Wind power blade and wind generating set
By setting stall elements on the windward and/or the leeward surface of the wind turbine blades, which are close to the tail edge, the problem of wind turbine blades being damaged and inverted towers during the shutdown of the wind turbine unit is solved, and the effect of reducing aerodynamics and reducing damage risks is achieved.
Patent Information
- Application Number
- CN202421462875.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-24
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-06-24
AI Technical Summary
When the wind turbine is shut down, the wind turbine blade tail edge is susceptible to greater aerodynamic power when facing the wind, resulting in damage to the blade or the wind turbine tower is reversed.
Stall elements are provided on the windward and/or leeward surface of the wind blade and are closer to the tail edge to reduce the aerodynamic force received by the wind blade.
By setting up stall elements, the aerodynamic power of the wind power blades during shutdown conditions can be effectively reduced, the risk of damage is reduced, and the situation of wind turbine tower reversing.
Smart Images
Figure CN222668297U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of wind power technology, and in particular to a wind power blade and a wind turbine generator set. Background Art
[0002] When a wind turbine encounters severe weather during operation, it needs to be shut down and load-reduced to ensure its safe operation.
[0003] Under shutdown conditions, the trailing edge of the wind turbine blades facing the wind is a wind-facing solution. However, in the actual implementation process, it is found that in the solution with the trailing edge of the wind turbine blades facing the wind, the wind turbine blades will be subject to greater aerodynamic forces, which can easily cause the wind turbine blades to be damaged and even cause the wind turbine tower to collapse. Summary of the invention
[0004] The embodiments of the present application provide a wind turbine blade and a wind turbine generator set, which can reduce the aerodynamic force exerted on the wind turbine blade in a wind-facing scheme in which the trailing edge of the wind turbine blade faces the wind.
[0005] The embodiment of the present application provides a wind turbine blade, wherein the wind turbine blade has a leading edge and a trailing edge disposed opposite to each other along a first direction, and the wind turbine blade has a windward surface and a leeward surface disposed opposite to each other along a second direction;
[0006] The wind turbine blade further comprises a stall element, wherein the stall element is arranged on the windward surface and / or the leeward surface, and the distance between the stall element and the trailing edge is smaller than the distance between the stall element and the leading edge;
[0007] The first direction is perpendicular to the second direction.
[0008] According to one aspect of an embodiment of the present application, the stall element includes a first stall element, which is arranged on the windward surface, and the ratio of the distance between the installation position of the first stall element and the trailing edge to the chord length at the corresponding position of the wind turbine blade is less than or equal to 5:100.
[0009] According to one aspect of an embodiment of the present application, a ratio between a distance between an installation position of the first stall element and the trailing edge and a chord length at a corresponding position of the wind turbine blade is 2:100.
[0010] According to one aspect of an embodiment of the present application, the stall element includes a second stall element, the second stall element is arranged on the leeward side, and the ratio between the distance between the installation position of the second stall element and the trailing edge and the chord length at the corresponding position of the wind turbine blade is less than or equal to 12:100.
[0011] According to one aspect of the embodiment of the present application, the ratio between the distance between the installation position of the second stall element and the trailing edge and the chord length at the corresponding position of the wind turbine blade is 10:100.
[0012] According to one aspect of the embodiment of the present application, the wind turbine blade has a blade root and a blade tip disposed opposite to each other along a third direction, the stall element extends along the third direction, and the distance between the stall element and the blade tip is smaller than the distance between the stall element and the blade root;
[0013] The first direction, the second direction and the third direction are perpendicular to each other.
[0014] According to one aspect of the embodiment of the present application, a ratio between a size of the stall element along the third direction and a size of the wind turbine blade along the third direction is greater than or equal to 30:100.
[0015] According to one aspect of the embodiment of the present application, in a plane defined by the first direction and the second direction, a cross-section of the stall element is an equilateral triangle.
[0016] According to one aspect of the embodiment of the present application, the ratio between the side length of the equilateral triangle and the chord length of the wind turbine blade at a corresponding position is 1:100 to 2:100.
[0017] An embodiment of the present application further provides a wind turbine generator set, wherein the wind turbine generator set includes the wind turbine blades as described above.
[0018] The wind turbine blade and wind turbine generator set provided in the embodiments of the present application can effectively reduce the aerodynamic force exerted on the wind turbine blade in the wind-facing scheme where the trailing edge faces the wind by arranging a stall element on the windward side and / or leeward side of the wind turbine blade and making the stall element closer to the trailing edge, thereby reducing the risk of the wind turbine blade being damaged by force during shutdown conditions or even the collapse of the wind turbine generator set. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.
