Aluminum core light underwater cable for shallow water and production device

Abstract

The utility model relates to an aluminum core light underwater cable for shallow water, which comprises three aluminum conductors, and a conductor shielding layer, a water-tree-resistant cross-linked polyethylene insulating layer, an insulating shielding layer and a copper strip metal shielding layer are sequentially wrapped outside each conductor to form a wire core; the three wire cores are twisted to form a cable core, the cable core is arranged in a waterproof comprehensive sheath which is formed by longitudinally wrapping and extruding an aluminum-plastic composite belt, and soft fillers are arranged between the waterproof comprehensive sheath and the cable core and in a gap in the middle of the cable core; a plurality of high-strength aluminum alloy wires are uniformly fixed on the outer surface of the waterproof comprehensive sheath by coating asphalt to form an armor layer, and the outer sheath is arranged outside the armor layer. The utility model further comprises a production device for manufacturing the cable. According to the utility model, the aluminum conductor is adopted to reduce weight and cost; the cable can operate in a humid environment or water for a long time by adopting the water-tree-resistant cross-linked polyethylene insulating material, so that the service life of the cable is prolonged; and the aluminum-plastic composite tape waterproof comprehensive sheath is adopted, so that the waterproof and anti-corrosion capabilities are strong, and the weight and the cost of the cable are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of electric wires and cables, and particularly relates to an aluminum core light underwater cable and a production device. Background Art

[0002] With the large-scale development of renewable and clean energy in my country, the National Energy Administration has issued an outline for offshore wind farm project planning. This outline specifies the development of regional offshore wind power development plans, taking into account the characteristics of regional offshore wind energy resources and development and construction conditions. my country boasts over 18,000 kilometers of coastline and over 6,000 islands. The continued development and utilization of shallow offshore wind power and solar photovoltaics will inevitably drive demand for grid-connected cables in these areas. These areas are primarily shallow and intertidal, with close distances from shore ranging from 3-5 kilometers to tens or hundreds of meters, and water depths generally not exceeding 50 meters.

[0003] In this specific water environment, using traditional long submarine cables to transmit power is difficult due to their heavy weight and high cost. Therefore, the market urgently needs a cost-effective underwater cable product to connect mainland China with shallow offshore wind farms, lakeshores with islands, and for underwater power transmission across rivers and lakes. Therefore, a lightweight aluminum-core underwater cable for shallow waters is needed to meet this market demand. Summary of the Invention

[0004] The utility model provides a shallow water aluminum core light underwater cable and a production device to solve the technical problems existing in the known technology. The cable has excellent waterproof and corrosion resistance and is light and quick to lay.

[0005] The utility model includes the following technical solutions: an aluminum core lightweight underwater cable for shallow water, comprising three aluminum conductors, each conductor being wrapped with a conductor shielding layer, an anti-water tree cross-linked polyethylene insulation layer, an insulation shielding layer and a copper tape metal shielding layer in sequence to form a wire core; the three wire cores are twisted into a cable core, the cable core is arranged in a waterproof comprehensive sheath formed by longitudinally extruding an aluminum-plastic composite tape, and soft fillings are provided between the waterproof comprehensive sheath and the cable core and in the gap in the middle of the cable core; the outer surface of the waterproof comprehensive sheath is coated with asphalt to evenly fix a plurality of high-strength aluminum alloy wires to form an armor layer, and an outer sheath is provided outside the armor layer.

[0006] Furthermore, the cross-section of the conductor is circular; the conductor is composed of a plurality of aluminum wires arranged in a circular array, and the columnar structure or cylindrical structure formed by the arrangement of the aluminum wires is each a stranded wire layer, the gaps in each stranded wire layer are filled with water-blocking powder, and a layer of longitudinally wrapped water-blocking tape is provided on the outside of each stranded wire layer and tied with water-blocking yarn; the multi-layer water-blocking structure of the conductor increases the conductor compression coefficient, making the conductor tighter.

[0007] Furthermore, the conductor is a Class 2 compressed aluminum conductor that complies with the national standard GB / T 3956-2008, and the DC resistance of the conductor at 20° C. is less than or equal to the value specified in the standard.

