JP2012246812A - Wind power generation blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the falling of a thunderbolt on a metallic thunder receiving part boundary and an inside anchor, while restraining a blade weight increase and separation of a conductive material coating film, in a wind power generation blade.SOLUTION: This wind power generation blade includes a blade body 1a, a metallic thunder receiving part (a tip thunder receiving part 2) arranged in the blade body 1a, and a down conductor 4 for electrically connecting the thunder receiving part and the earth, a thunder can be captured by a conductive material 6 when a lightening stroke falls in a position dislocated from the metallic thunder receiving part by covering the conductive material 6 on the surface side of at least the blade body 1a by limiting to the periphery of a boundary 5 between a thunder receiving part surface and a blade body 1a surface, and a lightening stroke current quickly flows to the vicinal metallic thunder receiving part via the covered conductive material 6, and damage of the blade body 1a is effectively prevented.

Description

  The present invention relates to a blade for wind power generation that suppresses lightning damage to FRP (fiber reinforced plastic) around a metal lightning receiving portion.

  Wind farms are preferably constructed in so-called windy areas where strong winds are stable, but these areas are open lands without high mountains and trees in the vicinity. There are many. In recent years, there are examples of constructing wind power plants in mountainous areas because the preferred land of flat areas is becoming limited. It is obvious that when a windmill with a blade tip height of around 100m is constructed in such an open land or in a mountainous area, it is easy to receive lightning strikes, and many windmills actually suffer lightning strikes every year. . The blades that are particularly susceptible to lightning strikes are blades that tend to concentrate the electric field in shape and have a short distance from the thundercloud. If a blade is severely damaged by a lightning strike, it often takes a lot of time and money to repair it.

In order to increase the lightning resistance of the blade for wind power generation, various devices have been made so far. For example, in Patent Document 1, it is said that lightning damage to an FRP blade body can be effectively prevented by providing an aluminum blade tip material on the blade body.
Patent Documents 2 and 3 propose means for covering the entire surface of the blade body with a conductive material, and it is possible to minimize damage to the blade body made of FRP regardless of where the blade surface is subjected to lightning strikes. Yes.
Patent Document 4 proposes a blade that is grounded after the conductive band is fixed over the entire length of the leading edge (LE, leading edge) or the trailing edge (TE, trailing edge). Patent Document 5 proposes a blade provided with a coupling band for electrically connecting both edges in addition to the conductive band of the leading edge (LE) and the trailing edge (TE).

JP 2005-113735 A JP 2004-245174 A JP 2005-171916 A JP 2010-223147 A JP 2009-115052

As a result of our own lightning damage records on windmills and various lightning tests using simulated specimens, it became clear that lightning strikes were concentrated in and around metal lightning strikes. . When the metal part receives a lightning stroke, the metal at the lightning stroke is slightly melted and a lightning current can be safely passed to the ground, and the FRP blade body is not damaged. However, when lightning strikes toward the lightning strike boundary or the embedded anchor portion, the FRP blade body is not a little damaged. In some cases, momentary evaporation of moisture and resin causes an increase in internal pressure, and the blade adhesion surface may be peeled off.
Therefore, it is difficult to say that a blade using aluminum at the tip as in Patent Document 1 is sufficient as a countermeasure against lightning strikes.

  On the other hand, as disclosed in Patent Documents 2 and 3, it is considered that the idea of covering the entire surface of the blade body with a conductive material can effectively reduce lightning damage including penetration of the blade body made of FRP. However, a considerable covering thickness is required for this conductive material to maintain sufficient durability against large current lightning often observed in strong lightning areas such as the coast of the Sea of Japan. Applying such a thick conductive material coating to the entire surface of the blade increases the weight of the blade, but due to differences in stiffness and thermal expansion coefficient between FRP and the conductive material. An adverse effect is considered that the conductive material is peeled off from the FRP blade body due to the deflection of the blade in service or the temperature change.

