High-current-carrying-capacity anti-corrosion armored medium-voltage submarine cable

Abstract

The invention relates to the technical field of submarine cables, in particular to a high-current-carrying-capacity anti-corrosion armored medium-voltage submarine cable which comprises three wire cores, and each wire core comprises a water-blocking conductor, a conductor shielding layer, a water-tree-resistant insulating layer, an insulating shielding layer, a first semi-conductive buffer water-blocking layer, a metal shielding layer and a second semi-conductive buffer water-blocking layer. According to the high-current-carrying-capacity anti-corrosion armored medium-voltage submarine cable, a traditional lead sleeve structure is replaced with copper wire and copper strip shielding, the weight of the submarine cable is reduced, and meanwhile the water-resistant performance of the submarine cable wire cores is compensated in a water-tree-resistant insulation and extrusion HDPE filling mode; the armoring layer adopts the galvanized non-magnetic steel wire, and is more economical than a copper wire armoring layer; the HDPE sheath is extruded outside the galvanized non-magnetic steel wire, so that the steel wire is prevented from being corroded in a seawater environment, meanwhile, the HDPE sheath can protect a zinc coating on the surface of the non-magnetic steel wire, and the problem that the tin coating on the surface of the galvanized non-magnetic steel wire is easy to fall off is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine cables, and in particular to a medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor. Background Art

[0002] Offshore wind power is an important part of achieving low-carbon transformation of energy. The offshore distance of offshore wind farms is getting farther and farther, and the capacity of wind farms is getting larger and larger, which brings technical challenges to 35kV and 66kV array submarine cables. At the same time, the market's further demand for cost reduction and efficiency improvement will be more urgent.

[0003] During the long-distance power transmission of submarine cables, eddy current effects will occur in the armor layer, resulting in losses, leading to temperature rise, and greatly reducing the current-carrying capacity of submarine cables. Traditionally, generally, the current-carrying capacity is increased by increasing the conductor cross-section or adopting a copper wire armor structure. Although this method can achieve the effect of capacity expansion, it greatly increases the raw material and manufacturing costs of submarine cables.

[0004] The armor structure provides mechanical protection for submarine cables and can withstand the huge tension generated by the self-weight of submarine cables during laying. After the submarine cable is laid underwater, its metal armor layer will be directly exposed to seawater. Although the industry currently adopts the methods of galvanizing the armor steel wire before production and coating asphalt on the armor layer during the production process to alleviate the degree of corrosion of the armor steel wire by seawater, relevant research shows that the failure life of the armor steel wire is still far less than the design life of the submarine cable itself. After the steel wire is corroded, it cannot play the due mechanical protection role for the submarine cable, greatly increasing the danger of submarine cable operation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that: currently, the failure life of the armor steel wire is still far less than the design life of the submarine cable itself. After the steel wire is corroded, it cannot play the due mechanical protection role for the submarine cable, greatly increasing the danger of submarine cable operation. At the same time, there are gaps in the armor connection surface of the submarine cable, which are very likely to cause corrosion at the joints. Moreover, during operation, the state of the cable cannot be detected, resulting in limited safety and inability to maintain it in time.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor, including three cores. Each core includes a water-blocking conductor, a conductor shielding layer, a water-tree resistant insulation layer, an insulation shielding layer, a first semi-conductive buffer water-blocking layer, a metal shielding layer, and a second semi-conductive buffer water-blocking layer. A wrapping layer, an HDPE sheath, an armor layer, and an armor outer sheath are sequentially arranged around the cores.

[0007] The water-blocking conductor is formed by stranding multiple single-wire conductors. Each layer of single wires is first stranded together with water-blocking yarns, then a water-blocking tape is longitudinally wrapped, and the outermost layer of single wires is stranded separately.

[0008] The conductor shielding layer is formed by winding a semiconductive tape and extruding a semiconductive shielding compound. The water tree resistant insulation layer is formed by extruding a water tree resistant insulation compound on the outer surface of the conductor shielding layer. The insulation shielding layer is formed by extruding a semiconductive shielding compound on the outer surface of the insulation layer. The conductor shielding layer, the water tree resistant insulation layer, and the insulation shielding layer are produced by triple extrusion.

[0009] The first semiconductive buffer water blocking layer is wound around the outer surface of the insulation shielding layer, and the second semiconductive buffer water blocking layer is wound around the outer surface of the metal shielding layer.

[0010] The metal shielding layer can be formed by winding a copper tape or winding copper wires on the surface of the first semiconductive buffer water blocking layer according to the requirements of the short-circuit current.

[0011] A central soft filling is arranged inside the core. The central soft filling is placed between three cores during cabling, and the wrapping layer is wound around the cabled cores.

[0012] The HDPE sheath is used as both the cabling filling and the bedding layer for the armor layer. The wrapping layer needs to be peeled off before extruding the HDPE sheath for filling.

[0013] The armor layer is formed by winding galvanized non-magnetic steel wires around the HDPE sheath.

