碳纳米管填料对相变储能式热沉性能的影响

为了评估纳米复合相变材料在相变储能式热管理技术中的应用潜力,采用实验方法研究碳纳米管填料对相变储能式电子器件热沉瞬态性能的影响.选用十六醇为基底相变材料,以多壁碳纳米管为填料制备了不同质量分数（0.3%、1%和3%）的纳米复合相变材料,对复合相变材料的关键热物性进行表征.在短时较高热流密度（高达7.0 W/cm2）加热条件下,比较热沉（分为有翅片和无翅片2种结构）的瞬态性能随纳米复合相变材料中碳纳米管质量分数的变化规律.实验结果表明,在添加了碳纳米管填料之后热沉的性能较采用纯十六醇的工况有所削弱.虽然加入碳纳米管后纳米复合相变材料的导热系数有所提升,但黏度的急剧增加极大地削弱了熔化过程中的自然对流效应,从而抵消了导热强化所带来的性能提升.

Effects of carbon nanotube fillers on performance of phase change energy storage-based heat sinks

The effects of carbon nanotube fillers on the transient performance of thermal energy storage-based heat sinks for electronics were experimentally analyzed in order to assess the potential of nanocomposite phase change materials as applied to thermal energy storage-based thermal management technologies. 1-hexadocanol and multi-walled carbon nanotubes were chosen as the matrix phase change material and fillers, respectively, to form nanocomposite phase change materials at various mass fractions (0.3%, 1%, and 3%), whose key thermophysical properties were characterized. Under the intensive pulsed heat loads (up to 7.0 W/cm2), the transient performances of the heat sinks (finned or unfinned) were compared with respect to the mass fraction of carbon nanotubes in the nanocomposite phase change materials. Results show that the performance of the heat sink is slightly deteriorated upon adding carbon nanotubes into 1-hexadocanol as a result of greatly suppressed natural convection effects during melting, due to the dramatically increased viscosity. Then the performance improvement caused by enhanced heat conduction was offset, even if the thermal conductivity of the nanocomposite phase change materials was increased by the addition of carbon nanotubes.