Submarine cable and method for manufacturing the same

Abstract

The present invention relates to the technical field of cables, and provides a submarine cable and a manufacturing method thereof. The above-mentioned submarine cable includes a water-blocking conductor, which is formed by stranding a plurality of metal conductors. A water-blocking material is filled between the plurality of metal conductors. Among them, the diameter of the first end of each metal conductor is smaller than that of the second end. The above-mentioned submarine cable realizes the continuous production of a variable cross-section conductor inside the entire submarine cable, breaks through the bottleneck that different cross-section submarine cables currently must be connected by a transition joint, shortens the manufacturing time of the submarine cable. At the same time, the submarine cable does not need to be provided with a transition joint, and the production quality is more stable and reliable. Under the condition of meeting the harsh environmental conditions of the landing section and requiring a higher transmission current, the project investment cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a submarine cable and a manufacturing method thereof. Background Art

[0002] Conventional submarine cable engineering routes include various working conditions such as the submarine section and the landing section. Among them, the heat dissipation condition of the landing section through the dike is relatively poor. The submarine cables in existing projects are all designed with equal cross-section conductors for the whole line with the heat dissipation severe section condition as the input. There is a 10% - 15% redundancy in the conductor cross-section design for the submarine section route. Currently, the production of submarine cables is all continuous production of conductors with the same cross-section, or it is necessary to use a pre-payment type intermediate joint or a factory soft joint form to connect two submarine cables with different diameters (different cross-section conductors) in the landing section. The main drawbacks of this method are as follows: When connecting submarine cables with different diameters using the factory joint form or the sea-land cable pre-payment type conversion joint form, the factory joint manufactured in the factory increases the operation risk of the submarine cable. At the same time, generally, the production of a soft joint usually takes 4 - 7 days, resulting in a waste of time and affecting the project delivery; while the sea-land cable conversion joint needs to be manufactured on-site, with a long construction period, increasing the construction time and the cost of the sea-land cable joint. Based on this, providing a submarine cable with a variable diameter conductor that does not require a conversion joint has become an urgent problem in the industry. Summary of the Invention

[0003] The present invention provides a submarine cable and a manufacturing method thereof to solve the defect that the submarine cable with a variable diameter conductor in the prior art needs to be connected by a conversion joint.

[0004] The present invention provides a submarine cable, including a water-blocking conductor, which is formed by stranding a plurality of metal conductors. A water-blocking material is filled between the plurality of metal conductors. Among them, the diameter of the first end of each metal conductor is smaller than that of the second end.

[0005] According to the submarine cable provided by the present invention, it further includes an insulation shielding structure, which is wrapped around the outside of the water-blocking conductor. After the water-blocking conductor is wrapped with the insulation shielding structure, a first cable core structure is formed. The diameter of the first end of the first cable core structure is smaller than that of the second end.

[0006] According to the submarine cable provided by the present invention, it further includes a water-blocking tape wrapping layer, which is wrapped around the outside of the insulation shielding structure to form a second cable core structure. The difference between the diameter of the second end and the diameter of the first end of the second cable core structure is less than 2 mm.

[0007] According to the submarine cable provided by the present invention, the insulation shielding structure includes: a conductor shielding layer, which is wrapped around the outside of the water-blocking conductor; an insulating layer, which is wrapped around the outside of the conductor shielding layer; and an insulation shielding layer, which is wrapped around the outside of the insulating layer.

[0008] A submarine cable provided by the present invention further includes: a metal sheath, which is wrapped around the outside of the water-blocking tape wrapping layer; a polyethylene sheath, which is wrapped around the outside of the metal sheath.

[0009] A submarine cable provided by the present invention further includes a lining layer, and the lining layer is wrapped around the outside of the polyethylene sheath.

[0010] A submarine cable provided by the present invention further includes: a plurality of optical fiber units, which are arranged between the polyethylene sheath and the lining layer; a filling protection layer, which is filled between the plurality of optical fiber units.

[0011] A submarine cable provided by the present invention further includes: an armor layer, which is wrapped around the outside of the lining layer; an outer sheath, which is wrapped around the outside of the armor layer.

