Simple Mathematical Model of a Thermal Storage with PCM

Aim of this work is to characterize the thermodynamics of a thermal storage system based on the latent heat of a paraffinic Phase Change Material (PCM). The heat exchange between the heat transfer fluid and the PCM and its phase change are investigated. Under simplifying assumptions, it is shown that the governing equations are the three energy conservation equations written for the heat transfer fluid, the wall and the PCM. The PCM energy conservation equation is written in terms of enthalpy. All three parabolic differential equations are numerically solved according to a finite difference approach implemented in MATLAB language. The simulations are conducted in order to derive the temperature profiles inside the PCM and to estimate the time needed to complete the melting of the PCM. Different simulation campaigns are conducted varying the inlet temperature of the heat transfer fluid. The obtained results can be used as guidelines for more careful studies of the thermal storage system and for subsequent analysis and optimization processes