  Patent Documents 4 and 5 disclose a device in which a lightning stroke is received by a conductive band fixed to the outer surface of a leading edge (LE) or a trailing edge (TE), and a lightning current is passed to the hub through the conductive band. ing. However, if the conductive band is laid on the outer surface in this manner, the conductive band may be damaged or dropped due to the impact of lightning strikes or blade deformation during service, and the current instantaneously reaches several hundred kA. It is unsuitable for applications where lightning currents flow.

  An object of the present invention is to suppress a lightning strike to the anchor when having a metal lightning strike boundary and an internal anchor while minimizing an increase in blade weight and peeling of a conductive material film. .

  That is, among the blades for wind power generation according to the present invention, the first aspect of the present invention is to electrically connect a blade body, a metal lightning receiving portion provided on the blade body, and the lightning receiving portion and the ground. And a down conductor for performing, and limited to the periphery of the boundary between the surface of the lightning receiving part and the surface of the blade body, and at least the surface side of the blade body is coated with a conductive material, To do.

  A blade for wind power generation according to a second aspect of the present invention is characterized in that, in the first aspect of the present invention, the power receiving portion includes a tip power receiving portion provided at a tip of a blade body as the lightning receiving portion.

  The blade for wind power generation according to the third aspect of the present invention is the blade according to the first or second aspect of the present invention, wherein one or more blades provided between the proximal end side and the distal end side of the blade body as the lightning receiving portion. It has an intermediate lightning receiving portion.

  The blade for wind power generation according to a fourth aspect of the present invention is the blade according to any one of the first to third aspects of the present invention, wherein the covering range of the conductive material is from the boundary between the surface of the lightning receiving part and the surface of the blade body. It is 0.1 m or more and 2 m or less on the main body side.

  The blade for wind power generation according to a fifth aspect of the present invention is the blade according to any one of the first to fourth aspects, wherein the conductive material is in contact with the lightning receiving portion over the entire length of the boundary. Features.

  The blade for wind power generation according to the sixth aspect of the present invention is the blade according to any one of the first to fifth aspects of the present invention, wherein the covering range of the conductive material is received from the boundary between the surface of the lightning receiver and the surface of the blade body. It is 0.1 m or more on the lightning part side.

  In the blade for wind power generation according to the seventh aspect of the present invention, in any one of the first to sixth aspects of the present invention, the coating thickness of the conductive material is 0.1 mm or more and 10 mm or less.

  The blade for wind power generation according to the eighth aspect of the present invention is characterized in that, in any of the first to seventh aspects of the present invention, the surface of the conductive material is coated.

According to the present invention, when a lightning strike falls to a position off the metal lightning receiving section, the lightning is captured by the conductive material, and the lightning strike current is quickly made from the nearby metal via the coated conductive material. It flows into the lightning section.
The metal lightning protection section is provided on the blade body, and shows the lightning protection section provided at the tip of the blade body and the intermediate lightning protection section provided between the base end and the tip of the blade body. It is. The number of intermediate lightning receiving portions may be one or more. In the present invention, the arrangement of the tip lightning receiving portion is essential, and the presence or absence and the number of intermediate lightning receiving portions are representative. However, it is not limited to this.
The lightning receiving part that is to be covered with a conductive material around the boundary may be the entire lightning part provided on the blade body, and in particular a part of the lightning receiving part that is particularly susceptible to lightning. It may be. Therefore, when it has a tip lightning-receiving part and an intermediate lightning-receiving part, you may provide the coating | cover with an electroconductive material only on the tip lightning-receiving part side.

The blade body is made of a material other than metal and is usually made of FRP (fiber reinforced plastic). Moreover, it may be a composite using FRP as a main component and partially using wood or foam.
The shape of the blade body is not particularly limited in the present invention, and the shape can be appropriately selected.

The shape of the metal lightning receiving portion is not particularly limited as the present invention, and the presence or absence of the anchor portion is not particularly limited.
The metal lightning receiving portion is selected from metals and alloys having conductivity and corrosion resistance. Among these, aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof is preferable. Further, the material may be changed between the lightning receiving parts, for example, the material may be different between the lightning receiving part and the intermediate lightning receiving part.

