Blade for a wind turbine and wind turbine

Abstract

The wind turbine blade and the wind turbine are provided by the present disclosure. The wind turbine blade comprises a blade body and an airflow channel. The blade body comprises a first surface and a second surface oppositely arranged along a first direction. The first surface and the second surface can be alternately switched to a windward state. The airflow channel is arranged in the blade body. The airflow channel comprises an air inlet and an air outlet. The air inlet is arranged on the first surface, and the air outlet is arranged on the second surface. The airflow channel is used to guide airflow to adhere to the second surface when the first surface is in the windward state.

Description

Technical Field

[0001] This disclosure relates to the field of wind power generation technology, and in particular to a wind turbine blade and a wind turbine generator. Background Technology

[0002] A wind turbine is a device that converts wind energy into electrical energy. It captures wind energy through blades and drives a generator to produce electricity. Vertical axis wind turbines have blades whose rotation axis is perpendicular to the ground, and have advantages such as good wind direction adaptability, compact structure, and low noise.

[0003] In related technologies, vertical axis wind turbines adopt NACA or DU airfoil designs, which result in significant airflow separation at high angles of attack, affecting the efficiency of the wind turbine. They also have poor performance at low wind speeds and are relatively heavy. Utility Model Content

[0004] The wind turbine blades and wind turbine provided in this disclosure can suppress or delay airflow separation and improve blade performance.

[0005] The technical solution of this disclosure embodiment is implemented as follows:

[0006] In a first aspect, embodiments of this disclosure provide a blade for a wind turbine, including a blade body and an airflow channel. The blade body includes a first surface and a second surface disposed opposite to each other along a first direction, and the first surface and the second surface can be alternately switched to a windward state. The airflow channel is opened in the blade body and includes an air inlet and an air outlet. The air inlet is disposed on the first surface and the air outlet is disposed on the second surface. The airflow channel is used to guide airflow to conform to the second surface when the first surface is in a windward state.

[0007] The technical solution of this embodiment includes a blade body comprising a first surface and a second surface disposed opposite to each other. During blade rotation, the first and second surfaces alternately switch to an upwind state, generating thrust through the pressure difference between the airflow on the first and second surfaces, thereby driving the blade to rotate. Furthermore, the blade body has an airflow channel. The air inlet of the airflow channel is located on the first surface, and the air outlet is located on the second surface. Airflow can enter the airflow channel through the inlet and exit through the outlet. By configuring the airflow channel, the airflow direction and velocity on the first and second surfaces can be altered, thereby suppressing or delaying the separation of airflow relative to the second surface. On one hand, suppressing airflow separation can improve the utilization rate of airflow, thus increasing the power coefficient of the wind turbine. On the other hand, the local acceleration of airflow through the airflow channel can delay airflow separation, allowing the blade to maintain good performance even at low wind speeds. Additionally, the airflow channel can improve the gravity distribution of the blade body, reducing weight and optimizing the structural stability of the blade under high wind speed conditions.

[0008] In some embodiments of this disclosure, the second surface includes an airflow separation position, and the air outlet is located within a preset range of the airflow separation position; wherein, the airflow separation position is the position where the airflow separates from the second surface when no airflow channel is provided.

[0009] The technical solution of this disclosure embodiment can effectively guide the airflow direction through the airflow channel by setting the air outlet within a preset range of the airflow separation position, so as to suppress the separation of airflow relative to the second surface and thus improve the performance of the blade.

[0010] In some embodiments of this disclosure, the air inlet has a first flow area, the air outlet has a second flow area, and the ratio of the second flow area to the first flow area is greater than or equal to 1 / 3 and less than or equal to 2 / 3.

[0011] In the technical solution of this embodiment, the air inlet has a large first flow area so that airflow can enter the airflow channel, and the air outlet has a small second flow area. By reducing the size of the airflow channel, the airflow is pressurized in the airflow channel, increasing the flow rate of the airflow through the air outlet, thereby delaying the separation of the airflow from the second surface.

[0012] In some embodiments of this disclosure, the airflow channel includes a first channel segment and a second channel segment. The first channel segment is provided with an air inlet, and the second channel segment is provided with an air outlet. The extension axis of the first channel segment and the extension axis of the second channel segment have an included angle.

[0013] The technical solution of this disclosure embodiment, by setting a first channel segment and a second channel segment, the extension axis of the first channel segment and the extension axis of the second channel segment, on the one hand, facilitates the adaptation of the extension axis of the first channel segment to the air inlet, which helps the airflow enter the airflow channel; on the other hand, the second channel segment can guide the airflow to change its direction so that the airflow flowing out of the air outlet can fit more closely to the second surface.

[0014] In some embodiments of this disclosure, the transition surface between the first channel segment and the second channel segment is an arc surface.

