Submarine cable for ultra-deep water

Abstract

A submarine cable for ultra-deep water. The submarine cable comprises: a plurality of cable cores, a plurality of pre-formed filler strips and an outer protective structure, wherein the plurality of cable cores are tightly twisted together; the plurality of pre-formed filler strips are arranged in gaps between the plurality of cable cores; the outer protective structure is wrapped around the peripheries of the plurality of cable cores and the plurality of pre-formed filler strips. Each pre-formed filler strip is provided with a cavity, which extends in the direction of length of the pre-formed filler strip, and through holes, which are arranged at intervals in the direction of length of the pre-formed filler strip and penetrate into the cavity in a radial direction; and the outer protective structure is provided with flow holes. When a submarine cable for ultra-deep water is laid and placed into a deep sea, seawater can enter gaps between a plurality of cable cores and cavities of pre-formed filler strips by means of flow holes, which allows the air inside the submarine cable to be completely discharged, so that the pressure inside and outside the submarine cable keeps balanced, thereby avoiding an internal structure of the submarine cable being crushed, and thus prolonging the service life of the submarine cable.

Description

Ultra-deepwater submarine cables

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on October 24, 2023, with application number 202311382456.4 and application name “Submarine Cable for Ultra-Deep Waters”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of deep-sea cables, and in particular to a submarine cable for ultra-deep water use. Background Art

[0003] Marine scientific research often uses winders and metal-armored cables to carry underwater vehicles and exploration equipment to conduct environmental surveys and collect resource samples in various areas of the ocean. In practice, the metal-armored cables bear not only their own weight but also the drag from the underwater vehicle. The greater the water depth, the greater the stress on the armor layer. Furthermore, corrosion and failure of the armor layer in seawater can increase the risk of failure in deep-sea exploration.

[0004] The ocean depths greater than 6,500 meters are called the hadal zone. The hadal zone accounts for 1.2% of the total ocean surface and is one of the last unexplored regions on Earth. As deep-sea oil and gas exploration, deep-sea mining, and hadal exploration expand into the deep ocean, dynamic submarine optoelectronic composite submarine cables connecting floating structures and underwater equipment must address challenges such as self-weight, circumferential compression due to high water pressure, and metal armor failure under repeated environmental loads. Existing submarine cables are primarily designed for use in water depths of less than 1,000 meters, with limited practical applications beyond that.

[0005] When existing submarine cables are used in ultra-deep waters, the following problems exist:

[0006] (1) When laying submarine cables in deep water, seawater will enter the submarine cable from one end. Due to the speed of laying, the air inside the submarine cable cannot be discharged in time. When the air accumulates, it will form a huge air pressure, causing the sheath to bulge or even rupture and damage.

[0007] (2) As the water depth increases, the radial pressure of seawater on the submarine cable increases. The air inside the submarine cable causes a large pressure difference between the inside and outside of the submarine cable. The high pressure formed by the seawater outside the submarine cable can easily collapse the submarine cable and cause it to fail.

[0008] (3) When submarine cables are operating at extremely deep water, the filling strips inside the submarine cables are in a sealed state. Under the squeezing effect of external seawater, the filling strips are easily crushed and damaged. The cable core is subjected to high pressure, which will also cause the insulation to shrink and be damaged. At the same time, seawater will penetrate into the phase-separation sheath, causing corrosion of the metal shielding layer.

[0009] (4) The armor layer of the submarine cable needs to withstand great tension when it is laid in deep water. If the armor layer is not strong enough, it will yield and fail, affecting the normal use of the submarine cable.

[0010] Summary of the Invention

[0011] The present application provides a submarine cable for ultra-deep waters, which is used to solve the defect in the prior art that when submarine cables are used in ultra-deep waters, there is air inside the submarine cable, which causes a pressure difference between the inside and outside of the submarine cable, resulting in the submarine cable being easily collapsed and failing, and the filling strips and cable core being easily crushed and damaged.

[0012] The present application provides an ultra-deepwater submarine cable, comprising: a plurality of cable cores, a plurality of preformed filling strips, and an outer protective structure. The plurality of cable cores are tightly twisted together, the plurality of preformed filling strips are arranged in the gaps between the plurality of cable cores, and the outer protective structure is wrapped around the outer circumference of the plurality of cable cores and the plurality of preformed filling strips.

[0013] The preformed filling strip is provided with a cavity extending along its length and through holes arranged at intervals along its length, the through holes radially penetrate into the cavity, and the outer protective structure is provided with flow holes arranged at intervals along its length, and the gaps between the cable cores and the cavity of the preformed filling strip are connected to the outside of the outer protective structure via the flow holes.

