Temperature detection device capable of being replaced on line for low-temperature pipeline and use method of temperature detection device

Abstract

The invention relates to an online replaceable temperature detection device for a low-temperature pipeline and a use method thereof, the online replaceable temperature detection device comprises an external heat insulation pipe mechanism, a protection pipe, a measurement mechanism, a first sealing assembly, a second sealing assembly and a gas guide mechanism, the external heat insulation pipe mechanism comprises an outer transverse pipe, an inner transverse pipe, an outer longitudinal pipe and an inner longitudinal pipe; the protection pipe is arranged in the inner longitudinal pipe, the first end of the protection pipe extends into the inner transverse pipe, the second end of the protection pipe is located outside the inner longitudinal pipe, and the first end of the protection pipe is further provided with a heat conduction structure. The measuring mechanism comprises a temperature sensor, a connecting line and a supporting rod, the supporting rod is fixedly arranged in the protection tube, the temperature sensor is installed on the supporting rod and detects the temperature of the heat conduction structure, the connecting line is installed on the supporting rod, the first end of the connecting line is connected with the temperature sensor, and the second end of the connecting line extends out of the protection tube; the second end of the protection tube is sealed by a second sealing assembly; and the air guide mechanism is connected with the protection pipe and is used for inflating or exhausting air in the protection pipe.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature detection, and in particular to a temperature detection device capable of being replaced online for a low-temperature pipeline and a method of using the device. Background Art

[0002] In the application of ultra-low temperature medium transportation, low temperature medium transportation faces the need for temperature collection and measurement, such as liquid nitrogen and other low temperature media. Generally, in superconducting cable refrigeration systems, liquid nitrogen circulation systems are widely used. The transportation pipeline is generally a double-layer vacuum insulated infusion pipeline. Generally, the internal pipeline has a certain pressure. The pipeline material is generally made of stainless steel. There are many problems in the collection and measurement of liquid nitrogen temperature in the pipeline system. At present, the more commonly used methods are the temperature sensor on the outer surface of the internal pipeline and the temperature sensor directly inserted into the pipeline liquid nitrogen. Among them, the temperature sensor on the outer surface of the internal pipeline is affected by the stainless steel material and the external environmental conditions, resulting in a large deviation in the temperature data collected by the temperature sensor, which cannot well reflect the temperature of the liquid nitrogen medium; and the temperature sensor is directly inserted into the pipeline liquid nitrogen, which belongs to the liquid nitrogen flushing and immersion type, which can feedback the temperature of the liquid nitrogen medium in real time without deviation. However, during installation and use or when replacement is required, due to the particularity of the low temperature medium, the entire pipeline has to be restored to normal temperature for disassembly, maintenance or replacement, which also greatly affects the use efficiency, especially in some low temperature medium pipeline systems that are not convenient to stop running, and have to be prepared or stopped, causing great losses or changes. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a temperature detection device for online replacement of low-temperature pipelines and a method of using the same, which can effectively measure the low-temperature medium in the low-temperature pipeline and realize online replacement.

