TLP floating wind turbine and anti-rolling control method for shallow sea

Abstract

The application belongs to the technical field of offshore wind power, and provides a TLP floating wind turbine for shallow sea and a stabilizing control method. The wind turbine body is fixed on a steel tower, the steel tower is fixedly connected to a truss tower, the bottom of the truss tower is connected to a plurality of variable-height pontoons, and adjustable tension keys are connected to the bottom of the variable-height pontoons. The variable-height pontoon comprises an inner cylinder and an outer cylinder. The inner cylinder is located inside the outer cylinder, and a jacking mechanism is arranged at the bottom of the outer cylinder to drive the up-and-down movement of the inner cylinder. A damping bin is arranged in the inner cylinder. The outer side wall of the damping bin is connected to the inner side wall and the inner bottom wall of the inner cylinder through elastic members. The damping bin is connected to a liquid supply device through a pipeline to increase the liquid when the floating body exceeds a set angle. The floating body is a combination of the plurality of variable-height pontoons. The application reduces the overall load while ensuring the support strength, and is suitable for the limited water depth working condition of shallow sea.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power technology, and in particular to a TLP floating wind turbine and a sway reduction control method for shallow seas. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the accelerated global energy transition, the focus of wind power development is shifting from nearshore to deep-sea areas. Nearshore wind energy, after years of development, is nearing saturation in some areas and is further limited by coastal topography, shipping lanes, and fisheries protection, restricting its expansion potential. Deep-sea areas, on the other hand, offer more stable wind speeds, higher wind energy density, and vast development space, circumventing nearshore constraints and becoming a key direction for large-scale wind power growth. However, a common geographical challenge has emerged in deep-sea development: many coastal areas, while meeting the "deep-sea" standard in terms of distance from shore, do not have significantly deeper seabeds, often remaining at a relatively shallow level of around 50 meters. This unique condition of "far from shore and shallow water" challenges the conventional understanding that "deep-sea is deep water," severely testing the adaptability and economic viability of floating wind power foundations originally designed for deep water in these areas, and creating obstacles to the large-scale development of global floating wind power in deep-sea areas.

[0004] Currently, semi-submersible foundations are the mainstream solution for floating wind power. After years of technological iteration, their structural stability and environmental adaptability have been verified, and they have achieved remarkable results in some deep-water projects. However, as development expands to conditions of "far from shore and shallow water," its bottlenecks have gradually become apparent: in shallow water areas of around 50 meters, to ensure stability, the size of the floating body needs to be increased or the ballast needs to be added, leading to increased material usage and manufacturing costs; moreover, the anchoring system is easily affected by seabed geology, resulting in reduced efficiency, further increasing construction and maintenance costs, weakening economic viability, and narrowing the space for technological optimization; tension leg platforms (TLPs) have become a potential cost-reduction solution due to their structural advantages. They connect the platform to the seabed anchoring through tension legs, using pretension to limit displacement, resulting in a more compact structure and less material usage, theoretically reducing costs and consumption. However, TLP applications are subject to strict limitations: they require high water depth, and it is difficult to form effective pretension in shallow water areas of around 50 meters, making the platform prone to swaying and affecting safety and efficiency; moreover, they are sensitive to tidal range, and when the tidal range is large, the tension of the tension legs fluctuates frequently, which not only aggravates fatigue damage but also disrupts the platform's attitude balance, making it difficult to promote in areas of "far from shore and shallow water" and unable to fill the technological gap of semi-submersible foundations. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a TLP floating wind turbine and anti-sway control method for shallow seas. Through a lightweight truss-type tower design, the overall load is reduced while maintaining support strength, making it suitable for shallow seas with limited water depth. A variable-height buoy (inner cylinder + outer cylinder + lifting mechanism) allows for flexible adjustment of the buoy's draft, solving the problem of insufficient pretension of the tension leg caused by varying water depths. A damping chamber, combined with a liquid supply device, can replenish liquid to stabilize the buoy when it exceeds a set angle, suppressing swaying caused by shallow sea waves. An adjustable tension key adapts to changes in tidal range in shallow seas, maintaining stable tension of the tension leg, thus overcoming the limitations of traditional TLPs in terms of water depth and tidal range in shallow seas.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a TLP floating wind turbine for shallow seas.

[0008] A TLP floating wind turbine for shallow seas includes: a wind turbine body, a steel tower, a truss tower, a variable height pontoon, and an adjustable tension key;

[0009] The wind turbine body is fixed to a steel tower, which is fixedly connected to a truss-type tower. Multiple variable-height floats are connected to the bottom of the truss-type tower, and an adjustable tension key is connected to the bottom of the variable-height floats.