[0008] Furthermore, the waterproof integrated sheath adopts a YLY polyethylene type double-sided aluminum-plastic composite tape longitudinal wrapping structure, and the longitudinal wrapping overlapping width is not less than 20mm; ensuring that the bonding strength of the longitudinal wrapping meets the requirements, and at the same time ensuring that the bonding is flat and smooth, thereby ensuring the continuity and integrity of the entire waterproofing and anti-corrosion.

[0009] Furthermore, the nominal thickness of the aluminum-plastic composite strip is 0.30 mm, and its minimum thickness is not less than 90% of the nominal thickness.

[0010] Furthermore, the waterproof composite sheath is a complete closed tube formed by extruding the surface of the aluminum-plastic belt after melting the polyethylene on the surface of the aluminum-plastic belt using a thermoplastic gun or hot melt adhesive and overlapping and adhering the longitudinal wrap; the temperature of the polyethylene extrusion melting melts the polyethylene film on the outer surface of the tube again and bonds it to the inner wall of the polyethylene sheath to form a complete metal-plastic composite protective layer, which has both the density and ductility of metal and the outstanding corrosion resistance of organic polymer materials.

[0011] Furthermore, the high-strength aluminum alloy wire is an aluminum-magnesium-silicon alloy round wire.

[0012] A production device for producing the above-mentioned aluminum core lightweight underwater cable for shallow water use, comprising a conductor stranding device, a cable core production device, a three-core cabling device, a waterproof integrated sheath production line, a steel wire armoring machine and an extrusion machine, which are arranged in sequence; the cable core production device includes a three-layer co-extrusion device and a copper tape wrapping device; the waterproof integrated sheath production line includes a pay-off device, a longitudinal wrapping platform, an extruder, a cooling water trough, a traction device and a take-up device, which are arranged in sequence; a longitudinal wrapping die with a diameter-bearing area length greater than or equal to 12 mm and less than or equal to 15 mm is provided in the middle of the longitudinal wrapping platform, the angle α between the longitudinal wrapping die and the longitudinal wrapping platform being ≤20°, and the aluminum-plastic composite tape is longitudinally wrapped and overlapped on the outside of the cable core through the longitudinal wrapping die; a sizing die is provided on the longitudinal wrapping platform near one end of the extruder.

[0013] Furthermore, the distance between the diameter-bearing area of the longitudinal wrapping die and the sizing die is no more than 100 mm, and the distance between the sizing die and the head of the extruder is no more than 180 mm.

[0014] Furthermore, the three-layer co-extrusion equipment is a German Telester or Mylafil cross-linking machine, through which the conductor shielding layer, the water-tree resistant cross-linked polyethylene insulation layer and the insulation shielding layer of the cable core are produced.

[0015] The advantages and positive effects of this utility model are:

[0016] 1. The underwater cable of the utility model adopts aluminum conductor instead of copper conductor, which reduces weight and cost.

[0017] 2. When ordinary cable insulation works in water for a long time, water trees will form inside the insulation. Under the action of the electric field for a long time, it may cause insulation breakdown, greatly reducing the life of the cable. The underwater cable in this utility model has a wet structure and adopts imported anti-water tree cross-linked polyethylene insulation material, so that the cable can operate in a humid environment or in water for a long time, thereby improving the cable life.

[0018] 3. The utility model adopts an aluminum-plastic composite tape waterproof integrated sheath to replace the lead sheath, which has excellent waterproof and corrosion resistance and greatly reduces the weight of the cable, reduces costs, and is more environmentally friendly. The production of lead alloy used in the lead sheath is a heavy pollution source and has serious environmental problems. At the same time, the loss and energy requirements of extruding or pressing the lead sheath are also very high.

[0019] 4. Since the water flow in shallow water areas is slow and the scouring force on cables is far less than that in the seabed environment, the present invention uses high-strength aluminum alloy wire instead of steel wire as the armor structure of underwater cables in shallow waters. It is safe and applicable and greatly reduces the weight of the cable, reduces the cost, and makes the transportation, installation and laying of the cable more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the cross-sectional structure of the cable in the utility model;

[0021] Figure 2 It is a schematic diagram of the cross-sectional structure of the conductor in the utility model;

[0022] Figure 3 It is a schematic diagram of the overall structure of the production device in the utility model;

[0023] In the figure, 1-conductor; 101-aluminum wire; 102-water-blocking powder; 103-water-blocking tape; 2-conductor shield; 3-water-tree-resistant cross-linked polyethylene insulation layer; 4-insulation shield; 5-copper tape metal shield; 6-soft filling; 7-waterproof composite sheath; 8-high-strength aluminum alloy wire; 9-outer sheath; 10-asphalt; 11-stranding equipment.

