CN108661852B - Composite protective layer and blade - Google Patents

Abstract

The invention provides a composite protective layer and a blade. The composite protective layer includes a coating layer and a preformed elastomeric layer, the coating layer being applied to an upper surface of the preformed elastomeric layer. According to the invention, a composite protective layer with reliable protection capability and a blade with reliable protection capability and easy maintenance of the leading edge can be provided.

Description

Composite cover and blades

technical field

The present invention relates to blade technology, in particular, to a blade leading edge protection structure.

Background technique

As the core component of capturing wind energy, wind turbine blades are huge and expensive. If the leading edge of the wind turbine blade is eroded, it will not only affect the power generation of the unit, but also bring hidden dangers to the safe operation of the unit. Studies have shown that moderate front edge erosion can result in a loss of more than 10% of annual power generation. If these leading edge erosions cannot be repaired in time, the damage to the leading edge of the blade will be further aggravated within 2-3 years, eventually leading to structural damage to the blade, bringing greater risks and losses. With the continuous enlargement of large-scale wind turbine blades, the blade tip speed continues to increase, which increases the rain erosion strength of the leading edge of the blade, and the requirements for the ability of the leading edge protective layer continue to increase.

Film protection is an effective protection technology for the leading edge of wind turbine blades. The protective film used is W8607 of 3M Company, which is the most widely used. It is a transparent polyurethane rubber film, which is coated with high-weather-resistant acrylic pressure-sensitive adhesive on one side. Treated blade surface coating. Its good rebound characteristics can disperse the impact force of moving particles on the blade protective film to nearby areas, so it has excellent erosion resistance. The film is pasted after the blade has completed the coating process and the paint is fully cured. Specifically, the surface of the filmed area of the leading edge of the blade was first sanded with fine sandpaper, followed by cleaning, then the protective film was wet-applied, the air bubbles were driven out with a soft scraper, and finally the protective film and the blade were coated with a polyurethane sealant. The overlapping parts of the layers are edge-sealed. Care must be taken throughout the construction process to ensure that the final protective capacity is properly established. The thickness of this protective film is usually 300 μm. One reason for not using a thicker film is that the step effect caused by the thick film will seriously affect the aerodynamic efficiency of the blade. Moreover, in the case of using film protection, it is very difficult to repair, and it is necessary to completely remove the film, rebuild the coating surface, and apply the film again.

In addition, coating technology is another effective protection technology for the leading edge of wind turbine blades. Compared with protective film technology, the advantage of coating technology lies in good weather resistance, which greatly improves the service life of the protective layer. However, the main problem with coating technology is that it is usually difficult to build a thick protective layer, prone to cracking and poor curing, and may require multiple applications to seriously affect the efficiency.

To sum up, the advantages of the protective film technology are that the film is prefabricated, and the thickness and thickness uniformity are guaranteed, but the weather resistance is poor, and air bubbles are easily included during construction; the coating technology has the advantage of good weather resistance, but it is not easy to Controls the thickness to be uniform, so both have their pros and cons.

SUMMARY OF THE INVENTION

In order to solve one or more of the above problems, the present invention provides a composite protective layer, the composite protective layer includes a coating layer and a prefabricated elastomer layer, and the coating layer is coated on the upper surface of the prefabricated elastomer layer.

Wherein, the pull-out strength between the prefabricated elastomer layer and the coating layer may be above 5MPa.

Wherein, the material of the prefabricated elastomer layer may be rubber.

Wherein, the prefabricated elastomer layer may be a film with a uniform thickness or a film with an uneven thickness.

Wherein, the prefabricated elastomer layer may be a film with a thick center and a thin edge, or the prefabricated elastomer layer may be a film with a thick edge and a thin center.

Wherein, the prefabricated elastomer layer may be provided with holes, and the coating material may be filled in the holes.

The hole diameter may be 0.5-1 mm, and the hole spacing of the plurality of holes may be 10-20 mm.

Wherein, the composite protective layer may include a plurality of prefabricated elastomer layers, and adjacent prefabricated elastomer layers may be butted against each other.

Wherein, the material of the prefabricated elastomer layer may be polyurethane, polyurea or ethylene propylene rubber.

