Dynamic submarine cable limiting device and dynamic submarine cable system

Abstract

The invention relates to the technical field of submarine cable protection, in particular to a dynamic submarine cable limiting device and a dynamic submarine cable system.The dynamic submarine cable limiting device comprises a base arranged on a seabed; the two first clamps are fixedly connected with the dynamic submarine cable; the transition module is arranged on the dynamic submarine cable between the two first clamps in a sleeving manner; one ends of the two first mooring ropes are connected with the base, and the other ends of the two first mooring ropes are connected with the two first clamps respectively; wherein the transition module is used for limiting the bending radius of the dynamic submarine cable at the transition module to be not smaller than the preset minimum bending radius, the dynamic submarine cable limiting device can effectively control the bending radius of the submarine cable, and the situation that the submarine cable is damaged due to excessive bending is reduced or even avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of submarine cable protection, and in particular to a dynamic submarine cable limiting device and a dynamic submarine cable system. BACKGROUND

[0002] With the continuous development of ocean resources, dynamic submarine cables play an increasingly important role in marine engineering. Dynamic submarine cables are the key transmission medium connecting offshore floating platforms (such as floating production storage and offloading devices FPSO, semi-submersible drilling platforms, floating wind power platforms, etc.) and static devices on the seabed (such as wellhead equipment, seabed control modules, substations, etc.), mainly used for transmitting power, control signals, communication data, etc.

[0003] In complex marine environments, dynamic submarine cables face severe working challenges. Offshore floating platforms will produce large-scale position deviation and attitude changes under the action of wind, wave, current and other marine environmental loads. These movements are transmitted to the submarine cable system through the submarine cable, making the dynamic submarine cable bear complex dynamic loads during operation. Especially in the area close to the seabed, due to the combined effects of submarine cable gravity, water flow resistance and platform movement, the submarine cable is prone to excessive bending.

[0004] Excessive bending of the submarine cable will have serious consequences. First, too small a bending radius will cause the internal conductor, insulation layer and sheath of the submarine cable to bear excessive mechanical stress, which may cause material fatigue, insulation breakdown or conductor breakage. Second, repeated bending loads will accelerate the fatigue damage of the submarine cable, shortening its service life. Most seriously, sudden rupture of the submarine cable will cause the entire marine engineering system to shut down, causing huge economic losses and safety risks.

[0005] In the prior art, in order to protect the dynamic submarine cable from bending damage, the following methods are usually used: First, a bending reinforcement is installed at the connection between the submarine cable and the platform to limit bending by increasing the stiffness of this area. However, this method can only protect the local area at the connection, and cannot effectively protect the middle and near-seabed sections of the submarine cable.

[0006] Second, distributed buoyancy blocks are installed on the submarine cable to control the shape of the submarine cable by adjusting the buoyancy distribution of the submarine cable. Although this method can improve the stress condition of the submarine cable to some extent, it cannot directly and accurately control the bending radius of the submarine cable, and there is still a risk of excessive bending when the marine environment is severe.

[0007] Third, high-strength and flexible submarine cable design is used to improve the bending resistance of the submarine cable itself. However, this method significantly increases the cost of the submarine cable, and still cannot completely avoid bending damage under extreme working conditions.

[0008] Therefore, the main technical problem existing in the prior art is that there is no direct and effective control means for the bending radius of the dynamic submarine cable, and the bending radius of the submarine cable in the complex marine environment cannot be ensured to always meet the safety requirements, resulting in the risk of damage of the submarine cable due to excessive bending. SUMMARY

[0009] The present application provides a dynamic submarine cable limiting device and a dynamic submarine cable system, which can effectively control the bending radius of the submarine cable and reduce or even avoid the damage of the submarine cable due to excessive bending.

[0010] In a first aspect, the present application provides a dynamic submarine cable limiting device, comprising: a base arranged on the seabed; two first clamps fixedly connected with the dynamic submarine cable; a transition module sleeved on the dynamic submarine cable between the two first clamps; two first mooring ropes, one end of the two first mooring ropes being connected with the base and the other end being connected with the two first clamps respectively; wherein the transition module is used to limit the bending radius of the dynamic submarine cable at the transition module to be not less than a preset minimum bending radius.

[0011] In a possible implementation, the transition module comprises chain links connected in series along the extension direction of the dynamic submarine cable, and the adjacent two chain links have a limiting structure, and the adjacent two chain links limit the relative rotation angle therebetween through the limiting structure, so that the bending radius of the transition module is greater than or equal to the minimum bending radius.

[0012] In a possible implementation, the two ends of the transition module are respectively connected or abutted with the two first clamps.

[0013] In a possible implementation, the transition module is provided with multiple sections in intervals, and the dynamic submarine cable limiting device further comprises: a second clamp fixedly connected with the dynamic submarine cable and located between the two sections of the transition module; and a second mooring rope, one end of the second mooring rope being connected with the base and the other end being connected with the second clamp.

[0014] In a possible implementation, the two ends of the second clamp are respectively connected or abutted with the end portions of the transition module.

[0015] In a possible implementation, the length of the second mooring rope is less than or equal to the length of the first mooring rope.

[0016] In a possible implementation, the first clamp is provided with a first connecting piece, the first connecting piece being rotatable around the circumference of the first clamp, and the first mooring rope is connected with the first connecting piece; and / or, the second clamp is provided with a second connecting piece, the second connecting piece being rotatable around the circumference of the second clamp, and the second mooring rope is connected with the second connecting piece.

[0017] In a possible implementation, the first bending reinforcement is tapered in diameter from the end connected to the first clamp to the other end.

[0018] In a possible implementation, the first bending reinforcement is tapered in diameter from the end connected to the first clamp to the other end.

[0019] In a possible implementation, the first bending reinforcement is tapered in diameter from the end connected to the first clamp to the other end.

[0020] In a possible implementation, the dynamic submarine cable system further comprises distributed buoyancy blocks arranged on the dynamic submarine cable, wherein the dynamic submarine cable limiting device is arranged between two adjacent distributed buoyancy blocks, and / or the dynamic submarine cable limiting device is arranged between the distributed buoyancy blocks and the subsea static equipment.

[0021] In a possible implementation, the distributed buoyancy blocks adopt a Harvard structure.

[0022] In a possible implementation, the dynamic submarine cable limiting device further comprises a second bending reinforcement arranged around the dynamic submarine cable and connected to the floating platform.

