JP2000220902A - Cooling system - Google Patents

Abstract

(57) [Problem] To reduce the cooling efficiency of a cooling device due to frictional heat caused by sliding of a piston ring in a low temperature part and leakage of a working medium from between a piston ring and a cylinder wall. SOLUTION: A piston ring 11, 14a,
Stirling refrigerator A1 having 14b and pulse tube refrigerator B using the working medium of Stirling refrigerator A1 as a pressure source
The Joule-Thompson circuit C1 is brought into thermal contact with the cold part 1.

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 superconducting magnet.

[0002]

2. Description of the Related Art A cooling device using a regenerative refrigerator according to the present invention is disclosed, for example, in Japanese Patent Publication No. 3-49021.

In FIG. 8, reference numeral 901 denotes a three-stage piston of a precooling refrigerator, 902 denotes a first-stage cylinder of the three-stage piston 901, 903 denotes a second-stage cylinder, 904 denotes a third-stage cylinder, and 905 denotes a first-stage cylinder. The first stage pre-cooling heat exchanger forming the head of the second stage, 906 is the second stage pre-cooling heat exchanger forming the head of the second stage cylinder, and 907 is the third stage pre-cooling heat exchanger forming the head of the third stage cylinder , 9
08 is a first-stage regenerator communicating with the first-stage cylinder 902 via the first-stage pre-cooling heat exchanger 905, and 909 is connected to the first-stage cylinder 902 via one port via the first-stage pre-cooling heat exchanger 905. The other port is connected to the second stage pre-cooling heat exchanger 906
The second regenerator 910 communicates with the second-stage cylinder 903 via the second stage, and one port thereof communicates with the second-stage cylinder 903 via the second-stage precooling heat exchanger 906, and the other port has the third port.
Third stage cylinder 904 via stage pre-cooling heat exchanger 907
911 is a first countercurrent heat exchanger, 912 is a second countercurrent heat exchanger, 913 is a third countercurrent heat exchanger, and 914 is a fourth countercurrent heat exchanger. The high-pressure circuit and the pre-cooling heat exchanger of these countercurrent heat exchangers are 911, 9
05, 912, 906, 913, 907, and 914 in this order via piping, and 915 is the fourth countercurrent heat exchanger 91.
A Joule-Thomson valve which communicates with the high pressure circuit outlet of No. 4 via a pipe, 916 is a compression piston, and 918 is a radiator forming the head of the compression cylinder of the compression piston.

A compression piston 916 and a three-stage piston 901
Reciprocates with a phase difference of about 90 °, the pre-cooling heat exchanger 9
05, 906, and 907, where the high-pressure refrigerant is cooled and the countercurrent heat exchangers 911, 912, and 91 are cooled.
The refrigerant is cooled by exchanging heat with the refrigerant flowing through the low-pressure circuit in the order of 3, 914, is expanded by Joule-Thomson by the Joule-Thomson valve 915, part of the refrigerant is liquefied, and the liquefied refrigerant cools the object to be cooled. The vaporized refrigerant is transferred to the countercurrent heat exchanger 9
14, 913, 912, and 911 exchange heat with the refrigerant flowing through the high-pressure circuit through the low-pressure circuit in the order of the counter-current heat exchanger 9
Go out of 11.

[0005]

However, in the conventional apparatus, since the piston rings 931 and 932 are provided in the low temperature portion of the multi-stage expansion piston 901 of the Stirling refrigerator, the sliding caused by the reciprocation of the expansion piston 901 is performed. Generates frictional heat, and the expanded portions 933, 934, 93
5, the refrigeration capacity generated decreases.

The piston rings 931 and 932 are generally made of a resin containing a filler, and have a large heat shrinkage. When the refrigerator is operating, the piston rings 931 and 932 are placed in a low-temperature environment, so that the outer diameter, the inner diameter, and the height of the piston rings become smaller due to heat shrinkage. As a result, the expansion section 933 is formed.
Since the refrigerant of about 80K passes through the piston ring 931 and flows into the expansion space 934 of about 30K, the expansion space 93
5, the refrigeration capacity generated decreases.

Further, the length of the expansion piston 901 becomes longer, and the tip of the expansion piston 901 comes into contact with the inner surface of the third-stage cylinder 904, so that the refrigerating capacity generated in the expansion space 935 is reduced.

The expansion space 934 includes a pre-cooling heat exchanger 906,
Because it communicates with the compression space 936 provided at normal temperature via the cool storages 909, 908 and the radiator 918, the dead volume and the flow path resistance of the pre-cooling heat exchanger 906, the cool storages 909, 908, and the radiator 918 , The PV diagram of the expansion space 934 becomes thinner, and the refrigerating capacity decreases.

The expansion space 935 includes a pre-cooling heat exchanger 907,
Since it communicates with the compression space 936 provided at room temperature through the cool storages 910, 909, 908 and the radiator 918,
For the same reason, the PV diagram of the expansion space 935 becomes thinner, and the refrigeration capacity becomes lower.

Due to the decrease in the refrigerating capacity, the gas temperature of the second refrigerant flowing into the Joule-Thomson valve 915 increases, and the amount of the second refrigerant liquid generated after passing through the Joule-Thomson valve 915 decreases, Problems such as a decrease in the refrigerating capacity of the cooling device occur.

