Submarine cable bend limiter with vortex-induced vibration suppression function

Abstract

The application discloses a submarine cable bending limiter with vortex-induced vibration suppression function, which comprises a body, the body is formed by a plurality of sleeves in series, the sleeve is provided with a sleeve hole for the cable to pass through on the axis of the sleeve, one end of the sleeve is provided with a ring-shaped bending limiting groove, the bending limiting groove is arranged on the inner ring of the sleeve, the other end of the sleeve is provided with a bending limiting ring, the bending limiting groove is sleeved on the bending limiting ring of the previous sleeve, the bending limiting ring is inserted into the bending limiting groove of the next sleeve, the groove width of the bending limiting groove is greater than the thickness of the bending limiting ring, the outer ring of the sleeve is provided with a plurality of turbulence pieces which are arranged in a uniform array along the circumference, and the body forms a plurality of turbulence lines arranged in a spiral through the turbulence pieces on the sleeves. The application provides a submarine cable bending limiter with vortex-induced vibration function for reducing fatigue damage of the submarine cable.

Description

Technical Field

[0001] This invention relates to the field of submarine cable accessories, specifically a submarine cable bending limiter with vortex-induced vibration suppression function. Background Technology

[0002] In marine energy and cross-sea communication engineering, the terminal routes of submarine cables, including power cables and composite umbilical cables, often involve various typical structural interfaces. In offshore wind power scenarios, submarine cables are typically laid along J-shaped pipes fixed to the outside of the wind turbine tower to the top of the tower or the nacelle wiring device. In offshore oil and gas development scenarios, the cable route is equally representative: part of the cable passes through the J-shaped pipe and connects to the jacket platform, while another part connects at the underwater end to an underwater terminal structure such as an umbilical cable terminal assembly (UTA) or a terminal head (UTH) at a certain installation height. Regardless of whether the cable exits from the J-shaped pipe outlet or from the underwater terminal port, a free suspension section will be formed between the terminal structure and the seabed or foundation. Under the coupling effect of the cable's own weight and loads from waves and ocean currents, this suspension section is prone to curvature concentration at the root or local locations. To ensure that the actual bending radius of the cable is always not lower than its minimum allowable bending radius, and to prevent plastic deformation of the armor layer, fatigue cracking of the sheath, or damage to internal functional units, bending limiters are commonly installed in the suspension section in engineering practice to constrain curvature.

[0003] However, existing bend limiters only provide bend protection and are insufficient for suppressing dynamic vibrations in the suspended section under continuous ocean currents. Submarine cables are susceptible to vortex-induced vibration (VIV) induced by transverse currents in their free suspension sections, leading to high-frequency alternating stress and localized fretting wear on the cable body. Under long-term alternating loads, fatigue damage accumulation in the suspension section is unavoidable, which can lead to structural fatigue failures such as armor wire breakage and sheath cracking in severe cases. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a submarine cable bending limiter with the function of reducing vortex-induced vibration and fatigue damage to submarine cables.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows: a submarine cable bending limiter with vortex-induced vibration suppression function, comprising a body, the body being composed of multiple sleeves connected in series, the sleeve having a sleeve hole on its axis for the cable to pass through, one end of the sleeve having an annular bending groove, the bending groove being located on the inner ring of the sleeve, the other end of the sleeve having a bending ring, the bending groove being sleeved on the bending ring of the previous sleeve, the bending ring being inserted into the bending groove of the next sleeve, the width of the bending groove being greater than the thickness of the bending ring, the outer ring of the sleeve having a number of baffles evenly arranged in a circumferential array, the body forming a number of helically arranged baffle lines through the baffles on the multiple sleeves.