[0023] The dynamic submarine cable limiting device provided by the application achieves direct and effective control of the bending radius of the dynamic submarine cable through the coordination of the base, the two first clamps, the transition module and the two first mooring ropes. The base is arranged on the seabed to provide a stable anchoring foundation for the entire device, the two first clamps are fixedly connected to the dynamic submarine cable to form an integrated structure of the device and the submarine cable, the transition module is arranged around the dynamic submarine cable between the two first clamps and has a preset minimum bending radius, can directly limit the bending degree of the submarine cable through its structural characteristics, and ensures that the bending radius of the submarine cable at the transition module will not be less than the minimum bending radius, and the two first mooring ropes are respectively connected to the base and the two first clamps to form a stable anchoring system, fixing the entire limiting device at a predetermined position. When the dynamic submarine cable tends to be excessively bent due to external forces such as wind and waves and water flow in a complex marine environment, the transition module can timely prevent the further bending of the submarine cable, avoiding the damage of the submarine cable caused by too small bending radius, and the anchoring effect of the mooring ropes ensures that the device can stably play the protection function and will not drift with the submarine cable. This design fundamentally solves the problem of lack of direct control means for the bending radius of the submarine cable in the prior art, provides reliable bending protection for the dynamic submarine cable, effectively reduces the risk of damage of the submarine cable due to excessive bending, and ensures the safe and stable operation of the marine engineering system. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to make the technical solutions in the present application or prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and all other embodiments obtained by a person of ordinary skill in the art without creative effort based on these drawings belong to the protection scope of the present application.

[0025] Figure 1 is a structural schematic view of a dynamic submarine cable limiting device and a dynamic submarine cable provided by the present application.

[0026] Figure 2 is a structural schematic view of another dynamic submarine cable limiting device and a dynamic submarine cable provided by the present application.

[0027] Figure 3 is a structural schematic view of a dynamic submarine cable system provided by the present application.

[0028] Reference signs: a, floating platform; 1, base; 2, first clamp; 21, first connecting piece; 3, dynamic submarine cable; 4, transition module; 41, chain link; 5, first mooring line; 6, second clamp; 61, second connecting piece; 7, second mooring line; 8, first bending reinforcement; 9, distributed buoyancy block; 10, second bending reinforcement; 11, counterweight. DETAILED DESCRIPTION

[0029] In order to make the technical solutions in the present application or prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and all other embodiments obtained by a person of ordinary skill in the art without creative effort based on these drawings belong to the protection scope of the present application.

[0030] The present application will be described below in combination with Figures 1-2 The embodiment of the present application provides a dynamic submarine cable limiting device, which comprises a base 1, two first clamps 2, a transition module 4 and two first mooring lines 5, wherein: The base 1 is arranged on the seabed. The base 1 is fixed on the seabed by its own gravity, and can also be fixed on the seabed by a connecting piece.

[0031] Two first clamps 2 are fixedly connected with the dynamic submarine cable 3.

[0032] The transition module 4 is sleeved on the dynamic submarine cable 3 between the two first clamps 2.

[0033] One end of the two first mooring ropes 5 is connected with the base 1, and the other end is connected with the two first clamps 2 respectively.

[0034] The transition module 4 is used to limit the bending radius of the dynamic submarine cable 3 at the transition module 4 to be not less than a preset minimum bending radius. The preset minimum bending radius is the minimum value of the safe bending radius of the dynamic submarine cable 3, so that the bending of the dynamic submarine cable 3 is always within the safe bending range.

[0035] In the application, through the coordination of the base 1, the two first clamps 2, the transition module 4 and the two first mooring ropes 5, a complete dynamic submarine cable limiting device is constructed, and effective control and protection of the bending radius of the dynamic submarine cable 3 are realized. The working principle of the device is that when the dynamic submarine cable 3 is subjected to external forces such as water flow and waves in the marine environment, the transition module 4 can limit the bending radius of the dynamic submarine cable 3 to be not less than the minimum bending radius, and the two first mooring ropes 5 provide stable anchoring effect for the entire limiting device by connecting the base 1 and the two first clamps 2, ensuring the stable position of the device on the seabed, thereby realizing reliable protection of the dynamic submarine cable 3.

[0036] Specifically, the base 1 is the anchoring foundation of the entire limiting device and is arranged on the seabed to provide a reliable connection point for the mooring rope. The two first clamps 2 are fixedly connected with the dynamic submarine cable 3, ensuring that the limiting device and the dynamic submarine cable 3 form an integrated structure and can move coordinately with the movement of the dynamic submarine cable 3. The transition module 4 is sleeved on the dynamic submarine cable 3 between the two first clamps 2 and has a preset minimum bending radius. When the dynamic submarine cable 3 is subjected to external forces and tends to bend, the transition module 4 limits the bending degree of the dynamic submarine cable 3 through its structural characteristics, so that the bending radius of the dynamic submarine cable 3 at the transition module 4 is always greater than or equal to the minimum bending radius. The two first mooring ropes 5 are connected with the base 1 and the two first clamps 2 respectively, forming a stable triangular or V-shaped stress structure. Through the tension of the mooring rope, the dynamic submarine cable limiting device is anchored at the predetermined position to prevent the device from drifting with the dynamic submarine cable 3.

[0037] In a specific embodiment, in a deep-sea oil development project, the dynamic submarine cable 3 connects a floating production storage and offloading (FPSO) with a subsea wellhead, the length of the dynamic submarine cable 3 exceeds 1000 meters, and the working water depth reaches 200 meters. In the marine environment, the FPSO will produce a large offset under the influence of wind and waves, and the dynamic submarine cable 3 is prone to excessive bending in the area close to the seabed. By installing the limiting device of the application at a position 50 meters away from the seabed of the dynamic submarine cable 3, the base 1 weighs 5 tons, the distance between the two first clamps 2 is 10 meters, and the minimum bending radius of the transition module 4 is set to 15 times the diameter of the dynamic submarine cable 3. When the FPSO produces the maximum offset, the limiting device can effectively limit the bending radius of the dynamic submarine cable 3, avoid damage to the dynamic submarine cable 3 due to excessive bending, and ensure the continuity and safety of the oil development operation.

[0038] In related art, the traditional dynamic submarine cable 3 protection scheme mainly relies on installing buoyancy blocks and counterweight blocks 11 on the dynamic submarine cable 3 to control the shape of the dynamic submarine cable 3, or installing bending stiffeners at the connection between the dynamic submarine cable 3 and the platform. Although these schemes can improve the stress condition of the dynamic submarine cable 3 to some extent, they cannot directly and accurately control the bending radius of the dynamic submarine cable 3. When the dynamic submarine cable 3 is subjected to strong water flow and wave action in a complex marine environment, there is still a risk of damage to the dynamic submarine cable 3 due to the local bending radius being too small. In addition, the traditional scheme lacks effective anchoring means and cannot ensure the stability of the protection device at the predetermined position.

[0039] In the embodiment of the application, by designing the minimum bending radius of the transition module 4, direct physical limitation of the bending degree of the dynamic submarine cable 3 is achieved, and this protection method is more direct and reliable. At the same time, through the anchoring system composed of the base 1 and the mooring line, it is ensured that the limiting device can stably play a protection role and will not deviate from the predetermined position due to the movement of the dynamic submarine cable 3. Compared with the traditional passive protection scheme, the application provides an active bending limitation function, and the protection effect is more reliable and reliable.