[0020] Figure 1 A schematic diagram of the cross-sectional structure of a wind turbine blade along its chord direction provided in an embodiment of the present application;
[0021] Figure 2 for Figure 1 A schematic diagram of the enlarged structure at A in the middle;
[0022] Figure 3 A schematic diagram of a partial structure of a wind turbine blade provided in an embodiment of the present application;
[0023] Figure 4A schematic diagram of the structure of the windward side of a wind turbine blade provided in an embodiment of the present application;
[0024] Figure 5 The figure is a schematic diagram of the airflow distribution around the periphery of an existing wind turbine blade;
[0025] Figure 6 A schematic diagram of airflow distribution around a wind turbine blade provided in an embodiment of the present application;
[0026] Figure 7 A schematic diagram of lift variation when the trailing edge of a wind turbine blade is facing the wind, provided in an embodiment of the present application;
[0027] Figure 8 A schematic diagram comparing lift changes before and after a stall element is installed on the windward surface of a wind turbine blade provided in an embodiment of the present application;
[0028] Fig. 9 A schematic diagram comparing the resistance changes before and after the stall element is installed on the windward surface of a wind turbine blade provided in an embodiment of the present application;
[0029] Fig.10 A schematic diagram comparing lift changes before and after a stall element is installed on the leeward side of a wind turbine blade provided in an embodiment of the present application;
[0030] Fig.11 A schematic diagram comparing the resistance changes before and after the stall element is installed on the leeward side of a wind turbine blade provided in an embodiment of the present application.
[0031] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale.
[0032] Description of Figure Numbers:
[0033] 1. Leading edge; 2. Trailing edge; 3. Windward side; 4. Leeward side; 5. Stall element; 51. First stall element; 52. Second stall element; 6. Blade tip; 7. Blade root; L, chord length;
[0034] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION
[0035] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating examples of the present application. In the accompanying drawings and the following description, at least some of the known structures and technologies are not shown to avoid unnecessary ambiguity in the present application; and, for clarity, the size of some structures may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.
[0036] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific steps and structures of the wind turbine blades and wind turbine generator sets of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0037] It should be noted that the words first direction X, second direction Y and third direction Z recorded in this application are only used to more clearly describe the specific structure of this application in conjunction with the drawings, and this application is not limited thereto. Among them, the first direction X, the second direction Y and the third direction Z have an angle between each other. Optionally, the first direction X, the second direction Y and the third direction Z are perpendicular to each other.
[0038] like Figures 1 to 4 As shown, an embodiment of the present application provides a wind turbine blade, wherein the wind turbine blade has a leading edge 1 and a trailing edge 2 disposed opposite to each other along a first direction X, and the wind turbine blade has a windward surface 3 and a leeward surface 4 disposed opposite to each other along a second direction Y.
[0039] The wind turbine blade also includes a stall element 5, which is arranged on the windward surface 3 and / or the leeward surface 4, and the distance between the stall element 5 and the trailing edge 2 is smaller than the distance between the stall element 5 and the leading edge 1; that is, compared with the leading edge 1, the stall element 5 is arranged at a position closer to the trailing edge 2, which can effectively reduce the aerodynamic force exerted on the wind turbine blade in the wind-facing scheme of the trailing edge 2, thereby reducing the situation in which the wind turbine blade is damaged by force under shutdown conditions or even the collapse of the wind turbine tower.
[0040] Specifically, see Figure 5For the wind turbine blades without stall element 5 in the prior art, according to the two-dimensional simulation calculation results, when the trailing edge 2 is facing the wind, the airflow on the side surface of the airfoil negative pressure will separate near the trailing edge 2 and reattach in the subsequent flow, so it can still provide considerable lift.
[0041] See also Figure 6 The wind turbine blade provided in the present application can realize the forced separation of the airflow and the blade surface by setting the stall element 5. For the windward surface 3, when the airflow passes through the stall element 5, a separation vortex will be generated in its downstream flow to form a negative pressure area; for the leeward surface 4, by setting the stall element 5, the original separation range of the airflow can be expanded and the lift of the trailing edge 2 in the wind state can be reduced.
[0042] In summary, the wind turbine blade provided by the present application, by providing the stall element 5, expands the airflow separation range on the negative pressure side, and makes the airflow reattach closer to the leading edge 1, thereby reducing the airfoil output and increasing the resistance (see Figure 7 ); forced separation of the airflow is achieved near the trailing edge 2 on the positive pressure side, so that the positive pressure in the separation range is reduced, thereby reducing the lift and achieving the effect of reducing the aerodynamic force on the wind turbine blade.
