Crosslinked polyethylene insulated submarine power cable

Abstract

The invention discloses a crosslinked polyethylene insulated submarine power cable, which relates to the technical field of submarine power cables, is used for carrying out power transmission in a deep seabed, and comprises a cable body, and the cable body sequentially comprises an insulated outer protective layer, a tensile layer, an anti-corrosion layer, a steel tape armoring layer and an insulating layer from outside to inside, the interior of the insulating layer is formed by mutually winding a plurality of groups of conductor insulating shielding layers, the interior of the conductor insulating layer is formed by mutually winding a plurality of groups of conductor shielding layers, and a conductor water-blocking layer is arranged between the conductor insulating shielding layers and the conductor shielding layers; the conductor shielding layer is composed of a first conductor, a semiconductor water-blocking tape and a second conductor in sequence from outside to inside, and the cable solves the problems that when the cable is used in the seabed for a long time, the cable sheath is damaged due to long-term seawater corrosion, high-pressure seawater is diffused in the longitudinal direction through gaps existing in the cable, the long-distance cable is damaged, and the service life of the cable is prolonged. Therefore, the problem that the power cable is damaged and cannot transmit power is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine power cables, and more specifically to a cross-linked polyethylene insulated submarine power cable. Background Art

[0002] A submarine power cable is a power transmission line specifically designed and laid on the seabed for transmitting power from one place to another, usually across the ocean or connecting offshore energy projects to the onshore power grid. Its main function is to achieve long-distance transmission of energy, especially in cases where connection through the onshore power grid is not possible, to provide power supply. Submarine power cables are installed on the seabed with a complex environment and are long-term affected by wave impacts, seawater corrosion, and many unknown factors. Their design, manufacturing, and installation requirements are much higher than those of ordinary cables. Moreover, the water-blocking effect of submarine power cables largely determines their service life.

[0003] Currently, submarine power cables mainly use sheaths such as lead sheaths that play a water-blocking role to achieve radial water-blocking. Although this method can effectively solve the problem of radial water leakage, due to the high-pressure environment on the seabed, the cable is in a long-term stressed state, and this sheath may be damaged by long-term seawater corrosion. Water will diffuse longitudinally along the gaps existing in the cable, resulting in damage to a relatively long section of the submarine cable and rendering it unusable. For this reason, water-blocking powder and water-blocking yarn are proposed to achieve longitudinal water-blocking. However, during the processing of power cables, it is difficult to ensure uniform distribution of the water-blocking powder, thereby reducing the longitudinal water-blocking effect of the power cable. The water-blocking yarn is usually wound between the conductor stranding layers at a certain pitch to form a discontinuous "water block" structure, and its swelling area is distributed in a point-like manner, unable to form a complete longitudinal seal, resulting in high-pressure water flow still being able to penetrate through the uncovered gaps, thereby reducing the water-blocking effect of the submarine power cable and further leading to the situation where the submarine power cable is damaged and unable to be used.

[0004] In view of the above situation, the present invention designs a cross-linked polyethylene insulated submarine power cable to solve the above technical problems. Summary of the Invention

[0005] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide a cross-linked polyethylene insulated submarine power cable, which solves the problem that when the cable is used on the seabed for a long time, due to long-term damage of the cable sheath by seawater corrosion, high-pressure seawater diffuses longitudinally along the gaps existing in the cable, resulting in damage to a long-distance cable, and thus the power cable is damaged and unable to transmit power.

[0006] To achieve the above object, the present invention provides the following technical solution: A cross-linked polyethylene insulated submarine power cable for power transmission in deep sea bottoms, comprising a cable body, which from outside to inside successively includes an insulating outer sheath, a tensile resistance layer, an anti-corrosion layer, a steel tape armor layer and an insulating layer. The inside of the insulating layer is composed of multiple groups of conductor insulation shielding layers wound around each other. The inside of the conductor insulation layer is composed of multiple groups of conductor shielding layers wound around each other. And a conductor water-blocking layer is provided between the conductor insulation shielding layer and the conductor shielding layer. The conductor shielding layer is composed of a first conductor, a semiconductor water-blocking tape and a second conductor from outside to inside.

