JPH09178279A - Pulse tube type refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the flow rate of a working fluid easily with high accuracy, radiate generated heat efficiently and improve refrigerating capability and reliability by using a capillary for a pipe which connects a pulse tube and a buffer tank with each other, and forming a heat radiator for cooling the capillary with a refrigerant. SOLUTION: The pressure of a working fluid in a buffer tank 8 is kept at a substantially constant level, and the buffer tank 8 and a flow straightener 14 in a pulse tube 5 are allowed to communicate to each other by a capillary 9 through which a working fluid flows due to a pressure difference between the buffer tank 8 and the flow straightener 14. The flow rate of the working fluid is decided by the inner diameter of the capillary 9 and the length thereof. Since the working fluid generates heat in the vicinity of the capillary 9, an outer block pipe 11 is set around the capillary 9 to form a heat radiator, and a medium is allowed to flow from a medium inlet port 12 to a medium outlet port 13, thus forming the heat radiator so that a temperature of the working fluid flowing inside the capillary 9 is kept at a constant level. With this arrangement, the heat radiation efficiency of the working fluid flowing through the capillary 9 is improved, and, further, the flow rate of the working fluid between the flow straightener 14 in the pulse tube 5 and the buffer tank 8 can be controlled with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse tube refrigerator, and more particularly to an orifice type pulse tube refrigerator for improving the refrigerating capacity.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing a configuration example of a conventional orifice type pulse tube refrigerator. As shown in the figure, the pulse tube refrigerator comprises a compressor 1, an aftercooler 2, a regenerator 3, a low temperature heat exchanger 4, a pulse tube 5, a high temperature heat exchanger 6, an orifice 7 and a buffer tank 8, which are piped. And / or the connection portion is used for connection.

The compressor 1 causes pressure oscillation of a working fluid (not shown) in a pulse tube refrigerator.
First, since the working fluid compressed by the compressor 1 is heated, it is cooled by the aftercooler 2 and then the working fluid in the regenerator 3, the low temperature heat exchanger 4, the pulse tube 5 and the high temperature heat exchanger 6 is cooled. Increase pressure.

The high temperature heat exchanger 6 and the buffer tank 8 are communicated with each other through the orifice 7. Since the flow rate of the working fluid is restricted by the orifice 7, the pressure fluctuation in the buffer tank 8 is suppressed to be extremely small. Due to the pressure vibration caused by the compressor 1, the working fluid in the pulse tube 5 repeats compression and expansion close to the adiabatic change, and the aftercooler 2, the regenerator 3, the low temperature heat exchanger 4 and the high temperature heat exchanger 6 The working fluid repeats compression and expansion close to the isothermal change.

Due to the movement of the working fluid as described above, refrigeration occurs in the low temperature heat exchanger 4. At the same time as the temperature of the low-temperature heat exchanger 4 decreases, a temperature gradient occurs in the regenerator 3 and the pulse tube 5. Since heat is generated in the aftercooler 2 and the high temperature heat exchanger 6, it is necessary to radiate heat with cooling water or another refrigerant. The pulse tube refrigerator is one that continuously performs this to generate a low temperature.

FIG. 6 is a diagram showing a configuration example of another orifice type pulse tube refrigerator. In this pulse tube refrigerator, the orifice 7 in FIG. 5 is replaced with a needle valve 10 to change the flow rate of the working fluid in the orifice portion. It is variable.

FIG. 7 is a diagram showing a structural example of another orifice type pulse tube refrigerator, in which the orifice 7 in FIG. 5 is replaced with a thin tube 9 (capillary tube).

[0008]

The general structure of an orifice type pulse tube refrigerator is as shown in FIG.
The high temperature heat exchanger 6 generally has a structure in which a copper wire mesh is deposited and filled in a casing, and the casing is cooled from the surroundings with cooling water or the like. In this case, it is difficult to sufficiently dissipate the heat generated by the working fluid in the high temperature heat exchanger 6,
This causes the temperature rise of the working fluid in the pulse tube 5 and the buffer tank 8.