[0004] To achieve the above-mentioned purpose, the present invention provides a temperature detection device that can be replaced online for low-temperature pipelines, including an external insulation pipe mechanism, a protection pipe, a measuring mechanism, a first sealing component, a second sealing component and an air guide mechanism, the external insulation pipe mechanism includes an outer transverse pipe, an inner transverse pipe, an outer longitudinal pipe and an inner longitudinal pipe, the inner transverse pipe is arranged in the outer transverse pipe, and a transverse pipe insulation space for thermal insulation is provided between the two, the first end of the outer longitudinal pipe is connected to the outer transverse pipe and the interiors thereof are kept in communication, the inner longitudinal pipe is arranged in the outer longitudinal pipe, and a longitudinal pipe insulation space for thermal insulation is provided between the two, the first end of the inner longitudinal pipe is connected to the outer transverse pipe and the interiors thereof are kept in communication, and the second end is located outside the outer longitudinal pipe, and the first end of the outer longitudinal pipe is connected to the outer transverse pipe and the interiors thereof are kept in communication, and the second end of the inner longitudinal pipe ... second end of the inner longitudinal pipe is located outside the outer longitudinal pipe, and the first end of the outer longitudinal pipe is connected to the outer transverse pipe and the second end of the inner longitudinal pipe is located outside the outer longitudinal pipe, and the first end of the outer longitudinal pipe is connected to the outer transverse pipe and the second end of the inner longitudinal pipe is located outside the outer longitudinal pipe, and the first end of the outer longitudinal pipe is connected to the outer transverse pipe and the second end of the inner longitudinal pipe The two ends are sealed; the protection tube is arranged in the inner longitudinal tube, and the first end of the protection tube extends into the inner transverse tube, and the second end is located outside the inner longitudinal tube, the first end of the protection tube is also provided with a heat-conducting structure, and the second end of the inner longitudinal tube is sealed by a first sealing component; the measuring mechanism includes a temperature sensor, a connecting wire and a support rod, the support rod is fixedly arranged in the protection tube, the temperature sensor is installed on the support rod, and detects the temperature of the heat-conducting structure, the connecting wire is installed on the support rod, and the first end of the connecting wire is connected to the temperature sensor, and the second end extends out of the protection tube, and the second end of the protection tube is sealed by a second sealing component; the air guide mechanism is connected to the protection tube, and is used to inflate or exhaust air in the protection tube.

[0005] Furthermore, the outer transverse tube and the inner transverse tube of the external insulation tube mechanism are coaxially arranged, and the outer longitudinal tube and the inner longitudinal tube are also coaxially arranged.

[0006] Furthermore, the outer transverse tube axis and the outer longitudinal tube axis are both straight lines and perpendicular to each other.

[0007] Furthermore, the measuring mechanism also includes a heat-conducting fixed structure made of heat-conducting material, the heat-conducting fixed structure is fixedly mounted on the support rod, the temperature sensor is mounted on and in contact with the heat-conducting fixed structure, and the heat-conducting fixed structure is in contact with the heat-conducting structure.

[0008] Furthermore, the heat-conducting fixing structure and the heat-conducting structure are both made of copper.

[0009] Furthermore, the air guide mechanism includes an air guide tube connected to the protection tube and a switch valve connected to the air guide tube, and the switch valve is used to be connected to the air pumping and charging device.

[0010] Furthermore, the first sealing assembly includes a first lower blade flange fixedly connected to the second end of the inner longitudinal tube, and a first upper tool magazine flange detachably fixedly connected to the first lower blade flange, the second end of the protective tube passes through the first upper tool magazine flange, and the two are sealed, and the first upper tool magazine flange is provided with a sealing ring that is in sealing contact with the first lower blade flange.

[0011] Furthermore, the second sealing assembly includes a second lower blade flange fixedly connected to the second end of the inner longitudinal tube, and a second upper tool magazine flange detachably fixedly connected to the second lower blade flange, the support rod is fixedly connected to the second upper tool magazine flange, the connecting line passes through the second upper tool magazine flange, and the second upper tool magazine flange is provided with a sealing ring that is in sealing contact with the second lower blade flange.

[0012] Furthermore, the measuring mechanism also includes a connecting terminal arranged on the second upper tool magazine flange, and the connecting wire is connected to the connecting terminal.

[0013] The present invention also provides a method for using the temperature detection device, comprising:

[0014] A. Testing work:

[0015] A1. Installation of temperature detection device: The temperature detection device is connected to the cryogenic pipeline to be detected. The cryogenic pipeline includes an inner tube and an outer tube. The outer transverse tube in the external insulation tube mechanism is connected to the outer tube, and the inner transverse tube is connected to the inner tube. According to the insulation conditions between the inner tube and the outer tube of the cryogenic pipeline, insulation materials and / or vacuum are provided in the transverse tube insulation space and the longitudinal tube insulation space; the protection tube, the measuring mechanism, the first sealing assembly, the second sealing assembly and the air guide mechanism are assembled; after the temperature detection device is installed, the cryogenic medium in the inner tube of the cryogenic pipeline can pass through the inner transverse tube;

