Split jet type throttling refrigeration infrared detector

Abstract

The invention provides a split jet type throttling refrigeration infrared detector which comprises a refrigerator assembly and a Dewar assembly, the refrigerator assembly is located outside the Dewar assembly, a jet pipe used for jetting cold fluid is arranged in the Dewar assembly, and the refrigerator assembly is communicated with the jet pipe through a refrigeration level hose. The refrigerator assembly and the Dewar assembly are arranged separately, the refrigerator assembly and the Dewar assembly are connected through the refrigeration level hose, relative 360-degree flexible arrangement of the refrigerator assembly and the Dewar assembly is achieved, meanwhile, the size of the refrigerator assembly is not limited by the cold finger size of the Dewar assembly, and higher heat exchange efficiency can be achieved; and the refrigeration performance of the detector is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of infrared detectors, and in particular relates to a split-jet throttling refrigeration infrared detector. Background Art

[0002] Infrared detectors are widely used in the fields of infrared thermal imagers, infrared forward vision and night vision, missile guidance, space applications and other civil and military equipment. Throttling coolers are used in detectors. Dewar cold fingers, as part of the cooler heat exchanger, are used to limit the flow direction of the throttling return fluid, so that the throttling return cold fluid exchanges heat with the heat exchanger wall, and then cools the inflow, achieving the amplified throttling effect.

[0003] However, the existing Dewar cold finger and throttling cooler are an integrated structure. The Dewar cold finger is a component of the cooler heat exchanger, so the size of the cooler is limited by the size of the Dewar cold finger, and the efficiency of the cooler is limited by parameters such as the heat exchange area; or in order to ensure the refrigeration performance, the volume of the Dewar is too large, which does not meet the use requirements, especially for the guidance head. Summary of the invention

[0004] The object of the present invention is to provide a split-ejection throttling refrigeration infrared detector, which can at least solve some of the defects existing in the prior art.

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

[0006] A split-jet throttling refrigeration infrared detector comprises a refrigerator assembly and a dewar assembly, wherein the refrigerator assembly is located outside the dewar assembly, the dewar assembly has an injection pipe for injecting cold fluid inside, and the refrigerator assembly is connected to the injection pipe through a refrigeration-level hose.

[0007] Furthermore, the refrigerator assembly includes a refrigerator shell and a core shaft arranged inside the refrigerator shell, a precooling stage pipe is provided between the refrigerator shell and the core shaft, the refrigeration stage hose includes a first hose segment, a second hose segment and a third hose segment connected in sequence, the first hose segment and the second hose segment are located in the refrigeration area of ​​the precooling stage pipe, the air inlet end of the precooling stage pipe and the end of the first hose segment are both connected to a high-pressure fluid source, and the end of the third hose segment passes through the refrigerator shell and is connected to the injection pipe.

[0008] Furthermore, an air inlet flange and an air inlet pipe are connected to the end of the refrigerator shell, a high-pressure fluid channel is provided on the air inlet flange, one end of the air inlet pipe is connected to the high-pressure fluid channel, and the other end of the air inlet pipe is provided with an air inlet connector for an external high-pressure fluid source, and the air inlet end of the pre-cooling stage pipe and the first hose section are both connected to the high-pressure fluid channel.

[0009] Furthermore, the precooling stage tube is wound around the core shaft, a precooling stage throttling element is provided on the top of the core shaft, an air outlet end of the precooling stage tube is connected to the precooling stage throttling element, the first hose section is wound around the precooling stage tube, and the second hose section is coiled outside the end of the core shaft and is opposite to the precooling stage throttling element.

[0010] Furthermore, the first hose segment, the second hose segment and the third hose segment are an integrated structure.

[0011] Furthermore, the Dewar assembly includes a Dewar shell and a cold finger, a cold plate and a cold screen arranged in sequence along the axis in the Dewar shell, the injection pipe is located in the cold finger, and the air outlet end of the injection pipe is arranged opposite to the cold plate, and the air outlet end of the injection pipe is connected to a refrigeration-stage throttling element.

[0012] Furthermore, the Dewar assembly also includes a fixing clamp and a connecting joint, the fixing clamp is located at the bottom of the cold finger, the connecting joint passes through the fixing clamp, and the two ends of the connecting joint are respectively connected to the refrigeration level hose and the injection pipe.

