An array cable end composite seal structure

Abstract

The utility model belongs to the technical field of submarine cable end sealing, specifically relates to an array submarine cable end composite sealing structure, including first waterproof layer, heat shrinkage seal cap, second waterproof layer and external reinforcing layer. The utility model eliminates basic leakage path through first waterproof layer, provides full circumferential pressure seal through heat shrinkage seal cap, strengthens waterproof and resists high pressure penetration, carries out secondary reinforcement to weak joint through second waterproof layer, blocks interface water vapor invasion, integrates integral structure through external reinforcing layer, and gives mechanical protection and corrosion resistance, so as to utilize four layers of collaborative protection mechanism, form progressive sealing redundancy, and make the tensile strength greatly improved, avoid the occurrence of the risk of submarine cable water inflow caused by the rupture of sealing structure in the laying process, and it does not need welding operation, thereby improving construction efficiency and reducing safety risk.

Description

Technical Field

[0001] This utility model belongs to the field of submarine cable end sealing technology, specifically relating to an array submarine cable end composite sealing structure. Background Technology

[0002] In offshore wind farm projects, array submarine cables are responsible for transmitting power to each wind turbine generator. To ensure the reliability of the cables during installation, they must undergo waterproofing treatment at the ends before being pulled from the seabed to the wind turbine foundation platform using a traction net. Due to the unpredictable weather conditions at sea, the speed and quality of sealing the cable ends are crucial. The traditional method involves wrapping waterproof tape around the cable ends and then welding lead alloy caps to achieve waterproofing.

[0003] However, traditional lead sealing processes involve welding, which is time-consuming and considered specialized operations, posing certain safety risks. Sealing a single submarine cable end takes approximately 2-3 hours. Furthermore, the lead sheath layer of array submarine cables is relatively thin (≤3.0mm). Due to the soft nature of lead alloy, excessive loads during installation can cause the lead alloy cap at the cable end to crack, leading to water ingress and economic losses. Utility Model Content

[0004] The purpose of this invention is to provide a composite sealing structure for the end of an array submarine cable, which solves the technical problems of low operating efficiency, significant safety risks, and easy pull-out and breakage of the sealing head of the submarine cable end in the prior art, which leads to water penetration and failure of the submarine cable.

[0005] This utility model discloses a composite sealing structure for the end of an array submarine cable. The array submarine cable includes a cable core, and the cable core is sequentially wrapped with a lead sheath and a PE sheath. At the end of the array submarine cable, the lead sheath protrudes beyond the PE sheath. The composite sealing structure includes: The first waterproof layer covers the end of the array submarine cable and the exposed lead sheath, and extends to cover the outer surface of the PE sheath and is tightly bonded to it; A heat-shrinkable cap is fitted and heat-shrinkably fastened to the outside of the first waterproof layer, with its tail end extending and heat-shrinkably fastened to the outer side of the PE sheath. The second waterproof layer is wrapped around the overlap area between the end of the heat-shrink cap and the PE sheath. An external reinforcing layer is wrapped around the heat-shrink cap and the second waterproof layer, and extends to cover the outer surface of the PE sheath and is tightly bonded to it.

[0006] This application eliminates the path of basic leakage through the first waterproof layer, provides a full-circumferential pressure seal through heat-shrinkable caps to enhance waterproofing and resist high-pressure penetration, reinforces weak joints with the second waterproof layer to block the intrusion of interface moisture through the second waterproof layer, and integrates the overall structure through the external reinforcement layer, providing mechanical protection and corrosion resistance. This four-layer synergistic protection mechanism forms a progressive sealing redundancy and significantly improves tensile strength, avoiding the risk of water ingress into the submarine cable due to the rupture of the sealing structure during laying. Furthermore, it eliminates the need for welding operations, improving construction efficiency and reducing safety risks.

