Ayyagari Veeresh, Shooshtari Amir, Ohadi Michael
Department of Mechanical Engineering, A James Clark School of Engineering, University of Maryland, College Park, MD 20742, USA.
Materials (Basel). 2025 Jun 24;18(13):2998. doi: 10.3390/ma18132998.
Phase change materials (PCMs) can be utilized in buildings for peak load shifting in air conditioning systems, and the use of salt hydrate-based PCMs can reduce the cost of thermal energy storage devices. Glauber's salt is an economical salt hydrate PCM with a melting point of around 32 °C. However, the desired melting range typically falls between 18 and 22 °C for building air conditioning applications. Although many researchers have characterized Glauber's salt and its composites with modified melting points, enthalpy-temperature curves for composites of Glauber's salt and NaCl are unavailable. In this study, we report the melting and solidification enthalpy-temperature curves for two different composites of Glauber's salt and NaCl with a melting point of 21 °C obtained by the T-history method. Both composites contain NaCl to suppress the melting point, borax to reduce supercooling, and sodium polyacrylate as a thickener to enhance cyclic stability. The first composite with 12 wt.% NaCl demonstrated 139 kJ·kg of latent heat of fusion, and the second composite with 9 wt.% NaCl demonstrated 171 kJ·kg. Both the composites have high volumetric energy densities compared to their organic counterparts with similar melting points.
相变材料（PCM）可用于建筑物的空调系统中以实现峰值负载转移，而使用基于水合盐的PCM可降低热能存储设备的成本。芒硝是一种经济的水合盐PCM，熔点约为32°C。然而，对于建筑空调应用而言，理想的熔化范围通常在18至22°C之间。尽管许多研究人员已对芒硝及其具有改性熔点的复合材料进行了表征，但芒硝与氯化钠复合材料的焓-温度曲线尚无报道。在本研究中，我们报告了通过T历史法获得的两种不同的芒硝与氯化钠复合材料的熔化和凝固焓-温度曲线，其熔点为21°C。两种复合材料均含有用于抑制熔点的氯化钠、用于减少过冷的硼砂以及作为增稠剂以增强循环稳定性的聚丙烯酸钠。含12 wt.%氯化钠的第一种复合材料的熔化潜热为139 kJ·kg，含9 wt.%氯化钠的第二种复合材料的熔化潜热为171 kJ·kg。与具有相似熔点的有机对应物相比，这两种复合材料均具有较高的体积能量密度。
