A crosslinked polyethylene insulated power cable for marine engineering

Abstract

The application discloses a kind of crosslinked polyethylene insulated power cables for ocean engineering, including outer covering, armoring layer, inner sheath, filling layer and three conductor structures;Buffer system is also provided at filling layer, buffer system includes fluid layer close to inner sheath, and fluid layer is filled with buffer fluid;Three buffer bodies are set between three conductor structures, buffer body is sequentially set into surface layer, intermediate layer and inner layer from fluid layer towards the direction of cable center, surface layer is in contact with fluid layer, and surface layer and fluid layer are communicated by a plurality of pores, surface layer is filled with polygonal hole structure, and the buffer fluid entering is guided to form laminar flow;Intermediate layer is filled with fractal pore structure, and the buffer fluid entering is guided to travel vortex flow;Inner layer is tubular hole structure, and is communicated with fluid layer, by guiding buffer fluid directional flow when under pressure, avoid local stress concentration, while forming three-dimensional multi-layer pressure distribution, prevent cable from being damaged under high strength pressure.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, specifically to a cross-linked polyethylene insulated power cable for marine engineering. Background Technology

[0002] Submarine cables are core infrastructure connecting offshore energy facilities (such as wind power and tidal power platforms), islands, and onshore power grids, as well as international communication networks. Based on function, they can be divided into submarine power cables, submarine communication cables, and fiber optic composite cables. Their core functions include power transmission and communication interconnection. Among these, with the increasing maturity of cross-linked polyethylene (XLPE) insulated power cable technology, choosing XLPE insulated submarine cables instead of traditional oil-impregnated paper-insulated submarine power cables offers superior mechanical properties and stability in application.

[0003] Due to the special and harsh environments in which submarine cables are used, high requirements are placed on their waterproof performance, corrosion resistance, compressive strength, and tensile strength. Existing cross-linked polyethylene insulated submarine cables only use rigid structures such as armor layers for protection. On the one hand, they lack pressure relief capabilities, requiring the use of higher-performance materials as armor layers in special environments, which increases costs. On the other hand, they are prone to excessive stress in localized areas under pressure, which can easily lead to structural damage. Therefore, there is an urgent need for cross-linked polyethylene insulated power cables for marine engineering to solve the problems existing in the current technology. Summary of the Invention

[0004] The purpose of this invention is to provide a cross-linked polyethylene insulated power cable for marine engineering, which can effectively solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: 1. A cross-linked polyethylene insulated power cable for marine engineering, comprising an outer sheath, an armor layer, an inner sheath, a filling layer, and three conductor structures, wherein the three conductor structures are uniformly distributed circumferentially; the filling layer is disposed between the inner sheath and the three conductor structures, and

[0006] A buffer system is also provided at the filling layer, the buffer system comprising:

[0007] A fluid layer closely adhering to the inner sheath, the fluid layer being filled with a buffer fluid;

[0008] Three buffer bodies are disposed between three conductor structures. The buffer bodies are arranged sequentially from the fluid layer toward the center of the cable as a surface layer, a middle layer, and an inner layer. The surface layer is in contact with the fluid layer and is connected to the fluid layer through several pores. The surface layer is filled with a polygonal pore structure to guide the incoming buffer fluid to form a laminar flow. The middle layer is filled with a fractal pore structure to guide the incoming buffer fluid to form a vortex. The inner layer has a tubular pore structure and is connected to the fluid layer.

[0009] Preferably, both the polygonal hole structure and the polygonal hole structure are elastic body structures.

[0010] Preferably, each of the conductor structures includes a water-blocking conductor, a conductor shielding layer wrapped around the water-blocking conductor, a cross-linked polyethylene insulation layer wrapped around the shielding layer, a flow-guiding layer wrapped around the cross-linked polyethylene insulation layer, a fluid layer attached to the flow-guiding layer, and at least partially connected between the flow-guiding layer and the fluid layer, guiding the incoming buffer fluid to flow along the flow-guiding layer.