[0015] In the technical solution of this embodiment, the transition surface between the first channel segment and the second channel segment is an arc surface, which facilitates the guidance of airflow direction within the airflow channel and can reduce wind resistance and improve the utilization rate of airflow.

[0016] In some embodiments of this disclosure, the blade body includes a leading edge and a trailing edge disposed opposite to each other along a second direction; the second direction has an angle with the first direction, and the airflow channel extends from the leading edge toward the trailing edge.

[0017] In the technical solution of this embodiment, the leading edge of the blade body is used to connect to an external support shaft, and the trailing edge serves as a free end. An airflow channel extends from the leading edge towards the trailing edge to guide airflow toward the trailing edge, thereby suppressing or slowing the separation of airflow relative to the second surface. Furthermore, the inner wall surface of the airflow channel near the trailing edge has a rounded transition with the first and / or second surfaces, which helps guide airflow into and out of the airflow channel.

[0018] In some embodiments of this disclosure, the blade body is provided with multiple airflow channels, which are arranged sequentially along a second direction.

[0019] The technical solution of this disclosure embodiment sets up multiple airflow channels, which are arranged sequentially along a second direction. These multiple airflow channels can guide airflow in segments so that airflow at different positions on the blade body can be effectively utilized, thereby improving the performance of the blade.

[0020] In some embodiments of this disclosure, both the first surface and the second surface extend along a third direction, which forms an angle with the first direction, and the cross-sectional profile of the airflow channel remains consistent along the third direction.

[0021] In the technical solution of this disclosure embodiment, the cross-sectional profile of the airflow channel remains consistent in the third direction. On the one hand, this simplifies the structure and facilitates processing; on the other hand, it facilitates the uniform guidance of airflow at different positions of the blade body in the third direction, forming a stable airflow and reducing turbulence.

[0022] In some embodiments of this disclosure, the blade body includes an adjustment section and a connecting section alternately arranged along a third direction, an airflow channel is disposed in the adjustment section, and at least one end of the blade body is provided with a connecting section.

[0023] The technical solution of this disclosure embodiment uses alternating adjustment sections and connecting ends. The adjustment section is provided with an airflow channel to adjust the airflow direction, and the connecting section is used to connect the adjustment section to provide stable support for the adjustment section and maintain the structural stability of the airflow channel.

[0024] Secondly, this disclosure provides a wind turbine generator, including a base, a generator set, and blades according to this disclosure. The base is rotatably connected to a support shaft; the blades are connected to the support shaft, and there are multiple blades, which surround the central axis of the support shaft; the generator set is connected to the base and the support shaft respectively, and the generator set generates electrical energy based on the movement of the blades relative to the base.

[0025] The technical solution of this disclosure embodiment is that the blade is provided with an airflow channel, which can suppress or delay the separation of airflow relative to the second surface, improve the efficiency of the wind turbine, and specifically improve the performance of the blade at low and high wind speeds.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0028] Figure 1 This is a cross-sectional schematic diagram of a blade with a single airflow channel provided in an embodiment of this disclosure;

[0029] Figure 2 This is a cross-sectional schematic diagram of a blade with dual airflow channels provided in an embodiment of this disclosure;

[0030] Figure 3 This is a schematic diagram of the adjustment section structure of the blade with a single airflow channel provided in an embodiment of this disclosure;

[0031] Figure 4 This is a schematic diagram of the adjustment section structure of the blade with dual airflow channels provided in an embodiment of this disclosure;

[0032] Figure 5 This is an isometric structural diagram of a blade with a single airflow channel provided in an embodiment of this disclosure;

[0033] Figure 6 This is an isometric structural diagram of a blade with dual airflow channels provided in an embodiment of this disclosure;

[0034] Figure 7 This is a schematic diagram of the structure of a wind turbine provided in an embodiment of this disclosure;

[0035] Figure 8 This is a comparison chart of the tip speed ratio-Cp of various airfoils provided in the embodiments of this disclosure;

[0036] Figure 9 This is an airflow velocity distribution diagram of the blade with a tip velocity ratio λ=1.2 when no airflow channel is provided, according to an embodiment of this disclosure;

[0037] Figure 10 This is an airflow velocity distribution diagram of the blade with a tip velocity ratio λ=1.6 when no airflow channel is provided, according to an embodiment of this disclosure;

[0038] Figure 11 This is a schematic cross-sectional view of a blade with a first flow channel and a second flow channel provided in an embodiment of this disclosure;

[0039] Figure 12 This is an airflow velocity distribution diagram of the blade with a tip velocity ratio λ=1.2 when an airflow channel is provided, according to an embodiment of this disclosure;

[0040] Figure 13 This is an airflow velocity distribution diagram of a blade with a tip velocity ratio λ=1.6 provided in an embodiment of this disclosure when an airflow channel is provided;

[0041] Figure 14 This is a performance comparison diagram of the blades before and after optimization, provided in an embodiment of this disclosure.