An object of the present invention is to share a working medium of a Stirling refrigerator which does not require a piston ring in a low temperature part, and a movable part in a low temperature part and a working medium of a pulse tube refrigerator which does not require a piston ring placed in a low temperature environment, It is an object of the present invention to increase the refrigerating capacity at each temperature level and to configure a cooling device in which a Joule-Thompson circuit is brought into thermal contact with a cold part of the refrigerator to improve the refrigerating capacity of the cooling device.

[0012]

According to a first aspect of the present invention, there is provided a Stirling compressing section for compressing a working medium, a Stirling radiator communicating with the Stirling compressing section and radiating heat from the working medium; A Stirling regenerator that cools the refrigeration of the working medium, a Stirling refrigerator that communicates with the Stirling regenerator and includes a Stirling expansion unit that expands the working medium, and a pulse tube regenerator that cools the refrigeration of the working medium. A pulse tube refrigerating device comprising a pulse tube communicating with the pulse tube regenerator and a pulse tube radiator communicating with the pulse tube and radiating heat from a working medium, wherein the Stirling refrigerator and the pulse tube refrigerator are And the pressure fluctuation generated in the Stirling refrigerator is used as a pressure source of the pulse tube refrigerator.

According to the first aspect of the invention, the piston ring of the expansion piston of the Stirling refrigerator is provided at a room temperature. The pressure source of the pulse tube refrigerator uses the pressure generated in the Stirling expansion part of the Stirling refrigerator as a pressure source, and a refrigeration at a lower temperature than the refrigeration generated in the Stirling expansion part of the Stirling refrigerator is obtained. There are no moving parts such as pistons or piston rings. Therefore, frictional heat due to sliding caused by the reciprocating motion of the piston ring in the low temperature portion and leakage from the piston ring are eliminated.

Further, since the pressure source of the pulse tube refrigerator is the pressure of the expansion part of the Stirling refrigerator that generates freezing, the working medium having a lower temperature than that of the case where the pressure source is at the normal temperature part is pulsed. To flow into the working space of the tube refrigerator,
Refrigeration at the cold end of the pulse tube increases.

According to a second aspect of the present invention, there is provided a phase shifter which communicates with a pulse tube radiator of the pulse tube refrigerator and enables a variable space.

According to the second aspect of the present invention, a phase shifter which enables a variable space communicating with the pulse tube radiator of the pulse tube refrigerator is provided, so that the pulse tube refrigerator can optimally generate refrigeration. Can be adjusted to

According to a third aspect of the present invention, the drive unit of the phase shifter is shared with the drive unit of the Stirling refrigerator.

According to the third aspect of the present invention, by sharing the drive of the phase shifter and the drive of the Stirling refrigerator, the structure of the drive can be simplified and made compact.

According to a fourth aspect of the present invention, there is provided a compressor for pumping refrigerant, a high-pressure circuit for supplying refrigerant from a discharge side of the compressor to a cooling heat exchanger for cooling a body to be cooled, A low-pressure circuit communicating from a heat exchanger to the suction side of the compressor; and a low-pressure circuit disposed between the high-pressure circuit and the low-pressure circuit, for exchanging heat between the refrigerant flowing through the high-pressure circuit and the refrigerant flowing through the low-pressure circuit. A flow heat exchanger, a pre-cooling heat exchanger disposed in the high-pressure circuit, a Joule-Thomson valve disposed in the high-pressure circuit to liquefy the refrigerant, and the refrigerant liquefied by the Joule-Thomson valve cools the refrigerant. The Stirling refrigerator and the cold part of the pulse tube refrigerator are in thermal contact with a Joule-Thomson circuit configured to flow into the heat exchanger for receiving refrigeration.

According to the fourth aspect of the invention, the Joule-Thomson circuit is in thermal contact with the cold part of the Stirling refrigerator and the pulse tube refrigerator. Because it can receive cold, it can efficiently cool the refrigerant,
Liquefaction at the Joule-Thomson valve increases.

According to a fifth aspect of the present invention, there is provided a branch circuit which branches from the high voltage circuit of the Joule-Thomson circuit and makes thermal contact with the cold section of the Stirling refrigerator and the pulse tube refrigerator. .

According to the fifth aspect of the present invention, the branch circuit is provided in the Joule-Thomson circuit, so that the refrigerant flowing in the high-pressure circuit of the countercurrent heat exchanger of the Joule-Thomson circuit is favorably cooled by the refrigerant flowing in the low-pressure circuit. Therefore, the cooling efficiency is improved.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The 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, which comprises a one-stage expansion Stirling refrigerator A1, a pulse tube refrigerator B1, and a Joule-Thomson circuit C1.

The Stirling compression section 1 is connected to the Stirling expansion section 8 via the Stirling radiator 2, the flow path 3, the flow path 4, the Stirling regenerator 5, and the flow path 7 in order. The Stirling compression unit 1 includes a compression cylinder 9, a compression piston 10, and a piston ring 11. The Stirling regenerator 5 is provided in an expansion piston 12, and the Stirling expansion unit 8 includes an expansion cylinder 13 and piston rings 14 a and 14 b. Rod 15, 1
6 is connected to the drive unit.

