A numerical analysis on a solar chimney with an integrated thermal energy storage with phase change material

In this paper, a two-dimensional numerical investigation on a prototypal solar chimney system integrated with an absorbing capacity wall in a south facade of a building is presented. The capacity wall is composed of a high absorbing plate and an assigned thickness of phase change material. The chimney consists of a converging channel with one vertical absorbing wall and the glass plate inclined of 2°. The chimney is 5.0 m high, with the channel height equal to 4.0 m, whereas the channel gap is at the inlet equal to 0.34 m and at the outlet it is 0.20 m. The thermal energy storage system is 4.0 m high with a paraffin wax. The transient analysis on a two-dimensional model in airflow is carried out and the governing equations for natural convection in turbulent flow with Boussinesq assumption and thermophysical properties temperature independent are given in terms of k-ε turbulence model. The problem is solved by means of the commercial code Ansys-Fluent using the finite volume method. The numerical analysis was intended to evaluate the thermal and fluid dynamic behavior of the solar chimney integrated with a latent thermal energy storage system for different values of the PCM thickness. The analysis is accomplished at the 21 June by the sunrise to sunset with the chimney oriented towards south. The simulations are performed considering the solar chimney located in Aversa, Italy. Results are given in terms of wall temperature distributions, air velocity and temperature fields and transversal profiles in the channel whereas in terms of liquid fractions, temperature and stream function fields for the phase change material. Thermal and fluid dynamics behaviors are evaluated in order to have some indications to improve the energy conversion system.