Intelligent early warning mineral insulated flexible fireproof cable

Abstract

The application provides an intelligent early warning mineral insulated flexible fireproof cable, which comprises a temperature monitoring unit and a conductor assembly covering the temperature monitoring unit, the temperature monitoring unit is connected to a DTS temperature measurement system, the temperature monitoring unit monitors temperature information of the conductor assembly, the conductor assembly is externally covered with an insulation layer, the insulation layer is externally covered with fireproof mud, and an abnormality monitoring unit is arranged in the fireproof mud, and the abnormality monitoring unit monitors sound information and vibration information in the environment. The temperature monitoring unit is adopted to realize real-time monitoring of the temperature of all lengths in the cable during the operation of the cable, the abnormality monitoring unit is adopted to monitor the vibration information and the sound information around the cable, the abnormality of the cable is monitored in real time, the internal and external of the cable are simultaneously monitored, measures are taken before accidents occur, power accidents are avoided, the fault position of the cable is determined after accidents occur, and the fault repair speed is improved.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and in particular to an intelligent early warning mineral-insulated flexible fireproof cable. Background Technology

[0002] Currently, intelligent cable monitoring primarily aims to ensure the safe and stable operation of power lines, enabling visualized monitoring and rapid fault location. Existing technologies mainly involve installing monitoring equipment inside cable tunnels for visualization and attaching temperature-sensing optical fibers to the cable surface to achieve intelligent monitoring. However, these technologies are costly and are mainly used in critical power transmission and transformation lines.

[0003] Existing cables have the following defects and shortcomings: 1. Fire-resistant cables are mostly statically fire-resistant, offering insufficient mechanical protection during fires, and are prone to short-circuit faults after being subjected to mechanical impact from falling objects. 2. Real-time temperature monitoring is not possible during cable operation. 3. Cables lack protection against external damage and intelligent early warning functions during operation. 4. Cable maintenance requires manual on-the-cable inspection, resulting in low accuracy in fault location, being time-consuming and labor-intensive, and failing to detect fault locations before accidents occur. Summary of the Invention

[0004] This invention solves the problem that cables in the prior art cannot be simultaneously monitored for temperature and anomalies. It proposes an intelligent early warning mineral-insulated flexible fireproof cable that monitors cable anomalies in real time and simultaneously monitors cable temperature to identify the cable's abnormal conditions, pinpoint the location of the cable fault, and improve the speed of fault repair.

[0005] To achieve the above objectives, the following technical solution is proposed:

[0006] A smart early warning mineral-insulated flexible fireproof cable includes a temperature monitoring unit and a conductor assembly covering the temperature monitoring unit. The temperature monitoring unit is connected to a DTS temperature measurement system and monitors the temperature information of the conductor assembly. The conductor assembly is covered with an insulation layer, and the insulation layer is covered with fireproof mud. An anomaly monitoring unit is installed inside the fireproof mud to monitor sound and vibration information in the environment.

[0007] Based on the monitoring of sound and vibration information by the anomaly monitoring unit, anomalies are identified. Based on the identification results, cable anomaly judgment is made to determine whether the cable has experienced a mechanical failure. At the same time, temperature monitoring is performed along the entire length of the cable to determine whether a power accident has occurred. The anomaly monitoring unit is placed in fireproof mud, which not only effectively protects the anomaly monitoring unit, but also allows the anomaly monitoring unit to monitor the external environment through the hardened ceramic protective layer formed by the fireproof mud.

[0008] Preferably, the temperature monitoring unit includes a seamless steel tube and a multimode optical fiber wrapped inside the seamless steel tube, with filler grease filling the space between the seamless steel tube and the multimode optical fiber.

[0009] The temperature information of the entire cable is detected by multimode optical fiber. The optical signal is fed back in real time through the multimode optical fiber. The DTS temperature measurement system analyzes the fed-back optical signal. The DTS monitoring system can monitor the temperature at all locations on the line and then analyze to obtain the temperature information of the entire cable length. Since the optical signal transmission is not affected by electromagnetic field interference, the monitoring accuracy is high. Filler grease and seamless steel pipe are used for mechanical protection of multimode optical fiber during the production process. Placing the entire temperature monitoring unit inside the conductor assembly can effectively improve the accuracy of temperature monitoring.

[0010] Preferably, the anomaly monitoring unit includes a single-mode optical fiber, a sound sensor, and a stainless steel armor covering the single-mode optical fiber. The stainless steel armor is covered with aramid fiber, and the aramid fiber is covered with a polyolefin sheath. The single-mode optical fiber transmits optical signals, and the sound sensor detects sound information.