[0016] A2. Inflate the protection tube through the air guide mechanism to maintain a certain vacuum degree in the protection tube;

[0017] A3. The low-temperature medium in the inner layer of the low-temperature pipeline contacts the heat-conducting structure when passing through the inner transverse pipe. The temperature sensor measures the temperature of the heat-conducting structure, and the detection signal is transmitted through the connecting line;

[0018] B. Change of job:

[0019] B1. When the temperature sensor needs to be replaced, fill the protective tube with water-free gas through the gas guide mechanism;

[0020] B2. Remove the second sealing assembly, pull out the support rod and the temperature sensor from the protection tube, then replace the new temperature sensor and connect the connecting wires;

[0021] B3. Insert the support rod together with the temperature sensor into the protection tube, and fix the support rod; then reinstall the second sealing assembly;

[0022] B4. Extract the gas in the protective tube through the gas guide mechanism to maintain a certain vacuum degree in the protective tube

[0023] As described above, the temperature detection device and the use method thereof according to the present invention have the following beneficial effects:

[0024] 1. The temperature detection device can be used in ultra-low temperature medium transportation applications to meet the needs of temperature collection and measurement for low temperature medium transportation. It can realize online measurement and online replacement of temperature sensors. The low temperature pipeline detected during replacement and maintenance does not need to stop normal operation, and can be filled with gas for protection during replacement to prevent water vapor from entering and reduce the impact on the low temperature medium in the low temperature pipeline, thereby realizing online replacement and maintenance with simple operation.

[0025] 2. By setting up an external insulation pipe mechanism, heat transfer can be reduced during the measurement process and replacement and maintenance process, thereby reducing the influence of the low-temperature medium in the low-temperature pipeline being tested.

[0026] 3. The heat-conducting part adopts a copper core material structure, which takes advantage of the good thermal conductivity of copper and can feedback the temperature of the low-temperature medium to the greatest extent and reduce the deviation; the other pressure-bearing parts are made of stainless steel, which has good pressure resistance and structural stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of the temperature detection device of the present invention.

[0028] Figure 2 It is a schematic diagram of the structures of the protection tube, the measuring mechanism and the gas guiding mechanism in the present invention.

[0029] Figure 3 It is a schematic diagram of the structure of the measuring mechanism in the present invention.

[0030] Figure 4 It is a schematic diagram of the structure of the protection tube in the present invention.

[0031] Figure 5 It is a schematic structural diagram of the external insulation pipe mechanism in the present invention.

