Performance of water based CuO and Al2O3 nanofluids in a Cu–Be alloy heat sink with rectangular microchannels
Performance of water based CuO and Al2O3 nanofluids in a Cu–Be alloy heat sink with rectangular microchannels
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DOI：
10.1016/j.enconman.2014.05.013
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发表时间：
2014-10
影响因子：
10.4
通讯作者：
S. Peyghambarzadeh;S. Hashemabadi;A. Chabi;M. Salimi
中科院分区：
文献类型：
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作者：
S. Peyghambarzadeh;S. Hashemabadi;A. Chabi;M. Salimi
在微通道散热器（MCHS）中实验研究了CuO/水和Al2O3/水纳米流体的单相强制对流换热和流体流动。该散热器由17个尺寸为400 μm × 560 μm的矩形截面微通道组成。所有实验均在恒热流密度为19 W/cm2，层流强度为500 < Re < 2000的条件下进行。测量了MCHS的传热系数、努数和压降，并与常规相关系数进行了比较。与纯水相比，两种纳米流体均表现出更高的传热性能和更大的压降。结果表明，0.2 vol.% CuO和1 vol.% al2o3纳米流体的换热系数分别提高了27%和49%。在这方面，纳米CuO颗粒可以在较低的浓度下使用，因此效率更高。此外，传热系数随纳米颗粒浓度的增加而增加，但传热增强并不随雷诺数的增加而增加。结合前人的研究结果表明，与传统直径换热器相比，MCHS具有更低的Nu数和更高的换热系数。这表明在这种换热器中，传导传热机制和对流传热机制都很重要。
Single phase forced convective heat transfer and fluid flow of CuO/water and Al2O3/water nanofluids have been experimentally investigated in a microchannel heat sink (MCHS). The heat sink consisted of 17 rectangular cross section microchannels with the dimensions of 400 μm × 560 μm. All the experiments have been performed at constant heat flux of 19 W/cm2and at the laminar flow regime 500 < Re < 2000. Heat transfer coefficient, Nu number, and also pressure drop in the MCHS have been measured and compared with the conventional correlations. Both nanofluids showed greater heat transfer performance and larger pressure drop in comparison with pure water. Results indicated that 0.2 vol.% CuO and 1 vol.% Al2O3nanofluids enhanced the heat transfer coefficient up to 27% and 49%, respectively. In this regards, CuO nanoparticle was more efficient since it could be used in lower concentration. Furthermore, it was shown that the heat transfer coefficient increased with increasing the nanoparticle concentration but it was not true to say that the heat transfer enhancement increased with Reynolds number. The results of this study in conjunction with previous papers indicated that lower Nu numbers and higher heat transfer coefficients would be obtained in the MCHS in comparison with the conventional diameter heat exchangers. It showed the greater importance of both conductive and convective heat transfer mechanisms in this kind of heat exchangers.