材料期刊网

相变材料在相变过程中由于材料本身状态的变化,其相变传热过程属于具有移动边界的非线性过程,针对相变材料相变传热过程中非线性传热特征,对月桂酸-癸酸混合脂肪酸相变材料的热性能进行了研究,利用差示扫描量热法（Differential Scanning Cal-orimetry）对相变材料的相变潜热和相变温度进行了测试,利用DRE-2C导热系数测定仪测试了不同摩尔比例脂肪酸相变材料以及相变材料在不同测试温度下的导热系数,通过将无机多孔材料硅藻土和脂肪酸相变材料混合制备了一种无机复合相变材料,并对其导热系数和蓄放热性能进行了测试,利用有限元法对相变材料的相变过程进行了数值模拟。研究表明,脂肪酸相变材料的导热系数和其相变温度呈反比关系,相变材料的相变温度越高,其导热系数越低。对于同一相变材料来说,相变材料的导热系数随着材料温度的升高而升高,硅藻土的掺入明显增加了相变材料的导热系数,复合相变材料蓄放热速率加快,改善了相变材料的传热性能。有限元模拟分析法可以较好地描述相变材料的传热过程,相变材料的导热性能需要强化以提高其蓄放热的速率和频率。

Due to the state change in the phase change process,the heat transfer process of the phase change materials（PCMs） is an non-line process which has a moving interface.For the non-line phase change characteristic of PCMs,the thermal performance of lauric acid and capric acid mixed fatty acid were studied.The phase change temperature and latent heat of the PCMs were measured by differential scanning calorimetry（DSC）,DRE-2C thermal conductivity coefficient instrument was used to test the thermal conductivity coefficient of different mole ratio PCMs and PCMs in different test temperature.A kind of composite PCMs made up of inorganic porous materials diatomite and fatty acid PCMs were produced,the thermal conductivity coefficient and the heat absorption-release performance of the materials were tested.Finite element method（FEM） was used for analyzing the heat transfer problems of the PCMs.The results showed that the thermal conductivity coefficient of fatty acid PCMs has an inversely proportional relationship with the phase change temperature,the higher the phase change temperature,the lower the thermal conductivity.Thermal conductivity of the PCMs grow larger as the test temperature increased.By admixing with diatomite,the thermal conductivity coefficient of the PCMs obviously increased,so did the heat absorption and release rate.Heat transfer progress of the PCMs can be well described by FEM analysis,the analysis of FEM showed that the heat conductivity performance of the PCMs should be enhanced to accelerate the phase change rate and frequency.