[0014] When ultra-deepwater submarine cables are laid in seawater, seawater can enter the gaps between multiple cable cores and the cavities of preformed filling strips through the flow holes on the outer protective structure, allowing the air inside the submarine cable to be discharged smoothly, thereby avoiding the accumulation of air pressure that may cause bulging and damage to the structure, and ensuring the normal laying of the submarine cable. In addition, the cavities of the preformed filling strips are filled with seawater, and the internal and external pressures of the submarine cable are balanced. The internal structure of the submarine cable will not be flattened, which can ensure the normal transmission of electricity and extend the service life of the submarine cable.

[0015] According to an ultra-deepwater submarine cable provided by the present application, the number of the cable cores is three, the number of the preformed filling strips is three, the three cable cores are tightly arranged along the circumferential direction of the ultra-deepwater submarine cable, the three preformed filling strips are sequentially and spaced between two adjacent cable cores, and the three preformed filling strips and the three cable cores together roughly form a cylindrical structure.

[0016] The inner wall of the preformed filling strip can fit with the cable core to position and support the cable core. In addition, the three preformed filling strips and the three cable cores together form a roughly cylindrical structure, which facilitates the outer protective structure to be sheathed on the outside.

[0017] According to an ultra-deepwater submarine cable provided by the present application, the preformed filling strip includes a first arc-shaped portion, a second arc-shaped portion and an outer arc-shaped portion connected end to end in sequence, the first arc-shaped portion and the second arc-shaped portion are respectively used to fit two adjacent cable cores, the cavity is arranged in the first arc-shaped portion, the second arc-shaped portion and the outer arc-shaped portion, the through hole is arranged on the outer arc-shaped portion, and the flow hole of the outer protective structure is connected to the cavity via the through hole of the outer arc-shaped portion.

[0018] The cross-sections of the first arc-shaped portion and the second arc-shaped portion are roughly constructed as circular arcs. The first arc-shaped portion and the second arc-shaped portion can be respectively adapted to fit the outer walls of two adjacent cable cores. The cross-section of the outer arc-shaped portion is also roughly constructed as circular arcs. The outer arc-shaped portions of each of the three preformed filling strips can jointly form a roughly cylindrical outer wall structure to facilitate the outer protective structure to be arranged on the outside of the three preformed filling strips.

[0019] According to an ultra-deepwater submarine cable provided by the present application, a first reinforcing rib is provided between the first arc-shaped portion and the outer arc-shaped portion, a second reinforcing rib is provided between the second arc-shaped portion and the outer arc-shaped portion, the first reinforcing rib and the second reinforcing rib split the cavity into three isolation cavities, and the outer arc-shaped portion is respectively provided with the through hole corresponding to each of the isolation cavities.

[0020] The first reinforcing rib and the second reinforcing rib can be respectively extended in the radial direction of the submarine cable, and the first reinforcing rib and the second reinforcing rib are spaced apart in the circumferential direction of the submarine cable. The cavity inside the preformed filling strip is sequentially divided into three isolation cavities by the first reinforcing rib and the second reinforcing rib. In this way, the preformed filling strip can be prevented from being squeezed and deformed under the external force of seawater.

[0021] According to the present application, an ultra-deepwater submarine cable is provided, wherein the cable core includes: a water-blocking conductor, and a conductor shielding layer, a cross-linked polyethylene insulation layer, an insulating shielding layer, an inner semi-conductive water-resistant tape wrapping layer, a metal shielding layer, an outer semi-conductive water-resistant tape wrapping layer, an aluminum-plastic composite tape layer, and a phase-separated sheath, which are sequentially arranged on the periphery of the water-blocking conductor.

[0022] The outer periphery of the water-blocking conductor can be extruded with a conductor shielding layer, the outer periphery of the conductor shielding layer can be provided with a cross-linked polyethylene insulation layer, the outer periphery of the cross-linked polyethylene insulation layer can be provided with an insulating shielding layer, the outer periphery of the insulating shielding layer can be wrapped with an inner layer of semi-conductive water-blocking tape wrapping layer, the outer periphery of the inner layer of semi-conductive water-blocking tape wrapping layer can be wrapped with a metal shielding layer, the outer periphery of the metal shielding layer can be wrapped with an outer layer of semi-conductive water-blocking tape wrapping layer, the outer periphery of the outer layer of semi-conductive water-blocking tape wrapping layer can be longitudinally wrapped with an aluminum-plastic composite tape layer, and finally, the phase-separated sheath can be extruded and adhered to the outer periphery of the aluminum-plastic composite tape layer, thereby achieving the protection effect of the cable core.

[0023] According to the ultra-deepwater submarine cable provided by the present application, the cable core and the periphery of the preformed filling strip are jointly provided with a cable wrapping tape.

