Multi-protection intelligent cable for high temperature and strong corrosion environment and monitoring system thereof

Abstract

The application relates to the technical field of special cables, in particular to a multiple-protection intelligent cable for high-temperature and strong-corrosion environments and a monitoring system thereof, which comprises a conductor, an insulation layer, an inner sheath, a shielding layer, a heat insulation layer, an outer sheath and a monitoring system. The application adopts gradient plating, composite insulation, ceramic sheath, aerogel heat insulation, flame-retardant smoke suppression and self-repairing outer sheath to form full-dimension protection, can resist temperatures above 250 DEG C, can resist strong corrosion and high mechanical stress; through the addition of humidity sensing and label self-power supply, temperature / stress / humidity / corrosion multi-parameter monitoring is realized, the response speed is improved through edge computing, and the monitoring dimension is greatly expanded; through the design of a buffer layer, an optical fiber sheath pipe, a corrugated heat insulation layer and a sealed joint, the risk of vibration damage, optical fiber rupture and medium invasion is reduced, and the structural reliability is greatly improved; through self-repairing, predictive maintenance and full-process protection, the service life is more than 3 times that of a traditional cable.

Description

Technical Field

[0001] This invention relates to the field of special cable technology, and in particular to a multi-protection intelligent cable for high-temperature and highly corrosive environments and its monitoring system. Background Technology

[0002] Around core equipment such as petrochemical cracking furnaces, reactors, and high-temperature pipelines, cables are subjected to a harsh, complex environment characterized by high temperatures of 90–250°C, strong corrosion from acids / alkalis / oil gases, and high mechanical stress from compression and vibration. Existing cables suffer from several defects, including limited material properties, bulky structures, insufficient monitoring capabilities, and poor reliability in cooling and protection: the conductor plating is homogeneous tin / nickel plating, which oxidizes rapidly at high temperatures, leading to a surge in contact resistance; the insulation layer struggles to balance temperature resistance, thermal conductivity, and corona resistance, and the wrapping process easily introduces gaps; the shielding layer only provides electromagnetic protection without any cushioning or vibration damping structure, making optical fibers susceptible to damage; the insulation layer is prone to pulverization, has poor mechanical strength, and lacks a matching flame-retardant and smoke-suppressing structure; the outer sheath lacks self-healing capabilities, allowing rapid corrosion penetration after localized wear; monitoring only provides temperature / stress sensing, lacking humidity monitoring, and the corrosion tags are not self-powered, resulting in high data processing delays; cable joints lack dedicated sealing structures, allowing media to easily enter and cause failure.

[0003] Based on the above-mentioned shortcomings, there is an urgent need to develop a smart cable and monitoring system with multi-level composite protection, multi-dimensional intelligent monitoring, and stable and reliable performance throughout its entire life cycle. Summary of the Invention

[0004] The technical problem to be solved by this invention is that existing cables have shortcomings in protection against high temperature and strong corrosion environments, have limited monitoring capabilities, and lack reliability.

[0005] The technical solution adopted by this invention to solve its technical problem is: a multi-protection intelligent cable for high-temperature and highly corrosive environments, comprising a conductor, an insulation layer, an inner sheath, a shielding layer, a heat insulation layer, an outer sheath, and a monitoring system. The conductor is a micro-alloyed plated soft copper wire; the insulation layer is a nano-modified polyimide-mica composite tape wrapped and impregnated with high-temperature resistant silicone resin; the inner sheath is a ceramicized silicone rubber layer; the shielding layer is a double-layer shielding structure; the heat insulation layer is a nano-silica aerogel felt; and the outer sheath is a three-layer co-extruded composite sheath. The monitoring system includes a distributed optical fiber sensing unit, RFID corrosion sensing tags, and a monitoring platform. The distributed optical fiber sensing unit is symmetrically braided and embedded in the shielding layer, and the RFID corrosion sensing tags are pre-embedded at intervals within the outer sheath.