[0042] Explanation of reference numerals in the attached figures

[0043] 100-Blade body; 110-First surface; 120-Second surface; 130-Leading edge; 140-Tail edge; 150-Adjustment section; 160-Connecting section; 200-Airflow channel; 210-Air inlet; 220-Air outlet; 230-First channel section; 240-Second channel section; 20a-First flow channel; 20b-Second flow channel; 300-Base; 400-Support shaft; 500-Generator set; X-First direction; Y-Second direction; Z-Third direction. Detailed Implementation

[0044] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses consistent with some aspects of this disclosure as detailed in the appended claims.

[0045] In the embodiments of this disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0046] In the embodiments disclosed herein, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0047] In embodiments of this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0048] In this disclosure, the terms "example" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "example" or "for example" in this disclosure should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of terms such as "example" or "for example" is intended to present the relevant concepts in a specific manner.

[0049] This disclosure provides a wind turbine, a device that converts wind energy into electrical energy. It captures wind energy through blades and drives a generator to produce electricity. Wind turbines include horizontal-axis wind turbines and vertical-axis wind turbines. Vertical-axis wind turbines have blades whose rotation axis is perpendicular to the ground, offering advantages such as good wind direction adaptability, compact structure, and low noise. Vertical-axis wind turbines have attracted much attention due to their independence from wind direction, simple structure, and stable operation, and possess broad development potential.

[0050] In some technical solutions, vertical axis wind turbines adopt airfoil designs based on the National Advisory Committee for Aeronautics (NACA) airfoil and the Delft University Airfoil (DU) airfoil. These airfoils are optimized for the aerodynamic characteristics of aircraft wings and fail to fully consider the unique operating conditions of vertical axis wind turbines, such as low speed, large angle of attack, high frequency periodic angle of attack changes, and dynamic stall. For example, the angle of attack is in the range of 20 degrees to 40 degrees and the angle of attack changes are in the range of 0.5 Hz to 5 Hz.

[0051] In actual operation, the NACA and DU series airfoils face the following key problems: First, significant airflow separation occurs at high angles of attack, leading to a sharp drop in lift coefficient and increased torque pulsation. Experimental data shows that when the angle of attack reaches 20 degrees, the lift loss of traditional airfoils exceeds 60%, and the energy loss caused by dynamic stall accounts for as much as 30% to 40%. Second, the mismatch between the airfoil surface pressure distribution and the vertical axis rotation trajectory results in aerodynamic efficiency degradation and poor low-wind-speed performance. For example, in low-speed conditions with wind speeds below 8 m / s, traditional airfoils struggle to maintain effective laminar adhesion, leading to a decrease in lift-to-drag ratio. This prevents vertical axis wind turbines from achieving the optimal tip speed ratio at low wind speeds, resulting in a significant decrease in actual operating efficiency compared to the design value. Third, existing airfoil selection is approaching the theoretical performance limit, severely restricting the improvement of the power coefficient (Cp) of vertical axis wind turbines, with Cp values ​​generally below 0.35. Fourth, the structural reliability of the blades is insufficient. Due to the characteristics of vertical axis wind turbines, during high-speed rotation, the mass is mainly concentrated at the end far from the support shaft, which generates a very large centrifugal force, posing a challenge to the strength of the blade connection structure.

[0052] Therefore, this disclosure also provides a blade for a wind turbine, referring to... Figure 1 and Figure 2 The blade includes a blade body 100 and an airflow channel 200. The blade body 100 includes a first surface 110 and a second surface 120 disposed opposite to each other along a first direction X. The first surface 110 and the second surface 120 can be alternately switched to a windward state. The airflow channel 200 is opened in the blade body 100 and includes an air inlet 210 and an air outlet 220. The air inlet 210 is disposed on the first surface 110 and the air outlet 220 is disposed on the second surface 120. The airflow channel 200 is used to guide the airflow to conform to the second surface 120 when the first surface 110 is in a windward state.

[0053] In this embodiment of the disclosure, the first direction X is the thickness direction of the blade body 100, the second direction Y is the width direction of the blade body 100, and the third direction Z is the length direction of the blade body 100. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. It should be noted that these directions are used to illustrate the structural features of this disclosure and should not be regarded as a limitation of this disclosure.

[0054] In some examples, the blade rotates 360 degrees around the axis of the support shaft 400. During the rotation of the blade from 0 degrees to 180 degrees, the first surface 110 is in the windward state and the second surface 120 is in the leeward state, that is, the first surface 110 is the pressure surface and the second surface 120 is the suction surface. During the rotation of the blade from 180 degrees to 360 degrees, the first surface 110 is in the leeward state and the second surface 120 is in the windward state, that is, the first surface 110 is the suction surface and the second surface 120 is the pressure surface.