[0006] Compared with existing technologies, the advantages of this invention are as follows: The bending limiter is formed by using a series design of multiple sleeves and a bend-limiting groove with a width greater than the thickness of the bend-limiting ring, thus limiting the bending angle between adjacent sleeves and preventing damage caused by excessive bending of the submarine cable. Furthermore, the design of the turbulence line guides and diverts the current when subjected to continuous ocean currents. When the diverted current flows in a different direction than the original current, it will cause a change in the direction of the subsequent current, thereby reducing the continuous impact of the current on the cable and reducing vortex-induced vibration that causes fatigue damage. In other words, the turbulence line design creates a turbulence zone on the surface of the cable that improves its safety. If the direction of the diverted current is similar to the direction of the ocean current, the vortex-induced vibration caused by the current itself is also smaller, making it less likely to cause fatigue damage to the cable.

[0007] As an improvement of the present invention, the spoilers are inclined and the inclination direction of each spoiler is the same. Through this improvement, the stability of the spoiler line formation is ensured, and the different guiding and diversion directions formed by each spoiler are avoided, which would prevent the formation of a strong and powerful spoiler line, thus failing to form a sufficient anti-interference effect and failing to achieve the purpose of reducing the fatigue damage of the body.

[0008] As an improvement of the present invention, a positioning part is provided at the connection between the spoiler and the sleeve. The positioning part is tapered with a narrower width along the radial direction of the sleeve. The sleeve is provided with a positioning groove that matches the positioning part. Through this improvement, radial positioning and circumferential positioning between the spoiler and the sleeve are achieved.

[0009] As an improvement of the present invention, the lower end of the positioning part is provided with a retaining tooth, and the positioning groove is provided with a retaining groove. Through the improvement, the turbulence plate is prevented from detaching from the positioning groove.

[0010] As an improvement of the present invention, the axial length of the spoiler increases radially outward. In the maximum bending state, there is an overlapping area between the spoilers on the outer ring of the bend on two adjacent sleeves. This improvement ensures the integrity of the spoiler line formation and avoids breakage of the spoiler line. During the formation of the spoiler area, the guiding flow is formed by the impact energy of the ocean current. Therefore, the energy of the guiding flow is less than that of the ocean current. In order to ensure the effectiveness of the guiding flow interference capability, the guiding flow energy over a large area must be converged to maximize the anti-interference capability of the guiding flow. If a large discontinuous area is formed between adjacent spoilers, the guiding flow in that area will be cut off by the ocean current, and its spoiler effect will be greatly reduced.

[0011] As an improvement of the present invention, the thickness of the spoiler is thinned along the outward radial direction. With this improvement, the overlap area between adjacent spoilers on the inner curved ring of the main body is large, which can easily cause contact and friction between the spoilers, which is not conducive to the safety of the spoilers. The closer to the inner curved side, the greater the probability of contact. Thus, by designing the thickness of the spoiler to be thinned along the outward radial direction, interference between spoilers can be avoided.

[0012] As an improvement of the present invention, the bending groove is provided with four circumferentially oriented limiting grooves evenly arrayed along the circumference, and the bending ring is provided with four circumferentially oriented limiting blocks that rotate within the circumferentially oriented limiting grooves. The width of the circumferentially oriented limiting groove is greater than the width of the circumferentially oriented limiting blocks. The circumferential arc distance between two adjacent spoilers on the same spoiler line is not less than the rotation arc of the circumferentially oriented limiting blocks within the circumferentially oriented limiting groove. Through this improvement, the bending groove and the bending ring can rotate when the body is not bent. If the rotation range is not limited, i.e., limited by the circumferential rotation of the circumferential limiting blocks and the circumferentially oriented limiting groove, it is easy to cause uneven distribution of the spacing between the spoilers, which may be too dense, too sparse, or even interfere with each other, thus hindering the stable formation of the spoiler line. Therefore, it is necessary to limit the circumferential rotation through the circumferential limiting groove and the circumferential limiting blocks. The design of the circumferential limiting groove being wider than the circumferential limiting block is to ensure smooth bending deformation. If the circumferential limiting block is located on the inner ring of the bend, and the plane where the circumferential limiting block changes direction is the same as the plane where the circumferential limiting groove is located along its length, then the circumferential limiting groove does not need to be wider than the circumferential limiting block. However, if the circumferential limiting block is located on the side of the bend, the plane where the circumferential limiting block changes direction is in a state of relative rotation with the plane where the circumferential limiting groove is located along its length. If the width of the circumferential limiting groove is equal to the width of the circumferential limiting block, bending between the sleeves cannot be achieved. The design of the circumferential arc spacing between two adjacent spoiler plates on the same spoiler line being no less than the rotation arc of the circumferential limiting block within the circumferential limiting groove is to avoid contact between the spoiler plates due to relative rotation between the sleeves.

