Simulación de un intercambiador de calor para el almacenamiento de energía térmica mediante el uso de materiales de cambio de fase: simulación de un intercambiador de calor para el almacenamiento de energía térmica a media temperatura.

Abstract

Solar energy is one of the most widely used energy alternatives, but there are problems for its use such as the intermittency between its periods of availability. which is why energy storage is a key factor for its application. There are three types of thermal energy storage: sensible heat, thermochemical or latent heat, in which the material changes phase. Phase change systems can be studied with computational fluid dynamics (CFD) that uses numerical methods to solve these problems. There are several CFD simulation programs, some examples are Ansys and COMSOL with friendly graphical interfaces and free student versions and OpenFoam with a free version, but without a graphical interface. 5 preliminary tests were carried out in COMSOL on the transfer of heat in solids and fluids; and 5 preliminary tests in Ansys. The complete initial exchanger geometries were done first in SolidWorks and then in Inventor; however, the final geometry was generated and simulated in the Ansys program. The phase change could not be simulated in COMSOL, which is why it was decided to change the program to Ansys where all the preliminary tests were successful. The final heat exchanger simulation lasted 4 hours and a water outlet temperature of 314 K and a final liquid fraction of the phase change material of 0.0586 were obtained. Convergence of energy, velocity, and continuity curves is achieved after 2400 seconds with a residual value of 1x10-3 or less.