CN109456738A - A kind of preparation method and aluminium base suppression frost experimental system of super-hydrophobic aluminium base - Google Patents

A kind of preparation method and aluminium base suppression frost experimental system of super-hydrophobic aluminium base Download PDF

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CN109456738A
CN109456738A CN201811549977.3A CN201811549977A CN109456738A CN 109456738 A CN109456738 A CN 109456738A CN 201811549977 A CN201811549977 A CN 201811549977A CN 109456738 A CN109456738 A CN 109456738A
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aluminium base
cooling
super
water
hydrophobic
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谷雅秀
王兴龙
王俊炜
刘广东
王文韬
孟庆龙
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Changan University
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    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K5/00Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
    • C09K5/08Materials not undergoing a change of physical state when used
    • C09K5/14Solid materials, e.g. powdery or granular
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23FNON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00Etching metallic material by chemical means
    • C23F1/10Etching compositions
    • C23F1/14Aqueous compositions
    • C23F1/16Acidic compositions
    • C23F1/20Acidic compositions for etching aluminium or alloys thereof
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25DREFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D21/00Defrosting; Preventing frosting; Removing condensed or defrost water
    • F25D21/04Preventing the formation of frost or condensate
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01MTESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M99/00Subject matter not provided for in other groups of this subclass
    • G01M99/002Thermal testing

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  • Organic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
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  • General Chemical & Material Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Metallurgy (AREA)
  • General Engineering & Computer Science (AREA)
  • Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)

Abstract

The invention discloses a kind of preparation methods of super-hydrophobic aluminium base and aluminium base to press down frost experimental system, the following steps are included: 1) take aluminium base, artificial coarse processing is carried out with 800 mesh~1500 mesh SiC sand paper to aluminium base surface again, to remove the sull on aluminium base surface, irregular protrusion and gully are formed on aluminium base surface simultaneously, ultrasonic vibration cleaning successively then is carried out to aluminium base using acetone, methanol and deionized water;2) hydrofluoric acid of 2~3mol/L and the hydrochloric acid of 3~4mol/L are configured, again by hydrofluoric acid to 12~15min of aluminium base surface etch, then by hydrochloric acid to 10~12min of aluminium base surface etch, then aluminium base is placed into constant temperature drying in baking oven, it is cleaned by ultrasonic again with deionized water, carries out the modification on aluminium base surface after drying with silicon fluoride, obtains super-hydrophobic aluminium base, the super-hydrophobic aluminium base hydrophobicity of this method preparation is preferable, which can carry out simulated experiment to the hydrophobicity of aluminium base.

Description

A kind of preparation method and aluminium base suppression frost experimental system of super-hydrophobic aluminium base
Technical field
The invention belongs to freeze and technical field of heat pumps, it is related to the preparation method and aluminium base suppression frost of a kind of super-hydrophobic aluminium base Experimental system.
Background technique
In many Shelter in South China Cities in China, winter is clammy, and the outdoor unit of air source heat pump will appear different degrees of frosting and ask Topic.The presence of frost layer can seriously affect the operation of heat pump unit, reduce the COP of unit, compressor emergency shutdown is even resulted in when serious.Cause This needs, which takes some measures, defrosts to the outdoor unit of heat pump unit, to ensure the normal operation of unit.
The common Defrost method for air source heat pump outdoor unit mainly has electric heated defrosting, inverse circulation both at home and abroad at present Defrosting, hot gas bypass defrosting and energy storage defrosting.Wherein, the energy consumption of electric heated defrosting process is more, and effective thermal energy for defrosting Less, heat utilization rate is low;When using reverse cycle defrosting, room temperature decline influences comfort level, and four-way reversing valve is frequent Conversion can make system pressure generate very big fluctuation, shorten the service life of unit;When hot gas bypass defrosting, the defrosting time compared with Long, the degree of superheat of refrigerant vapour is lower, is easy to appear compressor air suction band liquid, causes liquid hammer dangerous;Energy storage defrosting system Initial cost is high, and is difficult to find that a kind of not only economical and practical, heat storage capacity is strong but also reliable energy-accumulation material.If can find it is a kind of from The method for fundamentally carrying out suppression frost, neither influences the operation of heat pump system, and can delay or inhibit the formation of frost layer, then air The service performance of source heat pump will be greatly improved, and use scope can also be promoted.
