相变微胶囊的热导率测量

提出应用3ω谐波探测技术进行脲醛树脂-石蜡相变微胶囊的等效热导率测量方法。测试了跨越相变温度区间的微胶囊等效热导率,分析了等效热导率随温度的变化关系。在其相变温度区间内,热导率存在极大值,该极值点对应的温度与其相变温度峰值一致。同样温度下,降温时的等效热导率略小于升温,这主要是由降温时相变材料的过冷引起。

Thermal Conductivity Measurement of Phase Change Materials Microcapsules

A 3ωapproach was developed for the determination of effective thermal conductivity of phage change materials microcapsules based on urea-formaldehyde and paraffin wax.The effective thermal conductivity of phage change materials microcapsules within the phage change temperatures range were measured using the established system.At the same time,the relationship between the effective thermal conductivity and temperature was analyzed.The effective tliermal conductivity reaches its peak value within the phase change temperature range and its temperature peak value is consistent with the phase change temperature peak value.The effective thermal conductivity of decreasing process is slightly smaller than that of the increasing process at the same temperature. This is probably due to"too cold"phenomenon.