Abstract The interest in Phase Change Materials (PCMs) has been continuously growing, since they were identified as a suitable way to store large quantities of thermal energy. Despite many PCMs being available on the market, almost all present a relatively low thermal conductivity, which limits the efficiency and the convenience of their use inside Latent Thermal Energy Storage (LTES) units. This paper proposes a novel method to overcome the low thermal conductivity drawback: additive manufacturing was used to realize three innovative 3D metallic periodic structures, with different base pore sizes (10, 20, and 40 mm) and constant porosity, to be filled with a suitable PCM. The samples were experimentally tested by analyzing the temperature field in a paraffin wax, which has a melting temperature of around 55 °C. Furthermore, several videos and images were taken during the charging (i.e. heating and melting) process, obtained by electrical heating (three heat fluxes corresponding to 10, 20, and 30 W were applied) and the discharging (i.e. solidification and cooling) process, where the heat was only rejected by natural convection with ambient still air. The coupling of PCMs and aluminum structures was demonstrated to enhance both the charging and the discharging processes.

中文翻译：

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通过增材制造实现的嵌入 3D 周期结构的相变材料 (PCM) 的实验研究

摘要 相变材料 (PCM) 的兴趣一直在不断增长，因为它们被认为是储存大量热能的合适方式。尽管市场上有许多 PCM，但几乎所有 PCM 都具有相对较低的热导率，这限制了它们在潜热能储存 (LTES) 装置中使用的效率和便利性。本文提出了一种克服低导热性缺点的新方法：增材制造用于实现三种创新的 3D 金属周期结构，具有不同的基础孔径（10、20 和 40 毫米）和恒定的孔隙率，以填充适合的 PCM。通过分析石蜡中的温度场对样品进行了实验测试，石蜡的熔化温度约为 55 °C。此外，在充电（即加热和熔化）过程中拍摄了几个视频和图像，通过电加热（分别施加 10、20 和 30 W 对应的三种热通量）和放电（即凝固和冷却）过程获得，其中热量仅通过与周围静止空气的自然对流而被拒绝。PCMs 和铝结构的耦合被证明可以增强充电和放电过程。