Submarine cable and fixing device for submarine cable

Abstract

The present invention relates to the technical field of cables, and provides a submarine cable and a fixing device for the submarine cable. The submarine cable comprises a plurality of conductive units; each conductive unit comprises a conductor layer, a conductor shielding layer, an insulating layer, an insulating shielding layer, a first wrapping layer, a shielding layer, and a second wrapping layer which are sequentially wrapped from inside to outside; the conductor layer is formed by twisting a plurality of conductors; gaps between the plurality of conductors are filled with a semi-conductive water blocking adhesive; and semi-conductive wrapped tapes are wrapped outside the plurality of conductors. In the submarine cable, gaps between the conductors are filled with a semi-conductive water blocking adhesive, and the plurality of conductors are pressed when being twisted, so that the outer diameter of the submarine cable is reduced while the self-weight of the submarine cable is increased, and the effect of improving the stability of the submarine cable can be achieved without additionally providing counterweight blocks or without increasing the thickness of the structure of each layer, thereby simplifying the production process and reducing the manufacturing cost.

Description

Submarine cables and their fixing devices

[0001] This application claims priority to Chinese Patent Application No. 202410784063.4, filed on June 17, 2024, entitled "Submarine Cable and Fixing Device for Submarine Cable", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of cable technology, and more particularly to a submarine cable and a fixing device for the submarine cable. Background Technology

[0003] The environment for laying submarine cables is complex and diverse. The most common laying methods on the seabed are laying them directly on the seabed surface or burying them in the soil. The main purpose of burying them is to avoid displacement of the submarine cables by waves and ocean currents, as continuous displacement can cause mechanical damage to the cables.

[0004] Laying submarine cables requires specialized equipment, has a long laying period, and may also have an impact on the seabed environment. In addition, the seabed environment in many areas does not support trenching, so in some cases the only option is to lay them directly on the seabed.

[0005] Commonly used long-length submarine cables are static submarine cables, with their armor layers directly immersed in water and not torque-balanced, making them unsuitable for dynamic environments. Therefore, if laid directly on the seabed, cable stability must be guaranteed. Stability analysis reveals that some submarine cables struggle to achieve stability when facing significant ocean currents. In cases where burial is not feasible, two common solutions are used to ensure cable stability: one is to add counterweights or rocks to weigh down unstable sections of the cable; the other is to increase the thickness of each layer in the conventional cable design, or use double armor to increase the weight. Both methods undoubtedly increase the overall project cost. Summary of the Invention

[0006] This invention provides a submarine cable and a fixing device for the submarine cable, which solves the problem that the manufacturing cost increases in the prior art in order to ensure the stability of the submarine cable.

[0007] The present invention provides a submarine cable comprising multiple conductive units. Each conductive unit comprises, from the inside out, a conductor layer, a conductor shielding layer, an insulation layer, an insulation shielding layer, a first wrapping layer, a shielding layer, and a second wrapping layer. The conductor layer is formed by stranding multiple conductors, the gaps between the multiple conductors are filled with semiconducting resistive adhesive, and the multiple conductors are wrapped with semiconducting tape.

[0008] According to the present invention, when multiple conductors are stranded together, the compression factor is greater than or equal to 0.95.

[0009] According to the present invention, a submarine cable is provided in which the first wrapping layer and the second wrapping layer are semiconducting resistive water hoses.

[0010] According to the present invention, the shielding layer of a submarine cable is a flat metal wire shielding layer.

[0011] According to a submarine cable provided by the present invention, the submarine cable further includes an optical fiber unit, which is twisted together with a plurality of conductive units to form a cable; the optical fiber unit includes a stainless steel tube, a first armor layer and an outer sheath layer, which are sequentially wrapped from the inside to the outside.

[0012] According to a submarine cable provided by the present invention, the submarine cable further includes a filling layer, a second armor layer and an outer sheath layer that are sequentially wrapped from the inside to the outside, wherein the filling layer covers the outside of the cable.

[0013] According to the present invention, the filling layer of a submarine cable is a solid filling layer, and the filling coefficient of the filling layer is greater than or equal to 95%.

[0014] According to the present invention, in a submarine cable, the second armor layer is a flat metal wire armor layer.

