A flexible vacuum insulation tube for superconducting cables with self-diagnostic lifespan function

Abstract

This invention provides a flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function. It includes an inner tube, an outer tube, double-layer end caps, an insulation layer, a gas analysis module, a multi-parameter sensing module, and a lifespan self-diagnosis analysis system. The inner tube is fitted inside the outer tube, and the double-layer end caps are located at both ends of the inner and outer tubes, forming a vacuum interlayer between them. The insulation layer is located within the vacuum interlayer. The gas analysis module is connected to the vacuum interlayer and is used to detect the composition and concentration of residual gas within the vacuum interlayer. The multi-parameter sensing module is located within the vacuum interlayer and is used to detect multiple parameter values ​​of the flexible vacuum insulation tube. The lifespan self-diagnosis analysis system of this invention performs coupled analysis of multiple physical parameters and residual gas composition and concentration data, enabling early warning of potential faults such as gas leakage, getter failure, and insulation layer moisture absorption. This provides maintenance personnel with accurate maintenance information, reduces troubleshooting time, and lowers the operational risks of superconducting cables.

Description

Technical Field

[0001] This invention relates to the field of superconducting cable technology, and in particular to a flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function. Background Technology

[0002] Superconducting cables, with their advantages of low loss, large transmission capacity, energy saving, and environmental friendliness, have become one of the core equipment in the future power transmission field. The normal operation of superconducting cables depends on an extremely low temperature environment (typically liquid nitrogen temperature or lower), therefore, a highly efficient heat insulation structure must be installed externally. Flexible vacuum insulation tubes, as a key component of superconducting cables, are mainly used to maintain the low-temperature environment required for cable operation, while also adapting to bending and turning conditions during cable laying to ensure the stability of insulation performance.

[0003] Currently, existing flexible vacuum insulation tubes for superconducting cables mainly suffer from the following technical defects: 1. The monitoring methods for the operating status of thermal insulation tubes are limited. Most methods can only monitor vacuum level or a single temperature parameter, and cannot simultaneously acquire information on multiple physical quantities such as temperature, strain, and heat leakage gradient. This makes it difficult to comprehensively reflect the aging, damage, and failure trends of the thermal insulation tubes, and it is easy to have monitoring blind spots, resulting in failures not being detected in a timely manner.

[0004] 2. Lack of residual gas analysis. If leakage or getter failure occurs in the vacuum interlayer of the flexible vacuum insulation tube, residual gases such as H2, O2, N2, H2O, and CO2 will be introduced. These gases will not only significantly reduce the insulation performance, but may also corrode the insulation layer material and damage the superconducting cable itself. However, current technology cannot achieve in-situ, real-time detection of residual gases, and can only conduct offline sampling detection, which is inefficient and has a strong lag, and cannot meet the maintenance requirements of engineering operation.

[0005] 3. Poor compatibility between the sensing structure and the flexibility and vacuum performance of the insulation tube. Most existing sensing devices are external or rigidly embedded, which not only damages the vacuum sealing structure of the insulation tube, but also affects its bending performance. This can lead to problems such as sensing component detachment and seal failure during the installation or operation of the insulation tube, further reducing the reliability of the insulation tube.

[0006] 4. Lack of an effective fault early warning mechanism. Existing monitoring data are independent of each other, making it impossible to determine the fault type and severity of the insulation pipe through multi-physical quantity coupling analysis. It is difficult to provide early warning of potential problems such as air leakage, getter failure, and insulation layer dampness, which can easily lead to superconducting cable operation failures and cause significant economic losses. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function, in order to solve the problems existing in the prior art.

[0008] To achieve the above and other related objectives, this invention provides a flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function, comprising an inner tube, an outer tube, double-layer end caps, an insulation layer, a gas analysis module, a multi-parameter sensing module, and a lifespan self-diagnosis analysis system. The inner tube is fitted inside the outer tube, and the double-layer end caps are located at both ends of the inner and outer tubes, forming a vacuum interlayer between the inner and outer tubes. The insulation layer is disposed within the vacuum interlayer. The gas analysis module is connected to the vacuum interlayer and is used to detect the composition and concentration of residual gas within the vacuum interlayer. The multi-parameter sensing module is disposed within the vacuum interlayer and is used to detect multiple parameter values ​​of the flexible vacuum insulation tube. The lifespan self-diagnosis analysis system is communicatively connected to the gas analysis module and the multi-parameter sensing module, and is used to receive, read, and analyze the information fed back by the gas analysis module and the multi-parameter sensing module to automatically diagnose the lifespan of the flexible vacuum insulation tube.

[0009] Preferably, the double-layer head has an inner cavity that communicates with the vacuum interlayer; the double-layer head is provided with a first mounting port, a second mounting port, and a spare mounting port; the first mounting port is used to connect to a gas analysis module; the second mounting port is used to connect to a life self-diagnosis analysis system; the spare mounting port is detachably provided with a sealing cover plate for drawing a vacuum from the vacuum interlayer or as a backup for the first and second mounting ports.

