Abstract Recently, nanofluids have been extensively used in water desalination systems because of their superior photo-thermal properties and heat transfer characteristics. Most of inorganic nanoparticles such as metal, metal oxides and carbon have adverse environmental impacts due to the risk related to their production and disposal processes as well as the toxicity of some types of them. In addition, their high production cost is another issue that motivates researchers to find low cost and eco-friendly alternatives to inorganic nanoparticles. In this study, coffee-based colloid has been proposed as an organic, low cost, and eco-friendly alternative to conventional inorganic-based nanofluids to augment the fresh water productivity of solar stills (SS). The performance of the modified solar still (MSS) has been experimentally investigated and compared with another conventional solar still (CSS) under the same conditions. The daily freshwater productivity obtained from the MSS was 4865.73 ml/m2 which was greater than that of CSS by 35.14 %. Energy and exergy efficiencies of MSS were improved by 35.34 % and 46.44 %, respectively, compared with that of CSS. Finally, the economic evaluation of the MSS is carried out via performing cost analysis. The cost of distilled water per liter produced by the modified solar still is 0.0136 $/l.

中文翻译：

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用于提高太阳能蒸馏器性能的环保咖啡胶体

摘要 近年来，纳米流体因其优异的光热性能和传热特性而被广泛应用于海水淡化系统。大多数无机纳米粒子，如金属、金属氧化物和碳，由于与它们的生产和处置过程相关的风险以及某些类型的毒性，会对环境产生不利影响。此外，它们的高生产成本是另一个促使研究人员寻找低成本和环保的无机纳米粒子替代品的问题。在这项研究中，基于咖啡的胶体已被提议作为传统无机纳米流体的有机、低成本和环保替代品，以提高太阳能蒸馏器 (SS) 的淡水生产率。改进的太阳能蒸馏器 (MSS) 的性能已通过实验研究，并在相同条件下与另一种传统太阳能蒸馏器 (CSS) 进行了比较。从 MSS 获得的日淡水生产力为 4865.73 ml/m2，比 CSS 高 35.14%。与CSS相比，MSS的能效和火用效率分别提高了35.34%和46.44%。最后，通过成本分析对 MSS 进行经济评估。改进后的太阳能蒸馏器生产的每升蒸馏水成本为 0.0136 美元/升。分别与 CSS 相比。最后，通过成本分析对 MSS 进行经济评估。改造后的太阳能蒸馏器生产的每升蒸馏水成本为 0.0136 美元/升。分别与 CSS 相比。最后，通过成本分析对 MSS 进行经济评估。改造后的太阳能蒸馏器生产的每升蒸馏水成本为 0.0136 美元/升。