A horizontal tower type anti-icing surface microstructure applied to a fan blade and a preparation method thereof

Abstract

The present invention discloses a horizontal tower-shaped anti-icing surface microstructure applied to fan blades and a preparation method thereof, relating to the field of hydrophobic materials, including forming a hydrophobic surface coating with a horizontal tower-shaped structure on the surface of a fan blade; the horizontal tower-shaped structure is a trapezoidal body, wherein the hypotenuse faces upward and the front and rear end surfaces are open, and the opening at the front end is smaller than the opening at the rear end. The present invention adopts a method of chemical sputtering combined with wind speed to form a hydrophobic surface coating with a horizontal tower-shaped structure on the surface of the fan. When water droplets appear on the surface of the fan blade, during the rotation of the fan blade, the horizontal tower-shaped structure forms a wind collection function, that is, the air outlet changes from large to small, and the wind force per unit cross section changes from small to large. At the end of this open horizontal tower, it will be more difficult for water droplets to adhere.

Description

Technical Field

[0001] The present invention relates to the field of hydrophobic material preparation, in particular to a horizontal tower-shaped anti-icing surface microstructure applied to fan blades and a preparation method thereof. Background Art

[0002] Yardang landform is a special landform in the Lop Nur area of Xinjiang. It is a typical wind erosion landform. Through weathering, intermittent water scouring and wind erosion, a combination of wind erosion mounds and wind erosion depressions (grooves) parallel to the prevailing wind direction and arranged alternately is formed. The creativity of this patent comes from this structure. The icing of wind turbine blades has always been an important problem that is difficult for people in this field to solve. Especially under the blessing of the height of the wind turbine tower, the wind turbine blades of mountain wind power are more likely to freeze on their surfaces, whether the blades are in a stationary state or in an operating state; the icing of blades in winter brings great harm to the operation of wind turbines. After the wind turbine blades are covered with ice, the dynamic characteristics and aerodynamic characteristics of the wind turbine blades will be destroyed. The quality, stiffness and other properties of ice will affect the material properties of the blades, causing blade overload and uneven load, causing the wind turbine to fail to generate electricity normally, and even leading to serious operational safety accidents. In the ice melting process, there is a safety hazard that the flying ice cubes will hit nearby people and animals. Therefore, the wind turbine blades need super-hydrophobic surface treatment.

[0003] A superhydrophobic surface refers to a surface with a static contact angle of more than 150° and a rolling angle of less than 10° between the coating surface and water. [1] . refer to Figure 1 , the wetting mechanism is based on Young's equation [2] Development to the Wenzel model [3] , which eventually becomes the Cassie-Baxter model [4] In the Cassie-Baxter model, a water droplet is suspended on a rough surface. The droplet only contacts a small part of the surface and tends to roll off.

[0004] In the Cassie-Baxter model, since there are air grooves under the solid surface, if cold air enters, it is more likely to freeze. Therefore, further improvement is needed.

[0005] [1] Teng Fukang, Wang Han, Zhou Ziheng, et al. Research progress of superhydrophobic anti-icing coatings[J]. Western Leather, 2020, 42(3): 99.

[0006] [2]Young.An essay on the cohesion of fliuds[J].Trans.RSLondon,1805.

[0007] [3]Wenzel R N. Resistance of solid surfaces to wetting by water[J]. Industrial and engineering chemistry, 1936, 28(8):988-994.

[0008] [4]CASSIE ABD,BAXTER S.Wettability of porous surfaces[J].Transactions of the Faraday Society,1944,40:546-551. Summary of the Invention

[0009] The purpose of the present invention is to improve the anti-icing ability of wind turbine blades from another perspective through the design and preparation of surface microstructures based on the application of hydrophobic surface coatings, to solve at least one of the technical problems existing in the prior art, and to provide a horizontal tower-type anti-icing surface microstructure for wind turbine blades and a preparation method thereof.

