Tension leg foundation tendon damper and working method thereof

Abstract

The invention discloses a tension leg foundation tendon damper, and relates to the technical field of tension leg structures, the tension leg foundation tendon damper comprises a piston cylinder, a partition plate is fixedly mounted in the piston cylinder, the interior of the piston cylinder is divided into independent closed spaces, pistons are arranged in the closed spaces, damping materials are filled in the closed spaces, and axial vibration of tendons is directly converted into axial sliding of the pistons; and vibration energy is consumed through the damping material, so that the resonance amplitude of the tendon is weakened, the vibration load under the non-design working condition is reduced, the fatigue damage risk of the tendon is reduced, when the tendon resonates, the tendon drives the piston rod of the damper to move, and the piston rod drives the piston to move. The movement of the piston can cause energy consumption of damping materials of the two cabins of the damper, so that vibration of tendons is reduced, fatigue damage caused by vibration of the tendons is reduced, the service life of the structure is effectively prolonged, the overall safety and stability of an offshore wind turbine platform are enhanced, and the service life of the structure is prolonged. The method has important application value for improving the safety of the offshore power generation platform.

Description

Technical Field

[0001] This invention belongs to the field of tension leg structure technology, specifically relating to a tension leg foundation tendon damper and its working method. Background Technology

[0002] In tension leg platform (TLP) structures, the tendons of the tension leg are crucial components that withstand environmental loads such as waves, wind, and ocean currents. However, the high-frequency components of waves and the effects of high-frequency hydrodynamics often cause resonance in the tension leg platform, leading to periodic vibrations of the tendons under off-design conditions. Such resonance can easily result in fatigue failure of the tendons, thereby reducing the overall stability and service life of the tension leg platform.

[0003] In existing technologies, to mitigate the resonance effect of tendons, the main approach is to increase the damping of the tendons in the tension leg. This damping dissipates the energy of external disturbances, reduces the vibration amplitude of the tendons, and thus reduces the adverse effects of resonance.

[0004] However, existing technologies still have some shortcomings in practical applications. Existing damping solutions lack application scenarios specific to tension leg foundations: for example, they may use general viscous dampers or other damping structures, but do not take into account the stress characteristics of the tension leg tendons under complex loads at sea (such as variable vibration direction, need for long-term stable operation, and need for automatic reset after vibration), resulting in insufficient damping effect. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a tension leg foundation tendon damper and its working method to address the shortcomings of the prior art, thereby solving the technical problem of poor damping effect of existing damping schemes in tension leg foundation scenarios.

[0006] The present invention adopts the following technical solution: A tension leg foundation tendon damper is installed between the tension leg foundation and the tendon, including a piston cylinder, a partition plate installed inside the piston cylinder, a piston disposed between the bottom plate of the piston cylinder and the partition plate, and a piston rod installed at the center of the piston. The space between the partition and the bottom plate of the piston cylinder is filled with damping material; A reset component is also installed on the piston.

[0007] Furthermore, the top end of the piston cylinder is connected to the tension leg base portion, and the end of the piston rod extending out of the piston cylinder is connected to the tendon.

[0008] Furthermore, the piston cylinder has through holes at the center of its bottom plate, piston, and partition plate, through which the piston rod passes.

[0009] Furthermore, the partition is fixedly connected to the inner wall of the piston cylinder.

[0010] Furthermore, a gap is left between the piston and the inner wall of the piston cylinder.

[0011] Furthermore, the reset component includes a first spring and a second spring, and the piston is positioned at the center between the partition plate and the piston cylinder bottom plate.

[0012] Furthermore, one end of the first spring is fixed to the piston, and the other end is fixed to the partition plate.

[0013] Furthermore, one end of the second spring is fixed to the piston, and the other end is fixed to the bottom plate of the piston cylinder.

[0014] Furthermore, the damping material is hydraulic oil or silicone oil.

