Nanofluid preparation method, nanofluid, cooling device and data center
By preparing nanofluids with high thermal conductivity, the problem of poor cooling effect in data centers was solved, the efficient cooling effect was improved and the durability of the system was extended, reducing maintenance and usage costs.
Patent Information
- Application Number
- CN202510882066.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-10-17
AI Technical Summary
The cooling effect of data centers in the existing technology is poor, mainly due to the low thermal conductivity of the water and ethylene glycol mixture, which leads to low heat exchange efficiency.
A nanofluid preparation method is used to prepare a nanofluid with excellent thermal conductivity by mixing deionized water, dispersant, carbon nanotube powder and ethylene glycol. The high thermal conductivity of the carbon nanotube powder and the uniform dispersion effect of the dispersant are utilized to avoid the corrosion risk caused by metal particles. The uniform dispersion of the carbon nanotubes is achieved by a collaborative process of ultrasound and heating.
It significantly improves the cooling effect, enhances thermal conductivity by 30-50%, extends the system maintenance cycle to 3-5 years, reduces maintenance costs, and is suitable for large-scale and rapid deployment in data centers. It does not freeze in low-temperature environments, reducing maintenance and usage costs.
Smart Images
Figure CN120795879A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of nanomaterials, and particularly to a nanofluid preparation method and a nanofluid preparation method. BACKGROUND
[0002] In the field of communication technology, a data center is a key device for storing data and providing service. The data center is a high-energy-consumption device, and in order to reduce carbon emissions, the heat of the data center needs to be recycled. In the related art, a buried pipe is usually arranged at a location of the data center, and heat recovery of the data center is achieved by a heat exchange medium in the buried pipe. The heat exchange medium is a mixture of water and ethylene glycol. However, in the related art, the thermal conductivity of the mixture of water and ethylene glycol is low, which reduces the efficiency of heat exchange and leads to poor cooling effect.
[0003] It can be seen that the related art has the problem of poor cooling effect. SUMMARY
[0004] Embodiments of the present application provide a nanofluid preparation method, a nanofluid, a cooling device, and a data center to solve the problem of poor cooling effect in the related art.
[0005] To solve the above problems, the present application is implemented as follows:
[0006] In a first aspect, the embodiments of the present application provide a nanofluid preparation method, comprising:
[0007] mixing deionized water and a dispersant by ultrasonic oscillation to obtain a base solution;
[0008] adding carbon nanotube powder to the base solution, and synchronously heating, ultrasonic oscillating, and stirring the base solution to which the carbon nanotube powder is added to obtain a mixed solution;
[0009] adding ethylene glycol to the mixed solution to obtain a nanofluid.
[0010] In one embodiment, the dispersant is polyvinylpyrrolidone, and the mixing of the deionized water and the dispersant by ultrasonic oscillation to obtain the base solution comprises:
[0011] mixing deionized water and the polyvinylpyrrolidone to obtain a first solution;
[0012] ultrasonic oscillating the first solution for a first time under a first power interval to obtain the base solution, the first power interval including 200-300 watts, and the difference between the first time and 30 minutes is within a first preset range.
[0013] In one embodiment, the concentration of the polyvinylpyrrolidone is 0.2%.
[0014] In one embodiment, the adding the carbon nanotube powder into the base solution, and the base solution with the added carbon nanotube powder is simultaneously heated, ultrasonically vibrated and stirred to obtain a mixed solution, comprising:
[0015] adding the carbon nanotube powder into the base solution;
[0016] warming the base solution with the added carbon nanotube powder to a first temperature range, the first temperature range comprising 50℃ to 60℃;
[0017] ultrasonically vibrating the warmed base solution at a first frequency, and simultaneously stirring at a rotating speed within a first rotating speed range for a second time to obtain the mixed solution, the first frequency having a difference from 40kHZ within a second preset range, the first rotating speed range comprising 500rpm to 800rpm, and the second time having a difference from 120 minutes within a third preset range.
