CN116026089A - Technical method for realizing fixed-point frosting of surface - Google Patents

Abstract

The invention relates to the technical field of anti-icing, and discloses a technical method for realizing fixed-point frosting on the surface, which aims to solve the problem that the existing anti-icing and anti-frosting methods of solid components are poor in effect and comprises the following steps: cleaning and drying the solid component for standby, and fixing the solid component on a backboard on an operation table of the optical fiber marking machine; and inputting working parameters and laser ablation patterns of the optical fiber marking machine at a control computer end, and performing laser ablation treatment on the solid component. According to the invention, fixed-point frosting on the surface of the solid component is realized through the phase change process of the brine, under the low-temperature and high-humidity conditions, the salt particles can capture water vapor in the air to gradually reach the freezing point for icing, and frost crystals newly generated at the top of the ice beads can be easily removed, so that the effects of ice prevention and frost prevention on the whole surface of the solid component are realized through fixed-point frosting on the local area of the solid component, the frost on the surface of the solid component can be easily removed, and accumulation of freezing rain, snow and ice on the surface is delayed and even prevented, so that the effect of frost prevention is realized.

Description

Technical method for realizing fixed-point frosting of surface

Technical Field

The invention relates to the technical field of anti-icing, in particular to a technical method for realizing fixed-point frosting on a surface.

Background

Under the low-temperature and high-humidity environment, ice and frost widely exist on the surface of solids, and particularly in cold areas, due to extremely cold weather, the surface of various solid materials is frozen and frosted. Aiming at the icing behavior of the solid surface under the low-temperature condition, the traditional deicing method adopting the technologies such as machinery, heat, vibration and the like is easy to damage the surface of mechanical equipment, and has the problems of low efficiency, high energy consumption, high deicing cost and the like; the consumption of the antifreeze widely used at present is large and part of the antifreeze is harmful to the environment, so that it is necessary to develop an anti-frost surface which is durable and harmless to the environment.

The super-hydrophobic surface has good anti-icing property, can be used for communication and power transmission lines, prevents disasters caused by accumulation of ice and snow, realizes anti-icing and anti-frosting of aircraft wings and high-speed railways, reduces adhesion force among raindrops, wet snow and solid surfaces by a very small dynamic rolling angle, drops which do not jump away in time easily fall off under the action of external forces such as gravity, wind and the like, delays and even prevents accumulation of frost rain, snow and ice on the surfaces, and thus achieves the anti-icing effect. The delay icing time of the super-hydrophobic surface at low temperature is limited, particularly in low-temperature and high-humidity environments, the surface can be frosted hard, and the frosting layer of the solid surface is difficult to remove.

The method adopted at present mainly comprises active defrosting and deicing, including mechanical heating, mechanical vibration and the like. Active deicing and defrosting cause energy loss, and a compromise strategy has been proposed for anti-frost and anti-icing, i.e. passive anti-frost and anti-icing by introducing liquid or solid hygroscopic agents, such as 1, 2-propanediol, ethylene glycol, lithium bromide, etc., at the surface. At present, alcohol antifreezing solution is known to have certain corrosiveness to steel and galvanized materials, the moisture absorption capacity of the liquid moisture absorbent is limited, the replacement or supplementation of the moisture absorbent is not easy to operate, and the cost is high, so that a method with excellent anti-icing and anti-frost effects is needed.

Disclosure of Invention

The invention aims to solve the defects in the prior art, and provides a technical method for realizing surface fixed-point frosting.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a technical method for realizing fixed-point frosting of a surface comprises the following steps:

step 1: cleaning and drying the solid component for standby, and fixing the solid component on a backboard on an operation table of the optical fiber marking machine;

step 2, inputting working parameters and laser ablation patterns of the optical fiber marking machine at a control computer end, adjusting focal lengths of an operation table and a laser generator, and starting laser ablation treatment after marking a laser ablation area of a solid component by red light;

step 3, placing the solid component after ablation into ultrasound for cleaning, immersing the cleaned solid component into n-dodecyl mercaptan water solution, standing for 2 hours, taking out, and drying after washing to obtain the solid component with good superhydrophobicity;

