CN109152291B

CN109152291B - Method for enhancing spray cooling heat exchange performance

Info

Publication number: CN109152291B
Application number: CN201811038735.8A
Authority: CN
Inventors: 刘妮; 殷小明
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2018-09-06
Filing date: 2018-09-06
Publication date: 2020-08-11
Anticipated expiration: 2038-09-06
Also published as: CN109152291A

Abstract

The invention discloses a method for strengthening spray cooling heat exchange performance. It includes: taking FS-31 aqueous solution with the concentration of 50-200ppm as a spray cooling working medium for spray cooling; mixing a CTAB aqueous solution with the concentration of 200ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the ratio of 0: 100% -50% to 50%, or mixing an AOS aqueous solution with the concentration of 300ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the ratio of 0: 100% -50% to 50%, or mixing an SDS aqueous solution with the concentration of 400ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the ratio of 0: 100% -50% to 50%, and performing spray cooling by using the prepared solution as a spray cooling working medium. The method can improve the heat exchange performance of spray cooling, improve the heat exchange coefficient, reduce the surface temperature of a heat source, save working media and meet the cooling requirement of high-heat-flow-density electronic equipment.

Description

Method for enhancing spray cooling heat exchange performance

Technical Field

The invention belongs to the technical field of high heat flow density spray cooling heat exchange and application thereof, and relates to a method for strengthening spray cooling heat exchange performance.

Background

Spray cooling is a novel cooling technology, has the potential of greatly improving the heat dissipation of electronic components, and becomes one of the most concerned cooling modes in the field of high heat flux density electronic cooling. The mechanism is complicated because the spray cooling has more influence factors. In order to better develop the application of spray cooling in practical engineering, research on spray cooling working media is currently carried out.

The spray cooling working medium not only needs to meet the premise of heat dissipation requirements, but also needs to consider whether the spray cooling working medium has compatibility with electronic elements, has no influence on the environment, is safe to operate, has low cost and the like. The existing spray cooling working media mainly comprise two types: one is a conductor (such as water, ethanol, etc.), and a cold plate is required to be arranged between the working medium and the electronic element to prevent the coolant from directly contacting the electronic device; the other is an insulator (such as FC compounds), and the spray cooling working medium can be directly sprayed on the surface of the electronic device to take away heat. The insulator has high cost, and the heat conductivity, the latent heat of vaporization and the like are far lower than those of the conductor. Most spray cooling experimental researches select cheaper deionized water (distilled water) as a spray cooling working medium. Because of higher specific heat capacity, thermal conductivity and latent heat of vaporization, the spray cooling heat exchange has good performance no matter the distilled water is single-phase or two-phase, thereby meeting the heat dissipation requirement, having convenient application, low price and no pollution to the environment, being suitable for two experimental researches of open circuit and closed circulation loop, and having wider application range. In order to further improve the heat exchange effect of spray cooling, a surfactant is introduced into the spray cooling experimental process taking distilled water as a spray cooling working medium, and related researches are carried out.

The surfactant is a substance which can greatly reduce the surface tension of the solvent by adding a small dose into the solvent, change the interface state of a solution system and simultaneously can generate the effects of wetting, permeation, dispersion, air bubbles, compatibilization and the like. The surfactant can greatly reduce the surface tension of the solution at an extremely low concentration, and the performance is closely related to the molecular structure of the surfactant. The molecular structure of the surfactant has hydrophobic and hydrophilic groups, and on one hand, the hydrophilic group enables the surfactant to have excellent affinity with water molecules, so that the surfactant is endowed with water-soluble property; on the other hand, hydrophobic groups are transferred from the interior of an aqueous solution to the surface of a liquid because of their property of escaping from water. The surfactant molecules are held in the aqueous solution with hydrophilic groups, and the hydrophobic groups are closely arranged in a monomolecular adsorption layer in a state of facing the gas phase side, and are aligned. The reduction in surface tension can have a significant effect on spray droplet size and solid-liquid contact angle. The smaller the surface tension, the easier it is for the droplets to atomize into smaller diameter droplets against their surface tension. The reduction in droplet diameter increases the droplet density, which in turn causes more turbulence to be created by more frequent impacts on the heat source surface, promoting heat exchange in spray cooling. Meanwhile, the solid-liquid contact angle is reduced, and the spreadability and the wettability of the liquid drop on the surface are improved.

