关键词: 相变材料, 过冷度, 纳米颗粒, 超声处理

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