step 4, fixing the solid component obtained in the step 3 on the backboard again, inputting the laser ablation pattern again, and starting to perform laser ablation treatment again on a part of the area of the solid component;

step 5, placing a container filled with brine in the obliquely front of the solid component, and uniformly suspending brine drops in a secondary ablation area on the surface of the solid component after 4-5 times of spraying;

and 6, horizontally placing the surface of the solid component suspended saline water drops on a refrigerating table, opening a humidity controller, controlling the ambient humidity to be 65-75% RH, and waiting for the saline water drops on the surface of the solid component to freeze and frost.

Preferably, after the brine droplets on the surface of the solid component are frozen and frosted for 30min in the step 6, the dust-blowing balls are used for removing the surface frost crystals.

Preferably, in step 2, the operating parameters include: the diameter of the laser spot is 50 μm; the laser ablation step length is more than or equal to 0.01mm; the maximum size of the laser ablation pattern was 150×150mm.

Preferably, in step 2, before performing laser ablation treatment, deionized water, absolute ethyl alcohol and deionized water are respectively used for sequentially and ultrasonically cleaning the solid component for 15-30min.

Preferably, the solid part obtained in step 2 is dried in vacuo at 60℃for 30min and then placed in 2ml-40ml of n-dodecyl mercaptan aqueous solution as described in step 3 for a rest period of 2h.

Preferably, the solid component with good superhydrophobicity obtained in the step 3 is sequentially ultrasonically cleaned for 15-30min by using deionized water, absolute ethyl alcohol and deionized water respectively.

Preferably, the solid part obtained in step 3 is dried in vacuo at 60℃for 12 hours and then fixed to a backing plate as described in step 4.

Preferably, the brine concentration in step 5 is 2mol/L.

Preferably, in the step 6, the lowest refrigeration temperature of the refrigeration table is-20 ℃; the humidity controller includes a humidifier and a humidity monitor.

Preferably, the volume of the cold air blown out by the dust blowing ball is 40-50ml; the discharge speed of the cold air is 1.06-1.32 m/s.

The beneficial effects of the invention are as follows:

according to the invention, fixed-point frosting on the surface of the solid component is realized through the phase change process of the brine, the brine can capture water vapor in the air to gradually reach freezing point icing under the low-temperature high-humidity condition, and frost crystals newly generated on the top of the frozen brine ice can be easily removed, so that the effects of ice prevention and frost prevention on the surface of the solid component are realized through fixed-point frosting on the surface of the solid component, the frost on the surface of the solid component can be easily removed, and accumulation of freezing rain, snow and ice on the surface is delayed and even prevented, so that the effect of frost prevention is achieved.

In the technical method, after the brine is evaporated, salt particles are deliquesced in the secondary ablation area, and the inclined surface cannot cause salt water loss due to good hydrophilicity of the laser secondary ablation area, so that the application scene can be expanded, and the method has a wide application range.

Drawings

FIG. 1 is a graph of depth versus width of laser ablation power 2-20W on the surface of brass sheet prepared in example 1;

FIG. 2 is a profile of a surface with a laser step size of 0.01-0.1mm at the optimal laser ablation power prepared in example 1;

FIG. 3 is a 3D topography of the best power and laser step size of the brass sheet surface prepared in example 1;

FIG. 4 is the effect of laser ablation power 4,6, 10, 18W treatment prepared in example 1 on removal of S from n-dodecyl mercaptan (C22H 46S) on a brass surface;

FIG. 5 is a scanning electron microscope image of the laser power of the brass surface prepared in example 1, thiol separation of a circular area of 1mm diameter, with the upper right corner being the optical contact angle of the droplet on the corresponding surface;

FIG. 6 is an optical photograph of saline droplets immobilized on a secondary ablation zone and continuously evaporated after spraying saline on the surface prepared in example 1;

FIG. 7 is a scanning electron microscope image of salt crystals crystallized in the secondary ablation zone after evaporation of salt water droplets prepared in example 1;

