ES2363615A1 - Shelf for wind turbines (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Shovel for wind turbines that extends from a root (1) where the blade is attached to a rotor, to a point (2). The blade has fastening elements for replaceably mounting the tip (2) on one end (3) of the blade opposite the root. The tip (2) has the following characteristics: length l, 0'1m <= l <= 0.6m, volume less than 0.03m 3 ; it is aerodynamic and has a series of geometric tolerances: rope: -0.3mm; profile thickness: -0.2mm; output edge thickness: -0.1mm; torsion: -0.05º; has a thickness e and a string c, e> 14% c; it is made of machinable material. (Machine-translation by Google Translate, not legally binding)

Description

Wind turbine blade.

Field of the Invention

The invention relates to blades for wind turbines that incorporate an aerodynamic blade tip for decrease aerodynamic noise.

Background of the invention

The aerodynamic noise generated by the blades of The wind turbines can be classified according to the following criterion:

-

Noise of turbulent boundary layer at the trailing edge: it originates from a fluctuating pressure deficit between the pressure side and the side of suction when the flow reaches the trailing edge. Frequency is broadband and is related to boundary layer parameters (typically from 100 Hz to 10,000 Hz, more present at medium frequencies around 1000 Hz).

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Noise tip: originated by turbulence in the vortex of the tip. The frequency is broadband and is related to the diameter of the tip vortex (typically between 1000 Hz and 8000 Hz)

-

Noise loss input: it is caused by pressure fluctuations in the areas of flow separation, often present at high angles of attack The frequency is broadband and is related to the extent of the area of entry into loss (typically between 20 Hz and 1000 Hz).

-

Noise of vortexes of the laminar boundary layer: it originates from the instabilities on the pressure side of the boundary layer causing the Vortex formation The frequency is tonal and is related to the thickness of the boundary layer on the pressure side (typically between 1000 Hz and 4000 Hz).

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Noise blunt exit edge: originates from the small separation zone of flow behind a blunt exit edge that causes the formation of vortices (well known as von Karman's vortex formation). The frequency is tonal and is related to the thickness of the edge output (typically between 1000 Hz and 4000 Hz).

-

Noise of flow over holes, cuts, intrusions: originates from flows unstable and by the formation of vortices. The frequency is tonal and it is related to the dimension of the distorting elements of the flow (typically between 1000 Hz and 10000 Hz).

The blade object of the invention helps to reduce aerodynamic noise produced during the operation of the wind turbine

ES2161196 shows a lightning rod installation for wind turbines comprising an aluminum cap in the end of each blade, an aluminum profile on the edge of each blade and a conductor parallel to the blade mast so that the profile and the driver drift a lightning bolt in parallel.

WO2005031158 shows a shovel for wind turbines comprising lightning protection means. To the less a section of the blade tip is metal and is part of the means of protection.

Description of the invention

An aspect of the invention relates to a shovel for wind turbines that extends from a root where the shovel It is attached to a rotor, to a point. The tip of the shovel of the invention allows to achieve geometric tolerances in this area criticism of the blade that can not be achieved by design usual shovel; Normally, the blades are made of fiber carbon, and the blade tip of the invention allows to achieve some thicknesses that cannot be found with carbon fiber. This control dimensional implies that the dispersion in the noise generated in the blade tip, which is ± 1 dB in conventional blades, it can be reduced to ± 0.5 dB in the blades of the invention. The shovel:

understand means fixing to replace the tip at one end from the blade opposite the root;

the tip:

has a length L, 0.1 m? L0.6 m;

has a volume enough to achieve the required tolerances that allow solve noise problems, typically the volume is less than 0.03 m 3;

is aerodynamic and has a plurality of geometric tolerances comprised between:

string: ± 0.3 mm;

thickness of profile: ± 0.2 mm;

edge thickness output: ± 0.1 mm;

torsion: ± 0.05;

has a thickness E and a rope C, E> 14% C;

it is made of material machinable

The values in the tolerances that are achieved in conventional blades against those allowed by the present invention:

one

The fixing means may comprise first fasteners and second fasteners selected from:

a plurality of threaded holes and screws;

a plurality of overlap tabs;

a plurality of crimping edges;

and combinations thereof;

the first fasteners being located in a component selected between, the tip and the end, and the second fasteners in the conjugate component for constitute the fixation between both components.

The blade may also comprise:

a trailing edge of the material shovel metallic from the root to the tip.

In the blade of the invention, at least one element selected between the tip and the trailing edge, you can also comprise drainage means constituted by at least one drill through from an inner cavity to an outer surface, the outer surface being continuous.

Additionally, in the blade of the invention, the minus one element selected between the tip and the trailing edge it can also comprise beaconing means constituted by a accommodation provided with a light source covered by a housing flush with the outer surface.

On the other hand, at least one selected item between the tip and the trailing edge can be of a material added with conductive particles configured to derive a lightning discharge to a lightning transmission system included in the blade, with the tip along with the trailing edge weighing less than 90 kg

The trailing edge may comprise a plurality of sections joined one after the other, configured to be disassembled independently and to ensure a electrical conductivity from the tip to the root.

