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

Abstract

The present invention relates to the technical field of dynamic submarine cables, and provides a submarine cable for ultra-shallow water and a preparation method for an armor composite layer. The submarine cable for ultra-shallow water comprises: cable core structures, filler strips, an optical unit, an inner sheath, and an armor composite layer. When being twisted to form the cable, the cable core structures are filled with the filler strips, some of the filler strips being provided therein with the optical unit. The outer layer of the cable formed by the cable core structures, the filler strips, and the optical units is wrapped in the inner sheath, the outer side of the inner sheath being provided with the armor composite layer. The armor composite layer comprises a braided armor layer and a polymer matrix. The braided armor layer is formed by braiding a plurality of armor wires. The polymer matrix coats the braided armor layer, and fills pores of the braided armor layer, so as to be integrated with the braided armor layer. The minimum bending radius of the submarine cable for ultra-shallow water of the present invention is reduced, and the submarine cable can also form a dense solid body to enhance the longitudinal water-blocking capability and the lateral pressure resistance, thereby meeting the service requirements of the submarine cable for large offset in ultra-shallow water and good fatigue resistance.

Description

Preparation method of submarine cable and armored composite layer for ultra-shallow water

[0001] The present application claims priority to the Chinese patent application No. 202411256468.7, filed on September 6, 2024, and entitled "Preparation method of submarine cable and armored composite layer for ultra-shallow water", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of dynamic submarine cable, and in particular to a preparation method of submarine cable and armored composite layer for ultra-shallow water. BACKGROUND

[0003] In the new energy system, wind power and photovoltaic technologies are developing rapidly. The global offshore photovoltaic potential capacity is about 4000 GW. China has a long coastline, and the theoretical installable capacity of offshore photovoltaic is more than 70 GW. Dynamic submarine cable is used as a transmission device for floating wind power and photovoltaic power, and its use demand is also large.

[0004] Currently, the application water depth of the existing conventional dynamic submarine cable in China is generally greater than 30 meters, the platform offset is not greater than one half of the water depth, and it does not need to deal with floating ice. Therefore, when the existing dynamic submarine cable faces extreme harsh conditions with a water depth of less than 10 meters and a platform offset of not less than 10 meters, the dynamic submarine cable is prone to excessive bending and breaking, and excessive straightening and breaking. In addition, the dynamic submarine cable has no anti-floating ice capability, and the dynamic submarine cable is prone to damage when it faces the condition of large thickness and long time of floating ice in winter. SUMMARY

[0005] The present application provides a preparation method of submarine cable and armored composite layer for ultra-shallow water, which solves the problem of poor bending resistance and anti-floating ice capability of the submarine cable in the prior art in ultra-shallow water.

[0006] In order to solve the above technical problems, the present application is implemented as follows:

[0007] In a first aspect, the present application provides a submarine cable for ultra-shallow water, comprising: a cable core structure, a filling strip, an optical unit, an inner sheath, and an armored composite layer.

[0008] The cable core structure is filled with the filling strip when being stranded, part of the filling strip is provided with the optical unit, the cable core structure, the filling strip, and the optical unit are wrapped with the inner sheath after being stranded, and the outer side of the inner sheath is provided with the armored composite layer.

[0009] The armored composite layer comprises a braided armored layer and a polymer matrix, the braided armored layer is braided by a plurality of armored wires, the polymer matrix is wrapped on the braided armored layer and filled in the pores of the braided armored layer, and the braided armored layer and the polymer matrix are integrally arranged.

[0010] According to the submarine cable for ultra-shallow water provided by the application, the braided armored layer is a metal composite fiber braided armored layer.

[0011] The metal composite fiber braided armored layer is braided by metal composite fibers, and the metal composite fiber braided armored layer is in a mesh shape.

[0012] According to the submarine cable for ultra-shallow water provided by the application, the metal composite fiber comprises a core wire and a metal wire, and the metal wire is wound on the core wire.

[0013] According to the submarine cable for ultra-shallow water provided by the application, the material of the core wire comprises aramid fiber, nylon, carbon fiber, titanium alloy, copper wire, aluminum alloy wire or stainless steel wire; and the material of the metal wire comprises pure copper wire, tinned copper wire, aluminum alloy wire, stainless steel wire or titanium alloy wire.