[0032] Description of Figure Numbers

[0033] 1 External insulation pipe mechanism

[0034] 11 External cross tube

[0035] 12 Inner cross tube

[0036] 13 External longitudinal tube

[0037] 14 Inner longitudinal tube

[0038] 15 Transverse pipe insulation space

[0039] 16 Longitudinal pipe insulation space

[0040] 2 Protection tube

[0041] 21. Thermal Conductive Structure

[0042] 3. Measuring mechanism

[0043] 31 Temperature sensor

[0044] 32 Connection line

[0045] 33 Support rod

[0046] 34 Heat conduction fixed structure

[0047] 35 Terminal Block

[0048] 4. First sealing assembly

[0049] 41 First lower blade flange

[0050] 42 First upper tool magazine flange

[0051] 5 Second sealing assembly

[0052] 51 Second lower blade flange

[0053] 52 Second upper tool magazine flange

[0054] 6 Gas guide mechanism

[0055] 61 Airway

[0056] 62 Switch valve

[0057] 63 External interface DETAILED DESCRIPTION

[0058] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0059] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0060] See also Figures 1 to 5 The present invention provides an online replaceable temperature detection device for low-temperature pipelines, comprising an external heat-insulating pipe mechanism 1, a protective pipe 2, a measuring mechanism 3, a first sealing component 4, a second sealing component 5 and an air guide mechanism 6. The external heat-insulating pipe mechanism 1 comprises an outer transverse pipe 11, an inner transverse pipe 12, an outer longitudinal pipe 13 and an inner longitudinal pipe 14. The inner transverse pipe 12 is arranged in the outer transverse pipe 11, and a transverse pipe insulation space 15 for heat insulation is provided between the two. The first end of the outer longitudinal pipe 13 is connected to the outer transverse pipe 11 and the interiors thereof are kept in communication. The inner longitudinal pipe 14 is arranged in the outer longitudinal pipe 13, and a longitudinal pipe insulation space 16 for heat insulation is provided between the two. The first end of the inner longitudinal pipe 14 is connected to the outer transverse pipe 11 and the interiors thereof are kept in communication. The second end of the inner longitudinal pipe 14 is located outside the outer longitudinal pipe 13. The second end of the outer longitudinal pipe 13 is sealed. The transverse pipe insulation space 15 is provided between the outer transverse pipe 11 and the inner transverse pipe 1 ... 5 and the longitudinal tube insulation space 16 are preferably kept connected; the protection tube 2 is arranged in the inner longitudinal tube 14, and the first end of the protection tube 2 extends into the inner transverse tube 12, and the second end is located outside the inner longitudinal tube 14, the first end of the protection tube 2 is also provided with a heat-conducting structure 21, and the second end of the inner longitudinal tube 14 is sealed by the first sealing component 4; the measuring mechanism 3 includes a temperature sensor 31, a connecting line 32 and a support rod 33, the support rod 33 is fixedly arranged in the protection tube 2, the temperature sensor 31 is installed on the support rod 33, and detects the temperature of the heat-conducting structure 21, the connecting line 32 is installed on the support rod 33, and the first end of the connecting line 32 is connected to the temperature sensor 31, and the second end extends out of the protection tube 2, and the second end of the protection tube 2 is sealed by the second sealing component 5; the air guide mechanism 6 is connected to the protection tube 2, and is used to inflate or exhaust the protection tube 2.

[0061] The temperature detection device of the present invention can be connected to a low-temperature pipeline to detect the temperature of the low-temperature medium in the inner layer of the detector, and can also be connected to other similar occasions for detection. The use method and working principle of the temperature detection device are as follows:

[0062] A. Testing work:

[0063] A1. Installation of temperature detection device: The temperature detection device is connected to the cryogenic pipeline to be detected. The cryogenic pipeline includes an inner tube and an outer tube. The outer transverse tube 11 in the external insulation tube mechanism 1 is connected to the outer tube, and the inner transverse tube 12 is connected to the inner tube. According to the insulation conditions between the inner tube and the outer tube of the cryogenic pipeline, the transverse tube insulation space 15 and the longitudinal tube insulation space 16 can be provided with insulation material or vacuum, or both insulation material and vacuum are provided at the same time to form an insulation layer; the protection tube 2, the measuring mechanism 3, the first sealing assembly 4, the second sealing assembly 5 and the air guide mechanism 6 are all assembled; after the temperature detection device is installed, the low-temperature medium in the inner tube of the cryogenic pipeline can pass through the inner transverse tube 12.

[0064] When in use, the external insulation pipe mechanism 1 can be connected to a suitable middle position of the cryogenic pipeline to be measured, that is, both ends of the outer transverse pipe 11 and the inner transverse pipe 12 are connected to the cryogenic pipeline. The external insulation pipe mechanism 1 can also be connected to the end of the cryogenic pipeline. At this time, one end of the outer transverse pipe 11 and the inner transverse pipe 12 are connected to the cryogenic pipeline, and the other end is sealed. The outer transverse pipe 11 and the inner transverse pipe 12 of the external insulation pipe mechanism 1 can be integrally formed with the cryogenic pipeline, or they can be connected to the cryogenic pipeline in a detachable fixed connection manner, which can be conveniently disassembled as needed. After the temperature detection device is assembled, the inner longitudinal pipe 14 is sealed by the first sealing component 4 to form a closed space, which will not affect the transportation of the cryogenic medium in the cryogenic pipeline, and at the same time allow the protective tube 2 and the temperature sensor 31 inside it to extend into the interior of the cryogenic pipeline. The protective tube 2 is sealed by the first sealing component 4 to form a closed space.

