High-temperature-resistant shielding armor layer power cable and production process

Abstract

The invention discloses a high-temperature-resistant shielding armor layer power cable and a production process, and belongs to the technical field of power cables, the cable comprises a cable core, a heat transfer layer, a waterproof layer, a shielding heat conduction layer, an armor layer, a self-repairing layer and an outer protection layer which are sequentially arranged from inside to outside; wherein the heat transfer layer is made of a wood fiber composite graphene nanosheet (WF (at) G) biological composite material, and the heat conductivity coefficient is larger than or equal to 0.243 W / (m.K); the shielding heat conduction layer is integrated with a honeycomb soaking net, a silicon carbide heat conduction pad and an MXene-graphene heat dissipation sleeve, rotatable magnetic beads (phi 1 mm) are arranged in the shielding heat conduction layer, and 360-degree electromagnetic interference absorption and dynamic soaking are achieved under driving of an alternating magnetic field; the armor layer directly coats the outer surface of the heat dissipation sleeve to form a mechanical-electromagnetic shielding integrated structure; the self-repairing layer contains a thermal trigger cycloaddition reaction network, the fracture repairing efficiency is larger than 95%, an independent wall heat dissipation framework is constructed through a biaxial ice template method (Z-direction and X-direction temperature gradient) in the production process, and the vertical thermal conductivity reaches 1.64 W.m <-1 >. K <-1 >.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, specifically to a high-temperature resistant and crack-resistant power cable and its manufacturing process that integrates shielding, heat conduction and armor functions. Background Technology

[0002] Currently, power cables face three major technical bottlenecks under high temperature and high electromagnetic interference conditions: Low heat dissipation efficiency: Traditional cables rely on a single insulation layer for heat dissipation. When operating at high temperatures, internal heat accumulates, leading to insulation aging. PVC materials have a temperature resistance limit of only 70℃, which can easily cause fires. Electromagnetic shielding and mechanical protection are separated: the shielding layer needs to be independently set with metal braided mesh, the armor layer only provides mechanical strength, and the multi-layer structure increases the cost (accounting for 15%-20% of the total cost) and reduces flexibility; Irreversible damage: After the sheath breaks due to external impact, moisture intrusion accelerates insulation failure and cannot be repaired on-site.

[0003] Existing solutions such as CN202321941150.3 use graphene coating to improve thermal conductivity, but do not solve the problem of local overheating; CN202411576630.3 enhances shielding with built-in metal mesh, but increases weight by more than 30%, and traditional armored cables reach a surface temperature of 89°C under a 150A load, with an EMI shielding effectiveness of only 45dB (requiring an external shielding layer), and cannot be repaired after breakage. Therefore, there is an urgent need for a cable structure that integrates efficient heat dissipation, dynamic shielding, and mechanical self-healing. Summary of the Invention

[0004] 1. Technical problem to be solved: To address the problems existing in the prior art, the purpose of this invention is to provide a high-temperature resistant shielded armored power cable and its manufacturing process, achieving integrated high-efficiency heat dissipation, dynamic electromagnetic shielding, and self-repair.

[0005] 2. Technical Solution: To solve the above problems, the present invention adopts the following technical solution.

[0006] A high-temperature resistant shielded armored power cable includes, from the inside out, the following components arranged sequentially: Multiple cable cores; The heat transfer layer covering the cable core is made of WF@G bio-composite material, which is a wood fiber matrix composite graphene nanosheet. A waterproof layer covering the heat transfer layer; The heat shielding layer includes a honeycomb structure heat dissipation mesh, silicon carbide heat dissipation pad one and silicon carbide heat dissipation pad two, and MXene-graphene heat dissipation sleeve. The armor layer, which covers the outer surface of the shielding and heat-conducting layer, is made of steel strips or steel wires; Self-healing layer and outer protective layer.

[0007] A further improvement is that the shielding thermal conductive layer includes: The heat dissipation mesh is made of 3D-printed carbon fiber composite material woven into a honeycomb structure and attached to the surface of the waterproof layer; A closed annular through hole is formed between silicon carbide thermal pad one and silicon carbide thermal pad two, and a sliding magnetic bead is installed inside the hole; The heat dissipation sleeve covers the silicon carbide thermal pad II, which is composed of anisotropic three-dimensional MXene / graphene composite material with independent wall structure.

[0008] A further improvement is that the magnetic bead rotates under the drive of the cable's magnetic field, achieving 360° high-frequency electromagnetic interference absorption and heat dissipation from the thermal paste.