[0055] In some embodiments, the airflow channel 200 includes a single air inlet 210 and a single air outlet 220; in other embodiments, the airflow channel 200 may include a single air inlet 210 and multiple air outlets 220; or, the airflow channel 200 may include a single air outlet 220 and multiple air inlets 210.

[0056] In this embodiment of the disclosure, the airflow channel 200 can guide the direction of airflow and change the flow state of airflow, such as changing the pressure and velocity of the airflow, thereby adjusting the distribution of airflow on the second surface 120. In some examples, the separation of airflow from the second surface refers to the separation of laminar flow in the airflow from the second surface.

[0057] In the technical solution of this embodiment, the blade body 100 includes a first surface 110 and a second surface 120 disposed opposite to each other. During the rotation of the blade, the first surface 110 and the second surface 120 alternately switch to the windward state. The pressure difference between the airflow on the first surface 110 and the second surface 120 generates thrust so that the airflow drives the blade to rotate.

[0058] Based on this, the blade body 100 is provided with an airflow channel 200. The air inlet 210 of the airflow channel 200 is located on the first surface 110, and the air outlet 220 of the airflow channel 200 is located on the second surface 120. Airflow can enter the airflow channel 200 through the air inlet 210 and exit the airflow channel 200 through the air outlet 220. By setting the airflow channel 200, the airflow direction and velocity of the first surface 110 and the second surface 120 can be changed, so as to suppress or delay the phenomenon of airflow separation relative to the second surface 120. On the one hand, by suppressing airflow separation, the utilization rate of airflow can be improved, so as to improve the power coefficient of the wind turbine. On the other hand, the local acceleration of airflow through the airflow channel 200 can delay airflow separation, so that the blade has good performance even at low wind speeds. In addition, the setting of the airflow channel 200 can also improve the gravity distribution of the blade body 100, reduce weight, and optimize the structural stability of the blade under high wind speed conditions.

[0059] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4In some embodiments of this disclosure, the second surface 120 includes an airflow separation position, and the air outlet 220 is located within a preset range of the airflow separation position; wherein, the airflow separation position is the position where the airflow separates from the second surface 120 when the airflow channel 200 is not provided.

[0060] In some examples, the location of airflow separation can be determined based on the airflow distribution of a given-sized blade without an airflow channel 200 under simulation.

[0061] In this embodiment of the disclosure, the preset range can be determined based on the blade body 100 in the second direction Y dimension (width dimension). For example, the preset range is 10% of the width dimension. For instance, if the airflow separation position is 25% of the width dimension, the center point of the air outlet 220 can be set at a position of 20% to 30% of the width dimension.

[0062] In some examples, the blade body 100 has a leading edge 130 and a trailing edge 140 at its two ends along the second direction Y, respectively. The maximum size of the trailing edge 140 along the first direction X is smaller than the maximum size of the leading edge 130 along the first direction X. The air outlet 220 is located on the side of the airflow separation position facing the trailing edge 140. Alternatively, air outlets 220 are provided on both sides of the airflow separation position facing the leading edge 130 and the trailing edge 140.

[0063] The technical solution of this disclosure embodiment can effectively guide the airflow direction through the airflow channel 200 by setting the air outlet 220 within a preset range of the airflow separation position, so as to suppress the separation of the airflow relative to the second surface 120 and thereby improve the performance of the blade.

[0064] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 In some embodiments of this disclosure, the air inlet 210 has a first flow area, the air outlet 220 has a second flow area, and the ratio of the second flow area to the first flow area is greater than or equal to 1 / 3 and less than or equal to 2 / 3.

[0065] In some examples, the air inlet 210 and the air outlet 220 are rectangular in shape, with their long sides parallel to the third direction Z. The first flow area depends on the width of the air inlet 210, and the second flow area depends on the width of the air outlet 220. It should be noted that the air inlet 210 and the air outlet 220 can also be regular or irregular shapes such as circles, ellipses, rhombuses, or hexagons.

[0066] In some examples, the ratio of the second circulation area to the first circulation area is any value between 1 / 3 and 2 / 3, such as 1 / 2; in other examples, the ratio of the second circulation area to the first circulation area is 1 / 3; and in still other examples, the ratio of the second circulation area to the first circulation area is 1 / 3.

[0067] In the technical solution of this embodiment, the air inlet 210 has a large first flow area so that airflow enters the airflow channel 200, and the air outlet 220 has a small second flow area. By reducing the size of the airflow channel 200, the airflow is pressurized in the airflow channel 200, and the flow rate of the airflow through the air outlet 220 is increased, thereby delaying the separation of the airflow from the second surface 120.

