CN108661852B

CN108661852B - Composite protective layer and blade

Info

Publication number: CN108661852B
Application number: CN201810410745.3A
Authority: CN
Inventors: 贾智源; 李小明
Original assignee: Jiangsu Goldwind Science and Technology Co Ltd
Current assignee: Jiangsu Goldwind Science and Technology Co Ltd
Priority date: 2018-05-02
Filing date: 2018-05-02
Publication date: 2020-03-17
Anticipated expiration: 2038-05-02
Also published as: CN108661852A

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 protective layer and blade

Technical Field

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

Background

The wind power blade is used as a core component for capturing wind energy, and has huge size and high manufacturing cost. If the front edge of the wind power blade is corroded, the generated energy of the unit is influenced, and meanwhile, hidden dangers are brought to safe operation of the unit. It has been shown that moderate front erosion results in a loss of over 10% of annual energy production. If these leading edge erosion cannot be timely repaired, the damage to the leading edge of the blade can be further aggravated within 2-3 years, eventually leading to structural damage to the blade with greater risk and loss. With the continuous large-scale of the large-scale fan blade, the blade tip speed is continuously improved, the rain erosion strength borne by the front edge of the blade is increased, and the requirement on the capability of the front edge protective layer is continuously improved.

The film pasting protection is an effective protection technology for the front edge of the wind power blade. The protective film used is the most applied amount of W8607 of 3M company, is a transparent polyurethane rubber film, is coated with high weather-resistant acrylic pressure-sensitive adhesive on one side, has soft texture and excellent flexibility and ductility, and can be tightly attached to the surface coating of the treated blade. The good rebound characteristic can disperse the impact force of moving particles on the blade protective film to the nearby area, so that the blade protective film has excellent erosion resistance. The film pasting is to carry out pasting construction after the coating process of the blade is completed and the paint is fully cured. Specifically, the surface of a film pasting area at the front edge of the blade is firstly polished by fine sand paper, then cleaned, then a protective film is pasted by a wet method, bubbles are removed by a soft scraper, and finally the overlapping part of the protective film and the blade coating is subjected to edge sealing treatment by using a polyurethane sealant. The entire construction process must be careful to ensure that the final protective capacity is properly established. The thickness of such a protective film is typically 300 μm, and one reason for not using a thicker film is that the step effect caused by the thick film can seriously affect the aerodynamic efficiency of the blade. In addition, when the film is used for protection, it is very difficult to perform maintenance, and it is necessary to completely remove the film, reconstruct the coating surface, and apply the film again.

Besides, the coating technology is another effective protection technology for the leading edge of the wind power blade. Compared with the protective film technology, the coating technology has the advantages of good weather resistance and greatly prolonged service life of the protective layer. However, the coating technique has problems in that it is generally not easy to construct a thick protective layer, cracking and curing failure are easy, and further, it may require many times of construction to seriously affect efficiency.

In conclusion, the protective film technology has the advantages that the film is prefabricated, the thickness and the uniformity of the thickness are guaranteed, but the weather resistance is poor, and air bubbles are easily mixed during construction; the coating technology has the advantages of good weather resistance, but uniform thickness cannot be easily controlled, so that the coating technology and the coating technology have the advantages and the disadvantages.

Disclosure of Invention

To address one or more of the above concerns, the present invention provides a composite protective layer comprising a coating layer and a preformed elastomeric layer, the coating layer being applied to an upper surface of the preformed elastomeric layer.

Wherein the pullout strength between the preformed elastomer layer and the coating layer may be 5MPa or more.

Wherein the material of the preformed elastomer layer may be rubber.

The preformed elastomer layer may be a thin film of uniform thickness or a thin film of non-uniform thickness, among others.

Where the preformed elastomer layer may be a thick-in-the-middle and thin-in-the-middle film, or the preformed elastomer layer may be a thick-in-the-middle and thin-in-the-middle film.

Wherein holes may be provided in the preformed elastomeric layer and the material of the coating may fill the holes.

Wherein, the aperture of the hole can be 0.5-1 mm, and the hole interval of a plurality of holes can be 10-20 mm.

Wherein the composite protective layer may comprise a plurality of preformed elastomer layers, adjacent preformed elastomer layers may be butted against each other.

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

Wherein the preformed elastomer layer may have a thickness of 6000 microns or less and the coating may have a thickness of less than 500 microns.

