An underground intelligent early warning cable and a preparation method thereof

Abstract

The application discloses an underground intelligent early warning cable and a preparation method thereof, and belongs to the technical field of cables. The cable comprises, from inside to outside, a core assembly, a wrapping assembly and an outer sheath assembly. The core assembly comprises at least one conductive wire core and a communication optical cable unit. The conductive wire core is in a twisted distribution, and the communication optical cable unit is arranged outside the conductive wire core. Each conductive wire core comprises a conductor, a temperature sensing optical fiber conductor unit and an insulation layer. A copper tape shielding layer is arranged outside the conductive wire core. Mica tape is arranged in the gap of the core assembly. The outer sheath assembly is low-smoke halogen-free polyolefin. Through the application, the communication optical cable unit and the temperature sensing optical fiber conductor unit are arranged, and the communication optical cable unit is arranged in the gap surrounded by the conductive wire core, so that synchronous transmission and backhaul of monitoring information are realized. Operation data can be quickly transmitted through the communication optical cable unit, and the problems of dispersed monitoring signal link, unstable transmission and feedback lag of traditional cables are avoided.

Description

Technical Field

[0001] This invention relates to an underground intelligent early warning cable and its manufacturing method, belonging to the field of cable technology. Background Technology

[0002] In underground environments, cables can be installed to adapt to various buried laying scenarios such as underground energy transmission and distribution, municipal pipelines, integrated utility tunnels, and rail transit. In these environments, cables operate under complex conditions such as soil compression, moisture corrosion, temperature fluctuations, electromagnetic interference, and construction disturbances. They not only need to have stable power transmission capabilities but also need to perform functions such as operational status monitoring, fault early warning, and communication transmission to meet the needs of safe operation and rapid maintenance of underground facilities.

[0003] Currently, underground cables typically employ a basic structure consisting of copper conductors, insulation layers, shielding layers, and an outer sheath to achieve power transmission and basic protection. Some cables also incorporate additional shielding, filling, or flame-retardant layers to improve electromagnetic compatibility and fire resistance. These existing technologies have, to some extent, improved the performance of cables.

[0004] However, traditional cables have certain problems: they lack the ability to sense operating parameters such as temperature and stress in real time, making it difficult to detect local overheating, abnormal stress, or potential faults in a timely manner; they also have defects such as dispersed structural layers, poor independence of each functional unit, insufficient tensile and anti-interference capabilities, and insufficient stability for long-term underground use; the underground environment has high requirements for the cable's resistance to high and low temperatures, flame retardancy, moisture resistance, mildew resistance, and resistance to mechanical disturbance, while existing technologies often cannot simultaneously achieve multiple performance requirements.

[0005] Therefore, there is an urgent need for an underground smart early warning cable and its manufacturing method to solve the above problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an underground intelligent early warning cable and its preparation method, which solves the problems of traditional cables having difficulty in determining faults, insufficient anti-interference ability, and insufficient environmental adaptability.

[0007] The technical problem to be solved by this invention is achieved by the following technical solution: a smart early warning cable for underground applications, comprising... From the inside out, the components are arranged as follows: core assembly, wrapping assembly, and outer sheath assembly. The core assembly includes at least one conductive core and a communication optical cable unit. The conductive core is twisted together, and the communication optical cable unit is disposed on the outside of the conductive core. Each of the conductive wire cores includes a conductor, a temperature-sensitive optical fiber conductor unit disposed on the outer periphery of the conductor, and an insulating layer disposed on the outside of the temperature-sensitive optical fiber conductor unit. A copper strip shielding layer is provided on the outside of the conductive wire core; Mica strips are provided in the gaps of the core components; The wrapping assembly comprises, from the inside out, an aluminum-plastic composite strip, a semi-conductive strip, and a T1 copper strip; The outer sheath assembly is a low-smoke halogen-free polyolefin that covers the outside of the wrapping assembly.

[0008] Preferably, the temperature-sensing optical fiber conductor unit is a ring-shaped sleeve structure, and its inner diameter is adapted to the outer diameter of the conductor. The temperature-sensing optical fiber conductor unit is located inside the insulating layer.

[0009] Preferably, there are three conductive cores arranged close together, and the communication optical cable unit is arranged in the gap formed by the triangular twisting arrangement.