Currently, the application of single surfactant SDS to spray cooling has been studied, but the application of other types of surfactants and mixed surfactants to spray cooling has never been studied. The existing related research for introducing surfactant SDS into a spray cooling system considers that the heat exchange efficiency of spray cooling can be improved by adding SDS, mainly because the contact angle between liquid and a hot surface is changed, the contact area between the liquid and the hot surface is increased, and meanwhile, the survival time of atomized liquid drops on the hot surface is reduced; in addition, SDS has stronger foaming performance, and when being added into a spray cooling system, the SDS can generate abundant foam on the hot surface, thereby greatly enhancing the disturbance in a liquid film, strengthening the convection of the hot surface and improving the heat exchange effect of spray cooling. However, the conventional spray cooling technology still has the defects of low cooling efficiency, large consumption of working medium, poor surface temperature uniformity and the like even if a surfactant SDS is introduced into a spray cooling system.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for enhancing the spray cooling heat exchange performance by applying other types of surfactants and mixed surfactants to spray cooling heat exchange, which can improve the heat exchange performance of spray cooling, improve the heat exchange coefficient, reduce the surface temperature of a heat source and save working media.

The invention provides a method for enhancing spray cooling performance by using a DuPont FS-31 nonionic surfactant and a mixed surfactant of FS-31 and a cationic surfactant CTAB, an anionic surfactant AOS and SDS as spray cooling working media.

Heretofore, the use of the nonionic surfactant dupont FS-31 to improve the heat exchange efficiency of spray cooling has not been considered by those skilled in the art, because, according to the existing research, it is considered that to improve the heat exchange efficiency of spray cooling, a surfactant having a strong foaming property, which can reduce the surface tension of the system and reduce the solid-liquid contact angle, needs to be selected, and because the foaming property of dupont FS-31 is not good, it is not selected by people. However, a large number of theoretical explorations and experimental researches find that the DuPont FS-31 nonionic surfactant is added into a spray cooling system, so that the surface tension of the system can be greatly reduced, the solid-liquid contact angle is reduced, and moreover, because the DuPont FS-31 has lower foaming performance and less foam cannot form thermal resistance to heat transfer, the improvement of the heat exchange efficiency of spray cooling can be promoted, and because the FS-31 can be compatible with any ionic surfactant, the DuPont FS-31 can stably exist in common, acidic, salt-containing and hard water environments, and can be suitable for various systems; in addition, consider that DuPont FS-31 nonionic surfactants have minimal environmental pollution; therefore, the DuPont FS-31 and mixed surfactant prepared by mixing the FS-31 with CTAB, AOS and SDS respectively are finally selected to improve the heat exchange efficiency of spray cooling.

The purpose of the invention is realized by the following technical scheme:

the method for strengthening the spray cooling heat exchange performance comprises the following steps: adding nonionic surfactant DuPont

FS-31 is added into deionized water according to the concentration of 50ppm to 200ppm to prepare the solution with the concentration of 50ppm to 200ppm

The FS-31 aqueous solution is used as a spray cooling working medium for spray cooling.

And further, adding the DuPont FS-31 into deionized water according to the concentration of 100ppm to prepare an FS-31 aqueous solution with the concentration of 100ppm as a spray cooling working medium, and carrying out spray cooling.

Further, mixing a CTAB aqueous solution with the concentration of 150ppm-250ppm and an FS-31 aqueous solution with the concentration of 50ppm-200ppm according to the volume ratio of 0: 100% -50% to 50%, and taking the prepared solution as a spray cooling working medium for spray cooling; or, mixing the AOS aqueous solution with the concentration of 200ppm-400ppm and the FS-31 aqueous solution with the concentration of 50ppm-200ppm according to the volume ratio of 0: 100% -50% to 50%, and taking the prepared solution as a spray cooling working medium for spray cooling; or mixing SDS aqueous solution with the concentration of 300ppm-600ppm and FS-31 aqueous solution with the concentration of 50ppm-200ppm according to the volume ratio of 0: 100% -50% to 50%, and using the prepared solution as a spray cooling working medium for spray cooling.

