Floating offshore wind power plant

Abstract

The application discloses a floating offshore wind power device, which comprises a wind power mechanism and a floating foundation platform; wherein the floating foundation platform comprises a central column and a plurality of side columns which are arranged around the outer side of the circumference of the central column, and the central column and the side columns are fixedly connected through connecting assemblies; the wind power mechanism is fixedly connected to the upper end of the central column, and is used for converting offshore wind energy into electric energy; the lower end of each side column is fixedly connected with two heave plates which are arranged in an up-down mode, and the two heave plates have a preset distance in the vertical direction. The application can effectively reduce the motion response amplitude of the floating foundation platform, so as to ensure that the wind power mechanism can maintain stable wind power generation power and structural safety.

Description

Technical Field

[0001] This invention relates to the field of power generation equipment technology, and in particular to a floating offshore wind power generation device. Background Technology

[0002] Floating offshore wind power generation devices are devices that convert wind energy into electrical energy, offering advantages such as simple structure and economic reliability. As near-shore wind resources become increasingly saturated, global energy demand continues to grow rapidly. Therefore, deep-sea floating offshore wind power generation devices are destined to become the future development direction of the offshore wind power industry.

[0003] A typical floating offshore wind power generation system consists of two main parts: an upper wind turbine generator and a lower floating foundation platform. The motion response of the floating foundation platform to wind and waves inevitably affects the stress on the wind turbine generator and the inflow wind speed. Among these, the pitching and rolling motions of the floating foundation platform have the greatest impact on the inflow wind speed in the yaw direction of the wind turbine generator. The heave and yaw motions of the floating foundation platform also affect the inflow wind speed and blade rotation speed of the wind turbine generator to some extent. Therefore, reducing the motion response amplitude of the floating foundation platform is crucial for maintaining stable wind power generation and structural safety. In related technologies, heave plates are commonly used to reduce the motion response amplitude of floating foundation platforms. However, heave plates have drawbacks such as limited functionality and effectiveness, and there is room for improvement. Summary of the Invention

[0004] The main objective of this invention is to propose a floating offshore wind power generation device, which aims to effectively reduce the motion response amplitude of the floating foundation platform, so as to ensure that the wind power generation mechanism can maintain stable wind power generation and structural safety.

[0005] To achieve the above objectives, the present invention proposes a floating offshore wind power generation device, comprising a wind power generation mechanism and a floating foundation platform; wherein, the floating foundation platform includes a central column and a plurality of side columns surrounding the outer circumference of the central column, the central column and the side columns being fixedly connected by a connecting component; the wind power generation mechanism is fixedly connected to the upper end of the central column, and the wind power generation mechanism is used to convert offshore wind energy into electrical energy; each side column has two vertically arranged heave plates fixedly connected to its lower end, and the two heave plates are spaced at a predetermined distance in the vertical direction.

[0006] Optionally, the connecting assembly includes a horizontal brace and a pontoon arranged vertically. The two ends of the horizontal brace are respectively connected to the upper side of the central column and the side column, and the two ends of the pontoon are respectively connected to the lower side of the central column and the side column; and the cross-sectional area of ​​the pontoon is larger than the cross-sectional area of ​​the horizontal brace.

[0007] Optionally, it includes at least three side columns, which are arranged in a circular, equidistant array with the axis of the central column as the axis.

[0008] Optionally, the floating offshore wind power generation device further includes a wave energy generation mechanism, which is disposed between the two heave plates; the wave energy generation mechanism is used to convert offshore wave energy into electrical energy.

[0009] Optionally, the system includes several wave energy generation mechanisms arranged in a circular array around the axis of the heave plate. Each wave energy generation mechanism includes a vertically arranged rotating shaft and a blade rotor fixedly sleeved in the middle of the rotating shaft. The upper and lower ends of the rotating shaft are rotatably connected to the heave plate, and the end of the rotating shaft is connected to a gear transmission system. The rotating shaft is connected to a generator through the gear transmission system. The blade rotor is rotated by the waves, so that the rotating shaft drives the generator to operate through the gear transmission system to generate electricity. The gear transmission system is located inside the heave plate, and the generator is located inside the side column.

