Experimental investigations of the performance of a flat-plate solar collector using carbon and metal oxides based nanofluids
Experimental investigations of the performance of a flat-plate solar collector using carbon and metal oxides based nanofluids
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DOI：
10.1016/j.energy.2021.120452
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发表时间：
2021-04-01
期刊：
影响因子：
9
通讯作者：
Sarsam, Wail Sami
中科院分区：
文献类型：
--
作者：
Akram, Naveed;Montazer, Elham;Sarsam, Wail Sami
采用共价功能化碳纳米片和非共价功能化金属氧化物纳米颗粒（表面活性剂处理）制备了水基纳米流体。为了证明纳米流体的稳定性，使用了紫外可见光谱（UV-vis），结果表明纳米流体对碳的稳定性为60天，对金属氧化物的稳定性为30天。通过实验对其热物理性质进行了评价，并用理论模型进行了验证。f-GNPs、SiO2和ZnO纳米流体的导热系数分别提高了25.68%、11.49%和15.42%。Lu-Li和Bruggeman的热导率模型与实验数据吻合较好。同样，测量了纳米流体的粘度、密度和比热容，并与理论模型进行了比较。f-GNPs、ZnO和SiO2纳米流体的密度、比热和粘度提高幅度分别为0.12%、0.22%和0.12%；1.54%、0.96%、0.73%；与蒸馏水相比分别为12%、9.41%和24.05%。安装了一个平板太阳能集热器，并按照ASHRAE标准93-2003，在不同的热流密度（597、775和988 W/m）、质量流量（0.8、1.2和1.6 kg/min）、进口流体温度（30-50℃）和重量浓度（0.025-0.2%）下，使用碳和金属氧化物纳米流体对其热性能进行了评估。测量了平板太阳能集热器对蒸馏水的热效率，并与功能化碳基和金属氧化物基纳米流体的重量浓度（0.025-0.2%）进行了比较。由于在质量流量为1.6 kg/min时，平板太阳能集热器的热效率分别为17.45% > 13.05% > 12.36%，因此与水相比，0.1 wt%的水基纳米流体可以被测序为f-GNPs > ZnO > SiO2。(C) 2021 Elsevier Ltd版权所有。
Covalently functionalized carbon nanoplatelets and non-covalent functionalized metal oxides nanoparticles (surfactant-treated) have been used to synthesize water-based nanofluids in this paper. To prove nanofluid stability, ultraviolete-visible (UV-vis) spectroscopy is used, and the results show that nanofluid is stable for sixty days for carbon and thirty days for metal oxides. The thermophysical properties are evaluated experimentally and validated with theoretical models. Thermal conductivities of f-GNPs, SiO2, and ZnO nanofluids are enhanced by 25.68%, 11.49%, and 15.42%, respectively. Lu-Li and Bruggeman's thermal conductivity models are correctly matched with the experimental data. Similarly, the viscosity, density, and specific heat capacity of nanofluids are measured and compared with theoretical models. The enhancement in density, specific heat and viscosity of f-GNPs, ZnO, and SiO2 nanofluids are 0.12%, 0.22%, and 0.12%; 1.54%, 0.96%, and 0.73%; 12%, 9.41%, and 24.05% respectively in comparison of distilled water. A flat-plate solar collector is installed, and its thermal performance is evaluated by using carbon and metal oxides based nanofluids, following the ASHRAE standard 93-2003, at different heat flux intensities (597, 775, and 988 W/m(2)), mass flow rates (0.8, 1.2 and 1.6 kg/min), inlet fluid temperatures (30-50 degrees C) and the weight concentrations (0.025-0.2%). The thermal efficiency of the flat-plate solar collector is measured for distilled water and compared with the weight concentration (0.025-0.2%) of functionalized carbon and metal oxide-based nanofluids. A comparison of 0.1 wt% water-based nanofluids can be sequenced f-GNPs > ZnO > SiO2 because of a percentage improvement of thermal efficiency of the flat-plate solar collector obtained at a mass flow rate of 1.6 kg/min with values of 17.45% > 13.05% > 12.36%, respectively in comparison to water. (C) 2021 Elsevier Ltd. All rights reserved.