A two-stage throttling refrigerator and a refrigeration probe

Abstract

The application provides a double-stage throttling refrigerator, which comprises an inner core shaft, an inner cold finger and an outer core shaft arranged coaxially from inside to outside, a pre-cooling stage heat exchanger and a refrigeration stage gas inlet pipe are arranged between the inner core shaft and the inner cold finger, the refrigeration stage gas inlet pipe is located in a refrigeration area of the pre-cooling stage heat exchanger, a refrigeration stage heat exchanger is arranged on the outer core shaft, an inner cold disc is arranged at the top of the inner cold finger, an air inlet end of the inner cold disc is communicated with an air outlet end of the refrigeration stage gas inlet pipe, and an air outlet end of the inner cold disc is communicated with an air inlet end of the refrigeration stage heat exchanger. The double-stage throttling refrigerator adopts the design of two layers and two stages of heat exchangers, the pre-cooling stage heat exchanger is used for pre-cooling the refrigeration stage gas inlet, the refrigeration stage gas inlet enters the refrigeration stage heat exchanger for throttling at a low temperature, the throttled gas can further cool the gas in the refrigeration stage heat exchanger, and the heat exchange efficiency is greatly improved, so that the rapid cooling of the nitrogen working medium can be realized in a small volume.

Description

Technical Field

[0001] This invention belongs to the field of infrared detection technology, specifically relating to a two-stage throttling cooler and a cooling detector. Background Technology

[0002] Infrared detectors are the core component of infrared technology and a precursor to its development. Throttling coolers, with their compact structure, rapid cooling, small size, and light weight, are widely used in infrared cryogenic detection, cryogenic medicine, aerospace, and other fields.

[0003] Existing throttling refrigerators are relatively mature in application, mostly using nitrogen or argon as the refrigerant. Argon cools quickly but at a high temperature, while nitrogen cools at a lower temperature but at a slower rate. When using nitrogen as the refrigerant, achieving rapid cooling typically requires a large heat exchanger and a low back pressure. With the increasing demand for lightweight refrigerators, achieving rapid cooling using nitrogen in a smaller volume is a future development trend and a challenge that must be overcome. Summary of the Invention

[0004] The purpose of this invention is to provide a two-stage throttling refrigerator, which can at least solve some of the defects existing in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A two-stage throttling refrigerator includes an inner core shaft, an inner cooling finger, and an outer core shaft arranged coaxially from the inside to the outside. A pre-cooling stage heat exchanger and a refrigeration stage inlet pipe are disposed between the inner core shaft and the inner cooling finger. The refrigeration stage inlet pipe is located in the refrigeration area of ​​the pre-cooling stage heat exchanger. The refrigeration stage heat exchanger is disposed on the outer core shaft. An inner cooling plate is disposed on the top of the inner cooling finger. The inlet end of the inner cooling plate is connected to the outlet end of the refrigeration stage inlet pipe, and the outlet end of the inner cooling plate is connected to the inlet end of the refrigeration stage heat exchanger.

[0007] Furthermore, the outlet end of the refrigeration stage heat exchanger is connected to a refrigeration stage gas reflux space, and the refrigeration stage heat exchanger is located within the refrigeration stage gas reflux space.

[0008] Furthermore, the precooling stage heat exchanger is wound around the inner mandrel, and the refrigeration stage inlet pipe is wound around the precooling stage heat exchanger.

[0009] Furthermore, an inner nylon thread is wound around the outer ring of the refrigeration stage intake pipe, and the inner cooling finger is sleeved on the outer ring of the inner nylon thread.

[0010] Furthermore, a precooling stage gas reflux space is formed between the inner mandrel and the inner cooling finger. The precooling stage heat exchanger and the refrigeration stage inlet pipe are both located within this precooling stage gas reflux space, and the outlet end of the precooling stage heat exchanger is connected to the precooling stage gas reflux space.

[0011] Furthermore, the inner cooling plate includes a base plate section and a cylindrical section. The base plate section is connected to the top of the inner cooling plate. The base plate section is provided with a first through hole for connecting the refrigeration stage air inlet pipe and the cylindrical section. The cylindrical section is provided with a second through hole communicating with its interior. The second through hole is connected to the air inlet end of the refrigeration stage heat exchanger through a cold air pipe.

