Large Vertical Axis Wind Turbine with Bidirectional Automatic Retractable Cylindrical Vortex Generators

Abstract

The present invention discloses a large vertical-axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator. A row of holes are opened on both the upper and lower surfaces of the blade. Both ends of the bearing plate are respectively connected to two parallel side surfaces of the blade. Cylindrical vortex generator assemblies are provided on both sides. Each cylindrical vortex generator assembly includes: a cylindrical vortex generator mounting plate, a plurality of cylindrical vortex generators, a driving mechanism, and a guiding mechanism. The driving mechanism is used to drive the movement of the cylindrical vortex generator mounting plate so that the cylindrical vortex generators move in the holes at corresponding positions. The guiding mechanism is arranged on the bearing plate to define the sliding direction of the cylindrical vortex generator mounting plate and prevent the occurrence of movement position errors. The blade of the present invention can adjust the length of the cylindrical vortex generator extending out according to the magnitude of the angle of attack, thereby generating vortices adapted thereto, optimizing the aerodynamic performance of the blade at different angles of attack, and thus improving the comprehensive performance of the blade during the entire operation process.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbines, and specifically to a large vertical-axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator. Background Art

[0002] Nowadays, various types of energy in the world are facing huge challenges. All kinds of energy are approaching exhaustion and are non-renewable. In order to meet this challenge, countries around the world are vigorously developing the utilization of renewable resources, such as solar energy, wind energy, water energy, geothermal energy and other various renewable energies. Wind turbines are an embodiment of the utilization of wind energy. Now, on some remote mountains, one can see huge windmills standing on the mountain tops, which are wind turbines. They use wind energy to drive the blades to rotate into mechanical energy, and through some technologies, it can be transformed into the electric energy we need. Wind turbines are divided into two types. According to the direction of the shaft, they can be divided into horizontal-axis wind turbines and vertical-axis wind turbines. Horizontal-axis wind turbines: The wind wheel shaft of this type of generator is horizontal, and usually needs to face the wind direction to achieve the best efficiency. They usually have higher efficiency, but may need to adjust the direction when the wind direction changes. Vertical-axis wind turbines: The wind wheel shaft of this type of generator is vertical and can receive wind from any direction, without a wind alignment system.

[0003] During the operation of the blades of a vertical-axis wind turbine, due to factors such as wind speed, wind direction, and control strategies, the angle of attack will constantly change. A suitable angle of attack can enable the blade to obtain good lift, but too large or too small an angle of attack will affect the performance of the blade. However, the blades of existing vertical-axis wind turbines are difficult to adapt to different changes in the blade angle of attack in real time according to the wind speed and wind direction during operation, thus it is difficult to ensure the aerodynamic performance of the blade at different angles of attack, resulting in a lower efficiency of the vertical-axis wind turbine in capturing wind energy. Summary of the Invention

[0004] The purpose of the present invention is to provide a large vertical-axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator, so that the vertical-axis wind turbine has higher efficiency.

[0005] The technical solution of the present invention is as follows:

[0006] A large vertical-axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator has a row of holes on both the upper and lower surfaces of the blades of the vertical wind turbine. A bearing plate is provided inside the blade, and both ends of the bearing plate are respectively connected to two parallel side surfaces of the blade. On both surfaces of the bearing plate, there are cylindrical vortex generator assemblies. The two cylindrical vortex generator assemblies are symmetrically arranged. One of the cylindrical vortex generator assemblies is close to the upper surface of the blade, and the other cylindrical vortex generator assembly is close to the lower surface of the blade. Each cylindrical vortex generator assembly includes: a cylindrical vortex generator mounting plate parallel to the bearing plate; a plurality of cylindrical vortex generators, all of which are cylindrical structures, arranged on the surface of the cylindrical vortex generator mounting plate away from the bearing plate, and the plurality of cylindrical vortex generators are evenly spaced. The plurality of cylindrical vortex generators correspond to the plurality of holes one by one; a driving mechanism connected between the cylindrical vortex generator mounting plate and the bearing plate for driving the cylindrical vortex generator mounting plate to move so that the cylindrical vortex generator moves in the holes at corresponding positions; a guiding mechanism provided on the bearing plate, and the cylindrical vortex generator mounting plate is slidably fitted on the guiding mechanism to define the sliding direction of the cylindrical vortex generator mounting plate and prevent the occurrence of movement position errors. By effectively controlling the boundary layer separation and optimizing the aerodynamic performance of the blade, the bidirectional automatic telescopic cylindrical vortex generator can increase the lift coefficient of the blade, so that under the same wind speed and blade rotation speed, the wind turbine can capture more wind energy. At the same time, during the operation of the blade, due to factors such as wind speed, wind direction, and control strategies, the angle of attack will constantly change. A suitable angle of attack can enable the blade to obtain good lift, but too large or too small an angle of attack will affect the performance of the blade. The bidirectional automatic telescopic vortex generator in this embodiment can automatically adjust the extension length according to the change of the blade angle of attack, generate corresponding vortices, and optimize the aerodynamic performance of the blade at different angles of attack, thereby improving the comprehensive performance of the blade during the entire operation process.