FIG. 8 is a photograph of frosting of saline droplets of different concentrations prepared in example 1;

FIG. 9 is a plot of the diameter statistics of the inhibition zone generated by the different concentration brine droplets prepared in example 1;

FIG. 10 is a photograph of frosting of saline droplets of different diameters prepared in example 1;

FIG. 11 is a plot of the inhibition of frosting zone diameter statistics generated by the different diameter brine droplets prepared in example 1;

FIG. 12 is a deliquescence process on a cold table immediately after evaporation of 2mol/L saline droplets prepared in example 1 in a secondary ablation zone of 1mm diameter;

FIG. 13 is a graph of the inhibition of frosting zone change during deliquescence on a cold stage immediately after evaporation of 2mol/L saline droplets prepared in example 1 in a secondary ablation zone of 1mm diameter;

FIG. 14 is a photograph of the "silver mirror effect" of multiple 1mm diameter secondary ablation zones in semi-immersed water on the surface of a solid member prepared in example 1;

FIG. 15 is a photograph of an optical profile of icing and frosting of 2mol/L brine droplets prepared in example 1 on a surface;

FIG. 16 is a photograph showing the icing and frosting process of a plurality of 2mol/L brine droplets prepared in example 1 on a surface;

FIG. 17 is a photograph of long term frosting of the brass surface with fixed brine droplets, the superhydrophobic brass surface, the pristine surface, and the brass surface with fixed deionized water droplets prepared in example 1 placed outdoors for 8 hours;

FIG. 18 is a schematic diagram of the fixed point frosting surface prepared in example 1;

fig. 19 is a photograph of the fixed point frosting surface prepared in example 1 as repelling simulated frozen rain drops.

Description of the embodiments

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.

Examples

Polishing and smoothing the surface of a Q235 carbon steel plate, cleaning, fixing the Q235 carbon steel plate on a back plate of a commercial optical fiber laser marker, inputting working parameters (P=12W, b=0.05 mm) and laser ablation grid patterns, adjusting a red light indication ablation area after laser focal length, and performing laser ablation treatment after clicking 'execute';

washing the laser ablated surface of the obtained Q235 carbon steel plate with deionized water and absolute ethyl alcohol in an ultrasonic cleaner for three times, and drying in a 60 ℃ oven for 30min;

immersing the whole laser ablated surface of the dried Q235 carbon steel plate into 0.05mol/L stearic acid-ethanol water solution for modification for 2 hours, washing the super-hydrophobic Q235 carbon steel plate surface with deionized water and absolute ethyl alcohol in an ultrasonic cleaner for three times, and drying in a 60 ℃ oven for 30 minutes;

fixing a Q235 carbon steel plate on the back plate again, and inputting a secondary working parameter (P=10W, b=0.05mm) and a laser ablation pattern (a circular array with a diameter of 1mm and a spacing of 2.8 mm) for ablation;

placing a saline water spray bottle or a washing bottle with the concentration of 2mol/L in front of a Q235 carbon steel plate in an inclined manner, and uniformly hanging saline water drops in a secondary ablation area of the surface after spraying for 4-5 times;

horizontally placing the surface of the fixed saline water drops on a refrigeration table at the temperature of minus 20 ℃, opening a humidity controller, controlling the ambient humidity to be between 50 and 75 percent RH, and waiting for the saline water drops on the surface of the Q235 carbon steel plate to freeze and frost;

and (5) freezing and frosting saline water drops on the surface of the Q235 carbon steel plate for 30min, and removing surface frost crystals by using a dust blowing ball.

