Liquid nitrogen Dewar assembly and processing and assembling method thereof

Abstract

The invention provides a liquid nitrogen Dewar assembly. The liquid nitrogen Dewar assembly comprises an outer cylinder, an inner cylinder inserted into the outer cylinder and used for containing liquid nitrogen, a supporting column inserted into the inner cylinder, a base table, a top cover arranged at the top end of the supporting column in a sleeving mode and located above the base table, a cover plate arranged above the top cover, two vacuum valves, a liquid nitrogen filling valve and a pressure release valve. The base station is fixed above the outer cylinder and the inner cylinder so as to fix the outer cylinder and the inner cylinder together, and a first sealing cavity is defined among the outer cylinder, the inner cylinder and the base station; cooling tables are arranged at the top ends of the struts; the top cover is provided with side walls, the bottom of the top cover is sealed with the cooling table, the top of the top cover is sealed with the cover plate, and a second sealing cavity is formed among the top cover, the cooling table and the cover plate. The supporting columns are made of brass; the outer cylinder, the inner cylinder, the base, the cover plate and the top cover are made of epoxy resin and glass fiber polymers. The liquid nitrogen Dewar assembly has the advantages of being detachable and capable of working for a long time, and a liquid nitrogen temperature zone low-temperature working environment can be provided for devices and chips.

Description

Technical Field

[0001] The invention relates to a liquid nitrogen dewar component and a processing and assembling method thereof, which has the characteristics of simplicity and portability. Background Art

[0002] Dewar is a container and tool for storing liquid cryogenic gas, conducting cryogenic research and wafer protection, commonly seen in liquid helium Dewar and liquid nitrogen Dewar. Since cryogenic gas is expensive, especially liquid helium needs to be imported, which puts higher requirements on the evaporation rate and volume of Dewar. Simply put, the existing Dewar is an outer cylinder with a pressure relief valve, a filling valve, a safety valve and a liquid level gauge, and its appearance is similar to that of a small boiler. Usually, the Dewar used in the laboratory is larger in size, with a height of up to 1.5m and a diameter of about 1m; while the common commercial liquid helium Dewar is generally less than 1000 liters. Since the Dewar is equipped with a filling valve, a booster valve, a liquid level gauge, etc. for liquid cryogenic gas, the use of the Dewar is professional.

[0003] Therefore, the current large size, weight and professional use of the Dewar have seriously hindered the application of cryogenic devices and chips. The main disadvantage of the existing Dewar is not only the size and weight, but also that the previous Dewar only has the function of storing liquid helium or liquid nitrogen, and the chip needs to be inserted into the Dewar with a separate test rod before it can be used.

[0004] In addition, most of the existing dewars are metal shells, and in order to reduce heat exchange, they are all multi-layered. Especially for liquid helium dewars, the temperature is low, and China does not yet have the design and processing capabilities of liquid helium dewars. They are all imported from abroad, and the specific structure, materials, and processes are unknown.

[0005] Therefore, the market urgently needs a portable, simple and easy-to-operate Dewar to popularize the application scenarios of low-temperature devices and chips. This Dewar also has the function of directly placing chips and testing. Summary of the invention

[0006] The purpose of the present invention is to provide a liquid nitrogen dewar assembly which has the characteristics of being detachable and having the ability to work for a long time.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a liquid nitrogen Dewar assembly, comprising an outer cylinder, an inner cylinder inserted in the outer cylinder and used for accommodating liquid nitrogen, a pillar inserted in the inner cylinder, a base, a top cover sleeved on the top of the pillar and located above the base, a cover plate arranged above the top cover, two vacuum valves, a liquid nitrogen filling valve and a pressure relief valve; the base is fixed above the outer cylinder and the inner cylinder to fix the outer cylinder and the inner cylinder together, and a first sealed cavity is defined between the outer cylinder, the inner cylinder and the base; a cold stage is provided at the top of the pillar; the top cover has a side wall, the bottom of which is sealed with the cold stage, and the top of which is sealed with the cover plate, so as to form a second sealed cavity between the top cover, the cold stage and the cover plate; the pillar is made of brass; the outer cylinder, the inner cylinder, the base, the cover plate and the top cover are made of epoxy resin and glass fiber polymer.

[0008] Preferably, the overall diameter of the liquid nitrogen Dewar assembly is 25 cm, the height is 30 cm, the weight is 10 kg, the maximum capacity of liquid nitrogen is 1 liter, and the support column is a vertical column with a length of 19.5 cm.