[0018] In one embodiment, the carbon nanotube powder has a length within a first length range, the first length range comprising 5 microns to 10 microns; the carbon nanotube powder has a diameter less than 10 nanometers; and the carbon nanotube powder has a concentration within a first concentration range, the first concentration range comprising 1% to 3%.
[0019] In one embodiment, the adding the ethylene glycol into the mixed solution to obtain a nanofluid, comprising:
[0020] adding the ethylene glycol into the mixed solution under a first temperature to obtain the nanofluid, the nanofluid having a freezing point of a second temperature, the first temperature having a difference from 25℃ within a fourth preset range, and the second temperature having a difference from -20℃ within a fifth preset range.
[0021] In one embodiment, the ethylene glycol has a concentration of 15%.
[0022] In a second aspect, the embodiments of the present application further provide a nanofluid, which is prepared by the nanofluid preparation method of the first aspect.
[0023] In a third aspect, the embodiments of the present application further provide a cooling device, comprising a buried pipe and a nanofluid in the buried pipe, the nanofluid being prepared by the nanofluid preparation method of the first aspect.
[0024] In a fourth aspect, the embodiment of the present application further provides a data center comprising a cooling device, wherein the cooling device comprises a ground pipe and a nanofluid in the ground pipe, the ground pipe is arranged at a mounting position of the data center, and the nanofluid is prepared by the nanofluid preparation method in the first aspect.
[0025] One of the above technical solutions has the following advantages or beneficial effects:
[0026] In the embodiment of the present application, the nanofluid preparation method comprises: step 101, mixing deionized water and a dispersing agent by ultrasonic oscillation to obtain a base solution; step 102, adding carbon nanotube powder to the base solution, and simultaneously heating, ultrasonic oscillating and stirring the base solution with the added carbon nanotube powder to obtain a mixed solution; and step 103, adding ethylene glycol to the mixed solution to obtain a nanofluid. In this way, the nanofluid is prepared by deionized water, a dispersing agent, carbon nanotube powder and ethylene glycol, the carbon nanotube powder is uniformly dispersed in the mixed solution, so that the nanofluid can have high thermal conductivity, and cooling by the nanofluid can effectively improve the cooling effect. BRIEF DESCRIPTION OF DRAWINGS
[0027] To make the technical solutions of the embodiments of the present application clearer, the drawings needed in the description of the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and all other drawings obtained by those skilled in the art without creative labor are within the protection scope of the present application.
[0028] Figure 1 is a flow chart of a nanofluid preparation method provided by the embodiment of the present application. DETAILED DESCRIPTION
[0029] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.
[0030] Please refer to Figure 1 , Figure 1 is a flow chart of a nanofluid preparation method provided by the embodiment of the present application, as shown in Figure 1 , comprising the following steps:
[0031] Step 101, mixing deionized water and a dispersing agent by ultrasonic oscillation to obtain a base solution.
[0032] The dispersant is used to uniformly disperse the carbon nanotube powder in the fluid, so that the finally prepared nanofluid can improve the thermal conductivity of the nanofluid through the uniformly distributed carbon nanotubes.
[0033] In some embodiments, the dispersant can be an organic solvent, such as oleic acid or a high-concentration antifreeze agent (i.e., an antifreeze agent with a glycol content of more than 30%).
[0034] Step 102, add the carbon nanotube powder to the base fluid, and simultaneously heat, ultrasonically oscillate and stir the base fluid to which the carbon nanotube powder is added, to obtain a mixed solution.
[0035] The carbon nanotube powder has high thermal conductivity (the theoretical thermal conductivity of the carbon nanotube powder reaches 6000 W / m·K), and by mixing the carbon nanotube powder with the base fluid, a mixed solution with high thermal conductivity is obtained, which is 30-50% higher than traditional water-based fluids, and the finally prepared nanofluid also has high thermal conductivity.