[0013] As an improvement of the present invention, the sleeve is composed of two half-cylinders spliced ​​together, and the two half-cylinders are fixedly connected by fasteners. This improvement makes it easier to install and connect the sleeves.

[0014] As an improvement of the present invention, the main body is connected to the cable outlet end of the J-shaped tube. The cable outlet end of the J-shaped tube is provided with a first connecting seat. The first connecting seat is inserted and fixed in the J-shaped tube. The end of the first connecting seat near the main body is provided with a connecting sleeve. The connection end of the connecting sleeve and the main body is provided with a first connecting ring with the same bending limit ring structure. The end of the main body near the connecting sleeve is a bending limit groove fitted on the first connecting ring. The end of the main body away from the first connecting seat is provided with a bottoming section. The bottoming section is a conventional bending limiter structure or a main body without a baffle plate. Through this improvement, the main body can be installed and connected on the J-shaped tube.

[0015] As an improvement of the present invention, the main body is connected to the cable outlet of the underwater terminal, and the cable outlet of the underwater terminal is fixedly connected to a second connecting seat. A transition sleeve is provided at the connection between the second connecting seat and the main body. The connection end of the transition sleeve and the main body is provided with a second connecting ring with the same bending limit ring structure. The end of the main body near the transition sleeve is a bending limit groove fitted on the second connecting ring. The end of the main body away from the second connecting seat is provided with a bottom-touching section. The bottom-touching section is a conventional bending limiter structure or a main body without a turbulence deflector. Through this improvement, the main body can be installed and connected on the underwater terminal. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the cross-sectional connection structure of the two sleeves of the present invention.

[0018] Figure 3 This is a schematic diagram of the spoiler structure of the present invention.

[0019] Figure 4 This is a schematic diagram of the semi-cylindrical structure of the present invention.

[0020] Figure 5 This is a schematic diagram of the cross-sectional connection structure between the baffle and the half-cylinder of the present invention.

[0021] Figure 6 This is a schematic diagram of the connection structure between the bending groove and the bending ring section of the present invention.

[0022] Figure 7 This is a schematic diagram of another semi-cylindrical structure of the present invention.

[0023] Figure 8 This is a schematic diagram of another connection structure between the bending groove and the bending ring section of the present invention.

[0024] Figure 9 This is a schematic diagram of the connection structure between the J-shaped tube and the body of the present invention.

[0025] Figure 10This is a schematic diagram of the first connecting seat structure of the present invention.

[0026] Figure 11 This is a schematic diagram of the connection structure of the underwater terminal body of the present invention.

[0027] Figure 12 This is a schematic diagram of the second connecting seat structure of the present invention.

[0028] The figure shows: 1. Sleeve, 1.1. Half-cylinder, 1.2. Positioning groove, 1.3. Slot, 2. Sleeve hole, 3. Bending groove, 4. Bending ring, 5. Baffle, 5.1. Positioning part, 5.2. Slip teeth, 6. Circumferential limiting groove, 7. Circumferential limiting block, 8. J-shaped tube, 9. First connecting seat, 9.1. Connecting sleeve, 9.1.1. First connecting ring, 10. Underwater terminal, 11. Second connecting seat, 11.1. Transition sleeve, 11.1.1. Second connecting ring, 12. Bottom contact section. Detailed Implementation