[0009] Preferably, the bottom of the top cover is sealed to the cold stage by epoxy resin corner bonding, and the top of the top cover is sealed to the cover plate by epoxy resin corner bonding.

[0010] Preferably, the base and the top cover are both provided with snap-on screw openings, the base and the top cover are fastened together via the snap-on screw openings and snaps, and a sealing ring is provided between the base and the top cover.

[0011] Preferably, two vacuum valves are respectively installed on the first vacuum valve port on the outer cylinder and the second vacuum valve port on the top cover, the liquid nitrogen filling valve is installed on the liquid nitrogen filling valve port on the base, and the pressure relief valve is installed on the pressure relief valve port on the base; the vacuum valves on the first vacuum valve port and the second vacuum valve port are respectively used to evacuate the first sealed cavity and the second sealed cavity; the liquid nitrogen filling valve is used to fill liquid nitrogen into the inner cylinder; the pressure relief valve is used to vent the inner cylinder or discharge the remaining liquid nitrogen.

[0012] Preferably, the liquid nitrogen Dewar assembly further comprises an aviation joint, which is used for connecting the device and / or chip to be cooled with an external circuit, and the device and / or chip is fixed on the cold stage.

[0013] Preferably, an aviation joint opening for installing the aviation joint is provided on a side wall of the base.

[0014] Preferably, one end of the aviation connector facing the device and / or chip is electrically connected to the device and / or chip via a low-temperature twisted pair cable.

[0015] On the other hand, the present invention provides a processing and assembly method of a liquid nitrogen Dewar assembly, characterized in that it comprises:

[0016] S1: Determine the structural parameters of the liquid nitrogen Dewar assembly according to the usage scenario; the assembly includes an outer cylinder, an inner cylinder inserted in the outer cylinder and used to contain liquid nitrogen, a pillar inserted in the inner cylinder, a base, a top cover sleeved on the top of the pillar and located above the base, a cover plate arranged above the top cover, two vacuum valves, a liquid nitrogen filling valve and a pressure relief valve;

[0017] S2: According to the structural parameters of the liquid nitrogen Dewar assembly, determine the size parameters of the outer cylinder, inner cylinder, base, top cover and cover plate;

[0018] S3: according to the parameters of the outer cylinder, the inner cylinder, the base, the top cover and the handle, epoxy resin and glass fiber polymer material are used for cutting and molding to obtain the outer cylinder, the inner cylinder, the base, the top cover and the handle;

[0019] S4: Processing to obtain a brass support and a cooling platform, wherein the cooling platform is disposed at the top of the support;

[0020] S5: Obtain vacuum valve, buckle, and aviation connector;

[0021] S6: Assemble the outer tube, the inner tube, the base, the top cover, and the handle together, wherein the base is fixed above the outer tube and the inner tube to fix the outer tube and the inner tube together, and define a first sealed cavity between the outer tube, the inner tube, and the base; the top cover has a side wall, the bottom of which is sealed with the cold stage, and the top of which is sealed with the cover plate, and a second sealed cavity is formed between the top cover, the cold stage, and the cover plate; connect the base and the top cover with a snap, and install two vacuum valves, a liquid nitrogen filling valve, a pressure relief valve, and an aviation joint;

[0022] S7: Add liquid nitrogen through the liquid nitrogen filling valve to make the liquid nitrogen Dewar assembly work normally.

[0023] The step S7 also includes: during operation, opening the pressure relief valve and the liquid nitrogen filling valve, and filling liquid nitrogen through the liquid nitrogen filling valve, at which time the device and / or chip does not need to suspend operation; and / or, after the device and / or chip is completed, opening the pressure relief valve to empty the remaining liquid nitrogen refrigerant, dismantling the device and / or chip, and then transporting the Dewar as a whole or separating the components and transporting them separately.

[0024] The liquid nitrogen dewar assembly of the present invention is assembled in an independent component manner. Each component can be assembled by snap fasteners after being processed separately. In actual use, it can also be disassembled and easily transported. At the same time, a certain component can be optimized in a targeted manner according to actual use requirements. In addition, the use and maintenance costs are also reduced.

[0025] To increase portability, based on comprehensive consideration of weight, volume, evaporation rate, etc., the outer cylinder, inner cylinder, base, top cover, cover plate, handle and other main structures are made of epoxy resin and glass fiber polymer, the liquid nitrogen filling volume is 1L, and the temperature is maintained in the range of 63K to 77K. In order to achieve low temperature environment (liquid nitrogen or liquid helium temperature zone) when making Dewar, G10 (a mixture of glass fiber and resin) is generally selected because of its poor thermal conductivity and relatively long heat preservation time. Moreover, it is non-magnetic and will not cause interference when testing chips inside its Dewar.

