阅读说明：本技术 叶片边界层流动控制系统及包括其的风力发电机组 (Blade boundary layer flow control system and wind generating set comprising same ) 是由 赵越 金孝龙 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种叶片边界层流动控制系统及包括其的风力发电机组,叶片边界层流动控制系统包括：风机叶片,风机叶片为弹性体,具有吸力面、压力面、叶片前缘以及叶片后缘,其中,风机叶片的内部形成有叶片腔体；第一导流段,第一导流段与叶片腔体连通；第二导流段,第二导流段与第一导流段连通,且第二导流段设置于吸力面的靠近叶片后缘一侧,第二导流段具有导流气孔。本发明在不使用额外气泵、抽气机等气流产生设备,不额外消耗能量的情况下,仅利用风电机组运行过程中风机叶片自身弹性变形产生的空气流动,对叶片边界层进行流动控制,实现抑制叶片边界层分离,延迟风机叶片失速,提高风机叶片的气动性能,提升风力发电机组发电量的效果。(The invention discloses a blade boundary layer flow control system and a wind generating set comprising the same, wherein the blade boundary layer flow control system comprises: the fan blade is an elastic body and is provided with a suction surface, a pressure surface, a blade front edge and a blade rear edge, wherein a blade cavity is formed inside the fan blade; the first flow guide section is communicated with the blade cavity; and the second flow guide section is communicated with the first flow guide section, is arranged on one side of the suction surface close to the rear edge of the blade and is provided with a flow guide air hole. According to the invention, under the conditions of not using extra air pump, air extractor and other air flow generating equipment and not consuming extra energy, the flow control is carried out on the blade boundary layer only by utilizing the air flow generated by the elastic deformation of the fan blade in the running process of the wind turbine generator, so that the effects of inhibiting the separation of the blade boundary layer, delaying the stall of the fan blade, improving the pneumatic performance of the fan blade and improving the generating capacity of the wind turbine generator are realized.)

1. A blade boundary layer flow control system, comprising:

the fan blade is an elastic body and is provided with a suction surface, a pressure surface, a blade root end, a blade tip end, a blade front edge and a blade rear edge, wherein a blade cavity is formed inside the fan blade;

the first flow guide section is communicated with the blade cavity;

the second flow guide section is communicated with the first flow guide section and is arranged on one side, close to the trailing edge of the blade, of the suction surface, and provided with a flow guide air hole, wherein when the blade cavity is contracted, internal air is sprayed out of the flow guide air hole, and when the blade cavity is expanded, external air is sucked in from the flow guide air hole.

2. The blade boundary layer flow control system of claim 1, wherein a blade root baffle is disposed inside the blade root end, the blade root baffle is provided with a vent hole and a manhole cover, and the first flow guiding section is communicated with the blade cavity through the vent hole.

3. The blade boundary layer flow control system of claim 2, wherein the root end is connected to a hub, and the first inducer portion is routed from inside the hub to outside the root end and is in communication with the second inducer portion.

4. The blade boundary layer flow control system of claim 3, wherein the first flow guiding section is a soft pipe and the second flow guiding section is a hard pipe, wherein one end of the second flow guiding section is connected with the first flow guiding section and the other end is sealed.

5. The blade boundary layer flow control system of claim 2, wherein the second flow section extends from the root end toward the tip end.

6. The blade boundary layer flow control system of claim 2, wherein the air vent has a raised portion with respect to the root baffle, the raised portion being sealingly connected to the first inducer.

7. The blade boundary layer flow control system of claim 1, wherein the suction surface is provided with the second inducer proximate a trailing edge of the blade, and wherein the suction surface is provided with the second inducer or a vortex generator proximate a leading edge of the blade.

8. The blade boundary layer flow control system of claim 7, wherein a length of the second inducer proximate a side of the trailing edge of the blade corresponds to a length of the second inducer proximate a side of the leading edge or the vortex generator.

9. The blade boundary layer flow control system of claim 8, wherein the second inducer is disposed at a length between 0% and 50% of a total length of the fan blade.

10. The blade boundary layer flow control system of claim 1, wherein a side of the suction surface proximate the trailing edge of the blade is provided with a plurality of rows of the second inducer.

11. The blade boundary layer flow control system of claim 1, wherein the second inducer has a first surface facing upward and a second surface facing the blade trailing edge, wherein the first surface is streamlined and the inducer air holes are disposed in the second surface.

12. The blade boundary layer flow control system of claim 11, wherein an angle formed by a normal to the second surface and a tangent to the suction surface in a direction of the trailing edge of the blade ranges from 0 ° to 45 °.

13. The blade boundary layer flow control system of claim 1, wherein the second flow guiding section is attached to the suction surface by double-sided tape or adhesive, the double-sided tape or adhesive having a thickness of less than 1mm, the second flow guiding section having a height of less than 10mm normal to the suction surface.

