Submarine cable for ultra-shallow water and preparation method of armored composite layer

Abstract

The invention relates to the technical field of dynamic submarine cables, and provides a submarine cable for ultra-shallow water and a preparation method of an armored composite layer, and the submarine cable for ultra-shallow water comprises a cable core structure, a filling strip, an optical unit, an inner sheath and the armored composite layer. The cable core structure is filled with filling strips during cabling and twisting, part of the filling strips are internally provided with optical units, the cable core structure, the filling strips and the optical units are cabled and then wrapped with an inner sheath, and the outer side of the inner sheath is provided with an armored composite layer; wherein the armoring composite layer comprises a braided armoring layer and a polymer matrix, the braided armoring layer is formed by braiding a plurality of armoring wires, and the polymer matrix wraps the braided armoring layer, fills pores of the braided armoring layer and is integrated with the braided armoring layer. According to the submarine cable for the ultra-shallow water, the minimum bending radius of the submarine cable is reduced, a compact solid body can be formed, the longitudinal water blocking capacity and the lateral pressure resisting capacity are improved, and then the ultra-shallow water large-deviation use requirement and the good anti-fatigue capacity of the submarine cable are met.

Description

Technical Field

[0001] The invention relates to the technical field of dynamic submarine cables, and in particular to a method for preparing a submarine cable for ultra-shallow water and an armored composite layer. Background Art

[0002] In the new energy system, wind power and photovoltaic technologies are developing rapidly. The global offshore photovoltaic potential capacity is about 4000GW. As the transmission equipment for floating wind power and photovoltaic power, the demand for dynamic submarine cables is also relatively large.

[0003] At present, the application water depth of existing conventional dynamic submarine cables in China is generally greater than 30 meters, the platform offset is no more than half of the water depth, and there is no need to deal with floating ice. Therefore, when facing extremely harsh working conditions with a water depth of less than 10 meters and a platform offset of no less than 10 meters, the existing dynamic submarine cables are prone to excessive bending and breaking, or excessive straightening and breaking. In addition, the design of dynamic submarine cables has no ability to resist floating ice. When facing conditions in winter where the thickness of floating ice is large and the duration is long, the dynamic submarine cables are easily damaged. Summary of the invention

[0004] The invention provides a method for preparing a submarine cable for ultra-shallow water and an armored composite layer, which is used to solve the problem in the prior art that the submarine cable has poor anti-bending and anti-floating ice capabilities in ultra-shallow waters.

[0005] In order to solve the above-mentioned technical problems, the present invention is achieved as follows: In a first aspect, the present invention provides a submarine cable for ultra-shallow water, comprising: a cable core structure, a filling bar, an optical unit, an inner sheath and an armor composite layer; The cable core structure is filled with the filling strips when it is cabled and twisted, the optical unit is arranged in part of the filling strips, and the cable core structure, the filling strips and the optical unit are wrapped with the inner sheath as an outer layer after being cabled, and the armored composite layer is arranged on the outer side of the inner sheath; The armor composite layer includes a braided armor layer and a polymer matrix. The braided armor layer is woven from a plurality of armor wires. The polymer matrix is ​​coated on the braided armor layer and filled in the pores of the braided armor layer, and is integrally arranged with the braided armor layer.

[0006] According to the ultra-shallow water submarine cable provided by the present invention, the braided armor layer is a metal composite fiber braided armor layer; The metal composite fiber braided armor layer is braided by metal composite fibers, and the metal composite fiber braided armor layer is in a mesh shape.

[0007] According to the ultra-shallow water submarine cable provided by the present invention, the metal composite fiber includes a central wire and a metal wire, and the metal wire is wound around the central wire.

[0008] According to the ultra-shallow water submarine cable provided by the present invention, the material of the central wire includes aramid, nylon, carbon fiber, titanium alloy, copper wire, aluminum alloy wire or stainless steel wire; the material of the metal wire includes pure copper wire, tinned copper wire, aluminum alloy wire, stainless steel wire or titanium alloy wire.

[0009] According to the ultra-shallow water submarine cable provided by the present invention, the diameter of the metal composite fiber is 0.1-3 mm, and the tensile strength is ≥5 kg; And / or, the metal composite fiber braided armor layer has a thickness of 0.3-5 mm, a braiding density of ≥90%, a pitch of 50-500 mm, and an inner diameter of 20-150 mm.

[0010] According to the ultra-shallow water submarine cable provided by the present invention, the material of the polymer matrix includes: high-density polyethylene, medium-density polyethylene or linear low-density polyethylene.