[0009] A further improvement is that the WF@G biocomposite material of the heat transfer layer is prepared through the following steps: Graphene nanosheets are combined with polyamide epichlorohydrin to form positively charged GNP / PAE; Electrostatic adsorption forms graphene-coated wood fibers on the surface of negatively charged wood fibers. After drying, it is hot-pressed into shape using a sealed mold.

[0010] A further improvement is that the ratio of MXene to graphene filler in the heat sink is 1:1, and the vertical thermal conductivity is 1.64 W·m. -1 ·K -1 .

[0011] A manufacturing process for a high-temperature resistant shielded armored power cable includes the following steps: S1: Extruding WF@G bio-composite material to coat the cable core to form a heat transfer layer; S2: Multiple cable cores are bonded together and covered with a EPDM rubber waterproof layer; S3: Cover the surface of the waterproof layer with a heat-conducting shielding layer; S4: Wrap steel strips or wires around the surface of the shielding heat-conducting layer to form an armor layer; S5: A self-healing layer is applied to the surface of the armor layer; S6: Extruded silicone rubber outer protective layer.

[0012] A further improvement is that in step S31, the MXene / graphene independent wall structure framework is constructed under a biaxial (Z-direction + X-direction) temperature gradient using the ice template method.

[0013] A further improvement lies in the ice template method described above: The vertical thermal conductivity of the composite material under a uniaxial (Z-direction) temperature gradient is 1.09 W·m. -1 ·K -1 ; The vertical thermal conductivity under a biaxial (Z+X) temperature gradient is increased to 1.64 W·m. -1 ·K -1 .

[0014] A further improvement is that the armor layer is added in close contact with the outer surface of the heat dissipation sleeve of the shielding heat-conducting layer, forming an integrated structure of mechanical protection and electromagnetic shielding.

[0015] 3. Beneficial effects: Compared with the prior art, the technical solution provided by this invention has the following advantages: (1) Dual-layer high-efficiency thermal design: The inner heat transfer layer uses WF@G bio-composite material (wood fiber matrix composite graphene nanosheets) to achieve a thermal conductivity of ≥0.243W / (m·K), which quickly dissipates the heat from the cable core to the outside. The outer shielding and thermally conductive layer utilizes a biaxial ice template method (Z-axis + X-axis temperature gradient) to construct an MXene / graphene independent wall structure framework, achieving a vertical thermal conductivity of 1.64 W·m. -1 ·K -1 (50.5% improvement over single Z-axis gradient), completely solving the problem of high-temperature aging of insulation layer caused by insufficient heat dissipation in traditional cables.

[0016] (2) Dynamic heat dissipation mechanism: The sliding magnetic beads (Φ1mm) between the silicon carbide thermal pads rotate under the drive of an alternating magnetic field, forcibly diffusing local hot spots of the thermal paste. Combined with the 3D carbon fiber network of the honeycomb heat dissipation mesh, the surface temperature of the cable is only 58℃ under a 150A load (compared to 89℃ for traditional armored cables), and the temperature resistance rating breaks through to 180℃.

[0017] (3) Three-level cooperative broadband shielding: The heat transfer layer (WF@G) absorbs low-frequency electromagnetic interference (shielding effectiveness of 52dB in the 1MHz band). The rotating magnetic bead cuts the magnetic field lines to generate eddy current loss, which effectively absorbs high-frequency interference of 1-5GHz (with an additional 21dB). The MXene / graphene independent wall structure reflects residual electromagnetic waves (adding 10.2dB in the 5-10GHz band), and the overall cable shielding effectiveness reaches 83.2dB (traditional cables only have 45dB and require an additional shielding layer).

[0018] (4) Functional integration of armor layer: The steel strip / wire armor layer (tension 200±10N) is directly wrapped around the outer surface of the heat sink, forming an integrated structure of mechanical protection and electromagnetic shielding, reducing weight by 25% (compared to the CN114512226B solution) and increasing flexibility by 40%.

[0019] (5) Intelligent response and repair network: The self-healing layer releases repair guests through microcapsules (50-100μm in diameter) in the polyfluoroethylene propylene (FEP) matrix at temperatures above 80°C, triggering the Diels-Alder cycloaddition reaction. The repair efficiency is >95% (96.2% recovery rate of tensile strength at break) within 2 hours, eliminating the risk of insulation failure caused by moisture intrusion.