[0012] The present invention also provides a manufacturing method of the submarine cable as described above, including: cold-pressure welding one end of a first metal wire and one end of a second metal wire to form the metal conductor, wherein the diameter of the first metal wire is smaller than that of the second metal wire; after stranding the first metal wires among a plurality of the metal conductors, then stranding the second metal wires among the plurality of the metal conductors, and filling a water-blocking material during the two stranding processes to form the water-blocking conductor.

[0013] The manufacturing method of the submarine cable provided by the present invention further includes: extruding an insulation shielding structure outside the water-blocking conductor, wherein the insulation shielding structure includes a conductor shielding layer, an insulating layer, and an insulation shielding layer, and the conductor shielding layer, the insulating layer, and the insulation shielding layer are simultaneously extruded and formed.

[0014] The submarine cable provided by the present invention realizes the continuous production of a variable cross-section conductor inside the whole submarine cable, breaks through the bottleneck that a conversion joint must be used to connect submarine cables with different conductor cross-sections at present, shortens the manufacturing time of the submarine cable. At the same time, the submarine cable does not need to be provided with a conversion joint, and the production quality is more stable and reliable. When meeting the harsh environmental conditions of the landing section and the requirement of higher transmission current, the engineering investment cost is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0016] Figure 1It is a schematic structural diagram of the submarine cable provided by the present invention;

[0017] Figure 2 Schematic structural diagram of the die for stranding the variable cross-section metal conductor;

[0018] Figure 3 It is a schematic diagram of the stranding process of the variable cross-section metal conductor;

[0019] Reference numerals:

[0020] 10: Water-blocking conductor; 20: Insulation shielding structure; 21: Conductor shielding layer; 22: Insulation layer; 23: Insulation shielding layer; 30: Water-blocking tape wrapping layer; 40: Metal sheath; 50: Polyethylene sheath; 61: Optical fiber unit; 62: Filling protection layer; 70: Inner lining layer; 80: Armor layer; 90: Outer sheath; 101: First upper die; 102: First lower die; 111: Second upper die; 112: Second lower die; 201: First metal wire; 202: Second metal wire. Detailed implementation manners

[0021] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0022] The terms "first" and "second" in the description and claims of the present invention may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0023] The following combines Figures 1 - 3 to describe the submarine cable and the manufacturing method of the submarine cable of the present invention.

[0024] As Figure 1 shown, in the embodiment of the present invention, the submarine cable includes a water-blocking conductor 10, and the water-blocking conductor 10 is stranded by a plurality of metal conductors. A water-blocking material is filled between the plurality of metal conductors. Among them, the diameter of the first end of each metal conductor is smaller than the diameter of the second end.

[0025] Specifically, in this embodiment, the water-blocking conductor 10 is formed by stranding multiple metal conductors. The metal conductors can be single copper wires or single aluminum wires. A water-blocking tape or water-blocking glue is filled between the multiple metal conductors to play a waterproof role. The diameters at both ends of each metal conductor are unequal. Specifically, when manufacturing the water-blocking conductor 10, the small-diameter metal single wires are cold-pressed and welded together with the large-diameter metal single wires to form a metal conductor with a variable cross-section. When stranding the multiple metal conductors, first strand the small-diameter metal single wires among the multiple metal conductors, and then strand the large-diameter metal single wires among the multiple metal conductors. During the two stranding processes, a water-blocking tape or water-blocking glue is filled to form the water-blocking conductor 10 with a variable cross-section.

[0026] The submarine cable provided by the embodiment of the present invention realizes the continuous production of the variable cross-section conductor inside the entire submarine cable, breaks through the bottleneck that currently different cross-section submarine cables must be connected by conversion joints, shortens the manufacturing time of the submarine cable. At the same time, the submarine cable does not need to be provided with a conversion joint, and the production quality is more stable and reliable. In the case of meeting the harsh environmental conditions of the landing section and requiring higher transmission current requirements, the engineering investment cost is saved.

[0027] As Figure 1 shown, in the embodiment of the present invention, the submarine cable further includes an insulation shielding structure 20. The insulation shielding structure 20 is wrapped around the outside of the water-blocking conductor 10. After the water-blocking conductor 10 is wrapped with the insulation shielding structure, a first cable core structure is formed. The diameter of the first end of the first cable core structure is smaller than that of the second end.