[0007] Preferably, the material of the insulating outer sheath is cross-linked polyethylene

[0008] Preferably, the tensile resistance layer includes buffer pads, compressive steel tapes and water-blocking powder. A plurality of buffer pads are annularly arranged between the insulating outer sheath and the anti-corrosion layer, and compressive steel tapes are arranged between adjacent buffer pads. The gap between the buffer pads and the compressive steel tapes is filled with water-blocking powder, and the buffer pads and the compressive steel tapes are arranged in a spiral shape.

[0009] Preferably, a plurality of buffer holes are provided on each of the buffer pads, and the buffer holes are located at the center of the buffer pads.

[0010] Preferably, the steel tape armor layer includes steel tapes and steel wires. The steel tapes are annularly arranged between the anti-corrosion layer and the insulating layer, and the steel tapes are arranged in a spiral shape. Steel wires for tensile resistance are provided between the steel tapes and the insulating layer.

[0011] Preferably, after the steel wires are wound, they form a tensile-resistant cylindrical mesh structure. The shape of the mesh holes is a hexagon that increases the moment of inertia to improve the tensile strength. A water-blocking tape is wound outside the hexagonal mesh holes, and water-blocking powder is filled inside the hexagonal mesh holes.

[0012] Preferably, a plurality of fillers are wound along with the conductor insulation shielding layer inside the insulating layer, and the fillers are used to improve the tensile strength of the conductor insulation shielding layer.

[0013] Preferably, a large amount of water-blocking powder is filled in the gap between the conductor insulation shielding layer and the conductor shielding layer, and a plurality of wound conductor insulation shielding layers are fixed by steel tapes.

[0014] The beneficial effects of the present invention:

[0015] A cross-linked polyethylene insulated submarine power cable provided by the present invention uses cross-linked polyethylene material as the insulating outer layer of the cable body. The three-dimensional network structure formed by the molecular cross-linking of the cross-linked polyethylene material significantly improves the hardness, impact resistance and wear resistance, thereby reducing the phenomenon of damage to the cable body caused by the high water pressure in the submarine environment, and further reducing the risk of damage to the cable due to external forces. The anti-tensile layer can reduce the damage to the cable caused by the water pressure, and the buffer holes provided on the buffer pad can reduce the damage to the cable caused by the water pressure. At the same time, the water blocking powder between the buffer pad and the compression steel strip can prevent seawater from entering the cable through the insulating outer layer and causing a short circuit in the cable. At the same time, through the setting of the steel strip armor layer, the mesh shape is a hexagon that increases the moment of inertia and improves the anti-tensile strength, improving the deformation effect of the steel wire and realizing the rapid return of the steel wire. When the steel wire is deformed, the tensile strength is increased, and then the steel wire is used to assist the steel strip to improve the anti-tensile effect of the anti-tensile layer, thereby avoiding cracks in the cable caused by the high pressure in the submarine and seawater entering the cable, and further causing damage to the power cable and inability to transmit power. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall structure of the cable body of the present invention;

[0017] Figure 2 is a right view of the overall structure of the cable body of the present invention;

[0018] Figure 3 For the present invention Figure 2 is a partial enlarged view of part A;

[0019] Figure 4 is a schematic diagram of the overall structure of the steel strip armor layer of the cable body of the present invention;

[0020] Figure 5 For the present invention Figure 4 is a partial enlarged view of part B;

[0021] Figure 6 is a schematic diagram of the overall structure of the insulation layer and the conductor insulation shielding layer of the present invention in cooperation;

[0022] Figure 7 is an end view of the overall structure of the insulation layer and the conductor insulation shielding layer of the present invention in cooperation;

[0023] Figure 8 For the present invention Figure 7 is a partial enlarged view of part C.