[0011] An ultra-shallow water submarine cable provided by the present invention further comprises: a cushion layer; The cushion layer is sandwiched between the armor composite layer and the inner sheath.

[0012] According to the ultra-shallow water submarine cable provided by the present invention, the cable core structure comprises: a water-blocking conductor, an insulating layer, a metal shielding layer and an inner sheath; The water-blocking conductors are provided in plurality, and the water-blocking conductors, the insulating layer, the metal shielding layer and the inner protective layer are arranged in sequence from the inside to the outside.

[0013] In a second aspect, the present invention provides a method for preparing an armored composite layer of an ultra-shallow water submarine cable, comprising: Extruding a polymer matrix outside the armor wire; A plurality of armoring wires extruded with a polymer matrix are tightly woven to form a braided armor layer; The braided armor layer extruded with a polymer matrix is ​​subjected to a heating treatment to melt the polymer matrix and bond it to the braided armor layer to form a whole.

[0014] According to a method for preparing an armored composite layer of an ultra-shallow water submarine cable provided by the present invention, the method of heating the braided armor layer extruded with a polymer matrix comprises: The braided armor layer extruded with the polymer matrix is ​​passed into a hot oven for heating treatment.

[0015] The invention provides a method for preparing a submarine cable and an armored composite layer for ultra-shallow water. The armored composite layer is arranged on the outer side of an inner sheath. The armored composite layer includes a braided armor layer and a polymer matrix. A plurality of armor filaments are braided into a braided armor layer. The polymer matrix is ​​coated on the braided armor layer and filled in the pores of the braided armor layer, so that the braided armor layer and the polymer matrix are arranged in one piece. The braided armor layer can enable the submarine cable to maintain its own shape and structure when bending, ensure that the submarine cable will not be excessively bent or broken, and allow the submarine cable to be safely bent at a smaller radius, thereby reducing the minimum bending radius of the submarine cable. Moreover, the coating and filling of the braided armor layer by the polymer matrix can form a dense entity, improve the longitudinal water blocking capacity and the ability to resist lateral pressure, thereby achieving the ultra-shallow water large excursion use requirements and good fatigue resistance of the submarine cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of the ultra-shallow water submarine cable provided by the present invention.

[0018] Figure 2 It is a schematic diagram of the structure of the armored composite layer provided by the present invention.

[0019] Figure 3 It is a schematic structural diagram of the braided armor layer provided by the present invention.

[0020] Figure 4 It is a schematic diagram of the cross-sectional structure of the cable core structure provided by the present invention.

[0021] Figure 5 It is a schematic diagram of the process of preparing the armored composite layer provided by the present invention.

[0022] Reference numerals: 1. Cable core structure; 11. Water-blocking conductor; 12. Insulation layer; 13. Metal shielding layer; 14. Inner sheath; 2. Filling strip; 3. Light unit; 4. Inner sheath; 5. Armored composite layer; 51. Braided armor layer; 52. Polymer matrix; 511. Center wire; 512. Metal wire; 6. Cushion layer. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Combine the following Figures 1 to 5 , the preparation method of the ultra-shallow water submarine cable and the armored composite layer provided by the embodiment of the present invention is described in detail through specific embodiments and their application scenarios.

[0025] First, as Figure 1 and Figure 2 As shown, this embodiment provides a submarine cable for ultra-shallow water, including: a cable core structure 1, a filling strip 2, an optical unit 3, an inner sheath 4 and an armored composite layer 5.

[0026] The cable core structure 1 is filled with filling strips 2 when being cabled and twisted, and optical units 3 are arranged in some of the filling strips 2. After the cable core structure 1, the filling strips 2 and the optical units 3 are cabled, the outer layer is wrapped with an inner sheath 4, and an armored composite layer 5 is arranged on the outer side of the inner sheath 4.

[0027] The armor composite layer 5 includes a braided armor layer 51 and a polymer matrix 52 . The braided armor layer 51 is woven from a plurality of armor filaments. The polymer matrix 52 is coated on the braided armor layer 51 and filled in the pores of the braided armor layer 51 , and is integrally arranged with the braided armor layer 51 .

[0028] It is understandable that submarine cables are used in dynamic cable systems for floating photovoltaic platforms at sea and inland lakes, or in dynamic submarine cable systems for connecting floating wind turbines in floating wind farms, or in dynamic submarine cable systems for offshore oil and gas; or in dynamic submarine cable systems for new energy power generation platforms such as wave power generation. When the water depth is shallow, the submarine cables are subject to greater bending forces and the working conditions are more severe.

