RENEWABLE ENERGY
·
2023
·
IF 8.7
Jin Wen,Qingchao Chang,Jishi Zhu,Rui Cui,Cheng He,Xinxing Yan,Xiaoke Li
The selection of heat transfer medium is indispensable for the efficient realization of photothermal conversion. Nanofluids , thanks to their enhanced thermal properties and possible heat transfer applications, have been a topic of intense research. Also, nanofluid is an ideal working fluid for direct absorption solar collectors (DASCs). In this work, the stable ZrC/TiN nanofluids with high light absorption was prepared while a new irradiation mode was used to improve the photothermal conversion efficiency. Firstly, the composite optical characteristics of ZrC/TiN nanoparticles were numerically simulated by the finite-difference time-domain (FDTD) method. With the localized surface plasmon resonance (LSPR) effect by nano-TiN and the strong absorption exhibited by nano-ZrC, the 160 ppm ZrC/TiN nanofluids can achieve nearly 100% solar energy with a light distance of 1 cm. Secondly, the solar-to-thermal conversion efficiency of 160 ppm ZrC/TiN nanofluids was up to 73.7% though the side radiation, which was about 31% higher compared to the base fluids. In addition, this special flow model allows a lower temperature difference inside the ZrC/TiN nanofluids. Simulations and experiments showed that the ZrC/TiN nanofluids with the new irradiation mode has a relatively outstanding photothermal conversion capability, revealing the application prospects and potential of ZrC/TiN nanofluids in DASCs.
研究领域:
材料科学
·
能源工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Weizhun Jin,Linhua Jiang,Lin Han,Haimeng Huang,Jianfeng Zhang,Mingzhi Guo,Yue Gu,Fangfang Zhi,Zhiyou Chen,Guohui Yang
New nanofluids based on graphene (GR) and GR/MXene were prepared to enhance the thermal conductivity. The thermal conductivity and viscosity of nanofluids at various temperatures in the 5–60 °C range were tested, and their stability was investigated by zeta potential and visual observation. The thermal performance of the nanofluids was evaluated through numerical simulation analysis. The results demonstrate that MXene can effectively improve the dispersion stability of GR nanofluids. The nanofluid with 2.0 wt% GR at 60 °C exhibited the maximum thermal conductivity enhancement (65.34%) but also the maximum viscosity increment (70.69%). With the addition of MXene, the high thermal conductivity of nanofluids was maintained while the viscosity significantly decreased. GR can greatly improve the heat transfer efficiency of nanofluids, and the temperature at the monitoring point resulted from 2.0 wt% GR decreased by 9.19 ℃ compared to water. The heat transfer efficiency of GR/MXene nanofluids was almost identical to that of GR nanofluids.
研究领域:
材料科学
·
热力学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2024
·
IF 6.1
Yaode Li,Yanyu Wu,Mingshuai Qiao,Cong Qi,Zhiguo Zhang
Nanofluid boiling heat transfer in microchannels has the advantages of small size and high heat transfer efficiency, and can meet the requirements of large heat load and high structural integration. In this paper, the enhanced heat transfer characteristics experiment of nanofluids under electro-magnetic co-excitation were studied on a microchannel boiling flow experimental platform. The generation, deformation and motion mechanism of bubbles in nanofluids under electro-magnetic co-excitation were studied by high-speed photography and numerical simulation, achieving microscopic visualization of nanofluids. The experiment shows that the small bubbles are affected by the electric field force and pass through the electrode wire, and perform regular lateral reciprocating motion between the two sides of the wall. This motion of the bubbles can not only strengthen the orderly disturbance inside the fluid, but also will not disrupt the heat transfer mechanism between various media, making the heat transfer enhancement and not chaotic. Magnetic excitation causes the nanoparticles to form a magnetic coupling structure along the direction of the magnetic field, the average strengthening effect increased to 29%. When the current is applied and the electromagnetic coupling field is formed, the heat transfer effect is improved by 36%.