The invention also provides a blade, wherein the composite protective layer is arranged on the front edge surface of the blade, and the lower surface of the prefabricated elastomer layer is fixed on the front edge surface of the blade.

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

Wherein, the blade can be a blade of a wind generating set.

According to the invention, the protective film technology and the coating technology are cooperatively applied, so that the advantages of the protective film technology and the coating technology are combined, the defects of the protective film technology and the coating technology are overcome, a thick composite protective layer is jointly constructed, and the blade with reliable protective capability and easy front edge maintenance is realized.

Drawings

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

fig. 2 is a schematic view of a composite protective layer 1 of embodiment 2 of the present invention;

fig. 3 is a schematic view of the composite protective layer 1 of embodiment 3 of the present invention;

fig. 4 is a schematic view of a blade 20 having a composite protective layer 1 according to the invention attached to the leading edge.

Description of the symbols

1 composite protective layer

11 coating

12 preformed elastomeric layer

121 holes

122 step

2 glass fibre reinforced plastic

20 blade

Detailed Description

The blade of the invention is not limited to a blade of a wind generating set, but can also be applied to blades used in other occasions, such as a helicopter propeller blade.

Hereinafter, a blade of a wind turbine generator system will be taken as an example, and a specific embodiment of the composite protective layer according to the present invention will be described with reference to the drawings.

Example 1

Fig. 1 is a schematic view of a composite protective layer 1 of embodiment 1 of the present invention. As can be seen in fig. 1, the composite protective layer 1 comprises a coating layer 11 and a preformed elastomer layer 12, the coating layer 11 being applied to the upper surface of the preformed elastomer layer 12. Fig. 4 is a schematic view of a blade 20 having a composite cover 1 according to the present invention attached to the leading edge thereof. As can be seen from fig. 1 and 4, the leading edge surface of the blade 20 is provided with a composite protective layer 1, and the lower surface of the preformed elastomer layer 12 is fixed to the leading edge surface of the blade 20. In fig. 1, reference numeral 2 denotes glass fiber reinforced plastic, which is a material constituting the leading edge surface of the blade 20. The following describes each preferred parameter of the composite protective layer 1 of the present embodiment more specifically with reference to the process flow.

First, the preformed elastomer layer 12 is directly bonded to the glass fiber reinforced plastic 2 on the front edge surface of the trimmed blade 20 with an adhesive. In this process, the elastomer layer 12 may be integrally formed, or two or more preformed elastomer layers 12 may be connected to each other. Specifically, the joint between two or more preformed elastomer layers 12 is processed by butt joint. Here, butt-joint means that the edges of the two preformed elastomer layers 12 are completely bonded and do not cover each other. Then, after painting and thermosetting the surface of the bonded preformed elastomer layer 12, a coating layer 11 covering the upper surface of the preformed elastomer layer 12 is formed, and since the upper surface of the preformed elastomer layer 12 is completely covered with the coating layer 11, direct irradiation of the sun is prevented, thereby enhancing the weather resistance. In addition, it is preferable to activate the surface of the preformed elastomer layer 12 by physical means such as chemical treatment or plasma flame treatment to join the preformed elastomer layer 12. Due to the strong interaction at the chemical bond level between the coating 11 and the preformed elastomer layer 12, a sufficient interfacial strength is ensured. In the present example, the drawing strength between the coating layer 11 and the preformed elastomer layer 12 was 5MPa or more.

Thus, the preformed elastomer layer 12 and the coating 11 together form the composite protective layer 1, and the thickness of the final composite protective layer 1 can be adjusted by selecting preformed elastomer layers 12 of different thicknesses, so that the thickness of the composite protective layer 1 exceeds 1 mm.

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, theoretical analysis of raindrops impacting the glass fiber reinforced plastic coating can find that the thickness is a key factor affecting the protective layer capability, and therefore, thicker protective layers can provide better protective capability. Existing raindrop impact glass fiber reinforced plastic coating theory has shown that a 10% thickness increase may result in over 30% protection capability increase. In addition, the thick protective layer also helps to resist large diameter raindrops.

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

Furthermore, according to the solution of the invention, since the composite protective layer 1 comprises a preformed elastomer layer 12 and a coating layer 11 covering the upper surface of the elastomer layer 12, if the coating layer 11 is damaged during use of the blade, thereby compromising the underlying preformed elastomer layer 12, maintenance can be initiated, only rebuilding of the coating layer 11 being performed, thereby permanently retaining the preformed elastomer layer 12, the entire maintenance process being much easier than in the prior art, where complete removal of the foil and reprocessing of the blade surface is required.