[0013] Furthermore, the fixing clamp ring is a petal-type supporting ring.

[0014] Furthermore, the cold finger includes a cylindrical section and a conical section, the small-diameter end of the conical section is connected to the cylindrical section, the injection pipe passes through the cylindrical section, and the air outlet end of the injection pipe extends into the conical section, and the cold plate is installed at the large-diameter end of the conical section.

[0015] Furthermore, the refrigeration-grade hose is an annealed metal hose, and the injection pipe is a non-annealed metal hard pipe.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The present invention arranges the refrigerator assembly and the dewar assembly separately, and uses a refrigeration-grade hose to connect the refrigerator assembly and the dewar assembly, so as to realize a 360-degree flexible arrangement of the refrigerator assembly and the dewar assembly relative to each other. At the same time, the volume of the refrigerator assembly is not limited by the cold finger size of the dewar assembly, and a higher heat exchange efficiency can be achieved, which is beneficial to the improvement of the refrigeration performance of the detector.

[0018] (2) In the present invention, the cold finger of the Dewar assembly is designed as a combination of a columnar section and a columnar section, which can effectively reduce the cold loss of the cold plate through the cold finger, and at the same time optimize the flow of the fluid after throttling in the refrigeration stage. The fluid has a small flow dead zone in the expansion chamber formed by the conical section and the cold plate, and can basically cover the surface of the cold plate, thereby enhancing heat exchange.

[0019] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the split-type jet throttling refrigeration infrared detector of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the refrigerator assembly in the present invention;

[0022] Figure 3 It is a schematic diagram of the structure of the Dewar assembly in the present invention;

[0023] Figure 4 It is a structural schematic diagram of the fixing clamp ring in the present invention;

[0024] Figure 5 yes Figure 4 Schematic diagram of the cross section of AA;

[0025] Figure 6 It is a working principle diagram of the split-jet throttling refrigeration infrared detector of the present invention.

[0026] Explanation of the accompanying drawings: 1. Refrigerator assembly; 2. Refrigeration stage hose; 3. Dewar assembly; 4. Refrigerator shell; 5. Mandrel; 6. Precooling stage pipe; 7. Inlet flange; 8. High-pressure fluid channel; 9. Inlet pipe; 10. Inlet joint; 11. Precooling stage throttling element; 12. Dewar shell; 13. Press block; 14. Fixing clamp; 15. Connecting joint; 16. Injection pipe; 17. Column section; 18. Conical section; 19. Refrigeration stage throttling element; 20. Cold plate; 21. Chip; 22. Cold screen; 23. Window; 24. Lead ring; 25. Exhaust pipe. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0031] like Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a split-type injection throttling refrigeration infrared detector, including a refrigerator assembly 1 and a dewar assembly 3, wherein the refrigerator assembly 1 is located outside the dewar assembly 3, and the dewar assembly 3 has an injection pipe 16 for injecting cold fluid inside, and the refrigerator assembly 1 is connected to the injection pipe 16 through a refrigeration-level hose 2. In this embodiment, the refrigeration assembly 1 and the dewar assembly 3 are arranged separately, and the refrigeration-level hose 2 is used to connect the refrigeration assembly 1 and the dewar assembly 3, and the cold fluid generated by the refrigerator assembly 1 is transported to the dewar assembly 3 through the refrigeration-level hose 2, and the chip 21 installed on the dewar assembly 3 is cooled through the injection pipe 16 to reach the working temperature of the detector; this structural design of the refrigerator assembly 1 and the dewar assembly 3 in this embodiment can realize the flexible arrangement of the relative positions of the refrigerator assembly 1 and the dewar assembly 3, and at the same time, the volume of the refrigerator assembly 1 is not limited by the cold finger size of the dewar assembly 3, and can achieve greater heat exchange efficiency, which is conducive to the improvement of the refrigeration performance of the detector.

[0032] The refrigeration-grade hose 2 is an annealed metal hose, which transmits cold and connects the refrigerator assembly 1 and the Dewar assembly 3, so that the Dewar assembly 3 and the refrigerator assembly 1 can be flexibly arranged relative to each other at 360°.