[0036] The carbon nanotube powder has high thermal conductivity (the theoretical thermal conductivity of the carbon nanotube powder reaches 6000 W / m·K), and by mixing the carbon nanotube powder with the base fluid, a mixed solution with high thermal conductivity is obtained, which is 30-50% higher than traditional water-based fluids, and the finally prepared nanofluid also has high thermal conductivity.
[0037] It should be noted that in the prior art, metal particle materials are added to the fluid to improve the cooling effect (for example, copper oxide, iron-based and other metal nanoparticles are used to improve thermal conductivity), but such particles can have an electrochemical reaction with metal pipelines, causing pipeline corrosion and perforation, and the average service life of the system is only 5-8 years, frequent maintenance and replacement are required, and the operating cost is increased. In the embodiments of the present application, carbon nanotube powder is used to improve thermal conductivity, so that the nanofluid does not contain metal particles, and the risk of pipeline corrosion is eliminated from the root, the maintenance cycle of the system can be extended from 1 year in the traditional technology to 3-5 years, the durability is significantly improved, and the maintenance cost is effectively reduced.
[0038] Further, in the embodiments of the present application, the "ultrasonic + temperature control" one-step physical dispersion process is used, which does not require complex chemical reactions, and the preparation efficiency is improved by more than 50% compared with traditional chemical modification methods, which is suitable for large-scale and rapid deployment of data centers.
[0039] Step 103, add glycol to the mixed solution to obtain a nanofluid.
[0040] The ethylene glycol is used for diluting the mixed solution to prepare the nanofluid, so that the nanofluid has high heat conduction performance and antifreezing characteristics, and can be normally used in a low-temperature environment without freezing.
[0041] In the embodiment of the present application, the nanofluid preparation method comprises: step 101, mixing deionized water and a dispersant by ultrasonic oscillation to obtain a base solution. Step 102, adding carbon nanotube powder into the base solution, and synchronously heating, ultrasonic oscillating and stirring the base solution with the added carbon nanotube powder to obtain a mixed solution. Step 103, adding ethylene glycol into the mixed solution to obtain a nanofluid. In this way, the nanofluid is prepared by deionized water, a dispersant, carbon nanotube powder and ethylene glycol, and the carbon nanotube powder is uniformly dispersed in the mixed solution, so that the nanofluid has high heat conduction performance, and the cooling effect can be effectively improved by cooling with the nanofluid.
[0042] In one embodiment, the dispersant is polyvinyl pyrrolidone (PVP), and the mixing of the deionized water and the dispersant by ultrasonic oscillation to obtain the base solution comprises:
[0043] mixing the deionized water and the polyvinyl pyrrolidone to obtain a first solution;
[0044] ultrasonic oscillating the first solution for a first time under a first power interval to obtain the base solution, the first power interval comprising 200-300 watts, and the difference between the first time and 30 minutes is within a first preset range.
[0045] It should be noted that although the organic solvent can be used as a dispersant to disperse the carbon nanotube powder, the nanofluid may leak due to pipe damage during use of the nanofluid, and if the dispersant is oleic acid or a high-concentration antifreeze, it will pollute the soil or groundwater.
[0046] In order to avoid pollution caused by the dispersant in the nanofluid, PVP is used as the dispersant in the embodiment of the present application, which can disperse the carbon nanotube powder without polluting the soil or groundwater, and improves the environmental performance of the nanofluid. The toxicity LD50 of PVP is >10 g / kg, the half-life in soil is <6 months, and the pollution can be effectively reduced compared with organic solvents.
[0047] Specifically, the molecules of PVP are adsorbed on the surface of the carbon nanotube particles by hydrogen bonding to form a steric hindrance layer (i.e. an adsorption layer), thereby achieving ordered inhibition of particle agglomeration. Further, the adsorption by hydrogen bonding is less likely to fall off than the chemical adsorption of traditional dispersants, so as to achieve a better effect of inhibiting agglomeration of carbon nanotube particles.
