CN114213972B - Coating applied to deicing of rotating wind turbine blades and method for making the same - Google Patents

Abstract

The invention provides a coating applied to deicing of blades of a rotary wind turbine and a manufacturing method thereof, wherein the coating consists of a rigid substrate with the thickness of 0.3-0.5 mm and the surface roughness of 0.2-0.4 mm and a micro-deformation elastic layer with the thickness of 0.3-0.5 mm and the elastic modulus of 5 kPa-20 kPa; the rigid substrate is solidified after being thermally fused and adhered with the surface of the wind turbine blade to form a porous surface structure; the elastic layer is adhered on the rigid substrate and mutually hooked with the rigid substrate. Because the surface roughness of the rigid substrate is high, the thicknesses of different positions of the elastic layer are different, and the deformation under stress is different, an air gap is generated between the ice layer and the elastic layer, the adhesion force of the ice layer is reduced, and the ice layer falls off. The coating applied to deicing of the blades of the rotating wind turbine is simple to prepare, low in cost and easy to popularize.

Description

Coating for deicing blades of rotating wind turbines and method for making the same

technical field

The invention relates to the technical field of wind power generator deicing, in particular to a coating applied to the deicing of rotating wind power blades and a manufacturing method thereof.

Background technique

About 40% of the unit capacity in our country works in high cold and high humidity areas. When wind turbines work in high-cold and high-humidity areas, the surface of the blades is prone to icing. If the icing is too thick, the unit will be shut down and the power generation will be reduced. Otherwise, the unit will collapse, and the falling ice on the blades will threaten personal safety. There are three types of icing on fan blades: clear ice, frost ice, and mixed ice. Bright ice is transparent and hard ice formed under the conditions of mild cold, rain and high wind speed, with a density of more than 900kg/m3; frost ice is white opaque crystalline crushed ice formed under extremely cold and low wind speed, with a density of Below 600kg/m3; the formation conditions and form of mixed ice are between clear ice and frost ice, and the density is 600-900kg/m3. Among them, the density of clear ice and mixed ice is high, which is more harmful to the fan. The icing conditions at different positions on the blade are also different. The blade tip, which accounts for 1/3 of the total length of the blade, has a high linear velocity and frequent collisions with supercooled water droplets, resulting in the largest icing thickness.

At present, the existing fan deicing technology can be divided into two types:

Active deicing: Energy is input from the outside to heat the surface of the blade to melt the ice on the contact surface, reduce the adhesion of the ice on the surface, and use centrifugal force to shake off the ice. Active deicing includes electric deicing, microwave deicing, airflow deicing, etc. Electrothermal deicing lays a layer of resistance heating elements (such as carbon cloth) on the blade, and supplies heat through an external power supply; microwave deicing guides microwave energy to the surface of the blade, and uses microwave energy to increase the temperature of the blade surface; airflow deicing is performed on the blade A circulating warm current is formed in the cavity to transfer heat from the inner surface of the blade to the outer surface. For example, the Chinese patent document whose publication number is CN107939620A discloses a fan blade anti-icing and de-icing system, including an air-heat anti-icing device, an expansion tube de-icing device, an electric heating de-icing device, a layer de-icing device and a monitoring and control device. The heating and deicing device includes a plurality of parallel resistance wires arranged on the fan blades.

Although the active deicing technology has high heating efficiency, fast temperature rise, and quick deicing, the main disadvantages are: (1) high energy consumption for heating; (2) the heating element is easily struck by lightning; (3) the equipment is complicated and difficult to maintain.

Passive deicing: Coating chemical coatings on the surface of the blades can change the characteristics of the contact surface, making it difficult for ice to form on the blades or can be easily thrown off after forming. Compared with active deicing, it consumes less energy and is easier to use. Passive deicing includes chemicals, superhydrophobic coatings, ultrasmooth coatings, etc.

However, spraying isopropanol, ethylene glycol, ethanol and other chemicals on the surface of the blade to lower the freezing point and prevent freezing, this method has a short action time and is polluting; Condensation, this method has poor deicing effect and is not durable; the ultra-smooth coating forms a lubricating water film on the contact surface to reduce the adhesion of ice. This method is effective, but the preparation is complicated and expensive.

Contents of the invention

The invention provides a coating applied to deicing blades of a rotating wind turbine and a manufacturing method thereof. By spraying a deicing coating on the surface of a wind turbine blade, an air gap is generated between the ice cube and the coating by the action of centrifugal force, thereby reducing the The adhesion of ice cubes achieves the technical effect of deicing.

A coating applied to the deicing of rotating wind turbine blades, consisting of a rigid substrate with a thickness of 0.3mm to 0.5mm and a surface roughness of 0.2mm to 0.4mm and a coating with a thickness of 0.3mm to 0.5mm and an elastic modulus of 5kPa to 20kPa Composed of micro-deformation elastic layer.

Wherein, the rigid base is used for hot-melt bonding with the surface of the wind turbine blade and then solidified to form a porous surface structure; the elastic layer is adhered to the rigid base and interlinked with the rigid base.