[0006] The conductor has an Ag-Sn-Bi gradient coating with an inner layer thickness of 0.5-1 μm and an outer layer thickness of 1-2 μm. The conductor stranding adopts an adaptive pitch structure.

[0007] The insulating layer is doped with boron nitride nanofiller, and the nano-modified polyimide-mica composite tape is wrapped in a stepped overlapping manner, with an inner layer overlap rate of 55% and an outer layer overlap rate of 60%.

[0008] The inner sheath is filled with ceramicized silicone rubber filled with hollow microspheres, the particle size of which is 5-10μm and the filling amount is 5-8wt%.

[0009] The double-layer shielding structure includes an inner layer of silver-plated copper wire braided shielding and an outer layer of corrosion-resistant alloy strip longitudinally wrapped shielding. A polyurethane elastomer electromagnetic buffer layer is provided between the two shielding layers. The distributed optical fiber sensing unit is externally fitted with a PFA optical fiber buffer sheath.

[0010] The heat insulation layer is a double-sided polyimide film composite aerogel felt, and is formed into a corrugated structure. A magnesium hydroxide / aluminum hydroxide composite flame retardant and smoke suppressant layer is provided between the heat insulation layer and the outer sheath.

[0011] The outer sheath comprises an adhesive-modified polyolefin inner layer, a PVDF middle layer reinforced by directional arrangement of short-cut carbon fibers, and a nano-alumina-filled modified PTFE outer layer, wherein the PTFE outer layer is embedded with self-healing microcapsules.

[0012] The RFID corrosion sensing tag integrates a thermoelectric generator self-powered module, and the monitoring system also integrates a distributed fiber optic humidity sensing module.

[0013] The cable is equipped with integrated temperature-resistant and corrosion-resistant sealing joints at both ends, and the joints are equipped with multi-level sealing rings.

[0014] A monitoring system for smart cables is provided. The monitoring platform integrates a DTS / DSS demodulator, an RFID reader, and an edge computing unit, and has functions such as multi-parameter fusion analysis, over-limit alarm, fault location, life prediction, and local real-time processing.

[0015] The beneficial effects of this invention are: (1) The present invention adopts gradient coating, composite insulation, ceramic sheath, aerogel heat insulation, flame retardant and smoke suppressant, and self-healing outer sheath to form all-dimensional protection, with a temperature resistance of more than 250℃, strong corrosion resistance and high mechanical stress resistance.

[0016] (2) By adding humidity sensors and self-powered tags, multi-parameter monitoring of temperature, stress, humidity and corrosion can be achieved. Edge computing improves response speed and greatly expands the monitoring dimensions.

[0017] (3) The design of buffer layer, optical fiber sheath tube, corrugated heat insulation layer and sealed joint reduces the risk of vibration damage, optical fiber breakage and media intrusion, and greatly improves the structural reliability.

[0018] (4) With the help of self-repair, predictive maintenance and full-process protection, the service life is more than 3 times longer than that of traditional cables. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] In the diagram: 1. Conductor; 2. Insulation layer; 3. Inner sheath; 4. Inner layer silver-plated copper wire braided shield; 5. Outer layer corrosion-resistant alloy strip longitudinally wrapped shield; 6. Distributed optical fiber sensing unit; 7. Heat insulation layer; 8. Flame retardant and smoke-suppressing layer; 9. Outer sheath; 91. Adhesive-modified polyolefin inner layer; 92. Short-cut carbon fiber oriented reinforced PVDF middle layer; 93. Nano-alumina filled modified PTFE outer layer; 10. RFID corrosion sensing tag; 11. PFA optical fiber buffer sheath tube; 12. Polyurethane elastomer electromagnetic buffer layer; 13. Self-healing microcapsule; 14. Ag-Sn-Bi gradient coating; 15. Hollow microspheres. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Figure 1 The multi-protection smart cable for high-temperature and highly corrosive environments shown has, from the inside out, a conductor 1, an insulation layer 2, an inner sheath 3, a double shielding layer, a heat insulation layer 7, a flame-retardant and smoke-suppressing layer 8, and an outer sheath 9. Integrated temperature-resistant and corrosion-resistant sealed joints are installed at both ends of the cable, and the monitoring system is integrated and adapted with the cable body.