[0020] (6) Triple waterproof protection: The structure consists of a 0.8mm EPDM rubber waterproof layer, an armor layer gap seal, and a silicone rubber outer protective layer, achieving IP68 waterproof certification.

[0021] (7) Production cost and reliability optimization The integrated design of the shielding and thermal conductive layer and the armor layer reduces the need for separate metal braided mesh, thus lowering manufacturing costs by 15%-20%. The anti-jamming structure of the magnetic bead (through hole diameter 1.2-1.3mm, magnetic bead Φ1mm) ensures zero wear after 300,000 rotations, increasing the lifespan by 3 times; The production process is compatible with existing extrusion and winding equipment. The biaxial temperature control of the ice template method can be mass-produced through a symmetrical linear temperature control device (left -15℃ / right 5℃).

[0022] In summary, this invention overcomes industry bottlenecks such as high-temperature heat dissipation, electromagnetic interference, and irreversible mechanical damage through three core innovations: "biocomposite heat transfer layer - dynamic heat equalization of magnetic beads - self-healing network", providing a highly reliable cable solution for high-risk scenarios such as nuclear power and metallurgy. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the cable cross-section structure of the present invention, showing the layered structure from the cable core to the outer sheath; Figure 2 This is a schematic diagram of the shielding heat-conducting layer of the present invention, showing the heat dissipation mesh, the first silicon carbide heat-conducting pad, the second, the magnetic beads, and the heat dissipation sleeve; Figure 3 This is a schematic diagram of the repair mechanism of the self-healing layer of the present invention.

[0024] Explanation of the labels in the diagram: 1. Cable core; 2. Heat transfer layer; 3. Waterproof layer; 4. Shielding thermal conductive layer; 41. Heat dissipation mesh; 42. Silicon carbide thermal conductive pad one; 43. Silicon carbide thermal conductive pad two; 44. Magnetic beads; 45. Heat dissipation sleeve; 5. Armor layer; 6. Self-repairing layer; 7. Outer protective layer. Detailed Implementation

[0025] To facilitate understanding of the present invention, a more complete description of the invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the invention will be more thorough and complete.

[0026] A high-temperature resistant shielded armored power cable, comprising, from the inside out: Cable core 1: Multiple conductors twisted together; The heat transfer layer 2 covering the cable core 1 is a WF@G biocomposite material made of wood fiber (WF) matrix and graphene nanosheets (GNP), with a thermal conductivity ≥0.243W / (m·K). Waterproof layer 3 covering heat transfer layer 2: EPDM rubber; The heat-conducting shielding layer 4 includes: A 3D-printed honeycomb structure heat dissipation net 41 made of carbon fiber composite material is attached with a waterproof layer 3. Silicon carbide thermal pad 1 42 and silicon carbide thermal pad 2 43 form an annular through hole, with a sliding magnetic bead 44 inside. MXene / graphene independent wall structure heat dissipation sleeve 45 covers the outer side (MXene:graphene = 1:1, vertical thermal conductivity 1.64 W·m). -1 ·K -1 ); Armor layer 5: Steel strip / wire tightly wraps around the outside of the shielding and heat-conducting layer 4; Self-healing layer 6: Contains a poly(fluoroethylene propylene) matrix and a cycloaddition reaction repair network; Outer protective layer 7: Silicone rubber.

[0027] The manufacturing process includes: extrusion and coating of the heat transfer layer → bonding of the cable core → coating of the waterproof layer → construction of the shielding and heat-conducting layer → winding of the armor layer → extrusion of the self-healing layer and the outer sheath. Among them, the shielding and heat-conducting layer is formed into an independent wall skeleton by biaxial temperature control (Z-axis + X-axis) using the ice template method.

[0028] Example 1: Preparation of heat transfer layer 1. Raw material processing: Take 100g of graphene nanosheets (GNP) with a diameter of 6.5-10μm and dry grind them in a tungsten carbide ball mill jar at a ball-to-powder ratio of 7:2 for 4 hours (pausing for 20 minutes every 10 minutes to cool) to obtain 2500 mesh GNP powder.

[0029] 2. Electrostatic composite: Add GNP powder to 800 ml of polyamide epichlorohydrin (PAE) resin and ultrasonically disperse for 20 minutes; Ball milling for 2 hours under argon protection to form a positively charged GNP / PAE slurry; It is sprayed onto the surface of negatively charged wood fibers, where electrostatic adsorption forms a GNP-coated fiber.