[0012] Furthermore, the refrigeration stage heat exchanger is wound around the outer mandrel, and a layer of outer nylon thread is wound around the outer ring of the refrigeration stage heat exchanger.

[0013] Furthermore, the aforementioned two-stage throttling refrigerator also includes an inlet flange and an inlet port. The inlet flange is located below the inner mandrel, and the inlet port is located on the inlet flange. The inlet ends of the precooling stage heat exchanger and the refrigeration stage inlet pipe are both connected to the inlet port.

[0014] In addition, the present invention also provides a cooling detector, including a Dewar, a cooling-stage cold plate and the above-mentioned two-stage throttling cooler. The two-stage throttling cooler is disposed inside the Dewar. A cooling-stage throttling element is provided at the top of the outer mandrel. The cooling-stage throttling element is connected to the outlet end of the cooling-stage heat exchanger. The cooling-stage cold plate is disposed above the cooling-stage throttling element.

[0015] Furthermore, a refrigeration stage gas refrigeration space is formed between the outer mandrel and the Dewar, and the refrigeration stage heat exchanger is located in the refrigeration stage gas refrigeration space. The outlet end of the refrigeration stage heat exchanger is connected to the refrigeration stage gas refrigeration space, and the refrigeration stage gas refrigeration space is open to the atmosphere.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] The dual-stage throttling refrigerator provided by this invention adopts a design of two-stage heat exchangers with inner and outer layers. The pre-cooling stage heat exchanger pre-cools the intake gas of the refrigeration stage, so that the intake gas of the refrigeration stage enters the refrigeration stage heat exchanger at a lower temperature for throttling. The throttled gas can further cool the gas in the refrigeration stage heat exchanger, which greatly improves the heat exchange efficiency, thereby achieving rapid cooling of nitrogen working fluid in a small volume.

[0018] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the two-stage throttling refrigerator of the present invention;

[0020] Figure 2 This is a schematic diagram of the internal cooling plate in the two-stage throttling refrigerator of the present invention.

[0021] Explanation of reference numerals in the attached drawings: 1. Inner mandrel; 2. Precooling stage heat exchanger; 3. Refrigeration stage inlet pipe; 4. Inner nylon wire; 5. Inner cooling finger; 6. Inner cooling plate; 7. Outer mandrel; 8. Refrigeration stage throttling element; 9. Refrigeration stage heat exchanger; 10. Outer nylon wire; 11. Cold air pipe; 12. Inlet flange; 13. Inlet port; 14. First through hole; 15. Bottom plate section; 16. Second through hole; 17. Cylindrical section. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection", and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an abutting connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] Example 1:

[0027] like Figure 1As shown, this embodiment provides a two-stage throttling refrigerator, including an inner core shaft 1, an inner cooling finger 5, and an outer core shaft 7 arranged coaxially from the inside to the outside. A pre-cooling stage heat exchanger 2 and a refrigeration stage inlet pipe 3 are arranged between the inner core shaft 1 and the inner cooling finger 5. The refrigeration stage inlet pipe 3 is located in the refrigeration area of ​​the pre-cooling stage heat exchanger 2. A refrigeration stage heat exchanger 9 is provided on the outer core shaft 7. An inner cooling plate 6 is provided on the top of the inner cooling finger 5. The inlet end of the inner cooling plate 6 is connected to the outlet end of the refrigeration stage inlet pipe 3, and the outlet end of the inner cooling plate 6 is connected to the inlet end of the refrigeration stage heat exchanger 9.

[0028] During operation, the precooling stage heat exchanger 2 and the refrigeration stage heat exchanger 9 use the same gas source. High-pressure gas enters the precooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3 simultaneously through two separate paths. The high-pressure gas entering the precooling stage heat exchanger 2 is cooled to produce cold gas. This cold gas flows back and continuously exchanges heat with the high-pressure gas in the precooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3, thereby precooling the precooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3. At the same time, the high-pressure gas entering the refrigeration stage inlet pipe 3 is cooled by the cold gas flowing back from the precooling stage heat exchanger 2 and then enters the refrigeration stage heat exchanger 9 through the inner cooling plate 6. The refrigeration stage heat exchanger 9 further cools and lowers the temperature, forming a lower-temperature gas. This low-temperature gas continuously flows back and exchanges heat with the refrigeration stage heat exchanger 9, performing secondary precooling on the gas entering the refrigeration stage heat exchanger 9. This cycle repeats continuously, and the throttling cooling effect is continuously amplified until the temperature drops to the refrigeration temperature. This embodiment of the two-stage throttling refrigerator adopts a two-stage design, pre-cooling the refrigeration stage gas twice, which greatly improves the heat exchange efficiency, thereby enabling rapid cooling of nitrogen working fluid in a small volume.

