High tensile strength heat dissipating marine cable

Abstract

The utility model discloses a kind of high tensile strength's heat dissipation submarine cable, belong to submarine cable technical field.The submarine cable of the utility model has good heat dissipation performance and tensile strength, in terms of heat dissipation, the utility model is increased waterproof layer, waterproof layer is formed towards cable core with heat dissipation medium filled heat dissipation passage, ensure cable under higher load flow, continuous operation and not more than maximum allowable operating temperature, extruding HDPE pipeline outside tape layer can pass more heat dissipation medium, and heat dissipation medium is directly contacted with cable core, cooling heat dissipation effect is better;In tensile strength aspect, the armoring layer adopts double-layer aluminum wire+double-layer stainless steel layer structure, tensile strength can reach 1150MPa, can effectively improve the maximum allowable use tension of submarine cable, reduce submarine cable weight simultaneously, and effectively reduce the electromagnetic loss generated in armoring layer, improve the load flow of submarine cable.

Description

Technical Field

[0001] This utility model relates to the field of submarine cables, specifically to a high tensile strength heat dissipation submarine cable. Background Technology

[0002] Offshore wind power is one of the current directions for vigorous development of clean energy. Typically, the electricity output from offshore wind turbines is first collected via submarine cables to an offshore substation, where it is stepped up by transformers before being transmitted to land. The laying process of the submarine cable to land can be roughly divided into three parts: directional drilling into the sea → installing a protective pipe in the borehole → pulling the submarine cable from the protective pipe to land. This section is called the directional drilling section. The submarine cable in the directional drilling section can be buried at a depth of 10-20 meters. The thermal resistance of the surrounding soil is higher than that of the seabed, resulting in poor heat dissipation and a lower allowable current carrying capacity for the cable compared to other sections. Furthermore, the longer the directional drilling section, the greater the tensile force required to pull the cable from the seabed to land. Some projects require tensile forces exceeding 30 tons, placing high demands on the tensile strength of the submarine cable. However, the current main solution for the low current-carrying capacity of directional drilling submarine cables is to use copper wire armor instead of conventional galvanized steel wire armor to reduce losses caused by electromagnetic induction and thus increase current-carrying capacity. However, the tensile strength of copper wire armor is significantly lower than that of galvanized steel wire, which contradicts the high tensile strength requirements of directional drilling submarine cables. In addition, existing submarine cables usually have separate cooling liquid pipes inside to improve their heat dissipation capacity, but the contact area between the cooling liquid pipes and the cable core is small, resulting in insufficient heat dissipation. Summary of the Invention

[0003] The technical problem to be solved by this invention is that existing submarine cables have poor heat dissipation performance and low tensile strength.

[0004] To address the aforementioned technical problems, this invention provides a high-tensile-strength heat-dissipating submarine cable. This invention adds a waterproof layer outside the wrapping layer, forming a heat dissipation channel filled with a heat-dissipating medium facing the cable core. This heat dissipation channel directly contacts the cable core, thereby improving the heat dissipation efficiency and ensuring continuous operation of the cable core under high current carrying capacity without exceeding the maximum allowable operating temperature. Compared to other designs that separately install cooling liquid pipes inside the submarine cable, the heat dissipation channel formed by extruding a waterproof layer outside the wrapping layer allows for the passage of more heat dissipation medium, and the heat dissipation medium directly contacts the cable core, resulting in better cooling and heat dissipation effects. Regarding tensile strength, this invention uses a double-layer aluminum wire + double-layer stainless steel wire design in the armor layer, achieving a tensile strength of up to 1150 MPa, effectively increasing the maximum allowable tensile force of the submarine cable. Simultaneously, the two aluminum wire layers and two stainless steel layers reduce the weight of the submarine cable while maintaining tensile strength. The relative magnetic permeability of aluminum and stainless steel is essentially 1 (i.e., non-magnetic), effectively reducing electromagnetic losses generated in the armor layer and increasing the current carrying capacity of the submarine cable. The inner lining uses Kevlar fiber rope instead of conventional polypropylene fiber rope, further improving the permissible tensile strength of the submarine cable. An aluminum-plastic composite layer replaces the commonly used lead alloy sheath, reducing the weight of the submarine cable and lowering the tensile force required to tow it.

[0005] The first objective of this invention is to provide a high tensile strength heat dissipation submarine cable, which includes:

[0006] The cable core includes several electrical units and several fillers; the electrical units are symmetrically arranged around the central axis of the cable core, and the fillers are arranged between adjacent electrical units. The electrical units and the fillers are twisted together to form the cable core. The electrical unit includes a water-blocking conductor and an insulation layer, a metal shielding layer, an aluminum-plastic composite layer, and a semi-conductive polyethylene layer arranged sequentially along the outer radial direction of the water-blocking conductor.

