Water-blocking bending-resistant medium-voltage aluminum alloy cable
By using steel-core aluminum alloy conductors, butyl rubber water-blocking and reduced pressure layer and polypropylene moisture absorbing layer in medium voltage cables, the problems of poor flexibility and water seepage corrosion in low temperature environments are solved, and better installation adaptability and durability are achieved.
Patent Information
- Application Number
- CN202421927128.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-08-09
AI Technical Summary
The existing medium-voltage cables have poor flexibility in low temperature environments, difficulty in laying, easy to seepage, corrosion, and insufficient installation adaptability and durability.
The composite structure of steel-core aluminum alloy conductor, butyl rubber water-blocking and reduced pressure layer and polypropylene moisture absorbing layer is adopted, combined with the longitudinal groove design of the EVA sheath layer, enhance the flexibility and flexibility of the cable, and reduce costs by replacing copper materials with aluminum alloy.
It improves the flexibility and flexural resistance of the cable, enhances water resistance, extends the cable life, and reduces safety hazards and material costs.
Smart Images
Figure CN223140449U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of cables, and particularly relates to a water-blocking and flexure-resistant medium-voltage aluminum alloy cable. Background Art
[0002] Medium-voltage power cables transmit electrical energy for power transmission and distribution systems, and have characteristics such as light weight and moisture resistance. They can be laid in indoor and outdoor environments, such as direct burial, cable trays, pipe threading, brackets, and cable trenches. Although cross-linked polyethylene power cables are widely used due to their excellent characteristics such as simple manufacturing and safety processes, for ordinary cross-linked polyethylene cable products, the linear expansion coefficients of the insulation layer and the outer sheath have a large difference, resulting in layer gaps in the production process, which is likely to cause the displacement of the outer sheath position and reduce the electrical characteristics of the cable. Moreover, in outdoor low-temperature environments, ordinary cross-linked polyethylene cables have poor flexibility, making it difficult to carry out laying and wiring operations, and the outer skin is prone to wear and cracking. The damaged parts will get wet, and water vapor will penetrate into the cable. The water vapor is likely to penetrate into the overlapping parts of the copper tape or aluminum tape shielding layer, thereby corroding the shielding layer and damaging the insulation layer, reducing the cable life and having poor durability. In addition, during the installation and construction process, a smaller bending radius is allowed, and the cable also needs to have good flexibility and flexure resistance to improve the adaptability of laying and installation and reduce the difficulty of installation technology. Summary of the Utility Model
[0003] Aiming at the deficiencies of the prior art, the technical problem to be solved by this application is to provide a water-blocking and flexure-resistant medium-voltage aluminum alloy cable, which has better flexibility and flexure resistance, better adaptability to laying and installation in complex environments, enhanced water-blocking and moisture absorption characteristics, effectively prevents water vapor from penetrating into and corroding the shielding layer and the insulation layer, reduces potential safety hazards, and improves durability.
[0004] The above technical problems are solved by the following technical solutions in this application.
[0005] The water-blocking and flexure-resistant medium-voltage aluminum alloy cable includes a steel-core aluminum alloy conductor and a semiconductive nylon tape inner wrapping layer, an ethylene propylene diene monomer (EPDM) rubber insulation layer, a semiconductive nylon tape outer wrapping layer, an aluminum alloy tape interlocking shielding layer, a polyester fiber plain woven fabric wrapping layer, a butyl rubber water-blocking and pressure-reducing layer, a polypropylene moisture absorption layer, and an ethylene-vinyl acetate (EVA) sheath layer that are sequentially coated on the outside of the steel-core aluminum alloy conductor. The outer diameter of the steel-core aluminum alloy conductor is 5 mm to 12 mm, the thickness of the butyl rubber water-blocking and pressure-reducing layer does not exceed 1 mm, the thickness of the EVA sheath layer is 2 mm to 4 mm and does not exceed one-third of the thickness of the EPDM rubber insulation layer. A plurality of longitudinal grooves are circumferentially and evenly distributed on the inner circumferential surface of the EVA sheath layer, and the depth of the longitudinal grooves does not exceed 2 mm.
[0006] Preferably, the cross-section of the longitudinal groove is semi-circular or fan-shaped.
[0007] Preferably, the depth of the longitudinal groove is 0.5 mm to 1.5 mm.
[0008] Preferably, the steel core aluminum alloy conductor includes a galvanized steel strand inner core, and two layers of rare earth high-iron aluminum alloy sector conductors are stranded around the outside of the galvanized steel strand inner core to form an aluminum alloy conductor layer.
[0009] Preferably, the rare earth high-iron aluminum alloy sector conductor is formed by stranding and compacting a plurality of rare earth high-iron aluminum alloy wires into a sector conductor structure, and the diameter of the rare earth high-iron aluminum alloy wire is 1 mm to 3 mm.