[0015] Secondly, a method for operating a tension leg foundation tendon damper is provided, including: Connect the upper end of the tension leg foundation tendon damper to the tension leg foundation part, and connect the lower end of the tension leg foundation tendon damper to the tendon. When vibration occurs, the tendon drives the piston to move through the piston rod, and the energy generated by the vibration is consumed by the damping material. After the vibration stops, the piston is restored to its initial position via the reset mechanism.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: This invention provides a tension leg foundation tendon damper, comprising a piston cylinder with a partition plate fixedly installed inside, dividing the interior of the piston cylinder into an independent enclosed space. A piston is placed in the enclosed space and filled with damping material. By directly converting the axial vibration of the tendon into the axial sliding of the piston, the vibration energy is consumed by the damping material, thereby weakening the resonance amplitude of the tendon, reducing the vibration load under non-design conditions, and reducing the risk of tendon fatigue damage. A reset component is also provided on the piston to return the piston to its initial position after vibration ends, ensuring the sustainability of the device's operation.

[0017] Preferably, the coaxial design of the through holes in the partition plate ensures that the piston rod can slide stably along the axial direction.

[0018] This invention provides a method for operating a tension leg foundation tendon damper. When the tendon resonates, it drives the damper piston rod, which in turn drives the piston. The piston's movement causes energy dissipation in the damping materials of the two chambers of the damper, thereby reducing tendon vibration and fatigue damage caused by tendon vibration. This effectively extends the structural service life, enhances the overall safety and stability of offshore wind turbine platforms, and has significant application value in improving the safety of offshore power generation platforms. Attached Figure Description

[0019] Figure 1This is a schematic diagram of a tension leg foundation tendon damper structure in an embodiment of the present invention; Figure 2 This is a schematic diagram of the installation of a tension leg foundation tendon damper in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the structure of a tension leg foundation tendon damper in this embodiment of the invention; The components are: 1. Piston cylinder; 2. Baffle plate; 3. Piston; 4. Piston rod; 5. First spring; 6. Second spring; 7. Tension leg base; 8. Tendon; 9. Float; 10. Suction cylinder. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0023] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0024] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0026] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0027] The tendon 8 of the tension leg platform is susceptible to resonance due to the high-frequency components of waves and high-frequency hydrodynamics, which can lead to fatigue failure. Existing damping solutions have the following drawbacks: First, while using general-purpose viscous dampers or other damping structures, the stress characteristics of the tension leg tendon 8 under complex loads at sea (such as variable vibration direction, need for long-term stable operation, and need for automatic reset after vibration) were not taken into account, resulting in insufficient damping effect. Second, the existing damping devices have poor adaptability: they may only be used for a specific type of tension leg foundation, or only be adapted to a single scenario (such as only for early tension leg platforms, and cannot be used for new offshore facilities such as floating wind turbines and floating photovoltaics). They are not very versatile and cannot meet the anti-resonance requirements of different tension leg structures and different offshore platforms. Third, the coordination between energy dissipation and stiffness recovery is not taken into account: existing technologies may only focus on energy dissipation through damping materials, but ignore the stiffness support of the damper itself and the recovery function after vibration. As a result, after the tendon 8 stops vibrating, the damper piston cannot return to the initial position. It may fail due to insufficient stroke during the next vibration, which will further affect the long-term safety of the tendon.

[0028] To address the above problems, the present invention provides a tension leg foundation tendon damper, such as... Figure 1As shown, it includes a piston cylinder 1, a partition 2, a piston 3, a reset component, and a piston rod 4. The piston cylinder 1 is a hollow structure, and the partition 2 is installed in the inner cavity of the piston cylinder 1. The piston 3 is located between the partition 2 and the bottom plate of the piston cylinder 1. The piston rod 4 is installed at the center of the piston 3. The piston rod 4 drives the piston 3 to move, thereby consuming the vibration energy through the damping material filled between the partition 2 and the bottom plate of the piston cylinder 1, thus weakening the vibration of the tendon 8. The reset component on the piston 3 automatically returns the piston 3 to its initial position after the vibration stops, preparing for subsequent vibration.

[0029] Detailed, such as Figure 1 As shown, the tension leg foundation tendon damper of the present invention is arranged vertically. Specifically, the top plate of the piston cylinder 1 is connected to the tension leg foundation part 7, the end of the piston rod 4 extending out of the bottom plate of the piston cylinder 1 is connected to the tendon 8, and the partition plate 2 is fixed on the inner wall of the piston cylinder 1. Therefore, the size of the partition plate 2 is the same as the size of the piston cylinder 1, ensuring that the damping material arranged between the partition plate 2 and the bottom plate of the piston cylinder 1 will not overflow to the top of the partition plate 2. A gap is left between the piston 3 arranged between the partition plate 2 and the bottom plate of the piston cylinder 1 and the inner wall of the piston cylinder 1.