[0024] Preformed filling strips are arranged in the gaps between the three cable cores. During cabling, cabling tapes can be used to tightly bind the three cable cores and the preformed filling strips to ensure the roundness of the entire structure after cabling.

[0025] According to an ultra-deepwater submarine cable provided by the present application, the outer protective structure includes an inner sheath, a first armor layer, a first armor tape, a second armor layer, a second armor tape and an outer sheath, which are sequentially arranged on the cable core and the periphery of the preformed filling strip.

[0026] The inner sheath can be extruded around the periphery of the cabling tape, the first armor layer can be arranged around the periphery of the inner sheath, the first armor tape can be arranged around the periphery of the first armor layer, the second armor layer can be arranged around the periphery of the first armor tape, the second armor tape can be arranged around the periphery of the second armor layer, and finally, the outer sheath is extruded around the periphery of the second armor tape to further achieve a new protective effect of the cable.

[0027] According to an ultra-deepwater submarine cable provided by the present application, the flow holes of the outer protective structure include a first through hole provided on the inner sheath and a second through hole provided on the outer sheath.

[0028] In this way, the cavity in the preformed filling strip can be connected to the outside of the outer protective structure through the first through hole on the inner jacket and the second through hole on the outer jacket, allowing external seawater to enter the cavity in the preformed filling strip through the second through hole and the first through hole.

[0029] According to the ultra-deepwater submarine cable provided by the present application, the steel wires in the first armor layer and the steel wires in the second armor layer have opposite twisting directions.

[0030] The outer protective structure utilizes an armored structure comprised of multiple layers of high-strength steel wire. These layers are designed to withstand the immense tension during installation and deployment, ensuring compatibility with deep water depths. Furthermore, the even number of layers of anisotropically stranded metal armor ensures torque balance. During axial tension, each layer experiences uniform deformation, enhancing tensile strength.

[0031] According to an ultra-deepwater submarine cable provided by the present application, the steel wires in the first armor layer and the steel wires in the second armor layer are designed as high-strength steel wires.

[0032] In this way, the first armor layer and the second armor layer jointly bear the tension during the installation of the submarine cable, and also have good corrosion resistance.

[0033] In combination with the above technical solutions, the ultra-deepwater submarine cable provided by the present application is provided with an outer protective structure on the periphery of multiple cable cores and multiple preformed filling strips. The preformed filling strips are provided with cavities and through holes arranged at intervals along their length and radially extending into the cavities. The outer protective structure is provided with flow holes, so that when the ultra-deepwater submarine cable is laid and placed in the deep sea, seawater can enter the gaps between the multiple cable cores and the cavities of the preformed filling strips through the flow holes, allowing the air inside the submarine cable to be completely discharged, so that the pressure inside and outside the submarine cable is kept balanced, and the internal structure of the submarine cable is prevented from being crushed, thereby increasing the service life of the submarine cable. Moreover, the entire ultra-deepwater submarine cable adopts a lightweight structural design, which can reduce the overall outer diameter and deadweight, while also reducing material consumption and reducing costs, with certain economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] FIG1 is a schematic structural diagram of an ultra-deepwater submarine cable according to one embodiment of the present application;

[0036] FIG2 is a schematic diagram of the structure of the preformed filling strip in the ultra-deepwater submarine cable in FIG1 ;

[0037] FIG3 is a schematic diagram of the three-dimensional structure of the preformed filling strip in the ultra-deepwater submarine cable in FIG1 ;

[0038] FIG4 is a schematic structural diagram of the inner sheath of the ultra-deepwater submarine cable in FIG1 ;

[0039] FIG5 is a schematic structural diagram of the outer sheath of the ultra-deepwater submarine cable in FIG1 .

[0040] Reference numerals:

[0041] 10. Cable core; 11. Water-blocking conductor; 12. Conductor shielding layer; 13. Cross-linked polyethylene insulation layer; 14. Insulation shielding layer; 15. Inner semi-conductive water-blocking tape wrapping layer; 16. Metal shielding layer; 17. Outer semi-conductive water-blocking tape wrapping layer; 18. Aluminum-plastic composite tape layer; 19. Phase-separated sheath; 20. Preformed filling strip; 21. First arc-shaped portion; 22. Second arc-shaped portion; 23. Outer arc-shaped portion; 24. Through hole; 25. First reinforcing rib; 26. Second reinforcing rib; 27. First isolation cavity; 28. Second isolation cavity; 29. ​​Third isolation cavity; 30. Outer protective structure; 31. Inner sheath; 32. First armor layer; 33. First armor tape; 34. Second armor layer; 35. Second armor tape; 36. Outer sheath; 37. First through hole; 38. Second through hole; 40. Cabling tape. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0043] As those skilled in the art know, the ocean covers approximately 71% of the Earth's surface. It contains abundant energy resources such as oil, gas, natural gas hydrates, and solid minerals, making it a vital energy base and strategic activity space for humanity. Rich oil and mineral resources are often located thousands of meters underwater. Ocean areas deeper than 6,500 meters are known as the hadal zone, one of the last remaining unexplored regions on Earth.

