Dynamic submarine cable

Abstract

A dynamic submarine cable disclosed by the present invention comprises a conductor unit, an optical fiber unit, a filling strip and an armoring structure, the conductor unit is annularly arranged at the center position of the cable, the filling strip is arranged between the conductor unit and the armoring structure and is attached to the conductor unit and the armoring structure, and the cross section of the filling strip is of a hollow symmetrical structure. The middle position is provided with a fixing groove for fixing the optical fiber unit, and the filling strip is made of semi-conductive materials. Each conductor unit comprises an insulating wire core and a metal sheath arranged outside the insulating wire core; each insulated wire core sequentially comprises a conductor, a conductor shield, an insulator, an insulation shield and a water-blocking buffer layer from inside to outside, the plurality of insulated wire cores are annularly arranged along the center of the cable, and the metal sheath is extruded outside the insulated wire cores. The filling strip is made of a semi-conductive material and can be in direct contact with the metal sheath and the optical fiber unit, so that equipotential is realized among the metal sheath, the filling strip and the optical fiber unit, and the heating risk of the optical fiber unit in the submarine cable operation process is effectively reduced.

Description

Technical Field

[0001] The invention relates to a dynamic submarine cable and belongs to the technical field of cable preparation. Background Art

[0002] Submarine cables are important infrastructure for connecting communications and electricity between different lands. With the acceleration of globalization and technological advancement, the demand for transoceanic data exchange and power transmission is growing, making submarine cable technology an indispensable part of the modern information society. The structure and preparation process of the cable have a great impact on its performance. In the existing dynamic cable preparation process, copper wire or copper tape is generally used as the metal protective layer, which is heavy and uneconomical. In addition, the potential difference between the inner sheath and the outer armor structure is often too large, which causes excessive heating of the optical fiber unit during operation, eventually causing operational failures and triggering a large number of maintenance needs. In order to reduce the laying workload and solve the problem of optical fiber heating, it is necessary to carry out targeted design of the structure of the submarine cable. Summary of the invention

[0003] In order to solve the problems in the above-mentioned background technology, the present invention provides a dynamic submarine cable, which improves the cable structure.

[0004] The technical solution for achieving the purpose of the present invention is: a dynamic submarine cable, comprising a conductor unit, an optical fiber unit, a filling strip and an armor structure, wherein the conductor unit is arranged in a ring at the center of the cable, the filling strip is arranged between the conductor unit and the armor structure and is arranged in close contact with the conductor unit and the armor structure, the cross-section of the filling strip is a hollow symmetrical structure, and a fixing groove for fixing the optical fiber unit is provided in the middle position, and the filling strip is made of semi-conductive material; the conductor unit comprises an insulating core and a metal sheath arranged on the outside thereof; the insulating core comprises, from the inside to the outside, a conductor, a conductor shield, insulation, an insulating shield and a water-blocking buffer layer, a plurality of insulating cores are arranged in a ring along the center of the cable, the metal sheath is extruded outside the insulating core and has the same pitch as the insulating core.

[0005] The filling strip of the present application has a hollow structure and is lighter in weight, which is beneficial to reducing the dead weight of the cable and thus reducing the laying cost. The filling strip is made of semi-conductive material and can be in direct contact with the metal sheath and the optical fiber unit, so that the metal sheath, the filling strip and the optical fiber unit can achieve equal potential, thereby effectively reducing the risk of heating of the optical fiber unit during the operation of the submarine cable.

[0006] Further or optionally, the metal sheath has the same pitch as the insulating core.

[0007] In the dynamic submarine cable structure of the present application, the metal sheath is processed by extrusion and the pitch of the metal sheath is equal to that of the insulating core, which can effectively ensure the bending performance of the cable, fit more closely with the insulating core, and have a better overall heat dissipation effect.

[0008] The armor structure is composed of a cable wrapping tape, an inner sheath, a metal armor layer and an outer sheath from the inside to the outside. The metal armor layer is a double-layer reverse steel wire armor, which mainly enhances the mechanical strength and torsional resistance of the cable, balances the torsional torque through the asymmetric twisting design, reduces torsional and knotting problems during laying and use, and improves the fatigue resistance and service life of the cable, thereby ensuring the stability and reliability of the cable in complex marine environments.

[0009] Further or optionally, in order to reduce the weight of the submarine cable while ensuring its mechanical strength and electrical conductivity, the metal sheath material is aluminum, and its excellent ductility and extrusion properties are also conducive to reducing processing difficulty.

[0010] Further or optionally, in order to improve the corrosion resistance of the aluminum sheath, the surface of the metal sheath is provided with a sprayed anti-corrosion paint.

[0011] Further or optionally, in order to improve the wear resistance and corrosion resistance of the outer sheath, the outer sheath material is HDPE.

[0012] Further or optionally, additives such as UV stabilizers may be added to the sheath material to enhance its heat and ozone resistance and extend the service life of the dynamic cable.

[0013] Further or optionally, in order to improve the waterproofness and conductivity of the conductor, the conductor is a compressed round conductor and is filled with a water-blocking material.