[0068] Reference Figure 1 and Figure 2 In some embodiments of this disclosure, the airflow channel 200 includes a first channel segment 230 and a second channel segment 240. The first channel segment 230 is provided with an air inlet 210, and the second channel segment 240 is provided with an air outlet 220. The extension axis of the first channel segment 230 and the extension axis of the second channel segment 240 have an included angle.

[0069] In this embodiment of the disclosure, the extension axis of the first channel segment 230 and the extension axis of the second channel segment 240 may be set at a right angle, an acute angle, or an obtuse angle. In some examples, a rounded transition is used between the extension axis of the first channel segment 230 and the extension axis of the second channel segment 240.

[0070] The technical solution of this disclosure embodiment, by setting a first channel segment 230 and a second channel segment 240, the extension axis of the first channel segment 230 and the extension axis of the second channel segment 240, on the one hand, facilitates the adaptation of the extension axis of the first channel segment 230 to the air inlet 210, which helps the airflow enter the airflow channel 200; on the other hand, the second channel segment 240 can guide the airflow to change its direction so that the airflow flowing out from the air outlet 220 can fit more closely to the second surface 120.

[0071] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 In some embodiments of this disclosure, the transition surface between the first channel segment 230 and the second channel segment 240 is an arc surface.

[0072] In some examples, the extension axes of the first channel segment 230 and the second channel segment 240 are both set along an arc, and the curvature of the first channel segment 230 is greater than the curvature of the second channel segment 240.

[0073] In the technical solution of this embodiment, the transition surface between the first channel segment 230 and the second channel segment 240 is an arc surface, which facilitates the guidance of airflow direction within the airflow channel 200, and can reduce wind resistance and improve the utilization rate of airflow.

[0074] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 In some embodiments of this disclosure, the blade body 100 includes a leading edge portion 130 and a trailing edge portion 140 disposed opposite to each other along a second direction Y; the second direction Y has an angle with the first direction X, and the airflow channel 200 extends from the leading edge portion 130 toward the trailing edge portion 140; the inner wall surface of the airflow channel 200 near the trailing edge portion 140 transitions with the first surface 110 and / or the second surface 120 at a rounded corner.

[0075] In some examples, the distance between the vertex of the leading edge 130 and the vertex of the trailing edge 140 of the blade body 100 is the chord length, and the direction from the vertex of the leading edge 130 to the vertex of the trailing edge 140 is the chord length direction.

[0076] In this embodiment of the disclosure, the angle between the second direction Y and the first direction X is an acute angle, a right angle, or an obtuse angle. For example, the angle between the extension direction of the second channel segment 240 and the chord direction is an acute angle, so that the airflow passing through the air outlet 220 is directed toward the trailing edge 140.

[0077] In the technical solution of this embodiment, the leading edge 130 of the blade body 100 is used to connect to the external support shaft 400, the trailing edge 140 is the free end, and the airflow channel 200 extends from the leading edge 130 toward the trailing edge 140 so as to guide the airflow toward the trailing edge 140, thereby suppressing or slowing down the separation of the airflow relative to the second surface 120.

[0078] It should be noted that the blade body 100 may be provided with one or more airflow channels 200. In some examples, multiple airflow channels 200 are arranged along the second direction Y; in other examples, multiple airflow channels 200 are arranged along the third direction Z; and in still other examples, some of the multiple airflow channels 200 are arranged along the second direction Y, and another part is arranged along the third direction Z.

[0079] In some examples, the cross-section of the blade body 100 is a cross-section parallel to the first direction X and the second direction Y, and the cross-section of the blade body 100 may have one or more airflow channels 200 distributed thereon.

[0080] In some examples, the number of airflow channels 200 on the cross-section is related to the pitch angle of the blade body 100. For example, the cross-section of the blade body 100 is provided with one airflow channel 200, which is suitable for the case where the pitch angle of the blade body 100 is 6 degrees; or, for another example, the cross-section of the blade body 100 is provided with two airflow channels 200, which is suitable for the case where the pitch angle of the blade body 100 is 0 degrees.

[0081] In some examples, the inner wall surface of the first channel segment 230 near the trailing edge 140 transitions to the first surface 110 with a rounded corner.

[0082] In some examples, the inner wall surface of the second channel segment 240 near the trailing edge 140 transitions to the second surface 120 with a rounded corner.

[0083] In some examples, the inner wall surface of the first channel segment 230 near the trailing edge 140 transitions to the first surface 110 with a rounded corner, and the inner wall surface of the second channel segment 240 near the trailing edge 140 transitions to the second surface 120 with a rounded corner.

