Variable-temperature astronomical detection liquid nitrogen refrigeration device with focal plane capable of rotating by 360 degrees and manufacturing method of variable-temperature astronomical detection liquid nitrogen refrigeration device

Abstract

The invention relates to the technical field of vacuum refrigeration, and discloses a variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane capable of rotating by 360 degrees and a manufacturing method of the variable-temperature astronomical detection liquid nitrogen refrigeration device. The detector Dewar and the liquid nitrogen cold source are in vacuum sealing through a welding vacuum cavity and an O-shaped ring, the liquid nitrogen cold source is in airtight connection with the detector Dewar, and 360-degree rotation of a focal plane is achieved through a rotating block; the flexible cold chain adopts a plurality of beams of thin copper wires, two ends of each thin copper wire are welded and formed with an oxygen-free copper metal block, the flexible cold chain is arranged in the detector Dewar, one end of the flexible cold chain is connected with an output platform of the liquid nitrogen cold source, and the other end of the flexible cold chain is connected with a Dewar cold chain in the detector Dewar. The device is simple in structure, convenient to operate and low in cost; the device is suitable for various low-temperature vacuum occasions; the flexible cold chain solves the conflict problem that a cold focal plane needs to be rotated by 360 degrees and a liquid nitrogen plane needs to be vertically placed, and the 80K-300K temperature can be adjusted to meet different temperature requirements of the focal plane.

Description

Technical Field

[0001] The present invention relates to the field of vacuum refrigeration technology, and in particular to a variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees and a manufacturing method thereof. Background Art

[0002] Ground-based astronomy provides a way to image objects in space. Since most objects in space can be observed in the visible light wavelength range (380-700nm), optical astronomy has been at the forefront of astronomical observations. Many objects in space are very faint, and a camera with high sensitivity and minimal noise is needed to detect their weak signals. Back-illuminated CCD or CMOS with a quantum efficiency greater than 95% in visible light has always been the detector of choice for astronomical observations. In order to reduce detector noise, the detector needs to be cooled during actual use, and the operating temperature is mostly around 180K.

[0003] Liquid nitrogen has the characteristics of no mechanical vibration, no electrical interference, and no electromagnetic interference, and is widely used. During ground-based astronomical detection, the detector is generally hung on the telescope, and the focal plane is mostly facing upward or tilted upward, and meets a certain angle change. Liquid nitrogen refrigeration mostly requires the liquid nitrogen surface to be perpendicular to the horizontal line. Traditional technical solutions are mostly fixed in position between the liquid nitrogen surface and the detector mounting surface, which cannot meet the problem of continuous rotation of the focal plane. For example, patent 201710037351.3 "A liquid nitrogen dewar with a window on the upper end face" solves the problem that a large number of laser optical measurement equipment are needed to perform performance testing and characterization of products under low temperature conditions during the production and manufacturing of refrigerated focal plane detectors. Its sample mounting surface and liquid nitrogen surface are both parallel to the horizontal plane, the position is fixed and the temperature is about 80K; for example, patent 202010435783.1 "An integrated optical lens group MTF test equipment", in which the liquid nitrogen surface of the liquid nitrogen dewar in the equipment is parallel to the horizontal plane, the cold platform is installed perpendicular to the horizontal plane, the relative position is fixed, and the cold end temperature is about 80K. For example, Patent 202310845288.1 "New Liquid Nitrogen Test Dewar" adds three side workstations on the basis of the traditional liquid nitrogen side cover Dewar, which solves the need to test four samples at a time, but the four workstations are all perpendicular to the horizontal plane, and the liquid nitrogen surface is parallel to the horizontal plane. The relative positions of the two are fixed, and the temperature is around 80K.

