A noise reduction device for a wind turbine

Abstract

This invention discloses a noise reduction device for wind turbines, comprising: a rotating noise reduction cover plate; a plurality of folding noise reduction cover plates, the folding noise reduction cover plates being mounted on the rotating noise reduction cover plate and located at a target position on the tower, the target position corresponding to the end position of the wind turbine blades when they move to be parallel with the tower; a rotating mechanism for driving the rotating noise reduction cover plates to rotate circumferentially along the tower; a folding mechanism for retracting or unfolding the folding noise reduction cover plates; and a control mechanism for driving the rotating mechanism and the folding mechanism, the control mechanism being mounted on the tower. The device provided by this invention allows the entire device to yaw with the blades under the control of the yaw system, thereby further improving noise reduction efficiency; in extreme weather conditions, the folding mechanism can fold and retract the folding noise reduction cover plates, extending their service life; it requires no modification to the shape and structure of the tower itself, is easy to assemble and disassemble, has low cost, and provides good results.

Description

Technical Field

[0001] This invention relates to the field of wind turbine noise reduction equipment, and in particular to a noise reduction device for wind turbines. Background Technology

[0002] In response to the national dual-carbon goals of "peak carbon and carbon neutrality," wind power, as one of the most widely used renewable energy sources, is poised for rapid development. To continuously expand installed wind power capacity, wind farms will inevitably be located closer to residential areas. During this process, the noise problem of wind turbines will receive increasing attention.

[0003] Currently, wind turbine noise can be mainly divided into mechanical noise and aerodynamic noise. Mechanical noise can be effectively reduced by optimizing the manufacturing process of rotating mechanisms such as motors. However, research on the dominant aerodynamic noise is more complex, and scholars both domestically and internationally have conducted a series of noise reduction studies targeting the generation mechanisms of different noises. In existing technologies, most wind turbine aerodynamic noise reduction techniques focus on the aerodynamic noise generated by the blades, such as optimizing the blade shape, adding serrated trailing edges, blade tip winglets, and using porous media materials for sound absorption. Research on wind turbine tower noise reduction techniques is relatively limited.

[0004] Therefore, how to effectively reduce the aerodynamic noise of wind turbines is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a noise reduction device for wind turbines that does not require changes to the existing structure of the tower, has a wide adjustable range, and provides good noise reduction effect.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A noise reduction device for wind turbines, comprising:

[0008] A rotating noise reduction cover plate is rotatably installed on the outer periphery of the wind turbine tower.

[0009] Several folded noise reduction cover plates are located on the windward side of the tower and are installed on the rotating noise reduction cover plate. The folded noise reduction cover plates are located at a target position on the tower, and the target position corresponds to the end position of the wind turbine blade when it moves to be parallel to the tower.

[0010] A rotating mechanism, installed on the tower, is used to drive the rotating noise reduction cover plate to rotate circumferentially along the tower.

[0011] A folding mechanism is installed between the rotating noise reduction cover plate and the folding noise reduction cover plate for retracting or unfolding the folding noise reduction cover plate. When unfolded, the folding noise reduction cover plate is inclined relative to the axial direction of the tower.

[0012] A control mechanism is provided for driving the rotation mechanism and the folding mechanism to operate, and the control mechanism is mounted on the tower.

[0013] Preferably, the folding mechanism includes a vertical slide groove, a vertical connecting slider, and a connecting rod. The vertical slide groove is installed on the rotating noise reduction cover plate. The vertical connecting slider is slidably connected to the vertical slide groove. The connecting rod is installed between the vertical connecting slider and the folding noise reduction cover plate. The vertical connecting slider can drive the connecting rod to move and bend.

[0014] Preferably, the folding mechanism further includes several circumferential connecting brackets, one end of the folding noise reduction cover plate is hinged to the circumferential connecting brackets, and the connecting rod is connected to the middle of the folding noise reduction cover plate; the circumferential connecting brackets are mounted on the rotating noise reduction cover plate.

[0015] Preferably, the number of folded noise reduction cover plates is even, and each of the folded noise reduction cover plates is symmetrically distributed in a V-shape relative to the target position.

[0016] Preferably, the number of folding mechanisms is the same as the number of folding noise reduction cover plates and they correspond one-to-one. Each folding mechanism includes at least two sets of vertical slide grooves, vertical connecting sliders and connecting rods, and at least one set of vertical slide grooves, vertical connecting sliders and connecting rods are provided on both the left and right sides of the folding noise reduction cover plate.

