通过高温熔融-机械搅拌制备方法,将20 nm SiO2纳米颗粒均匀分散到三元混合熔盐（KNO3-NaNO2-Na2CO3）中,制备含有不同质量分数SiO2纳米颗粒（0.1%、0.5%、1.0%、1.5%、2.0%）的熔盐纳米流体,以研究SiO2纳米颗粒添加量对熔融盐比热容和导热率的影响。采用同步热分析仪和激光热导率仪测试并分析三元混合熔盐及熔盐纳米流体的比热容和导热率,使用扫描电镜（SEM）对样品的微观结构进行观察和分析。实验表明,当SiO2纳米颗粒质量分数为1.0%时,熔盐纳米流体的平均比热容达到2.09 J/（g·K）,平均导热率达到1.073 W/（m·K）,相较于三元混合熔盐分别提高29.6%和97.9%,这归因于三元混合熔盐表面形成的高密度网状结构,该网状结构拥有较高的比表面积和高表面能,进而可增强熔融盐的比热容和导热率。
Abstract
Using the high-temperature melting-mechanical stirring preparation method, 20 nm SiO2 nanoparticles were uniformly dispersed into a ternary mixed molten salt （KNO3-NaNO2-Na2CO3） to prepare molten salt nanofluids containing different mass fractions of SiO2 nanoparticles （0.1%, 0.5%, 1.0%, 1.5%, 2.0%）, in order to investigate the effect of the SiO2 nanoparticle content on the specific heat capacity and thermal conductivity of the molten salt. A synchronous thermal analyzer and a laser thermal conductivity meter were employed to test and analyze the specific heat capacity and thermal conductivity of both the ternary mixed molten salt and the molten salt nanofluids. Scanning electron microscopy （SEM） was utilized to observe and analyze the microstructure of the samples. The experimental results demonstrate that when the mass fraction of SiO2 nanoparticles is 1.0%, the average specific heat capacity of the molten salt nanofluid reaches 2.09 J/（g·K）, and the average thermal conductivity reaches 1.073 W/（m·K）, representing increases of 29.6% and 97.9%, respectively, compared to the ternary mixed molten salt. This enhancement is attributed to the formation of a high-density network structure on the surface of the ternary mixed molten salt, which possesses a high specific surface area and surface energy, thereby improving the specific heat and thermal conductivity of the molten salt.
关键词
SiO2纳米颗粒 /
比热容 /
导热系数 /
熔融盐 /
纳米结构
Key words
SiO2 nanoparticles /
specific heat /
thermal conductivity /
molten salt /
nanostructure
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 潘科, 徐海涛, 冯祥奕. “双碳” 目标下我国新材料重点方向发展研究[J]. 信息通信技术与政策, 2022(3): 74-81.
PAN K, XU H T, FENG X Y.Research on the development of vital directions on advanced materials in China under the carbon peak and neutrality goals[J]. Information and communications technology and policy, 2022(3): 74-81.
[2] 逄敏. 基于可再生能源与储能耦合的建筑能源规划与利用[J]. 储能科学与技术, 2024, 13(2): 586-588.
PANG M.Research on building energy planning and utilization based on the coupling of renewable energy and energy storage[J]. Energy storage science and technology, 2024, 13(2): 586-588.
[3] 刘文彬. 新能源将在国家新型能源体系建设中发挥关键作用[J]. 水电与新能源, 2023, 37(12): 75-78.
LIU W B.New energy resources: key roles in the construction of Chinese national new energy system[J]. Hydropower and new energy, 2023, 37(12): 75-78.
[4] 杨友淑. 新型电力系统中电力储能技术展望分析[J]. 中文科技期刊数据库(全文版)工程技术, 2024(1): 118-121.
YANG Y S.Prospect analysis of electric energy storage technology in new power system[J]. Engineering technology, 2024(1): 118-121.
[5] LI Y L, WEI Y F, ZHU F Q, et al.The path enabling storage of renewable energy toward carbon neutralization in China[J]. eTransportation, 2023, 16: 100226.
[6] 赵嵩颖, 秦雨晴, 颜萍, 等. 相变蓄热电采暖沼气池蓄热结构优化[J]. 中国科技论文, 2021, 16(8): 830-835.
ZHAO S Y, QIN Y Q, YAN P, et al.Heat storage structure optimization of phase change storage thermoelectric heating digester[J]. China sciencepaper, 2021, 16(8): 830-835.
[7] 邵桂萍, 许洪华. 可再生能源综合系统现状与未来发展趋势研究[J]. 太阳能, 2024(7): 127-132.
SHAO G P, XU H H.Research on present situation and future development trend of renewable energy integrated system[J]. Solar energy, 2024(7): 127-132.
[8] 千存存, 李明佳, 张洪泰. 糖醇基复合相变材料的制备及其光热转换与存储性能研究[J]. 太阳能学报, 2024, 45(11): 627-635.
QIAN C C, LI M J, ZHANG H T.Preparation and study on photothermal conversion and storage performance of sugar alcohol-based composite phase change materials[J]. Acta energiae solaris sinica, 2024, 45(11): 627-635.
[9] 贾笃雨, 田丽亭, 闵春华, 等. 壁面下方圆管加热熔盐自然对流换热的数值研究[J]. 中国科技论文, 2017, 12(23): 2737-2741.
JIA D Y, TIAN L T, MIN C H, et al.Numerical study on natural convection heat transfer of molten salt around circular tube under upper-wall[J]. China sciencepaper, 2017, 12(23): 2737-2741.
[10] 马丽娜, 吴玉庭, 张灿灿, 等. 奥氏体不锈钢在四元硝酸盐中的动态腐蚀行为研究[J]. 太阳能学报, 2023, 44(3): 497-503.
