High-precision profound hypothermia explosion-proof thermometer suitable for temperature measurement of vacuum heat insulation equipment

Abstract

The invention relates to the technical field of profound hypothermia temperature measuring instruments, in particular to a high-precision profound hypothermia explosion-proof thermometer suitable for temperature measurement of vacuum heat insulation equipment. The temperature sensor comprises a protection tube, a temperature sensing chip is packaged in the protection tube, and the protection tube is provided with a threading hole and a winding groove for a lead to penetrate and wind; the protection tube comprises a temperature sensing tube and a connecting tube; the device further comprises a heat insulation connecting rod, a welding flange, a socket sealing piece, a plug flange, a contact pin sealing piece and the like, the heat insulation connecting rod is made of low-heat-conductivity materials, corresponding connecting and sealing structures are arranged among the components, and the device further comprises an anti-explosion junction box, a cold end connecting rod, a loose-joint threaded connector and the like. The device achieves the technical effects of being suitable for the temperature measurement of the vacuum heat insulation equipment, being capable of achieving high-precision measurement and having an explosion-proof function.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of cryogenic temperature measuring instruments, in particular to a high-precision cryogenic explosion-proof thermometer suitable for temperature measurement of vacuum insulation equipment. BACKGROUND

[0002] In the field of cryogenic engineering, the key to efficient transportation and storage of deep cryogenic fluids (such as liquid helium and liquid hydrogen) is vacuum insulation equipment. Vacuum insulation equipment usually adopts a double-layer vacuum insulation structure (the inner layer transports or stores low-temperature medium, and the outer layer is vacuum insulated with the inner layer). Precise measurement of the temperature of the medium in the vacuum insulation equipment is crucial for transportation or storage process control, safety monitoring, and thermodynamic analysis.

[0003] However, existing temperature measurement technologies for vacuum insulation equipment face multiple challenges in such applications: Extreme temperature adaptability: Wide-range measurement from liquid helium temperature zone (4.2K) to room temperature (300K) requires the sensor to maintain high precision and stability at ultra-low temperature; conventional temperature sensors have a sharp decline in precision below 77K due to changes in material physical and chemical properties, and their packaging process and materials cannot adapt to stable measurement at extremely low temperatures; Vacuum sealing reliability: Temperature measurement of vacuum insulation equipment requires penetration of the vacuum interlayer, and poor flange or lead sealing can cause vacuum instability, affecting the insulation performance of the pipeline; although the patent (CN222087157U) improves the vacuum sealing by double sealing, the structure is complex and inconvenient to maintain; Explosion-proof safety requirements: In an environment containing flammable medium (such as liquid hydrogen), the temperature sensor electrical interface needs to meet the ExdIIC level explosion-proof standard; Installation and maintenance difficulties: Existing sensors mostly use welding fixation or integrated structure, and when a fault occurs, the outer layer needs to be destroyed and the entire sensor needs to be replaced. SUMMARY

[0004] To improve the measurement accuracy in deep cryogenic environments, the application provides a high-precision cryogenic explosion-proof thermometer suitable for temperature measurement of vacuum insulation equipment.

[0005] The high-precision cryogenic explosion-proof thermometer suitable for temperature measurement of vacuum insulation equipment provided by the application adopts the following technical solutions: A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement of vacuum insulation equipment, comprising a protective tube, a temperature sensing chip is packaged in the protective tube, the protective tube is provided with a threading hole and a winding groove, The threading hole penetrates the inner and outer walls of the protection tube, and is used for threading the lead wire connected to the temperature sensing chip, The winding groove is located at the outer wall of the protection tube, and is used for winding the lead wire.

[0006] By adopting the above technical scheme, the measurement error introduced by the lead wire heat leakage is reduced, the lead wire is wound along the winding groove for heat anchor treatment, the lead wire is inserted into the protection tube through the threading hole, and the lead wire is pre-cooled to the temperature of the protection tube wall before contacting the temperature sensing chip. The temperature sensing chip packaged in the protection tube can realize temperature measurement of the vacuum insulation equipment.

[0007] Preferably, the protection tube comprises a temperature sensing tube and a connecting tube, The temperature sensing tube is used for abutting against the vacuum insulation equipment, and the temperature sensing tube is used for packaging the temperature sensing chip, The connecting tube is connected to the temperature sensing tube, and the threading hole and the winding groove are both located at the connecting tube.

