JP2844435B2 - Pulse tube refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerator and a pulse tube which are connected to each other, and a gas from a compressor is taken in and out to generate cold heat in a heat absorbing portion formed at a connection portion between the regenerator and the pulse tube. The present invention relates to a pulse tube refrigerator.

[0002]

2. Description of the Related Art Conventionally, a pulse tube refrigerator has a low temperature end (51) of a pulse tube (50) and a low temperature end (5) of a regenerator (52) as shown in FIG.
3) through a heat absorbing connecting pipe (54) serving as a cold head, and a regenerator (5) from a compressor (55) through a gas passage (56).
The gas supplied to the high-temperature end (57) of 2) is directed from the low-temperature end (51) of the pulse tube (50) to the high-temperature end (58) through the regenerator (52) and the endothermic connecting pipe (54). And a phase shifter composed of a needle valve (59) and a buffer tank (60) is arranged at the high temperature end (58) of the pulse tube (50).

[0003]

However, in a conventional pulse tube refrigerator, a buffer tank is connected to a high-temperature end of the pulse tube via a needle valve to form a phase shifter. Due to the communication with the buffer tank, turbulence occurs in the pulse tube when gas flows from the buffer tank into the pulse tube, and gas movement in the pulse tube and adiabatic expansion in the system become unstable, resulting in low temperature generation efficiency Has not been able to be sufficiently increased. The present invention has been made in view of such a point, and it is an object of the present invention to provide a pulse tube refrigerator having a small size, light weight, and high cooling efficiency.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a flexible partition disposed at a high temperature end of a pulse tube so as to cut off communication between the inside of the pulse tube and a buffer tank. It is characterized by doing.

[0005]

According to the present invention, a flexible partition is disposed at the high-temperature end of the pulse tube to cut off communication between the inside of the pulse tube and the buffer tank. The gas will not flow, but the pressure will be transmitted. Therefore, the gas flow in the pulse tube is not disturbed, and the gas movement and the adiabatic expansion in the system can be performed stably, so that the low-temperature generation efficiency can be increased.

[0006]

1 and 2 show an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a pulse tube refrigerator, and FIG. 2 is a longitudinal sectional view of a cold generation part. This pulse tube refrigerator has a cold generating part (4) configured by connecting one end of a pulse tube (1) and a regenerator (2) to each other via a heat absorbing connection path (3).
It comprises a compressor unit (5) and a rotary valve unit (6) for switching and controlling the supply and discharge of high-pressure gas generated by the compressor unit (5) to the cold generation unit (4).

[0007] The compressor unit (5) includes a compressor (7) and a cooler.
(8), an oil separator (9), an oil adsorber (10) and a pressure holding valve (11), and the rotary valve unit (6) is provided with a rotary valve (1).
2) and a valve drive motor (13). The high-pressure gas passage (14) derived from the adsorber (10) is connected to the primary high-pressure port of the rotary valve (12) by a flexible hose, and the flexible high-pressure gas derived from the primary low-pressure port of the rotary valve (12) is connected. A hose is connected to the compressor (7) via a low pressure gas return line (15).

[0008] The cold generating part (4) is composed of two stainless steel pipes
(18) and (19) are arranged in parallel, the lower end is fitted to the copper end cap (20), and the upper end is attached to the mounting flange (2
1) and is formed by fitting one stainless steel pipe (1
8) A stainless steel mesh body (22) is layered and arranged inside, and rectifier plates (23) are arranged at both upper and lower ends to constitute a regenerator (2), and the lower end of the other stainless steel pipe (19) A rectifying plate (24) is arranged in the portion to constitute a pulse tube (1). The spacer (2) is attached to the copper end cap (20).
6) By forming the heat absorbing communication path (3) by mounting
The regenerator (2) communicates with the pulse tube (1).

The upper end of the regenerator (2) communicates with a gas introduction plug (27) mounted on the mounting flange (21), and a refrigerant gas introduction pipe (28) extended from the gas introduction plug (27). Is connected to a secondary port of the rotary valve (12) through a flexible hose (29). The high-pressure refrigerant gas generated in the compressor unit (5) by switching the rotary valve (12) is stored in the regenerator (2).
To be supplied.

A flexible partition wall (30) is mounted inside the upper end of the pulse tube (1), and the upper end of the pulse tube (1) is connected to a gas conducting plug (31) mounted on a mounting flange (21). ) Is connected to a gas reservoir (buffer tank) (33) via a flow control device (34), and a flexible partition (30) of the pulse tube (1) is connected.
The space above is communicated with the gas reservoir (33).

The flexible partition wall (30) includes a disk-shaped plate (35) movable along the axis of the pulse tube (1), and an outer peripheral edge of the disk-shaped plate (35) and the pulse tube (1). ) And a flexible membrane (36) connecting the upper end of the pulse tube (1) to the space connected to the regenerator (2) of the pulse tube (1) and to the gas reservoir (33). The disc-shaped plate member (35) moves up and down by the pressure balance in the space where it is located.

[0012] Further, a flow rate adjuster disposed between the upper space of the flexible partition wall (30) of the pulse tube (1) and the gas reservoir (33).
(34) is constituted by a sheet in which a large number of fine through holes are formed, such as ceramics, sintered metal, or a filter film.

