Deep and far sea wind wave combined power generation system based on nonlinear internal resonance principle

Abstract

The invention discloses a deep and far sea wind wave combined power generation system based on a nonlinear internal resonance principle, and belongs to the technical field of offshore power generation. The system comprises a semi-submersible base, a wind power generation mechanism and a wave energy power generation device. The semi-submersible base comprises three buoys which are annularly and uniformly distributed, and the upper ends and the lower ends of every two adjacent buoys are fixed through a second flexible connecting piece and a third flexible connecting piece which are horizontally arranged respectively; the wind power generation mechanism comprises a tower tube located in the center of the three floating barrels, and an adjustable tuned mass damper is arranged on the tower tube; a wave energy power generation device is arranged between the second flexible connecting piece and the third flexible connecting piece and comprises a wave energy floater; a water cabin is arranged in the wave energy floater; the tower drum vibrates due to wind, energy is transmitted to the wave energy floater, and nonlinear internal resonance is triggered; the wave energy floater converts absorbed energy into electric energy by driving the wave energy conversion device through the heaving plate, and residual kinetic energy is dissipated through the water tank.

Description

Technical Field

[0001] The present invention belongs to the technical field of offshore power generation, and particularly relates to a deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance. Background Technique

[0002] With the global emphasis on environmental protection and sustainable development, the development and utilization of renewable energy have become the focus of the world today. Traditional fossil energy not only has limited resources, but also the greenhouse gases and other pollutants generated during its use have caused serious damage to the environment. In order to address climate change, reduce environmental pollution, and ensure energy security, countries have increased their investment and research efforts in renewable energy such as solar energy, wind energy, and hydropower. Among many renewable energies, ocean energy has attracted much attention due to its huge potential and wide distribution. Especially in the deep - sea area, wind energy and wave energy resources are rich and stable, with great development and utilization value.

[0003] The wind energy and wave energy resources in the deep - sea area are highly complementary. Combining the two for combined power generation can significantly improve the energy capture efficiency and the stability of the system. The wind - wave combined power generation structure system usually consists of a floating platform, a wind turbine, and a wave energy power generation device. The wind turbine can effectively capture wind energy and convert it into electrical energy, while the wave energy power generation device generates electricity by capturing the kinetic energy in wave motion. This multi - energy complementary method can not only make full use of ocean energy resources, but also enhance the system's anti - risk ability and reduce the uncertainty brought by a single energy source. However, traditional wind - wave combined power generation systems are vulnerable to vibration in harsh sea conditions, resulting in equipment damage or reduced efficiency. Therefore, effective vibration reduction measures are needed to ensure the long - term stable operation of the system. For this reason, a deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance is proposed. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance, which solves the problems in the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance includes a semi - submersible base, and a wind power generation mechanism and a wave energy power generation device are arranged on the semi - submersible base;

[0007] The semi-submersible base includes three pontoons evenly distributed in a ring; the wind power generation mechanism includes a tower barrel located at the central position of the three pontoons, and an adjustable tuned mass damper is arranged on the tower barrel; the lower ends of the pontoons and the lower end of the tower barrel are fixed by a horizontally placed first flexible connecting member; the upper and lower ends of adjacent pontoons are fixed by a horizontally placed second flexible connecting member and a third flexible connecting member respectively;

[0008] A wave energy power generation device is connected between the second flexible connecting member and the third flexible connecting member through a support column. The wave energy power generation device includes a wave energy float, a heaving plate and a wave energy conversion device; a water tank is arranged inside the wave energy float;

[0009] The vibration of the tower barrel caused by the wind causes energy to be transmitted to the wave energy float, triggering non-linear internal resonance; the wave energy float converts the absorbed energy into electrical energy through the heaving plate to drive the wave energy conversion device, and dissipates the residual kinetic energy through the fluid sloshing in the water tank.

[0010] Further, the three pontoons are arranged in an equilateral triangle on the sea surface, and the three second flexible connecting members are respectively located on the three sides of the equilateral triangle.