[0008] By adopting the above technical scheme, the temperature sensing tube abuts against the vacuum insulation equipment and packages the temperature sensing chip, and the temperature can be accurately sensed; the threading hole and the winding groove are both located at the connecting tube, and the influence of the lead wire on the temperature sensing tube is reduced.

[0009] Preferably, it further comprises an adiabatic connecting rod, The adiabatic connecting rod is provided with a cavity and a through hole, The protection tube is connected to one end of the adiabatic connecting rod, and the cavity penetrates the other end of the adiabatic connecting rod, The through hole is located at the outer wall of the adiabatic connecting rod, the through hole is connected to the cavity, and the through hole is used for threading the lead wire into the cavity.

[0010] By adopting the above technical scheme, the cavity penetrates the adiabatic connecting rod and the through hole is connected to the cavity for threading the lead wire, which can provide a channel for the lead wire, and at the same time, the protection tube realizes the adiabatic of the temperature sensing component and the mounting flange. The through hole is connected to the cavity, and the cavity is also effectively connected to the vacuum interlayer of the vacuum insulation equipment.

[0011] Preferably, the adiabatic connecting rod is made of a material with low thermal conductivity.

[0012] By adopting the above technical scheme, the heat transfer is reduced, the interference of the external temperature on the temperature measurement of the temperature sensing chip is reduced, and the measurement precision of the thermometer in the deep low temperature environment is improved.

[0013] Preferably, it further comprises a welding flange, a socket sealing element, a plug flange and a plug pin sealing element, The welding flange is used for being connected to the vacuum insulation equipment, The socket sealing element is embedded in the welding flange, the socket sealing element is packaged with a socket, one end of the socket extends out of the socket sealing element for connecting the lead wire, and the other end of the socket is exposed to the socket sealing element, The plug flange is used for connecting to the welding flange, The pin seal is connected to the plug flange, the pin seal encapsulates the pin, both ends of the pin extend out of the pin seal, and the pin is used for connecting to the socket.

[0014] By adopting the above technical scheme, the socket and the welding flange are in a split structure to realize quick installation and lead welding construction in the manufacturing process.

[0015] Preferably, it further comprises a sealing ring, The sealing ring is located between the welding flange and the plug flange, The pin seal is sealed between the plug flange.

[0016] By adopting the above technical scheme, the sealing between the welding flange and the plug flange is realized, good airtightness is realized, the vacuum stability of the vacuum insulation equipment is ensured, the vacuum instability affects the pipeline insulation performance is avoided, and the sealing mode is simple and reliable.

[0017] Preferably, the plug flange is provided with an external threaded interface, The external threaded interface is used for connecting the loose threaded joint.

[0018] By adopting the above technical scheme, the threaded joint is used to facilitate the welding and maintenance of the internal cable and the sealing plug.

[0019] Preferably, one end of the socket seal is embedded in the welding flange, and the other end of the socket seal is used for embedding into the plug flange.

[0020] By adopting the above technical scheme, the accurate and reliable connection between the socket and the pin is facilitated.

[0021] Preferably, it further comprises a welding flange, a socket seal and an insulation connecting rod, The welding flange is used for connecting to the vacuum insulation equipment, The socket seal is embedded in the welding flange, the socket seal encapsulates the socket, one end of the socket extends out of the socket seal for connecting the lead, and the other end of the socket is exposed to the socket seal, The insulation connecting rod is provided with a cavity and a through hole, The protection tube is connected to one end of the insulation connecting rod, and the cavity penetrates the other end of the insulation connecting rod, The through hole is located at the outer wall of the insulation connecting rod, the through hole is communicated with the cavity, and the through hole is used for the lead to enter the cavity, The other end of the insulation connecting rod is embedded in the welding flange, and the cavity is opposite to the socket.

[0022] By adopting the technical scheme, the cavity penetrates through the heat insulation connecting rod, and the through hole communicates with the cavity to allow the lead wire to pass in, so that the lead wire can be connected to the socket.

[0023] Preferably, the explosion-proof junction box, the cold-end connecting rod and the detachable threaded joint are further included, One end of the cold-end connecting rod is provided with a female plug / male plug, and the detachable threaded joint is connected to one end of the cold-end connecting rod, The other end of the cold-end connecting rod is connected to the explosion-proof junction box.