[0004] The working temperature of astronomical visible detectors is mostly around 180K. Liquid nitrogen is used as a cold source to achieve a temperature change from 77K to about 180K through a variable temperature structure, and the variable temperature structure must meet the purpose of focal plane rotation. At present, there are four main methods for achieving temperature change using liquid nitrogen as a cold source: 1) Control the amount of liquid nitrogen and achieve variable temperature through heating compensation. For example, a conical regulating valve is set in the middle of the lower end of the inner shell of the patent CN201820062200 "A liquid nitrogen variable temperature metal dewar flask", and a heater is set on the variable temperature head. The automatic adjustment of the cold and heat amount during the temperature change process is achieved through the cooperation of the conical regulating valve and the heater; for example, the low temperature head of the patent CN89213854.8 "Liquid nitrogen variable temperature dewar flask" is a variable temperature structure, using liquid nitrogen refrigerant as a cold source and electric heating as a heat source. By controlling the cold and heat balance, the low temperature head can obtain the required low temperature temperature at a certain point. A novel technical structure for controlling cold and heat is adopted, thereby realizing the variable temperature control of the liquid nitrogen metal dewar flask. For example, patent CN201210019382.3 "A low-energy consumption temperature control dewar" sequentially installs a low heat transfer plate, a temperature measuring element and a heating plate on the lower side of the inner cylinder, and the temperature controller realizes heating compensation temperature control. This technical solution adopts heater heating compensation, and the current of the heater will bring external electromagnetic interference, which is not suitable for the low noise requirements of astronomical detection; 2) Control the distance between the liquid nitrogen cold surface and the cold focal surface, and realize variable temperature through heating compensation. For example, patents CN201510029336.5 "A refrigeration structure for variable temperature testing of integrated dewar components" and CN201510028939.3 "A temperature control method based on a refrigeration structure for variable temperature testing of integrated dewar components" both adjust the different distances between the liquid nitrogen surface and the cold platform to achieve a refrigeration structure with a test temperature of 85-130K, and achieve precise control of the test temperature through heat compensation. This technical solution also uses heating compensation, which will bring external electromagnetic interference, which is not suitable for the low noise requirements of astronomical detection; 3) Control the pressure value of the liquid nitrogen surface to achieve variable temperature control. For example, patent CN201210274005.4 "Pressure-controlled temperature-variable system for infrared detectors cooled by liquid nitrogen" achieves precise temperature control by controlling the pressure of the liquid surface in the Dewar liquid nitrogen container. The temperature variation range of this system is 63K~126K. Since the temperature variation of the Dewar detector is controlled by pressure, the temperature-variable system has no external electromagnetic interference and is particularly suitable for small signal temperature-variable testing of infrared detectors and astronomical detection, but the structure is complex and the focal plane and the liquid nitrogen surface are fixed. The temperature variation range cannot meet about 180K; 4) Change the contact area of ​​the heat transfer path between liquid nitrogen and the cold focal plane, and achieve temperature variation through series thermal resistance. For example, CN200710304622.3 "A liquid nitrogen refrigeration device with composite variable temperature refrigeration temperature coupling mechanism" has a temperature adjustment gap, and uses an adjustable axial cold storage tube and a cold head clamping mechanism to increase the axial displacement of the cold head, reduce the transmission path of the cold amount, and achieve temperature variation. Its purpose is to improve the refrigeration efficiency and obtain a lower refrigeration temperature and a larger refrigeration capacity.It cannot achieve temperature changes to around 180K, and its structure is complex, which does not meet the requirements of astronomical detection of cold focal plane position changes.

[0005] Therefore, it is necessary to provide a variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees and a manufacturing method thereof to solve the problems of complex structure and poor performance of refrigeration devices in the prior art. Summary of the invention

[0006] In view of this, the present invention proposes a variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees and a manufacturing method thereof, aiming to solve the problem of complex structure and poor performance of refrigeration devices in the prior art.

[0007] On the one hand, the present invention provides a variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees, comprising:

[0008] Liquid nitrogen cooling source;

[0009] The detector Dewar, the liquid nitrogen cold source is vacuum sealed by welding the vacuum chamber and the O-ring, the liquid nitrogen cold source is airtightly connected to the detector Dewar, and the 360-degree rotation of the focal plane is achieved by the rotating block;

[0010] The flexible cold chain is made of oxygen-free copper and adopts multiple bundles of thin copper wires. The two ends of the thin copper wires are welded to oxygen-free copper metal blocks. The flexible cold chain is arranged in the detector Dewar, one end of the flexible cold chain is connected to the output platform of the liquid nitrogen cold source, and the other end of the flexible cold chain is connected to the Dewar cold chain in the detector Dewar. The change of the heat transfer capacity of the flexible cold chain is realized to realize the change of the temperature of the cold end of the detector Dewar.