Further, mixing a CTAB aqueous solution with the concentration of 150ppm-250ppm and an FS-31 aqueous solution with the concentration of 50ppm-200ppm according to the volume ratio of 25% to 75%, and taking the prepared solution as a spray cooling working medium for spray cooling; or, mixing the AOS aqueous solution with the concentration of 200ppm-400ppm and the FS-31 aqueous solution with the concentration of 50ppm-200ppm according to the volume ratio of 25% to 75%, and taking the prepared solution as a spray cooling working medium for spray cooling; or mixing SDS aqueous solution with the concentration of 300ppm-600ppm and FS-31 aqueous solution with the concentration of 50ppm-200ppm according to the volume ratio of 25% to 75%, preparing solution as a spray cooling working medium, and carrying out spray cooling.

Further, mixing a CTAB aqueous solution with the concentration of 200ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the volume ratio of 0: 100% -50% to 50%, and using the prepared solution as a spray cooling working medium for spray cooling.

Further, mixing an AOS aqueous solution with the concentration of 300ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the volume ratio of 0: 100% -50%: 50%, and using the prepared solution as a spray cooling working medium for spray cooling.

Further, mixing an SDS aqueous solution with the concentration of 400ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the volume ratio of 0: 100% -50%: 50%, and preparing a solution serving as a spray cooling working medium for spray cooling.

Further, mixing a CTAB aqueous solution with the concentration of 200ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the volume ratio of 25% to 75%, and using the prepared solution as a spray cooling working medium for spray cooling.

Further, mixing an AOS aqueous solution with the concentration of 300ppm and an FS-31 aqueous solution with the concentration of 100ppm according to the volume ratio of 25% to 75%, and using the prepared solution as a spray cooling working medium for spray cooling.

Further, SDS aqueous solution with the concentration of 400ppm and FS-31 aqueous solution with the concentration of 100ppm are mixed according to the volume ratio of 25 percent to 75 percent, and the prepared solution is used as a spray cooling working medium for spray cooling.

The invention has the beneficial effects that:

the invention provides a method for strengthening spray cooling heat exchange performance, which can overcome the defects of low cooling efficiency, large working medium consumption, poor surface temperature uniformity and the like in the existing spray cooling technology.

The invention firstly provides a novel surfactant DuPont FS-31 for improving the spray cooling heat exchange efficiency, and relevant experimental data verification is carried out. On the basis, the volume ratio test of FS-31 and other different surfactants such as CTAB, AOS, SDS and the like is carried out, and the application of Dupont FS-31 and mixed surfactant in improving the heat exchange performance of spray cooling is studied in detail.

The DuPont FS-31 surfactant is used for improving the spray cooling heat exchange performance, a series of heat exchange influences of different concentrations on spray cooling are expanded, the optimal concentration is found, and the DuPont FS-31 surfactant used in the invention is proved to have a better effect of improving the spray cooling heat exchange efficiency than the SDS surfactant used in the prior art. According to the invention, the DuPont FS-31 is mixed with different surfactants such as CTAB, AOS, SDS and the like, the optimal concentration volume ratio is found, and the heat exchange effect of spray cooling is improved to be the best when the optimal concentration volume ratio of CTAB to FS-31, AOS to FS-31 and SDS to FS-31 is 25% to 75%.

The method for enhancing the spray cooling heat exchange performance by using the DuPont FS-31 surfactant and the combination of the FS-31 surfactant and the surfactants such as CTAB, AOS, SDS and the like can better improve the spray cooling heat exchange performance, improve the heat exchange coefficient, reduce the surface temperature of a heat source, save working media and meet the cooling requirement of high heat flow density electronic equipment.

Drawings

FIG. 1 is a graph of spray cooling heat transfer coefficients for different surfactant concentrations in the present invention;

FIG. 2 is a graph showing the variation of the average temperature of the surface of the heat source according to the volume ratio of the mixed solution in the present invention;

FIG. 3 is a graph showing the change of heat transfer coefficient of spray cooling according to the volume ratio of the mixed solution in the present invention.

Detailed Description

The invention is further described below with reference to the following figures and examples.