Examples

Polishing and cleaning the surface of a 6061 alloy plate, fixing the 6061 alloy plate on a back plate of a commercial optical fiber laser marker, inputting working parameters (P=12W, b=0.05 mm) and laser ablation grid patterns, adjusting a red light indication ablation area after laser focal length, and clicking 'executing' to perform laser ablation treatment;

washing the laser ablated surface of the 6061 alloy plate with deionized water and absolute ethyl alcohol in an ultrasonic cleaner for three times, and drying in a 60 ℃ oven for 30min;

immersing the whole laser ablated surface of the dried 6061 alloy plate into 0.05mol/L stearic acid-ethanol water solution for modification for 2 hours, washing the surface of the super-hydrophobic 6061 alloy plate with deionized water and absolute ethyl alcohol in an ultrasonic cleaner for three times, and drying in a 60 ℃ oven for 30 minutes;

fixing the 6061 alloy plate on the back plate again, and inputting a secondary working parameter (P=10W, b=0.05 mm) and a laser ablation pattern (circular array with the diameter of 1mm and the interval of 2.8 mm) for ablation;

placing a saline spray bottle or a wash bottle with the concentration of 2mol/L in front of a 6061 alloy plate, spraying for 4-5 times, and uniformly hanging saline drops in a secondary surface ablation area;

horizontally placing the surface of the fixed saline water drops on a refrigeration table at the temperature of minus 20 ℃, opening a humidity controller, controlling the ambient humidity to be between 50 and 75 percent RH, and waiting for the saline water drops on the surface of the 6061 alloy plate to freeze and frost;

and after salt water droplets on the surface of the 6061 alloy plate are frozen and frosted for 30min, removing surface frost crystals by using a dust blowing ball.

Examples

Polishing and cleaning a surface of a 304 stainless steel plate, fixing the 304 stainless steel plate on a back plate of a commercial optical fiber laser marker, inputting working parameters (P=12W, b=0.05 mm) and laser ablation grid patterns, adjusting a red light indication ablation area after laser focal length, and clicking 'executing' to perform laser ablation treatment;

washing the laser ablated surface of the 304 stainless steel plate with deionized water and absolute ethyl alcohol in an ultrasonic cleaner for three times, and drying in a 60 ℃ oven for 30min;

immersing the whole laser ablated surface of the dried 304 stainless steel plate into 0.05mol/L stearic acid-ethanol water solution for modification for 2 hours, washing the surface of the super-hydrophobic 304 stainless steel plate with deionized water and absolute ethyl alcohol in an ultrasonic cleaner for three times, and drying in a 60 ℃ oven for 30 minutes;

fixing a 304 stainless steel plate on the back plate again, and inputting a secondary working parameter (P=10W, b=0.05 mm) and a laser ablation pattern (circular array with the diameter of 1mm and the interval of 2.8 mm) for ablation;

placing a saline spray bottle or a wash bottle with the concentration of 2mol/L in front of a 304 stainless steel plate, and uniformly suspending saline drops in a secondary ablation area of the surface after spraying for 4-5 times;

horizontally placing the surface of the fixed saline water drops on a refrigeration table at the temperature of minus 20 ℃, opening a humidity controller, controlling the ambient humidity to be 50% -75% RH, and waiting for the saline water drops on the surface of the 304 stainless steel plate to freeze and frost;

and (3) freezing and frosting the saline water drops on the surface of the 304 stainless steel plate for 30min, and removing surface frost crystals by using a dust blowing ball.

The technical method for realizing surface fixed-point frosting disclosed in the above embodiments 1-3 of the present invention can be successfully prepared on widely used solid components such as metal surfaces, e.g. Q235 carbon steel plate, 6061 aluminum alloy, 304 stainless steel, and other metal surfaces. After the surface is uniformly dipped with saline or sprayed with saline, the secondary ablation area is covered by saline droplets, and because the saturated vapor pressure of saline and ice is lower than that of water below zero, even after the saline is frozen, the frosting area is still inhibited around the saline droplets. Thus, in a subzero humid environment, the superhydrophobic region on the surface of the decorative brine droplet will remain unbrosted for a long period of time until the frost on top of the iced bead overlaps, and even if the surface is completely frosted, the adhesive strength of the frost layer is much lower than other surfaces.

The laser of experimental example 1 above was subjected to one ablation on a polished smooth brass surface. FIG. 1 is a graph of depth and width of laser ablation power 2-20W on the surface of brass sheet prepared in example 1; FIG. 2 is a summary of the profile of the surface texture produced by the surface of the superhydrophobic brass sheet with a laser ablation step size of 0.01-0.1mm prepared in example 1. The 3D topography of the superhydrophobic surface with the primary laser ablation power of 12W and the laser ablation step length of 0.05mm in FIG. 3 is determined according to the method.

