A wind turbine blade power-increasing, resistance-reducing and noise-reducing device

Abstract

The application provides a wind turbine power increasing, drag reducing and noise reducing device. The front edge part of the main airfoil of the wind turbine is slotted, and the slot shape is the pressure surface of the airfoil. The front edge part of the main airfoil of the wind turbine is reshaped, and the shape is the suction surface of the airfoil. The main airfoil of the wind turbine is divided into two parts after the slotting. The front edge part is the front edge airfoil. The end of the slot of the front edge airfoil, i.e. the suction surface of the main airfoil of the wind turbine, is provided with a rotatable strip-shaped plate. The whole of the two airfoils meets the requirements of aerodynamic structure. The rear edge part is additionally provided with a rear edge power increasing and noise reducing device, which can rotate around the rear edge of the suction surface of the main airfoil. When the speed is low and the attack angle is large, the strip-shaped plate is bounced by the airflow, the channel in the middle of the two airfoils is opened, and the purpose of increasing the lift and delaying the separation is achieved. The power increasing plate of the rear edge part is retracted when the attack angle is large. The protruding part is a noise reducing plate, which is serrated or brush-shaped, so as to absorb the aerodynamic noise.

Description

TECHNICAL FIELD

[0001] The present application relates to a blade power-increasing, drag-reducing and noise-reducing device of a wind turbine in new energy, and belongs to the field of application of wind turbines. BACKGROUND

[0002] The state made a commitment to "carbon peak" and "carbon neutrality" in 2020. This goal is a great challenge to the energy field, and wind energy technology is one of the key technologies in this field. As the main device for converting wind energy, the blade is the key component of the wind turbine for capturing wind energy, and the aerodynamic performance of the blade determines the power generation performance of the entire wind turbine. At present, the blade is developing towards large-scale, and various studies have been conducted on the power-increasing and drag-reducing of the blade.

[0003] At present, the main power-increasing and drag-reducing devices of the wind turbine blade include vortex generators, slotted airfoils, aerodynamic flaps, Gurney flaps, setting grooves, changing roughness, etc. These devices have simple structures and are easy to install. However, these devices can only increase power in specific conditions, and their application in some working conditions may have adverse effects, such as the Gurney flap can significantly increase the lift of the wind turbine and increase the output power of the blade at low speed, but as the tip speed ratio increases, the Gurney flap will increase the loss of the wind turbine, resulting in a decrease in the performance of the wind turbine.

[0004] The problem of aerodynamic noise of the wind turbine is becoming increasingly prominent with the increase in the size of the wind turbine. Aerodynamic noise mainly includes trailing edge noise, blunt trailing edge noise, tip noise, separation noise, etc. The existing noise reduction technology mainly changes the material or shape of the airfoil surface, such as laying porous materials on the airfoil surface. Although it can effectively reduce noise, these noise reduction technologies more or less sacrifice the performance of the wind turbine, and are not flexible enough for noise reduction in different working conditions of the wind turbine.

[0005] Therefore, it is necessary to study a device that can increase power, reduce drag and reduce noise for the wind turbine blade in high wind speed or low wind speed conditions. SUMMARY

[0006] The present application is directed to the technical problems of the limited working conditions of the power-increasing and drag-reducing of the current wind turbine blade and the aerodynamic noise of the wind turbine, and proposes a wind turbine power-increasing, drag-reducing and noise-reducing device. The principle of the present application is clear, and it can achieve power-increasing, drag-reducing and noise-reducing in most working conditions, and has the advantages of simple structure, easy installation, etc.

[0007] A wind turbine blade power-increasing, drag-reducing and noise-reducing device, comprising a leading edge power-increasing and drag-reducing device and a trailing edge power-increasing and noise-reducing device,

[0008] The front edge power-increasing and drag-reducing device is located at the front edge of the main airfoil, a slotted channel is arranged at the front edge of the main airfoil, the slotted channel separates the front edge of the main airfoil into a front edge airfoil, the trailing edge of the front edge airfoil is connected with a rotatable strip-shaped plate, the strip-shaped plate is in contact with the suction surface of the main airfoil when the slotted channel is in a closed state, air flows into the slotted channel when the wind turbine is running at a low speed, the strip-shaped plate is separated from the suction surface of the main airfoil at an adaptive angle θ1, the strip-shaped plate is unfolded to increase the chord length of the front edge airfoil, the strip-shaped plate is pressed against the suction surface of the main airfoil at a high speed when air flows along the suction surface of the main airfoil at a high speed, and air cannot flow into the slotted channel.