The piston rings 14a, 14b, 11 are disposed at a room temperature, and the compression piston 10 and the expansion piston 12
Means that the expansion piston 12 advances from 60 ° to 120 ° in phase with the compression piston. Thus, a one-stage expansion Stirling refrigerator A1 is configured.

The Stirling expansion section 8 includes a flow path 17, a pulse tube regenerator 18, a heat exchanger 19, a flow path 20, and a pulse tube 2.
1 communicates with the low-temperature end. The hot end of the pulse tube 21 is
The flow path 22 communicates with the flow path 28 via the pulse tube radiator 34, the flow path 22 communicates with the space 23 of the phase shifter 30, and the flow path 28 communicates with the buffer tank 31 via the throttle valve 29. ing. The space 23 includes a piston 24, a piston ring 25, and a cylinder 26, and the rod 27 is connected to a driving unit. Thus, the pulse tube refrigerator B1 is configured.

The buffer tank 31 and the throttle valve 29 need not be provided. In that case, the configuration is simple, but the volume of the space 23 of the phase shifter 30 is large. Also, without providing the phase shifter 30, the buffer tank 31,
Only the throttle valve 29 may be provided. Also in this case, the pulse tube refrigerator has no mechanical movable parts.

A shared working medium is sealed in the Stirling refrigerator A1 and the pulse tube refrigerator B1. Refrigeration of about 70K is generated in the expansion section 8 by the reciprocating motion of the compression piston 10 and the expansion piston 12 of the Stirling refrigerator A1.
The heat exchanger 19 of the pulse tube refrigerator B1 and the low temperature end of the pulse tube 21 generate about 15K of refrigeration.

The Joule-Thompson circuit C1 basically includes a compressor 50, first countercurrent heat exchangers 51 and 52, a second countercurrent heat exchanger 53, precooling heat exchangers 54, 55a and 55b,
It comprises a Joule-Thomson valve 56 and a liquid reservoir 57 which is a heat exchanger for cooling.

The precooling heat exchangers 54, 55a and 55b are respectively composed of the Stirling expansion section 8 of the Stirling refrigerator A1, the heat exchanger 19 of the pulse tube refrigerator B1 and the pulse tube 21.
Is in thermal contact with the low temperature end of A first countercurrent heat exchanger 51,
52, in the second counter-flow heat exchanger 53, the high-pressure channels 51a, 52a, 53a and the low-pressure channels 51b, 52, respectively.
b and 53b exchange heat. Tank 6
0, the control valves 58 and 59 operate when the refrigerant in the circuit is excessive.
The refrigerant is sent to the tank 60, and when there is a shortage, the tank 6
0 is supplied to the low pressure side of the compressor 50. 57a is a refrigerant liquid phase, and 57b is a refrigerant gas phase.

The pressure fluctuation generated in the Stirling expansion section 8 is used as a pressure source for the pulse tube refrigerator B1. That is, the working medium of the Stirling expansion unit 8 flows into and out of the pulse tube regenerator 18 and generates about 15K of refrigeration at the low-temperature ends of the heat exchanger 19 and the pulse tube 55. The phase shifter 30, the throttle 29, and the buffer tank 31 create displacement such that the working medium causes refrigeration at the cold ends of the heat exchanger 19 and the pulse tube 21.

The refrigerant discharged from the compressor 50 of the Joule-Thomson circuit C1 is supplied to the first countercurrent heat exchangers 51, 5
2. High-pressure side flow paths 51a, 52 of the second counter-current heat exchanger 53
a, 53a, the low pressure side flow paths 51b, 52b, 5b
It is cooled by a low-pressure, low-temperature refrigerant flowing through 3b, and the temperature gradually decreases.

The refrigerant flowing through the pre-cooling heat exchangers 54, 55a and 55b is supplied to the Stirling expansion section 8 of the Stirling refrigerator A1 and the heat exchangers 55a and 55a of the pulse tube refrigerator B1, respectively.
It is cooled by the freezing generated at the low temperature end of the pulse tube 21. When the Joule-Thomson valve 56 undergoes isenthalpy expansion from a high pressure to a low pressure, a part of the gas is liquefied and becomes mist and flows into the gas phase 57b of the liquid reservoir 57, and the liquid is converted into the liquid phase 57b.
a, and cools the object to be cooled 61. The refrigerant in the gas phase 57b flows into the low-pressure side channel 53b of the second counter-flow heat exchanger 53.

According to this embodiment, the piston ring 14 of the expansion piston 12 of the one-stage expansion Stirling refrigerator A1 is used.
a and 14b are provided at a normal temperature part, and the pressure source of the pulse tube refrigerator B1 uses the pressure generated in the Stirling expansion unit 8 of the Stirling refrigerator A1 as a pressure source. Freezing at a lower temperature than the freezing generated in the Stirling expansion section 8 of the refrigerator A1 is obtained, and there is no movable part such as a piston or a piston ring in the low temperature section. Therefore, frictional heat due to sliding caused by reciprocation of the piston rings 14a and 14b in the low temperature portion,
And the amount of refrigeration generated in the heat exchanger 19 provided at the low-temperature end of the pulse tube 21 and the low-temperature end of the regenerator 18 of the pulse tube refrigerator B1 is smaller than that of the conventional refrigerator. Increase.