In the present embodiment, the preformed elastomer layer 12 is directly bonded to the glass fiber reinforced plastic 2 on the leading edge surface by an adhesive, but the present invention is not limited thereto. The preformed elastomer layer 12 may also be secured to the glass reinforced plastic 2 by mechanical attachment or the like.

In the present embodiment, the material of the preformed elastomer layer 12 is rubber, specifically, a homogeneous polyurethane elastomer, but the material of the preformed elastomer layer 12 of the present invention is not limited thereto, and may be any other rubber-based material such as polyurea, ethylene propylene rubber, and the like.

In this embodiment, the preformed elastomer layer 12 is a thin film having a uniform thickness. However, the present invention is not limited thereto, and the preformed elastomer layer 12 may be a film having a non-uniform thickness (i.e., a film having a variable thickness). In actual production applications, the thicknesses of the different portions of the preformed elastomer layer 12 may be set as desired (e.g., leading edge surface condition of the blade 20), for example, the preformed elastomer layer 12 may be a thick-in-the-middle and thin-in-the-edge film, or the preformed elastomer layer 12 may also be a thick-in-the-edge and thin-in-the-middle film.

The thickness of the preformed elastomer layer 12 is not limited, and the thickness of the preformed elastomer layer 12 may be appropriately set in consideration of factors such as processing requirements, use environment, reduction of the influence of step effect, or improvement of aerodynamic performance. For example, the thickness of the preformed elastomer layer 12 may be set in consideration of the rainfall intensity, the air temperature, the annual rainfall amount, and the like of the place of use. Specifically, in regions with small rainfall drops, such as northwest of China, the thickness of the preformed elastomer layer 12 may be set relatively thin, while in regions with large rainfall drops, such as thailand, the thickness of the preformed elastomer layer 12 may be set relatively thick. Since the thickness of the preformed elastomer layer 12 is preferably also comparable to the diameter of local raindrops, typically between 0 and 6000 microns, the thickness of the preformed elastomer layer 12 may be 6000 microns or less, preferably 4000 microns or less, and more preferably 3000 microns or less, taking into account all aspects of the effects.

In the present embodiment, the material of the coating layer 11 is a highly elastic aliphatic polyurethane top coat, but the material of the coating layer 11 of the present invention is not limited as long as it has a protective function. For example, the coating material may be various polymer materials such as other polyurethane, polyurea, epoxy resin, fluorine resin, and the like, and specifically, may be polyvinylidene fluoride-acrylate, an alternating copolymer of trifluoroethylene and alkyl vinyl ether, a polyaspartic acid coating material, and the like. The material of the coating layer 11 may be other inorganic coating materials such as metallic coating materials.

The thickness of the coating layer 11 is not limited and may be set as appropriate as needed. The thickness of the coating layer 11 can be set to about 100 μm in general, and if the thickness of the coating layer 11 is too thick, it is easily affected by the environment. For example, in an environment where the temperature is high and the humidity is high, the excessively thick coating layer 11 is likely to crack due to the material of the coating layer 11. Thus, 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, 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 preformed elastomer layer 12 and the coating layer 11 are, the more advantageous it is to form an effective chemical bond between the preformed elastomer layer 12 and the coating layer 11, and to enhance the pull strength between the preformed elastomer layer 12 and the coating layer 12.

Example 2

Fig. 2 is a schematic view of the composite protective layer 1 of embodiment 2 of the present invention. The composite protective layer 1 of the present embodiment is different from the composite protective layer 1 of embodiment 1 in that a plurality of holes 121 are uniformly distributed on the preformed elastomer layer 12, and the material of the coating layer 11 is filled in the holes 121.

Specifically, the preformed elastomer layer 12 provided with the plurality of holes 121 in advance is bonded to the glass fiber reinforced plastic 2. Air bubbles generated during the film attaching process can be discharged through the holes 121. The polymer material is then brushed, which fills the holes 121 and forms a coating 11 on the surface of the preformed elastomer layer 12 covering the preformed elastomer layer 12 during brushing.

In the present embodiment, the plurality of holes 121 are uniformly distributed on the preformed elastomer layer 12, but the present invention is not limited thereto, and the plurality of holes 121 may be non-uniformly distributed on the preformed elastomer layer 12.