[0024] 12-cable core production equipment; 121-three-layer co-extrusion equipment; 122-copper tape wrapping equipment;

[0025] 13-Three-core cable assembly device; 14-Waterproof integrated sheath production line; 141-Paying device; 142-Longitudinal wrapping platform; 143-Extruder; 144-Cooling water trough; 145-Traction device; 146-Taking device;

[0026] 15-Steel wire armoring machine; 16-Extrusion machine; 17-Longitudinal wrapping die; 18-Sizing die; 19-Electrical cabinet. DETAILED DESCRIPTION

[0027] In order to further disclose the content, features and effects of the invention, the following examples are given and described in detail with reference to the accompanying drawings. In the description of the following embodiments, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting this patent.

[0028] In the description of the following embodiments, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "set" should be understood in a broad sense. For example, they may refer to fixed connection or set, detachable connection or set, or integral connection or set. Those skilled in the art will understand the specific meanings of the above terms in this patent based on specific circumstances.

[0029] Example: See attached Figure 1 A lightweight aluminum-core underwater cable for shallow waters includes three aluminum conductors 1 with circular cross-sections. The conductors 1 are composed of several aluminum wires 101 arranged in a circular array. Each of the aluminum wires 101 forms a single stranded layer, each formed into a columnar or cylindrical structure (columnar at the center, cylindrical at the outer ring). The gaps in each stranded layer are filled with water-blocking powder 102. Each stranded layer is longitudinally wrapped with a water-blocking tape 103 and bound with water-blocking yarn. The multi-layered water-blocking structure of the conductors 1 increases the compaction coefficient of the conductors 1, making them more compact. The water-blocking tape 103 is made from polyacrylate expansion powder added to polyester non-woven fibers. Upon contact with water, the expansion powder rapidly expands to a certain height within a certain period of time, acting as a moisture barrier. The conductors 1 utilize Class 2 compressed aluminum conductors 1 that comply with the national standard GB / T 3956-2008. At 20°C, the DC resistance of the conductors 1 is less than or equal to the standard value.

[0030] Each conductor 1 is sequentially wrapped with a conductor shield 2, a water-tree-resistant cross-linked polyethylene insulation layer 3, an insulation shield 4, and a copper tape metal shield 5 to form a core. Three of these cores are twisted together to form a cable core, which is enclosed in a waterproof composite sheath 7. Soft filler 6 is provided between the sheath 7 and the core, as well as in the gaps within the core. The outer surface of the waterproof composite sheath 7 is coated with asphalt 10, and several high-strength aluminum alloy wires 8 are evenly fixed to form an armor layer. An outer sheath 9 is provided over the armor layer. The high-strength aluminum alloy wires 8 are round aluminum-magnesium-silicon alloy wires.

[0031] The waterproof composite sheath 7 utilizes a YLY polyethylene-type double-sided aluminum-plastic composite tape longitudinally wrapped in a structure with a nominal thickness of 0.30 mm and a minimum thickness of no less than 90% of the nominal thickness. The longitudinal overlap width is no less than 20 mm, ensuring that the longitudinal overlap meets the required bonding strength and that the bond is smooth and even, thereby ensuring the integrity of the entire waterproof and corrosion-resistant system. The waterproof composite sheath 7 is formed into a complete, sealed tubular structure by extruding the surface of the aluminum-plastic tape using a thermoplastic gun or hot melt adhesive to melt the polyethylene on the surface of the aluminum-plastic tape, thereby bonding the longitudinal overlaps. The temperature of the extruded polyethylene melts the polyethylene film on the outer surface of the tubular structure again, bonding it to the inner wall of the polyethylene sheath to form a complete metal-plastic composite sheath. This sheath combines the density and ductility of metal with the superior corrosion resistance of organic polymer materials.