The conductive material disposed around the boundary between the lightning receiving portion surface and the blade body surface is coated on the blade body surface in the form of a metal mesh, metal foil, metal plating, metal spraying, conductive paint, or the like.
Although it is possible for the present invention to cover a part of the entire boundary length, it is desirable to cover the entire boundary length.
The conductive material is selected from metals and alloys having conductivity and corrosion resistance. Among these, aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof is preferable. The material of the lightning receiver and the conductive material may be the same or different. However, when the ionization tendency of the lightning receiving portion and the conductive material are greatly different, it is generally easy to cause corrosion. Therefore, it is desirable to consider the combination of the lightning receiving member material and the conductive material material.
As the filler of the conductive paint, aluminum, copper, silver, tungsten, nickel, carbon and the like can be considered, but are not particularly specified in the present invention. A plurality of the above conductive materials may be selected and combined (for example, a conductive paint is applied on a metal mesh).

The coating thickness of the conductive material is not limited to a specific range in the present invention, but can be determined from the viewpoint of durability against lightning strikes and adhesive strength. For example, 0.1 mm or more and 10 mm or less are desirable.
If it is less than 0.1 mm, it cannot be said that it is sufficient in terms of durability against lightning strikes. On the other hand, when the thickness exceeds 10 mm, the adhesive strength is lowered and peeling is likely to occur. For this reason, the said range is desirable for the coating thickness of an electroconductive material. In the same range, it is more desirable that the lower limit is 0.5 mm and the upper limit is 3 mm.

Further, from the results of the lightning strike test, it was found that the covering range of the conductive material is preferably 0.1 m or more and 2 m or less from the boundary between the lightning receiving portion and the blade body toward the blade body.
If it is less than 0.1 m, lightning cannot be sufficiently captured when the lightning strike falls to a position off the metal lightning receiving portion. On the other hand, even if the covering range of the conductive material exceeds 2 m, the effect is only saturated, and the weight of the entire blade for wind power generation increases.
For the same reason, it is more desirable that the lower limit of the covering range is 0.2 m and the upper limit is 1 m.

In addition, if the contact area between the coated conductive material and the metal lightning receiving portion is small, it may not be able to withstand a large current load and may be burned out. Therefore, it is desirable that the conductive material and the metal lightning receiving portion are in contact over the entire length of the boundary. Furthermore, in order to obtain sufficient durability against electric current, it is preferable to cover a range of 0.1 m or more from the boundary between the lightning receiving portion and the blade body to the lightning receiving portion side with a conductive material. Since the upper limit is not defined, the entire surface of the lightning receiving portion may be covered with a conductive material.
Further, in order to improve the aesthetic appearance, the coated conductive material may be coated with putty or paint. The paint can be made the same color as the other blade body, so that it can be integrated.

According to the present invention, since the conductive material is coated on the surface of the blade body around the metal lightning portion where lightning strikes are easily induced, even if the lightning strike falls off the metal lightning portion. Lightning can be captured on conductive materials. The lightning strike current quickly flows to the nearby metal lightning receiving portion via the coated conductive material, and can effectively prevent damage to the blade body.
In addition, since the covering range of the conductive material is limited to the periphery of the metal lightning receiving portion, an increase in the weight of the blade can be minimized. At the same time, since the coating range is narrow, even if a deflection or temperature difference occurs during service, the conductive material film easily follows the deformation of the blade body, and the possibility of peeling is very low.

In addition, since the down conductor is provided as a main path for flowing the lightning strike current to the ground, the loss of the conductive path, which is a concern in Patent Documents 4 and 5, does not occur.
As described above, according to the present invention, it is possible to dramatically improve the lightning resistance of the blade while suppressing increase in blade weight and peeling of the conductive material.