[0010] The technical solutions of the present invention are as follows:

[0011] A horizontal tower-shaped anti-icing surface microstructure applied to a fan blade, comprising forming a hydrophobic surface coating having a horizontal tower-shaped structure on the surface of the fan blade;

[0012] The tower-shaped structure is a trapezoidal body, with the hypotenuse facing upwards and the front and rear end surfaces being open, and the opening at the front end being smaller than the opening at the rear end.

[0013] Preferably, the horizontal tower structure is parallel to the linear velocity direction of the fan blades during operation.

[0014] The present invention also discloses a method for preparing a horizontal tower-shaped anti-icing surface microstructure applied to fan blades, which adopts a chemical sputtering method to form a hydrophobic surface coating with a horizontal tower-shaped structure on the surface of the fan blades.

[0015] Preferably, a rough surface with a horizontal tower structure is first constructed on the surface of the fan blade, and then a hydrophobic film is sputtered on the rough surface to obtain the product.

[0016] Preferably, a high energy ion beam is used in combination with wind flow to bombard the surface of the fan blade to generate the rough structure.

[0017] Preferably, the method specifically includes the following steps:

[0018] The fan blades are cleaned and then placed in a vacuum chamber in a chemical sputtering device. The gas ion source is turned on while maintaining a constant flow of argon gas on the fan blade surface. A high-voltage power supply is applied at 500-800 Hz, a pulse width of 2-10 μs, a voltage amplitude of -60-40 kV, and a bombardment time of 20-70 minutes.

[0019] Turn off the high-voltage power supply, turn off the argon gas, introduce the reaction gas, turn on the low-voltage pulse bias power supply, adjust the power supply frequency to 40-60kHz, the duty cycle to 25-50%, and the bias voltage to -200-100V for hydrophobic film deposition. The deposition time is 20-80 minutes.

[0020] Preferably, the reaction gas is a fluorocarbon gas.

[0021] The beneficial effects of the present invention are as follows: a horizontal tower type anti-icing surface microstructure for wind turbine blades and a preparation method thereof are used in the present invention. A hydrophobic surface coating with a horizontal tower type structure is formed on the surface of the wind turbine by using a method of chemical sputtering combined with wind speed. When water droplets appear on the surface of the wind turbine blades, the horizontal tower type structure forms a wind collecting function during the rotation of the wind turbine blades. That is, the air outlet changes from large to small, and the wind force per unit cross section changes from small to large. At the end of this open horizontal tower, water droplets will be more difficult to adhere. That is, when the temperature is too low and ice can form, it will take precedence over ice forming on the short side of the horizontal tower and seal the outlet. Due to the influence of wind force, the horizontal tower takes precedence over forming surface coverage. The hollow horizontal tower structure changes from the previous groove type structure to a lying open cup type structure. That is, only the air inlet is open, and the other five surfaces are closed. When the ice surface formed becomes larger and larger, the wind resistance of the structure becomes greater, and the formed ice surface becomes easier to fall off, achieving easier de-icing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of an ideal model of a hydrophobic surface in background technology;

[0023] Figure 2 Schematic diagram of the ideal model of the hydrophobic surface of the present invention;

[0024] In the figure, 1- horizontal tower structure. DETAILED DESCRIPTION

[0025] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0027] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0028] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0029] Reference Figure 2 , the preferred embodiment of the present invention:

[0030] A horizontal tower-shaped anti-icing surface microstructure applied to a wind turbine blade, comprising forming a hydrophobic surface coating having a horizontal tower-shaped structure on the surface of the wind turbine blade;

[0031] The tower-shaped structure 1 is a trapezoidal body, with the hypotenuse facing upwards and the front and rear end surfaces being open, with the front opening being smaller than the rear opening.

[0032] Specifically, the BCEF surface is the surface of the fan blade, and the ABEH surface and DCFG surface are two vertical surfaces in the horizontal tower structure. Under low temperatures, the ADGH surface is easy to freeze and become an ice surface. When the fan blade rotates, the HGEF surface forms an air inlet. When the ice surface formed becomes larger and larger, the ABCD surface also freezes and gradually forms an ice surface. The wind resistance of the structure becomes larger and larger, and the formed ice surface becomes easier to fall off, thereby achieving easier de-icing.