[0011] By connecting single-mode optical fiber to the DAS vibration monitoring system, the single-mode fiber transmits optical signals. The DAS vibration monitoring system identifies the vibration state of the cable based on the transmitted optical signals. Sound sensors are set up to monitor the ambient sound around the cable. Combining vibration and sound information, the system comprehensively judges the abnormal state of the cable, which can more clearly identify abnormal situations and achieve faster pre-fault warning. At the same time, it can achieve faster fault location after a fault occurs, ensuring the overall safety of the cable and reducing the occurrence of power accidents. The sheath provided can provide effective protection during production and construction, ensuring the safety of the entire abnormality monitoring unit during the integration of the cable and its protective properties during cable laying.

[0012] Preferably, the single-mode fiber optic connection identification system identifies vibration information based on the optical signal transmitted through the single-mode fiber and combines this with sound information transmitted by a sound sensor to identify the cable's hazard level. The identification system includes a DAS vibration monitoring system and a sound information identification system.

[0013] Preferably, a flame-retardant strip is provided between the insulating layer and the fireproof putty. The flame-retardant strip is a low-smoke, halogen-free, high-flame-retardant strip, which can effectively improve the adhesion during the extrusion process of the fireproof putty, resulting in a better and more uniform sealing of the ceramic protective layer formed by the fireproof putty.

[0014] Preferably, the fireproof putty is wrapped with fiberglass tape. The fiberglass tape is used to protect the fireproof putty during the production process, and has flame-retardant and fire-resistant properties, further improving the overall fire resistance of the cable.

[0015] Preferably, the fiberglass tape is covered with an outer sheath. The outer sheath is made of low-smoke halogen-free flame-retardant polyolefin, which is a sheath material that is flame-retardant and does not produce harmful gases and smoke in the event of a fire, further improving the flame-retardant properties of the cable.

[0016] Preferably, the insulation layer comprises a mineral insulation layer and a polyolefin insulation layer. The mineral insulation layer is made of synthetic mica tape uniformly wrapped around the conductor surface, possessing fire resistance and electrical insulation properties under high-temperature combustion. The polyolefin insulation layer is a ceramicized polyolefin, which remains soft at room temperature and has high insulation resistance; under high-temperature combustion conditions, it can be ceramicized to form electrical isolation, improve the safety of the cable, and achieve dynamic barrier properties of the insulation layer.

[0017] Preferably, a sound warning table is formulated based on the sound information. The sound warning level is obtained by comparing the real-time acquired sound information with the sound warning table, and a first weighted value is calculated. A vibration warning table is formulated based on the vibration information. The vibration warning level is obtained by comparing the real-time acquired vibration information with the vibration warning table, and a second weighted value is calculated. The cable hazard level is calculated based on the first weighted value and the second weighted value. Based on the cable hazard level, it is determined whether to issue a warning.

[0018] Preferably, when the vibration warning level is an abnormal level, the abnormal location information is obtained based on the vibration information, and the abnormal location information, cable hazard level information, and temperature information are used as warning information to issue a warning.

[0019] The beneficial effects of this invention are: by using a temperature monitoring unit, the temperature of the cable along its entire length can be monitored in real time during operation; by using an anomaly monitoring unit, vibration and sound information around the cable can be monitored, and anomalies of the cable can be monitored in real time, achieving simultaneous monitoring of the inside and outside of the cable, taking measures before an accident occurs to avoid power accidents, and identifying the fault location of the cable after an accident occurs, thereby improving the speed of fault repair. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cable structure according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the temperature monitoring unit structure according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the anomaly monitoring unit structure according to an embodiment of the present invention.

[0023] In the diagram: 1. Temperature monitoring unit; 1.1. Multimode optical fiber; 1.2. Filler grease; 1.3. Seamless steel pipe; 2. Conductor assembly; 3. Mineral insulation layer; 4. Polyolefin insulation layer; 5. Flame retardant tape; 6. Fireproof putty; 7. Anomaly monitoring unit; 7.1. Single-mode optical fiber; 7.2. Stainless steel armor; 7.3. Aramid fiber; 7.4. Polyolefin sheath; 8. Fiberglass wrapping tape; 9. Outer sheath. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention, and not all embodiments. Based on the embodiments described in the embodiments, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of the present invention.