[0048] The first solution is ultrasonically vibrated under the first power interval for the first time to obtain the base solution, so that the PVP can be uniformly distributed in the base solution, facilitating subsequent dispersion of the carbon nanotube powder. Further, the first solution is ultrasonically vibrated under the first power interval for the first time at a normal temperature (25℃).
[0049] In some embodiments, the first power interval and the first time can be set according to actual environment, so that the PVP can be uniformly distributed in the base solution according to the first power interval and the first time. In the present application, the first power interval includes 200-300 watts, and the first time is within a first preset range from 30 minutes, so that the PVP can be uniformly distributed in the base solution.
[0050] The first preset range can be an error range, which can be set according to experience or obtained by testing.
[0051] In one embodiment, the concentration of the polyvinylpyrrolidone is 0.2%.
[0052] In the embodiments of the present application, the concentration of the polyvinylpyrrolidone is 0.2%, which can achieve dispersion of the carbon nanotube powder without the need for a higher concentration, thereby effectively controlling the cost.
[0053] In one embodiment, the carbon nanotube powder is added to the base solution, and the base solution with the added carbon nanotube powder is simultaneously heated, ultrasonically vibrated and stirred to obtain a mixed solution, including:
[0054] The carbon nanotube powder is added to the base solution.
[0055] The base solution with the added carbon nanotube powder is heated to a first temperature interval, which includes 50-60℃.
[0056] The heated base solution is ultrasonically vibrated at a first frequency and simultaneously stirred at a rotating speed within a first rotating speed interval for a second time to obtain the mixed solution, the first frequency is within a second preset range from 40kHZ, the first rotating speed interval includes 500-800rpm, and the second time is within a third preset range from 120 minutes.
[0057] In the embodiment of the present application, the carbon nanotube powder is added into the base solution; the base solution with the added carbon nanotube powder is heated to a first temperature interval, the first temperature interval including 50-60℃; the heated base solution is subjected to ultrasonic oscillation at a first frequency and simultaneously stirred at a rotating speed within a first rotating speed interval for a second time, to obtain the mixed solution, the first frequency having a difference from 40kHZ within a second preset range, the first rotating speed interval including 500-800rpm, and the second time having a difference from 120 minutes within a third preset range. In this way, through the synergistic effect of heating and ultrasonic oscillation, a dense adsorption layer of PVP is formed on the surface of the carbon nanotube particles, thereby effectively realizing the uniform dispersion of the carbon nanotubes.
[0058] In some embodiments, the first temperature interval, the first rotating speed interval, the first frequency and the second time can be set according to the actual environment, so that the first temperature interval, the first rotating speed interval and the second time can realize the uniform dispersion of the carbon nanotubes. The second preset range and the third preset range can be error ranges, which can be set according to experience or obtained through testing.
[0059] Further, in the embodiment of the present application, the first temperature interval includes 50-60℃, the first frequency is 40kHZ, the first rotating speed interval includes 500-800rpm, and the second time is 120 minutes, so that the prepared mixed solution has a settling rate of <5% after standing for 30 days, the dispersion stability is 2-3 times that of the traditional method, and the carbon nanotubes are uniformly distributed to exhibit high thermal conductivity.
[0060] It should be noted that in the present application, the base solution with the added carbon nanotube powder is heated to the first temperature interval, so that the molecular chains of PVP are stretched, and the adsorption capacity of PVP is further enhanced.
[0061] In one embodiment, the length of the carbon nanotube powder is within a first length interval, the first length interval including 5-10 microns; the diameter of the carbon nanotube powder is less than 10 nanometers; and the concentration of the carbon nanotube powder is within a first concentration interval, the first concentration interval including 1-3%.
[0062] In the embodiment of the present application, the length of the carbon nanotube powder is within a first length interval, the first length interval including 5-10 microns; the diameter of the carbon nanotube powder is less than 10 nanometers; and the concentration of the carbon nanotube powder is within a first concentration interval, the first concentration interval including 1-3%, so that the carbon nanotubes can effectively improve the thermal conductivity of the nanofluid after being uniformly dispersed by the dispersant.