[0009] The trailing edge power-increasing and noise-reducing device is located at the trailing edge of the main airfoil, the trailing edge of the main airfoil is connected with a rotatable power-increasing plate, the power-increasing plate can be in contact with or separated from the suction surface of the trailing edge of the main airfoil at a certain angle, the other end of the power-increasing plate is fixedly connected with a noise-reducing plate at a fixed angle θ3, the noise-reducing plate stands on the suction surface of the trailing edge of the main airfoil when the power-increasing plate is in contact with the suction surface of the trailing edge of the main airfoil, the power-increasing plate is unfolded to increase the chord length and camber of the main airfoil, and the noise-reducing plate reduces the noise of the trailing flow when the wind turbine is running at a high speed, the power-increasing plate is in contact with the suction surface of the trailing edge of the main airfoil when the wind turbine is running at a low speed, the noise-reducing plate reduces the noise of the separated vortex flow, and the power-increasing plate generates turbulence.

[0010] Further, the front edge power-increasing and drag-reducing device is installed in the length range of 5% to 40% of the distance from the blade tip of the wind turbine.

[0011] Further, the chord length of the main airfoil is a, the chord length b of the front edge airfoil is 0.1a to 0.3a, the thickness of the front edge airfoil is 10% to 30%, the camber is 5% to 10%, and the front edge airfoil is in a negative angle of attack state when the incoming airflow is at 0 degree angle of attack with the main airfoil.

[0012] Further, the strip-shaped plate is connected with the trailing edge of the front edge airfoil through a hinge, θ1 is in the range of 10° to 30°, and the length c of the strip-shaped plate is 0.1b to 0.3b.

[0013] Further, when the strip-shaped plate is connected with the trailing edge of the front edge airfoil through a hinge, a spring is additionally arranged on the pressure surface of the strip-shaped plate and the trailing edge of the front edge airfoil, so that the strip-shaped plate has resilience towards the suction surface of the main airfoil.

[0014] Further, the shape of the slotted channel is the same as that of the pressure surface of the front edge airfoil, and the width of the slotted channel is 10mm to 60mm.

[0015] Further, the power-increasing plate is installed in the range of 0m to 0.3m from the trailing edge of the main airfoil, the power-increasing plate is connected with the trailing edge of the main airfoil through a spring hinge, the power-increasing plate has resilience towards the suction surface of the trailing edge of the main airfoil, θ2 is in the range of 100° to 180°, and the length C1 of the power-increasing plate is 0.1m to 0.3m.

[0016] Further, the length C2 of the noise reduction plate is 0.05m-0.15m, and θ3 is 60°-150°.

[0017] Further, the noise reduction plate is made of a composite flexible material, and has flexibility and corrosion resistance.

[0018] Further, the tail end of the noise reduction plate is sawtooth or brush-shaped.

[0019] Beneficial effects

[0020] The power-increasing, drag-reducing and noise-reducing device of the application can achieve the purposes of power-increasing, drag-reducing and noise-reducing under most working conditions of the wind turbine, such as low speed and high speed, and has the following advantages:

[0021] The device covers the power-increasing and noise-reducing under most working conditions of the wind turbine by installing the combined structure on the leading and trailing edges of the main airfoil. The structure of the leading edge is mainly used for power-increasing, drag-reducing and noise-reducing when the wind turbine is at low speed, and ensures that the performance of the wind turbine is not affected at high speed. The structure of the trailing edge is mainly used for power-increasing when the wind turbine is at high speed, and for noise-reducing under all working conditions of high and low speed.