[0028] Specifically, the insulation shielding structure 20 is extruded around the outside of the water-blocking conductor 10. Since the diameters at both ends of the water-blocking conductor 10 are unequal, the diameters at both ends of the first cable core structure formed after extruding the insulation shielding structure 20 are still unequal.

[0029] Further, as Figure 1 shown, in the embodiment of the present invention, the insulation shielding structure includes: a conductor shielding layer 21, an insulating layer 22, and an insulation shielding layer 23. The conductor shielding layer 21 is wrapped around the outside of the water-blocking conductor 10. The insulating layer 22 is wrapped around the outside of the conductor shielding layer 21. The insulation shielding layer 23 is wrapped around the outside of the insulating layer 22.

[0030] Specifically, the conductor shielding layer 21 is an extruded semi-conductive material, or a semi-conductive tape can be wound first and then a conductive shielding material is extruded. The insulating layer 22 is made of cross-linked polyethylene insulation by extrusion, and the insulation shielding layer 23 is made of extruded semi-conductive material.

[0031] As Figure 1As shown, in an embodiment of the present invention, the submarine cable further includes a water-blocking tape wrapping layer 30. The water-blocking tape wrapping layer 30 is wrapped around the outside of the insulation shielding structure 20 to form a second cable core structure, and the difference between the diameter of the second end and the diameter of the first end of the second cable core structure is less than 2 mm.

[0032] Specifically, the water-blocking tape wrapping layer 30 is composed of a semiconductive tape wrapping, and the lapping wrapping is adopted. To ensure the water-blocking performance of the submarine cable and the influence of thermal expansion during the operation of the cable core, the lapping rate of the water-blocking tape wrapping is not less than 15%. Further, in this embodiment, the diameters of the two ends of the first cable core structure formed after the water-blocking conductor 10 is wrapped around the insulation shielding structure 20 are not equal. When wrapping the water-blocking tape around the outside of the first cable core structure, the water-blocking tape can be wound according to the difference in the diameters of the two ends of the first cable core structure. When the difference in the diameters of the two ends is large, a water-blocking tape with a thicker thickness can be wrapped around the end with a smaller diameter, while when the difference in the diameters of the two ends is small, a water-blocking tape with a thinner thickness can be wrapped around the end with a smaller diameter to reduce the diameter difference between the two ends of the first cable core structure and make the diameter difference between them less than 2 mm. Optionally, in an embodiment of the present invention, the thickness of the water-blocking tape can be 0.4 mm - 1.0 mm.

[0033] As Figure 1 shown, in an embodiment of the present invention, the submarine cable further includes: a metal sheath 40 and a polyethylene sheath 50. The metal sheath 40 is wrapped around the outside of the water-blocking tape wrapping layer 30, and the polyethylene sheath 50 is wrapped around the outside of the metal sheath 40.

[0034] Specifically, the metal sheath 40 serves as a radial water-blocking layer and is composed of an extruded alloy lead sheath. The polyethylene sheath 50 is composed of an insulating polyethylene or a semiconductive polyethylene extrusion.

[0035] As Figure 1 shown, in an embodiment of the present invention, the submarine cable further includes an inner liner layer 70, and the inner liner layer 70 is wrapped around the outside of the polyethylene sheath 50. Specifically, the inner liner layer 70 is formed by winding a polypropylene winding rope at a certain pitch.

[0036] As Figure 1 shown, in an embodiment of the present invention, the submarine cable further includes: a plurality of optical fiber units 61 and a filling protection layer 62. The plurality of optical fiber units 61 are arranged between the polyethylene sheath 50 and the inner liner layer 70, and the filling protection layer 62 is filled between the plurality of optical fiber units 61.

[0037] Specifically, the optical fiber unit 61 includes an optical fiber, a stainless steel tube, an inner polyethylene protection layer, a steel wire armor layer, and an outer polyethylene protection layer wrapped around from the inside to the outside in sequence. The filling protection layer 62 is composed of a polypropylene rope or a polyethylene molded filling strip, and the cross-section of the polyethylene molded filling strip is circular. The filling protection layer 62 is filled between the plurality of optical fiber units 61 to ensure the roundness of the cable core structure.