[0010] Optionally, a shaft sleeve is fitted on the outer side of the shaft, and the shaft sleeve has a notch in the middle for avoiding the blade rotor; the upper and lower ends of the shaft sleeve are respectively fixedly connected to the sway plate.

[0011] Optionally, a protective ring is provided on the outer circumference of the blade rotor, and both the upper and lower sides of the protective ring are fixedly connected to the shaft sleeve by support rods.

[0012] Optionally, the system includes a plurality of support rods, which are distributed in a ring at equal intervals around the axis of the rotating shaft.

[0013] Optionally, the support rod is inclined so that the plane in which the support rod, the rotating shaft sleeve, and the protective ring are located combines to form a triangular structure.

[0014] Optionally, the gear transmission system includes a driving gear and a driven gear that are meshed together. The driving gear is fixedly connected to the rotating shaft, and the driven gear is connected to the generator through a transmission rod.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] This invention improves the motion response performance of the floating foundation platform by setting two heave plates at the lower end of the side columns of the floating foundation platform, with the two heave plates having a preset distance in the vertical direction. Compared with the prior art which only sets one heave plate, the two heave plates can effectively improve the motion response performance of the floating foundation platform, thereby effectively reducing the motion response amplitude of the floating foundation platform and ensuring that the wind power generation mechanism can maintain stable wind power generation and structural safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the floating offshore wind power generation device of the present invention;

[0019] Figure 2 For the appendix Figure 1 Enlarged view of a portion at point A;

[0020] Figure 3 This is a schematic diagram of the wave energy generation mechanism in one embodiment of the floating offshore wind power generation device of the present invention;

[0021] Figure 4 For the appendix Figure 3 A magnified view of section B;

[0022] Figure 5 This is a schematic diagram of the hourglass-shaped protective ring in one embodiment of the floating offshore wind power generation device of the present invention;

[0023] Figure 6 This is a schematic diagram of the internal structure of the hourglass-shaped protective ring in one embodiment of the floating offshore wind power generation device of the present invention;

[0024] Figure 7 This is a graph showing the experimental data of heave motion performance and pitch and roll motion performance in one embodiment of the floating offshore wind power generation device of the present invention.

[0025] The names of the components shown in the diagram are as follows:

[0026]

[0027] Detailed Implementation

[0028] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a portion of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] This embodiment discloses a floating offshore wind power generation device, as shown in the attached figure. Figure 1-4 The system includes a wind power generation mechanism 1 and a floating foundation platform 2. The floating foundation platform 2 includes a central column 201 and several side columns 202 surrounding the outer circumference of the central column 201. The central column 201 and the side columns 202 are fixedly connected by a connecting component 203. The wind power generation mechanism 1 is fixedly connected to the upper end of the central column 201 and is used to convert offshore wind energy into electrical energy. The lower end of each side column 202 is fixedly connected to two vertically arranged heave plates 4, and the two heave plates 4 have a preset distance in the vertical direction.

[0030] In this embodiment, two heave plates 4 are installed at the lower end of the side column 202 of the floating foundation platform 2, and the two heave plates 4 are at a preset distance in the vertical direction. Compared with the prior art which only has one heave plate 4, the two heave plates 4 can effectively improve the motion response performance of the floating foundation platform 2, thereby effectively reducing the motion response amplitude of the floating foundation platform 2 and ensuring that the wind power generation mechanism 1 can maintain stable wind power generation and structural safety.

[0031] Specifically, the connecting component 203 includes horizontal braces 2031 and pontoons 2032 arranged vertically. The two ends of the horizontal braces 2031 are connected to the upper sides of the central column 201 and the side columns 202, respectively. The two ends of the pontoons 2032 are connected to the lower sides of the central column 201 and the side columns 202, respectively. The cross-sectional area of ​​the pontoons 2032 is larger than that of the horizontal braces 2031. This arrangement, with the horizontal braces 2031 and pontoons 2032 connecting the upper and lower sides of the central column 201 and the side columns 202, ensures the connection strength between the central column 201 and the side columns 202. Designing the cross-sectional area of ​​the pontoons 2032 to be larger than that of the horizontal braces 2031 lowers the center of gravity of the entire floating foundation platform 2, reducing the probability of the floating offshore wind power generation device capsizing due to waves.

