Pulse tube refrigerator and space infrared detection device

Abstract

The invention provides a pulse tube refrigerator. The pulse tube refrigerator comprises a compressor, a cold head and a flexible connecting tube. And the flexible connecting pipe is connected between the compressor and the cold head. The compressor converts electric energy into acoustic power of gas, the flexible connecting pipe conveys the acoustic power of the gas output by the compressor to the cold head, and the cold head generates cooling capacity through the acoustic power of the gas in the power-heat conversion process. According to the pulse tube refrigerator, the compressor and the cold head are connected through the flexible connecting tube, compared with a hard connecting tube, the flexible connecting tube can better isolate vibration of the compressor, the vibration of the compressor can be effectively prevented from being transmitted to the cold head through the flexible connecting tube, after the cold head is connected with an infrared camera, vibration of an infrared chip of the infrared camera can be reduced, and the service life of the infrared camera is prolonged. And the imaging effect is improved. Moreover, the flexible connecting pipe is deformable, so that the cold head can move relative to the compressor, and therefore, when the infrared camera is focused, the cold head can move along with the infrared focal plane.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and particularly relates to a pulse tube refrigerator and a space infrared detection device. Background Art

[0002] In the field of space small cryogenic refrigerators, compared with traditional Stirling refrigerators, the cold head of a pulse tube refrigerator has no moving parts, so it has advantages such as simple structure, high reliability, and long service life, and is a new generation of small cryogenic refrigerators for space use. Pulse tube refrigerators are currently mainly applied in the field of space infrared detection. Infrared chips need to be cooled to a relatively low temperature to obtain better imaging effects. Moreover, during the imaging process, to avoid image blurring, it is necessary to avoid the jitter of the infrared chip.

[0003] In the prior art, the cold head of the refrigerator is connected to the infrared chip, and the jitter of the cold head will directly affect the imaging quality of the infrared camera. Since there are moving parts inside the compressor, which is one of the sources of micro-vibration, and there are no moving parts inside the cold head, therefore, in order to meet the extremely high requirements of space infrared detectors for micro-vibration, pulse tube refrigerators generally adopt a split structure design, that is, the compressor and the cold head are connected by a rigid metal connecting pipe, which can isolate the compressor vibration from being transmitted to the cold head to a certain extent.

[0004] However, currently, some high-precision infrared cameras have put forward higher requirements for the micro-vibration of the cold head of the refrigerator. The vibration isolation ability of conventional metal connecting pipes can no longer meet the usage requirements. In addition, some infrared cameras have also put forward high-frequency focusing requirements. During focusing, the infrared camera needs to move continuously, while the compressor is fixed, and the cold head connected by the metal connecting pipe cannot move either, which obviously cannot meet the focusing requirements of the infrared camera. Summary of the Invention

[0005] The present invention provides a pulse tube refrigerator and a space infrared detection device to solve the defect in the prior art that the compressor and the cold head are connected by a rigid metal connecting pipe, and the metal connecting pipe cannot isolate vibration and causes the cold head to be unable to move relative to the compressor, and to achieve the effect of using a flexible connecting pipe to connect the compressor and the cold head, which can effectively isolate vibration and the cold head can move relative to the compressor.

[0006] The present invention provides a pulse tube refrigerator, which includes a compressor, a cold head, and a flexible connecting pipe, and the flexible connecting pipe is connected between the compressor and the cold head.

[0007] According to the pulse tube refrigerator provided by the present invention, the flexible connecting pipe is a metal braided pipe.

[0008] According to the pulse tube refrigerator provided by the present invention, the metal braided pipe is in a space spiral shape.

[0009] According to the pulse tube refrigerator provided by the present invention, the cold head includes a phase modulation mechanism and a cold finger. The cold finger is connected to the compressor through the flexible connecting pipe, and the phase modulation mechanism is connected to the cold finger.

[0010] According to the pulse tube refrigerator provided by the present invention, the phase modulation mechanism includes an inertia tube and an air reservoir. The air reservoir is connected to the flexible connecting pipe, and the inertia tube is connected between the air reservoir and the cold finger.

[0011] According to the pulse tube refrigerator provided by the present invention, the inertia tube is a slender metal tube with different diameter combinations.

[0012] According to the pulse tube refrigerator provided by the present invention, the compressor is a moving coil linear compressor.

[0013] According to the pulse tube refrigerator provided by the present invention, both ends of the flexible connecting pipe are welded to the compressor and the cold head respectively.

[0014] According to the pulse tube refrigerator provided by the present invention, both ends of the flexible connecting pipe are detachably connected to the compressor and the cold head respectively.

