Combined bending protection device based on dynamic design

Abstract

The invention discloses a combined bending protection device based on dynamic design, and relates to the technical field of submarine cable protection. Oyster reefs are arranged around the protection device, the protection device comprises a J-shaped pipe, a center clamp, a conical pipe and a bending limiter which are sequentially connected, one end of the center clamp is connected with the J-shaped pipe, and the other end of the center clamp is connected with the bending limiter through the conical pipe. The bending limiter comprises a plurality of bending limiting units connected in sequence, each bending limiting unit comprises two bending limiting single bodies, one side of each bending limiting single body is provided with a rotating protruding block, the other side of each bending limiting single body is provided with a rotating groove, and the rotating protruding blocks are rotationally connected with the rotating grooves. Through cooperation of the J-shaped pipe, the conical pipe and the bending limiting device, the stress concentration problem can be effectively relieved, the protection performance of the submarine cable in a complex dynamic environment is enhanced, the construction efficiency is remarkably improved through cooperation of the rotating protruding block and the rotating groove, meanwhile, the submarine cable can be prevented from being scoured through cooperation of the protection device and the oyster reef, and the service life of the submarine cable is prolonged. The method has good protective property and ecological property, and can generate economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine cable protection, and particularly to a combined bending protection device based on dynamic design. Background Art

[0002] Under the complex wave and current actions on the seabed, submarine cables are long-term affected by the superposition of dynamic scouring and bending loads, and there is a high risk of damage. At present, the bending protection measures for submarine cables mainly use bending limiters, which limit the excessive bending of submarine cables through a locking structure and transfer their forces. However, the design of traditional bending limiters is usually based on a static environment, ignoring the dynamic effects under complex hydrodynamic conditions, resulting in a high failure rate in actual engineering. In some areas, the failure rate of bending limiters is even as high as 50%, among which 80% of the failures occur concentrated at the connection between the first bending limiter and the second bending limiter. After the bending limiter fails, the submarine cable will lose protection. If the bending limiter cannot be repaired or replaced in time, the submarine cable is extremely likely to break, bringing serious economic losses and maintenance problems.

[0003] In addition, the submarine cables near the booster station or pile foundation are often subject to stronger scouring effects, resulting in erosion and hollowing of the seabed soil, thereby changing the stress state of the submarine cable and further increasing the fracture risk. The existing structural design of bending limiters is difficult to effectively deal with the additional mechanical problems caused by scouring and cannot fully guarantee the long-term operation safety of submarine cables.

[0004] Chinese patent document CN113497432A discloses a bending limit method and a bending limiter for parallel submarine cables and monitoring cables, including a limiter main body, a submarine cable channel, a rotation limiter, etc. Inside the bending limiter, in addition to the submarine cable channel, the layout of monitoring cables is added, and a rotation limiter is added to limit the rotational displacement between adjacent limiter main bodies, without cutting off the monitoring cables and retaining part of the rotation space to facilitate the submarine cable to release torsional stress. However, there are still many problems in the above document: First, the structure is complex, resulting in a high production cost and it is difficult to ensure long-term stability on the seabed, and frequent maintenance and replacement are required; second, the environmental adaptability is poor, the dynamic environment of the suspended submarine cable is not considered, and at the same time, the problem that the submarine cable at the mud entry end will peel off the seabed surface under the scouring action is ignored, and there is a relatively high failure rate. Summary of the Invention

[0005] Aiming at the problems that the current bending limiters have a complex structure, cannot ensure the long-term operation stability on the seabed, and do not consider the dynamic environment of the suspended submarine cable and the scouring situation of the submarine cable, and have a high failure rate, the present invention provides a combined bending protection device based on dynamic design.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions: A combined bending protection device based on dynamic design, one side of the protection device is arranged in the seabed, and the other side is located in seawater. Oyster reefs are arranged around the protection device, and the oyster reefs are used to enhance the stability of the seabed; the protection device includes a J-shaped pipe, a central clamp, a conical pipe and a bending limiter. The J-shaped pipe, the central clamp, the conical pipe and the bending limiter are connected. One end of the central clamp is fixedly connected to the J-shaped pipe, and the other end is fixedly connected to the bending limiter through the conical pipe; the J-shaped pipe, the central clamp, the conical pipe 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 number of bending limit units connected in sequence. Each bending limit unit includes two bending limit monomers. One side of each bending limit monomer has a rotating convex block, and the other side has a rotating groove adapted to the rotating convex block. The two bending limit monomers are rotatably connected through the rotating convex block and the rotating groove.

