Experimental analysis of aluminum foams as heat transfer medium for PCM thermal storages.

The latent heat absorption phenomenon associated with melting of a suitable Phase Change Material (PCM) can be an effective way to improve the Thermal Energy Storage (TES) behavior in many applications. However, the most suitable PCMs to be used in HVAC and refrigeration systems find intrinsic limitations due to their poor heat transfer capabilities. This work experimentally investigates the use of Aluminum foams as heat transfer medium to improve the overall heat transfer of paraffin waxes that can be possible PCMs to be implemented in hybrid sensible-latent water TESs. The experimental tests were run in a new dedicated setup designed, developed, and built at the Department of Management and Engineering of the University of Padova to study the water hybrid TES. The experimental results are presented in terms of loading and unloading times at constant water tank temperature. The effects of the use of Aluminum foams as enhancing heat transfer medium were studied by comparing the loading and unloading processes of a paraffin wax with melting temperature around 40 °C, with and without metal foams, in a water thermal storage unit. The effects of three different foams with 5, 20, and 40 Pores Per Inch (PPI) were investigated.

合适的相变材料（Phase Change Material, PCM）熔化时伴随的潜热吸收现象，可有效改善多种应用中热能存储（Thermal Energy Storage, TES）的性能。然而，适用于暖通空调（HVAC）和制冷系统的最佳PCM因传热性能不佳而存在固有局限。本研究通过实验探究了将铝泡沫作为传热介质，以提升石蜡的整体传热性能——这类石蜡有望作为PCM应用于混合显热-潜热水基TES中。实验测试在帕多瓦大学管理与工程系设计、开发并搭建的新型专用实验装置中进行，该装置旨在研究水基混合TES。实验结果以恒定水箱温度下的充热与放热时间为指标呈现。通过对比水基储热单元中熔点约为40°C的石蜡在有无金属泡沫情况下的充热与放热过程，研究了铝泡沫作为强化传热介质的效果；同时探究了孔隙率为5、20和40孔/英寸（Pores Per Inch, PPI）的三种不同泡沫的影响。