[0029] Specifically, the precooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3 are disposed between the inner mandrel 1 and the inner cooling finger 5, and are coiled around the surface of the inner mandrel 1; in some embodiments, the precooling stage heat exchanger 2 is wound around the inner mandrel 1, and the refrigeration stage inlet pipe 3 is wound around the precooling stage heat exchanger 2. Both the precooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3 can adopt, but are not limited to, a finned tube structure.

[0030] Preferably, an inner nylon thread 4 is wound around the outer ring of the refrigeration stage inlet pipe 3, and the inner cooling finger 5 is sleeved on the outer ring of the inner nylon thread 4. The inner nylon thread 4 fills the gap between the refrigeration stage inlet pipe 3 and the inner cooling finger 5 to improve the heat exchange effect of the pre-cooling stage gas return channel.

[0031] In one specific implementation, a pre-cooling stage gas reflux space is formed between the inner mandrel 1 and the inner cooling finger 5. The pre-cooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3 are both located within this pre-cooling stage gas reflux space, and the outlet end of the pre-cooling stage heat exchanger 2 is connected to the pre-cooling stage gas reflux space. Specifically, a pre-cooling stage throttling element is connected to the pre-cooling stage heat exchanger 2. This pre-cooling stage throttling element can be, but is not limited to, a manifold throttling pipe, and is connected to the pre-cooling stage gas reflux space. High-pressure gas enters the pre-cooling stage heat exchanger 2, and the throttling cooling effect of the pre-cooling stage throttling element produces cold gas. The cold gas flows back through the pre-cooling stage gas reflux space, cooling the high-pressure gas in the pre-cooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3.

[0032] As one specific implementation method, such as Figure 2 As shown, the inner cooling plate 6 includes a base plate section 15 and a cylindrical section 17. The base plate section 15 is connected to the top of the inner cooling finger 5 and covers the inner cooling finger 5. The base plate section 15 is provided with a first through hole 14 for connecting the refrigeration stage inlet pipe 3 and the cylindrical section 17. The cylindrical section 17 is provided with a second through hole 16, which communicates with the interior of the cylindrical section 17. The second through hole 16 is connected to the inlet end of the refrigeration stage heat exchanger 9 through a cold air pipe 11. The cold air pipe 11 is located in the area between the inner cooling finger 5 and the outer mandrel 7. The low-temperature gas in the refrigeration stage inlet pipe 3, after being pre-cooled by the return cold gas in the pre-cooling stage heat exchanger 2, enters the cylindrical section 17 of the inner cooling plate 6 through the first through hole 14, and then enters the refrigeration stage heat exchanger 9 through the second through hole 16 and the cold air pipe 11. Preferably, a cap is provided at the top of the cylindrical section 17 of the inner cold plate 6. The cap can seal the cold gas entering the cylindrical section 17, so that the cold gas can only enter the cold air pipe 11 through the second through hole 16. On the other hand, the cap and the bottom plate section 15 can clamp and limit the cold air pipe 11 connected to the cylindrical section 17 to ensure the stability of the connection of the cold air pipe 11.

[0033] In some embodiments, a planar spiral gas channel can be formed inside the inner cooling plate 6. One end of the gas channel is connected to the outlet end of the refrigeration stage inlet pipe 3, and the other end of the gas channel is connected to the cold gas pipe 11. The low-temperature gas in the refrigeration stage inlet pipe 3, after being pre-cooled by the return cold gas in the pre-cooling stage heat exchanger 2, undergoes sufficient heat exchange in the gas channel of the inner cooling plate 6, thereby further reducing the temperature of the refrigeration gas.