[0024] Reference numerals:

[0025] 1. Cable body; 11. Insulating outer sheath; 12. Anti-tensile layer; 121. Buffer pad; 122. Buffer hole; 123. Compressive steel strip; 124. Water-blocking powder; 13. Anticorrosive layer; 14. Steel tape armor layer; 141. Steel tape; 142. Steel wire; 15. Insulating layer; 151. Filler; 16. Conductor insulation shielding layer; 17. Conductor water-blocking layer; 18. Conductor shielding layer; 19. First conductor; 101. Semiconductor water-blocking tape; 102. Second conductor; Detailed implementation manner

[0026] In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0027] Refer to Figures 1 to 8 As shown, a cross-linked polyethylene insulated submarine power cable for power transmission in deep sea bottoms includes a cable body 1. The cable body 1 sequentially includes an insulating outer sheath 11, an anti-tensile layer 12, an anticorrosive layer 13, a steel tape armor layer 14, and an insulating layer 15 from outside to inside. The inside of the insulating layer 15 is composed of multiple groups of conductor insulation shielding layers 16 wound around each other. The inside of the conductor insulating layer 15 is composed of multiple groups of conductor shielding layers 18 wound around each other. A conductor water-blocking layer 17 is provided between the conductor insulation shielding layer 16 and the conductor shielding layer 18. The conductor shielding layer 18 is composed of a first conductor 19, a semiconductor water-blocking tape 101, and a second conductor 102 from outside to inside.

[0028] Specifically, the material of the insulating outer sheath 11 is cross-linked polyethylene

[0029] Specifically, the anti-tensile layer 12 includes buffer pads 121, compressive steel strips 123, and water-blocking powder 124. A plurality of buffer pads 121 are annularly arranged between the insulating outer sheath 11 and the anticorrosive layer 13, and compressive steel strips 123 are arranged between adjacent buffer pads 121. The gap between the buffer pads 121 and the compressive steel strips 123 is filled with water-blocking powder 124. The buffer pads 121 and the compressive steel strips 123 are arranged in a spiral shape.

[0030] Specifically, buffer holes 122 are formed in each of the plurality of buffer pads 121, and the buffer holes 122 are located at the center of the buffer pads 121.

[0031] When the cable sinks to the bottom of the sea, the sea water pressure will impact the insulating outer sheath 11 of the cable. At this time, the insulating outer sheath 11 is concave inward. The design of the buffer hole 122 on the buffer pad 121 can prevent high pressure from directly acting on the conductor, and the spirally distributed tensile steel belt can make the tensile force evenly distributed along the axial direction of the tensile steel belt, avoiding local excessive stress and causing material breakage, especially reducing the risk of deformation under dynamic load or large-span laying scenarios. At the same time, the spirally wound compressive steel belt absorbs energy through deformation, and cooperates with the elastic deformation of the buffer pad 121 to significantly improve the overall tensile strength of the cable.

[0032] Specifically, the steel belt armor layer 14 includes steel belts 141 and steel wires 142. The steel belts 141 are arranged in an annular array between the anti-corrosion layer 13 and the insulating layer 15, and the steel belts 141 are arranged in a spiral shape. The steel wires 142 for resisting tensile strength are arranged between the steel belts 141 and the insulating layer 15.

[0033] Specifically, the steel wire 142 is wound to form a tensile-resistant cylindrical mesh structure, the mesh shape is a hexagon that increases the moment of inertia and improves tensile strength, a water-blocking tape is wound around the outside of the hexagonal mesh, and the inside of the hexagonal mesh is filled with water-blocking powder 124.

[0034] The hexagonal mesh increases the cross-sectional moment of inertia through geometric design, so that the steel wire 142 mesh tube produces a more uniform stress distribution when subjected to axial force, reducing the risk of local fracture. The outer water-blocking tape forms a physical barrier through high-density winding to block external moisture penetration; the water-blocking powder 124 filled inside can quickly close the hexagonal mesh pores after swelling when in contact with water, forming double water-blocking protection. The water-blocking powder 124 adopts a composite formula of super absorbent resin and silicate, which can maintain stable expansion performance in long-term immersion or humid environment, thereby avoiding the failure of traditional water-blocking materials due to hydrolysis.