[0015] The present invention also provides a space infrared detection device, including the pulse tube refrigerator as described above.

[0016] The pulse tube refrigerator provided by the present invention includes a compressor, a cold head and a flexible connecting pipe. The flexible connecting pipe is connected between the compressor and the cold head. The compressor converts electrical energy into the acoustic work of the gas, and the flexible connecting pipe transports the gas acoustic work output by the compressor to the cold head. The cold head generates cold by using the gas acoustic work through a work-heat conversion process. The pulse tube refrigerator provided by the present invention uses a flexible connecting pipe to connect the compressor and the cold head. Compared with a rigid metal connecting pipe, the flexible connecting pipe can better isolate the vibration of the compressor, effectively block the vibration transmission of the compressor to the cold head. When the cold head is connected to an infrared camera, the vibration of the infrared chip of the infrared camera can be reduced, thereby improving the imaging effect. Moreover, the flexible connecting pipe can be deformed, enabling the cold head to move relative to the compressor. Thus, when the infrared camera focuses, the cold head can move with the infrared focal plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic structural diagram of the pulse tube refrigerator provided by the present invention.

[0019] Reference Signs:

[0020] 100, compressor; 200, flexible connecting pipe; 300, cold head; 310, cold finger; 320, inertia tube; 330, gas reservoir. Detailed Implementation Manner

[0021] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0022] In the field of space small cryocoolers, compared with traditional Stirling cryocoolers, pulse tube cryocoolers have no moving parts in their cold heads, so they have advantages such as simple structure, high reliability and long life, and are a new generation of small cryocoolers for space use.

[0023] Pulse tube cryocoolers are currently mainly applied in the field of space infrared detection. To obtain a better imaging effect, the infrared chip needs to be cooled to a lower temperature. At the same time, during the imaging process, it is also necessary to avoid image blurring caused by chip jitter.

[0024] A pulse tube cryocooler includes a compressor and a cold head. There are moving parts inside the compressor, which is one of the sources of micro-vibrations. Although there are no moving parts inside the cold head, the cold head is connected to the infrared chip, and the vibrations of the compressor will still be transmitted to the infrared chip, thereby affecting the imaging quality of the infrared camera.

[0025] In order to meet the extremely high requirements for micro-vibrations of space infrared detectors, in related technologies, pulse tube cryocoolers usually adopt a split structure design, connecting the compressor and the cold head through a rigid metal connecting pipe. In this way, the vibration transmission of the compressor to the cold head can be isolated to a certain extent.

[0026] However, at present, some high-precision infrared cameras have put forward higher requirements for the micro-vibrations of cryocoolers. The vibration isolation ability of conventional rigid metal connecting pipes can no longer meet the use requirements. In addition, some infrared cameras have also put forward high-frequency focusing requirements. However, the compressor is fixed, and the cold head is fixed to the compressor through a rigid metal connecting pipe and cannot move relative to the compressor. When the infrared camera focuses, the cold head needs to move with the infrared focal plane. Obviously, the existing pulse tube cryocoolers cannot meet the above use requirements.

[0027] To this end, the present invention provides a pulse tube refrigerator, which connects a compressor and a cold head by a flexible connecting pipe. The flexible connecting pipe can undergo flexible deformation, which can meet the requirement of the relative movement between the cold head and the compressor. Moreover, compared with a rigid metal connecting pipe, the flexible connecting pipe can further reduce the transmission of vibration.

[0028] The following will describe Figure 1 the pulse tube refrigerator and the space infrared detection device of the present invention.

[0029] An embodiment of the present invention provides a pulse tube refrigerator, which includes a compressor 100, a cold head 300, and a flexible connecting pipe 200.

[0030] The compressor 100 can be a moving coil linear compressor, which can convert electrical energy into acoustic work of gas. The flexible connecting pipe 200 is connected between the compressor 100 and the cold head 300, and is used to transport the acoustic work of the gas output by the compressor 100 to the cold head 300. The cold head 300 can generate cooling capacity by using the acoustic work of the gas through a work-heat conversion process, and then cool the infrared chip of the infrared camera to ensure the imaging effect.

[0031] The pulse tube refrigerator provided by the present invention uses the flexible connecting pipe 200 to connect the compressor 100 and the cold head 300. Compared with a rigid connecting pipe, the flexible connecting pipe 200 can better isolate the transmission of the vibration of the compressor 100 to the cold head 300. In this way, the vibration of the infrared chip can be reduced to meet the high imaging requirements of the infrared camera. At the same time, the flexible connecting pipe 200 can be deformed. In this way, when the infrared camera is focused, the cold head 300 can move with the infrared focal plane.