Summary of the invention
It is an object of the invention to overcome the above-mentioned prior art, a kind of preparation method of super-hydrophobic aluminium base is provided And aluminium base presses down frost experimental system, the super-hydrophobic aluminium base hydrophobicity of this method preparation is preferable, which can be to the hydrophobic of aluminium base Property carry out simulated experiment.
In order to achieve the above objectives, super-hydrophobic aluminium base of the present invention preparation method the following steps are included:
1) aluminium base is taken, then artificial coarse processing is carried out with 800 mesh~1500 mesh SiC sand paper to aluminium base surface, to remove The sull on aluminium base surface, while forming irregular protrusion and gully on aluminium base surface, then using acetone, methanol and Deionized water successively carries out ultrasonic vibration cleaning to aluminium base;
2) hydrofluoric acid of 2~3mol/L and the hydrochloric acid of 3~4mol/L are configured, then by hydrofluoric acid to aluminium base surface etch 12 Then aluminium base is then placed into constant temperature drying in baking oven to aluminium base 10~12min of surface etch by hydrochloric acid by~15min, then It is cleaned by ultrasonic with deionized water, carries out the modification on aluminium base surface after drying with silicon fluoride, obtains super-hydrophobic aluminium base.
Aluminium base suppression frost experimental system of the present invention includes cold plate refrigeration system and change wind speed supply air system, wherein Become wind speed supply air system include centrifugal blower, air hose, honeycomb screen, gauze, for being humidified to centrifugal blower local environment Humidifier and fan speed regulation device for controlling centrifugal blower, cold plate refrigeration system include copper sheet, temperature detect switch (TDS), cooling piece, Controller, the temperature sensor for detecting copper plate temperature and for providing the power-supply system of electric energy;
Super-hydrophobic aluminium base to be tested is pasted on upside of a tossed coin, and the back side of copper sheet, which sticks, is reserved with cooling piece placing chamber Heat-preservation cotton, cooling piece are located in cooling piece placing chamber, and the chill surface of cooling piece is close to copper sheet, and the radiating surface of cooling piece has sticked Water-cooling head, wherein water-cooling head is connected with cooling water recirculation system, and power-supply system is connected by temperature detect switch (TDS) with cooling piece, The output end of temperature sensor and the control terminal of temperature detect switch (TDS) are connected with controller;
The outlet of the air outlet and humidifier of centrifugal blower is connected with air hose, and gauze, honeycomb screen and copper sheet are located at wind In pipe, and the direction of wind flow is sequentially arranged along air hose.
Super-hydrophobic aluminium base to be tested is pasted on upside of a tossed coin by heat-conducting silicone grease.
The chill surface of cooling piece is pasted on the back side of copper sheet by heat-conducting silicone grease.
Water-cooling head is pasted on the radiating surface of cooling piece by heat-conducting silicone grease.
The number of cooling piece is two, and the number of water-cooling head is two, and two water-cooling heads pass through hose serial communication.
Cooling water recirculation system includes cooling water tank and cooling water cycle water pump, wherein the outlet of cooling water tank is through cooling Water water circulating pump is connected with water-cooling head.
Temperature sensor is thin film temperature sensor.
Air hose is bonded by acrylic board.
Copper sheet is vertically placed in the center axial position of air hose.
