Magnetocalorically accelerated charging of latent thermal energy storage systems

Abstract

In the present research, the phase change behavior of a latent thermal energy storage system in the presence of a uniform magnetic field (MF) is numerically studied via a detailed three-dimensional simulation of the melting process. The thermal energy storage unit consists of a triplex tube heat exchanger (TTHX) filled with a phase change material (PCM) in its middle annulus surrounded by the streams of heat transfer fluid (HTF) in the middle tube and the outer annulus. The exclusive exertion of the MF on the PCM or the HTF zone is shown to have a positive influence on the thermal response. This is due to the formation of excessive vortical flow in the melted PCM zone in the first case or the formation of swirling flow in the HTF zone in the second case. Exerting the MF on all zones results in a profound acceleration of the charging process due to the synergy between the two mentioned heat transfer (HT) enhancement mechanisms. Compared to the base case without nanoparticles, the total melting time of the PCM is reduced by 30%, 27%, and 57% when the MF is imposed on the PCM zone, the HTF zones, and all zones, respectively.