[0010] Preferably, the communication optical cable unit includes a conductor and a tensile element, wherein the conductor and the tensile element extend along the same axial direction to form the communication optical cable unit.

[0011] Preferably, the mica tape fills the gaps formed between the conductive cores and between the communication optical cable unit and the conductive cores, and forms a continuous filling layer around the core assembly.

[0012] Preferably, the copper strip shielding layer is a single-layer copper strip wrapping layer, and the overlap rate of the copper strip shielding layer is not less than 35%.

[0013] Preferably, the outer sheath is an extruded low-smoke halogen-free polyolefin layer.

[0014] A method for manufacturing an underground smart early warning cable, preferably comprising the following steps: S1. Prepare the conductive wire core, select a conductor, the conductor adopts a five-type conductor structure, the single wire elongation is 23%-25%, the conductor is stranded and then stranded in multiple layers, and the stranding direction is left-handed. S2. A temperature-sensing optical fiber conductor unit is sleeved around the outer periphery of each conductor, and the insulating layer is wrapped around the outside of the temperature-sensing optical fiber conductor unit. S3. The multiple conductive cores are twisted together and the communication optical cable unit is placed in the gap formed by the conductive cores. At the same time, mica tape is filled between the conductive cores and between the communication optical cable unit and the conductive cores to form the core assembly. S4. Wrap a copper strip shielding layer around the outside of the core assembly; S5. An aluminum-plastic composite strip, a semi-conductive strip, and a T1 copper strip are sequentially wrapped around the outside of the copper strip shielding layer to form the wrapping assembly; S6. Extruding low-smoke halogen-free polyolefin onto the outside of the wrapping assembly.

[0015] Preferably, in step S3, the plurality of conductive cores are configured as three, and the three conductive cores are arranged in close contact with each other.

[0016] Preferably, in step S4, the copper strip shielding layer is a single-layer copper strip wrapping layer, and the overlap rate of the copper strip shielding layer is not less than 35%.

[0017] The beneficial effects of this invention are: This invention employs a temperature-sensing optical fiber conductor unit positioned coaxially with the conductor and located inside the insulation layer, enabling direct sensing of the conductor's operating temperature and stress state. The temperature-sensing optical fiber conductor unit, closely attached to the conductor, can promptly capture changes in optical signals when the conductor heats up or is subjected to external forces. These signals are then collected and processed by an external optical fiber demodulation device, achieving real-time monitoring of the cable's operating status. The invention also incorporates a communication optical cable unit and the temperature-sensing optical fiber conductor unit, with the communication optical cable unit positioned within the gap formed by the conductive cores, enabling synchronous transmission and feedback of monitoring information. This structure allows operating data such as temperature and stress to be rapidly transmitted to an external monitoring system via the communication optical cable unit, avoiding the problems of scattered signal links, unstable transmission, and delayed feedback inherent in traditional cable monitoring systems.

[0018] This invention, through the arrangement of stranded conductive cores, the placement of communication optical cable units within the gaps formed by the conductive cores, and the filling and positioning of the core gaps with mica tape, achieves structural stability in the fault area, clear line boundaries, and stable internal configuration. This structure fixes the relative positions of the functional units within the cable, reducing detection distortion caused by component misalignment during laying, bending, and pulling. It also makes it easier to associate abnormal locations with corresponding line segments, thereby facilitating rapid identification and narrowing of the fault location.

[0019] This invention utilizes mica tape to form a continuous filling layer around the core assembly, achieving a comprehensive effect of filling core gaps, positioning components, and providing fire resistance and heat insulation. The mica tape not only supports and fills the gaps between conductive cores and between communication optical cable units and conductive cores, preventing internal structural loosening or relative displacement, but also slows heat transfer to the core under heating conditions, improving the cable's survivability in fire or high-temperature environments. The addition of a low-smoke halogen-free polyolefin outer sheath, covering the outside of the wrapping assembly, provides long-term protection against complex underground environments. Low-smoke halogen-free polyolefin materials possess good high and low temperature resistance, low smoke and low toxicity, and certain resistance to moisture and aging, reducing damage caused by temperature changes, moisture corrosion, and fire spread in underground laying environments. Attached Figure Description