[0022] When the wind turbine is at low speed and large attack angle, the leading edge airfoil is at a small attack angle, and can provide part of the lift. The strip-shaped plate is in an open state, so that the airflow in the slotted channel flows into the boundary layer and fills the trailing edge extension plate of the leading edge airfoil, achieving the effect of power-increasing and drag-reducing. At the same time, the power-increasing plate of the trailing edge of the main airfoil is attached to the surface of the main airfoil, the noise reduction plate reduces vortex noise, and can act as a spoiler to further increase power.

[0023] When the wind turbine is at high speed and large attack angle, the strip-shaped plate is in a closed state due to the high flow of the gas on the upper surface of the main airfoil, the leading edge airfoil reworks as the leading edge part of the main airfoil and works normally, the slotted channel cannot flow air, and will not affect the original performance of the wind turbine. At the same time, the power-increasing plate of the trailing edge of the main airfoil is opened, which lengthens the chord length and camber of the main airfoil, and increases the lift and reduces the drag while reducing the noise of the wake. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The device structure diagram of the application;

[0025] Figure 2 The A-A sectional view of the application at low speed;

[0026] Figure 3 The A-A sectional view of the application at high speed;

[0027] Figure 4 The schematic diagram of the sawtooth-shaped noise reduction plate;

[0028] Figure 5Schematic diagram of the brush-shaped noise reduction plate;

[0029] Wherein, the reference signs are: main airfoil-1, slotted passage-2, leading edge airfoil-3, strip plate-4, power augmentation plate-5, noise reduction plate-6. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the structure of the present application is specifically described below in combination with examples and drawings.

[0031] The present application is installed in the front section of the wind turbine blade, and the structure of the present application is divided into a leading edge power augmentation and drag reduction device and a trailing edge power augmentation and noise reduction device: the combination structure of the strip plate 4 and the slotted passage 2 is used in the leading edge of the main airfoil 1, and the slotted passage 2 divides the leading edge part of the main airfoil 1 into another airfoil, which is set as the leading edge airfoil 3; the trailing edge power augmentation and noise reduction device includes the combination structure of the power augmentation plate 5 and the noise reduction plate 6.

[0032] 1) The leading edge airfoil 3 and the strip plate 4 and the slotted passage 2 structure of the leading edge part of the main airfoil 1 are mainly used for power augmentation and drag reduction when the wind turbine is at low speed, and at the same time, the performance of the wind turbine blade at high speed is ensured not to be affected.

[0033] The leading edge airfoil 3 is another airfoil structure reshaped from the leading edge of the main airfoil 1, and the main airfoil 1 and the leading edge airfoil 2 both meet the requirements of aerodynamic structure, the chord length of the main airfoil 1 is a, the leading edge airfoil 3 is a sharp trailing edge, and the chord length b of the leading edge airfoil 3 ranges from 0.1a to 0.3a. The thickness of the leading edge airfoil 3 is 10%-30%, and the camber is 5%-10%. When the incoming flow is at 0 degree angle of attack with the main airfoil 1, the leading edge airfoil 3 is in a negative angle of attack and low head state.

[0034] The working principle is that when the wind turbine is at low speed, the front section of the wind turbine blade is in a large angle of attack separation state, and the leading edge airfoil 3 is in a small angle of attack state, which is a linear segment part of the lift of the main airfoil 1, and can provide part of the lift.

[0035] The length c of the strip plate 4 ranges from 0.1b to 0.4b, and the trailing edge of the leading edge airfoil 3 is connected with a hinge, and the maximum activity angle is θ1, which ranges from 10° to 30°. The shape of the strip plate 4 is attached to the surface of the main airfoil 1, and the strip plate 4 is a lengthening plate of the trailing edge of the leading edge airfoil 3 in structure, and also a baffle plate of the slotted passage 2. In some special working conditions, the strip plate 4 and the trailing edge of the leading edge airfoil 3 can also be connected with a spring hinge, so that the strip plate 4 has a rebounding force tending to the suction surface of the main airfoil 1.