Due to the high surface roughness of the rigid base, the thickness of the elastic layer is different at different positions, and the deformation under force is different.

For the working environment of rotating wind turbine blades, in order to improve the service life of the deicing coating, the preferred rigid substrate is a solid meltable polymer resin with high surface roughness, and the elastic layer is connected with the rigid substrate to make The elastic layer is firmly fixed to the rigid base.

In order to improve the application effect of the deicing coating, preferably, the elastic layer is a combination of silicone rubber and silica gel at a mass ratio of 9:1.

In order to facilitate the production of the coating, preferably, the elastic layer is a combination of silicone rubber and silica gel, and then diluted with an organic solvent and sprayed uniformly on the rigid substrate. More preferably, the organic solvent is absolute ethanol or hexamethyl di Silicone

In order to further improve the application effect of the deicing coating, preferably, the elastic layer is a hydrophobic smooth surface with a contact angle of 115°-125°.

In order to ensure the deicing effect of the deicing coating, increase the service life, and reduce the cost of use, the total thickness of the coating is 0.8 mm to 1 mm. If the coating is too thin, it cannot achieve a good deicing effect; if the coating is too thick, the service life of the coating will be affected, and the aerodynamic characteristics of the wind turbine blades will be damaged, and the use cost will increase.

After the coating is covered with ice, under the action of centrifugal force and periodic gravity, the elastic layer on the coating is deformed, air pockets are generated between the elastic layer and the ice layer, and the adhesion of the ice layer is reduced. fall off under action.

Specifically, during the operation of the fan, the elastic layer deforms under the action of the tangential force. Since the thickness of the elastic layer is different at different positions, the amount of deformation under the force is different. In some areas, the separation of the ice layer and the elastic layer creates an air gap. , under the action of centrifugal force and periodic gravity, the air gap increases and the adhesion of the ice layer decreases. At the same time, as the thickness of the ice increases, the centrifugal force on the ice increases, and finally the ice layer falls off under the action of centrifugal force .

The present invention also provides a method for making a deicing coating applied to a rotating wind turbine blade, comprising the following steps:

(1) Clean the surface of the wind turbine blade;

(2) Spray the heated solid meltable polymer resin on the surface of the wind turbine blade to form a rigid substrate with a porous surface structure;

(3) Mix silicone rubber and silica gel according to the mass ratio of 9:1;

(4) Dilute the mixed silicone rubber and silica gel with an organic solvent in a mass ratio of 3:2, and stir evenly;

(5) Spray coating on a rigid substrate to form an elastic layer;

(6) After the elastic layer is dried, a deicing coating is formed.

Further, in step (2), the thickness of the rigid substrate of the porous surface structure is 0.3mm-0.5mm; in step (5), the thickness of the elastic layer is 0.3mm-0.5mm.

Further, in step (6), the dried rigid base of the deicing coating and the elastic layer are interlocked to prevent the elastic layer from falling off, thereby increasing the life of the elastic layer.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention reduces the adhesive force of the ice layer through the combination of the rigid base and the elastic layer, so that the ice layer can fall off under the centrifugal force of the blade rotation of the wind turbine when the thickness is very thin, avoiding the shutdown of the wind turbine due to icing In the case of wind turbines, the power generation capacity of the wind turbines is increased. The coating is simple to prepare, low in cost and easy to popularize.

Description of drawings

Fig. 1 is the schematic diagram of a kind of coating structure that is applied to the deicing of rotary wind turbine blade of the present invention;

Fig. 2 is the time-varying diagram of the icing thickness of the test blade in the embodiment of the present invention;

Fig. 3 is the icing situation of the test wind turbine blade in the embodiment of the present invention.

In the figure: 1-wind turbine blade surface; 2-rigid base; 3-elastic layer; 4-ice layer; 5-air gap.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, but do not limit it in any way.

As shown in Figure 1, a coating applied to the deicing of rotating wind turbine blades consists of a rigid substrate 2 with a thickness of 0.4 mm and a surface roughness of 0.3 mm, and a slightly deformed elastic layer 3 with a thickness of 0.4 mm and an elastic modulus of 10 kPa.

Wherein, the rigid base 2 is thermally bonded to the wind turbine blade surface 1 and solidified to form a porous surface structure; the elastic layer 3 is adhered to the rigid base 2 and interlinked with the rigid base 2 . Due to the high surface roughness of the rigid base 2, the thickness of the elastic layer 3 is different at different positions, and the deformation amount under stress is different.

For the working environment of rotating wind turbine blades, in order to improve the service life of the deicing coating, the rigid base 2 is a solid meltable polymer resin with high surface roughness, and the elastic layer 3 is connected to the rigid base 2, Make the elastic layer 3 and the rigid base 2 tightly fixed.

In order to improve the use effect of the deicing coating, the elastic layer 3 is a combination of silicone rubber and silica gel at a mass ratio of 9:1.

In order to facilitate the coating, the elastic layer 3 is a combination of silicone rubber and silica gel, and then diluted with an organic solvent and evenly sprayed on the rigid substrate 2. The organic solvent is absolute ethanol.