[0033] The horizontal tower structure 1 is parallel to the linear velocity direction of the fan blades during operation, that is, the front opening is parallel to the direction of rotation of the fan blades.

[0034] A method for preparing a horizontal tower-shaped anti-icing surface microstructure applied to a fan blade adopts a chemical sputtering method to form a hydrophobic surface coating with a horizontal tower-shaped structure on the surface of the fan blade.

[0035] The method comprises the following steps: firstly constructing a rough surface with a horizontal tower structure on the surface of a fan blade, and then sputtering a layer of hydrophobic film on the rough surface to obtain the product.

[0036] Preferably, a high energy ion beam is used in combination with wind flow to bombard the surface of the fan blade to generate the rough structure.

[0037] Preferably, the method specifically includes the following steps:

[0038] The fan blades are cleaned and then placed in a vacuum chamber in a chemical sputtering device. The gas ion source is turned on while maintaining a constant flow of argon gas on the fan blade surface. A high-voltage power supply is applied at 500-800 Hz, a pulse width of 2-10 μs, a voltage amplitude of -60-40 kV, and a bombardment time of 20-70 minutes.

[0039] Turn off the high-voltage power supply, turn off the argon gas, introduce the reaction gas, turn on the low-voltage pulse bias power supply, adjust the power supply frequency to 40-60kHz, the duty cycle to 25-50%, and the bias voltage to -200-100V for hydrophobic film deposition. The deposition time is 20-80 minutes.

[0040] Preferably, the reaction gas is a fluorocarbon gas.

[0041] The solutions of the present invention are further described below with reference to specific embodiments.

[0042] Example 1

[0043] Cleaning of fan blades: In the vacuum chamber of the chemical sputtering equipment, the gas ion source is turned on, while maintaining a certain wind speed and flow rate of argon gas (3m / s) on the surface of the fan blades. A high voltage power supply of 500Hz, a pulse width of 2μs, a voltage amplitude of -40kV, and a bombardment time of 20min is applied.

[0044] Turn off the high-voltage power supply, turn off the argon gas, introduce the reaction gas, turn on the low-voltage pulse bias power supply, adjust the power frequency to 40kHz, the duty cycle to 25%, and the bias to -100V for hydrophobic film deposition. The deposition time is 20 minutes.

[0045] The reaction gas is fluoromethane.

[0046] Example 2

[0047] The fan blades were cleaned and then placed in a vacuum chamber in a chemical sputtering device. The gas ion source was turned on while maintaining a constant flow rate of argon gas (4 m / s) on the fan blade surface. A high-voltage power supply was applied at 600 Hz, a pulse width of 8 μs, a voltage amplitude of -45 kV, and a bombardment time of 50 minutes.

[0048] Turn off the high-voltage power supply, turn off the argon gas, introduce the reaction gas, turn on the low-voltage pulse bias power supply, adjust the power frequency to 45kHz, the duty cycle to 30%, and the bias to -150V for hydrophobic film deposition. The deposition time is 40 minutes.

[0049] The reaction gas is fluoromethane.

[0050] Example 3

[0051] The fan blades were cleaned and then placed in a vacuum chamber in a chemical sputtering device. The gas ion source was turned on while argon gas flowed at a constant velocity (5 m / s) over the fan blade surface. A high-voltage power supply was applied at 800 Hz, a pulse width of 10 μs, a voltage amplitude of -60 kV, and a bombardment time of 70 minutes.

[0052] Turn off the high-voltage power supply, turn off the argon gas, introduce the reaction gas, turn on the low-voltage pulse bias power supply, adjust the power frequency to 60kHz, the duty cycle to 50%, and the bias to -200V for hydrophobic film deposition. The deposition time is 80 minutes.

[0053] The reaction gas is fluoromethane.

[0054] Comparative Example 1 (no wind speed)

[0055] The fan blades were cleaned and then placed in a vacuum chamber in a chemical sputtering device. The gas ion source was turned on and a high-voltage power supply of 800 Hz, a pulse width of 10 μs, a voltage amplitude of -60 kV, and a bombardment time of 70 minutes was applied.