[0011] Preferably, the inner side of the flow guiding layer facing the cross-linked polyethylene insulation layer is a first inner wall, and the other inner wall opposite the first inner wall is a second inner wall, wherein the stiffness of the first inner wall is greater than that of the second inner wall.

[0012] Preferably, a plurality of elastic buffer fluids are arranged circumferentially within the flow guide layer, and the elastic buffer fluids are configured to slow down the entry of buffer fluids into the flow guide layer through their own elasticity.

[0013] Preferably, a pressure-resistant inner core is provided at the convergence center of the three flow guiding layers, and a plurality of cavities are provided along the circumferential direction of the second inner wall, the cavity types including truncated cavities and circular cavities.

[0014] More preferably, the circular cavity is provided with a compressive-resistant internal support structure, the internal support structure comprising:

[0015] A central concave structure is located at the center of the circular cavity, and the central concave structure is configured to contract along the concave line when subjected to force.

[0016] A constant pressure chamber is evenly distributed at the four corners of the central concave structure and fits against the inner wall of the circular cavity; and

[0017] The constant pressure cavity is connected to the four corners of the central concave structure via connecting ribs.

[0018] More preferably, the central concave structure is provided with a central rib along the concave line direction, and both ends of the central rib are connected to the inner wall of the circular cavity.

[0019] Furthermore, the pressure plane of each of the central concave structures corresponds to various types of trapezoidal cavities.

[0020] Preferably, at least a portion of the cable is provided with a microcapsule repair layer, the microcapsule repair layer being filled with self-healing microcapsule material.

[0021] Beneficial effects: This invention incorporates a buffer system within the filling layer. The fluid layer allows the internal buffer fluid to disperse stress through deformation under pressure. Combined with the buffer body, this guides the buffer fluid to flow directionally under pressure, preventing localized stress concentration. Furthermore, the porous structure ensures the buffer fluid uniformly fills the gaps under high pressure. In this invention, the buffer fluid guided by the polygonal porous structure in the surface layer forms a laminar flow; the fractal porous structure in the middle layer guides the buffer fluid to form vortices, slowing the flow rate; finally, some of the buffer fluid converges through the internal tubular porous structure, forming a three-dimensional, multi-layered pressure distribution, preventing cable damage under high-intensity pressure. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0023] In the attached diagram:

[0024] Figure 1 This is a schematic diagram of the cross-linked polyethylene insulated power cable of the present invention;

[0025] Figure 2 This is a front view of the cross-linked polyethylene insulated power cable of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the three buffer bodies of the present invention;

[0027] Figure 4 This is a front view of the three buffer bodies of the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of the flow guiding layer of the present invention;

[0029] Figure 6 This is a schematic diagram of the structure of the pressure-resistant inner core of the present invention.

[0030] The diagram labels are as follows: 1. Outer sheath; 21. Outer protective layer; 22. Inner armored steel wire layer; 3. Inner sheath; 4. Filler layer; 5. Binding strap layer; 61. Water-blocking conductor; 62. Conductor shielding layer; 63. Cross-linked polyethylene insulation layer; 64. Fluid guiding layer; 641. First inner wall; 642. Second inner wall; 643. Elastic slow-flowing fluid; 71. Fluid layer; 72. Surface layer; 721. Polygonal pore structure; 73. Intermediate layer; 731. Fractal pore structure; 74. Inner layer; 741. Tubular pore structure; 8. Pressure-resistant inner core; 81. Quadrupole-shaped cavity; 82. Circular cavity; 83. Central concave structure; 84. Constant pressure cavity; 85. Connecting rib; 86. Central rib; 9. Microcapsule repair layer. Detailed Implementation

[0031] The embodiments of the present invention will now be described with reference to the accompanying drawings. The terminology used in the embodiments section is for illustrative purposes only and is not intended to limit the scope of the invention. The embodiments of this application will now be described with reference to the accompanying drawings.

[0032] Example: Figure 1 As shown, a cross-linked polyethylene insulated power cable for marine engineering comprises, from the outside in, an outer sheath 1, an armor layer, an inner sheath 3, a filler layer 4, and three conductor structures. Multiple armor layers can be provided, including an outer protective layer 21 and an inner armor steel wire layer 22. Alternatively, a binding layer 5 or other structures can be provided inside the cable as needed.

