JPH10115472A - Pulse tube refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse tube refrigerator having a high reliability, in which thermal conduction loss is so lowered as to prevent a fall of refrigerating capacity and which can be assembled with improved efficiency. SOLUTION: A pulse tube refrigerator comprises a compressor 1, cold reservoir 3, heat exchanger (low temperature heat exchanger 4, high temperature heat exchanger 6), pulse tube 5, and piping and/or connection part for their connection and a working fluid flowing through the inside produces a refrigerating effect. The pulse tube 5 and the cold reservoir 3 are arranged in the form of a coaxial double cylinder with the pulse tube 5 on the inner side and the cold reservoir 3 on the outer side. A film type cold storage material 12 is wound around the pulse tube 5 and held inside the cold reservoir 3.

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 a pulse tube refrigerator capable of improving a refrigerating capacity and a manufacturing method.

[0002]

2. Description of the Related Art FIG. 6 is a diagram showing a configuration example of a conventional pulse tube refrigerator. As shown in the figure, the pulse tube refrigerator includes 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, a flow control valve 7, and a reservoir 8, These are connected by piping and / or a connection part.

[0003] The compressor 1 generates pressure oscillation of a working gas (not shown) in a pulse tube refrigerator.

The regenerator 3 has a regenerator 16 made of a material having a large heat capacity. The regenerator 16 is formed by laminating thin strands in a dense net-like shape and punching them into a shape that matches the cross section of the regenerator 3 to be stored in the regenerator 3. The pulse tube 5 has a simple cylindrical structure, and the reservoir 8 is a container having a larger volume than other components.

[0005] First, the working fluid compressed by the compressor 1 is cooled by the aftercooler 2 to raise the temperature, 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 removed. Increase the working fluid pressure.

The high-temperature heat exchanger 6 and the reservoir 8 communicate with each other through a flow control valve 7, and the flow rate of the working fluid is restricted by the flow control valve 7, so that the pressure fluctuation in the reservoir 8 is extremely suppressed. I have. Due to the pressure vibration generated by the compressor 1, the working fluid reciprocates in the machine, the working fluid in the pulse tube 5 repeats compression and expansion close to adiabatic change, and also includes an aftercooler 2, a regenerator 3 The working fluid in the low-temperature heat exchanger 4 and the high-temperature heat exchanger 6 repeats compression and expansion close to isothermal changes.

The movement of the working fluid causes refrigeration 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, the cooling water (or other refrigerant) 13
It is necessary to radiate heat. The pulse tube refrigerator continuously performs this to generate a low temperature.

FIG. 9 is a diagram showing an example of a temperature distribution during a steady operation in the conventional pulse tube refrigerator shown in FIG. Aftercooler 2 and high-temperature heat exchanger 6 are provided with cooling water 13.
(See FIG. 6), the temperature is kept constant at 300 K (27 ° C.) and the heat generated inside is released. The low-temperature heat exchanger 4 cools an object to be cooled (not shown) at a low temperature generated inside. This figure shows that the low-temperature heat exchanger 4 removes heat from the object to be cooled and is kept at 100 K (−173 ° C.).

The working fluid in the pulse tube 5 undergoes compression and expansion changes close to adiabatic changes, and the temperature also fluctuates with time. FIG. 9 shows the time average temperature in the pulse tube 5. On the other hand, since the regenerator 3 is filled with the regenerative material 16 having a large heat capacity, the working fluid exchanges heat with the regenerative material 16 and the time variation of the temperature is extremely small.

FIG. 7 is a diagram showing a configuration example of another pulse tube refrigerator. This pulse tube refrigerator is described in FIG.
In the regenerator 3 described above, the regenerator 16 is filled with a wire mesh, whereas the regenerator 12 in a film form is wound around a core rod 17 and stored in the regenerator 3.

FIG. 8 is a diagram showing a configuration example of a pulse tube refrigerator generally called a double cylinder system. This pulse tube refrigerator has the same components as those in FIG. 6 described above, but differs in that the pulse tube 5 is arranged outside the regenerator 3. Reference numeral 10 is a cooling plate, 9 is a cooling water chamber, and 14 and 15 are a cooling water inlet and a cooling water outlet, respectively. This pulse tube refrigerator has a lower overall height than the pulse tube refrigerator shown in FIG. 6, and can be downsized.

[0012]

In the conventional pulse tube refrigerator shown in FIGS. 6 and 8, the regenerator material 16 of the regenerator 3 is made of a finely woven mesh of fine strands, one by one, using tweezers. A method of filling by stacking thousands of sheets is generally performed.