[0065] A2. The protective tube 2 is evacuated through the air guide mechanism 6 to maintain a certain vacuum degree in the protective tube 2 to play a protective role and facilitate online processing. This can reduce the heat transfer generated by the protective tube 2 and avoid affecting the low-temperature medium flowing through the inner horizontal tube 12.

[0066] A3. The low-temperature medium in the inner tube of the low-temperature pipeline contacts the heat-conducting structure 21 when passing through the inner transverse tube 12. The temperature sensor 31 measures the temperature of the heat-conducting structure 21 and transmits it through the connecting line 32. When the low-temperature medium passes through the inner transverse tube 12, since the heat-insulating space 15 of the transverse tube and the heat-insulating space 16 of the longitudinal tube are provided with insulating materials and / or vacuum, the heat transfer is reduced, thereby reducing the impact on the low-temperature medium. The temperature sensor 31 indirectly measures the temperature of the low-temperature medium by measuring the heat-conducting structure 21. The heat-conducting structure 21 preferably adopts a material with good thermal conductivity, such as copper, which can well maintain the same temperature as the low-temperature medium when immersed in the low-temperature medium. The temperature sensor 31 can adopt a thermocouple type or other suitable types, directly or indirectly contacting the heat-conducting structure 21, so as to measure the temperature of the heat-conducting structure 21. The electrical signal of the temperature sensor 31 transmits the signal through the connecting line 32 to achieve accurate online measurement.

[0067] B. Change of job:

[0068] B1. When the temperature sensor 31 needs to be replaced, the protective tube 2 is filled with a gas without moisture through the gas guide mechanism 6, preferably an inert gas such as helium or nitrogen, so that the protective tube 2 is filled with gas.

[0069] B2. Remove the second sealing assembly 5, pull the support rod 33 out of the protection tube 2 together with the temperature sensor 31, then replace the new temperature sensor 31, and connect the connecting wire 32. When the second sealing assembly 5 is removed, since the protection tube 2 is filled with gas, it can prevent air containing moisture from entering the protection tube 2, and prevent water vapor from solidifying in the protection tube 2 due to low temperature, which affects the measurement work of the temperature sensor 31.

[0070] B3. The support rod 33 extends into the protection tube 2 together with the temperature sensor 31. After the temperature sensor 31 is installed in place, the support rod 33 is fixed so that the temperature sensor 31 is stably in direct or indirect contact with the heat conductive material; then the second sealing component 5 is reinstalled to ensure that the protection tube 2 is a closed cavity.

[0071] B4. The gas in the protection tube 2 is extracted through the gas guide mechanism 6 to maintain a certain vacuum degree in the protection tube 2, and the temperature sensor 31 starts to perform normal measurement work.

[0072] The temperature sensor 31 is replaced and maintained in the above manner. During the replacement and maintenance process, the detected low-temperature pipeline does not need to stop normal operation, and the replacement has little impact on the low-temperature medium in the low-temperature pipeline, thereby realizing online replacement and maintenance with simple operation.

[0073] See also Figures 1 to 5 The present invention is further described below with a specific embodiment:

[0074] In this embodiment, see Figure 1 and Figure 5 As a preferred design, the outer transverse tube 11 and the inner transverse tube 12 of the external insulation pipe mechanism 1 are coaxially arranged, and the outer longitudinal tube 13 and the inner longitudinal tube 14 are also coaxially arranged, wherein the axes of the outer transverse tube 11, the inner transverse tube 12, the outer longitudinal tube 13 and the inner longitudinal tube 14 are all straight lines, that is, they are all straight tubes, and the axis of the outer transverse tube 11 and the axis of the outer longitudinal tube 13 are perpendicular to each other, which is convenient for the installation of the protection tube 2 and the measuring mechanism 3. The outer transverse tube 11, the inner transverse tube 12, the outer longitudinal tube 13 and the inner longitudinal tube 14 can all be made of stainless steel, which has good pressure resistance and stable structure. In other embodiments, the outer transverse tube 11, the inner transverse tube 12, the outer longitudinal tube 13 and the inner longitudinal tube 14 can also be in other forms.