[0015] The present invention also provides a fixing device for a submarine cable, including a fixing bracket and the submarine cable as described above; the fixing bracket includes a fixing component and a plurality of legs, the fixing component is used to fix the submarine cable, the plurality of legs are connected to the fixing component, and each leg is inclined to the horizontal plane.

[0016] According to the present invention, a fixing device for a submarine cable includes a pair of clamps and a connector, wherein the first ends of the pair of clamps are rotatably connected, and the second ends of the pair of clamps are connected through the connector.

[0017] The submarine cable provided by this invention increases the weight of the submarine cable while reducing its outer diameter by filling the gaps between the conductors with semiconducting resistive water adhesive and compressing the multiple conductors when they are twisted together. This achieves the effect of improving the stability of the submarine cable without the need to add counterweights or increase the thickness of each layer of the structure, thus simplifying the production process and reducing manufacturing costs. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the structure of the submarine cable provided by the present invention;

[0019] Figure 2 is one of the structural schematic diagrams of the submarine cable fixing device provided by the present invention;

[0020] Figure 3 is a second schematic diagram of the structure of the fixing device for submarine cables provided by the present invention;

[0021] Figure 4 is one of the schematic diagrams of the fixing device for the submarine cable provided by the present invention located on the seabed soil;

[0022] Figure 5 is a second schematic diagram of the fixing device for the submarine cable provided by the present invention located on the seabed soil.

[0023] Explanation of reference numerals in the attached drawings: 10-Conductor layer; 11-Conductor shielding layer; 12-Insulation layer; 13-Insulation shielding layer; 14-First wrapping layer; 15-Shielding layer; 16-Second wrapping layer; 20-Fiber optic unit; 30-Filling layer; 40-Second armor layer; 50-Outer sheath layer; 100-Submarine cable; 200-Fixing bracket; 201-Clamp; 202-Connector; 203-Leg; 2011-Nut. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] The terms "first" and "second" in the specification and claims of this invention may explicitly or implicitly include one or more of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] The submarine cable and its fixing device of the present invention are described below with reference to Figures 1-5.

[0029] As shown in Figure 1, in an embodiment of the present invention, the submarine cable 100 includes multiple conductive units. Each conductive unit includes, from the inside out, a conductor layer 10, a conductor shielding layer 11, an insulation layer 12, an insulation shielding layer 13, a first wrapping layer 14, a shielding layer 15, and a second wrapping layer 16. The conductor layer 10 is formed by stranding multiple conductors, with the gaps between the conductors filled with semiconducting resistive adhesive, and the conductors are wrapped with semiconducting tape.

[0030] Specifically, in this embodiment, the conductor can be a copper conductor or a copper alloy conductor, and the number of conductors is three. When the three conductors are stranded, each layer is tightly compressed, with a compression factor greater than or equal to 0.95. In this embodiment, the compression factor refers to the ratio of the actual cross-sectional area of ​​the stranded wire to the circular area calculated based on the outer diameter of the stranded wire. The pitch of each layer is controlled at 8-10 times the outer diameter. The gaps between the conductors are filled with semi-conductive resistive adhesive with a density of 1.2 g / cm³. A layer of semi-conductive PBT tape is wrapped around the outside of the conductor to secure it, forming the cable core.

[0031] The submarine cable provided in this invention increases the weight of the submarine cable while reducing its outer diameter by filling the gaps between the conductors with semiconducting resistive water adhesive and compressing the multiple conductors when they are twisted together. This achieves the effect of improving the stability of the submarine cable without the need to add counterweights or increase the thickness of each layer of the structure, thus simplifying the production process and reducing manufacturing costs.

[0032] Furthermore, a semi-conductive shielding material is extruded onto the outside of the cable core to form a conductor shielding layer 11. In this embodiment, the thickness of the conductor shielding layer 11 is based on the standard of insulation without indentation. Considering the minimum thickness design, for submarine cables 100 below 66kV, a nominal thickness of 0.6mm can be designed.

[0033] An insulating layer 12 is formed by extruding cross-linked polyethylene material on the outside of the conductor shielding layer 11. The thickness of the insulating layer 12 is designed to be thin insulation based on the maximum field strength verified by type testing for the corresponding voltage level.

