阅读说明：本技术 激光精密加工技术制备风电叶片主动防冰表面 (Active anti-icing surface of wind power blade prepared by laser precision machining technology ) 是由 管迎春 李欣欣 于 2020-11-02 设计创作，主要内容包括：本发明主要涉及激光精密加工技术制备风电叶片主动防冰表面,属于风电叶片制造技术领域。该方法利用脉冲激光直接在风电叶片表面和薄膜表面制备微纳结构,利用液滴与激光处理表面和激光未处理表面之间单位时间内传递的热量不同,实现防冰功能。当液滴在功能结构表面时,液滴与结构界面之间存在空气层较多,而对于激光未处理表面而言,在液滴下方没有空气层,所以激光处理表面可以有效的减少热量损失；并且液滴与激光处理表面相接触的表面积小于与激光未处理表面,有利于减少通过热传导方式而产生的热量损耗。因此这种方法使得液滴热量损耗较慢,从而使液滴具有较短的延迟冻结时间,防止结冰产生。该方法较传统的风电叶片防冰方法,具有工艺简单、制备方便等优点,真正实现风电叶片主动防冰功能。(The invention mainly relates to a method for preparing an active anti-icing surface of a wind power blade by using a laser precision machining technology, and belongs to the technical field of wind power blade manufacturing. According to the method, pulse laser is used for directly preparing micro-nano structures on the surface of the wind power blade and the surface of the film, and the anti-icing function is realized by utilizing the difference of heat transferred in unit time between liquid drops and the laser processing surface and the laser unprocessed surface. When the liquid drop is on the surface of the functional structure, more air layers exist between the liquid drop and the structure interface, and for the laser untreated surface, no air layer exists below the liquid drop, so that the laser treated surface can effectively reduce heat loss; and the surface area of the liquid drop contacted with the laser processing surface is smaller than that of the laser unprocessed surface, so that the heat loss generated by a heat conduction mode is reduced. Therefore, the method causes the heat loss of the liquid drops to be slow, so that the liquid drops have short freezing delay time and are prevented from being frozen. Compared with the traditional wind power blade anti-icing method, the method has the advantages of simple process, convenience in preparation and the like, and the active anti-icing function of the wind power blade is really realized.)

1. The method for preparing the active anti-icing surface of the wind power blade by using the laser precision machining technology mainly comprises the following steps:

the method comprises the following steps: preparing a micro-nano structure by using pulse laser according to set laser process parameters and laser scanning paths;

step two: and performing an anti-icing test on the surface of the wind power blade with or without the micro-nano structure under the same external environment condition.

2. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: step one, the laser process parameters are as follows: the pulse width is 10 fs-1000 ns, the laser wavelength is 200-1100 nm, the repetition frequency is 30-2000 kHz, the output power is 1-1500W, the scanning speed is 10-5000 mm/s, and the processing times are 1-200.

3. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: step one, the micro-nano structure preparation substrate is a wind power blade surface and a film capable of being attached to the wind power blade surface.

4. The wind blade surface of claim 2, wherein: the surface protective coating material of the wind power blade can be polyurethane, fluororesin, acrylic resin and polyaspartic acid.

5. The film attachable to the surface of a wind turbine blade according to claim 2, wherein: the film material can be polyvinylidene fluoride, vinyl and silicone rubber.

6. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: in the first step, the scanning path of the laser process can be a group of parallel straight lines and two groups of mutually orthogonal straight lines, and the scanning distance is 15-300 mu m.

7. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: the micro-nano structure in the first step can be a columnar micro-structure, a groove-shaped micro-structure and a nano-particle structure distributed on the surface of the columnar micro-structure in a grid-shaped distribution, and a conical micro-structure is periodically distributed.

8. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: the same conditions as those in the second step mean that: the same ambient conditions of temperature, humidity, etc., and the same time the sample was left in the test environment.

9. The same ambient conditions of temperature, humidity, etc. as set forth in claim 8, wherein: temperature range: 0 ℃ to-40 ℃, humidity range: 0 to 95 percent.

10. The sample of claim 8 being placed in the test environment at the same time, wherein: and (4) placing the sample in the test environment for the same time until the temperature of the sample is the same as the temperature of the placing environment.

11. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: and step two, in the anti-icing test, the same volume of deionized water is dripped on the surface of the wind power blade with or without laser treatment, and the freezing delay time of two different surfaces is recorded.

The technical field is as follows:

the invention belongs to the technical field of wind power blade manufacturing, and particularly relates to a method for manufacturing an active anti-icing surface of a wind power blade by using a laser precision machining technology.

Background art:

wind energy is used as a high-quality green renewable energy source, and the global available generated energy is about 2 multiplied by 10⁴GW has wide application market prospect and is widely concerned by various countries. However, the icing phenomenon often occurs whenever the wind power blades are distributed in winter ice and snow weather and low-temperature and high-humidity weather, and at high altitude or high latitude areas, which is one of the important reasons for shortening the service life thereof. Wind power generationBlade icing not only becomes extra unbalanced load of the blade, endangers normal operation of the wind power blade, and even causes serious accidents such as wind power blade breakage and the like; the aerodynamic characteristics of the wind power blades can be influenced, the load of a unit is increased, and the generating efficiency of the fan is influenced. Therefore, the anti-icing of the wind power blade is always the subject of research by a plurality of scholars.

Patent CN201010537132.X discloses a preparation method of an anti-icing and wear-resistant coating for a wind power blade, wherein the coating is coated on the surface of the wind power blade to realize an anti-icing function; patent CN201710916688.1 discloses a method for arranging a thermal resistor in a slot on one plate surface of a wind turbine blade, so as to realize the anti-icing function of the wind turbine blade; patent CN201821562294.7 discloses an anti-icing wind power blade, and this patent realizes the wind power blade anti-icing function through the method of at wind power blade surface coating super hydrophobic coating and at wind power blade cavity internal surface attached ultrasonic transducer. Although the method can realize the anti-icing function of the wind power blade, additional coatings or devices are needed, so that the weight of the wind power blade is increased, the chemical coatings are easy to fall off and need to be supplemented regularly, and the environmental pollution is caused.

In conclusion, developing a manufacturing process method for the surface with the anti-icing function, which is simple in process and high in preparation efficiency and can be applied to the wind power blade, is an urgent problem to be solved by researchers at present.

The invention content is as follows:

in order to achieve the purpose, the active anti-icing surface of the wind power blade is prepared by the laser precision machining technology, and the following technical scheme is adopted:

1. the method comprises the following steps: preparing a micro-nano structure by using pulse laser according to set laser process parameters and laser scanning paths;

step two: and performing an anti-icing test on the surface of the wind power blade with or without the micro-nano structure under the same external environment condition.

2. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: step one, the laser process parameters are as follows: the pulse width is 10 fs-1000 ns, the laser wavelength is 200-1100 nm, the repetition frequency is 30-2000 kHz, the output power is 1-1500W, the scanning speed is 10-5000 mm/s, and the processing times are 1-200.

3. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: firstly, preparing a substrate of the micro-nano structure, namely a wind power blade surface and a film capable of being attached to the wind power blade surface;

4. the wind blade surface of claim 2, wherein: the surface protective coating material of the wind power blade can be polyurethane, fluororesin, acrylic resin and polyaspartic acid.

5. The film attachable to the surface of a wind turbine blade according to claim 2, wherein: the film material can be polyvinylidene fluoride, vinyl and silicone rubber;

6. the active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: in the first step, the scanning path of the laser process can be a group of parallel straight lines and two groups of mutually orthogonal straight lines, and the scanning distance is 15-300 mu m.

7. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: the micro-nano structure in the first step can be a columnar micro-structure, a groove-shaped micro-structure and a nano-particle structure distributed on the surface of the columnar micro-structure in a grid-shaped distribution, and a conical micro-structure is periodically distributed.

8. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: the same conditions as those in the second step mean that: the same ambient conditions of temperature, humidity, etc., and the same time the sample was left in the test environment.

9. The same ambient conditions of temperature, humidity, etc. as set forth in claim 8 wherein: temperature range: 0 ℃ to-40 ℃, humidity range: 0% -95%;

10. the sample of claim 8 being placed in the testing environment at the same time, wherein: and (4) placing the sample in the test environment for the same time until the temperature of the sample is the same as the temperature of the placing environment.