[0032] Specifically, it includes at least three side columns 202, which are arranged in a circular, equidistant array around the axis of the central column 201. This arrangement ensures the balance of the floating offshore wind power generation device by setting at least three side columns 202 in a circular, equidistant array around the axis of the central column 201.

[0033] As a preferred embodiment of the above, the floating offshore wind power generation device further includes a wave energy generation mechanism 5, which is disposed between two heave plates 4. The wave energy generation mechanism 5 is used to convert ocean wave energy into electrical energy. This arrangement allows the wave energy generation mechanism 5 to convert the mechanical energy of the floating base platform 2 caused by wave motion into electrical energy, thereby effectively supplementing wind power generation and improving the overall multi-energy utilization efficiency of the system. Distributing the wave energy generation mechanism 5 between the upper and lower heave plates 4 effectively improves the motion response performance of the floating base platform 2 using the double-layer heave plates 4, and also provides stable structural support and protection for the arrangement of the wave energy generation mechanism 5.

[0034] Specifically, the system includes several wave energy generation mechanisms 5, arranged in a circular array around the axis of the heave plate 4. Each wave energy generation mechanism 5 includes a vertically mounted rotating shaft 6 and a blade rotor 7 fixedly sleeved in the middle of the rotating shaft 6. The upper and lower ends of the rotating shaft 6 are rotatably connected to the heave plate 4, and the end of the rotating shaft 6 is connected to a gear transmission system 8. The rotating shaft 6 is connected to a generator 9 through the gear transmission system 8. The blade rotor 7 is rotated by the waves, causing the rotating shaft 6 to drive the generator 9 through the gear transmission system 8 to generate electricity. The gear transmission system 8 is located inside the heave plate 4, and the generator 9 is located inside the side column 202. This configuration, combining the rotating shaft 6 and the blade rotor 7, forms a rotor-type wave energy generation mechanism 5. The incident waves cause the floating base platform 2 to move, creating a relative water flow velocity around the heave plate 4. The wave energy generation mechanism 5 is driven by this relative water flow to rotate the blade rotor 7, thereby directly converting the mechanical energy of the wave-induced motion into electrical energy, achieving the purpose of converting ocean wave energy into electrical energy. Furthermore, by installing the gear transmission system 8 and the generator 9 inside the heave plate 4 and the side column 202 respectively, the internal space utilization rate of the heave plate 4 and the side column 202 can be increased, thereby increasing the economic benefits of this application at the same cost. At the same time, by setting up several wave energy generation mechanisms 5, multiple wave energy generation mechanisms 5 can operate simultaneously and cope with incident waves from different directions, thereby improving the wave energy generation efficiency.

[0035] The principle of wave energy generation is explained in detail below. When the incident wave causes the floating base platform 2 to undergo heaving and rolling motions, corresponding vertical motion components are generated, forming the inflow of water into the blade rotor 7. The inflow of water causes the blade rotor 7 to rotate, driving the shaft 6 to rotate. Through the gear transmission system 8 set in the heaving plate 4, the rotational motion of the blade rotor 7 ultimately drives the generator 9 to rotate and generate electricity. Thus, the mechanical energy of the floating base platform 2 caused by wave energy is converted into electrical energy. It should be noted that since the motion of the floating base platform 2 is reciprocating, the blade rotor 7 will also experience forward and reverse rotation. If the generator 9 is directly connected in reverse, it will cause great damage to the power generation system. Therefore, it is necessary to add a mechanism to limit reverse rotation in the gear transmission system 8 to protect the generator 9. Alternatively, a program can be set to disconnect the power generation system and allow the generator 9 to idle when it reverses.

