纳米粒子的团簇普遍存在于纳米流体的沉降过程中,该文研究了TiO2纳米粒子团簇对纳米流体辐射特性的影响。运用时域有限差分（FDTD）方法计算单个纳米粒子和团簇体的散射因子和吸收因子,根据独立散射理论计算出纳米流体的相关辐射特性参数。讨论了单团簇结构纳米流体和多团簇结构共存纳米流体的多光谱辐射特性。研究发现,在入射波长为0.40~1.00 μm时,单个团簇体的吸收系数要远高于未发生团簇的单个纳米粒子,对于水基纳米流体,纳米粒子的团簇对纳米流体的辐射特性有较大影响。且在对多组分纳米流体的研究中发现,当入射波长在0.30~0.40 μm时,不同比例的团簇体对多团簇结构共存纳米流体的吸收系数影响不大。另外,研究发现纳米流体的反照率与单个团簇体所包含的纳米粒子个数在较短入射波长和较长入射波长下存在反向变化趋势。
Abstract
Nanofluids are widely used in solar photothermal conversion systems to improve the efficiency of the system. The radiation characteristics of nanoparticles are the key to influence solar energy absorption. In this paper, the effects of TiO2 nanoparticle clusters on the radiation properties of nanofluids were studied. The scattering and absorption factors of individual nanoparticles and clusters were calculated by FDTD method, and the relevant radiation characteristic parameters of nanofluids were calculated according to the independent scattering theory. The multispectral radiation properties of single-cluster and multi-cluster nanofluids are discussed. It is found that the absorption coefficient of single clusters is much higher than that of single nanoparticles without clusters when the incident wavelength is 0.40-1.00 μm. For water-based nanofluids, the clusters of nanoparticles have a great influence on the radiation properties of the nanofluids. When the incident wavelength is 0.30-0.40 μm, it is found that the different proportion of clusters have little effect on the absorption coefficient of the multi-cluster nanofluids. In addition, it is found that the albedo of the nanofluid and the number of nanoparticles contained in a single cluster changes inversely at short and long incident wavelengths.
关键词
太阳能 /
纳米粒子 /
热辐射 /
光学物性 /
团簇 /
TiO2
Key words
solar energy /
nanoparticles /
thermal radiation /
optical properties /
cluster /
TiO2
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 王鑫, 陈叔平, 朱鸣. 液氢储运技术发展现状与展望[J]. 太阳能学报, 2024, 45(1): 500-514.
WANG X, CHEN S P, ZHU M.Development status and prospect of liquid hydrogen storage and transportation technology[J]. Acta energiae solaris sinica, 2024, 45(1): 500-514.
[2] 姚玉璧, 郑绍忠, 杨扬, 等. 中国太阳能资源评估及其利用效率研究进展与展望[J]. 太阳能学报, 2022, 43(10): 524-535.
YAO Y B, ZHENG S Z, YANG Y, et al.Progress and prospects on solar energy resource evaluation and utilization efficiency in China[J]. Acta energiae solaris sinica, 2022, 43(10): 524-535.
[3] 宣益民. 纳米流体能量传递理论与应用[J]. 中国科学(技术科学), 2014, 44(3): 269-279.
XUAN Y M.An overview on nanofluids and applications[J]. Scientia sinica (technologica), 2014, 44(3): 269-279.
[4] KUMAR P G, VIGNESWARAN S, MEIKANDAN M, et al.Exploring the photo-thermal conversion behavior and extinction coefficient of activated carbon nanofluids for direct absorption solar collector applications[J]. Environmental science and pollution research international, 2022, 29(9): 13188-13200.
[5] MENBARI A, ALEMRAJABI A A, REZAEI A.Heat transfer analysis and the effect of CuO/water nanofluid on direct absorption concentrating solar collector[J]. Applied thermal engineering, 2016, 104: 176-183.
[6] LEE S L, SAIDUR R, SABRI M F M, et al. Effects of the particle size and temperature on the efficiency of nanofluids using molecular dynamic simulation[J]. Numerical heat transfer part A - applications, 2016, 69(9): 996-1013.
[7] DU M, TANG G H.Optical property of nanofluids with particle agglomeration[J]. Solar energy, 2015, 122: 864-872.
[8] 凌智勇, 黄跃涛, 张忠强, 等. 表面活性剂对Cu-H2O和ZrO2-H2O纳米流体稳定性的影响[J]. 功能材料, 2015, 46(10): 10100-10103, 10109.
LING Z Y, HUANG Y T, ZHANG Z Q, et al.Effect of surfactants on the stability of Cu-H2O and ZrO2-H2O nanofluids[J]. Journal of functional materials, 2015, 46(10): 10100-10103, 10109.
[9] 徐小娇, 刘妮, 王玉强, 等. 纳米流体悬浮液稳定性的最新研究进展[J]. 流体机械, 2012, 40(10): 46-49, 45.
XU X J, LIU N, WANG Y Q, et al.Review of latest developments on stability of nanofluids[J]. Fluid machinery, 2012, 40(10): 46-49, 45.
[10] CAI J C, HU X Y, XIAO B Q, et al.Recent developments on fractal-based approaches to nanofluids and nanoparticle aggregation[J]. International journal of heat and mass transfer, 2017, 105: 623-637.
[11] CHEN J, ZHAO C Y, WANG B X.Effect of nanoparticle aggregation on the thermal radiation properties of nanofluids: an experimental and theoretical study[J]. International journal of heat and mass transfer, 2020, 154: 119690.
[12] JIANG W T, DING G L, PENG H, et al.Modeling of nanoparticles’ aggregation and sedimentation in nanofluid[J]. Current applied physics, 2010, 10(3): 934-941.
[13] YEE K E.Numerical solution of initial boundary value problems involving Maxwell’s equations in isotropic media[J]. IEEE transactions on antennas and propagation, 1966, 14(3): 302-307.
[14] MA L X, TAN J Y, ZHAO J M, et al.Dependent scattering and absorption by densely packed discrete spherical particles: effects of complex refractive index[J]. Journal of quantitative spectroscopy and radiative transfer, 2017, 196: 94-102.
[15] HALE G M, QUERRY M R.Optical constants of water in the 200-nm to 200- 744 micrometer wavelength region[J]. Applied optics, 1973, 12: 555-563.
[16] PANG C W, LEE J W, KANG Y T.Review on combined heat and mass transfer characteristics in nanofluids[J]. International journal of thermal sciences, 2015, 87: 49-67.
基金
河北省自然科学基金（E2024502018）; 中央高校基本科研业务费（2023MS115）; 河北省重点研发计划（21374501D）
PDF(1807 KB)