[0084] In some examples, the fillet settings between the inner wall surface of the first channel segment 230 and the first surface 110 are the same as the fillet settings between the inner wall surface of the second channel segment 230 and the second surface 120; in other examples, the fillet settings between the inner wall surface of the first channel segment 230 and the first surface 110 are different from the fillet settings between the inner wall surface of the second channel segment 230 and the second surface 120.

[0085] The inner wall surface of the airflow channel 200 near the trailing edge 140 transitions to the first surface 110 and / or the second surface 120 at a rounded corner, which helps guide the airflow into or out of the airflow channel 200.

[0086] In some examples, the inner wall surface of the first channel segment 230 near the leading edge 130 transitions to the first surface 110 with a rounded corner.

[0087] In some examples, the inner wall surface of the second channel segment 240 near the leading edge 130 transitions to the second surface 120 with a rounded corner.

[0088] In some examples, the inner wall surface of the first channel segment 230 near the leading edge 130 transitions to the first surface 110 with a rounded corner, and the inner wall surface of the second channel segment 240 near the leading edge 130 transitions to the second surface 120 with a rounded corner.

[0089] Reference Figure 2 and Figure 4 In some embodiments of this disclosure, the blade body 100 is provided with a plurality of airflow channels 200, which are arranged sequentially along the second direction Y.

[0090] In some examples, the airflow channel 200 can be disposed at the leading edge 130, trailing edge 140 or middle of the blade body 100. The middle of the blade body 100 is located between the leading edge 130 and the trailing edge 140. The airflow channel 200 located at the leading edge 130 suppresses airflow separation by accelerating the airflow. The flow channel located in the middle of the blade body 100 can guide the airflow to adhere to the surface of the blade body 100. The airflow channel 200 located at the trailing edge 140 delays turbulent separation by vortex regeneration.

[0091] In some examples, by arranging multiple airflow channels 200 at positions such as the leading edge 130 and the middle of the blade body 100, the stall angle of attack of the blade under high angle of attack conditions is delayed by 5 to 8 degrees, which can significantly improve lift, so that the vertical axis wind turbine can break through the boundaries of aerodynamic performance beyond the traditional airfoil.

[0092] In some examples, multiple airflow channels 200 include a first flow channel 20a and a second flow channel 20b, with the first flow channel 20a corresponding to the leading edge 130 and the second flow channel 20b corresponding to the middle of the blade body 100.

[0093] In some examples, the distance between the apex of the leading edge 130 and the apex of the trailing edge 140 of the blade body 100 is the chord length. From the leading edge 130 toward the trailing edge 140, the first flow channel 20a can be set in the 20% to 30% chord length region, for example, the first flow channel 20a is set in the 25% chord length region; the second flow channel 20b can be set in the 35% to 45% chord length region, for example, the second flow channel 20b is set in the 40% chord length region.

[0094] The technical solution of this disclosure embodiment provides a plurality of airflow channels 200, which are arranged sequentially along the second direction Y. The plurality of airflow channels 200 can guide the airflow in segments so that the airflow at different positions of the blade body 100 can be effectively utilized, thereby improving the performance of the blade.

[0095] Reference Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments of this disclosure, the first surface 110 and the second surface 120 both extend along a third direction Z, and the third direction Z forms an angle with the first direction X. Along the third direction Z, the cross-sectional profile of the airflow channel 200 remains consistent.

[0096] In some examples, maintaining a consistent cross-sectional profile means that the position, shape, and size of the airflow channel 200 remain unchanged in different cross-sections.

[0097] For example, maintaining a consistent cross-sectional profile means that the profile projections of the same airflow channel 200 overlap at different cross-sections when projected along the third direction Z.

[0098] In the technical solution of this disclosure embodiment, the cross-sectional profile of the airflow channel 200 remains consistent along the third direction Z. On the one hand, this simplifies the structure and facilitates processing; on the other hand, it facilitates the uniform guidance of airflow at different positions of the blade body 100 along the third direction Z, forming a stable airflow and reducing turbulence.

[0099] Reference Figure 5 and Figure 6 In some embodiments of this disclosure, the blade body 100 includes an adjustment section 150 and a connecting section 160 alternately arranged along a third direction Z, the airflow channel 200 is disposed in the adjustment section 150, and at least one end of the blade body 100 is provided with the connecting section 160.

[0100] In some examples, both ends of the blade body 100 are set as connecting sections 160, and an adjustment section 150 is set between the two connecting sections 160; in other examples, the end of the blade body 100 closer to the ground is set as the connecting section 160, and the end of the blade body 100 farther from the ground is set as the adjustment section 150; in still other examples, the end of the blade body 100 closer to the ground is set as the adjustment section 150, and the end of the blade body 100 farther from the ground is set as the connecting section 160.