[0010] Preferably, the vacuum interlayer is further provided with a getter, which is used to adsorb residual gas in the vacuum interlayer and maintain the vacuum environment in the vacuum interlayer.

[0011] Preferably, the insulation layer is disposed in the vacuum interlayer and is attached to the outer wall of the inner tube; the insulation layer includes several layers of insulation paper and several layers of reflective layer, and the insulation paper and reflective layer are stacked alternately.

[0012] Preferably, the gas analysis module includes a miniature residual gas sampling chamber, a miniature mass spectrometer core, and a signal conversion unit. The miniature residual gas sampling chamber is connected to a vacuum interlayer and is used to collect residual gas in the vacuum interlayer. The miniature mass spectrometer core is used to analyze the composition and concentration of the collected residual gas. The signal conversion unit is communicatively connected to a lifetime self-diagnosis analysis system and is used to feed back the detection results to the lifetime self-diagnosis analysis system.

[0013] Preferably, the micro residual gas sampling chamber is further provided with a micro filter membrane, which is used to filter impurities in the residual gas.

[0014] Preferably, the multi-parameter sensing module includes a flexible shielded microduct, a distributed optical fiber, and a micro-sensing composite strip. The flexible shielded microduct is disposed on the outer surface of the insulation layer and extends along the length of the flexible vacuum insulation tube. The distributed optical fiber and the micro-sensing composite strip are inserted inside the flexible shielded microduct. The micro-sensing composite strip integrates an FBG temperature sensor, a piezoelectric strain sensor, and a capacitive vacuum sensor. The FBG temperature sensor is used to detect the temperature parameters of the flexible vacuum insulation tube, the piezoelectric strain sensor is used to detect the strain parameters of the flexible vacuum insulation tube, and the capacitive vacuum sensor is used to detect the vacuum parameters of the flexible vacuum insulation tube. The distributed optical fiber is used to detect the temperature parameters of the flexible vacuum insulation tube. Both the distributed optical fiber and the micro-sensing composite strip are communicatively connected to the lifetime self-diagnosis analysis system to feed back the detection results to the lifetime self-diagnosis analysis system.

[0015] Preferably, the flexible shielded microcatheter is made of a composite of a polytetrafluoroethylene insulating layer and a copper wire shielding layer, and the flexible shielded microcatheter has several through holes, the interior of the flexible shielded microcatheter being connected to the vacuum interlayer through the through holes.

[0016] Preferably, the gas analysis module and the lifetime self-diagnostic analysis system are connected via a signal conversion unit transmission line, which is inserted through a through-hole into a flexible shielded microcatheter.

[0017] Preferably, the lifespan self-diagnostic analysis system includes an information interface, a signal line, and a microcontroller. The information interface is located on the double-layer end cap and is used for communication with the gas analysis module and the multi-parameter sensing module. The information interface is connected to the microcontroller via the signal line and is used to transmit information to the microcontroller. The microcontroller includes an edge computing unit, an alarm unit, and a communication unit. The edge computing unit is used to receive and process the information transmitted by the information interface. The alarm unit triggers an alarm based on the information processed by the edge computing unit. The communication unit is used to transmit the information processed by the edge computing unit.

[0018] As described above, the flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function, as disclosed in this invention, has the following beneficial effects: 1. The flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function, as disclosed in this invention, enables simultaneous monitoring of multiple physical parameters and residual gas composition concentration. This application incorporates a multi-parameter sensing module within the vacuum interlayer to simultaneously detect temperature, strain, and vacuum parameters; and a gas analysis module to detect the composition and concentration of residual gas within the vacuum interlayer. This comprehensive approach reflects the operational status of the flexible vacuum insulation tube, solving the problems of limited monitoring methods and the inability to monitor residual gas in real time in existing technologies.

[0019] 2. The flexible vacuum insulation tube for superconducting cables with self-diagnostic lifespan function involved in this invention exhibits good performance compatibility between the multi-parameter sensing module, the gas analysis module, and the flexible vacuum insulation tube. The gas analysis module is installed in the pre-reserved installation port of the multi-layer end cap, without affecting the bending and turning of the flexible vacuum insulation tube. The multi-parameter sensing module is embedded on the outer surface of the insulation layer and is equipped with a flexible shielded microconduct. The flexible shielded microconduct adopts a flexible design, which will not damage the sealing structure of the vacuum interlayer and will not affect the flexible bending performance of the flexible vacuum insulation tube. It is suitable for bending and turning during the laying of superconducting cables, avoiding the problems of sealing failure and sensor component detachment caused by rigid sensing devices in the prior art.

[0020] 3. The flexible vacuum insulation tube for superconducting cables with life self-diagnosis function involved in this invention is equipped with a life self-diagnosis analysis system. The life self-diagnosis analysis system performs coupled analysis of multiple physical parameters and residual gas composition concentration data, which can provide early warning of potential faults such as gas leakage, getter failure, and insulation layer dampness, providing maintenance personnel with accurate maintenance basis, reducing fault diagnosis time, and reducing the operation risk of superconducting cables.