Fig. 4 is a scanning electron microscope image of the surface of a laser ablated n-dodecyl mercaptan modified brass sheet and a corresponding line scan map of the energy spectrum S element. The n-dodecyl mercaptan chain is chemically bonded on the surface of the brass, when the secondary ablation power is 4W and 6W, obvious laser ablation marks are formed on the surface, and the S element cannot be eliminated; when the secondary ablation power is 10W, the elimination effect of the S element is most obvious, so that the power is 10W when the secondary ablation is performed; at a power of 18W, the S element is significantly removed, but the integrity of the surrounding area is compromised. FIG. 5 is a scanning electron microscope image of the surface of a brass sheet subjected to laser ablation twice, the surface morphology of the surface after the two ablations is slightly changed and the wettability is greatly changed, and an optical profile image of the contact angle is placed in the inset.

Fig. 6 is a picture of saline droplets remaining after 4-5 surface flushes with a wash bottle, where the flushed area of saline droplets uniformly covered the secondary ablation area, and after 11 minutes the saline droplets were all evaporated. In fig. 7, the salt water in the secondary ablation area is evaporated and then uniformly dispersed and crystallized on the surface, and it is obvious that the bottom of the salt particles is combined with the rough texture structure, so that a large number of anchor points are provided for the salt particles, and the adhesive force is further improved.

In FIG. 8, the salt solution drops with different concentrations always keep a state of no frosting within a certain range around the salt solution drops with different concentrations, and FIG. 9 shows the relationship between the diameter of a frosting inhibition area and the concentration of the salt solution drops; FIG. 10 is a photograph of different brine droplet diameters and corresponding frost-inhibiting dry areas, and FIG. 11 is a statistical plot of brine droplet diameters and corresponding frost-inhibiting dry areas, wherein the ratio of the frost-inhibiting dry areas to the brine droplet diameters is smaller in tendency to increase when the brine concentration is 1.5-4mol/L, and 2mol/L brine is selected; FIG. 12 shows that as the substrate temperature decreases, water vapor rapidly condenses on the superhydrophobic surface, salt particles are dissolved, and even if the concentration of salt water is diluted during cooling, the material undergoes a series of phase changes, while the annular frost prevention region is permanently present; the size of the frosting zone is shown to remain substantially unchanged in fig. 13.

Fig. 14 shows that the surface containing the laser ablation pattern is semi-immersed in water, and the other areas reflect silver white light due to superhydrophobicity, except for the circular black secondary ablation area. The brine droplets in fig. 14 were placed on a cold stage to observe the freezing and frosting process, and it is clear from fig. 15 that after the brine droplets were frozen, frost only grew on top of the ice beads. There is no frost in the area around the bottom of the iceball. It can be concluded that the brine decorated superhydrophobic pattern surface, when cooled, does not condense water vapor in the superhydrophobic region at the bottom of the iceball.

The same conclusion can be drawn when viewed vertically, with the ice beads starting to frost on top of them in fig. 16, while the middle superhydrophobic region is clean. At the same time, frost begins to condense on the superhydrophobic surface away from the iceball. Even if frost covers the edge area, the frost on the tops of the beads overlaps, the superhydrophobic surface in the middle is still clean, and the frost on the beads always grows vigorously, however, the contact area of the frost and the tops of the beads is very small. Therefore, frost is very fragile and can be removed even by the dust-blown balls. As shown in fig. 16, after defrosting the surface, the middle superhydrophobic surface is uncovered, while the edge area is still covered by white frost. Fig. 17 is an experiment of icing and frosting for 8 hours with the brine droplet decorated surface (upper left), the original brass surface (lower left), the brass superhydrophobic surface (upper right), and the deionized water droplet decorated surface (lower right) left outdoors, and the other surfaces were frosted vigorously except for the surface covered with the brine droplet.

