JPH04313649A - Refrigerating plant - Google Patents

Abstract

PURPOSE:To provide a cryogenic refrigerating plant with a simple structure and a high refrigerating capacity. CONSTITUTION:A compressor 1 filled with a gaseous refrigerant in it, a cold heat accumulator 2 filled with a cold heat accumulation agent 22, a hollow pulse tube 4 and a buffer tank 7 are connected in series through pipes 3, 5 and 8. A low temperature taking-out heat exchanger 6 is disposed between the cold heat accumulation device 2 and the pulse tube 4, and a porous heat exchanger 42 is disposed between the buffer tank 7 and the pulse tube 4.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention uses pulse tubes to heat exchangers for low temperature extraction at temperatures of 100 to 20K (-173K).
The present invention relates to a refrigeration system that achieves extremely low temperatures (~-253°C).

0002

2. Description of the Related Art A conventional refrigeration system of this type proposed by the present applicant in Japanese Patent Application No. 1-335564 is shown in FIG.

In the figure, reference numeral 1 denotes a compressor filled with a gaseous refrigerant, such as helium, which becomes liquid at extremely low temperatures (below 20 K), and a piston 12 is movably provided in a cylinder 11. .

Reference numeral 2 denotes a regenerator connected to the compressor 1 through a pipe 3, and a regenerator 2 containing a regenerator material such as copper or lead inside.
1 is filled.

A pulse tube 4 is connected to the regenerator 2 via a pipe 5, and is made of stainless steel.

Reference numeral 6 denotes a heat exchanger for extracting extremely low temperatures of 100 to 20 K, which is made of a material with high thermal conductivity such as copper, and is provided in the middle of the pipe 5.

A buffer tank 7 is connected to the pulse tube 4 via a pipe 8, and an orifice valve 9 such as a needle valve is provided in the middle of the pipe 8.

Reference numeral 21 denotes a heat radiation heat exchanger provided at the end of the regenerator 2 on the compressor 1 side, and 41 represents a heat radiation heat exchanger provided at the end of the pulse tube 4 on the buffer tank 7 side. , water-cooled or air-cooled radiation fins are used. Further, as these materials, copper or the like having high thermal conductivity is used.

[0009] The regenerator 2 and the low-temperature extraction heat exchanger 6
, the pulse tube 4, and the pipe 5 connecting these are housed in a vacuum chamber 10 (with a degree of vacuum of 10-4 torr or less).In the above configuration, the compressor 1 The compressed gaseous refrigerant is cooled while passing through the heat radiation heat exchanger 21 and the regenerator 2, and flows into the pulse tube 4.
The residual refrigerant in the pulse tube 4 is compressed and the heat of compression is radiated to the heat radiating heat exchanger 41. Furthermore, while the refrigerant passes through the orifice valve 9, it is cooled by adiabatic expansion and flows into the buffer tank 7. .

Thereafter, the gaseous refrigerant accumulated in the buffer tank 7 is moved back by suctioning the refrigerant into the compressor 1 during the expansion process due to the upward movement of the piston 11 in FIG. is adiabatically expanded in the pulse tube 4 and further lowered in temperature to cool the low-temperature extraction heat exchanger 6 and regenerator 2, and then returned to the compressor 1.

By repeating the reciprocating cycle of the refrigerant in this way, the low temperature extraction heat exchanger 6 is made to obtain a very low temperature.

0012

[Problems to be Solved by the Invention] However, in this type of conventional refrigeration system, when the low-temperature extraction heat exchanger 6 reaches a certain level of temperature, the refrigerant in the heat radiation heat exchanger 41 loses the heat for low-temperature extraction. There was a problem in that heat intrusion from the outside occurred when it entered the exchanger 6, and the temperature that could be obtained was limited due to this.

[0013]Also, as a method for preventing the heat intrusion, it is possible to lengthen the 4 portions of the pulse tube, but this method increases the size of the refrigeration system itself and requires a large compressor. There was a point.

[0014] In view of the problems of the prior art, the present invention
The object of the present invention is to provide a cryogenic refrigeration device with a simple structure and high refrigeration capacity.