Wherein, the thickness of the prefabricated elastomer layer may be less than 6000 microns, and the thickness of the coating layer may be less than 500 microns.

The present invention also provides a blade, wherein the above-mentioned composite protective layer is provided on the leading edge surface of the blade, and the lower surface of the prefabricated elastomer layer is fixed on the leading edge surface of the blade.

Wherein, the coating can completely cover the prefabricated elastomer layer, and the material of the coating can smoothly fill and cover the step formed by the edge of the prefabricated elastomer layer and the surface of the leading edge of the blade.

Wherein, the blade may be a blade of a wind turbine.

Through the invention, through the synergistic application of the protective film technology and the coating technology, the advantages of the two are combined and the shortcomings of the two are avoided, a thick composite protective layer is jointly constructed, and a blade with reliable protective ability and easy leading edge maintenance is realized. .

Description of drawings

Fig. 1 is the schematic diagram of the composite protective layer 1 of the embodiment 1 of the present invention;

Fig. 2 is the schematic diagram of the composite protective layer 1 of embodiment 2 of the present invention;

Fig. 3 is the schematic diagram of the composite protective layer 1 of embodiment 3 of the present invention;

FIG. 4 is a schematic view of the blade 20 with the composite protective layer 1 of the present invention pasted on the leading edge.

Symbol Description

1 Composite protective layer

11 Coatings

12 Prefabricated elastomer layers

121 holes

122 steps

2 FRP

20 blades

Detailed ways

The blade of the present invention is not limited to the blade of the wind turbine, and can also be applied to blades used in other occasions, such as helicopter propeller blades.

Hereinafter, specific embodiments of the composite protective layer of the present invention will be described with reference to the accompanying drawings, taking the blade of the wind turbine as an example.

Example 1

FIG. 1 is a schematic diagram of the composite protective layer 1 of Example 1 of the present invention. As can be seen from FIG. 1 , the composite protective layer 1 includes a coating layer 11 and a prefabricated elastomer layer 12 , and the coating layer 11 is coated on the upper surface of the prefabricated elastomer layer 12 . In addition, FIG. 4 is a schematic view of the blade 20 to which the composite protective layer 1 of the present invention is attached to the leading edge. 1 and 4 , the composite protective layer 1 is provided on the leading edge surface of the blade 20 , and the lower surface of the prefabricated elastomer layer 12 is fixed on the leading edge surface of the blade 20 . In FIG. 1 , 2 denotes glass fiber reinforced plastic, which is a material constituting the leading edge surface of the blade 20 . The preferred parameters of the composite protective layer 1 of this embodiment will be described in more detail below with reference to the process flow.

First, the prefabricated elastomer layer 12 is directly bonded with an adhesive on the FRP 2 on the leading edge surface of the blade 20 after the modification treatment. During this process, the elastomer layer 12 may be integrally formed or formed by connecting two or more prefabricated elastomer layers 12 . Specifically, the connection between two or more prefabricated elastomer layers 12 is handled by butt joint. Wherein, the so-called butt joint means that the edges of the two prefabricated elastomer layers 12 are completely abutted without covering each other. Then, on the surface of the bonded prefabricated elastomer layer 12, paint is applied, and after thermal curing, a coating layer 11 covering the upper surface of the prefabricated elastomer layer 12 is formed. Since the upper surface of the prefabricated elastomer layer 12 is completely coated The layer 11 wraps and thus avoids direct sunlight, thereby enhancing weather resistance. In addition, it is preferable to activate the surface of the prefabricated elastomer layer 12 by chemical treatment or physical means such as plasma flame, so as to connect the prefabricated elastomer layer 12 . Sufficient interfacial strength is ensured due to the strong interaction between the coating 11 and the prefabricated elastomer layer 12 up to the level of chemical bonds. In this embodiment, the pull-out strength between the coating layer 11 and the prefabricated elastomer layer 12 is 5 MPa or more.

In this way, the prefabricated elastomer layer 12 and the coating layer 11 together construct the composite protective layer 1, and the thickness of the final composite protective layer 1 can be adjusted by selecting prefabricated elastomer layers 12 with different thicknesses, so that the thickness of the composite protective layer 1 exceeds 1mm.

