A combined bending guard based on dynamic design

Abstract

The application discloses a kind of combined bending protection device based on dynamic design, it is related to submarine cable protection technical field.The protection device is arranged with oyster reef around, and the protection device includes J-type pipe, center clamp, conical pipe and bending limiter connected in sequence, one end of center clamp is connected with J-type pipe, and the other end is connected with bending limiter through conical pipe;Bending limiter includes a plurality of sequentially connected bending limiting units, each bending limiting unit includes two bending limiting units, one side of each bending limiting unit has rotating lug, and the other side has rotating groove, and rotating lug is rotatably connected with rotating groove.The application cooperates J-type pipe, conical pipe and bending limiter, can effectively alleviate stress concentration problem, enhance the protection performance of submarine cable in complex dynamic environment, and cooperate rotating lug and rotating groove, significantly improve construction efficiency, while the protection device cooperates oyster reef, can avoid submarine cable from being washed, has good protection, ecology, and can produce economic benefit.

Description

Technical Field

[0001] This invention relates to the field of submarine cable protection technology, and in particular to a combined bending protection device based on dynamic design. Background Technology

[0002] Under the complex influence of waves and currents on the seabed, submarine cables are constantly subjected to the combined effects of dynamic scouring and bending loads, posing a high risk of damage. Currently, bending protection measures for submarine cables mainly employ bend limiters, which use locking structures to restrict excessive bending and transfer stress. However, traditional bend limiter designs are typically based on static environments, neglecting the dynamic effects under complex hydrodynamic conditions. This leads to a high failure rate in actual engineering projects, with failure rates reaching as high as 50% in some areas. Of these failures, 80% occur at the connection between the first and second bend limiter sections. Failure of the bend limiter results in the submarine cable losing its protection. If the bend limiter is not repaired or replaced in a timely manner, the cable is highly susceptible to breakage, leading to severe economic losses and maintenance challenges.

[0003] Furthermore, submarine cables near substations or pile foundations are often subjected to more intense scouring, leading to erosion and scouring of the seabed soil. This alters the stress state of the submarine cables, further increasing the risk of breakage. Current finite benders are poorly designed to effectively address the additional mechanical problems caused by scouring, failing to adequately guarantee the long-term operational safety of submarine cables.

[0004] Chinese patent document CN113497432A discloses a bending restriction method and a bending limiter for parallel bending of submarine cables and monitoring cables. The method includes a limiter body, a submarine cable channel, and a rotation limiter. Inside the bend limiter, in addition to the submarine cable channel, a monitoring cable is also installed. The addition of a rotation limiter restricts the rotational displacement between adjacent bend limiter bodies, thus avoiding cutting the monitoring cable while preserving some rotational space to facilitate the release of torsional stress from the submarine cable. However, the aforementioned document still has several problems: First, the complex structure leads to high production costs and makes it difficult to guarantee long-term stability on the seabed, requiring frequent maintenance and replacement. Second, it has poor environmental adaptability, failing to consider the dynamic environment of the suspended submarine cable and neglecting the issue of the submarine cable at the mud-entry end being detached from the seabed surface under scouring, resulting in a relatively high failure rate. Summary of the Invention

[0005] In view of the problems of existing bend limiters, such as complex structure, inability to guarantee long-term stability on the seabed, failure to consider the dynamic environment of the suspended submarine cable and the scouring of the cable, and high failure rate, the present invention provides a combined bend protection device based on dynamic design.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a combined bending protection device based on dynamic design, wherein one side of the protection device is set in the seabed and the other side is located in the seawater, and oyster reefs are arranged around the protection device to enhance the stability of the seabed; the protection device includes a J-shaped tube, a central clamp, a conical tube, and a bending limiter, the J-shaped tube, the central clamp, the conical tube, and the bending limiter are connected, one end of the central clamp is fixedly connected to the J-shaped tube, and the other end is fixedly connected to the bending limiter through the conical tube; the J-shaped tube, the central clamp, the conical tube, and the bending limiter all have channels for accommodating submarine cables, and the submarine cables are arranged in the channels; the bending limiter includes a plurality of bending limiting units connected in sequence, each bending limiting unit includes two bending limiting units, one side of each bending limiting unit has a rotating protrusion, and the other side has a rotating groove adapted to the rotating protrusion, and the two bending limiting units are rotatably connected through the rotating protrusion and the rotating groove.