[0034] In one specific embodiment, the cooling-stage heat exchanger 9 is wound around the outer mandrel 7. The outlet end of the cooling-stage heat exchanger 9 is connected to a cooling-stage gas return space, and the cooling-stage heat exchanger 9 is located within this cooling-stage gas return space. Specifically, the outlet end of the cooling-stage heat exchanger is connected to a cooling-stage throttling element 8. The throttling orifice of the cooling-stage throttling element 8 is connected to the cooling-stage gas return space through an expansion chamber. The cooling-stage throttling element 8 can be, but is not limited to, a manifold throttling pipe. The low-temperature gas entering the cooling-stage heat exchanger 9 generates a throttling cooling effect at the cooling-stage throttling element 8, further cooling and lowering the low-temperature gas to form an even lower-temperature cooling-stage gas. This cooling-stage gas cools the element requiring cooling on one hand, and on the other hand, it flows back through the cooling-stage gas return space to pre-cool the low-temperature gas in the cooling-stage heat exchanger 9. Optionally, when the dual-stage throttling cooler of this embodiment is applied to a cooling detector, the cooling-stage gas return space can be the area between the outer mandrel 7 and the Dewar.

[0035] Preferably, an outer nylon thread 10 is wound around the outer ring of the refrigeration stage heat exchanger 9. In application, a refrigeration stage gas return channel is formed between the refrigeration stage heat exchanger 9 and the Dewar shell. The outer nylon thread 10 can reduce the gap between the refrigeration stage heat exchanger 9 and the Dewar shell, thereby improving the heat exchange effect of the refrigeration stage gas return channel.

[0036] In an optional implementation, the two-stage throttling refrigerator in this embodiment further includes an inlet flange 12 and an inlet port 13. The inlet flange 12 is located below the inner mandrel 1, and the inlet port 13 is located on the inlet flange 12. The inlet port 13 is connected to an external high-pressure gas source. The inlet ends of the precooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3 are both connected to the inlet port 13. The high-pressure gas enters the precooling stage heat exchanger 2 and the refrigeration stage inlet pipe 3 simultaneously through the inlet flange 12.

[0037] In this embodiment, the connection method of each component in the two-stage throttling refrigerator is as follows: the inner mandrel 1 is installed on the inlet flange 12 by adhesive bonding; the precooling stage heat exchanger 2 is wound around the inner mandrel 1, the refrigeration stage inlet pipe 3 is wound around the precooling stage heat exchanger 2, the outer ring of the refrigeration stage inlet pipe 3 is wound with an inner nylon thread 4, and the outer ring of the inner nylon thread 4 is fitted with an inner cooling finger 5; the precooling stage heat exchanger 2, the refrigeration stage inlet pipe 3 and the inlet flange 12 are connected by induction brazing, and the inner cooling finger 5 and the inlet flange 12 are connected by laser welding; the inner cooling plate 6 is installed on the top of the inner cooling finger 5 and is connected by laser welding; the refrigeration stage inlet pipe 3, the refrigeration stage heat exchanger 9 and the inner cooling plate 6 are connected by soldering, the refrigeration stage heat exchanger 9 is wound around the outer mandrel 7, and the outer mandrel 7 is installed on the inlet flange 12 by adhesive bonding; the outermost ring of the refrigeration stage heat exchanger 9 is wound with a nylon thread 10.

[0038] Example 2:

[0039] This embodiment provides a cooled detector, including a Dewar (not shown in the figure), a cooling-stage cold plate, and a two-stage throttling cooler as described in the above embodiment. The two-stage throttling cooler is disposed inside the Dewar. A cooling-stage throttling element 8 is provided at the top of the outer mandrel 7. The cooling-stage throttling element 8 is connected to the outlet end of the cooling-stage heat exchanger 9. The cooling-stage cold plate is disposed above the cooling-stage throttling element 8. The two-stage throttling cooler achieves cooling through heat exchange structures and throttling orifices. Through thermodynamic processes such as heat exchange and throttling, cooling gas is generated at the cooling-stage cold plate, carrying away the surrounding heat, thereby cooling the chips, circuits, and cold shield components on the cooling-stage cold plate.

[0040] Specifically, a refrigeration stage gas reflux space is formed between the outer mandrel 7 and the Dewar radiator. The refrigeration stage heat exchanger 9 is located within this refrigeration stage gas reflux space, with its outlet end connected to the refrigeration stage gas reflux space, which is open to the atmosphere. The refrigeration stage gas generated by the throttling refrigeration of the refrigeration stage heat exchanger 9 cools the chips, cold screens, and other optoelectronic components on the refrigeration stage cold plate before entering the atmosphere through the refrigeration stage gas reflux space. During this process, the refrigeration stage gas refluxing within the refrigeration stage gas reflux space further cools the gas inside the refrigeration stage heat exchanger 9, fully utilizing the energy of the refrigeration stage gas. Simultaneously, the reflux channel of the refrigeration stage gas is connected to the atmosphere, resulting in lower flow resistance within the reflux channel and increasing the pressure difference before and after throttling, thereby enhancing the throttling refrigeration effect.

