Offshore low-voltage power cable

Abstract

The utility model provides an offshore low-voltage power cable. The offshore low-voltage power cable comprises a plurality of cable core assemblies, a sheath assembly and a filling part, the sheath assembly comprises a glass fiber belt, an aluminum alloy composite belt and an outer sheath which are sequentially arranged on the peripheries of the cable core assemblies in a wrapping mode, and the aluminum alloy composite belt is arranged in a longitudinal wrapping mode; the filling member is arranged in the sheath assembly, and the filling member is filled among the plurality of cable core assemblies. In the offshore low-voltage power cable provided by the invention, the glass fiber tape has relatively good tensile strength and corrosion resistance, and the aluminum alloy composite tape is made of an aluminum alloy composite material, has relatively good anti-extrusion strength, and can replace a steel tape armor layer. Besides, the aluminum alloy composite belt is wrapped on the periphery of the glass fiber belt in a longitudinal wrapping mode, a closed structure can be formed, seawater, salt mist and the like are prevented from entering the cable, excellent waterproof performance is achieved, and therefore the service life of the cable is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cables, in particular to a low-voltage power cable for offshore use. BACKGROUND

[0002] The sheath structure of the existing photovoltaic medium-voltage power cable is generally formed by combining a polyethylene inner sheath layer, a galvanized steel tape armor layer, a tape wrapping layer and a flame-retardant polyethylene outer sheath layer. When such a cable is applied to an offshore floating photovoltaic power station, the cable is in a humid and salt-fog environment for a long time. Seawater will gradually penetrate from the outer surface of the cable to the inside of the cable, which is prone to corrosion and aging and affects the service life of the cable. SUMMARY

[0003] The present application provides a low-voltage power cable for offshore use to solve the problem of low service life of the cable in known technology.

[0004] The present application provides a low-voltage power cable for offshore use, which comprises a plurality of cable core assemblies, a sheath assembly and a filler. The sheath assembly comprises a glass fiber tape, an aluminum alloy composite tape and an outer sheath which are sequentially wrapped around the outer periphery of the plurality of cable core assemblies, and the aluminum alloy composite tape is longitudinally wrapped. The filler is arranged in the sheath assembly, and the filler is filled between the plurality of cable core assemblies.

[0005] In a possible implementation, the aluminum alloy composite tape is longitudinally wrapped around the outer periphery of the glass fiber tape by a welding process.

[0006] In a possible implementation, the aluminum alloy composite tape is an aluminum-magnesium alloy composite tape.

[0007] In a possible implementation, the cable core assembly comprises:

[0008] a conductor;

[0009] an insulation layer arranged around the outer periphery of the conductor;

[0010] a shielding structure along the radial direction of the insulation layer, the shielding structure being arranged at least on one side of the insulation layer.

[0011] In a possible implementation, the shielding structure comprises:

[0012] an inner shielding layer arranged between the conductor and the insulation layer;

[0013] an outer shielding layer arranged around the outer periphery of the insulation layer.

[0014] In a possible implementation, the shielding structure further comprises a metal shielding layer arranged around the outer periphery of the outer shielding layer.

[0015] In a possible implementation, the metal shielding layer is a copper strip.

[0016] In a possible implementation, the metal shielding layer is wrapped around the outer periphery of the outer shielding layer in an overlapping manner.

[0017] In a possible implementation, the inner shielding layer, the insulating layer, and the outer shielding layer are formed by three-layer co-extrusion.

[0018] In a possible implementation, the offshore low-voltage power cable further comprises a communication line, which is arranged in the sheath assembly.

[0019] In the offshore low-voltage power cable, the sheath assembly is formed by a glass fiber strip, an aluminum alloy composite strip, and an outer sheath. The glass fiber strip has good tensile strength and corrosion resistance. The aluminum alloy composite strip is made of aluminum alloy composite material and has good extrusion resistance, which can replace the steel strip armor layer. In addition, the aluminum alloy composite strip is wrapped around the outer periphery of the glass fiber strip in a longitudinal manner, which can form a closed structure to block seawater, salt mist, and the like from entering the cable, and has excellent waterproof performance, thereby improving the service life of the cable. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 FIG. 1 is a structural schematic diagram of an offshore low-voltage power cable in an embodiment of the present application.