[0034] An insulating shielding layer 13 is extruded onto the outside of the insulating layer 12. In this embodiment, the material of the insulating shielding layer 13 is a semi-conductive shielding material, and the thickness of the insulating shielding layer 13 is the thickness of the conductor shielding layer 11 minus 0.2 mm.

[0035] The first wrapping layer 14 and the second wrapping layer 16 are semiconducting resistive water tapes. The first wrapping layer 14 is wrapped around the outside of the insulating shielding layer 13, and the second wrapping layer 16 is wrapped around the outside of the shielding layer 15.

[0036] The shielding layer 15 uses a flat metal wire shielding layer, such as flat copper wire. Copper wire, as the shielding layer 15, has high conductivity and can be designed with a smaller thickness. The flat copper wire should cover the surface of the first wrapping layer 14 as completely as possible; therefore, the width, thickness, and number of flat copper wires need to be designed based on the short-circuit current requirements of the cable system. To meet the same short-circuit current requirements, the thickness of flat copper wire is only half that of round copper wire, and compared to other metal wires, it is thinner, which can effectively reduce the overall outer diameter of the submarine cable.

[0037] The submarine cable provided in this embodiment of the invention reduces the outer diameter of the submarine cable by setting the shielding layer as a flat metal wire shielding layer, which is thinner than a conventional shielding layer.

[0038] As shown in Figure 1, in an embodiment of the present invention, the submarine cable 100 further includes an optical fiber unit 20, which is twisted together with multiple conductive units to form a cable. The optical fiber unit 20 includes a stainless steel tube, a first armor layer, and an outer sheath layer, which are sequentially wrapped from the inside to the outside.

[0039] As shown in Figure 1, in an embodiment of the present invention, the submarine cable 100 further includes a filling layer 30, a second armor layer 40 and an outer sheath layer 50, which are sequentially wrapped from the inside to the outside, with the filling layer 30 covering the outside of the cable.

[0040] In this embodiment, the filler layer 30 is a solid filler layer made of polyvinyl chloride (PVC). It is produced using an extrusion die, achieving a fill factor greater than or equal to 95%, and a fill density significantly higher than that of conventional filler strips or ropes. The density of PVC is 1.3-1.45 g / cm³, which does not cause increased buoyancy or reduced weight in water. Furthermore, the filler layer 30 can additionally serve as a protective layer for the phase-separated cable core and an inner padding layer for conventional cable armor. While increasing overall weight, the increase in outer diameter is minimized. Compared to the conventional structure of a phase-separated sheath layer + filler layer + inner padding layer, this design results in lower material and manufacturing costs and simplifies the production process.

[0041] The second armor layer 40 uses a flat metal wire armor layer. Compared with conventional round metal wire, the flat metal wire has a higher filling degree of the armor layer. Under the same tension requirements, the thickness of the flat metal wire is only half that of the round metal wire, which can effectively reduce the overall outer diameter of the submarine cable 100.

[0042] The outer sheath 50 is composed of two layers of polypropylene fiber rope directly wrapped around the second armor layer 40, serving as an armor protection layer.

[0043] The submarine cable provided in this embodiment of the invention improves each structural layer of the submarine cable, increasing the proportion of each layer and thus increasing the self-weight of the submarine cable, while reducing the outer diameter of the submarine cable. Under installation conditions where burial is not permitted, the submarine cable can achieve a self-stabilizing state, reducing fatigue and mechanical damage to the submarine cable and extending its service life.

[0044] As shown in Figure 2, this embodiment of the invention also provides a fixing device for a submarine cable, including a submarine cable 100 and a fixing bracket 200. The fixing bracket 200 includes a fixing component and a plurality of legs 203. The fixing component is used to fix the submarine cable 100, and the plurality of legs 203 are connected to the fixing component, with each leg 203 being inclined to the horizontal plane.

[0045] Specifically, to further improve the stability of the submarine cable 100, this embodiment of the invention also provides a fixing device. As shown in Figure 4, during the actual installation process, when the submarine cable 100 reaches an unstable or extreme location area as determined by the route survey, the unstable section or extreme location of the submarine cable 100 is fixed within the fixing bracket 200. To improve the stability of the submarine cable 100, a fixing bracket 200 can be set at regular intervals. The submarine cable 100 and the fixing bracket 200 are constructed together to the seabed surface, and the position is adjusted by an underwater robot according to the actual seabed conditions. When the submarine cable 100 and the fixing bracket 200 reach the seabed surface, as shown in Figure 5, the ocean currents and the movement of the seabed soil will bury the support leg 203, thereby fixing the fixing bracket 200 in the soil and ensuring the stability of the submarine cable 100. Furthermore, due to the large surface area of ​​the support leg 203, marine organisms will gradually attach to the support leg 203 over time, which will further improve the stability of the fixed support 200, thereby further improving the stability of the submarine cable 100.

