Direct-current high-voltage submarine cable capable of preventing seawater corrosion

Abstract

The utility model discloses a direct-current high-voltage submarine cable capable of preventing seawater corrosion. Comprising an inner conductor, an EVA water-blocking bonding layer, a double-layer polyethylene longitudinally-wrapped water-blocking inner isolating layer, an HDPE inner semi-conductive shielding layer, an irradiation crosslinking low-density polyethylene insulating layer, an HDPE outer semi-conductive shielding layer, a double-layer polyethylene longitudinally-wrapped water-blocking middle isolating layer, an extruded lead sleeve anticorrosive layer, a double-layer polyethylene longitudinally-wrapped water-blocking outer isolating layer, a polyvinyl chloride liner layer and a galvanized steel wire armor layer. The diameter of the inner conductor ranges from 26 mm to 48 mm, and the outer diameter of the polyvinyl chloride outer sheath ranges from 110 mm to 142 mm. The submarine cable is suitable for being used for transmitting electric power to islands and oil platforms along banks, resists mechanical external force, has excellent performance of preventing seawater erosion and seawater corrosion, and is better in durability.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a seawater corrosion-resistant DC high-voltage submarine cable. Background Art

[0002] With the continuous improvement of technologies related to power transmission systems, cross-linked polyethylene power cables are being adopted by more and more distribution systems due to their excellent performance, simple and easy manufacturing and safety processes, and other excellent features. Cross-linked polyethylene power cables have advantages in electrical and mechanical parameters that other types of power cable products cannot match in dry environments. However, in the application of submarine cables, such as power transmission to coastal islands and oil platforms, cross-linked polyethylene power cables are required to not only have mechanical force resistance, but also have the performance of anti-seawater erosion and anti-seawater corrosion. Ordinary cross-linked polyethylene power cables cannot meet the complex environmental requirements of power transmission in the above application areas. Utility Model Content

[0003] The utility model aims to solve the technical problem of providing a seawater corrosion-resistant DC high-voltage submarine cable, which is suitable for transmitting electricity to coastal islands and oil platforms, is resistant to mechanical external forces, has excellent seawater erosion and seawater corrosion resistance, and has better durability.

[0004] The utility model solves the above technical problems through the following technical solutions.

[0005] The invention discloses a seawater corrosion resistant DC high-voltage submarine cable, comprising an inner conductor and an EVA water-blocking adhesive layer, a double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer, a HDPE inner semi-conductive shielding layer, an irradiated cross-linked low-density polyethylene insulation layer, an HDPE outer semi-conductive shielding layer, a double-layer polyethylene longitudinally wrapped water-blocking middle isolation layer, an extruded lead sheath anti-corrosion layer, a double-layer polyethylene longitudinally wrapped water-blocking outer isolation layer, a polyvinyl chloride lining layer, a galvanized steel wire armor layer, a nylon wire torsion-resistant winding layer and a polyvinyl chloride outer sheath, which are sequentially coated on the outside of the inner conductor. The inner, middle and outer isolation layers of the double-layer polyethylene longitudinally wrapped water-blocking are all longitudinally overlapped and wrapped structures of double-layer polyethylene water-blocking tapes with an overlap rate of not less than 40%. The double-layer polyethylene water-blocking tapes are formed by co-extrusion of an MDPE water-blocking inner layer and an LDPE water-blocking outer layer. The diameter of the inner conductor is 26 mm to 48 mm, and the outer diameter of the polyvinyl chloride outer sheath is 110 mm to 142 mm.

[0006] Preferably, the inner conductor is composed of a plurality of tinned copper strands twisted around a stainless steel monofilament central reinforcement wire, the tinned copper strands are composed of a plurality of tinned copper monofilaments twisted in bundles, and the twisting direction of the tinned copper strands is opposite to that of the tinned copper monofilaments.

[0007] Preferably, the diameter of the tinned copper monofilament is 0.1 mm to 0.5 mm.

[0008] Preferably, the lay length of the tinned copper strands is 10 to 30 times the outer diameter of the tinned copper strands.

[0009] Preferably, the thickness of the extruded lead sheath anti-corrosion layer is 2.9 mm, 3 mm or 3.1 mm.

[0010] Preferably, the thickness of the radiation cross-linked low-density polyethylene insulation layer is 23 mm or 24 mm.

[0011] Preferably, the nylon wire anti-twist wrapping layer is composed of inner and outer double layers of nylon wires that are spirally wound and braided in opposite directions.

[0012] Preferably, the thickness ratio of the MDPE water-blocking inner layer to the LDPE water-blocking outer layer is 1:10 to 1:12.

[0013] Preferably, the thickness of the inner, middle and outer isolation layers of the double-layer polyethylene longitudinal water-blocking package is not less than 1 mm.