The invention has the following advantages:
The preparation method of super-hydrophobic aluminium base of the present invention is when specific operation, to 800 mesh~1500 of aluminium base surface Purpose SiC sand paper carries out artificial coarse processing, to remove the sull on aluminium base surface, while being formed and not being advised on aluminium base surface Protrusion and gully then, the protrusion and gully will eventually become a part of Super-hydrophobic aluminium primary surface micro-nano dual structure, then Ultrasonic vibration cleaning successively is carried out to aluminium base using acetone, methanol and deionized water, is occurred by methanol and a small amount of aluminium element Reaction reduces the free energy on aluminium base surface, increases water droplet in the contact angle on aluminium base surface, finally by hydrofluoric acid and hydrochloric acid to aluminium Primary surface performs etching so that super hydrophilic characteristic is presented in aluminium base surface, finally in order to prevent aluminium base remained on surface liquid to the later period The influence of chemical modification, dries aluminium base, through detecting, when using silicon fluoride modification 40min, and the Super-hydrophobic aluminium prepared The average contact angle of base is up to 154.6 °.In addition, aluminium base suppression frost experimental system of the present invention is at work, super-hydrophobic aluminium base Copper sheet is transferred heat to, copper sheet transfers heat to water-cooling head, and heat is cooled by water-cooling head by cooling water recirculation system Water absorbs, in addition, realizing the refrigeration of super-hydrophobic aluminium base by temperature sensor, controller and cooling piece, while passing through centrifugation wind Machine simulates influence of the wind speed to super-hydrophobic aluminium base, and to test the suppression frost of aluminium base, structure is simple, and easy to operate, practicability is extremely strong.
Detailed description of the invention
Fig. 1 is the measurement figure of Super-hydrophobic aluminium primary surface water droplet contact angle;
Fig. 2 a is the electron-microscope scanning figure that Super-hydrophobic aluminium primary surface amplifies 5000 times;
Fig. 2 b is the electron-microscope scanning figure that Super-hydrophobic aluminium primary surface amplifies 10000 times;
Fig. 3 is the electron-microscope scanning figure that Super-hydrophobic aluminium primary surface amplifies 20000 times;
Fig. 4 is structural schematic diagram of the invention;
Condensation phenomenon figure of the vapor on conventional aluminium base surface when Fig. 5 a is 300s;
Condensation phenomenon figure of the vapor in Super-hydrophobic aluminium primary surface when Fig. 5 b is 300s;
Fig. 6 is that two kinds of aluminium base surfaces the time comparison diagram of condensing drip occur;
Fig. 7 a is that conventional aluminium base surface the schematic diagram of freezing frozen beads occurs;
Fig. 7 b is the schematic diagram that freezing frozen beads occurs in Super-hydrophobic aluminium primary surface;
Fig. 8 a is conventional aluminium base surface frosting schematic diagram;
Fig. 8 b is Super-hydrophobic aluminium primary surface frosting schematic diagram;
Fig. 9 is that two kinds of aluminium base surfaces the time comparison diagram of needle-shaped frost layer occur;
Figure 10 a is that conventional aluminium base surface the relational graph of the time of frost layer and wind speed occurs;
Figure 10 b is that Super-hydrophobic aluminium primary surface the relational graph of the time of frost layer and wind speed occurs;
Figure 11 a is the melting process figure of conventional aluminium base surface frost layer;
Figure 11 b is the melting process figure of Super-hydrophobic aluminium primary surface frost layer.
Wherein, 1 it is cooling water cycle water pump, 2 be power-supply system, 3 be temperature detect switch (TDS), 4 be copper sheet, 5 be air hose, 6 is whole Stream grid, 7 be gauze, 8 be centrifugal blower, 9 be cooling cooling water tank, 10 be temperature sensor, 11 be cooling piece, 12 be water cooling Head, 13 be fan speed regulation device, 14 be humidifier.