[0075] In this embodiment, see Figure 1 , Figure 2 and Figure 3As a preferred design, the measuring mechanism 3 also includes a heat-conducting fixed structure 34 made of a heat-conducting material. The heat-conducting fixed structure 34 uses the same copper core material as the heat-conducting structure 21, and can also use other materials with good heat conductivity such as silver. The heat-conducting fixed structure 34 is fixedly installed on the first end of the support rod 33, and the temperature sensor 31 is installed on and in contact with the heat-conducting fixed structure 34. The heat-conducting fixed structure 34 is in contact with the heat-conducting structure 21, that is, the temperature sensor 31 is indirectly in contact with the heat-conducting structure 21 through the heat-conducting fixed structure 34. The temperature sensor 31 measures the temperature of the heat-conducting structure 21 by directly measuring the temperature of the heat-conducting fixed structure 34. In this way, the temperature sensor 31 can be stably fixed in the heat-conducting fixed structure 34. When the measuring mechanism 3 is installed, when the support rod 33 and the temperature sensor 31 are extended into the protection tube 2, it only needs to make the heat-conducting fixed structure 34 stably contact with the heat-conducting structure 21 to be installed in place, and the temperature sensor 31 will not be squeezed and damaged. Preferably, multiple temperature sensors 31 can be used to better realize temperature detection.

[0076] In this embodiment, see Figure 1 , Figure 2 and Figure 4 As a preferred design, the air guide mechanism 6 includes an air guide tube 61 connected to the protection tube 2 and a switch valve 62 connected to the air guide tube 61. When working, the switch valve 62 is connected to the pumping and charging device through the external interface 63 to inflate or pump air into the protection tube 2. The switch valve 62 is opened during pumping and charging, and is closed after the pumping and charging are completed.

[0077] In this embodiment, see Figure 1 , Figure 2 and Figure 4 As a preferred design, the first sealing component 4 includes a first lower blade flange 41 fixedly connected to the second end of the inner longitudinal tube 14, and a first upper tool magazine flange 42 detachably fixedly connected to the first lower blade flange 41. The second end of the protection tube 2 passes through the first upper tool magazine flange 42, and the two are sealed. The first upper tool magazine flange 42 is provided with a sealing ring that is in sealing contact with the first lower blade flange 41. The first upper tool magazine flange 42 is preferably fixedly connected to the outer wall of the protection tube 2. The first sealing component 4 with the above design is easy to install. It only needs to extend the protection tube 2 into the inner longitudinal tube 14, and then fix the first upper tool magazine flange 42 on the first lower blade flange 41. The metal sealing ring on the first upper tool magazine flange 42 is pressed against the first lower blade flange 41, so that the second end of the inner longitudinal tube 14 is sealed, and the sealing performance is good and the pressure bearing capacity is strong. In other embodiments, the first sealing component 4 can also adopt other existing suitable structures that can achieve the function of sealing the second end of the inner longitudinal tube 14.

[0078] In this embodiment, see Figure 1 , Figure 2 and Figure 4 As a preferred design, the second sealing assembly 5 includes a second lower blade flange 51 fixedly connected to the second end of the inner longitudinal tube 14, and a second upper tool magazine flange 52 detachably fixedly connected to the second lower blade flange 51, the support rod 33 is fixedly connected to the second upper tool magazine flange 52, the connecting wire 32 passes through the second upper tool magazine flange 52, and the second upper tool magazine flange 52 is provided with a sealing ring that is in sealing contact with the second lower blade flange 51, and the sealing ring can be a metal sealing ring. Further, the measuring mechanism 3 also includes a wiring terminal 35 arranged on the second upper tool magazine flange 52, the connecting wire 32 is connected to the wiring terminal 35, and the connecting wire 32 of the temperature sensor 31 is connected to the external data processing center through the wiring terminal 35. The second sealing assembly 5 of the above design has good sealing performance and is easy to install. When installing the measuring mechanism 3, it is only necessary to extend the first end of the support rod 33 into the protective tube 2, and fix the second upper tool magazine flange 52 fixed to the second end of the support rod 33 with the second lower blade flange 51. Through the sealing contact between the metal sealing ring on the second upper tool magazine flange 52 and the second lower blade flange 51, the second end of the protective tube 2 is sealed well, and the sealing performance is good and the pressure bearing capacity is strong; when replacing, it is only necessary to disassemble the second upper tool magazine flange 52 and the second lower blade flange 51 to pull out the support rod 33. In other embodiments, the second sealing assembly 5 can also adopt other existing suitable structures that can achieve the function of sealing the second end of the protective tube 2.