[0015]

[Means for Solving the Problems] The present invention connects a compressor filled with a gaseous refrigerant, a regenerator filled with a regenerator, a hollow pulse tube, and a buffer tank through pipes. connected in series, and providing a low-temperature extraction heat exchanger between the regenerator and the pulse tube;
A porous heat exchanger is provided between the buffer tank and the pulse tube.

[0016]

[Operation] By the above means, the compressor
When the compressed gaseous refrigerant passes through the porous heat exchanger between the buffer tank and the pulse tube, the flow path becomes narrow at each pore, and the gaseous refrigerant expands adiabatically due to decompression expansion and is cooled. It is further cooled by a heat exchanger for heat radiation. Next, when the refrigerant flows into the buffer tank from the radiation heat exchanger,
Expands and cools.

Thereafter, when the compressor performs a suction operation during the expansion process, the gas in the pulse tube expands adiabatically and becomes lower in temperature. Then, the refrigerant in the buffer tank moves back and is cooled by the porous heat exchanger to lower the temperature, and then enters the pulse tube and pushes out the gas inside the tube. In this way, the refrigerant in the pulse tube cools the low temperature extraction heat exchanger and the regenerator, and returns to the compressor.

Therefore, the refrigerant in the heat exchanger section for heat radiation carries heat to the heat exchanger section for low-temperature extraction, thereby suppressing heat intrusion into the heat exchanger for low-temperature extraction. Due to the expansion effect when passing through the container, the refrigeration generation effect is enhanced compared to the conventional structure, and the refrigeration capacity of the refrigeration device is improved.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the refrigeration system of the present invention will be described in detail below with reference to FIG. Components that are the same as those of the prior art example described above are designated by the same reference numerals.

In the figure, reference numeral 1 denotes a compressor, in which a reciprocating piston 12 is housed inside a cylinder 11, and the inside is filled with helium as a gaseous refrigerant.

Reference numeral 2 denotes a regenerator connected to the compressor 1 through piping, and stores a regenerator material 22 made of lead, copper, or the like. Reference numeral 21 denotes a heat exchanger for heat dissipation on the regenerator side, which is provided at the end of the regenerator 2 on the compressor 1 side and is water-cooled or air-cooled.

Reference numeral 6 denotes a low temperature extraction heat exchanger which is connected to the regenerator 2 via a pipe 5, and 4 is a stainless steel pulse tube which is connected to the low temperature extraction heat exchanger 6 through piping.

7 is a buffer tank connected to the pulse tube 4 via a pipe 8; 9 is an orifice valve such as a needle valve provided in the middle of the pipe 8; and 41 is a buffer tank connected to the pulse tube 4 through a pipe 8; This is a heat exchanger for heat radiation provided on the side of the buffer tank 7.

42 is the heat exchanger 4 of the pulse tube 4
This is a porous heat exchanger with a built-in mesh provided at one side end, and is used to radiate compression heat due to the expansion effect and to reduce heat intrusion from high temperature parts such as the heat exchanger 41.

The regenerator 2, pipe 5, and pulse tube 4 are housed in a vacuum chamber 10 with a degree of vacuum of 10-4 torr or less and are thermally insulated.

In the above configuration, in the compression process, the refrigerant pushed out from the pulse tube 4 passes through the orifice valve 9 and enters the buffer tank 7, and in the expansion process, conversely, the refrigerant from the buffer tank 7 is It passes through the orifice valve 9 and the porous heat exchanger 42 and flows into the pulse tube 4.

The porous heat exchanger 42 is connected between the pulse tube 4 and the heat radiating heat exchanger 41 so that a refrigerant flows through the inside of the heat exchanger 42. be. Specifically, the heat exchanger 42 is a mesh made of a material with poor thermal conductivity such as stainless steel or nylon. The heat exchanger 42 narrows the flow path in the porous portion formed by the mesh spacing, expands and injects the refrigerant under reduced pressure, and functions to reduce heat intrusion from the heat exchanger 41. .