[0017] Preferably, both the rotating noise reduction cover plate and the folding noise reduction cover plate are arc-shaped plates. The arc range of the rotating noise reduction cover plate is 220°-260°, and the arc range of the folding noise reduction cover plate is 100°-140°. The sum of the arcs of the rotating noise reduction cover plate and the folding noise reduction cover plate is 360°. The length of the rotating noise reduction cover plate is greater than 0.3 times the length of the tower, and the total length of all the folding noise reduction cover plates is greater than the length of the rotating noise reduction cover plate.

[0018] Preferably, the control mechanism includes a control cabinet and hydraulic pipes, and the control cabinet controls the operation of the rotating mechanism and the folding mechanism through the hydraulic pipes.

[0019] Preferably, both the rotating noise reduction cover plate and the folding noise reduction cover plate include a porous dielectric substrate layer and a plurality of porous dielectric ribs, wherein each of the porous dielectric ribs is sequentially arranged and installed on the porous dielectric substrate layer, and a groove is formed between adjacent porous dielectric ribs.

[0020] Preferably, the rotating mechanism includes a circumferential slide groove and a circumferential connecting slider. The circumferential slide groove is installed on the outer periphery of the tower, and the circumferential connecting slider is slidably connected to the circumferential slide groove. The rotating noise reduction cover plate is installed on the circumferential connecting slider and can slide along the circumferential slide groove following the circumferential connecting slider.

[0021] Preferably, it also includes a rudder installed on the leeward side of the tower. The rudder is mounted on the rotating noise reduction cover plate and the position of the rotating noise reduction cover plate in the circumference of the tower can be adjusted according to the wind direction.

[0022] The wind turbine noise reduction device provided by the present invention includes: a rotating noise reduction cover plate, which is rotatably mounted on the outer periphery of the wind turbine tower; a plurality of folding noise reduction cover plates, which are mounted on the rotating noise reduction cover plate and are located at a target position on the tower, the target position corresponding to the end position of the wind turbine blade when it moves to be parallel with the tower; a rotating mechanism mounted on the tower for driving the rotating noise reduction cover plate to rotate circumferentially along the tower; a folding mechanism mounted between the rotating noise reduction cover plate and the folding noise reduction cover plate for retracting or unfolding the folding noise reduction cover plate, wherein the folding noise reduction cover plate is inclined relative to the axial direction of the tower when unfolded; and a control mechanism for driving the rotating mechanism and the folding mechanism to operate, the control mechanism being mounted on the tower. The noise reduction device for wind turbines provided by this invention increases the contact area between the fluid and the folded noise reduction cover plate by installing the folded noise reduction cover plate on the windward side of the tower, thereby further improving the noise reduction effect. Through the coordinated arrangement of the rotation mechanism, the folding mechanism, and the control mechanism, the entire device can yaw with the blades under the control of the yaw system, thereby further improving the noise reduction efficiency. In extreme weather conditions, the folding mechanism can fold and retract the folded noise reduction cover plate, thereby reducing the load and extending the service life. In addition, as an auxiliary device installed on the surface of the tower, this device does not require any changes to the shape and structure of the tower itself, can be installed or disassembled at any time, and is low in cost and effective.

[0023] In a preferred embodiment, a rudder is further included, mounted on the leeward side of the tower. The rudder is installed on the rotating noise-reducing cover plate, and its position around the tower can be adjusted according to wind direction. This configuration, through the rudder, assists in yaw control. By adding a driving force to the control and rotating mechanisms, the yaw action of the device is ensured to be accurate, and the folded noise-reducing cover plate is moved to the windward side of the tower, thereby guaranteeing the noise reduction effect of the device. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a specific embodiment of the noise reduction device for wind turbines provided by the present invention.

[0026] Figure 2-1 This is a schematic diagram of the structure of the noise reduction cover plate in the noise reduction device for wind turbines provided by the present invention.

[0027] Figure 2-2 for Figure 2-1 Dimensional diagram of the noise reduction cover plate;

[0028] Figure 2-3 for Figure 2-1 A schematic diagram of another embodiment of the noise reduction cover plate;

[0029] Figure 2-4 for Figure 2-1 A schematic diagram of the third embodiment of the noise reduction cover plate;

[0030] Figure 3-1 for Figure 1 The left image shows the folded noise reduction cover plate in the noise reduction device for the wind turbine.

[0031] Figure 3-2 for Figure 1 A partial enlarged view of the folded noise reduction cover plate in the noise reduction device for the wind turbine shown;

[0032] Figure 4-1 for Figure 1 Left view of the folding mechanism in the noise reduction device for the wind turbine shown;

[0033] Figure 4-2 for Figure 1 A partial enlarged view of the folding mechanism in the noise reduction device for the wind turbine shown;

[0034] Figure 5 for Figure 1 A schematic diagram of the rotating mechanism in the noise reduction device for a wind turbine shown.