[0043] On the other hand, since the stall element 5 is arranged close to the trailing edge 2 and has a small volume, the effect on lift and drag under normal operating conditions is relatively small and will not affect the normal operation of the wind turbine generator set. It is particularly suitable for airfoils that have high lift characteristics.
[0044] Specifically, Figure 8 and Fig. 9 As shown, under normal operating conditions, the airfoil faces the wind. When the angle of attack is greater than a certain angle (such as 5°), the airflow on the leeward side 4 is prone to separation near the trailing edge 2, so it will have a more obvious impact on small angles of attack, and a slight impact on large angles of attack. Therefore, the impact on lift and drag is relatively small. Specifically, the lift is slightly reduced and the drag is slightly increased at small angles of attack, and the impact is not obvious at large angles of attack and after stall.
[0045] like Fig.10 and Fig.11 As shown, the airflow on the windward surface 3 always remains attached before stall occurs (i.e., before reaching the position of the stall element 5), so it will have an impact on the flow. However, since the stall element 5 will play a similar effect to the blunt trailing edge 2 when installed on the windward surface 3, it will increase the lift while increasing the drag, so the lift-to-drag ratio is kept unchanged to a certain extent.
[0046] Therefore, no matter in shutdown condition or normal operation condition, the stall element 5 can be installed on the wind turbine blade for a long time without repeatedly disassembling and assembling it.
[0047] It should be noted that the lift force on the wind turbine blades is in opposite directions during shutdown and normal operation. Figure 7 , Figure 8 and Fig.10 In the shutdown condition, the lift line is below the horizontal coordinate axis, and in the normal operating condition, the lift line is above the horizontal coordinate axis. Regardless of the shutdown condition or the normal operating condition, the closer to the horizontal coordinate axis, the smaller the lift, and the farther from the horizontal coordinate axis, the greater the lift.
[0048] like Figure 1 , Figure 2 and Figure 4 As shown, according to one aspect of the embodiment of the present application, the stall element 5 includes a first stall element 51, the first stall element 51 is bonded and fixed on the windward surface 3, and the ratio between the distance between the installation position of the first stall element 51 and the trailing edge 2 and the chord length L at the corresponding position of the wind turbine blade is less than or equal to 5:100. That is, the distance between the first stall element 51 and the trailing edge 2 is roughly within 5% of the chord length L at the corresponding position. Within this range, the effect of the first stall element 51 on the airflow can be guaranteed, and the first stall element 51 will not affect the normal operation of the wind turbine blade when it is in normal working conditions.
[0049] Optionally, the ratio of the distance between the installation position of the first stall element 51 and the trailing edge 2 to the chord length L at the corresponding position of the wind turbine blade is 2:100, that is, the distance between the first stall element 51 and the trailing edge 2 is approximately 2% of the chord length L at the corresponding position. The first stall element 51 is arranged at this position, which can effectively reduce the aerodynamic force exerted on the wind turbine blade.
[0050] like Figures 1 to 3 As shown, according to one aspect of the embodiment of the present application, the stall element 5 includes a second stall element 52, the second stall element 52 is arranged on the leeward surface 4, and the ratio between the distance between the installation position of the second stall element 52 and the trailing edge 2 and the chord length L at the corresponding position of the wind turbine blade is less than or equal to 12:100. That is, the distance between the second stall element 52 and the trailing edge 2 is roughly within 12% of the chord length L at the corresponding position. Within this range, the effect of the first stall element 51 on the airflow can be guaranteed, and the first stall element 51 will not affect the normal operation of the wind turbine blade when it is in normal working conditions.
[0051] Optionally, the ratio between the distance between the installation position of the second stall element 52 and the trailing edge 2 and the chord length L at the corresponding position of the wind turbine blade is 10:100. That is, the distance between the second stall element 52 and the trailing edge 2 is approximately 10% of the chord length L at the corresponding position. The second stall element 52 is arranged at this position, and can effectively cooperate with the first stall element 51 to reduce the aerodynamic force exerted on the wind turbine blade.
[0052] like Figure 4 As shown, according to one aspect of the embodiment of the present application, the wind turbine blade has a blade root 7 and a blade tip 6 disposed opposite to each other along the third direction Z, the stall element 5 extends along the third direction Z, and the distance between the stall element 5 and the blade tip 6 is smaller than the distance between the stall element 5 and the blade root 7; that is, the stall element 5 is disposed at a position of the wind turbine blade close to the blade tip 6. Under shutdown conditions, since the load on the blade root 7 is the integral of the product of the spanwise aerodynamic force of the blade and its length from the blade root 7, the aerodynamic force provided near the blade tip 6 accounts for a high proportion of the load, and it is obvious that arranging the device close to the blade tip 6 is more efficient.