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

[0021] In the diagram: 111-Conductor, 112-Temperature-sensing optical fiber conductor unit, 113-Insulation layer, 12-Communication optical cable unit, 13-Mica tape, 21-Copper tape shielding layer, 31-Aluminum-plastic composite tape, 32-Semi-conductive tape, 33-T1 copper tape, 41-Outer sheath assembly. Detailed Implementation

[0022] To facilitate a clear understanding of the technical means, creative features, objectives, and effects of this invention, the invention will be further described below in conjunction with specific embodiments. Example 1

[0023] like Figure 1 As shown, an underground smart early warning cable includes a core assembly, a wrapping assembly, and an outer sheath assembly 41 arranged sequentially from the inside to the outside. The core assembly includes at least one conductive core and a communication optical cable unit 12. The conductive cores are twisted together, and the communication optical cable unit 12 is disposed on the outside of the conductive core.

[0024] The conductive core includes a conductor 111, a temperature-sensitive optical fiber conductor unit 112 disposed on the outer periphery of the conductor 111, and an insulating layer 113 disposed on the outer side of the temperature-sensitive optical fiber conductor unit 112.

[0025] In this embodiment, there are three conductive cores, which are attached to each other and connected by twisting. During the twisting process, the communication optical cable unit 12 is disposed in the gap formed between the conductive cores. During the twisting process, mica tape 13 is disposed to fill the gaps between the core components, that is, between the conductive cores and the communication optical cable unit 12.

[0026] A copper strip shielding layer 21 is provided on the outside of the conductive wire core.

[0027] The outer side of the core component is provided with a wrapping assembly, which consists of an aluminum-plastic composite strip 31, a semi-conductive strip 32, and a T1 copper strip 33 from the inside to the outside.

[0028] The outer sheath assembly 41 is disposed on the outside of the wrapping assembly, and the outer sheath assembly 41 is a low-smoke halogen-free polyolefin covering the outside of the wrapping assembly.

[0029] Reference Figure 1 In this embodiment, The core assembly includes a conductive wire core and a communication optical cable unit 12. The conductive wire core includes a conductor 111, a temperature-sensing optical fiber conductor unit 112, and an insulating layer 113, which are arranged in a radial direction from the inside to the outside.

[0030] The conductor 111 preferably adopts a Category 5 copper conductor structure. The conductor 111 is formed by multi - strand stranding of multiple single wires followed by multi - layer stranding, and the stranding direction of each layer is left - hand. The elongation rate of the single wire is preferably 23% - 25% to ensure that the conductor 111 has good flexibility and anti - bending ability.

[0031] The whole of the conductor 111 is preferably a cylindrical or nearly cylindrical stranded body, which is composed of multiple fine copper wires tightly combined inside and forms a continuous and stable conductive layer on the outer periphery. The multi - layer left - hand stranding structure is beneficial to improving the mechanical stability and anti - torsion performance of the conductor on the one hand, and is beneficial to reducing looseness, deformation and local stress concentration during laying on the other hand.

[0032] The temperature - sensing optical fiber conductor unit 112 is sleeved on the outer periphery of the conductor 111, preferably in an annular sleeved structure or a nearly annular sleeve structure, and its inner diameter is adapted to the outer diameter of the conductor 111, so that the temperature - sensing optical fiber conductor unit 112 can be stably sleeved outside the conductor and is not likely to shift or break away.

[0033] The temperature - sensing optical fiber conductor unit 112 is located inside the insulating layer 113, between the conductor 111 and the insulating layer 113. This structure enables the temperature - sensing optical fiber conductor unit 112 to be closely arranged against the conductor 111, so as to more directly sense the temperature change and stress change during the operation of the conductor and transmit the monitoring information along the optical fiber path.

[0034] Structurally, the temperature - sensing optical fiber conductor unit 112 adopts an elongated strip, ribbon or annular coating structure, and its outer shape continuously extends along the axial direction of the cable and is coaxially arranged with the conductor 111. This setting makes the temperature and stress detection positions closer to the heat source and stress source, and can improve the timeliness and accuracy of monitoring response.

[0035] In this embodiment, the temperature - sensing optical fiber conductor unit 112 includes a temperature - sensing optical fiber, and an optical fiber demodulation device is equipped on the outer side of the cable. The optical fiber demodulation device can collect the signal change of the temperature - sensing optical fiber.