The orifice 7 controls the flow rate of the working fluid that connects the high temperature heat exchanger 6 and the buffer tank 8 and is an important element related to the refrigerating capacity. In order to ensure the stable performance of a small orifice tube refrigerator and to provide a highly reliable product, the orifice 7 must be precision processed.

The present invention has been made in view of the above points, and eliminates the above problems, easily and accurately controls the flow rate of the working fluid, and efficiently radiates the heat generated by the working fluid, thereby providing a refrigerating capacity. It is an object of the present invention to provide a pulse tube refrigerator that can improve the reliability and the reliability.

[0011]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a compressor, a regenerator, a heat exchanger,
A pulse tube refrigerator comprising a pulse tube, a buffer tank, and a pipe and / or a connecting portion connecting the pulse tube and a refrigerating machine that generates refrigeration by the action of a working fluid. The thin tube is used as the pipe connecting the pulse tube and the buffer tank. Is configured to be cooled by a refrigerant.

The invention described in claim 2 is the first invention.
In the pulse tube refrigerator according to claim 1, characterized in that an outer pipe having a diameter larger than the thin pipe is installed around the thin pipe, and a radiator is configured by flowing a medium between the thin pipe and the outer pipe. To do.

[0013] The invention described in claim 3 is the first invention.
In the pulse tube refrigerator described in (1), the thin tube is thermally contacted with a pipe through which a medium is passed to cool the thin tube.

The invention described in claim 4 is the first invention.
In the pulse tube refrigerator described in (1), the thin tube is provided with a heat radiation fin, or an object having the heat radiation fin is brought into thermal contact with the thin tube to cool the thin tube.

By adopting the above configuration in the pulse tube refrigerator, it is possible to easily control the flow rate of the working fluid between the pulse tube and the buffer tank with high accuracy by selecting the inner diameter and the length of the thin tube. Become. In addition, the thin tube has a larger area for heating heat with the outside in proportion to the flow path area, which is effective as a heat exchanger.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is an example, and the present invention is not limited to this embodiment.

FIG. 1 is a diagram showing the structure of an orifice type pulse tube refrigerator of the present invention. This pulse tube refrigerator comprises a compressor 1, an aftercooler 2, a regenerator 3, a low temperature heat exchanger 4, a pulse tube 5, a rectifier 14 and a buffer tank 8. The rectifier 14 and the buffer tank 8 are connected by a narrow tube 9. Further, an outer pipe 11 having a diameter larger than that of the thin tube 9 is installed around the thin tube 9.

The compressor 1 applies pressure oscillation to the working fluid (not shown) in the pulse tube refrigerator, and the aftercooler 2 connected to the compressor 1 is operated by being compressed by the compressor 1 and heated. It is a heat exchanger for keeping the temperature of the working fluid constant by radiating the fluid with cooling water or the like (not shown).

The regenerator 3 is filled with a metal material having a large heat capacity, and exchanges heat with the working gas cooled by the refrigeration generated in the low temperature heat exchanger 4 to keep refrigeration inside the machine. The pulse tube 5 is a simple cylinder, and the working fluid inside repeats compression and expansion. The rectifier 14 is for rectifying the flow of the working fluid in the pulse tube 5 so as not to be disturbed.

The pressure of the working fluid in the buffer tank 8 is kept substantially constant, and the buffer tank 8 and the rectifier 14 in the pulse tube 5 are connected (connected) by the thin tube 9 as described above. The working fluid flows in the narrow tube 9 due to the pressure difference between the two. The flow rate of the working fluid is determined by the inner diameter and the length of the thin tube 9. Since the working fluid in the vicinity of the thin tube 9 is accompanied by heat generation, the outer pipe 11 is installed around the thin pipe 9 to form a radiator as described above, and the medium is introduced from the medium inlet 12 between the thin pipe 9 and the outer pipe 11. It is made to flow and discharged from the medium outlet 13, and the temperature of the working fluid flowing in the narrow tube 9 is kept constant.