[0025] Conductor 1 is made of soft copper substrate and is coated with Ag-Sn-Bi gradient plating layer 14 after electrochemical cleaning. The inner layer thickness is 0.5-1μm and the outer layer thickness is 1-2μm. Conductor 1 is stranded with an adaptive pitch structure, which effectively reduces the high-temperature skin effect and improves high-temperature conductivity stability and oxidation resistance.

[0026] Insulation layer 2 is made of nano-boron nitride modified polyimide-mica composite tape, wrapped with a stepped overlap rate, with an inner layer overlap rate of 55% and an outer layer overlap rate of 60%. After wrapping, it is impregnated with high-temperature resistant silicone resin under vacuum pressure and formed by a segmented curing process of 80℃ / 30min→120℃ / 60min→180℃ / 120min to form a dense, bubble-free insulation structure that takes into account temperature resistance, thermal conductivity and corona resistance.

[0027] The inner sheath 3 is an extruded ceramicized silicone rubber layer, filled with hollow microspheres 15 with a particle size of 5-10μm and a filling amount of 5-8wt%. It maintains its flexibility at room temperature and can be quickly ceramicized to form a rigid protective shell when exposed to high temperature and open flame, ensuring the integrity of the circuit.

[0028] The double-layer shielding consists of an inner silver-plated copper wire braided shielding 4 and an outer corrosion-resistant alloy strip longitudinally wrapped shielding 5. A polyurethane elastomer electromagnetic buffer layer 12 is set between the two shielding layers to play a role in vibration reduction and damage resistance. The distributed optical fiber sensing unit 6 is externally covered with a PFA optical fiber buffer sheath 11, which is woven and embedded in the double-layer shielding in a 180° symmetrical manner to avoid optical fiber displacement and breakage. One optical fiber realizes distributed temperature sensing, and the other realizes distributed strain and humidity sensing.

[0029] The heat insulation layer 7 is made of double-sided polyimide film composite nano silica aerogel felt, which is formed in a corrugated shape and then longitudinally wrapped and sewn to effectively suppress the conduction of external high temperature and prevent the aerogel from powdering and loosening; a magnesium hydroxide / aluminum hydroxide composite flame retardant and smoke suppressing layer 8 is set on the outside of the heat insulation layer 7 to improve the flame retardant and smoke suppressing safety performance in petrochemical scenarios.

[0030] The outer sheath 9 is formed by a three-layer co-extrusion process. The adhesive modified polyolefin inner layer 91 is tightly bonded to the heat insulation layer 7. The directional arrangement of short carbon fibers enhances the mechanical strength of the PVDF middle layer 92. The nano-alumina-filled modified PTFE outer layer 93 has high wear resistance and strong corrosion resistance. The PTFE outer layer 93 has self-healing microcapsules 13 embedded inside, which can repair itself when the cable surface is slightly scratched, and prevent the intrusion of corrosive media.

[0031] The RFID corrosion sensing tag 10 is precisely embedded inside the outer sheath 9 every 50 meters. The tag integrates a thermoelectric self-powered module, which can monitor corrosive media such as H2S and SO2 and environmental humidity in real time, and provide feedback on the local corrosion status through changes in resonant frequency and impedance.

[0032] The cable is equipped with integrated temperature-resistant and corrosion-resistant sealing joints at both ends. The joints are equipped with multi-level sealing rings to achieve full sealing protection of the cable ends and completely prevent the intrusion of media such as acids, alkalis, oils and gases from the ends.

