石蜡/膨胀石墨复合相变材料的结构与热性能

Structure and Thermal Properties of Composite Paraffin/Expanded Graphite Phase-Change Material

以有机物石蜡为相变材料、膨胀石墨为支撑结构,利用膨胀石墨的多孔吸附特性,制备出了石蜡含量分别为50%(质量分数,下同),60%,70%和80%的石蜡/膨胀石墨复合相变储热材料.采用扫描电镜(SEM)和差示扫描量热分析(DSC)对复合相变储热材料的结构和热性能进行了表征.结果表明:膨胀石墨吸附石蜡后仍然保持了原来疏松多孔的蠕虫状形态,石蜡被膨胀石墨微孔所吸附;复合相变储热材料的相变温度与石蜡相似,其相变潜热与基于复合材料中石蜡含量的潜热计算值相当.储(放)热性能测试结果表明,含80%石蜡的复合相变储热材料其储热时间比石蜡减少69.7%,放热时间减少80.2%.

Composite paraffin/expanded graphite phase-change materials （PCMs） respectively containing 50% （mass fraction, below the same） , 60% , 70% and 80% of paraffin were prepared by using paraffin as a latent heat-storage material and expanded graphite as a supporting matrix. The structure and thermal properties of PCMs were then characterized by means of SEM and DSC. It is shown that paraffin can be uniformly absorbed into the pore network of expanded graphite, that expanded graphite remains its vermiform structure in PCMs, that the phasechange temperatures of compos equivalent to the calculated val ite PCMs are similar to that of paraffin, and that the latent heat of composite PCMs is ues based on the mass fraction of paraffin in the composite materials. Moreover, tes- ted results of heat storage and release indicate that the time of thermal-energy storage and release of the composite PCM containing 80% of paraffin decreases respectively by 69.7% and 80.2%, as compared with that of paraffin.