Since the rain erosion resistance of the leading edge protective layer is greatly affected by the thickness of the protective layer in practical production applications, the theoretical analysis of the impact of raindrops on the glass fiber reinforced plastic coating shows that the thickness is the key factor affecting the ability of the protective layer. Therefore, , a thicker protective layer can provide better protection. The existing theory of raindrops impacting FRP coatings has shown that a 10% increase in thickness may bring more than a 30% increase in protection capability. In addition, the thick protective layer also helps to resist large diameter raindrops.

According to the technical solution of the present invention, the thickness of the composite protective layer 1 can reach more than 1000 microns.

Moreover, according to the technical solution of the present invention, since the composite protective layer 1 includes the prefabricated elastomer layer 12 and the coating layer 11 covering the upper surface of the elastomer layer 12, if the coating layer 11 is damaged during the use of the blade, it will endanger the lower layer. When the prefabricated elastomer layer 12 is removed, maintenance can be initiated and only the reconstruction of the coating layer 11 is performed, thereby permanently retaining the prefabricated elastomer layer 12. Compared with the prior art, which requires complete removal of the film and reprocessing of the blade surface, the entire maintenance process is more efficient. simple.

In addition, in this embodiment, the prefabricated elastomer layer 12 is directly attached to the glass fiber reinforced plastic 2 on the front edge surface through an adhesive, but the present invention is not limited to this. The prefabricated elastomer layer 12 can also be fixed on the FRP 2 by means of mechanical connection or the like.

In addition, in this embodiment, the material of the prefabricated elastomer layer 12 is rubber, specifically, a homogeneous polyurethane elastomer. However, the material of the prefabricated elastomer layer 12 of the present invention is not limited to this, and may also be polyurea , ethylene propylene rubber and any other rubber materials.

In addition, in this embodiment, the prefabricated elastomer layer 12 is a film with a uniform thickness. However, the present invention is not limited thereto, and the prefabricated elastomer layer 12 may also be a film with a non-uniform thickness (ie, a film with a variable thickness). In practical production applications, the thicknesses of different parts of the prefabricated elastomer layer 12 can be reasonably set according to requirements (eg, the surface condition of the leading edge of the blade 20 ). For example, the prefabricated elastomer layer 12 can be thick in the middle and thin at the edges. The film, or the prefabricated elastomer layer 12 can also be a film that is thick at the edges and thin in the middle.

In addition, the thickness of the prefabricated elastomer layer 12 is not limited, and the thickness of the prefabricated elastomer layer 12 can be reasonably set by considering factors such as processing needs, use environment, reducing the influence of the step effect, or improving the aerodynamic performance. For example, the thickness of the prefabricated elastomer layer 12 can be set in consideration of the rainfall intensity, air temperature, average annual rainfall, etc. of the site of use. Specifically, the thickness of the prefabricated elastomer layer 12 can be set relatively thin in areas with small rainfall and small raindrops, such as northwestern my country, while in Thailand and other areas with heavy rainfall and large raindrops, the prefabricated elastomer layer 12 can be set relatively thin. The thickness of the layer 12 is set relatively thick. Since the thickness of the prefabricated elastomer layer 12 is also preferably equal to the diameter of the local raindrops, usually the diameter of the raindrops is between 0 and 6000 microns. Therefore, considering various influences, the thickness of the prefabricated elastomer layer 12 can be 6000 microns or less. , the thickness of the prefabricated elastomer layer 12 is preferably 4000 microns or less, and more preferably the thickness of the prefabricated elastomer layer 12 is 3000 microns or less.

In this embodiment, the material of the coating layer 11 is a high-elasticity aliphatic polyurethane topcoat, but the coating layer 11 of the present invention only needs to have a protective function, and its material is not limited. For example, it can be various polymer materials such as other polyurethane, polyurea, epoxy resin, fluororesin, etc. Specifically, it can be polyvinylidene fluoride-acrylate, trifluoroethylene and alkyl vinyl ether alternating copolymer , Polyaspartic acid coatings, etc. Furthermore, the material of the coating layer 11 may be other inorganic paints such as metallic paints.