It is a figure which shows the whole blade for wind power generation which has a tip lightning-receiving part. It is a figure which shows the braid | blade front-end | tip part using a chip | tip tip lightning-receiving part, (a) is explanatory drawing which does not coat | cover with a conductive material, (b) is explanatory drawing which coat | covered the conductive material, (c) ) Is an explanatory view of a modified example of the covering of the conductive material. It is a figure which shows the braid | blade front-end | tip part using a disk type front lightning-receiving part, (a) is explanatory drawing which does not coat | cover with a conductive material, (b) is explanatory drawing which coat | covered the conductive material. It is a figure which shows the braid | blade front-end | tip part which used the rod-type front-end | tip lightning receiving part, (a) is explanatory drawing which does not coat | cover with a conductive material, (b) is explanatory drawing which coat | covered the conductive material. It is a figure which shows the whole blade for wind power generation which has a front lightning receiving part and an intermediate | middle lightning receiving part. It is a figure which shows the braid | blade intermediate part using an intermediate | middle lightning-receiving part, (a) is explanatory drawing which does not coat | cover with a conductive material, (b) is explanatory drawing which coat | covered the conductive material.

Below, the blade for wind power generation of one embodiment of the present invention is explained.
FIG. 1 shows an overall view of a blade 1 for wind power generation.
The blade 1 for wind power generation has an overall shape and has a blade body 1a made of FRP, and a metal tip light-receiving section 2 is provided at the tip. The metal tip lightning receiving portion 2 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof. The front lightning receiving part 2 and the blade body 1a are formed with the same surface. A down conductor 4 is connected to the tip lightning receiving portion 2. The down conductor 4 is electrically connected to the tip lightning receiving portion 2 and wired to the base of the blade body 1 a, and then a hub, nacelle, not shown, It is grounded via a tower. By configuring the down conductor 4 with a conductive wire having a sufficiently large cross-sectional area, a lightning strike current can be passed to the ground without causing personal injury or equipment damage.

Next, the part which expanded the front-end | tip part of the blade for wind power generation is demonstrated below.
FIG. 2A shows a connection structure of the tip lightning receiving portion 2. As shown in the drawing, the tip lightning receiving portion 2 is a tip type lightning receiving portion which is a type of the tip lightning receiving portion.
The tip lightning receiving portion 2 has an anchor portion 20 at a base portion to prevent dropping due to centrifugal force. By embedding the anchor portion 20 in the blade body 1a, the tip lightning receiving portion 2 can be securely attached to the blade body. 1a is fixed. The down conductor 4 is electrically connected to the anchor portion 20.

As an embodiment of the present invention, the tip of the blade for wind power generation shown in FIG. 2A is coated with a conductive material as shown in FIGS. 2B and 2C.
In the form of FIG. 2 (b), the entire surface of the tip lightning receiving portion 2 and conductive over the blade body 1a side in a predetermined range beyond the boundary 5 between the surface of the tip lightning receiving portion 2 and the surface of the blade body 1a. The material 6 is coated.
The conductive material 6 is coated in the form of metal mesh, metal foil, metal plating, metal spraying, conductive paint, etc., but the present invention is not limited to a specific method. The coating is preferably performed in the range of 0.1 mm to 10 mm.

The conductive material 6 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof.
The conductive material 6 is preferably coated in a range of 0.1 m or more from the boundary 5 to the tip lightning receiving portion 2 side over the entire tip lightning receiving portion 2. The conductive material 6 is preferably coated on the blade body 1a side surface in a range of 0.1 m to 2 m.

In the form of FIG. 2 (c), a blade body within a predetermined range beyond a boundary 5 between the surface of the tip lightning receiving portion 2 and the surface of the blade body 1a in a partial region excluding the tip end side of the tip lightning receiving portion 2. The conductive material 6 is covered over the 1a side.
On the blade body 1a side, similarly to the above, the blade body 1a side is preferably coated in the range of 0.1 m to 2 m. In addition, the tip power receiving unit 2 side is preferably covered within a range of 0.1 m or more from the boundary 5 to the tip light receiving unit 2 side and not reaching the tip of the tip light receiving unit 2.

Next, a description will be given of the blade 1 to which the disk-type tip lightning receiving portion 21 which is a type of the lightning receiving portion is applied.
FIG. 3A is a diagram showing an arrangement configuration of the disk-type tip lightning receiving portion 21 in the blade body 1a.
That is, a metal columnar disc type lightning striker 21 is embedded on the front end side of the blade body 1a so that the surface is exposed. The disk-type tip lightning detector 21 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof.
The surface of the disk-type tip lightning receiving portion 21 and the surface of the blade body 1a are flush with each other, and the boundary between the surface of the disk-type tip lightning receiving portion 21 and the surface of the blade body 1a is formed at the periphery of the disk-type tip lightning receiving portion 21. 5a. Further, the down conductor 4 is electrically connected to the disk-type tip lightning receiver 21.