研究领域:
热力学
·
纳米科技
·
传热学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 24
·4217
·
IF 2.972
Dong Xiang,Liangping Shen,Hanbin Wang
Al2O3/AlN–mineral oil nanofluids were prepared by dispersing commercially available Al2O3and AlN nanoparticles into mineral oil. SEM measurements showed that the average diameter of the Al2O3and AlN nanoparticles was about 55 and 50 nm, respectively. The experiments showed that the thermal conductivity systematically improved as the Al2O3and AlN nanoparticles were introduced into the mineral oil. The thermal conductivity of the mineral oil-based nanofluids increased by 18% with a 1% volume fraction of Al2O3and increased by 7% with a 0.5% volume fraction of AlN. The experimental data were compared with the values that were predicted by four typical thermal conductivity models, and a large disparity was disclosed between the models and the experimental data. After considering the thermal dynamic factors in the Al2O3/AlN–mineral oil nanofluids, a universal model is proposed that agrees well with the variation of thermal conductivity of the nanofluids.Keywords:oil-based nanofluids;thermal conductivity;theoretical models
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
·
2023
·
IF 5.2
Wenjie Sun,Tong Xiao,Qingyi Liu,Jiateng Zhao,Changhui Liu
Glycerol is a bio-based low-cost chemical, which has been widely studied in the field of heat conduction because of its wide working temperature range and superior thermopysical. However, high viscosity of glycerol is a prominent problem that limit the application of glycerol. In this work, low viscosity and high thermal conductivity of glycerol nanofluids are prepared under the dual role of nanoparticles, in which nanoparticles work as the nanoadditives enable an enhancement of thermal conductivity and specific heat capacity of nanofluids and the catalyst make a decline of viscosity of nanofluids. The thermal and viscosity properties of the nanofluid were investigated, and the addition of 15% acetylacetone and 2% TiO 2 increased the thermal conductivity of the nanofluid to 0.3194 W/m·K, which was 8.12% higher than that of the glycerol. Meanwhile, the viscosity was reduced to 357.4 mPa (30 °C) with 15% acetylacetone and 0.5% TiO 2 nanoparticles, which was 47% lower than that of glycerol at the same temperature. Additionally, results of fourier transform infrared spectrometer and proton nuclear magnetic resonance demonstrate that acetal reaction plays an important role in reducing the viscosity of nanofluids, meanwhile, the tests of X-ray diffraction show that nanoparticles can be utilized circularly.
研究领域:
材料科学
·
热管理工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2018
·
IF 0
Jotham Muthoka Munyalo,Xuelai Zhang,Xioafeng Xu
With increasing concerns over global warming, there is compelling need to apply energy technologies to improve energy efficiencies. One of the new technologies is the use of phase change materials (PCMs) to store energy and release it on demand. However, most of these materials undergo supercooling, aggregation and have low thermal conductivity that inhibits effective heat transfer. In this paper supercooling, stability, energy storage,thermal conductivity and latent heat of fusion of water based nanofluid of barium chloride dehydrate (BaCl 2 ·2H 2 O) were experimentally studied by adding a mass fraction of 0.2 w.t%–1 wt.% magnesium oxide (MgO) and 0.2 wt.%–1 wt.% multi-walled carbon nanotubes (MWCNTs). Results show that by adding separately mass fraction of 1.% of MgO and MWCNTs reduce the supercooling degree of barium chloride dehydrate by 85% and 92% respectively. At the same mass fraction, thermal conductivity also improves by 6% on addition of MWCNTs and 17% on addition of MgO. However, the enthalpies reduce by 7% at 1 wt.% MgO and by 12.3% at 1 wt% MWCNTs. It was found that MgO exhibited relatively higher thermal conductivity and a lower reduction in latent heats at a mass fraction of 1 wt.%. Surfactant was also found to prevent aggregation at low temperatures.
研究领域:
能源技术
·
材料科学
✓ 已验证
产品关联
DOI
POWDER TECHNOLOGY
·
2022
·
IF 5.64
Jinxin Zhang,Xiaoping Luo,Liangfeng Wang,Zhenfei Feng,Tengfei Li
In this work, electric field and nanofluid are coupled to enhance flow boiling heat transfer in minichannel. Pin electrodes are adopted to create non-uniform electric field. The effects of nanoparticle mass concentration, surfactant type and mass concentration under electric field on nanofluid flow boiling heat transfer are studied. Image analysis technique is used to quantify boiling bubble behaviors. The results demonstrate that without electric field, bubbles for nanofluid flow boiling are smaller and more discrete than R141b. Under electric field, bubble size reduces and the number of bubbles increases, which reveals synergy effect of electric field and nanofluid on bubble behaviors is effective. Besides, electric forces mitigate bubble coalescence and delay transition from bubbly to slug flow. Maximum heat transfer coefficient of nanofluid is 80% higher than R141b. Under electric field, boiling heat transfer of nanofluid modified by anionic surfactant (SDBS) is better than cationic (CTAB) and nonionic (Span80) surfactant.