[0010] Preferably, the galvanized steel strand inner core is formed by stranding a plurality of galvanized steel wires with a wire diameter of 0.5 mm to 2 mm.
[0011] Preferably, the thickness of the ethylene propylene diene monomer (EPDM) rubber insulation layer is 8 mm to 16 mm.
[0012] Preferably, the thickness of the butyl rubber water-blocking and pressure-reducing layer is not less than 0.8 mm.
[0013] Preferably, both the semi-conductive nylon tape inner wrapping layer and the semi-conductive nylon tape outer wrapping layer are multi-layer overlapping wrapping structures of semi-conductive nylon tape with an overlapping rate of 40% to 50%, the thickness of the semi-conductive nylon tape is 0.4 mm to 0.5 mm, and the width of the semi-conductive nylon tape is 30 mm to 60 mm.
[0014] Preferably, the thickness of the aluminum alloy tape interlocking shielding layer is 0.8 mm to 1 mm.
[0015] Advantages of the present application:
[0016] 1. By providing a double-layer water-blocking and moisture-absorbing composite structure of a butyl rubber water-blocking and pressure-reducing layer and a polypropylene moisture-absorbing layer between the aluminum alloy tape interlocking shielding layer and the EVA sheath layer, when the EVA sheath layer is damaged and gets wet, the water vapor seeping in can be absorbed by the polypropylene moisture-absorbing layer. Due to the excellent water-blocking property of the butyl rubber water-blocking and pressure-reducing layer, the diffusion of moisture to the shielding layer and the insulation layer is effectively blocked, effectively protecting the electrical insulation property of the cable, extending the service life of the cable, reducing potential safety hazards, and enabling more durable use.
[0017] 2. By adding longitudinal grooves on the inner circumferential surface of the EVA sheath layer and controlling the depth of the longitudinal grooves not to exceed 2 mm, while ensuring the mechanical strength of the sheath layer, the friction area between the sheath layer and the polypropylene moisture-absorbing layer is reduced. While reducing the frictional force, it helps to improve the flexibility and flexure resistance characteristics of the cable, reduce the torque force during bending, protect the sheath layer, and increase safety and reliability. Moreover, by using an ethylene propylene diene monomer (EPDM) rubber insulation layer and an EVA sheath layer, optimizing the thickness of the EVA sheath layer to be 2 mm to 4 mm and not exceeding one-third of the thickness of the EPDM rubber insulation layer, and the linear expansion coefficient ratio between the insulation layer and the sheath layer is 1.3, voids between the insulation layer and the sheath layer are effectively suppressed through the production process, which is beneficial to improving the flexibility and flexure resistance characteristics of the cable, and the adaptability to laying and installation in complex environments is stronger.
[0018] 3. By replacing the traditional copper core conductor and copper tape shielding layer with a steel core aluminum alloy conductor and an aluminum alloy tape interlocking shielding layer, the aluminum alloy conductor has creep resistance and elongation equivalent to those of a copper conductor, is safe, stable and reliable, can significantly reduce the material cost and procurement cost, and is conducive to a large-scale popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic cross-sectional structure diagram of an embodiment of the present application.
[0020] DESCRIPTION OF THE REFERENCE NUMERALS:
[0021] 1 - Steel core aluminum alloy conductor, 2 - Inner semi-conductive nylon tape wrapping layer, 3 - Ethylene propylene diene monomer (EPDM) rubber insulation layer, 4 - Outer semi-conductive nylon tape wrapping layer, 5 - Aluminum alloy tape interlocking shielding layer, 6 - Polyester fiber plain woven fabric wrapping layer, 7 - Butyl rubber water-blocking and pressure-reducing layer, 8 - Polypropylene moisture-absorbing layer, 9 - EVA sheath layer, 10 - Longitudinal groove, 11 - Galvanized steel strand inner core, 12 - Rare earth high-speed aluminum alloy sector conductor. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.
[0023] See Figure 1, the water-blocking and flexure-resistant medium-voltage aluminum alloy cable of the embodiment of the present application includes a steel-core aluminum alloy conductor 1. Specifically, the steel-core aluminum alloy conductor 1 includes a galvanized steel strand inner core 11. Two layers of rare-earth high-strength aluminum alloy sector conductors 12 are stranded around the outside of the galvanized steel strand inner core 11 to form an aluminum alloy conductor layer. Further, the galvanized steel strand inner core 11 is formed by stranding a plurality of galvanized steel wires with a wire diameter of 0.5 mm to 2 mm. The rare-earth high-strength aluminum alloy sector conductor 12 is formed by stranding a plurality of rare-earth high-strength aluminum alloy wires and compacting them into a sector conductor structure. The diameter of the rare-earth high-strength aluminum alloy wire is 1 mm to 3 mm. The outer diameter of the steel-core aluminum alloy conductor 1 is 5 mm to 12 mm.
