An ultrafast laser processing close-packed concentric hexagonal array solar evaporator and a preparation method thereof

Abstract

The application discloses a kind of superfast laser processing close-packed concentric hexagonal array solar evaporator and its preparation method, belongs to solar evaporator technical field.The front surface of substrate is processed using superfast laser to obtain a kind of close-packed concentric hexagonal array microstructure surface, the close-packed concentric hexagonal array microstructure surface is an array structure that is closely arranged by many concentric hexagonal structure units, each concentric hexagonal structure unit is formed by the nesting of multistage hexagonal groove with the same center and spacing of about 30um, and the six edges of each concentric hexagonal structure unit are respectively in contact with the six edges of the outermost concentric hexagonal structure unit, and so on.By using superfast laser processing to obtain a kind of close-packed concentric hexagonal array microstructure surface, the light absorbance, wettability, surface area and the like of the metal surface are improved, which is conducive to improving the surface evaporation performance, and can solve the problems of complex preparation process and low evaporation efficiency of existing solar evaporator.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solar evaporation water collection, in particular to a superfast laser processing close-packed concentric hexagonal array type solar evaporator and a preparation method thereof. BACKGROUND

[0002] With the frequent occurrence of extreme weather worldwide and the continuous shortage of freshwater resources on Earth, the demand for simple, stable and reliable freshwater resource acquisition devices continues to rise. Solar water evaporator is a key device that can convert solar light into heat energy and be used for seawater desalination, wastewater treatment and other applications.

[0003] However, the traditional preparation method of solar water evaporator has many limitations, such as low production efficiency and long preparation period, so there is an urgent need for a new preparation method to overcome these challenges.

[0004] Based on the above problems of solar water evaporator, the present application designs a superfast laser processing close-packed concentric hexagonal array type solar evaporator and a preparation method thereof with simple process and high evaporation efficiency. SUMMARY

[0005] The present application provides a superfast laser processing close-packed concentric hexagonal array type solar evaporator and a preparation method thereof, which uses superfast laser processing on a copper substrate to obtain a close-packed concentric hexagonal array microstructure surface, so that the light absorbance, wettability, surface area and capillary effect of the surface are improved, which is beneficial to improve the evaporation efficiency of the surface, and can solve the problems of complex preparation process and poor durability of the existing solar evaporator.

[0006] In order to achieve the above purpose, the present application provides a close-packed concentric hexagonal array microstructure surface prepared by superfast laser processing technology.

[0007] A superfast laser processing close-packed concentric hexagonal array type solar evaporator, characterized in that the front surface of the substrate is processed by superfast laser to obtain a close-packed concentric hexagonal array microstructure surface.

[0008] The close-packed concentric hexagonal array microstructure is a close-packed array structure composed of many close-packed concentric hexagonal structure units, each of which is composed of a plurality of nested hexagonal line grooves with the same center and a spacing of about 30um, and the six outermost edges of each concentric hexagonal structure unit are respectively in contact with the six outermost edges of another concentric hexagonal structure unit, and so on. The inside and around the groove are covered with a large number of micro-particles due to the use of superfast laser processing. By adjusting the superfast laser processing parameters, the appropriate groove processing depth is obtained.

[0009] The groove width is about 30-50 um, the distance between two adjacent hexagons in the nested multi-stage hexagonal line groove is 30, and the groove depth is 3-5 um; each unit is nested with 5-10 stages of hexagons, i.e. 5-10 hexagons with different side lengths are nested.

[0010] The back of the substrate is provided with a foam floating material, which is polystyrene foam.

[0011] The substrate is a polycrystalline copper substrate.

[0012] The center of each concentric hexagonal structure unit is a solid convex.

[0013] The ultrafast laser processor is a picosecond laser processor, which includes a displacement table for sample positioning.