[0036] The strip plate 4 is a lengthened plate of the trailing edge of the leading edge airfoil 3. Its working principle is that the strip plate 4 opens an adaptive angle θ1 due to the airflow pushing of the slotted channel 2 at a low rotating speed, so as to increase the chord length of the leading edge airfoil 3 and guide the trailing flow of the leading edge airfoil 3, thereby further improving the lift of the leading edge airfoil 3 part.

[0037] The strip plate 4 is a baffle of the slotted channel 2. Its working principle is that, when the wind turbine is normally working, the front section of the blade is in a high wind speed and small attack angle state, and the strip plate 4 is closed due to the strong airflow of the suction surface of the main airfoil 1. At this time, the structure of the leading edge airfoil 3 is an integral part of the main airfoil 1, so as to ensure that the leading edge power increasing and drag reducing device does not affect the overall aerodynamic performance of the main airfoil 1 in this working condition.

[0038] The shape of the slotted channel 2 is the same as that of the pressure surface of the leading edge airfoil 3, and the channel width ranges from 10mm to 60mm, so as to ensure the high-speed flow of the airflow in the slotted channel 2.

[0039] Its working principle is that, when the strip plate 4 opens at a low speed, the airflow flows through the suction surface of the main airfoil 1 at a high speed, and injects energy into the boundary layer, so as to achieve the purpose of inhibiting the flow separation of the suction surface and increasing the lift and reducing the drag. When the strip plate 4 is closed, the airflow in the slotted channel 2 cannot flow to the suction surface of the main airfoil 1, and the leading edge airfoil 3 will be reconnected as a part of the main airfoil 1, so as to ensure that the performance of the wind turbine will not be affected at a high rotating speed.

[0040] 2) The trailing edge power increasing and noise reducing device of the trailing edge of the main airfoil 1 is mainly used for power increasing and drag reducing at a high rotating speed of the wind turbine, and noise reducing at most working conditions of high and low rotating speeds.

[0041] The trailing edge power increasing and noise reducing device has two parts, one is a power increasing plate 5, and the other is a noise reducing plate 6.

[0042] The power increasing plate 5 is connected with the trailing edge of the main airfoil 1 by a spring hinge device, and has a rebound force tending to the suction surface of the trailing edge of the main airfoil 1. The length C1 of the power increasing plate 5 ranges from 0.1m to 0.3m, and the maximum activity angle θ2 ranges from 100° to 180°, which has a small rebound elasticity. In the windless state, the power increasing plate 5 is attached to the trailing edge of the suction surface of the main airfoil 1.

[0043] The working principle of the power increasing plate 5 is that, at a high rotating speed of the wind turbine, the airflow at the trailing edge of the main airfoil 1 is fast and smooth, the airflow pushes the trailing edge power increasing and noise reducing device, and the power increasing plate 5 rotates outward by an adaptive angle, so as to increase the chord length and camber of the main airfoil 1, thereby achieving the effect of increasing the lift and power. At a low rotating speed of the wind turbine, the airflow energy of the trailing surface of the main airfoil 1 is low, and the power increasing plate 5 continues to attach to the trailing edge of the main airfoil 1.

[0044] The noise reduction plate 6 is fixedly connected with the power increasing plate 5 at a fixed angle θ3, θ3 ranges from 60° to 150°, the length C2 of the noise reduction plate 6 ranges from 0.05m to 0.15m, and the noise reduction plate 6 is erected on the surface of the main airfoil 1 when the power increasing plate 5 is attached to the trailing edge of the main airfoil 1. The noise reduction plate 6 is mainly made of composite flexible material and has certain flexibility and corrosion resistance. The rear end of the noise reduction plate 6 is sawtooth-shaped or brush-shaped.

[0045] The working principle of the noise reduction plate 6 is that the sawtooth-shaped and brush-shaped shape has the effect of absorbing and buffering noise. When the wind turbine rotates at high speed, the power increasing plate 5 is unfolded, and the noise reduction plate 6 is located at the trailing edge to reduce the noise of the wake. When the wind turbine rotates at low speed, the noise reduction plate 6 can also act as a spoiler while reducing noise at the vortex.

[0046] The application will be described in detail below with reference to the accompanying drawings.

