Abstract In this study, a recoverable nanofluid was prepared with brine water in an attempt to enhance the performance of solar stills. Herein, the recoverable multiwalled carbon nanotubes (MWCNTs) nanofluids which were prepared by dispersing Fe3O4 modified MWCNTs nanoparticles in saline water with high stability and recyclability. The optical properties of magnetic MWCNTs nanofluids were thoroughly investigated and showed that prepared nanofluids could successfully ameliorate the utilization rate of solar energy to provide more heat energy for saline water evaporation. Especially, for 0.04 wt% magnetic MWCNTs nanofluids, almost 100% solar energy was absorbed when the thickness of fluid exceeded 1 cm. Furthermore, the evaporation efficiencies of nanofluids were measured under the natural solar irradiation. The evaporation efficiency was obviously enhanced with the increase of magnetic MWCNTs nanofluids concentration from 24.91% (0 wt%) to 76.65% (0.04 wt%). To better understand the enhancement mechanism of nanofluids for fresh water yield, the optical-to-heat conversion in bulk liquid was synthetically investigated and a potential enhancement mechanism for evaporation process was proposed. In summary, the advantageous performance ensured the potential of recoverable-nanofluids to broaden the application prospect of solar stills.

中文翻译：

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可回收碳纳米管纳米流体在太阳能海水淡化系统中的应用：实验研究

摘要 在这项研究中，为了提高太阳能蒸馏器的性能，用盐水制备了一种可回收的纳米流体。在此，通过将 Fe3O4 改性的 MWCNTs 纳米粒子分散在盐水中制备了具有高稳定性和可回收性的可回收多壁碳纳米管 (MWCNTs) 纳米流体。对磁性多壁碳纳米管纳米流体的光学性质进行了深入研究，结果表明制备的纳米流体可以成功地提高太阳能的利用率，为盐水蒸发提供更多的热能。特别是，对于 0.04 wt% 磁性 MWCNTs 纳米流体，当流体厚度超过 1 cm 时，几乎 100% 的太阳能被吸收。此外，在自然太阳照射下测量了纳米流体的蒸发效率。随着磁性 MWCNTs 纳米流体浓度从 24.91% (0 wt%) 增加到 76.65% (0.04 wt%)，蒸发效率明显提高。为了更好地理解纳米流体对淡水产量的增强机制，综合研究了大量液体中的光热转换，并提出了蒸发过程的潜在增强机制。总之，优越的性能保证了可回收纳米流体的潜力，拓宽了太阳能蒸馏器的应用前景。综合研究了大量液体中的光热转换，并提出了蒸发过程的潜在增强机制。总之，优越的性能保证了可回收纳米流体的潜力，拓宽了太阳能蒸馏器的应用前景。综合研究了大量液体中的光热转换，并提出了蒸发过程的潜在增强机制。总之，优越的性能保证了可回收纳米流体的潜力，拓宽了太阳能蒸馏器的应用前景。