【摘要】 针对有机相变材料(phase-change material, PCM)热导率低的问题,研制一种正辛酸(OA)与肉豆蔻酸(MA)的质量比为87∶13的基液,并添加膨胀石墨(EG)增强其热导率,用于医药冷藏运输系统中相变温度为2～8℃的复合PCM。利用EG表面多孔结构的吸附性原理,制备了EG最佳质量分数为7%的OA-MA/EG低温复合PCM。通过差示扫描量热仪(DSC)测得溶液的相变温度为6.8℃,相变潜热为136.3 J/g。使用Hot Disk热常数分析仪测得OA-MA的热导率为0.297 1 W/(m·K),OA-MA/EG的热导率为0.997 5 W/(m·K),加入EG使得OA-MA的热导率提高了2.36倍。对OA-MA/EG进行100次冻融循环,测得其相变温度、潜热值和热导率均未发生明显变化。该有机复合PCM在医药冷藏运输系统中具有很大的应用前景。更多还原

【Abstract】 Aiming at the problem of low thermal conductivity of organic phase-change materials(PCMs), the mixture of octanoic acid(OA) to myristic acid(MA) with mass ratio of 87∶13 is used as the base fluid, and the expanded graphite(EG) is added to enhance its thermal conductivity. It is used for the composite PCM with phase-change temperature of 2 ℃ to 8 ℃ in the medical refrigeration transportation system. The OA-MA/EG low-temperature composite PCM with EG optimum mass fraction of 7% is prepared according to the adsorption principle of porous structure on EG surface. The phase-change temperature and latent heat measured by the differential scanning calorimetry(DSC) are 6.8 ℃ and 136.3 J/g, respectively. The thermal conductivities of OA-MA and OA-MA/EG measured by Hot Disk thermal constant analyzer are 0.297 1 W/(m·K) and 0.997 5 W/(m·K), respectively, and the thermal conductivity of OA-MA is increased by 2.36 times with the addition of EG. After 100 freeze-thaw cycles, the changes of the phase-change temperature, the latent heat and the thermal conductivity are not significant. The organic composite PCM has a great application prospect in the medical refrigeration transportation system.更多还原