[0029] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0030] like Figure 1-2 As shown, a submarine cable bending limiter with vortex-induced vibration suppression function includes a body, which is composed of multiple sleeves 1 connected in series. The sleeve 1 has a sleeve hole 2 on its axis for the cable to pass through. One end of the sleeve 1 has an annular bending groove 3, which is located on the inner ring of the sleeve 1. The other end of the sleeve 1 has a bending ring 4. The bending groove 3 is sleeved on the bending ring 4 of the previous sleeve 1, and the bending ring 4 is inserted into the bending groove 3 of the next sleeve 1. The width of the bending groove 3 is greater than the thickness of the bending ring 4. The outer ring of the sleeve 1 has several baffles 5 arranged in a uniform array along the circumference. The body forms several spirally arranged baffle lines through the baffles 5 on the multiple sleeves 1. The baffles 5 are inclined, and the inclination direction of each baffle 5 is the same.

[0031] like Figure 3-5 As shown, a positioning part 5.1 is provided at the connection between the spoiler 5 and the sleeve 1. The positioning part 5.1 is tapered with a narrower width along the radial direction of the sleeve 1. The sleeve 1 is provided with a positioning groove 1.2 that fits into the positioning part 5.1. The lower end of the positioning part 5.1 is provided with a retaining tooth 5.2. A retaining groove 1.3 is provided in the positioning groove 1.2. The axial length of the spoiler 5 increases radially outward. In the maximum bending state, there is an overlapping area between the spoilers 5 on the outer ring of the bending of two adjacent sleeves 1. The thickness of the spoiler 5 decreases radially outward.

[0032] like Figure 4 , Figure 6As shown, the bend limiting groove 3 is provided with four circumferential limiting grooves 6 evenly arrayed along the circumference. The bend limiting ring 4 is provided with four circumferential limiting blocks 7 that rotate within the circumferential limiting grooves 6. The width of the circumferential limiting groove 6 is greater than the width of the circumferential limiting block 7. The circumferential arc distance between two adjacent spoiler plates 5 on the same spoiler line is not less than the rotation arc of the circumferential limiting block 7 within the circumferential limiting groove 6. The sleeve 1 is composed of two half-cylinders 1.1 spliced ​​together, and the two half-cylinders 1.1 are fixedly connected by screws and nuts. In the unbent state, the bending groove 3 and the bending ring 4 can rotate. If their rotation range is not limited, i.e., limited by the circumferential rotation of the circumferential limiting block 7 and the circumferential limiting groove 6, it is easy to cause uneven distribution of the spacing between the spoilers 5, which may be too dense, too sparse, or even interfere with each other, thus hindering the stable formation of the spoiler lines. Therefore, it is necessary to connect the circumferential limiting groove 6 and the circumferential limiting block 7 for circumferential rotation limitation. The groove width of the circumferential limiting groove 6 is designed to be greater than the width of the circumferential limiting block 7 in order to ensure smooth bending deformation. If the circumferential limiting block 7 is set on the outer and inner rings of the bend, the plane where the circumferential limiting block 7 changes direction and the circumferential limiting... Since the length direction of the slot 6 is the same as the plane, the width of the circumferential limiting slot 6 does not need to be greater than the width of the circumferential limiting block 7. However, the circumferential limiting block 7 is located on the curved side, and the plane where the circumferential limiting block 7 changes direction is in a state of relative rotation with the plane where the length direction of the circumferential limiting slot 6 is located. If the width of the circumferential limiting slot 6 is equal to the width of the circumferential limiting block 7, the bending between the sleeves 1 cannot be achieved. The design that the arc distance between two adjacent baffles 5 on the same baffle line along the circumferential direction is not less than the rotation arc of the circumferential limiting block 7 in the circumferential limiting slot 6 is to avoid contact between the baffles 5 due to the relative rotation between the sleeves 1.