研究领域:
热力学
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2018
·Vol. 11
·期 8
·1385
·
IF 2.467
Mingwei Zhao,Wenjiao Lv,Yuyang Li,Caili Dai,Hongda Zhou,Xuguang Song,Yining Wu
Nanofluids have increasingly drawn interest in recent years with their various applications in a number of fields. The method for the preparation of stable nanofluids is a key concern for extending the application of nanofluids. This study focuses on the effect of pH, dosage of surfactant (TX-100), and nanofluid concentration on the stability of a silica nanofluid. Particle size and zeta potential are two important factors to consider in evaluating the stability of the silica nanofluid. Results indicate that the stability of the silica nanofluid highly depends on pH, dosage of surfactant (TX-100), and nanofluid concentration. On the basis of these experiments, the best conditions for the preparation of a silica nanofluid are 0.1 wt. % for the concentration of silica nanoparticles and TX-100 and 10 for pH. A transparent and stable silica nanofluid can thus be obtained.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2023
·Vol. 17
·期 11
·1776-1787
·
IF 4.5
Zhang Jing-Xuan,Wang Xuan,Feng Yan-Ru,An Jia-Yu,Chi Yu-Xuan,Liu Ya-Tai,Zhang Ling-Fei,Zhao Yun-Bo,Zeng Xiang-Feng,Wang Zi-Bo,Liu Jia-Shuai,Wang Yi-Fan,Dou Shuai-Yong,Duan Er-Hong,Meng Tao
Compared with traditional hydrodesulfurization, new nonhydrodesulfurization methods have the advantage of a high removal efficiency for thiophene compounds under mild conditions. However, independent nonhydrodesulfurization technologies are faced with their own shortcomings, such as limitations of the desulfurization performance and regeneration of materials. To overcome these limitations, four nanofluids were prepared by dispersing different metal-modified MCM-41 particles in deep eutectic solvent as multifunctional promoters to develop a comprehensive desulfurization method. Based on the excellent adsorbability and high catalytic activity of the dispersed particles and the outstanding extractability of deep eutectic solvent in nanofluids, a high sulfur removal of 99.33% was achieved for model oil under mild conditions in 15 min. The nanofluids also showed excellent reusability due to their high structural stability. In addition, NF@Cu/Al-MCM-41-2.5% exhibited the best desulfurization performance among the prepared nanofluids. This result was obtained because the introduction of Al ions increased the number of acid sites and defect sites to improve the catalytic activity and adsorbability, and the best affinity of Cu/Al-MCM-41 for the deep eutectic solvent favored the reaction mass transfer. This work opens the door to the development of a comprehensive nonhydrodesulfurization method based on the design of nanofluid materials.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xin Huang,Le-Tian Wang,Yan-Fang Song,Fang Ge,Yi Zhang,Xin-Jing Meng,Hong-Hua Ge,Yu-Zeng Zhao
The use of nanofluids as vehicle coolant can significantly improve the heat exchange efficiency, but it is necessary to understand its corrosiveness to metals before use. Corrosion behavior of aluminum alloy in simulated vehicle coolant (SVC), nano Al 2 O 3 coolant (SVC-Al 2 O 3 ), simulated coolant containing sodium dodecyl benzene sulfonate (SVC-SDBS) and nano Al 2 O 3 coolant containing SDBS (SVC-Al 2 O 3 -SDBS) was investigated by electrochemical impedance spectroscopy , polarization curve, weight loss analysis and surface analysis in this paper. The results showed that in the three media of SVC, SVC-SDBS and SVC-Al 2 O 3 -SDBS, the impedance modulus at the frequency of 10 mHz |Z| 0.01 , the charge transfer resistance R ct and the film resistance R f of aluminum alloy electrode increased with the immersion time. Compared with the three media, the aluminum alloy in SVC-Al 2 O 3 medium had the lowest |Z| 0.01 , R ct and R f , and had the highest corrosion current density, implying that Al 2 O 3 nanoparticles promoted the corrosion of aluminum alloy in SVC, and the corrosion products formed on the alloy surface were Al 2 O 3 , Al(OH) 3 , AlOOH, which were loose and not protective. The R f values of aluminum alloy