14. A wind park according to any of claims 1-13, wherein the wind park comprises a blade boundary layer flow control system.

Technical Field

The invention relates to a blade boundary layer flow control system and a wind generating set comprising the same.

Background

When the wind generating set operates, if the attack angle of the blade is too large, the blade can generate a boundary layer flow separation phenomenon called as blade stall, the lift force of the blade can be rapidly reduced due to the flow separation, the resistance can be rapidly increased, the aerodynamic performance of the blade can be reduced, and the power generation amount loss is serious. With the maximization of wind power blades, the requirements on the blade structure are higher and higher, and the airfoil profile with large thickness and blunt trailing edge becomes the first choice of the airfoil profile at the end of the blade root. In the operation process of the wind turbine generator, boundary layer flow separation is easy to occur in a blade root area using a large-thickness airfoil, and then three-dimensional flow along the span direction of the blade is generated, so that the aerodynamic performance of the blade is reduced.

The airfoil boundary layer flow control technology is an effective means for inhibiting boundary layer flow separation and delaying blade stall, and comprises technologies such as a vortex generator and surface blowing and sucking.

Chinese patent document CN108087193A relates to a blade, a blade synergistic system and a wind turbine generator system, in which a draft tube is embedded in a suction surface and a pressure surface of the blade, and an air pump is controlled to suck air or inject air through the draft tube based on wind speed and incoming flow attack angle, so as to achieve the purpose of flow control and further avoid stall.

Chinese patent document CN106762402A relates to a wind turbine blade flow control device based on a combined jet technology and a control method thereof, the device is provided with a high-pressure air chamber and a front edge jet orifice on the front edge of the blade, a low-pressure air chamber and a rear edge suction port on the rear edge, the high-pressure air chamber is connected with the front edge jet orifice, the low-pressure air chamber is connected with the rear edge suction port, the high-pressure air chamber and the low-pressure air chamber are connected with an air pump device, and through the combination of the front edge jet orifice and the rear edge suction, the cut-in speed of the blade can be effectively reduced, the.

According to the scheme, extra air flow generating equipment such as an air pump and an air extractor is needed to blow and suck air to the surface of the blade, extra electric energy is consumed, and if the energy consumed by the air flow generating equipment such as the air pump and the air extractor is more than the generated energy increased by the wind turbine generator through the flow control means, energy loss is caused, and the significance of increasing work is lost.

Disclosure of Invention

The invention aims to overcome the defects that in the prior art, extra electric energy is consumed for blowing and sucking air to the surface of a blade, energy loss is caused, and the significance of power increase is lost, and provides a blade boundary layer flow control system and a wind generating set comprising the same.

The invention solves the technical problems through the following technical scheme:

a blade boundary layer flow control system, comprising:

the fan blade is an elastic body and is provided with a suction surface, a pressure surface, a blade root end, a blade tip end, a blade front edge and a blade rear edge, wherein a blade cavity is formed inside the fan blade;

the first flow guide section is communicated with the blade cavity;

the second flow guide section is communicated with the first flow guide section and is arranged on one side, close to the trailing edge of the blade, of the suction surface, and provided with a flow guide air hole, wherein when the blade cavity is contracted, internal air is sprayed out of the flow guide air hole, and when the blade cavity is expanded, external air is sucked in from the flow guide air hole.

The blade boundary layer flow control system provided by the invention utilizes the gas flow generated by the elastic deformation of the fan blade in the operation process of the wind generating set to blow and suck the gas in the blade boundary layer. When the internal volume of the blade cavity is reduced, the extruded air can flow through the first flow guide section, is sprayed out from the second flow guide section to the flow guide air holes, and is injected with high-energy gas into the boundary layer by blowing, so that the boundary layer is further developed towards the rear edge, the boundary layer separation is delayed, the load of the fan blade is reduced, the pneumatic performance of the fan blade is improved, and the power generation is improved;

when the internal volume of the blade cavity is increased, external air is sucked into the blade cavity from the guide air holes of the second guide section by the low pressure in the blade cavity, and low-energy gas in a blade boundary layer is sucked into the blade cavity, so that external high-energy gas is supplemented into the boundary layer, the boundary layer can be further developed towards the rear edge, the boundary layer separation is delayed, the blade load is reduced, the pneumatic performance of the fan blade is improved, and the generating capacity is improved.

Therefore, the boundary layer flow control system can perform flow control on the boundary layer of the blade by only utilizing the airflow change generated by the elastic deformation of the fan blade in the running process of the wind turbine generator set without using additional airflow generation equipment such as an air pump and an air extractor and without additionally consuming energy, thereby realizing the effects of inhibiting the separation of the boundary layer of the blade, delaying the stall of the fan blade, improving the pneumatic performance of the fan blade and improving the power generation capacity of the wind turbine generator set.