[0044] Underwater drilling equipment is necessary for seabed exploration and energy resource extraction. When using underwater drilling equipment, power must be transmitted from the oil and gas platform to the equipment via submarine cables long enough to withstand the water depth. Submarine cables are subject to compression in the deep sea, which can easily cause structural deformation and failure.

[0045] In order to meet the demand for mining in ultra-deep waters, in one embodiment according to the present application, an ultra-deep water submarine cable is provided, which can be used to transmit electrical energy to underwater drilling and production equipment.

[0046] This ultra-deepwater submarine cable includes multiple cable cores, a number of preformed filler strips, and an outer protective structure. The preformed filler strips are provided with cavities and through-holes, and the outer protective structure is provided with flow holes. When the ultra-deepwater submarine cable is placed in the deep sea, seawater can enter the cavities of the preformed filler strips through the flow holes, maintaining pressure balance inside and outside the submarine cable, preventing damage to the internal structure of the submarine cable, and thereby extending the service life of the submarine cable. The ultra-deepwater submarine cable in this embodiment is further described below with reference to Figures 1 to 5.

[0047] As shown in FIG. 1 , the ultra-deepwater submarine cable in this embodiment includes: a plurality of cable cores 10 , a plurality of preformed filling strips 20 , and an outer protective structure 30 .

[0048] The plurality of cable cores 10 are tightly twisted together, the plurality of preformed filling strips 20 are arranged in the gaps between the plurality of cable cores 10 , and the outer protective structure 30 is wrapped around the periphery of the plurality of cable cores 10 and the plurality of preformed filling strips 20 .

[0049] For example, as shown in Figure 1, a cable core 10 is constructed in an elongated strip shape. A current-carrying conductor is disposed within the cable core for transmitting electrical energy. Multiple cable cores 10 are tightly twisted and installed in the center of an ultra-deepwater submarine cable. Preformed filler strips 20 are positioned closely against the cable cores 10 to fill the gaps between the cable cores 10, providing positioning and support for the cable cores 10.

[0050] The outer protective structure 30 is generally constructed as an elongated cylindrical structure, with the cable core 10 and preformed filler strips 20 disposed within the outer protective structure 30. When the ultra-deepwater submarine cable is placed in the deep sea, the outer protective structure 30 is in direct contact with the seawater, thereby protecting the cable core 10.

[0051] In this embodiment, the preformed filling strip 20 is provided with a cavity extending along its length and through holes 24 arranged at intervals along its length. The through holes 24 radially penetrate into the cavity. The outer protective structure 30 is provided with flow holes arranged at intervals along its length. The cavity of the preformed filling strip 20 is connected to the outside of the outer protective structure 30 via the flow holes.

[0052] It can be understood that the preformed filling strip 20 has a hollow structure, and the cavity in the preformed filling strip 20 extends along the length direction of the ultra-deepwater submarine cable. In addition, the cavity of the preformed filling strip 20 can be connected to the outside via the through hole 24 and the flow hole on the outer protective structure 30.

[0053] Furthermore, since ultra-deepwater submarine cables are of considerable length, it is necessary to ensure that seawater can promptly enter the cavity of the preformed filler strip 20 when the ultra-deepwater submarine cable is laid in seawater. To address this issue, in this embodiment, the through-holes 24 are sequentially spaced along the length of the preformed filler strip 20, and the flow holes are sequentially spaced along the length of the outer protective structure 30.

[0054] When the ultra-deepwater submarine cable in this embodiment is laid in seawater, seawater can enter the gaps between the multiple cable cores and the cavities of the preformed filling strips 20 through the flow holes on the outer protective structure 30, allowing the air inside the submarine cable to be discharged smoothly, thereby avoiding the accumulation of air pressure that causes bulging and damage to the structure, and ensuring the normal laying of the submarine cable.

[0055] When the ultra-deepwater submarine cable in this embodiment is laid in seawater, the cavity of the preformed filling strip 20 is filled with seawater, the internal and external pressures of the submarine cable are balanced, and the internal structure of the submarine cable will not be flattened, which can ensure the normal transmission of electricity and extend the service life of the submarine cable.