[0014] The preparation method of the above-mentioned ultrafast laser processing dense-packed concentric hexagonal array solar evaporator comprises the following steps:

[0015] Firstly, the substrate is placed in a container containing an acid washing solution, and the container is placed in an ultrasonic cleaner for cleaning; then the substrate is taken out and dried;

[0016] Then, the substrate is polished using sandpaper to ensure that the oxide layer is completely removed and the connecting surface is level, and after polishing, the substrate is polished and dried;

[0017] After that, the laser control system is started, and the parameters of the ultrafast laser processing equipment are adjusted to prepare for processing the dense-packed concentric hexagonal array microstructure;

[0018] Then, the pretreated substrate is placed in the irradiation range of the laser beam, and the position of the displacement table is adjusted to ensure that the substrate is in the laser processing area; then the ultrafast laser processing equipment is controlled to process the substrate surface according to the target pattern, and the laser processing power and other parameters are adjusted;

[0019] Finally, polystyrene foam is pasted on the back of the processed substrate to form a floating evaporator device.

[0020] Preferably, the acid washing solution is an H2SO4 solution.

[0021] When the ultrafast laser processing dense-packed concentric hexagonal array solar evaporator is used, the polystyrene foam faces downward, the surface with the dense-packed concentric hexagonal array microstructure faces upward, and the device floats in water, and the surface with the dense-packed concentric hexagonal array microstructure is below the water surface, so that there is a layer of water on the surface with the dense-packed concentric hexagonal array microstructure.

[0022] The present application has the advantages that a close-packed concentric hexagonal array microstructure surface is obtained by using ultrafast laser processing, the light absorbance, wettability, surface area and the like of the metal surface are improved, the surface evaporation performance is improved, and the problems of complex preparation process and low evaporation efficiency of the existing solar evaporator can be solved. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present patent, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the following drawings.

[0024] Figure 1 It is a surface structure schematic diagram and a microstructure diagram of the laser-processed close-packed concentric hexagonal array microstructure surface.

[0025] Figure 2 It is a complete processing flow schematic diagram.

[0026] Figure 3 It is an evaporation efficiency reference diagram of Example 1.

[0027] Figure 4 It is a surface structure schematic diagram of the ultrafast laser-processed copper substrate in Comparative Example 2.

[0028] Figure 5 It is an evaporation efficiency comparison of Comparative Example 1, the optimal sample in Example 1 and Comparative Example 2. DETAILED DESCRIPTION

[0029] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The described embodiments are only some of the embodiments of the present application, not all. All other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0030] The present application will be further described below in combination with the embodiments, but the present application is not limited to the following embodiments.

[0031] Example 1: The following specifically describes the implementation of the patent

[0032] 1. Preparation of copper substrate: a square copper substrate with a size of 40mm*40mm*1mm is made by wire cutting;

[0033] 2. Preparation of polystyrene: a polystyrene foam with a size of 40mm*40mm*1mm is cut by a knife;

[0034] 3. The copper sheet with purity greater than 99.99wt%, size of 40mm x 40mm x 1mm is immersed in prepared 30% H2SO4 aqueous solution for several minutes to remove the surface oxide and contaminants of the copper substrate. After cleaning, drying, sanding, ensuring the complete removal of the oxide layer and making the surface flat, polishing treatment is performed, and the copper sheet is ready for use;

[0035] 4. The pretreated substrate is placed on the ultrafast laser processing platform, leveled and focused using a laser range finder, and then placed at the processing position. The parameters of the laser are adjusted as follows: scanning power 10-50w, scanning speed 15mm / s, scanning once, scanning frequency 400kHz, pulse width 0.05ms, and processing according to the pattern shown in FIG. 1, with an interval of 30um; Figure 1

[0036] 5. The polystyrene foam is pasted on the back of the processed copper substrate to form a solar evaporator;

[0037] 6. The prepared solar evaporator is tested for standard evaporation performance under sunlight.

[0038] Comparative Example 1: The following specifically describes the implementation of the patent

[0039] Except that the ultrafast laser processing is not performed, and the cleaned, sanded and polished copper sheet is directly used as the substrate of the evaporator, the rest is basically the same as Example 1.

[0040] The prepared evaporator is tested for evaporation performance.

[0041] Comparative Example 2: The following specifically describes the implementation of the patent

[0042] Except that the ultrafast laser processing parameters in step 4 are different, the rest is basically the same as Example 1.