[0033] refer to Figures 1-4 As shown, in this embodiment, the three conductor structures are evenly distributed circumferentially, i.e., equilateral triangularly; the filling layer 4 is disposed between the inner sheath 3 and the three conductor structures to stabilize the state of the three conductor structures; and a buffer system is also provided at the filling layer 4, the buffer system including:

[0034] The fluid layer 71 is closely attached to the inner sheath 3, and the fluid layer 71 is filled with buffer fluid.

[0035] Three buffer bodies are disposed between the three conductor structures. The buffer bodies are arranged sequentially from the fluid layer 71 toward the center of the cable as a surface layer 72, a middle layer 73, and an inner layer 74. The surface layer 72 is in contact with the fluid layer 71, and the surface layer 72 and the fluid layer 71 are connected by several pores. The surface layer 72 is filled with a polygonal pore structure 721, which guides the incoming buffer fluid to form a laminar flow. The middle layer 73 is filled with a fractal pore structure 731, which guides the incoming buffer fluid to form a vortex and slows down the flow rate. The inner layer 74 has a tubular pore structure 741 and is connected to the fluid layer 71.

[0036] When fluid layer 71 experiences a force, it compresses the buffer fluid into the surface layer 72 of the three buffer bodies, forming laminar flow within the polygonal pore structures 721 of the surface layer 72. This initially disperses the stress. As the buffer fluid penetrates deeper and flows to the intermediate layer 73, the fractal pore structure 731 within the intermediate layer 73 creates vortices to further slow the buffer fluid's velocity. Finally, the buffer fluid is pre-compressed through the tubular pore structure 741 of the inner layer 74, causing it to flow back into fluid layer 71. (Reference) Figure 3As shown, the buffer fluid can be returned to the fluid layer 71 from the side wall of the buffer body through the tubular hole structure 741, thereby forming a large loop in the buffer body. The polygonal hole structure 721 and the polygonal hole structure 721 are both elastic body structures. When pressure forces the liquid in, a certain amount of buffer fluid can be temporarily stored through the deformation of the internal hole structure. When the pressure disappears, a portion of the buffer fluid can be squeezed back to the fluid layer 71 under the elastic restoring action. This allows the force on the fluid layer 71 to be distributed layer by layer in each fluid layer 71, realizing a vertical three-dimensional and layer-by-layer pressure relief function, and maximizing the pressure resistance.

[0037] Among them, a suitable buffer fluid can be selected according to specific needs, with priority given to liquid materials with high thermal conductivity and chemical stability, which can disperse stress during deformation and relieve thermal stress by absorbing heat through phase change.

[0038] refer to Figures 1-2 and Figure 5 As shown, each conductor structure includes a water-blocking conductor 61, a conductor shielding layer 62 wrapped around the water-blocking conductor 61, a cross-linked polyethylene insulation layer 63 wrapped around the shielding layer, and a flow-guiding layer 64 wrapped around the cross-linked polyethylene insulation layer 63. The flow-guiding layer 64 is attached to a fluid layer 71, and at least partially connected to the fluid layer 71 (not shown in the figure; for this connection, a protrusion with a cavity can be provided in the fluid layer 71 near the flow-guiding layer 64, extending into the interior of the flow-guiding layer 64, as shown in the reference). Figure 3 As shown, each buffer body has a direct channel for the protrusion to enter the interior of the flow guide layer 64. Then, the protrusion is densely covered with pores to form a connection. The buffer fluid in the fluid layer 71 enters the interior of the protrusion, and then enters the interior of the flow guide layer 64 through the pores on the protrusion, so as to realize that the buffer fluid in the fluid layer 71 can stably enter the flow guide layer 64, and guide the entering buffer fluid to flow along the flow guide layer 64.