[0036] When the temperature of the conductor 111 rises or stress changes occur under external force during operation, the propagation characteristics of the optical signal in the temperature - sensing optical fiber change, specifically manifested as changes in scattered light intensity, reflection wavelength drift or scattered spectrum distribution; the externally - equipped optical fiber demodulation device collects and calculates the above changes, and then the temperature and stress information at the corresponding position can be obtained. Thus, the temperature - sensing optical fiber conductor unit 112 can realize real - time monitoring and early warning of the operating state of the cable.

[0037] In this embodiment, the temperature - sensing optical fiber conductor unit 112 is arranged inside the insulating layer 113.

[0038] The insulating layer 113 is preferably formed of cross-linked polyethylene material and has a circular tubular structure. The insulating layer 113 is formed by water boiling cross-linking, and the preferred cross-linking conditions are 90℃ / 6h.

[0039] The insulating layer 113 is coaxially arranged with the conductor 111 and the temperature-sensing optical fiber conductor unit 112, forming the outer electrical isolation structure of the conductive core. On the one hand, the insulating layer 113 can provide reliable electrical isolation to the conductor 111, avoiding short circuits between adjacent conductive cores; on the other hand, the cross-linking treatment improves the heat resistance, aging resistance and long-term stability of the material, making the conductive core 11 suitable for long-term underground burial environments.

[0040] The communication optical cable unit 12 is disposed in the gap enclosed by the conductive core 11. Its structure preferably includes a conductor and a tensile element, both extending along the same axis and combined to form the communication optical cable unit 12. The conductor can be a copper conductor, and the tensile element can be a reinforcing member with certain tensile strength.

[0041] In this embodiment, the conductor of the communication optical cable unit 12 is a single flexible copper conductor that extends along the axial direction of the communication optical cable unit 12. The tensile element is preferably an aramid fiber bundle, which also extends continuously along the axial direction. The tensile element covers the outside of the single flexible copper conductor, forming an integral structure, thus forming a communication optical cable unit 12 with a nearly circular or near-circular cross-section.

[0042] In terms of structural arrangement, the communication optical cable unit 12 is disposed in the gap formed by the conductive core 11, located on the outside or in the center of the gap. This ensures that the communication optical cable unit 12 does not damage the stranded main structure of the conductive core 11, and can form a communication channel independently within the core assembly 1. The communication conductor is used to carry communication signals or auxiliary electrical connections, and the tensile element is used to improve the structural stability of the entire communication optical cable unit 12 under laying, bending, and tension conditions, preventing the communication unit from breaking, deforming, or displacing during underground construction and long-term operation.

[0043] The mica tape 13 is disposed in the gaps of the core assembly, namely the gaps formed between the conductive wire cores 11 and the gaps formed between the communication optical cable unit 12 and the conductive wire core 11, and forms a continuous filling layer around the core assembly 1.

[0044] Structurally, the mica tape 13 is preferably a strip or sheet material that extends along the cable axis and forms a layered filling or covering between adjacent conductive cores 11 and around the communication optical cable unit 12. The mica tape 13 makes the internal structure of the core assembly 1 more compact.

[0045] After the mica tape 13 is installed, it can fill and position the gaps inside the core assembly, preventing relative displacement of the components during laying or bending. Furthermore, the mica material has high-temperature resistance, flame retardancy, and heat insulation properties, which can delay heat transfer to the interior when heated externally, improving the overall fire resistance and heat resistance of the cable. By installing the mica tape 13, the core assembly can be made to have an overall circular shape.

[0046] A copper strip shielding layer 21 is provided on the outside of the conductive wire core. The copper strip shielding layer 21 is preferably a single layer of copper strip, which is provided on the outside of the conductive wire core by wrapping. After wrapping, it forms a near-cylindrical shielding layer with an overlap rate of not less than 35%.

[0047] The copper tape shielding layer 21 is coaxially arranged with the outer periphery of the conductive core, which can effectively shield external electromagnetic interference and reduce the impact of external noise in complex underground environments on conductor 111 and communication optical cable unit 12. At the same time, the copper tape shielding layer 21 can also improve the overall electromagnetic compatibility of the cable and enhance operational stability.