[0010] The variable height pontoon includes an inner tube and an outer tube. The inner tube is located inside the outer tube, and the lifting mechanism is arranged at the bottom inside the outer tube to drive the inner tube to move up and down.

[0011] The inner cylinder is equipped with a damping chamber. The outer wall of the damping chamber is connected to the inner wall and bottom wall of the inner cylinder through an elastic element. The damping chamber is connected to a liquid supply device through a pipeline to add liquid when the float exceeds a set angle. The appendage is a combination of multiple variable height floats.

[0012] In one implementation of the first aspect of the present invention, the inner cylinder, the outer cylinder, and the damping chamber are all cylindrical.

[0013] In one implementation of the first aspect of the present invention, the outer wall of the damping chamber is connected to the inner wall of the inner cylinder by multiple springs, the bottom of the damping chamber is connected to the inner bottom wall of the inner cylinder by springs, and the top of the damping chamber is connected to the inner top wall of the inner cylinder by springs.

[0014] In one implementation of the first aspect of the present invention, a cable reel is fixed to the bottom of the outer cylinder, and the cable reel is used to wind up and unwind the tension key according to the tidal range.

[0015] In one implementation of the first aspect of the present invention, the lifting mechanism includes: a hydraulic oil tank, a hydraulic drive device, and an actuator. The hydraulic drive device is connected to the hydraulic oil tank via a pipeline, the output end of the hydraulic drive device is connected to the actuator, and the actuator is connected to the bottom of the inner cylinder.

[0016] Secondly, the present invention provides a method for reducing sway control.

[0017] A rockfall reduction control method, utilizing a TLP floating wind turbine for shallow seas according to the first aspect of the present invention, includes the following processes:

[0018] When the float rolls beyond a set angle, seawater is added to each damping chamber by 5% to 10% of the float's mass.

[0019] When seawater is added, if the buoy still rolls beyond the set angle, seawater is poured into each damping chamber.

[0020] In one implementation of the second aspect of the present invention, under normal power generation conditions and when the cut-out wind speed has not been reached, the lifting mechanism raises the inner cylinder to the top limit value and then raises the wind turbine body so that the wind turbine body can obtain a greater wind speed.

[0021] When the wind speed exceeds the cut-out wind speed, or when the fan body is in a shutdown condition, the lifting mechanism will lower the inner cylinder to the bottom limit value to reduce the load on the fan body.

[0022] In one implementation of the second aspect of the invention, the natural period of the damping chamber is calculated such that the natural period of the damping chamber is different from the natural period of the float.

[0023] In one implementation of the second aspect of the invention, the damping chamber has an inherent period. The formula is: Where L is the length of the cross-sectional area corresponding to the maximum degree of freedom. It is the acceleration due to gravity. This refers to the height of the loaded liquid level.

[0024] In one implementation of the second aspect of the invention, the damping chambers are already filled with ballast water before seawater is added to each damping chamber.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention utilizes a lightweight truss-type tower design to reduce overall load while maintaining support strength, making it suitable for shallow water conditions with limited depth. The variable-height buoy (inner cylinder + outer cylinder + lifting mechanism) allows for flexible adjustment of the buoy's draft, solving the problem of insufficient pretension of the tension leg caused by varying water depths in shallow water. The damping chamber, combined with a liquid supply device, can replenish liquid and stabilize the buoy when it exceeds a set angle, suppressing swaying caused by shallow sea waves. The adjustable tension key adapts to changes in tidal range in shallow water, maintaining stable tension of the tension leg. Overall, this invention breaks through the limitations of traditional TLP in shallow water depth and tidal range, effectively reducing buoy movement and tower base load by 5% to 10%.

[0027] The inner cylinder, outer cylinder, and damping chamber of this invention are cylindrical, which can make the structure uniformly stressed and reduce the local impact and scouring of the floating body by shallow sea currents and waves. At the same time, the cylindrical structure is easy to manufacture and assemble, reduces the processing difficulty, optimizes the hydrodynamic characteristics, reduces water resistance, and improves the stability and durability of the floating body in the complex hydrological environment of shallow sea.

[0028] The damping chamber of this invention is connected to each wall of the inner cylinder by multiple springs. The springs can help absorb the vibration energy of the floating body and form a dual anti-sway mechanism of "elastic buffer + liquid damping" with the liquid in the damping chamber. This can not only speed up the reset speed of the damping chamber and improve the anti-sway response efficiency, but also reduce the hard impact between the damping chamber and the inner cylinder, reduce structural fatigue damage, and adapt to the frequent swaying conditions in shallow seas.