[0007] Furthermore, the bend limiter has a half-symmetrical structure, with each bend limiter unit having a male bend limiter head at one end and a female bend limiter head at the other end. Several fixing holes are provided on the contact surface between two bend limiter units within the same bend limiter unit, and these fixing holes are fixedly connected by bolts and double-sided toothed washers.

[0008] Furthermore, the rotating protrusion and the rotating groove have coaxial pivot holes, and the rotating protrusion and the rotating groove are detachably connected by bolts. If a bolt is provided in the pivot hole on one side and no bolt is provided in the fixing hole, then a bolt is provided in the fixing hole on the other side and no bolt is provided in the pivot hole.

[0009] Furthermore, the bending limiter is made of polyurethane material and incorporates glass fiber.

[0010] Furthermore, the submarine cable is divided into suspension section, reserved section and buried section according to different locations. The J-shaped tube, central clamp and tapered tube are sleeved on the suspension section, and the bend limiter is sleeved on the suspension section, reserved section and buried section.

[0011] Furthermore, the central clamp includes a first connecting pipe, a second connecting pipe, and several limiting plates. The limiting plates are fixed on both sides of the first connecting pipe, one side of which is fixedly connected to one side of the second connecting pipe, and a flange male is fixedly connected to the other side of the second connecting pipe. Each limiting plate and flange male has a through hole adapted to the submarine cable.

[0012] Furthermore, each of the limiting plates is circular, with its edges protruding beyond the first and second connecting pipes, and each limiting plate has a rubber gasket fitted on its edge. The lower end of the J-shaped tube is provided with a flared opening, and the upper part of the central clamp is fixed inside the J-shaped tube by each of the rubber gaskets, while the lower part is located within the space of the flared opening.

[0013] Furthermore, several connecting wing plates are fixedly connected to both the first connecting pipe and the second connecting pipe. The ends of the connecting wing plates on the first connecting pipe are fixedly connected to the two limiting plates, and the ends of the connecting wing plates on the second connecting pipe are fixedly connected to the limiting plates and the flange male head, respectively.

[0014] Furthermore, the tapered tube has an inverted frustum-shaped cross section, and the channel within the tapered tube is curved. The tapered tube includes a tube body, a male tube end, and a female tube end. The female tube end is detachably connected to the central clamp, and the male tube end is locked to the bend-limiting female tube end.

[0015] Furthermore, the tapered tube is made of polyurethane elastomer material and has an internal stainless steel skeleton.

[0016] The beneficial effects of this invention are as follows: By combining J-shaped tubes, tapered tubes, and bend limiters, the protection of the suspended section of the submarine cable can be improved, effectively alleviating stress concentration problems and enhancing the cable's protective performance in complex dynamic environments. Furthermore, the bend limiter unit adopts a modular structure design, and the rotating concave block and rotating groove are connected by a pivot shaft, facilitating installation and disassembly, significantly improving construction efficiency and reducing maintenance costs. This invention utilizes a combination of marine aquaculture and submarine cable protection, along with oyster reef anti-erosion measures. Artificially cultivated oyster reefs are laid on the seabed surface near the submarine cable. The oyster reefs reduce the boundary layer water flow velocity through their rough surface and further stabilize the seabed with their strong adhesion characteristics, mitigating localized erosion effects. This avoids the risk of erosion of the submarine cable and its surrounding substrate, significantly improving the overall protective performance of the system. This makes the protective device suitable for complex marine environments, possessing good protective and ecological properties, while also generating economic benefits. Attached Figure Description

[0017] Figure 1 The diagram shown is a schematic representation of the structural principle of one embodiment of the present invention.

[0018] Figure 2 for Figure 1 The partial structural diagram shows the structure of the central clamp.

[0019] Figure 3 As shown Figure 2 A side view.

[0020] Figure 4for Figure 1 The partial structural diagram shows the structure of the tapered tube.

[0021] Figure 5 for Figure 1 The partial structural diagram shows the structure of the limiter.

[0022] Figure 6 As shown Figure 5 A sectional view.

[0023] Figure 7 As shown Figure 6 A side view.

[0024] Figure 8 for Figure 5 The partial structural diagram shows the structure of the bending-limiting unit.