[0040] In some embodiments, the transition module 4 includes chain links 41 connected in series along the extension direction of the dynamic submarine cable 3, and the adjacent two chain links 41 have a limiting structure. The adjacent two chain links 41 limit the relative rotation angle between them through the limiting structure, so that the bending radius of the transition module 4 is greater than or equal to the minimum bending radius.

[0041] In the present application, by the transition module 4 includes the chain 41 which is connected in series along the extension direction of the dynamic submarine cable 3, and the limiting structure arranged between the adjacent two chains 41, the accurate control of the bending radius of the dynamic submarine cable 3 is realized. The chain 41 structure makes the transition module 4 have a certain flexibility, which can adapt to the normal bending requirement of the dynamic submarine cable 3, and the limiting structure plays a role when the relative rotation angle between the chains 41 reaches the preset value, limiting further rotation, so as to ensure that the bending radius of the whole transition module 4 will not be less than the minimum bending radius. This design not only ensures the flexible adaptation ability of the dynamic submarine cable 3, but also provides reliable bending protection.

[0042] Specifically, each chain 41 in the transition module 4 is an independent structural unit, and the chains 41 are connected in series by a connecting mode, so that the whole transition module 4 presents a structure similar to a spine. When the dynamic submarine cable 3 is subjected to a small external force, the adjacent chains 41 can be moderately relatively rotated, so that the transition module 4 can follow the flexible bending of the dynamic submarine cable 3, and will not limit the normal movement of the dynamic submarine cable 3. The limiting structure is arranged between the adjacent two chains 41, and when the relative rotation angle of the adjacent chains 41 gradually increases, the limiting structure begins to play a role. When the rotation angle reaches the preset limiting value, the limiting structure prevents further rotation between the chains 41, and at this time the bending radius of the transition module 4 is just equal to the set minimum bending radius. Through this step-by-step limiting mode, it is ensured that the bending radius of the dynamic submarine cable 3 at the transition module 4 is always within the safe range.

[0043] In a specific embodiment, in a sea wind power plant project, the dynamic submarine cable 3 connects the offshore wind power platform with the submarine transformer station, the diameter of the dynamic submarine cable 3 is 150 mm, and the bending radius is required to be not less than 2.25 m. The transition module 4 is designed to be 20 chains 41 connected in series, the length of each chain 41 is 200 mm, and the maximum allowed rotation angle between the adjacent chains 41 is 6 degrees. When the dynamic submarine cable 3 is subjected to strong sea current, the transition module 4 can follow the flexible bending of the dynamic submarine cable 3 in the early stage, and when the bending degree approaches the safety limit, the limiting structures between the chains 41 play a role in turn, preventing excessive bending. This gradual limiting mode avoids sudden rigid constraint, reduces the impact on the dynamic submarine cable 3, and at the same time ensures the accurate control of the bending radius, effectively protecting the safety of the dynamic submarine cable 3.

[0044] In the related art, the existing dynamic cable 3 bending protection scheme mainly adopts an integral bending reinforcement, which usually has fixed stiffness characteristics, being either completely flexible or completely rigid. Although the flexible reinforcement does not restrict the movement of the dynamic cable 3, it cannot provide effective bending protection; the rigid reinforcement can restrict bending, but will cause excessive constraint to the normal movement of the dynamic cable 3, which may lead to stress concentration in other parts. These traditional schemes cannot find an ideal balance point between flexible adaptation and rigid protection.

[0045] In the embodiment of the present application, through the ingenious combination of the chain link 41 and the limiting structure, the variable stiffness protection characteristic is realized. Under normal circumstances, the transition module 4 behaves as a flexible structure and does not interfere with the normal movement of the dynamic cable 3; when the bending tends to be dangerous, the stiffness of the transition module 4 gradually increases to provide progressive protection. This intelligent protection method not only ensures the freedom of movement of the dynamic cable 3, but also ensures bending safety, which has obvious technical advantages compared with the traditional fixed stiffness scheme.

[0046] In some embodiments, the two ends of the transition module 4 are respectively connected or abutted to the two first clamps 2.

[0047] In the present application, through the design that the two ends of the transition module 4 are respectively connected or abutted to the two first clamps 2, reliable connection and effective force transmission between the components of the limiting device are realized. As the core bending limiting component, the transition module 4 needs to form a stable structural whole with the first clamps 2 fixed on the dynamic cable 3, and the connection or abutment design ensures that the transition module 4 can reliably transmit the load from the dynamic cable 3, while ensuring the effective play of the limiting function. This connection mode avoids the relative sliding between components, improves the structural integrity and working reliability of the entire device.

[0048] Specifically, the two ends of the transition module 4 are designed with special connecting interfaces or abutting surfaces, which cooperate with the corresponding parts of the first clamps 2. The connection mode can adopt mechanical connection forms such as bolt connection, buckle connection, etc., to ensure that the transition module 4 and the first clamps 2 form a firm structural connection. The abutment mode makes the end surface of the transition module 4 tightly fit the corresponding surface of the first clamps 2 through precise geometric cooperation, and realizes force transmission through friction and extrusion force. Whether connection or abutment is adopted, it can ensure that when the dynamic cable 3 is subjected to external force, the load can be transmitted from the dynamic cable 3 to the first clamps 2, then to the transition module 4, and finally to the base 1 through the first mooring line 5, forming a complete force transmission path.

[0049] In a specific embodiment, in a deep-sea mining project, the dynamic submarine cable 3 connects the surface vessel with the seabed mining equipment, and the working environment is harsh, so the dynamic submarine cable 3 needs to bear a large dynamic load. The transition module 4 is 8 meters long and is fixedly connected with the first clamp 2 through flange connection at both ends. The flange connection adopts high-strength stainless steel material, and the bolt pre-tightening torque reaches 500 Nm. In the case of severe sea conditions, the maximum tension that the dynamic submarine cable 3 can bear can reach 100 kN, and through reliable connection design, the load can be effectively transmitted from the dynamic submarine cable 3 to the transition module 4 and then to the mooring system. The stress analysis at the connection shows that the maximum stress is only 60% of the material yield strength, which has sufficient safety margin and ensures the structural integrity of the device under extreme sea conditions.

[0050] In the related art, some components of the dynamic submarine cable 3 protection device lack effective connection design between components, and only rely on gravity or friction to maintain the relative position. Such a design is prone to relative sliding or separation between components when the dynamic submarine cable 3 bears a large load, resulting in failure of the protection device. Especially under dynamic load, the relative movement between components will cause wear and tear, which may lead to connection failure after long-term use.

[0051] In the embodiment of the present application, through explicit connection or abutment design, the reliable connection between the transition module 4 and the first clamp 2 is ensured, and the risk of component separation is avoided. Such a design not only improves the reliability of the device, but also facilitates installation and maintenance. Compared with the traditional loose connection scheme, the connection design of the present application is more reliable and durable, and can work stably for a long time in harsh marine environments.