[0007] Based on the above technical solution, the solution of this application can be further improved as follows: Preferably, the external reinforcing layer comprises two layers of two-component modified polyurea coating, and the coating thickness of the two-component modified polyurea coating is ≥1.5mm. This solution enhances the sealing and seepage prevention effect, improves the adaptability to the deep-sea environment, and increases the protective tensile strength.

[0008] Preferably, the first waterproof layer comprises: The first waterproof tape is semi-overlapping and continuously wrapped around the end of the array submarine cable and the exposed lead sheath, and extends to cover the outer surface of the PE sheath. Several layers of first PVC tape are wrapped around the first waterproof tape in a semi-overlapping manner. This solution achieves a dual seal of self-adaptive filling and mechanical locking, which significantly improves the robustness of interface sealing under high pressure in deep-sea environments, while also taking into account the convenience of construction and maintainability.

[0009] Preferably, the width of the first waterproof tape is 20-60mm, and the wrapping angle of the first PVC tape is <45°. This solution can flexibly fit complex curved surfaces, avoid gaps caused by wrinkles, reduce the number of wrapping layers, reduce the risk of interface delamination, improve the axial projection coverage of the tape, significantly extend the potential water seepage path, and avoid radial shearing and peeling caused by deep-sea pressure.

[0010] Preferably, the second waterproof layer comprises: The second waterproof tape is semi-overlapping and continuously wrapped around the overlap area between the open end of the heat shrink cap and the PE sheath. Several layers of second PVC tape are wrapped around the second waterproof tape in a semi-overlapping manner. This solution achieves a dual seal of self-adaptive filling and mechanical locking, which significantly improves the robustness of interface sealing under high pressure in deep-sea environments, while also taking into account the convenience of construction and maintainability.

[0011] Preferably, the second waterproof layer wraps around the heat-shrink cap in an area of ​​30-50mm before and after the end of the cap; this solution provides a coverage redundancy of more than twice that of the failure risk area, ensuring a sealing and seepage prevention effect.

[0012] Preferably, the distance between the end of the external reinforcement layer and the end of the PE sheath is ≥50mm; by adopting this solution, the direct damage to the end of the PE sheath by external force is isolated by the over-boundary coverage, reducing the risk of sheath tearing.

[0013] Through the above technical solution, this utility model achieves the following beneficial effects: 1. This application eliminates the leakage path of the foundation through the first waterproof layer, provides full circumferential pressure sealing through the heat shrink cap, strengthens waterproofing and resists high pressure penetration, reinforces weak joints through the second waterproof layer to block the intrusion of interface moisture through the second waterproof layer, and integrates the overall structure through the external reinforcement layer, and provides mechanical protection and corrosion resistance. In this way, the four-layer synergistic protection mechanism forms a progressive sealing redundancy and greatly improves the tensile strength, avoiding the risk of water ingress into the submarine cable due to the rupture of the sealing structure during the laying process. Moreover, it does not require welding operations, thereby improving construction efficiency and reducing safety risks. 2. The external reinforcement layer of this application includes two layers of two-component modified polyurea coating, which enhances the sealing and seepage prevention effect, improves the adaptability to the deep-sea environment, and enhances the protective tensile strength. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the composite sealing structure of the array submarine cable end as described in a specific embodiment of this application; Figure 2 for Figure 1 A schematic cross-sectional view of point AA in the composite sealing structure of the submarine cable end shown in the diagram. Explanation of reference numerals in the attached figures: 1. Cable core; 2. Lead sheath; 3. PE sheath; 4. First waterproof layer; 41. First waterproof tape; 42. First PVC tape; 5. Heat shrink cap; 6. Second waterproof layer; 61. Second waterproof tape; 62. Second PVC tape; 7. External reinforcement layer. Detailed Implementation

[0016] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0017] The terms “first” and “second” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as “first” or “second” may explicitly or implicitly include one or more of the stated features.