[0025] Explanation of reference numerals in the attached drawings: 1. J-shaped pipe; 2. Center clamp; 201. First connecting pipe; 202. Second connecting pipe; 203. Limiting plate; 204. Male flange; 205. Rubber gasket; 206. Connecting wing plate; 3. Tapered pipe; 301. Male pipe; 302. Female pipe; 4. Bending limiter; 401. Male bending limiter; 402. Female bending limiter; 403. Fixing hole; 404. Rotating protrusion; 405. Rotating groove; 406. Shaft hole; 5. Submarine cable; 6. Seabed; 7. Oyster reef. Detailed Implementation

[0026] This invention discloses a combined bending protection device based on dynamic design. The following describes one embodiment of the invention in detail with reference to the accompanying drawings.

[0027] like Figure 1 As shown, a combined bending protection device based on dynamic design has one side located within the seabed 6 and the other side located in the seawater. The device is surrounded by artificially cultivated oyster reefs 7, which enhance the stability of the seabed 6. The protection device includes a J-shaped tube 1, a central clamp 2, a tapered tube 3, and a bend limiter 4. These components are connected sequentially, and each has a channel for accommodating a submarine cable 5, which is placed within the channel. The lower end of the J-shaped tube 1 has a flared opening. The upper end of the central clamp 2 is fixedly connected to the inner wall of the J-shaped tube 1, and its lower end is located within the space at the flared opening of the J-shaped tube 1.

[0028] Combination Figure 2 and Figure 3As shown, the central clamp 2 includes a first connecting pipe 201, a second connecting pipe 202, a limiting plate, and a flange male head 204. One side of the first connecting pipe 201 and one side of the second connecting pipe 202 are fixedly connected by the limiting plate. The other side of the first connecting pipe 201 is fixedly connected to the limiting plate, and an outwardly protruding annular plate is fixed to the end of the other side of the first connecting pipe 201. The other side of the second connecting pipe 202 is fixedly connected to the flange male head 204. Each limiting plate and flange male head 204 has a through hole adapted to the submarine cable 5. Each limiting plate is circular, with its edge protruding beyond the first connecting pipe 201 and the second connecting pipe 202. Each limiting plate has a rubber gasket 205 fitted on its edge. The lower end of the J-shaped pipe 1 is provided with a flared opening. The upper part of the central clamp 2 is fixed inside the J-shaped pipe 1 by the friction and elasticity of the J-shaped pipe 1 through the rubber gaskets 205. The lower part of the central clamp 2 is located within the space of the flared opening. Several connecting wing plates 206 are fixedly connected to both the first connecting pipe 201 and the second connecting pipe 202. The ends of the connecting wing plates 206 on the first connecting pipe 201 are fixedly connected to two limiting plates 203, and the ends of the connecting wing plates 206 on the second connecting pipe 202 are fixedly connected to the limiting plates 203 and the flange male head 204, respectively. In this embodiment, the central clamp 2 is made of 316L stainless steel to extend its service life.

[0029] like Figure 4 As shown, the tapered tube 3 has an inverted frustum-shaped cross-section, and the channel within the tapered tube 3 has a certain curvature. The length of the tapered tube 3 is 2 to 3 times the length of the bending limiting unit. The tapered tube 3 includes a tube body, a male connector 301, and a female connector 302. The male connector 301 is located at the upper end of the tube body, and the female connector 302 is located at the lower end of the tube body. The diameter of the female connector 302 is larger than the diameter of the male connector 301. The female connector 302 is detachably connected to the flange male connector 204 of the central clamp 2, and the male connector 301 is locked to the bending limiting female connector 402. The tapered tube 3 is cast from polyurethane elastomer material, which has a certain degree of elasticity, which helps to alleviate the stress concentration problem of the submarine cable 5 under dynamic environment. A stainless steel skeleton is embedded inside the tapered tube 3. The stainless steel skeleton is embedded inside the tube body during the casting of the tapered tube 3 to improve strength and shear resistance, ensure stable connection with the central clamp 2, and avoid failures such as breakage or detachment at the connection point.