[0033] As a specific implementation method, Figure 2As shown, the refrigerator assembly 1 includes a refrigerator shell 4 and a mandrel 5 arranged inside the refrigerator shell 4, a precooling stage pipe 2 is arranged between the refrigerator shell 4 and the mandrel 5, and the refrigeration stage hose 4 includes a first hose segment, a second hose segment and a third hose segment connected in sequence, the first hose segment and the second hose segment are located in the refrigeration area of ​​the precooling stage pipe 2, the air inlet end of the precooling stage pipe 2 and the end of the first hose segment are both connected to a high-pressure fluid source, and the end of the third hose segment passes through the refrigerator shell 4 and is connected to the injection pipe 16. Among them, after the third hose segment of the refrigeration stage hose 2 passes through the refrigerator shell 4, a soldering seal is performed between the refrigerator shell 4 and the third hose segment. Preferably, the first hose segment, the second hose segment and the third hose segment of the refrigeration stage hose 4 are an integrated structure, so as to ensure the sealing of the refrigeration stage hose 4. In this embodiment, the precooling stage pipe 6 and the refrigeration stage hose 2 use the same gas source, and the high-pressure room temperature gas enters the precooling stage pipe 6 and the refrigeration stage hose 2 in two ways at the same time. The high-pressure gas entering the precooling stage pipe 6 is refrigerated to produce cold gas, and the cold gas refluxes and continuously exchanges heat with the high-pressure room temperature gas in the precooling stage pipe 6 and the first hose section and the second hose section of the refrigeration stage hose 2, thereby precooling the gas in the precooling stage pipe 6 and the refrigeration stage hose 2. At the same time, the high-pressure gas entering the refrigeration stage hose 2 is cooled by the cold gas refluxed by the precooling stage pipe 6, and then transported by the third hose section of the refrigeration stage hose 2 to the external Dewar assembly 3 for refrigeration, and then sprayed by the injection pipe 16 to cool the chip 21 on the Dewar assembly 3.

[0034] Specifically, an air inlet flange 7 and an air inlet pipe 9 are connected to the end of the refrigerator shell 4, a high-pressure fluid channel 8 is provided on the air inlet flange 7, one end of the air inlet pipe 9 is connected to the high-pressure fluid channel 8, and the other end of the air inlet pipe is provided with an air inlet connector 10 for an external high-pressure fluid source, the air inlet end of the precooling stage pipe 6 and the first hose section of the refrigeration stage hose 2 are both connected to the high-pressure fluid channel 8; at the same time, the precooling stage pipe 6 is designed to be wound around the core shaft 5, a precooling stage throttling element 11 is provided on the top of the core shaft 5, the air outlet end of the precooling stage pipe 6 is connected to the precooling stage throttling element 11, the first hose section of the refrigeration stage hose 2 is wound around the precooling stage pipe 6, and the second hose section is coiled outside the end of the core shaft 5 and is directly opposite to the precooling stage throttling element 11. A reflux space for the cold gas generated by the precooling stage pipe 6 (i.e., the refrigeration area of ​​the precooling stage pipe 6) is formed between the refrigerator shell 4 and the core shaft 5. The precooling stage pipe 6 and the first hose section and the second hose section of the refrigeration stage hose 2 are all arranged in the reflux space of the cold gas. The air outlet end of the precooling stage pipe 6 is connected with the precooling stage throttling element 11 at the top of the core shaft 5, and the precooling stage throttling element 11 is connected with the reflux space of the cold gas. The high-pressure normal-temperature gas enters the precooling stage pipe 6, and the throttling refrigeration effect of the precooling stage throttling element 11 generates cold gas. The cold gas refluxes through the reflux space to cool the high-pressure normal-temperature gas in the precooling stage pipe 6 and the first hose section and the second hose section of the refrigeration stage hose 2. At the same time, the second hose section of the refrigeration stage hose 2 is designed to be arranged opposite to the precooling stage throttling element 11, so that the cold gas can better precool the gas in the refrigeration stage hose 2 to be flowed out of the refrigerator assembly.

[0035] Optionally, the core shaft 5 is made of non-metallic material to reduce the thermal mass and axial cooling loss of the refrigerator; the precooling stage tube 6 can adopt but is not limited to a fin tube structure, and the precooling stage throttling element 11 can be but is not limited to a converging throttling tube.

[0036] Preferably, a layer of nylon thread (not shown in the figure) is wrapped around the outer circle of the refrigeration-grade hose 2 located inside the refrigerator shell 4, and the gap between the refrigeration-grade hose 2 and the refrigerator shell 4 is filled with the nylon thread to improve the heat exchange effect of the return space of the cold gas.

