A variable blade pitch angle vertical axis wind turbine power generation device

Abstract

The present invention relates to the technical field of wind power generation, and particularly to a variable blade pitch angle vertical axis wind turbine power generation device. The device includes: a base; a vertical axis, which is arranged on the base in the vertical direction; a generator, which includes a stator and a rotor, the rotor is rotatably connected to the vertical axis, the stator is arranged on the outer periphery of the rotor, and the rotor can rotate relative to the stator; an energy storage device, which is connected to the generator and is used for storing the electric energy generated by the generator; blades, which are circumferentially distributed around the vertical axis in the vertical direction; a pitch-changing mechanism, which is connected to the blades and the rotor, and the pitch-changing mechanism can change the pitch angle of the blades; by controlling the pitch-changing mechanism, under different wind speed conditions, according to the optimization calculation results, the change of the blade pitch angle is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a variable blade pitch angle vertical axis wind turbine power generation device. Background Art

[0002] Due to the cleanliness, renewability of wind energy and the increasing maturity of its large-scale application technology, wind power generation has increasingly become the most promising clean power generation method in the new energy field except for nuclear power.

[0003] The basic principle of wind power generation mostly utilizes the rotation of the wind turbine under the action of wind, converts wind energy into mechanical work, the mechanical work drives the rotor to rotate, and finally drives the generator to convert kinetic energy into electrical energy. Experiments show that the variable pitch vertical axis wind turbine has good self-starting performance, and its power generation is higher than that of the fixed pitch vertical axis wind turbine.

[0004] Wind power generation is divided into horizontal axis and vertical axis. With the development of technology, people have realized some disadvantages brought by the horizontal axis, while the vertical axis wind turbine has attracted more and more attention due to its simple structure, multi-directional wind reception, environmental protection, easy installation and maintenance, etc.

[0005] During the rotation of the vertical axis wind turbine, the blade angle of attack changes continuously with the azimuth angle and cannot be maintained at the optimal angle of attack, which is the main reason for its low wind energy utilization rate. Changing the pitch angle to adjust the angle of attack is the main way to improve the wind energy utilization rate of the wind turbine. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, an object of the present invention is to provide a variable blade pitch angle vertical axis wind turbine power generation device, which is simple to use. When the device generates electricity, the blades can adjust the blade pitch angle in real time according to the wind speed, improving the power generation efficiency.

[0007] To achieve the above object, an embodiment of the present invention provides a variable blade pitch angle vertical axis wind turbine power generation device, including:

[0008] A base;

[0009] A vertical axis, which is arranged on the base in the vertical direction;

[0010] A generator, the generator includes a stator and a rotor, the rotor is rotatably connected to the vertical axis, the stator is arranged on the outer periphery of the rotor, and the rotor can rotate relative to the stator;

[0011] An energy storage device, which is connected to the generator and is used for storing the electric energy generated by the generator;

[0012] Blades, which are circumferentially distributed around the vertical axis in the vertical direction;

[0013] A pitch-changing mechanism, connected to the blade and the rotor, and the pitch-changing mechanism can change the pitch angle of the blade;

[0014] It is characterized in that the pitch-changing mechanism includes:

[0015] A guide plate, which is fixedly connected to the top end of the vertical axis, and a guide groove is formed on the guide plate;

[0016] A first connecting rod, one end of which is fixedly connected to the rotor and the other end is hinged to the blade;

[0017] A second connecting rod, one end of which is movably connected to the guide groove and the other end is fixedly connected to the blade;

[0018] Wherein, the inclination angle of the guide groove is γ, the length of the first connecting rod is b, the distance between the connection points of the first connecting rod and the second connecting rod on the blade is c, the length of the second connecting rod is d, and the length of the guide groove is a, and the following is satisfied:

[0019] Preferably, the blade adopts the symmetric airfoil of the vertical axis wind turbine blade NACA0015.