[0007] Further, the bending limiter is a Haff symmetric structure. One end of each bending limit unit has a male bending limit head, and the other end has a female bending limit head. A number of fixing holes are arranged on the contact surface between the two bending limit monomers in the same bending limit unit. The fixing holes between the two bending limit monomers are fixedly connected by bolts and double-sided toothed washers.

[0008] Further, the rotating convex block and the rotating groove have coaxial rotating shaft holes, and the rotating convex block and the rotating groove are detachably connected by bolts. If a bolt is arranged in the rotating shaft hole on one side and no bolt is arranged in the fixing hole, then a bolt is arranged in the fixing hole on the other side and no bolt is arranged in the rotating shaft hole.

[0009] Further, the bending limiter is made of polyurethane material and doped with glass fiber.

[0010] Further, the submarine cable is divided into a suspension section, a reserved section and a buried section according to different positions. The J-shaped pipe, the central clamp and the conical pipe are sleeved on the suspension section, and the bending limiter is sleeved on the suspension section, the reserved section and the buried section.

[0011] Further, the central clamp includes a first connecting pipe, a second connecting pipe and a number of limiting plates. Limiting plates are fixed on both sides of the first connecting pipe. One side is fixedly connected to one side of the second connecting plate, and the other side of the second connecting plate is fixedly connected to a male flange head. Each limiting plate and male flange head have through holes adapted to the submarine cable.

[0012] Further, each of the limiting plates is circular, with the edge protruding from the first connecting pipe and the second connecting pipe, and a rubber gasket is sleeved on the edge of each limiting plate. A flared opening is provided at the lower end of the J-shaped pipe, and the upper part of the central fixture is fixed in the J-shaped pipe through each rubber gasket, and the lower part is located in the space of the flared opening.

[0013] Further, a number of connecting wing plates are fixedly connected to both the first connecting pipe and the second connecting pipe. The end parts of the connecting wing plates on the first connecting pipe are fixedly connected to the two limiting plates respectively, and the end parts of the connecting wing plates on the second connecting pipe are fixedly connected to the limiting plate and the male flange respectively.

[0014] Further, the cross-section of the conical pipe is an inverted frustum of a cone, and the channel located inside the conical pipe has a radian. The conical pipe includes a pipe body, a pipe male head and a pipe female head. The pipe female head is detachably connected to the central fixture, and the pipe male head is locked and connected to the female head of the bending limiter.

[0015] Further, the conical pipe is made of polyurethane elastomer material with a stainless steel skeleton embedded inside.

[0016] The beneficial effects of the present invention are as follows: In the present invention, through the cooperation of the J-shaped pipe, the conical pipe and the bending limiter, the protection of the suspension section in the submarine cable can be improved, the problem of stress concentration can be effectively alleviated, and the protection performance of the submarine cable in a complex dynamic environment can be enhanced. At the same time, the bending limiting monomer adopts a modular structure design, and the rotating concave block and the rotating groove are connected by a rotating shaft, which is convenient for installation and disassembly, can significantly improve the construction efficiency and reduce the maintenance cost. The present invention combines the method of marine organism cultivation and submarine cable protection, combines the oyster reef anti-scour protection measures, lays the oyster reef formed by artificial cultivation on the surface of the seabed near the submarine cable. The oyster reef reduces the water flow velocity of the boundary layer through the rough surface, and further stabilizes the seabed by virtue of the strong adhesion characteristics, slows down the local scouring effect, thereby avoiding the erosion risk of the submarine cable and the bottom sediment around it, significantly improving the overall protection performance of the system, making the protection device applicable to complex marine environments, having good protection and ecological properties, and at the same time being able to generate economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 2 For Figure 1 partial structure diagram of, showing the structure of the central fixture.

