A new fan blade and its static stall control method

Abstract

The application discloses a novel fan blade and a static stall control method thereof. The novel fan blade comprises a blade body and a plurality of blade static stall control modules arranged on the leading edge surface of the blade body. The blade static stall control module comprises an elastic sealing structure connected with the surface of the blade body. The air pressure in the blade static stall control module is adjustable. When the air pressure in the blade static stall control module changes, the elastic sealing structure vibrates. The fan blade combines the blade body and the blade static stall control module comprising the elastic sealing structure. By adjusting the air pressure in the blade static stall control module, the vibration of the elastic sealing structure connected with the surface of the blade body is caused, and the stall vortex generated on the leading edge surface of the blade body is effectively broken, so that the active adjustment of the stall condition of the fan blade is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power technology, in particular to a novel wind turbine blade and a static stall control method thereof. BACKGROUND

[0002] In recent years, wind energy as a large-scale commercial clean renewable energy has been widely concerned by countries. With the rapid development of China's wind power industry and the continuous large-scale of wind turbine blades, high-performance wind turbine blades have attracted widespread attention around the world. The wind turbine blade is the core component of wind turbine to capture wind energy, and its operating state is directly related to the utilization efficiency of wind energy.

[0003] However, the wind turbine blade often accompanies the occurrence of stall phenomenon during operation. Generally, the stall phenomenon is mainly divided into dynamic stall and static stall. When the angle between the incoming flow and the chord direction of the blade exceeds a certain critical value, the lift coefficient decreases with the increase of the angle, and the drag coefficient instantaneously increases, thereby causing the static stall of the blade. At present, the trailing edge is often used to control the static stall of the blade. The wind turbine blade is often in a non-steady complex flow field such as shear, yaw, and variable pitch during operation due to the influence of the surrounding environment, thereby causing the dynamic stall phenomenon of the blade. When the blade is in the dynamic stall state, the lift coefficient, the drag coefficient and the pitch moment coefficient will produce hysteresis loop. The generation of hysteresis loop will cause strong disturbance to the airflow flowing on the surface of the blade, thereby reducing the wind energy utilization efficiency of the blade and possibly causing damage or safety accidents to the blade. Therefore, it is necessary to improve the wind turbine blade to weaken the stall phenomenon of the wind turbine blade and improve the wind energy utilization efficiency of the wind turbine blade.

[0004] For the above-mentioned blade stall problem, passive control method is often used for adjustment, such as installing a small cylinder or installing a vortex generator on the wind turbine blade to weaken the influence of the stall vortex of the wind turbine blade. However, the passive control method has limited effect. For example, when the vortex generator is installed on the wind turbine blade, the adjustment effect of the vortex generator on the stall of the wind turbine blade is constant, and cannot be adjusted according to the actual working environment of the wind turbine blade. In actual application, the resistance and other forces borne by the wind turbine blade are constantly changing due to the influence of the environment, and the regulation flexibility of the above-mentioned passive control method is low. SUMMARY

[0005] The purpose of the present application is to provide a novel wind turbine blade and a method thereof. The wind turbine blade combines a blade body and a blade static stall control module comprising an elastic sealing structure. By adjusting the air pressure state in the blade static stall control module, the elastic sealing structure connected to the surface of the blade body is vibrated, thereby effectively breaking the stall vortex generated on the leading edge surface of the blade body, and actively adjusting the stall condition of the wind turbine blade.

[0006] In order to achieve the above object, the present application realizes the technical scheme as follows:

[0007] A novel fan blade comprises:

[0008] A blade body;

[0009] A plurality of blade static stall control modules are arranged on the leading edge surface of the blade body, the blade static stall control module comprises an elastic sealing structure connected with the surface of the blade body, the air pressure in the blade static stall control module is adjustable, and the elastic sealing structure vibrates when the air pressure in the blade static stall control module changes.

[0010] Optionally, the blade static stall control module further comprises:

[0011] An accommodation space is a groove structure on the surface of the blade body, and the elastic sealing structure is covered on the top of the accommodation space;

[0012] A gas supply device supplies gas into the accommodation space through a gas inlet channel to change the air pressure in the accommodation space, and the elastic sealing structure vibrates when the air pressure in the accommodation space changes.

[0013] Optionally, the blade static stall control module further comprises:

[0014] An exhaust channel is in communication with the accommodation space to exhaust the gas in the accommodation space.

[0015] Optionally, the groove structure is square, rectangular, rhombic or irregularly shaped;

[0016] And / or, the width of the groove structure ranges from 1% to 2% of the chord length of the blade body;

[0017] And / or, the depth of the groove ranges from 3mm to 4mm;

[0018] And / or, the gas inlet channel is a circular channel;

[0019] And / or, the gas supply device is an air pump.