[0035] Figure 6 for Figure 1 The left view of the folding noise reduction cover plate in the noise reduction device for the wind turbine shown, when folded up.

[0036] Among them: hub 1, blade 2, nacelle 3, tower 4, rudder 5, rotating noise reduction cover plate 6, folding noise reduction cover plate 7, folding mechanism 8, rotating mechanism 9, vertical slide groove 10, vertical connecting slider 11, connecting rod 12, circumferential slide groove 13, circumferential connecting slider 14, hinge 15, control cabinet 16, hydraulic pipe 17, circumferential connecting bracket 18, porous media rib 19-1, porous media base layer 19-2, groove 20. Detailed Implementation

[0037] The core of this invention is to provide a noise reduction device for wind turbines, which can effectively reduce the aerodynamic noise of wind turbines and is easy to install.

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please refer to Figures 1 to 6 , Figure 1 This is a schematic diagram of a specific embodiment of the noise reduction device for wind turbines provided by the present invention. Figure 2-1 This is a schematic diagram of the structure of the noise reduction cover plate in the noise reduction device for wind turbines provided by the present invention. Figure 2-2 for Figure 2-1 Dimensional diagram of the noise reduction cover plate; Figure 2-3 for Figure 2-1 A schematic diagram of another embodiment of the noise reduction cover plate; Figure 2-4 for Figure 2-1 A schematic diagram of the third embodiment of the noise reduction cover plate; Figure 3-1 for Figure 1 The left image shows the folded noise reduction cover plate in the noise reduction device for the wind turbine. Figure 3-2 for Figure 1 A partial enlarged view of the folded noise reduction cover plate in the noise reduction device for the wind turbine shown; Figure 4-1 for Figure 1 Left view of the folding mechanism in the noise reduction device for the wind turbine shown; Figure 4-2for Figure 1 A partial enlarged view of the folding mechanism in the noise reduction device for the wind turbine shown; Figure 5 for Figure 1 A schematic diagram of the rotating mechanism in the noise reduction device for a wind turbine shown. Figure 6 for Figure 1 The left view of the folding noise reduction cover plate in the noise reduction device for the wind turbine shown, when folded up.

[0040] In this embodiment, the noise reduction device for wind turbines includes:

[0041] The noise reduction cover plate 6 is rotatably installed on the outer periphery of the wind turbine tower 4.

[0042] Several folded noise reduction cover plates 7 are located on the windward side of the tower 4 and are installed on the rotating noise reduction cover plate 6. The folded noise reduction cover plates 7 are located at the target position of the tower 4, and the target position corresponds to the end position of the wind turbine blade 2 when it moves to be parallel with the tower 4.

[0043] The rotating mechanism 9 is installed on the tower 4 and is used to drive the rotating noise reduction cover plate 6 to rotate around the circumference of the tower 4.

[0044] Folding mechanism 8 is installed between rotating noise reduction cover plate 6 and folding noise reduction cover plate 7, and is used to fold or unfold folding noise reduction cover plate 7. When unfolded, folding noise reduction cover plate 7 is tilted relative to the axial direction of tower 4.

[0045] A control mechanism is used to drive the rotation mechanism 9 and the folding mechanism 8. The control mechanism is mounted on the tower 4.

[0046] Specifically, a nacelle 3 is mounted on the top of the tower 4. A hub 1 is located on one side of the nacelle 3, and several blades 2 are mounted on the hub 1. A rotating noise reduction cover 6 is located on the leeward side of the tower 4, and a folding noise reduction cover 7 is located on the windward side of the tower 4. The rotating and folding noise reduction cover 6, together with the folding cover 7, cover the entire outer perimeter of the tower 4. The folding noise reduction cover 7 is located at a target position on the tower 4, which refers to the end position of the blade 2 when it moves parallel to the tower 4. In other words, the folding noise reduction cover 7 is installed close to the lowest point of the blade 2 during rotation. The setting is due to the fact that the aerodynamic noise generated at the end of blade 2 is the greatest; the folding mechanism 8 is installed on the rotating noise reduction cover plate 6, located on both sides of the folding noise reduction cover plate 7, and connected to the folding noise reduction cover plate 7 to control the opening and closing angle of the folding noise reduction cover plate 7; the number of rotating mechanisms 9 is preferably two, the rotating mechanisms 9 are close to the wall of the tower 4, and are respectively connected to the top and bottom of the inner wall of the rotating noise reduction cover plate 6, so that the rotating noise reduction cover plate 6 can yaw around the tower 4; the control mechanism is used to provide power to the rotating mechanism 9 and the folding mechanism 8, thereby providing power for the rotation of the rotating noise reduction cover plate 6 and the opening and closing of the folding noise reduction cover plate 7.