[0026] The liquid nitrogen dewar assembly of the present invention adopts epoxy resin on the basis of small volume, which reduces weight as much as possible under the premise of sacrificing a part of thermal insulation performance, thereby greatly improving portability. The liquid nitrogen dewar assembly of the present invention reduces the size of the previous dewar with a diameter of one meter and a height of 1.5 meters to a size of about 30 cm in height and about 25 cm in diameter, thereby increasing portability and lightness.

[0027] The liquid nitrogen Dewar assembly of the present invention is mainly used to provide a necessary liquid nitrogen temperature zone working environment for low-temperature devices and / or chips, and is particularly suitable for special application scenarios that require temporary and emergency provision of a cold source. It is not only equipped with necessary pressure relief valves, vacuum valves, aviation joints and other interfaces, but also separately equipped with a liquid nitrogen filling valve interface. Under the condition of uninterrupted device and chip operation, liquid nitrogen can be added without heating, thereby realizing the function of continuously providing a low-temperature working environment. It not only avoids the complicated operation of heating up the traditional Dewar, then adding refrigerant, and cooling down again, but also helps to prevent devices and chips from being damaged during repeated heating and cooling processes.

[0028] In summary, the liquid nitrogen Dewar assembly of the present invention is detachable and has long-term working ability according to working scenarios with strict restrictions on the volume and weight of the liquid nitrogen Dewar under certain working conditions, and can provide a low-temperature working environment in the liquid nitrogen temperature zone for devices and chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is an overall structural diagram of a liquid nitrogen Dewar assembly of the present invention;

[0030] Figure 2 It is a structural diagram of an outer cylinder of a liquid nitrogen Dewar assembly of the present invention;

[0031] Figure 3 It is a structural diagram of an inner cylinder of a liquid nitrogen Dewar assembly of the present invention;

[0032] Figure 4 It is a structural diagram of a base of a liquid nitrogen Dewar assembly of the present invention;

[0033] Figure 5 It is a structural diagram of a top cover of a liquid nitrogen Dewar assembly of the present invention;

[0034] Figure 6 It is a structural diagram of a handle of a liquid nitrogen Dewar assembly of the present invention;

[0035] Figure 7 It is a structural diagram from one perspective of a support column of a liquid nitrogen Dewar assembly of the present invention;

[0036] Figure 8 It is a structural diagram of another perspective of a support of a liquid nitrogen Dewar assembly of the present invention;

[0037] Fig. 9 This is an assembly diagram of the support, top cover and base of the liquid nitrogen dewar assembly. DETAILED DESCRIPTION

[0038] like Figure 1-Figure 9 The figure shows a liquid nitrogen dewar assembly according to an embodiment of the present invention, which includes an outer cylinder 10, an inner cylinder 20 inserted in the outer cylinder 10 and used to contain liquid nitrogen, a support column 30 inserted in the inner cylinder 20, a base 40 fixed above the outer cylinder 10 and the inner cylinder 20, a top cover 50 sleeved on the top of the support column 30 and located above the base 40, and a cover plate 60 disposed above the top cover 50. A handle 70 is designed at the outer cylinder for easy transportation.

[0039] The outer cylinder 10 and the inner cylinder 20 are cylindrical structures with closed bottom and open top. The base 40 is fixed above the outer cylinder 10 and the inner cylinder 20 to fix the outer cylinder 10 and the inner cylinder 20 together, and a first sealed cavity is defined between the outer cylinder 10, the inner cylinder 20 and the base 40. The outer cylinder 10 and the inner cylinder 20 are sealed with the base 40 by a sealant. Among them, the first sealed cavity needs to be evacuated to avoid heat convection with the external environment, reduce cold loss, and facilitate maintaining a vacuum environment at the cold stage 31 where the device and / or chip is placed.

[0040] For low-temperature devices and chips, it is very important to stably maintain their low-temperature working environment. The Dewar of the present invention uses a brass support 30 to transfer cold. Brass is an alloy of copper and zinc. In this embodiment, the length of the support 30 is 19.5 cm. In other embodiments, the length of the support is 12-19.5 cm.