[0007] The wrapping layer is placed outside the cable core;

[0008] A waterproof layer is installed outside the wrapping layer, and the waterproof layer faces the cable core to form a heat dissipation channel to accommodate the heat dissipation medium;

[0009] A protective layer is disposed outside the waterproof layer.

[0010] Furthermore, this invention adds a waterproof layer that faces the cable core to form a heat dissipation channel. This channel can be filled with a heat dissipation medium, ensuring the cable core can operate continuously under high current carrying capacity without exceeding the maximum allowable operating temperature. Compared to other designs that separately install cooling liquid pipes inside the submarine cable, extruding a waterproof layer outside the wrapping layer creates a heat dissipation channel that allows more heat dissipation medium to pass through, and the medium directly contacts the cable core, resulting in better cooling and heat dissipation effects.

[0011] Furthermore, the waterproof layer is made of polyethylene, with a density of 0.95-0.98 g / cm³. 3 Preferably, the waterproof layer is made of high-density polyethylene (HDPE) corrugated pipe. HDPE corrugated pipe has strong corrosion resistance, and HDPE material has excellent chemical stability and non-polar molecules. Except for a few strong oxidizing agents, most chemical media do not damage it, thus it can resist long-term seawater erosion and is not easily corroded like metal pipes, effectively protecting the submarine cable from chemical corrosion by seawater. In the marine environment, various microorganisms may damage the submarine cable protection pipe, but HDPE corrugated pipe is not prone to microbial growth, avoiding pipe damage caused by microbial activity and thus ensuring the integrity of the submarine cable. The wrapping layer's main function is to bind the filler strip and the electrical unit cable core tightly into a single, round piece for subsequent production processes. Therefore, the wrapping layer is placed inside the waterproof layer.

[0012] Furthermore, the heat dissipation medium is selected from one or more of water, thermal oil, fluorinated liquid, nano-carbon, and thermal gel.

[0013] Furthermore, the protective layer consists of an inner lining layer, an armor layer, and an outer sheath layer, arranged radially outward from the cable core.

[0014] Furthermore, the armor layer consists of two layers of aluminum wire and two layers of stainless steel arranged radially outward from the cable core.

[0015] Furthermore, the aluminum wire layer and the stainless steel layer are spaced apart, and the armor layer consists of an aluminum wire layer, a stainless steel layer, another aluminum wire layer, and a stainless steel layer radially outward from the cable core. Aluminum wire is lightweight, while stainless steel wire is high-strength, and both are non-magnetic materials with virtually no electromagnetic loss. The spaced arrangement ensures more uniform armor strength, and the greater number of stainless steel wires allows for greater tensile strength.

[0016] Furthermore, the armor layer consists of an aluminum wire layer, an aluminum wire layer, a stainless steel layer, and a stainless steel layer, arranged radially outward from the cable core.

[0017] Furthermore, the aluminum wire layer is LY9 aluminum wire bonded with asphalt, and the stainless steel layer is chromium-nickel austenitic stainless steel wire bonded with asphalt. This utility model adopts an armor structure of two aluminum wire layers + two stainless steel layers. The aluminum wire is LY9 round aluminum wire as specified in GB / T3955, and the stainless steel wire is chromium-nickel austenitic stainless steel wire (i.e., 12Cr18Ni9 cold-drawn steel wire), with a tensile strength of up to 1150MPa, which can effectively increase the maximum allowable tensile strength of the submarine cable. At the same time, the two layers of aluminum wire and two layers of stainless steel wire can reduce the weight of the cable while ensuring tensile strength. In addition, the relative magnetic permeability of aluminum and stainless steel is basically 1 (i.e., non-magnetic), which can effectively reduce the electromagnetic loss generated in the armor layer and increase the current carrying capacity of the submarine cable.

[0018] Furthermore, the insulated core layer consists of a conductor shielding layer, an insulation layer, and an insulation shielding layer arranged radially outward from the cable core.

[0019] Furthermore, the metal shielding layer consists of a first water-blocking layer, a metal layer, and a second water-blocking layer, arranged radially outward from the cable core.

[0020] Furthermore, the inner lining layer is a Kevlar fiber rope bonded with asphalt. This invention uses Kevlar fiber rope to replace conventional polypropylene fiber rope, further improving the permissible tensile strength of the submarine cable.