[0048] The wrapping assembly is disposed on the outside of the core assembly, and preferably includes an aluminum-plastic composite strip 31, a semi-conductive strip 32, and a T1 copper strip 33 arranged sequentially from the inside to the outside. The aluminum-plastic composite strip 31, the semi-conductive strip 32, and the T1 copper strip 33 all extend continuously along the cable axis and form the wrapping assembly layer by layer by wrapping.

[0049] The aluminum-plastic composite tape 31 is located in the innermost layer and is directly wrapped around the outside of the copper tape shielding layer 21. It is preferably a tape structure, which is continuously arranged around the circumference of the cable to form the first outer wrapping layer.

[0050] The aluminum-plastic composite strip 31 is preferably a strip structure formed of aluminum foil and plastic film; in this embodiment, aluminum foil and polyester film are used. This strip is flexible, continuous, and has good isolation properties. After wrapping, it is located in the innermost layer, closely attached to the outside of the copper strip shielding layer 21. Its function is to form the first external barrier layer, enhance the flatness of the structure, and provide a stable supporting foundation.

[0051] The semiconducting strip 32 is located outside the aluminum-plastic composite strip 31 and serves as an intermediate transition layer. Structurally, this layer has a strip-like wrapping structure, which makes the potential distribution between adjacent layers more uniform and helps improve the stability of the outer layer coating.

[0052] The semiconductive strip 32 is preferably a polymer strip doped with conductive fillers. In this embodiment, the polymer strip is made of polyethylene matrix, with carbon black, graphite, or other conductive particles incorporated into the polyethylene matrix to form a strip-shaped material. This layer is located outside the aluminum-plastic composite strip 31, serving as an intermediate transition layer. Its structural feature is that its resistance is between that of a conductor and an insulator. After wrapping, it can improve the local potential distribution and make the outer wrapping more uniform and smooth.

[0053] The T1 copper strip 33 is located on the outermost layer, wrapped around the outside of the semiconducting strip 32, forming an outer wrapping shielding reinforcement layer. The T1 copper strip 33 and the aforementioned two layers together constitute a multi-layer wrapping structure, enabling the cable to have better mechanical integrity, shielding capability and structural stability in underground environments.

[0054] The T1 copper strip 33 is preferably a T1 pure copper strip, located on the outermost layer and wrapped around the outside of the semiconducting strip 32. This layer forms an outer wrapping reinforcement layer, which can further improve electromagnetic shielding capability, mechanical protection capability, and interlayer stability.

[0055] The wrapping assembly creates a multi-layer continuous wrapping structure on the outside of the copper strip shielding layer 21, which not only enhances the overall tightness but also further improves the resistance to electromagnetic interference, external compression, and laying disturbances.

[0056] The outer sheath assembly 41 covers the outside of the wrapping assembly and is preferably formed by extrusion molding of low-smoke halogen-free polyolefin. The outer sheath assembly 41 is a cylindrical or annular covering layer that fits tightly against the outer periphery of the wrapping assembly 3, forming the outermost protective structure of the cable.

[0057] The outer sheath assembly 41 is made of low-smoke halogen-free polyolefin, which has the characteristics of low smoke and halogen-free, and produces less smoke and releases less corrosive and toxic gases when burning, which can reduce secondary hazards from fire. At the same time, as a polyolefin system material, it has good resistance to low temperature and high temperature and environmental adaptability, making it suitable for underground, humid, buried, and large temperature difference laying scenarios.

[0058] In this embodiment, the conductive cores are coaxially connected by conductor 111, temperature-sensing optical fiber conductor unit 112, and insulation layer 113; multiple conductive cores are then arranged by twisting, and communication optical cable unit 12 is arranged in the gaps formed outside the conductive cores, and the gaps are filled and positioned by mica tape 13 to form a core assembly; aluminum-plastic composite tape 31, semi-conductive tape 32, and T1 copper tape 33 are wrapped around the outside of the core assembly in sequence; the outermost layer is formed by extruding low-smoke halogen-free polyolefin to form an outer sheath assembly 41, thereby forming a complete underground smart early warning cable.

[0059] Conductor 111 is responsible for power transmission, temperature-sensing optical fiber conductor unit 112 is responsible for temperature and stress monitoring, and communication optical cable unit 12 is responsible for communication data transmission. The three work together to enable the cable to have power supply, monitoring and communication functions.

[0060] The mica tape 13 fills and positions the gaps in the conductive core, while improving the fire resistance and heat insulation performance, making the structure of the conductive core more stable.