[0021] Figure 2 FIG. 2 is a structural schematic diagram of a shielding structure of an offshore low-voltage power cable in an embodiment of the present application.

[0022] Figure 3 FIG. 3 is a structural schematic diagram of an offshore low-voltage power cable in another embodiment of the present application.

[0023] Main element symbol explanation: 100, offshore low-voltage power cable; 10, cable core assembly; 11, conductor; 12, insulating layer; 13, shielding structure; 131, inner shielding layer; 132, outer shielding layer; 133, metal shielding layer; 14, silicone oil layer; 20, sheath assembly; 21, glass fiber strip; 22, aluminum alloy composite strip; 23, outer sheath; 30, filler; 40, communication line.

[0024] The following specific embodiments will further illustrate the present application in combination with the above drawings. DETAILED DESCRIPTION

[0025] The following description will refer to the accompanying drawings to provide a more complete picture of the present application. The drawings illustrate exemplary embodiments of the present application. However, the present application may be implemented in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided to make the present application thorough and complete, and to fully convey the scope of the present application to those skilled in the art. Similar reference numerals denote the same or similar components.

[0026] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to limit the application. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to also include the plural forms. Furthermore, when used herein, “comprising” and / or “including” and / or “having,” integers, steps, operations, components, and / or components, but does not exclude the presence or addition of one or more other features, regions, integers, steps, operations, components, and / or groups thereof.

[0027] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. Furthermore, unless expressly defined herein, terms such as those defined in a general dictionary should be interpreted as having the same meaning as they have in the relevant art and in the content of this application, and will not be interpreted as having an idealized or overly formal meaning.

[0028] The sheath structure of photovoltaic medium-voltage power cables is generally formed by a composite of a polyethylene inner sheath, a galvanized steel tape armor layer, a wrapping layer, and a flame-retardant polyethylene outer sheath. When this type of cable is used in offshore floating photovoltaic power stations, the cable is in a humid and salt spray environment for a long time. Seawater will gradually penetrate from the outer surface of the cable into its interior, which can easily lead to corrosion and aging problems, affecting the service life of the cable.

[0029] Based on this, this application provides a marine low-voltage power cable that combines fiberglass tape, aluminum alloy composite tape, and an outer sheath to form a sheath assembly. The fiberglass tape has good tensile strength and corrosion resistance, while the aluminum alloy composite tape, made of aluminum alloy composite material, has good compressive strength and can replace the steel tape armor layer. Furthermore, the aluminum alloy composite tape is longitudinally wrapped around the outer periphery of the fiberglass tape, forming a closed structure that prevents seawater and salt spray from entering the cable, providing excellent waterproof performance and thus extending the cable's service life.

[0030] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0031] like Figure 1 As shown, this embodiment provides a marine low-voltage power cable 100, including multiple cable core assemblies 10, sheath assemblies 20, and filling components 30.

[0032] The sheath assembly 20 comprises a glass fiber tape 21, an aluminum alloy composite tape 22 and an outer sheath 23 which are sequentially arranged on the outer periphery of the plurality of cable core assemblies 10. The aluminum alloy composite tape 22 is longitudinally arranged. The filler 30 is arranged in the sheath assembly 20, and the filler 30 is filled between the plurality of cable core assemblies 10.

[0033] Thus, in the offshore low-voltage power cable 100 of the present application, the sheath assembly 20 is formed by the glass fiber tape 21, the aluminum alloy composite tape 22 and the outer sheath 23. The glass fiber tape 21 has good tensile strength and corrosion resistance. The aluminum alloy composite tape 22 is made of aluminum alloy composite material, which has good extrusion strength and can replace the steel tape armor layer. In addition, the aluminum alloy composite tape 22 is arranged on the outer periphery of the glass fiber tape 21 in a longitudinal manner, which can form a closed structure to block seawater, salt mist and the like from entering the cable, and has excellent waterproof performance, thereby improving the service life of the cable.