Since the pressure source of the pulse tube refrigerator B1 is the pressure of the Stirling expansion section 8 which generates the freezing of the Stirling refrigerator A1, the temperature is higher than when the pressure source is at room temperature. Low working medium is pulse tube refrigerator B
Since it flows into the first working space, the amount of refrigeration generated at the low-temperature end of the pulse tube 21 increases.

Further, the Stirling refrigerator A1 has a capacity of about 70
Around the temperature of K, the efficiency is higher than other refrigeration cycles. That is, in the present invention, since the refrigerator of the refrigeration cycle with high efficiency is combined at each temperature, the cooling efficiency of the cooling device of the present invention combining the refrigerator of the present invention and the Joule-Thomson circuit C1 is improved. .

The refrigerator has a Joule-Thomson circuit C1.
As described above, since the amount of refrigeration generated in the pulse tube refrigerator B1 is larger than that of the conventional refrigerator, the liquefied amount of the refrigerant passing through the Joule-Thomson valve 56 increases, and the cooling device The cooling capacity of the conventional cooling device is also increased.

In this embodiment, the pulse tube refrigerator B1 has one stage, but may have multiple stages. In this case, although the structure is complicated, the amount of refrigeration generated by the pulse tube refrigerator B1 increases. Further, a plurality of pulse tube refrigerators B1 may be provided. In this case, refrigeration at different temperatures can be obtained. Further, the configuration of the refrigerator becomes complicated, but the cooling capacity of the cooling device further increases.

Second Embodiment FIG. 2 shows a second embodiment of the present invention, in which the phase shifter 30 shown in FIG. 1 is not provided, and instead, a function of a phase shifter is provided in the room temperature portion of the expansion cylinder 13 of the Stirling refrigerator A1. It is a thing.

The Stirling compressor 1 includes a Stirling radiator 2, channels 3 and 4, a Stirling regenerator 5, and a channel 7.
Through the Stirling expansion portion 8. The rods 15, 16 are connected to a drive unit, and the piston rings 14a, 14b, 14c, 11 are disposed at a room temperature portion. The movement between the compression piston 10 and the expansion piston 12a is such that the expansion piston 12a leads the phase from the compression piston by 60 ° to 120 °. Thus, the Stirling refrigerator A2 is configured.

The pulse tube refrigerator B1 includes a Stirling expansion section 8, a flow path 17, a pulse tube regenerator 18, a heat exchanger 19,
The flow path 20 and the low temperature end of the pulse tube 21 communicate with each other. The high-temperature end of the pulse tube 21 is connected to a flow path 22 and a flow path 28 via a pulse tube radiator 34, and the flow path 22 is provided with a valve 35 and communicates with a space 23 having a phase shifter function. ing. The flow path 28 communicates with the buffer tank 31 via a throttle valve 29. The space 23 of the phase shifter
Piston ring 14b provided on the narrow side of convex expansion piston 12a, piston ring 14c provided on the thick side
And a convex expansion cylinder 13.

The other structure is the same as that of the first embodiment shown in FIG. In the present invention, there is an advantage that the configuration is simplified because the phase shifter 30 does not need to be installed.

Third Embodiment FIG. 3 shows a third embodiment of the present invention, which has a branch circuit C32. That is, the Stirling refrigerator A3
, Pulse tube refrigerator B3, and Joule-Thomson circuit C
3 constitutes a cooling device.

The Stirling compression section 101 communicates with a Stirling expansion section 106 via a Stirling radiator 102, a Stirling regenerator 103, a heat exchanger 104, and a flow path 105 in this order. The Stirling compression unit 101
It comprises a compression cylinder 107, a compression piston 108, and a piston ring 109. Stirling expansion part 10
6 includes an expansion cylinder 110 and a piston ring 111. The rods 112 and 113 are connected to a driving unit, and the piston rings 109 and 111 are disposed at a room temperature part.

The compression piston 108 and the expansion piston 114
Is such that the expansion piston 114 leads the compression piston 108 in phase by 60 ° to 120 °.
Thus, the Stirling refrigerator A3 is configured.

The Stirling expansion section 106 has a flow path 117
And communicates with the high-temperature end of the pulse tube regenerator 118. The low-temperature end of the pulse tube regenerator communicates with the heat exchanger 119, and sequentially communicates with the flow path 120 and the low-temperature end of the pulse tube 121.
The high temperature end of the pulse tube 121 communicates with the pulse tube radiator 134, the flow path 122 and the flow path 128, and the flow path 122 communicates with the space 123 of the phase shifter 130. Channel 128
Communicates with a buffer tank 131 through a throttle valve 129, and a space 123 is formed by a piston 124, a piston ring 1
25, a cylinder 126 is formed, and a rod 127 is connected to the drive unit. Thus, the pulse tube refrigerator B3 is configured.