[0021] 4. The flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function involved in this invention has stable insulation performance and high reliability. The vacuum interlayer in this application contains an insulation layer and a getter, which effectively maintains the vacuum environment and reduces heat loss. Simultaneously, a gas analysis module is included to monitor residual gas in real time, promptly detect leaks, further improve the insulation performance and operational reliability of the flexible vacuum insulation tube, and extend the service life of the superconducting cable.

[0022] 5. The flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function involved in this invention has strong engineering applicability. The structure of this application is simple and the design is reasonable. All components use mature low-temperature and vacuum-compatible materials, the manufacturing process is feasible, and it can achieve mass production. It can be adapted to superconducting cables of different specifications to meet the needs of engineering operation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the internal structure of the flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function, which is involved in this invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Inner tube; 2. Outer tube; 3. Insulation layer; 4. Double-layer end cap; 5. Information interface; 6. Gas analysis module; 7. Flexible shielded microcatheter; 8. Microcontroller; 9. CF type vacuum interface; 10. Sealing cover plate; 11. Distributed optical fiber; 12. Microsensor composite strip; 13. Signal line; 14. Signal conversion unit transmission line; 15. Vacuum interlayer. Detailed Implementation

[0026] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0027] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0028] like Figure 1 As shown, this invention provides a flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function (hereinafter referred to as the vacuum insulation tube), including an inner tube 1, an outer tube 2, a double-layer end cap 4, an insulation layer 3, a gas analysis module 6, a multi-parameter sensing module, and a lifespan self-diagnosis analysis system. The inner tube 1 is sleeved in the outer tube 2, and the double-layer end cap 4 is disposed at both ends of the inner tube 1 and the outer tube 2, forming a vacuum interlayer 15 with the gap between the inner tube 1 and the outer tube 2. The insulation layer 3 is disposed in the vacuum interlayer 15. The gas analysis module 6 is connected to the vacuum interlayer 15 and is used to detect the composition and concentration of residual gas in the vacuum interlayer 15. The multi-parameter sensing module is disposed in the vacuum interlayer 15 and is used to detect multiple parameter values ​​of the vacuum insulation tube. The lifespan self-diagnosis analysis system is communicatively connected to the gas analysis module 6 and the multi-parameter sensing module and is used to receive, read, and analyze the information fed back by the gas analysis module 6 and the multi-parameter sensing module to automatically diagnose the lifespan of the vacuum insulation tube.

[0029] The present invention relates to a flexible vacuum insulation tube for superconducting cables with a lifespan self-diagnosis function, which is equipped with a gas analysis module 6, a multi-parameter sensing module, and a lifespan self-diagnosis analysis module. The gas analysis module 6 is used to detect the composition and concentration of residual gas in the vacuum interlayer 15. The multi-parameter sensing module is used to detect multiple physical parameters (e.g., temperature parameters, strain parameters, vacuum degree parameters, etc.) in the vacuum interlayer 15 and feeds the above parameter information back to the lifespan self-diagnosis analysis system. The lifespan self-diagnosis analysis system performs coupled analysis on multiple physical parameters and residual gas composition and concentration data to perform real-time lifespan diagnosis of the vacuum insulation tube.

[0030] Preferred, such as Figure 1 As shown, both the inner tube 1 and the outer tube 2 are made of flexible corrugated pipes, and the material is stainless steel or aluminum. The corrugation spacing and depth of the corrugated pipes are determined according to actual needs. The wall thickness of the inner tube 1 and the outer tube 2 is between 0.3mm and 0.8mm, which effectively ensures the flexibility and sealing performance of the vacuum insulation pipe, and gives the vacuum insulation pipe good low temperature resistance and corrosion resistance.

[0031] Preferred, such as Figure 1 As shown, the double-layer head 4 has an inner cavity that communicates with the vacuum jacket 15. The double-layer head 4 is provided with a first mounting port, a second mounting port, and a spare mounting port. The first mounting port is used to connect to the gas analysis module 6. The second mounting port is used to connect to the life self-diagnosis analysis system. The spare mounting port is detachably provided with a sealing cover plate 10, which is used to evacuate the vacuum jacket 15 or as a backup for the first and second mounting ports.

[0032] In this embodiment, there are two double-layer end caps 4, and the double-layer end caps 4 are annular in shape. The double-layer end caps 4 are welded to the inner tube 1 and the outer tube 2, respectively. An inner cavity is formed within the double-layer end cap 4, which communicates with the vacuum interlayer 15 to form a sealed cavity. A vacuum is then evacuated from this cavity to form the vacuum interlayer 15, thereby reducing heat convection inside the vacuum insulation tube and ensuring that the interior of the inner tube 1 remains at a low temperature, thus guaranteeing the transmission of the superconducting cable. The double-layer end caps 4 are made of the same material as the inner tube 1 and the outer tube 2, such as 304 stainless steel or 316L stainless steel.