[0020] Preferably, when λ = 2, a = 45 mm is taken.

[0021] Preferably, there are 5 blades and 5 guide grooves.

[0022] Preferably, a guide post is fixedly connected to one end of the second connecting rod where it connects to the guide groove, and the guide post is inserted and connected in the guide groove.

[0023] Preferably, it further includes a third connecting rod, which is located directly below the first connecting rod. One end of the third connecting rod is fixedly connected to the rotor and the other end is hinged to the blade.

[0024] Its working principle is: by controlling the length of the guide groove in the pitch-changing mechanism, under different wind speed conditions, according to the optimization calculation results, the extension length of the second connecting rod is adjusted, that is, one end of the second connecting rod connecting the guide groove moves in the guide groove, driving the second connecting rod to pull the blade to swing, so as to realize the change of the blade pitch angle. When the oncoming wind direction is parallel to the direction indicated by the tail rudder, it is used as the adjustment reference of the pitch-changing strategy, and the tail rudder can realize the real-time wind alignment of the wind turbine. When the wind direction changes, the tail rudder also rotates with the wind, so that the oncoming wind direction is always parallel to the direction indicated by the tail rudder, ensuring that the pitch-changing strategy is always carried out on the adjustment reference to adapt to the change of the wind direction.

[0025] In the design of the double-crank pitch-changing mechanism studied in this application, the basic conditions for forming a double-crank mechanism must be met first: the length of each rod is greater than zero and satisfies the rod length condition, and for the convenience of later control, the inclination angle of the guide groove should be between 0° and 25°.

[0026] The additional aspects and advantages of the present invention will be partly given in the following description, partly become obvious from the following description, or be understood through the practice of the present invention. Brief Description of the Drawings

[0027] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0028] Figure 1 is a schematic structural diagram of a vertical-axis wind turbine power generation device with a variable blade pitch angle according to an embodiment of the present invention;

[0029] Figure 2 is Figure 1 a partial structural diagram at M in

[0030] Figure 3 is a simplified schematic diagram of the pitch-changing mechanism in a vertical-axis wind turbine power generation device with a variable blade pitch angle;

[0031] Figure 4 is a schematic structural diagram of the blade in a vertical-axis wind turbine power generation device with a variable blade pitch angle.

[0032] In the figure:

[0033] Base 1;

[0034] Vertical axis 2;

[0035] Blade 3;

[0036] Guide plate 41;

[0037] Guide groove 411;

[0038] First connecting rod 42;

[0039] Second connecting rod 43;

[0040] Guide rod 431;

[0041] Rotor 51;

[0042] Stator 52. Detailed Description of the Embodiment

[0043] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. The embodiments of the present invention will be described in detail below.

[0044] Vertical-axis wind turbines are gradually becoming popular due to their advantages such as simple structure, no need for wind alignment, low manufacturing and maintenance costs, and environmental friendliness. However, when the wind turbine is operating, the angle of attack of the blade changes continuously with the azimuth angle, and it cannot always stay at the optimal angle of attack. Dynamic stall also occurs, which interferes with the flow field of the wind turbine and reduces the aerodynamic performance of the wind turbine. At present, the method of adjusting the angle of attack by changing the blade pitch angle is one of the effective ways to improve the wind energy utilization rate of the wind turbine. It has gradually been favored by people due to its simple and efficient adjustment method, low manufacturing, installation, and maintenance costs, etc.

[0045] In order to achieve real-time adjustment of the pitch angle, the influence of dynamic stall on the pitch angle adjustment is considered, and dynamic data is introduced into the calculation of the pitch angle adjustment law.

[0046] According to the locally fitted adjustment law of the blade pitch angle, a transmission mechanism is designed to ensure that the blade pitch angle is closest to the fitted pitch angle adjustment curve, so as to realize the pitch-changing law of the wind turbine under different wind speeds. In order to make the pitch angle of the vertical-axis wind turbine change periodically according to a quasi-sine law during the whole-week rotation process, and to meet the requirements of compact structure and reliable transmission, etc., a double-crank pitch-changing mechanism is selected as the design prototype for the pitch-changing mechanism, and further improvements are made on this basis.