Compression piston 1 of Stirling refrigerator A3
08 and the reciprocating motion of the expansion piston 114 generates about 70K of freezing in the Stirling expansion section 106. Refrigeration of about 13K occurs at the heat exchanger 119 of the pulse tube refrigerator B3 and the low temperature end of the pulse tube 121.

The Joule-Thomson circuit C3 is composed of a main circuit C
31 and a branch circuit C32. Main circuit C31
The compressor 150, the first countercurrent heat exchangers 151, 15
2, the second countercurrent heat exchanger 153, the pre-cooling heat exchanger 154
a, 154b, 155a, 155b, a Joule-Thomson valve 156, and a liquid reservoir 157, which is a cooling heat exchanger.

Pre-cooling heat exchangers 154a, 154b, 155
a and 155b are in thermal contact with the heat exchanger 104 of the Stirling refrigerator A3, the Stirling expansion unit 106, the heat exchanger 119 of the pulse tube refrigerator B3, and the low-temperature end of the pulse tube 121, respectively. First countercurrent heat exchangers 151, 152,
In the second countercurrent heat exchanger 153, each of the high-pressure side channels 1
51a, 152a, 153a and the low-pressure side passages 151b, 1
52b and 153b exchange heat.

The branch circuit C32 branches from the discharge port of the compressor 150, and via the heat exchangers 171 and 172 for transmitting cold, the junction P1 at the inlet of the high pressure side flow path of the precooling heat exchanger 155a.
To join the main circuit C31. Heat exchanger 171 for cold transmission
Is the Stirling regenerator 10 of the Stirling refrigerator A3.
No. 3 is continuously in thermal contact from the high temperature side to the low temperature side, and the cold transfer heat exchanger 172 is in continuous thermal contact from the high temperature end to the low temperature end of the pulse tube regenerator 118 of the pulse tube refrigerator B3. Note that, as shown by the dotted line, the flow may merge with the main circuit C31 at the junction Q1 at the inlet of the low-pressure side flow path of the first countercurrent heat exchanger 152.

The tank 160 and the control valves 158 and 159 feed the refrigerant into the tank 160 when the refrigerant in the circuit is excessive, and supply the refrigerant to the low pressure side of the compressor 150 from the tank 160 when the refrigerant is insufficient. 157a is the liquid phase of the refrigerant, and 157b is the gas phase of the refrigerant.

Since a part of the high-pressure refrigerant pumped from the compressor 150 is diverted to the branch circuit C32, the first counter-current heat exchangers 151 and 152 are connected to the high-pressure side channels 151a and 152.
The flow rate of the refrigerant flowing through the low pressure side flow paths 151b, 152
The flow rate becomes smaller than the flow rate flowing through the branch circuit C32 by the amount flowing into the branch circuit C32.

Therefore, the high pressure side flow paths 151a, 152
is cooled by the refrigerant flowing through the low-pressure side flow paths 151b and 152b to a lower temperature than in the case where there is no conventional branch circuit, and the pre-cooling heat exchangers 154a and 154 are further cooled.
b and the pre-cooling heat exchangers 155a and 155b
K, cooled to about 13K.

The refrigerant diverted to the branch circuit C32 is continuously cooled from room temperature to about 70K by the working medium flowing in the Stirling regenerator 103 of the Stirling refrigerator A3 in the cold transfer heat exchanger 171. . This is more efficient than cooling only at certain lower temperatures.

Similarly, the refrigerant flowing through the cold-transfer heat exchanger 172 is the working medium flowing in the pulse tube regenerator 118 of the pulse tube refrigerator B3, and is continuously cooled from about 70K to about 13K. At the point P1, the refrigerant merges with the refrigerant flowing through the main circuit C31 and flows into the high-pressure side flow path 153a of the second counter-current heat exchanger 153, where it is further cooled by the low-pressure refrigerant flowing through the low-pressure side flow path 153b.・ Thomson valve 1
It flows into 56.

In the Joule-Thomson valve 156, the refrigerant expands isentropically, and a part of the refrigerant liquefies and becomes mist, flows into the gas phase 157b of the liquid reservoir 157, and the refrigerant liquid is stored in the liquid phase 157a and cooled. The body 161 is cooled. The refrigerant in the gas phase 157b is supplied to the low-pressure side flow path 1 of the second countercurrent heat exchanger.
53b.

As described above, not only the refrigerant in the main circuit C31 is cooled to a lower temperature than in the conventional case, but also the refrigerant flowing in the branch circuit is efficiently cooled. Second countercurrent heat exchanger 15
Also, the temperature of the refrigerant flowing into the high-pressure side flow path 153a is lower than before, and the temperature of the refrigerant flowing into the Joule-Thomson valve 156 is also lower than before, so that the liquefaction rate of the refrigerant is improved.

In this embodiment, the piston ring 111 of the expansion piston 114 of the Stirling refrigerator A3 is provided at a normal temperature portion, and the pressure source of the pulse tube refrigerator B3 is generated at the Stirling expansion portion of the Stirling refrigerator A3. Since the pressure is used as the pressure source, the pulse tube refrigerator B3 can obtain refrigeration at a lower temperature than the refrigeration generated in the Stirling expansion unit 106 of the Stirling refrigerator A3, and a movable part such as a piston or a piston ring is provided in the low temperature part. There is no.