However, in this method, much work time is spent for charging the regenerator material. Further, since the cold storage material 16 has a net shape, the cold storage material filling density is as low as about 30% to about 35%.
Since the specific heat of the heat storage material 6 itself becomes small, a heat capacity shortage is caused in a portion of the cold storage material 16 where the temperature is low (near the low temperature heat exchanger 4), which causes a decrease in performance.

In the conventional pulse tube refrigerator shown in FIG. 8, the diameter of the pulse tube 5 is inevitably increased because the pulse tube 5 is provided on the outer periphery of the regenerator 3. As a result, the cross-sectional area of the thick wall portion of the tube wall surrounding the outer periphery of the pulse tube 5 increases, and the heat conduction loss from the low-temperature heat exchanger 4 to the high-temperature heat exchanger 6 along the tube wall increases. , Causing a decrease in refrigeration capacity. At the same time, the outer peripheral area of the pulse tube 5 increases, and the amount of heat transfer due to the exchange of heat between the working gas in the pulse tube 5 and the pulse tube wall itself increases, resulting in a corresponding heat loss. Invites a decline in ability.

On the other hand, in the conventional pulse tube refrigerator shown in FIG.
7, the core rod 17 receives heat from the aftercooler 2 to the low-temperature heat exchanger 4 by heat conduction, and the refrigeration capacity of the low-temperature heat exchanger 4 generating the refrigeration effect is reduced. Lower it.

As described above, in the case of the conventional pulse tube refrigerator, the heat input to the low-temperature heat exchanger 4 having a very low temperature due to heat transfer is large, and each component constituting the pulse tube refrigerator has Insufficient heat insulation and heat transfer with the working fluid has caused a decrease in refrigeration capacity.
Further, the generation of a very large temperature gradient in the regenerator 3 also causes heat input to the low-temperature heat exchanger 4. In order to minimize the heat transfer loss while maintaining the configuration of the above-described conventional pulse tube refrigerator, a component made of a special material is used separately, or the structure is considered by using a heat insulating member. This requires not only an increase in cost but also a lot of time for assembling the regenerator 3.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in consideration of the above problems, and has been made in view of the above-mentioned problems. It is an object to provide a high pulse tube refrigerator.

[0018]

According to a first aspect of the present invention, there is provided a compressor, a regenerator, a heat exchanger, a pulse tube, and a pipe and / or a connecting portion connecting them. In a pulse tube refrigerator that generates refrigeration by the action of a working fluid flowing through the inside thereof, the pulse tube and the regenerator are arranged in a coaxial double cylindrical shape such that the pulse tube is inside and the regenerator is outside. In addition, a film-shaped cold storage material wound around the outer periphery of the pulse tube was housed in the regenerator.

According to a second aspect of the present invention, in the pulse tube refrigerator according to the first aspect, as shown in FIG. 3, the film-shaped regenerator is provided with a protrusion on one surface of the film.

According to a third aspect of the present invention, in the pulse tube refrigerator according to the first aspect, as shown in FIG. 4, the film-shaped regenerator is provided with a protrusion on one side of the film and the film is provided with a projection. It was configured with a hole through which it passed.

According to a fourth aspect of the present invention, in the pulse tube refrigerator of the first aspect, the film-shaped regenerator is formed in a net shape as shown in FIG.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that this embodiment is an example, and the present invention is not limited to this embodiment. FIG. 1 is a diagram showing a configuration example of a pulse tube refrigerator of the present invention. The pulse tube refrigerator includes 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, a flow control valve 7, a reservoir 8, a cooling water chamber 9, a cooling plate. The regenerator 3 is arranged on the coaxial outer periphery of the pulse tube 4.

Here, the compressor 1 applies pressure vibration to a working fluid (not shown) in the pulse tube refrigerator, and an aftercooler 2 connected to the compressor 1 is compressed by the compressor 1 and rises. This is a heat exchanger for radiating the heated working fluid with the cooling water 13 in the cooling water chamber 9 and keeping the temperature of the working fluid constant.

Next, the pulse tube 5 has a simple cylindrical structure, and the working fluid inside is repeatedly compressed and expanded. The pressure of the working fluid in the reservoir 8 is kept substantially constant, and the reservoir 8 and the high-temperature heat exchanger 6 in the pulse tube 5 communicate with each other via a flow control valve 7.