[0079] As can be seen from the above, the temperature detection device and the use method thereof of the present invention have the following beneficial effects:

[0080] 1. The temperature detection device can be used in ultra-low temperature medium transportation applications to meet the needs of temperature collection and measurement faced by low temperature medium transportation, can realize online measurement, and can realize online replacement of temperature sensor 31. During the replacement and maintenance process, the low-temperature pipeline detected does not need to stop normal operation, and can be filled with gas for protection during replacement to prevent water vapor from entering and reduce the impact on the low-temperature medium in the low-temperature pipeline, thereby realizing online replacement and maintenance with simple operation.

[0081] 2. By providing an external heat-insulating pipe mechanism 1, heat transfer is reduced during the measurement process and the replacement and maintenance process, thereby reducing the influence of the cryogenic medium in the detected cryogenic pipeline.

[0082] 3. The heat-conducting part adopts a copper core material structure, which takes advantage of the good thermal conductivity of copper and can feedback the temperature of the low-temperature medium to the greatest extent and reduce the deviation; the other pressure-bearing parts are made of stainless steel, which has good pressure resistance and structural stability.

[0083] In summary, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0084] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A temperature detection device for online replacement of low-temperature pipelines, characterized in that: The invention comprises an external heat-insulating pipe mechanism (1), a protective pipe (2), a measuring mechanism (3), a first sealing assembly (4), a second sealing assembly (5) and an air guide mechanism (6); the external heat-insulating pipe mechanism (1) comprises an outer transverse pipe (11), an inner transverse pipe (12), an outer longitudinal pipe (13) and an inner longitudinal pipe (14); the inner transverse pipe (12) is arranged in the outer transverse pipe (11), and a transverse pipe insulation space (15) for heat insulation is provided between the two; the first end of the outer longitudinal pipe (13) is connected to the outer transverse pipe (11) and the interiors thereof are kept in communication; the inner longitudinal pipe (14) is arranged in the outer longitudinal pipe (13), and a longitudinal pipe insulation space (16) for heat insulation is provided between the two; the first end of the inner longitudinal pipe (14) is connected to the outer transverse pipe (11) and the interiors thereof are kept in communication; the second end of the inner longitudinal pipe (14) is located outside the outer longitudinal pipe (13); the second end of the outer longitudinal pipe (13) is sealed; the protective pipe (2) is arranged in the inner longitudinal pipe (14); , and the first end of the protection tube (2) extends into the inner transverse tube (12) and the second end is located outside the inner longitudinal tube (14); the first end of the protection tube (2) is also provided with a heat-conducting structure (21), and the second end of the inner longitudinal tube (14) is sealed by a first sealing assembly (4); the measuring mechanism (3) comprises a temperature sensor (31), a connecting wire (32) and a support rod (33); the support rod (33) is fixedly arranged in the protection tube (2); the temperature sensor (31) is mounted on the support rod (33) and detects the temperature of the heat-conducting structure (21); the connecting wire (32) is mounted on the support rod (33), and the first end of the connecting wire (32) is connected to the temperature sensor (31) and the second end extends out of the protection tube (2); the second end of the protection tube (2) is sealed by a second sealing assembly (5); the air guide mechanism (6) is connected to the protection tube (2) and is used to inflate or exhaust air in the protection tube (2).

2. The temperature detection device according to claim 1, characterized in that: The outer transverse tube (11) and the inner transverse tube (12) of the external heat-insulating tube mechanism (1) are coaxially arranged, and the outer longitudinal tube (13) and the inner longitudinal tube (14) are also coaxially arranged.