Therefore, frictional heat due to sliding caused by reciprocation of the piston ring in the low-temperature portion and leakage from the piston ring are eliminated, and the low-temperature end of the pulse tube 121 and the pulse tube regenerator of the pulse tube refrigerator B3. The amount of refrigeration generated in the heat exchanger 119 provided at the low-temperature end of 118 is larger than that of the conventional refrigerator.

Fourth Embodiment FIG. 4 shows a fourth embodiment of the present invention, in which a branch circuit C42 is provided in a Joule-Thomson circuit C4, and the countercurrent heat exchanger is provided according to the temperature range of the countercurrent heat exchanger. Cold transfer heat exchangers 271, 272a, 272 of branch circuit C42 corresponding to the heat exchangers
b, 273, 274a, and 274b are characterized by optimizing the flow rate of the refrigerant flowing therethrough and by simplifying the Joule-Thomson circuit.

That is, the branch circuit C3 of the third embodiment shown in FIG.
2 is a circuit for further improving the heat exchange, and the configuration is simplified by eliminating the pre-cooling heat exchanger of the main circuit. Other configurations are the same as those of the third embodiment in FIG.

The Joule-Thompson circuit C4 is a main circuit C4
1 and a branch circuit C42. The main circuit C41 is
Basically, the compressor 250, the first countercurrent heat exchangers 251, 2
52, a second countercurrent heat exchanger 253, a Joule-Thomson valve 256, and a liquid reservoir 257 as a cooling heat exchanger.

The first countercurrent heat exchangers 251 and 252, the second
The counter-flow heat exchangers 253 each include a high-pressure side flow path 251.
a, 252a, 253a and the low pressure side flow passages 251b, 252
b and 253b exchange heat.

The branch circuit C42 branches from the discharge port of the compressor 250, and has a throttle 270, a heat exchanger 271 for cold transmission,
Through the 272a, 272b, 273, 274a, and 274b, they merge at the junction P2 at the outlet of the high-pressure side flow path 252a of the first countercurrent heat exchanger 252. Then, it branches from the outlet of the high-pressure side flow path 251a of the first counter-flow heat exchanger 251 and joins via the throttle 275 at the junction R2 of the outlet of the cold transfer heat exchanger 272a. In addition, as shown by the dotted line, the merging point Q at the inlet of the low-pressure side flow path 252b of the first counter-flow heat exchanger 252
2 may be joined. Also, the junction R2 may be joined to the branch circuit C42 having a temperature substantially equal to the temperature of the outlet of the high-pressure side flow path 251a of the first countercurrent heat exchanger 251.

It should be noted that the throttle 275 can be replaced by the throttle 276 or the heat exchangers 272b, 273, 274a for cold transmission.
In the middle of 274b, the heat exchanger 272 for transmitting cold
b, 273, 274a, and 274b may have a restriction resistance in the flow path itself. Also, the throttle 270 may have resistance of the throttle in the middle of the cold transfer heat exchangers 271, 272a or in the flow passage itself of the cold transfer heat exchangers 271, 272a.

If the flow rate of the refrigerant in the high-pressure side flow path 252a of the first counter-flow heat exchanger 252 is too large for the flow rate of the refrigerant flowing through the heat exchanger 273 for transmitting cold, the junction point P2 A throttle may be provided between the inlets of the side flow paths 252a. Similarly, the high-pressure side flow path 25 of the first countercurrent heat exchanger 251
When the flow rate of the refrigerant 1a is too large for the flow rate of the refrigerant flowing through the heat exchanger 271 for cold transfer, a throttle may be provided in the high-pressure side flow path 251a between the branch point M2 and the branch point N2. . The branch point N2 is located in the middle of the high-pressure side flow path 251a.
It may be provided in the middle of the high pressure side channel 252a.

The cold transfer heat exchanger 271 is in continuous thermal contact from the high temperature side to the low temperature side of the regenerator 103 of the Stirling refrigerator A4.
Are in thermal contact with the Stirling expansion 106. The cold transfer heat exchanger 273 is in continuous thermal contact from the high temperature end to the low temperature end of the pulse tube regenerator 172, and the cold transfer heat exchangers 274a and 274b are respectively the heat exchangers of the pulse tube refrigerator B4. 119 is in thermal contact with the low temperature end of the pulse tube 121.

When the refrigerant is helium as shown in FIG.
At a temperature of about 10K, the constant pressure specific heat is higher at higher pressures than at lower pressures, and this characteristic becomes more pronounced at lower temperatures. When this characteristic is applied to the main circuit C41 of the Joule-Thomson circuit C4, the high-pressure side flow passages 251a, 252 of the countercurrent heat exchangers 251, 252, 253 of the main circuit C41.
a, 253a, as the temperature decreases up to about 10K, the countercurrent heat exchangers 251, 252, 25
The heat exchange can be favorably performed by reducing the amount of the refrigerant flowing through the low-pressure side flow paths 251b, 252b, and 253b of the third flow path.