[0056] In this embodiment, as shown in Figure 1, the number of cable cores 10 is three, and the number of preformed filling strips 20 is three. The three cable cores 10 are tightly arranged along the circumferential direction of the ultra-deepwater submarine cable, and the three preformed filling strips 20 are sequentially filled between two adjacent cable cores 10. The three preformed filling strips 20 and the three cable cores 10 together form a roughly cylindrical structure.

[0057] Specifically, the three cable cores 10 can be tightly fitted around the central axis of the submarine cable. The cable cores 10 are generally elongated cylindrical structures, with gaps existing around the peripheries of two adjacent cable cores 10. The three preformed filler strips 20 are disposed in these three gaps in a one-to-one correspondence. Furthermore, the inner walls of the preformed filler strips 20 can be tightly fitted with the cable cores 10 to position and support the cable cores 10. At the same time, the outer walls of the preformed filler strips 20 can be roughly arc-shaped. In this case, the three preformed filler strips 20 and the three cable cores 10 together form a roughly cylindrical structure, thereby facilitating the external mounting of the outer protective structure 30.

[0058] In a specific embodiment, as shown in Figure 2, the preformed filling strip 20 includes a first arc-shaped portion 21, a second arc-shaped portion 22 and an outer arc-shaped portion 23 connected end to end in sequence. The first arc-shaped portion 21 and the second arc-shaped portion 22 are respectively used to fit two adjacent cable cores 10. The first arc-shaped portion 21, the second arc-shaped portion 22 and the outer arc-shaped portion 23 are connected end to end in sequence to form a cavity inside. The through hole 24 is provided on the outer arc-shaped portion 23, and the flow hole of the outer protective structure 30 is connected to the cavity via the through hole 24 of the outer arc-shaped portion 23.

[0059] It can be understood that the cross-sections of the first arc-shaped portion 21 and the second arc-shaped portion 22 are roughly constructed as a circular arc, and the first arc-shaped portion 21 and the second arc-shaped portion 22 can be respectively adapted to fit the outer walls of the two adjacent cable cores 10. The cross-section of the outer arc-shaped portion 23 is also roughly constructed as a circular arc, and the outer arc-shaped portions 23 of each of the three preformed filling strips 20 can together form a roughly cylindrical outer wall structure to facilitate the outer protective structure 30 to be set on the outside of the three preformed filling strips 20.

[0060] Furthermore, in order to prevent the preformed filling strip 20 from being squeezed and deformed under the external force of seawater, as shown in Figure 2, a first reinforcing rib 25 is provided between the first arc-shaped portion 21 and the outer arc-shaped portion 23, and a second reinforcing rib 26 is provided between the second arc-shaped portion 22 and the outer arc-shaped portion 23. The first reinforcing rib 25 and the second reinforcing rib 26 divide the cavity into three isolation cavities, and the outer arc-shaped portion 23 is respectively provided with a through hole 24 corresponding to each isolation cavity.

[0061] It can be understood that the first reinforcing rib 25 and the second reinforcing rib 26 can be respectively extended in the radial direction of the submarine cable, and the first reinforcing rib 25 and the second reinforcing rib 26 are spaced apart in the circumferential direction of the submarine cable, and the cavity inside the preformed filling strip 20 is sequentially divided into three isolation cavities by the first reinforcing rib 25 and the second reinforcing rib 26.

[0062] For example, as shown in FIG. 2 , the cavity inside the preformed filling strip 20 is divided into a first isolated cavity 27 , a second isolated cavity 28 and a third isolated cavity 29 .

[0063] 2 and 3 , the outer arcuate portion 23 is provided with a through hole 24 corresponding to each isolation cavity. In this case, each outer arcuate portion 23 is provided with three through holes 24 in sequence along the circumferential direction of the submarine cable.

[0064] Of course, in other embodiments, based on the analysis of water pressure at different water depths, other numbers of reinforcing ribs may be provided to ensure that the preformed filling strip will not be crushed in actual use.

[0065] In this embodiment, as shown in Figure 1, the cable core 10 includes: a water-blocking conductor 11, and a conductor shielding layer 12, a cross-linked polyethylene insulation layer 13, an insulating shielding layer 14, an inner semi-conductive water-blocking tape wrapping layer 15, a metal shielding layer 16, an outer semi-conductive water-blocking tape wrapping layer 17, an aluminum-plastic composite tape layer 18 and a phase-separation sheath 19, which are sequentially arranged on the periphery of the water-blocking conductor 11.