[0007] Further, the guiding mechanism includes: two guiding rods, each guiding rod is vertically arranged on the bearing plate, and a groove is opened on one side of the two guiding rods facing each other. The groove is opened along the length direction of the guiding rod; two roller assemblies are respectively arranged at both ends of the cylindrical vortex generator mounting plate. Each roller assembly includes a bracket and a roller arranged on the bracket. The bracket is connected to the cylindrical vortex generator mounting plate, and the roller cooperates with the groove. Through the movement of the cylindrical vortex generator mounting plate, the roller moves linearly in the groove.

[0008] Furthermore, the driving mechanism is selected as a hydraulic driving system. The base of the hydraulic cylinder of the hydraulic driving system is connected to the bearing plate, and the hydraulic rod of the hydraulic cylinder is connected to the cylindrical vortex generator mounting plate. In this case, hydraulic driving has a fast response speed, is responsive in a timely manner, can perform stepless motion, the hydraulic components can be connected over a long distance, and can be arranged at different positions.

[0009] Furthermore, the vortex generator plate moves with the movement of the hydraulic rod, and the maximum stroke of the hydraulic rod in the hydraulic cylinder is 1% of the chord length. The maximum stroke of the hydraulic rod is the maximum height at which the cylindrical vortex generator extends out of the airfoil surface.

[0010] Furthermore, it also includes a control system and a wind direction sensor. The wind direction sensor is installed at the top of the tower to collect the direction of the oncoming flow and transmit the wind direction signal to the control system. The control system is connected to the driving mechanism and is used to control the movement of the driving mechanism when the airfoil of the wind turbine is at different angles of attack.

[0011] Furthermore, in order to reduce the overall mass of the blade, the cylindrical vortex generator mounting plate and the cylindrical vortex generator are made of aluminum alloy material, and the cylindrical vortex generator is a hollow cylinder.

[0012] Furthermore, when the cylindrical vortex generator is in a state of not protruding from the hole, the end face of the cylindrical vortex generator forms a smooth curve with the airfoil surface.

[0013] Furthermore, taking the chord line formed by connecting the leading edge and the trailing edge of the airfoil blade as the X-axis, the vertical direction of the two parallel planes of the airfoil blade as the Y-axis, and the direction perpendicular to the plane formed by X and Y as the Z-axis, a space rectangular coordinate system is established. The cylindrical vortex generator mounting plate is perpendicular to the two parallel planes of the airfoil blade, and the width of the cylindrical vortex generator is perpendicular to the plane formed by the Y-axis and the Z-axis. The length of the cylindrical vortex generator mounting plate is 80%b, where b is the perpendicular distance between the two parallel side faces of the airfoil blade. In order to facilitate the installation of the guide rod, 10%b of space is left between the two end faces of the cylindrical vortex generator mounting plate and the two parallel side faces of the airfoil blade. The width of the cylindrical vortex generator mounting plate is greater than the diameter of the cylindrical vortex generator. For example, the width of the cylindrical vortex generator mounting plate is 6% of the chord length, and the chord length refers to the length of the connection line between the leading edge and the trailing edge. The interval between two adjacent cylindrical vortex generators is 2%-3% of the chord length, and the diameter of the cylindrical vortex generator is 2% of the chord length, so as to achieve a relatively high efficiency in suppressing the airflow separation. The length of the cylindrical vortex generator can make its end face just form a smooth curved surface with the airfoil surface when it is in a non-working state.