[0101] In some examples, the blade body 100 includes two adjustment sections 150 and three connecting sections 160, wherein two connecting sections 160 are located at both ends of the blade body 100 and another connecting section 160 is located between the two adjustment sections 150.

[0102] The technical solution of this embodiment of the disclosure alternately sets the adjustment section 150 and the connecting end. The adjustment section 150 is provided with an airflow channel 200 to adjust the airflow direction, and the connecting section 160 is used to connect the adjustment section 150 to provide stable support for the adjustment section 150 and maintain the structural stability of the airflow channel 200.

[0103] Reference Figure 7 In some embodiments of this disclosure, the wind turbine includes a base 300, a generator set 500, and blades according to the embodiments of this disclosure. The base 300 is rotatably connected to a support shaft 400. The blades are connected to the support shaft 400, and there are multiple blades that surround the central axis of the support shaft 400. The generator set 500 is connected to the base 300 and the support shaft 400 respectively, and the generator set 500 generates electrical energy based on the movement of the blades relative to the base 300.

[0104] In some examples, the wind turbine is a vertical axis wind turbine, with the central axis of the support shaft 400 perpendicular to the ground, the third direction Z corresponding to the blade perpendicular to the ground, and the first direction X and the second direction Y corresponding to the blade parallel to the ground.

[0105] In some examples, generator set 500 includes a stator and a rotor. The stator is fixedly connected to the base 300, and the rotor is fixedly connected to the support shaft 400. In the scenario, wind energy drives the blades to rotate through airflow. The blades drive the support shaft 400 to rotate, and the support shaft 400 drives the rotor to rotate relative to the stator, generating electrical energy through electromagnetic induction.

[0106] The technical solution of this disclosure embodiment is that the blade is provided with an airflow channel 200. The airflow channel 200 can suppress or delay the separation of airflow relative to the second surface 120, improve the efficiency of the wind turbine, and specifically improve the performance of the blade at low and high wind speeds.

[0107] The blades of this embodiment can be designed and obtained by the following method:

[0108] Step S1: Based on the wind conditions of the application site and the preset blade size, select a basic airfoil from the airfoil library using computational fluid dynamics numerical simulation.

[0109] For example, computational fluid dynamics numerical simulations are used to select the best-performing airfoil from the NACA series airfoils as the base airfoil. The wind energy utilization coefficient or power coefficient Cp of multiple NACA series airfoils at different tip speed ratios is shown below. Figure 8 As shown, the NACA0016 airfoil was selected as the base airfoil to balance performance at low and high speeds.

[0110] In some examples, the wind conditions of the site include one or more of the following: average wind speed, wind speed distribution, frequency of wind direction changes, and turbulence intensity. Preset blade dimensions include blade height (the dimension along the third direction Z), thickness (the dimension along the first direction X), and chord length.

[0111] Step S2: Analyze the numerical simulation flow field results and determine the location of the airflow channel 200 based on the airflow distribution and velocity under different working conditions;

[0112] For example, refer to Figure 9 and Figure 10 Find the airflow separation position between the leading edge 130 and the trailing edge 140 under the two operating conditions of optimal tip speed ratio and low operating tip speed ratio. Arrange the air outlets 220 of two airflow channels 200 at the airflow separation position along the chord length direction (such as the second direction Y). For example, the air outlets 220 of the first flow channel 20a and the second flow channel 20b. Set the air inlet 210 of the pressure surface according to the parameterization. The width of the air outlet 220 is set to 1 / 2 of the width of the air inlet 210.

[0113] Reference Figure 9 At a low tip speed ratio λ=1.2, the airflow at the leading edge 130° of the blade separates first. (Refer to...) Figure 10When λ=1.6, the airflow adhesion on the blade surface is good, and the separation point is very close to the trailing edge 140. Therefore, when setting the airflow channels 200, the outlets of the two airflow channels 200 are set in front of and / or behind these two separation points to suppress and delay airflow separation.

[0114] Reference Figure 11 , Figure 12 and Figure 13 Computational fluid dynamics simulations were performed on the improved airfoil to analyze and compare the flow field characteristics with the actual effects. It can be found that the airflow separation positions at the leading edge 130 and trailing edge 140 of the airfoil were significantly delayed.

[0115] Step S3: Based on the airfoil performance curve simulation, optimize the size of the air inlet 210 and air outlet 220 of the airflow channel 200, as well as the position of the air inlet 210 and air outlet 220, to obtain the structure of the adjustment section 150 of the blade body 100.

[0116] Reference Figure 14 To compare the performance curves of the optimized airfoil with those of the unoptimized airfoil, after optimizing the airflow channel 200, the tip speed ratio corresponding to its optimal Cp value was reduced, and the overall Cp value after optimization was higher than that before optimization.