[0014] According to the submarine cable for ultra-shallow water provided by the application, the diameter of the metal composite fiber is 0.1-3 mm, and the tensile strength is greater than or equal to 5 kg.

[0015] And / or, the thickness of the metal composite fiber braided armored layer is 0.3-5 mm, the braiding density is greater than or equal to 90%, the pitch is 50-500 mm, and the inner diameter is 20-150 mm.

[0016] According to the submarine cable for ultra-shallow water provided by the application, the material of the polymer matrix comprises high-density polyethylene, medium-density polyethylene or linear low-density polyethylene.

[0017] According to the submarine cable for ultra-shallow water provided by the application, the submarine cable further comprises a cushion layer.

[0018] The cushion layer is arranged between the armored composite layer and the inner sheath.

[0019] According to the submarine cable for ultra-shallow water provided by the application, the cable core structure comprises a water-blocking conductor, an insulating layer, a metal shielding layer and an inner protective layer.

[0020] The water-blocking conductor is provided in plurality, and the plurality of water-blocking conductors, the insulating layer, the metal shielding layer and the inner protective layer are sequentially arranged from inside to outside.

[0021] In the second aspect, the application provides a preparation method of an armored composite layer of a submarine cable for ultra-shallow water, comprising the following steps:

[0022] The plurality of armored wires are extruded with the polymer matrix;

[0023] The plurality of armored wires extruded with the polymer matrix are tightly woven to form a woven armored layer;

[0024] The woven armored layer extruded with the polymer matrix is subjected to heat treatment to melt the polymer matrix and bond the woven armored layer to form an integrated body.

[0025] According to the present application, a preparation method of the armored composite layer of the ultra-shallow water submarine cable is provided, and the method for heat treating the woven armored layer extruded with the polymer matrix comprises:

[0026] The woven armored layer extruded with the polymer matrix is passed into a hot oven for heat treatment.

[0027] The ultra-shallow water submarine cable and the preparation method of the armored composite layer provided by the present application set the armored composite layer on the outside of the inner sheath, the armored composite layer comprises a woven armored layer and a polymer matrix, a plurality of armored wires are woven into the woven armored layer, and the polymer matrix is wrapped on the woven armored layer and filled in the pores of the woven armored layer, so that the woven armored layer and the polymer matrix are integrally arranged. The woven armored layer can keep the shape and structure of the submarine cable when it is bent, ensure that the submarine cable will not be excessively bent or broken, allow the submarine cable to be safely bent at a smaller radius, thereby reducing the minimum bending radius of the submarine cable, and the wrapping and filling of the polymer matrix on the woven armored layer can form a dense entity, improve the longitudinal water resistance and lateral pressure resistance, and further achieve the use requirements of the submarine cable in ultra-shallow water and large deviation and good fatigue resistance. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Fig. 1 is a schematic view of the cross-sectional structure of the ultra-shallow water submarine cable provided by the present application.

[0030] Fig. 2 is a schematic view of the structure of the armored composite layer provided by the present application.

[0031] Fig. 3 is a schematic view of the structure of the woven armored layer provided by the present application.

[0032] Fig. 4 is a schematic view of the cross-sectional structure of the cable core structure provided by the present application.

[0033] Fig. 5 is a flowchart of the preparation method of the armored composite layer provided by the present application.

[0034] Fig. 1 is a cable core structure; 11 is a water-blocking conductor; 12 is an insulation layer; 13 is a metal shielding layer; 14 is an inner protective layer; Fig. 2 is a filling strip; 3 is an optical unit; 4 is an inner sheath; Fig. 5 is an armored composite layer; 51 is a braided armored layer; 52 is a polymer matrix; 511 is a center wire; 512 is a metal wire; Fig. 6 is a cushion layer. DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0036] The preparation method of the submarine cable for ultra-shallow water and the armored composite layer provided by the embodiments of the present application will be described in detail below in combination with specific embodiments and application scenarios of the present application.

[0037] In a first aspect, as shown in FIGS. 1 and 2, the present embodiment provides a submarine cable for ultra-shallow water, comprising: a cable core structure 1, a filling strip 2, an optical unit 3, an inner sheath 4 and an armored composite layer 5.