[0014] Furthermore, the position of the holes is at a distance of 15%-20% from the leading edge of the blade in the X-axis direction starting from the leading edge of the blade. The distance from the center of the vortex generator located at the edge on the vortex generator plate to the end face of the plate is 5%b. The multiple holes are in a straight line along the Y-axis direction, and the axes of the holes on the upper surface of the blade are coaxial with the holes on the lower surface of the blade.

[0015] Furthermore, the width and height of the carrier plate are the same as those of the cylindrical vortex generator mounting plate. The length of the carrier plate is the vertical distance b between the two parallel sides of the blade, and the height position of the carrier plate inside the blade is at the midpoint of the center line connecting the upper and lower holes of the airfoil.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] The problem of low energy capture ability is solved:

[0018] During the operation of the wind turbine blade of the present invention, the bidirectional automatic telescopic vortex generator can automatically adjust the extension length according to the change of the blade angle of attack, generate corresponding vortices, and optimize the aerodynamic performance of the blade at different angles of attack, thereby improving the comprehensive performance of the blade during the entire operation process. At the same time, under different working conditions of wind speed, wind direction, and blade angle of attack, the bidirectional automatic telescopic cylindrical vortex generator generates vortices by extending or retracting an appropriate length to control the boundary layer, effectively control the boundary layer separation, and optimize the aerodynamic performance of the blade, increasing the lift coefficient of the blade, so that the wind turbine can capture more wind energy at the same wind speed and blade rotation speed. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the internal structure of the blade of the present invention.

[0020] Figure 2 It is a partially enlarged schematic diagram of the structure of the guiding mechanism of the present invention.

[0021] Figure 3 It is a partially enlarged schematic diagram of the structure of the driving device of the present invention.

[0022] Figure 4 It is a schematic diagram of the hole position structure of the present invention.

[0023] Figure 5 It is a schematic diagram of the position of the cylindrical vortex generator of the present invention.

[0024] Figure 6 It is a schematic diagram of the structure of the cylindrical vortex generator mounting plate, cylindrical vortex generator, driving mechanism, and roller assembly of the present invention.

[0025] Figure 7 It is a schematic diagram of the structure of the cylindrical vortex generator of the present invention after extending out of the hole.

[0026] Figure 8 Schematic structural diagram of the blade of the present invention, in which as the angle of attack of the blade increases during operation, the hydraulic cylinder on one side works to drive the cylindrical vortex generator to extend.

[0027] Figure 9 Schematic diagram of the extension length of the cylindrical vortex generator when there is an oncoming flow on one side of the blade of the present invention at different positions (angles of attack).

[0028] Figure 10 Schematic diagram of the chord line of the blade of the present invention.

[0029] Among them, 1, hole; 2, bearing plate; 3, mounting plate of cylindrical vortex generator; 4, cylindrical vortex generator; 5, driving mechanism; 6, guiding mechanism, 61, guiding rod, 62, roller assembly. Specific embodiments

[0030] The following combines Figures 1 to 10 , and describes in detail the specific embodiments of the present invention. In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0031] The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features; in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0032] It should be noted that the pipeline connection of the hydraulic system and the circuit connection of the control system involved in the present invention both adopt conventional connection methods and do not involve any innovation. Embodiment

[0033] The blade in this embodiment is a NACA series blade, specifically a NACA0025 blade. There are no obvious protrusions and depressions on the blade surface. Its upper surface and lower surface are symmetric blades. The blade also has a certain thickness, and the maximum thickness is 25% of the airfoil length. The surface roughness of the blade is small, and the frame of the blade itself is firm and does not deform.