[0053] like Figure 4 As shown, according to one aspect of the embodiment of the present application, the ratio between the size of the stall element 5 along the third direction Z and the wind turbine blade along the third direction Z is greater than or equal to 30:100. That is, the stall element 5 must at least cover 30% of the length of the wind turbine blade near the blade tip 6 along the length direction to ensure the contact size of the stall element 5 with the airflow and the effect of the stall element 5 on the airflow.
[0054] like Figure 1 and Figure 2 As shown, according to one aspect of an embodiment of the present application, in a plane defined by a first direction X and a second direction Y, the cross section of the stall element 5 is an equilateral triangle, so that the stall element 5 has a uniform and stable structure, is not easily damaged when subjected to force, and ensures its service life.
[0055] According to one aspect of the embodiment of the present application, the ratio between the side length of the equilateral triangle and the chord length L of the wind turbine blade at the corresponding position is 1:100 to 2:100. The desired effect can be achieved by a small size.
[0056] An embodiment of the present application further provides a wind turbine generator set, wherein the wind turbine generator set includes the wind turbine blades as described above.
[0057] The wind turbine blade and wind turbine generator set provided in the embodiments of the present application can effectively reduce the aerodynamic force exerted on the wind turbine blade in the wind-facing scheme where the trailing edge 2 faces the wind, by arranging the stall element 5 on the windward side 3 and / or the leeward side 4 of the wind turbine blade, and making the stall element 5 closer to the trailing edge 2, thereby reducing the risk of the wind turbine blade being damaged by force during shutdown conditions or even the collapse of the wind turbine generator set.
[0058] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A wind turbine blade, characterized in that: The wind turbine blade has a leading edge (1) and a trailing edge (2) disposed opposite to each other along a first direction (X), and the wind turbine blade has a windward surface (3) and a leeward surface (4) disposed opposite to each other along a second direction (Y); The wind turbine blade further comprises a stall element (5), wherein the stall element (5) is arranged on the windward surface (3) and / or the leeward surface (4), and the distance between the stall element (5) and the trailing edge (2) is smaller than the distance between the stall element (5) and the leading edge (1); The first direction (X) is perpendicular to the second direction (Y).
2. The wind turbine blade according to claim 1, characterized in that: The stall element (5) comprises a first stall element (51), wherein the first stall element (51) is arranged on the windward surface (3), and the ratio between the distance between the installation position of the first stall element (51) and the trailing edge (2) and the chord length (L) at a corresponding position of the wind turbine blade is less than or equal to 5:
100.
3. The wind turbine blade according to claim 2, characterized in that: The ratio between the distance between the installation position of the first stall element (51) and the trailing edge (2) and the chord length (L) at the corresponding position of the wind turbine blade is 2:
100.
4. The wind turbine blade according to any one of claims 1 to 3, characterized in that: The stall element (5) comprises a second stall element (52), wherein the second stall element (52) is arranged on the leeward surface (4), and the ratio between the distance between the installation position of the second stall element (52) and the trailing edge (2) and the chord length (L) at the corresponding position of the wind turbine blade is less than or equal to 12:
100.
5. The wind turbine blade according to claim 4, characterized in that: The ratio between the distance between the installation position of the second stall element (52) and the trailing edge (2) and the chord length (L) at the corresponding position of the wind turbine blade is 10:
100.
6. The wind turbine blade according to claim 1, characterized in that: The wind turbine blade has a blade root (7) and a blade tip (6) disposed opposite to each other along a third direction (Z), the stall element (5) extends along the third direction (Z), and the distance between the stall element (5) and the blade tip (6) is smaller than the distance between the stall element (5) and the blade root (7); The first direction (X), the second direction (Y) and the third direction (Z) are perpendicular to each other.
7. The wind turbine blade according to claim 6, characterized in that: The ratio between the size of the stall element (5) along the third direction (Z) and the size of the wind turbine blade along the third direction (Z) is greater than or equal to 30:
100.
8. The wind turbine blade according to claim 6, characterized in that: In a plane defined by the first direction (X) and the second direction (Y), the cross-section of the stall element (5) is an equilateral triangle.
9. The wind turbine blade according to claim 8, characterized in that: The ratio between the side length of the equilateral triangle and the chord length (L) of the wind turbine blade at the corresponding position is 1:100 to 2:
100.
10. A wind turbine generator set, characterized in that: The wind turbine generator set comprises the wind turbine blade according to any one of claims 1 to 9.