[0063] In one embodiment, the adding of the ethylene glycol into the mixed solution to obtain the nanofluid comprises:
[0064] The ethylene glycol is added into the mixed solution under the condition of a first temperature to obtain the nanofluid, the freezing point of the nanofluid is a second temperature, the difference between the first temperature and 25℃ is within a fourth preset range, and the difference between the second temperature and -20℃ is within a fifth preset range.
[0065] It should be noted that the temperature varies in different regions, and in some regions, the temperature is relatively low. In this case, the nanofluid needs to flow normally under low-temperature conditions and cannot freeze to cause subsequent refrigeration failure. In the prior art, the fluid needs to be heated to prevent freezing, resulting in high maintenance and use costs.
[0066] Therefore, in the embodiment of the present application, the ethylene glycol is added into the mixed solution under the condition of a first temperature to obtain the nanofluid, the freezing point of the nanofluid is a second temperature, the difference between the first temperature and 25℃ is within a fourth preset range, and the difference between the second temperature and -20℃ is within a fifth preset range. In this way, by adding ethylene glycol to the mixed solution, the freezing point of the fluid is reduced to the second temperature, so that the nanofluid does not freeze when the ambient temperature is higher than the second temperature, so that the nanofluid can flow normally under low-temperature conditions, thereby realizing stable cooling of the equipment and reducing maintenance and use costs.
[0067] In some embodiments, the first temperature and the second temperature can be set according to the actual environment, so that the prepared nanofluid does not freeze under the ambient temperature. The fourth preset range and the fifth preset range can be error ranges, and the fourth preset range and the fifth preset range can be set according to experience or testing.
[0068] In one embodiment, the concentration of the ethylene glycol is 15%.
[0069] In the embodiment of the present application, the concentration of the ethylene glycol is 15%, which is lower than the 30% to 50% concentration of the ethylene glycol in the traditional method of preparing the fluid, thereby further reducing the consumption of ethylene glycol and effectively controlling the cost.
[0070] Further, the nanofluid prepared by the present application has a thermal conductivity of 1.0-1.2 W / m·K (30-50% higher than pure water), and a viscosity of only 1.5 mPa·s (20℃), which can not only reduce the pumping energy consumption, but also maintain efficient flow and heat exchange in the dense layout scene of the data center buried pipe, effectively improving the cooling effect.
[0071] In some embodiments, the nanofluid prepared by the method of the present application has the advantages shown in Table 1 compared with the prior art method for preparing the fluid (taking the preparation of copper oxide nanofluid as an example) :
[0072] Table 1 Preparation comparison table
[0073]
[0074]
[0075] In the embodiment of the present application, a nanofluid is also provided, which is prepared by the nanofluid preparation method shown in the above Figure 1 .
[0076] It should be noted that, since the nanofluid is prepared by the method in the above embodiment in the present embodiment, the nanofluid provided by the present embodiment has the same beneficial effects as the above embodiment, i.e. improving the heat conduction performance of the nanofluid and further improving the cooling effect, which will not be repeated here.
[0077] In the embodiment of the present application, a cooling device is also provided, which comprises a buried pipe and a nanofluid in the buried pipe, the nanofluid being prepared by the nanofluid preparation method shown in the above Figure 1 .
[0078] It should be noted that, since the nanofluid is prepared by the method in the above embodiment in the present embodiment, the cooling device provided by the present embodiment has the same beneficial effects as the nanofluid in the above embodiment, i.e. improving the heat conduction performance of the nanofluid and further improving the cooling effect, which will not be repeated here.
[0079] In the embodiment of the present application, a data center is also provided, which comprises a cooling device, the cooling device comprising a buried pipe and a nanofluid in the buried pipe, the buried pipe being arranged at a mounting position of the data center, the nanofluid being prepared by the nanofluid preparation method shown in the above Figure 1 .