In order to further improve the application effect of the deicing coating, the elastic layer 3 is a hydrophobic and smooth surface with a contact angle of 115°-125°.

In order to ensure the deicing effect of the deicing coating, improve the service life and reduce the use cost, the thickness of the coating is 0.8-1 mm. If the coating is too thin, it cannot achieve a good deicing effect; if the coating is too thick, the service life of the coating will be affected, and the aerodynamic characteristics of the wind turbine blades will be damaged, and the use cost will increase.

In order to improve the application effect of the deicing coating, the elastic layer 3 is deformed under the action of the tangential force. Since the thickness of the elastic layer 3 is different at different positions, the amount of deformation under the force is different.

As shown in Figure 1, in a local area, the ice layer 4 is separated from the elastic layer 3 to form an air gap 5, and under the action of centrifugal force and periodic gravity, the air gap 5 increases, and the adhesion force of the ice layer 4 decreases. With the increase of freezing thickness, the centrifugal force suffered by the ice cube increases, and finally the ice layer 4 falls off under the effect of centrifugal force.

In order to verify the effect of the present invention, a local stress coating was applied on a certain experimental small wind machine, and the three blades of the small wind machine were labeled as one, two, and three, wherein blade one was not coated, as a blank control; blade two Coating is applied to the tip of blade three.

The coated blades were assembled to the wind turbine, and the blades were observed every hour under icing weather conditions, and the icing thickness of the wind turbine blades was recorded. The change of the icing thickness of the blades with time is shown in Figure 2.

With the increase of time, the icing thickness of the uncoated blade increased with time, while the icing thickness of the coated blade did not change much. The icing condition of the blades of the wind turbine after 5 hours of the test is shown in Figure 3. In the figure, (a) is the icing condition of blade 1, (b) is the icing condition of blade 2, and (c) is the icing condition of blade 3 . After measurement, blade 1 has no coating, and the icing thickness is 57.0mm in 5h. Blade 2 and blade 3 have coating, and 5h icing thickness is 2.5mm and 3.0mm respectively, and the icing thickness is much smaller than blade 1.

The results of the above experiments show that the deicing coating of the present invention can significantly reduce the accumulation of ice cubes on the surface of the blades, allow the blades to rotate and shake off the ice cubes faster, and achieve the effect of deicing.

The embodiments described above have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. All within the scope of the principles of the present invention Any modifications, supplements and equivalent replacements should be included within the protection scope of the present invention.

Claims (7)

1. A coating applied to deicing of blades of a rotary wind turbine is characterized by comprising a rigid substrate with the thickness of 0.3-0.5 mm and the surface roughness of 0.2-0.4 mm and a micro-deformation elastic layer with the thickness of 0.3-0.5 mm and the elastic modulus of 5-20 kPa; the rigid substrate is used for being solidified after being hot-melted and bonded with the surface of the wind turbine blade to form a porous surface structure; the elastic layer is adhered to the rigid substrate and is mutually hooked with the rigid substrate;

after the coating is coated with ice, under the action of centrifugal force and periodic gravity, the elastic layer on the coating deforms, air pockets are generated between the elastic layer and the ice layer, the adhesion force of the ice layer is reduced, and the ice layer falls off under the action of the centrifugal force.

2. The coating as claimed in claim 1, wherein the rigid substrate is a solid meltable polymer resin.

3. The coating applied to deicing blades of rotating wind turbines as claimed in claim 1, wherein said elastomeric layer is a combination of silicone rubber and silicone rubber in a mass ratio of 9.

4. The coating applied to deicing blades of rotating wind turbines as claimed in claim 1, wherein the elastic layer is formed by combining silicone rubber and silica gel, and then uniformly spraying the silicone rubber and silica gel onto a rigid substrate after being diluted by an organic solvent.

5. The coating applied to deicing blades of rotating wind turbines as claimed in claim 1, wherein said elastomeric layer is a hydrophobic smooth surface having a contact angle of 115 ° to 125 °.

6. The coating applied to deicing blades of rotating wind turbines as claimed in claim 1, wherein the total thickness of the coating is 0.8mm to 1mm.

7. The manufacturing method of the deicing coating applied to the blades of the rotary wind turbines according to any one of claims 1 to 6, characterized by comprising the following steps of:

(1) Cleaning the surface of the wind turbine blade;

(2) Spraying heated solid meltable polymer resin on the surface of the wind turbine blade to form a rigid substrate with a porous surface structure; the thickness of the rigid substrate is 0.3mm to 0.5mm, and the surface roughness is 0.2mm to 0.4 mm;

(3) Mixing silicone rubber and silica gel according to a mass ratio of 9;

(4) Diluting the mixed silicone rubber and silica gel with an organic solvent according to a mass ratio of 3;

(5) Spraying an elastic layer on the rigid substrate; the thickness of the elastic layer is 0.3mm to 0.5mm, and the elastic modulus is 5-20 kPa;

(6) And forming a deicing coating after the elastic layer is aired, and mutually hooking the rigid substrate of the aired deicing coating and the elastic layer to prevent the elastic layer from falling off.

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