[0020] Optionally, the diameter of the gas inlet channel ranges from 1mm to 2mm.

[0021] Optionally, the distance between the blade static stall control module and the top end of the blade body ranges from 10% to 12% of the chord length of the blade body;

[0022] The blade static stall control module is arranged on the upper surface and / or the lower surface of the leading edge of the blade body;

[0023] And / or, the elastic modulus of the elastic sealing structure ranges from 0.003 to 0.05;

[0024] And / or, the elastic sealing structure is an elastic film.

[0025] And / or, the elastic sealing structure is bonded to the surface of the blade body.

[0026] Optionally, a static stall control method for the new fan blade comprises:

[0027] When the new fan blade is in a rated operating condition, the air pressure in the blade static stall control module changes, and the elastic sealing structure vibrates.

[0028] Optionally, it further comprises:

[0029] The gas supply device delivers gas to the containing space through the gas inlet channel;

[0030] The air pressure in the containing space changes, and the elastic sealing structure vibrates.

[0031] Optionally, it further comprises:

[0032] The containing space discharges gas to the outside through the gas outlet channel, and the air pressure in the containing space continues to change.

[0033] Compared with the prior art, the present application has the following advantages:

[0034] In the new fan blade and the static stall control method thereof, the fan blade combines the blade body and the blade static stall control module comprising the elastic sealing structure, adjusts the air pressure state in the blade static stall control module, makes the elastic sealing structure connected to the surface of the blade body vibrate, effectively breaks the stall vortex generated on the surface of the leading edge of the blade body, and actively adjusts the stall condition of the fan blade.

[0035] Further, the containing space of the blade static stall control module of the fan blade is respectively communicated with the gas inlet channel and the gas outlet channel, the gas supply device delivers gas to the containing space through the gas inlet channel, and the gas in the containing space is discharged to the outside through the gas outlet channel, so that the gas in the containing space is in a dynamic balance state, and the elastic sealing structure is in a continuous vibration state, thereby continuously regulating and controlling the stall condition of the fan blade. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A schematic diagram of the new fan blade of the present application;

[0037] Figure 2 A partial schematic diagram of the new fan blade of the present application. DETAILED DESCRIPTION

[0038] The application will be further described in connection with the preferred embodiment with reference to the drawings attached hereto.

[0039] As Figure 1 and Figure 2 In combination shown, a new fan blade of the application mainly comprises a blade body 1 and a plurality of blade static stall control modules 2. The blade static stall control module 2 is arranged on the leading edge surface of the blade body 1, and the blade static stall control module 2 comprises an elastic sealing structure 21 connected with the surface of the blade body 1. The air pressure in the blade static stall control module 2 is adjustable, and the elastic sealing structure 21 vibrates when the air pressure in the blade static stall control module 2 changes.

[0040] In actual application, it is found that the deep stall vortex of the fan blade is mostly formed on the airfoil leading edge of the blade body 1. In the embodiment, the airfoil leading edge of the fan blade is provided with the blade static stall control module 2, and the elastic sealing structure 21 of the blade static stall control module 2 is connected with the surface of the blade body 1. When the air pressure in the blade static stall control module 2 changes, the elastic sealing structure 21 on the surface of the blade body 1 vibrates, thereby effectively breaking the stall vortex on the surface of the airfoil leading edge, so as to effectively control the stall condition of the fan blade surface. At the same time, according to the actual working environment of the fan blade, the resistance received by the fan blade is also different, and the air pressure change range in the blade static stall control module 2 can be adjusted according to the resistance received by the fan blade, so as to realize the active adjustment of the stall state.

[0041] Optionally, the blade static stall control module 2 is arranged on the upper surface and / or the lower surface of the leading edge of the blade body 1, so as to weaken the deep stall vortex generated on the upper surface and / or the lower surface of the airfoil leading edge, thereby effectively controlling the stall condition of the fan blade.

[0042] In the application, the elastic sealing structure 21 can adopt a film structure with different elastic modulus. Optionally, the elastic modulus of the elastic sealing structure 21 ranges from 0.003 to 0.05, and the film structure with appropriate elastic modulus is selected according to the size of the fan blade and the parameter conditions of the use environment. In the embodiment, the elastic sealing structure 21 is a transparent elastic film arranged on the upper surface of the leading edge of the blade body 1, and the transparent elastic film vibrates when the air pressure in the blade static stall control module 2 changes, thereby breaking the stall vortex on the surface of the blade body 1.