[0047] The noise reduction device for wind turbines provided by this invention increases the contact area between the fluid and the folded noise reduction cover plate 7 by installing a folded noise reduction cover plate 7 on the windward side of the tower 4, thereby further improving the noise reduction effect. Through the coordinated arrangement of the rotating mechanism 9, the folding mechanism 8, and the control mechanism, the entire device can yaw with the blade 2 under the control of the yaw system, thereby further improving the noise reduction efficiency. In extreme weather conditions, the folding mechanism 8 can fold and retract the folded noise reduction cover plate 7, thereby reducing the load and extending the service life. In addition, as an additional device installed on the surface of the tower 4, this device does not require any changes to the shape and structure of the tower 4 itself, and can be installed or disassembled at any time, with low cost and good effect.

[0048] In some embodiments, the folding mechanism 8 includes a vertical slide groove 10, a vertical connecting slider 11, and a connecting rod 12. The vertical slide groove 10 is mounted on the rotating noise reduction cover plate 6, the vertical connecting slider 11 is slidably connected to the vertical slide groove 10, and the connecting rod 12 is mounted between the vertical connecting slider 11 and the folding noise reduction cover plate 7. The vertical connecting slider 11 can drive the connecting rod 12 to move and bend. Specifically, the folding mechanism 8 includes a connecting rod 12, a vertical connecting slider 11, and a vertical slide groove 10; one end of the connecting rod 12 is connected to the folding noise reduction cover plate 7, and the other end is connected to the vertical connecting slider 11. The vertical connecting slider 11 is engaged with the vertical slide groove 10. The vertical slide groove 10 is formed on the rotating noise reduction cover plate 6 on the tower 4, and one rotating noise reduction cover plate 6 corresponds to two sets of folding mechanisms 8. Specifically, the connecting rod 12 includes a first rod body and a second rod body. The first rod body and the second rod body are hinged together. The first rod body is connected to the folding noise reduction cover plate 7, and the second rod body is connected to the vertical connecting slider 11. The vertical connecting slider 11 drives the connecting rod 12 to move up and down in the vertical slide groove 10. At the same time, the vertical connecting slider 11 can drive the second rod body to rotate, thereby realizing the bending between the first rod body and the second rod body, and finally realizing the folding of the noise reduction cover plate 7. When it is necessary to unfold the folding noise reduction cover plate 7, the operation is reversed.

[0049] In some embodiments, the folding mechanism 8 further includes several circumferential connecting brackets 18, one end of the folding noise reduction cover plate 7 is hinged to the circumferential connecting bracket 18, and the connecting rod 12 is connected to the middle of the folding noise reduction cover plate 7; the circumferential connecting bracket 18 is installed on the rotating noise reduction cover plate 6, and the circumferential connecting bracket 18 plays an effective supporting role.

[0050] In some embodiments, the number of folding noise reduction cover plates 7 is even, and each folding noise reduction cover plate 7 is symmetrically distributed in a V-shape relative to the target position. Specifically, the number of folding noise reduction cover plates 7 is preferably N pieces, where N is preferably 4-8. Each folding noise reduction cover plate 7 is the same size and is installed on the windward side of the tower 4 in a V-shape arrangement, with the top and bottom pieces arranged in pairs. The base of the folding noise reduction cover plate 7 is fixed to the circumferential connecting bracket 18 by a hinge 15, which serves to support and assist in folding. The two sides of the folding noise reduction cover plate 7 are connected to the folding mechanism 8 to control the folding. It should be noted that the unfolding angle of the folding noise reduction cover plate 7 should not be too large to prevent collision with the wind turbine blades 2. Meanwhile, each folded noise reduction cover plate 7 is symmetrically distributed in a V-shape relative to the target position. This is because the end of the blade 2 is prone to shifting during rotation. By aligning the middle of the V-shaped structure of each folded noise reduction cover plate 7 with the end of the blade 2, interference between the end of the blade 2 and the folded noise reduction cover plate 7 during swaying can be effectively prevented, thus ensuring the safety of the blade 2's operation.

[0051] In some embodiments, the number of folding mechanisms 8 is the same as the number of folding noise reduction cover plates 7 and they correspond one-to-one. Each folding mechanism 8 includes at least two sets of vertical slide grooves 10, vertical connecting sliders 11 and connecting rods 12. The left and right sides of the folding noise reduction cover plate 7 are provided with at least one set of vertical slide grooves 10, vertical connecting sliders 11 and connecting rods 12 to ensure the stability of the folding noise reduction cover plate 7 when it is unfolded and folded up.

