Single-stand-column type draught fan foundation with mechanical energy storage and output control method

Abstract

The invention discloses a single stand column type fan foundation configured with mechanical energy storage and a force output control method.The single stand column type fan foundation comprises a single stand column floating body, flywheel energy storage devices and a mooring device, the single stand column floating body is of a hollow cylindrical structure, the flywheel energy storage devices are arranged in the single stand column floating body in the axial direction and are arranged in the mode that the lower portion is dense and the upper portion is sparse, and the mooring device is connected with the flywheel energy storage devices. The flywheel energy storage device has the balance weight function so as to greatly reduce the overall gravity center of a fan system, and through mutual conversion of electric energy and flywheel kinetic energy, the whole-course peak regulation of the generated power of the floating type fan is achieved through the flywheel energy storage device. A flywheel rotating at a high speed is arranged in the flywheel energy storage device and has the gyroscopic effect, the output torque generated by rotation of the flywheel can be used for resisting the horizontal load action of wind, waves, flow and the like, and swing of the floating fan is reduced. And therefore, the influence of the wake effect on the power generation efficiency of the floating fan can be reduced, and the influence of swinging on the structural stability of the fan can be avoided.

Description

Technical Field

[0001] The invention relates to a single-column wind turbine foundation configured with mechanical energy storage and an output control method, belonging to the field of offshore floating wind turbine structure design. Background Art

[0002] Offshore floating wind turbines include wind turbines and wind turbine foundations. The wind turbine foundations are used to provide stable support for the wind turbines.

[0003] Due to unstable wind speed, wind power generation is highly volatile and intermittent, which leads to more serious problems in power system frequency stability and increasing demand for grid peak regulation.

[0004] Traditional peak load regulation relies primarily on thermal power generation, such as installing diesel generators. However, due to the specific requirements of diesel engines, they must be shut down within 30 minutes of starting. Wind power, on the other hand, often intermittently lasts for seconds to minutes. Frequent diesel generator starts shorten the service life of the generator set, and when the wind turbine restarts, the diesel engine also operates simultaneously, resulting in excess electricity.

[0005] Furthermore, offshore floating wind turbines are susceptible to periodic oscillation due to the influence of wind, waves, and currents. This oscillation can cause the blades to enter the wake region, where wind speeds decrease, thereby reducing power generation efficiency. Furthermore, this oscillation can also cause structural fatigue failure or capsize. Wind turbine oscillation reduction has become a key issue for offshore floating wind turbines. In summary, the challenges of wind turbine grid peak regulation and floating wind turbine oscillation reduction remain significant, necessitating the development of a new wind turbine technology solution.

[0006] Based on this, the present invention proposes a solution based on a flywheel energy storage device to solve the above problems. The system can realize a device for mutual conversion of kinetic energy and electrical energy, that is, when charging, the electric motor drives the flywheel to rotate at high speed so that the electrical energy is converted into kinetic energy and stored; when discharging, the high-speed rotating flywheel drives the generator to run and convert the kinetic energy into electrical energy. Compared with other grid peak regulation solutions, such as supercapacitors, superconducting magnetic energy storage, and pumped water storage, the flywheel energy storage response time is milliseconds, and has the characteristics of long continuous energy release time and fast response time. It can effectively smooth the output power of the wind farm and thus adjust the grid frequency. And because there is a gyroscopic effect when the flywheel energy storage device rotates, it can effectively reduce shaking. Summary of the Invention

[0007] The purpose of the present invention is to provide a single-column wind turbine foundation configured with mechanical energy storage and an output control method to solve the problems of output power fluctuation and the swaying of the wind turbine itself in the above-mentioned background technology of the offshore single-column wind turbine.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a single-column wind turbine foundation equipped with mechanical energy storage, the wind turbine foundation comprising a single-column float, a plurality of flywheel energy storage devices and a mooring device; one end of the mooring device is fixed to the seabed, and the other end is fixed to the single-column float; the single-column float is a hollow cylindrical structure; the plurality of flywheel energy storage devices are axially fixed inside the single-column float, and the spacing between adjacent flywheel energy storage devices gradually decreases from top to bottom; the single-column float floats on the sea, and the upper end is used to set a wind turbine.

