Research on Performance and Safety of Composite Inorganic Phase-Change Materials (NaNO₃/SiO₂/C) under Low-temperature Cold Shock

This article studies the cold shock resistance and safety performance of NaNO₃/SiO₂/C composite inorganic phase-change thermal storage materials at extremely low temperatures. A low-temperature cold shock test system is built, and the composite inorganic phase-change thermal storage materials of different raw material particle sizes are carried out through the static cold shock and dynamic cold shock at − 40, − 60, − 80 and − 196 °C. The changes in quality, volume, surface morphology phase and thermal properties of the phase-change thermal storage materials are respectively analyzed by means of characterization methods such as scale, vernier caliper, DSC, SEM, and XRD. The results show that the thermal performance of phase-change thermal storage materials with different particle sizes is only 1.97-8.89%, especially under cryogenic shock at − 196 °C. The cold shock resistance is better with the increase in particle size. The physical properties, chemical properties and thermal storage capacity of the material under impact are basically stable, and it has good cold shock resistance. The cold shock of the two methods does not affect the thermal storage function of the material and does not cause thermal energy waste, and the safety performance is better.