[0056] Turn off the high-voltage power supply, turn off the argon gas, introduce the reaction gas, turn on the low-voltage pulse bias power supply, adjust the power frequency to 60kHz, the duty cycle to 50%, and the bias to -200V for hydrophobic film deposition. The deposition time is 80 minutes.

[0057] The reaction gas is fluoromethane.

[0058] The icing performance test was carried out on the embodiments and comparative examples, and the test results are shown in Table 1.

[0059] (1) Hydrophobicity

[0060] The static contact angle between the fan blade surface and a 4 μL water droplet was measured using a DropMeter™ A-100P contact angle meter. Each test was repeated three times and the average value was taken.

[0061] (2) At a temperature of -10°C, take a section of the fan blade from the same area after 0 days of operation and after 7 days of operation, weigh it, and record the increase in mass M per square centimeter.

[0062] Sample Static contact angle (°) Increased mass (g) Example 1 158 0.52 Example 2 159 0.49 Example 3 155 0.53 Comparative Example 1 152 2.3

[0063] As can be seen from the above table, the performance of the embodiment is better than that of the comparative example, mainly because the embodiment adopts a method of chemical sputtering combined with wind speed to form a hydrophobic surface coating with a horizontal tower structure on the surface of the fan. When water droplets appear on the surface of the fan blades, during the rotation of the fan blades, the horizontal tower structure forms a wind collection function, that is, the air outlet changes from large to small, and the wind force per unit cross section changes from small to large. At the end of the open horizontal tower, water droplets will be more difficult to adhere, that is, when the temperature is too low and ice can form, it will take precedence over ice forming on the short side of the horizontal tower and sealing the outlet. Due to the influence of wind force, the horizontal tower takes precedence over forming surface coverage, and the hollow horizontal tower structure changes from the previous groove structure to a lying open cup-type structure, that is, only the air inlet is open, and the other five surfaces are closed. When the ice surface formed becomes larger and larger, the wind resistance of the structure becomes greater, and the formed ice surface becomes easier to fall off, achieving easier de-icing.

[0064] Under the premise that no conflict occurs, those skilled in the art may freely combine and superimpose the above-mentioned additional technical features.

[0065] The above descriptions are merely preferred embodiments of the present invention. Any technical solution that achieves the purpose of the present invention by substantially the same means shall fall within the scope of protection of the present invention.

Claims

1. A horizontal tower type anti-icing surface microstructure applied to wind turbine blades, characterized in that: The method comprises forming a hydrophobic surface coating having a horizontal tower-shaped structure (1) on the surface of a fan blade; The horizontal tower structure (1) is a trapezoidal body, wherein the hypotenuse faces upward and the front and rear end surfaces are open, and the opening at the front end is smaller than the opening at the rear end; The surface of the fan blade is bombarded by high-energy ion beam combined with wind flow to construct a rough surface with a horizontal tower structure on the surface of the fan blade, and then a hydrophobic film is sputtered on the rough surface to obtain the product.

2. The horizontal tower type anti-icing surface microstructure for wind turbine blades according to claim 1, characterized in that: The horizontal tower structure (1) is parallel to the linear velocity direction of the fan blades during operation.

3. The horizontal tower type anti-icing surface microstructure for wind turbine blades according to claim 1, characterized in that: It specifically includes the following steps: The fan blades are cleaned and then placed in a vacuum chamber in a chemical sputtering device. The gas ion source is turned on while maintaining a constant flow of argon gas on the fan blade surface. A high-voltage power supply is applied at 500-800 Hz, a pulse width of 2-10 μs, a voltage amplitude of -60-40 kV, and a bombardment time of 20-70 minutes. Turn off the high-voltage power supply, turn off the argon gas, introduce the reaction gas, turn on the low-voltage pulse bias power supply, adjust the power supply frequency to 40-60kHz, the duty cycle to 25-50%, and the bias to -200-100V for hydrophobic film deposition. The deposition time is 20-80min.

4. The horizontal tower type anti-icing surface microstructure for wind turbine blades according to claim 3, characterized in that: The reaction gas is a fluorocarbon gas.

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