[0009] Furthermore, each of the flywheel energy storage devices includes a vacuum pump, a housing, a first bearing, a vacuum chamber, a shaft core, an electric motor / generator, a flywheel, and a second bearing; the housing is a closed hollow cylinder, and the housing is fixed on the inner wall of the single-column float; the vacuum pump is arranged on the outer surface of the housing to ensure the vacuum inside the housing to form a vacuum chamber; the first bearing and the second bearing are respectively installed on the upper surface and the lower surface of the housing, and the shaft core is fixed on the first bearing and the second bearing, and the first bearing, the second bearing and the shaft core are all located on the central axis of the housing; the electric motor / generator and the flywheel are installed on the shaft core in sequence from top to bottom.

[0010] Furthermore, the outer diameter of the flywheel is equivalent to the inner diameter of the housing, and a flywheel with a diameter as large as possible can improve the energy storage density.

[0011] Furthermore, the single-column float includes a variable-section column, a vertical column and a fairlead; a flywheel energy storage device is fixed inside the vertical column, and the inner diameter of the vertical column is equivalent to the outer diameter of the flywheel energy storage device; the variable-section column is narrow at the top and wide at the bottom, with the upper end used to connect the wind turbine and the lower end connected to the vertical column to increase the diameter of the vertical column, thereby increasing the diameter of the flywheel energy storage device; the fairlead is fixed on the vertical column and connected to the mooring device; the variable-section column and the vertical column together constitute a hollow cylindrical component that is sealed on the outside and connected on the inside, which is used to provide buoyancy for the wind turbine.

[0012] Furthermore, the mooring device includes at least three mooring chains and at least three anchors; one end of each mooring chain is fixed to a cable guide ring on the single-column float, and the other end is fixed to the anchor; the anchors are evenly fixed on the seabed with the single-column float as the center.

[0013] A method for controlling the output of a single-column wind turbine foundation configured with mechanical energy storage is obtained based on any of the above-described wind turbine foundations, and is used to implement grid peak regulation. The specific control method is as follows: the electric motor / generator is both a motor and a generator. When the power generation of the wind turbine set decreases, the electric motor / generator acts as a generator, converting the kinetic energy of the high-speed rotating flywheel into electrical energy; when the power generation of the wind turbine set increases, the electric motor / generator acts as a motor, converting the electrical energy into flywheel kinetic energy for storage.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) Multiple flywheel energy storage devices are installed longitudinally within the foundation of a single-column floating wind turbine. Through the mutual conversion of electrical energy and flywheel kinetic energy, the grid frequency is adjusted to achieve full peak regulation. Compared with peak regulation methods such as thermal power generation, supercapacitors, superconducting magnetic energy storage, and pumped water storage, flywheel energy storage has a response time of milliseconds and has the advantages of long continuous energy release time and fast load response.

[0016] (2) Multiple flywheel energy storage devices are arranged longitudinally within the foundation of a single-column floating wind turbine, with a dense arrangement at the bottom and a sparse arrangement at the top. This helps lower the overall center of gravity of the wind turbine system, making the center of gravity further below the center of buoyancy, thereby improving the stability of the floating wind turbine system. When the wind turbine tilts, a larger restoring force is formed between the center of gravity and the center of buoyancy to resist the tilting movement of the platform.

[0017] (3) Multiple flywheel energy storage devices are installed longitudinally within the foundation of a single-column floating wind turbine. The flywheels rotate at high speed around the vertical axis, thereby generating a gyroscopic effect and forming a stabilizing torque. The stabilizing torque can be used to resist horizontal loads such as wind, waves, and currents, reducing the sway of the floating wind turbine. This can reduce the impact of the "wake effect" on the power generation efficiency of the floating wind turbine and avoid the impact of sway on the structural stability of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an overall perspective view of the single-column fan structure according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the overall structure of a single-column fan according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of a flywheel energy storage device according to an embodiment of the present invention;

[0021] Figure 4 A top view of a flywheel energy storage device according to an embodiment of the present invention;

[0022] Figure 5 This is a three-dimensional schematic diagram of the AA section of a flywheel energy storage device according to an embodiment of the present invention;

[0023] Figure 6 This is a side view of the AA section of a flywheel energy storage device according to an embodiment of the present invention;

[0024] In the figure: 1. Wind turbine; 2. Single-column floating body; 201. Variable-section column; 202. Vertical column; 203. Cable guide ring; 3. Flywheel energy storage device; 301. Vacuum pump; 302. Housing; 303. First bearing; 304. Vacuum chamber; 305. Shaft core; 306. Electric / generator; 307. Flywheel; 308. Second bearing; 4. Mooring device; 401. Mooring chain; 402. Anchor. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] The present invention is a wind turbine foundation for a floating wind turbine. The floating wind turbine generally comprises a wind turbine group 1 and a wind turbine foundation. The wind turbine group 1 is arranged on the wind turbine foundation.