[0021] Furthermore, the core material of the aluminum-plastic composite layer is polyethylene, and the outer layer is aluminum alloy. This invention utilizes an aluminum-plastic composite layer to replace the existing lead alloy sheath, reducing the weight of the submarine cable and lowering the tensile force required to tow it.

[0022] Furthermore, the filler includes a main body and extensions extending along both sides of the main body; a notch is formed between the extensions on both sides of the main body, and the opening of the notch faces the wrapping layer; the main body is disposed between two adjacent electrical units, and the surface of the extensions away from the electrical units is attached to the wrapping layer.

[0023] Furthermore, a composite optical cable unit is installed within the gap.

[0024] Furthermore, the outer sheath is a polypropylene fiber rope bonded with asphalt. The outer sheath uses impregnated polypropylene rope and is coated with asphalt to provide better corrosion protection and adhesion.

[0025] The beneficial effects of this utility model are:

[0026] This invention provides a submarine cable with excellent heat dissipation performance and tensile strength. Regarding heat dissipation, this invention adds a waterproof layer, which, together with the cable core, forms a heat dissipation channel. This channel can be filled with a heat-dissipating medium to ensure continuous operation of the cable under high current carrying capacity without exceeding the maximum allowable operating temperature. Compared to other designs that separately install cooling liquid pipes inside the cable, the waterproof layer extruded outside the sheath layer creates a heat dissipation channel that allows more heat-dissipating medium to pass through, and the medium directly contacts the cable core, resulting in better cooling and heat dissipation. In terms of tensile strength, the armor layer of this invention adopts a double-layer aluminum wire layer + double-layer stainless steel layer design. The aluminum wire is LY9 round aluminum wire as specified in GB / T 3955, and the stainless steel wire is 12Cr18Ni9 cold-drawn steel wire, with a tensile strength of up to 1150MPa. This effectively increases the maximum allowable tensile strength of the submarine cable. Simultaneously, the two aluminum wire layers plus the two stainless steel layers reduce the cable weight while ensuring tensile strength. In addition, the relative permeability of aluminum and stainless steel is essentially 1 (i.e., non-magnetic), which effectively reduces electromagnetic losses in the armor layer and increases the current carrying capacity of the submarine cable. The inner lining uses Kevlar fiber rope instead of conventional polypropylene fiber rope, further increasing the allowable tensile strength of the submarine cable. An aluminum-plastic composite layer replaces the commonly used lead alloy sheath, reducing the weight of the submarine cable and lowering the tensile force required to tow it. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the submarine cable structure of this utility model;

[0028] Explanation of the numbers in the diagram: 100, heat dissipation submarine cable; 1, cable core; 2, wrapping layer; 3, waterproof layer; 4, protective layer; 11, electrical unit; 12, filler; 111, water-blocking conductor; 112, insulated core layer; 113, metal shielding layer; 114, aluminum-plastic composite layer; 115, semi-conductive polyethylene layer; 10, heat dissipation channel; 41, inner lining layer; 42, armor layer; 43, outer sheath layer; 421, aluminum wire layer; 422, stainless steel layer; 1121, conductor shielding layer; 1122, insulation layer; 1123, insulation shielding layer; 1131, first water-blocking layer; 1132, metal layer; 1133, second water-blocking layer; 121, main body; 122, extension; 123, notch. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0030] Example

[0031] Reference Figure 1 As shown, the heat dissipation submarine cable 100 in this embodiment includes:

[0032] The cable core 1 includes several electrical units 11 and several fillers 12. The electrical units 11 are symmetrically arranged around the center of the central axis (i.e., the center of symmetry O) of the cable core 1, and each adjacent electrical unit 11 is provided with a filler 12. The electrical units 11 and the fillers 12 are twisted together to form the cable core 1. The electrical unit 11 includes several water-blocking conductors 111 and an insulating core layer 112 (the insulating core layer 112 is arranged radially outward from the several water-blocking conductors 111, which consists of a conductor shielding layer 1121, an insulating layer 1122 and an insulating shielding layer 1123), a metal shielding layer 113 (the metal shielding layer 113 is arranged radially outward from the first water-blocking layer 1131, a metal layer 1132 and a second water-blocking layer 1133), an aluminum-plastic composite layer 114 and a semi-conductive polyethylene layer 115.