[0033] like Figure 4 , Figure 7 As shown, during the design process, to ensure the stability of the installation and structure of the spoiler 5, the spoiler 5 is installed in a fixed position on the half-cylinder 1.1, thus avoiding the situation where the positioning groove 1.2 is located on the split line of the two half-cylinders 1.1. In the design process of the corresponding circumferential limiting groove 6 and circumferential limiting block 7, in order to meet the forming of the spoiler line, the design positions of the circumferential limiting groove 6 and circumferential limiting block 7 between two adjacent sleeves 1 need to be relatively rotated and distributed along the circumferential direction. The specific rotation angle depends on the design requirements of the spoiler line. At this time, the circumferential limiting groove 6 and circumferential limiting block 7 on all sleeves 1 at the same angle can be kept on the same plane of the body. The circumferential limiting block 7 located on the split line of the half-cylinder 1.1 or on the screw connection hole can be designed separately or its design can be cancelled. Its circumferential limiting function can be completed by the cooperation of the other two circumferential limiting blocks 7 and circumferential limiting grooves 6.

[0034] Or such as Figure 8 As shown, on the same sleeve, there is a relative deflection angle between the circumferential limiting groove 6 and the circumferential limiting block 7. The relative deflection angle is the deflection angle between two adjacent baffles 5. This design can unify the design of the sleeve, and the circumferential limiting groove 6 and the circumferential limiting block 7 on the whole body are also distributed in a threaded manner.

[0035] Application Example 1: like Figure 9 , Figure 10 As shown, the main body is connected to the cable outlet of the J-tube 8. A first connecting seat 9 is provided on the cable outlet of the J-tube 8. The first connecting seat 9 is inserted and fixed inside the J-tube 8. A connecting sleeve 9.1 is provided at the end of the first connecting seat 9 near the main body. The connection end of the connecting sleeve 9.1 to the main body has a first connecting ring 9.1.1 with the same structure as the bending limit ring 4. In the figure, because the first connecting seat 9 does not protrude from the J-tube 8 after insertion, directly connecting the main body to the first connecting seat 9 could easily cause interference. The flow plate 5 interferes with the opening of the J-shaped tube 8, so a connecting sleeve 9.1 without the flow plate 5 is added. The end of the body near the connecting sleeve 9.1 is a bend limiting groove 3 that fits onto the first connecting ring 9.1.1. The end of the body away from the first connecting seat 9 is provided with a bottoming section 12. The bottoming section 12 is a conventional bend limiter structure or a body without the flow plate 5, but the connecting groove on the bottoming section sleeve that connects the bottoming section 12 to the body needs to be modified in the same way as the bend limiting groove 3 to meet the connection requirements.

[0036] Application Example 2: like Figure 11-12 As shown, the main body is connected to the cable outlet of the underwater terminal 10. The cable outlet of the underwater terminal is fixedly connected to a second connecting seat 11. A transition sleeve 11.1 is provided at the connection between the second connecting seat 11 and the main body. In the figure, because the baffle 5 is longer than the length of the sleeve 1, if the main body is directly connected to the second connecting seat 11, it is easy to cause interference between the baffle 5 and the second connecting seat 11. Therefore, a transition sleeve 11.1 without the baffle 5 is added. The connection end of the transition sleeve 11.1 and the main body is provided with a second connecting ring 11.1.1 with the same structure as the bend limiting ring 4. The end of the main body near the transition sleeve 11.1 is a bend limiting groove 3 fitted on the second connecting ring 11.1.1. The end of the main body away from the second connecting seat 11 is provided with a bottoming section 12. The bottoming section 12 is a conventional bend limiter structure or a main body without the baffle 5. However, the connecting groove on the bottoming section sleeve connected to the main body needs to be modified in the same way as the bend limiting groove 3 to meet the connection requirements.

[0037] The conventional bending limiter is a bending limiting design structure with only the limiting bend groove 3 and the limiting bend ring 4.

[0038] By designing a submarine cable bending limiter with vortex-induced vibration suppression function, when subjected to continuous impact from ocean currents, the ocean currents will be guided and diverted by the disturbance lines. When the direction of the guided diversion is different from that of the ocean current, the guided diversion will cause a change in the direction of the subsequent ocean currents and surges, thereby reducing the continuous impact of the ocean currents on the cable body and reducing vortex-induced vibration that causes fatigue damage to the submarine cable.

[0039] The above description only illustrates the preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All modifications made within the scope of the independent claims of this invention are also within the scope of protection of this invention.