[0037] Optionally, the precooling stage pipe 6 and the refrigeration stage hose 2 can be provided with the same air inlet channel or different air inlet channels to achieve the purpose of using the same type or different types of refrigerant gas, thereby achieving better refrigeration performance and different target temperatures.

[0038] As a specific implementation method, Figure 3As shown, the dewar assembly 3 includes a dewar shell 12 and a cold finger, a cold plate 20 and a cold shield 22 arranged in sequence along the axis in the dewar shell 12, the injection pipe 16 is located in the cold finger, and the outlet end of the injection pipe 16 is arranged directly opposite to the cold plate 20, and the outlet end of the injection pipe 16 is connected to a refrigeration stage throttling element 19. In this embodiment, the pre-cooled gas in the first hose section and the second hose section of the refrigeration stage hose 2 in the refrigerator assembly 1 is transported to the cold finger through the third hose section of the refrigeration stage hose 2, and is further cooled and cooled in the cold finger by throttling by the refrigeration stage throttling element 19, so as to cool the chip 21 installed on the cold plate 20 to reach the working temperature of the detector.

[0039] Preferably, the cold finger is designed to include a cylindrical section 17 and a conical section 18, the small-diameter end of the conical section 18 is connected to the cylindrical section 17, the injection pipe 16 passes through the cylindrical section 17, and the air outlet end of the injection pipe 16 extends into the conical section 18, and the cold plate 20 is installed at the large-diameter end of the conical section 18. In this embodiment, the inner diameter value of the cylindrical section 17 of the cold finger depends on the outer diameter of the injection pipe 16 and the design value of the reflux gap. The cold gas delivered by the refrigerator assembly 1 enters the cold finger. Since the conical section 18 of the cold finger is in the shape of a conical funnel, its diameter is large near the end of the cold plate 20. Therefore, compared with the existing conventional cylindrical or conical cold finger structure with a small top and a large bottom, the cold gas can stay at the cold end of the cold finger (i.e., the conical section 18) for a longer time, and the fluid disturbance of the cold gas at the cold end of the cold finger can also be increased. The cold gas has a small flow dead zone in the expansion chamber formed by the conical section 18 and the cold plate 20, and can basically cover the surface of the cold plate 20, thereby making full use of the cold gas cooling capacity, improving the utilization efficiency of the cold gas, and strengthening the heat exchange between the cold gas and the cold plate 20, so that the Dewar cold head has a faster cooling effect.

[0040] In order to ensure the centering degree of the injection pipe 16 in the cold finger and prevent the pipe position deviation caused by the refrigerant gas injection process, it is preferred that the injection pipe 16 adopts a non-annealed metal hard pipe and the injection pipe 16 is fixedly installed.

[0041] Preferably, the Dewar assembly 3 further comprises a fixing clamp ring 14 and a connecting joint 15, wherein the fixing clamp ring 14 is located at the bottom of the cold finger, the connecting joint 15 penetrates the fixing clamp ring 14, the connecting joint 15 is cured and bonded to the fixing clamp ring 14, and a tool is used during the bonding and curing process to ensure the axial centering deviation, and the two ends of the connecting joint 15 are respectively connected to the refrigeration-level hose 2 and the injection pipe 16. Specifically, a cold finger flange for connecting to the Dewar shell 12 is provided at the bottom of the cold finger, the fixing clamp ring 14 is located in the cold finger flange, and a pressing block 13 is designed to be pressed on the fixing clamp ring 14, the pressing block 13 is a hollow structure, and the pressing block 13 is fixedly connected to the cold finger flange. When working, the gas coming out of the refrigeration-level throttling element 19 at the end of the injection pipe 16 first flows back through the channel between the injection pipe 16 and the cold finger, and then passes through the gap of the fixing clamp ring 14 and the gap in the middle of the pressing block 13 in sequence and is discharged to the external environment.

[0042] Optimized, such as Figure 4 and Figure 5 As shown, the fixed clamp ring 14 can be designed as a petal-type support ring. The petal-type structural design can ensure the refrigeration-level gas refrigeration generated by the refrigeration-level throttling element 19. The pressure difference between the back pressure and the atmospheric pressure after the refrigeration-level throttling is less than 100 kPa, and the refrigeration temperature reaches the boiling point, avoiding the influence of high back pressure on the refrigeration temperature; further, the fixed clamp ring 14 can be designed to be made of low thermal conductivity non-metallic material. The design of low thermal conductivity non-metallic material can effectively reduce the cold loss of low-temperature gas in the injection pipe 16 through the fixed clamp ring 14. The low thermal conductivity non-metallic material can be selected from but not limited to peek (polyetheretherketone), polytetrafluoroethylene, etc.