[0047] The following refers to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 describe a vertical-axis wind turbine power generation device with a variable blade pitch angle according to an embodiment of the present invention.

[0048] The vertical-axis wind turbine power generation device with a variable blade 3 pitch angle includes: a base 1, a vertical axis 2, a mechanical system for energy capture and transmission, and an electrical system for electric energy generation and conversion.

[0049] Among them, the base 1 is used to support on the bottom surface, or support on a test bench or test rack, which can facilitate the verification and simulation of the design.

[0050] Among them, the mechanical system includes blades 3 and a pitch-changing mechanism. The pitch-changing mechanism is placed at the upper end of the vertical axis 2 and is formed by a crank-link mechanism composed of a plurality of connecting rods and guide plates 41.

[0051] The electrical system includes a generator and an energy storage device. The generator forms a power generation system with the mechanical system, and the energy storage device converts and stores the electric energy generated by the generator.

[0052] Specifically, the vertical axis 2 is arranged on the base 1 in the vertical direction. The vertical axis 2 forms the main shaft of the wind turbine power generation device. A plurality of blades 3 for receiving wind energy are arranged circumferentially along the vertical axis 2. The blades 3 transmit the received wind energy to the generator through the mechanical system.

[0053] Among them, the generator includes a stator 52 and a rotor 51. The rotor 51 is rotatably connected to the vertical shaft 2. The stator 52 is provided on the outer periphery of the rotor 51. The rotor 51 can rotate relative to the stator 52. The stator 52 and the rotor 51 are provided with power generation coils. Thus, the blade 3 is connected to the rotor 51. When the blade 3 receives wind energy and rotates, the rotational force is transmitted to the rotor 51, driving the rotor 51 to rotate relative to the stator 52, thereby realizing the generation of electric energy.

[0054] To realize the conversion and storage of the electric energy generated by the generator, the generator is connected to an energy storage device. The energy storage device is used to convert and store the electric energy generated by the generator. The energy storage device is designed and selected by those skilled in the art according to needs, and the present invention does not limit it.

[0055] The blades 3 of the vertical-axis 2 wind turbine power generation device are distributed circumferentially around the vertical axis 2 in the vertical direction. This structure has the advantages of simple structure, multi-directional wind reception, environmental protection, easy installation and maintenance, etc. compared with the horizontal-axis wind power generation device.

[0056] Specifically, the wind energy received by the above-mentioned blade 3 is transmitted to the generator through a mechanical system. Specifically, the blade 3 is connected to the rotor 51 of the generator through a pitch-changing mechanism. The pitch-changing structure can change the pitch angle of the blade 3 and transmit the wind energy received by the blade 3 to the rotor 51.

[0057] Specifically, the pitch-changing mechanism includes a guide plate 41, a first connecting rod 42 and a second connecting rod 43 connecting the rotor 51 and the blade 3. Among them, the guide plate 41 is fixedly connected to the top end of the vertical shaft 2. The guide plate 41 can be a plate-shaped circle. A plurality of guide grooves 411 are opened on the guide plate 41. The shape of the guide grooves 411 is a racetrack shape. The size of the guide grooves 411 defines the change range of the pitch angle of the blade 3.

[0058] The above-mentioned guide plate 41, first connecting rod 42, second connecting rod 43 and blade 3 form a double-crank linkage mechanism. Their connection relationship is: one end of the first connecting rod 42 is fixedly connected to the rotor 51, and the other end is hinged to the blade 3, so that the blade 3 can rotate relative to the first connecting rod 42. Specifically, one end of the first connecting rod 42 is fixedly connected to the outer surface of the rotor 51 through a plurality of screws, and the other end is connected to the blade 3 through a spherical hinge; one end of the second connecting rod 43 is movably connected to the guide groove 411, and the other end is fixedly connected to the blade 3, so that when one end of the second connecting rod 43 moves in the guide groove 411, it drives the blade 3 to rotate relative to the connection point of the first connecting rod 42. When designing, there is a certain distance between the positions where the first connecting rod 42 and the second connecting rod 43 are connected to the blade 3.