Specific embodiment
The invention will be described in further detail with reference to the accompanying drawing:
The preparation method of super-hydrophobic aluminium base of the present invention the following steps are included:
1) aluminium base is taken, then artificial coarse processing is carried out with 800 mesh~1500 mesh SiC sand paper to aluminium base surface, to remove The sull on aluminium base surface, while forming irregular protrusion and gully on aluminium base surface, then using acetone, methanol and Deionized water successively carries out ultrasonic vibration cleaning to aluminium base;
2) hydrofluoric acid of 2~3mol/L and the hydrochloric acid of 3~4mol/L are configured, then by hydrofluoric acid to aluminium base surface etch 12 Then aluminium base is then placed into constant temperature drying in baking oven to aluminium base 10~12min of surface etch by hydrochloric acid by~15min, then It is cleaned by ultrasonic with deionized water, carries out the modification on aluminium base surface after drying with silicon fluoride, obtains super-hydrophobic aluminium base.
Aluminium base suppression frost experimental system of the present invention includes cold plate refrigeration system and change wind speed supply air system, wherein Become wind speed supply air system include centrifugal blower 8, air hose 5, honeycomb screen 6, gauze 7, for adding to centrifugal blower local environment Wet humidifier 14 and the fan speed regulation device 13 for controlling centrifugal blower 8, cold plate refrigeration system include that copper sheet 4, temperature control are opened Close 3, cooling piece 11, controller, the temperature sensor 10 for detecting 4 temperature of copper sheet and for providing the power-supply system of electric energy 2;Super-hydrophobic aluminium base to be tested is pasted on the front of copper sheet 4, and the back side of copper sheet 4 sticks the heat preservation for being reserved with cooling piece placing chamber Cotton, cooling piece 11 are located in cooling piece placing chamber, and the chill surface of cooling piece 11 is close to copper sheet 4, the heat dissipation face paste of cooling piece 11 It is covered with water-cooling head 12, wherein water-cooling head 12 is connected with cooling water recirculation system, and power-supply system 2 passes through temperature detect switch (TDS) 3 and refrigeration Piece 11 is connected, and the output end of temperature sensor 10 and the control terminal of temperature detect switch (TDS) 3 are connected with controller;Centrifugal blower 8 The outlet of air outlet and humidifier 14 is connected with air hose 5, and gauze 7, honeycomb screen 6 and copper sheet 4 are located in air hose 5, and along wind The direction of wind flow is sequentially arranged in pipe 5.
Super-hydrophobic aluminium base to be tested is pasted on the front of copper sheet 4 by heat-conducting silicone grease;The chill surface of cooling piece 11 is by leading Hot silicone grease is pasted on the back side of copper sheet 4;Water-cooling head 12 is pasted on the radiating surface of cooling piece 11 by heat-conducting silicone grease.
The number of cooling piece 11 is two, and the number of water-cooling head 12 is two, and two water-cooling heads 12 are connected by hose Connection;Cooling water recirculation system includes cooling water tank 9 and cooling water cycle water pump 1, wherein the outlet of cooling water tank 9 is through cooling Water water circulating pump 1 is connected with water-cooling head 12.
Temperature sensor 10 is thin film temperature sensor;Air hose 5 is bonded by acrylic board;Copper sheet 4 is vertically put It is placed in the center axial position of air hose 5.
As shown in Figure 1, it is measured through contact angle measurement, titrates water droplet in the Super-hydrophobic aluminium primary surface prepared and show class It is spherical.
With reference to Fig. 2 a, small that many rectangular boss and pit are constituted is clear that from 5000 times of amplification of figure Rank, these steps are deep mixed, and are mutually communicated, to form the structure in similar labyrinth.It is then coarse in non-step-like region The irregular gully and mastoid process that processing and etching cooperatively form.To can see in 10,000 times of amplification of Fig. 2 b, in non-step Irregular micro-nano structure is presented in shape region surface.To in 20,000 times Fig. 3 of amplification it can be seen that, on big boss in the micron-scale EDS maps some nanoscale small boss, small boss be layering, form step-like distribution, show prepared by the present invention surpass Hydrophobic aluminium base surface has formed micro-nano dual structure, the size mastoid process structure very phase of the micro-nano coarse structure and lotus leaf surface Seemingly, water droplet can be prevented from completely attaching to aluminium base surface, to form higher static contact angle.