[0011] Furthermore, the flexible cold chain includes:

[0012] a first mounting block connected to the output platform via the first mounting block;

[0013] The middle section of the cold chain has one end connected to the end of the first mounting block away from the output platform by vacuum brazing;

[0014] One end of the second mounting block is connected to an end of the middle section of the cold chain away from the output platform through vacuum brazing, and the other end of the second mounting block is connected to the Dewar cold chain.

[0015] Further, the liquid nitrogen cooling source includes:

[0016] An upper cover, a shell and a lower cover, wherein the upper cover is arranged at one end of the shell, and the lower cover is arranged at the other end of the shell;

[0017] A cold pipe, an inner liner and a support, wherein the cold pipe is arranged in the outer shell, one end of the cold pipe is connected to the upper cover, the other end of the cold pipe is connected to one end of the inner liner, one end of the inner liner away from the cold pipe is connected to the support, and one end of the support away from the inner liner is fixed to the lower cover;

[0018] An O-ring is arranged on one side of the lower cover;

[0019] A rotating block is sleeved on the outer side wall of the O-ring;

[0020] The output platform is arranged on a side of the inner tank close to the detector dewar.

[0021] Further, the detector Dewar comprises:

[0022] An upper shell, a lower shell and a cold chain cover plate, wherein the upper shell and the lower shell are connected to form a cavity, and a cold chain cover plate is embedded on a side wall of the lower shell away from the upper shell;

[0023] A connecting cavity, one end of which is connected to the lower shell by vacuum brazing, and one end of the connecting cavity away from the lower shell is connected to the rotating block;

[0024] A cold platform, arranged inside the upper housing;

[0025] A Dewar cold chain, one end of which is connected to the cold platform, and the other end of which is connected to the second mounting block;

[0026] A heat-insulating support, one end of which is fixed on the cold platform, and the other end of which is fixed on the inner bottom surface of the lower shell.

[0027] Furthermore, the heat-insulating support is respectively connected to the lower shell and the cold platform through low-temperature-resistant glue.

[0028] Furthermore, the cold chain cover plate and the lower shell are welded airtightly by laser welding or argon arc welding;

[0029] The lower shell and the upper shell are welded in an airtight manner by means of a rubber ring and screws.

[0030] Furthermore, the Dewar cold chain and the cold platform are connected by screws.

[0031] Furthermore, the cooling tube is made of stainless steel;

[0032] The cooling tube is airtightly welded to the inner liner by vacuum brazing;

[0033] The cooling pipe is welded to the upper cover by laser welding or argon arc welding to achieve airtight welding.

[0034] Furthermore, the upper cover is provided with an air suction nozzle.

[0035] Compared with the prior art, the beneficial effects of the present invention are: the present invention has a simple structure, is easy to operate and has a low cost; it is suitable for low-temperature vacuum environments required for visible light, near-infrared and short-wave astronomical detection for ground-based astronomical observations, and is also suitable for other variable-temperature low-temperature vacuum environments that require multi-station switching; the problem of the conflict between the need for 360-degree rotation of the cold focus surface and the need for vertical placement of the liquid nitrogen surface is solved through a flexible cold chain, while at the same time achieving 80K-300K adjustable temperature to meet different focal surface temperature requirements; the present invention also meets the problems of different temperatures, multi-tool switching and low noise required for astronomical detection.

[0036] On the other hand, the present application also provides a method for manufacturing a variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees, comprising:

[0037] (1) The cooling tube is welded to the inner tank by vacuum brazing to achieve airtightness, and a leak test is performed to ensure that the leak rate is less than 8E-10 Torr·l / S;

[0038] (2) The assembly formed in step (1) is welded to the upper cover by laser welding or argon arc welding to achieve airtightness;

[0039] (3) The assembly formed in step (2) is airtightly welded to the housing with the rubber ring groove by laser welding or argon arc welding;

[0040] (4) Connect the output platform and the inner tank through threads;

[0041] (5) Connect the support member to the inner liner through low-temperature resistant glue and cure it;

