Abstract Direct absorption solar collector (DASC) is a promising technology for solar energy harvesting. Recently, nanofluids have shown great potential for DASC applications due to their tunable optical absorption properties. An advanced composite combining plasmonic gold nanoparticles (Au NPs) and hedgehog-like hierarchically structured ZnO particles (HPs) was prepared and used in DASCs. The nanofluid prepared with 1.0 mg mL −1 HP-Au exhibited excellent stability and broadband optical absorption properties, and reached an equilibrium temperature of ~125 °C within 1 h of solar heating at an irradiation power of 10 kW m −2 . A new photothermal conversion efficiency model was established to evaluate the solar harvesting performance of the HP-Au/oil nanofluid by simultaneously considering the effect of the working fluid temperature on the heating and cooling efficiencies. Compared to the base fluid, the HP-Au/oil nanofluid exhibits a 240% enhancement in photothermal conversion efficiency. The HP-Au/oil nanofluid shows great potential as a working fluid in direct absorption solar collectors.

中文翻译：

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用于直接吸收太阳能集热器的 ZnO-Au 复合分级颗粒分散油基纳米流体

摘要 直接吸收太阳能集热器（DASC）是一种很有前途的太阳能收集技术。最近，纳米流体由于其可调谐的光吸收特性而在 DASC 应用中显示出巨大的潜力。制备了一种结合等离子体金纳米粒子 (Au NPs) 和刺猬状分层结构 ZnO 粒子 (HPs) 的先进复合材料，并将其用于 DASC。用 1.0 mg mL -1 HP-Au 制备的纳米流体表现出优异的稳定性和宽带光吸收特性，并在 10 kW m -2 的照射功率下在太阳能加热 1 小时内达到~125°C 的平衡温度。通过同时考虑工作流体温度对加热和冷却效率的影响，建立了一种新的光热转换效率模型来评估HP-Au/油纳米流体的太阳能收集性能。与基液相比，HP-Au/油纳米流体的光热转换效率提高了 240%。HP-Au/油纳米流体作为直接吸收太阳能集热器中的工作流体显示出巨大的潜力。