[0038] The cable core structure 1 is filled with the filling strip 2 when being stranded, part of the filling strip 2 is provided with the optical unit 3, the cable core structure 1, the filling strip 2 and the optical unit 3 are wrapped with the inner sheath 4 after being stranded, and the outer side of the inner sheath 4 is provided with the armored composite layer 5.

[0039] The armored composite layer 5 comprises a braided armored layer 51 and a polymer matrix 52, the braided armored layer 51 is braided by a plurality of armored wires, the polymer matrix 52 is coated on the braided armored layer 51 and filled in the pores of the braided armored layer 51, and the braided armored layer 51 and the polymer matrix 52 are integrally arranged.

[0040] It can be understood that the submarine cable is applied to a floating photovoltaic platform dynamic cable system of a sea and an inland lake, or is applied to a dynamic submarine cable system connecting between floating wind turbines of a floating wind farm, or is applied to a dynamic submarine cable system of offshore oil and gas, or is applied to a dynamic submarine cable system used in a wave energy power generation platform of new energy power generation, when the application water depth is shallow, the bending force borne by the submarine cable is larger, and the working condition is more severe.

[0041] The embodiment is provided with a filling strip 2 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 sector, and there is a hole in the middle of the filling strip 2 for placing the optical unit 3, and the size of the filling strip 2 matches the cable core structure 1.

[0042] The inner sheath 4 of the embodiment is wrapped outside the cabling structure of the cable core structure 1, the filling strip 2 and the optical unit 3, and provides fixed and stable support for the cable core structure 1, the filling strip 2 and the optical unit 3, and the material of the inner sheath 4 includes high-density polyethylene, medium-density polyethylene, linear low-density polyethylene or polyurethane.

[0043] Further, the armored composite layer 5 of the embodiment is composed of a braided armored layer 51 and a polymer matrix 52 wrapped on the braided armored layer 51, the braided armored layer 51 is woven by metal wires 512 or non-metal wires 512, when the submarine cable is subjected to bending force, the braided armored layer 51 can uniformly distribute stress, avoid stress concentration in a certain point to cause damage to the submarine cable, and the braided armored layer 51 can keep the shape and structure of the submarine cable when it is bent, thereby allowing the submarine cable to be safely bent at a smaller radius, thereby effectively reducing the minimum bending radius of the submarine cable, at the same time, since the braided armored layer 51 is wrapped by the polymer matrix 52, and the pores of the braided armored layer 51 are filled by the polymer matrix 52 to form a dense entity, the longitudinal water resistance and the ability to resist lateral pressure of the submarine cable are increased, and thus the submarine cable can resist ice impact in winter or at a lower temperature.

[0044] The submarine cable for ultra-shallow water provided by the application is provided with an armored composite layer 5 outside the inner sheath 4, the armored composite layer 5 includes a braided armored layer 51 and a polymer matrix 52, a plurality of armored wires are braided into the braided armored layer 51, and the polymer matrix 52 is wrapped on the braided armored layer 51 and filled in the pores of the braided armored layer 51, so that the braided armored layer 51 and the polymer matrix 52 are integrally arranged, the braided armored layer 51 can keep the shape and structure of the submarine cable when it is bent, ensure that the submarine cable will not be excessively bent or broken, allow the submarine cable to be safely bent at a smaller radius, thereby reducing the minimum bending radius of the submarine cable, and the wrapping and filling of the braided armored layer 51 by the polymer matrix 52 can form a dense entity, improve the longitudinal water resistance and the ability to resist lateral pressure, and thus realize the use requirement of the submarine cable for ultra-shallow water large deviation and good fatigue resistance.

[0045] In some embodiments, as shown in FIGS. 2 and 3, the braided armored layer 51 of the embodiment is a metal composite fiber braided armored layer.

[0046] 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.

[0047] It can be understood that, since the metal composite fiber has good low-temperature performance and can still maintain mechanical strength and ductility at low temperature, braiding the metal composite fiber into a mesh-shaped armor layer can meet the low-temperature requirement in the ice floe environment, and the metal composite fiber can also maintain high tensile strength, which helps to resist the impact of ice floes.

[0048] In some embodiments, as shown in FIG. 2, the metal composite fiber of the embodiment includes a center wire 511 and a metal wire 512, and the metal wire 512 is wound around the center wire 511.

