Abstract Diathermic oil has high boiling point, low vapor pressure and low pour point, so it has been widely used as a heat carrier in heat transfer systems. Due to the excellent thermo-physical property of nanofluids, a kind of hybrid nanoparticles (SiC/TiO 2 ) was dispersed in diathermic oil to fabricate nanofluids with concentration up to 1 vol% in this paper. And there was no visually observable sedimentation or stratification even after ten days. As two characteristics of thermo-physical property, the thermal conductivity and viscosity were measured under the same conditions respectively, and the experimental results showed that the thermal conductivity of nanofluids increased with increasing volume fractions of nanoparticles and increasing of temperature. With the loading further increasing, the thermal conductivity of SiC/TiO 2 nanofluids is higher than SiC or TiO 2 nanofluids’, and the maximum of thermal conductivity enhancement ratio is 8.39% at 1 vol%. Thermal conductivity enhancement ratio was a linear relationship with the volume fraction. Suspending SiC/TiO 2 nanoparticles can enhance thermal capacity of the system. In rheological experiment, the shear viscosity almost maintained constant with shear rate increasing at the given temperature, which means that the samples are Newtonian fluid. And the higher the nanofluids concentration was, the larger value of their shear viscosity. There were some anomalous phenomena occurred in rheological behavior, which may be caused by the breaking up of hybrid of two types of nanoparticles.

中文翻译：

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用于传热应用的透热油基混合纳米流体的热物理性能评估

摘要 导热油沸点高、蒸气压低、倾点低，因此被广泛用作传热系统中的热载体。由于纳米流体优异的热物理性质，本文将一种杂化纳米粒子（SiC/TiO 2 ）分散在透热油中制备浓度高达1 vol%的纳米流体。并且即使在十天之后也没有肉眼观察到的沉淀或分层。作为热物理性质的两个特性，分别在相同条件下测量了热导率和粘度，实验结果表明纳米流体的热导率随着纳米颗粒体积分数的增加和温度的升高而增加。随着负载的进一步增加，SiC/TiO 2 纳米流体的热导率高于SiC或TiO 2 纳米流体，1 vol%时热导率增强率最大为8.39%。导热率增强率与体积分数呈线性关系。悬浮SiC/TiO 2 纳米颗粒可以提高系统的热容量。在流变实验中，在给定温度下，随着剪切速率的增加，剪切粘度几乎保持恒定，这意味着样品是牛顿流体。纳米流体浓度越高，其剪切粘度值越大。流变行为出现了一些异常现象，这可能是由于两种纳米粒子的杂化断裂造成的。39% 在 1 体积%。导热率增强率与体积分数呈线性关系。悬浮SiC/TiO 2 纳米颗粒可以提高系统的热容量。在流变实验中，在给定温度下，随着剪切速率的增加，剪切粘度几乎保持恒定，这意味着样品是牛顿流体。纳米流体浓度越高，其剪切粘度值越大。流变行为出现了一些异常现象，这可能是由于两种纳米粒子的杂化断裂造成的。39% 在 1 体积%。导热率增强率与体积分数呈线性关系。悬浮SiC/TiO 2 纳米颗粒可以提高系统的热容量。在流变实验中，在给定温度下，随着剪切速率的增加，剪切粘度几乎保持恒定，这意味着样品是牛顿流体。纳米流体浓度越高，其剪切粘度值越大。流变行为出现了一些异常现象，这可能是由于两种纳米粒子的杂化断裂造成的。在给定温度下，随着剪切速率的增加，剪切粘度几乎保持不变，这意味着样品是牛顿流体。纳米流体浓度越高，其剪切粘度值越大。流变行为出现了一些异常现象，这可能是由于两种纳米粒子的杂化断裂造成的。在给定温度下，随着剪切速率的增加，剪切粘度几乎保持不变，这意味着样品是牛顿流体。纳米流体浓度越高，其剪切粘度值越大。流变行为出现了一些异常现象，这可能是由于两种纳米粒子的杂化断裂造成的。