[0034] Please combine Figure 1 In an embodiment, the number of cable core assemblies 10 is three, and the three cable core assemblies 10 are arranged in a substantially triangular shape. The filler 30 is arranged in the gap between any two adjacent cable core assemblies 10 and the gap between any one cable core assembly 10 and the glass fiber tape 21, so as to ensure the roundness of the entire cable and improve the pressure resistance of the cable. The filler 30 is a polypropylene filler rope.

[0035] It can be understood that in other embodiments, the number of cable core assemblies 10 can also be four or five or other numbers. The number of cable core assemblies 10 can be adaptively adjusted according to actual use requirements. In addition, the distribution mode of the cable core assemblies 10 can also be adaptively adjusted according to actual use requirements. In the present application, the number of cable core assemblies 10 and the specific distribution mode are not specifically limited.

[0036] Further, the cable core assembly 10 comprises a conductor 11, an insulation layer 12 and a shielding structure 13.

[0037] In the present embodiment, the conductor 11 is made of a metal material having a conductive function. For example, the conductor 11 is made of an aluminum alloy material, and specifically an 8030 type aluminum alloy material. In addition, the conductor 11 is formed by tightly twisting a plurality of single wires.

[0038] The insulation layer 12 is arranged on the outer periphery of the conductor 11. The insulation layer 12 is made of cross-linked polyethylene material. The insulation layer 12 made of cross-linked polyethylene material not only has high dielectric strength and insulation resistance, which can effectively prevent current leakage and short circuit phenomenon, but also has good resistance to moisture and the like, so that the insulation layer 12 is suitable for use in a humid environment and has good waterproof effect.

[0039] In the embodiment, the shielding structure 13 is arranged at least on one side of the insulation layer 12 in the radial direction of the insulation layer 12 to prevent electromagnetic interference from affecting signal transmission and ensure the stability of the conductor 11 during signal transmission.

[0040] Please combine Figures 1 to 2 In an embodiment, the shielding structure 13 includes an inner shielding layer 131 and an outer shielding layer 132.

[0041] The inner shielding layer 131 is arranged between the conductor 11 and the insulation layer 12, and the inner shielding layer 131 is clamped by the conductor 11 and the insulation layer 12. In addition, the outer shielding layer 132 is wrapped around the outer periphery of the insulation layer 12 to form a double shielding function through the outer shielding layer 132 and the inner shielding layer 131, thereby enhancing the electromagnetic shielding effect of the conductor 11. The inner shielding layer 131 and the outer shielding layer 132 are both made of semi-conductive shielding material.

[0042] The inner shielding layer 131, the insulation layer 12, and the outer shielding layer 132 are formed on the outer periphery of the conductor 11 in a three-layer co-extrusion manner. This three-layer co-extrusion processing method can improve production efficiency, and the connection between the inner shielding layer 131, the insulation layer 12, and the outer shielding layer 132 is more secure.

[0043] Further, the shielding structure 13 also includes a metal shielding layer 133 wrapped around the outer periphery of the outer shielding layer 132. The metal shielding layer 133 is made of copper tape, and the metal shielding layer 133 is arranged in one layer. The metal shielding layer 133 is wrapped around the outer periphery of the outer shielding layer 132 in an overlapping manner, which can avoid gaps in the metal shielding layer 133 during wrapping, ensure that the metal shielding layer 133 has excellent electromagnetic shielding effect on the conductor 11, and this wrapping method can also play a waterproof role to prevent seawater or fog from entering the metal shielding layer 133.

[0044] Please combine Figure 3 In an embodiment, the offshore low-voltage power cable 100 also includes a communication line 40 arranged in the sheath assembly 20. The communication line 40 is arranged in the gap between the three cable assemblies, and the communication line 40 can transmit signals, so that the offshore low-voltage power cable 100 not only has the ability to transmit power, but also can transmit control signals and other signals as needed, thereby enriching the capabilities of the offshore low-voltage power cable 100.

[0045] Please combine Figure 1 In an embodiment, the aluminum alloy composite tape 22 is longitudinally wrapped around the outer periphery of the glass fiber tape 21 through a welding process. When the aluminum alloy composite tape 22 is longitudinally wrapped, the gap between the adjacent two sections of the aluminum alloy composite tape 22 is closed by laser welding.