[0029] The bottom winding mechanism of the outer cylinder of this invention can retract and extend the tension key in real time according to the tidal range in shallow sea, avoiding breakage due to excessive tightness or instability due to excessive looseness caused by tidal range changes; ensuring that the tension leg always maintains reasonable pretension, solving the problem of traditional TLP being sensitive to tidal range, and ensuring the long-term safety of TLP structure under shallow sea conditions.

[0030] The hydraulic lifting mechanism of this invention, through the cooperation of a hydraulic oil tank, a drive device and an actuator, can accurately and stably control the lifting and lowering of the inner cylinder. Compared with other driving methods, hydraulic drive has strong load-bearing capacity and high adjustment precision, can adapt to different water depth requirements in shallow seas, accurately adjust the draft of the float, ensure that the pretension of the tension leg meets the standard, and improve the reliability of the variable height float.

[0031] The graded roll reduction control of this invention (adding 5% to 10% seawater first, then filling the container) can avoid a sudden increase in the load on the buoy caused by a single large-scale replenishment of liquid; it can flexibly adjust the roll reduction force according to the amplitude of the sway to ensure the roll reduction effect, and protect the structure from impact. It is suitable for wave swaying of different intensities in shallow seas, improving control safety and economy.

[0032] This invention adjusts the height of the inner cylinder according to the operating conditions (raising the cylinder to obtain higher wind speeds for power generation, and reducing load by exceeding the cut-out wind speed / shutting down), which can reduce the wind load and wave load on the wind turbine body under extreme wind conditions while ensuring power generation efficiency; it is adapted to the characteristics of large wind speed fluctuations in shallow seas, balances power generation needs and equipment protection, and extends the life of the wind turbine.

[0033] This invention makes the damping chamber and the floating body have different natural periods, which can avoid the resonance between the two and the resulting swaying. It solves the problem that the floating body and the damping chamber are prone to structural damage due to resonance in shallow seas, significantly improves the overall stability of the floating body, and ensures the normal operation of the wind turbine in shallow sea conditions.

[0034] This invention provides a formula for the natural period of a damping chamber, which can be applied based on actual working conditions in shallow seas (…). , , The parameters are used to accurately calculate the cycle, avoiding empirical design errors; ensuring that the damping chamber cycle and the floating body cycle are precisely staggered to maximize the roll reduction effect and provide a scientific basis for TLP design in different shallow sea areas.

[0035] The damping chamber of this invention is pre-configured with ballast water, which can adjust the initial attitude of the float in advance and ensure the balance of the float during the installation stage; at the same time, it reduces the response time during dynamic liquid replenishment, improves the timeliness of roll reduction, and avoids the float tilting during initial installation in shallow water or during low sway, thus laying a stable foundation for subsequent roll reduction.

[0036] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0037] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0038] Figure 1 A schematic diagram of a TLP floating fan provided as an exemplary embodiment of the present invention;

[0039] Figure 2 A schematic diagram of a variable-height pontoon provided for an exemplary embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a damping chamber provided for an exemplary embodiment of the present invention;

[0041] The components include: 1. Wind turbine body; 2. Steel tower; 3. Truss tower; 4. Variable height pontoon; 5. Inner cylinder; 6. Outer cylinder; 7. Adjustable tension key; 8. Hydraulic oil tank; 9. Hydraulic drive device; 10. Actuator; 11. Damping chamber; 12. Spring. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0044] Because floating wind turbines experience greater movement compared to traditional stationary turbines, TLP-type floating bodies offer better mobility than semi-submersible floating bodies. However, in shallow waters with significant tidal ranges, traditional TLP-type floating bodies are difficult to apply. Therefore, this implementation proposes a TLP-type floating wind turbine designed for shallow seas, such as... Figure 1 , Figure 2 and Figure 3 As shown, it includes: wind turbine body 1, steel tower 2, truss tower 3, variable height pontoon 4, and adjustable tension key 7 (tension key is a component that describes the connection between the floating platform and the seabed anchoring structure).

[0045] The wind turbine body 1 is fixed on the steel tower 2, the steel tower 2 is fixedly connected to the truss tower 3, and the bottom of the truss tower 3 is connected to multiple variable height floats 4, and the adjustable tension key 7 is connected to the bottom of the variable height floats 4.

[0046] The variable height pontoon 4 includes an inner cylinder 5 and an outer cylinder 6. The inner cylinder 5 is located inside the outer casing, and the lifting mechanism is arranged at the bottom inside the outer cylinder 6 to drive the inner cylinder 5 to move up and down.