[0018] In this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0019] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0020] Example: like Figure 1 and Figure 2 As shown in the figure, this application discloses a composite sealing structure for the end of an array submarine cable, which has the advantages of being weld-free, having high tensile strength, and being quick to install. Its specific structure includes: a first waterproof layer 4, a heat-shrinkable cap 5, a second waterproof layer 6, and an external reinforcing layer 7.

[0021] It should be noted that the array submarine cable includes a cable core 1, which is wrapped with a lead sheath 2 and a PE sheath 3 in sequence, and the lead sheath 2 at the end of the array submarine cable is exposed outside the PE sheath 3.

[0022] The first waterproof layer 4 covers the end of the array submarine cable and the exposed lead sheath 2, and extends to cover and tightly bond with the outer surface of the PE sheath 3. It forms a direct bonding interface with the lead sheath 2 and the PE sheath 3, thereby blocking the axial penetration path of water vapor and filling the step difference between the lead sheath 2 and the PE sheath 3, providing a flat base for the heat shrink cap 5, thereby improving the sealing effect.

[0023] The heat-shrink cap 5 is fitted and heat-shrinkably fastened to the outside of the first waterproof layer 4. Its tail end extends and is heat-shrinkably fastened to the outer side of the PE sheath 3. It is used to achieve a uniform pressure seal in the whole circumference through heat shrinkage stress, thereby strengthening the seepage prevention capability of the first waterproof layer 4. After shrinkage, it provides clamping force to prevent the composite sealing structure from loosening or shifting.

[0024] The second waterproof layer 6 wraps around the overlap area between the end of the heat shrink cap 5 and the PE sheath 3. It is used to strengthen the seal between the two, provide secondary waterproofing, and prevent the end of the heat shrink cap 5 from lifting due to bending or vibration, thereby improving the sealing and seepage prevention effect.

[0025] The outer reinforcing layer 7 wraps around the heat-shrink cap 5 and the second waterproof layer 6, and extends to cover the outer surface of the PE sheath 3 and is tightly bonded to it, providing rigid protection against external force damage caused by factors such as installation dragging. It also connects the end sealing structure with the submarine cable sheath as a whole, thereby improving tensile strength and isolating seawater from chemical corrosion of the internal layers.

[0026] This invention eliminates basic leakage paths through a first waterproof layer 4, provides a full-circumferential pressure seal through a heat-shrinkable cap 5 to enhance waterproofing and resist high-pressure penetration, reinforces weak joints through a second waterproof layer 6 to block the intrusion of interface moisture through a second waterproof layer 6, and integrates the overall structure through an external reinforcing layer 7 to provide mechanical protection and corrosion resistance. This four-layer synergistic protection mechanism forms a progressive sealing redundancy and significantly improves tensile strength, avoiding the risk of water ingress into the submarine cable due to sealing structure rupture during laying. Furthermore, it eliminates the need for welding operations, thereby improving construction efficiency and reducing safety risks.

[0027] In some embodiments, the external reinforcing layer 7 includes two layers of two-component modified polyurea coating, the coating thickness of which is ≥1.5 mm.

[0028] It should be noted that the two-component modified polyurea has rapid curing properties, which can form a continuous and seamless shell, thereby completely sealing the internal waterproof layer, and its dense molecular chain structure can block the penetration of water molecules.

[0029] Understandably, the two-component modified polyurea coating with a spray thickness of ≥1.5mm provides sufficient mechanical redundancy and elastomer properties to buffer deformation caused by deep-sea pressure fluctuations, while its salt spray resistance and hydrolysis resistance ensure corrosion resistance.

[0030] It should be noted that the double-layer spraying forms a gradient structure, with the inner layer focusing on bonding with the PE sheath 3, and the outer layer focusing on resisting impact, tension and abrasion. The two work together to greatly improve the overall protective effect.

[0031] The design of the external reinforcement layer 7 enhances the sealing and seepage prevention effect, improves the adaptability to the deep-sea environment, and enhances the protective tensile strength.