[0041] like Figure 6 and Figure 7 As shown, the pillar 30 includes a main body 32 of the pillar 30 and a cold stage 31 disposed at the top of the pillar 30. A groove is processed at the cold stage 31 for fixing the device and / or chip to be cooled. In this embodiment, the groove extends vertically downward from the top surface of the cold stage 31, and the cross-section of the groove is annular, which is used to divide the cold stage 31 into a middle part and a plurality of discrete surrounding parts. The bottom of the pillar 30 is in contact with liquid nitrogen. The top cover 50 is sleeved and fixed to the outer side of the cold stage 31 of the pillar 30.

[0042] The diameters of the cold stage 31 and the main part of the pillar 30 are the same, except that the cross-sectional profile of the cold stage 31 is circular, while the main part 32 of the pillar 30 is cut, and the cross-sectional profile of the main part 32 of the pillar 30 is a rounded rectangle, and the width of the cross-sectional profile of the main part 32 of the pillar 30 after cutting is 23.80 cm.

[0043] See also Figure 1 The base 40 is supported on the bottom of the cold platform 31 to support the pillar 30 and further place the device and / or chip.

[0044] In addition, the top cover 50 has a side wall, the bottom of the top cover 50 is sealed with the cold stage 31 by epoxy resin corner bonding, and the top of the top cover 50 is sealed with the cover plate 60 by epoxy resin corner bonding, thereby forming a second sealed cavity between the top cover 50, the cold stage 31 and the cover plate 60 to facilitate vacuuming.

[0045] The base 40 and the top cover 50 are both provided with snap screw holes 51, and the base 40 and the top cover 50 are fastened together through the snap screw holes 51 and the snaps, and a sealing ring is provided between the base 40 and the top cover 50 to ensure sealing. The snaps are preferably latch-type clamps.

[0046] The liquid nitrogen dewar assembly of the present invention is also equipped with two vacuum valves, a liquid nitrogen filling valve and a pressure relief valve, wherein the two vacuum valves are respectively installed at the first vacuum valve port 81 on the outer cylinder 10 and the second vacuum valve port 82 on the top cover 50, the liquid nitrogen filling valve is installed at the liquid nitrogen filling valve port 83 on the base 40, and the pressure relief valve is installed at the pressure relief valve port 84 on the base 40. The vacuum valves on the first vacuum valve port 81 and the second vacuum valve port 82 are respectively used to evacuate the first sealed cavity between the outer cylinder 10 and the inner cylinder 20 and the second sealed cavity at the cold stage 31, which are opened during evacuation and closed after evacuation; the liquid nitrogen filling valve is used to fill liquid nitrogen into the inner cylinder 20, but the pressure relief valve needs to be opened during filling to avoid pressure increase in the cavity; the pressure relief valve is used to exhaust the inner cylinder 20 or discharge the remaining liquid nitrogen. In addition, in order to achieve electrical connection of devices and / or chips, an aviation connector opening 41 for installing an aviation connector is designed on the side wall of the base 40 . A model with vacuum sealing performance must be selected to ensure the vacuum environment at the cold stage 31 .

[0047] Therefore, since liquid nitrogen has the characteristics of being colorless, odorless, non-corrosive, and non-flammable, the liquid nitrogen Dewar assembly of the present invention only retains necessary liquid nitrogen filling, pressure relief, and vacuum valves, thereby reducing the use of openings and valves on the basis of the original Dewar, which is beneficial to maintaining the sealing performance and reducing the volatilization of liquid nitrogen on the one hand, and also reduces the volume and weight of the liquid nitrogen Dewar assembly on the other hand.

[0048] The aviation connector is used to connect the device and / or chip to be cooled with an external circuit (such as a source meter), and the device and / or chip is fixed on the cold stage 31. The end of the aviation connector facing the device and / or chip is electrically connected to the device and / or chip through a low-temperature twisted pair. Specifically, one end of the low-temperature twisted pair is welded to the aviation connector, and the other end is welded to two pin headers, which can be inserted into the socket of the device and / or chip, thereby realizing the electrical connection between the aviation connector and the device and / or chip, and then realizing the electrical connection between the external circuit and the device and / or chip.

[0049] Therefore, the use of aviation connectors to connect the internal chip with the external circuit part can meet the number of channels required for testing the performance of the device and / or chip to be cooled.

[0050] The liquid nitrogen dewar assembly of the present invention is assembled in an independent component manner. Each component can be assembled by snap fasteners after being processed separately. In actual use, it can also be disassembled and easily transported. At the same time, a certain component can be optimized in a targeted manner according to actual use requirements. In addition, the use and maintenance costs are also reduced.