[0011] Further, a power conversion nacelle is fixed at the upper end of the tower barrel. A hub is rotatably connected to the power conversion nacelle. The central axis of the hub is horizontally arranged. Three blades evenly distributed in the circumferential direction are fixed on the circumferential wall of the hub. The power conversion nacelle is used to convert the mechanical energy generated by the rotation of the blades into electrical energy;

[0012] Further, the adjustable tuned mass damper is installed at the top of the tower barrel through a connecting member to absorb the vibration energy generated by the wind force acting on the tower barrel.

[0013] Further, the water tank is vertically divided into an upper water tank, a middle water tank and a lower water tank.

[0014] Further, the condition for the non-linear internal resonance is:

[0015] 2ω1 = ω2

[0016] Wherein, ω1 is the first-order bending mode frequency of the tower barrel, and ω2 is the heaving mode frequency of the float ω2; by adjusting the mass of the adjustable tuned mass damper, the first-order bending mode frequency ω1 of the tower barrel can be obtained, and by injecting and discharging water to change the added mass of the wave energy float, the heaving mode frequency ω2 of the float can be changed.

[0017] Further, the calculation formula for the first-order bending mode frequency ω1 of the tower barrel is:

[0018]

[0019] In the formula, EI is the flexural rigidity of the tower barrel, L is the height of the tower barrel, m 塔筒is the equivalent mass of the tower barrel itself, m TMD is the equivalent mass of the adjustable tuned mass damper.

[0020] Furthermore, the first flexible connector, the second flexible connector, and the third flexible connector are all made of carbon fiber reinforced polymer material.

[0021] Furthermore, the tower barrel adopts a tapered steel pipe structure.

[0022] Advantages of the present invention:

[0023] 1. Through the directional energy transfer mechanism of nonlinear internal resonance, the vibration energy of the wind turbine tower barrel is efficiently transmitted to the wave energy device and preferentially dissipated by its damping system. Compared with traditional rigid connection or passive damping schemes, the vibration amplitude at the top of the tower barrel is more significantly reduced;

[0024] 2. The reduction of the vibration amplitude directly reduces the number of structural alternating stress cycles, and the fatigue damage rate at the connection part between the tower barrel and the platform is significantly reduced, and the overall life of the system can be extended;

[0025] 3. Vibration reduction is achieved through the dynamic characteristics of the structure itself, without relying on active actuators or external energy supply devices, saving energy consumption costs;

[0026] 4. The hydraulic system of the wave energy device operates in the mode of "dissipation first and power generation second", ensuring the vibration reduction goal while almost maintaining the original wave energy power generation efficiency.

[0027] 5. This design method only needs to adjust the frequency matching ratio and the non-linear energy transfer path, and can be extended to other combinations of marine renewable energy. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 is the overall structural schematic diagram of the combined wind and wave power generation system of the present invention;

[0030] Figure 2 is the structural schematic diagram of another perspective of the combined wind and wave power generation system of the present invention;

[0031] Figure 3 is the structural schematic diagram of the float of the present invention;

[0032] Figure 4 is the structural schematic diagram of the tower barrel of the present invention;

[0033] In the figure: 1 - semi - submersible base, 2 - wave energy float, 3 - wind power generating mechanism; 11 - buoy, 12 - first flexible connector, 13 - second flexible connector, 14 - third flexible connector; 21 - water tank, 211 - upper - level water tank, 212 - middle - level water tank, 213 - lower - level water tank; 31 - tower barrel, 32 - power conversion machine cabin, 33 - hub, 34 - blade, 311 - connector, 312 - adjustable tuned mass damper. Detailed implementation mode

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0035] As Figure 1 and Figure 2 shown, a deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance includes a semi - submersible base 1. A wind power generating mechanism 3 and a wave energy power generation device are arranged on the semi - submersible base 1 to convert wind energy and wave energy into electric energy respectively;

[0036] The semi - submersible base 1 includes three buoys 11 evenly distributed in a ring shape. The upper ends of adjacent buoys 11 are fixedly connected by a horizontally placed second flexible connector 13, and the lower ends of adjacent buoys 11 are fixedly connected by a horizontally placed third flexible connector 14;