[0014] Further or optionally, in order to improve the tightness of interlayer bonding, reduce interlayer defects, and shorten the preparation process, a three-layer co-extrusion process is adopted between the conductor shielding, insulation, and insulation shielding.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects:

[0016] (1) The filling strip of the present application has a hollow structure and is lighter in weight, which is beneficial to reducing the weight of the cable and thus reducing the laying cost; the filling strip is made of semi-conductive material and can be in direct contact with the metal sheath and the optical fiber unit, so that the metal sheath, the filling strip and the optical fiber unit can achieve equipotentiality, thereby effectively reducing the risk of heating of the optical fiber unit during the operation of the submarine cable.

[0017] (2) In the dynamic submarine cable structure of the present application, the metal sheath is processed by extrusion and the pitch of the metal sheath is equal to that of the insulating core, which can effectively ensure the bending performance of the cable, fit more closely with the insulating core, and have a better overall heat dissipation effect.

[0018] (3) The metal armor layer of the present application is a double-layer reverse steel wire armor, which mainly enhances the mechanical strength and torsional resistance of the cable, balances the torsional torque through the anisotropic twisting design, reduces the torsion and knotting problems during laying and use, and improves the fatigue resistance and service life of the cable, thereby ensuring the stability and reliability of the cable in complex marine environments.

[0019] (4) The metal sheath of the present application adopts an extruded aluminum sheath, which effectively reduces the weight of the submarine cable and has better mechanical properties and conductive properties.

[0020] (5) The surface of the aluminum sheath of the present application has an anti-corrosion coating, which can enhance the anti-corrosion ability of the aluminum sheath.

[0021] (6) The inner sheath material of the present application is HDPE, which has better corrosion resistance and waterproof performance.

[0022] (7) The outer sheath material of the present application is HDPE, which has better wear resistance and corrosion resistance.

[0023] (8) The conductor of the present application is a compact circular conductor and the gaps are filled with water-blocking material, so the conductor has stronger waterproof performance and better conductive performance.

[0024] (9) The conductor shielding, insulation, and insulation shielding of the present application adopt a three-layer co-extrusion process, which has better interlayer bonding and higher production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] The reference numerals in the accompanying drawings are:

[0028] Conductor unit 1, insulated core 11, conductor 111, conductor shield 112, insulation 113, insulation shield 114, water-blocking buffer layer 115, metal sheath 12, optical fiber unit 2, filling strip 3, armor structure 4, cabling tape 41, inner sheath 42, metal armor layer 43, outer sheath 44. DETAILED DESCRIPTION

[0029] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of the embodiments of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is conventionally placed when used, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The present invention is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0035] (Example 1)

[0036] See Figure 1A submarine cable comprises a conductor unit 1, an optical fiber unit 2, a filling strip 3 and an armor structure 4, wherein the conductor unit 1 is arranged in a ring at the center of the cable, the filling strip 3 is arranged between the conductor unit 1 and the armor structure 4 and is arranged in close contact with the conductor unit 1 and the armor structure 4, the cross section of the filling strip 3 is a hollow symmetrical structure, and a fixing groove 31 for fixing the optical fiber unit 2 is provided in the middle position, and the filling strip 3 is made of semi-conductive material; the conductor unit 1 comprises an insulating core 11 and a metal sheath 12 arranged outside the insulating core 11; the insulating core 11 comprises a conductor 111, a conductor shield 112, an insulation 113, an insulating shield 114 and a water-blocking buffer layer 115 from the inside to the outside, a plurality of insulating cores 11 are arranged in a ring along the center of the cable, the metal sheath 12 is extruded outside the insulating core 11, and has the same pitch as the insulating core 11.

[0037] In the above structure, the conductor 111 is first prepared. Specifically, the conductor 111 is obtained by twisting multiple conductor cores, wherein the central conductor core adopts a circular structure, and a tile-shaped structure is adopted from the second layer. After being laid layer by layer, they are twisted. After twisting, the conductor shield 112, the insulation 113, and the insulation shield 114 are co-extruded. After extrusion, a water-blocking buffer layer 115 is coated on the outside to form an insulating core 11. After multiple insulating cores 11 are twisted, their overall cross-sectional shape and radius are measured, and then the metal sheath 12 is prepared.

[0038] The metal sheath 12 is prepared by an extrusion process. In the actual production process, the insulated core 11 is twisted while the metal sheath 12 is extruded. In order to balance the mechanical strength while meeting the conductivity, the material is optimized. Specifically, aluminum can be selected as the material of the metal sheath 12.

[0039] During the extrusion process, attention should be paid to controlling the pitch. The thickness of the insulating core 11 needs to be reduced at the nodes to form an equal movable pitch at the pitch position of the insulating core 11. In this way, when the cable is twisted, the outer metal sheath 12 can also rotate, greatly improving its flexibility.