[0047] As shown in Figure 1 , the main drawing is the main body of the wind turbine blade, and the power increasing, drag reducing and noise reducing device of the application is installed in the front section of the wind turbine blade and is installed within the length range of 5%-40% of the blade tip.

[0048] As shown in Figure 2 and Figure 3 , the pressure surface of the leading edge airfoil 3 is reshaped from the leading edge part of the main airfoil 1, and the suction surface of the leading edge airfoil 3 is consistent with the shape of the slotted channel 2. The chord length b of the leading edge airfoil 3 ranges from 0.1a to 0.3a. The thickness of the leading edge airfoil 3 is 10%-30%, and the camber is 5%-10%.

[0049] The length of the strip-shaped plate 4 is c, and the trailing edge of the leading edge airfoil 3 is connected with a hinge, and the maximum activity angle is θ1;

[0050] The width of the slotted channel 2 is d, and the airflow of the pressure surface of the main airfoil 1 can be injected into the boundary layer of the suction surface.

[0051] The power increasing plate 5 is hingedly connected with the main airfoil 1 through a spring device and has certain resilience, and the maximum activity angle is θ2.

[0052] As shown in Figure 4 and Figure 5 , the trailing edge power increasing and noise reducing device is composed of two parts, one is the power increasing plate 5 with a length of C1 and the other is the noise reduction plate 6 with a length of C2, the included angle between the two structures is θ3, the noise reduction plate 6 is mainly sawtooth-shaped and brush-shaped and is made of composite flexible material and has certain flexibility and corrosion resistance and has the effect of absorbing noise.

[0053] As shown in Figure 2The working state of the invention at low speed of the blade is shown. The front section of the wind turbine blade is in a large angle of attack separation state, and the leading edge airfoil 3 is in a small angle of attack state, which is a linear section of the lift of the main airfoil 1, and can provide part of the lift. The strip plate 4 will open an angle due to the airflow pushing of the slotted channel 2 at low speed, for increasing the chord length of the leading edge airfoil 3, and guiding the wake of the leading edge airfoil 3, thereby further improving the lift of the leading edge airfoil 3. The power increasing plate 5 at the trailing edge of the blade is in a retracted state, and the noise reduction plate 6 can reduce noise at the vortex and also act as a spoiler.

[0054] As Figure 3 The working state of the invention at low speed of the blade is shown. The front section of the wind turbine blade is in a large angle of attack separation state, and the leading edge airfoil 3 is in a small angle of attack state, which is a linear section of the lift of the main airfoil 1, and can provide part of the lift. The strip plate 4 will open an angle due to the airflow pushing of the slotted channel 2 at low speed, for increasing the chord length of the leading edge airfoil 3, and guiding the wake of the leading edge airfoil 3, thereby further improving the lift of the leading edge airfoil 3. The power increasing plate 5 at the trailing edge of the blade is in a retracted state, and the noise reduction plate 6 can reduce noise at the vortex and also act as a spoiler.

[0055] The above is only the preferred embodiment of the invention, and the protection scope of the invention is not limited to the above-mentioned embodiments. Any technical solution falling within the concept of the invention shall fall within the protection scope of the invention. It should be noted that for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the invention shall be considered as the protection scope of the invention.