[0032] In some embodiments, such as Figure 2 As shown, the first waterproof layer 4 includes: The first waterproof strip 41 is semi-overlapping and continuously wrapped around the end of the array submarine cable and the exposed lead sheath 2, and extends to cover the outer surface of the PE sheath 3 to form a continuous, dead-angle-free elastic seal. It can closely fit the stepped surface, actively fill the gaps between uneven surfaces, eliminate micro-leakage channels caused by interface deformation differences, and achieve initial sealing and impermeability. Several layers of first PVC tape 42 are partially overlapped and wrapped around the first waterproof tape 41, which serves to bind and fix the tape, improve the roundness, provide uniform circumferential pressure, forcefully compact the first waterproof tape 41 so that it fits the cable body with zero gap, and resist the compression deformation of the soft waterproof tape by the hydrostatic pressure of the deep sea, thus preventing the sealing layer from collapsing and failing.

[0033] Preferably, the first waterproofing strip 41 is made of butyl rubber-polyisobutylene blend substrate, which utilizes polyisobutylene to greatly improve low temperature toughness and high pressure stability, meeting the harsh working conditions of deep sea. Through polyisobutylene, it is endowed with permanent adhesion and dynamic self-healing ability, which can actively fill micro gaps and achieve high-strength bonding of the two materials of lead sheath 2 / PE sheath 3.

[0034] The design of the first waterproof layer 4 described above achieves a dual seal of adaptive filling and mechanical locking, significantly improving the robustness of the interface seal under high pressure in the deep sea environment, while also taking into account the ease of construction and maintainability.

[0035] Based on the above embodiments, the width of the first waterproof tape 41 is 20-60mm, which can flexibly fit complex curved surfaces, avoid gaps caused by wrinkles, and reduce the number of wrapping layers, thereby reducing the risk of interface delamination; the wrapping angle of the first PVC tape 42 is <45°, which improves the axial projection coverage of the tape, significantly extends the potential water seepage path, and avoids radial shear peeling caused by deep-sea pressure.

[0036] In some embodiments, such as Figure 2 As shown, the second waterproof layer 6 includes: The second waterproof strip 61 is semi-overlapping and continuously wrapped around the opening end of the heat shrink cap 5 and the overlapping area of ​​the PE sheath 3 to form a continuous elastic seal without dead angles. It can closely fit the stepped surface, actively fill the gaps between the uneven surfaces, eliminate the micro-leakage channels caused by the interface deformation difference, and achieve sealing and seepage prevention. Several layers of second PVC tape 62 are semi-overlapping and wrapped around the second waterproof tape 61, which serves to bind and fix it, improves the roundness, provides uniform circumferential pressure, and forcibly compacts the second waterproof tape 61 to achieve zero-gap adhesion. At the same time, it resists the compression deformation of the soft waterproof tape by the hydrostatic pressure of the deep sea, and avoids the collapse and failure of the sealing layer.

[0037] The design of the second waterproof layer 6 described above achieves a dual seal of adaptive filling and mechanical locking, significantly improving the robustness of interface sealing under high-pressure deep-sea environments, while also taking into account ease of construction and maintainability.

[0038] In some embodiments, such as Figure 2 As shown, the second waterproof layer 6 wraps around the heat-shrink cap 5 in a 30-50mm area before and after it, with a coverage redundancy of more than twice that of the failure risk area, ensuring a sealing and seepage prevention effect.

[0039] In some embodiments, the distance between the end of the outer reinforcing layer 7 and the end of the PE sheath 3 is ≥50mm. This distance, through the over-boundary coverage, isolates the end of the PE sheath 3 from direct damage by external forces, reducing the risk of sheath tearing.

[0040] The assembly process of the above-mentioned composite sealing structure with the array submarine cable end is as follows: Step 1: On the cross-section of the submarine cable end, the lead sheath 2 and the PE sheath 3, the first waterproof tape 41 is wrapped continuously with half overlap; after wrapping the first waterproof tape 41, wrap 1-3 layers of the first PVC tape 42 with half overlap, requiring longitudinal tensile force > 5N and winding angle < 45°.

