cooled object that is in thermal contact with a low-temperature end portion of the pulse tube. 3. The cooling device according to claim 2, wherein the first cooled object is a shield case that is in thermal contact between a high-temperature end and a low-temperature end of the pulse tube. 4. The cooling device according to claim 2, wherein said first cooled object is in thermal contact with a heat exchanger disposed between a high temperature end and a low temperature end of said pulse tube. . 5. A cooling heat exchanger in thermal contact with the first cooled object, a cold transfer heat exchanger communicating with the cooling heat exchanger by refrigerant flow, and the cold transfer heat exchanger. 3. The cooling device according to claim 1, wherein said pulse tube is in thermal contact between a high-temperature end and a low-temperature end of said pulse tube. 6. A radiator communicating with the high-temperature end of the pulse tube is arranged at a high-temperature end of the pulse tube.
The cooling device according to any one of claims 1 to 5.