[0034] As Figure 1As shown in the figure, a large vertical-axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator has a row of holes 1 opened on both the upper surface and the lower surface of the blade of the vertical wind turbine. A bearing plate 2 is provided inside the blade, and both ends of the bearing plate 2 are respectively connected to two parallel side surfaces of the blade; cylindrical vortex generator assemblies are provided on both surfaces of the bearing plate 2, and the two cylindrical vortex generator assemblies are symmetrically arranged. One cylindrical vortex generator assembly is close to the upper surface of the blade, and the other cylindrical vortex generator assembly is close to the lower surface of the blade. As Figure 1 and Figure 6 shown, each cylindrical vortex generator assembly includes: a cylindrical vortex generator mounting plate 3, a plurality of cylindrical vortex generators 4, a driving mechanism 5, and a guiding mechanism 6. The cylindrical vortex generator mounting plate 3 is parallel to the bearing plate 2; the plurality of cylindrical vortex generators 4 are all cylindrical structures, arranged on the surface of the cylindrical vortex generator mounting plate 3 away from the bearing plate 2, and the plurality of cylindrical vortex generators 4 are evenly spaced, and the plurality of cylindrical vortex generators 4 correspond to the plurality of holes 1 one by one. As Figure 8 shown, the driving mechanism 5 is connected between the cylindrical vortex generator mounting plate 3 and the bearing plate 2, and is used to drive the cylindrical vortex generator mounting plate 3 to move, so that the cylindrical vortex generator 4 moves in the hole 1 at the corresponding position; the guiding mechanism 6 is arranged on the bearing plate 2, and the cylindrical vortex generator mounting plate 3 is slidably matched with the guiding mechanism 6 to define the sliding direction of the cylindrical vortex generator mounting plate 3. Prevent the occurrence of moving position errors.

[0035] In the embodiment as Figure 2 shown, the guiding mechanism 6 includes: two guiding rods 61 and two roller assemblies 62. Each guiding rod 61 is vertically arranged on the bearing plate 2, and a groove is opened on one side of the two guiding rods 61 facing each other, and the groove is opened along the length direction of the guiding rod 61; the two roller assemblies 62 are respectively arranged at both ends of the cylindrical vortex generator mounting plate 3. Each roller assembly 62 includes a bracket and a roller arranged on the bracket. The bracket is connected to the cylindrical vortex generator mounting plate 3, and the roller is matched with the groove. Through the movement of the cylindrical vortex generator mounting plate 3, the roller moves linearly in the groove, so that the movement of the cylindrical vortex generator mounting plate 3 is more stable.

[0036] In some embodiments, the driving mechanism 5 is a hydraulic driving system. The hydraulic cylinder base of the hydraulic driving system is connected to the bearing plate 2, and the hydraulic rod of the hydraulic cylinder is connected to the cylindrical vortex generator mounting plate 3. Hydraulic driving has a fast response speed, timely response, and can also perform stepless movement. The hydraulic components can be connected over a long distance and can be arranged at different positions on the bearing plate.

[0037] As Figure 10As shown, the vortex generator plate moves with the movement of the hydraulic rod, and the maximum stroke of the hydraulic rod in the hydraulic cylinder is 1% of the chord length. The maximum stroke of the hydraulic rod is the maximum height that the cylindrical vortex generator 4 extends out of the airfoil surface.

[0038] In some embodiments, it further includes: a control system and a wind direction sensor. The control system is connected to the driving mechanism 5 and is used to control the movement of the driving mechanism 5 when the wind turbine airfoil is at different angles of attack; the wind direction sensor is installed at the top of the tower to receive the wind direction signal faster and more accurately. It is used to collect the direction of the oncoming flow and transmit the wind direction signal to the control system. When there is no wind, the wind direction sensor does not detect and transmit a signal, so the control system cannot control the driving mechanism 5 to start, the hydraulic cylinder does not extend or retract, that is, the vertical axis wind turbine does not work, the cylindrical vortex generator 4 on the vertical axis wind turbine blade does not extend, and the end face of the cylindrical vortex generator 4 forms a smooth curved surface with the surface of the blade; when there is wind, the vertical axis wind turbine can rotate the wind turbine blade due to the special geometric shape of the blade.

[0039] In some embodiments, in order to reduce the overall mass of the blade, the cylindrical vortex generator mounting plate 3 and the cylindrical vortex generator 4 are made of aluminum alloy material, and the cylindrical vortex generator 4 is a hollow cylinder.

[0040] As Figure 8 shown, when the cylindrical vortex generator 4 is in the state of not extending out of the hole, the end face of the cylindrical vortex generator 4 forms a smooth curve with the airfoil surface.