As an embodiment of the present invention, the tip of the blade for wind power generation shown in FIG. 3 (a) is coated with a conductive material as shown in FIG. 3 (b).
That is, in the form of the blade 1 having the disk-type tip lightning-receiving portion 21, as shown in FIG. In this range, the conductive material 7 is coated. The conductive material 7 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof. The conductive material 7 is coated in the form of metal mesh, metal foil, metal plating, metal spraying, conductive paint, etc., and preferably has a thickness of 0.1 mm to 10 mm.

  The disk-type tip lightning receiving portion 21 has a diameter of 0.2 m or more in the surface direction. As a result, the disk-type tip lightning receiving portion 21 extends from the boundary 5a to the lightning receiving portion side. The conductive material 7 is covered in a range of 0.1 m or more. Further, the conductive material 7 is coated on the surface on the blade body 1a side from the boundary 5a in a range of 0.1 m to 2 m at any position.

Next, the blade 1 to which the rod-type tip lightning receiving portion 22 which is a type of the tip lightning receiving portion is applied will be described.
FIG. 4A is a diagram illustrating a configuration in which the rod-type tip lightning receiving portion 22 is attached to the blade body 1a.
That is, the rod-type tip lightning receiving portion 22 is embedded in the blade body 1a from the tip of the blade body 1a in the longitudinal direction of the blade body 1a, and only the tip is exposed from the blade body 1a. The boundary between the peripheral edge of the exposed portion of the rod-type tip lightning receiver 22 and the surface of the blade body 1a is the boundary 5b of the present invention.
The rod-type tip lightning detector 22 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof. A down conductor 4 is electrically connected to the base end side of the rod-type tip lightning receiving portion 22.

  In the form of the blade 1 having the rod-type tip lightning receiving portion 22, in the embodiment of the present invention, as shown in FIG. 4B, the conductive material 8 is within a predetermined range from the tip of the blade body 1a to the base end. Is covered. The conductive material 8 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof. The conductive material 8 is coated in the form of a metal mesh, metal foil, metal plating, metal spraying, conductive paint, etc., and preferably has a thickness of 0.1 mm to 10 mm.

As a result, if the rod-type tip lightning-receiving part 22 has a diameter of 0.2 m or more, the conductive material 8 is covered in a range of 0.1 m or more from the boundary 5b to the lightning-receiving part side. become.
In addition, the conductive material 8 is coated in a range extending beyond the boundary 5b toward the base end side of the blade body 1a, and from the boundary 5b to the blade body 1a surface toward the base end side within 0.1 m to 2 m. In this range, the conductive material 8 is coated.

Next, FIG. 5 shows the entire wind power generation blade 10 having an intermediate lightning receiving portion.
This blade 10 for wind power generation also has a blade body 10a that is formed in an overall shape and is made of FRP, and is provided with a metal tip light-receiving section 23 at the tip. The tip lightning detector 23 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof. As described above, the tip-type lightning detector, the disk-type tip lightning detector, and the rod Various types of tip lightning detectors such as a mold tip lightning detector can be selected.

Further, between the base end portion and the tip end portion of the blade main body 10a, a plurality of metal intermediate lightning receiving portions 3 are provided on the flap surface of the blade main body 10a at predetermined intervals (for example, equal intervals) in the longitudinal direction. . The metal intermediate lightning receiving portion 3 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof.
The tip lightning receiver 23 and the intermediate lightning receiver 3 are each electrically connected to the down conductor 14. The down conductor 14 is grounded via a hub, a nacelle, and a tower after being wired to the base of the blade 1 for wind power generation.