[0066] As an implementation method, the outer periphery of the water-blocking conductor 11 can be extruded with a conductor shielding layer 12, the outer periphery of the conductor shielding layer 12 can be provided with a cross-linked polyethylene insulation layer 13, the outer periphery of the cross-linked polyethylene insulation layer 13 can be provided with an insulating shielding layer 14, the outer periphery of the insulating shielding layer 14 can be wrapped with an inner layer semi-conductive water-blocking tape wrapping layer 15, the outer periphery of the inner layer semi-conductive water-blocking tape wrapping layer 15 can be wrapped with a metal shielding layer 16, the outer periphery of the metal shielding layer 16 can be wrapped with an outer layer semi-conductive water-blocking tape wrapping layer 17, the outer periphery of the outer layer semi-conductive water-blocking tape wrapping layer 17 can be longitudinally wrapped with an aluminum-plastic composite tape layer 18, and finally, the phase-separation sheath 19 can be extruded and adhered to the outer periphery of the aluminum-plastic composite tape layer 18.

[0067] In this embodiment, the three cable cores 10 have the same structure. In this case, a total of three water-blocking conductors 11 are provided in the ultra-deepwater submarine cable.

[0068] For example, the water-blocking conductor 11 is made of copper or aluminum. When stranded, the conductor 11 can be filled with a semi-conductive water-resistant adhesive. This adhesive has strong water-blocking properties, effectively preventing seawater from penetrating the conductor, meeting the requirements for use at great depths. Furthermore, the outermost layer of the water-blocking conductor 11 can be wrapped with two layers of semi-conductive water-resistant binding tape, thereby ensuring longitudinal water-blocking properties within the core of the conductor 11.

[0069] Optionally, the volume resistivity of the semiconducting water-blocking adhesive used in the water-blocking conductor 11 is ≤1×105Ω·cm (23±2℃), the thermal weight loss under 200℃ for 2 hours is less than 2%, and the elongation at break after the water-blocking adhesive is cured is ≥600%, ensuring the adhesion between the water-blocking adhesive and the conductor when the conductor is repeatedly bent.

[0070] Exemplarily, the conductor shielding layer 12 is made of extruded semi-conductive shielding material.

[0071] Exemplarily, the cross-linked polyethylene insulation layer 13 is made of water-tree resistant cross-linked polyethylene material, which is uniformly extruded around the outer periphery of the conductor shielding layer 12 .

[0072] Optionally, the cross-linked polyethylene insulation layer 13 may be designed to have the thinnest thickness that meets the field strength requirement.

[0073] Illustratively, the insulating shielding layer 14 may be made of a semi-conductive shielding material, which is directly extruded onto the outer periphery of the cross-linked polyethylene insulating layer 13 .

[0074] For example, both the inner semiconducting tape wrapping layer 15 and the outer semiconducting tape wrapping layer 17 may be made of semiconducting tape, and both are synchronously wrapped around the outer periphery of the insulating shielding layer 14 with the metal shielding layer 16 .

[0075] For example, the metal shielding layer 16 can be made of two layers of 0.1 or 0.12 mm thick copper tapes. Moreover, the metal shielding layer 16 can be wrapped with a single layer overlap or a double layer gap overlap. The width can be selected according to the outer diameter of the cable core and the short-circuit current requirements.

[0076] For example, the aluminum-plastic composite tape layer 18 can be longitudinally wrapped with a layer of 0.245 mm thick aluminum-plastic composite tape, and the overlapping parts of the longitudinal wrapping are sealed by welding. The width is selected according to the outer diameter of the cable core and the process method.

[0077] For example, the phase separation sheath 19 is made of semi-conductive polyethylene material, which is directly extruded on the outer periphery of the aluminum-plastic composite tape layer 18 so as to protect the entire cable core 10 and also has a certain water-blocking effect.

[0078] In the cable core 10, the cross-linked polyethylene insulation layer 13 is designed with the thinnest thickness that meets the field strength requirements, and the metal shielding layer 16 is designed with the thinnest metal strip that meets the short-circuit current requirements. This can reduce the outer diameter of the submarine cable, while also reducing the overall weight and the tension required for deep water laying, thereby meeting the requirements for deep water use.

[0079] Furthermore, the outer periphery of the metal shield 16 is wrapped with an aluminum-plastic composite tape, which acts as a radial water barrier in ultra-deepwater environments, effectively reducing the possibility of seawater penetrating through the phase-separated sheath into the metal shield 16 and causing corrosion. Furthermore, under high water pressure, the pressure on the internal insulated core is significantly reduced, effectively preventing the insulated core from being squeezed and damaged.

[0080] Furthermore, the preformed filling strip 20 can be made of plastics such as polyethylene, polyvinyl chloride, etc. mixed with calcium carbonate for extrusion, wherein the calcium carbonate is used to increase the strength of the preformed filling strip.

[0081] In this embodiment, as shown in FIG. 1 , a cabling tape 40 is provided on the outer peripheries of the cable core 10 and the preformed filling strip 20 .

