Diani Andrea, Rossetto Luisa
Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy.
Materials (Basel). 2021 Mar 4;14(5):1195. doi: 10.3390/ma14051195.
A smart possible way to cool electronics equipment is represented by passive methods, which do not require an additional power input, such as Phase Change Materials (PCMs). PCMs have the benefit of their latent heat being exploited during the phase change from solid to liquid state. This paper experimentally investigates the melting of different PCMs having different melting temperatures (42, 55 and 64 °C). Two copper foams, having 10 PPI and relative densities of 6.7% and 9.5%, i.e., porosities of 93.3% and 90.5%, respectively, are used to enhance the thermal conductivity of PCMs. The block composed by the PCM and the copper foam is heated from one side, applying three different heat fluxes (10, 15 and 20 kW m): the higher the heat flux, the higher the temperature reached by the heated side and the shorter the time for a complete melting of the PCM. The copper foam with a relative density of 9.5% shows slightly better performance, whereas the choice of the melting temperature of the PCM depends on the time during which the passive cooling system must work. The effect of the foam material is also presented: a copper foam presents better thermal performances than an aluminum foam with the same morphological characteristics. Finally, experimental dimensionless results are compared against values predicted by a correlation previously developed.
一种为电子设备降温的可行明智方法是采用被动方法，这种方法不需要额外的电力输入，例如相变材料（PCM）。相变材料的优点是在从固态转变为液态的相变过程中能利用其潜热。本文通过实验研究了具有不同熔化温度（42、55和64°C）的不同相变材料的熔化情况。使用了两种孔隙率分别为93.3%和90.5%（即相对密度分别为6.7%和9.5%）、孔隙率指数为10 PPI的泡沫铜来提高相变材料的热导率。由相变材料和泡沫铜组成的块体从一侧加热，施加三种不同的热通量（10、15和20 kW/m²）：热通量越高，加热侧达到的温度越高，相变材料完全熔化所需的时间越短。相对密度为9.5%的泡沫铜表现出稍好的性能，而相变材料熔化温度的选择取决于被动冷却系统必须工作的时间。还展示了泡沫材料的影响：具有相同形态特征的泡沫铜比泡沫铝具有更好的热性能。最后，将实验无量纲结果与先前开发的关联式预测值进行了比较。