[0024] By adopting the technical scheme, the Exd IIC junction box is separated by using the detachable threaded joint, so that explosion-proof sealing can be realized, and internal cables can be prevented from being damaged by high temperature welding. At the same time, the threaded joint is convenient for welding and maintenance of the internal cables and the sealing plug.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: Split explosion-proof structure: The Exd IIC junction box is separated from the lower sealing flange by using the detachable threaded joint, so that explosion-proof sealing can be realized, and internal cables can be prevented from being damaged by high temperature welding. At the same time, the threaded joint is convenient for welding and maintenance of the internal cables and the sealing plug. Plug-in sealing flange: Glass sintering sealing is used as the main vacuum sealing measure, and the metal-glass interface air tightness can reach 10⁻ 9 Pa·m³ / s order of magnitude; O-ring sealing method is used between the plug flange and the welded flange, which is simple, reliable and has good air tightness; the socket and the welded flange are in a split structure to realize quick installation and lead wire welding construction in the manufacturing process; the leakage rate is reduced by one order of magnitude, and the vacuum is maintained through the glass sintering layer when the probe sends a rupture fault.

[0026] Thermosensitive component replaceable heat insulation structure design: The detachable heat insulation hollow connecting rod and the thermosensitive device protection tube can realize separate replacement of the thermosensitive probe, greatly reducing the maintenance cost and avoiding the disadvantages of the traditional integrated structure which needs to be scrapped as a whole; At the same time, when the temperature sensor is repaired and replaced, the outer layer of the vacuum heat insulation equipment does not need to be disassembled, greatly reducing the maintenance difficulty. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic diagram of a high-precision deep low-temperature explosion-proof thermometer suitable for temperature measurement of vacuum heat insulation equipment.

[0028] Reference signs: 11, welded flange; 12, plug flange; 21, explosion-proof junction box; 22, cold end connecting rod; 23, loose threaded joint; 3, pin seal; 4, socket seal; 5, heat insulation connecting rod; 51, through hole; 6, protective tube; 61, temperature sensing tube; 62, connecting tube; 63, threading hole; 64, winding groove. DETAILED DESCRIPTION

[0029] The application will be further described in detail below with reference to the accompanying drawings.

[0030] In the field of cryogenic engineering, the key to efficient delivery and storage of deep cryogenic fluid (such as liquid helium, liquid hydrogen) is vacuum insulation equipment. Vacuum insulation equipment usually adopts double-layer vacuum insulation structure, the inner layer delivers or stores low-temperature medium, and the outer layer is vacuum insulated with the inner layer.

[0031] Reference Figure 1 The embodiment of the application discloses a high-precision deep cryogenic explosion-proof thermometer suitable for temperature measurement of vacuum insulation equipment, which comprises a welded flange 11, a plug flange 12 and a sealing ring.

[0032] The welded flange 11 is a circular variable-diameter flange with a welded interface at one end. When installed, the welded interface of the welded flange 11 is welded and connected with the opening of the outer layer of the vacuum insulation equipment.

[0033] The inside of the welded flange 11 is a three-segment circular hole with different diameters. The third segment circular hole is the circular hole with the smallest diameter, which is located at one end of the welded flange 11; the first segment circular hole is the circular hole with the largest diameter, which is located at the other end of the welded flange 11; and the second segment circular hole is located in the middle of the welded flange 11.

[0034] The plug flange 12 is connected with the welded flange 11 through a plurality of bolts, and is sealed by using a sealing ring. The sealing ring can be an O-ring.

[0035] One end of the plug flange 12 is provided with an annular protrusion, which is used for embedding into the first segment circular hole of the welded flange 11. The other end of the plug flange 12 is provided with an external threaded interface.

[0036] The thermometer further comprises an explosion-proof junction box 21, a cold end connecting rod 22 and a loose threaded joint 23.

[0037] One end of the cold end connecting rod 22 is provided with a female plug / male plug; and the loose threaded joint 23 is connected to one end of the cold end connecting rod 22. The loose threaded joint 23 is used for being threadedly connected to the external threaded interface of the plug flange 12. The other end of the cold end connecting rod 22 is connected to the explosion-proof junction box 21.

[0038] The thermometer further comprises a pin seal 3 and a socket seal 4.

[0039] The pin seal 3 is fixedly connected in the plug flange 12, and the pin seal 3 encapsulates a pin, both ends of the pin extending out of the pin seal 3. The female / male plug of the cold end connecting rod 22 is used to connect to one end of the pin in the case that the union threaded joint 23 is screwed to the external threaded interface of the plug flange 12.