[0025] Example:

[0026] Because existing cables often use a single conductor for power transmission and a single optical fiber for data transmission, the optical fiber can only perform single-function temperature or vibration monitoring. Even if the optical fiber can transmit both types of information simultaneously, the inaccurate data is caused by the unreasonable arrangement of the optical fibers within the cable. To address the problems existing in the prior art, this invention proposes an intelligent early warning mineral-insulated flexible fire-resistant cable, such as... Figure 1-3 As shown, the device includes a temperature monitoring unit 1 and a conductor assembly 2 covering the temperature monitoring unit. The temperature monitoring unit is connected to the DTS temperature measurement system and monitors the temperature information of the conductor assembly. The conductor assembly is covered with an insulating layer, and the insulating layer is covered with fireproof putty 6. An anomaly monitoring unit 7 is installed inside the fireproof putty. The anomaly monitoring unit monitors the sound and vibration information in the environment.

[0027] This invention monitors sound and vibration information based on an anomaly monitoring unit. Anomalies are identified based on the acquired sound and vibration information. Based on the identification results, cable anomaly judgment is made to determine whether the cable has experienced a mechanical failure. At the same time, temperature is monitored along the entire length of the cable to determine whether a power failure has occurred. The anomaly monitoring unit is placed in fireproof mud, which effectively protects the anomaly monitoring unit and allows it to monitor external environmental information through the hardened ceramic protective layer formed by the fireproof mud.

[0028] like Figure 2 As shown, the temperature monitoring unit includes a seamless steel tube and a multimode optical fiber 1.1 wrapped inside the seamless steel tube, with filling grease 1.2 filling the space between the seamless steel tube 1.3 and the multimode optical fiber.

[0029] The temperature monitoring of this invention adopts a distributed optical fiber temperature sensor (DTS). The multimode optical fiber is connected to the distributed optical fiber temperature sensor system, and the optical signal is transmitted to the distributed optical fiber temperature sensor system for analysis to obtain the cable temperature information. Since the optical signal transmission is not affected by electromagnetic field interference, the monitoring accuracy is high, and the distributed optical fiber temperature sensor system can monitor the temperature at all locations on the line.

[0030] The multimode optical fiber is placed inside a seamless steel tube and isolated from the conductor assembly. This ensures that the optical signal transmitted by the multimode optical fiber does not interfere with the electrical energy transmitted by the conductor assembly. The filling grease is petroleum grease, which has a high melting temperature, suitable hardness, viscosity and good low-temperature toughness. It also has good insulation and fireproofing effects, which can better achieve the isolation between the multimode optical fiber and the conductor assembly.

[0031] The conductor assembly, or core, is made of multiple stranded copper wires. The stranded conductor has excellent bending properties, which allows it to better cover the temperature monitoring unit during the manufacturing process for power transmission.

[0032] Since the temperature monitoring unit of the present invention is located inside the conductor assembly, temperature monitoring is mainly performed on the conductor assembly. That is, when the conductor assembly is transmitting power, if the temperature of the conductor assembly rises due to excessive power or other factors, the temperature monitoring unit of the present invention can monitor the temperature in real time, so as to facilitate the management personnel to adjust the power of the cable transmission, reduce the occurrence of power accidents, and extend the service life of the cable.

[0033] Because multiple insulation layers and flame-retardant tape are set outside the conductor assembly, the temperature monitoring unit of the present invention has difficulty sensing temperature changes in the outside of the cable, thus reducing the error of temperature monitoring.

[0034] like Figure 3 As shown, the anomaly monitoring unit includes a single-mode optical fiber 7.1, a sound sensor, and a stainless steel armor 7.2 covering the single-mode optical fiber. The stainless steel armor is covered with aramid fiber 7.3, and the aramid fiber is covered with a polyolefin sheath 7.4. The single-mode optical fiber transmits optical signals, and the sound sensor detects sound information.

[0035] The anomaly monitoring unit of this invention is installed inside fireproof mud, which is a mixture of sodium silicate adhesive and magnesium hydroxide powder. Under high-temperature combustion conditions, it forms a hard ceramic protective layer. Combined with the polyolefin sheath of the anomaly monitoring unit, it effectively reduces mechanical damage to the cable from falling objects during a fire.

[0036] Since the anomaly monitoring unit is located outside the insulation layer, inside the fireproof mud, and close to the surface of the cable, it can clearly report abnormal vibrations around the cable. Therefore, the anomaly monitoring unit of the present invention can monitor the sound and vibration information of the cable's surrounding environment without the monitoring effect being reduced due to the influence of the insulation layer.