[0061] The copper strip shielding layer 21 and the multi-layer wrapping assembly can effectively suppress external electromagnetic interference and reduce signal distortion and transmission instability in complex underground environments.

[0062] The outer sheath assembly 41 is made of low-smoke halogen-free polyolefin, which can improve the weather resistance, flame retardancy and safety of the cable under long-term underground laying conditions.

[0063] A method for preparing an underground smart early warning cable, comprising: S1. Preparation of the conductive core. A copper conductor is selected as conductor 111. The copper conductor adopts a Class V conductor structure with a single wire elongation of 23%-25%. The copper conductor is first stranded and then stranded in multiple layers, with each layer stranded in a left-hand direction, thereby forming conductor 111 with good flexibility and torsional resistance. Conductor 111 is preferably a cylindrical or near-cylindrical stranded body, with multiple fine copper wires tightly combined to form a continuous conductive layer inside.

[0064] S2. A temperature-sensing fiber optic conductor unit 112 is installed around the outer periphery of the conductor 111, and an insulating layer 113 is wrapped around the outside of the temperature-sensing fiber optic conductor unit 112 to form a single conductive core 11. The temperature-sensing fiber optic conductor unit 112 is preferably a ring-shaped or near-ring-shaped sleeve structure, with its inner diameter matching the outer diameter of the conductor 111, and located inside the insulating layer 113, i.e., between the conductor 111 and the insulating layer 113. The temperature-sensing fiber optic conductor unit 112 can be a composite structure consisting of a temperature-sensing fiber body, an outer buffer protective layer, and a positioning covering layer, used to collect temperature and stress change information during the operation of the conductor 111.

[0065] S3, Cable forming core components.

[0066] Multiple conductive cores are twisted together to form a central gap between them, and the communication optical cable unit 12 is placed within this central gap. The communication optical cable unit 12 preferably includes a single flexible copper conductor and a tensile element, which extend along the same axial direction and are combined to form the communication optical cable unit 12. Mica tape 13 is filled between the conductive cores and between the communication optical cable unit 12 and the conductive cores to form a core assembly. The mica tape 13 is preferably a strip-shaped or sheet-like material, extending along the cable axial direction, and forming a continuous filling layer between adjacent conductive cores 11 and around the communication optical cable unit 12 to position and support the internal gaps of the core assembly.

[0067] S4. Wrapping Shielding Layer. A copper strip shielding layer 21 is wrapped around the outside of the core assembly. The copper strip shielding layer 21 is coaxially arranged with the core assembly and can form external electromagnetic shielding for the conductor 111, the temperature-sensing optical fiber conductor unit 112, and the communication optical cable unit 12.

[0068] S5. Reinforcing Wrapping Layer. An aluminum-plastic composite tape 31, a semi-conductive tape 32, and a T1 copper tape 33 are sequentially wrapped around the outside of the copper tape shielding layer 21 to form a wrapping assembly. The aluminum-plastic composite tape 31 is located as the innermost layer, directly wrapped around the outside of the copper tape shielding layer 21; the semi-conductive tape 32 is located outside the aluminum-plastic composite tape 31, serving as an intermediate transition layer; and the T1 copper tape 33 is located as the outermost layer, wrapped around the outside of the semi-conductive tape 32. All three extend continuously along the cable axis and form a continuous wrapping structure layer by layer through a spiral wrapping method.

[0069] S6. Extruded outer sheath assembly 41. Low-smoke halogen-free polyolefin is extruded onto the outside of the wrapping assembly to form the outer sheath assembly 41, thereby producing an underground smart early warning cable. The outer sheath assembly 41 is a cylindrical covering layer that fits tightly against the outer periphery of the wrapping assembly, forming the outermost protective structure of the cable.

[0070] In this embodiment, the conductive core in step S3 is set to three, and the three conductive cores are arranged in a triangular twisted arrangement. The communication optical cable unit 12 is disposed in the gap formed by the triangular twisted arrangement.

[0071] In step S4, the copper strip shielding layer 21 is preferably a single-layer copper strip wrapping layer, which forms a near-cylindrical shielding layer after wrapping, and its overlap rate is not less than 35%.

