Thermal performance characterization of a thermal energy storage tank with various phase change materials

Abstract

Thermal energy storage technologies are a crucial aspect of a sustainable energy supply system, with latent heat thermal energy storage tanks being among the best thermal energy storage systems. The use of phase change materials (PCMs) is a suitable way to enhance the energy efficiency of the system and fill the gap between demand and supply. The objective of this work is to conduct a numerical and experimental investigation of the thermal storage tank capacity of different types of PCMs, such as wax, salt hydrate, and salt hydrate mixtures. An experimental investigation was conducted to determine the melting and super cooling temperature, which indicates the temperature gap for all the PCMs that were used in this study. A numerical model was developed to investigate the proposed heating system to determine the maximum heat storage capacity. Streamlines of the melting PCM, melting fraction, and temperature distribution were presented. According to experimental results showed that wax is the most stable PCM. The numerical stage showed that the thermal response of sample C (8:2 of used Ca(NO3)2·4H2O:Mg(NO3)2·6H2O) was comparatively better than that of the other samples (i.e., samples A and B) in terms of thermal capacity storage PCM. In sum, the samples/composite PCMs are favorable for thermal energy storage system utilization.

Keywords

• Phase change materials
• CFD
• Thermal energy storage
• Salt hydrates
• Wax