[0052] As shown in FIG. 1, Figure 2 In some embodiments, the transition module 4 is spaced apart and has multiple sections, and the dynamic submarine cable limiting device further comprises: a second clamp 6 fixedly connected with the dynamic submarine cable 3 and located between the two sections of the transition module 4; and a second mooring line 7, one end of the second mooring line 7 being connected with the base 1 and the other end being connected with the second clamp 6.

[0053] In the present application, by spacing apart the transition module 4 into multiple sections and arranging the second clamp 6 and the second mooring line 7 between the two sections of the transition module 4, effective protection of the longer section of the dynamic submarine cable 3 and optimization of load distribution are achieved. The arrangement of the multiple sections of the transition module 4 increases the connection length between the limiting device and the dynamic submarine cable 3, thereby expanding the coverage of the bending protection, and the addition of the second clamp 6 and the second mooring line 7 provides additional anchor points, so that the load can be dispersed at multiple points, avoiding the problem of single-point overload, and further enhancing the limiting effect on the dynamic submarine cable 3.

[0054] Specifically, the interval arrangement of the multi-section transition module 4 means that independent transition module 4 sections are respectively installed at different positions of the dynamic submarine cable 3, and each section of the transition module 4 has an independent bending limiting function. The second clamp 6 is located between two sections of the transition module 4 and is fixedly connected with the dynamic submarine cable 3, and plays a role of intermediate support and load transmission. One end of the second mooring line 7 is connected with the base 1, and the other end is connected with the second clamp 6, thereby providing additional anchoring support for the dynamic submarine cable 3 at the intermediate position. The multi-point anchoring design makes the load on the dynamic submarine cable 3 be dispersed to the base 1 through multiple mooring points, and the load borne by each anchoring point is relatively small, thereby improving the carrying capacity and safety of the entire system. Meanwhile, the arrangement of the multi-section transition module 4 makes the bending protection no longer be limited to a single section, but provides continuous protection for a longer section of the dynamic submarine cable 3.

[0055] In a specific embodiment, in the Ocean Observing Network project, the total length of the dynamic submarine cable 3 reaches 500 meters, and it is necessary to provide bending protection in the range of 200 meters to 400 meters. A design of three sections of the transition module 4 is adopted, each section has a length of 10 meters, and the distance between sections is 60 meters. The first clamp 2 is arranged at the two ends of the first section and the third section of the transition module 4 respectively, and the second clamp 6 is arranged at the two ends of the second section of the transition module 4. The entire device is anchored on the seabed through four mooring lines (two first mooring lines 5 and two second mooring lines 7). Under the action of strong sea currents, the maximum load borne by the dynamic submarine cable 3 is 80 kilonewtons, and through multi-point dispersion, the load borne by each anchoring point is about 20 kilonewtons, which greatly reduces the single-point load. Meanwhile, the 200-meter-long section of the dynamic submarine cable 3 is effectively protected from bending, and local excessive bending is avoided.

[0056] In the related art, the traditional single-section protection scheme can only provide protection for a limited length of the dynamic submarine cable 3, and when the length of the dynamic submarine cable 3 is large, the unprotected section still has a bending risk. Moreover, the single-point anchoring mode is prone to overload failure when bearing a large load, and the reliability and safety of the system are limited.

[0057] In the embodiment of the present application, through the design of the multi-section transition module 4 and multi-point anchoring, comprehensive protection of the long section of the dynamic submarine cable 3 and reasonable distribution of the load are realized. This design not only expands the protection range, but also improves the carrying capacity of the system, and has obvious technical advantages compared with the traditional single-section scheme. Multi-point anchoring also provides system redundancy, and even if a certain anchoring point fails, other anchoring points can still maintain the basic functions of the system.

[0058] In some embodiments, the two ends of the second clamp 6 are respectively connected with or abut against the end portions of the transition module 4.

[0059] In the present application, the reliable connection between components in the multi-section limiting system and the continuous transmission of load are achieved by the design that the two ends of the second clamp 6 are connected or abutted with the end of the transition module 4 respectively. The second clamp 6, as an intermediate connecting component, forms a stable connection with the end of the adjacent transition module 4 at both ends, ensuring the structural continuity of the entire multi-section system, avoiding the load concentration and stress mutation at the connection site, ensuring the smooth transmission of load in the entire system, and improving the overall performance and reliability of the multi-section limiting device.

[0060] Specifically, the second clamp 6 is designed with a special end connection interface, which can form an accurate fit with the end of the transition module 4. The connection method can adopt threaded connection, flange connection or plug-in connection, etc., to ensure the firmness and reliability of the connection. The abutment method is through precise geometric design, so that the end face of the second clamp 6 closely fits with the end face of the transition module 4, forming an effective force transmission interface. This double-end connection design makes the second clamp 6 a key hub in the multi-section system, which can coordinate the work of adjacent transition module 4 sections and ensure that the entire system functions as a whole. When the dynamic submarine cable 3 is subjected to load, the load can be transmitted and distributed between adjacent transition module 4 sections through the second clamp 6.

[0061] In a specific embodiment, in a submarine cable laying project, a five-section transition module 4 design is used to protect a 1000-meter-long dynamic submarine cable 3 section. One second clamp 6 is arranged between every two transition module 4 sections, and a total of three second clamps 6 are needed. The two ends of each second clamp 6 are connected to the end of the adjacent transition module 4 through high-strength bolts, the bolt grade is 10.9, and the connection torque is 600 Nm. Under the working condition that the dynamic submarine cable 3 bears a load of 100 kN, the load is evenly distributed between the transition module 4 sections through the second clamp 6, and each transition module 4 bears a load of about 20 kN. Finite element analysis of the connection site shows that the maximum stress appears at the bolt connection, with a value of 280 MPa, which is much lower than the yield strength of the material, ensuring the safety and reliability of the connection.

[0062] In the embodiment of the present application, the double-end connection design of the second clamp 6 connects multiple independent transition module 4 sections into a continuous protection system, achieving coordinated distribution of load and smooth transmission of stress. This design not only improves the overall performance of the system, but also eliminates the stress concentration problem between sections, which has a significant technical advantage compared to the traditional segmented independent scheme.

[0063] In some embodiments, the length of the second mooring line 7 is less than or equal to the length of the first mooring line 5.

[0064] In the present application, by controlling the length of the second mooring line 7 to be less than or equal to the length of the first mooring line 5, the optimization of load distribution and the improvement of system stability in the multi-point mooring system are achieved. Due to the relatively short length of the second mooring line 7, the second mooring line 7 will preferentially bear the load when the system is loaded, playing a role in load sharing, while the first mooring line 5 provides backup protection. This hierarchical load design avoids excessive concentration of force on the mooring line, improving the reliability and safety of the entire mooring system.