[0059] Among them, the inclination angle of the guiding groove 411 is γ, the length of the first connecting rod 42 is b, the distance between the connection points of the first connecting rod 42 and the second connecting rod 43 on the blade 3 is c, the length of the second connecting rod 43 is d, and the length of the guiding groove 411 is a, and the following conditions are satisfied:

[0060] In the design of the double-crank pitch-changing mechanism studied in this application, first, the basic conditions for forming a double-crank mechanism must be met: the length of each rod is greater than zero and the rod-length condition is satisfied. And for the convenience of later control, the inclination angle of the guiding groove 411 should be between 0° and 25°.

[0061] The working principle of the double-crank pitch-changing mechanism of the vertical-axis 2 wind turbine is as Figure 3 shown. Among them, the rod OA is the guiding groove 411 of the double-crank pitch-changing mechanism. When the wind direction and wind speed remain unchanged, the rod OA always maintains the position as Figure 3 shown, and the length remains unchanged; the rod OC serves as the first connecting rod 42 connecting the blade 3 and always remains unchanged during the operation; BC is the chord length of the blade 3, which is the distance between the connection points of the first connecting rod and the second connecting rod 43 on the blade 3 and serves as the connecting rod between the two cranks; the rod AB is the second connecting rod 43, which is the rod for realizing the change of the pitch angle of the blade 3. When the wind turbine rotates a full circle, the rod AB drives the blade 3BC to rotate around the point C through the rotating pairs at points A and B, thereby realizing the change of the pitch angle of the blade 3.

[0062] Its working principle is: the extended length of the electric push rod is equivalent to Figure 3 the rod OA, that is, the length of the guiding groove 411 in the pitch-changing mechanism. Under different wind speed conditions, according to the optimization calculation results, the extended length of the second connecting rod 43 is adjusted to drive the second connecting rod 43 to pull the blade 3 to swing, so as to realize the change of the pitch angle of the blade 3. When the oncoming wind direction is parallel to the direction indicated by the tail rudder, it is used as the adjustment reference for the pitch-changing strategy, and the tail rudder can realize the real-time wind alignment of the wind turbine. When the wind direction changes, the tail rudder also rotates with the wind, so that the oncoming wind direction is always parallel to the direction indicated by the tail rudder, ensuring that the pitch-changing strategy is always carried out on the adjustment reference to adapt to the change of the wind direction.

[0063] This application conducts a theoretical design for the double-crank pitch-changing mechanism designed above. For this vertical-axis 2 wind turbine, the linkage mechanism is used to control the angle of the blade 3 and does not transmit power. Therefore, for the sake of simplifying the calculation, the pressure angle and transmission angle of the mechanism can be temporarily not considered. Only the consistency between the angle change of the connecting rod and the designed pitch angle adjustment scheme is considered. During the process of the mechanism rotating one week, the square difference between the actual pitch angle and the ideal pitch angle is used as the objective function, and a mathematical model is established with the minimum of this objective function as the optimization goal, and the change law of the actual pitch angle is deduced according to the Figure 3 geometric relationships in it.

[0064] Optimal solutions of each parameter in Table 1

[0065]

[0066] As can be seen from Table 1, where β is the pitch angle. When the tip speed ratio changes, the length d and the angle β of the push rod AB change little. Therefore, in actual work, only the length a of the frame OA is adjusted when the tip speed ratio changes. At the same time, for the convenience of machining the pitch-changing mechanism, a is taken as an integer. When λ = 2, a = 45 mm is taken. The above optimal solutions can guide the specific parameter design of the crank-slider mechanism.