The branch circuit C42 is provided with a branch point M2 and a branch point N2 at the discharge side of the compressor 250 and at the outlet of the high-pressure side flow path 251a of the first countercurrent heat exchanger 251, respectively. The flow rate of the refrigerant flowing through the high-pressure flow path 252a of the countercurrent heat exchanger 252 is smaller than the flow rate of the refrigerant flowing through the high-pressure flow path 251a of the first countercurrent heat exchanger 251.

That is, the low pressure side flow path 252 b and the low pressure side flow path 25
Since the flow rate of the refrigerant flowing through 1b is the same, it becomes larger than the difference in the flow rate of the refrigerant in the first counter-flow heat exchanger 252, and the difference in the flow rate of the refrigerant can be appropriately adjusted by the throttles 270 and 275. , First countercurrent heat exchanger 25
The refrigerant flowing through the high-pressure side flow passages 251a and 252a of the first and second 252 is cooled well.

Therefore, the temperature of the refrigerant at the inlet of the Joule-Thomson valve 256 is further lowered, and the cooling efficiency of the cooling device is improved.

Fifth Embodiment FIG. 6 shows a fifth embodiment of the present invention, which is characterized in that the branch point M2 of the fourth embodiment in FIG. 4 is eliminated and the configuration is simplified.
Other configurations are the same as those in FIG.

Branch circuit C of Joule-Thomson circuit C5
52 is a high-pressure side flow path 351 of the first countercurrent heat exchanger 351.
a from the outlet of a, and through the throttle 375, the heat exchangers 371, 372a, 372b, 373, 374 for cold transmission.
a and 374b to merge at the junction P3 at the outlet of the high-pressure side flow path 352a of the first counter-flow heat exchanger 352.

The cold transfer heat exchanger 371 is in continuous thermal contact with the Stirling regenerator 103 of the Stirling refrigerator A5 from midway to a low temperature, and the cold transfer heat exchangers 372a and 372b are respectively Stirling refrigerators. A5 is in thermal contact with heat exchanger 104 and Stirling expansion 106.

The cold transfer heat exchanger 373 is in continuous thermal contact from the high temperature end to the low temperature end of the pulse tube regenerator 118 of the pulse tube refrigerator B5.
a and 374b are in thermal contact with the heat exchanger 119 of the pulse tube refrigerator B5 and the low temperature end of the pulse tube 121, respectively.

Sixth Embodiment FIG. 7 shows a sixth embodiment of the present invention, in which a Joule-Thomson circuit C6 includes a branch circuit C32 of the third embodiment of FIG. 3 and a branch circuit C42 of the fourth embodiment of FIG. The combination is characterized by improving the cooling efficiency of the cooling device. Other configurations are the same as those of the fourth embodiment in FIG.

The Joule-Thompson circuit C6 includes a main circuit C
61 and a branch circuit C62. Main circuit C61
Are the compressor 450, the first countercurrent heat exchangers 451 and 45
2, the second countercurrent heat exchanger 453, the pre-cooling heat exchanger 454,
455, a Joule-Thomson valve 456, and a liquid reservoir 457.

The pre-cooling heat exchangers 454 and 455 are in thermal contact with the low temperature end of the Stirling expansion section 106 of the Stirling refrigerator A6 and the pulse tube 121 of the pulse tube refrigerator B6. The first counter-current heat exchangers 451 and 452 and the second counter-current heat exchanger 453 include high-pressure side flow passages 451a and 452, respectively.
a, 453a and the low temperature side flow paths 451b, 452b, 45
3b exchanges heat.

The branch circuit C62 branches from the discharge port of the compressor 450, and sequentially restricts 470 and the heat exchanger 47 for transmitting cold.
1, 472, 473, and 474, merge at the junction P4 at the outlet of the high-pressure side flow path 452a of the first counter-current heat exchanger 452, branch from the outlet of the pre-cooling heat exchanger 454, and
5 via a junction point R4 at the outlet of the heat exchanger 472 for cold transmission.

As shown by a dotted line, the first and second heat exchangers 452 may join at the junction Q4 at the inlet of the low-pressure side flow path 452b. Also, the junction R4 may be joined to the branch circuit C62 having a temperature substantially equal to the temperature of the outlet of the precooling heat exchanger 454. The restrictor 475 may provide a flow path resistance to the cold transfer heat exchangers 473 and 474 either at the stop 476 or in the middle of the cold transfer heat exchangers 473 and 474 to have the function of the restrictor. The throttle 470 is also provided in the middle of the cold transfer heat exchangers 471 and 472 or in the cold transfer heat exchanger 4.
The flow path resistance may be given to 71 and 472 to give a flow path resistance.

If the flow rate of the refrigerant in the high-pressure side flow path 452a of the first counter-flow type heat exchanger 452 is too large relative to the flow rate of the refrigerant flowing in the cold transfer heat exchanger 473, the confluence point P4 A throttle may be provided between the inlet and the inlet of the high-pressure side channel 452a.

Similarly, when the flow rate of the refrigerant in the high-pressure side flow path 451a of the counter-flow type heat exchanger 451 is too large relative to the flow rate of the refrigerant flowing in the cold transfer heat exchanger 471, the branch point M
A throttle may be provided in the high-pressure side flow path 451a between the branch 4 and the branch point N4. Further, the branch point N4 may be provided in the middle of the high-pressure side flow path 451a or in the middle of the high-pressure side flow path 452a.