On the other hand, the regenerator 3 contains a film-like regenerator material 12 wound around the pulse tube 5 as shown in FIG. 2, and contains a working fluid cooled by refrigeration generated in the low-temperature heat exchanger 4. It exchanges heat and keeps the refrigeration inside the machine.

As shown in FIG. 3, the film-like cold storage material 12 has a large number of rod-like projections 12 on one side of a film 121 made of cold storage material.
3 or a plurality of rod-like projections 123 protruding on one side of a film 121 made of a cold storage material and provided with a number of holes 125 passing through the film 121 as shown in FIG. Or by knitting a linear cold storage material into a net as shown in FIG.

As described above, the film-like cold storage material 12 is supplied to the pulse tube 5
7 is housed in the regenerator 3 by being wound around the outer periphery of the pulse tube 4, so that a special member such as the core rod 17 shown in FIG. 7 is not required. For this reason, the heat conduction loss from the aftercooler 2 to the low-temperature heat exchanger 4 can be reduced. The film-like cold storage material 12 also has an advantage that the assembling work is simpler and the working time can be shortened as compared with a stacked cold storage material storage system such as the cold storage material 16 shown in FIGS.

Further, the pulse tube 5 is arranged in a coaxial double cylindrical shape so that the pulse tube 5 is inside and the regenerator 3 is outside, so that the pulse tube 5
Is arranged outside the regenerator 3 (see FIG. 8), the wall area of the pulse tube 4 can be reduced. Therefore, the amount of heat transfer between the working fluid in the pulse tube 5 and the pulse tube wall is reduced, and the adiabatic compression and compression of the working fluid, which is closer to ideal,
A larger refrigeration capacity is obtained by the expansion change.

The film-like cold storage material 12 shown in FIGS.
In the case of this, when this is wound, the adjacent protrusions 12
The concave portion between 3,123 serves as a working fluid passage. And in the case of these film-like cold storage materials 12, since all parts except the passage part are filled with the cold storage material 12,
The regenerator material filling density becomes 50% or more, and shortage of heat capacity hardly occurs even in a low temperature part near the low temperature heat exchanger 4 in the film regenerator material 12.

The reason why the holes 125 are provided in the film-like cold storage material 12 shown in FIG. 4 is that many working fluid passages formed by winding the film-like cold storage material 12 communicate with each other. This is for equalizing the flow rate of the working fluid in.

[0031]

As described above in detail, according to the present invention, the pulse tube is arranged in a coaxial double cylindrical shape so that the regenerator is on the inside and the regenerator is on the outside. Is stored in the regenerator so that the refrigerating capacity can be improved and the assembling efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a pulse tube refrigerator of the present invention.

FIG. 2 is a diagram showing a structure for attaching a film-like cold storage material 12 to a pulse tube 5;

FIG. 3 is a view showing an example of a film-like cold storage material 12;

FIG. 4 is a diagram showing an example of a film-like cold storage material 12-2.

FIG. 5 is a diagram showing an example of a film-like cold storage material 12-3.

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

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

FIG. 8 is a diagram showing a configuration of a conventional pulse tube refrigerator.

FIG. 9 is a diagram showing a temperature distribution of each part of a general pulse tube refrigerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Aftercooler 3 Regenerator 4 Low-temperature heat exchanger 5 Pulse tube 6 High-temperature heat exchanger 7 Flow control valve 8 Reservoir 9 Cooling water chamber 10 Cooling plate 11 Piston 12 Film cold storage material 123 Projection 125 Hole 13 Cooling water 14 Cooling water inlet 15 Cooling water outlet

Claims (4)

[Claims] 1. A pulse tube refrigerator comprising a compressor, a regenerator, a heat exchanger, a pulse tube and a pipe and / or a connecting portion connecting them, and generating refrigeration by the action of a working fluid flowing inside the pulse tube refrigerator. The pulse tube and the regenerator are arranged in a coaxial double cylindrical shape such that the pulse tube is on the inside and the regenerator is on the outside, and the regenerator contains a film-like regenerator wound around the outer periphery of the pulse tube. A pulse tube refrigerator characterized by: 2. The pulse tube refrigerator according to claim 1, wherein the film-shaped regenerator has a protrusion on one surface of the film. 3. The pulse tube refrigerator according to claim 1, wherein the film-shaped regenerator has a protrusion on one surface of the film and a hole passing through the film. Tube refrigerator. 4. The pulse tube refrigerator according to claim 1, wherein the film-shaped regenerator is formed in a net shape.