Heat transfer performance and transport properties of ZnO-ethylene glycol and ZnO-ethylene glycol-water nanofluid coolants
Heat transfer performance and transport properties of ZnO-ethylene glycol and ZnO-ethylene glycol-water nanofluid coolants
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DOI：
10.1016/j.apenergy.2014.09.023
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发表时间：
2014-12
期刊：
影响因子：
11.2
通讯作者：
K. Suganthi;V. L. Vinodhan;K. S. Rajan
中科院分区：
文献类型：
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作者：
K. Suganthi;V. L. Vinodhan;K. S. Rajan
对氧化锌-乙二醇(EG)和氧化锌-乙二醇水纳米流体的制备、表征及其作为冷却剂的性能进行了实验研究。氧化锌纳米颗粒与乙二醇分子之间良好的相互作用保证了氧化锌-乙二醇纳米流体具有优异的传输性能。这些相互作用被用于制备氧化锌-乙二醇-水纳米流体，并在氧化锌纳米颗粒的表面保留乙二醇分子，使其具有更好的传输性能。在27℃时，含4%纳米粒子的ZnO-EG纳米流体的导热系数提高了33.4%，粘度降低了39.2%。同样，体积分数为2%的ZnO-EG-水纳米流体在27℃时，导热系数提高了17.26%，粘度降低了17.34%。建立了预测纳米流体的导热系数增强和粘度降低的经验模型，并阐明了其机理。瞬时换热实验表明，与各自的基础流体相比，氧化锌-乙二醇和氧化锌-乙二醇水纳米流体具有更好的吸热性能。热传递的增强与导热系数的增强成正比，这表明纳米流体的优异导热性能可以用于冷却应用。
Experiments were carried out on preparation and characterization of ZnO–ethylene glycol (EG) and ZnO–ethylene glycol–water nanofluids and analysis of their performance as coolants. Favorable interactions between ZnO nanoparticles and ethylene glycol molecules ensured superior transport properties of ZnO–EG nanofluids. These interactions were utilized during formulation of ZnO–EG–water nanofluids with preservation of ethylene glycol molecules over ZnO nanoparticles’ surface rendering them with better transport properties. ZnO–EG nanofluids containing 4 vol.% nanoparticles showed thermal conductivity enhancement of 33.4% and viscosity reduction of 39.2% at 27 °C. Similarly, 2 vol.% ZnO–EG–water nanofluids showed thermal conductivity enhancement of 17.26% and viscosity reduction of 17.34% at 27 °C. Disturbance of hydrogen bonding network of ethylene glycol by ZnO nanoparticles resulted in reduced dispersion viscosity. Empirical models were developed to predict the thermal conductivity enhancement and viscosity reduction of the nanofluids apart from elucidating mechanisms for the same. Transient heat transfer experiments showed that ZnO–EG and ZnO–EG–water nanofluids had better heat absorption characteristics compared to their respective base fluids. The enhancements in heat transfer were proportional to thermal conductivity enhancements, which showed that superior thermal conductivity of nanofluids could be harnessed for cooling applications.