Three-buoyancy-box tension leg platform mooring system and working method thereof

Abstract

The invention discloses a three-buoyancy-box tension leg platform mooring system and a working method thereof.The system adopts a three-buoyancy-box tension leg platform as an ocean platform, the system further comprises a damping assembly and three mooring ropes, the damping assembly comprises a floating anchoring part, three first springs and three reset spring sets, and the floating anchoring part is connected with the three first springs; the floating anchoring parts are arranged at the joints between the stand columns and the three floating boxes. Wherein the stand column is used for loading a fan, and the three buoyancy tanks and the stand column serve as a foundation structure of the fan; when the fan is subjected to environmental load, the buoyancy tank section of at least one of the three mooring cables applies tensile force opposite to the environmental load to the buoyancy tank corresponding to the buoyancy tank section through the corresponding reset spring set, and the initial sections of the rest mooring cables are pulled by the floating anchoring part to enable the buoyancy tank section of the other mooring cables to be fixed. The corresponding reset spring sets apply pulling force opposite to the environmental load to the corresponding buoyancy tanks, the three buoyancy tanks and the stand columns are prevented from fluctuating along with the environmental load, and the foundation structure of the draught fan tends to be in a stable state.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of offshore engineering floating wind turbine, in particular to a three pontoon tension leg platform mooring system and its working method. BACKGROUND

[0002] In recent years, with the gradual saturation of offshore wind energy resource market, the development and utilization of deep sea wind energy resources has become a current hot topic. The deep sea wind energy reserves are very considerable, but the cost of fixed platform increases sharply with the increase of water depth, and the development of deep sea wind energy needs to rely on floating platform. Tension leg platform (TLP) is a very competitive floating foundation in the current floating wind power field, and it has become a current research hotspot due to its simple structure, economical construction cost and good stability.

[0003] The buoyancy of TLP is significantly greater than its own gravity, so there is a large pre-tension on the tension leg. When it bears external marine environmental load, the tension on the tension leg changes, thereby generating a restoring moment, which ensures that the platform hardly occurs longitudinal and transverse roll, effectively ensuring the normal work of the floating wind turbine generator. The excellent hydrodynamic performance of the platform relies on the reliability of the mooring system, so the mooring design is a very key link in the TLP floating wind power scheme design.

[0004] The tension leg bears a high pre-tension, and under the action of complex marine environmental load and upper wind turbine vibration, the tension on the tension leg is always in a high-frequency change state, and its fatigue problem is more significant. For the TLP mooring fatigue problem, there are generally two solutions: using more fatigue-resistant mooring materials; optimizing the floating body design to reduce the stress of the platform.

[0005] The most commonly used material in the field of offshore engineering is anchor chain and steel cable. Generally, its fatigue performance is reliable, but when it is applied in TLP platform, it bears high pre-tension and high-frequency load, and often appears the case of insufficient fatigue strength. Although new materials such as carbon fiber have excellent fatigue resistance, the cost is too high, and they cannot be widely used in the field of floating wind power, so the mainstream mooring material of future TLP wind power is still anchor chain and steel cable.

[0006] The optimization of floating body shape is an important research topic for engineers in the current marine industry. Through reasonable design of the floating body, the platform motion and stress are reduced, thereby ensuring the reliability of the platform as a whole. However, under the condition that the type of marine platform has been determined, most of the floating body designs are not much different, and on the basis of the past engineering cases, the optimization space of the floating body is already very small. The optimization of floating body shape is also limited by the performance of the material, and the end of the TLP floating body bears a large bending moment, and excessive optimization will lead to insufficient structural strength of the platform.

[0007] Currently, floating wind turbines used in marine engineering are prone to large fluctuations in sea wind environments, which is detrimental to their normal operation. Summary of the Invention

[0008] To address the aforementioned problems, the purpose of this invention is to provide a three-float tension leg platform mooring system and its operating method, which solves the problem that floating wind turbines in current marine engineering are prone to large fluctuations in sea wind environments, which is detrimental to the normal operation of the wind turbines.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, this invention discloses a three-buoy tension leg platform mooring system, employing a three-buoy tension leg platform as an offshore platform. The three-buoy tension leg platform includes three buoys and a column, with each buoy floating on the sea surface and one end of each of the three buoys approaching each other. The bottom end of the column is fixed to the connection point of the three buoys, connecting them together. The system also includes a damping assembly and three mooring cables.