[0043] The ultrafast laser processing of this comparative example is adjusted as follows: scanning power 30w, scanning speed 15mm / s, scanning once (line-shaped, not grid), scanning frequency 400kHz, pulse width 0.05ms, and processing with an interval of 100um between adjacent lines as shown in FIG. 2; Figure 4

[0044] The prepared evaporator is tested for evaporation performance.

[0045] The implementation steps of the present application are described in detail above with reference to the accompanying drawings. The present embodiment is implemented on the premise of the technical solution of the present application, and gives a detailed implementation and specific operation process. However, the protection scope of the present application is not limited to the following examples. Those skilled in the art can modify and polish it without changing the spirit and content of the present application.​​

Claims

1. A solar evaporator with a close-packed concentric hexagonal array formed by ultrafast laser processing, characterized in that, The front side of the substrate is processed using ultrafast laser to obtain a closely packed concentric hexagonal array microstructure surface. The closely packed concentric hexagonal array microstructure is a closely packed array structure, which is an array structure composed of many concentric hexagonal structural units arranged closely. Each concentric hexagonal structural unit is composed of multi-level hexagonal line trenches with the same center and a spacing of 30 μm. The six outermost sides of each concentric hexagonal structural unit are respectively connected and overlapped with the six outermost sides of another concentric hexagonal structural unit, and so on. The inside and around the trenches are covered with a large number of microparticles due to the ultrafast laser processing. The trench width is 30-50 μm, the spacing between two adjacent hexagons is 30 μm when the multi-level hexagonal line trenches are nested, and the trench depth is 3-5 μm. Each unit is nested with 5-10 levels of hexagons, that is, there are 5-10 hexagons with different side lengths.

2. The ultrafast laser-processed close-packed concentric hexagonal array solar evaporator according to claim 1, characterized in that, The back of the substrate is provided with a foam floating material, which is polystyrene foam.

3. The ultrafast laser-processed close-packed concentric hexagonal array solar evaporator according to claim 1, characterized in that, The substrate is a polycrystalline copper substrate.

4. A solar evaporator with a close-packed concentric hexagonal array processed by ultrafast laser processing according to claim 1, characterized in that, The ultrafast laser processor is a picosecond laser processor that includes a displacement stage for sample positioning.

5. A method for preparing an ultrafast laser-processed close-packed concentric hexagonal array solar evaporator according to any one of claims 1-4, characterized in that, Includes the following steps: First, place the substrate in a container filled with pickling solution, and then place the container in an ultrasonic cleaner for cleaning; then remove the substrate and let it air dry. Then, use sandpaper to polish the substrate to ensure that the oxide layer is completely removed and the bonding surface is level. After polishing, polish and dry. Next, the laser control system is activated, and the parameters of the ultrafast laser processing equipment are adjusted in preparation for processing the close-packed concentric hexagonal array microstructure. Subsequently, the pre-treated substrate is placed within the irradiation range of the laser beam, and the position of the displacement stage is adjusted to ensure that the substrate is within the laser processing area; then, the ultrafast laser processing equipment is controlled to process the substrate surface according to the target pattern by adjusting parameters such as laser processing power. Finally, polystyrene foam is glued to the back of the processed substrate to form a floating evaporation device.

6. The method for preparing an ultrafast laser-processed close-packed concentric hexagonal array solar evaporator according to claim 5, characterized in that, The pickling solution is an H2SO4 solution.

7. A method for preparing an ultrafast laser-processed close-packed concentric hexagonal array solar evaporator according to claim 5, characterized in that, The laser parameters were adjusted as follows: scanning power 10~50W, scanning speed 15mm / s, one scan, scanning frequency 400kHz, and pulse width 0.05ms.

8. The application of the ultrafast laser-processed close-packed concentric hexagonal array solar evaporator according to any one of claims 1-4, wherein when the ultrafast laser-processed close-packed concentric hexagonal array solar evaporator is used, the polystyrene foam faces downwards, and the side with the close-packed concentric hexagonal array microstructure faces upwards, floating in water, while the side with the close-packed concentric hexagonal array microstructure is below the water surface, so that there is a layer of water on the side with the close-packed concentric hexagonal array microstructure.

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