Examples

The spray cooling experiments of the present invention using the combination of DuPont FS-31 surfactant and FS-31 with CTAB, AOS, SDS, etc. surfactant respectively are as follows:

the spray cooling experiment is carried out on a spray cooling test device (the test device is applied for a patent, and the patent number is CN201610404055.8) which is a test bench based on spray cooling, the experiment adopts a vertical spraying mode, and the spray flow rate is 20-40 ml/min. The whole test device system mainly comprises four parts: the system comprises a liquid supply and spraying system, a simulated heat source system, a data acquisition system and a control circuit system. Before the experiment begins, the air tightness of the system is detected, and the air tightness of the system is ensured to be good so as to maintain a vacuum environment. In the experimentation, cooling liquid is taken out from the thermostatic waterbath through miniature diaphragm pump, the working medium temperature is invariable through temperature controller control nozzle entry working medium, solid small particle impurity in the liquid is detached again through the filter, prevent to block up solenoid valve and nozzle, high-pressure liquid flows through the flowmeter, weave the hose through the stainless steel and reach miniature solenoid valve, it is atomized into the droplet and sprays to cooled surface and cool off to reach the nozzle again, liquid working medium after carrying out the heat exchange gets into the thermostatic waterbath liquid storage pot through the exit hole of cavity bottom again, accomplish whole circulation. In the cooling process, a part of working medium is evaporated to be steam, the part of steam can be cooled by the condensing coils distributed on the side surface and the top of the cavity, and flows back to the low-temperature constant-temperature water bath together with other working media after being condensed into liquid, so that the liquid can continuously participate in circulation, and waste can not be caused.

Before the experiment, a surfactant was added to deionized water in a constant temperature water bath, and experimental studies were sequentially performed.

First, experimental studies of single surfactants were performed:

several single surfactants are: dupont FS-31(

FS-31 is a fluorine-containing nonionic fluorocarbon surfactant), CTAB (cetyl trimethyl ammonium bromide, cationic surfactant), AOS (α -sodium alkenyl sulfonate, anionic surfactant), SDS (sodium dodecyl sulfate, molecular formula is CH)₃(CH₂)₁₁OSO₃Na, anionic surfactant).

The experimental method is as follows: mixing deionized water in a constant-temperature water bath with a single surfactant according to different concentrations, and oscillating the mixture by an ultrasonic oscillation instrument to fully dissolve the surfactant; the concentration variation range of the DuPont FS-31 solution in the thermostatic water bath is 10ppm-500ppm, the concentration variation range of the CTAB solution in the thermostatic water bath is 50ppm-350ppm, the concentration variation range of the AOS solution in the thermostatic water bath is 100ppm-700ppm, and the concentration variation range of the SDS solution in the thermostatic water bath is 100ppm-1000 ppm. The spraying pressure is 700kpa, the temperature of the thermostatic water bath is set to 20 ℃, and the pressure of the cavity is kept at 10 kpa. And monitoring pressure change at any time by using a data acquisition instrument and improving. And after the system is stable, turning on the heater, setting the heating power to be 300W, respectively carrying out a surfactant concentration experiment, and when the temperature acquired by the data acquisition instrument is stable and the fluctuation range is small, determining that the system has reached the maximum cooling effect and analyzing.

Experimental results and findings (as can be seen in the graph of fig. 1): (1) when the concentration of FS-31 is 50ppm-200ppm, the concentration of CTAB is 150ppm-250ppm, the concentration of AOS is 200ppm-400ppm, and the concentration of SDS is 300ppm-600ppm, the heat exchange coefficient is larger, the heat exchange effect of the system is relatively better, namely the effect of improving spray cooling heat exchange is better. (2) Dupont FS-31's concentration is when 100ppm, and CTAB's concentration is when 200ppm, and AOS's concentration is when 300ppm, and the concentration of SDS is when 400ppm, and the heat transfer coefficient is the biggest, and the heat transfer effect of system is best, and the effect that promotes the spray cooling heat transfer is the best promptly, obtains from this: the optimum concentration of DuPont FS-31 is 100ppm, the optimum concentration of CTAB is 200ppm, the optimum concentration of AOS is 300ppm, and the optimum concentration of SDS is 400 ppm. (3) As can be seen from fig. 1, the heat exchange coefficient of dupont FS-31 at the optimal concentration is increased by 21% compared with that of SDS at the optimal concentration, and therefore, under the same experimental conditions, the effect of improving the heat exchange efficiency of spray cooling is better (much better) when the single surfactant, dupont FS-31, is used in the present invention than when the single surfactant, SDS, is used in the prior art. The DuPont FS-31 is a nonionic surfactant, so that the surface tension of a system can be effectively reduced, the solid-liquid contact angle is reduced, and the generated less foam can not form heat resistance to heat transfer under a proper concentration due to the low foaming performance, so that the improvement of the heat exchange efficiency of spray cooling can be promoted. And the SDS has stronger foaming performance, so that abundant foams can be generated on the thermal surface when the SDS is added into a spray cooling system, and although the foams enhance the disturbance in a liquid film, strengthen the convection of the thermal surface and promote the heat transfer, the excessive foams can also form stronger thermal resistance to the heat transfer, and the improvement of the heat exchange efficiency of spray cooling can be influenced.

