Energy storage systems have become increasingly important to reduce environmental impact and to solve the mismatch between temporal and methodical energy demanded and the energy produced. The purpose of this paper is to describe the results obtained from the numerical simulation of the Latent Heat Thermal Energy Storage System (LHTESS) with a geometry of a vertical shell and tube, made of aluminum metal foam filled with a paraffin wax phase change material (PCM). In the numerical simulations the inner surface of the hollow cylinder is assumed to be at a constant temperature above the PCM melting temperature, the external surface to lose heat toward the outside external ambient, and the top and bottom surfaces are considered adiabatic. The phase change process is modeled with the enthalpy-porosity theory, while the Darcy-Forchheimer model and the Local Thermal Non-Equilibrium (LTNE) assumption are adopted to analyze the aluminum foam-filled by the paraffin. The results of numerical simulations, concerning LHTESS charging phase, are reported as a function of time and are compared in terms of melting time, average temperature, and energy storage rate. The presence of the metal foam is known to significantly improve heat transfer in the LHTESS, and the obtained results show that it is necessary to consider systems with an external heat loss to simulate real operating conditions and understand how this different heat transfer coefficient affects system storage.

The paper presents a two-dimensional numerical investigation of a solar chimney combined with an absorbing capacity wall in a building’s south façade. The analysis was carried out in Aversa (Italy), in July and December, from sunrise to sunset. The chimney is made up of a converging channel, a vertical absorbing wall, and a two-degree angled glass plate. It is 5.0 m tall, while the height of the channel is 4.0 m, with an inlet of 0.34 m and an outlet portion of 0.20 m. A phase change material with metal foam makes up the thermal energy storage system. Four possible configurations are investigated to identify the ideal hybrid system arrangement in terms of thermal performance; the commercial code Ansys-Fluent is used to solve the problem. The results of the thermal energy storage system with metal foam and PCM are provided in terms of liquid fractions, stored energy, and stream function fields, while the ones of the wall temperature distributions in the channel are reported. Thermal and fluid dynamics behaviours are so evaluated to have some useful indications to improve the system.

In the present work, a vertical shell and tube Latent Heat Thermal Energy Storage System is analyzed. The cylinder is filled with phase change material and parts of metal foam. The inner face of the cylinder is corrugated, and it is assumed a constant temperature over the melting temperature of the paraffin wax to simulate the heat transfer. The external surface loses heat to the outside and the top and bottom surfaces are adiabatic. Paraffin wax is used as phase change material that melts over a range of temperatures and has a high latent heat of fusion. The thermal conductivity of the phase change material is low and due to this, it is enhanced with metal foam. In this numerical simulation, it is used the aluminum foam. Enthalpy-porosity theory is used to simulate the phase transition process, and the Local Thermal Equilibrium and Darcy-Forchheimer models are used to examine heat transport between the paraffin and the metal foam. Using the commercial code Ansys-Fluent, the governing equations’ solutions are calculated. In the paper, it is considered different conductivity variations on the external wall and the distinct filling ratio of metal foam. The melting time, enthalpy stored, and energy loss from the numerical simulations of the LHTESS charging phase are provided as a function of time and evaluated.

In the present work, a numerical investigation of the Latent Heat Thermal Energy Storage system (LHTESs) is performed on a vertical shell and tube geometry, made of a porous medium filled with a phase change material (PCM). The LHTESs is a cylinder with a corrugated inner surface at a constant temperature above the PCM melting temperature; on the external surface there are heat losses to the outside and the top and bottom surfaces are adiabatic. The PCM used is a pure paraffin wax, the metal foam, instead, is made of aluminum. The phase change process is modelled with the enthalpy-porosity theory, while the Local Thermal Non-Equilibrium (LTNE) and the Darcy-Forchheimer models are adopted to analyse the heat transfer between the paraffin and the metal foam. The solutions of the governing equations are computed with Ansys-Fluent commercial code. The survey considers different conductivity variations on the external wall and distinct corrugated wall geometric parameters, with different wavelengths and wave amplitudes. The results of the numerical simulations, concerning the LHTESs charging phase, are reported as a function of time and compared in terms of melting time, enthalpy stored, and energy loss.