[0027] A single-column wind turbine foundation and output control method with high-density mechanical energy storage can reduce the impact of the "wake effect" on the power generation efficiency of floating wind turbines and avoid the impact of swing on the stability of the wind turbine structure.

[0028] Based on the above requirements, a single-column wind turbine foundation with mechanical energy storage is provided, wherein the wind turbine foundation includes a single-column floating body 2, a plurality of flywheel energy storage devices 3 and a mooring device 4;

[0029] One end of the mooring device 4 is fixed to the seabed, and the other end is fixed to the single column floating body 2;

[0030] The single column float 2 is a hollow cylindrical structure;

[0031] The plurality of flywheel energy storage devices 3 are axially fixed inside the single-column float 2, and the spacing between adjacent flywheel energy storage devices 3 gradually decreases from top to bottom;

[0032] The single-column buoy 2 floats on the sea, and the upper end is used to install the wind turbine 1.

[0033] Example 1:

[0034] See also Figure 1-6 Specifically, a single-column wind turbine foundation with mechanical energy storage includes a single-column float 2, a flywheel energy storage device 3, and a mooring device 4. The single-column float 2 is located below the wind turbine 1. The single-column float 2 is a hollow cylindrical structure with multiple flywheel energy storage devices 3 axially arranged inside. The mooring device 4 includes a mooring chain 401 and an anchor 402. The upper end of the mooring chain 401 is fixed to a cable guide ring 203 provided on the outer surface of the single-column float 2, and the lower end is fixed to the anchor 402.

[0035] like Figure 1The single-column buoy 2 comprises a variable-section column 201, an upright column 202, and a fairlead 203. The variable-section column 201 is narrow at the top and wide at the bottom, connected to the wind turbine 1 at its top and the upright column 202 at its bottom. This increases the diameter of the upright column 202, thereby increasing the diameter of the flywheel energy storage device 3. The variable-section column 201 and the upright column 202 together form a hollow cylindrical member, sealed on the outside and connected on the inside, providing buoyancy and restoring force for the floating wind turbine system.

[0036] like Figure 3-6 The flywheel energy storage device 3 is arranged inside the upright column 202, with its outer diameter corresponding to the inner diameter of the upright column 202. Five flywheel energy storage devices 3 are arranged longitudinally within the upright column 202. The flywheel energy storage devices 3 below the upright column 202 are spaced closer than those above, and the flywheel energy storage devices 3 below are arranged more densely than those above. Multiple flywheel energy storage devices 3 increase the total amount of energy stored, and placing more flywheel energy storage devices 3 below helps lower the overall center of gravity, improve the stability of the floating wind turbine system, and resist tilting movements of the floating wind turbine platform.

[0037] The flywheel energy storage device 3 comprises a vacuum pump 301, a housing 302, a first bearing 303, a vacuum chamber 304, a shaft core 305, a motor / generator 306, a flywheel 307, and a second bearing 308. The vacuum pump 301 is arranged above the housing 302. The sealed housing 302 forms a cylindrical sealed vacuum chamber 304, and vacuum is drawn by the vacuum pump 301 to reduce the resistance to the rotation of the flywheel 307 and improve energy conversion efficiency.

[0038] Inside the housing 302 of the flywheel energy storage device 3, a first bearing 303, a motor / generator 306, a flywheel 307 and a second bearing 308 are arranged in order from top to bottom and connected via a shaft core 305. The outer diameter of the flywheel 307 is equivalent to the inner diameter of the housing 302.

[0039] like Figure 2 The fairlead 203, a fixed point for connecting mooring chains 401, is located in the middle of the upright column 202. To ensure the reliable anchoring of the floating wind turbine foundation, at least three mooring chains 203 are connected to the fairlead 203. The lower ends of the mooring chains 203 are connected to three anchors 402 fixed to the seabed, thereby securing the anchor to the seabed.

[0040] Due to the gyroscopic effect, the flywheel 307 naturally forms a gyroscopic anti-roll device while rotating at high speed. The stabilizing torque generated by the rotation of the flywheel 307 can be used to resist horizontal loads such as wind, waves, and currents, thereby reducing the sway of the offshore floating wind turbine 1.