[0117] Step S4: Replace part of the structure in the basic airfoil with the adjustment section 150, and use the remaining part as the connecting section 160.

[0118] With this configuration, a portion of the basic airfoil is replaced with a separate regulating section 150, and the airflow distribution and velocity are optimized through the airflow channel 200, while the remaining portion of the basic airfoil remains unchanged, in order to maintain the structural integrity and stability of the blade.

[0119] The technical solution of this disclosure achieves structural lightweighting while improving the aerodynamic performance of the blade airfoil through a collaborative design method of aerodynamics and structure. Firstly, regarding efficiency improvement, related technologies employing a single airfoil profile or simple leading-edge modification cannot effectively control airflow separation at high angles of attack. The blade of this disclosure features a multi-channel design, with airflow channels 200 on the suction and pressure surfaces of the blade body 100, significantly extending the airflow separation point compared to traditional airfoils, thus expanding the effective operating angle of attack range and improving the power coefficient of the wind turbine through multi-segment flow channels. Secondly, regarding low-speed performance, related technologies struggle to maintain airflow adhesion. The blade of this disclosure has airflow channels 200 in different chord length regions, increasing the local flow velocity by 15%-20%, thereby delaying the airflow separation process. Numerical simulation results show that by using the airfoil of this disclosure, the optimal tip speed ratio can be reduced by approximately 20%, allowing the wind turbine to reach its optimal tip speed ratio operating range even at low speeds, resulting in higher power generation efficiency at low wind speeds. Thirdly, regarding the reconstruction of mass distribution, related technologies use NACA or DU airfoils, resulting in an unbalanced blade weight. The airfoil disclosed in this paper constructs one, two, or multiple hollow airflow channels along the chord direction (the direction of the chord length) on the blade, which can achieve topological optimization of the material and reduce the material weight. This lightweight design strategy effectively reduces the blade surface weight while ensuring aerodynamic performance. Furthermore, the establishment of multiple hollow airflow channels 200 in the blade body 100 can improve the center of gravity distribution of the blade and enhance the structural strength of the blade at high speeds.

[0120] The above description is only a partial embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A blade for a wind turbine, characterized in that, include: The blade body includes a first surface and a second surface disposed opposite to each other along a first direction, and the first surface and the second surface can alternately switch to a windward state; An airflow channel is provided on the blade body. The airflow channel includes an air inlet and an air outlet. The air inlet is located on the first surface, and the air outlet is located on the second surface. The airflow channel is used to guide the airflow to conform to the second surface when the first surface is in the windward state.

2. The blade of the wind turbine according to claim 1, characterized in that, The second surface includes an airflow separation location, and the air outlet is located within a preset range of the airflow separation location; The airflow separation position is the position where the airflow separates from the second surface when the airflow channel is not provided.

3. The blade of the wind turbine according to claim 1, characterized in that, The air inlet has a first flow area, and the air outlet has a second flow area. The ratio of the second flow area to the first flow area is greater than or equal to 1 / 3 and less than or equal to 2 / 3.

4. The blade of the wind turbine according to any one of claims 1 to 3, characterized in that, The airflow channel includes a first channel segment and a second channel segment. The first channel segment is provided with the air inlet, and the second channel segment is provided with the air outlet. The extension axes of the first channel segment and the extension axes of the second channel segment have an angle.

5. The blade of the wind turbine according to claim 4, characterized in that, The transition surface between the first channel segment and the second channel segment is an arc surface.

6. The blade of the wind turbine according to any one of claims 1 to 3, characterized in that, The blade body includes a leading edge portion and a trailing edge portion disposed opposite to each other along a second direction; The second direction forms an angle with the first direction, and the airflow channel extends from the leading edge toward the trailing edge.

7. The blade of the wind turbine according to claim 6, characterized in that, The blade body is provided with a plurality of airflow channels, which are arranged sequentially along the second direction.

8. The blade of the wind turbine according to any one of claims 1 to 3, characterized in that, Both the first surface and the second surface extend along a third direction, and the third direction forms an angle with the first direction; Along the third direction, the cross-sectional profile of the airflow channel remains consistent.

9. The blade of the wind turbine according to claim 8, characterized in that, The blade body includes an adjustment section and a connecting section alternately arranged along the third direction, the airflow channel is disposed in the adjustment section, and the connecting section is disposed at at least one end of the blade body.

10. A wind turbine generator, characterized in that, include: The base is rotatably connected to a support shaft; The blades of the wind turbine generator according to any one of claims 1 to 9 are connected to the support shaft, and there are multiple blades, with the multiple blades surrounding the central axis of the support shaft; A generator set is connected to the base and the support shaft respectively, and the generator set generates electrical energy based on the movement of the blades relative to the base.

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