[0065] Specifically, in the multi-point mooring system, the force conditions of mooring lines at different positions will be different due to differences in geometric position and load path. By reasonably designing the length relationship between the second mooring line 7 and the first mooring line 5, reasonable load distribution can be achieved. When the length of the second mooring line 7 is less than that of the first mooring line 5, the second mooring line 7 will first tighten and begin to bear the load at the beginning of the system loading, while the first mooring line 5 is still in a relatively relaxed state. As the load increases, the second mooring line 7 will elongate, and the first mooring line 5 will also begin to tighten and share the load. This phased load bearing method enables effective load distribution among multiple mooring lines, avoiding the situation where one mooring line is overloaded while others are underloaded.

[0066] In a specific embodiment, in a marine platform mooring project, the dynamic submarine cable limiting device adopts a configuration of six mooring lines, four of which are first mooring lines 5 with a length of 80 meters, and two of which are second mooring lines 7 with a length of 75 meters. Under normal working conditions, when the dynamic submarine cable 3 load is 60 kilonewtons, the two second mooring lines 7 first bear the load, each bearing about 25 kilonewtons of load, and the four first mooring lines 5 are in a light load state. When the load increases to 120 kilonewtons, the elongation of the second mooring lines 7 causes the first mooring lines 5 to begin to bear the load, at which time the load is evenly distributed among the six mooring lines, each bearing about 20 kilonewtons. This design ensures that the mooring lines are fully utilized under various load conditions, while avoiding overloading of a single mooring line.

[0067] In related technologies, multi-point mooring systems often use mooring lines of the same length. This design can achieve uniform load distribution in ideal conditions, but in actual applications, due to factors such as manufacturing errors, installation errors, and material property differences, it is difficult to achieve true uniform stress. Often, some mooring lines are overloaded while others are underloaded, reducing the efficiency and safety of the system.

[0068] In the embodiments of the present application, by intentionally designing different mooring line lengths, active load distribution control is achieved. This design can adapt to various uncertain factors in actual applications, ensuring reliable operation of the mooring system. Compared with the traditional equal-length design, the hierarchical length design of the present application is more in line with actual engineering needs, and has better practicality and reliability.

[0069] In some embodiments, the first clamp 2 is provided with a first connecting member 21 rotatable around the circumference of the first clamp 2, and the first mooring line 5 is connected to the first connecting member 21; and / or, the second clamp 6 is provided with a second connecting member 61 rotatable around the circumference of the second clamp 6, and the second mooring line 7 is connected to the second connecting member 61.

[0070] In the present application, by providing the first clamp 2 and the second clamp 6 with the first connecting member 21 and the second connecting member 61 rotatable around the circumference of the clamps respectively, and connecting the mooring lines to these connecting members, flexible connection between the clamps and the mooring lines is achieved, effectively solving the adverse effects of the rotation of the dynamic submarine cable 3 on the mooring system. When the dynamic submarine cable 3 twists or rotates under the action of the current, the connecting members can rotate around the circumference of the clamps, avoiding the transmission of the twisting force to the mooring lines, preventing the mooring lines from kinking and excessive stress, and ensuring the long-term stable operation of the mooring system.

[0071] Specifically, the first connecting member 21 and the second connecting member 61 usually adopt the structure forms of a rotating ring, a slip ring, or a spherical joint, etc. These connecting members can freely rotate 360 degrees around the circumference of the clamps. When the dynamic submarine cable 3 twists under the action of the current, the clamps will rotate together with the dynamic submarine cable 3, while the connecting members, due to their rotating characteristics, can maintain a stable orientation relative to the mooring lines, without transmitting the twisting force to the mooring lines. This design not only ensures the rigid connection between the clamps and the dynamic submarine cable 3, but also realizes the flexible connection between the clamps and the mooring lines. The first mooring line 5 is connected to the first connecting member 21, and the second mooring line 7 is connected to the second connecting member 61, forming a complete rotatable connection system. The rotating function of the connecting members also helps the mooring lines to find the best stress angle during the stress process, reducing the adverse effects of the side force on the mooring lines.

[0072] In a specific embodiment, in the dynamic submarine cable system of an offshore wind farm, the dynamic submarine cable 3 often twists due to the complexity of the current and the swing of the wind turbine platform. A spherical rotating ring is used as the connecting member, and the inner ball of the rotating ring can freely rotate in the outer shell with a rotating resistance less than 10 newton-meters. Under the action of strong current, the dynamic submarine cable 3 twists about 30 turns per hour, and through the rotating function of the connecting member, the mooring lines do not kink. Comparative tests show that in the traditional scheme with fixed connection, the mooring lines will kink seriously under the same conditions, resulting in a 40% decrease in the effective load capacity, while in the scheme with rotating connecting members, the load capacity of the mooring lines remains above 95% of the design value.

[0073] In the related art, the clamps are usually fixedly connected with the mooring lines, such as by direct welding or bolt connection. Although this connection method is simple in structure, it cannot adapt to the rotation requirement of the dynamic submarine cable 3. When the dynamic submarine cable 3 is twisted, the torsional force is directly transmitted to the mooring line, causing the mooring line to be twisted and knotted, and seriously affecting the load capacity and service life of the mooring line. Long-term torsional action can also cause fatigue failure of the mooring line.

[0074] In the embodiments of the present application, the influence of the torsion of the dynamic submarine cable 3 on the mooring line is effectively isolated through the design of the rotary connecting piece, and the mooring line can maintain a good working state under various working conditions. This design not only improves the reliability of the mooring system, but also prolongs the service life of the mooring line, and has obvious technical and economic advantages compared with the traditional fixed connection scheme.

[0075] In some embodiments, the dynamic submarine cable limiting device further comprises two first bending stiffeners 8, which are sleeved on the outer periphery of the dynamic submarine cable 3 and connected with the two first clamps 2 away from the transition module 4, for limiting the bending radius of the dynamic submarine cable 3 at the first clamps 2.

[0076] In the present application, by adding two first bending stiffeners 8 in the dynamic submarine cable limiting device, and sleeving them on the outer periphery of the dynamic submarine cable 3 and connecting them with the two first clamps 2 away from the transition module 4, further control and protection of the bending radius of the dynamic submarine cable 3 at the clamps are achieved. The first bending stiffener 8 provides a stiffness transition from the clamp to the free section of the dynamic submarine cable 3, avoids the occurrence of sharp stiffness change of the dynamic submarine cable 3 at the end of the clamp, reduces stress concentration, and ensures that the bending radius of the dynamic submarine cable 3 in the vicinity of the clamp meets the safety requirements, providing more comprehensive protection for the entire limiting device.

[0077] Specifically, the two first bending stiffeners 8 are respectively installed on the outer sides of the two first clamps 2, covering the transition area from the end of the clamp to the free section of the dynamic submarine cable 3. The first bending stiffener 8 usually adopts a tapered or gradually changing cross-sectional design, one end of which is connected with the rigid first clamp 2, and the other end of which is connected with the flexible dynamic submarine cable 3, forming a smooth transition of stiffness. When the dynamic submarine cable 3 is subjected to bending load, the first bending stiffener 8 can disperse the load within a certain length range, avoiding the sudden release of the load at the end of the clamp. This design is particularly important because the end of the clamp, as a rigid component, is often a high-risk area of stress concentration, and if there is no appropriate transition protection, the dynamic submarine cable 3 is prone to excessive bending or even damage at the end of the clamp. The addition of the first bending stiffener 8 effectively eliminates this hidden danger.