[0011] The damping assembly includes a floating anchor, three first springs, and three sets of return springs. The floating anchor is located at the connection between the column and the three pontoons. Each mooring cable is divided into a starting section, a pontoon section, and a dangling section from top to bottom. The starting section of each mooring cable is mounted on the floating anchor via a first spring. The pontoon sections of the three mooring cables are respectively inserted into the three pontoons, and each pontoon section is connected to the starting section via a set of return springs. Each set of return springs is fixedly connected to its corresponding pontoon. Three fixed anchors are fixed to the seabed below the three pontoons. The dangling section of each mooring cable extends into the seabed, and its bottom end is fixed to a fixed anchor. The column is used to mount the wind turbine, and the three pontoons and the column form the foundation structure of the wind turbine.

[0012] When the wind turbine is subjected to environmental loads, at least one of the three mooring cables, through its pontoon section, applies a tension opposite to the environmental load to its corresponding pontoon via a corresponding set of return springs. The starting sections of the remaining mooring cables, held by floating anchors, also apply a tension opposite to the environmental load to their corresponding pontoons via corresponding set of return springs. This prevents the three pontoons and columns from fluctuating with the environmental load, thus stabilizing the wind turbine's foundation structure.

[0013] Preferably, in the three pontoons, the included angle between the longitudinal centerlines of adjacent pontoons is 120 degrees.

[0014] Preferably, the three mooring cables are designated as a first mooring cable, a second mooring cable, and a third mooring cable, which are respectively positioned along the longitudinal centerline of the three buoys.

[0015] Preferably, the starting section of each mooring cable begins at the floating anchor and ends at its corresponding buoy, with the buoy section of each mooring cable extending through its corresponding buoy; the drooping section of each mooring cable begins at its extension from its corresponding buoy and ends at its corresponding fixed anchor.

[0016] Preferably, a pulley is provided at the corner between the buoy section and the sag section of each mooring cable.

[0017] Preferably, the first spring is a return spring, and the top end of the starting section of each mooring cable is fixed to the floating anchor by a first spring.

[0018] Preferably, each set of return springs includes a buoy fixing plate, two second springs, and a suspension plate. The buoy fixing plates of the three sets of return springs are respectively fixed on their respective buoys. The top ends of the buoy sections of the first mooring cable, the second mooring cable, and the third mooring cable are respectively fixed on their respective buoy fixing plates. The second springs are return springs. The suspension plates of the three sets of return springs are set on the corresponding buoy fixing plates through two second springs, and the two second springs are arranged parallel to each other at both ends between the buoy fixing plate and the suspension plate. The suspension plate of each set of return springs is connected to the corresponding first spring through the starting section of its respective mooring cable.

[0019] Preferably, a hydraulic inertial container is provided at the beginning of each mooring cable between the suspension plate and the first spring.

[0020] Preferably, a flywheel-type inertial container is configured on the buoy section of the mooring cable within each buoy.

[0021] Preferably, a limiter is provided on the outer side of the floating anchor, the limiter is annular, and rubber is provided on the inner wall of the limiter.

[0022] Secondly, the present invention also discloses a method for operating a three-float tension leg platform mooring system. Using the aforementioned three-float tension leg platform mooring system, the method includes the following steps:

[0023] When the wind turbine is subjected to environmental load disturbance, the wind turbine will swing greatly. The wind turbine will transfer the load generated by the swing to the column, and the column will then transfer the load to the floating box.

[0024] At least one of the three mooring cables has its buoy section applying a tension opposite to the environmental load to its corresponding buoy through a corresponding set of return springs. The starting sections of the remaining mooring cables, held by floating anchors, also apply a tension opposite to the environmental load to their corresponding buoys through corresponding set of return springs, preventing the three buoys and columns from fluctuating with the environmental load and making the wind turbine's foundation structure tend to be stable.

