石蜡基碳纳米管复合相变蓄冷材料的热性能研究

Thermophysical Properties of Cool Storage of Paraffin-based Composite Phase Change Materials Filled with Carbon Nanotubes

针对石蜡导热系数低，传热性能差的缺点，采用向其中添加碳纳米管来改善其导热性能。实验制备了碳纳米管质量分数为1％、2％和5％的石蜡基复合相变材料，通过差示扫描量热仪和热传导系数仪研究了复合材料的相变性能，导热性能和稳定性。实验结果表明，随着碳纳米管质量分数的增加，复合材料的导热系数逐渐增大，相变焓有所减小。质量分数为5％的石蜡基碳纳米管复合材料相变温度为4-8℃，相变焓为137.6-142.7 kJ/kg，比纯石蜡下降了约18％，液态导热系数为0.28 W/（ m·K），比纯石蜡提高了40％，稳定性较好，可作为蓄冷材料广泛应用于蓄冷系统。

To address thermal conductivity of paraffin wax （ PW）, carbon nanotubes （ CNTs） were mixed with PW to form PW-CNTs composites. PW-CNTs composites has been prepared with various mass fractions （1% 、2%、5%） of carbon nanotubes. The thermal prop-erties including phase transition temperature, latent heat of phase change, thermal conductivity and thermal stability during the phase change process are investigated. The phase change property was characterized using differential scanning calorimeter（ DSC） and the ther-mal conductivity was measured by using transient hot wire method. The results show that with the increasing of mass fraction of CNTs, ther-mal conductivity become larger, and the latent heat decrease gradually. Phase transition temperature of PW-5CNTs is 4-8 ℃, latent heat of phase change is 137. 6-142. 7 kJ/kg, thermal conductivity is 0. 28 W/（m.K）（liquid）, and PW-5CNTs have good enough stability to be widely used as cool storage materials.