[0032] See attached Figure 2 A production device for producing the above-mentioned aluminum core lightweight underwater cable for shallow water use, including a conductor stranding device 11, a cable core production device 12, a three-core cabling device 13, a waterproof integrated sheath production line 14, a steel wire armoring machine 15 and an extrusion machine 16 arranged in sequence; the cable core production device 12 includes a three-layer co-extrusion device 121 and a copper tape wrapping device 122; the three-layer co-extrusion device 121 is a German Telester or Mylafil cross-linking machine, through which the conductor shielding layer 2, the water-tree-resistant cross-linked polyethylene insulation layer 3 and the insulation shielding layer 4 of the cable core are produced.

[0033] The waterproof integrated sheathing production line 14 includes a pay-off device 141, a longitudinal wrapping platform 142, an extruder 143, a cooling water trough 144, a traction device 145, and a take-up device 146, which are arranged in sequence. A longitudinal wrapping die 17 with a diameter-bearing area greater than or equal to 12 mm and less than or equal to 15 mm is located in the middle of the longitudinal wrapping platform 142. The angle α between the longitudinal wrapping die 17 and the longitudinal wrapping platform 142 is ≤ 20°. The aluminum-plastic composite tape is longitudinally wrapped and overlapped around the cable core through the longitudinal wrapping die 17. A sizing die 18 is located at one end of the longitudinal wrapping platform 142 near the extruder 143. The diameter-bearing area of the longitudinal wrapping die 17 is no more than 100 mm from the sizing die 18, and the sizing die 18 is no more than 180 mm from the head of the extruder 143. An electrical cabinet 19 is located above the cooling water trough 144.

[0034] Production process:

[0035] S1. Use a stranding device 11 to compact multiple aluminum wires 101 to produce a compacted aluminum conductor 1. When stranding, evenly spread water-blocking powder 102 between the aluminum wires 101. A layer of longitudinal water-blocking tape 103 is provided on the outside of each stranded layer and tied with water-blocking yarn.

[0036] S2. Using a three-layer co-extrusion device 121, the conductor shielding layer 2, the water-tree resistant cross-linked polyethylene insulation layer 3, and the insulation shielding layer 4 are co-extruded outside the conductor 1 and then degassed.

[0037] S3. Overlapping 0.1 mm copper tape and color tape is performed on the outside of the insulating shielding layer 4 by using the copper tape wrapping equipment 122 to produce a copper tape metal shielding layer 5. The overlap rate of the copper tape is greater than or equal to 15% and less than or equal to 20%. The copper tape joints in S3 are not allowed to be plugged in and must be firmly fixed by spot welding.

[0038] S4. Three-core cabling is performed using a three-core cabling device 13. During cabling, soft filler 6 is added around the cable core, and its shape is rounded and wrapped with two layers of non-woven fabric to tighten and prevent the core from loosening. The roundness of the semi-finished cable in S4 is greater than or equal to 92%, and the colors are yellow, green, and red.

[0039] S5. Use YLY polyethylene double-sided aluminum-plastic composite tape to longitudinally wrap, overlap and bond to form a waterproof comprehensive sheath 7. Before the semi-finished cable is longitudinally wrapped on the longitudinal wrapping platform 142 and enters the head of the extruder 143, use a thermoplastic gun or hot melt adhesive to melt the polyethylene on the surface of the aluminum-plastic tape to form a sealed tubular whole. Heat and pre-bond the overlapping parts of the aluminum-plastic composite tape to ensure that the connection position is tightly overlapped and then cover with the extruded sheath and cool. The width of the aluminum-plastic composite tape in S5 is calculated by W=π(D1+2t)+35, where W is the width of the aluminum-plastic composite tape; D1 is the cable core diameter; t is the thickness of the aluminum-plastic composite tape; after S5 is completed, the diameter of the semi-finished cable D2=D1+3t; the diameter of the sizing die 18 used in the production process of S5 is D3=D2+(0.5~1).

[0040] S6. Asphalt 10 is applied to the outside of the waterproof integrated sheath 7 to produce high-strength aluminum alloy armor. After the coating is completed, two layers of environmentally friendly rubberized cloth tape are wrapped around it to tighten and prevent leakage. The entire production process of S6 is completed in one process using a 152-reel (800 / 68+84) steel wire armoring machine 15.

[0041] S7: An outer sheath 9 is extruded over the armor layer using an extrusion machine 16. After completion, the cable undergoes factory testing and is packaged for storage. In S7, the outer sheath 9 is coated with a graphite lubricating layer to reduce friction between the cable and the surrounding medium during construction. The outer sheath 9 is printed with the cable model and meter mark.