[0037] Based on the layout design of the temperature monitoring unit and the anomaly monitoring unit of the present invention, the temperature monitoring of the internal conductor and the sound and vibration monitoring of the external environment can be effectively realized. This allows the cable of the present invention to simultaneously perform real-time temperature monitoring and anomaly monitoring. Temperature monitoring mainly monitors the power transmission inside the cable, while anomaly monitoring mainly monitors the mechanical collision situation outside the cable. This avoids cable damage from the inside out, realizes early warning of cable anomalies, and accurate location of faults, thus achieving good protection of the cable from the inside out.

[0038] The single-mode fiber optic connection identification system identifies vibration information based on the optical signals transmitted through the single-mode fiber and combines this with sound information transmitted by a sound sensor to identify the hazard level of the cable.

[0039] The insulation layer includes a mineral insulation layer 3 and a polyolefin insulation layer 4. The mineral insulation layer is made of synthetic mica tape uniformly wrapped around the conductor surface, which has fire resistance and electrical insulation properties under high temperature combustion. The polyolefin insulation layer is ceramicized polyolefin, which remains soft at room temperature and has high insulation resistance; under high temperature combustion conditions, it can be ceramicized to form electrical isolation, improve the safety of the cable, and realize the dynamic barrier of the insulation layer.

[0040] A flame-retardant strip 5 is set between the insulation layer and the fireproof putty. The flame-retardant strip is a low-smoke, halogen-free, and highly flame-retardant strip, which can effectively improve the adhesion of the fireproof putty during the extrusion process, making the ceramic protective layer formed by the fireproof putty more airtight and more uniform.

[0041] The fireproof putty is wrapped with fiberglass tape 8. The fiberglass tape is used to protect the fireproof putty during the production process. It has flame-retardant and fire-resistant properties, further improving the overall fire resistance and flame retardancy of the cable.

[0042] The cable is covered with a fiberglass tape outer sheath. The outer sheath is made of low-smoke halogen-free flame-retardant polyolefin, which is a flame-retardant material that does not produce harmful gases or smoke in the event of a fire, further improving the flame-retardant properties of the cable.

[0043] Existing cables, when exposed to fire, have significant limitations due to their static fire resistance (i.e., as the flames burn, the cable relies on its own fire-resistant materials for flame retardancy, but once the flame temperature exceeds the material's threshold, the cable will be burned layer by layer). This invention employs dynamic protection, which can significantly improve the cable's fire resistance and maintain normal power transmission even when the cable is burning.

[0044] The insulating material of this invention adopts a mica tape combined with a ceramicized polyolefin structure. It maintains its softness during normal laying and use, making it easy to install. In the event of a fire, the ceramicized polyolefin can form a ceramic layer, which keeps the conductor isolated from other conductors or other metals. The mica tape maintains its insulating properties inside, ensuring the normal operation of the line. Furthermore, the fireproof mud extruded on the outside of the wire core can form a hard shell under high-temperature combustion conditions. After ceramicization, it will not lose its strength as the burning time increases, providing effective mechanical protection for the inside of the cable.

[0045] The ceramic layer formed by ceramicized polyolefin provides dynamic insulation protection, while the ceramic layer formed by fireproof putty provides dynamic flame-retardant protection for the cable sheath. In the event of a fire, the fireproof putty provides dynamic protection first, preventing hard external objects from falling and damaging the cable's interior, thus achieving mechanical dynamic protection. At the same time, the hardened ceramic protective layer has better flame retardancy, protecting the abnormal monitoring unit inside the fireproof putty. Meanwhile, the hardening of the polyolefin insulation layer effectively protects the conductor components and their internal temperature monitoring unit. With these two layers of dynamic protection, the cable's power transmission and signal transmission can function normally.

[0046] The identification system includes a DAS vibration monitoring system and a sound information recognition system. The specific method for anomaly identification by the identification system is as follows: a sound warning table is created based on sound information; the sound warning table is compared with the real-time acquired sound information to obtain the sound warning level and calculate the first weighted value; a vibration warning table is created based on vibration information; the vibration warning table is compared with the real-time acquired vibration information to obtain the vibration warning level and calculate the second weighted value; the cable hazard level is calculated based on the first weighted value and the second weighted value; and a warning prompt is determined based on the cable hazard level.