[0033] The wrapping layer 2 is disposed outside the cable core 1;

[0034] Waterproof layer 3 is disposed outside the wrapping layer 2, and the waterproof layer 3 forms a heat dissipation channel 10 filled with heat dissipation medium facing the cable core 1;

[0035] The protective layer 4, located outside the waterproof layer 3, consists of an inner lining layer 41, an armor layer 42, and an outer sheath layer 43, arranged sequentially. The inner lining layer 41 is located outside the waterproof layer 3; the armor layer 42 is located outside the inner lining layer 41; and the outer sheath layer 43 is located outside the armor layer 42.

[0036] The materials used in the heat dissipation submarine cable 100 provided in this embodiment are as follows:

[0037] Water-blocking conductor 111: It adopts a tightly twisted round copper conductor, and the space between each layer of the conductor is filled with water-blocking tape or water-blocking adhesive;

[0038] Conductor shielding layer 1121: Made of semi-conductive cross-linked polyethylene or other semi-conductive shielding cable material;

[0039] Insulation layer 1122: Made of water-resistant cross-linked polyethylene to cope with possible seawater infiltration;

[0040] Insulation shielding layer 1123: Made of semi-conductive cross-linked polyethylene or other semi-conductive shielding cable material;

[0041] First water-blocking layer 1131: adopts semi-conductive water-blocking tape, which is composed of polyester fiber non-woven fabric, semi-conductive material and super absorbent material;

[0042] Metal layer 1132: Wrapped with aluminum wire;

[0043] Second water-blocking layer 1133: The material is the same as the first water-blocking layer 1131;

[0044] Aluminum-plastic composite layer 114: Uses polyethylene or copolymer type double-sided aluminum-plastic composite tape;

[0045] Semi-conductive polyethylene layer 115: Semi-conductive polyethylene is used to ensure good electrical contact between the heat dissipation submarine cable 100 and seawater;

[0046] Filler 12: The filler 12 includes a main body 121 and extensions 122 extending along both sides of the main body 121; a notch 123 is formed between the extensions 122 on both sides of the main body 121, and the opening of the notch 123 faces the wrapping layer 2; the main body 121 is disposed between two adjacent electrical units 11, the surface of the extensions 122 away from the electrical units 11 is attached to the wrapping layer 2, and a composite optical cable unit (not shown) is provided in the notch 123;

[0047] 2. Packaging layer: Adhesive-coated fabric tape or polyester tape;

[0048] Waterproof layer 3: Made of high-density polyethylene (HDPE) material, with a sealed structure, allowing water to be filled inside the pipe;

[0049] Inner lining 41: Wrapped with Kevlar fiber rope;

[0050] Armor layer 42: It adopts a double-layer aluminum wire layer 421 + double-layer stainless steel layer 422 structure. The aluminum wire is LY9 round aluminum wire as specified in GB / T3955, and the stainless steel wire is 12Cr18Ni9 cold-drawn steel wire. Asphalt is coated on the armor metal wire to ensure better anti-corrosion effect.

[0051] Outer sheath 43: Made of impregnated polypropylene rope and coated with asphalt to provide better corrosion protection and adhesion of outer sheath 43.

[0052] In this embodiment, the heat dissipation submarine cable 100 is manufactured in the following manner:

[0053] (1) Use a wire drawing machine and a frame stranding machine to strand the water-blocking tape or water-blocking adhesive into a conductor to obtain a water-blocking conductor 111;

[0054] (2) Use a vertical tower cross-linking production line or other cross-linking production line to perform the three-layer co-extrusion production of conductor shielding layer 1121-insulation layer 1122-insulation shielding layer 1123, followed by a degassing process;

[0055] (3) Wrap the first water-blocking layer 1131, the metal layer 1132, and the second water-blocking layer 1133 sequentially around the insulated wire core;

[0056] (4) Continue to wrap the aluminum-plastic composite layer 114, and then extrude the semi-conductive polyethylene layer 115 to complete the production of the electrical unit 11.

[0057] (5) The three electrical units 11 and the filler 12 are used to complete the three-core cabling of the heat dissipation submarine cable 100 on the cabling machine to form cable core 1. The cable core 1 is wrapped with polyester tape or coated cloth tape as wrapping layer 2.

[0058] (6) The waterproof layer 3 is produced on the wrapping layer 2 using an extrusion process.

[0059] (7) Wrap Kevlar fiber rope as inner lining layer 41, and then complete the production of armor layer 42 with double aluminum wire layer 421 + double stainless steel layer 422 structure on armoring machine, while coating with asphalt to achieve corrosion protection of armor layer 42.

[0060] (8) Finally, polypropylene fiber rope is wrapped around the outer layer and coated with asphalt to form an outer layer 43, which ensures better anti-corrosion effect and provides adhesion for the outer layer 43.

[0061] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

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