Study on the improvement of supercooling and thermal properties of erythritol-based phase change energy storage materials

Ultrasound and nanoparticles are used to control the supercooling degree of the erythritol-based phase change material. The effects of particle type, ultrasonic power and initial ultrasonic temperature on the crystallization supercooling degree (SD), crystallization progress and supercooling instability of nanofluids are investigated. Meanwhile, the preparation scheme of nanofluids that satisfy both high-quality thermal performance and economic value is explored. The results show that when the particle concentrations are 0.05%, 0.1%, 0.2% and 0.3%, respectively, the SD of the nanofluids added with C decreased by 27.34%, 27.16%, 22.52% and 12.90% (24.39%, 19.91%, 5.49% and 1.22%), respectively, compared with those added with Cu (ZnO) at the same concentration. High-quality nanofluids can be obtained when the addition amounts of C, Cu, and ZnO are 0.1%, 0.3%, and 0.2%, respectively. A nanofluid with good crystallization effect can be obtained when high (low) concentration of nanoparticles is introduced and high (low) power of ultrasound is input. At the initial ultrasonic temperatures of 130 °C, 120 °C, 110 °C and 100 °C, the crystallization effect of the fluid would be worse after adding nanoparticles. With the ultrasonic power of 150W, ultrasonic time of 30 min and particle concentration of 0.5%, ET nanofluids with the best thermal property and optimal sample in economy can be produced.