[0036] Meanwhile, this invention uses the potential flow boundary element method to perform a rough calculation and analysis of the structural motion response before and after the improvement. The analysis found that although the improved floating foundation platform 2 does not show a significant improvement in heave motion performance, its pitch and roll motion performance will be greatly improved. Figure 7 As shown in (a), the amplitude of the heave motion response (RAO) of the foundation before and after the improvement of the heave plate 4 does not change much at the natural frequency of heave (wave frequency = 0.3 rad / s), and increasing the number of heave plates 4 will shift the natural frequency to a lower frequency. At the same time, the second peak appearing in the wave frequency range of 0.5 to 0.6 rad / s increases significantly with the increase of the heave plate 4. This is mainly caused by the change in wave excitation force after the shape is changed, although this will increase the heave motion amplitude of the floating foundation platform 2 at this frequency. However, considering that this increase is limited (in fact, the wave spectrum obtained from the statistical information of the open sea waves in the coastal waters of my country is usually a bimodal spectrum, and the wave energy is generally concentrated at the wave frequency of 0.3 to 0.4 rad / s and the wave frequency greater than 1.2 rad / s, and rarely concentrated at the second peak of the heave motion), the heave motion itself has a very limited impact on the inflow conditions of the upper wind power generation mechanism 1, and at this time the heave motion of the floating foundation platform 2 has a gain for the wave energy rotor power generation, so it can be considered as a beneficial balance. In contrast, the longitudinal and lateral rolling motions of the floating foundation before and after the improvement are as follows: Figure 7As shown in (b) and (c), when the single-layer heave plate 4 is increased to two layers, the amplitude of the longitudinal and lateral motions at the natural frequencies of the floating foundation platform 2 can be reduced by about 20%. If the damping effect generated by the wave energy generation mechanism 5 arranged between the heave plates 4 is also considered, and preliminary calculations are performed using an equivalent type of heave plate 4, the results show that the amplitude of the longitudinal and lateral motions can be reduced by 30-40%. This is of great significance for maintaining the stability of the floating foundation and the wind power generation mechanism 1 on top of it, thereby ensuring the power generation efficiency of the wind power generation mechanism 1.

[0037] Furthermore, a shaft sleeve 11 is fitted around the outer side of the rotating shaft 6, and a notch 1101 is provided in the middle of the shaft sleeve 11 to avoid the blade rotor 7; the upper and lower ends of the shaft sleeve 11 are fixedly connected to the heave plate 4 respectively. With this configuration, the shaft sleeve 11 protects the rotating shaft 6 and prevents debris in the ocean from getting entangled in the rotating shaft 6, which would cause the wave energy generation mechanism 5 to malfunction.

[0038] Furthermore, a protective ring 12 is provided on the outer circumference of the blade rotor 7. The upper and lower sides of the protective ring 12 are fixedly connected to the shaft sleeve 11 by multiple support rods 13. These support rods 13 are evenly distributed in a ring around the axis of the shaft 6. This arrangement, using multiple support rods 13 to fix the protective ring 12, forms a cage-like structure around the blade rotor 7, preventing debris in the ocean from entangled and causing the wave energy generation mechanism 5 to malfunction, thus protecting the blade rotor 7. In addition, changing the shape of the protective ring 12 can also increase the power generation efficiency of the wave energy generation mechanism 5. Specifically, see attached... Figure 5-6 As shown, the upper and lower sides of the protective ring 12 extend outward into a funnel-shaped structure, making the entire protective ring 12 resemble a funnel shape. In this way, when the floating foundation platform 2 generates corresponding vertical motion, the cross-sectional area of ​​the opening facing the flow is larger, and the flow rate is correspondingly larger. When it reaches the middle of the hourglass-shaped protective ring 12, the cross-sectional area decreases. Under the condition of flow rate conservation, the flow velocity at the blade rotor 7 located in the middle of the hourglass-shaped protective ring 12 increases accordingly, causing the blade rotor 7 to rotate faster, thereby increasing the power generation efficiency of the wave energy generation mechanism 5. It should be noted that in order to ensure that adjacent protective rings 12 do not interfere with each other, the spacing between each wave energy generation mechanism 5 will also be increased accordingly, which can be adjusted according to the actual design.