[0041] Specifically, as Figure 4 、 Figure 5 and Figure 10 shown, taking the chord line formed by connecting the leading edge and the trailing edge of the airfoil blade as the X-axis, the vertical direction of the two parallel planes of the airfoil blade as the Y-axis, and the direction perpendicular to the plane formed by X and Y as the Z-axis, a space rectangular coordinate system is established. The cylindrical vortex generator mounting plate 3 is perpendicular to the two parallel planes of the airfoil blade, and the width of the cylindrical vortex generator 4 is perpendicular to the plane formed by the Y-axis and the Z-axis. The length of the cylindrical vortex generator mounting plate 3 is 80%b, where b is the perpendicular distance between the two parallel side surfaces of the airfoil blade. In order to facilitate the installation of the guide rod, a space of 10%b is left between the two end faces of the cylindrical vortex generator mounting plate 3 and the two parallel side surfaces of the airfoil blade. The width of the cylindrical vortex generator mounting plate 3 is greater than the diameter of the cylindrical vortex generator 4; for example, the width of the cylindrical vortex generator mounting plate 3 is 6% of the chord length, and the chord length refers to the length of the connection line between the leading edge and the trailing edge. Specifically, as Figure 10As shown; the spacing between two adjacent cylindrical vortex generators 4 is 2%-3% of the chord length, and the diameter of the cylindrical vortex generator 4 is 2% of the chord length, so as to achieve a relatively high efficiency in suppressing airflow separation. The length of the cylindrical vortex generator 4 can make its end face just form a smooth curved surface with the airfoil surface when it is in the non-working state.

[0042] As Figure 4 shown, the position of the hole 1 is at 15%-20% of the leading edge distance from the leading edge of the blade in the X-axis direction. The distance from the center of the vortex generator 4 located at the edge on the vortex generator plate 3 to the end face of the plate is 5%b. A plurality of holes 1 are in a straight line along the Y-axis direction, and the axes of the holes 1 on the upper surface of the blade and the holes 1 on the lower surface of the blade are coaxial.

[0043] In some embodiments, the width and height of the carrier plate 2 are the same as those of the cylindrical vortex generator mounting plate 3. The length of the carrier plate 2 is the vertical distance b between the two parallel sides of the blade, and the height position of the carrier plate 2 inside the blade is at the midpoint of the connection line of the centers of the upper and lower holes of the airfoil.

[0044] The blade of the large vertical axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator in this embodiment can change the flow state of the fluid by generating vortices in the fluid, so as to achieve the purposes of enhancing mixing, delaying separation, etc. And the entire control system consists of a controller and a wind direction sensor. The wind direction sensor installed at the top of the tower receives the oncoming flow and converts it into an electrical signal and transmits it to the controller installed on the tower for processing. When the control system detects that the azimuth angle of the blade is the stall angle of attack, the controller will control the drive of the drive device hydraulic system, and the hydraulic system drives the vortex generator to extend, and adjusts the extended length of the cylindrical vortex generator according to the size of the angle of attack.

[0045] At a small angle of attack, the fluid separation trend is small, and only a relatively short extended length of the vortex generator can effectively control the boundary layer. Because at this time, the stability of the boundary layer is relatively high, and the vortices generated by the relatively short generator are sufficient to enhance the momentum exchange in the boundary layer and maintain a good fluid attachment state.

[0046] As the angle of attack increases, the trend of fluid separation increases. In order to more effectively postpone fluid separation, the extended length of the cylindrical vortex generator is increased to generate stronger and more effective vortices. Through the longer cylindrical vortex generator, the high-energy fluid in the outer layer can be better introduced into the boundary layer to counteract the adverse pressure gradient and the flow separation trend caused by the increase of the angle of attack, thereby improving the hydrodynamic performance of the object.

[0047] Specifically, when there is no wind, the wind direction sensor does not detect and transmit signals, so the control system cannot control the driving mechanism 5 to start, the hydraulic cylinder does not extend or retract, that is, the vertical axis wind turbine does not work. Therefore, the cylindrical vortex generators 4 on the blades of the vertical axis wind turbine do not extend, and the end faces of the cylindrical vortex generators 4 and the surfaces of the blades form a smooth curved surface.

[0048] When there is wind, the vertical axis wind turbine can rotate the wind turbine blades due to the special geometric shape of the blades. As Figure 9 shown, when the oncoming flow comes from one direction, the entire wind turbine is divided into an upwind area and a downwind area. The side closer to the oncoming flow direction is the upwind area, and the other side is the downwind area.