In the pulse tube refrigerator configured as described above,
The gas in the pulse tube is compressed by the high-pressure refrigerant gas flowing into the pulse tube (1) through the regenerator (2), and the pressure in the pulse tube increases. As the pressure in the pulse tube increases, the flexible partition wall (30) moves upward, and the pressure in the gas reservoir (33) also increases. Then, when the regenerator (2) communicates with the low pressure side of the compressor (7) by switching the rotary valve (12), the pressure in the regenerator (1) decreases, and the regenerative energy is stored in the pulse tube (1). The gas moves to the vessel (2), and a low temperature lower than the liquid nitrogen temperature (77K) is generated in the copper end cap (20) due to the adiabatic expansion during this movement.

At this time, the inside of the gas reservoir (33) is a compressor.
In the compression stop state of (7), the intermediate pressure {(P _H +
P _L ) / 2}, and when the gas inflows from the regenerator (2), the pressure in the pulse tube (1) becomes higher than the pressure filled in the gas reservoir (33). (30) starts ascending movement, and the flexible partition (30) rises until the pulse tube (1) switches the rotary valve (12) and the pressure in the pulse tube reaches the pressure of the gas reservoir (33). Then, since the pressure drop starts, the pressure change in the pulse tube (1) is delayed by a certain time (phase) with respect to the gas pressure change accompanying the switching of the rotary valve (12) ).

Further, the inside of the pulse tube (1) and the gas reservoir (33)
Because between the inside is partitioned by the flexible partition (30),
There is no gas flow disturbance in the pulse tube (1) due to gas flowing into the pulse tube (1) from the gas reservoir (33) side.
Gas transfer and adiabatic expansion are performed stably.

Further, the pulse tube (1) and the gas reservoir (33)
Is formed of a sheet having a large number of fine through-holes, so that a stable whole-section traveling wave can be generated.

In the above embodiment, the flow control device (34) is constituted by a sheet having a large number of fine through holes. However, the flow control device (34) may be an orifice. The orifice may be formed by a communication hole formed in a flange arranged so as to close the upper end of 1).

Further, in the above embodiment, the flexible partition wall (30) is composed of the disk-shaped plate body and the flexible film body movable along the axis of the pulse tube (1). Or a paper cone of a voice coil or a diaphragm having a large deformation amount.

Further, a thermal compressor that generates a pressure wave due to a temperature difference may be used as the compressor. In this case, a switching valve for switching and controlling the supply and discharge of the high-pressure gas to and from the cold generating section can be omitted.

[0020]

According to the present invention, the flexible partition is disposed at the high-temperature end of the pulse tube so as to cut off the communication between the inside of the pulse tube and the buffer tank. Gas flow from the side
Since the turbulence of the gas is eliminated, the gas movement and the adiabatic expansion can be stabilized, and the low-temperature generation efficiency of the pulse tube refrigerator can be increased.

Further, since the gas transfer and the adiabatic expansion in the system can be performed stably, a stable low temperature can be generated even if the length of the pulse tube is set short. It is possible to obtain a high-performance refrigerator having a small thickness such as a plate.

[Brief description of the drawings]

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

FIG. 2 is a vertical cross-sectional view of a cold generation part in an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional pulse tube refrigerator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pulse tube, 2 ... Regenerator, 3 ... Heat-absorbing connection path, 7 ... Compressor, 28 ... Refrigerant gas path, 30 ... Flexible partition wall, 33 ... Buffer tank, 34 ... Flow rate adjusting tool, 35 ... Plate material, 36 ... Flexible membrane.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 9/00 311

Claims (6)

(57) [Claims] 1. A low-temperature end of a pulse tube (1) and a low-temperature end of a regenerator (2) are communicated via a heat-absorbing connection path (3), and a compressor (7) is provided.
The refrigerant gas supplied to the high-temperature end of the regenerator (2) through the refrigerant gas passage (28) from the low-temperature end of the pulse tube (1) through the regenerator (2) and the heat absorbing connection path (3) In the pulse tube refrigerator configured to be introduced toward the high temperature end, a buffer tank (33) is connected to the high temperature end of the pulse tube (1) via a flow rate adjusting device (34), and the inside of the pulse tube (1) is A pulse tube refrigerator characterized in that a flexible partition wall (30) is arranged at the high temperature end of the above-mentioned, and the inside of the pulse tube (1) and the buffer tank (33) are not communicated. 2. A plate member (35) movable along an axis in the pulse tube (1), and a flexible member for connecting an outer peripheral edge of the plate member (35) to a high-temperature side end of the pulse tube (1). Flexible membrane (36) and flexible partition (3
The pulse tube refrigerator according to claim 1, wherein the pulse tube refrigerator (0) is configured. 3. The pulse tube refrigerator according to claim 1, wherein the flexible partition (30) is a welding bellow. 4. The pulse tube refrigerator according to claim 1, wherein the flexible partition (30) is a paper cone. 5. The pulse tube refrigerator according to claim 1, wherein the flow rate adjuster (34) is formed of a sheet made of a microporous material. 6. The pulse tube refrigerator according to claim 1, wherein the flow rate adjuster is constituted by an orifice.