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    Öğe
    Investigating the effects of using MgO-CuO/water hybrid nanofluid in an evacuated solar water collector: A comprehensive survey
    (Elsevier, 2023) Aytac, Ipek; Tuncer, Azim Dogus; Khanlari, Ataollah; Variyenli, Halil Ibrahim; Mantici, Sedat; Gungor, Levent; Unvar, Sinan
    In thy. work, the effects of utilizing Mg0-CuO, water nanofluid on the energetic t nd exergetic performances of a heat pipe evacut ted ;olar water collector have been analyzed experimentally. In this regard, two identical heat pipe evacuated sola, water collectors have been installed. In the first system, deionized water has been utilized. In the second collector, newly prepared nanofluid have been used and both collectors have been tested under the same climatic conditions at three flow rates containing 0.016, 0.033 and 0.050 kg/s. According to the experi mentally obtained outcomes, mean theimal efficiencies of the system using deionized water were obtained between 49.62 and 56.18 %. Also, average [hernial efficiencies of the system with Mg0-010/water as working fluid were obtained between 69.89 and 77.21 %. Average sustainability index values were attained in the range of 1.0271-1.0676 for both investigated systems. moreover, utilizing hybrid nanofluid in the system reduced the payback period between 25.14 and 27.74 %. The yearly ..7.02 savings for the system with and without nanofluid were attained between 0.307-0.343 and 0.217-0.251 ton/year, respectively. General outcomes of this study exhibited notable effects of utilizing Mg0-CuO/water on improving the thermal performance of the heat pipe evacuated solar water collector.
  • [ X ]
    Öğe
    Performance improvement of a heat pipe evacuated solar water collector using quartz/water nanofluid: A numerical and experimental study
    (Pergamon-Elsevier Science Ltd, 2024) Aytac, Ipek; Khanlari, Ataollah; Tuncer, Azim Dogus; Variyenli, Halil Ibrahim; Unvar, Sinan
    Solar water collectors (SWCs) are the major element of any solar power system. Evacuated tube solar water collectors (ESWCs) contain multiple evacuated tubes formed between the tubular absorber and the glass cover in each tube to reduce heat losses. In this survey, it is aimed to improve the thermal performance of a heat pipe evacuated tube water solar collectors (HP-ESWCs) by using quartz nanofluid as the working fluid and experimentally and numerically obtained results are explained in detail. The numerical simulation of the heat pipe part of the system aims to present a general view of energy gain by the heat pipe, evaporation of the working liquid inside the pipe and condensation of the vapor by releasing its energy in the condenser section. Also, the performance of the whole collector was experimentally examined utilizing four different working fluids. The outcomes indicate that the thermal efficiency of the HP-EWSC using deionized water varied between 29.63 and 55.78 %, 36.50-61.13 %, 40.73-64.35 % and 32.81-75.92 % at 0.008, 0.016, 0.033 and 0.050 kg/s flow rates, respectively. Also, the efficiency of HP-EWSC using quartz/water changed between the ranges of 43.87-71.95 %, 50.86-78.22 %, 46.37-79.66 % and 55.60-85.64 % at 0.008, 0.016, 0.033 and 0.050 kg/s flow rates, respectively. Average exergy efficiency enhancement by utilizing quartz/water nanofluid in the present work varied in the range of 34.23-99.97 %. General findings of this study clearly showed the positive impacts of using quartz/water as working fluid in the HP-ESWCs on the overall performance.