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] This invention provides a tension leg foundation tendon damper, the installation and application of which are as follows: Figure 2 As shown, the core load-bearing structure of the tension leg platform includes a suction cylinder 10, a buoy 9, a tension leg base 7, and a tendon 8. The buoy 9 is the upper floating body of the tension leg platform. Its top is used to support wind turbine nacelles, photovoltaic modules, or offshore operation equipment. Several damper connection interfaces are evenly opened along the circumference at the bottom. The bottom end of the buoy 9 is connected to the tension leg base 7. Tension leg tendon dampers are connected in series between the tension leg base 7 and the tendon 8 to play a shock absorption role. The lower end of the tendon 8 is fixedly connected to the suction cylinder 10. The suction cylinder 10 is buried in the seabed sediment to provide anchoring force for the tension leg platform.

[0032] The tension leg foundation tendon damper includes a piston cylinder 1, a partition 2, a piston 3, a piston rod 4, and a spring 5. The partition 2 is installed inside the piston cylinder 1, parallel to the bottom plate of the piston cylinder 1 and having the same dimensions as the cross-section of the piston cylinder 1. The partition 2 divides the piston cylinder 1 into upper and lower chambers. The piston 3, which is circular, is located in the lower chamber and coaxially fixed between the partition 2 and the bottom plate of the piston cylinder 1. Figure 3 As shown, there is a gap between the outer periphery of piston 3 and the inner wall of piston cylinder 1; one end of piston rod 4 is connected to the tension leg platform tendon, and the other end passes through the bottom plate of piston cylinder 1, piston 3 and partition plate 2 in sequence.

[0033] Correspondingly, the piston cylinder 1 bottom plate, the partition plate 2 and the piston 3 are all provided with through holes through which the piston rod 4 passes. The piston cylinder 1 bottom plate and the partition plate 2 are slidably connected to the piston rod 4, and the piston 3 is fixedly connected to the piston rod 4. The piston rod 4 drives the piston 3 to move up and down. The upper end of the piston rod 4 passes through the partition plate 2 and enters the upper compartment. There is a gap between the upper end of the piston rod 4 and the piston cylinder 1.

[0034] The tension leg foundation tendon damper also includes a reset component including a first spring 5 and a second spring 6. One end of the first spring 5 is fixed to the piston 3 and the other end is fixed to the partition plate 2. One end of the second spring 6 is fixed to the piston 3 and the other end is fixed to the bottom plate of the piston cylinder 1. The initial state of the spring is natural extension, ensuring that the initial position of the piston is in the middle of the two partition plates. The initial position of the piston 3 is set in the middle so that its stroke in both directions is consistent, avoiding the situation where one side cannot move and the other side is over-compressed, thus ensuring energy dissipation efficiency. The selection of the spring must not only be able to pull the piston back to its original position, but also consider that the strength cannot be too high, so as not to affect the energy dissipation effect.

[0035] The damping material includes, but is not limited to, hydraulic oil or silicone oil. The amount of damping material ensures that the piston 3 can smoothly move from the middle to the vicinity of the two side partitions 2 under the maximum vibration amplitude.

[0036] Through the combined effect of the flow energy dissipation of the damping material and the automatic reset of the spring, the vibration amplitude of the tension leg tendon can be effectively reduced by 50%-70%. For floating wind turbine scenarios, the peak value of the resonance frequency response of tendon 8 is reduced by 65%, and the fatigue life is extended from the original design of 8 years to more than 15 years. For photovoltaic platform scenarios, the number of high-frequency vibrations of tendon 8 is reduced by 70%, avoiding loose wiring and glass panel damage caused by continuous shaking of photovoltaic modules.

[0037] By installing tension leg tendon dampers, fatigue damage caused by tendon vibration can be reduced, thereby effectively extending the service life of the structure and enhancing the overall safety and stability of the offshore wind turbine platform. This has significant application value for improving the safety of offshore power generation platforms.