[0037] The three buoys 11 are arranged in an equilateral triangle on the sea surface. The three second flexible connectors 13 are respectively located on the three sides of the equilateral triangle, and the wind power generating mechanism 3 is located at the center of the three buoys 11, which can improve the stability of the semi - submersible base 1;

[0038] The wind power generating mechanism 3 includes a tower barrel 31. The tower barrel 31 is arranged at the center of the three buoys 11. The three buoys 11 are evenly distributed in a ring shape around the central axis of the tower barrel 31. A power conversion machine cabin 32 is fixed at the upper end of the tower barrel 31. A hub 33 is rotatably connected to the power conversion machine cabin 32. The central axis of the hub 33 is horizontally arranged. Three blades 34 evenly distributed in the circumferential direction are fixed on the circumferential wall of the hub 33. The power conversion machine cabin 32 is used to convert the mechanical energy generated by the rotation of the blades 34 into electric energy; The wind at sea drives the blades 34 to rotate, and the power conversion machine cabin 32 converts the mechanical energy generated by the rotation of the blades 34 into electric energy. The power conversion machine cabin 32 is connected to an offshore booster station;

[0039] In this embodiment, the ends of the first flexible connectors 12 far from the buoys 11 are all fixed to the tower barrel 31;

[0040] As Figure 4 shown, an adjustable tuned mass damper 312 is provided inside the tower barrel 31. The adjustable tuned mass damper 32 is installed at the top of the tower barrel 31 in a suspended manner through a connecting member 311 and close to the rotation axis of the blade 34 to absorb the vibration energy generated by the tower barrel 31 due to the action of wind force to the maximum extent.

[0041] A wave energy power generation device is provided between the second flexible connecting member 13 and the third flexible connecting member 14 and is uniformly fixed between the second flexible connecting member 13 and the third flexible connecting member 14 through a support column; the wave energy power generation device is used to generate electric energy by using the up and down floating of the semi-submersible base 1;

[0042] The first flexible connecting member 12, the second flexible connecting member 13 and the third flexible connecting member 14 flexibly connect the wind power generation mechanism 3 and the wave energy power generation device for physical coupling to form a multi-degree-of-freedom vibration system;

[0043] The wave energy power generation device includes a wave energy float 2, a heaving plate and a wave energy conversion device; the wave energy float is a device floating on the water surface, and captures wave energy through the up and down undulating motion of the wave; the heaving plate is a special float that effectively absorbs wave energy through the vertical fluctuation. The motion of these devices can be converted into electric energy by a wave energy conversion device (such as a generator).

[0044] As Figure 3 shown, a water tank 21 is arranged inside the wave energy float 2. The water tank 21 is divided into an upper water tank 211, a middle water tank 212 and a lower water tank 213 along the vertical direction, and the additional mass of the wave energy float 2 is changed by injecting and discharging water to change the float heaving modal frequency ω2 of the wave energy float 2.

[0045] In this embodiment, the first flexible connecting member 12, the second flexible connecting member 13 and the third flexible connecting member 14 are all made of composite materials with high elastic modulus but excellent flexibility, such as carbon fiber reinforced polymer, to ensure sufficient strength while bearing large deformations; in this embodiment, the tower barrel 31 adopts a tapered steel pipe structure.

[0046] The mass of the adjustable tuned mass damper 312 should be selected according to the total mass of the tower barrel 31 and the vibration mode to be controlled; the selection process is as follows:

[0047] 1) Simplify the tower barrel 31 into a cantilever beam model with a concentrated mass at the top, and the formula for the first-order bending modal frequency ω1 of the tower barrel 31 is obtained as;

[0048]

[0049] In the formula, EI is the flexural rigidity of the tower barrel, L is the height of the tower barrel, m 塔筒is the equivalent mass of the tower barrel itself, m TMD is the equivalent mass of the adjustable tuned mass damper 312; by presetting the mass of the adjustable tuned mass damper 312, the natural frequency (first-order bending mode frequency) ω1 of the tower barrel can be obtained;

[0050] 2) By adjusting the mass of the mass block of the adjustable tuned mass damper 312, the first-order bending mode frequency ω1 of the tower barrel and the heaving mode frequency ω2 of the buoy are made to satisfy the nonlinear internal resonance condition of 2ω1 = ω2;

