Numerical Investigation on Shell and Tube Latent Heat Thermal Energy Storage with External Heat Losses Partially Filled with Metal Foam

Abstract

An investigation on a Latent Heat Thermal Energy Storage System (LHTESS) based on a phase change material (PCM) partially filled with metal foam is accomplished. The geometry of the system under investigation is a vertical shell and tube LHTES made with two concentric aluminum tubes with an internal circular tube. The internal surface of the hollow cylinder is assumed at a constant temperature above the melting temperature of the PCM. The external upper and lower surfaces are assumed adiabatic whereas heat losses toward the ambient on the lateral surface of the external cylinder are considered. A numerical model is employed to simulate the behavior of the PCM embedded with the metal foam. The phase change of the PCM is modeled with the enthalpy porosity theory while the metal foam is considered as porous media using the Darcy-Forchheimer law. The results are given in terms of average liquid fraction, average temperature, enthalpy and heat loss. It is shown that the metal foam filling ratio increase determines a decrease of melting time whereas the increase of external heat transfer causes a decrease of the stored energy and an increase of melting time.

Numerical Study on Phase Change Material with Metal Foam in Shell and Convergent/Divergent Tube Thermal Energy Storage Systems with External Heat Losses

“…The coil's outside portion included pure PCM, while its interior region contained PCM embedded within open-cell metal foams. Some different configurations were studied in studies [11][12][13].…”