By flowing the medium between the thin tube 9 and the outer pipe 11 as described above, the heat radiation efficiency of the working fluid flowing in the thin tube 9 can be improved. Further, the flow rate of the working fluid between the rectifier 14 in the pulse tube 5 and the buffer tank 8 can be accurately controlled by selecting the inner diameter and the length of the thin tube 9. Therefore, it is possible to improve the refrigerating capacity and reliability.

FIG. 2 is a diagram showing another structure of the orifice type pulse tube refrigerator of the present invention. This pulse tube refrigerator is substantially the same as the pulse tube refrigerator shown in FIG. 1, but the radiator can be miniaturized by bundling the thin tubes 9 when the thin tubes 9 become long.

FIG. 3 is a view showing another structure of the orifice type pulse tube refrigerator of the present invention. This pulse tube refrigerator is substantially the same as the pulse tube refrigerator shown in FIG. 1, except that a heat radiation fin is brought into thermal contact with the thin tube 9 to radiate heat from the working fluid by natural convection of air as a medium. Is promoting. In this example, the radiating fins are thermally connected to the thin tubes 9, but the thin tubes 9 may be thermally contacted with an object having the radiating fins.

FIG. 4 is a diagram showing another structure of the orifice type pulse tube refrigerator of the present invention. This pulse tube refrigerator is substantially the same as the pulse tube refrigerator shown in FIG. 1, except that the thin tube 9 is brought into contact with the medium pipe 16 and the medium is flown from the medium inlet 12 of the medium pipe 16 to the medium outlet 13. With this, the heat from the working fluid is positively radiated.

[0025]

As described above, according to the present invention, a thin pipe is used as the pipe connecting the pulse pipe and the buffer tank,
This thin tube is used to radiate heat from the working fluid, so that the flow rate of the working fluid can be controlled accurately and the heat generated from the working fluid is actively radiated to improve the refrigerating capacity and reliability of the pulse tube refrigerator. That is an excellent effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an orifice type pulse tube refrigerator of the present invention.

FIG. 2 is a diagram showing a configuration of an orifice type pulse tube refrigerator of the present invention.

FIG. 3 is a diagram showing a configuration of an orifice type pulse tube refrigerator of the present invention.

FIG. 4 is a diagram showing a configuration of an orifice type pulse tube refrigerator of the present invention.

FIG. 5 is a diagram showing a configuration of a conventional orifice type pulse tube refrigerator.

FIG. 6 is a diagram showing a configuration of a conventional orifice type pulse tube refrigerator.

FIG. 7 is a diagram showing a configuration of a conventional orifice type pulse tube refrigerator.

[Explanation of symbols]

 1 compressor 2 aftercooler 3 regenerator 4 low temperature heat exchanger 5 pulse tube 6 high temperature heat exchanger 7 orifice 8 buffer tank 9 narrow tube 10 needle valve 11 outer pipe 12 medium inlet 13 medium outlet 14 rectifier 15 radiating fin 16 medium pipe

Claims (4)

[Claims] 1. A compressor, a regenerator, a heat exchanger, a pulse tube,
A pulse tube refrigerator comprising a buffer tank and a pipe and / or a connecting portion connecting the buffer tank to generate refrigeration by the action of a working fluid, wherein a thin pipe is used as a pipe connecting the pulse pipe and the buffer tank, and the thin pipe is A pulse tube refrigerator, which is configured to be cooled by a refrigerant. 2. The pulse tube refrigerator according to claim 1, wherein an outer pipe having a diameter larger than the thin pipe is installed around the thin pipe, and a medium is flowed between the thin pipe and the outer pipe. A pulse tube refrigerator comprising a radiator. 3. The pulse tube refrigerator according to claim 1, wherein the thin tube is cooled by thermally contacting the thin tube with a pipe through which a medium passes. 4. The pulse tube refrigerator according to claim 1, wherein the thin tube is provided with a radiation fin, or an object having a radiation fin is thermally brought into contact with the thin tube to cool the thin tube. A pulse tube refrigerator characterized in that