[0040] The pin seal 3 can be made of a glass sintered body as a pin sealing material. As a main vacuum sealing measure, the metal-glass interface air tightness can reach 10⁻ 9 Pa·m³ / s order of magnitude.

[0041] The socket seal 4 can be a cylindrical glass sintered body. The socket seal 4 is detachably embedded in the second section circular hole of the welded flange 11, and is also detachably embedded in the plug flange 12. The socket seal 4 encapsulates a socket, one end of the socket extending out of the socket seal 4 for connecting to a lead wire, and the other end of the socket being exposed to the socket seal 4 for connecting to the other end of the pin.

[0042] The thermometer further comprises an adiabatic connecting rod 5. The adiabatic connecting rod 5 is made of a low thermal conductivity material, which can be a low thermal conductivity glass fiber material.

[0043] One end of the adiabatic connecting rod 5 extends out of the welded flange 11 after sequentially passing through the second section circular hole and the third section circular hole, and the other end of the adiabatic connecting rod 5 is connected with a circular flange embedded in the second section circular hole. The circular flange and the socket seal 4 are connected through a plurality of bolts, for example, the bolts are screwed to the socket seal 4 after penetrating the circular flange.

[0044] The adiabatic connecting rod 5 is provided with a cavity and a through hole 51. The cavity at least penetrates the other end of the adiabatic connecting rod 5, so that the cavity is opposite to the socket. The through hole 51 is located at the outer wall of the adiabatic connecting rod 5, and the through hole 51 is communicated with the cavity, and the through hole 51 is used for the lead wire to penetrate into the cavity. The through hole 51 can be provided with two or more.

[0045] The outer periphery of one end of the adiabatic connecting rod 5 is further provided with external threads. The thermometer further comprises a protective tube 6 and a temperature sensing chip.

[0046] The protective tube 6 comprises an integrated temperature sensing tube 61 and a connecting tube 62. The temperature sensing tube 61 is used to abut against a vacuum adiabatic device, and the temperature sensing tube 61 is used to encapsulate the temperature sensing chip. The connecting tube 62 is communicated with the temperature sensing tube 61, and the connecting tube 62 is screwed to one end of the adiabatic connecting rod 5.

[0047] The connecting tube 62 is provided with a threading hole 63 and a winding groove 64. The threading hole 63 penetrates the inner and outer walls of the connecting tube 62, and is used for the lead wire connected to the temperature sensing chip to penetrate in. The winding groove 64 is located at the outer wall of the connecting tube 62, and is used for winding the lead wire. The winding groove 64 can be spiral.

[0048] The lead wire connected to the temperature sensing chip is extended from the connecting pipe 62 through the threading hole 63 and is wound around the wire groove 64 to pre-cool the lead wire before it contacts the temperature sensing chip, and finally enters the cavity of the heat insulation connecting rod 5 through the through hole 51 and is connected to the socket upward.

[0049] The thermometer design can match both insertion and attachment installation modes: When the inner tube diameter of the vacuum tube is large or is used for temperature measurement of a vacuum insulation container, the insertion mode can be used: a blind tube is welded on the inner layer pipe (the inner wall of the container), the tube opening faces outward, and then the protective tube 6 is inserted into the blind tube, and the outer wall of the protective tube 6 can be coated with a low-temperature grease or the like heat-conducting material; When the inner tube diameter of the vacuum tube is small, the attachment mode can be used: the attachment block is designed as a circular arc surface structure, the curvature of which matches the outer diameter of the corresponding pipe, and is attached to the outer wall of the inner tube through a vacuum compatible adhesive (such as epoxy resin EP62); the attachment block is provided with a socket, the protective tube 6 is inserted into the socket, and the outer wall of the protective tube 6 can be coated with a low-temperature heat-conducting grease to enhance the thermal contact; the attachment block can be fixed on the outer wall of the inner tube through a clamp.

[0050] The implementation principle of the high-precision deep low-temperature explosion-proof thermometer for temperature measurement of a vacuum insulation device according to the embodiment of the present application is as follows: through reasonable design and cooperation of various components, wide-temperature-range high-precision measurement is achieved. The threading hole 63 and the wire groove 64 of the protective tube 6 are designed to reduce lead wire heat leakage error, the heat insulation connecting rod 5 is made of a low-thermal-conductivity material to reduce heat transfer, and the measurement accuracy is ensured. The plug-in type sealing flange and the sealing ring ensure the reliability of the vacuum seal, the split type explosion-proof structure meets the explosion-proof safety requirements. The detachable connection mode makes it convenient to replace and maintain the temperature sensing chip and other components when they fail, thereby reducing the maintenance cost and difficulty.