[0042] (6) The assembly formed in step (5) is welded to the lower cover by laser welding or argon arc welding to achieve airtightness, and a leak test is performed to ensure that the leak rate is less than 8E-10 Torr·l / S;

[0043] (7) Connecting the middle section of the cold chain to the first mounting block and the second mounting block respectively by vacuum brazing;

[0044] (8) installing the first mounting block of the flexible cold chain formed in step (7) on the output platform;

[0045] (9) Pre-sleeve the rotating block on the connecting cavity, and weld the connecting cavity and the lower shell airtight by vacuum brazing, and check for leaks to ensure that the leakage rate is less than 8E-10Torr·l / S;

[0046] (10) Install the Dewar cold chain and insulation support on the cold platform;

[0047] (11) Install and fix the heat insulation support formed in step (10) and the lower shell formed in step (9), and install and fix the second mounting block and the Dewar cold chain;

[0048] (12) The upper housing and the lower housing formed in step (11) are sealed and fixed by a rubber ring;

[0049] (13) The cold chain cover and the lower shell are sealed and fixed by laser welding or argon arc welding, and leak detection is performed to ensure that the leakage rate is better than 8E-10Torr·l / S;

[0050] (14) The detector dewar formed in step (13) and the liquid nitrogen cold source formed in step (8) are sealed and fixed by pressing the O-ring through a rotating block.

[0051] It can be understood that the variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees and the manufacturing method thereof provided in the present application have the same beneficial effects and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0053] Figure 1 A cross-sectional view of a variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees provided by an embodiment of the present invention;

[0054] Figure 2 A front view provided for an embodiment of the present invention;

[0055] Figure 3 A schematic diagram of the structure of a flexible cold chain provided by an embodiment of the present invention;

[0056] Figure 4 A flow chart of a method for manufacturing a variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees provided in an embodiment of the present invention.

[0057] In the figure: 100, liquid nitrogen cold source; 110, upper cover; 111, exhaust nozzle; 120, outer shell; 130, lower cover; 140, cold pipe; 150, liner; 160, support; 170, O-ring; 180, rotating block; 190, output platform; 200, detector Dewar; 210, upper outer shell; 220, lower outer shell; 230, cold chain cover; 240, connecting cavity; 250, cold platform; 260, Dewar cold chain; 270, thermal insulation support; 300, flexible cold chain; 310, first mounting block; 320, middle section of cold chain; 330, second mounting block. DETAILED DESCRIPTION

[0058] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0059] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0060] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0061] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a communication between the inner sides of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0062] In some embodiments of the present application, see Figure 1-3 As shown, this embodiment provides a variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees, including:

[0063] Liquid nitrogen cooling source 100;

[0064] The detector dewar 200 and the liquid nitrogen cold source 100 are vacuum-sealed by welding the vacuum chamber and the O-ring 170. The liquid nitrogen cold source 100 is airtightly connected to the detector dewar 200, and the 360-degree rotation of the focal plane is achieved by the rotating block 180.

[0065] The flexible cold chain 300 is made of oxygen-free copper and uses multiple bundles of thin copper wires. The two ends of the thin copper wires are welded to oxygen-free copper metal blocks. The flexible cold chain 300 is arranged in the detector Dewar 200. One end of the flexible cold chain 300 is connected to the output platform 190 of the liquid nitrogen cold source 100, and the other end of the flexible cold chain 300 is connected to the Dewar cold chain 260 in the detector Dewar 200. The change of the heat transfer capacity of the flexible cold chain 300 is realized to change the cold end temperature of the detector Dewar 200.

[0066] Specifically, the flexible cold chain 300 is made of oxygen-free copper. To meet the function of rotation, multiple bundles of thin copper wires are used, and the ends of the thin copper wires are welded to the oxygen-free copper metal blocks. Furthermore, the change in the temperature of the cold end of the detector Dewar 200 is achieved by changing the heat transfer capacity of the flexible cold chain 300. Since the flexible cold chain 300 is a multi-strand wire bundle, the wire bundle can rotate with it when the focal plane rotates without affecting heat transfer.