[0078] In a specific embodiment, in a dynamic submarine cable system of a submarine oil pipeline, the dynamic submarine cable 3 has a diameter of 200 mm, and the first clamp 2 has a length of 1 m and a high rigidity. To avoid stress concentration of the dynamic submarine cable 3 at the end of the clamp, a first bending reinforcement 8 is installed at each end of the first clamp 2, and has a length of 2 m and an outer diameter gradually decreasing from 250 mm at the first clamp 2 to 200 mm at the dynamic submarine cable 3. Through finite element analysis, it is shown that, when the bending reinforcement is not installed, the maximum stress of the dynamic submarine cable 3 at the end of the clamp is 150 MPa, close to the safety limit of the material; after the bending reinforcement is installed, the maximum stress is reduced to 80 MPa, and the safety margin is significantly improved. In a long-term fatigue test, the service life of the dynamic submarine cable 3 with the bending reinforcement is increased by 60% compared with that without the bending reinforcement.

[0079] In the related art, the dynamic submarine cable limiting device often only focuses on the main bending limiting function, and ignores the influence of the rigid components such as the clamp on the local area of the dynamic submarine cable 3. The sudden change of the rigidity at the end of the clamp is a common but easily overlooked problem, which can cause stress concentration of the dynamic submarine cable 3 in this area and become a weak link of the whole system. The traditional solution mainly relies on increasing the strength of the dynamic submarine cable 3 itself, but this method is high in cost and limited in effect.

[0080] In the embodiment of the present application, the stress concentration problem at the end of the clamp is solved by the specially designed first bending reinforcement 8, which is more economical and effective. The bending reinforcement not only protects the dynamic submarine cable 3, but also improves the reliability of the whole limiting device, and has better performance-price ratio and technical effect compared with the traditional scheme which simply relies on the strength of the dynamic submarine cable 3.

[0081] In some embodiments, the outer diameter of the first bending reinforcement 8 is gradually reduced from one end connected with the first clamp 2 to the other end.

[0082] In the present application, by designing the outer diameter of the first bending reinforcement 8 to be gradually reduced from one end connected with the first clamp 2 to the other end, the smooth transition of rigidity and the uniform distribution of stress are realized. The gradually reduced outer diameter design makes the rigidity of the bending reinforcement gradually change along the axial direction, smoothly transitions from high rigidity at the connection with the clamp to low rigidity at the connection with the dynamic submarine cable 3, avoids the sudden change of rigidity, ensures the uniform distribution of load and stress in the transition area, and maximally reduces the stress concentration phenomenon.

[0083] Specifically, the first bending reinforcement 8 adopts a taper or parabolic outer diameter variation curve, at the end connected with the first clamp 2, the outer diameter is the largest, which matches the stiffness of the first clamp 2; gradually decreases towards the other end, at the end connected with the dynamic submarine cable 3, the outer diameter is close to the outer diameter of the dynamic submarine cable 3, which matches the stiffness of the dynamic submarine cable 3. The taper design makes the cross-sectional modulus and bending stiffness of the bending reinforcement continuously change along the axial direction without abrupt change points. When the dynamic submarine cable 3 is subjected to bending load, the stress gradually changes along the length direction of the bending reinforcement, and no stress peak value is generated at a specific position. The taper of the outer diameter also helps to reduce the hydrodynamic resistance and improve the fluid mechanics performance of the bending reinforcement in seawater.

[0084] In a specific embodiment, in the deep-sea mining dynamic submarine cable system, the first bending reinforcement 8 has a length of 3 meters, the outer diameter of the end connected with the first clamp 2 is 300 millimeters, and the outer diameter of the end connected with the dynamic submarine cable 3 is 180 millimeters, and a linear taper design is adopted. Through computational fluid mechanics analysis, it is shown that the taper design reduces the hydrodynamic resistance by 30% compared with the equal-diameter design. Under the action of bending load, the stress distribution along the length direction of the bending reinforcement is more uniform, the maximum stress position moves from the end to the middle of the equal-diameter design, and the numerical value is reduced by 25%. Fatigue life evaluation shows that the fatigue life of the bending reinforcement of the taper design is increased by 45% compared with the equal-diameter design, which greatly improves the reliability of the system.

[0085] In the embodiment of the present application, through the taper outer diameter design, the true stiffness smooth transition is realized, and the design is more in line with the basic principles of material mechanics, and can maximize the performance of the material. Compared with the traditional design of equal cross section, the taper design not only improves the mechanical properties of the structure, but also improves the fluid mechanics performance, and is a more optimized technical solution.

[0086] As shown in Figure 3 The present application provides a dynamic submarine cable system, comprising: a dynamic submarine cable 3, one end of the dynamic submarine cable 3 is connected with a floating platform a, and the other end is connected with a seabed static device; and at least one dynamic submarine cable limiting device.

[0087] In the present application, by integrating the dynamic submarine cable limiting device into the dynamic submarine cable system, a complete system including the dynamic submarine cable 3, the floating platform a connection, the seabed static device connection and at least one limiting device is constructed, and the overall protection and safety guarantee of the entire dynamic submarine cable system are realized. The dynamic submarine cable 3 is a key transmission medium connecting the floating platform a and the seabed static device, and faces various threats in complex marine environment. By integrating a special limiting device in the system, the bending protection of the dynamic submarine cable 3 is provided, and the safe and stable operation of the entire dynamic submarine cable system under various working conditions is ensured.

[0088] Specifically, the dynamic submarine cable system is a complex engineering system, which includes the dynamic submarine cable 3, connecting devices, protection devices and other components. One end of the dynamic submarine cable 3 is connected to the floating platform a and bears the dynamic load of the platform; the other end is connected to the static seabed equipment and needs to ensure stable signal or energy transmission. In the middle section of the dynamic submarine cable 3, at least one dynamic submarine cable limiting device is installed according to the specific engineering requirements and marine environmental conditions. The position of the limiting device is usually selected in the area where the dynamic submarine cable 3 is under greater stress or has a higher risk of bending, such as the section close to the seabed or the middle of the dynamic submarine cable 3 suspension section. Through the protection of the limiting device, it is ensured that the dynamic submarine cable 3 will not be excessively bent in these critical areas, thereby protecting the integrity and functionality of the entire dynamic submarine cable system.

[0089] In a specific embodiment, in the dynamic submarine cable system of the offshore oil platform, the total length of the dynamic submarine cable 3 is 800 meters, connecting the floating production platform and the seabed wellhead control system. According to the marine engineering analysis, two sets of dynamic submarine cable limiting devices are installed at positions 100 meters and 300 meters from the seabed. The first set of limiting devices mainly protects the bottom section of the dynamic submarine cable 3 to prevent excessive bending caused by seabed water flow and platform deviation; the second set of limiting devices protects the middle section of the dynamic submarine cable 3 to prevent middle sagging bending caused by excessive length of the suspension section. Through the cooperative protection of the two sets of limiting devices, the entire dynamic submarine cable system operates stably during the 25-year design life and no bending-induced failure occurs, ensuring the continuity of oil production operations.