[0014] Preferably, the thickness of the HDPE inner semi-conductive shielding layer and the HDPE outer semi-conductive shielding layer are both not less than 1.5 mm.

[0015] Beneficial effects of the utility model:

[0016] 1. The inner, middle and outer isolation layers of the double-layer polyethylene longitudinal water-blocking tape are divided into three layers to prevent seawater and water vapor from penetrating into the insulation layer, delaying the water tree aging phenomenon of the insulation layer. The longitudinal overlap wrapping structure of the double-layer polyethylene water-blocking tape is adopted with an overlap rate of not less than 40%. The longitudinal wrapping structure strengthens the waterproof and water-blocking properties and has better anti-bending performance. It is not easy to loosen and expose gaps. The double-layer polyethylene water-blocking tape adopts a double-layer co-extruded molding structure of MDPE water-blocking inner layer and LDPE water-blocking outer layer, and optimizes the design of the thickness ratio of the inner and outer layers to enhance the water-blocking properties. By adding an EVA water-blocking adhesive layer between the inner conductor and the insulation layer, the diffusion of seawater and water vapor into the insulation layer can be enhanced, the insulation electrical properties of the cable can be protected, and the service life can be extended. The extruded lead sheath anti-corrosion layer can effectively prevent seawater corrosion, so that the cable has excellent anti-seawater erosion and anti-seawater corrosion properties, meeting the characteristics of submarine cables and better durability.

[0017] 2. The inner and outer sides of the extruded lead sheath anti-corrosion layer are double-layer polyethylene longitudinally wrapped water-blocking middle and outer isolation layers. The longitudinally wrapped structure is beneficial to improving the bending resistance and protecting the extruded lead sheath anti-corrosion layer. When the cable is bent, the protective layer will slip accordingly to prevent the extruded lead sheath anti-corrosion layer from cracking, thereby ensuring the cable's excellent anti-seawater corrosion properties and better durability.

[0018] 3. A galvanized steel wire armor layer and a nylon anti-twist wrapping layer are arranged between the polyvinyl chloride liner and the outer sheath, which greatly improves the mechanical impact resistance of the entire cable, and also improves the flexibility and bending resistance. The nylon anti-twist wrapping layer helps to improve the tensile strength and torsion resistance of the cable, effectively protects the cable sheath and prolongs its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the cross-sectional structure of an embodiment of the utility model.

[0020] In the figure: 1-inner conductor, 2-EVA water-blocking adhesive layer, 3-double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer, 4-HDPE inner semi-conductive shielding layer, 5-irradiated cross-linked low-density polyethylene insulation layer, 6-HDPE outer semi-conductive shielding layer, 7-double-layer polyethylene longitudinally wrapped water-blocking intermediate isolation layer, 8-extruded lead sheath anti-corrosion layer, 9-double-layer polyethylene longitudinally wrapped water-blocking outer isolation layer, 10-polyvinyl chloride lining layer, 11-galvanized steel wire armor layer, 12-nylon wire anti-twist winding layer, 13-polyvinyl chloride outer sheath. DETAILED DESCRIPTION

[0021] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0022] like Figure 1 As shown, the seawater corrosion resistant DC high-voltage submarine cable of an embodiment of the utility model comprises an inner conductor 1, the diameter of the inner conductor 1 is 26 mm to 48 mm, specifically, the inner conductor 1 is composed of a plurality of tinned copper strands twisted around a stainless steel monofilament central reinforcement wire, the tinned copper strands are composed of a plurality of tinned copper monofilament bundles twisted together, the twisting direction of the tinned copper strands is opposite to that of the tinned copper monofilaments, further, the diameter of the tinned copper monofilaments is 0.1 mm to 0.5 mm, and the lay length of the tinned copper strands is 10 to 30 times the outer diameter of the tinned copper strands.