[0049] Generally, a wind turbine has multiple blades. Here, Figure 9 one of the blades is used as an illustrative object. When the wind turbine is at 0°, the angle of attack of the blade is 0° at this time, so there is no airflow separation. Therefore, the cylindrical vortex generators 4 in both cylindrical vortex generator assemblies in the blade do not extend. As the blade gradually rotates, the angle of attack also gradually increases, and the airflow force on the blade also increases. As Figure 9 shown, in order to suppress airflow separation, the cylindrical vortex generators on the side closer to the inside of the entire vertical axis wind turbine gradually extend. In order to reduce resistance, the corresponding outer cylindrical vortex generators 4 remain stationary, and the outer cylindrical vortex generators 4 and the blade surface form a smooth curved surface.

[0050] As Figure 9 shown, it is to express the variation law of the telescopic amount of the cylindrical vortex generator 4 with the azimuth angle. Assuming one-sided oncoming flow, when a single blade rotates, as the angle of attack gradually increases, the cylindrical vortex generator 4 extends longer. In Figure 9 , the blade rotates from 0°. At this time, the angle of attack is 0 and the vortex generator does not extend. When the blade rotates to Figure 9 90° in, it is the maximum angle of attack. At this time, the length of the extended vortex generator is the longest. Continuing to rotate, the angle of attack gradually decreases until the vortex generator gradually descends to Figure 9 the 180° position in. The inner vortex generator at the 180° position and the blade surface form a smooth curved surface. Continuing to rotate at 180°, at this time the blade faces away from the oncoming flow, so the cylindrical vortex generators 4 on the side closer to the outside of the entire vertical axis wind turbine gradually extend as Figure 9 shown. In order to reduce resistance, the corresponding inner cylindrical vortex generators 4 remain stationary. The larger the angle of attack, the longer the cylindrical vortex generator 4 extends. When the blade rotates to Figure 9 the 270° position in, it is the maximum angle of attack. At this time, the length of the extended cylindrical vortex generator 4 is the longest. Continuing to rotate, the angle of attack gradually decreases, so the cylindrical vortex generator 4 gradually descends until Figure 9At the 360° (0°) position, the cylindrical vortex generator 4 outside the 360° (0°) position descends to form a smooth curved surface with the blade surface. The above is the telescopic process of the cylindrical vortex generator 4 when a blade of the vertical axis wind turbine rotates one week.

[0051] A large vertical axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator in this embodiment can adjust the extended length of the cylindrical vortex generator according to the magnitude of the angle of attack, thereby generating corresponding vortices, optimizing the aerodynamic performance of the blade at different angles of attack, and thus improving the comprehensive performance of the blade during the entire operation process. For example, in an actual wind power generation environment, gusts are a common phenomenon. Gusts will cause sudden changes in wind speed and direction, having a great impact on the aerodynamic performance of the wind turbine blades. The bidirectional automatic telescopic cylindrical vortex generator can quickly respond to this change. When a gust comes, it can timely adjust the extended length, change the vortex structure on the blade surface, and reduce the adverse effects of gusts on the blade, such as reducing blade vibration and sudden changes in aerodynamic loads caused by gusts, and improving the stability and reliability of the wind turbine.

[0052] It is worth noting that flow separation refers to the phenomenon that the airflow near the surface of the wind turbine blade no longer adheres to the blade surface but detaches from the blade surface. Under normal circumstances, when the airflow flows through the blade, due to the effect of viscosity, a boundary layer will be formed on the blade surface. The airflow velocity in the boundary layer gradually changes from zero at the blade surface to the same as the external mainstream velocity.

[0053] Dynamic stall refers to the phenomenon that under unsteady flow conditions, the aerodynamic characteristics of an airfoil (for structures such as wind turbine blades) or wing change drastically, the lift coefficient drops sharply, and the drag coefficient increases sharply, resulting in the occurrence of stall. Different from traditional static stall, dynamic stall is mainly caused by dynamic characteristics of the flow, such as rapid pitching motion, rotational motion of the airfoil, or rapid changes in the oncoming flow velocity and other factors.

[0054] The stall angle of attack refers to a critical angle reached by an airfoil blade in the airflow. When the angle of attack increases to the stall angle of attack, the airflow on the upper surface of the wing will undergo severe separation, resulting in a sharp drop in the lift coefficient generated by the wing and a sharp increase in the drag coefficient.