[0049] It can be understood that, in the embodiment, the center wire 511 is made of high-strength metal material wire, and a metal wire 512 is densely wound around the center wire 511. Specifically, the material of the center 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, and the metal wire 512 is spirally and densely wound on the center wire 511 to obtain the metal composite fiber. The metal wire 512 is braided in a mesh shape relative to the center wire 511 to obtain the metal composite fiber braided armor layer.

[0050] In some embodiments, the diameter of the metal composite fiber of the embodiment is 0.1-3 mm, and the tensile strength is ≥5 kg.

[0051] It can be understood that, in the embodiment, the diameter of the center wire 511 and the metal wire 512 is 0.1-3 mm, and the tensile strength of the center wire 511 and the metal wire 512 is ≥5 kg, which ensures the small diameter and large tensile strength of the center wire 511 and the metal wire 512.

[0052] In some embodiments, the thickness of the metal composite fiber braided armor layer is 0.3-5 mm, the braiding density is ≥90%, the pitch is 50-500 mm, and the inner diameter is 20-150 mm.

[0053] It can be understood that the thickness of the metal composite fiber braided armor layer refers to the size of the protection layer formed by the armor layer outside the submarine cable, and the thickness of the embodiment is 0.3-5 mm. The braiding density refers to the coverage degree of the armor layer in unit length or unit area, and the braiding density of the 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 adjacent two layers of armored materials when the armored material is wrapped on the inner sheath 4, and the pitch of the embodiment is 50-500 mm, which ensures the mechanical protection and electrical performance of the submarine cable. The inner diameter of the armor layer of the embodiment is 20-150 mm, which is matched with the outer diameter of the inner sheath 4, so as to tightly fit the inner sheath 4 and provide uniform protection.

[0054] In some embodiments, as shown in FIG. 2, the material of the polymer matrix 52 of the embodiment includes high-density polyethylene, medium-density polyethylene or linear low-density polyethylene.

[0055] It can be understood that the polymer matrix 52 of the embodiment includes polyethylene and polyurethane with different densities, which can be extruded on the metal composite fiber braided armor layer during the processing of the submarine cable, and melted and bonded with the armor layer to form an integrated body when heated. The polymer matrix 52 is coated outside the armor layer and filled in the pores of the braided layer, so that the armor layer and the polymer matrix 52 form a compact entity.

[0056] Based on the thermoplasticity of polyethylene, polyethylene becomes soft and plastic when heated, and becomes hard after cooling, which is beneficial to the melting of the armor layer when heated, and the formation of a compact entity with the armor layer after cooling.

[0057] In some embodiments, as shown in FIG. 1, the submarine cable for ultra-shallow water of the embodiment further includes a cushion layer 6.

[0058] The cushion layer 6 is arranged between the armored composite layer 5 and the inner sheath 4.

[0059] It can be understood that the cushion layer 6 is arranged between the armored composite layer 5 and the inner sheath 4 in the embodiment, which can quickly peel off the inner sheath 4 through the cushion layer 6, and can also fix the armored composite layer 5 by using the anchor fixture on the cushion layer 6, so as to meet the demand of quickly anchoring the armored layer.

[0060] In some embodiments, as shown in FIG. 4, the cable core structure 1 of the embodiment includes a water-blocking conductor 11, an insulating layer 12, a metal shielding layer 13 and an inner protective layer 14.

[0061] The water-blocking conductor 11 is provided with a plurality of water-blocking conductors 11, and the water-blocking conductor 11, the insulating layer 12, the metal shielding layer 13 and the inner protective layer 14 are arranged from inside to outside.

[0062] It can be understood that the water-blocking conductor 11 of the embodiment is filled with a water-blocking tape or a water-blocking glue when stranded, which can meet the water-blocking requirement of 4000m water depth. The water-blocking tape adopts a two-layer water-blocking tape of the seawater type, 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.

[0063] Specifically, the number of the water-blocking conductor 11 is not less than two, which can be three or more.

[0064] In the second aspect, in some embodiments, as shown in FIG. 5, the embodiment provides a preparation method of an armored composite layer of a submarine cable for ultra-shallow water, which includes the following steps:

[0065] Step 511: extruding a polymer matrix outside the armored wire;

[0066] Step 512: tightly weaving the plurality of armored wires extruded with the polymer matrix to form a woven armored layer.