[0067] In some embodiments of the present application, the flexible cold chain 300 includes:

[0068] A first mounting block 310, connected to the output platform 190 via the first mounting block 310;

[0069] One end of the cold chain middle section 320 is connected to the end of the first mounting block 310 away from the output platform 190 by vacuum brazing;

[0070] One end of the second mounting block 330 is connected to the end of the cold chain middle section 320 away from the output platform 190 by vacuum brazing, and the other end of the second mounting block 330 is connected to the Dewar cold chain 260 .

[0071] In some embodiments of the present application, the liquid nitrogen cooling source 100 includes:

[0072] An upper cover 110, a housing 120 and a lower cover 130, wherein the upper cover 110 is disposed at one end of the housing 120, and the lower cover 130 is disposed at the other end of the housing 120;

[0073] The cold pipe 140, the inner liner 150 and the support member 160, the cold pipe 140 is arranged in the outer shell 120, one end of the cold pipe 140 is connected to the upper cover 110, the other end of the cold pipe 140 is connected to one end of the inner liner 150, the end of the inner liner 150 away from the cold pipe 140 is connected to the support member 160, and the end of the support member 160 away from the inner liner 150 is fixed to the lower cover 130;

[0074] An O-ring 170 is disposed on one side of the lower cover 130;

[0075] The rotating block 180 is sleeved on the outer side wall of the O-ring 170;

[0076] The output platform 190 is disposed on a side of the inner tank 150 close to the detector dewar 200 .

[0077] In some embodiments of the present application, the detector dewar 200 includes:

[0078] An upper shell 210, a lower shell 220 and a cold chain cover plate 230, wherein the upper shell 210 and the lower shell 220 are connected to form a cavity, and a cold chain cover plate 230 is embedded on a side wall of the lower shell 220 away from the upper shell 210;

[0079] The connecting cavity 240 has one end connected to the lower housing 220 by vacuum brazing, and one end of the connecting cavity 240 away from the lower housing 220 is connected to the rotating block 180;

[0080] A cold platform 250 is disposed inside the upper housing 210;

[0081] A Dewar cold chain 260, one end of which is connected to the cold platform 250, and the other end of the Dewar cold chain 260 is connected to the second mounting block 330;

[0082] One end of the heat insulation support 270 is fixed on the cold platform 250 , and the other end of the heat insulation support 270 is fixed on the inner bottom surface of the lower shell 220 .

[0083] In some embodiments of the present application, the heat insulating support 270 is respectively connected to the lower housing 220 and the cold platform 250 through low temperature resistant glue.

[0084] In some embodiments of the present application, the cold chain cover 230 and the lower housing 220 are welded airtightly by laser welding or argon arc welding;

[0085] The lower housing 220 and the upper housing 210 are welded airtightly by means of a rubber ring and screws.

[0086] In some embodiments of the present application, the Dewar cold chain 260 and the cold platform 250 are connected by screws.

[0087] In some embodiments of the present application, the cold pipe 140 is made of stainless steel;

[0088] The cooling tube 140 is airtightly welded to the inner liner 150 by vacuum brazing;

[0089] The cooling pipe 140 is welded to the upper cover 110 by laser welding or argon arc welding to achieve airtightness.

[0090] In some embodiments of the present application, the upper cover 110 is provided with an air suction nozzle 111 .

[0091] Specifically, the present invention first loosens the rotating block 180, manually rotates the positional relationship between the detector Dewar 200 and the liquid nitrogen cold source 100 along the long side direction of the flexible cold chain 300 as the normal direction, and then presses the O-ring 170 through the rotating block 180 to achieve sealing and fixation, so that the focal plane can be rotated 360 degrees. After the vacuum exhaust of the suction nozzle 111 of the device is completed by an external pump source, liquid nitrogen is injected into the liner 150 through the cold pipe 140, and the cold amount of liquid nitrogen is successively transmitted to the cold platform 250 through the output platform 190, the flexible cold chain 300 and the Dewar cold chain 260 to achieve cooling. The temperature of the cold platform 250 is adjusted by changing the number of roots of the cold chain middle section harness of the flexible cold chain 300 (that is, the size of the effective cold transfer cross-sectional area).