[0025] During the process of elongating one of the mooring cables, the damping assembly prevents the three pontoons from undergoing excessive deformation; the hydraulic inertial container and the flywheel inertial container generate energy consumption during the process of the damping assembly preventing the three pontoons from undergoing excessive deformation, so that the foundation structure of the wind turbine tends to be stable.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (I) This invention discloses a three-float tension leg platform mooring system, which uses a three-float tension leg platform as an offshore platform. The three-float tension leg platform includes three floats and one column. Each float floats on the sea surface, and one end of each of the three floats is close to the other. The bottom end of the column is fixed to the connection point of the three floats, connecting the three floats together. The three-float tension leg platform mooring system also includes a damping assembly and three mooring cables. The damping assembly includes a floating anchor, three first springs, and three sets of return springs. The floating anchor is located between the column and the three floats. The connection between the boxes; each mooring cable is divided into a starting section, a floating box section, and a dangling section from top to bottom. The starting section of each mooring cable is set on a floating anchor by a first spring; the floating box sections of the three mooring cables are respectively inserted into three floating boxes, and each floating box section of the mooring cable is connected to the starting section by a set of return springs, and each set of return springs is fixedly connected to its corresponding floating box; three fixed anchors are fixed on the seabed below the three floating boxes, and the dangling section of each mooring cable extends into the seabed, and its bottom end is fixed to a fixed anchor. The column is used to mount the wind turbine, and the three pontoons and the column form the foundation structure of the wind turbine. When the wind turbine is subjected to environmental loads, at least one of the three mooring cables, through its pontoon section, applies a tension opposite to the environmental load to its corresponding pontoon through a corresponding set of return springs. The starting sections of the remaining mooring cables, under the tension of the floating anchors, also apply a tension opposite to the environmental load to their corresponding pontoons through their corresponding set of return springs, preventing the three pontoons and the column from fluctuating with the environmental load and making the foundation structure of the wind turbine tend to a stable state.

[0028] Furthermore, the three-float tension leg platform mooring system disclosed in this invention also has the following advantages:

[0029] (1) When the TLP platform with this mooring arrangement is subjected to external loads and the tension amplitude changes, it will drive the internal hydraulic inertial device and floating anchors, effectively consume energy, thereby reducing the tension amplitude and improving the mooring life of the TLP wind power platform.

[0030] (2) The hydraulic inertial capacity device and spring device inside the platform can adjust the natural period of the mooring cable, avoid dangerous frequencies, and prevent modal resonance with the platform motion.

[0031] (3) The internal structure design of the platform is based on the principle that when the tension leg platform moves under horizontal load, the tension peaks of the tension legs on different side floats alternate. The movement of the inertial capacity device and floating anchor can be adjusted in real time according to the changes in mooring tension, without the need for manual monitoring and adjustment. Attached Figure Description

[0032] Figure 1 This is an elevation view of the three-buoy tension leg platform mooring system provided in Embodiment 1 of the present invention;

[0033] Figure 2 yes Figure 1 A magnified view of point A in the image;

[0034] Figure 3 yes Figure 2 A magnified view of section B in the image;

[0035] Figure 4 This is a top view of the three-buoy tension leg platform mooring system provided in Embodiment 2 of the present invention;

[0036] Figure 5 yes Figure 4 A magnified view of a section at point C;

[0037] Figure 6 yes Figure 5 A magnified view of a section at point D.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1-Float, N1-First float, N2-Second float, N3-Third float;

[0040] 2-Column, 20-Fan;

[0041] 3-Mooring cable, 31-First mooring cable, 32-Second mooring cable, 33-Third mooring cable;

[0042] 40-Floating anchor; 41-First spring; 42-Reset spring assembly; 421-Float box fixing plate; 422-Second spring; 423-Suspension plate; 43-Limiter; 44-Hydraulic inertia container; 45-Flywheel inertia container;

[0043] 5-Fixed anchors;

[0044] 6-Pulley;

[0045] 7-Rubber sealing plug. Detailed Implementation

[0046] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0047] Example 1: A mooring system for a three-float tension leg platform

[0048] Embodiment 1 of the present invention provides a three-float tension leg platform mooring system, which uses a three-float tension leg platform as an ocean platform. The three-float tension leg platform includes three floats 1 and one column 2. Each float 1 floats on the sea surface and one end of the three floats 1 is close to each other. The bottom end of the column 2 is fixed to the connection point of the three floats 1 and connects the three floats 1 together. Its structure will be described in detail below with reference to the accompanying drawings.

[0049] refer to Figures 1 to 6 The three-float tension leg platform mooring system also includes a damping assembly and three mooring cables.

[0050] The damping assembly includes a floating anchor 40, three first springs 41, and three sets of return springs 42.

[0051] The floating anchor 40 is installed at the connection between the column 1 and the three floating boxes 2;

[0052] Each mooring cable 3 is divided into three sections from top to bottom: the starting section, the buoy section, and the descent section.