Brief description of the drawings

Then it goes on to describe very brief a series of drawings that help to better understand the Invention and that expressly relate to an embodiment of said invention presented as a non-limiting example of is.

Figure 1 is a side view of a wind turbine showing the blade of the invention.

Figures 2A, 2B, 2C show different means fixing the tip to the end.

Figure 3 shows a shovel tip and an edge output

Description of a preferred embodiment of the invention

An embodiment of the invention relates to a wind turbine blade that extends from a root (1) where The blade is attached to a rotor, up to a tip (2). The shovel:

understand means for mounting the tip (2) in a replaceable way end (3) of the blade opposite the root;

tip (2):

has a length L, 0.1 m? L0.6 m;

has a volume less than 0.03 m 3;

is aerodynamic and has a plurality of geometric tolerances comprised between:

string: ± 0.3 mm;

thickness of profile: ± 0.2 mm;

edge thickness output: ± 0.1 mm;

torsion: ± 0.05;

has a thickness E and a rope C, E> 14% C;

it is made of material machinable

The fixing means comprise first fasteners (100, 101, 102) and second elements of fixing (200, 201, 202) selected from:

a plurality of threaded holes (100) and screws (200);

a plurality of overlap tabs (101, 201);

a plurality of crimping edges (102, 202);

and combinations thereof;

the first fasteners being (100, 101, 102) located on a component selected from the tip (2) and the end (3), and the second fixing elements (200, 201, 202) in the conjugate component (3, 2) to constitute the fixation between both components.

The blade also includes:

an edge of output (4) of the metal material blade from the root (1) to the tip (2).

In an embodiment of the invention, at least one element selected between the tip (2) and the trailing edge (4), it also includes drainage means constituted by at least one through hole (22, 32) from an inner cavity (20, 30) to an outer surface (21, 31), the outer surface being (21, 31) continue.

Additionally, in another embodiment of the invention, at least one element selected between the tip (2) and the trailing edge (4) also comprises beaconing means constituted by an accommodation (23, 33) provided with a source light (24, 34) covered by a housing (25, 35) flush with the outer surface (21, 31).

\hbox{junto con
el borde de salida (4) un peso inferior a 90 kg.}

In another embodiment of the invention, at least one element selected between the tip (2) and the trailing edge (4) is of a material added with conductive particles configured to derive a lightning discharge to an included lightning transmission system. on the shovel, having the tip (2)

 \ hbox {along with
the trailing edge (4) weighing less than 90 kg.} 

The trailing edge (4) comprises a plurality of sections joined one after the other, configured to be disassembled independently and to ensure a electrical conductivity from the tip (2) to the root (1).

Claims (7)

1. A wind turbine blade that extends from a root (1) where the blade is attached to a rotor, to a tip (2), characterized in that:

understand means for mounting the tip (2) in a replaceable way end (3) of the blade opposite the root;

tip (2):

has a length L, 0.1 m? L0.6 m;

has a volume less than 0.03 m 3;

is aerodynamic and has a plurality of geometric tolerances comprised between:

string: ± 0.3 mm;

thickness of profile: ± 0.2 mm;

edge thickness output: ± 0.1 mm;

torsion: ± 0.05;

has a thickness E and a rope C, E> 14% C;

it is made of material machinable

2. The blade of claim 1 characterized in that the fixing means comprise first fixing elements (100, 101, 102) and second fixing elements (200, 201, 202) selected from:

a plurality of threaded holes (100) and screws (200);

a plurality of overlap tabs (101, 201);

a plurality of crimping edges (102, 202);

and combinations thereof,

the first fasteners being (100, 101, 102) located on a component selected from the tip (2) and the end (3), and the second fixing elements (200, 201, 202) in the conjugate component (3, 2) to constitute the fixation between both components. 3. The blade of any of claims 1-2 characterized in that it further comprises an exit edge (4) of the blade of metallic material from the root (1) to the tip (2). The blade of any one of claim 3 characterized in that at least one element selected between the tip (2) and the trailing edge (4), furthermore comprises drainage means constituted by at least one through hole (22, 32) from an inner cavity (20, 30) to an outer surface (21, 31), the outer surface (21, 31) being continuous. 5. The blade of any of claims 3-4 characterized in that at least one element selected between the tip (2) and the trailing edge (4) further comprises beaconing means constituted by a housing (23, 33) provided with a light source (24, 34) covered by a housing (25, 35) flush with the outer surface (21, 31). 6. The blade of any one of claims 3-5 characterized in that at least one element selected between the tip (2) and the trailing edge (4) is of a material added with conductive particles configured to derive a lightning strike discharge. a lightning transmission system included in the blade, the tip (2) together with the trailing edge weighing less than 90 kg. 7. The blade of claim 6-7 characterized in that the trailing edge (4) comprises a plurality of sections joined one after the other, configured to be disassembled independently and to ensure an electrical conductivity from the tip (2) to the root (1).