With reference to Fig. 4, the heat of super-hydrophobic aluminium base is taken away by copper sheet 4, and the heat of copper sheet 4 is inhaled by the refrigeration side of cooling piece 11 It receives, the radiating surface through cooling piece 11 passes to water-cooling head 12, and heat is passed through the cooled water of cooling water recirculation system by water-cooling head 12 It absorbs.In addition, the present invention realizes the refrigeration of super-hydrophobic aluminium base by temperature sensor 10, controller and cooling piece 11, specifically, The real time temperature of copper sheet 4 is monitored by temperature sensor 10, controller is according to the feedback of desired temperature and temperature sensor 10 Temperature difference controls the start and stop of cooling piece 11 by temperature detect switch (TDS) 3.When the sensing temperature of temperature sensor 10 is higher than set temperature, Temperature detect switch (TDS) 3 is channel status, the starting refrigeration of cooling piece 11;When the sensing temperature of temperature sensor 10 is lower than set temperature, Temperature detect switch (TDS) 3 is off state, and cooling piece 11 stops refrigeration, and the temperature deviation control precision of temperature detect switch (TDS) 3 is ± 0.2 DEG C, from And 4 surface temperature of copper sheet is made to be a certain set temperature value.
With reference to Fig. 4, the revolving speed of centrifugal blower 8 is adjusted by fan speed regulation device 13, to control the wind speed of 5 section of air hose, by The frosting situation using thousand wolf high speed camera shooting Super-hydrophobic aluminium primary surfaces is needed in experimentation, therefore air hose 5 is using sub- Gram force plate is bonded.To make 5 internal gas flow of air hose uniform, it is equipped with honeycomb screen 6 and gauze 7 inside air hose 5, it is equal to play decompression The effect of stream.Meanwhile in order to increase the relative humidity of Laboratory air, use humidifier 14 to space air in experimentation Carry out humidification process.
Test experience
1, by taking air velocity is 2m/s as an example, research with temperature reduction, common aluminium base and Super-hydrophobic aluminium primary surface Vapor phase transition process.
It was found that, only there is the solidifying of vapor in 4 surface of copper sheet when 4 temperature of copper sheet is respectively 0 DEG C, -1 DEG C, -2 DEG C Tie phenomenon.And the time that condensing drip occurs in Super-hydrophobic aluminium primary surface is obviously later than conventional aluminium base.If Fig. 5 a and Fig. 5 b are to work as aluminium Primary surface temperature is -2 DEG C, when experiment starts 300s, the condensation phenomenon of two kinds of aluminium base surface vapor.It can be seen from the figure that The condensing drip quantity on conventional aluminium base surface is more, volume is big, and the condensing drip of Super-hydrophobic aluminium primary surface is comparatively fine, some areas Domain even naked eyes are invisible.
As shown in fig. 6, the time that condensation droplet occurs in aluminium base surface is more and more early with the reduction of temperature, and compared to normal Aluminium base is advised, the time that condensation droplet occurs in Super-hydrophobic aluminium primary surface wants late 150~200s.The reason is that the water of Super-hydrophobic aluminium primary surface It is high to drip contact angle, water droplet and the contact area on aluminium base surface are small, and phase transformation energy barrier is big, hinder the generation and growth of condensing drip.
When temperature is -3 DEG C, the time that condensation droplet occurs in conventional aluminium base surface is that experiment starts 102s, and droplet becomes Time for frozen beads is that experiment starts 418s, and Super-hydrophobic aluminium primary surface the time of condensation droplet and frozen beads occurs than conventional aluminium Base distinguishes evening 98s and 119s.When aluminium base surface temperature is -4 DEG C, two kinds of aluminium base surfaces occur condensing drip and frozen beads when Between all shifted to an earlier date, but the time that both phenomenons occurs in Super-hydrophobic aluminium primary surface compares conventional aluminium base and is postponed.Two It is similar that the frozen beads on kind aluminium base surface are distributed in condensation droplet distribution: the frozen beads quantity on conventional aluminium base surface is more, volume is big, and super thin The frozen beads volume on water aluminium base surface is comparatively fine.The reason is that freezing frozen beads were formed for the reduction of condensation early period droplet temperature, and And the droplet of Super-hydrophobic aluminium primary surface and the contact area on aluminium base surface are small, heat transfer rate is slow, so the cooling velocity of droplet is slow. But since the condensed water pearl small volume that Super-hydrophobic aluminium primary surface is formed becomes frozen beads from droplet and is spent so comprehensively considering The time taken is many there is no extending, and Fig. 7 a and Fig. 7 b are comparison diagram when freezing frozen beads occur in two kinds of aluminium base surfaces.