[0014] A hollow monitoring chamber is arranged on the inner surface of the HDPE sheath near the outer armor sheath. A one-way check valve is threadedly assembled on the side wall of the connection surface of the HDPE sheath, and a pressure sensor is fixedly assembled on the inner side surface of the one-way check valve.

[0015] The hollow monitoring chamber is arranged in a staggered manner inside the HDPE sheath.

[0016] The beneficial effects of the present invention are as follows: (1) A medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor of the present invention replaces the traditional lead sheath structure with copper wire and copper tape shielding, reducing the weight of the submarine cable. At the same time, the water tree resistant insulation and the extrusion of HDPE filling are adopted to compensate for the water blocking performance of the cable core. (2) The armor layer uses galvanized non-magnetic steel wires, which is more economical than copper wire armor. (3) The galvanized non-magnetic steel wires are extruded with an HDPE sheath, which avoids the corrosion of the steel wires in the seawater environment. At the same time, the HDPE sheath can protect the galvanized layer on the surface of the non-magnetic steel wires, solving the problem that the tin plating layer on the surface of the galvanized non-magnetic steel wires is easy to fall off. (4) The structure of the medium-voltage submarine cable is simplified. The extrusion of the sheath outside the armor steel wires enables the armor layer to also serve as the outer sheath layer, shortening the manufacturing cycle of the submarine cable and reducing the manufacturing cost. (5) By providing a hollow monitoring chamber with a dislocation inside the HDPE sheath and threadedly assembling a one-way check valve on the side wall of the connection surface of the HDPE sheath, it is possible to inflate the hollow monitoring chamber through the one-way check valve, thereby improving the fitting degree between the HDPE and the armored outer sheath, reducing the contact gap, and enhancing the external shock absorption effect. (6) By fixedly assembling a pressure sensor on the inner side surface of the one-way check valve, it is possible to monitor the air pressure inside the hollow monitoring chamber in real time, and quickly judge the state and protection state of the cable according to the change of the internal air pressure, which is convenient for remote monitoring personnel to quickly maintain and improve the safety of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the drawings and embodiments.

[0018] Figure 1 It is a schematic structural diagram of the present invention.

[0019] Figure 2 It is a schematic cross-side structure diagram of the HDPE sheath in the present invention.

[0020] Figure 3 It is a partial schematic diagram of the assembly end of the one-way check valve in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will now be further described in detail with reference to the drawings. These drawings are all simplified schematic diagrams, only showing the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0022] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "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 a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0023] Figure 1 、 Figure 2 and Figure 3 As shown in, a medium-voltage submarine cable with high current-carrying capacity and corrosion protection includes three cores. The core includes a water-blocking conductor 1, a conductor shielding layer 2, a water-tree-resistant insulating layer 3, an insulating shielding layer 4, a first semi-conductive buffer water-blocking layer 5, a metal shielding layer 6, and a second semi-conductive buffer water-blocking layer 7. A wrapping layer 8, an HDPE sheath 9, an armored layer 10, and an armored outer sheath 11 are sequentially arranged around the core.

[0024] The water-blocking conductor 1 is formed by stranding multiple single-wire conductors. Each layer of single wires is first stranded together with water-blocking yarns, then a water-blocking tape is longitudinally wrapped, and the outermost layer of single wires is stranded separately.

[0025] The conductor shielding layer 2 is formed by winding a semi-conductive tape and extruding a semi-conductive shielding material. The water-tree resistant insulation layer 3 is formed by extruding a water-tree resistant insulating material on the outer surface of the conductor shielding. The insulation shielding layer 4 is formed by extruding a semi-conductive shielding material on the outer surface of the insulation shielding. The conductor shielding layer 2, the water-tree resistant insulation layer 3, and the insulation shielding layer 4 are produced by triple co-extrusion.

[0026] The first semi-conductive buffer water-blocking layer 5 is wound around the outer surface of the insulation shielding layer 4, and the second semi-conductive buffer water-blocking layer 7 is wound around the outer surface of the metal shielding layer 6.

[0027] The metal shielding layer 6 can be formed by winding a copper tape or winding copper wires on the surface of the first semi-conductive buffer water-blocking layer 5 according to the requirements of the short-circuit current.

[0028] To ensure internal support, a central soft filling 12 is provided inside the core. The central soft filling 12 is placed between three cores during cabling, and the wrapping layer 8 is wound around the cabled cores to play a binding role.

[0029] To cooperate with filling and support, the HDPE sheath 9 also serves as a filling for cabling and a cushion layer for the armor layer 10. The wrapping layer 8 needs to be peeled off before extruding the HDPE sheath 9.

[0030] To cooperate with external protection assembly, the armor layer 10 is formed by winding galvanized non-magnetic steel wires around the HDPE sheath 9.

[0031] Before production, a layer of HDPE outer sheath 9 is first extruded outside the galvanized non-magnetic steel wires. The HDPE outer sheath 9 of the galvanized non-magnetic steel wires can effectively prevent the metal wires from contacting seawater, avoid the metal wires from being corroded by seawater, and at the same time, the HDPE outer sheath 9 can protect the galvanized layer of the metal wires and prevent the tin plating layer from falling off.