electrode increased significantly with time in the media containing SDBS. The aluminum alloy exhibited the best corrosion resistance in the medium of SVC-SDBS and no obvious loose corrosion products but compact passivation film could be seen on the alloy surface. SDBS exhibited a good corrosion inhibition effect on aluminum alloy, which may be due to the adsorption of SDBS on the metal surface and the fact that SDBS promoted the formation of the passive film by preventing the transformation of alumina film to loose AlOOH layer. In the medium containing both SDBS and Al 2 O 3 nanoparticles, the corrosion inhibition effect of SDBS was weakened. This maybe due to the electrostatic attraction of positively charged Al 2 O 3 nanoparticles and negatively charged SDBS, which reduced the adsorption of SDBS on the metal surface, thereby weakening the protective effect of SDBS on the metal surface.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2020
·Vol. 30
·期 46
·2006544
·
IF 16.836
Junping Ju,Longyun Hao,Shiwen Yang,Dandan Wang,Yongzhi Zhang,Hua Yuan,Xianze Yin,Yeqiang Tan
Advanced medical dressings need to meet these requirements of breathability, moisture absorption balance, antibacterial activity, and mechanical strength. Both breathability and moisture absorption balance strongly depend on the porous structure that inversely sacrifice their mechanical properties and bulk antibacterial activity. Herein, multifunctional porous structure is designed that can synchronously realize excellent antibacterial activity, breathability, superhydrophilicity, and enhanced mechanical properties just using nanofluids templating. The pore sizes, density, and functionality of porous polymers are regulated through nanofluids loading and multiple functional components including inorganic nanoparticles core and organic corona/canopy composed of organic long chains with different charges. An ionically tethered, nonylphenol polyoxyethylene ether sulfate as a canopy of nanofluids can be removed with sodium chloride solution to form porous structure, greatly improving the breathability of membrane and achieving superhydrophilicity to obtain moisture absorption balance. Meantime, exposed polysiloxane quaternary ammonium salts as covalently bonded corona of nanofluids exhibit excellent antibacterial activity. Finally, nanoparticles core endows supreme tensile strength ratio (115%) of porous membrane. Overall, nanofluids templating approach is expected to develop into a universal strategy to construct a series of multifunctional porous polymer materials via varying the component of nanofluids, which provide a promising application in biomedicine, human health, and life science.
研究领域:
材料科学
·
生物医学工程
·
生命科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2021
·
IF 7.147
Boyu Li,Wenpeng Hong,Haoran Li,Jingrui Lan,Junliang Zi
Configuring a nanofluid spectrum splitter (NSS) with the thermally decoupled photovoltaic/thermal (PV/T) system is a feasible approach to achieve net-zero emissions. In this work, the gold nanofluid was used in the PV/T system as an optical filter because of the abilities to manage energy balance and enhance thermal collection. The energy distribution management was optimized via the NSS thickness ( L ) and nanoparticle concentration ( C ) based on exergy efficiency analysis. The results indicated that a higher nanoparticle concentration and NSS thickness enhanced output thermal energy and solar utilization efficiency. The solar utilization efficiency and merit function reached 88.50% and 2.48 at C = 75 ppm and L = 20 mm if the worth factor ω = 3. Furthermore, the optimized concentration was only 20 ppm, which achieved the highest exergy efficiency of 13.71%.The NSS-assisted PV/T device reached the highest equilibrium temperature of 49.9 °C at L = 18 mm. Moreover, the exergy efficiency reached 12.77%, which was higher than that at L = 22 mm, due to the heat loss. These findings suggest that energy distribution can be flexibly controlled according to the demand of service users, and an optimized NSS thickness can improve thermal energy storage .
研究领域:
能源工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）