Next, an experimental study of the mixed surfactant was performed:

several mixed surfactants are: CTAB mixed with FS-31, AOS mixed with FS-31, SDS mixed with FS-31.

The experimental method comprises the following steps: the experimental procedure for each mixed surfactant experimental study was the same as for each single surfactant experimental study.

Among the several single surfactants studied above, FS-31 and SDS, FS-31 and CTAB, FS-31 and AOS, etc. were mixed at the optimum concentration for study. The components are mixed in pairs respectively, the volume ratio is 0: 100%, 25%: 75%, 50%: 50%, 75%: 25%, 100%: 0, and experimental research is carried out, namely: FS-31 aqueous solution with the concentration of 100ppm and SDS aqueous solution with the concentration of 400ppm are mixed according to the volume ratio of 0: 100%, 25%: 75%, 50%: 50%, 75%: 25% and 100%: 0 respectively, FS-31 aqueous solution with the concentration of 100ppm and CTAB aqueous solution with the concentration of 200ppm are mixed according to the volume ratio of 0: 100%, 25%: 75%, 50%: 50%, 75%: 25% and 100%: 0 respectively, FS-31 aqueous solution with the concentration of 100ppm and AOS aqueous solution with the concentration of 300ppm are mixed according to the volume ratio of 0: 100%, 25%: 75%, 50%: 50%, 75%: 25% and 100%: 0 respectively, and the prepared solution is used as spray cooling working medium to carry out spray cooling experimental study. The obtained experimental result graphs are shown in fig. 2 and fig. 3.

Experimental results and findings (as can be seen from the graphs of fig. 2, 3): (1) when CTAB and FS-31, AOS and FS-31, and SDS and FS-31 are mixed according to the volume ratio of 0: 100% -50% to 50%, the heat transfer coefficient is larger, the average temperature of the surface of a heat source is lower, and the effect of improving spray cooling heat exchange is better. (2) When the volume ratio of CTAB to FS-31, AOS to FS-31 and SDS to FS-31 is 25%: 75%, the heat transfer coefficient is the largest, and the average temperature of the surface of the heat source is the lowest, i.e. the effect of improving the spray cooling heat exchange is the best. (3) In the mixing volume ratio of 1: 100% -50%: 50%, CTAB mixed with FS-31 was the best, AOS mixed with FS-3 was the second, SDS mixed with FS-31 was not very good. (4) Under the condition that the mixing volume ratio is 25% to 75%, the mixing ratio of CTAB and FS-31 improves the spray cooling heat exchange effect, the spray cooling heat exchange effect is improved by being much better than that of AOS and FS-31 (the heat exchange coefficient is improved by 12%), and the spray cooling heat exchange effect is improved by being much better than that of SDS and FS-31 (the heat exchange coefficient is improved by 20%). Therefore, when a mixed surfactant solution prepared by mixing CTAB and FS-31 in a volume ratio of 25% to 75% is used as a spray cooling working medium and a spray cooling experiment is carried out, the heat exchange coefficient is the largest, the average temperature of the surface of a heat source is the lowest, and the effect of improving the spray cooling heat exchange is the best. The heat exchange effect is improved because CTAB is a cationic surfactant, FS-31 is a nonionic surfactant, and the nonionic surfactant is added into the cationic surfactant, so that the critical micelle concentration can be obviously reduced, and the positive addition and synergistic effects can be generated; in addition, due to the reduction of the surface tension and the reduction of the contact angle, the liquid drop can better wet the hot surface, and the liquid drop is quickly evaporated from the hot surface, so that the heat exchange performance is improved.

In addition, comparing the experimental results of the mixed surfactant experimental study with those of the single surfactant experimental study, it was found that: compared with the single surfactant, the mixed surfactant with a proper proportion can improve the spray cooling heat exchange effect, and has better evaporation efficiency, larger heat transfer coefficient and lower surface temperature of a heat source. The point 0: 100% in fig. 2 and 3 is the experimental result of using a single surfactant FS-31, the point 25: 75% is the experimental result of mixing the surfactants in a proper proportion, and the latter has a larger heat transfer coefficient and a lower surface temperature of a heat source than the former, so that the effect of improving the spray cooling heat exchange is better.