11. The active anti-icing surface of the wind power blade prepared by the laser precision machining technology of claim 1 is characterized in that: and step two, in the anti-icing test, the same volume of deionized water is dripped on the surface of the wind power blade with or without laser treatment, and the freezing delay time of two different surfaces is recorded.

The micro-nano composite structure for fluid drag reduction and the laser processing method have the advantages that:

(1) the processing range is wide. The micro-nano structure is processed by adopting pulse laser, various protective coating materials and film materials can be processed, and the processing range is wide.

(2) The parameters are easy to adjust. By adopting laser processing, laser processing parameters can be conveniently adjusted, and micro-nano structures with different geometric sizes and distribution densities can be obtained.

(3) The structure is simple to prepare. According to the micro-nano structure, the micro-nano structure is directly processed on the surface of the wind power blade and the surface of the film by using laser, additional attachment devices such as a thermal resistor and the like are not needed, active anti-icing of the wind power blade is realized, and the weight and the air performance of the wind power blade are not influenced.

Drawings

FIG. 1 is a laser confocal microscope image of an anti-icing micro-nano structure on the surface of a wind power blade, which is manufactured by simultaneously utilizing femtosecond laser and nanosecond laser processing according to an embodiment of the invention;

FIG. 2 is a laser confocal microscope image of an anti-icing micro-nano structure on the surface of a wind power blade prepared by femtosecond laser processing according to an embodiment of the invention;

FIG. 3 is a schematic diagram of the wind turbine blade anti-icing micro-nano structure surface prepared by femtosecond laser and nanosecond laser processing simultaneously according to the embodiment of the invention for realizing anti-icing function;

the method comprises the following specific implementation steps:

for a better understanding of the present invention, reference will now be made in detail to the present embodiments of the invention, which are illustrated in the accompanying drawings and specific examples, which are set forth to illustrate, but are not to be construed to limit the scope of the invention.

The specific implementation process of the method is described in detail by combining the attached drawings:

step 1: a wind power blade sample piece with the size of 30 multiplied by 10mm (length multiplied by width multiplied by height) is taken, and the surface of the wind power blade to be processed is cleaned by absolute ethyl alcohol.

Step 2: a wind power blade sample to be processed is placed on a laser processing platform, a femtosecond laser and an auxiliary mechanical system thereof are started, the laser output power is set to be 4W, the laser scanning speed is 5000mm/s, the scanning frequency is 100 times, the repetition frequency is 50kHz, and the laser wavelength is 1026 nm. Setting a laser scanning area to be 8mm multiplied by 8mm, setting a scanning path to be a group of vertically intersected straight lines, setting the distance between two adjacent lines to be 0.23 mu m, and processing a micro-nano structure on the surface of the wind power blade sample wafer.

And step 3: the nanosecond laser and the accessory mechanical system thereof are started, the laser output power is set to be 4W, the laser scanning speed is 5000mm/s, the scanning times are 2 times, the repetition frequency is 100kHz, and the laser wavelength is 1026 nm. Setting a laser scanning area to be 8mm multiplied by 8mm, setting a scanning path to be a group of parallel straight lines, setting the distance between two adjacent lines to be 0.02 mu m, and carrying out nanosecond laser processing on the surface of the wind power blade sample wafer with the processed micro-nano structure. The laser processing anti-icing micro-nano structure is shown in figure 1.

And 4, step 4: and (3) placing the processed wind power blade sample wafer into a refrigerator freezing layer, wherein the temperature is-16 ℃, the humidity is 20%, the placing time is 1h, and finally the temperature of the wind power blade sample wafer is consistent with the temperature of the refrigerator freezing layer.

And 5: and (3) dropping 100 mul of deionized water drops dropwise on the sample micro-nano structure and the original surface by using a 100 mul-1000 mul of pipette gun. Two surface freezing delay times were recorded.

Step 6: through real-time monitoring and recording, the freezing delay time of the water drops on the original surface of the wind power blade is 2 minutes, and the freezing delay time of the water drops on the laser processing surface of the wind power blade is 20 minutes, as shown in fig. 3.

The above-mentioned embodiments of the present invention are examples for illustrating the present invention, and are not intended to limit the embodiments of the present invention, and any modifications, improvements, etc. made to the method, steps or conditions of the present invention within the spirit and principle of the present invention are within the scope of the present invention.