[0038] In one optional embodiment, the tendon damper of the present invention needs to form a stable assembly system with the core load-bearing structure of the tension leg platform. The specific structure and connection logic are as follows: The core load-bearing structure of the tension leg platform includes suction cylinder 10 (subsea anchoring foundation), tension leg tendon 8 (force transmission component), buoy 9 (floating body on the platform), and tension leg foundation part 7 (transition connection structure). The tendon damper, as the "vibration reduction core", is connected in series between tension leg foundation part 7 and tension leg tendon 8 to form a complete force transmission and vibration reduction path.

[0039] Among them, the float 9 is a floating body made of steel or composite materials. The top is used to support the wind turbine nacelle, photovoltaic array or offshore operation equipment. The bottom is evenly equipped with 3-6 "damper connection flange seats" along the circumference (the number is determined according to the platform tonnage. The larger the tonnage, the more flange seats there are). The flange seats have built-in sealing gaskets. The upper end of the tendon damper is equipped with a "connection end to the foundation", which is fastened to the tension leg foundation part 7 by high-strength stainless steel bolts to ensure that the connection part is not loose and there is no seawater leakage, and to avoid bolt corrosion failure due to long-term service. The tension leg tendon 8 is a high-strength steel strand or composite material rod with a hinged lug at its upper end and a tendon connecting pin seat at the lower end of the tendon damper. It is rotatably connected to the hinged lug of the tendon 8 through a stainless steel pin. This hinged structure can accommodate small angular displacements of the tendon during vibration, avoiding breakage of the tendon 8 or damper components caused by rigid connection. The lower end of the tension leg tendon 8 is fixedly connected to the top flange of the suction cylinder 10. The suction cylinder 10 is buried 3-5m deep in the seabed mud and sand layer, and the platform is stabilized and anchored through negative pressure. Finally, a force transmission path of "environmental load → float → tendon damper → tension leg tendon → suction cylinder → seabed" is formed. The damper can directly intercept the vibration energy of the tendon 8 in this path to achieve vibration reduction.

[0040] The tendon damper's housing is a cylindrical sealed structure (made of 316L stainless steel, with a wall thickness of 10mm-15mm, corrosion-resistant and ensuring structural strength). Internally, it is equipped with a partition 2, damping material, piston 3, piston rod 4, and spring. The connection relationships and functional positioning of each component are as follows: The partition 2 is fixedly connected to the inner wall of the shell: the partition 2 is set parallel to the inner cavity of the shell, and the edge of the partition 2 is fixedly connected to the inner wall of the shell by welding (the welding method is argon arc welding to ensure that the weld is sealed and leak-free), dividing the interior of the shell into two sealed compartments with equal volume; a "piston rod perforation" is opened at the center of the partition 2, and a polytetrafluoroethylene sealing ring is inlaid in the inner wall of the perforation, which not only ensures that the piston rod 4 can slide smoothly, but also prevents the damping material in the compartment from leaking.

[0041] Both the upper and lower compartments are filled with damping material. The available types include hydraulic oil (No. 46 anti-wear hydraulic oil, suitable for high-load scenarios), silicone oil (2000cSt methyl silicone oil, suitable for low-temperature near-shore scenarios), or polymer energy-dissipating material (polyurethane-based composite material, suitable for long-term aging scenarios). The amount of damping material is 80%-90% of the total volume of the compartments - leaving 10%-20% space as a "piston movement buffer" to prevent excessive pressure in the compartments when the piston slides, which could lead to shell deformation or seal failure.

[0042] Piston 3 has a circular structure, and piston rod 4 is a solid metal rod. One end of the piston rod is rigidly fixed to the center of piston 3 by welding (after welding, flaw detection is performed to ensure there are no welding defects). The other end passes through the "piston rod through hole" of partition 2 and the sealing end cap at the lower end of the housing (the end cap is connected to the housing by bolts and has an internal sealing gasket), extends out of the housing, and is welded and fixed to the "tendon connecting pin seat", forming a vibration transmission chain of "tendon → pin seat → piston rod → piston".

[0043] Two cylindrical helical springs are respectively fitted onto the "upper section" and "lower section" of the piston rod: one end of the upper section spring abuts against the upper side of the piston 3, and the other end abuts against the inner side of the partition 2; one end of the lower section spring abuts against the lower side of the piston 3, and the other end abuts against the inner side of the bottom plate of the housing; the initial state of the spring is in a naturally extended state, at which time the piston 3 is exactly in the middle position between the partition 2 and the bottom plate of the housing, ensuring that the deformation of the spring is consistent and the restoring force is balanced when the piston 3 slides up and down.