[0019] Figure 3 Shown as Figure 2 side view of.

[0020] Figure 4 is Figure 1 a partial structural diagram of

[0021] Figure 5 is Figure 1 a partial structural diagram of

[0022] Figure 6 Shown is Figure 5 a cross-sectional view of

[0023] Figure 7 Shown is Figure 6 a side view of

[0024] Figure 8 is Figure 5 a partial structural diagram of

[0025] Explanation of reference numerals: 1, J-shaped pipe; 2, central clamp; 201, first connecting pipe; 202, second connecting pipe; 203, limiting plate; 204, male flange; 205, rubber gasket; 206, connecting wing plate; 3, conical pipe; 301, male pipe head; 302, female pipe head; 4, bending limiter; 401, male bending limiter head; 402, female bending limiter head; 403, fixing hole; 404, rotating convex block; 405, rotating groove; 406, rotating shaft hole; 5, submarine cable; 6, seabed; 7, oyster reef. Detailed implementation manners

[0026] The present invention discloses a combined bending protection device based on dynamic design. The following is a specific description of an implementation manner of the present invention in conjunction with the accompanying drawings.

[0027] As Figure 1 shown, one side of a combined bending protection device based on dynamic design is located in the seabed 6, and the other side is located in seawater. There is an oyster reef 7 formed by artificial cultivation around the protection device, and the oyster reef 7 is used to enhance the stability of the seabed 6. The protection device includes a J-shaped pipe 1, a central clamp 2, a conical pipe 3, and a bending limiter 4. The J-shaped pipe 1, the central clamp 2, the conical pipe 3, and the bending limiter 4 are connected in sequence, and each component has a channel for accommodating the submarine cable 5, and the submarine cable 5 is arranged in the channel. The lower end of the J-shaped pipe 1 is provided with a flared opening, the upper end of the central clamp 2 is fixedly connected to the inner wall of the J-shaped pipe 1, and the lower end is located in the space at the flared opening of the J-shaped pipe 1.

[0028] Combined with Figure 2 and Figure 3As shown in the figure, the central fixture 2 includes a first connecting pipe 201, a second connecting pipe 202, a limiting plate, and a male flange 204. One side of the first connecting pipe 201 is fixedly connected to one side of the second connecting pipe 202 through the limiting plate. The other side of the first connecting pipe 201 is fixedly connected with a limiting plate, and an annular plate protruding outward is fixed at the end of the other side of the first connecting pipe 201. The other side of the second connecting pipe 202 is fixedly connected with a male flange 204. Each limiting plate and male flange 204 has a through hole adapted to the submarine cable 5. Each limiting plate is circular, and its edge protrudes from the first connecting pipe 201 and the second connecting pipe 202. A rubber washer 205 is sleeved on the edge of each limiting plate. The lower end of the J-shaped pipe 1 is provided with a flared opening. The upper part of the central fixture 2 is fixed in the J-shaped pipe 1 under the action of friction of each rubber washer 205 and the elasticity of the J-shaped pipe 1, and the lower part of the central fixture 2 is located in the space of the flared opening. A plurality of connecting wing plates 206 are fixedly connected to both the first connecting pipe 201 and the second connecting pipe 202. The end parts of the connecting wing plates 206 on the first connecting pipe 201 are respectively fixedly connected to the two limiting plates 203, and the end parts of the connecting wing plates 206 on the second connecting pipe 202 are respectively fixedly connected to the limiting plate 203 and the male flange 204. In this embodiment, the central fixture 2 is made of 316L stainless steel material to extend its service life.