[0052] In some embodiments, both the rotating noise-reducing cover plate 6 and the folding noise-reducing cover plate 7 are arc-shaped plates. The arc range of the rotating noise-reducing cover plate 6 is 220°-260°, and the arc range of the folding noise-reducing cover plate 7 is 100°-140°. The sum of the arcs of the rotating noise-reducing cover plate 6 and the folding noise-reducing cover plate 7 is 360°. Preferably, the length of each folding noise-reducing cover plate 7 should be at least greater than one-Nth of the axial length of the rotating noise-reducing cover plate 6, so that the two parallel folding noise-reducing cover plates 7 have a certain overlap area in the horizontal direction, and the arc range of the folding noise-reducing cover plate 7 in the circumferential direction is preferably 120°, which just matches the coverage range of the windward side.

[0053] The length of the rotating noise reduction cover plate 6 is greater than 0.3 times the length of the tower 4, and the total length of all folded noise reduction cover plates 7 is greater than the length of the rotating noise reduction cover plate 6. Specifically, the rotating noise reduction cover plate 6 is symmetrical about the lowest horizontal position that the wind turbine blade 2 can reach by rotation, i.e., the target position of the tower 4. The axial coverage area of ​​the rotating noise reduction cover plate 6 on the tower 4 must be no less than one-third of the length of the tower 4, and the circumferential coverage area of ​​the rotating noise reduction cover plate 6 is all circumferential areas except for the areas where the folded noise reduction cover plates 7 are installed.

[0054] In some embodiments, the control mechanism includes a control cabinet 16 and hydraulic pipes 17. The control cabinet 16 controls the rotation mechanism 9 and the folding mechanism 8 via the hydraulic pipes 17. Preferably, the control mechanism is mounted on the tower 4, and at least two control mechanisms are provided, located above and below the rotating noise reduction cover plate 6, respectively. One control mechanism can control the rotation mechanism 9, and the other can control the folding mechanism 8, or other configurations can be set as needed. Furthermore, the control cabinet 16 is preferably mounted on both sides of the tower 4 without affecting the normal folding operation of the folding noise reduction cover plate 7. A hydraulic mechanism is used, connected to the rotating mechanism 9 for sliding rotation and the folding mechanism 8 for folding and opening via hydraulic pipes 17, without affecting the rotation and yaw functions of the entire device.

[0055] In some embodiments, both the rotating noise reduction cover plate 6 and the folding noise reduction cover plate 7 include a porous media substrate layer 19-2 and a plurality of porous media ribs 19-1. The porous media ribs 19-1 are sequentially arranged on the porous media substrate layer 19-2, and a groove 20 is formed between adjacent porous media ribs 19-1. Specifically, the rotating noise reduction cover plate 6 includes a porous media substrate layer 19-2 and a plurality of porous media ribs 19-1 arranged along the axial direction of the tower 4. The groove 20 structure between adjacent porous media ribs 19-1 can change the flow separation and vortex shedding on the surface of the column, thus having a certain noise reduction capability. In addition, the porous media material itself has certain sound absorption characteristics. When some sound waves pass through the porous media material with a certain porosity, they rub against each other with the surrounding medium inside, causing some sound energy to dissipate in the form of heat energy, which can further increase the noise reduction effect of the tower 4. Similarly, the folded noise reduction cover plate 7 includes a porous dielectric substrate layer 19-2 and a plurality of porous dielectric ribs 19-1, which extend along the length direction of the folded noise reduction cover plate 7.

[0056] It should be noted that the structure and materials of the rotating noise reduction cover plate 6 and the folding noise reduction cover plate 7 can be the same or different, as long as they can achieve a good noise reduction effect, and are not limited to the method given in this embodiment.

[0057] In some embodiments, the groove 20 is V-shaped, U-shaped, or arc-shaped; that is, the cross-section of the porous medium rib 19-1 can be triangular, triangular-like, or rectangular, etc., so that different forms of groove 20 structures such as V-shaped and U-shaped are formed between two adjacent porous medium ribs 19-1; the characteristic dimensions of the groove 20 are preferably such that the groove depth h is 0.001D≤h≤0.05D, and the groove width d is 5h≤d≤10h, where D refers to the diameter corresponding to the arc of the rotating noise reduction cover plate 6 or the folded noise reduction cover plate 7.

[0058] In some embodiments, when the porous medium rib 19-1 is made of non-metallic materials such as nylon fiber or composite plastic foam, it can be connected to the circumferential connecting slider 14 by adhesive bonding; if it is made of metallic materials such as aluminum foam, it can be connected to the circumferential connecting slider 14 by bolting.