[0041] Step 2: Install heat shrink caps 5 on the outside of the first PVC tape 42. The inner diameter of the heat shrink cap 5 should be ≤ the diameter of the non-metallic sheath of the array submarine cable + 20mm. Divide the heat shrink cap 5 into 4 to 6 sections according to the diameter of the array submarine cable. After installation, heat each section gradually, with a total heating time of not less than 30 seconds. After heating, the heat shrink cap 5 should be tightly attached to the first waterproof layer 4 and should not collapse when pressed. After heat shrinking, repeat step 1 and wrap the heat shrink cap 5 with the second waterproof tape 61 and the second PVC tape 62 around the front and back of the end of the heat shrink cap 5 for 30-50mm.

[0042] Step 3: Spray two layers of two-component modified polyurea coating on the heat-shrink cap 5 and the second waterproof layer 6. The thickness of each layer should be ≥1.5mm. The spraying pressure should be 2000~2500psi. The interval between layers should be 2-5 minutes. The spraying area must extend ≥50mm to the non-metallic sheath of the submarine cable.

[0043] This application overcomes the shortcomings of insufficient mechanical strength and low construction efficiency of traditional lead alloy cap end sealing technology. Through composite sealing structure and rapid construction technology, the sealing time of a single end is shortened from the original 2-3 hours to 30-40 minutes. At the same time, the tensile strength is increased by 3 times, avoiding the risk of water ingress into the submarine cable caused by the breakage of the lead cap end during the laying process.

[0044] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A composite sealing structure for the end of an array submarine cable, the array submarine cable comprising a cable core, the cable core being sequentially wrapped with a lead sheath and a PE sheath, the lead sheath at the end of the array submarine cable protruding beyond the PE sheath, characterized in that, The composite sealing structure includes: The first waterproof layer covers the end of the array submarine cable and the exposed lead sheath, and extends to cover the outer surface of the PE sheath and is tightly bonded to it; A heat-shrinkable cap is fitted and heat-shrinkably fastened to the outside of the first waterproof layer, with its tail end extending and heat-shrinkably fastened to the outer side of the PE sheath. The second waterproof layer is wrapped around the overlap area between the tail end of the heat-shrink cap and the PE sheath; An external reinforcing layer is wrapped around the heat-shrink cap and the second waterproof layer, and extends to cover the outer surface of the PE sheath and is tightly bonded to it.

2. The composite sealing structure for the end of an array submarine cable according to claim 1, characterized in that, The external reinforcement layer comprises two layers of two-component modified polyurea coating, the coating thickness of which is ≥1.5mm.

3. The composite sealing structure for the end of an array submarine cable according to claim 1, characterized in that, The first waterproof layer includes: The first waterproof tape is semi-overlapping and continuously wrapped around the end of the array submarine cable and the exposed lead sheath, and extends to cover the outer surface of the PE sheath. Several layers of first PVC tape are wrapped around the first waterproof tape in a semi-overlapping manner.

4. The composite sealing structure for the end of an array submarine cable according to claim 3, characterized in that, The width of the first waterproof tape is 20-60mm, and the wrapping angle of the first PVC tape is <45°.

5. The composite sealing structure for the end of an array submarine cable according to claim 1, characterized in that, The second waterproof layer includes: The second waterproof tape is semi-overlapping and continuously wrapped around the overlap area between the open end of the heat shrink cap and the PE sheath. Several layers of second PVC tape are wrapped around the second waterproof tape in a semi-overlapping manner.

6. The composite sealing structure for the end of an array submarine cable according to claim 1, characterized in that, The second waterproof layer wraps around the front and rear 30-50mm areas of the heat-shrink cap's tail end.

7. The composite sealing structure for the end of an array submarine cable according to claim 1, characterized in that, The distance between the end of the external reinforcement layer and the end of the PE sheath is ≥50mm.

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