[0040] In the above structure, the cross section of the filling strip 3 is a triangular structure with two symmetrical wings, and there is an optical fiber fixing groove between the two wings. The two wings of the filling strip 3 are composed of triangular areas of unequal areas. In actual design, the side close to the insulating core 11 is set as the inner arc surface, and the side close to the metal sheath 12 is set as the outer arc surface. There are many different inner arc surface structures according to the twisting method of the insulating core 11. The outer arc surface needs to be divided into a symmetrical first outer arc surface and a second outer arc surface because a fixing groove needs to be left to facilitate the embedding of the optical fiber unit. In order to reduce the number of divisions in the setting of the triangular area, increase the blank area and thus reduce the deadweight of the filling strip 3 to the greatest extent, for one side of the two wings, a connection point can be set at the midpoint of the inner arc surface and the midpoint of the outer arc surface, and then a first connection line is drawn from the intersection of the fixed groove and the outer arc surface to the midpoint of the inner arc surface, and then a second connection line is drawn from the midpoint of the inner arc surface to the midpoint of the outer arc surface. This structure divides the two wing areas into triangles, and while forming a stable support, the sum of the lengths between the connection lines can be minimized, thereby effectively reducing the overall material usage of the filling strip 3. Since the filling strip 3 also has the function of conducting the metal sheath and the optical fiber unit, its material needs to be selected. It is best to use a semi-conductive material, such as a polyethylene-based composite material doped with graphite or carbon black, a cross-linked polyethylene-based composite material, an ethylene-propylene rubber-based composite material or a silicone rubber-based composite material. The specific selection is carefully based on the overall temperature test data of the submarine cable. When designing, it is necessary to select between material density and temperature resistance, and it is also necessary to consider practical issues such as the stability of raw material supply.

[0041] In terms of electrical structure, in order to effectively homogenize the electric field distribution, reduce the electric field concentration phenomenon, thereby reducing the risk of local discharge, and at the same time avoid the problem of interface air gap in the traditional double sheath structure, the electrical performance of the cable is significantly improved, and the electrical performance and service life of the cable are improved. The metal sheath 12 is in direct contact with the semi-conductive PE filling strip 3.

[0042] After the metal sheath 12 is extruded, anti-corrosion paint is sprayed on the surface, the filling strip 3 is placed in the gap of the metal sheath 12, and then a cable wrapping tape 41 is wrapped around the outer layer, and then an inner sheath 42 is wrapped around the outer layer, and then the outer layer is armored, a metal armor layer 43 is set, and finally an outer sheath 44 is set.

[0043] In the above structure, in order to improve the stability and reliability of the dynamic cable in a dynamic environment, a double-layer reverse steel wire armor is adopted. The reverse twisting of the inner and outer steel wires can effectively offset the torque generated by the cable during the twisting process, thereby significantly reducing the risk of knotting and breakage caused by twisting during the laying and use of the cable.

[0044] In the above structure, in order to improve corrosion resistance and waterproofness, it is necessary to select the material of the inner sheath 42. In actual tests, HDPE has a better effect. In order to improve the wear resistance and corrosion resistance of the outer sheath, HDPE is used as the outer sheath material.

[0045] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A dynamic submarine cable, characterized in that: The invention comprises a conductor unit (1), an optical fiber unit (2), a filling strip (3) and an armor structure (4), wherein the conductor unit (1) is arranged in a ring shape at the center of the cable, the filling strip (3) is arranged between the conductor unit (1) and the armor structure (4) and is arranged in close contact with the conductor unit (1) and the armor structure (4), the filling strip (3) has a hollow symmetrical structure in cross section, and has a fixing groove (31) in the middle for fixing the optical fiber unit (2), and the filling strip (3) is made of semi-conductive material; the conductor unit (1) comprises an insulating core (11) and a metal sheath (12) arranged outside the insulating core (11); the insulating core (11) comprises, from inside to outside, a conductor (111), a conductor shield (112), insulation (113), an insulating shield (114) and a water-blocking buffer layer (115), a plurality of insulating cores (11) are arranged in a ring shape along the center of the cable, and the metal sheath (12) is extruded outside the insulating core (11).

2. A dynamic submarine cable according to claim 1, characterized in that: The metal sheath (12) and the insulating core (11) have the same pitch.

3. A dynamic submarine cable according to claim 1, characterized in that: The armor structure (4) comprises, from the inside to the outside, a cable wrapping tape (41), an inner sheath (42), a metal armor layer (43) and an outer sheath (44).

4. A dynamic submarine cable according to claim 1, characterized in that: The material of the metal sheath (12) is aluminum.

5. A dynamic submarine cable according to claim 2, characterized in that: The metal armor layer (43) is a double-layer reverse armor with nylon tapes arranged between them.

6. A dynamic submarine cable according to claim 2, characterized in that: The inner sheath (42) is made of HDPE.

7. A dynamic submarine cable according to claim 2, characterized in that: The outer sheath (44) is a HDPE sheath.

8. A dynamic submarine cable according to claim 2, characterized in that: The conductor (111) is a compacted circular conductor and is filled with a water-blocking material.

9. A dynamic submarine cable according to claim 2, characterized in that: A three-layer co-extrusion process is used between the conductor shield (112), the insulation (113) and the insulation shield (114).

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