Abstract:

Taking 80^# paraffin as the phase change material and expanded graphite with network structure as the framework, we have prepared the 80^# paraffin/expanded graphite composite phase change material by using the multi-layer adsorption and pressing die method. The thermal stability and cycle stability of 80^# paraffin were analyzed by cyclic thawing experiment. The leakage rate of the composite phase change material with different components was determined through the titration filter paper leakage test. The latent heat, adsorption structure, thermal conductivity and leakage rate of the composite phase change materials were analyzed by using differential scanning calorimeter(DSC), scanning electron microscope(SEM), Hot Disk thermal constant analyzer and other instruments. The results show that when the amount of the added expanded graphite reaches 8% of the total component, the transformation temperature of the composite phase change material is 80.86℃ (endothermic) and 76.08℃ (exothermic), the latent heat is 130.12kJ/kg, and the leakage rate is less than 0.3%. The composite phase change material has the features of stable shape, low leakage rate, high heat storage density, and long life.

Key words: paraffin, expanded graphite, phase change, adsorption, support

摘要：

以80^#石蜡为相变材料，利用不同粒径膨胀石墨的多孔隙结构，以多层吸附、模压法压制方式制备了80^#石蜡/膨胀石墨定形复合相变材料。通过循环融冻实验分析了80^#石蜡的热稳定性和循环稳定性，滴定滤纸渗漏实验确定了不同组分复合相变材料的渗漏率。采用差示扫描量热仪(DSC)、扫描电子显微镜（SEM）、Hot Disk热常数分析仪等仪器对所制备复合相变材料的相变潜热、多孔基吸附结构、热导率、渗漏率等特性进行了分析。结果表明：当膨胀石墨的添加质量分数达到整体组分的8%时，复合定形相变材料的相变温度为80.86℃（吸热）和76.08℃（放热），相变潜热为130.12kJ/kg，且渗漏率小于0.3%。制备的复合定形相变材料具有形状稳定、渗漏率低、蓄热密度高的特点，且具有较长的使用寿命。

关键词: 石蜡, 膨胀石墨, 相变, 吸附, 载体