[0038] As Figure 1 shown, in an embodiment of the present invention, the submarine cable further includes: an armor layer 80 and an outer sheath layer 90. The armor layer 80 is wrapped around the outside of the inner liner layer 70, and the outer sheath layer 90 is wrapped around the outside of the armor layer 80.

[0039] Specifically, the armor layer 80 is wound by circular galvanized steel wires, flat galvanized steel wires, or stainless steel wires, copper wires, etc. The outer sheath layer 90 is composed of anti-corrosion asphalt and polyethylene ropes wound around.

[0040] The embodiment of the present invention also provides a manufacturing method of a submarine cable, which specifically includes the following steps:

[0041] Step 01: Cold press and weld one end of the first metal wire 201 and one end of the second metal wire 202 to form a metal conductor, wherein the diameter of the first metal wire 201 is smaller than the diameter of the second metal wire 202; Step 02: Strands of the first metal wires 201 in multiple metal conductors are stranded, and then the second metal wires 202 in the multiple metal conductors are stranded, and a water-blocking material is filled during the two stranding processes to form a water-blocking conductor 10.

[0042] Specifically, in the prior art, conductors are usually made by stranding different metals through a conductor stranding die at a certain pitch. For a conductor of the same cross-section, only one stranding die can be used for production. The stranding die is usually an integral tungsten carbide die or a nano and polycrystalline die, and the size of the stranding die requires the outer diameter of each layer of the conductor to be the same. As Figure 2 shown, in an embodiment of the present invention, a new type of split nano-stranding die is provided. The stranding die includes a first die and a second die with different diameters. Among them, the first die includes a first upper die 101 and a first lower die 102, and the second die includes a second upper die 111 and a second lower die 112. During the production process, each stranding body changes the production method of stranding with one die in the traditional mode. As Figure 3 shown, during the preparation of the water-blocking conductor 10, first, one end of the first metal wire 201 and one end of the second metal wire 202 are cold press welded to form a metal conductor, wherein the diameter of the first metal wire 201 is smaller than the diameter of the second metal wire 202. Then, the first metal wires 201 in multiple metal conductors are stranded through the first die. After stranding, the first die is removed. Then, the second metal wires 202 in the multiple metal conductors are stranded through the second die to produce a continuous water-blocking conductor 10 with an unequal cross-section.

[0043] The manufacturing method of the submarine cable provided by the embodiment of the present invention forms a metal conductor with a variable cross-section by connecting a first metal wire and a second metal wire with unequal cross-sections, and then stranding the first metal wires in multiple metal conductors through a first die, and stranding the second metal wires in multiple metal conductors through a second die to form a water-blocking conductor, realizing the continuous production of a variable cross-section water-blocking conductor, breaking through the bottleneck that currently different cross-section submarine cables must be connected by a transition joint, shortening the manufacturing time of the submarine cable. At the same time, the submarine cable does not need to be provided with a transition joint, and the production quality is more stable and reliable. When meeting the requirements of harsh environmental conditions in the landing section and higher transmission current requirements, the engineering investment cost is saved.

[0044] Further, in the embodiment of the present invention, the manufacturing method of the submarine cable further includes the following steps: extruding and attaching an insulation shielding structure 20 outside the water-blocking conductor 10, where the insulation shielding structure 20 includes a conductor shielding layer 21, an insulation layer 22, and an insulation shielding layer 23, and the conductor shielding layer 21, the insulation layer 22, and the insulation shielding layer 23 are simultaneously extruded and formed and wrapped outside the water-blocking conductor 10.

[0045] Specifically, the insulation shielding structure 20 adopts a three-layer co-extrusion cross-linking production line. Before production, the water-blocking conductor 10 first enters a shielding extruder, a cross-linked polyethylene insulation extruder, and an insulation shielding extruder, and is formed through a head and an extrusion die. The method for starting up the cross-linking with unequal-diameter cross-sections is mainly the die ratio to ensure the uniform extrusion of the variable cross-section water-blocking conductor 10 and the control of the outer diameter. Specifically, the diameter D1 of the die core = the diameter d1 of the large end of the water-blocking conductor 10 + (0.5 - 1.0) mm; the diameter D2 of the liner die = the diameter of the large end after the water-blocking conductor 10 is wrapped with the conductor shielding layer 21 + (0.1 - 0.3) mm, and the diameter D3 of the die sleeve = the diameter d1 of the large end of the water-blocking conductor + 2 × the thickness of the conductor shielding layer + 2 × the thickness of the insulation layer × (1.02 - 1.05) + 2 × the thickness of the insulation shielding layer. The die ratio method is reasonably determined by considering the influence of the large cross-section conductor structure on the extrusion control of the small cross-section.