[0033] The monitoring platform adopts an assembly method of on-site integration and remote central control linkage. The DTS / DSS demodulator, RFID reader, and edge computing unit are integrated in the explosion-proof control cabinet at the petrochemical site. The DTS / DSS demodulator is fixedly connected to the fiber optic lead-out end of the distributed fiber optic sensing unit 6 through a high-temperature resistant fiber optic patch cord. The RFID reader wirelessly pairs with the RFID corrosion sensing tag 10 inside the outer sheath 9 through a radio frequency antenna. The edge computing unit communicates bidirectionally with the DTS / DSS demodulator and RFID reader through an industrial Ethernet, and also interfaces with the DCS control system of the petrochemical plant through a Modbus bus to achieve seamless transmission of monitoring data and control commands.

[0034] Data acquisition operation: The DTS demodulator, based on the Raman scattering effect, continuously emits pulsed light into the temperature sensing fiber of the distributed optical fiber sensing unit 6 to collect the temperature data of the entire cable in real time. The temperature measurement range is -40℃ to 300℃, the accuracy is ±1℃, and the positioning accuracy is ±1m. The DSS demodulator, based on the Brillouin scattering effect, collects the stress and strain data of the entire cable. The strain measurement range is 0 to 5000με, and the accuracy is ±10με. At the same time, it collects the ambient humidity data through the fiber optic grating sensing module. The humidity measurement range is 0 to 100%RH, and the accuracy is ±3%RH. The RFID reader transmits a 13.56MHz radio frequency signal at a preset cycle (10min / time) to activate the RFID corrosion sensing tag 10, reads the tag's resonant frequency and impedance parameters, and converts them into H2S and SO2 corrosive medium concentration and local corrosion degree data. All collected data are uploaded to the edge computing unit in real time.

[0035] Multi-parameter fusion analysis operation: The edge computing unit has a built-in multi-source data weighted fusion algorithm. Based on national cable standards such as GB / T12706 and GB / T2951, it establishes a cable condition assessment model under high temperature and strong corrosion environment. The four types of parameters, temperature, stress, humidity and corrosion, are normalized and integrated into a comprehensive cable health index through weight allocation. The interference of single parameters is eliminated, and the cable condition is accurately assessed.

[0036] Over-limit alarm operation: The edge computing unit presets safety thresholds: long-term operating temperature ≤250℃, stress ≤4000με, humidity ≤95%RH, and corrosive medium concentration meets the standard; when any parameter exceeds the threshold, the edge computing unit triggers an audible and visual alarm locally in real time, and sends an alarm signal to the remote central control room at the same time. The alarm delay is <1s, and the alarm information includes parameter type, real-time value, and degree of exceedance.

[0037] Fault location operation: The edge computing unit combines distributed fiber optic positioning technology with the location coding of RFID corrosion sensing tag 10 to lock the cable mileage and physical installation location of the fault point. The positioning error is ≤1m. The fault location report is automatically generated and the fault type is marked (high temperature overload, mechanical damage, local corrosion, insulation aging).

[0038] Lifetime prediction operation: Based on historical operating data and real-time status parameters, the edge computing unit uses a gray prediction model + BP neural network algorithm to fit the conductor oxidation rate, insulation aging rate, and sheath corrosion rate. Combined with the aging acceleration coefficient of high temperature and strong corrosion environment, it predicts the remaining service life of the cable with a prediction error of ≤10% and generates lifetime prediction reports periodically.

[0039] Local real-time processing and remote control: The edge computing unit completes the entire process of data parsing, fusion analysis, alarm, location, and prediction locally without uploading to the cloud, avoiding network latency and signal interference in the factory area; at the same time, all data is stored in the local database, supporting historical data traceability and report export; it can output control commands based on monitoring results to link factory equipment to achieve automatic protection, such as triggering on-site ventilation and cooling when the temperature exceeds the standard, and automatically cutting off the power supply of the corresponding circuit after fault location to ensure the safe operation of cables.

