This experimental study deals with the critical heat flux (CHF) of aqua-based reduced graphene oxide (rGO) nanofluids at 0.2 %, 0.6 %, and 0.8 % concentrations. This investigation also interprets the results of different characterization studies of rGO nanofluid namely atomic force microscopy (AFM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), zeta potential and Branauer–Emmett–Teller (BET) surface area analysis to confirm the existence. Thermal conductivity and dynamic viscosity of the working fluid are measured over a range of temperatures (30–70 °C). From this investigation, it is inferred that the thermal conductivity increases with the increase in temperature while its viscosity gets reduced for both deionized water and rGO nanofluid. The heat transfer coefficient (HTC) augmentation is observed to be 0.9, 1.8, and 2.3 times greater than deionized water corresponding to 0.2 %, 0.6 %, and 0.8 % concentrations of rGO nanofluids. The HTC of the synthesized nanofluid increases with increase in concentration of rGO and its compared than deionized water. The CHF enhancement or deterioration by rGO nanofluids is due to the different volume concentrations including heat transfer surface and their interaction and the nanoparticles suspended in the liquid.

中文翻译：

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用于池沸腾表面的还原氧化石墨烯水族纳米流体的性能和表征研究

本实验研究涉及浓度为 0.2%、0.6% 和 0.8% 的水基还原氧化石墨烯 (rGO) 纳米流体的临界热通量 (CHF)。这项研究还解释了 rGO 纳米流体的不同表征研究的结果，即原子力显微镜 (AFM)、X 射线衍射 (XRD)、高分辨率透射电子显微镜 (HRTEM)、动态光散射 (DLS)、zeta 电位和 Branauer –Emmett–Teller (BET) 表面积分析以确认存在。在温度范围 (30–70 °C) 内测量工作流体的热导率和动态粘度。从这项研究中可以推断出，去离子水和 rGO 纳米流体的热导率随着温度的升高而增加，而其粘度降低。观察到传热系数 (HTC) 增加比对应于 0.2%、0.6% 和 0.8% 浓度的 rGO 纳米流体的去离子水大 0.9、1.8 和 2.3 倍。与去离子水相比，合成的纳米流体的 HTC 随着 rGO 浓度的增加而增加。rGO 纳米流体对 CHF 的增强或恶化是由于不同的体积浓度，包括传热表面及其相互作用以及悬浮在液体中的纳米粒子。