Abstract:

The phase change material with erythritol/mannitol as the base liquid was prepared. During the process, the addition of nano-titanium dioxide provided crystal adhesion for the solidification of the phase change material and promoted the formation of crystal growth crystals. Through ultrasonic treatment, the phase change material locally produced high temperature and high pressure to promote the generation and growth of crystal nuclei. The effects of nanoparticle content, ultrasonic time and ultrasonic power in the preparation process of the material on the supercooling degree and solidification process of erythritol/mannitol were analyzed. The experimental results showed that the increase in the content of nanoparticles and the extension of the ultrasound time would reduce the subcooling of the material, while with the increase of the ultrasound power, the subcooling first decreased and then increased. When the mass fraction of nanoparticles, ultrasonic time and ultrasonic power were used as single variables, the subcooling was the lowest at 11.3℃, 16.2℃ and 10.8℃, respectively, and the corresponding shortening of solidification time was 38.0%, 18.4%, and 16.4%.

Key words: phase change materials, undercooling, nanoparticles, ultrasonic treatment

摘要：

制备了以赤藻糖醇/甘露醇为基液的相变材料，期间通过添加纳米二氧化钛为相变材料的凝固提供了结晶附着力，促进晶体生长结晶的形成；通过超声波处理使得相变材料局部产生高温高压，促使晶核产生和生长。本文分析了材料制备过程中的纳米颗粒含量、超声时间、超声功率对赤藻糖醇/甘露醇过冷度和凝固过程的影响。实验结果表明，纳米颗粒含量的增加、超声时间的延长都会导致材料的过冷度降低，而随着超声功率的增加，过冷度则先降低后升高。纳米颗粒质量分数、超声时间、超声功率分别作为单一变量时，过冷度最低为11.3℃、16.2℃、10.8℃，对应凝固时间缩短最高为38.0%、18.4%、16.4%。

关键词: 相变材料, 过冷度, 纳米颗粒, 超声处理