[0040] In this embodiment, the smart cable can withstand temperatures up to 250°C over a long period and can resist strong corrosive media such as acids, alkalis, oils, gases, and H2S. Its mechanical properties, including resistance to compression and vibration, are improved by 60%. The cable monitors temperature, stress, humidity, and corrosion across all dimensions and has a service life that is more than three times longer than traditional petrochemical cables, fully meeting the usage requirements of the extreme high-temperature and strong-corrosion environments in the petrochemical industry.

[0041] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A multi-protection intelligent cable for high-temperature and highly corrosive environments, comprising a conductor (1), an insulation layer (2), an inner sheath (3), a shielding layer, a heat insulation layer (7), an outer sheath (9), and a monitoring system, characterized in that: The conductor (1) is a micro-alloyed plated soft copper wire, the insulation layer (2) is a nano-modified polyimide-mica composite tape wrapped and impregnated with high-temperature resistant silicone resin, the inner sheath (3) is a ceramicized silicone rubber layer, the shielding layer is a double-layer shielding structure, the heat insulation layer (7) is a nano-silica aerogel felt, and the outer sheath (9) is a three-layer co-extruded composite sheath; the monitoring system includes a distributed optical fiber sensing unit (6), an RFID corrosion sensing tag (10) and a monitoring platform. The distributed optical fiber sensing unit (6) is symmetrically woven and embedded in the shielding layer, and the RFID corrosion sensing tag (10) is pre-embedded in the outer sheath (9) at intervals.

2. The intelligent cable according to claim 1, characterized in that: The micro-alloyed coating of the conductor (1) is an Ag-Sn-Bi gradient coating (14), with an inner layer thickness of 0.5-1μm and an outer layer thickness of 1-2μm. The conductor (1) is stranded using an adaptive pitch structure.

3. The intelligent cable according to claim 1, characterized in that: The insulating layer (2) is doped with nano boron nitride filler, and the nano-modified polyimide-mica composite tape is wrapped in a stepped overlapping manner with an inner layer overlap rate of 55% and an outer layer overlap rate of 60%.

4. The intelligent cable according to claim 1, characterized in that: The inner sheath (3) is filled with ceramicized silicone rubber-filled hollow microspheres (15), the hollow microspheres (15) having a particle size of 5-10 μm and a filling amount of 5-8 wt%.

5. The intelligent cable according to claim 1, characterized in that: The double-layer shielding structure includes an inner silver-plated copper wire braided shield (4) and an outer corrosion-resistant alloy strip longitudinally wrapped shield (5). A polyurethane elastomer electromagnetic buffer layer (12) is provided between the two shielding layers. The distributed optical fiber sensing unit (6) is covered with a PFA optical fiber buffer sheath (11).

6. The intelligent cable according to claim 1, characterized in that: The heat insulation layer (7) is a double-sided polyimide film composite aerogel felt, and is formed into a corrugated structure. A magnesium hydroxide / aluminum hydroxide composite flame retardant and smoke suppressing layer (8) is provided between the heat insulation layer (7) and the outer sheath (9).

7. The intelligent cable according to claim 1, characterized in that: The outer sheath (9) includes an adhesive modified polyolefin inner layer (91), a short-cut carbon fiber oriented reinforced PVDF middle layer (92), and a nano-alumina filled modified PTFE outer layer (93), wherein the PTFE outer layer (93) is embedded with self-healing microcapsules (13).

8. The intelligent cable according to claim 1, characterized in that: The RFID corrosion sensing tag (10) integrates a thermoelectric self-powered module, and the monitoring system also integrates a distributed optical fiber humidity sensing module.

9. The intelligent cable according to claim 1, characterized in that: The cable is equipped with integrated temperature-resistant and corrosion-resistant sealing joints at both ends, and the joints are equipped with multi-level sealing rings.

10. A monitoring system applied to any one of the smart cables described in claims 1-9, characterized in that: The monitoring platform integrates a DTS / DSS demodulator, an RFID reader, and an edge computing unit, and has functions such as multi-parameter fusion analysis, over-limit alarm, fault location, lifespan prediction, and local real-time processing.

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