[0047] The inner cylinder 5 is equipped with a damping chamber. The outer wall of the damping chamber is connected to the inner wall and the inner bottom wall of the inner cylinder 5 through an elastic element. The damping chamber is connected to a liquid supply device through a pipeline to add liquid when the float exceeds a set angle. The appendage is a combination of multiple variable height floats 4.

[0048] Considering that the megawattage of wind turbines is increasing and the thrust of wind turbines is increasing, the increased load on the tower base makes the tower design difficult. Therefore, this implementation method adopts a truss-type tower 3 to reduce the design difficulty of the tower and at the same time reduce the load on the tower under extreme working conditions.

[0049] In this implementation, preferably, the inner cylinder 5, the outer cylinder 6, and the damping chamber are all cylindrical; in other implementations, the inner cylinder 5, the outer cylinder 6, and the damping chamber can also adopt other shapes, such as cubes, rectangles, prisms, etc., which will not be elaborated here.

[0050] In this implementation, preferably, the outer wall of the damping chamber is connected to the inner wall of the inner cylinder 5 by multiple springs 12, the bottom of the damping chamber is connected to the inner bottom wall of the inner cylinder 5 by springs 12, and the top of the damping chamber is connected to the inner top wall of the inner cylinder 5 by springs 12; alternatively, springs 12 in six degrees of freedom can be used for connection to maintain stability, so that the damping chamber 11 can play a damping effect and avoid collision with the pontoon wall.

[0051] In this implementation, preferably, a cable reel is fixed to the bottom of the outer cylinder 6, and the cable reel is used to wind up and unwind the tension key according to the tidal range.

[0052] In this implementation, preferably, the lifting mechanism includes: a hydraulic oil tank 8, a hydraulic drive device 9, and an actuator 10. The hydraulic drive device 9 is connected to the hydraulic oil tank 8 through a pipeline, the output end of the hydraulic drive device 9 is connected to the actuator 10, and the actuator 10 is connected to the bottom of the inner cylinder 5.

[0053] Based on the above-mentioned TLP floating wind turbine for shallow seas, this implementation also proposes a sway reduction control method, including the following process:

[0054] When the float rolls beyond the set angle, seawater is added to each damping chamber by 5% to 10% of the float's mass; if the float still rolls beyond the set angle after adding seawater, seawater is filled into each damping chamber.

[0055] In this implementation, the key values ​​for the damping chamber 11 to function are the mass of the damping chamber 11 (including water) and the stiffness K of its spring 12.

[0056] In this implementation, preferably, under normal power generation conditions and when the cut-out wind speed has not been reached, the lifting mechanism raises the inner cylinder 5 to the top limit value, thereby raising the wind turbine body 1 (increasing the height of the wind turbine surface), so that the wind turbine body 1 can obtain a greater wind speed and power generation.

[0057] When the wind speed exceeds the cut-out wind speed (i.e. the maximum wind speed threshold for safe operation of the wind turbine generator set), or when the wind turbine body 1 is in a shutdown condition, the lifting mechanism will lower the inner cylinder 5 to the bottom limit value to reduce the load on the wind turbine body 1.

[0058] In this implementation, preferably, the natural period of the damping chamber 11 is calculated so that the natural period of the damping chamber is different from the natural period of the float. The formula for the natural period of the damping chamber 11 includes the liquid level height h, so it is related to the mass of water in the damping chamber 11. In this invention, it is necessary to ensure that when the mass of the injected seawater is 5% to 10% of the mass of the float, the natural period of the damping chamber is not equal to the natural period of the float, so that the damping effect is optimal.

[0059] In this implementation, preferably, the damping chamber 11 has a natural period. The formula is:

[0060] (1);

[0061] in, The length of the cross-section corresponding to the maximum degree of freedom. It is the acceleration due to gravity. This refers to the height of the loaded liquid level.

[0062] In this implementation, preferably, before adding seawater to each damping chamber, the damping chamber 11 is already equipped with ballast water, which is generally half of the internal space of the damping chamber 11.

[0063] As mentioned before, traditional methods that rely on empirical values ​​for adjustment can easily lead to excessive tension fluctuations in the tension key (above ±15%), causing the floating body to deviate in attitude (draft deviation exceeding 0.5m) and even exacerbating the load on the tower base. At the same time, the impact of dynamic changes in tide level (such as short-term tidal surges) on the tension key tension is not considered, making it impossible to achieve real-time matching of "tide level - length - tension".

