ABSTRACT In the present study, an experimental investigation of performance evaluation of plate heat exchanger (PHE) with the rough surface using AL2O3/water nanofluid was achieved. The experiments were developed for different surface roughnesses of 0.978 µm (smooth surface), 1.276 µm, 2.825 µm and 3.657 µm with different volume fractions of nanoparticles of 1.2 vol.%, 1.9 vol.% and 2.6 vol.% at Reynolds number of 500 ≤ Re ≤5000. The Nusselt number (Nu), the friction factor (f) and the heat transfer enhancement factor (HTEF) were estimated. The results show that increasing the volume fraction of nanoparticles and surface roughness enhances the heat transfer rate as well as increases the pressure drop in PHE. Hence, the influence of surface roughness is more considerable than that of volume fraction of nanoparticles on PHE performance. Furthermore, for smooth surface, the HTEF is improved by 2%, 3.7% and 5.4% for volume fraction of nanoparticles of 1.2 vol.%, 1.9 vol.% and 2.6 vol.%, respectively; while these values for the highest value of surface roughness, i.e., 3.657 µm, are 9.4%, 11.8% and 13.7%. Based on the experimental results, a new empirical correlation to predict Nu for base fluid is obtained with a maximum deviation of 2.87%.

中文翻译：

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Al2O3/水纳米流体粗板式换热器传热及流体流动的实验研究

摘要 在本研究中，实现了使用 AL2O3/水纳米流体对具有粗糙表面的板式换热器 (PHE) 进行性能评估的实验研究。这些实验是针对 0.978 µm（光滑表面）、1.276 µm、2.825 µm 和 3.657 µm 的不同表面粗糙度进行的，在雷诺数为 500 时，纳米粒子的不同体积分数为 1.2 vol.%、1.9 vol.% 和 2.6 vol.% ≤ Re ≤5000。估计了努塞尔数 (Nu)、摩擦系数 (f) 和传热增强系数 (HTEF)。结果表明，增加纳米颗粒的体积分数和表面粗糙度可提高传热速率并增加 PHE 中的压降。因此，表面粗糙度对 PHE 性能的影响比纳米颗粒的体积分数更显着。此外，对于光滑表面，纳米粒子体积分数分别为 1.2 vol.%、1.9 vol.% 和 2.6 vol.% 时，HTEF 分别提高了 2%、3.7% 和 5.4%；而这些最高表面粗糙度值（即 3.657 µm）的值分别为 9.4%、11.8% 和 13.7%。根据实验结果，获得了预测基液 Nu 的新经验相关性，最大偏差为 2.87%。