[0033] Furthermore, in this embodiment, the first mounting port and the second mounting port are respectively located on the double-layered end cap 4 at the left end, and the spare mounting port is located on the double-layered end cap 4 at the right end. The first mounting port is used to connect the gas analysis module 6, and the second mounting port is used to connect the life self-diagnosis analysis system. Since the gas analysis module 6 and the life self-diagnosis analysis system are connected in communication, setting the first and second mounting ports on the same end of the double-layered end cap 4 can shorten the length of the transmission line between them, making installation easier. In addition, a sealing cover plate 10 is detachably provided on the spare mounting port. When the first and second mounting ports malfunction, the spare mounting port can be used to connect the gas analysis module 6 or the life self-diagnosis analysis system; the spare mounting port can also be connected to a vacuum pump to evacuate the vacuum jacket 15, so that the vacuum jacket 15 is in a vacuum environment.

[0034] Preferably, in this embodiment, a getter is also provided in the vacuum interlayer 15. The getter is used to adsorb residual gas in the vacuum interlayer 15 and maintain the vacuum environment in the vacuum interlayer 15. In this embodiment, the getter is made of activated carbon combined with molecular sieves, palladium oxide and other adsorbents, which are uniformly filled into the gaps of the vacuum interlayer 15 in a certain proportion. The filling amount is placed according to the actual structure of the vacuum insulation tube, and is used to continuously adsorb residual gas in the vacuum interlayer 15 and prolong the vacuum maintenance time.

[0035] Preferred, such as Figure 1 As shown, the insulation layer 3 is disposed in the vacuum interlayer 15 and is attached to the outer wall of the inner tube 1. The insulation layer 3 includes several layers of insulation paper and several layers of reflective layer, which are alternately stacked. In this embodiment, the insulation paper is made of polyimide, which can effectively ensure the insulation performance and also adapt to the flexibility of the vacuum insulation tube. The reflective layer is made of aluminum foil.

[0036] Preferably, in this embodiment, the gas analysis module 6 includes a miniature residual gas sampling chamber, a miniature mass spectrometer core, and a signal conversion unit. The miniature residual gas sampling chamber is connected to the vacuum interlayer 15 and is used to collect residual gas in the vacuum interlayer 15. The miniature mass spectrometer core is used to analyze the composition and concentration of the collected residual gas. The signal conversion unit is communicatively connected to the lifetime self-diagnosis analysis system and is used to feed back the detection results to the lifetime self-diagnosis analysis system. In this embodiment, the gas analysis module 6 is also referred to as a miniature RGA module.

[0037] Furthermore, such as Figure 1 As shown, the miniature residual gas sampling chamber is connected to the first mounting port via a metal sealing ring and a CF-type vacuum interface 9. The residual gas in the vacuum jacket 15 includes H2, O2, N2, H2O, CO2, etc. The signal conversion unit is used to convert the analysis signal into an electrical signal and feed it back to the lifetime self-diagnosis analysis system. The signal conversion unit is communicatively connected to the lifetime self-diagnosis analysis system via the signal conversion unit transmission line 14.

[0038] Preferably, in this embodiment, a micro-filter membrane is also provided in the micro residual gas sampling chamber. The micro-filter membrane is used to filter impurities in the residual gas, effectively preventing impurities from entering the micro mass spectrometer core and affecting the detection accuracy. The detection accuracy of the micro mass spectrometer core is 10. -9 With a response time of ≤10s, it can meet the requirements for in-situ real-time detection.

[0039] Preferred, such as Figure 1As shown, the multi-parameter sensing module includes a flexible shielded microconduct 7, a distributed optical fiber 11, and a micro-sensing composite strip 12. The flexible shielded microconduct 7 is disposed on the outer surface of the insulation layer 3 and extends along the length of the vacuum insulation tube. The distributed optical fiber 11 and the micro-sensing composite strip 12 are inserted inside the flexible shielded microconduct 7. The micro-sensing composite strip 12 integrates an FBG temperature sensor, a piezoelectric strain sensor, and a capacitive vacuum sensor. The FBG temperature sensor is used to detect the temperature parameter of the vacuum insulation tube, the piezoelectric strain sensor is used to detect the strain parameter of the vacuum insulation tube, and the capacitive vacuum sensor is used to detect the vacuum parameter of the vacuum insulation tube. The distributed optical fiber 11 is used to detect the temperature parameter of the vacuum insulation tube. Both the distributed optical fiber 11 and the micro-sensing composite strip 12 are communicatively connected to the life self-diagnosis analysis system to feed back the detection results to the life self-diagnosis analysis system. In this embodiment, the microsensing composite strip 12 is also called the MEMS microsensing composite strip. The width of the microsensing composite strip 12 is 1-2 mm and the thickness is 0.1-0.3 mm. It is made of a flexible polymer that is resistant to high temperature and low temperature.