[0055] The above discloses only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A large vertical axis wind turbine with a bidirectional automatic telescopic cylindrical vortex generator, characterized in that: A row of holes (1) are provided on both the upper and lower surfaces of a blade of a vertical wind turbine, a bearing plate (2) is provided inside the blade, two ends of the bearing plate (2) are respectively connected to two parallel side surfaces of the blade, and cylindrical vortex generator assemblies are provided on both plate surfaces of the bearing plate (2), the two cylindrical vortex generator assemblies are symmetrically arranged, one of the cylindrical vortex generator assemblies is close to the upper surface of the blade, and the other cylindrical vortex generator assembly is close to the lower surface of the blade, and each cylindrical vortex generator assembly comprises: A cylindrical vortex generator mounting plate (3) parallel to the bearing plate (2); A plurality of cylindrical vortex generators (4) are arranged on a surface of the cylindrical vortex generator mounting plate (3) away from the bearing plate (2), and the plurality of cylindrical vortex generators (4) are arranged at even intervals, and the plurality of cylindrical vortex generators (4) correspond one-to-one to the plurality of holes (1); a driving mechanism (5) connected between the cylindrical vortex generator mounting plate (3) and the bearing plate (2), and used for driving the cylindrical vortex generator mounting plate (3) to move so that the cylindrical vortex generator (4) moves in the hole (1) at a corresponding position; A guide mechanism (6) is arranged on the bearing plate (2), and the cylindrical vortex generator mounting plate (3) is slidably fitted on the guide mechanism (6) to limit the sliding direction of the cylindrical vortex generator mounting plate (3); The guiding mechanism (6) comprises: Two guide rods (61), each guide rod (61) is vertically arranged on the bearing plate (2), and grooves are provided on opposite sides of the two guide rods (61), and the grooves are provided along the length direction of the guide rods (61); Two roller assemblies (62) are respectively arranged at two ends of the cylindrical vortex generator mounting plate (3), each roller assembly (62) comprises a bracket and a roller arranged on the bracket, the bracket is connected to the cylindrical vortex generator mounting plate (3), the roller cooperates with the groove, and the roller moves linearly in the groove through the movement of the cylindrical vortex generator mounting plate (3).

2. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 1, characterized in that: The driving mechanism (5) is a hydraulic driving system, wherein a hydraulic cylinder base of the hydraulic driving system is connected to the bearing plate (2), and a hydraulic rod of the hydraulic cylinder is connected to the cylindrical vortex generator mounting plate (3).

3. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 2, characterized in that: The maximum stroke of the hydraulic rod in the hydraulic cylinder is the maximum height of the cylindrical vortex generator (4) extending out of the airfoil surface.

4. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 1, characterized in that: Also includes: A control system and a wind direction sensor, wherein the wind direction sensor is installed at the top of the tower and is used to collect the direction of the incoming flow and transmit the wind direction signal to the control system. The control system is connected to the drive mechanism (5) and is used to control the movement of the drive mechanism (5) when the wind turbine airfoil is at different angles of attack.

5. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 1, characterized in that: The cylindrical vortex generator mounting plate (3) and the cylindrical vortex generator (4) are made of aluminum alloy material, and the cylindrical vortex generator (4) is a hollow cylinder.

6. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 1, characterized in that: When the cylindrical vortex generator (4) is in a state of not protruding from the hole, the end surface of the cylindrical vortex generator (4) and the airfoil surface form a smooth curve.

7. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 1, characterized in that: The width of the cylindrical vortex generator mounting plate (3) is greater than the diameter of the cylindrical vortex generator (4); the interval between two adjacent cylindrical vortex generators (4) is 2%-3% of the chord length, and the length of the cylindrical vortex generator (4) is such that when it is not in operation, the end surface of the cylindrical vortex generator just forms a smooth curved surface with the airfoil surface.

8. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 7, characterized in that: The plurality of holes (1) form a straight line along the Y-axis direction, and the axes of the holes (1) on the upper surface of the blade and the holes (1) on the lower surface of the blade are coaxial.

9. A large vertical axis wind turbine with bidirectional automatic telescopic cylindrical vortex generator according to claim 7, characterized in that: The width and height of the bearing plate (2) and the cylindrical vortex generator mounting plate (3) are the same, the length of the bearing plate (2) is the vertical distance b between two parallel sides of the blade, and the height position of the bearing plate (2) inside the blade is the midpoint of a line connecting the centers of the upper and lower holes of the airfoil.

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