[0059] In some embodiments, the rotating mechanism 9 includes a circumferential slide groove 13 and a circumferential connecting slider 14. The circumferential slide groove 13 is installed on the outer periphery of the tower 4, and the circumferential connecting slider 14 is slidably connected to the circumferential slide groove 13. The rotating noise reduction cover plate 6 is installed on the circumferential connecting slider 14 and can slide along the circumferential slide groove 13 following the circumferential connecting slider 14. Specifically, the rotating mechanism 9 includes a circumferential slide groove 13 and a circumferential connecting slider 14; the arc range of the circumferential slide groove 13 is 360° and it is in close contact with the wall of the tower 4; the arc range of the circumferential connecting slider 14 is preferably 240° and it is in close contact with the outer rotating noise reduction cover plate 6; the number of rotating mechanisms 9 is preferably two, which are respectively installed on the inner side of the top and bottom ends of the rotating noise reduction cover plate 6.

[0060] In some embodiments, a rudder 5 is also included, installed on the leeward side of the tower 4. The rudder 5 is mounted on the rotating noise reduction cover plate 6, and its position around the tower 4 can be adjusted according to the wind direction. This configuration, through the rudder 5, assists in completing the yaw action. In addition to the control mechanism and the rotating mechanism 9, an additional driving force is added to ensure accurate yaw action of the device and to ensure that the folded noise reduction cover plate 7 moves to the windward side of the tower 4, thereby ensuring the noise reduction effect of the device.

[0061] Furthermore, the operation of this noise reduction device for wind turbines includes the following steps:

[0062] When the wind turbine needs to perform a yaw operation, the yaw system sends a yaw signal to the control mechanism.

[0063] The control mechanism sends a command to the hydraulic system, which drives the rotating mechanism 9 to rotate via hydraulic pipe 17, so that the entire device yaws around the tower 4 to align with the wind.

[0064] When encountering extreme weather, typhoons or strong winds, the control mechanism sends a command to the hydraulic system, which hydraulically drives the folding mechanism 8 through the hydraulic pipe 17, causing the folding noise reduction cover plate 7 to fold up and fit tightly against the wall of the tower 4.

[0065] After extreme weather, typhoons, or strong winds, the control mechanism sends another command to the hydraulic system, which hydraulically drives the folding mechanism 8 through the hydraulic pipe 17, causing the folding noise reduction cover 7 to open at a certain angle and operate normally.

