泡沫石墨作为相变储能材料填充物的研究

以石蜡为相变材料、泡沫石墨为支撑结构,文章利用泡沫石墨的多孔吸附特性,采用多次真空灌注方法制备了泡沫石墨/石蜡复合相变储热材料。采用Hot Disk热常数分析仪和差示扫描量热分析(DSC)对复合相变储热材料的热性能进行了表征。结果表明,石蜡充分吸附到泡沫石墨的蜂窝状微孔中,泡沫石墨的填充极大地强化了相变材料的导热能力;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。设计了储能过程实验,并与纯石蜡试件进行了对比;储热性能测试结果表明,复合相变储热材料的储热速率比纯石蜡有了极大的提高。

Investigation of composite phase change heat storage material filled with graphite foam

The phase change material(PCM),paraffin,was absorbed in the graphite foam which has porous structure and high thermal conductivity by melting and perfusion under vacuum condition in order to prepare a composite phase change heat storage material of graphite foam and paraffin.The thermal properties of the composite material were characterized by using thermal constant analyzer Hot Disk and differential scanning calorimeter(DSC).The test results show that the paraffin can be uniformly absorbed into the pores network of graphite foam,and the composite exhibits much higher thermal conductivity than pure paraffin due to the heat transfer enhancement of graphite foam.The phase change temperature of the composite material is similar to that of paraffin,and the latent heat of the composite material is equivalent to the calculated values based on the mass fraction of paraffin in the composite material.A comparative study was also made between the energy storage processes of composite material and pure paraffin.The experimental results indicate that the heat storage speed of the composite material is significantly raised in comparison to that of pure paraffin.