石蜡/膨胀石墨复合相变储热材料的研究

以膨胀石墨为基体,石蜡为相变储热介质,利用膨胀石墨对石蜡良好的吸附性能,制备出了石蜡／膨胀 石墨复合相变储热材料。由于毛细作用力和表面张力的作用,石蜡在固-液相变时,很难从膨胀石墨的微孔中渗 透出来。实验结果表明,石蜡/膨胀石墨复合相变储热材料没有改变膨胀石墨的结构和石蜡的固-液相变温度, 且其结合了石墨高的导热系数和石蜡大的相变潜热,因而储热密度较高,导热性能好。其相变潜热与对应质量 分率下的石蜡相当,储/放热时间比石蜡明显减少。

STUDY ON PARAFFIN/EXPANDED GRAPHITE COMPOSITE PHASE CHANGE THERMAL ENERGY STORAGE MATERIAL

Paraffin and expanded graphite were chose as a phase change material and matrix, paraffin/expanded graphite composite phase change thermal energy storage material was prepared to utilize the characteristic that expanded graphite can adsorb paraffin well. Because of the effect of capillary force and surface tension force, liquid paraffin was very difficult to leak out from the porous of expanded paraffin during solid-liquid phase change happened. The experimental results showed that the inherent structure of expanded graphite and solid-liquid phase change temperature of paraffin is not changed, its thermal storage capacity and thermal conductivity are high owing the high latent heat of paraffin with the large thermal conductivity of graphite,. The latent heat of composite phase change material was equivalent to that of paraffin based on mass ratio among composite phase change material, the time of storing and releasing of the composite phase change material obviously became shorter than that of paraffin.