[0051] In order to increase portability, based on comprehensive consideration of weight, volume, evaporation rate, etc., the outer cylinder 10, inner cylinder 20, base 40, top cover 50, cover plate 60, handle 70, and other main structures are made of epoxy resin and glass fiber polymer, the liquid nitrogen filling amount is 0.8-1.5L, and the temperature is maintained in the range of 63K to 77K. In order to achieve a low temperature environment (liquid nitrogen or liquid helium temperature zone) when making a dewar, G10 (a mixture of glass fiber and resin) is generally selected because of its poor thermal conductivity and relatively long heat preservation time. Moreover, it is non-magnetic and will not cause interference when testing chips inside its dewar.

[0052] The liquid nitrogen dewar assembly of the present invention adopts epoxy resin on the basis of small volume, which reduces weight as much as possible under the premise of sacrificing a part of thermal insulation performance, thereby greatly improving portability. The liquid nitrogen dewar assembly of the present invention reduces the size of the previous dewar with a diameter of one meter and a height of 1.5 meters to a size of about 30 cm in height and about 25 cm in diameter, thereby increasing portability and lightness.

[0053] The liquid nitrogen dewar assembly of the present invention adopts an overall structural design, material selection and processing, etc., and realizes a simple and portable liquid nitrogen dewar under the premise of meeting the evaporation rate and basic use functions. It is particularly suitable for application scenarios that require strict control of the volume and quality of the dewar; and after determining the needs, the structure can be quickly adjusted on the basis of the standard template to meet the requirements. The overall diameter of the entire liquid nitrogen dewar assembly is 23-27cm, the height is 28-35cm, the weight is 9-13kg, and the maximum capacity of liquid nitrogen is 0.8-1.5L.

[0054] The liquid nitrogen Dewar assembly of the present invention is mainly used to provide a necessary liquid nitrogen temperature zone working environment for low-temperature devices and / or chips, and is particularly suitable for special application scenarios that require temporary and emergency provision of a cold source. It is not only equipped with necessary pressure relief valves, vacuum valves, aviation joints and other interfaces, but also separately equipped with a liquid nitrogen filling valve interface. Under the condition of uninterrupted device and chip operation, liquid nitrogen can be added without heating, thereby realizing the function of continuously providing a low-temperature working environment. It not only avoids the complicated operation of heating up the traditional Dewar, then adding refrigerant, and cooling down again, but also helps to prevent devices and chips from being damaged during repeated heating and cooling processes.

[0055] In summary, the liquid nitrogen dewar assembly of the present invention is designed to be a detachable, simple and portable liquid nitrogen dewar with long-term working ability according to the working scenarios with strict restrictions on the volume and weight of the liquid nitrogen dewar under certain working conditions, so as to provide a low-temperature working environment in the liquid nitrogen temperature zone for devices and chips.

[0056] Compared with the prior art, the liquid nitrogen dewar assembly of the present invention omits the liquid level gauge and the safety valve, has a small size, and is equipped with liquid nitrogen in a small amount, so there is no need to separately install the liquid level gauge and the safety valve. Compared with the prior art, the liquid nitrogen dewar assembly of the present invention adds a vacuum valve, because the previous dewar only has the function of storing liquid helium and does not have the function of chip installation and testing, so there is no need to evacuate. The liquid nitrogen dewar assembly of the present invention is equipped with a vacuum valve, so that it works under vacuum conditions, so it can be used to test high-temperature superconducting chips.

[0057] The liquid nitrogen Dewar assembly of the present invention can provide a low-temperature working environment in the liquid nitrogen temperature zone for devices and chips through strict material selection, optimized structural design, and control of processing accuracy. After comprehensively considering the characteristics of the liquid nitrogen Dewar, the outer cylinder 10, inner cylinder 20, support 30, base 40, top cover 50, and cover plate 60 components are independently designed and assembled, which is easy to process, store, transport and maintain. It is especially advantageous for scenes where liquid nitrogen temperature zones need to be provided quickly and transportation is inconvenient. And this Dewar has secondary development and transformation capabilities. In places with extremely stringent requirements on volume, weight, etc., it can be quickly processed and assembled after re-determining the size of each component through scaling operations, and quickly put into practical use. In addition, this Dewar can complete liquid nitrogen filling during normal operation and has continuous working capabilities.