[0042] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, those skilled in the art can devise various forms without departing from the spirit of the present invention and the scope of protection of the claims. All such forms fall within the scope of protection of the present invention.

Claims

1. A light-weight aluminum core underwater cable for shallow water use, characterized by: It includes three aluminum conductors, and each conductor is wrapped with a conductor shielding layer, an anti-water tree cross-linked polyethylene insulation layer, an insulation shielding layer and a copper tape metal shielding layer in sequence to form a wire core; the three wire cores are twisted into a cable core, and the cable core is arranged in a waterproof comprehensive sheath made of longitudinally extruded aluminum-plastic composite tape, and soft fillings are provided between the waterproof comprehensive sheath and the cable core and in the gap in the middle of the cable core; the outer surface of the waterproof comprehensive sheath is coated with asphalt to evenly fix a number of high-strength aluminum alloy wires to form an armor layer, and an outer sheath is provided outside the armor layer.

2. The aluminum core lightweight underwater cable for shallow water use according to claim 1, characterized in that: The cross-section of the conductor is circular; the conductor is composed of several aluminum wires arranged in a circular array, and the columnar structure or cylindrical structure formed by the aluminum wires is a stranded wire layer. The gaps in each stranded wire layer are filled with water-blocking powder, and a layer of longitudinally wrapped water-blocking tape is provided on the outside of each stranded wire layer and tied with water-blocking yarn.

3. The aluminum core lightweight underwater cable for shallow water use according to claim 2, characterized in that: At 20°C, the DC resistance of the conductor is less than or equal to the value specified in the standard.

4. The aluminum core lightweight underwater cable for shallow water use according to claim 1, characterized in that: The waterproof comprehensive sheath adopts a YLY polyethylene type double-sided aluminum-plastic composite tape longitudinal wrapping structure, and the longitudinal wrapping overlapping width is not less than 20mm.

5. The aluminum core lightweight underwater cable for shallow water use according to claim 4, characterized in that: The nominal thickness of the aluminum-plastic composite strip is 0.30 mm, and its minimum thickness is not less than 90% of the nominal thickness.

6. The aluminum core lightweight underwater cable for shallow water use according to claim 4, characterized in that: The waterproof integrated sheath is a complete closed tubular shape formed by extruding the surface of the aluminum-plastic strip after the polyethylene on the surface of the aluminum-plastic strip is melted by a thermoplastic gun or hot melt adhesive so as to overlap and adhere the strip longitudinally.

7. The aluminum core lightweight underwater cable for shallow water use according to claim 1, characterized in that: The high-strength aluminum alloy wire is an aluminum-magnesium-silicon alloy round wire.

8. A production device for producing an aluminum core lightweight underwater cable for shallow water use according to any one of claims 1 to 7, characterized in that: It includes conductor stranding equipment, cable core production equipment, three-core cabling equipment, waterproof integrated sheath production line, steel wire armoring machine and extrusion machine which are arranged in sequence; the cable core production equipment includes three-layer co-extrusion equipment and copper tape wrapping equipment; the waterproof integrated sheath production line includes a pay-off device, a longitudinal wrapping platform, an extruder, a cooling water trough, a traction device and a take-up device which are arranged in sequence; a longitudinal wrapping mold with a diameter-bearing area length greater than or equal to 12 mm and less than or equal to 15 mm is provided in the middle of the longitudinal wrapping platform, and the angle α between the longitudinal wrapping mold and the longitudinal wrapping platform is ≤20°, and the aluminum-plastic composite tape is longitudinally wrapped and overlapped on the outside of the cable core through the longitudinal wrapping mold; a sizing mold is provided on the longitudinal wrapping platform near one end of the extruder.

9. The production device according to claim 8, characterized in that: The distance between the diameter-bearing area of the longitudinal wrapping die and the sizing die is no more than 100 mm, and the distance between the sizing die and the head of the extruder is no more than 180 mm.

10. The production device according to claim 8, characterized in that: The three-layer co-extrusion equipment is a cross-linking machine, through which the conductor shielding layer, the water-tree resistant cross-linked polyethylene insulation layer and the insulation shielding layer of the cable core are produced.

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