[0090] In the related art, the protection of the dynamic submarine cable system mainly relies on the mechanical properties of the dynamic submarine cable 3 itself and some simple protection measures, such as installing bending reinforcement at the connection or installing buoyancy blocks on the dynamic submarine cable 3. These measures, although having a certain protective effect, are often passive and local protection and cannot provide systematic safety protection for the entire dynamic submarine cable system. When the marine environmental conditions are severe or the dynamic submarine cable 3 has a large working load, the traditional protection measures are often insufficient to ensure the safety of the system.

[0091] In the embodiments of the present application, by integrating the specially designed limiting device into the dynamic submarine cable system, active and targeted bending protection is provided, and this system-level protection scheme is more comprehensive and reliable. The addition of the limiting device not only protects the dynamic submarine cable 3, but also improves the reliability and economy of the entire system, which has significant technical advantages compared to the traditional passive protection scheme.

[0092] In some embodiments, it further includes a distributed buoyancy block 9 arranged on the dynamic submarine cable 3; wherein the dynamic submarine cable limiting device is arranged between two adjacent distributed buoyancy blocks 9; and / or, the dynamic submarine cable limiting device is arranged between the distributed buoyancy block 9 and the static seabed equipment.

[0093] In the present application, by adding distributed buoyancy blocks 9 in the dynamic submarine cable system and setting the dynamic submarine cable limiting device between two adjacent distributed buoyancy blocks 9 or between the distributed buoyancy block 9 and the static seabed equipment, the organic combination of dynamic submarine cable 3 buoyancy control and bending protection is realized. The distributed buoyancy block 9 provides buoyancy support, controls the shape and position of the dynamic submarine cable 3 in the water, and the limiting device provides bending protection at the key position, both of which work together to ensure the ideal shape of the dynamic submarine cable 3 and the safety of the key area, realizing the overall optimization of the performance of the dynamic submarine cable system.

[0094] Specifically, the distributed buoyancy blocks 9 are installed along the length direction of the dynamic submarine cable 3, providing distributed buoyancy support for the dynamic submarine cable 3, so that the dynamic submarine cable 3 presents a designed suspension curve in the water. The installation position of the limiting device is carefully designed. When it is set between two adjacent distributed buoyancy blocks 9, it mainly protects the dynamic submarine cable 3 segment between the buoyancy blocks, which is prone to excessive bending under the action of gravity and water flow due to the lack of buoyancy support; when it is set between the distributed buoyancy block 9 and the static seabed equipment, it mainly protects the bottom section of the dynamic submarine cable 3, which is usually affected by the complex seabed topography and water flow. Through this regional protection strategy, each section of the dynamic submarine cable 3 is properly protected.

[0095] In a specific embodiment, in the dynamic submarine cable system of the seabed observation network, the total length of the dynamic submarine cable 3 is 1200 meters, and 12 distributed buoyancy blocks 9 are installed along the length direction with a spacing of 100 meters. Limiting devices are installed between the 3rd and 4th buoyancy blocks, between the 8th and 9th buoyancy blocks, and between the last buoyancy block and the seabed equipment. This configuration makes the dynamic submarine cable 3 present a good suspension shape, avoiding dragging or excessive suspension of the dynamic submarine cable 3. Under the action of strong currents, the limiting device effectively prevents the excessive bending of the dynamic submarine cable 3 segment between the buoyancy blocks, protecting the integrity of the dynamic submarine cable 3. Long-term monitoring data shows that the maximum bending radius of the dynamic submarine cable 3 is always controlled within a safe range, and the system operates in good condition.

[0096] In the embodiment of the present application, by systematically considering the coordination between the buoyancy block and the limiting device, the unified optimization of dynamic submarine cable 3 shape control and safety protection is realized. This integrated design method not only improves the overall performance of the system, but also reduces the engineering cost, and has obvious technical and economic advantages compared with the traditional scheme of separate design.

[0097] In some embodiments, the distributed buoyancy block 9 adopts a Harvard structure.

[0098] The present invention utilizes distributed buoyancy blocks 9 with a Harvard-style structure, providing optimized buoyancy support and fluid dynamics for the dynamic submarine cable system. The Harvard-style structure, with its unique geometry and mechanical properties, minimizes hydrodynamic resistance while providing sufficient buoyancy. This reduces the load on the dynamic submarine cable system under the influence of water flow, reduces pressure on the stoppers, and improves the stability and efficiency of the entire system.

[0099] Specifically, the distributed buoyancy blocks 9 of the Harvard structure adopt a streamlined shape design, usually with ellipsoidal or teardrop-shaped geometric features. This shape can effectively reduce the eddies and resistance generated when the water flows around the buoyancy blocks. The Harvard structure also has good structural strength and stability, and can withstand various loads in the marine environment without deformation or damage. In terms of material selection, Harvard buoyancy blocks usually use lightweight, high-strength composite materials, which not only ensure the buoyancy effect, but also ensure the durability of the structure. When used in conjunction with a limit device, the excellent performance of the Harvard buoyancy blocks helps to reduce the overall load of the dynamic submarine cable system and reduce the working pressure of the limit device.

[0100] In some embodiments, a second bending stiffener 10 is further included. The second bending stiffener 10 is sleeved on the outer circumference of the dynamic submarine cable 3 and connected to the floating platform a.

[0101] In the present invention, a second bend stiffener 10 is added to the dynamic submarine cable system and placed around the outer periphery of the dynamic submarine cable 3, connecting it to the floating platform a. This provides specialized protection for the connection between the dynamic submarine cable 3 and the floating platform a. Floating platform a experiences complex six-degree-of-freedom motion under the influence of wind and waves, causing the dynamic submarine cable 3 to experience complex dynamic loads at the connection. The second bend stiffener 10 provides rigid support and load distribution, effectively preventing excessive bending at the critical connection point of the dynamic submarine cable 3, ensuring the reliability of the connection and the safety of the dynamic submarine cable 3.

[0102] Specifically, the second bending reinforcement 10 is installed in the connection area between the dynamic submarine cable 3 and the floating platform a, covering the transition area from the platform connection interface to the free hanging section of the dynamic submarine cable 3. Due to the movement characteristics of the floating platform a, the dynamic submarine cable 3 needs to withstand a variety of composite loads such as tension, bending, and torsion at the connection point, and these loads have strong dynamic characteristics. The second bending reinforcement 10 can adapt to the movement requirements of the platform through its special structural design, while providing the necessary support and protection for the dynamic submarine cable 3. The shape of the bending reinforcement usually adopts a conical design, gradually transitioning from the large diameter at the platform connection to the small diameter of the dynamic submarine cable 3, to achieve a smooth transition in stiffness. In material selection, it is necessary to consider the corrosiveness of the marine environment and the influence of fatigue loads.