[0058] The present invention provides a processing and assembling method of a liquid nitrogen Dewar assembly, which has strong operability and high practicality, and the specific steps are as follows:

[0059] Step S1: Determine the structural parameters of the liquid nitrogen Dewar assembly according to the usage scenario;

[0060] The structural parameters of the liquid nitrogen Dewar assembly include at least one of length, width, height, weight and maximum liquid nitrogen capacity, etc. The maximum liquid nitrogen capacity is the volume of the inner cylinder of the liquid nitrogen Dewar assembly.

[0061] In this embodiment, the structural parameters of the liquid nitrogen Dewar assembly include: the overall diameter of the liquid nitrogen Dewar assembly is about 25 cm, the height is about 30 cm, the weight is about 10 kg, and the maximum capacity of liquid nitrogen is 1 liter.

[0062] In other embodiments, the overall diameter of the liquid nitrogen Dewar assembly is 23-27 cm, the height is 28-35 cm, the weight is 9-13 kg, and the maximum capacity of liquid nitrogen is 0.8-1.5 L.

[0063] Step S2: Determine the size parameters of the outer cylinder 10, the inner cylinder 20, the base 40, the top cover 50, and the cover plate 60 according to the structural parameters of the liquid nitrogen Dewar assembly;

[0064] Among them, the size parameters of the outer tube 10, the inner tube 20, the base 40, the top cover 50, the cover plate 60 and the handle 70 are obtained by appropriately scaling the template; however, it should be noted that the openings of the two vacuum valves 81, the liquid nitrogen filling valve 82 and the pressure relief valve 83, the openings of the aviation joint 41, and the openings of the snap screws cannot be scaled, and sufficient fixing space must be reserved;

[0065] Step S3: according to the parameters of the outer tube 10, the inner tube 20, the base 40, the top cover 50, and the handle 70, epoxy resin and glass fiber polymer material are used for cutting and molding to obtain the outer tube 10, the inner tube 20, the base 40, the top cover 50, and the handle 70;

[0066] Step S4: Processing to obtain the brass support 30 and the cooling platform 31;

[0067] The size of the cold stage 31 needs to be designed individually according to the device and chip specifications. In this embodiment, the length of the pillar 30 is 19.5 cm. In other embodiments, the length of the pillar is 12-19.5 cm.

[0068] Step S5: Obtain the vacuum valve, buckle, and aviation joint;

[0069] Among them, vacuum valves, clips, and aviation joints need to be purchased according to the reserved dimensions when the components are designed, and the aviation joints should have sealing properties.

[0070] Step S6: Assemble the outer cylinder 10, the inner cylinder 20, the base 40, the top cover 50, and the handle 70 together, wherein the base is fixed above the outer cylinder and the inner cylinder to fix the outer cylinder and the inner cylinder together, and a first sealed cavity is defined between the outer cylinder, the inner cylinder, and the base, and the top cover has a side wall, the bottom of which is sealed with the cold stage, and the top of which is sealed with the cover plate, and a second sealed cavity is formed between the top cover, the cold stage, and the cover plate; connect the base 40 and the top cover 50 with a snap, and install two vacuum valves, a liquid nitrogen filling valve, a pressure relief valve, and an aviation connector; fix the device and / or chip on the cold stage 31, and electrically connect the end of the aviation connector facing the device and / or chip to the device and / or chip, and the end of the aviation connector facing away from the device and / or chip is connected to an external circuit, so that the liquid nitrogen Dewar assembly is assembled.

[0071] The step S6 specifically includes: placing the inner cylinder 10 into the outer cylinder according to the bayonet position and compacting it to avoid air leakage during subsequent actual use; placing the base on the outer cylinder, and also aligning it with the bayonet position and fixing it; placing the top cover on the base, paying attention to the angle, staggering the reserved valve positions, and avoiding installation and use difficulties caused by the consistent orientation of the valves; installing the handle on the outer cylinder, and installing the valve, aviation connector, and buckle; inserting the processed brass pillar into the reserved hole at the base and fixing it, with the cold table facing upward; vacuuming the space between the outer cylinder and the inner cylinder through the vacuum valve to reduce thermal convection between the refrigerant and the external environment; installing the device and / or chip on the cold table, and making electrical connections through the aviation connector.