[0051] The wind-induced vibration energy of the tower barrel is transferred to the wave energy buoy 2 through the nonlinear coupling term of the flexible hinge, triggering 2:1 internal resonance; the wave energy buoy 2 converts the absorbed energy into electrical energy by driving the wave energy conversion device through the large-amplitude motion of the heaving plate, and at the same time dissipates the residual kinetic energy through the fluid sloshing in the water tank 21;

[0052] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0053] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance, characterized in that, It includes a semi-submersible base (1), on which a wind power generation mechanism (3) and a wave energy power generation device are provided. The semi-submersible base (1) includes three pontoons (11) evenly distributed in a ring shape; the wind power generation mechanism (3) includes a tower barrel (31) located at the central position of the three pontoons (11), and an adjustable tuned mass damper (312) is provided on the tower barrel (31); the lower end of the pontoon (11) is fixed to the lower end of the tower barrel (31) through a horizontally placed first flexible connecting member (12); the upper and lower ends of two adjacent pontoons (11) are respectively fixed through a horizontally placed second flexible connecting member (13) and a third flexible connecting member (14). A wave energy power generation device is connected between the second flexible connecting member (13) and the third flexible connecting member (14) through a support column. The wave energy power generation device includes a wave energy float (2), a heaving plate, and a wave energy conversion device; a water tank (21) is arranged inside the wave energy float (2). The wind-induced vibration of the tower barrel (31) transfers energy to the wave energy float (2), triggering non-linear internal resonance; the wave energy float (2) converts the absorbed energy into electrical energy through the heaving plate to drive the wave energy conversion device, and dissipates the residual kinetic energy through the fluid sloshing of the water tank (21).

2. The far-reaching sea and wind wave combined power generation system based on the principle of nonlinear internal resonance according to claim 1, characterized in that, The three pontoons (11) are arranged in an equilateral triangle on the sea surface, and the three second flexible connecting members (13) are respectively located on the three sides of the equilateral triangle.

3. The deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance according to claim 1, characterized in that, A power conversion machine cabin (32) is fixed at the upper end of the tower barrel (31). A hub (33) is rotatably connected to the power conversion machine cabin (32). The central axis of the hub (33) is horizontally arranged. Three blades (34) evenly distributed in the circumferential direction are fixed on the circumferential wall of the hub (33). The power conversion machine cabin (32) is used to convert the mechanical energy generated by the rotation of the blades (34) into electrical energy.

4. The deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance according to claim 1, characterized in that The adjustable tuned mass damper (32) is installed at the top of the tower barrel (31) through a connecting member (311) to absorb the vibration energy generated by the action of wind on the tower barrel (31).

5. The deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance according to claim 1, characterized in that, The water tank (21) is vertically divided into an upper water tank (211), a middle water tank (212), and a lower water tank (213).

6. The far-reaching sea and wind wave combined power generation system based on the principle of nonlinear internal resonance according to claim 1, characterized in that The conditions for the said non-linear internal resonance are: 2ω1 = ω2 Wherein, ω1 is the first-order bending mode frequency of the tower barrel, and ω2 is the heaving mode frequency of the float ω2; by adjusting the mass of the adjustable tuned mass damper (312), the first-order bending mode frequency ω1 of the tower barrel can be obtained, and by injecting or discharging water to change the added mass of the wave energy float (2), the heaving mode frequency ω2 of the float can be changed.

7. The deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance according to claim 7, characterized in that, The calculation formula for the first-order bending mode frequency ω1 of the tower barrel is: where EI is the flexural rigidity of the tower barrel, L is the height of the tower barrel, and m 塔筒 is the equivalent mass of the tower barrel itself, and m TMD is the equivalent mass of the adjustable tuned mass damper (312).

8. The deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance according to claim 2, characterized in that, The first flexible connecting member (12), the second flexible connecting member (13), and the third flexible connecting member (14) are all made of carbon fiber reinforced polymer material.

9. The deep - sea wind - wave combined power generation system based on the principle of nonlinear internal resonance according to claim 1, wherein The tower barrel (31) adopts a tapered steel pipe structure.

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