[0039] refer to Figure 5 As shown, the inner wall of the flow guiding layer 64 facing the cross-linked polyethylene insulation layer 63 is the first inner wall 641, and the opposite inner wall is the second inner wall 642. The stiffness of the first inner wall 641 is greater than that of the second inner wall 642. When the fluid layer 71 is subjected to force, in addition to being buffered by the three buffer bodies, a portion of the buffer fluid in the fluid layer 71 will enter the flow guiding layer 64 and flow along the flow guiding layer 64. It will also pass through the conductor structure corresponding to each flow guiding layer 64 and flow around the conductor structure, forming an annular flow pressure around the conductor structure to avoid excessive local pressure on the conductor structure.

[0040] Multiple elastic buffer fluids 643 are arranged circumferentially within the flow guide layer 64. These elastic buffer fluids 643 are configured to slow down the flow entering the flow guide layer 64 through their own elasticity. Figure 5 For example, the elastic buffer fluid 643 is an elastic arc-shaped plate. When the buffer fluid flows, it first passes through the elastic arc-shaped plate to block and slow down its flow speed. When the flow speed is too high, the buffer fluid can also be deformed by impacting the elastic arc-shaped plate to buffer the impact force.

[0041] Furthermore, in this embodiment, a pressure-resistant inner core 8 is provided at the convergence center of the three flow guide layers 64, and a number of cavities are provided circumferentially in the second inner wall 642, including a truncated cavity 81 and a circular cavity 82. The pressure deformation of the truncated cavity 81 and the circular cavity 82 is used to counteract the force at the convergence of the three flow guide layers 64.

[0042] refer to Figure 6 As shown, in this embodiment, a compressive-resistant internal support structure is provided inside the circular cavity 82. The internal support structure includes:

[0043] The central concave structure 83 is located at the center of the circular cavity 82. The central concave structure 83 is configured to contract along the concave line when subjected to force.

[0044] The constant pressure chamber 84 is evenly distributed at the four corners of the central concave structure 83 and fits against the inner wall of the circular cavity 82; and

[0045] The constant pressure chamber 84 is connected to the four corners of the central concave structure 83 via connecting ribs 85.

[0046] When the circular cavity 82 is compressed, the constant pressure cavity 84 deforms and transmits the force to the four corners of the central concave structure 83 through the connecting ribs 85. The central concave structure 83 is subjected to force and undergoes compressive deformation along the concave line, forming a globally stable contraction. When the pressure increases, the connecting ribs 85 and the constant pressure cavity 84 can effectively suppress unstable deformation. The synergistic interaction between the local ribs enhances the integrity of the internal structure and provides considerable resistance. Among them, a central rib 86 is provided along the concave line of the central concave structure 83. Both ends of the central rib 86 are connected to the inner wall of the circular cavity 82, further forming the constraint of the rib. This makes the internal support structure exhibit significant recovery behavior and achieves asymptotic stability after nonlinear instability, thus enhancing the overall mechanical response.

[0047] refer to Figure 6 As shown, in this embodiment, two types of circular cavities 82 are provided: one between connected frustum-shaped cavities 81 and the other at the center. The central ribs 86 of the inner support structure in each circular cavity 82 tend to be arranged vertically to achieve pressure balance.

[0048] Among them, reference Figure 6As shown, the pressure plane of each central concave structure corresponds to the planes on both sides of the concave line and various types of trapezoidal cavities. It is used to support the formation caused by the deformation of the trapezoidal cavity and can simultaneously guide the trapezoidal cavity to reset when the central concave structure performs the reset behavior.

[0049] Example 2, based on Example 1, in this example, refers to Figure 1 As shown, at least a portion of the cable is also equipped with a microcapsule repair layer 9. The location of the microcapsule repair layer 9 can be set according to specific needs, and multiple layers can be set both inside and outside to achieve layered protection. The microcapsule repair layer 9 is filled with self-healing microcapsule material. The installation area of ​​the microcapsule repair layer 9 can be determined according to actual conditions, such as in cable sections in vulnerable areas. Microcapsules containing repair agents and curing agents or catalysts are evenly dispersed in the microcapsule repair layer 9. When cracks occur on the outer wall of the microcapsule repair layer 9, the microcapsules at the crack tip rupture due to concentrated stress, and the repair agent flows out and seeps into the crack under capillary action. The curing agent scattered on the outer wall of the microcapsule repair layer 9 meets the repair agent that has seeped into the crack and reacts. Under the action of the catalyst or curing agent, the repair agent undergoes a cross-linking polymerization reaction, which closes the crack surface, thereby achieving the effect of automatic crack repair and preventing further damage to the cable for a certain period of time.