[0043] In a preferred embodiment, the structure of the cold plate 20 of the Dewar assembly 2 is improved, and a concave-convex structure can be provided on the disk surface of the cold plate 20 facing the cold finger; in some embodiments, a stagnation zone is formed on the disk surface of the cold plate 20 facing the cold finger, and a plurality of grooves are arranged at intervals in the stagnation zone, wherein the grooves can be countersunk holes, strip grooves or annular grooves, and the cold plate 20 is usually disc-shaped, and the grooves are preferably arranged in the stagnation zone to form a disc shape. Of course, the grooves can also be arranged in other shapes according to the actual situation of the cold plate 20; a plurality of ribs protruding toward the cold finger are also provided on the disk surface of the cold plate 20 facing the cold finger, and a plurality of the ribs are located outside the stagnation zone, wherein the ribs can be convex ribs or strip convex ridges, and the ribs are arranged to form a multi-circle annular structure. In this embodiment, ribs are designed on one side of the cold plate 20 for heat exchange with the cold gas, which is beneficial to strengthening the convective heat exchange between the cold plate 20 and the cold gas in the cold finger. At the same time, the design of the groove can destroy the film heat exchange between the cold gas and the cold plate 20 during heat exchange, thereby enhancing the heat exchange between the cold gas and the cold plate 20, thereby accelerating the heat transfer speed and reducing the heat transfer time.

[0044] Furthermore, an annular flange is provided on one side of the cold plate 20 close to the cold finger, and the annular flange is used to connect with the cold finger. Meanwhile, the ribs and grooves on the cold plate 20 are located in the area enclosed by the annular flange.

[0045] In a preferred embodiment, the cold shield 22 is mainly used to suppress stray light. In this embodiment, the cold shield 22 is designed as an integrated structure that is wide at the bottom and narrow at the top, and the bottom of the cold shield 22 is widened. Specifically, Figure 3 As shown, the cold shield 22 includes a conical barrel section and a prismatic barrel section, wherein the prismatic barrel section can be formed by cutting the bottom of the conical barrel section. Through this structural design, the thermal mass of the cold shield is reduced, and the cold loss on the heat conduction path is reduced; further, the bottom of the prismatic barrel section is designed to have a connecting portion extending radially outward, and the connecting portion is used to connect with the cold plate. At the same time, the connecting portion is designed to have a group of relatively distributed first connecting edges and a group of relatively distributed second connecting edges, and the radial width of the first connecting edge along the prismatic barrel section is smaller than the radial width of the second connecting edge along the prismatic barrel section. In this way, the contact area between the first connecting edge with a smaller extension width in the connecting portion and the cold plate is reduced. By widening the bottom of the cold shield 22 and reducing its contact area with the cold plate 20, the cold loss on the heat conduction path of the cold shield 22 is effectively reduced.

[0046] In an optional embodiment, the Dewar housing 12 includes a detachably connected cold finger housing and a window frame, the cold finger is placed in the cold finger housing, the cold plate 20 and the cold screen 22 are placed in the window frame, a window sheet 23 is provided on the top of the window frame, and an exhaust pipe 25 is provided on the cold finger housing at a position corresponding to the columnar section 17 of the cold finger. The Dewar assembly 3 also includes a lead ring 24, which is arranged between the cold finger housing and the window frame. The detector receives the optical signal, and the chip 21 installed on the cold plate 20 converts the optical signal into an electrical signal, which is then led out by the lead ring 24.