[0053] The starting section of each mooring cable 3 is mounted on the floating anchor 40 by a first spring 41;

[0054] The float sections of the three mooring cables 3 are respectively installed in the three floats 1, and the float section of each mooring cable 3 is connected to the starting section by a set of return springs 42, and each set of return springs 42 is fixedly connected to its corresponding float 1.

[0055] Three fixed anchors 5 are fixed to the seabed below the three pontoons 1 respectively. The drooping section of each mooring cable 3 extends into the seabed and its bottom end is fixed to a fixed anchor 5 respectively.

[0056] The column 2 is used to mount the fan 20, and the three float boxes 1 and the column 2 serve as the basic structure of the fan 20.

[0057] When the wind turbine 20 is subjected to environmental loads, at least one of the three mooring cables 3, through its pontoon section, applies a tension opposite to the environmental load to its corresponding pontoon 1 via a corresponding set of return springs 42. The starting sections of the remaining mooring cables 3 also apply a tension opposite to the environmental load to their corresponding pontoons 1 via corresponding set of return springs 42, preventing the three pontoons 1 and the column 2 from fluctuating with the environmental loads, thus stabilizing the foundation structure of the wind turbine.

[0058] Preferably, in the three pontoons 1, the included angle between the longitudinal centerlines of adjacent pontoons 1 is 120 degrees.

[0059] Specifically, the three mooring cables 3 are the first mooring cable 31, the second mooring cable 32, and the third mooring cable 33, which are respectively set on the longitudinal centerline of the three buoys 1.

[0060] The division of the starting section, pontoon section, and sag section of mooring cable 3 is as follows:

[0061] The starting section of each mooring cable 3 begins at the floating anchor 40 and ends at its corresponding buoy 1.

[0062] Each mooring cable 3 has a buoy section that runs through its corresponding buoy 1;

[0063] The sag section of each mooring cable 3 begins at the point where it extends from its corresponding buoy 1 and ends at its corresponding fixed anchor 5.

[0064] As a conventional technical means to enable the horizontal extension from the pontoon section into the descent section, a pulley 6 is provided at the corner between the pontoon section and the descent section of each mooring cable 3.

[0065] As a specific example of implementing the first spring, the first spring 41 is a return spring, and the top end of the starting section of each mooring cable 3 is fixed to the floating anchor 40 by a first spring 41.

[0066] As a specific example of implementing a reset spring assembly, each reset spring assembly 42 includes a float plate 421, two second springs 422, and a suspension plate 423.

[0067] The float fixing plates 421 of the three sets of return springs 42 are respectively fixed on their respective floats 1, and the top ends of the float sections of the first mooring cable 31, the second mooring cable 32 and the third mooring cable 33 are respectively fixed on their respective float fixing plates 421.

[0068] The second spring 422 is a reset spring. The suspension plate 423 of the three sets of reset springs 42 is set on the corresponding float box fixing plate 421 by two second springs 422, and the two second springs 422 are arranged in parallel at both ends between the float box fixing plate and the suspension plate.

[0069] Each set of return springs 42 has its suspension plate 423 connected to the corresponding first spring 41 via the starting section of its respective mooring cable 3. Specifically, the starting section of each mooring cable 3 is attached to the first spring 41, and its end is attached to the suspension plate 423.

[0070] In order to shorten the travel of the upper end of the mooring cable, a hydraulic inertial container 44 is provided at the beginning of each mooring cable 3 between the suspension plate 423 and the first spring 41.

[0071] To shorten the travel of the mooring cable within the pontoon, a flywheel-type inertial container 45 is installed on the pontoon section of the mooring cable 3 within each pontoon 1.

[0072] To protect the floating anchor 40, preferably, a limiter 43 is provided on the outer side of the floating anchor 40. The limiter 43 is annular and has rubber on its inner wall.

[0073] To prevent seawater from entering the compartment through the gap between the pontoon section of the mooring cable 3 and the pontoon 1, several rubber sealing plugs 7 are installed at the joint between the pontoon section of the mooring cable 3 and the pontoon 1. Specifically, 3-5 rubber sealing plugs 7 are fitted on the mooring cable 3 inside the pontoon 1 and near the end of the pontoon 1.