When aluminium base surface temperature is -5 DEG C, first there is one layer of tiny droplet film being visually observed in aluminium base surface, The needle-shaped frost layer being generated later is covered.When temperature is lower than -5 DEG C, two kinds of aluminium base surfaces directly generate needle-shaped frost layer.From Fig. 8 a And as can be seen that the frost layer on conventional aluminium base surface is dense in Fig. 8 b, thickness is big, and the frost layer of Super-hydrophobic aluminium primary surface is in contrast More frivolous, thickness is small, and it is more obvious to press down white effect.The reason is that the heat transfer resistance of super hydrophobic surface is big, phase transformation energy barrier is big, frost layer The speed of growth is slow.The specific time that needle-shaped frost layer occur in two kinds of aluminium base surfaces is as shown in Figure 9.As seen from Figure 9, Super-hydrophobic aluminium The time that needle-shaped frost layer occurs in primary surface is more late than conventional aluminium base, there is the effect for obviously delaying frosting.
2, influence of the wind speed to aluminium base surface Frost formation process
Comparison is lower than -5 DEG C when temperature, and needle-shaped frost occur in two kinds of aluminium base surfaces when wind speed is respectively 1m/s, 2m/s and 3m/s The time of layer, as shown in Figure 10 a and Figure 10 b.
With reference to Figure 10 a, when temperature is higher, wind speed is bigger, and the frost layer on aluminium base surface occurs more early, the reason is that working as wind speed When increase, the heat transfer rate of aluminium base and neighbouring air increases, and accelerates the phenomenon of sublimating of water vapor in air, frost layer formation speed Also accelerate.With the reduction of temperature, influence of the wind speed to frost layer gradually weakens, the reason is that the temperature on aluminium base surface has reached at this time To low-down degree, the vapor in air can sublimate into frost layer in a short period of time, so the influence of wind speed can neglect Slightly.With reference to Figure 10 b, with the variation of wind speed, the time that frost layer occurs in Super-hydrophobic aluminium primary surface does not have significant change rule, reason It is on the one hand to increase heat convection speed when wind speed increases, and on the other hand, since established frost layer is more frivolous, It can be blown away by air, wind speed is bigger, this phenomenon is more obvious.The influence of both comprehensive factors, causes the variation pair of wind speed The formation of frost layer is without the result very influenced.
3, the experimental result and analysis of defrosting process
When aluminium base surface temperature is -15 DEG C, wind speed is 2m/s, frosting performance is carried out to conventional aluminium base and super-hydrophobic aluminium base Test after twenty minutes, turns off cooling water recirculation system, with the natural melting process of two kinds of aluminium base surface frost layers of camera record, by Figure 11 a and Figure 11 b are it is found that in 130s, and conventional aluminium base surface can see apparent thawing region, and when arriving 140s, frost layer is It all is melted into droplet, droplet volume is larger, and the attachment time on aluminium base surface is longer;And Super-hydrophobic aluminium primary surface frost layer starts The time of thawing slightly a little later, but its surface melt after droplet volume it is tiny, quantity is few, the rapid evaporation having, in 140s When, the region of more than half has been changed to arid region.The reason is that the thawing droplet contact angle of Super-hydrophobic aluminium primary surface is big, droplet It is small with the contact area of aluminium base, it is big with the contact area of air, it is easier to absorb the heat of air to evaporate.On the whole, The droplet evaporating completely that Super-hydrophobic aluminium primary surface can be such that its surface melts within the shorter time, can effectively avoid in air In the heat pump of source, when closing defrosting mode, the secondary of fin surface melt water freezes.