[0040] Furthermore, the flexible shielded microcatheter 7 is made of a composite of a polytetrafluoroethylene insulating layer and a copper wire shielding layer. The flexible shielded microcatheter 7 has several through holes, and the interior of the flexible shielded microcatheter 7 is connected to the vacuum interlayer 15 through the through holes.

[0041] In this embodiment, the flexible shielding microcatheter 7 is disposed on the outer surface of the insulation layer 3, and can be elongated and attached to the outer surface of the insulation layer 3 (e.g., Figure 1 As shown, it can also be spirally wound and attached to the outer surface of the insulation layer 3. Compared with the long strip method, spiral winding on the outer surface of the insulation layer 3 allows for more comprehensive testing of the vacuum insulation tube, and the test results are more accurate. Therefore, the spiral winding method is preferred for setting the flexible shielding microcatheter 7.

[0042] In this embodiment, the flexible shielded microconductor 7 is made of a composite of a polytetrafluoroethylene (PTFE) insulating layer and a copper wire shielding layer. The inner diameter of the flexible shielded microconductor 7 is 1-3 mm, and the wall thickness is 0.2-0.5 mm. PTFE has good insulation and flexibility, does not damage the sealing performance of the vacuum interlayer 15, and does not affect the flexible bending of the vacuum insulation tube. The copper wire shielding layer avoids electromagnetic interference generated during the operation of the superconducting cable, ensuring the accuracy of the detection results of the distributed optical fiber 11 and the micro-sensing composite strip 12. The copper wire shielding layer is wrapped around the outer wall of the flexible shielded microconductor 7, and the PTFE insulating layer is wrapped around the outer peripheral surface of the copper wire shielding layer. The flexible shielded microconductor 7 in this application combines insulation, shielding, and flexibility.

[0043] In addition, in this embodiment, the flexible shielded microcatheter 7 is provided with several through holes. The purpose of providing through holes is twofold: firstly, the interior of the flexible shielded microcatheter 7 is connected to the vacuum interlayer 15 through the through holes. When the vacuum interlayer 15 is evacuated, the air inside the flexible shielded microcatheter 7 is also extracted, avoiding the presence of residual gas in the flexible shielded microcatheter 7, which could affect the detection results; secondly, since the gas analysis module 6 is also connected to the lifetime self-diagnosis analysis system, the through holes allow the signal conversion unit transmission line 14 to pass through. The signal conversion unit transmission line 14 passes through the through holes and enters the flexible shielded microcatheter 7 to connect with the lifetime self-diagnosis analysis system, which can effectively protect the signal conversion unit transmission line 14 and avoid electromagnetic interference.

[0044] Preferred, such as Figure 1 As shown, the lifespan self-diagnostic analysis system includes an information interface 5, a signal line 13, and a microcontroller 8. The information interface 5 is located on the double-layer head 4 and is used for communication with the gas analysis module 6 and the multi-parameter sensing module. The information interface 5 is connected to the microcontroller 8 via the signal line 13 and is used to transmit information to the microcontroller 8. The microcontroller 8 is equipped with an edge computing unit, an alarm unit, and a communication unit. The edge computing unit is used to receive and process the information transmitted by the information interface 5. The alarm unit alarms based on the information processed by the edge computing unit. The communication unit is used to transmit the information processed by the edge computing unit.

[0045] In this embodiment, the information interface 5 is located in the second mounting port. The information interface 5 has several pins. One end of each pin is used to connect to the distributed optical fiber 11, the micro-sensing composite strip 12, and the conversion unit in the gas analysis module 6. The other end of each pin is connected to the microcontroller 8 through the signal line 13.

[0046] Furthermore, the edge computing unit incorporates a data coupling analysis algorithm capable of correlating and analyzing temperature, strain, vacuum, and residual gas composition and concentration data, and diagnosing the lifespan of the vacuum insulation tube in real time. When these parameters exceed set thresholds or exhibit abnormal fluctuations, the edge computing unit automatically issues a warning signal, which is then activated by the alarm unit. The communication unit transmits information processed by the edge computing unit, ensuring the vacuum insulation tube's operational status is constantly monitored.

[0047] The life self-diagnosis analysis system in this application automatically diagnoses the life of the vacuum insulation tube by receiving, reading, and analyzing the information fed back by the multi-parameter sensing module and the gas analysis module 6. At the same time, it can realize vacuum deterioration early warning, residual gas composition trend judgment, and fault location.

[0048] To describe in more detail the flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function involved in this application, an embodiment is disclosed, and the parameters of each component are as follows: Inner tube 1 and outer tube 2: Both are flexible corrugated pipes made of stainless steel. Inner tube 1 has an outer diameter of 130mm, and outer tube 2 has an inner diameter of 170mm. The corrugation spacing is 15mm, and the wall thickness is 0.8mm. Inner tube 1 is fitted inside outer tube 2, forming an annular vacuum interlayer 15 between them. The thickness of vacuum interlayer 15 is 20mm, and the initial vacuum level in vacuum interlayer 15 is ≤10. -3 Pa.