[0046] In the embodiment, the aluminum alloy composite tape 22 adopts an aluminum magnesium alloy composite tape, specifically, an aluminum alloy material of type 5052. The aluminum alloy composite tape 22 adopting the aluminum alloy material of type 5052 has good weldability and corrosion resistance, so that the aluminum alloy composite tape 22 has excellent waterproof capability while being convenient for welding processing.

[0047] The outer sheath 23 adopts a special composite material, specifically, a composite material of polyethylene, polyvinyl chloride, etc. The special composite material has excellent chemical resistance and mechanical strength. When the offshore low-voltage power cable 100 of the present application is tested, salt spray (generated by 5% sodium chloride solution) is sprayed continuously towards the offshore low-voltage power cable 100 of the present application at a temperature of 50℃ for 336 hours, and then the tensile strength change rate and the breaking elongation change rate of the outer sheath 23 are measured to be ≤-30%. It can be seen that the outer sheath 23 adopted by the offshore low-voltage power cable 100 of the present application can meet the use in the long-term salt spray environment above the sea surface, and the mechanical properties of the outer sheath 23 after accelerated aging still meet the use requirements.

[0048] In addition, the outer sheath 23 adopts a special composite material. After the outer sheath 23 is placed in a damp heat test chamber (simulating seawater concentration) at a temperature of 90℃ and a relative humidity of 85% for 2000h, the tensile strength change rate and the breaking elongation change rate of the outer sheath 23 are tested to be ≤-30%. It can be seen that the outer sheath 23 of the present application can meet the use in the environment of being soaked in seawater at high temperature above the sea surface, and the mechanical properties of the outer sheath 23 after accelerated aging in this environment still meet the use requirements.

[0049] In the above, the specific embodiments of the present application are described with reference to the accompanying drawings. However, those skilled in the art can understand that various changes and replacements can be made to the specific embodiments of the present application without departing from the scope of the present application. These changes and replacements are within the scope defined by the present application.

Claims

1. A marine low voltage power cable, characterized in that, The offshore low-voltage power cable comprises: a plurality of cable core assemblies; a sheath assembly comprising a glass fiber tape, an aluminum alloy composite tape and an outer sheath which are sequentially arranged on the outer periphery of the plurality of cable core assemblies, the aluminum alloy composite tape being longitudinally arranged; a filler arranged in the sheath assembly, the filler being filled between the plurality of cable core assemblies.

2. The marine low voltage power cable according to claim 1, c h a r a c t e r i s e d in that, The aluminum alloy composite tape is longitudinally arranged on the outer periphery of the glass fiber tape through a welding process.

3. The marine low voltage power cable according to claim 1, c h a r a c t e r i z e d i n that The aluminum alloy composite tape is an aluminum-magnesium alloy composite tape.

4. The marine low voltage power cable according to claim 1, c h a r a c t e r i z e d i n that The cable core assembly comprises: a conductor; an insulation layer arranged on the outer periphery of the conductor; a shielding structure arranged along the radial direction of the insulation layer, the shielding structure being arranged on at least one side of the insulation layer.

5. The marine low voltage power cable according to claim 4, c h a r a c t e r i z e d i n that The shielding structure comprises: an inner shielding layer arranged between the conductor and the insulation layer; an outer shielding layer arranged on the outer periphery of the insulation layer.

6. The marine low voltage power cable according to claim 5, c h a r a c t e r i z e d i n that The shielding structure further comprises a metal shielding layer arranged on the outer periphery of the outer shielding layer.

7. The marine low voltage power cable according to claim 6, c h a r a c t e r i z e d i n that The metal shielding layer is a copper tape.

8. The marine low voltage power cable according to claim 6, c h a r a c t e r i z e d i n that The metal shielding layer is wrapped on the outer periphery of the outer shielding layer in an overlapping manner.

9. The marine low voltage power cable according to claim 5, c h a r a c t e r i z e d i n that The inner shielding layer, the insulation layer and the outer shielding layer are formed by three-layer co-extrusion.

10. The marine low voltage power cable according to claim 1, c h a r a c t e r i z e d i n that The offshore low-voltage power cable further comprises a communication line arranged in the sheath assembly.

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