[0047] Among them, the sound warning table and the vibration warning table are standard databases obtained through multiple tests in different scenarios.

[0048] When the vibration warning level is abnormal, the abnormal location information is obtained based on the vibration information, and the abnormal location information, cable hazard level information, and temperature information are used as warning information to issue a warning.

[0049] The principle of obtaining the location of vibration anomalies based on vibration information is as follows: when there is vibration outside the cable, the length and refractive index of the optical fiber will change accordingly, which will eventually cause the phase of the optical signal transmitted by the optical fiber to change. By analyzing the phase change and calculating the phase difference, the vibration location can be accurately located.

[0050] The method for obtaining the sound warning level and calculating the first weighted value by comparing the real-time acquired sound information with the sound warning table is as follows: The sound warning table records different signals and the sound warning level corresponding to different signals. At the same time, different weight values ​​are recorded after different sound warning levels. By comparing the sound warning tables established under different scenarios, multiple sound warning levels and multiple weight values ​​are obtained. The first weighted value is obtained by averaging.

[0051] Similarly, after obtaining the second weighted value, it is averaged with the first weighted value to obtain the warning value. The cable hazard level is obtained by looking up the corresponding table, which is a data table established through multiple experiments to correspond different warning values ​​with different cable hazard levels.

[0052] The sound warning level includes three levels: normal, oscillation and fluctuation, and abnormal. The vibration warning level also includes three levels: normal, oscillation and fluctuation, and abnormal.

[0053] This invention employs a temperature monitoring unit to monitor the temperature along the entire length of the cable in real time during operation, and an anomaly monitoring unit to monitor vibration and sound information around the cable, enabling real-time monitoring of cable anomalies. This allows for simultaneous monitoring of both the internal and external aspects of the cable, enabling measures to be taken before accidents occur to prevent power accidents, and, after an accident, to pinpoint the location of the cable fault and improve the speed of fault repair.

[0054] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention, but it should not be construed as limiting the specific implementation of the invention to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention.

Claims

1. A smart early warning mineral-insulated flexible fire-resistant cable, characterized in that, The temperature monitoring unit and the conductor assembly covering the temperature monitoring unit are connected to the DTS temperature measurement system. The temperature monitoring unit monitors the temperature information of the conductor assembly. The conductor assembly is covered with an insulating layer. The insulating layer is covered with fireproof putty. An anomaly monitoring unit is installed inside the fireproof putty. The anomaly monitoring unit monitors sound and vibration information in the environment.

2. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 1, characterized in that, The temperature monitoring unit includes a seamless steel tube and a multimode optical fiber wrapped inside the seamless steel tube, with filler grease filling the space between the seamless steel tube and the multimode optical fiber.

3. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 1, characterized in that, The anomaly monitoring unit includes a single-mode optical fiber, a sound sensor, and a stainless steel armor covering the single-mode optical fiber. The stainless steel armor is covered with aramid fiber, and the aramid fiber is covered with a polyolefin sheath. The single-mode optical fiber transmits optical signals, and the sound sensor detects sound information.

4. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 3, characterized in that, The single-mode fiber optic connection identification system identifies vibration information based on the optical signal transmitted by the single-mode fiber and combines it with the sound information transmitted by the sound sensor to identify the hazard level of the cable.

5. A smart early warning mineral-insulated flexible fireproof cable according to claim 1, 2, or 3, characterized in that, A flame-retardant strip is provided between the insulating layer and the fireproof putty.

6. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 1, characterized in that, The fireproof putty is covered with fiberglass tape.

7. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 6, characterized in that, The fiberglass tape is covered with an outer protective sleeve.

8. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 1, characterized in that, The insulating layer includes a mineral insulating layer and a polyolefin insulating layer.

9. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 1, characterized in that, A sound warning table is created based on the sound information. The sound warning level is obtained by comparing the real-time acquired sound information with the sound warning table and a first weighted value is calculated. A vibration warning table is created based on the vibration information. The vibration warning level is obtained by comparing the real-time acquired vibration information with the vibration warning table and a second weighted value is calculated. The cable hazard level is calculated based on the first weighted value and the second weighted value, and a warning prompt is determined based on the cable hazard level.

10. The intelligent early warning mineral-insulated flexible fireproof cable according to claim 9, characterized in that, When the vibration warning level is abnormal, based on the vibration information, abnormal location information is obtained, and the abnormal location information, cable hazard level information, and temperature information are used as warning information to issue a warning.

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