Claims

1. A wind turbine blade power augmentation, drag reduction and noise reduction device, characterized in that, The device comprises a front edge power-increasing and drag-reducing device and a tail edge power-increasing and noise-reducing device. The front edge power increasing and drag reducing device is located at the front edge of the main airfoil (1), a slotted passage (2) is arranged at the front edge of the main airfoil (1), the slotted passage (2) separates the front edge of the main airfoil (1) into a front edge airfoil (3), the trailing edge of the front edge airfoil (3) is connected with a rotatable strip plate (4), when the strip plate (4) is attached to the suction surface of the main airfoil (1), the slotted passage (2) is in a closed state, when the wind turbine is running at a low speed, air flow enters the slotted passage (2), the strip plate (4) is at a self-adapting angle with the suction surface of the main airfoil (1) When the wind turbine is running at a high speed, air flow flows at a high speed along the suction surface of the main airfoil (1) and cannot enter the slotted passage (2), the strip plate (4) is attached to the pressure surface of the main airfoil (1), the strip plate (4) is separated from the suction surface of the main airfoil (1), the strip plate (4) is unfolded to increase the chord length of the front edge airfoil (3). The tail edge power increasing and noise reducing device is located at the tail edge of the main airfoil (1), the tail edge of the main airfoil (1) is connected with a rotatable power increasing plate (5), the power increasing plate (5) is adherable to or is separated at a certain angle from the suction surface of the tail edge of the main airfoil (1), the other end of the power increasing plate (5) is connected with a noise reducing plate (6) at a fixed angle When the power increasing plate (5) is adhered to the suction surface of the tail edge of the main airfoil (1), the noise reducing plate (6) is erected on the suction surface of the tail edge of the main airfoil (1), when the wind turbine rotates at high speed, the noise reducing plate (6) drives the power increasing plate (5) to expand, the power increasing plate (5) is at a self-adaptive angle with the suction surface of the tail edge of the main airfoil (1) The power increasing plate (5) increases the chord length and the camber of the main airfoil (1), the noise reducing plate (6) reduces the noise of the wake flow, when the wind turbine rotates at low speed, the power increasing plate (5) is adhered to the suction surface of the tail edge of the main airfoil (1), the noise reducing plate (6) reduces the noise of the separated vortex flow and performs turbulence.

2. A wind turbine blade power augmentation, drag reduction and noise reduction device according to claim 1, characterised in that, The front edge power-increasing and drag-reducing device is installed on the wind turbine blade at a distance of 5%-40% of the length of the blade tip.

3. A wind turbine blade power augmentation, drag reduction and noise reduction device according to claim 2, characterised in that, The chord length of the main airfoil (1) is a, the chord length of the front edge airfoil (3) is b, and b is 0.1a-0.3a; the thickness of the front edge airfoil (3) is 10%-30%, and the camber is 5%-10%; when the coming airflow is at 0 degree angle of attack with the main airfoil (1), the front edge airfoil (3) is in a negative angle of attack state.

4. A windmill blade power increasing, resistance reducing and noise reducing device according to claim 3, characterized in that, The strip plate (4) is connected with the trailing edge of the leading edge airfoil (3) through a hinge, The range is 10°-30°, and the length c of the strip plate (4) is 0.1b-0.3b.

5. A windmill blade power increasing, resistance reducing and noise reducing device according to claim 4, characterized in that, When the strip-shaped plate (4) is hingedly connected to the tail edge of the front edge airfoil (3), a spring is additionally installed on the pressure surface of the strip-shaped plate (4) and the tail edge of the front edge airfoil (3), so that the strip-shaped plate (4) has resilience towards the suction surface of the main airfoil (1).

6. A windmill blade power increasing, resistance reducing and noise reducing device according to claim 4, characterized in that, The shape of the slotted channel (2) is the same as that of the pressure surface of the front edge airfoil (3), and the width of the slotted channel (2) is 10mm-60mm.

7. A windmill blade power increasing, resistance reducing and noise reducing device according to claim 6, characterized in that, The power increasing plate (5) is installed at a distance of 0m~0.3m from the trailing edge of the main airfoil (1), the power increasing plate (5) is connected with the trailing edge of the main airfoil (1) through a spring hinge, the power increasing plate (5) has resilience towards the suction surface of the trailing edge of the main airfoil (1), The range is 100°~180°, and the length C1 of the power increasing plate (5) is 0.1m~0.3m.

8. A windmill blade power increasing, resistance reducing and noise reducing device according to claim 7, characterized in that, The length C2 of the noise reduction plate (6) is 0.05m~0.15m, is 60°~150°.

9. A windmill blade power increasing, resistance reducing and noise reducing device according to claim 8, characterized in that, The noise-reducing plate (6) is made of a composite flexible material and has flexibility and corrosion resistance.

10. A windmill blade power increasing, resistance reducing and noise reducing device according to claim 9, characterized in that, The tail end of the noise-reducing plate (6) is in the shape of a sawtooth or a brush.

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