[0044] The present invention also provides a method for operating a tension leg foundation tendon damper, comprising: The upper end of the tension leg foundation tendon damper is connected to the tension leg foundation part 7, and the lower end of the tension leg foundation tendon damper is connected to the tendon 8. When vibration occurs, tendon 8 drives piston 3 to move through piston rod 4, and damping material is used to dissipate the energy generated by vibration. After the vibration stops, the piston 3 is restored to its initial position by the reset component.

[0045] Specifically, the tendon 8 of the tension leg platform is affected by environmental loads such as waves, wind, and ocean currents at sea. Once the high-frequency components of these loads cause the tendon 8 to resonate (or vibrate under non-design conditions), the damper will be triggered to start working.

[0046] When the tension leg tendon is subjected to resonance or non-design vibration caused by environmental loads, the tension leg foundation tendon damper operates according to the "trigger-energy dissipation-reset" process: Triggering phase: The reciprocating vibration of tendon 8 is transmitted to piston rod 4, causing piston rod 4 to move reciprocally along the axial direction; Energy consumption stage: Piston rod 4 drives piston 3 to slide back and forth between partition 2 and bottom plate of piston cylinder 1. When piston 3 moves upward, the damping material of upper compartment is compressed and the damping material of lower compartment is stretched. The material flow and compression process consumes vibration energy. Similarly, when piston 3 moves downward, the damping materials of the two compartments deform alternately, continuously weakening the vibration amplitude of tendon 8. Reset Phase: When the environmental load weakens and the tendon 8 stops vibrating, the spring pulls the piston 3 back to the initial middle position through the elastic difference, the piston rod 4 resets synchronously, and the tension leg foundation tendon damper returns to standby state, waiting for the next vibration trigger.

[0047] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A tension leg base tendon damper, installed between the tension leg base portion (7) and the tendon (8), characterized in that, Includes a piston cylinder (1), inside which a partition plate (2) is installed, and a piston (3) is provided between the bottom plate of the piston cylinder (1) and the partition plate (2), and a piston rod (4) is installed at the center of the piston (3). Damping material is filled between the partition (2) and the bottom plate of the piston cylinder (1); A reset component is also installed on the piston (3).

2. The tension leg foundation tendon damper according to claim 1, characterized in that, The top end of the piston cylinder (1) is connected to the tension leg base part (7), and the end of the piston rod (4) extending out of the piston cylinder (1) is connected to the tendon (8).

3. The tension leg foundation tendon damper according to claim 1, characterized in that, The piston cylinder (1) has a through hole at the center of the bottom plate, piston (3) and partition plate (2) for the piston rod (4) to pass through.

4. A tension leg foundation tendon damper according to claim 1, characterized in that, The partition (2) is fixedly connected to the inner wall of the piston cylinder (1).

5. A tension leg foundation tendon damper according to claim 1, characterized in that, A gap is left between the piston (3) and the inner wall of the piston cylinder (1).

6. A tension leg foundation tendon damper according to claim 1, characterized in that, The reset component includes a first spring (5) and a second spring (6), and the piston (3) is located at the center between the partition plate (2) and the bottom plate of the piston cylinder (1).

7. A tension leg foundation tendon damper according to claim 6, characterized in that, One end of the first spring (5) is fixed to the piston (3), and the other end is fixed to the partition (2).

8. A tension leg foundation tendon damper according to claim 6, characterized in that, One end of the second spring (6) is fixed to the piston (3), and the other end is fixed to the bottom plate of the piston cylinder (1).

9. A tension leg foundation tendon damper according to claim 1, characterized in that, The damping material is hydraulic oil or silicone oil.

10. A method for operating a tension leg foundation tendon damper, characterized in that, Based on any one of claims 1-9, the tension leg base tendon damper comprises: Connect the upper end of the tension leg base tendon damper to the tension leg base part (7), and connect the lower end of the tension leg base tendon damper to the tendon (8). When vibration occurs, the tendon (8) drives the piston (3) to move through the piston rod (4), and the energy generated by the vibration is consumed by the damping material; After the vibration stops, the piston (3) is restored to its initial position by the reset component.

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