[0047] The working process of the split-jet throttling refrigeration infrared detector of the present invention is as follows: Figure 6As shown, the high-pressure normal-temperature gas enters the precooling stage pipe 6 and the refrigeration stage hose 2 through the air inlet joint 10, the air inlet pipe 9, and the air inlet flange 7. The high-pressure normal-temperature gas in the precooling stage pipe 6 is throttled at the precooling stage throttling element 11. The throttled gas cools down and circulates in the gap between the precooling stage pipe 6 and the refrigerator shell 4. A part of the gas cools the intake air in the precooling stage pipe 6, and a part of the gas cools the intake air in the first hose section of the refrigeration stage hose 2. At the same time, the cold gas generated at the precooling stage throttling element 11 also exchanges heat with the gas in the second hose section of the refrigeration stage hose 2 at the top of the mandrel 5; the gas in the refrigeration stage hose 2 has a lower temperature after being cooled by the precooling stage, and is further throttled at the refrigeration stage throttling element 19 to reach a lower temperature. After the refrigeration stage throttling, the gas exchanges heat with the cold plate 20 of the Dewar assembly 3, thereby cooling the chip to reach the working temperature of the detector. The present invention adopts a design of two-stage refrigeration and atmospheric pressure after the refrigeration stage throttling, so that the refrigerator assembly can achieve the boiling point temperature of the working medium in a very short time.

[0048] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A split-jet throttling refrigeration infrared detector, comprising a refrigerator assembly and a Dewar assembly, characterized in that: The refrigerator assembly is located outside the Dewar assembly. The Dewar assembly has an injection pipe for injecting cold fluid inside. The refrigerator assembly is connected to the injection pipe through a refrigeration-level hose.

2. The split-ejection throttling refrigeration infrared detector according to claim 1, characterized in that: The refrigerator assembly includes a refrigerator shell and a core shaft arranged inside the refrigerator shell. A precooling stage pipe is provided between the refrigerator shell and the core shaft. The refrigeration stage hose includes a first hose segment, a second hose segment and a third hose segment which are connected in sequence. The first hose segment and the second hose segment are located in the refrigeration area of ​​the precooling stage pipe. The air inlet end of the precooling stage pipe and the end of the first hose segment are both connected to a high-pressure fluid source. The end of the third hose segment passes through the refrigerator shell and is connected to the injection pipe.

3. The split-ejection throttling refrigeration infrared detector according to claim 2, characterized in that: An air inlet flange and an air inlet pipe are connected to the end of the refrigerator shell, a high-pressure fluid channel is provided on the air inlet flange, one end of the air inlet pipe is connected to the high-pressure fluid channel, and the other end of the air inlet pipe is provided with an air inlet connector for an external high-pressure fluid source, and the air inlet end of the pre-cooling stage pipe and the first hose section are both connected to the high-pressure fluid channel.

4. The split-ejection throttling refrigeration infrared detector according to claim 2, characterized in that: The precooling stage tube is wound on the core shaft, a precooling stage throttling element is provided on the top of the core shaft, an air outlet end of the precooling stage tube is connected to the precooling stage throttling element, the first hose section is wound on the precooling stage tube, and the second hose section is coiled outside the end of the core shaft and directly opposite to the precooling stage throttling element.

5. The split-ejection throttling refrigeration infrared detector according to claim 2, characterized in that: The first hose section, the second hose section and the third hose section are an integrated structure.

6. The split-ejection throttling refrigeration infrared detector according to claim 1, characterized in that: The dewar assembly includes a dewar shell, and a cold finger, a cold plate and a cold screen arranged in sequence along the axis in the dewar shell. The injection pipe is located in the cold finger, and the air outlet end of the injection pipe is arranged opposite to the cold plate. The air outlet end of the injection pipe is connected to a refrigeration-stage throttling element.

7. The split-ejection throttling refrigeration infrared detector according to claim 6, characterized in that: The Dewar assembly also includes a fixing clamp ring and a connecting joint, wherein the fixing clamp ring is located at the bottom of the cold finger, the connecting joint passes through the fixing clamp ring, and the two ends of the connecting joint are respectively connected to the refrigeration-level hose and the injection pipe.

8. The split-ejection throttling refrigeration infrared detector according to claim 7, characterized in that: The fixing clamp ring is a petal-type supporting ring.

9. The split-ejection throttling refrigeration infrared detector according to claim 6, characterized in that: The cold finger includes a cylindrical section and a conical section, the small-diameter end of the conical section is connected to the cylindrical section, the injection pipe runs through the cylindrical section, and the air outlet end of the injection pipe extends into the conical section, and the cold plate is installed at the large-diameter end of the conical section.

10. The split-ejection throttling refrigeration infrared detector according to claim 1, characterized in that: The refrigeration-grade hose is an annealed metal hose, and the injection pipe is a non-annealed metal hard pipe.

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