[0082] It can be understood that the preformed filling strips 20 are provided in the cabling gaps between the three cable cores 10 , and the cabling tape 40 can be used to tightly bind the three cable cores 10 and the preformed filling strips 20 during cabling.

[0083] For example, the cabling tape 40 may be a layer of 0.3 mm thick rubberized cotton tape, which is used to bind the three cable cores 10 and the preformed filling strips 20 tightly, so as to ensure the roundness of the entire structure after cabling.

[0084] In this embodiment, as shown in Figure 1, the outer protective structure 30 includes an inner sheath 31, a first armor layer 32, a first armor tape 33, a second armor layer 34, a second armor tape 35 and an outer sheath 36, which are sequentially arranged on the periphery of the cable core 10 and the preformed filling strip 20.

[0085] As an implementation method, the inner sheath 31 can be extruded around the outer periphery of the cabling tape 40, the first armor layer 32 can be arranged around the outer periphery of the inner sheath 31, the first armor tape 33 can be arranged around the outer periphery of the first armor layer 32, the second armor layer 34 can be arranged around the outer periphery of the first armor tape 33, the second armor tape 35 can be arranged around the outer periphery of the second armor layer 34, and finally, the outer sheath 36 is extruded around the outer periphery of the second armor tape 35.

[0086] For example, the inner sheath 31 may be made of high-density polyethylene material, which is directly extruded onto the cabling tape 40 .

[0087] For example, the first armor layer 32 may be a layer of galvanized high-strength steel wire, which is used to withstand the tension during installation of the submarine cable and also has good corrosion resistance.

[0088] Similarly, the second armor layer 34 may also be made of a layer of galvanized high-strength steel wire, which can jointly withstand the tension exerted on the submarine cable during installation with the first armor layer 32 and also has good corrosion resistance.

[0089] It can be understood that galvanized steel wire has good corrosion resistance, can effectively prevent seawater corrosion, and meet the requirements of use in deep water.

[0090] At the same time, the steel wires in the first armor layer 32 and the steel wires in the second armor layer 34 may have opposite twist directions, for example, the twist direction of the steel wires in the first armor layer 32 is to the right and the twist direction of the steel wires in the second armor layer 34 is to the left, thereby balancing the torque.

[0091] The outer protective structure utilizes an armored structure comprised of multiple layers of high-strength steel wire. These layers can withstand the immense tension during installation and deployment, ensuring compatibility with deep water depths. Furthermore, the even number of layers of anisotropically stranded metal armor ensures torque balance. During axial tension, each layer experiences uniform deformation, enhancing tensile strength.

[0092] For example, the first armor wrapping tape 33 is a 0.3 mm thick rubberized cotton tape, which is used to tighten the steel wires in the first armor layer 32 to ensure the roundness of the structure after the first layer of armoring.

[0093] Similarly, the second armor tape 35 uses two layers of 0.5 mm thick PBT tape to tighten the steel wires in the second armor layer 34 and all internal structures to ensure the roundness of the structure after the second layer of armor is applied.

[0094] For example, the outer sheath 36 may be made of high-density polyethylene material, which is directly extruded onto the outer circumference of the second armor tape 35 .

[0095] The outer sheath 36, as the structure that directly contacts the outside world, may be marked on its outer surface for easy identification. For example, the outer sheath 36 may be primarily yellow with narrow, elongated black stripes. The yellow main color facilitates identification of the submarine cable in deep water, while the narrow, elongated black stripes allow monitoring of the torsion angle during cable tension.

[0096] In this embodiment, as shown in FIG. 4 and FIG. 5 , the flow holes of the outer protective structure 30 include first through holes 37 provided on the inner jacket 31 and second through holes 38 provided on the outer jacket 36 .

[0097] That is to say, the cavity in the preformed filling strip 20 can be connected to the outside of the outer protective structure 30 by means of the first through hole 37 on the inner jacket 31 and the second through hole 38 on the outer jacket 36, so that external seawater can enter the cavity in the preformed filling strip 20 through the second through hole 38 and the first through hole 37.

[0098] For example, the first through holes 37 on the inner sheath 31 can be arranged in sequence along the length direction of the inner sheath 31 at intervals, and the distance between two adjacent first through holes 37 can be determined according to the laying speed of the submarine cable and water pressure analysis. Moreover, the opening size of the first through holes 37 is determined according to the free overflow rate and water pressure analysis.

[0099] Similarly, the second through holes 38 on the outer sheath 36 can be arranged in sequence along the length direction of the outer sheath 36 at intervals. The distance between two adjacent second through holes 38 can be determined based on the laying speed of the submarine cable and water pressure analysis. Moreover, the opening size of the second through holes 38 is determined based on the free overflow rate and water pressure analysis.