[0066] Specifically, in one embodiment, the noise reduction device for the wind turbine includes a rotating noise reduction cover plate 6, a folding noise reduction cover plate 7, a folding mechanism 8, a rotating mechanism 9, a rudder 5, and a control cabinet 16. The rotating noise reduction cover plate 6 is installed and covers the cylindrical surface of the tower 4. There are four folding noise reduction cover plates 7, arranged in a "V" shape on the windward side of the tower 4. There are eight sets of folding mechanisms 8, installed on both sides of the tower 4 and connected to the folding noise reduction cover plates 7 to control their opening and closing angles. There are two sets of rotating mechanisms 9, which are close to the wall of the tower 4 and connected to the top and bottom ends of the rotating noise reduction cover plates 6 respectively, so that they can yaw around the tower 4 to align with the wind. The rudder 5 is installed on the leeward side of the tower 4 and connected to the rotating noise reduction cover plate 6 to assist in completing the yaw action. There are two control cabinets 16, installed on one side of the tower 4. Further, see Figures 2-1 to 2-4 The rotating noise reduction cover plate 6 comprises several axially arranged porous media ribs 19-1 and a porous media base layer 19-2, installed on the column surface of the tower 4. Grooves 20 are formed between adjacent porous media ribs 19-1. The cross-section of the porous media ribs 19-1 can be triangular, triangular-like, or rectangular, etc., so that different forms of groove 20 structures such as V-shaped, U-shaped, and rectangular are formed between two adjacent ribs. The optimal groove 20 form and structural arrangement can be selected according to local operating conditions. Experiments show that for a column of a given diameter, increasing the number of grooves 20 on its surface or increasing the depth of the grooves 20 can effectively reduce the local Reynolds number. However, even very shallow grooves 20 have a significant noise reduction effect. According to experimental and simulation results, setting V-shaped or U-shaped grooves 20 has better noise reduction potential under the same working conditions. Simple changes and adjustments to the depth, width, and shape of the grooves 20 are all within the protection scope of this invention. Furthermore, the porous medium material used in the porous medium ribs 19-1 has a certain amount of porosity. It should be noted that the axial coverage range of the rotating noise reduction cover plate 6 should be no less than one-third of the length of the tower 4, and symmetrical about the lowest horizontal position achievable by the rotation of the wind turbine blades 2. The circumferential coverage range is 240° circumferential, excluding the area where the folded noise reduction cover plate 7 is installed. Figure 3-1 and Figure 3-2As shown, the folding noise reduction cover plate 7 comprises four identical pieces, arranged in a "V" shape and installed on the windward side of the tower 4. Its base is fixed to the circumferential connecting bracket 18 by hinges 15, serving to support and assist in folding. The length of the folding noise reduction cover plate 7 should be at least one-quarter greater than the axial length of the rotating noise reduction cover plate 6, ensuring a certain overlap area between the parallel cover plates in the horizontal direction, with an circumferential arc range of 120°. The control cabinet 16 is installed on both sides of the tower 4 without affecting the normal folding operation of the folding noise reduction cover plate 7. It employs a hydraulic mechanism, connected via hydraulic pipes 17 to drive the sliding rotation of the rotating mechanism 9 and the folding opening and closing of the folding mechanism 8, without affecting the rotation and yaw function of the entire device. Figure 4-1 and Figure 4-2 As shown, the folding mechanism 8 includes a connecting rod 12, a vertical connecting slider 11, and a vertical slide groove 10; one end of the connecting rod 12 is connected to the folding noise reduction cover plate 7, and the other end is connected to the vertical connecting slider 11. The vertical connecting slider 11 is engaged with the vertical slide groove 10, which is located on the rotating noise reduction cover plates 6 on both sides of the tower 4. Each foldable rotating noise reduction cover plate 6 corresponds to two sets of folding mechanisms 8. Figure 5 As shown, the rotating mechanism 9 includes a circumferential slide groove 13 and a circumferential connecting slider 14. The circumferential slide groove 13 has an arc range of 360° and is in close contact with the wall of the tower 4. The circumferential connecting slider 14 has an arc range of 240° and is in close contact with the outer rotating noise reduction cover plate 6. There are two rotating mechanisms 9, which are respectively installed on the inner side of the top and bottom ends of the rotating noise reduction cover plate 6. The rotating noise reduction cover plate 6 effectively reduces the aerodynamic noise generated by the blades 2 and the tower 4 by combining the sound absorption characteristics of the porous medium material with the aerodynamic noise reduction characteristics of the groove 20 structure, which can reduce the pressure pulsation of the flow field. In addition, the foldable noise reduction cover plate 7 installed on the windward side of the tower 4 increases the contact area between the fluid and the porous medium groove 20 structure, which further improves the noise reduction effect. The cooperation between the rotating mechanism 9 and the hydraulic system allows the entire device to yaw with the wind turbine under the control of the yaw system, thereby further improving the noise reduction efficiency. In extreme weather conditions, the folding mechanism 8 can fold and retract the foldable noise-reducing cover 7, thereby reducing the load and extending its service life. Finally, this device, as an additional device installed on the surface of the tower 4, does not require any changes to the shape and structure of the tower 4 itself, and can be installed or removed at any time.

[0067] The noise reduction device for wind turbines provided in this embodiment utilizes the sound absorption properties of porous media material 6 combined with the aerodynamic noise reduction properties of the groove 20 structure to reduce pressure pulsation in the flow field, effectively reducing the aerodynamic noise generated by the blades 2 and the tower 4. The folded noise reduction cover 7 installed on the windward side of the tower 4 increases the contact area between the fluid and the porous media groove 20, further improving the noise reduction effect. The cooperation between the rotating mechanism 9 and the hydraulic system allows the entire device to yaw with the wind turbine under the control of the yaw system, thereby further improving the noise reduction efficiency. In extreme weather conditions, the folding mechanism 8 can fold and retract the folded noise reduction cover 7, thereby reducing the load and extending the service life. Finally, this device, as an additional device installed on the surface of the tower 4, does not require any changes to the shape and structure of the tower 4 itself and can be installed or removed at any time.

[0068] In addition to the noise reduction device for wind turbines mentioned above, the present invention also provides a wind turbine including the aforementioned noise reduction device for wind turbines. For the structure of other parts of the wind turbine, please refer to the prior art, which will not be described in detail here.