[0035] Specifically, a plurality of fillers 151 are arranged inside the insulating layer 15 along with the conductor insulating shielding layer 16 . The fillers 151 are used to improve the tensile strength of the conductor insulating shielding layer 16 .

[0036] Specifically, a large amount of water-blocking powder 124 is filled in the gap between the conductor insulation shielding layer 16 and the conductor insulation shielding layer 18, and a plurality of wound conductor insulation shielding layers 16 are fixed with steel belts. The water-blocking powder 124 rapidly expands upon contact with water to form a gel-like substance, which can seal the micron-level air gap between the conductor insulation shielding layer 18 and the conductor insulation shielding layer 16, and block the channel for moisture to penetrate along the longitudinal gap.

[0037] The above embodiments are only exemplary embodiments of the present invention and are not used to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be regarded as falling within the protection scope of the present invention.

Claims

1. A cross-linked polyethylene insulated submarine power cable for power transmission in deep sea bottoms, comprising a cable body (1), characterized in that, The cable body (1) sequentially includes an insulating outer sheath (11), a tensile resistance layer (12), an anti-corrosion layer (13), a steel strip armor layer (14), and an insulating layer (15) from outside to inside. The inside of the insulating layer (15) is composed of multiple groups of conductor insulation shielding layers (16) wound around each other. The inside of the conductor insulating layer (15) is composed of multiple groups of conductor shielding layers (18) wound around each other. A conductor water-blocking layer (17) is arranged between the conductor insulation shielding layer (16) and the conductor shielding layer (18). The conductor shielding layer (18) is composed of a first conductor (19), a semiconductive water-blocking tape (101), and a second conductor (102) from outside to inside.

2. The cross-linked polyethylene insulated submarine power cable according to claim 1, characterized in that: The material of the insulating outer sheath (11) is cross-linked polyethylene.

3. The cross-linked polyethylene insulated submarine power cable according to claim 1, characterized in that: The tensile resistance layer (12) includes buffer pads (121), compressive steel strips (123), and water-blocking powder (124). A plurality of buffer pads (121) are annularly arranged between the insulating outer sheath (11) and the anti-corrosion layer (13), and compressive steel strips (123) are arranged between adjacent buffer pads (121). The gap between the buffer pads (121) and the compressive steel strips (123) is filled with water-blocking powder (124). The buffer pads (121) and the compressive steel strips (123) are arranged in a spiral shape.

4. A cross-linked polyethylene insulated submarine power cable according to claim 3, characterized in that: A plurality of buffer holes (122) are formed in each of the buffer pads (121), and the buffer holes (122) are located at the central position of the buffer pads (121).

5. A crosslinked polyethylene insulated submarine power cable according to claim 1, characterized in that: The steel strip armor layer (14) includes steel strips (141) and steel wires (142). The steel strips (141) are annularly arranged between the anti-corrosion layer (13) and the insulating layer (15), and the steel strips (141) are arranged in a spiral shape. Steel wires (142) for tensile resistance are arranged between the steel strips (141) and the insulating layer (15).

6. The cross-linked polyethylene insulated submarine power cable according to claim 5, characterized in that: After being wound, the steel wires (142) form a tensile-resistant cylindrical mesh structure. The shape of the mesh is a hexagon that increases the moment of inertia to improve the tensile strength. A water-blocking tape is wound outside the hexagonal mesh, and water-blocking powder (124) is filled inside the hexagonal mesh.

7. A cross-linked polyethylene insulated submarine power cable according to claim 1, characterized in that: A plurality of fillers (151) are arranged inside the insulating layer (15) along with the winding of the conductor insulation shielding layer (16). The fillers (151) are used to improve the tensile strength of the conductor insulation shielding layer (16).

8. A crosslinked polyethylene insulated submarine power cable according to claim 1, characterized in that: A large amount of water-blocking powder (124) is filled in the gap between the conductor insulation shielding layer (16) and the conductor shielding layer (18), and the plurality of wound conductor insulation shielding layers (16) are fixed by steel strips (141).

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