[0100] In addition, the thickness of the outer sheath 36 can be determined according to the water pressure requirement to ensure that the outer sheath 36 has better protection effect and mechanical properties such as wear resistance and pressure resistance.

[0101] It can be seen that the ultra-deepwater submarine cable in this embodiment includes: multiple cable cores, multiple preformed filling strips and an outer protective structure. The outer protective structure is arranged on the periphery of the multiple cable cores and the multiple preformed filling strips. The preformed filling strips are provided with cavities and through holes arranged at intervals along their length and radially penetrating into the cavities. The outer protective structure is provided with flow holes. When the ultra-deepwater submarine cable is laid and placed in the deep sea, seawater can enter the gaps between the multiple cable cores and the cavities of the preformed filling strips through the flow holes, so that the air inside the submarine cable can be completely discharged, so that the pressure inside and outside the submarine cable is balanced, and the internal structure of the submarine cable is prevented from being crushed, thereby improving the service life of the submarine cable.

[0102] Moreover, the entire ultra-deepwater submarine cable adopts a lightweight structural design, which can reduce the overall outer diameter and weight, while also reducing material consumption and lowering costs, thus achieving certain economic benefits.

[0103] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An ultra-deepwater submarine cable, characterized in that: include: A plurality of cable cores, a plurality of preformed filling strips and an outer protective structure, wherein the plurality of cable cores are tightly twisted together, the plurality of preformed filling strips are arranged in the gaps between the plurality of cable cores, and the outer protective structure is wrapped around the periphery of the plurality of cable cores and the plurality of preformed filling strips. Among them, the preformed filling strip is provided with a cavity extending along its length direction and through holes arranged at intervals along its length direction, the through holes radially penetrate into the cavity, and the outer protective structure is provided with flow holes arranged at intervals along its length direction, and the gap between the cable cores and the cavity of the preformed filling strip are connected to the outside of the outer protective structure via the flow holes.

2. The ultra-deepwater submarine cable according to claim 1, characterized in that: The number of the cable cores is three, the number of the preformed filling strips is three, the three cable cores are tightly fitted along the circumferential direction of the ultra-deepwater submarine cable, the three preformed filling strips are sequentially and spaced and filled between two adjacent cable cores, and the three preformed filling strips and the three cable cores together roughly form a cylindrical structure.

3. The ultra-deepwater submarine cable according to claim 2, characterized in that: The preformed filling strip includes a first arc-shaped portion, a second arc-shaped portion and an outer arc-shaped portion which are connected end to end in sequence, the first arc-shaped portion and the second arc-shaped portion are respectively used to fit two adjacent cable cores, the cavity is arranged in the first arc-shaped portion, the second arc-shaped portion and the outer arc-shaped portion, the through hole is arranged on the outer arc-shaped portion, and the flow hole of the outer protective structure is connected with the cavity via the through hole of the outer arc-shaped portion.

4. The ultra-deepwater submarine cable according to claim 3, characterized in that: A first reinforcing rib is arranged between the first arc-shaped portion and the outer arc-shaped portion, and a second reinforcing rib is arranged between the second arc-shaped portion and the outer arc-shaped portion. The first reinforcing rib and the second reinforcing rib divide the cavity into three isolation cavities, and the outer arc-shaped portion is respectively provided with the through hole corresponding to each of the isolation cavities.

5. The ultra-deepwater submarine cable according to claim 1, characterized in that: The cable core comprises: a water-blocking conductor, and a conductor shielding layer, a cross-linked polyethylene insulation layer, an insulation shielding layer, an inner semiconductor water-blocking tape wrapping layer, a metal shielding layer, an outer semiconductor water-blocking tape wrapping layer, an aluminum-plastic composite tape layer and a phase-separated sheath which are sequentially arranged on the outer periphery of the water-blocking conductor.

6. The ultra-deepwater submarine cable according to claim 1, characterized in that: The outer peripheries of the cable core and the preformed filling strip are jointly provided with a cabling wrapping tape.

7. The ultra-deepwater submarine cable according to claim 1, characterized in that: The outer protection structure comprises an inner sheath, a first armor layer, a first armor tape, a second armor layer, a second armor tape and an outer sheath which are sequentially arranged on the outer periphery of the cable core and the preformed filling strip.

8. The ultra-deepwater submarine cable according to claim 7, characterized in that: The flow holes of the outer protection structure include a first through hole provided on the inner jacket and a second through hole provided on the outer jacket.

9. The ultra-deepwater submarine cable according to claim 7, characterized in that: The steel wires in the first armor layer and the steel wires in the second armor layer have opposite twisting directions.

10. The ultra-deepwater submarine cable according to claim 7, characterized in that: The steel wires in the first armor layer and the steel wires in the second armor layer are designed as high-strength steel wires.

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