Descripción
As Phase Change Materials (PCM) have a high energy storage capacity in relation to
their volume, they have a high potential for use in mechanisms to improve energy
efficiency. Their thermal energy storage occurs through latent heat during the phase
change process. Therefore, they can be widely used in heat exchangers, since the
thermal exchange that occurs in this process allows the solidification and/or fusion
process of materials depending on their temperature. In this essay, a numerical study
of the fusion process of the PCM RT - 82 contained in an elliptical multiple tube heat
exchanger is performed. This condition is analyzed by varying the geometric conditions
of the tubes, the vertical eccentricity of the tubes in relation to the PCM rings and their
orientation. The analysis is conducted by using CFD (Computational Fluid Dynamics)
on the FLUENT software. The problem presented is two-dimensional, vertically
symmetric and transient. The mathematical model is composed of the equations for
the conservation of mass, energy and momentum. The numerical model is validated
with experimental and numerical results from the literature. The results for total melting
time, liquid fraction as well as liquid fraction and velocity fields are presented. The
results show that among the geometric variations carried out in the study, the factor
that most influences the reduction of the total melting time of the PCM is the tube
eccentricity.