Next, the part which expanded the intermediate part in the blade main body 10a of the said blade for wind power generation is demonstrated based on Fig.6 (a) (b).
FIG. 6A shows the arrangement structure of the intermediate lightning receiver 3.
That is, the tip-shaped, circular-shaped intermediate lightning light receiving portion 3 is embedded on the surface of the blade body 10a with the surface exposed.
A boundary 5 c between the surface of the intermediate lightning receiver 3 and the surface of the blade body 10 a is along the periphery of the intermediate lightning receiver 3. Here, the shape of the intermediate lightning receiving portion 3 is circular in terms of surface shape, but may be polygonal or elliptical in terms of surface shape.

As shown in FIG. 6 (b), the surface of the blade body 10a covers the surface of the blade body 10a so as to extend beyond the boundary 5c, including the surface of the intermediate lightning section 3, as shown in FIG. 6 (b). Has been. The conductive material 9 is made of aluminum, copper, tungsten, nickel, titanium, stainless steel, or an alloy thereof. The conductive material 9 is coated in the form of metal mesh, metal foil, metal plating, metal spraying, conductive paint, etc., and preferably has a thickness of 0.1 mm or more and 10 mm or less.
In addition, if the intermediate lightning receiving part 3 has a diameter of 0.2 m or more, the conductive material 9 is covered in a range of 0.1 m or more from the boundary 5 c to the lightning receiving part side. .
Further, the conductive material 9 is coated so as to extend beyond the boundary 5c to the blade body 1a side, and the conductive material 9 is coated on the blade body 1a side within a range of 0.1 m to 2 m from the boundary 5c. Has been.

  Although the tip lightning receiving portion 23 has not been described in detail above, the tip lightning receiving portion 23 is similar to the tip lightning receiving portion 2, the disk-type tip lightning receiving portion 21, and the rod-type tip lightning receiving portion 22 described above. The conductive material is preferably coated with a thickness of 0.1 mm or more and 10 mm or less on the surface side of the blade body 10a and the surface side of the tip lightning receiver 23 only around the boundary between the lightning portion 23 and the blade body 10a. . In this case, on the tip lightning receiving portion 23 side, the conductive material is coated in a range of 0.1 m or more from the boundary between the tip lightning receiving portion 23 and the blade body 1a, and on the blade body 1a side, the tip lightning receiving portion 23 and The conductive material is coated in the range of 0.1 m to 2 m from the boundary with the blade body 1a.

  As described above, the present invention has been described based on the above embodiment, but the scope of the present invention is not limited to the contents described above, and appropriate modifications can be made without departing from the scope of the present invention. It is.

DESCRIPTION OF SYMBOLS 1 Wind power generation blade 1a Blade body 2 Tip lightning receiving part 21 Disk type tip lightning receiving part 22 Rod type tip lightning receiving part 3 Intermediate lightning receiving part 4 Down conductor 5 Boundary 5a Boundary 5b Boundary 5c Boundary 6 Conductive material 7 Conductivity Material 8 Conductive material 9 Conductive material

Claims (8)

  A blade main body, a metal lightning receiving portion provided on the blade main body, and a down conductor for electrically connecting the lightning receiving portion and the ground, the lightning receiving portion surface and the blade A blade for wind power generation, characterized in that the conductive material is coated on at least the surface side of the blade body, limited to the periphery of the boundary with the body surface.   2. The blade for wind power generation according to claim 1, further comprising a tip power receiving portion provided at a tip of a blade body as the lightning receiving portion.   3. The blade for wind power generation according to claim 1, wherein the lightning receiving portion includes one or more intermediate lightning receiving portions provided between a proximal end side and a distal end side of the blade body. .   The covering range of the conductive material is 0.1 m or more and 2 m or less from the boundary between the lightning receiving portion surface and the blade body surface to the blade body side. The blade for wind power generation described.   The blade for wind power generation according to any one of claims 1 to 4, wherein the conductive material is in contact with the lightning receiving portion over the entire length of the boundary.   The covering range of the conductive material is 0.1 m or more from the boundary between the surface of the lightning receiving portion and the surface of the blade body to the lightning receiving portion side. Blade for wind power generation.   The blade for wind power generation according to any one of claims 1 to 6, wherein a coating thickness of the conductive material is 0.1 mm or more and 10 mm or less.   The blade for wind power generation according to any one of claims 1 to 7, wherein the surface of the conductive material is coated.

Images