[0043] Further, in the embodiment, the blade static stall control module 2 further comprises a containing space 22 and a gas supply device. The containing space 22 is a groove structure on the surface of the blade body 1, and the elastic sealing structure 21, i.e. the transparent elastic film, covers the top of the containing space 22 to seal the containing space 22. The gas supply device supplies gas to the containing space 22 through a gas inlet channel 23 to change the air pressure in the containing space 22, and when the air pressure in the containing space 22 changes, the transparent elastic film vibrates. In the embodiment, the gas supply device can actively control the stall condition of the fan blade, and according to actual needs and actual working environment, the gas supply device can be set to a corresponding gas supply speed or gas supply amount to accurately regulate the surface state of the leading edge of the fan blade. For example, in an embodiment, the gas supply device provides an air pressure of 100 Pa to the groove structure, and in this process, the transparent elastic film is in a vibrating state.

[0044] Further, the distance between the blade static stall control module 2 and the top end of the blade body 1 is in the range of 10% to 12% of the chord length of the blade body 1, i.e. the distance between the groove structure and the transparent elastic film and the top end of the blade body 1 is in the range of 10% to 12% of the chord length of the blade body 1. It is arranged at the leading edge position of the top end of the blade body 1, and the vibrating transparent elastic film can effectively break the stall vortex at this position, thereby controlling the stall condition of the fan blade.

[0045] Optionally, the groove structure is square, rectangular, rhombic or irregularly shaped; the width of the groove structure is in the range of 1% to 2% of the chord length of the blade body 1; and the depth of the groove is in the range of 3 mm to 4 mm. In the embodiment, the groove structure is a rectangular structure arranged along the airfoil leading edge of the fan blade. At the same time, the transparent elastic film is adhered to the surface of the blade body 1 by double-sided adhesive to cover the top of the groove structure. Of course, the mounting and connecting mode of the elastic sealing structure 21 is not limited to the above, and it can also be other fixing modes, which are not limited by the present application. In the embodiment, the gas supply device is an air pump, and in another embodiment, the gas supply device is other device that can supply gas to the containing space 22, and the present application does not limit the specific structure of the gas supply device as long as it can supply gas.

[0046] Further, in order to make the elastic sealing structure 21 continuously vibrate, the blade static stall control module 2 further comprises an exhaust passage. The exhaust passage is in communication with the containing space 22, i.e. the groove structure, to exhaust the gas in the containing space 22. In actual application, the air supply device supplies gas into the containing space 22 to change the air pressure in the containing space 22, and the exhaust passage exhausts the gas in the containing space 22 outward, so that the air pressure in the containing space 22 is always in a dynamic change process, thereby making the elastic sealing structure 21 always vibrate, effectively breaking the stall vortex on the upper surface of the airfoil, and effectively controlling the stall condition of the airfoil surface. According to actual needs, the air supply rate of the air supply device can be set according to the size of the air inlet passage 23 and the air hole of the exhaust passage. In a certain state, the air inlet and exhaust rates of the containing space 22 are similar, the leading edge of the blade main body 1 remains smooth, and the aerodynamic performance of the fan blade is not affected.

[0047] Optionally, the air inlet passage 23 and / or the exhaust passage are circular passages, square passages or the like. In the embodiment, the air inlet passage 23 and the exhaust passage are both circular passages, and the output pipe of the air pump is a circular pipe. The circular air inlet passage 23 is matched with the circular pipe, so that the air pump can supply gas to the containing space 22, and the air tightness of gas transmission is also ensured to prevent air leakage. Optionally, the diameter of the air inlet passage 23 and / or the exhaust passage ranges from 1mm to 2mm, which can be set according to actual needs.

[0048] Based on the same inventive concept, the application further provides a static stall control method of the new fan blade. The method comprises: when the new fan blade is in a rated working condition, the air pressure in the blade static stall control module 2 changes, and the elastic sealing structure 21 vibrates. As known from the above, when the elastic sealing structure 21 on the surface of the blade main body 1 vibrates, the stall vortex on the leading edge of the airfoil can be effectively broken, thereby effectively controlling the stall condition of the fan blade surface. Meanwhile, according to the actual working environment of the fan blade, the air pressure in the blade static stall control module 2 is adjusted, and the stall condition can be actively adjusted.

[0049] Further, the static stall control method of the new fan blade further comprises: the air supply device supplies gas to the containing space 22 through the air inlet passage 23; the air pressure in the containing space 22 changes, and the elastic sealing structure 21 vibrates. By adjusting the amount or speed of the gas supplied to the containing space 22 by the air supply device, the vibration frequency or amplitude of the elastic sealing structure 21 can be effectively controlled, the stall flow condition of the fan blade surface is improved, the stall vortex on the leading edge of the airfoil is effectively broken, and the stall noise of the fan blade surface is reduced.