[0072] Among them, two vacuum valves are respectively installed on the first vacuum valve port 81 on the outer cylinder 10 and the second vacuum valve port 82 on the top cover 50, the liquid nitrogen filling valve is installed on the liquid nitrogen filling valve port 83 on the base 40, and the pressure relief valve is installed on the pressure relief valve port 84 on the base 40. The vacuum valves on the first vacuum valve port 81 and the second vacuum valve port 82 are respectively used to evacuate the first sealed cavity between the outer cylinder 10 and the inner cylinder 20 and the second sealed cavity at the cold stage 31, which are opened during evacuation and closed after evacuation; the liquid nitrogen filling valve is used to add liquid nitrogen, but the pressure relief valve needs to be opened during the addition of liquid nitrogen to avoid the pressure in the cavity from increasing; the pressure relief valve is used to exhaust or discharge the remaining liquid nitrogen. The aviation joint is installed on the side wall of the base 40.

[0073] The end of the aviation connector facing the device and / or chip is electrically connected to the device and / or chip through a low-temperature twisted pair cable, wherein the low-temperature twisted pair cable should be fixed relative to the base 40 and have an appropriate length to avoid cooling loss.

[0074] Step S7: Liquid nitrogen is added through the liquid nitrogen filling valve to enable the liquid nitrogen Dewar assembly to operate normally, thereby stably and continuously providing a low-temperature working environment for the device and / or chip.

[0075] Specifically, open the pressure relief valve and liquid nitrogen filling valve, and fill the Dewar with liquid nitrogen refrigerant through the liquid nitrogen filling valve. After the filling is completed, close the pressure relief valve and liquid nitrogen filling valve. Let it stand for about half an hour to reach the preset liquid nitrogen temperature zone. At this time, the liquid nitrogen Dewar assembly works normally, allowing the device and / or chip to work normally.

[0076] Step S7 also includes: during operation, opening the pressure relief valve and the liquid nitrogen filling valve, and filling liquid nitrogen through the liquid nitrogen filling valve, at which time the device and / or chip does not need to suspend work; and / or, after the device and / or chip is completed, opening the pressure relief valve to empty the remaining liquid nitrogen refrigerant, dismantling the device and / or chip, and then transporting the Dewar as a whole or separating the components and transporting them separately.

[0077] Before step S7, step S70 may also be included: using a vacuum pump to perform a vacuum operation through a vacuum valve, closing the vacuum valve and disconnecting the vacuum pump when a preset vacuum degree is reached, so as to reduce vibration and electromagnetic interference caused by the operation of the vacuum pump to the device and chip.

[0078] Therefore, the dimensions of each component involved in the present invention are obtained through structural simulation using 3DMax software, and the dimensions of the outer cylinder 10 and the inner cylinder 20 are strictly defined, and a gap is reserved between the outer cylinder 10 and the inner cylinder 20 for blocking the heat exchange between the refrigerant and the external environment after vacuuming. Positioning marks are provided at the joints of each component to facilitate subsequent assembly operations and to reinforce the assembled dewar. The dewar is cylindrical as a whole, and a handle is designed at the outer cylinder 10 for easy transportation. The vacuum valve, liquid nitrogen filling valve, and pressure relief valve are designed for post-installation. When long-distance transportation or transportation conditions are limited, they can be removed first and temporarily installed when actually used. The cold stage of the brass column can be specially designed according to the device and chip. When devices and / or chips of different sizes and structures need to be replaced in different application scenarios, the brass pillar can be replaced at the same time.

[0079] The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The above embodiments of the present invention can also be modified in various ways. All simple, equivalent changes and modifications made according to the claims and the description of the present invention fall within the scope of protection of the claims of the present invention. The contents not described in detail in the present invention are all conventional technical contents.

Claims

1. A liquid nitrogen Dewar assembly, characterized in that: It includes an outer cylinder, an inner cylinder inserted in the outer cylinder and used for accommodating liquid nitrogen, a pillar inserted in the inner cylinder, a base, a top cover sleeved on the top of the pillar and located above the base, a cover plate arranged above the top cover, two vacuum valves, a liquid nitrogen filling valve and a pressure relief valve; The base is fixed above the outer cylinder and the inner cylinder to fix the outer cylinder and the inner cylinder together, and a first sealed cavity is defined between the outer cylinder, the inner cylinder and the base; The top of the pillar is provided with a cold stage; the top cover has a side wall, the bottom of which is sealed with the cold stage, and the top of which is sealed with the cover plate, so as to form a second sealed cavity between the top cover, the cold stage and the cover plate; The support is made of brass; the outer cylinder, inner cylinder, base, cover plate and top cover are made of epoxy resin and glass fiber polymer.