3. The temperature detection device according to claim 2, characterized in that: The axis of the outer transverse tube (11) and the axis of the outer longitudinal tube (13) are both straight lines and perpendicular to each other.

4. The temperature detection device according to claim 1, characterized in that: The measuring mechanism (3) further comprises a heat-conducting fixed structure (34) made of a heat-conducting material, the heat-conducting fixed structure (34) being fixedly mounted on the support rod (33), the temperature sensor (31) being mounted on and in contact with the heat-conducting fixed structure (34), and the heat-conducting fixed structure (34) being in contact with the heat-conducting structure (21).

5. The temperature detection device according to claim 4, characterized in that: The heat-conducting fixing structure (34) and the heat-conducting structure (21) are both made of copper.

6. The temperature detection device according to claim 1, characterized in that: The air guide mechanism (6) comprises an air guide tube (61) connected to the protection tube (2) and a switch valve (62) connected to the air guide tube (61); the switch valve (62) is used to be connected to the pumping and charging device.

7. The temperature detection device according to claim 1, characterized in that: The first sealing assembly (4) comprises a first lower blade flange (41) fixedly connected to the second end of the inner longitudinal tube (14), and a first upper tool magazine flange (42) detachably fixedly connected to the first lower blade flange (41); the second end of the protection tube (2) passes through the first upper tool magazine flange (42), and a seal is formed between the two; and a sealing ring is provided on the first upper tool magazine flange (42) for sealing contact with the first lower blade flange (41).

8. The temperature detection device according to claim 1, characterized in that: The second sealing assembly (5) comprises a second lower blade flange (51) fixedly connected to the second end of the inner longitudinal tube (14), and a second upper tool magazine flange (52) detachably fixedly connected to the second lower blade flange (51); the support rod (33) is fixedly connected to the second upper tool magazine flange (52); the connecting line (32) passes through the second upper tool magazine flange (52); and the second upper tool magazine flange (52) is provided with a sealing ring in sealing contact with the second lower blade flange (51).

9. The temperature detection device according to claim 8, characterized in that: The measuring mechanism (3) further comprises a connecting terminal (35) arranged on the second upper tool magazine flange (52), and the connecting wire (32) is connected to the connecting terminal (35).

10. A method for using the temperature detection device according to claim 1, characterized in that: include: A. Testing work: A1. Installation of the temperature detection device: The temperature detection device is connected to the cryogenic pipeline to be detected. The cryogenic pipeline includes an inner tube and an outer tube. The outer transverse tube (11) in the external heat-insulating tube mechanism (1) is connected to the outer tube, and the inner transverse tube (12) is connected to the inner tube. According to the heat insulation conditions between the inner tube and the outer tube of the cryogenic pipeline, insulation materials and / or vacuum are provided in the transverse tube insulation space (15) and the longitudinal tube insulation space (16). The protective tube (2), the measuring mechanism (3), the first sealing component (4), the second sealing component (5) and the air guide mechanism (6) are assembled. After the temperature detection device is installed, the cryogenic medium in the inner tube of the cryogenic pipeline can pass through the inner transverse tube (12). A2, inflating the protection tube (2) through the air guide mechanism (6) so that a certain vacuum degree is maintained in the protection tube (2); A3, the low-temperature medium in the inner layer pipe of the low-temperature pipeline contacts the heat-conducting structure (21) when passing through the inner transverse pipe (12), and the temperature sensor (31) measures the temperature of the heat-conducting structure (21), and the detection signal is transmitted through the connecting line (32); B. Change of job: B1. When the temperature sensor (31) needs to be replaced, the protective tube (2) is filled with gas without moisture through the gas guide mechanism (6); B2. Remove the second sealing assembly (5), pull the support rod (33) together with the temperature sensor (31) out of the protection tube (2), then replace the new temperature sensor (31) and connect the connecting wire (32); B3. Extend the support rod (33) together with the temperature sensor (31) into the protection tube (2), fix the support rod (33), and then reinstall the second sealing assembly (5); B4. The gas in the protective tube (2) is extracted through the gas guide mechanism (6) so that a certain vacuum degree is maintained in the protective tube (2).

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