[0050] Further, the static stall control method of the new fan blade of the present application further comprises that the accommodating space 22 is externally exhausted through the exhaust passage, and the air pressure in the accommodating space 22 continuously changes. The gas supply device supplies gas to the accommodating space 22 through the gas inlet passage 23, and simultaneously discharges the gas in the accommodating space 22 externally through the exhaust passage, so that the gas in the accommodating space 22 is always in a dynamic flow state, and the changing air pressure in the accommodating space 22 makes the elastic sealing structure 21 at the top thereof keep a vibrating state, so as to continuously break the stall vortex on the surface of the airfoil blade body 1, and realize the active control of the stall condition of the fan blade.

[0051] In summary, in the new fan blade and the static stall control method thereof, the fan blade combines the blade body 1 and the blade static stall control module 2 containing the elastic sealing structure 21, adjusts the air pressure state in the blade static stall control module 2, makes the elastic sealing structure 21 connected with the surface of the blade body 1 vibrate, effectively breaks the stall vortex generated on the leading edge surface of the blade body 1, and realizes the active adjustment of the stall condition of the fan blade.

[0052] Further, the accommodating space 22 of the blade static stall control module 2 of the fan blade is respectively communicated with the gas inlet passage 23 and the exhaust passage, the gas supply device supplies gas to the accommodating space 22 through the gas inlet passage 23, and simultaneously the gas in the accommodating space 22 is discharged externally through the exhaust passage, so that the gas in the accommodating space 22 is in a dynamic balance state, and the elastic sealing structure 21 is in a continuous vibrating state, so as to realize the continuous regulation and control of the stall condition of the fan blade.

[0053] Although the content of the present application has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present application. After the above description is read by those skilled in the art, various modifications and substitutions of the present application will be apparent. Therefore, the protection scope of the present application should be defined by the appended claims.

Claims

1. A new type of fan blade characterized in that, The new fan blade comprises: a blade body; a plurality of blade static stall control modules arranged on the leading edge surface of the blade body, the blade static stall control module comprising an elastic sealing structure connected with the surface of the blade body, the air pressure in the blade static stall control module being adjustable, and the elastic sealing structure vibrating when the air pressure in the blade static stall control module changes; wherein the distance between the blade static stall control module and the top end of the blade body ranges from 10% to 12% of the chord length of the blade body; the blade static stall control module further comprising: a containing space which is a groove structure on the surface of the blade body, and the elastic sealing structure being arranged on the top of the containing space; a gas supply device which supplies gas into the containing space through a gas inlet channel to change the air pressure in the containing space, and the elastic sealing structure vibrating when the air pressure in the containing space changes; a gas outlet channel which is in communication with the containing space to discharge the gas in the containing space; in actual application, the gas supply device delivers gas into the containing space to change the air pressure in the containing space, and the gas outlet channel discharges the gas in the containing space to the outside, so that the air pressure in the containing space is always in a dynamic change process, and the elastic sealing structure is always kept vibrating.

2. The new fan blade according to claim 1, wherein: the groove structure is square, rectangular, rhombic or irregular in shape; and / or, the width of the groove structure ranges from 1% to 2% of the chord length of the blade body; and / or, the depth of the groove ranges from 3mm to 4mm; and / or, the gas inlet channel is a circular channel; and / or, the gas supply device is an air pump.

3. The new fan blade according to claim 2, wherein: the diameter of the gas inlet channel ranges from 1mm to 2mm.

4. The new fan blade according to claim 1, wherein: the blade static stall control module is arranged on the upper surface and / or the lower surface of the leading edge of the blade body; and / or, the elastic modulus of the elastic sealing structure ranges from 0.003 to 0.05; and / or, the elastic sealing structure is an elastic film; and / or, the elastic sealing structure is bonded with the surface of the blade body.

5. A method of stall control of a new type of fan blade according to any one of claims 1 to 4, characterized in that, When the new fan blade is in the rated operating condition, the air pressure in the blade static stall control module changes, and the elastic sealing structure vibrates. Further comprising:

6. A novel static stall control method for a fan blade as claimed in claim 5, characterized by, the gas supply device delivers gas into the containing space through the gas inlet channel; the air pressure in the containing space changes, and the elastic sealing structure vibrates. Further comprising:

7. The novel static stall control method of a fan blade as claimed in claim 6, wherein, the containing space discharges gas to the outside through the gas outlet channel, and the air pressure in the containing space continuously changes. ​

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