[0074] Regarding the three-floating-box tension leg platform, the selected offshore platform is a three-floating-box tension leg platform using vertical mooring with steel cables. Taking one tension leg on each side as an example, the principle is the same for multiple tension legs on each side. The tension leg platform is the Seastar type three-floating-box tension leg wind turbine platform commonly used in the current offshore engineering field. It uses mooring cables as the material for the tension legs and adopts a vertical mooring scheme (i.e., the mooring point is located directly above the anchor point). The number of tension legs at the end of each floating box can be one or more, depending on the specific situation. In this embodiment, each floating box has one tension leg, and its material is steel cable. The tension leg is arranged such that one side is connected to the seabed pile foundation, and the other side is not locked on the outside of the floating box end, but is connected to the inside of the floating box through a guide cable set at the end of the floating box and a pipe at the end of the floating box, and is connected to the roller inside the platform. Another mooring cable is connected at one end to a roller bound to the gear on the inner side, and the other end extends towards the central column, passes through a spring assembly and a hydraulic inertial container 44, and finally connects to the floating anchor 40 at the center of the platform.

[0075] The three first springs (41) and three sets of return springs (42) in the damping assembly serve to: reduce the series stiffness to protect the inertial capacity device; and provide a buffer when the floating anchor 40 contacts the limiting device.

[0076] The floating anchor 40 is a weight connected to the mooring cable from the buoy via a buffer spring. It dissipates energy through its own movement and friction. Its function is to increase system damping and dissipate energy through its own movement and friction.

[0077] The floating anchor 40 is subjected to traction forces in three directions at the center of the platform. The peak values ​​of these traction forces alternate, and the tension in the three directions is always unbalanced, thus driving the floating anchor 40 to move continuously and further dissipate energy. The limiter 43 ensures that the movement of the floating anchor 40 is controllable. The limiter is equipped with a rubber buffer layer to provide cushioning when the floating anchor 40 collides with the limiter, ensuring the durability of the floating anchor 40 system.

[0078] The limiter 43 is typically made of a steel structure wrapped with a buffer rubber layer and is located on the outer ring of the floating anchor 40.

[0079] The hydraulic inertial container 44 is the core device for energy absorption. The inertial container can convert translational motion into rotation, generating a large moment of inertia through the rotation of a relatively small mass, thereby achieving energy dissipation. Furthermore, this inertial container can alter structural modes, avoiding dangerous frequencies and preventing resonance. The hydraulic inertial container 44 used in this invention consists of a shell, a hydraulic piston, an inlet pipe, an outlet pipe, a hydraulic motor, and a flywheel. The hydraulic piston is connected to the mooring cable. When the tension on the piston changes, it moves, causing hydraulic oil to flow along the inlet and outlet pipes, driving the hydraulic motor and causing the flywheel to rotate at high speed, thus achieving energy dissipation.

[0080] As is common knowledge in this field, a guide cable is provided on the free end face of the pontoon. The guide cable includes a bracket and rollers. The mooring cable starts from the seabed pile, passes around the guide cable rollers at the end of the pontoon, and connects to the gear device inside the pontoon. The gear device inside the pontoon consists of three gears, two large and one small, used to increase the movable length of the mooring cable and adjust the high stiffness and low deformation of the outer mooring cable to low stiffness and high deformation. A spring device located inside the central column can buffer the force transmitted by the mooring cable to a certain extent. The hydraulic inertia container 44, located inside the central column and directly connected to the mooring cable, specifically includes a shell connected to the inner mooring cable, a hydraulic piston connected to the outer mooring cable, an oil inlet pipe, an oil outlet pipe, a hydraulic motor, and a flywheel as the core energy storage device. The rotation of the rollers connecting the mooring cable is bound to the gear set, which is fixed to the platform. The purpose of the gear set is to adjust stiffness and motion. Assuming a gear ratio of 5:1, a 10cm displacement of the outer mooring cable will result in a corresponding 50cm displacement of the inner mooring cable. This facilitates the effective functioning of the subsequent inertial capacity device and floating anchor 40. According to Hooke's Law F=kx, the mooring cables on both sides of the gear set experience the same tension, but the inner mooring cable experiences a larger displacement. Consequently, the overall series stiffness is smaller, which helps prevent the hydraulic inertial capacity device from overloading and prevents the floating anchor 40 from violently impacting the limiting device. Simultaneously, the stiffness of both sides is to some extent independent, reducing the impact of the internal inertial capacity and spring device on the mooring stiffness of the outer tension leg, ensuring that the mooring system performance remains essentially unchanged.