[0029] In this embodiment, a filling strip 2 is arranged in the cabling gap of the cable core structure 1. The filling strip 2 is compatible with the insulating material of the submarine cable and suitable for the operation of the submarine cable. The material of the filling strip 2 includes high-density polyethylene, medium-density polyethylene, linear low-density polyethylene or polypropylene. The filling strip 2 is solid or hollow fan-shaped, and there is a hole in the middle of the filling strip for placing the optical unit 3. The filling strip 2 matches the size of the cable core structure 1.

[0030] The inner sheath 4 of this embodiment is wrapped around the cable core structure 1, the filling strip 2 and the cable structure of the optical unit 3 to provide fixed and stable support for the cable core structure 1, the filling strip 2 and the optical unit 3. The material of the inner sheath 4 includes high-density polyethylene, medium-density polyethylene, linear low-density polyethylene or polyurethane.

[0031] Furthermore, the armored composite layer 5 of the present embodiment comprises a braided armor layer 51 and a polymer matrix 52 coated on the braided armor layer 51. The braided armor layer 51 is braided with metal wires 512 or non-metal wires 512. When the submarine cable is subjected to bending force, the braided armor layer 51 can evenly distribute stress to avoid stress concentration at a certain point causing damage to the submarine cable. Moreover, the braided armor layer 51 enables the submarine cable to maintain its own shape and structure when bending, thereby allowing the submarine cable to bend safely at a smaller radius, thereby effectively reducing the minimum bending radius of the submarine cable. At the same time, since the braided armor layer 51 is coated with the polymer matrix 52, and the pores of the braided armor layer 51 are filled with the polymer matrix 52 to form a dense entity, the longitudinal water resistance and lateral pressure resistance of the submarine cable are increased, so that it can resist the impact of floating ice in winter or when the temperature is low.

[0032] The ultra-shallow water submarine cable provided by the present invention is provided with an armored composite layer 5 on the outer side of an inner sheath 4, the armored composite layer 5 comprising a braided armor layer 51 and a polymer matrix 52, a plurality of armor filaments are woven into the braided armor layer 51, and the polymer matrix 52 is coated on the braided armor layer 51 and filled in the pores of the braided armor layer 51, so that the braided armor layer 51 and the polymer matrix 52 are integrally arranged, the braided armor layer 51 can enable the submarine cable to maintain its own shape and structure when bending, ensure that the submarine cable will not be excessively bent or broken, and allow the submarine cable to be safely bent at a smaller radius, thereby reducing the minimum bending radius of the submarine cable, and the coating and filling of the braided armor layer 51 by the polymer matrix 52 can form a dense entity, improve the longitudinal water blocking ability and the ability to resist lateral pressure, thereby achieving the ultra-shallow water large excursion use requirements and good fatigue resistance of the submarine cable.

[0033] In some embodiments, Figure 2 and Figure 3 As shown, the braided armor layer 51 of this embodiment is a metal composite fiber braided armor layer.

[0034] The metal composite fiber braided armor layer is woven from metal composite fibers, and the metal composite fiber braided armor layer is in a mesh shape.

[0035] It is understandable that since metal composite fibers have good low-temperature properties and can still maintain mechanical strength and ductility at low temperatures, weaving metal composite fibers into a mesh armor layer can meet the low-temperature requirements in a floating ice environment. In addition, the metal composite fibers can also maintain a high tensile strength, which helps to resist the impact of floating ice.

[0036] In some embodiments, Figure 2 As shown, the metal composite fiber of this embodiment includes a central wire 511 and a metal wire 512 , and the metal wire 512 is wound around the central wire 511 .

[0037] It can be understood that the central wire 511 of the present embodiment is made of high-strength metal material wire, and a metal wire 512 is densely wound around the central wire 511. Specifically, the material of the central wire 511 includes aramid, nylon, carbon fiber, titanium alloy, copper wire, aluminum alloy wire or stainless steel wire; the material of the metal wire 512 includes pure copper wire, tinned copper wire, aluminum alloy wire, stainless steel wire or titanium alloy wire. The metal wire 512 is densely wound on the central wire 511 in a spiral shape to obtain a metal composite fiber. The metal wire 512 is mesh-woven relative to the central wire 511 to obtain a metal composite fiber braided armor layer.

[0038] In some embodiments, the diameter of the metal composite fiber of this embodiment is 0.1-3 mm, and the tensile strength is ≥5 kg.