[0032] In some embodiments of the present invention, the flexible connecting pipe 200 can be a metal braided pipe. The metal braided pipe has appropriate stiffness, which can not only maintain its own shape, but also deform when subjected to external force. When the external force is removed, the metal braided pipe can maintain its current shape.

[0033] If a flexible connecting pipe 200 with a smaller stiffness is used, after the cold head 300 moves relative to the compressor 100, the flexible connecting pipe 200 may swing due to inertia, generating unnecessary vibration, which will affect the imaging effect of the infrared camera.

[0034] In some embodiments of the present invention, the metal braided pipe can be a space spiral shape. Setting the metal braided pipe as a space spiral shape can improve the deformation ability of the metal hose and improve the stress of the metal braided pipe when the cold head 300 moves.

[0035] If the metal braided pipe adopts a straight pipe design, when the cold head 300 moves, it may drive some parts of the metal braided pipe to bend excessively at a high frequency, and long-term bending may cause the metal braided pipe to break.

[0036] Moreover, by arranging the metal braided tube in a spatial spiral shape, the metal braided tube can also be deformed in the spiral direction. If the metal braided tube is designed as a straight tube, it cannot be deformed in the axial direction.

[0037] In addition, by arranging the metal braided tube in a spatial spiral shape, the metal braided tube can also have better elasticity, further improving the performance of blocking micro-vibrations.

[0038] In some embodiments of the present invention, the cold head 300 includes a phase modulation mechanism and a cold finger 310. The cold finger 310 is connected to the compressor 100 through a flexible connecting tube 200, and the phase modulation mechanism is connected to the cold finger 310.

[0039] The phase modulation mechanism can adjust the mass flow of the working fluid and the phase of the pressure wave, so that the pulse tube refrigerator achieves a better refrigeration effect.

[0040] In a further embodiment, the phase modulation mechanism includes an inertia tube 320 and an air reservoir 330. The inertia tube 320 can be an elongated metal tube with different diameter combinations, and the air reservoir 330 is a container with a certain volume. The phase modulation mechanism can play a role in adjusting the mass flow of the gas working fluid and the pressure wave in the cold finger 310.

[0041] In some embodiments of the present invention, both ends of the flexible connecting tube 200 can be directly welded to the compressor 100 and the cold head 300. Alternatively, nuts can be provided at both ends of the flexible connecting tube 200, and external threads can be provided at the positions where the compressor 100 and the cold head 300 are connected to the flexible connecting tube 200 to achieve detachable connection between the flexible connecting tube 200 and the compressor 100 and the cold head 300.

[0042] The embodiments of the present invention also provide a space infrared detection device, which can be, for example, an infrared camera. Since the above-mentioned pulse tube refrigerator is used to cool the working components of the infrared camera, it has the same advantages as described above.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pulse tube refrigerator, characterized in that, It includes a compressor (100), a cold head (300), and a flexible connection pipe (200), and the flexible connection pipe (200) is connected between the compressor (100) and the cold head (300).

2. The pulse tube refrigerator according to claim 1, characterized in that, The flexible connection pipe (200) is a metal braided pipe.

3. The pulse tube refrigerator according to claim 2, wherein The metal braided pipe is in a spatial spiral shape.

4. The pulse tube refrigerator according to claim 1, wherein The cold head (300) includes a phase adjustment mechanism and a cold finger (310). The cold finger (310) is connected to the compressor (100) through the flexible connection pipe (200), and the phase adjustment mechanism is connected to the cold finger (310).

5. The pulse tube refrigerator according to claim 4, characterized in that, The phase adjustment mechanism includes an inertia tube (320) and an air reservoir (330), and the inertia tube (320) is connected between the air reservoir (330) and the cold finger (310).

6. The pulse tube refrigerator according to claim 5, wherein, The inertia tube (320) is an elongated metal tube with a combination of different diameters.

7. The pulse tube refrigerator according to claim 1, characterized in that, The compressor (100) is a moving coil linear compressor (100).

8. The pulse tube refrigerator according to claim 1, characterized in that, Both ends of the flexible connection pipe (200) are welded to the compressor (100) and the cold head (300) respectively.

9. The pulse tube refrigerator according to claim 1, wherein Both ends of the flexible connection pipe (200) are detachably connected to the compressor (100) and the cold head (300) respectively.

10. A space infrared detection device, characterized in that, It includes a pulse tube refrigerator according to any one of claims 1 to 9.

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