[0050] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. For those skilled in the art, after learning the contents described in the present invention, several equivalent changes and substitutions can be made without departing from the principle of the present invention. These equivalent changes and substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. A cross-linked polyethylene insulated power cable for marine engineering, comprising an outer sheath, an armor layer, an inner sheath, a filler layer, and three conductor structures, characterized in that: The three conductor structures are evenly distributed circumferentially; the filling layer is disposed between the inner sheath and the three conductor structures, and A buffer system is also provided at the filling layer, the buffer system comprising: A fluid layer closely adhering to the inner sheath, the fluid layer being filled with a buffer fluid; Three buffer bodies are disposed between three conductor structures. The buffer bodies are arranged sequentially from the fluid layer toward the center of the cable as a surface layer, a middle layer, and an inner layer. The surface layer is in contact with the fluid layer and is connected to the fluid layer through several pores. The surface layer is filled with a polygonal pore structure to guide the incoming buffer fluid to form a laminar flow. The middle layer is filled with a fractal pore structure to guide the incoming buffer fluid to form a vortex. The inner layer has a tubular pore structure and is connected to the fluid layer.

2. The cross-linked polyethylene insulated power cable for marine engineering according to claim 1, characterized in that: Both the polygonal hole structure and the polygonal hole structure are elastic body structures.

3. The cross-linked polyethylene insulated power cable for marine engineering according to claim 1, characterized in that: Each of the conductor structures includes a water-blocking conductor, a conductor shielding layer wrapped around the water-blocking conductor, a cross-linked polyethylene insulation layer wrapped around the shielding layer, a flow-guiding layer wrapped around the cross-linked polyethylene insulation layer, a fluid layer attached to the flow-guiding layer, and at least partially connected between the flow-guiding layer and the fluid layer, guiding the incoming buffer fluid to flow along the flow-guiding layer.

4. A cross-linked polyethylene insulated power cable for marine engineering according to claim 3, characterized in that: The inner side of the flow guiding layer facing the cross-linked polyethylene insulation layer is the first inner wall, and the other inner wall opposite the first inner wall is the second inner wall. The stiffness of the first inner wall is greater than that of the second inner wall.

5. A cross-linked polyethylene insulated power cable for marine engineering according to claim 4, characterized in that: Multiple elastic buffer fluids are arranged circumferentially within the flow guide layer. These elastic buffer fluids are configured to slow down the entry of the fluids into the flow guide layer through their own elasticity.

6. A cross-linked polyethylene insulated power cable for marine engineering according to claim 5, characterized in that: A pressure-resistant inner core is provided at the convergence center of the three flow-guiding layers, and a number of cavities are provided along the circumferential direction of the second inner wall. The cavity types include truncated cavities and circular cavities.

7. A cross-linked polyethylene insulated power cable for marine engineering according to claim 6, characterized in that: The circular cavity is provided with a compressive-resistant internal support structure, which includes: A central concave structure is located at the center of the circular cavity, and the central concave structure is configured to contract along the concave line when subjected to force. A constant pressure chamber is evenly distributed at the four corners of the central concave structure and fits against the inner wall of the circular cavity; and The constant pressure cavity is connected to the four corners of the central concave structure via connecting ribs.

8. A cross-linked polyethylene insulated power cable for marine engineering according to claim 7, characterized in that: The central concave structure has a central rib along the concave line, and both ends of the central rib are connected to the inner wall of the circular cavity.

9. A cross-linked polyethylene insulated power cable for marine engineering according to claim 7, characterized in that: The pressure plane of each of the central concave structures corresponds to various types of trapezoidal cavities.

10. A cross-linked polyethylene insulated power cable for marine engineering according to claim 1, characterized in that: At least a portion of the cable is provided with a microcapsule repair layer, which is filled with self-healing microcapsule material.

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