In addition, the thickness of the coating layer 11 is not limited, and can be reasonably set as required. Generally, the thickness of the coating layer 11 can be set to about 100 microns. If the thickness of the coating layer 11 is too thick, it will be easily affected by the environment. For example, an excessively thick coating 11 is prone to cracking due to the material of the coating 11 in an environment with high temperature and high humidity. Therefore, the thickness of the coating 11 of the present invention may be less than 500 microns, preferably the thickness of the coating 11 is less than 400 microns, and more preferably the thickness of the coating 11 is less than 300 microns. It should be noted that the closer the elastic moduli of the prefabricated elastomer layer 12 and the coating layer 11 are, the more favorable it is to form an effective chemical connection between the prefabricated elastomer layer 12 and the coating layer 11, and strengthen the prefabricated elastomer layer 12 and the coating layer 11. Pull strength between layers 12.

Example 2

FIG. 2 is a schematic diagram of the composite protective layer 1 of Example 2 of the present invention. The difference between the composite protective layer 1 of this embodiment and the composite protective layer 1 of Embodiment 1 is that the prefabricated elastomer layer 12 is provided with a plurality of holes 121 evenly distributed, and the material of the coating layer 11 is filled in the holes 121 .

Specifically, the prefabricated elastomer layer 12 provided with a plurality of holes 121 in advance is pasted on the FRP 2 . Air bubbles generated during the film sticking process can be discharged through the hole 121 . Then, the polymer material is painted. During the painting process, the polymer material fills the holes 121 and forms a coating layer 11 covering the prefabricated elastomer layer 12 on the surface of the prefabricated elastomer layer 12 .

In this embodiment, the plurality of holes 121 are evenly distributed on the prefabricated elastomer layer 12 , but the present invention is not limited thereto, and the plurality of holes 121 may also be unevenly distributed on the prefabricated elastomer layer 12 .

With such a configuration, when the prefabricated elastomer layer 12 is pasted, it is possible to facilitate exhaust air and prevent the generation of air bubbles. Furthermore, by filling the material of the coating layer 11 in the holes 121, the connection strength between the prefabricated elastomer layer 12 and the coating layer 11 can be improved.

In addition, although the installation of holes 121 on the prefabricated elastomer layer 12 can facilitate the pasting construction and increase the connection strength between the prefabricated elastomer layer 12 and the coating layer 11, after the prefabricated elastomer layer 12 is perforated, the The opening may become hard, and the protection may fail prematurely at the opening during use, resulting in uneven protection performance. Moreover, in the case of opening the pores, too large a pore diameter may make it difficult to fill the pores 121 with the material of the coating 11 , and if the pore diameter is too small, it is difficult to effectively improve the connection strength between the prefabricated elastomer layer 12 and the coating 11 . , considering the above factors comprehensively, the diameter of the hole 121 of the present invention may be 0.5-1 mm, preferably 0.7-0.9 mm, and more preferably 0.8 mm. In addition, the hole pitch of the holes 121 may be 10 to 20 mm, preferably 12 to 18 mm, and more preferably 13 to 17 mm.

It should be noted that, in the case where the prefabricated elastomer layer 12 does not have holes, it is not necessary to have holes if the basic requirements for construction and the interface connection between layers are met. The surface of the prefabricated elastomer layer 12 can be subjected to surface treatment without opening pores, for example, by increasing the surface roughness of the prefabricated elastomer layer 12, setting textures, etc. to increase the interface between the prefabricated elastomer layer 12 and the coating layer 11 connection strength.

Example 3

FIG. 3 is a schematic diagram of the composite protective layer 1 of Example 3 of the present invention. The difference between the composite protective layer 1 of the present embodiment and the composite protective layer 1 of the embodiment 2 is that for the step 122 formed between the edge of the prefabricated elastomer layer 12 and the surface of the glass fiber reinforced plastic 2, the material of the coating layer 11 is filled smoothly and Step 122 is covered.

With this configuration, the step 122 at the edge of the prefabricated elastomer layer 12 is filled and covered with the material of the coating layer 11 , so that the smoothness is excessive and the influence on the aerodynamic efficiency caused by the step effect can be reduced.