[0067] Among them, the blade 3 adopts the airfoil NACA0015 of the symmetric wing vertical wind turbine blade 3. To make the force effect of the wind turbine better, specifically, the airfoil of the 1 kW H-type symmetric wing vertical axis 2 wind turbine blade 3 adopts the symmetric airfoil NACA0015.

[0068] In order to experimentally verify the variable blade 3 pitch angle vertical axis 2 wind power generation device designed in this application, when λ = 2, a = 45 mm is taken, the pitch angle β = 0.15 is obtained, and a corresponding test model is made.

[0069] Specifically, there are 5 blades 3 and 5 guide grooves 411 in this test model.

[0070] During specific optimization and improvement, in order to facilitate the adjustment of the second connecting rod 43 at one end of the guide groove 411, a guide post 431 is fixedly connected to the second connecting rod 43 at one end of the guide groove 411, and the guide post 431 is inserted and connected into the guide groove 411.

[0071] In order to make the fixation of the blade 3 and the wind energy transmission stable and reliable, it further includes a third connecting rod. The third connecting rod is located directly below the first connecting rod 42. One end of the third connecting rod is fixedly connected to the rotor 51, and the other end is hinged to the blade 3.

[0072] This partial pitch-changing vertical axis 2 wind turbine uses a double-crank pitch-changing mechanism to realize the real-time adjustment of the pitch angle of the blade 3, further improving the wind energy utilization rate of the vertical axis 2 wind turbine.

[0073] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means 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 expressions of the above terms do not necessarily refer to the same embodiment or example.

[0074] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A variable blade pitch angle vertical axis wind turbine power generation device, Characterized in that, Comprising: A base; A vertical axis, which is arranged on the base in the vertical direction; A generator, the generator includes a stator and a rotor, the rotor is rotatably connected to the vertical axis, the stator is arranged on the outer periphery of the rotor, and the rotor can rotate relative to the stator; An energy storage device, which is connected to the generator and is used to store the electric energy generated by the generator; Blades, the blades are distributed circumferentially around the vertical axis in the vertical direction; A pitch-changing mechanism, which is connected to the blades and the rotor, and the pitch-changing mechanism can change the pitch angle of the blades; The pitch-changing mechanism includes: A guide plate, which is fixedly connected to the top end of the vertical axis, and a guide groove is provided on the guide plate; A first connecting rod, one end of the first connecting rod is fixedly connected to the rotor, and the other end is hinged to the blade; A second connecting rod, one end of the second connecting rod is movably connected to the guide groove, and the other end is fixedly connected to the blade; wherein, the inclination angle of the guiding groove is , wherein, is between 1° and 25°, the length of the first connecting rod is b, the distance between the connection points of the first connecting rod and the second connecting rod on the blade is c, the length of the second connecting rod is d, the length of the guiding groove is a, and it satisfies: .

2. The variable blade pitch angle vertical axis wind turbine power generation device according to claim 1, Characterized in that, The blade adopts the symmetrical airfoil vertical axis wind turbine blade airfoil NACA0015.

3. The variable blade pitch angle vertical axis wind turbine power generation device according to claim 1, Characterized in that, At the said = 2, take the said .

4. The variable blade pitch angle vertical axis wind turbine power generation device according to claim 1, Characterized in that, There are 5 blades and 5 guide grooves.

5. The variable blade pitch angle vertical axis wind turbine power generation device according to claim 1, Characterized in that, A guide post is fixedly connected to one end of the second connecting rod where it is connected to the guide groove, and the guide post is inserted and connected in the guide groove.

6. The variable blade pitch angle vertical axis wind turbine power generation device according to claim 1, Characterized in that, It further includes a third connecting rod, the third connecting rod is located directly below the first connecting rod, one end of the third connecting rod is fixedly connected to the rotor, and the other end is hinged to the blade.

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