In any of the embodiments, the number of pulse tube refrigerators may be one or more, or any number of stages, and a plurality of pulse tube refrigerators may be provided. In addition, the pulse tube refrigerator can be any pulse tube refrigerator such as a variable space of a phase shifter, a combination of a throttle valve and a buffer, a combination of a switching valve and a buffer, or a combination of a long and thin tube and a buffer. good.

[0085]

According to the present invention, since there is no piston ring in the low temperature part of the pulse tube refrigerator and the Stirling refrigerator,
A decrease in refrigeration capacity due to frictional heat due to sliding can be prevented, and the thermal contraction of the piston ring is small, so that leakage of the working medium from between the piston ring and the cylinder is reduced.

[0086] Further, since cooling can be received from a wide temperature range from room temperature to low temperature of the Stirling refrigerator and the pulse tube refrigerator, a cooling device with high cooling efficiency can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram of a cooling device embodying a second embodiment.

FIG. 3 is a conceptual diagram of a cooling device embodying a third embodiment.

FIG. 4 is a conceptual diagram of a cooling device that embodies a fourth embodiment.

FIG. 5 is a graph showing the specific heat at a constant pressure of a refrigerant (helium).

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

FIG. 7 is a conceptual diagram of a cooling device embodying a sixth embodiment.

FIG. 8 is an explanatory view showing a conventional cooling device.

[Explanation of symbols]

 A1: Stirling refrigerator B1: Pulse tube refrigerator C1: Joule-Thomson circuit C11a: High-pressure circuit C11b: Low-pressure circuit 1: Stirling compression section 2: Stirling radiator 3: Flow path 4: Flow path 5: Stirling regenerator 7: Channel 8 Stirling expansion part 9 Compression cylinder 10 Compression piston 11 Piston ring 12 Expansion piston 13 Expansion cylinder 14a, 14b Piston ring 15, 16 Rod 17 Flow channel 18 Pulse tube regenerator 19 Heat exchanger 20 ... flow path 21 ... pulse tube 22 ... flow path 23 ... space 24 ... piston 25 ... piston ring 26 ... cylinder 27 ... rod 28 ... flow path 29 ... throttle valve 30 ... phase shifter 31 ... buffer tank 34 ... pulse Pipe radiator 35 ... valve 50 ... compressor 51, 52 ... first countercurrent type Heat exchanger 53: Second counter-flow heat exchanger 51a, 52a, 53a: High-pressure side channel 51b, 52b, 53b: Low-pressure side channel 54, 55a, 55b: Pre-cooling heat exchanger 56: Joule-Thomson valve 57 ... Liquid reservoir (cooling heat exchanger) 57a ... Refrigerant liquid phase 58b ... Refrigerant gas phase 58,59 ... Control valve 60 ... Tank 61 ... Cooled object

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideo Misawa 2-1-1 Asahi-cho, Kariya-shi, Aichi Pref. Aisin Seiki Co., Ltd.

Claims (5)

[Claims] 1. A Stirling compressor for compressing a working medium, a Stirling radiator communicating with the Stirling compressor and radiating heat from the working medium, and a Stirling cool storage communicating with the Stirling radiator to cool refrigeration of the working medium. A Stirling refrigerator including a Stirling expansion unit that communicates with the Stirling regenerator and expands the working medium, a pulse tube regenerator that cools the refrigeration of the working medium, and a pulse tube that communicates with the pulse tube regenerator And a pulse tube radiator comprising a pulse tube radiator communicating with the pulse tube and radiating heat from the working medium, wherein the Stirling refrigerator communicates with the working space of the pulse tube refrigerator. A pressure fluctuation generated in the cooling device is used as a pressure source of the pulse tube refrigerator. 2. The cooling device according to claim 1, further comprising a phase shifter which communicates with a pulse tube radiator of the pulse tube refrigerator and enables a variable space. 3. The cooling device according to claim 2, wherein a drive unit of the phase shifter is shared with a drive unit of the Stirling refrigerator. 4. A compressor for pumping refrigerant, a high-pressure circuit for supplying refrigerant from a discharge side of the compressor to a cooling heat exchanger for cooling an object to be cooled, and A low-pressure circuit communicating with the suction side of the compressor, and a counter-flow heat exchanger disposed between the high-pressure circuit and the low-pressure circuit, for exchanging heat between the refrigerant flowing through the high-pressure circuit and the refrigerant flowing through the low-pressure circuit. And a pre-cooling heat exchanger disposed in the high-pressure circuit,
A Joule-Thomson valve disposed in the high-pressure circuit for liquefying the refrigerant, and the Stirling refrigerator in a Joule-Thomson circuit configured so that the refrigerant liquefied by the Joule-Thomson valve flows into the cooling heat exchanger. 4. The cooling device according to claim 1, wherein the cooling device is in thermal contact with a cold part of the pulse tube refrigerator to receive refrigeration. 5. The branch circuit according to claim 4, further comprising a branch circuit branching from the high-pressure circuit of the Joule-Thomson circuit and thermally contacting the cold section of the Stirling refrigerator and the pulse tube refrigerator. Cooling system.