碳纳米管–氮化硼/肉豆蔻酸复合相变材料的蓄热性能研究

Study on the Thermal Storage Performance for Carbon Nanotubes-boron Nitride/Myristic Acid Composite Phase Change Material

为了研究混合纳米颗粒复合有机相变材料蓄热性能,以肉豆蔻酸为基体,利用2步法将纳米氮化硼碳纳米管按照不同配比与不同混合质量分数,制备了碳纳米管-氮化硼/肉豆蔻酸复合相变材料。采用热常数分析仪、差示扫描量热仪以及X射线衍射仪对其进行了蓄热性能测试,并重点分析了这2种纳米颗粒的配比、碳纳米管的管径、混合纳米颗粒的质量分数以及不同环境温度对复合相变材料的等效导热系数的影响。结果表明:复合相变材料的相变潜热、相变温度等热性能变化不大,而导热系数有明显增高。同时,在Maxwell模型基础上建立了适用于碳纳米管–氮化硼的复合相变蓄热材料等效导热系数计算模型,并将计算结果与实验结果对比,验证了其正确性。

In order to study the thermal storage performance of organic phase change materials(PCMs), carbon nanotubes boron nitride/myristic acid composites were prepared by two-step method with myristic acid as the matrix. The thermal storage performance of the composite was tested by thermal constant analyzer, differential scanning calorimeter and X-ray diffraction instrument. The effects of the ratio of the two kinds of nanoparticles, the diameter of carbon nanotubes, the mass fraction of mixed nanoparticles and different environmental temperatures on the effective thermal conductivity of the composite phase change materials were analyzed. The results show that the thermal properties such as latent heat of phase change and phase change temperature change little, but the thermal conductivity of the composite increases obviously. At the same time, based on the Maxwell model, a calculation model for the effective thermal conductivity of carbon nanotube boron nitride composite phase change thermal storage material was established, and the correctness of the model was verified by comparing the calculated results with the experimental results.