[0049] Double-layer end caps 4: Two end caps are provided, each ring-shaped, and are respectively installed at both ends of the inner tube 1 and the outer tube 2 and welded to them. Each double-layer end cap 4 has an inner cavity, which communicates with the vacuum jacket 15 to form a sealed cavity. The double-layer end caps 4 are made of the same material as the inner tube 1 and the outer tube 2, namely stainless steel.

[0050] Insulation layer 3: Lays in the vacuum interlayer 15 and adheres to the outer wall of the inner tube 1. The insulation paper is made of polyimide, and the reflective layer is made of aluminum foil. The insulation paper and reflective layer are stacked alternately, for a total of 20 layers. The insulation paper is 0.2 mm thick, the reflective layer is 0.02 mm thick, and the total thickness of insulation layer 3 is 6 mm.

[0051] Getter: Evaporable zirconium-aluminum getter is used. 1.0 kg of getter is used per cubic meter of vacuum interlayer 15. The getter is evenly filled in the gaps of the insulation layer 3 to adsorb residual gas in the vacuum interlayer 15 and maintain the vacuum environment in the vacuum interlayer 15.

[0052] Gas analysis module 6: Fixed to the first mounting port of the left-end double-layer head 4 via a metal sealing ring and CF-type vacuum interface 9. It adopts a miniaturized design, with dimensions of 50mm*30mm*20mm, adaptable to the space of the vacuum jacket 15. The micro-filter membrane has 0.01mm pores for filtering impurities in residual gases. The miniature mass spectrometer core uses a quadrupole mass spectrometer core with a detection accuracy of 10... -9 With a Pa rating and a response time ≤8s, it can detect the composition and concentration of H2, O2, N2, H2O, and CO2 in vacuum interlayer 15 in situ, with a detection range of 10 Pa. -9 mol / L~10 -3 mol / L. The signal conversion unit converts the detection signal from the miniature mass spectrometer core into a standard electrical signal of 4-20mA for easy transmission.

[0053] Multi-parameter sensing module: The micro-sensing composite strip 12 is 2mm wide and 0.2mm thick, encapsulated with PTFE flexible polymer, and has good low-temperature resistance (adaptable to a temperature range of -210℃ to 50℃). The micro-sensing composite strip 12 is composited with an FBG temperature sensor (temperature range -210℃ to 100℃, accuracy ±0.5℃), a piezoelectric strain sensor (strain range 0-5000με, accuracy ±1με), and a capacitive vacuum sensor (measurement range 10...). -6 Pa~10 5 Pa (accuracy ±5%FS); Distributed optical fiber 11 and micro-sensing composite tape 12 are placed inside the flexible shielded microduct 7, with two tapes evenly distributed along the outer wall of the insulation layer 3 and the length of the vacuum insulation tube. The included angle between two adjacent micro-sensing composite tapes 12 is 180°, simultaneously detecting temperature parameters, strain parameters, and vacuum parameters. The distributed optical fiber 11 can detect the temperature parameters in the entire vacuum interlayer 15, and the FBG temperature sensor can detect the temperature parameters at its location. The combined action of the distributed optical fiber 11 and the FBG temperature sensor enables real-time detection of the temperature parameters of the entire vacuum interlayer 15.

[0054] The flexible shielded microcatheter 7 is made of a composite of a polytetrafluoroethylene (PTFE) insulation layer and a copper wire shielding layer. The flexible shielded microcatheter 7 has several through holes, an inner diameter of 2 mm, and a wall thickness of 0.3 mm. Two flexible shielded microcatheters 7 are evenly distributed along the outer surface of the insulation layer 3 and along the length of the vacuum insulation tube. The two flexible shielded microcatheters 7 are spirally wound around the outer surface of the insulation layer 3, with an included angle of 180° between adjacent flexible shielded microcatheters 7, and penetrate the entire vacuum interlayer 15. The signal conversion unit transmission line 14 of the gas analysis module 6 passes through the through holes and runs through the flexible shielded microcatheters 7. The copper wire shielding layer effectively shields electromagnetic interference, and the PTFE insulation layer ensures insulation performance. Simultaneously, the PTFE insulation layer and the copper wire shielding layer are flexible enough to adapt to the bending deformation of the vacuum insulation tube without compromising the sealing performance of the vacuum interlayer 15.