[0039] It is understandable that the diameter of the central wire 511 and the metal wire 512 of this embodiment ranges from 0.1 to 3 mm, and the tensile strength of the central wire 511 and the metal wire 512 is ≥5 kg, ensuring that the central wire 511 and the metal wire 512 have a smaller diameter and a larger tensile strength.

[0040] In some embodiments, the metal composite fiber braided armor layer has a thickness of 0.3-5 mm, a braiding density of ≥90%, a pitch of 50-500 mm, and an inner diameter of 20-150 mm.

[0041] It is understandable that the thickness of the metal composite fiber braided armor layer refers to the size of the protective layer formed by the armor layer on the outside of the submarine cable. The thickness of this embodiment is 0.3~5mm. The braiding density refers to the coverage of the armor layer per unit length or unit area. The braiding density of this embodiment is ≥90%, which ensures the compactness and shielding effect of the submarine cable. The pitch of the armor layer refers to the distance between two adjacent layers of armor material when the armor layer material is wrapped around the inner sheath 4. The pitch of this embodiment is 50~500mm, which ensures the mechanical protection and electrical performance of the submarine cable. The inner diameter of the armor layer of this embodiment is 20~150mm, which is compatible with the outer diameter of the inner sheath 4 to fit the inner sheath 4 tightly and provide uniform protection.

[0042] In some embodiments, Figure 2 As shown, the material of the polymer matrix 52 of this embodiment includes: high-density polyethylene, medium-density polyethylene or linear low-density polyethylene.

[0043] It can be understood that the polymer matrix 52 of the present embodiment includes polyethylene and polyurethane of different densities, which can be extruded onto the metal composite fiber braided armor layer during the processing of the submarine cable, and melt and bond with the armor layer to form a whole when heated, and is coated on the outside of the armor layer and filled in the pores of the braided layer, so that the armor layer and the polymer matrix 52 form a dense entity.

[0044] Based on the thermoplasticity of polyethylene, polyethylene becomes soft and plastic when heated and hardens after cooling, which is conducive to melting with the armor layer when heated and forming a dense entity with the armor layer after cooling.

[0045] In some embodiments, Figure 1 As shown, the ultra-shallow water submarine cable of this embodiment further includes: a cushion layer 6.

[0046] The cushion layer 6 is sandwiched between the armor composite layer 5 and the inner sheath 4 .

[0047] It is understandable that in this embodiment, a cushion layer 6 is provided between the armor composite layer 5 and the inner sheath 4, and the inner sheath 4 can be quickly peeled off through the cushion layer 6. In addition, the armor composite layer 5 can also be fixed to the cushion layer 6 using an anchoring fixture to meet the need for quickly anchoring the armor layer.

[0048] In some embodiments, Figure 4 As shown, the cable core structure 1 of this embodiment includes: a water-blocking conductor 11 , an insulating layer 12 , a metal shielding layer 13 and an inner protective layer 14 .

[0049] There are multiple water-blocking conductors 11 , and the multiple water-blocking conductors 11 , the insulating layer 12 , the metal shielding layer 13 and the inner protective layer 14 are arranged in sequence from the inside to the outside.

[0050] It can be understood that the water-blocking conductor 11 of this embodiment is filled with water-blocking tape or water-blocking glue when twisted, which can meet the water-blocking requirements of a water depth of 4000m, and the water-blocking tape adopts a two-layer seawater-blocking type water-blocking tape, and the material of the inner protective layer 14 includes high-density polyethylene, medium-density polyethylene, linear low-density polyethylene or polyurethane to meet the protection strength of the water-blocking conductor 11, the insulating layer 12 and the metal shielding layer 13.

[0051] Specifically, the number of the water-blocking conductors 11 is not less than two, and may be three or more.

[0052] In a second aspect, in some embodiments, as Figure 5 As shown, this embodiment provides a method for preparing an armored composite layer of an ultra-shallow water submarine cable, comprising the following steps: Step 511, extruding a polymer matrix outside the armor wire; Step 512, tightly weave a plurality of armor wires extruded with a polymer matrix to form a braided armor layer.

[0053] Step 513, heat the braided armor layer extruded with the polymer matrix to melt the polymer matrix and bond it to the braided armor layer to form a whole.