MA L N, WU Y T, ZHANG C C, et al.Dynamic corrosion behaviors of autennitic stainless steel in quaternary nitrate-niotrite molten salt[J]. Acta energiae solaris sinica, 2023, 44(3): 497-503.
[11] 张静如, 韦安柱. 熔盐在太阳能热发电中的应用与发展前景[J]. 石油商技, 2017, 35(2): 16-21.
ZHANG J R, WEI A Z.Application and development prospect of molten salt in solar thermal power generation[J]. Petroleum products application research, 2017, 35(2): 16-21.
[12] FENG J H, MAO L, YUAN G C, et al.Grain size effect on corrosion behavior of Inconel 625 film against molten MgCl2-NaCl-KCl salt[J]. Corrosion science, 2022, 197: 110097.
[13] YU Q, ZHANG C C, LU Y W, et al.Comprehensive performance of composite phase change materials based on eutectic chloride with SiO2 nanoparticles and expanded graphite for thermal energy storage system[J]. Renewable energy, 2021, 172: 1120-1132.
[14] RAADE J W, PADOWITZ D.Development of molten salt heat transfer fluid with low melting point and high thermal stability[J]. Journal of solar energy engineering, 2011, 133(3): 031013.
[15] GUPTA S K, MAO Y B.Recent developments on molten salt synthesis of inorganic nanomaterials: a review[J]. The journal of physical chemistry C, 2021, 125(12): 6508-6533.
[16] HO M X, PAN C.Optimal concentration of alumina nanoparticles in molten Hitec salt to maximize its specific heat capacity[J]. International journal of heat and mass transfer, 2014, 70: 174-184.
[17] ANDREU-CABEDO P, MONDRAGON R, HERNANDEZ L, et al.Increment of specific heat capacity of solar salt with SiO2 nanoparticles[J]. Nanoscale research letters, 2014, 9(1): 582.
[18] CHEN X, WU Y T, ZHANG L D, et al.Experimental study on thermophysical properties of molten salt nanofluids prepared by high-temperature melting[J]. Solar energy materials and solar cells, 2019, 191(3): 191-197.
[19] SHIN D, BANERJEE D.Enhanced thermal properties of SiO2 nanocomposite for solar thermal energy storage applications[J]. International journal of heat and mass transfer, 2015, 84: 898-902.
[20] CHEN X, WU Y T, ZHANG L D, et al.Experimental study on the specific heat and stability of molten salt nanofluids prepared by high-temperature melting[J]. Solar energy materials and solar cells, 2018, 176: 42-48.
[21] YAN C, LIANG J F, ZHONG X B, et al.BN white graphene well-dispersed solar salt nanofluids with significant improved thermal properties for concentrated solar power plants[J]. Solar energy materials and solar cells, 2022, 245: 111875.
[22] NA H Y, ZHANG C C, WU Y T, et al.Effect of Na2CO3 content on thermophysical properties, corrosion behaviors of KNO3-NaNO2 molten salt[J]. Energy, 2024, 311: 133378.
[23] 王元媛, 鹿院卫, 樊占胜, 等. KNO3-NaNO2-KNO2三元系相图筛选及物性测试[J]. 太阳能学报, 2024, 45(9): 662-667.
WANG Y Y, LU Y W, FAN Z S, et al.Phase diagram screening and physical property testing of KNO3-NaNO2-KNO2 ternary system[J]. Acta energiae solaris sinica, 2024, 45(9): 662-667.
[24] JO B, BANERJEE D.Enhanced specific heat capacity of molten salt-based nanomaterials: effects of nanoparticle dispersion and solvent material[J]. Acta materialia, 2014, 75: 80-91.
[25] WANG L, TAN Z C, MENG S H, et al.Enhancement of molar heat capacity of nanostructured Al2O3[J]. Journal of nanoparticle research, 2001, 3(5): 483-487.
[26] WANG B X, ZHOU L P, PENG X F.Surface and size effects on the specific heat capacity of nanoparticles[J]. International journal of thermophysics, 2006, 27(1): 139-151.
[27] MUNYALO J M, ZHANG X L.Particle size effect on thermophysical properties of nanofluid and nanofluid based phase change materials: a review[J]. Journal of molecular liquids, 2018, 265: 77-87.
[28] RIZVI S M M, SHIN D. Mechanism of heat capacity enhancement in molten salt nanofluids[J]. International journal of heat and mass transfer, 2020, 161: 120260.
[29] 吴健. 金属氧化物微纳米结构的热力学研究[D]. 西安: 西北大学, 2011.
WU J.Thermodynamic study on micro-nano structure of metal oxides[D]. Xi'an: Northwest University, 2011.
[30] TRONG TAM N, VIET PHUONG N, HONG KHOI P, et al.Carbon nanomaterial-based nanofluids for direct thermal solar absorption[J]. Nanomaterials, 2020, 10(6): 1199.
[31] 吴玉庭, 明苏布道, 张灿灿, 等. 三元混合碳酸熔盐热物性实验研究[J]. 储能科学与技术, 2021, 10(4): 1292-1296.
WU Y T, MING S B D, ZHANG C C, et al. Experimental research of the thermophysical properties of ternary mixed carbonate molten salts[J]. Energy storage science and technology, 2021, 10(4): 1292-1296.
[32] DUDDA B, SHIN D.Effect of nanoparticle dispersion on specific heat capacity of a binary nitrate salt eutectic for concentrated solar power applications[J]. International journal of thermal sciences, 2013, 69: 37-42.
[33] RASHMI W, KHALID M, ONG S S, et al.Preparation, thermo-physical properties and heat transfer enhancement of nanofluids[J]. Materials research express, 2014, 1(3): 032001.
基金
国家重点研发计划（2022YFB2405202）
PDF(3309 KB)