[0023] The inner conductor 1 is coated with an EVA water-blocking adhesive layer 2, a double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer 3, an HDPE inner semi-conductive shielding layer 4, an irradiated cross-linked low-density polyethylene insulation layer 5, an HDPE outer semi-conductive shielding layer 6, a double-layer polyethylene longitudinally wrapped water-blocking intermediate isolation layer 7, an extruded lead sheath anti-corrosion layer 8, a double-layer polyethylene longitudinally wrapped water-blocking outer isolation layer 9, a polyvinyl chloride cushion layer 10, a galvanized steel wire armor layer 11, a nylon wire anti-twist winding layer 12 and a polyvinyl chloride outer sheath 13. The irradiated cross-linked low-density polyethylene insulation layer 5 has a thickness of 23 mm or 24 mm. The double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer 3, the middle isolation layer 7, and the outer isolation layer 9 are all double-layer polyethylene water-blocking tape longitudinally overlapped and wrapped structures with an overlap rate of not less than 40%. The double-layer polyethylene water-blocking tape is formed by co-extrusion of the MDPE water-blocking inner layer and the LDPE water-blocking outer layer. Further, the thickness ratio of the MDPE water-blocking inner layer and the LDPE water-blocking outer layer is 1:10 to 1:12. The thickness of the double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer 3, the middle isolation layer 7, and the outer isolation layer 9 is not less than 1mm, such as 1mm to 2mm. The thickness of the HDPE inner semi-conductive shielding layer 4 and the HDPE outer semi-conductive shielding layer 6 is not less than 1.5mm. The thickness of the extruded lead sheath anti-corrosion layer 8 is 2.9mm, 3mm or 3.1mm. In one embodiment, the nylon wire anti-twist wrapping layer 12 is composed of inner and outer double-layer nylon wires that are mutually reversely spirally wound and woven. The outer diameter of the polyvinyl chloride outer sheath 13 is 110mm to 142mm.

[0024] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. Seawater corrosion-resistant DC high-voltage submarine cable, characterized by: The invention comprises an inner conductor (1) and an EVA water-blocking adhesive layer (2) sequentially coated on the outside of the inner conductor (1), a double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer (3), an HDPE inner semi-conductive shielding layer (4), an irradiated cross-linked low-density polyethylene insulation layer (5), an HDPE outer semi-conductive shielding layer (6), a double-layer polyethylene longitudinally wrapped water-blocking intermediate isolation layer (7), an extruded lead sheath anti-corrosion layer (8), a double-layer polyethylene longitudinally wrapped water-blocking outer isolation layer (9), a polyvinyl chloride cushion layer (10), a galvanized steel wire armor layer (11), and a nylon wire anti-twist wrapping layer. (12) and a polyvinyl chloride outer sheath (13), the double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer (3), the double-layer polyethylene longitudinally wrapped water-blocking middle isolation layer (7) and the double-layer polyethylene longitudinally wrapped water-blocking outer isolation layer (9) are all double-layer polyethylene water-blocking tape longitudinally overlapped and wrapped structures with an overlap rate of not less than 40%, the double-layer polyethylene water-blocking tape is formed by co-extrusion of an MDPE water-blocking inner layer and an LDPE water-blocking outer layer, the inner conductor (1) has a diameter of 26 mm to 48 mm, and the outer diameter of the polyvinyl chloride outer sheath (13) is 110 mm to 142 mm.

2. The seawater corrosion resistant DC high voltage submarine cable according to claim 1 is characterized in that: The inner conductor (1) is composed of a plurality of tinned copper strands twisted around a stainless steel monofilament central reinforcement wire, the tinned copper strands are composed of a plurality of tinned copper monofilaments twisted together, and the twisting direction of the tinned copper strands is opposite to that of the tinned copper monofilaments.

3. The seawater corrosion resistant DC high voltage submarine cable according to claim 2 is characterized in that: The diameter of the tinned copper monofilament is 0.1 mm to 0.5 mm.

4. The seawater corrosion resistant DC high voltage submarine cable according to claim 2 is characterized in that: The lay length of the tinned copper strands is 10 to 30 times the outer diameter of the tinned copper strands.

5. The seawater corrosion resistant DC high voltage submarine cable according to claim 1 is characterized in that: The thickness of the extruded lead sheath anti-corrosion layer (8) is 2.9 mm, 3 mm or 3.1 mm.

6. The seawater corrosion resistant DC high voltage submarine cable according to claim 1 is characterized in that: The thickness of the radiation cross-linked low-density polyethylene insulation layer (5) is 23 mm or 24 mm.

7. The seawater corrosion resistant DC high voltage submarine cable according to claim 1 is characterized in that: The nylon wire anti-twist wrapping layer (12) is formed by inner and outer double layers of nylon wires being twisted and braided in opposite directions.

8. The seawater corrosion resistant DC high voltage submarine cable according to claim 1 is characterized by: The thickness ratio of the MDPE water-blocking inner layer to the LDPE water-blocking outer layer is 1:10 to 1:

12.

9. The seawater corrosion resistant DC high voltage submarine cable according to claim 1 is characterized by: The thickness of the double-layer polyethylene longitudinally wrapped water-blocking inner isolation layer (3), the double-layer polyethylene longitudinally wrapped water-blocking middle isolation layer (7) and the double-layer polyethylene longitudinally wrapped water-blocking outer isolation layer (9) are all not less than 1 mm.

10. The seawater corrosion resistant DC high voltage submarine cable according to claim 1 is characterized by: The thickness of the HDPE inner semi-conductive shielding layer (4) and the HDPE outer semi-conductive shielding layer (6) are both not less than 1.5 mm.

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