[0041] Example 2:

[0042] Grid peak regulation is achieved by using a single-column wind turbine foundation configured with mechanical energy storage as described in Example 1. The specific control method is as follows: the electric / generator 306 is both an electric motor and a generator. When the power generation of the wind turbine set 1 decreases, it acts as a generator to convert the kinetic energy of the high-speed rotating flywheel 307 into electrical energy; when the power generation of the wind turbine set 1 increases, it acts as a motor to convert the electrical energy into kinetic energy for storage in the flywheel 307.

[0043] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the ideas and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A single-column fan foundation with mechanical energy storage, It is characterized in that The wind turbine foundation comprises a single column floating body (2), a plurality of flywheel energy storage devices (3) and a mooring device (4); One end of the mooring device (4) is fixed on the seabed, and the other end is fixed to the single-column floating body (2); The single column floating body (2) is a hollow cylindrical structure; The plurality of flywheel energy storage devices (3) are axially fixed inside the single-column floating body (2), and the spacing between adjacent flywheel energy storage devices (3) gradually decreases from top to bottom; The single-column floating body (2) floats on the sea, and the upper end is used to arrange a wind turbine generator set (1).

2. A single-column wind turbine foundation with mechanical energy storage according to claim 1, It is characterized in that Each of the flywheel energy storage devices (3) comprises a vacuum pump (301), a housing (302), a first bearing (303), a vacuum chamber (304), a shaft core (305), a motor / generator (306), a flywheel (307) and a second bearing (308); The shell (302) is a closed hollow cylinder, and the shell (302) is fixed on the inner wall of the single-column floating body (2); The vacuum pump (301) is arranged on the outer surface of the housing (302) to ensure the vacuum inside the housing (302) to form a vacuum chamber (304); The first bearing (303) and the second bearing (308) are respectively mounted on the upper surface and the lower surface of the housing (302), and the shaft core (305) is fixed on the first bearing (303) and the second bearing (308), and the first bearing (303), the second bearing (308) and the shaft core (305) are all located on the central axis of the housing (302); The motor / generator (306) and the flywheel (307) are sequentially mounted on the shaft core (305) from top to bottom.

3. A single-column wind turbine foundation with mechanical energy storage according to claim 2, It is characterized in that The outer diameter of the flywheel (307) is equivalent to the inner diameter of the housing (302).

4. A single-column wind turbine foundation with mechanical energy storage according to claim 1, It is characterized in that The single-column floating body (2) comprises a variable-section column (201), a vertical column (202) and a cable guide ring (203); The flywheel energy storage device (3) is fixed inside the upright column (202), and the inner diameter of the upright column (202) is equivalent to the outer diameter of the flywheel energy storage device (3); The variable cross-section column (201) is narrow at the top and wide at the bottom, with the upper end being used to connect to the wind turbine (1) and the lower end being connected to the upright column (202) so as to increase the diameter of the upright column (202) and thereby increase the diameter of the flywheel energy storage device (3); The cable guide ring (203) is fixed on the upright column (202) and connected to the mooring device (4); The variable-section columns (201) and the upright columns (202) together form a hollow cylindrical component that is sealed on the outside and connected on the inside, and is used to provide buoyancy for the wind turbine generator set.

5. A single-column wind turbine foundation with mechanical energy storage according to claim 4, It is characterized in that The mooring device (4) comprises at least three mooring chains (401) and at least three anchors (402); One end of each mooring anchor chain (401) is fixed to a cable guide ring (203) on the single-column floating body (2), and the other end is fixed to the anchor (402); The anchor (402) is evenly fixed on the seabed with the single column floating body (2) as the center.

6. A method for controlling the output of a single-column wind turbine foundation with mechanical energy storage, obtained according to the wind turbine foundation according to any one of claims 1 to 5, It is characterized in that The wind turbine foundation is used to implement grid peak regulation, and the specific control method is as follows: the electric motor / generator (306) is both a motor and a generator. When the power generation of the wind turbine set (1) decreases, the electric motor / generator (306) acts as a generator to convert the kinetic energy of the high-speed rotating flywheel (307) into electrical energy; when the power generation of the wind turbine set (1) increases, the electric motor / generator (306) acts as a motor to convert the electrical energy into the kinetic energy of the flywheel (307) for storage.

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