TOWARDS CONTROLLING THE PERFORMANCE OF PHASE-CHANGE MATERIALS BY USING AN EXTERNAL MAGNETIC FIELD

Abstract

Large amounts of heat can be stored and released by phase change materials (PCM) with little to no temperature change. They have been recognized for their crucial role in energy conversion and high energy storage capacity, which can reduce energy consumption, enhance the functionality of energy systems, and play a crucial role in temperature management, all of which help to lower CO2 emissions. Nevertheless, phase change materials have some disadvantages such as the spontaneous release of heat during solidification. The goal of this study is to ascertain how the magnetic field affects phase change materials to determine whether it can operate as an energy barrier to control the rate at which they solidify and melt. Both numerical and experimental techniques are used to address this issue. A numerical model utilizing the finite volume method and the enthalpy-porosity technique was developed using the open-source computational fluid dynamic toolbox, OpenFOAM. Numerical and experimental results published in the literature were used to validate the model's findings, and they agreed well. Our findings show that increasing the magnetic field strength leads to a decrease in the rate of melting of PCM. This becomes more obvious as the melting front moves forward and the convection gets stronger. Moreover, the aspect ratio of the PCM enclosure influences the degree of the effect of the magnetic field. Adding metallic nanoparticles to PCM increases the conductivity and its magnetic susceptibility. Experimental investigation shows that the selection of magnetic field properties may not necessarily need to be in terms of magnetic field strength alone, the dimension and the distribution of the magnetic field should also be considered in correlation with the cavity of the sample.