[0072] Through the above preparation method, conductor 111 is responsible for power transmission, temperature-sensing optical fiber conductor unit 112 is responsible for monitoring conductor operating temperature and stress, and communication optical cable unit 12 is responsible for monitoring data transmission and communication signal carrying. The three work together to form an integrated structure of power transmission and intelligent early warning. Mica tape 13 fills and positions the core gaps and improves the core fire resistance. Copper tape shielding layer 21 and wrapping assembly 3 provide multi-level shielding against external electromagnetic interference. Outer sheath 41 provides low-smoke halogen-free protection and environmental adaptability for the entire cable, thus making the cable suitable for long-term use in complex underground laying environments.

[0073] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention, all of which fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A smart early warning cable for underground applications, comprising: From the inside out, the components are arranged as follows: core assembly, wrapping assembly, and outer sheath assembly. Its features are: The core assembly includes at least one conductive core and a communication optical cable unit. The conductive core is stranded and distributed, and the communication optical cable unit is disposed on the outside of the conductive core. Each conductive core includes a conductor, a temperature-sensing optical fiber conductor unit disposed on the outer periphery of the conductor, and an insulating layer disposed on the outside of the temperature-sensing optical fiber conductor unit. A copper tape shielding layer is disposed on the outside of the conductive core. Mica tape is disposed in the gaps of the core assembly. The wrapping assembly comprises, from the inside out, an aluminum-plastic composite strip, a semi-conductive strip, and a T1 copper strip; The outer sheath assembly is a low-smoke halogen-free polyolefin that covers the outside of the wrapping assembly.

2. The underground intelligent early warning cable according to claim 1, characterized in that: The temperature-sensing optical fiber conductor unit has a ring-shaped sleeve structure, and its inner diameter is adapted to the outer diameter of the conductor. The temperature-sensing optical fiber conductor unit is located inside the insulating layer.

3. The underground intelligent early warning cable according to claim 1, characterized in that: The conductive cores are arranged in three ways, and the communication optical cable unit is arranged in the gap formed by the triangular twisting arrangement.

4. The underground intelligent early warning cable according to claim 1, characterized in that: The communication optical cable unit includes a conductor and a tensile element, wherein the conductor and the tensile element extend along the same axial direction to form the communication optical cable unit.

5. A smart early warning cable for underground applications according to claim 1, characterized in that: The mica tape fills the gaps formed between the conductive cores and between the communication optical cable unit and the conductive cores, and forms a continuous filling layer around the core assembly.

6. A smart early warning cable for underground applications according to claim 1, characterized in that: The copper strip shielding layer is a single-layer copper strip wrapping layer, and the overlap rate of the copper strip shielding layer is not less than 35%.

7. A smart early warning cable for underground use according to claim 1, characterized in that: The outer sheath is an extruded low-smoke halogen-free polyolefin layer.

8. A method for manufacturing an underground intelligent early warning cable, characterized in that: The method for preparing an underground smart early warning cable as described in any one of claims 1-7 includes the following steps: S1. Prepare the conductive wire core, select a conductor, the conductor adopts a five-type conductor structure, the single wire elongation is 23%-25%, the conductor is stranded and then stranded in multiple layers, and the stranding direction is left-handed. S2. A temperature-sensing optical fiber conductor unit is sleeved around the outer periphery of each conductor, and the insulating layer is wrapped around the outside of the temperature-sensing optical fiber conductor unit. S3. The multiple conductive cores are twisted together and the communication optical cable unit is placed in the gap formed by the conductive cores. At the same time, mica tape is filled between the conductive cores and between the communication optical cable unit and the conductive cores to form the core assembly. S4. Wrap a copper strip shielding layer around the outside of the core assembly; S5. An aluminum-plastic composite strip, a semi-conductive strip, and a T1 copper strip are sequentially wrapped around the outside of the copper strip shielding layer to form the wrapping assembly; S6. Extruding low-smoke halogen-free polyolefin onto the outside of the wrapping assembly.

9. A method for manufacturing an underground intelligent early warning cable according to claim 8, characterized in that: In step S3, the plurality of conductive cores are configured as three, and the three conductive cores are arranged in close contact with each other.

10. A method for manufacturing an underground intelligent early warning cable according to claim 8, characterized in that: In step S4, the copper strip shielding layer is a single-layer copper strip wrapping layer, and the overlap rate of the copper strip shielding layer is not less than 35%.

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