[0030] 3. Hot pressing: After drying, the preforms were hot-pressed at 180℃ and 15MPa for 30 minutes to obtain WF@G biocomposite material with a thermal conductivity of 0.243W / (m·K) and an EMI shielding effectiveness of 52dB. Five WF@G samples were tested. The thermal conductivity ranged from 0.243 to 0.258 W / (m·K) at a frequency of 1MHz, and the EMI shielding effectiveness was 52dB. (Note: This is the performance of the material as a single unit, not the final shielding value of the cable).

[0031] Example 2: Preparation of the shielding thermal conductive layer 4 – Ice template method The principle of the ice template method is to control the temperature gradient in the freezing direction to induce water to crystallize in a directional manner to form an ice crystal template, which is then sublimated to leave a porous framework.

[0032] 1. Constructing MXene / graphene slurry: Ti3C2Tx MXene and graphene were dispersed in deionized water at a 1:1 ratio (concentration 5wt%).

[0033] 2. Biaxial temperature-controlled freezing: Z-axis gradient: The slurry is placed between a -25℃ cold table (bottom) and a 0℃ environment (top) and vertically frozen to form a honeycomb aerogel; X-axis superposition: A horizontal temperature gradient is achieved through symmetrically arranged linear temperature control devices on both sides (a -15℃ cold source on the left and a 5℃ heat source on the right).

[0034] 3. Freeze-drying: Vacuum drying at -50℃ and 10 Pa for 48 hours yielded an independent wall structure skeleton with a vertical thermal conductivity of 1.64 W·m. -1 ·K -1 (Compared to 1.09 W·m in the single Z direction) -1 ·K -1 ).

[0035] Example 3: Preparation of self-healing layer 6 1. Repair material synthesis: Matrix: FEP (Fluoropolymer) particles; Repair objects: perfluoro-1,10-decanediol (fluorinated compound) and isophorone diisocyanate (carbamate group). 2. Construction of the ring-additive repair network: Microcapsules (50-100 μm in diameter) are injected into the FEP matrix to repair the object. The Diels-Alder reaction is triggered at 120°C to form a reversible cross-linked network.

[0036] 3. Extrusion molding: Plasticized by a twin-screw extruder (temperature range 180-220℃), it is coated onto the outer armor layer 5, with a repair efficiency of >95%.

[0037] Repair mechanism of self-repair layer 6: The matrix is ​​perfluoroethylene propylene (FEP), which contains microcapsules with a diameter of 50-100μm. The microcapsules contain perfluoro-1,10-decanediol and isophorone diisocyanate repair agents. After rupture, the microcapsules melt and release the repair agents at temperatures above 80°C, triggering a Diels-Alder cycloaddition reaction to form a cross-linked network.

[0038] Self-repair efficiency test: The broken cable was placed in a 100℃ environment for 2 hours, and the tensile strength recovery rate after repair was tested using a tensile testing machine (repaired strength / original strength × 100%). The average repair efficiency of 5 groups of samples was 96.2%.

[0039] Example 4: Cable Assembly and Performance Testing 1. Layered coating: Three copper cable cores 1 (25mm² cross-section) are twisted together and extruded to cover the heat transfer layer 2 (1.0mm thick). 3. EPDM rubber waterproof layer (0.8mm thick); Four key processes for shielding and heat-conducting layers: 3D printed carbon fiber honeycomb mesh (2mm aperture) coated with a waterproof layer 3; Lay out silicon carbide thermal pad 1 42 / silicon carbide thermal pad 2 43 (spacing 0.5mm), annular through hole diameter 1.2mm, and fill the annular cavity with Φ1mm ferrite magnetic beads 44; The MXene-graphene heat sink 45 (1.2mm thick) is wrapped with thermal paste on its outer surface.

[0040] Ultimately, the shielding effectiveness of the entire cable reached 83.2dB in the 1-10GHz frequency band.

[0041] 2. Armor Layer 5 Integration: Galvanized steel wire (0.8mm in diameter) is wound around the heat sink sleeve at a 45° helix angle, with tension controlled at 200±10N.

[0042] 3. Performance Comparison:

[0043] In this invention, the ice template directional temperature control mechanism is as follows: The biaxial temperature gradient forces ice crystals to grow along a predetermined direction, forming vertically arranged microchannels. Heat is rapidly dissipated along these channels, breaking through the isotropic limitations of traditional materials.

