Abstract In present study, performance of two nanofluid-based solar stills at the peak of Mount Tochal nearly 4000 m and city of Tehran during four consecutive days in July 2018 for the first time was examined. Silver nanofluid due to prominent advantages such as excellent optical properties, high thermal conductivity, and anti-bacterial characteristics at 0.04% weight of concentration was used. Since the rate of ultra-violet (UV) at the apex of Tochal is ~30% higher than Tehran; the produced water from systems collected in transparent plastic bottle and expose under sunlight during 8 h of experiment to use the advantage of solar water disinfection (SODIS). Results showed that from energetic point of view, utilizing nanofluid has great impact on the systems while from exergetic viewpoint the altitude has the greatest impact on the systems. The highest instantaneous energy and exergy efficiency was obtained by Tochal-located loaded with nanofluid by 55.98% and 9.27% respectively. Also, overall energy and exergy efficiency of Tochal-located system loaded with nanofluid compared to Tehran-located without nanofluid improved by about 106% and 196% respectively. Finally, using silver nanoparticle for double-purposes (anti-bacterial and enhancing heat/mass transfer) and exposure the distilled water under sunlight for SODIS can results to produce healthier water.

中文翻译：

---

基于纳米流体的高空太阳能蒸馏器用于海水淡化和太阳能水消毒（SODIS）的第一种方法

摘要 在本研究中，首次考察了 2018 年 7 月连续四天在 Tochal 山近 4000 m 峰和德黑兰市的两个基于纳米流体的太阳能蒸馏器的性能。银纳米流体由于具有突出的优点，例如优异的光学性能、高导热性和抗菌特性，浓度为 0.04%。由于 Tochal 顶点的紫外线 (UV) 率比德黑兰高约 30%；将系统产生的水收集在透明塑料瓶中并在 8 小时的实验中暴露在阳光下，以利用太阳能水消毒 (SODIS) 的优势。结果表明，从能量的角度来看，利用纳米流体对系统有很大的影响，而从能量的角度来看，高度对系统的影响最大。加载纳米流体的 Tochal-located 获得最高的瞬时能量和火用效率分别为 55.98% 和 9.27%。此外，与没有纳米流体的德黑兰相比，装有纳米流体的 Tochal 定位系统的整体能量和火用效率分别提高了约 106% 和 196%。最后，将银纳米颗粒用于双重用途（抗菌和增强热/质量传递）和将蒸馏水暴露在阳光下进行 SODIS 可以产生更健康的水。