Claims (10)

1. a kind of preparation method of super-hydrophobic aluminium base, which comprises the following steps:
1) aluminium base is taken, then artificial coarse processing is carried out with 800 mesh~1500 mesh SiC sand paper to aluminium base surface, to remove aluminium base The sull on surface, while forming irregular protrusion and gully on aluminium base surface, then using acetone, methanol and go from Sub- water successively carries out ultrasonic vibration cleaning to aluminium base;
2) configure 2~3mol/L hydrofluoric acid and 3~4mol/L hydrochloric acid, then by hydrofluoric acid to aluminium base surface etch 12~ Then aluminium base is then placed into constant temperature drying in baking oven, then use to aluminium base 10~12min of surface etch by hydrochloric acid by 15min Deionized water is cleaned by ultrasonic, and carries out the modification on aluminium base surface after drying with silicon fluoride, obtains super-hydrophobic aluminium base.
2. a kind of aluminium base presses down frost experimental system, which is characterized in that including cold plate refrigeration system and become wind speed supply air system, In, become wind speed supply air system and includes centrifugal blower (8), air hose (5), honeycomb screen (6), gauze (7), is used for locating for centrifugal blower The humidifier (14) that environment is humidified and the fan speed regulation device (13) for controlling centrifugal blower (8), cold plate refrigeration system Including copper sheet (4), temperature detect switch (TDS) (3), cooling piece (11), controller, the temperature sensor (10) for detecting copper sheet (4) temperature And the power-supply system (2) for providing electric energy;
Super-hydrophobic aluminium base to be tested is pasted on the front of copper sheet (4), and the back side of copper sheet (4), which has sticked, is reserved with cooling piece placing chamber Heat-preservation cotton, cooling piece (11) is located in cooling piece placing chamber, and the chill surface of cooling piece (11) is close to copper sheet (4), cooling piece (11) radiating surface has sticked water-cooling head (12), wherein water-cooling head (12) is connected with cooling water recirculation system, power-supply system (2) it is connected by temperature detect switch (TDS) (3) with cooling piece (11), the control of the output end and temperature detect switch (TDS) (3) of temperature sensor (10) End processed is connected with controller;
The outlet of the air outlet and humidifier (14) of centrifugal blower (8) is connected with air hose (5), gauze (7), honeycomb screen (6) And copper sheet (4) is located in air hose (5), and is sequentially arranged along the direction of the interior gas flowing of air hose (5).
3. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that super-hydrophobic aluminium base to be tested is by leading Hot silicone grease is pasted on the front of copper sheet (4).
4. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that the chill surface of cooling piece (11) passes through Heat-conducting silicone grease is pasted on the back side of copper sheet (4).
5. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that water-cooling head (12) passes through heat-conducting silicone grease It is pasted on the radiating surface of cooling piece (11).
6. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that the number of cooling piece (11) is two A, the number of water-cooling head (12) is two, and two water-cooling heads (12) pass through hose serial communication.
7. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that cooling water recirculation system includes cooling Water tank (9) and cooling water cycle water pump (1), wherein the outlet of cooling water tank (9) is through cooling water cycle water pump (1) and water-cooling head (12) it is connected.
8. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that temperature sensor (10) is diaphragm type Temperature sensor.
9. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that air hose 5 is bonded by acrylic board It forms.
10. aluminium base according to claim 2 presses down frost experimental system, which is characterized in that copper sheet (4) is vertically placed in air hose (5) center axial position.
CN201811549977.3A 2018-12-18 2018-12-18 A kind of preparation method and aluminium base suppression frost experimental system of super-hydrophobic aluminium base Pending CN109456738A (en)

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