[0044] The self-healing layer trigger logic is as follows: Cable rupture → FEP matrix cracking → High temperature environment > 80℃ → Yes → Microcapsule melting and decomposition to repair the guest → Contact of fluorinated compound / carbamate group → Diels-Alder cycloaddition reaction → Crosslinking network reconstruction.

[0045] Principle of dynamic shielding of magnetic beads: When the cable is energized, it generates an alternating magnetic field → the magnetic bead rotates and cuts the magnetic field lines in the annular cavity → eddy current loss absorbs high-frequency interference → heat is conducted away through the silicon carbide thermal pad (synergistic heat dissipation).

[0046] The above-described embodiments are merely illustrative of certain implementations of the present invention, and are described in a relatively specific and detailed manner. However, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A high-temperature resistant shielded armored power cable, characterized in that, Including the following, arranged sequentially from the inside out: Multiple cable cores (1); The heat transfer layer (2) covering the cable core (1) is made of WF@G biocomposite material of wood fiber matrix composite graphene nanosheets; Waterproof layer (3) covering the heat transfer layer (2); The shielding heat-conducting layer (4) includes a honeycomb structure heat-spreading mesh (41) attached to the surface of the waterproof layer (3), a silicon carbide heat-conducting pad one (42) and a silicon carbide heat-conducting pad two (43) disposed on the outside of the heat-spreading mesh (41), and an MXene-graphene heat dissipation sleeve (45) covering the silicon carbide heat-conducting pad two (43), wherein a closed annular through hole is formed between the silicon carbide heat-conducting pad one (42) and the silicon carbide heat-conducting pad two (43), and a sliding magnetic bead (44) is provided in the hole. The armor layer (5) that is directly covered on the outer surface of the heat sink sleeve (45) is made of steel strip or steel wire; The self-healing layer (6) covering the armor layer (5) contains a thermally triggered ring addition reaction network; and Outer protective layer (7).

2. The high-temperature resistant shielded armored power cable according to claim 1, characterized in that, The magnetic bead (44) has a diameter of 1 mm and a through hole diameter of 1.2-1.3 mm. The magnetic bead rotates under the drive of an alternating magnetic field to achieve 360° electromagnetic interference absorption and dynamic heat dissipation.

3. The high-temperature resistant shielded armored power cable according to claim 1, characterized in that, The WF@G biocomposite material of the heat transfer layer (2) is prepared by the following steps: Graphene nanosheets are combined with polyamide epichlorohydrin to form positively charged GNP / PAE; Electrostatic adsorption forms graphene-coated wood fibers on the surface of negatively charged wood fibers. After drying, it is hot-pressed into shape using a sealed mold.

4. The high-temperature resistant shielded armored power cable according to claim 1, characterized in that: The heat dissipation sleeve (45) contains MXene and graphene filler in a 1:1 ratio, and forms an independent wall structure using a biaxial ice template method, with a vertical thermal conductivity of 1.64 W·m. -1 ·K -1 .

5. A manufacturing process for a high-temperature resistant shielded armored power cable, characterized in that, Includes the following steps: S1: Extruding WF@G bio-composite material to cover the cable core (1) to form a heat transfer layer (2); S2: Bond multiple cable cores (1) and cover with EPDM rubber waterproof layer (3); S3: A honeycomb heat dissipation mesh (41), silicon carbide heat conduction pad one (42) and silicon carbide heat conduction pad two (43) (containing magnetic beads 44) and MXene-graphene heat dissipation sleeve (45) are sequentially wrapped on the surface of the waterproof layer (3) to form a shielded heat conduction layer (4). S4: A steel strip or wire is wrapped around the surface of the shielding heat-conducting layer (4) to form an armor layer (5); S5: Cover the self-healing layer (6) onto the surface of the armor layer (5); S6: Extruded silicone rubber outer protective layer (7).

6. The production process according to claim 5, characterized in that, In step S31, the MXene / graphene independent wall structure framework is constructed under a biaxial (Z-direction + X-direction) temperature gradient using the ice template method.

7. The production process according to claim 6, characterized in that, In the ice template method: The vertical thermal conductivity of the composite material under a uniaxial (Z-direction) temperature gradient is 1.09 W·m. -1 ·K -1 ; The vertical thermal conductivity under a biaxial (Z+X) temperature gradient is increased to 1.64 W·m. -1 ·K -1 .

8. The production process according to claim 5, characterized in that, The armor layer (5) is added in close contact with the outer surface of the heat dissipation sleeve (45) of the shielding heat conduction layer (4), forming an integrated structure of mechanical protection and electromagnetic shielding.

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