[0046] In this embodiment, each support leg 203 is inclined to the horizontal plane, thereby enabling the support leg 203 to support the fixing component. In this embodiment, there are two pairs of support legs 203, with the two support legs 203 in each pair arranged symmetrically, thus forming a stable structure with four support legs 203. Optionally, in an embodiment of the present invention, the angle between the support leg 203 and the horizontal plane is 30°, and each support leg 203 has a length of 500 mm and a thickness of 15 mm.

[0047] The submarine cable fixing device provided in this embodiment of the invention increases the stability of the submarine cable by setting a fixing bracket. The fixing bracket is easy to install, and compared with the previous construction method, it has low manufacturing cost, simple construction method, shortens the construction cycle, and also reduces construction cost.

[0048] As shown in Figures 2 and 3, in an embodiment of the present invention, the fixing component includes a pair of clamps 201 and a connector 202. The first ends of the pair of clamps 201 are rotatably connected, and the second ends of the pair of clamps 201 are connected through the connector 202.

[0049] Specifically, each clamp 201 is a semi-circular clamp. When two clamps 201 are connected, the diameter of the cavity they form is slightly larger than the outer diameter of the submarine cable 100. One end of the two clamps 201 is connected by a pivot, allowing the two clamps 201 to rotate relative to each other, so that the submarine cable 100 can be placed in the cavity. The second end of each clamp 201 is provided with a nut 2011, and the connector 202 passes through a pair of nuts 2011 to connect the pair of clamps 201.

[0050] Optionally, in an embodiment of the present invention, the connector 202 is a bolt.

[0051] Optionally, in an embodiment of the present invention, the diameter of the cavity is approximately 10 mm larger than the diameter of the submarine cable 100, and the thickness of the clamp 201 is 15 mm.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A submarine cable, characterized in that, It includes multiple conductive units, each of which includes, from the inside out, a conductor layer, a conductor shielding layer, an insulating layer, an insulating shielding layer, a first wrapping layer, a shielding layer, and a second wrapping layer. The conductor layer is made of multiple conductors twisted together, with the gaps between the conductors filled with semiconducting resistive adhesive, and the conductors wrapped with semiconducting tape.

2. The submarine cable according to claim 1, characterized in that, When multiple conductors are stranded together, their compression factor is greater than or equal to 0.

95.

3. The submarine cable according to claim 1, characterized in that, The first wrapping layer and the second wrapping layer are semiconducting resistive water tapes.

4. The submarine cable according to claim 1, characterized in that, The shielding layer is a flat metal wire shielding layer.

5. The submarine cable according to claim 1, characterized in that, The submarine cable also includes an optical fiber unit, which is twisted together with a plurality of conductive units to form a cable; The optical fiber unit comprises, from the inside out, a stainless steel tube, a first armor layer, and an outer sheath layer.

6. The submarine cable according to claim 5, characterized in that, The submarine cable also includes a filling layer, a second armor layer and an outer sheath layer, which are wrapped from the inside out, with the filling layer covering the outside of the cable.

7. The submarine cable according to claim 6, characterized in that, The filling layer is a solid filling layer, and the filling factor of the filling layer is greater than or equal to 95%.

8. The submarine cable according to claim 6, characterized in that, The second armor layer is a flat metal wire armor layer.

9. A fixing device for a submarine cable, characterized in that, Includes a fixed support and the submarine cable according to any one of claims 1-8; The fixing bracket includes a fixing component and multiple legs. The fixing component is used to fix the submarine cable, and the multiple legs are connected to the fixing component. Each leg is inclined to the horizontal plane.

10. The fixing device for submarine cables according to claim 9, characterized in that, The fixing component includes a pair of clamps and a connector, with the first ends of the pair of clamps rotatably connected and the second ends of the pair of clamps connected through the connector.

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