[0030] Combination Figure 5 and Figure 6As shown, the bend limiter 4 includes several bend-limiting units connected in sequence. The bend limiter 4 has a half-symmetrical structure, with identical structures between two bend-limiting units. Each bend-limiting unit has a bend-limiting male connector 401 at one end and a bend-limiting female connector 402 at the other end. Adjacent bend-limiting units are locked together by the bend-limiting male connector 401 and the bend-limiting female connector 402, which can transfer the force to the bend limiter 4 when the submarine cable 5 is subjected to excessive force, thus preventing the submarine cable 5 from breaking. Each bend-limiting unit includes two bend-limiting units. Several fixing holes 403 are provided on the contact surface between the two bend-limiting units in the same bend-limiting unit. The two bend-limiting units are fixedly connected by bolts and double-sided toothed washers. Each bend-limiting unit has an outwardly protruding rotating protrusion 404 on the upper side near the female connector on the contact surface, and an inwardly recessed rotating groove 405 on the lower side near the female connector on the contact surface. The rotating protrusion 404 is disposed in the rotating groove 405 between the two bend-limiting units in the same bend-limiting unit. Figure 7 and Figure 8 As shown, both the rotating protrusion 404 and the rotating groove 405 have coaxial through-holes 406. The rotating protrusion 404 and the rotating groove 405 are detachably connected by bolts, allowing relative rotation between them. When connected by bolts, if a bolt is installed in the upper shaft hole 406 and no bolt is installed in the fixing holes 403, then the corresponding lower shaft hole 406 will not have a bolt installed, while the fixing holes 403 will have a bolt installed. The two corresponding bending limiting units are connected by a shaft, which ensures a stable connection between the two bending limiting units while significantly reducing the difficulty of underwater replacement and maintenance operations, reducing underwater operation time, improving construction efficiency, and reducing operating costs. In this embodiment, the bending limiting device 4 is made of polyurethane material and contains glass fiber, giving it high tensile strength, hardness, and wear resistance.

[0031] In use, one side of the submarine cable 5 is laid on the surface of the seabed 6, and then a certain length is reserved before being buried in the seabed 6. The other side is connected to the wind turbine after passing through the J-shaped pipe 1. The submarine cable 5 is divided into suspension section, reserved section and buried section according to its distribution location. The J-shaped pipe 1, the central clamp 2 and the tapered pipe 3 are all fitted on the suspension section, and the bend limiter 4 is fitted on the suspension section, reserved section and buried section. The submarine cable 5 buried in the seabed 6 still needs to be fitted with the bend limiter 4 for a certain length. The reason is that after the buried submarine cable 5 is exposed by the scouring of seawater, the bend limiter 4 can still limit the bend of the submarine cable 5, and strengthen the protection of the scouring position of the submarine cable 5. Among them, the rotating protrusion 404 and the rotating groove 405 on one side can be connected by bolts before going into the sea. The other side can be fixed by bolts when it is installed and fixed on the submarine cable 5 on the seabed. When a section of the bending limiting unit is damaged, the staff can remove the bolt located in the fixing hole 403 on one side, and then rotate it between the rotating protrusion 404 and the rotating groove 405 on the other side to remove the bending limiting unit from the submarine cable 5 for replacement.

[0032] Compared with existing bend limiters, this invention not only ensures a stable connection of the bend limiter 4, but also significantly reduces underwater operation time, improves construction efficiency, and lowers operating costs through its swivel-type connection. The protective device is surrounded by artificially cultivated oyster reefs 7, which are laid on the seabed 6 near the submarine cable 5. The artificially cultivated oyster reefs 7 can reduce the velocity of boundary layer water flow through their rough surface and stabilize the seabed 6 with the strong adhesion of oysters, mitigating local erosion effects. This avoids the risk of erosion of the submarine cable 5 and its surrounding geology, significantly improving the overall protective performance of the protective device. It possesses excellent protective and ecological properties, while also generating economic benefits.