[0069] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0070] The noise reduction device for wind turbines provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A noise reduction device for a wind turbine, characterized in that include: Rotate noise reduction cover plate (6), which is rotatably installed on the outer periphery of the wind turbine tower (4); Several folded noise reduction cover plates (7) are located on the windward side of the tower (4) and installed on the rotating noise reduction cover plate (6). The folded noise reduction cover plates (7) are located at the target position of the tower (4), which corresponds to the end position of the wind turbine blade (2) when it moves to be parallel to the tower (4). The number of folded noise reduction cover plates (7) is even, and each folded noise reduction cover plate (7) is symmetrically distributed in a V-shape relative to the target position. The middle of the V-shaped structure of each folded noise reduction cover plate (7) corresponds exactly to the end of the blade (2). A rotating mechanism (9) is installed on the tower (4) to drive the rotating noise reduction cover plate (6) to rotate around the tower (4). A folding mechanism (8) is installed between the rotating noise reduction cover plate (6) and the folding noise reduction cover plate (7) for retracting or unfolding the folding noise reduction cover plate (7). When unfolded, the folding noise reduction cover plate (7) is inclined relative to the axial direction of the tower (4). A control mechanism for driving the rotation mechanism (9) and the folding mechanism (8) to operate, the control mechanism being mounted on the tower (4); The folding mechanism (8) includes a vertical slide groove (10), a vertical connecting slider (11), and a connecting rod (12). The vertical slide groove (10) is installed on the rotating noise reduction cover plate (6). The vertical connecting slider (11) is slidably connected to the vertical slide groove (10). The connecting rod (12) is installed between the vertical connecting slider (11) and the folding noise reduction cover plate (7). The vertical connecting slider (11) can drive the connecting rod (12) to move and bend. The connecting rod (12) includes a first rod body and a second rod body. The first rod body is hinged to the second rod body. The first rod body is connected to the folding noise reduction cover plate (7). The second rod body is connected to the vertical connecting slider (11). The vertical connecting slider (11) can drive the second rod body to rotate, thereby realizing the bending of the first rod body and the second rod body.

2. A noise reduction device for wind turbines according to claim 1, characterized in that, The folding mechanism (8) further includes several circumferential connecting brackets (18), one end of the folding noise reduction cover plate (7) is hinged to the circumferential connecting bracket (18), and the connecting rod (12) is connected to the middle part of the folding noise reduction cover plate (7); the circumferential connecting bracket (18) is installed on the rotating noise reduction cover plate (6).

3. The noise reduction device for wind turbines according to claim 1, characterized in that, The number of folding mechanisms (8) is the same as the number of folding noise reduction cover plates (7) and they correspond one-to-one. Each folding mechanism (8) includes at least two sets of vertical slide grooves (10), vertical connecting sliders (11) and connecting rods (12). The left and right sides of the folding noise reduction cover plates (7) are provided with at least one set of vertical slide grooves (10), vertical connecting sliders (11) and connecting rods (12).

4. The noise reduction device for wind turbines according to claim 1, characterized in that, Both the rotating noise reduction cover plate (6) and the folding noise reduction cover plate (7) are arc-shaped plates. The arc range of the rotating noise reduction cover plate (6) is 220°-260°, and the arc range of the folding noise reduction cover plate (7) is 100°-140°. The sum of the arcs of the rotating noise reduction cover plate (6) and the folding noise reduction cover plate (7) is 360°. The length of the rotating noise reduction cover plate (6) is greater than 0.3 times the length of the tower (4), and the total length of each of the folding noise reduction cover plates (7) is greater than the length of the rotating noise reduction cover plate (6).

5. The noise reduction device for wind turbines according to claim 1, characterized in that, The control mechanism includes a control cabinet (16) and a hydraulic pipe (17). The control cabinet (16) controls the rotation mechanism (9) and the folding mechanism (8) through the hydraulic pipe (17).

6. The noise reduction device for wind turbines according to claim 1, characterized in that, The rotating noise reduction cover plate (6) and the folding noise reduction cover plate (7) both include a porous medium substrate layer (19-2) and a plurality of porous medium ribs (19-1). Each of the porous medium ribs (19-1) is arranged sequentially on the porous medium substrate layer (19-2), and a groove (20) is formed between adjacent porous medium ribs (19-1).

7. A noise reduction device for wind turbines according to any one of claims 1 to 6, characterized in that, The rotating mechanism (9) includes a circumferential slide groove (13) and a circumferential connecting slider (14). The circumferential slide groove (13) is installed on the outer periphery of the tower (4). The circumferential connecting slider (14) is slidably connected to the circumferential slide groove (13). The rotating noise reduction cover plate (6) is installed on the circumferential connecting slider (14) and can slide along the circumferential slide groove (13) following the circumferential connecting slider (14).

8. A noise reduction device for wind turbines according to any one of claims 1 to 6, characterised in that, It also includes a rudder (5) installed on the leeward side of the tower (4), the rudder (5) is installed on the rotating noise reduction cover plate (6), and the position of the rotating noise reduction cover plate (6) in the circumference of the tower (4) can be adjusted according to the wind direction.

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