[0024] The outside of the steel-core aluminum alloy conductor 1 is sequentially coated with a semi-conductive nylon tape inner wrapping layer 2, an ethylene propylene diene monomer (EPDM) rubber insulation layer 3, a semi-conductive nylon tape outer wrapping layer 4, an aluminum alloy tape interlocking shielding layer 5, a polyester fiber plain woven fabric wrapping layer 6, a butyl rubber water-blocking and pressure-reducing layer 7, a polypropylene moisture-absorbing layer 8, and an ethylene-vinyl acetate (EVA) sheath layer 9. In one embodiment, both the semi-conductive nylon tape inner wrapping layer 2 and the semi-conductive nylon tape outer wrapping layer 4 are multi-layer overlapping wrapping structures of semi-conductive nylon tape with a lapping rate of 40% to 50%. The thickness of the semi-conductive nylon tape is 0.4 mm to 0.5 mm, and the width of the semi-conductive nylon tape is 30 mm to 60 mm. The thickness of the EPDM rubber insulation layer 3 is 8 mm to 16 mm. The thickness of the butyl rubber water-blocking and pressure-reducing layer 7 is not less than 0.8 mm and not more than 1 mm. The thickness of the aluminum alloy tape interlocking shielding layer 5 is 0.8 mm to 1 mm. The thickness of the EVA sheath layer 9 is 2 mm to 4 mm and does not exceed one-third of the thickness of the EPDM rubber insulation layer 3. A plurality of longitudinal grooves 10 are circumferentially and uniformly distributed on the inner circumferential surface of the EVA sheath layer 9. Further, the cross-section of the longitudinal groove 10 is semi-circular or sector-shaped. In this embodiment, the cross-section of the longitudinal groove 10 is semi-circular. The depth of the longitudinal groove 10 does not exceed 2 mm. Further, the depth of the longitudinal groove 10 is 0.5 mm to 1.5 mm.
[0025] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.
Claims
1. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable is characterized in that: It includes a steel-cored aluminum alloy conductor (1), a semiconductive nylon tape inner wrapping layer (2), an ethylene propylene diene monomer (EPDM) rubber insulation layer (3), a semiconductive nylon tape outer wrapping layer (4), an aluminum alloy tape interlocking shielding layer (5), a polyester fiber plain woven fabric wrapping layer (6), a butyl rubber water-blocking and pressure-reducing layer (7), a polypropylene moisture-absorbing layer (8), and an ethylene-vinyl acetate (EVA) sheath layer (9) successively coated outside the steel-cored aluminum alloy conductor (1). The outer diameter of the steel-cored aluminum alloy conductor (1) is 5 mm to 12 mm. The thickness of the butyl rubber water-blocking and pressure-reducing layer (7) does not exceed 1 mm. The thickness of the EVA sheath layer (9) is 2 mm to 4 mm and does not exceed one-third of the thickness of the EPDM rubber insulation layer (3). A plurality of longitudinal grooves (10) are circumferentially and uniformly distributed on the inner circumferential surface of the EVA sheath layer (9), and the depth of the longitudinal grooves does not exceed 2 mm.
2. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 1, wherein: The cross-section of the longitudinal groove (10) is semi-circular or fan-shaped.
3. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 2, characterized in that: The depth of the longitudinal groove (10) is 0.5 mm to 1.5 mm.
4. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 1, wherein: The steel-cored aluminum alloy conductor (1) includes a galvanized steel strand inner core (11), and two layers of rare-earth high-speed railway aluminum alloy sector conductors (12) are stranded around the outside of the galvanized steel strand inner core (11) to form an aluminum alloy conductor layer.
5. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 4, wherein: The rare-earth high-speed railway aluminum alloy sector conductor (12) is formed by stranding and compacting a plurality of rare-earth high-speed railway aluminum alloy wires into a sector conductor structure, and the diameter of the rare-earth high-speed railway aluminum alloy wires is 1 mm to 3 mm.
6. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 4, characterized in that: The galvanized steel strand inner core (11) is formed by stranding a plurality of galvanized steel wires with a wire diameter of 0.5 mm to 2 mm.
7. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 1, wherein: The thickness of the EPDM rubber insulation layer (3) is 8 mm to 16 mm.
8. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 1, wherein: The thickness of the butyl rubber water-blocking and pressure-reducing layer (7) is not less than 0.8 mm.
9. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 1, characterized in that: Both the semiconductive nylon tape inner wrapping layer (2) and the semiconductive nylon tape outer wrapping layer (4) are multi-layer overlapping wrapping structures of semiconductive nylon tape with a lapping rate of 40% to 50%. The thickness of the semiconductive nylon tape is 0.4 mm to 0.5 mm, and the width of the semiconductive nylon tape is 30 mm to 60 mm.
10. The water-blocking and flexure-resistant medium-voltage aluminum alloy cable according to claim 1, characterized in that: The thickness of the aluminum alloy tape interlocking shielding layer (5) is 0.8 mm to 1 mm.