[0032] To monitor the operating state, a hollow monitoring chamber 13 is provided on the surface of the HDPE sheath 9 near the armor outer sheath 11. A one-way check valve 14 is threadedly assembled on the side wall of the connection surface of the HDPE sheath 9, and a pressure sensor 15 is fixedly assembled on the inner side surface of the one-way check valve 14.

[0033] An installation chamber for installing a one-way check valve 14 is opened on one side of the connection surface of the HDPE sheath 9. Then, an internally threaded metal pipe for fixing the one-way check valve 14 is fixed at the connection end between the installation chamber and the central control monitoring chamber 13. The external threaded pipe at the connection end of the one-way check valve 14 is screwed into the internally threaded metal pipe for fixed connection and communication. The pressure sensor 15 is used to monitor the air pressure inside the hollow monitoring chamber 13. By the change of the air pressure inside the central control monitoring chamber 13, it can be judged whether the submarine cable is bent or whether the surface of the HDPE sheath 9 is damaged. Once it is bent, the internal air pressure will increase, and once it is damaged, the internal air pressure will decrease.

[0034] In order to increase the protection area, the hollow monitoring chamber 13 is staggeredly arranged inside the HDPE sheath 9.

[0035] Through the staggered setting of the inner and outer sides, the hollow monitoring chamber 13 includes an arc-shaped chamber and an internal diversion pipe connected to the arc-shaped chamber. One end of the internal diversion pipe is fixedly connected and communicated with the inside of the one-way check valve 14. The one-way check valve 14 is connected by an external air supply pipe to supply air into the internal diversion pipe, thereby increasing the internal air pressure of the hollow monitoring chamber 13, and thus improving the adhesion between the HDPE sheath 9 and the armored outer sheath 11 and reducing the gap.

[0036] Inspired by the ideal embodiments of the present invention described above, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A medium-voltage submarine cable with high current-carrying capacity and corrosion-resistant armor, comprising three wire cores, characterized in that: The core includes a water-blocking conductor (1), a conductor shielding layer (2), a water-tree resistant insulation layer (3), an insulation shielding layer (4), a first semi-conductive buffer water-blocking layer (5), a metal shielding layer (6), and a second semi-conductive buffer water-blocking layer (7). A wrapping layer (8), an HDPE sheath (9), an armor layer (10), and an armor outer sheath (11) are sequentially arranged around the core.

2. The medium-voltage submarine cable with high current-carrying capacity and corrosion-resistant armor according to claim 1, characterized in that: The water-blocking conductor (1) is formed by stranding multiple single-wire conductors. Each layer of single wires is first stranded together with water-blocking yarns, then a water-blocking tape is longitudinally wrapped, and the outermost single wires are stranded separately.

3. The medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor according to claim 1 is characterized in that: The conductor shielding layer (2) is formed by wrapping a semi-conductive tape and extruding a semi-conductive shielding material. The water-tree resistant insulation layer (3) is formed by extruding a water-tree resistant insulation material on the outer surface of the conductor shielding layer. The insulation shielding layer (4) is formed by extruding a semi-conductive shielding material on the outer surface of the insulation layer. The conductor shielding layer (2), the water-tree resistant insulation layer (3), and the insulation shielding layer (4) are produced by three-layer co-extrusion.

4. The medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor according to claim 1 is characterized in that: The first semi-conductive buffer water-blocking layer (5) is wrapped around the outer surface of the insulation shielding layer (4), and the second semi-conductive buffer water-blocking layer (7) is wrapped around the outer surface of the metal shielding layer (6).

5. The medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor according to claim 1, characterized in that: The metal shielding layer (6) can be formed by wrapping a copper tape or winding copper wires on the surface of the first semi-conductive buffer water-blocking layer (5) according to the requirements of the short-circuit current.

6. The medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor according to claim 1, characterized in that: A central soft filling (12) is arranged inside the core. The central soft filling (12) is placed between three cores during cabling, and the wrapping layer (8) is wrapped around the cabled cores.

7. The medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor according to claim 1, characterized in that: The HDPE sheath (9) is used as both a cabling filling and a cushion layer for the armor layer (10). Before extrusion filling, the wrapping layer (8) needs to be peeled off from the HDPE sheath (9).

8. The medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor according to claim 1 is characterized in that: The armor layer (10) is formed by winding galvanized non-magnetic steel wires around the HDPE sheath (9).

9. The medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor according to claim 1, characterized in that: A hollow monitoring chamber (13) is provided on the surface of the HDPE sheath (9) near the armor outer sheath (11). A one-way check valve (14) is threadedly assembled on the side wall of the connecting surface of the HDPE sheath (9). A pressure sensor (15) is fixedly assembled on the inner side surface of the one-way check valve (14).

10. A medium-voltage submarine cable with high current-carrying capacity and anti-corrosion armor, as claimed in claim 9, wherein: The hollow monitoring chamber (13) is offset and opened inside the HDPE sheath (9).

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