Preferably, a blade root baffle is arranged inside the blade root end, a vent hole and a manhole cover are arranged on the blade root baffle, and the first flow guide section is communicated with the blade cavity through the vent hole. Through the setting of the air vent on the blade root baffle, the shell of the fan blade can be prevented from being perforated, and therefore the structural strength of the fan blade cannot be reduced. The vent hole is used as the only inlet and outlet of the airflow in the blade cavity and is connected with the first flow guide section.

Preferably, the blade root end is connected to the hub, and the first flow guide section is wound out from the inside of the hub to the outer side of the blade root end and communicated with the second flow guide section. The first flow guide section bypasses the hub, and extension between the inner side and the outer side of the blade root end is achieved.

Preferably, the first flow guiding section is a soft pipe, the second flow guiding section is a hard pipe, wherein one end of the second flow guiding section is connected with the first flow guiding section, and the other end of the second flow guiding section is sealed. The soft tube facilitates extension of the first flow guide section between the inner side and the outer side of the root end of the blade.

Preferably, the second flow guide section extends from the root end towards the tip end. Therefore, the covering distance of the second guide section along the longitudinal direction of the fan blade can be increased, particularly, the phenomenon of boundary layer flow separation is easily generated at the end of the blade root, and therefore the aerodynamic performance can be obviously improved.

Preferably, the ventilation hole has a raised portion relative to the root baffle, and the raised portion is in sealing connection with the first flow guide section.

Preferably, one side of the suction surface, which is close to the trailing edge of the blade, is provided with the second guide section, and one side of the suction surface, which is close to the leading edge of the blade, is provided with the second guide section or the vortex generator. The second guide section and the vortex generator which are arranged close to one side of the front edge of the blade can further improve the aerodynamic performance of the fan blade.

Preferably, the length of the second flow guiding section near the trailing edge of the blade is the same as the length of the second flow guiding section or the vortex generator near the leading edge.

Preferably, the length of the second guide section is 0-50% of the total length of the fan blade.

Preferably, a plurality of rows of the second guide sections are arranged on one side of the suction surface close to the trailing edge of the blade. The multiple rows of the second guide sections can further reduce the phenomenon of boundary layer flow separation, so that the aerodynamic performance can be obviously improved.

Preferably, the second guide section has a first surface facing upward and a second surface facing the trailing edge of the blade, wherein the first surface is streamlined, and the guide air holes are disposed on the second surface. The streamlined first surface minimizes its effect on the aerodynamic profile of the fan blade. The orientation of the second surface enables the blowing and sucking air of the diversion air holes to act on the boundary layer more accurately.

Preferably, the angle formed by the normal direction of the second surface and the tangential direction of the suction surface facing the trailing edge direction of the blade is in the range of 0 ° to 45 °.

Preferably, the second flow guide section is attached to the suction surface through a double-sided tape or an adhesive layer, the thickness of the double-sided tape or the adhesive layer is less than 1mm, and the height of the second flow guide section in the normal direction of the suction surface is less than 10 mm. Therefore, the height of the second guide section is reduced as much as possible, and the influence on the aerodynamic shape of the fan blade is reduced.

A wind park according to any of the preceding claims, characterised in that the wind park comprises the blade boundary layer flow control system.

The positive progress effects of the invention are as follows: the boundary layer flow control system can perform flow control on the boundary layer of the blade by only utilizing the air flow generated by the elastic deformation of the fan blade in the running process of the wind turbine generator set under the conditions of not using additional air pump, air extractor and other air flow generating equipment and not additionally consuming energy, thereby realizing the effects of inhibiting the separation of the boundary layer of the blade, delaying the stall of the fan blade, improving the pneumatic performance of the fan blade and improving the generating capacity of the wind turbine generator set.

Drawings

FIG. 1 is a schematic top view of a blade boundary layer flow control system according to embodiment 1 of the present invention.

Fig. 2 is a schematic structural view of a fan blade according to embodiment 1 of the present invention.

FIG. 3 is a schematic side view of a blade boundary layer flow control system according to embodiment 1 of the present invention.

Fig. 4 is a schematic cross-sectional view of a second flow guide section in embodiment 1 of the present invention.

Fig. 5 is a schematic structural view of a blade root baffle of a fan blade according to embodiment 1 of the present invention.

Fig. 6 is a schematic view of connection of a root end of a fan blade according to embodiment 1 of the present invention.

Fig. 7 is a schematic structural view of a wind turbine generator system according to embodiment 1 of the present invention.

FIG. 8 is a schematic top view of a blade boundary layer flow control system according to embodiment 2 of the present invention.

FIG. 9 is a schematic side view of a blade boundary layer flow control system according to embodiment 2 of the present invention.

FIG. 10 is a schematic top view of a blade boundary layer flow control system according to embodiment 3 of the present invention.

FIG. 11 is a schematic side view of a blade boundary layer flow control system according to embodiment 3 of the present invention.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.