Jwo Ching-Song, Chang Ho, Teng Tun-Ping, Kao Mu-Jnug, Guo Yu-Ting
Department of Air-Conditioning and Refrigeration Engineering, National Taipei University of Technology, Taipei 106, Taiwan, Republic of China.
J Nanosci Nanotechnol. 2007 Jun;7(6):2161-6. doi: 10.1166/jnn.2007.787.
By using copper oxide nanofluid fabricated by the self-made Submerged Arc Nanofluid Synthesis System (SANSS), this paper measures the thermal conductivity under different volume fractions and different temperatures by thermal properties analyzer, and analyzes the correlation among the thermal conductivity, volume fraction, and temperature of nanofluid. The CuO nanoparticles used in the experiment are needle-like, with a mean particle size of about 30 nm. They can be stably suspended in deionized water for a long time. The experimental results show that under the condition that the temperature is 40 degrees C, when the volume fraction of nanofluid increases from 0.2% to 0.8%, the thermal conductivity increment of the prepared nanofluid towards deionized water can be increased from 14.7% to 38.2%. Under the condition that the volume fraction is 0.8%, as the temperature of nanofluid rises from 5 degrees C to 40 degrees C, the thermal conductivity increment of the prepared nanofluid towards deionized water increases from 5.9% to 38.2%. Besides, the effects of temperature change are greater than the effects of volume fraction on the thermal conductivity of nanofluid. Therefore, when the self-made copper oxide nanofluid is applied to the heat exchange device under medium and high temperature, an optimal radiation effect can be acquired.
本文利用自制的埋弧纳米流体合成系统（SANSS）制备的氧化铜纳米流体，通过热性能分析仪测量了不同体积分数和不同温度下的热导率，并分析了纳米流体热导率、体积分数和温度之间的相关性。实验中使用的CuO纳米颗粒为针状，平均粒径约为30nm，能在去离子水中长时间稳定悬浮。实验结果表明，在温度为40℃的条件下，当纳米流体的体积分数从0.2%增加到0.8%时，制备的纳米流体相对于去离子水的热导率增量可从14.7%提高到38.2%。在体积分数为0.8%的条件下，随着纳米流体温度从5℃升高到40℃，制备的纳米流体相对于去离子水的热导率增量从5.9%增加到38.2%。此外，温度变化对纳米流体热导率的影响大于体积分数的影响。因此，将自制的氧化铜纳米流体应用于中高温热交换装置时，可获得最佳的散热效果。