[0055] Lifetime self-diagnostic analysis system: Information interface 5 is located in the second mounting port. The gas analysis module 6 and the multi-parameter sensing module are both connected to information interface 5. Information interface 5 is connected to microcontroller 8 via signal line 13. Microcontroller 8 is industrial-grade, small in size, and low in power consumption. The edge computing unit within microcontroller 8 incorporates a data coupling analysis algorithm. The edge computing unit performs correlation analysis on temperature parameters, strain parameters, vacuum parameters, and residual gas concentration parameters, with a preset residual gas concentration threshold H2 ≤ 10. -7 mol / L, O2≤10 -7 mol / L, N2≤10 -6 mol / L, H2O≤10 -8 mol / L, CO2≤10-8 mol / L. When the concentration of one or more residual gases exceeds the preset threshold, or when abnormal fluctuations occur in temperature, strain, and vacuum parameters (e.g., sudden increase in vacuum, sudden increase in local temperature, strain exceeding 3000 με), the edge computing unit sends a start signal to the alarm unit. The alarm unit automatically issues an audible and visual warning signal. At the same time, the edge computing unit transmits the detection data and warning information to the background monitoring system through the communication unit (using wireless or wired methods), so that maintenance personnel can monitor the operating status of the vacuum insulation tube in real time.

[0056] The flexible vacuum insulation tube for superconducting cables with self-diagnostic lifespan function involved in this invention operates on the following principle: First, according to the appendix Figure 1 Based on the descriptions of the aforementioned components, the components are manufactured and assembled. Two double-layer end caps 4 are provided, one at each end of the vacuum insulation tube. The left end double-layer end cap 4 has a first mounting port and a second mounting port, while the right end double-layer end cap 4 has a spare mounting port. The miniature residual gas sampling chamber of the gas analysis module 6 is fixedly connected to the first mounting port via a metal sealing ring and a CF-type vacuum interface 9. The information interface 5 of the lifespan self-diagnostic analysis system is installed in the second mounting port.

[0057] Next, a vacuum is drawn into the vacuum jacket 15. The vacuum pump is installed into the spare mounting port via the CF-type vacuum interface 9 and the metal sealing ring. The vacuum pump is started, and it draws a vacuum into the vacuum jacket 15 until the initial vacuum level in the vacuum jacket 15 is ≤10. -3 Pa.

[0058] Then, the superconducting cable is installed in the inner tube 1, and liquid nitrogen is introduced into the inner tube 1 to place the superconducting cable in a liquid nitrogen environment. When the superconducting cable is working, the miniature residual gas sampling chamber in the gas analysis module 6 collects the residual gas in the vacuum interlayer 15. The miniature mass spectrometer core is used to analyze the composition and concentration of the collected residual gas, and the signal conversion unit feeds back the detection results to the life self-diagnosis analysis system. At the same time, the distributed optical fiber 11 in the multi-parameter sensing module detects the temperature parameters in the vacuum interlayer 15, the FBG temperature sensor on the micro-sensing composite strip 12 detects the temperature parameters of the vacuum insulation tube, the piezoelectric strain sensor detects the strain parameters of the vacuum insulation tube, and the capacitive vacuum sensor detects the vacuum degree parameters of the vacuum insulation tube. The detection results are sent to the microcontroller 8 through the information interface 5 and the signal line 13. The edge computing unit in the microcontroller 8 performs correlation analysis on the temperature parameters, strain parameters, vacuum degree parameters, residual gas composition and concentration data, and diagnoses the life of the vacuum insulation tube in real time. When temperature, strain, vacuum, residual gas composition, and concentration exceed set thresholds, or when these parameters fluctuate abnormally, the edge computing unit automatically issues a warning signal, and the alarm unit activates an alarm upon receiving the warning signal. The communication unit transmits information processed by the edge computing unit, ensuring that the working status of the vacuum insulation tube is constantly monitored.

[0059] The flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function, as disclosed in this invention, can realize the synchronous monitoring of multiple physical parameters and residual gas component concentration. It can realize the synchronous monitoring of temperature parameters, strain parameters, vacuum degree parameters and residual gas component concentration during the operation of the vacuum insulation tube, solve the problems of single monitoring method, inability to detect residual gas in real time, poor adaptability of sensor structure and lack of fault early warning in the prior art, and improve the safety, reliability and maintenance convenience of superconducting cables.

[0060] In this application, a multi-parameter sensing module is set in the vacuum interlayer 15, which can simultaneously detect temperature parameters, strain parameters and vacuum degree parameters; a gas analysis module 6 is set to detect the composition and concentration of residual gas in the vacuum interlayer 15, which can comprehensively reflect the operating status of the vacuum insulation tube, and solve the problems of single monitoring methods and inability to monitor residual gas in real time in the prior art.

