The experimental exploration of sodium chloride solution on thermal behavior of phase change materials

Phase change materials (PCMs) are the effective substances for thermal energy storage. Unfortunately, various problems such as high supercooling degree, low crystal growth rate and poor thermal conductivity greatly hinder the large-scale utilization of PCMs. The present study focuses on improving the crystallization and decreasing supercooling degree by adding various proportions of NaCl/NaCl solutions into the n-octadecane-based PCMs for thermal energy storage. The experimental results show that 20 wt% NaCl solutions have the greatest effect on the thermal performance of PCMs. The supercooling degree has been minimized up to 6 °C with the addition of NaCl. It can not only promote crystallization under 1 wt% addition rate, but also enhance latent heat storage performance. Such observations have been verified by the kinetics of crystallization. The researches on supercooling could advance the application of PCMs on solar energy.