FIG. 18 is an anti-frosting mechanism and process for a patterned salt particle decorated surface, where the relative humidity of air in the area of the decorated salt particle on the solid part surface increases rapidly while the water vapor concentration remains unchanged upon cooling. When the concentration of water vapor exceeds the saturated vapor pressure, i.e., the relative humidity exceeds 100%, the water vapor must condense, becoming brine droplets as the salt particles absorb more moisture and eventually dissolve in the absorbed water, and the concentrated brine droplets freeze into ice droplets, the arrangement of the decoration areas of the salt particles on the superhydrophobic surface not only changing the diffusion path and position of the water vapor, but also changing the growth law of frost.

Fig. 19 is a super-hydrophobic surface decorated with salt particles simulating the descent of freezing rain in a pattern distribution, and it is apparent that freezing rain is very easy to leave on an inclined surface, leaving only a small portion of supercooled water droplets, and thus the surface has great potential for resisting freezing rain.

The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.

Claims (10)

1. The technical method for realizing the fixed-point frosting of the surface is characterized by comprising the following steps of:

step 1: cleaning and drying the solid component for standby, and fixing the solid component on a backboard on an operation table of the optical fiber marking machine;

step 2, inputting working parameters and laser ablation patterns of the optical fiber marking machine at a control computer end, adjusting focal lengths of an operation table and a laser generator, and starting laser ablation treatment after marking a laser ablation area of a solid component by red light;

step 3, placing the solid component after ablation into ultrasound for cleaning, immersing the cleaned solid component into n-dodecyl mercaptan water solution, standing for 2 hours, taking out, and drying after washing to obtain the solid component with good superhydrophobicity;

step 4, fixing the solid component obtained in the step 3 on the backboard again, inputting the laser ablation pattern again, and starting to perform laser ablation treatment again on a part of the area of the solid component;

step 5, placing a container filled with brine in the obliquely front of the solid component, and uniformly suspending brine drops in a secondary ablation area on the surface of the solid component after 4-5 times of spraying;

and 6, horizontally placing the surface of the solid component suspended saline water drops on a refrigerating table, opening a humidity controller, controlling the ambient humidity to be 65-75% RH, and waiting for the saline water drops on the surface of the solid component to freeze and frost.

2. The method according to claim 1, wherein after the brine droplets on the surface of the solid component are frozen and frosted for 30min in step 6, the surface frost crystals are removed by using a dust-blowing ball.

3. A technical method for realizing fixed-point frosting of surfaces according to claim 1, wherein in step 2, the working parameters include: the diameter of the laser spot is 50 μm; the laser ablation step length is more than or equal to 0.01mm; the maximum size of the laser ablation pattern was 150×150mm.

4. The method according to claim 1, wherein in step 2, deionized water and absolute ethanol are respectively used for ultrasonic cleaning for 15-30min before laser ablation treatment is performed on the solid component.

5. The method according to claim 1, wherein the solid part obtained in step 2 is dried at 60 ℃ for 30min under vacuum and then placed in 2ml-40ml of n-dodecyl mercaptan aqueous solution according to step 3, and the standing time is 2h.

6. The technical method for realizing surface fixed-point frosting according to claim 1, wherein deionized water, absolute ethyl alcohol and deionized water are respectively used for sequentially and ultrasonically cleaning the solid component with good superhydrophobicity obtained in the step 3 for 15-30min.

7. The method according to claim 1, wherein the solid component obtained in step 3 is dried at 60 ℃ for 12 hours under vacuum and then fixed on the back plate according to step 4.

8. The method according to claim 1, wherein the brine concentration in step 5 is 2mol/L.

9. The technical method for realizing surface fixed-point frosting according to claim 1, wherein in the step 6, the lowest refrigerating temperature of the refrigerating table is-20 ℃;

the humidity controller includes a humidifier and a humidity monitor.

10. The method for realizing surface fixed-point frosting according to claim 2, wherein the volume of cold air blown out by the dust blowing ball is 40-50ml each time; the discharge speed of the cold air is 1.06-1.32 m/s.

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