[0046] Further, in the embodiment of the present invention, when wrapping a metal sheath 40 and a polyethylene sheath 50 outside the insulation shielding layer 23, the method for determining the diameter of the die is as follows: the diameter D3 of the lead extrusion die core = the diameter of the large end of the cable core + (0.5 - 1.8) mm; the diameter D4 of the lead extrusion die cover = the diameter D3 of the die core + 2.25 × the thickness of the lead sheath; the extrusion die for the polyethylene sheath 50 is selected as an extrusion tube die according to the diameter of the large end of the cable core.

[0047] Furthermore, in the embodiments of the present invention, both the submarine cable cabling die and the metal armor die can be used as split dies. During the production process, they are selected according to the diameters of the cable core cabling die and the metal armor die corresponding to the diameter of the polyethylene sheath 50. Among them, the diameter D5 of the cabling die = 2.16 × the diameter after the water-blocking conductor is coated with the polyethylene sheath + (8 - 12) mm, and the diameter D6 of the wire armor die = the diameter after the water-blocking conductor is coated with the armor layer + (5 - 8) mm. When the water-blocking conductor 10 is coated with the outer sheath 90, different-color polypropylene ropes are wound at intervals to distinguish the cable cores with unequal cross-sectional diameters as marks during the construction process.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or equivalently replace some of the technical features. These modifications or replacements 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. An undersea cable, characterized in that, It includes a water-blocking conductor which is formed by stranding a plurality of metal conductors, and a water-blocking material is filled between the plurality of metal conductors. Wherein, the diameter of the first end of each metal conductor is smaller than that of the second end; The forming process of the water-blocking conductor is as follows: One end of a first metal wire is cold-pressed and welded to one end of a second metal wire to form a metal conductor with a variable cross-section, wherein the diameter of the first metal wire is smaller than that of the second metal wire; After stranding the first metal wires among the plurality of metal conductors, then stranding the second metal wires among the plurality of metal conductors, and filling the water-blocking material during the two stranding processes to form the water-blocking conductor.

2. The submarine cable according to claim 1, characterized in that, It further includes an insulating shielding structure which is wrapped around the outside of the water-blocking conductor. After wrapping the insulating shielding structure, the water-blocking conductor forms a first cable core structure, and the diameter of the first end of the first cable core structure is smaller than that of the second end.

3. The submarine cable according to claim 2, wherein, It further includes a water-blocking tape wrapping layer which is wrapped around the outside of the insulating shielding structure to form a second cable core structure, and the difference between the diameter of the second end and the diameter of the first end of the second cable core structure is less than 2 mm.

4. The submarine cable according to claim 2, characterized in that, The insulating shielding structure includes: A conductor shielding layer which is wrapped around the outside of the water-blocking conductor; An insulating layer which is wrapped around the outside of the conductor shielding layer; An insulating shielding layer which is wrapped around the outside of the insulating layer; Wherein, the conductor shielding layer, the insulating layer and the insulating shielding layer are simultaneously extruded and formed.

5. The submarine cable according to claim 3, characterized in that, It further includes: A metal sheath which is wrapped around the outside of the water-blocking tape wrapping layer; A polyethylene sheath which is wrapped around the outside of the metal sheath.

6. The submarine cable according to claim 5, characterized in that, It further includes an inner liner layer which is wrapped around the outside of the polyethylene sheath.

7. The submarine cable according to claim 6, characterized in that, It further includes: A plurality of optical fiber units which are arranged between the polyethylene sheath and the inner liner layer; A filling protection layer which is filled between the plurality of optical fiber units.

8. The submarine cable according to claim 6, characterized in that, It further includes: An armor layer which is wrapped around the outside of the inner liner layer; An outer sheath which is wrapped around the outside of the armor layer.

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