[0067] Step 513: performing heat treatment on the woven armored layer extruded with the polymer matrix to make the polymer matrix melt and bond with the woven armored layer to form an integrated body.

[0068] It can be understood that the preparation method of the armored composite layer of the embodiment includes: first, extruding a polymer matrix outside the armored wire. In some examples, after the polymer matrix is heated and melted outside the metal composite fiber through an extruder, a uniform tubular or strip-shaped covering layer is formed through a mold, which is tightly attached to the outside of the metal composite fiber. 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 at a high density using a weaving machine to form a woven armored layer. Finally, the woven armored layer extruded with the polymer matrix is subjected to heat treatment, the polymer matrix melts on the woven armored layer, and the woven armored layer is integrated into one body, and the pores of the woven armored layer are filled, so that the woven armored layer and the polymer matrix form a dense entity. 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 improve the longitudinal water-blocking capacity and lateral pressure resistance.

[0069] In some embodiments, as shown in FIG. 5, the method of performing heat treatment on the woven armored layer extruded with the polymer matrix of the embodiment includes:

[0070] The woven armored layer extruded with the polymer matrix is put into a hot oven for heat treatment.

[0071] It can be understood that the embodiment uses a hot oven to heat the braided armor layer and the polymer matrix, and because the oven can accurately control the heating temperature, the heating time and provide a uniform heat field, the braided armor layer and the polymer matrix can be stably and continuously heated in the oven, so that the effect of the dense entity formed by the polymer matrix and the braided armor layer is better.

[0072] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An undersea cable for ultra-shallow water, characterized by, It comprises: a cable core structure, a filling strip, an optical unit, an inner sheath and a armored composite layer; the cable core structure is filled with the filling strip when being twisted into a cable, part of the filling strip is provided with the optical unit, the cable core structure, the filling strip and the optical unit are wrapped with the inner sheath after being twisted into a cable, and the outer side of the inner sheath is provided with the armored composite layer; wherein the armored composite layer comprises a braided armored layer and a polymer matrix, the braided armored layer is braided by a plurality of armored wires, and the polymer matrix is coated on the braided armored layer and filled in the pores of the braided armored layer, and is integrally arranged with the braided armored layer.

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

3. The subsea cable for ultra-shallow water according to claim 2, characterized in that, The metal composite fiber comprises a center wire and a metal wire, and the metal wire is wound on the center wire.

4. The subsea cable for ultra-shallow water according to claim 3, characterized by, The material of the center wire comprises aramid, nylon, carbon fiber, titanium alloy, copper wire, aluminum alloy wire or stainless steel wire; the material of the metal wire comprises pure copper wire, tin-plated copper wire, aluminum alloy wire, stainless steel wire or titanium alloy wire.

5. The subsea cable for ultra-shallow water according to claim 2, characterized by, The diameter of the metal composite fiber is 0.1-3mm, and the tensile strength is greater than or equal to 5kg. And / or, the thickness of the metal composite fiber braided armored layer is 0.3-5mm, the braiding density is greater than or equal to 90%, the pitch is 50-500mm, and the inner diameter is 20-150mm.

6. The subsea cable for ultra-shallow water according to claim 1, characterized by The material of the polymer matrix comprises high-density polyethylene, medium-density polyethylene or linear low-density polyethylene.

7. The subsea cable for ultra-shallow water according to claim 1, characterized by It also comprises: a cushion layer; the cushion layer is arranged between the armored composite layer and the inner sheath.

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

9. A method of manufacturing the armour composite layer of a submarine cable for ultra-shallow water according to any one of claims 1 to 8, characterized in that, It comprises: extruding a polymer matrix outside the armored wire; tightly braiding a plurality of armored wires extruded with the polymer matrix to form a braided armored layer; heating treatment is performed on the braided armored layer extruded with the polymer matrix to make the polymer matrix melt and bond with the braided armored layer to form an integral whole.

10. The method of claim 9, wherein the armor composite layer is prepared by, The method for heating treatment of the braided armored layer extruded with the polymer matrix comprises: passing the braided armored layer extruded with the polymer matrix into a hot oven for heating treatment.

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