In the refrigeration system of this embodiment, when the compressor 1 is operated during the compression process, the compressed refrigerant gas transfers its compression heat to the heat radiating heat exchanger 21 and the regenerator 4.
The heat is radiated and flows into the pulse tube 4, and the residual gas in the pulse tube 4 is compressed. The heat of compression in the pulse tube 4 is radiated by the porous heat exchanger 18 and the heat radiation heat exchanger 41, cooled, and flows into the buffer tank 7.

After that, during the expansion process, the compressor 1
When the suction operation is performed, the refrigerant gas flows into the buffer tank 7.
After moving back and discharging heat in the heat exchanger 41, it expands adiabatically in the pulse tube 4, further lowers the temperature, cools the low temperature extraction heat exchanger 6 and the regenerator 2, and returns to the compressor 1.

By repeating the reciprocating cycle of the refrigerant in this way, the refrigerant is heated to a temperature of 150 to 20
Extremely low temperatures of K (-123 to -253°C) can now be obtained.

Furthermore, in the refrigeration system, when the refrigerant gas in the compression process passes through the porous portion of the porous heat exchanger 42, it is cooled by expansion under reduced pressure in each pore. Furthermore, during the expansion process, when the refrigerant gas at a temperature around room temperature (300K) in the buffer tank 7 and the heat radiation heat exchanger 41 enters the pulse tube 4, it exchanges heat with the extremely low temperature refrigerant gas. This prevents heat from entering the pulse tube 4 for replacement. Therefore, the refrigerating capacity of the refrigerating device as a system increases.

FIG. 2 shows another embodiment of the invention. This embodiment has a double structure in which the compressor 1 of a conventional orifice pulse tube refrigerator and the pulse tube high-temperature end portions 31 and 32 are connected by a thin tube 23, and an orifice valve 24 for adjusting the flow rate is added in the middle. This is an example of application to an orifice pulse tube refrigerator called an inlet type.

In this refrigeration system, a thin tube 23 and an orifice valve 24 are added between the compressor 1 and the high-temperature ends 31 and 32 of the pulse tube to enhance the effect of compression and expansion within the pulse tube 4. That is.

This embodiment has the same structure as the previous embodiment except for the addition of a thin pipe 22 and an orifice valve 23, so a description of the other structures will be omitted.

Furthermore, instead of the reciprocating type compressor 1, it is also possible to use a combination of a rotary compressor and gas intake/exhaust valves.

[0036]

[Effects of the Invention] The present invention connects a compressor filled with a gaseous refrigerant inside, a regenerator filled with a regenerator, a hollow pulse tube, and a buffer tank in series via a pipe. A heat exchanger for low-temperature extraction is provided between the regenerator and the pulse tube, and a porous heat exchanger is provided between the buffer tank and the pulse tube. - When the refrigerant gas compressed in the tube passes through the porous part of the heat exchanger, it expands adiabatically, improving the cooling effect, and during the expansion process, heat intrusion from the high temperature end can be reduced, A cryogenic refrigeration device with high refrigeration capacity can be provided.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of a refrigeration apparatus showing one embodiment of the present invention.

FIG. 2 is a system configuration diagram of a refrigeration apparatus showing another embodiment of the present invention.

FIG. 3 is a system configuration diagram of a conventional refrigeration device.

[Explanation of symbols]

1 Compressor 11 Cylinder 12 Piston 2　　　　　　　Regenerator 22 Cold storage material 21, 41 Heat exchanger for heat radiation 6 Heat exchanger for low temperature extraction 4 Pulse tube 42 Porous heat exchanger 19 Heat exchanger for heat radiation 7 Buffer tank 9 Orifice valve

Claims (1)

[Claims] 1. A compressor filled with a gaseous refrigerant, a regenerator filled with a regenerator, a hollow pulse tube, and a buffer tank are connected in series through a pipe, and the regenerator is connected in series through a pipe. A refrigeration system comprising a low temperature extraction heat exchanger provided between the buffer tank and the pulse tube, and a porous heat exchanger provided between the buffer tank and the pulse tube.