Mathematical modeling of a thermal storage system by numerical resolution

Abstract The study explores the integration of phase change materials in a solar water heater to store energy via latent heat and release it as needed. Numerical simulations compare three configurations of a thin phase change materials layer. The melting rate, the evolution of the outlet temperature, and the fluid phase change materials heat transfer are analyzed. Configuration 2 shows controlled melting at 82%, thanks to a stable heat flux (2 W m −2 ) and optimized transfer, limiting losses. Configuration 1 melts at 1% (inefficient heat capture), and configuration 3 at 25% irregularly, with unstable flows. These results highlight the importance of the phase change materials location: configuration 2, by balancing storage and release, improves the energy efficiency of the system.