[0081] Example 2: A working method of a three-float tension leg platform mooring system

[0082] Embodiment 2 of the present invention provides a method for operating a three-float tension leg platform mooring system, using the three-float tension leg platform mooring system of Embodiment 1. The method includes the following steps:

[0083] Step 1: When the wind turbine 20 is disturbed by environmental loads such as sea wind and waves, and the wind turbine 20 will swing greatly, the wind turbine 20 will transfer the load generated by the swing to the column 2, and the column 2 will then transfer the load to the floating box 1.

[0084] Step 2: At least one of the three mooring cables 3, through its pontoon section, applies a tension opposite to the environmental load to its corresponding pontoon 1 via a corresponding set of return springs 42. The starting sections of the remaining mooring cables 3, under the tension of the floating anchors 40, also apply a tension opposite to the environmental load to their corresponding pontoons 1 via corresponding set of return springs 42, preventing the three pontoons 1 and the column 2 from fluctuating with the environmental load, thus stabilizing the foundation structure of the wind turbine.

[0085] For ease of explanation, assume the environmental load direction is to the right, and the three buoys 1 are designated as first buoy N1, second buoy N2, and third buoy N3. The mooring cables 3 installed in the first buoy N1, second buoy N2, and third buoy N3 are designated as first mooring cable 31, second mooring cable 32, and third mooring cable 33, respectively.

[0086] Specifically, refer to Figure 1 and Figure 5 When an environmental load acting to the right applies to the wind turbine 20, the wind turbine 20 drives the second pontoon N2 and the third pontoon N3 to move to the right via the column 2. At this time, since the floating anchor 40 needs to remain stationary, it pulls the initial sections of the second mooring cable 32 and the third mooring cable 33 to remain stationary as well. The initial sections of the second mooring cable 32 and the third mooring cable 33 are subjected to a rightward pulling force. After the floating anchor 40 tightens the second mooring cable 32 and the third mooring cable 33, the second mooring cable 32 and the third mooring cable 33 react on the second pontoon N2 and the third pontoon N3 respectively, generating a leftward pulling force that causes the second pontoon N2 and the third pontoon N3 to return to their original positions, forming a resistance that opposes the rightward movement of the second pontoon N2 and the third pontoon N3.

[0087] Meanwhile, since the first mooring cable 31 remains stationary, while the first buoy N1 moves to the right with the column 2, the buoy section and its drooping section of the first mooring cable 31 continuously exert a rightward pulling force on the first buoy N1.

[0088] The end result is that the first mooring cable 31 is lengthened, while the second mooring cable 32 and the third mooring cable 33 are shortened.

[0089] During the stretching of one of the mooring cables 3, the damping assembly prevents excessive deformation of the three buoys 1. For details, please refer to... Figure 1 and Figure 5 The damping component prevents the three buoys 1 from undergoing excessive deformation as the first mooring cable 31 is stretched.

[0090] The hydraulic inertial container 44 and the flywheel inertial container 45 generate energy consumption during the process of the damping assembly preventing the three float boxes 1 from undergoing excessive deformation, so that the foundation structure of the wind turbine tends to be stable.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-buoy tension leg platform mooring system, employing a three-buoy tension leg platform as an offshore platform, the three-buoy tension leg platform comprising three buoys (1) and a column (2), each buoy (1) floating on the sea surface and one end of each of the three buoys (1) being close to each other; the bottom end of the column (2) being fixed to the connection point of the three buoys (1) and connecting the three buoys (1) together, characterized in that, It also includes a damping assembly and three mooring cables (3), The damping assembly includes a floating anchor (40), three first springs (41), and three sets of return springs (42). The floating anchor (40) is located at the connection between the column (1) and the three floating boxes (2); Each mooring cable (3) is divided into the starting section, the buoy section, and the descent section from top to bottom. The starting section of each mooring cable (3) is set on the floating anchor (40) by a first spring (41); The float sections of the three mooring cables (3) are respectively installed in the three floats (1), and the float section of each mooring cable (3) is connected to the starting section by a set of return springs (42), and each set of return springs (42) is fixedly connected to its corresponding float (1). Three fixed anchors (5) are fixed to the seabed below the three pontoons (1). The drooping section of each mooring cable (3) extends into the seabed and its bottom end is fixed to a fixed anchor (5). The column (2) is used to mount the fan (20), and the three floats (1) and the column (2) serve as the basic structure of the fan (20); When the wind turbine (20) is subjected to environmental load, at least one of the three mooring cables (3) applies a tension opposite to the environmental load to its corresponding pontoon (1) through the corresponding reset spring group (42) of its pontoon section. The starting sections of the remaining mooring cables (3) are held by the floating anchor (40) and apply a tension opposite to the environmental load to their corresponding pontoons (1) through the corresponding reset spring group (42), preventing the three pontoons (1) and the column (2) from fluctuating with the environmental load, so that the foundation structure of the wind turbine tends to be stable.