[0029] As Figure 4 shown, the cross-section of the tapered pipe 3 is an inverted frustum of a cone, and the channel located inside the tapered pipe 3 has a certain bending curvature. The length of the tapered pipe 3 is 2 to 3 times the length of the bending limit unit. The tapered pipe 3 includes a pipe body, a male pipe 301, and a female pipe 302. The male pipe 301 is located at the upper end of the pipe body, and the female pipe 302 is located at the lower end of the pipe body. The diameter of the female pipe 302 is larger than that of the male pipe 301. The female pipe 302 is detachably connected to the male flange 204 of the central fixture 2, and the male pipe 301 is lockingly connected to the female head of the bending limiter 4. The tapered pipe 3 is formed by pouring polyurethane elastomer material and has certain elasticity itself, which is beneficial to alleviating the problem of stress concentration of the submarine cable 5 in a dynamic environment. A stainless steel skeleton is embedded inside the tapered pipe 3. The stainless steel skeleton is embedded inside the pipe body when the tapered pipe 3 is poured, which is used to enhance strength and shear resistance, ensure stable connection with the central fixture 2, and avoid failures such as fracture and detachment at the connection.

[0030] Combined Figure 5 with Figure 6As shown, the bending limiter 4 includes a number of sequentially connected bending limit units. The bending limiter 4 has a Haff symmetric structure, and the structures between two adjacent bending limit units are the same. One end of each bending limit unit has a male bending limit head 401, and the other end has a female bending limit head 402. The adjacent bending limit units are locked and connected through the male bending limit head 401 and the female bending limit head 402, which can transfer the force to the bending limiter 4 when the submarine cable 5 is subjected to excessive force, avoiding the breakage of the submarine cable 5. Each bending limit unit includes two bending limit monomers. A number of fixing holes 403 are provided on the contact surface between the two bending limit monomers in the same bending limit unit, and the two bending limit monomers are fixedly connected through bolts and double-sided serrated washers. On the upper side of the contact surface of each bending limit monomer near the female head position, there is a rotatable convex block 404 protruding outward, and on the lower side of the contact surface of each bending limit monomer near the female head position, there is a rotatable groove 405 recessed inward. Between the two bending limit monomers in the same bending limit unit, the rotatable convex block 404 is arranged in the rotatable groove 405. Combining Figure 7 and Figure 8 As shown, both the rotatable convex block 404 and the rotatable groove 405 have coaxial through shaft holes 406. The rotatable convex block 404 and the rotatable groove 405 are detachably connected by bolts, enabling relative rotation between the rotatable convex block 404 and the rotatable groove 405. When connecting by bolts, if bolts are assembled in the upper shaft hole 406 and no bolts are assembled in each fixing hole 403, then no bolts are assembled in the corresponding lower shaft hole 406 and bolts are assembled in each fixing hole 403. The two corresponding bending limit monomers are connected by a shaft type connection, which can not only ensure the stable connection of the two bending limit monomers, but also significantly reduce the difficulty of underwater replacement and maintenance operations, reduce the underwater operation time, improve the construction efficiency, and reduce the operation cost. In this embodiment, the bending limiter 4 is made of polyurethane material and doped with glass fibers, so that the bending limiter 4 has 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 after reserving a certain length, it is buried into 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 a suspension section, a reserved section, and a buried section according to different distribution positions. The J-shaped pipe 1, the central clamp 2, and the conical pipe 3 are all sleeved on the suspension section, and the bending limiter 4 is sleeved on the suspension section, the reserved section, and the buried section. The submarine cable 5 buried in the seabed 6 still needs to be sleeved with the bending limiter 4 for a certain length. The reason is that after the buried submarine cable 5 is exposed under the action of seawater scouring, the bending limiter 4 can still apply a bending limit to the submarine cable 5, strengthening the protection of the scoured position on the submarine cable 5. Among them, the rotating convex block 404 and the rotating groove 405 on one side can be connected by bolts before going to sea, and on the other side, the two bending limit monomers can be fixed by bolts when installed and fixed on the submarine cable 5 at the seabed. When a certain bending limit unit has a damage problem, the staff can remove the bolt in the fixing hole 403 on one side, and then rotate through the rotating convex block 404 and the rotating groove 405 on the other side to disassemble the bending limit unit from the submarine cable 5 for replacement.

