癸酸-棕榈酸-硬脂酸/膨胀石墨蓄能复合相变材料的制备与热性能研究

Preparation and Thermal Properties of Capric-palmitic-stearic Acid/Expanded Graphite Composite Phase Change Material for Energy Storage

癸酸、棕榈酸、硬脂酸形成的三元低共熔物与膨胀石墨通过真空浸渍法制备出新型癸酸-棕榈酸-硬脂酸/膨胀石墨储能复合相变材料,适宜的质量比为m(癸酸)∶m(棕榈酸)∶m(硬脂酸)=77.0∶11.5∶11.5,m(癸酸-棕榈酸-硬脂酸)∶m(膨胀石墨)=13∶1。采用DSC、FT-IR、TG、SEM、冷热循环实验和蓄/放热实验研究了材料的结构和热性能。SEM和FT-IR分析结果表明低共熔物与膨胀石墨是通过物理吸附方式结合。DSC结果表明复合材料融化和凝固时的相变温度为28.93℃和16.32℃,相变潜热为137.38J/g和141.51J/g。TG结果表明复合相变材料在100℃以下具有良好的热稳定性。500次热循环和蓄/放热实验表明循环前后复合相变材料的热可靠性好,且使用寿命长。膨胀石墨的添加改善了复合材料的热性能和热导率。研究表明制备的新型复合相变材料具有合适的相变温度、较高的相变潜热和热导率,热性能稳定可靠,可用于低温蓄能领域。

A novel capric-palmitic-stearic acid/expanded graphite composite phase change material（CPCM）has been prepared by vacuum impregnation method through phase change material（PCM）derived from a ternary eutectic,which was a mixture of capric acid,palmitic acid and stearic acid.The appropriate mass ratio were m（CA）∶m（PA）∶m（SA）=77.0∶11.5∶11.5and m（CAPA-SA）∶m（EG）=13∶1.Different analytical methods including DSC,FT-IR,TG,SEM,cold/thermal cycling test and thermal storage/release performance methods were adopted to study the structure and thermal properties of the material.The SEM and FTIR results showed that CA-PA-SA was dispersed into the pores of EG through physical interaction.The DSC results indicated that the melting and freezing temperatures of CA-PA-SA/EG CPCM were 28.93 ℃ and 16.32 ℃,and the latent heats were 137.38J/g and 141.51J/g.TG analysis results revealed that CA-PA-SA/EG CPCM had a reliable thermal stability under 100℃.The results of500 thermal cycles and thermal storage/release performance showed that CA-PA-SA/EG CPCM had good thermal reliability and long service life.Thermal conductivity of CA-PA-SA/EG CPCM was improved by high thermal conductivity of the EG.All the results indicated that the prepared CA-PA-SA/EG CPCM had proper phase change temperature,high latent heat and thermal conductivity,good thermal reliability and stability.The proposed new material is suitable for application in energy storage.