[0054] It can be understood that the preparation method of the armored composite layer of the present embodiment includes: first, extruding a polymer matrix outside the armor wire, in some examples, after heating and melting the polymer matrix outside the metal composite fiber through an extruder, it is extruded through a die to form a uniform tubular or strip-shaped covering layer, which is tightly attached to the outside of the metal composite fiber, and then, the metal composite fiber extruded with the polymer matrix is ​​woven into a mesh structure, and the metal composite fiber extruded with the polymer matrix is ​​woven with a high density using a braiding machine to form a braided armor layer, and finally, the braided armor layer extruded with the polymer matrix is ​​heated, and the polymer matrix is ​​melted on the braided armor layer, integrated with the braided armor layer, and fills the pores of the braided armor layer, so that the braided armor layer and the polymer matrix form a dense entity, and the dense entity provides additional impact resistance, tensile resistance and compression resistance, which can improve the overall stability and rigidity of the submarine cable, and enhance the longitudinal water blocking ability and lateral pressure resistance.

[0055] In some embodiments, Figure 5 As shown, the method of heating the braided armor layer extruded with a polymer matrix in this embodiment includes: The braided armor layer extruded with the polymer matrix is ​​passed into a hot oven for heating treatment.

[0056] It can be understood that this embodiment uses a hot oven to perform heat treatment on the braided armor layer and the polymer matrix. Since the oven can accurately control the heating temperature, heating time and provide a uniform thermal field, the braided armor layer and the polymer matrix can be stably and continuously heated in the oven, so that the dense entity formed by the polymer matrix and the braided armor layer has a better effect.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-shallow water submarine cable, characterized in that: include: Cable core structure, filler strips, optical units, inner sheath and armor composite layer; The cable core structure is filled with the filling strips when it is cabled and twisted, the optical unit is arranged in part of the filling strips, and the cable core structure, the filling strips and the optical unit are wrapped with the inner sheath as an outer layer after being cabled, and the armored composite layer is arranged on the outer side of the inner sheath; The armor composite layer includes a braided armor layer and a polymer matrix. The braided armor layer is woven from a plurality of armor wires. The polymer matrix is ​​coated on the braided armor layer and filled in the pores of the braided armor layer, and is integrally arranged with the braided armor layer.

2. The ultra-shallow water submarine cable according to claim 1, characterized in that: The braided armor layer is a metal composite fiber braided armor layer; The metal composite fiber braided armor layer is braided by metal composite fibers, and the metal composite fiber braided armor layer is in a mesh shape.

3. The ultra-shallow water submarine cable according to claim 2, characterized in that: The metal composite fiber includes a central wire and metal wires, wherein the metal wires are wound around the central wire.

4. The ultra-shallow water submarine cable according to claim 3, characterized in that: The material of the central wire includes aramid, nylon, carbon fiber, titanium alloy, copper wire, aluminum alloy wire or stainless steel wire; the material of the metal wire includes pure copper wire, tinned copper wire, aluminum alloy wire, stainless steel wire or titanium alloy wire.

5. The ultra-shallow water submarine cable according to claim 2, characterized in that: The diameter of the metal composite fiber is 0.1-3 mm, and the tensile strength is ≥5 kg; And / or, the metal composite fiber braided armor layer has a thickness of 0.3-5 mm, a braiding density of ≥90%, a pitch of 50-500 mm, and an inner diameter of 20-150 mm.

6. The ultra-shallow water submarine cable according to claim 1, characterized in that: The material of the polymer matrix includes: high-density polyethylene, medium-density polyethylene or linear low-density polyethylene.

7. The ultra-shallow water submarine cable according to claim 1, characterized in that: Also includes: Cushion; The cushion layer is sandwiched between the armor composite layer and the inner sheath.

8. The ultra-shallow water submarine cable according to claim 1, characterized in that: The cable core structure comprises: a water-blocking conductor, an insulating layer, a metal shielding layer and an inner protective layer; The water-blocking conductors are provided in plurality, and the water-blocking conductors, the insulating layer, the metal shielding layer and the inner protective layer are arranged in sequence from the inside to the outside.

9. A method for preparing an armored composite layer of an ultra-shallow water submarine cable according to any one of claims 1 to 8, characterized in that: include: Extruding a polymer matrix outside the armor wire; A plurality of armoring wires extruded with a polymer matrix are tightly woven to form a braided armor layer; The braided armor layer extruded with a polymer matrix is ​​subjected to a heating treatment to melt the polymer matrix and bond it to the braided armor layer to form a whole.

10. The method for preparing an armored composite layer according to claim 9, characterized in that: The method for heating the braided armor layer extruded with a polymer matrix comprises: The braided armor layer extruded with the polymer matrix is ​​passed into a hot oven for heating treatment.

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