[0032] Compared with the existing bending limiters, the present invention can not only ensure the stable connection of the bending limiter 4, but also the shaft-type connection can significantly reduce the underwater operation time, improve the construction efficiency, and reduce the operation cost. The oyster reef 7 formed by artificial cultivation is arranged around the protection device, and the oyster reef 7 is laid on the surface of the seabed 6 near the submarine cable 5. The oyster reef 7 formed by artificial cultivation can reduce the velocity of the boundary layer flow through its rough surface, and can stabilize the seabed 6 by virtue of the strong adhesion characteristics of the oysters, slowing down the local scouring effect, thereby avoiding the erosion risk of the submarine cable 5 and the surrounding geology, significantly improving the overall protection performance of the protection device, having good protection and ecological properties, and at the same time being able to generate economic benefits.

[0033] Certainly, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the essence 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 arranged in the seabed (6), and the other side is located in the seawater. Oyster reefs (7) are arranged around the protective device, and the oyster reefs (7) are used to enhance the stability of the seabed (6); the protective device comprises a J-shaped tube (1), a center clamp (2), a tapered tube (3) and a bend limiter (4); the J-shaped tube (1), the center clamp (2), the tapered tube (3) and the bend limiter (4) are connected; one end of the center clamp (2) is connected to the J-shaped tube (1), and the other end is connected to the bend limiter (4) through the tapered tube (3); The J-shaped tube (1), the center clamp (2), the tapered tube (3) and the bend limiter (4) all have a channel for accommodating a submarine cable (5), and the submarine cable (5) is arranged in the channel; the bend limiter (4) comprises a plurality of bend limiter units connected in sequence, each of the bend limiter units comprises two bend limiter monomers, one side of each bend limiter monomer has a rotating protrusion (404), and the other side of each bend limiter monomer has a rotating groove (405) adapted to the rotating protrusion (404), and the two bend limiter monomers are rotatably connected via the rotating protrusion (404) and the rotating groove (405).

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

3. A combined bending protection device based on dynamic design according to claim 2, characterized in that: The rotating protrusion (404) and the rotating groove (405) are provided with a coaxial rotating shaft hole (406), and the rotating protrusion (404) and the rotating groove (405) are detachably connected via bolts; If a bolt is disposed in the rotating shaft hole (406) on one side and no bolt is disposed in the fixing hole (403), a bolt is disposed in the fixing hole (403) on the other side and no bolt is disposed in the rotating shaft hole (406).

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

5. The combined bending protection device based on dynamic design according to claim 1 is characterized in that: The submarine cable (5) is divided into a hanging section, a reserved section and a buried section according to different positions; the J-shaped tube (1), the center clamp (2) and the conical tube (3) are sleeved on the hanging section; and the bend limiter (4) is sleeved on the hanging section, the reserved section and the buried section.

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

7. The combined bending protection device based on dynamic design according to claim 6, characterized in that: Each of the limiting plates is circular, with an edge protruding from the first connecting tube (201) and the second connecting tube (202), and a rubber gasket (205) is sleeved on the edge of each of the limiting plates; The lower end of the J-shaped tube (1) is provided with a bell mouth, the upper part of the central clamp (2) is fixed in the J-shaped tube (1) through the rubber gaskets (205), and the lower part is located in the space of the bell mouth.

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

9. The combined bending protection device based on dynamic design according to claim 1, characterized in that: The cross section of the tapered tube (3) is in the shape of an inverted truncated cone, and the channel inside the tapered tube (3) has a curvature; The tapered tube (3) comprises a tube body, a tube male head (301) and a tube female head (302); the tube female head (302) is detachably connected to the central clamp (2); and the tube male head (301) is locked and connected to the female head of the bend limiter (4).

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

Images