[0080] It should be noted that, since the nanofluid is prepared by the method in the above embodiment in the present embodiment, the data center provided by the present embodiment has the same beneficial effects as the nanofluid in the above embodiment, i.e. improving the heat conduction performance of the nanofluid and further improving the cooling effect, which will not be repeated here.
[0081] The terms "first", "second", etc. in the embodiments of the present application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices. In addition, "and / or" is used in the present application to represent at least one of the connected objects, for example, A and / or B and / or C represents 7 cases including A alone, B alone, C alone, A and B both exist, B and C both exist, A and C both exist, and A, B and C all exist.
[0082] It should be noted that in this document, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.
[0083] From the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be realized by means of software and necessary general hardware platforms, of course, they can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes a plurality of instructions for making a terminal (which can be a mobile phone, computer, server, air conditioner, or second terminal device, etc.) execute the methods of various embodiments of the present application.
[0084] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above-mentioned specific embodiments, which are only illustrative and not limiting. Those skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the protection scope of the claims.
Claims
1. A method for preparing a nanofluid, characterized in that: include: Mixing deionized water and dispersant by ultrasonic vibration to obtain a base liquid; adding carbon nanotube powder to the base liquid, and simultaneously heating, ultrasonically vibrating, and stirring the base liquid to obtain a mixed solution; Ethylene glycol is added to the mixed solution to obtain a nanofluid.
2. The method according to claim 1, wherein The dispersant is polyvinyl pyrrolidone, and the deionized water and the dispersant are mixed by ultrasonic vibration to obtain a base liquid, comprising: Mixing deionized water and the polyvinyl pyrrolidone to obtain a first solution; The first solution is ultrasonically oscillated for a first time under a first power range to obtain the base liquid, wherein the first power range includes 200 watts to 300 watts, and the difference between the first time and 30 minutes is within a first preset range.
3. The method according to claim 2, wherein The concentration of polyvinyl pyrrolidone is 0.2%.
4. The method according to any one of claims 1 to 3, characterized in that The step of adding the carbon nanotube powder to the base liquid and simultaneously heating, ultrasonically oscillating, and stirring the base liquid to obtain a mixed solution comprises: adding the carbon nanotube powder into the base liquid; Heating the base liquid to which the carbon nanotube powder is added to a first temperature range, wherein the first temperature range includes 50° C. to 60° C.; The heated base liquid is ultrasonically oscillated at a first frequency and simultaneously stirred at a speed within a first speed range for a second time to obtain the mixed solution, wherein the difference between the first frequency and 40 kHz is within a second preset range, the first speed range includes 500 rpm to 800 rpm, and the difference between the second time and 120 minutes is within a third preset range.
5. The method according to claim 4, wherein The length of the carbon nanotube powder is within a first length range, which includes 5 microns to 10 microns; the diameter of the carbon nanotube powder is less than 10 nanometers; the concentration of the carbon nanotube powder is within a first concentration range, which includes 1% to 3%.
6. The method according to any one of claims 1 to 3, characterized in that The step of adding ethylene glycol to the mixed solution to obtain the nanofluid comprises: The ethylene glycol is added to the mixed solution under the condition of a first temperature to obtain the nanofluid, the freezing point of the nanofluid is a second temperature, the difference between the first temperature and 25°C is within a fourth preset range, and the difference between the second temperature and -20°C is within a fifth preset range.
7. The method according to claim 6, wherein The concentration of the ethylene glycol is 15%.
8. A nanofluid, characterized in that: The nanofluid is prepared by the nanofluid preparation method according to any one of claims 1 to 7.
9. A cooling device, characterized in that: The invention comprises a buried pipe and a nanofluid in the buried pipe, wherein the nanofluid is prepared by the nanofluid preparation method according to any one of claims 1 to 7.
10. A data center, characterized in that: The cooling device comprises a buried pipe and a nanofluid in the buried pipe. The buried pipe is arranged at the installation position of the data center. The nanofluid is prepared by the nanofluid preparation method according to any one of claims 1 to 7.