Claims

1. A submarine cable bending limiter with vortex-induced vibration suppression function, comprising a body, characterized in that: The main body is composed of multiple sleeves (1) connected in series. The sleeve (1) has a sleeve hole (2) for the cable to pass through on its axis. One end of the sleeve (1) has an annular bend-limiting groove (3). The bend-limiting groove (3) is located on the inner ring of the sleeve (1). The other end of the sleeve (1) has a bend-limiting ring (4). The bend-limiting groove (3) is fitted onto the bend-limiting ring (4) of the previous sleeve (1). The bend-limiting ring (4) is inserted into the bend-limiting groove (3) of the next sleeve (1). The width of the bend-limiting groove (3) is greater than the thickness of the bend-limiting ring (4). The outer ring of the sleeve (1) has several baffles (5) arranged in a uniform array along the circumference. The main body forms several spiral baffle lines through the baffles (5) on the multiple sleeves (1).

2. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 1, characterized in that: The baffles (5) are arranged at an angle, and the angles of each baffle (5) are the same.

3. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 2, characterized in that: The connection between the spoiler (5) and the sleeve (1) is provided with a positioning part (5.1). The positioning part (5.1) is a tapered shape with a narrower width along the radial direction of the sleeve (1). The sleeve (1) is provided with a positioning groove (1.2) that matches the positioning part (5.1).

4. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 3, characterized in that: The lower end of the positioning part (5.1) is provided with a locking tooth (5.2), and the positioning groove (1.2) is provided with a locking groove (1.3).

5. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 2, characterized in that: The length of the baffle (5) in the axial direction increases radially outward. In the maximum bending state, there is an overlapping area between the baffles (5) on the outer ring of the bending on two adjacent sleeves (1).

6. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 5, characterized in that: The thickness of the baffle (5) decreases radially outward.

7. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 1, characterized in that: The bend limiting groove (3) is provided with four circumferential limiting grooves (6) arranged in a uniform array along the circumference. The bend limiting ring (4) is provided with four circumferential limiting blocks (7) that rotate within the circumferential limiting grooves (6). The width of the circumferential limiting groove (6) is greater than the width of the circumferential limiting block (7). The circumferential arc distance between two adjacent spoilers (5) on the same spoiler line is not less than the rotation arc of the circumferential limiting block (7) within the circumferential limiting groove (6).

8. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 1, characterized in that: The sleeve (1) is composed of two half-cylinders (1.1) spliced ​​together, and the two half-cylinders (1.1) are fixedly connected by fasteners.

9. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 1, characterized in that: the main body is connected to the cable outlet end of the J-shaped tube (8), the cable outlet end of the J-shaped tube (8) is provided with a first connecting seat (9), the first connecting seat (9) is inserted and fixed in the J-shaped tube (8), the end of the first connecting seat (9) near the main body is provided with a connecting sleeve (9.1), the connection end of the connecting sleeve (9.1) and the main body is provided with a first connecting ring (4) with the same structure as the bending limit ring (4). 9.1.1), the end of the body near the connecting sleeve (9.1) is a bend limiting groove (3) fitted onto the first connecting ring (9.1.1), and the end of the body away from the first connecting seat (9) is provided with a bottoming section (12). The bottoming section (12) is a conventional bend limiter structure or a body without a baffle plate (5).

10. The submarine cable bending limiter with vortex-induced vibration suppression function according to claim 1, characterized in that: The main body is connected to the cable outlet of the underwater terminal (10). The cable outlet of the underwater terminal is fixedly connected to a second connecting seat (11). A transition sleeve (11.1) is provided at the connection between the second connecting seat (11) and the main body. The connection end of the transition sleeve (11.1) and the main body is provided with a second connecting ring with the same structure as the bend limiting ring (4). 11.1.1), the end of the body near the transition sleeve (11.1) is sleeved on the second connecting ring ( The bending groove (3) on 11.1.1) has a bottoming section (12) at one end of the body away from the second connecting seat (11). The bottoming section (12) is a conventional bending limiter structure or a body without a baffle plate (5).

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