Claims

1. A method for strengthening spray cooling heat exchange performance is characterized in that a nonionic surfactant DuPont FS-31 is added into deionized water according to the concentration of 100ppm-200ppm to prepare 100ppm-200ppm FS-31 aqueous solution serving as a spray cooling working medium, and spray cooling is carried out.

2. The method for strengthening the spray cooling heat exchange performance as claimed in claim 1, wherein CTAB aqueous solution with concentration of 150ppm-250ppm and FS-31 aqueous solution with concentration of 100ppm-200ppm are mixed according to volume ratio of 0: 100% -50%: 50%, and the prepared solution is used as spray cooling working medium for spray cooling; or, mixing the AOS aqueous solution with the concentration of 200ppm-400ppm and the FS-31 aqueous solution with the concentration of 100ppm-200ppm according to the volume ratio of 0: 100% -50% to 50%, and taking the prepared solution as a spray cooling working medium for spray cooling; or mixing SDS aqueous solution with the concentration of 300ppm-600ppm and FS-31 aqueous solution with the concentration of 100ppm-200ppm according to the volume ratio of 0: 100% -50% to 50%, and using the prepared solution as a spray cooling working medium for spray cooling.

3. The method for enhancing the spray cooling heat exchange performance as claimed in claim 2, wherein CTAB aqueous solution with concentration of 150ppm-250ppm and FS-31 aqueous solution with concentration of 100ppm-200ppm are mixed according to volume ratio of 25% to 75% to prepare solution as spray cooling working medium for spray cooling; or, mixing the AOS aqueous solution with the concentration of 200ppm-400ppm and the FS-31 aqueous solution with the concentration of 100ppm-200ppm according to the volume ratio of 25% to 75%, and taking the prepared solution as a spray cooling working medium for spray cooling; or mixing SDS aqueous solution with the concentration of 300ppm-600ppm and FS-31 aqueous solution with the concentration of 100ppm-200ppm according to the volume ratio of 25% to 75%, preparing solution as a spray cooling working medium, and carrying out spray cooling.

4. The method for enhancing the spray cooling heat exchange performance as claimed in claim 2, wherein the CTAB aqueous solution with the concentration of 200ppm and the FS-31 aqueous solution with the concentration of 100ppm are mixed according to the volume ratio of 0: 100% -50%: 50%, and the prepared solution is used as the spray cooling working medium for spray cooling.

5. The method for enhancing the spray cooling heat exchange performance as claimed in claim 2, wherein the AOS aqueous solution with the concentration of 300ppm and the FS-31 aqueous solution with the concentration of 100ppm are mixed according to the volume ratio of 0: 100% -50%: 50%, and the prepared solution is used as the spray cooling working medium for spray cooling.

6. The method for enhancing the heat exchange performance of spray cooling as claimed in claim 2, wherein the SDS aqueous solution with the concentration of 400ppm and the FS-31 aqueous solution with the concentration of 100ppm are mixed according to the volume ratio of 0: 100% -50%: 50%, and the prepared solution is used as the spray cooling working medium for spray cooling.

7. The method for enhancing the spray cooling heat exchange performance as claimed in claim 4, wherein the CTAB aqueous solution with the concentration of 200ppm and the FS-31 aqueous solution with the concentration of 100ppm are mixed according to the volume ratio of 25% to 75%, and the prepared solution is used as the spray cooling working medium for spray cooling.

8. The method for enhancing the spray cooling heat exchange performance as claimed in claim 5, wherein the AOS aqueous solution with the concentration of 300ppm and the FS-31 aqueous solution with the concentration of 100ppm are mixed according to the volume ratio of 25% to 75%, and the prepared solution is used as the spray cooling working medium for spray cooling.

9. The method for enhancing the heat exchange performance of spray cooling as claimed in claim 6, wherein the SDS aqueous solution with the concentration of 400ppm and the FS-31 aqueous solution with the concentration of 100ppm are mixed according to the volume ratio of 25% to 75%, and the prepared solution is used as the spray cooling working medium for spray cooling.