[0092] On the other hand, see Figure 4 As shown, the present application also provides a method for manufacturing a variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees, which is used to apply the variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees, comprising the following steps:

[0093] (1) The cooling tube 140 is airtightly welded to the inner liner 150 by vacuum brazing, and a leak test is performed to ensure that the leak rate is less than 8E-10 Torr·l / S;

[0094] (2) The assembly formed in step (1) is welded to the upper cover 110 by laser welding or argon arc welding to achieve airtightness;

[0095] (3) The assembly formed in step (2) is airtightly welded to the housing 120 with the rubber ring groove by laser welding or argon arc welding;

[0096] (4) Connect the output platform 190 and the inner container 150 by threads;

[0097] (5) Connect the support member 160 to the inner liner 150 through low-temperature resistant glue and cure it;

[0098] (6) The assembly formed in step (5) is welded to the lower cover 130 by laser welding or argon arc welding to achieve airtightness, and a leak test is performed to ensure that the leak rate is less than 8E-10 Torr·l / S;

[0099] (7) Connecting the cold chain middle section 320 to the first mounting block 310 and the second mounting block 330 respectively by vacuum brazing;

[0100] (8) Installing the first mounting block 310 of the flexible cold chain 300 formed in step (7) on the output platform 190;

[0101] (9) Pre-sleeve the rotating block 180 on the connecting cavity 240, and weld the connecting cavity 240 and the lower housing 220 airtightly by vacuum brazing, and perform a leak test to ensure that the leak rate is less than 8E-10 Torr·l / S;

[0102] (10) Install the Dewar cold chain 260 and the insulation support 270 on the cold platform 250;

[0103] (11) Install and fix the heat insulation support 270 formed in step (10) and the lower shell 220 formed in step (9), and install and fix the second mounting block 330 and the Dewar cold chain 260;

[0104] (12) The upper housing 210 and the lower housing 220 formed in step (11) are sealed and fixed by a rubber ring;

[0105] (13) The cold chain cover plate 230 and the lower housing 220 are sealed and fixed by laser welding or argon arc welding, and leak detection is performed to ensure that the leakage rate is better than 8E-10 Torr·l / S;

[0106] (14) The detector dewar 200 formed in step (13) and the liquid nitrogen cold source 100 formed in step (8) are pressed against the O-ring 170 by the rotating block 180 to achieve sealing and fixing.

[0107] In summary, the present invention has a simple structure, is easy to operate and has low cost. It is suitable for low-temperature vacuum environments required for visible light, near-infrared and short-wave astronomical detection for ground-based astronomical observations, and is also suitable for other variable-temperature low-temperature vacuum environments that require multi-station switching. The flexible cold chain 300 solves the conflict between the need for 360-degree rotation of the cold focal plane and the need for vertical placement of the liquid nitrogen surface, while achieving 80K-300K adjustable temperature to meet different focal plane temperature requirements. The present invention also meets the needs of different temperatures, multi-tool switching and low noise required for astronomical detection.

[0108] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0109] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0110] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0112] 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 it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees, characterized in that: include: Liquid nitrogen cooling source; The detector Dewar, the liquid nitrogen cold source is vacuum sealed by welding the vacuum chamber and the O-ring, the liquid nitrogen cold source is airtightly connected to the detector Dewar, and the 360-degree rotation of the focal plane is achieved by the rotating block; The flexible cold chain is made of oxygen-free copper and adopts multiple bundles of thin copper wires. The two ends of the thin copper wires are welded to oxygen-free copper metal blocks. The flexible cold chain is arranged in the detector Dewar, one end of the flexible cold chain is connected to the output platform of the liquid nitrogen cold source, and the other end of the flexible cold chain is connected to the Dewar cold chain in the detector Dewar. The change of the heat transfer capacity of the flexible cold chain is realized to realize the change of the temperature of the cold end of the detector Dewar.

2. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 1 is characterized in that: The flexible cold chain includes: a first mounting block connected to the output platform via the first mounting block; The middle section of the cold chain has one end connected to the end of the first mounting block away from the output platform by vacuum brazing; One end of the second mounting block is connected to an end of the middle section of the cold chain away from the output platform through vacuum brazing, and the other end of the second mounting block is connected to the Dewar cold chain.

3. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 2 is characterized in that: Liquid nitrogen cooling sources include: An upper cover, a shell and a lower cover, wherein the upper cover is arranged at one end of the shell, and the lower cover is arranged at the other end of the shell; A cold pipe, an inner liner and a support, wherein the cold pipe is arranged in the outer shell, one end of the cold pipe is connected to the upper cover, the other end of the cold pipe is connected to one end of the inner liner, one end of the inner liner away from the cold pipe is connected to the support, and one end of the support away from the inner liner is fixed to the lower cover; An O-ring is arranged on one side of the lower cover; A rotating block is sleeved on the outer side wall of the O-ring; The output platform is arranged on a side of the inner tank close to the detector dewar.

4. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 3 is characterized in that: The detector dewar comprises: An upper shell, a lower shell and a cold chain cover plate, wherein the upper shell and the lower shell are connected to form a cavity, and a cold chain cover plate is embedded on a side wall of the lower shell away from the upper shell; A connecting cavity, one end of which is connected to the lower shell by vacuum brazing, and one end of the connecting cavity away from the lower shell is connected to the rotating block; A cold platform, arranged inside the upper housing; A Dewar cold chain, one end of which is connected to the cold platform, and the other end of which is connected to the second mounting block; A heat-insulating support, one end of which is fixed on the cold platform, and the other end of which is fixed on the inner bottom surface of the lower shell.

5. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 4 is characterized in that: The heat-insulating support is respectively connected to the lower shell and the cold platform through low-temperature-resistant glue.

6. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 4 is characterized in that: The cold chain cover plate and the lower shell are welded airtightly by laser welding or argon arc welding; The lower shell and the upper shell are welded in an airtight manner by means of a rubber ring and screws.

7. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 4 is characterized in that: The Dewar cold chain and the cold platform are connected by screws.

8. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 3 is characterized in that: The cooling tube is made of stainless steel; The cooling tube is airtightly welded to the inner liner by vacuum brazing; The cooling pipe is welded to the upper cover by laser welding or argon arc welding to achieve airtight welding.

9. The variable temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees according to claim 3, characterized in that: The upper cover is provided with an air extraction nozzle.

10. A method for manufacturing a variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees, applied to the variable-temperature astronomical detection liquid nitrogen refrigeration device with a focal plane that can rotate 360 ​​degrees as claimed in any one of claims 1 to 9, characterized in that: include: (1) The cooling tube is welded to the inner tank by vacuum brazing to achieve airtightness, and a leak test is performed to ensure that the leak rate is less than 8E-10 Torr·l / S; (2) The assembly formed in step (1) is welded to the upper cover by laser welding or argon arc welding to achieve airtightness; (3) The assembly formed in step (2) is airtightly welded to the housing with the rubber ring groove by laser welding or argon arc welding; (4) Connect the output platform to the inner tank through threads; (5) Connect the support member to the inner liner through low-temperature resistant glue and cure it; (6) The assembly formed in step (5) is welded to the lower cover by laser welding or argon arc welding to achieve airtightness, and a leak test is performed to ensure that the leak rate is less than 8E-10 Torr·l / S; (7) Connecting the middle section of the cold chain to the first mounting block and the second mounting block respectively by vacuum brazing; (8) installing the first mounting block of the flexible cold chain formed in step (7) on the output platform; (9) Pre-sleeve the rotating block on the connecting cavity, and weld the connecting cavity and the lower shell airtight by vacuum brazing, and check for leaks to ensure that the leakage rate is less than 8E-10Torr·l / S; (10) Install the Dewar cold chain and insulation support on the cold platform; (11) Install and fix the heat insulation support formed in step (10) and the lower shell formed in step (9), and install and fix the second mounting block and the Dewar cold chain; (12) The upper housing and the lower housing formed in step (11) are sealed and fixed by a rubber ring; (13) The cold chain cover and the lower shell are sealed and fixed by laser welding or argon arc welding, and leak detection is performed to ensure that the leakage rate is better than 8E-10Torr·l / S; (14) The detector dewar formed in step (13) and the liquid nitrogen cold source formed in step (8) are sealed and fixed by pressing the O-ring through a rotating block.

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