以十八醇(OC)为相变材料、膨胀石墨(EG)为支撑材料,通过"熔融共混、压制定形"的方法制备了16种不同混合比例的OC/EG定形复合相变材料。通过扫描电镜(SEM)、X射线衍射仪(XRD)和傅里叶变换红外光谱仪(FT-IR)对复合材料的微观形貌、结晶相和官能团分布进行了分析,并利用差示扫描量热仪(DSC)和Hotdisk对复合相变材料的相变焓、相变温度和热导率进行了测试。结果表明,当EG质量分数为28%、样品密度为900 kg/m³时,其熔融焓和凝固焓分别为181.48 kJ/kg和161.52 kJ/kg,熔化温度和结晶温度分别为57.14℃和55.46℃,有效热导率高达13.08 W/(m·K),表现出较高的充放热性能和导热性能,约为纯OC[0.38 W/(m·K)]的34倍;在此基础上对样品进行了50次充放热循环稳定性测试,结果EG质量分数为28%、密度为900 kg/m³和1 000 kg/m³的样品具有较好的循环稳定性、导热性和凝固放热特性。

Taking octadecanol (OC) as phase change material and the expanded graphite (EG) as the supporting material,sixteen kinds of shaped composite phase change materials with different ratios of OC/EG are fabricated through a melt blending-press setting method.The micro morphology,crystalline phase and functional group distribution of the fabricated materials are analyzed by means of scanning electron microscope (SEM),X-ray diffractometer (XRD) and Fourier transform infrared spectrometer (FT-IR).The phase change enthalpy,phase change temperature and thermal conductivity of the materials are tested by using differential scanning calorimeter (DSC) and Hot-disk.Studies show that the material with an EG content of 28% and a sample density of 900 kg·m^-3 has a melting enthalpy of 181.48 kJ·kg^-1,a solidification enthalpy of 161.52 kJ·kg^-1,a melting temperature of -57.14℃,a crystallization temperature of 55.46℃,and an effective thermal conductivity of 13.08 W·m^-1·K^-1 that is about 34 times that of pure OC (0.38 W·m^-1·K^-1),showing high heat storage/release performance and thermal conductivity.On this basis,fifty times heat storage/release cyclic stability test is performed on the samples.It is found that the samples with an EG content of 28% and a high density such as 900 kg·m^-3 or 1000 kg·m^-3 have better cycle stability,good thermal conductivity and solidification exothermic characteristics.

王建众(1970-),男,本科,高级政工师,研究方向为电网规划及智能电网、储能材料与系统,136078901@qq.com