[0041] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A two-stage throttling refrigerator, characterized in that: The device includes an inner mandrel, an inner cooling finger, and an outer mandrel arranged coaxially from the inside out. A pre-cooling stage heat exchanger and a refrigeration stage inlet pipe are disposed between the inner mandrel and the inner cooling finger. The refrigeration stage inlet pipe is located in the refrigeration area of ​​the pre-cooling stage heat exchanger. The refrigeration stage heat exchanger is mounted on the outer mandrel. An inner cooling plate is located at the top of the inner cooling finger. The inlet end of the inner cooling plate is connected to the outlet end of the refrigeration stage inlet pipe, and the outlet end of the inner cooling plate is connected to the inlet end of the refrigeration stage heat exchanger. A partition is formed between the inner mandrel and the inner cooling finger. A precooling stage gas reflux space is formed, in which the precooling stage heat exchanger and the refrigeration stage inlet pipe are both located. The outlet end of the precooling stage heat exchanger is connected to the precooling stage gas reflux space. High-pressure gas enters the precooling stage heat exchanger and the refrigeration stage inlet pipe simultaneously through two paths. The high-pressure gas entering the precooling stage heat exchanger is cooled to produce cold gas. This cold gas refluxes and continuously exchanges heat with the high-pressure gas in the precooling stage heat exchanger and the refrigeration stage inlet pipe, thereby precooling the precooling stage heat exchanger and the refrigeration stage inlet pipe.

2. The two-stage throttling refrigerator as described in claim 1, characterized in that: The outlet of the refrigeration stage heat exchanger is connected to a refrigeration stage gas reflux space, and the refrigeration stage heat exchanger is located within the refrigeration stage gas reflux space.

3. The two-stage throttling refrigerator as described in claim 1, characterized in that: The precooling stage heat exchanger is wound around the inner mandrel, and the refrigeration stage inlet pipe is wound around the precooling stage heat exchanger.

4. The two-stage throttling refrigerator as described in claim 3, characterized in that: A layer of inner nylon thread is wound around the outer ring of the refrigeration stage intake pipe, and the inner cooling finger is sleeved on the outer ring of the inner nylon thread.

5. The two-stage throttling refrigerator as described in claim 1, characterized in that: The internal cooling plate includes a base plate section and a cylindrical section. The base plate section is connected to the top of the internal cooling plate. The base plate section is provided with a first through hole for connecting the refrigeration stage air inlet pipe and the cylindrical section. The cylindrical section is provided with a second through hole communicating with its interior. The second through hole is connected to the air inlet end of the refrigeration stage heat exchanger through a cold air pipe.

6. The two-stage throttling refrigerator as described in claim 1, characterized in that: The refrigeration stage heat exchanger is wound around the outer mandrel, and a layer of outer nylon thread is wound around the outer ring of the refrigeration stage heat exchanger.

7. The two-stage throttling refrigerator as described in claim 1, characterized in that: It also includes an air inlet flange and an air inlet. The air inlet flange is located below the inner mandrel, and the air inlet is located on the air inlet flange. The air inlet ends of the precooling stage heat exchanger and the refrigeration stage air inlet pipe are both connected to the air inlet.

8. A cooled detector, characterized in that: The device includes a Dewar, a refrigeration stage cold plate, and a two-stage throttling refrigerator as described in any one of claims 1-7. The two-stage throttling refrigerator is disposed inside the Dewar. A refrigeration stage throttling element is provided at the top of the outer mandrel. The refrigeration stage throttling element is connected to the outlet end of the refrigeration stage heat exchanger. The refrigeration stage cold plate is disposed above the refrigeration stage throttling element.

9. The cooled detector as claimed in claim 8, characterized in that: The outer mandrel and the Dewar form a refrigeration stage gas reflux space. The refrigeration stage heat exchanger is located in the refrigeration stage gas reflux space. The outlet end of the refrigeration stage heat exchanger is connected to the refrigeration stage gas reflux space, and the refrigeration stage gas reflux space is open to the atmosphere.

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