It should be noted that although in this embodiment, the material of the coating layer 11 smoothly fills and covers the step 122 formed by the edge of the prefabricated elastomer layer 12 and the surface of the FRP 2, the present invention is not limited to this. The material of the coating 11 can smoothly fill and cover any unevenness (such as gaps, etc.) formed at the edge of the prefabricated elastomer layer 12 to achieve a smooth transition, thereby reducing the impact on aerodynamic efficiency caused by the step effect. That is, in order to prevent the step effect from affecting the aerodynamic efficiency of the blade 20 , the coating 11 completely covers the prefabricated elastomer layer 12 .

Of course, the composite protective layer 1 in this embodiment is not limited to be fixedly formed on the outer surface of the leading edge of the blade 20 that has already satisfied the aerodynamic performance design, that is, fixedly formed on the surface of the blade 20 that has been formed. In order to further reduce the possible step effect caused by adding the composite protective layer 1 , a groove can be machined on the surface of the leading edge of the blade, and the size of the groove is basically the same as that of the composite protective layer 1 .

To sum up, according to the present invention, through the synergistic application of protective film technology and coating technology, the advantages of the two are combined to avoid the disadvantages of the two, and a thick protective layer is jointly constructed to realize the improvement of the protective ability. The basic idea is to build a prefabricated elastomer layer with or without openings, and then coat the surface of the prefabricated elastomer layer with a polymer coating to form an integrated composite protective layer. Among them, prefabricated elastomer layers are used to increase thickness, and coatings are used to resist the effects of natural aging. This technology facilitates the efficient construction of composite protective layers with thicknesses over 1mm. Also, it is easier to maintain. Specifically, according to the present invention, the difficulty of making a thick protective layer is reduced, and a thick protective layer can be produced on the premise of ensuring stable material properties; the disadvantage of poor weather resistance of prefabricated films is avoided, and the reliability of the protective layer is improved. ; Enhance the protective ability of the protective layer, improve the service life of the protective layer, and ensure the construction efficiency; only rebuild the coating during maintenance, which makes the entire maintenance process easier.

Although the present invention has been described in conjunction with the above-described embodiments, the present invention is not limited to the embodiments, and various variations and modifications may be made without departing from the scope of the present invention.

Claims (12)

1. The utility model provides a composite protective layer (1), its characterized in that, composite protective layer (1) includes coating (11) and prefabricated elastomer layer (12), coating (11) coat in the upper surface on prefabricated elastomer layer (12) be equipped with hole (121) on prefabricated elastomer layer (12), the material of coating (11) fill in hole (121), the aperture of hole (121) is 0.5 ~ 1 mm.

2. The composite protective layer (1) according to claim 1, characterized in that the pull strength between the preformed elastomer layer (12) and the coating layer (11) is 5MPa or more.

3. Composite protective layer (1) according to claim 1, wherein the material of the preformed elastomer layer (12) is rubber.

4. Composite protective layer (1) according to claim 1, characterized in that said preformed elastomeric layer (12) is a film of uniform thickness or a film of non-uniform thickness.

5. Composite protective layer (1) according to claim 4, characterized in that the preformed elastomer layer (12) is a thin film thick in the middle and thin at the edges, or the preformed elastomer layer (12) is a thin film thick at the edges and thin in the middle.

6. The composite protective layer (1) according to claim 1, wherein the plurality of holes (121) have a hole pitch of 10 to 20 mm.

7. Composite protective layer (1) according to claim 1, characterized in that the composite protective layer (1) comprises a plurality of preformed elastomer layers (12), adjacent preformed elastomer layers (12) abutting each other.

8. Composite protective layer (1) according to claim 3, characterized in that the material of the preformed elastomer layer (12) is polyurethane, polyurea or ethylene propylene rubber.

9. Composite protective layer (1) according to any one of claims 1 to 8, wherein the thickness of the preformed elastomer layer (12) is 6000 microns or less and the thickness of the coating layer (11) is less than 500 microns.

10. A blade, characterized in that a composite protective layer (1) according to any one of claims 1-9 is provided on the leading edge surface of the blade, and that the lower surface of the preformed elastomer layer (12) is fixed to the leading edge surface of the blade.

11. Blade according to claim 10, characterized in that the coating (11) completely covers the preformed elastomer layer (12), the material of the coating (11) filling and covering smoothly the step (122) formed by the edge of the preformed elastomer layer (12) and the leading edge surface of the blade.

12. A blade according to claim 10 or 11, wherein the blade is a blade of a wind park.

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