2. The three-buoy tension leg platform mooring system according to claim 1, characterized in that, In the three pontoons (1), the included angle between the longitudinal centerlines of adjacent pontoons (1) is 120 degrees.

3. The three-buoy tension leg platform mooring system according to claim 2, characterized in that, The three mooring cables (3) are the first mooring cable (31), the second mooring cable (32) and the third mooring cable (33), which are respectively set on the longitudinal center line of the three pontoons (1).

4. The three-buoy tension leg platform mooring system according to claim 3, characterized in that, The starting segment of each mooring cable (3) begins at the floating anchor (40) and ends at its corresponding buoy (1). The buoy section of each mooring cable (3) passes through its corresponding buoy (1); The drooping section of each mooring cable (3) begins at the point where it extends from its corresponding buoy (1) and ends at its corresponding fixed anchor (5).

5. The three-buoy tension leg platform mooring system according to claim 4, characterized in that, Each mooring cable (3) has a pulley (6) at the corner between the buoy section and the sag section.

6. The three-buoy tension leg platform mooring system according to claim 4, characterized in that, The first spring (41) is a return spring, and the top end of the starting section of each mooring cable (3) is fixed to the floating anchor (40) by a first spring (41).

7. The three-buoy tension leg platform mooring system according to claim 4, characterized in that, Each set of return springs (42) includes a float plate (421), two second springs (422), and a suspension plate (423). The float fixing plates (421) of the three sets of return spring groups (42) are fixed on their respective floats (1), and the top ends of the float sections of the first mooring cable (31), the second mooring cable (32) and the third mooring cable (33) are fixed on their respective float fixing plates (421). The second spring (422) is a return spring. The suspension plate (423) of the three sets of return springs (42) is set on the corresponding float fixing plate (421) by two second springs (422), and the two second springs (422) are set in parallel at both ends between the float fixing plate and the suspension plate. The suspension plate (423) of each set of return springs (42) is connected to the corresponding first spring (41) via the starting section of their respective mooring cable (3).

8. The three-buoy tension leg platform mooring system according to claim 7, characterized in that, A hydraulic inertial container (44) is provided at the beginning of each mooring cable (3) between the suspension plate (423) and the first spring (41); Each pontoon (1) has a flywheel inertial container (45) mounted on the pontoon section of the mooring cable (3).

9. The three-buoy tension leg platform mooring system according to claim 8, characterized in that, The floating anchor (40) is provided with a limiter (43) on its outer side. The limiter (43) is annular and has rubber on its inner wall.

10. A method for operating a three-float tension leg platform mooring system, employing the three-float tension leg platform mooring system as described in any one of claims 1 to 9, characterized in that, This working method includes the following steps: When the fan (20) is subjected to environmental load disturbance, the fan (20) will swing greatly. The fan (20) will transfer the load generated by the swing to the column (2), and the column (2) will then transfer the load to the floating box (1). At least one of the three mooring cables (3) has its pontoon section applying a tension opposite to the environmental load to its corresponding pontoon (1) through the corresponding reset spring group (42). The starting sections of the remaining mooring cables (3) are held by the floating anchor (40) and apply a tension opposite to the environmental load to their corresponding pontoons (1) through the corresponding reset spring group (42), preventing the three pontoons (1) and the column (2) from fluctuating with the environmental load, so that the foundation structure of the wind turbine tends to be stable. During the process of elongating one of the mooring cables (3), the damping assembly prevents the three floats (1) from undergoing excessive deformation; the hydraulic inertial container (44) and the flywheel inertial container (45) generate energy consumption during the process of the damping assembly preventing the three floats (1) from undergoing excessive deformation, so that the foundation structure of the wind turbine tends to be stable.

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