[0103] In some embodiments, the dynamic submarine cable 3 is further provided with a plurality of weight blocks 11, which are arranged on the dynamic submarine cable 3 and cooperate with the distributed buoyancy blocks 9 to make the dynamic submarine cable 3 present a preset suspension shape.

[0104] In the present application, by adding the weight blocks 11 in the dynamic submarine cable system and cooperating them with the distributed buoyancy blocks 9, the accurate control and optimization of the suspension shape of the dynamic submarine cable 3 are realized. The weight blocks 11 provide negative buoyancy, which balances the positive buoyancy of the distributed buoyancy blocks 9. By reasonably adjusting the positions, weights and buoyancy sizes of the two, the dynamic submarine cable 3 can present an ideal suspension curve in water, avoiding excessive floating or sinking of the dynamic submarine cable 3, and at the same time creating an optimal working environment for the limiting device, ensuring the stability and safety of the entire dynamic submarine cable system.

[0105] Specifically, the weight blocks 11 are usually made of high-density materials such as cast iron, lead alloy or high-density concrete, and are installed at specific positions of the dynamic submarine cable 3 to provide downward gravity. The cooperation of the weight blocks 11 with the distributed buoyancy blocks 9 follows precise mechanical calculations, and by adjusting the distribution and weight of the two, the net buoyancy distribution of each section of the dynamic submarine cable 3 can be controlled. In the upper section of the dynamic submarine cable 3, more buoyancy blocks are usually configured to offset the weight of the dynamic submarine cable 3 and provide upward force; in the middle and lower sections of the dynamic submarine cable 3, appropriate weight blocks 11 are configured to control the sinking speed and angle of the dynamic submarine cable 3. This distributed weight-buoyancy balance system enables the dynamic submarine cable 3 to present a suspension shape as required by design, such as catenary shape, S shape or multi-peak shape, to adapt to different marine environments and engineering requirements.

[0106] In a specific embodiment, in a dynamic submarine cable system for deep-sea oil development, the total length of the dynamic submarine cable 3 is 1500 meters, the working water depth is 300 meters, and it is connected between a floating drilling platform and a subsea blowout preventer control system. According to marine engineering analysis, the dynamic submarine cable 3 needs to present a double-peak suspension shape to adapt to the large-scale deviation of the platform. The system is configured with 15 distributed buoyancy blocks 9, each with a net buoyancy of 800 kilograms, and 8 weight blocks 11, each with a weight of 1200 kilograms. Through precise position configuration, the dynamic submarine cable 3 presents an ideal double-peak shape when in static balance, with the first peak located 200 meters away from the platform and the second peak located 100 meters away from the seabed. Under the working condition of the maximum deviation of the platform of 150 meters, the shape of the dynamic submarine cable 3 changes smoothly, the bending radii of each section are controlled within a safe range, the working load of the limiting device is moderate, and the entire system runs stably.

[0107] The dynamic submarine cable system provided by the application is in a "U" shape instead of a "V" shape under the action of the plurality of mooring ropes, so as to prevent the dynamic cable from being bent too much. The dynamic submarine cable line type with a plurality of wave crests can satisfy large-scale deviation of the floating foundation, and simultaneously relieve the axial tension on the submarine cable body. The movement of the dynamic cable in severe sea conditions can be limited, so that the dynamic cable cannot drift greatly.

[0108] The device embodiments described above are merely illustrative, wherein the units illustrated as separate components can or can not be physically separated, and the components illustrated as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0109] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A dynamic submarine cable limiting device, characterized in that: include: A base (1) is provided on the seabed; Two first clamps (2) are fixedly connected to the dynamic submarine cable (3); A transition module (4) is sleeved on the dynamic submarine cable (3) between the two first clamps (2); Two first mooring ropes (5), one end of each of the two first mooring ropes (5) is connected to the base (1), and the other end is connected to the two first clamps (2) respectively; The transition module (4) is used to limit the bending radius of the dynamic submarine cable (3) at the transition module (4) to be no less than a preset minimum bending radius.

2. The dynamic submarine cable limiting device according to claim 1, characterized in that: The transition module (4) comprises chain links (41) sequentially connected in series along the extension direction of the dynamic submarine cable (3), and a limiting structure is provided between two adjacent chain links (41). The limiting structure limits the relative rotation angle between the two adjacent chain links (41), so that the bending radius of the transition module (4) is greater than or equal to the minimum bending radius.

3. The dynamic submarine cable limiting device according to claim 1, characterized in that: Two ends of the transition module (4) are respectively connected to or abut against the two first clamps (2).

4. The dynamic submarine cable limiting device according to claim 1, characterized in that: The transition module (4) is provided with multiple sections at intervals, and the dynamic submarine cable limiting device further comprises: A second clamp (6) is fixedly connected to the dynamic submarine cable (3) and is located between two sections of the transition module (4); A second mooring rope (7), one end of the second mooring rope (7) is connected to the base (1), and the other end is connected to the second clamp (6).

5. The dynamic submarine cable limiting device according to claim 4, characterized in that: Both ends of the second clamp (6) are respectively connected to or abut against the ends of the transition module (4).

6. The dynamic submarine cable limiting device according to claim 4, characterized in that: The length of the second mooring rope (7) is less than or equal to the length of the first mooring rope (5).

7. The dynamic submarine cable limiting device according to claim 4, characterized in that: A first connecting member (21) is provided on the first clamp (2), the first connecting member (21) being rotatable around the circumference of the first clamp (2), and the first mooring rope (5) is connected to the first connecting member (21); And / or, a second connecting member (61) is provided on the second clamp (6), the second connecting member (61) can rotate around the circumference of the second clamp (6), and the second mooring rope (7) is connected to the second connecting member (61).

8. The dynamic submarine cable limiting device according to any one of claims 1 to 7, characterized in that: Also includes: Two first bending reinforcement members (8) are sleeved on the outer periphery of the dynamic submarine cable (3), and the two first bending reinforcement members (8) are respectively connected to one end of the two first clamps (2) away from the transition module (4), so as to limit the bending radius of the dynamic submarine cable (3) at the first clamps (2).

9. A dynamic submarine cable system, characterized in that: include: A dynamic submarine cable (3), one end of the dynamic submarine cable (3) is connected to the floating platform, and the other end is connected to the static equipment on the seabed; At least one dynamic submarine cable limiting device according to any one of claims 1 to 8.

10. The dynamic submarine cable system according to claim 9, characterized in that: It also includes a distributed buoyancy block (9) arranged on the dynamic submarine cable (3); Wherein, the dynamic submarine cable limiting device is arranged between two adjacent distributed buoyancy blocks (9); And / or, the dynamic submarine cable limiting device is arranged between the distributed buoyancy block (9) and the seabed static equipment.

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