[0061] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0062] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can 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 those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A flexible vacuum insulation tube for superconducting cables with self-diagnostic lifespan function, characterized in that: It includes an inner tube (1), an outer tube (2), a double-layer end cap (4), an insulation layer (3), a gas analysis module (6), a multi-parameter sensing module, and a life self-diagnosis analysis system. The inner tube (1) is fitted inside the outer tube (2), and the double-layer end cap (4) is set at both ends of the inner tube (1) and the outer tube (2), and forms a vacuum interlayer (15) with the gap between the inner tube (1) and the outer tube (2). The insulation layer (3) is disposed in the vacuum interlayer (15); The gas analysis module (6) is connected to the vacuum interlayer (15) and is used to detect the composition and concentration of residual gas in the vacuum interlayer (15). The gas analysis module (6) includes a miniature residual gas sampling chamber, a miniature mass spectrometer core, and a signal conversion unit. The miniature residual gas sampling chamber is connected to the vacuum interlayer (15) and is used to collect residual gas in the vacuum interlayer (15). The miniature mass spectrometer core is used to analyze the composition and concentration of the collected residual gas. The signal conversion unit is communicatively connected to the lifetime self-diagnosis analysis system and is used to feed back the detection results to the lifetime self-diagnosis analysis system. The multi-parameter sensing module is disposed in the vacuum interlayer (15) and is used to detect multiple parameter values ​​of the flexible vacuum insulation tube. The multiple parameter values ​​include temperature parameter, strain parameter and vacuum degree parameter. The multi-parameter sensing module includes a flexible shielded microconduct (7), a distributed optical fiber (11) and a micro-sensing composite tape (12). The flexible shielded microconduct (7) is disposed on the outer surface of the insulation layer (3) and extends along the length direction of the flexible vacuum insulation tube. The distributed optical fiber (11) and the micro-sensing composite tape (12) are inserted inside the flexible shielded microconduct (7). The microsensor composite strip (12) integrates an FBG temperature sensor, a piezoelectric strain sensor, and a capacitive vacuum sensor; the FBG temperature sensor is used to detect the temperature parameters of the flexible vacuum insulation tube, the piezoelectric strain sensor is used to detect the strain parameters of the flexible vacuum insulation tube, and the capacitive vacuum sensor is used to detect the vacuum parameters of the flexible vacuum insulation tube. The distributed optical fiber (11) is used to detect the temperature parameters of the flexible vacuum insulation tube; the distributed optical fiber (11) and the micro-sensing composite tape (12) are both connected to the life self-diagnosis analysis system for feeding back the detection results to the life self-diagnosis analysis system. The flexible shielded microcatheter (7) is spirally wrapped and attached to the outer surface of the insulation layer (3); The flexible shielded microcatheter (7) is made of a composite of polytetrafluoroethylene insulation layer and copper wire shielding layer. The flexible shielded microcatheter (7) has several through holes. The interior of the flexible shielded microcatheter (7) is connected to the vacuum interlayer (15) through the through holes. The gas analysis module (6) is connected to the life self-diagnosis analysis system via a signal conversion unit transmission line (14), which is inserted through a through hole in the flexible shielded microcatheter (7). The life self-diagnosis analysis system is connected to the gas analysis module (6) and the multi-parameter sensing module for receiving, reading and analyzing the information fed back by the gas analysis module (6) and the multi-parameter sensing module, and automatically diagnosing the life of the flexible vacuum insulation tube. The life self-diagnosis analysis system includes a microcontroller (8), which is equipped with an edge computing unit. The edge computing unit has a built-in data coupling analysis algorithm that can perform correlation analysis on temperature parameters, strain parameters, vacuum parameters, residual gas composition and concentration data, and diagnose the life of the vacuum insulation tube in real time.

2. The flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function according to claim 1, characterized in that: The double-layer head (4) has an inner cavity that is connected to the vacuum jacket (15). The double-layer head (4) is provided with a first installation port, a second installation port and a spare installation port. The first installation port is used to connect to the gas analysis module (6). The second installation port is used to connect to the life self-diagnosis analysis system. The spare installation port is detachably provided with a sealing cover plate (10) for drawing a vacuum from the vacuum jacket (15) or as a spare for the first installation port and the second installation port.

3. The flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function according to claim 1, characterized in that: The vacuum interlayer (15) is also provided with a getter, which is used to adsorb residual gas in the vacuum interlayer (15) and maintain the vacuum environment in the vacuum interlayer (15).

4. The flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function according to claim 1, characterized in that: The insulation layer (3) is disposed in the vacuum interlayer (15) and is attached to the outer wall of the inner tube (1); the insulation layer (3) includes several layers of insulation paper and several layers of reflective layer, and the insulation paper and reflective layer are stacked alternately.

5. The flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function according to claim 1, characterized in that: The micro residual gas sampling chamber is also equipped with a micro filter membrane, which is used to filter impurities in the residual gas.

6. The flexible vacuum insulation tube for superconducting cables with lifespan self-diagnosis function according to claim 1, characterized in that: The life self-diagnosis analysis system includes an information interface (5) and a signal line (13). The information interface (5) is set on the double-layer end cap (4) and is used to communicate with the gas analysis module (6) and the multi-parameter sensing module. The information interface (5) is connected to the microcontroller (8) through the signal line (13) and is used to transmit information to the microcontroller (8). The microcontroller (8) is equipped with an alarm unit and a communication unit. The edge computing unit is used to receive and process the information transmitted by the information interface (5). The alarm unit alarms according to the information processed by the edge computing unit. The communication unit is used to transmit the information processed by the edge computing unit.

Images