[0064] Therefore, alternatively, in some other implementations, a method for calculating the real-time adjustable length of the adjustable tension key 7 is proposed, including:

[0065] (2);

[0066] (3);

[0067] in, represent The real-time target length of the tension key 7 can be adjusted at any time; This represents the initial installation length of the tension key; represent Real-time tide level; The reference tide level corresponding to the design draft of the floating body; represent The tension deviation value of the tension key at any given time; Represents the maximum allowable tension of the tension bond; Represents seawater density; represent Real-time displacement volume of the floating body; Represents gravitational acceleration; Represents the total weight of the floating body; The elastic modulus of the tension bond material; Represents the cross-sectional area of ​​the tension bond.

[0068] Real-time calculation The control system of the cable reel, which transmits data to the bottom of the pontoon, drives the motor of the cable reel to rotate forward (releasing the cable). > (Time) or reverse (reel in the cable, < (At that time), to achieve automatic adjustment of the tension key length;

[0069] when When the tension is greater than 0 (exceeding the allowable value), increase the tension first. (Lowering the cable) to reduce tension; when When the tension is less than 0 (insufficient tension), priority should be given to reducing it. (Take the cable in) to increase tension and ensure that the tension is always within a safe range.

[0070] Through the above design, the "tide level-tension dual closed loop" precise adjustment of the length of the adjustable tension key 7 is realized, avoiding tension key breakage due to tension overload or float drift due to insufficient tension; real-time correction of length deviation caused by sudden tide level changes (such as short-term tidal surge) provides a basis for the stable operation of the damping chamber 11 (avoiding uncontrolled ballast water sloshing); and indirectly reduces the amplitude of tower base load fluctuation.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for reducing sway control, characterized in that, The TLP floating wind turbine, designed for shallow seas, includes a wind turbine body, a steel tower, a truss-type tower, a variable-height pontoon, and an adjustable tension key. The wind turbine body is fixed to the steel tower, the steel tower is fixedly connected to the truss-type tower tube, and the bottom of the truss-type tower tube is connected to multiple variable-height floats, and the adjustable tension key is connected to the bottom of the variable-height floats; The variable height pontoon includes an inner cylinder and an outer cylinder, with the inner cylinder located inside the outer cylinder. A lifting mechanism is arranged at the bottom inside the outer cylinder to drive the inner cylinder to move up and down. The inner cylinder is equipped with a damping chamber. The outer wall of the damping chamber is connected to the inner wall and the inner bottom wall of the inner cylinder through an elastic element. The damping chamber is connected to a liquid supply device through a pipeline to add liquid when the float exceeds a set angle. The float is an assembly of multiple variable height floats. The anti-roll control method includes the following processes: When the buoy rolls beyond a set angle, seawater is added to each of the damping chambers by an amount equal to 5% to 10% of the buoy's mass. When seawater is added, if the buoy still rocks beyond the set angle, seawater is poured into each of the damping chambers. Under normal power generation conditions, and when the cut-out wind speed has not been reached, the lifting mechanism will raise the inner cylinder to the top limit value and thus raise the wind turbine body, so that the wind turbine body can obtain a greater wind speed. When the wind speed exceeds the cut-out wind speed, or when the fan body is in a shutdown condition, the lifting mechanism will lower the inner cylinder to the bottom limit value to reduce the load on the fan body. Calculate the natural period of the damping chamber such that the natural period of the damping chamber is different from the natural period of the buoy. Damping chamber natural period The formula is: Where L is the length of the cross-sectional area corresponding to the maximum degree of freedom. It is the acceleration due to gravity. This refers to the height of the loaded liquid level.

2. The anti-roll control method as described in claim 1, characterized in that, The inner cylinder, the outer cylinder, and the damping chamber are all cylindrical.

3. The anti-roll control method as described in claim 1, characterized in that, The outer wall of the damping chamber is connected to the inner wall of the inner cylinder by multiple springs, the bottom of the damping chamber is connected to the inner bottom wall of the inner cylinder by springs, and the top of the damping chamber is connected to the inner top wall of the inner cylinder by springs.

4. The anti-roll control method as described in claim 1, characterized in that, A cable reel is fixed to the bottom of the outer cylinder, and the cable reel is used to wind up and unwind the tension key according to the tidal range.

5. The anti-roll control method as described in claim 1, characterized in that, The lifting mechanism includes a hydraulic oil tank, a hydraulic drive device, and an actuator. The hydraulic drive device is connected to the hydraulic oil tank via a pipeline, the output end of the hydraulic drive device is connected to the actuator, and the actuator is connected to the bottom of the inner cylinder.

6. The anti-roll control method as described in claim 1, characterized in that, Before seawater is added to each of the damping chambers, the interior of the damping chambers is already filled with ballast water.

Images