2. The liquid nitrogen Dewar assembly according to claim 1, characterized in that: The overall diameter of the liquid nitrogen Dewar assembly is 23-27 cm, the height is 28-35 cm, the weight is 9-13 kg, the maximum capacity of liquid nitrogen is 0.8-1.5 L, and the length of the pillar is 12-19.5 cm.

3. The liquid nitrogen Dewar assembly according to claim 1, characterized in that: The bottom of the top cover is sealed with the cold stage by epoxy resin corner bonding, and the top of the top cover is sealed with the cover plate by epoxy resin corner bonding.

4. The liquid nitrogen Dewar assembly according to claim 1, characterized in that: The base and the top cover are both provided with snap screw openings, the base and the top cover are fastened together through the snap screw openings and snaps, and a sealing ring is provided between the base and the top cover.

5. The liquid nitrogen Dewar assembly according to claim 1, characterized in that: Two vacuum valves are respectively installed at the first vacuum valve port on the outer cylinder and the second vacuum valve port on the top cover, the liquid nitrogen filling valve is installed at the liquid nitrogen filling valve port on the base, and the pressure relief valve is installed at the pressure relief valve port on the base; The vacuum valves on the first vacuum valve port and the second vacuum valve port are used to evacuate the first sealed cavity and the second sealed cavity respectively; the liquid nitrogen filling valve is used to fill liquid nitrogen into the inner cylinder; and the pressure relief valve is used to vent the inner cylinder or discharge the remaining liquid nitrogen.

6. The liquid nitrogen Dewar assembly according to claim 1, characterized in that: It also includes an aviation connector, which is used to connect the device and / or chip to be cooled with an external circuit, and the device and / or chip is fixed on the cold platform.

7. The liquid nitrogen Dewar assembly according to claim 6, characterized in that: The aviation joint opening for installing the aviation joint is arranged on the side wall of the base.

8. The liquid nitrogen Dewar assembly according to claim 6, characterized in that: One end of the aviation connector facing the device and / or chip is electrically connected to the device and / or chip via a low-temperature twisted pair wire.

9. A processing and assembly method for a liquid nitrogen Dewar assembly, characterized in that: include: Step S1: Determine the structural parameters of the liquid nitrogen Dewar assembly according to the usage scenario; the assembly includes an outer cylinder, an inner cylinder inserted in the outer cylinder and used to contain liquid nitrogen, a pillar inserted in the inner cylinder, a base, a top cover sleeved on the top of the pillar and located above the base, a cover plate arranged above the top cover, two vacuum valves, a liquid nitrogen filling valve and a pressure relief valve; Step S2: Determine the size parameters of the outer cylinder, inner cylinder, base, top cover, and cover plate according to the structural parameters of the liquid nitrogen Dewar assembly; Step S3: according to the parameters of the outer cylinder, the inner cylinder, the base, the top cover and the handle, epoxy resin and glass fiber polymer material are used for cutting and molding to obtain the outer cylinder, the inner cylinder, the base, the top cover and the handle; Step S4: Processing to obtain a brass support and a cooling platform, wherein the cooling platform is disposed at the top of the support; Step S5: Obtain the vacuum valve, buckle, and aviation joint; Step S6: Assemble the outer tube, the inner tube, the base, the top cover, and the handle together, wherein the base is fixed above the outer tube and the inner tube to fix the outer tube and the inner tube together, and a first sealed cavity is defined between the outer tube, the inner tube, and the base; the top cover has a side wall, the bottom of which is sealed with the cold stage, and the top of which is sealed with the cover plate, and a second sealed cavity is formed between the top cover, the cold stage, and the cover plate; the base and the top cover are connected with a buckle, and two vacuum valves, a liquid nitrogen filling valve, a pressure relief valve, and an aviation joint are installed; Step S7: Liquid nitrogen is added through the liquid nitrogen filling valve to make the liquid nitrogen Dewar assembly work normally.

10. The processing and assembling method of the liquid nitrogen Dewar assembly according to claim 9, characterized in that: The step S7 also includes: during operation, opening the pressure relief valve and the liquid nitrogen filling valve, and filling liquid nitrogen through the liquid nitrogen filling valve, at which time the device and / or chip does not need to suspend operation; and / or, after the device and / or chip is completed, opening the pressure relief valve to empty the remaining liquid nitrogen refrigerant, dismantling the device and / or chip, and then transporting the Dewar as a whole or separating the components and transporting them separately.

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