[0039] Furthermore, the support rod 13 is inclined so that the plane containing the support rod 13, the shaft sleeve 11, and the protective ring 12 forms a triangular structure. This arrangement utilizes the good stability of the triangular structure to better fix the protective ring 12, ensuring that the protective ring 12 can continuously protect the blade rotor 7 during ocean floating.

[0040] Furthermore, the gear transmission system 8 includes a driving gear 801 and a driven gear 802 that are meshed together. The driving gear 801 is fixedly connected to the rotating shaft 6, and the driven gear 802 is connected to the generator 9 through a transmission rod 803. With this configuration, the force transmission between the rotating shaft 6 and the generator 9 is achieved through the meshing driving gear 801 and the driven gear 802, resulting in a simple structure and strong practicality.

[0041] It should be noted that other aspects of the floating offshore wind power generation device disclosed in this invention are prior art and will not be described in detail here.

[0042] Additionally, it should be noted that if any directional indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of the present invention, the directional indication is only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0043] Furthermore, it should be noted that the descriptions involving "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0044] The above are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. Any application of the present invention directly or indirectly in other related technical fields is included within the patent protection scope of the present invention.

Claims

1. Floating offshore wind power plant, characterized in that The system includes a wind power generation mechanism and a floating foundation platform. The floating foundation platform includes a central column and several side columns surrounding the outer circumference of the central column, with the central column and side columns fixedly connected by connecting components. The wind power generation mechanism is fixedly connected to the upper end of the central column and is used to convert offshore wind energy into electrical energy. Each side column has two vertically arranged heave plates fixedly connected to its lower end, with the two heave plates having a predetermined distance in the vertical direction. The floating offshore wind power generation device also includes a wave energy generation mechanism, which is disposed between two heave plates. The wave energy generation mechanism is used to convert sea wave energy into electrical energy. Specifically, it includes several wave energy generation mechanisms arranged in a circular array around the axis of the heave plate. Each wave energy generation mechanism includes a vertically arranged rotating shaft and a blade rotor fixedly sleeved in the middle of the rotating shaft. The upper and lower ends of the rotating shaft are rotatably connected to the heave plate, and the end of the rotating shaft is connected to a gear transmission system. The rotating shaft is connected to a generator through the gear transmission system. The blade rotor is driven to rotate by sea waves, so that the rotating shaft drives the generator to operate through the gear transmission system to generate electricity. The gear transmission system is disposed inside the heave plate, and the generator is disposed inside the side column.

2. Floating offshore wind power plant according to claim 1, characterized in that: The connecting assembly includes a horizontal brace and a buoy arranged vertically. The two ends of the horizontal brace are respectively connected to the upper side of the central column and the side column, and the two ends of the buoy are respectively connected to the lower side of the central column and the side column; and the cross-sectional area of ​​the buoy is larger than the cross-sectional area of ​​the horizontal brace.

3. Floating offshore wind power plant according to claim 1, characterized in that: It includes at least three side columns, which are arranged in a circular, equidistant array with the axis of the central column as the axis.

4. Floating offshore wind power plant according to claim 1, characterized in that: A shaft sleeve is fitted on the outer side of the shaft, and a notch is provided in the middle of the shaft sleeve to avoid the blade rotor; the upper and lower ends of the shaft sleeve are respectively fixedly connected to the sway plate.

5. Floating offshore wind power plant according to claim 4, characterized in that: A protective ring is provided on the outer circumference of the blade rotor, and the upper and lower sides of the protective ring are fixedly connected to the shaft sleeve by support rods.

6. Floating offshore wind power plant according to claim 5, characterized in that: It includes a plurality of support rods, which are distributed in a ring at equal intervals around the axis of the rotating shaft.

7. Floating offshore wind power plant according to claim 5, characterized in that: The support rod is inclined so that the plane in which the support rod, the rotating shaft sleeve, and the protective ring are located can be combined to form a triangular structure.

8. The floating offshore wind power generation device according to claim 1, characterized in that: The gear transmission system includes a driving gear and a driven gear that are meshed together. The driving gear is fixedly connected to the rotating shaft, and the driven gear is connected to the generator through a transmission rod.

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