[0033] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A combined bending protection device based on dynamic design, characterized in that: One side of the protective device is located inside the seabed (6), and the other side is located in the seawater. Oyster reefs (7) are arranged around the protective device to enhance the stability of the seabed (6). The protective device includes a J-shaped tube (1), a central clamp (2), a conical tube (3), and a bend limiter (4). The J-shaped tube (1), the central clamp (2), the conical tube (3), and the bend limiter (4) are connected in sequence. One end of the central clamp (2) is connected to the J-shaped tube (1), and the other end is connected to the bend limiter (4) through the conical tube (3). The J-shaped tube (1), the center clamp (2), the tapered tube (3), and the bend limiter (4) all have channels for accommodating the submarine cable (5), and the submarine cable (5) is disposed in the channels; the bend limiter (4) includes a number of bend limiting units connected in sequence, each bend limiting unit includes two bend limiting units, each bend limiting unit has a rotating protrusion (404) on one side and a rotating groove (405) adapted to the rotating protrusion (404) on the other side, and the two bend limiting units are rotatably connected through the rotating protrusion (404) and the rotating groove (405); The rotating protrusion (404) and the rotating groove (405) have coaxial pivot holes (406), and the rotating protrusion (404) and the rotating groove (405) are detachably connected by bolts, so that the rotating protrusion (404) and the rotating groove (405) can rotate relative to each other; The submarine cable (5) has a buried section depending on the location. The bend limiter (4) is sleeved on the buried section. The submarine cable (5) buried in the seabed (6) is sleeved with the bend limiter (4).

2. The combined bending protection device based on dynamic design according to claim 1, characterized in that: The bending limiter (4) has a half-symmetrical structure, and each bending limiter unit has a bending limiter male head (401) at one end and a bending limiter female head (402) at the other end. A plurality of fixing holes (403) are provided on the contact surface between the two bending limiting units located in the same bending limiting unit. The fixing holes (403) between the two bending limiting units are fixedly connected by bolts and double-sided toothed washers.

3. A combined bending protection device based on dynamic design according to claim 2, characterized in that: If a bolt is provided in the pivot hole (406) on one side and no bolt is provided in the fixing hole (403), then a bolt is provided in the fixing hole (403) on the other side and no bolt is provided in the pivot hole (406).

4. The combined bending protection device based on dynamic design according to claim 1, characterized in that: The bending limiter (4) is made of polyurethane material and contains glass fiber.

5. A combined bending protection device based on dynamic design according to claim 1, characterized in that: The submarine cable (5) is also provided with a suspension section and a reserved section depending on the location. The J-shaped tube (1), the center clamp (2) and the tapered tube (3) are sleeved on the suspension section, and the bend limiter (4) is sleeved on the suspension section and the reserved section.

6. A combined bending protection device based on dynamic design according to claim 1, characterized in that: The central clamp (2) includes a first connecting pipe (201), a second connecting pipe (202) and several limiting plates. The limiting plates are fixed on both sides of the first connecting pipe (201), one side of which is fixedly connected to one side of the second connecting pipe (202), and the other side of the second connecting pipe (202) is fixedly connected to a flange male (204). Each limiting plate and flange male (204) has a through hole that is compatible with the submarine cable (5).

7. A combined bending protection device based on dynamic design according to claim 6, characterized in that: Each of the limiting plates is circular, with its edge protruding beyond the first connecting pipe (201) and the second connecting pipe (202). Each of the limiting plates is fitted with a rubber gasket (205) on its edge. The lower end of the J-shaped tube (1) is provided with a flared opening. The upper part of the central clamp (2) is fixed inside the J-shaped tube (1) by each of the rubber gaskets (205), and the lower part is located in the space of the flared opening.

8. A combined bending protection device based on dynamic design according to claim 6, characterized in that: A plurality of connecting wing plates (206) are fixedly connected to the first connecting pipe (201) and the second connecting pipe (202). The ends of the connecting wing plates (206) on the first connecting pipe (201) are fixedly connected to the two limiting plates respectively, and the ends of the connecting wing plates (206) on the second connecting pipe (202) are fixedly connected to the limiting plates and the flange male head (204) respectively.

9. A combined bending protection device based on dynamic design according to claim 2, characterized in that: The tapered tube (3) has an inverted frustum shape in cross section, and the channel inside the tapered tube (3) has an arc. The tapered tube (3) includes a tube body, a male tube head (301) and a female tube head (302). The female tube head (302) is detachably connected to the central clamp (2), and the male tube head (301) is locked to the bend-limiting female tube head (402).

10. A combined bending protection device based on dynamic design according to claim 9, characterized in that: The tapered tube (3) is made of polyurethane elastomer material and has a stainless steel skeleton embedded inside.

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