With this configuration, it is possible to facilitate air release and prevent the generation of bubbles when the preformed elastic layer 12 is bonded. Further, by filling the material of the coating layer 11 in the hole 121, the connection strength between the preformed elastomer layer 12 and the coating layer 11 can be improved.

In addition, although the bonding work can be facilitated by providing the hole 121 in the preformed elastomer layer 12 and the strength of the connection between the preformed elastomer layer 12 and the coating layer 11 can be increased, after the preformed elastomer layer 12 is perforated, the perforated portion may become hard, and the position of the perforated portion may fail in advance during use, resulting in uneven protective performance. Furthermore, in the case of opening the holes, too large a hole diameter may cause the holes 121 to be hardly filled with the material of the coating layer 11, and too small a hole diameter may cause the holes 121 to be hardly filled with the material of the coating layer 11, and it is difficult to effectively improve the connection strength between the preformed elastomer layer 12 and the coating layer 11, and therefore, the hole diameter of the holes 121 of the present invention may be 0.5 to 1mm, preferably 0.7 to 0.9mm, and more preferably 0.8mm, in consideration of the above factors. In addition, the hole pitch of the holes 121 may be 10 to 20mm, preferably 12 to 18mm, and more preferably 13 to 17 mm.

It should be noted that in the case of a preformed elastomer layer 12 that is not apertured, it may be left un-apertured if the construction basic requirements and interlayer interface connections are met. The surface of preformed elastomer layer 12 may be surface treated without opening the pores, for example, by increasing the surface roughness of preformed elastomer layer 12, providing texture, etc. to increase the interfacial bond strength between preformed elastomer layer 12 and coating 11.

Example 3

Fig. 3 is a schematic view of the composite protective layer 1 according to embodiment 3 of the present invention. The composite protective layer 1 of the present embodiment is different from the composite protective layer 1 of embodiment 2 in that, with respect to the step 122 formed by the edge of the preformed elastomer layer 12 and the surface of the glass fiber reinforced plastic 2, the material of the coating layer 11 smoothly fills and covers the step 122.

With such a configuration, the step 122 at the edge of the preformed elastomer layer 12 is filled with the material of the coating layer 11 and covered, and therefore, the step effect can reduce the influence on the aerodynamic efficiency.

It should be noted that, although in the present embodiment, the material of the coating layer 11 smoothly fills and covers the step 122 formed by the edge of the preformed elastomer layer 12 and the surface of the glass fiber reinforced plastic 2, the present invention is not limited thereto. The material of the coating 11 may smoothly fill and cover any irregularities (e.g., gaps, etc.) formed at the edges of the preformed elastomer layer 12 to achieve a smooth transition, thereby reducing the impact on aerodynamic efficiency due to the step effect. That is, to avoid the step effect affecting the aerodynamic efficiency of the blade 20, the coating 11 is made to completely cover the preformed elastomer layer 12.

Of course, the composite protective layer 1 in the present embodiment is not limited to be fixedly formed on the outer surface of the leading edge of the blade 20 that has been designed to satisfy aerodynamic performance, 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 the addition of the composite protective layer 1, a groove may be machined in the surface of the leading edge of the blade, the groove having substantially the same dimensions as the composite protective layer 1.

In summary, according to the present invention, the protective film technology and the coating technology are applied cooperatively, and the advantages of the protective film technology and the coating technology are combined to avoid the disadvantages of the protective film technology and the coating technology, so as to construct a thick protective layer together, thereby improving the protective capability. The basic idea is to embed a prefabricated elastomer layer with or without holes, and then coat a polymer coating on the surface of the prefabricated elastomer layer, thereby forming an integrated composite protective layer. Wherein a preformed elastomer layer is used to increase the thickness and a coating is used to resist the effects of natural aging. This technique facilitates the efficient construction of composite protective layers having a thickness in excess of 1 mm. Moreover, the maintenance is easier. Particularly, according to the invention, the difficulty of manufacturing a thick protective layer is reduced, and the thick protective layer can be manufactured on the premise of ensuring the stable performance of the material; the defect of poor weather resistance of the prefabricated film is avoided, and the reliability of the protective layer is improved; the protective capability of the protective layer is enhanced, the service life of the protective layer is prolonged, and meanwhile, the construction efficiency is ensured; only the coating is rebuilt during maintenance, so that the whole maintenance process is simpler and easier.

While the present invention has been described in conjunction with the above 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

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.