[0051] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A high-precision deep low-temperature explosion-proof thermometer suitable for temperature measurement of a vacuum insulation device, characterized in that, Including protective tube (6), The protective tube (6) is used to encapsulate the temperature sensing chip. The protective tube (6) is provided with a wire hole (63) and a winding groove (64). The through hole (63) penetrates the inner and outer walls of the protective tube (6), and the through hole (63) is used for the lead wire connected to the temperature sensing chip to pass through. The winding groove (64) is located on the outer wall of the protective tube (6) and is used for winding the lead wire.

2. The high-precision cryogenic explosion-proof thermometer for temperature measurement in vacuum insulation equipment according to claim 1, characterized in that, The protective tube (6) includes a temperature sensing tube (61) and a connecting tube (62). The temperature sensing tube (61) is used to resist the vacuum insulation device, and the temperature sensing tube (61) is used to encapsulate a temperature sensing chip. The connecting pipe (62) is connected to the temperature sensing pipe (61), and the wire hole (63) and the winding groove (64) are both located at the connecting pipe (62).

3. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 1, characterized in that, It also includes the thermally insulating connecting rod (5). The thermally insulating connecting rod (5) is provided with a cavity and a through hole (51). The protective tube (6) is connected to one end of the insulating connecting rod (5), and the cavity extends through the other end of the insulating connecting rod (5). The through hole (51) is located on the outer wall of the heat-insulating connecting rod (5), the through hole (51) is connected to the cavity, and the through hole (51) is used to allow the lead wire to pass into the cavity.

4. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 3, characterized in that, The thermally insulating connecting rod (5) is made of a material with low thermal conductivity.

5. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 1, characterized in that, It also includes a welding flange (11), a socket seal (4), a plug flange (12), and a pin seal (3). The welded flange (11) is used to connect to the vacuum insulation equipment. The socket seal (4) is embedded in the welding flange (11). The socket seal (4) contains a socket. One end of the socket extends out of the socket seal (4) for lead wire connection, and the other end of the socket protrudes from the socket seal (4). The plug flange (12) is used to connect to the welding flange (11). The pin seal (3) is connected to the plug flange (12). The pin seal (3) contains a pin, and both ends of the pin extend out of the pin seal (3). The pin is used to connect to the socket.

6. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 5, characterized in that, It also includes sealing rings, The sealing ring is located between the welding flange (11) and the plug flange (12). The pin seal (3) is sealed to the plug flange (12).

7. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 5, characterized in that, The plug flange (12) is provided with an external thread interface. The external threaded interface is used for connection of the live threaded connector (23).

8. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 5, characterized in that, One end of the socket seal (4) is embedded in the welding flange (11), and the other end of the socket seal (4) is used to be embedded in the plug flange (12).

9. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 1, characterized in that, It also includes a welding flange (11), a socket seal (4), and an insulating connecting rod (5). The welded flange (11) is used to connect to the vacuum insulation equipment. The socket seal (4) is embedded in the welding flange (11). The socket seal (4) contains a socket. One end of the socket extends out of the socket seal (4) for lead wire connection, and the other end of the socket protrudes from the socket seal (4). The thermally insulating connecting rod (5) is provided with a cavity and a through hole (51). The protective tube (6) is connected to one end of the insulating connecting rod (5), and the cavity extends through the other end of the insulating connecting rod (5). The through hole (51) is located on the outer wall of the insulating connecting rod (5), and the through hole (51) communicates with the cavity. The through hole (51) is used to allow the lead wire to pass into the cavity. The other end of the insulating connecting rod (5) is embedded in the welding flange (11), and the cavity is directly opposite the socket.

10. A high-precision cryogenic explosion-proof thermometer suitable for temperature measurement in vacuum insulation equipment according to claim 1, characterized in that, It also includes an explosion-proof junction box (21), a cold end connecting rod (22), and a union threaded connector (23). One end of the cold end connecting rod (22) is provided with a female plug / male plug, and the threaded union (23) is connected to one end of the cold end connecting rod (22). The other end of the cold end connecting rod (22) is connected to the explosion-proof junction box (21).

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