采用八水氢氧化钡(Ba(OH)2·8H2O)作为相变储热材料,经过150次熔化—凝固热循环实验,发现随着热循环次数的增加,Ba(OH)2·8H2O的相变点温度变化很小,但是该相变材料结晶时存在严重的过冷现象.通过扫描电子显微镜获得50次热循环后Ba(OH)2·8H2O与铝合金和紫铜金属材料之间的腐蚀情况图像,图像分析表明,Ba(OH)2·8H2O与紫铜有良好的相容性.搭建了含/未含泡沫铜的相变储能装置的实验台,对比实验结果表明,泡沫铜填充不仅可以提高相变材料的传热效率,而且能够有效地降低Ba(OH)2·8H2O的过冷度.
Thermal cycling tests were performed to determine the phase change temperature shift of pure barium hydroxide octahydrate( Ba( OH)2·8H2O) phase change material( PCM) with respect to 150 accelerated thermal cycles. The results show a slightly phase change temperature shift and a severe supercooling phenomenon with the increasing number of thermal cycles. The compatibility of Ba( OH)2·8H2O with the PCM containing materials like aluminum alloy and copper was also studied by using scanning electron microscope( SEM) after 50 thermal cycles. Ba( OH)2·8H2O was a stable PCM with good compatibility with copper as a containing material. An experimental setup was built to study the heat transfer performances of Ba( OH)2·8H2O with / without copper foams. The contrast experiments conclude that high porosity metal foams not only significantly enhance the heat transfer rate of PCMs,but also effectively reduce the supercooling degree of Ba( OH)2·8H2O.