Numerical investigation on melting of various nanoparticles enhanced phase change material inside a square enclosure

In this paper, the numerical simulation on melting of phase change material was run by using ANSYS Workbench 17.0 that included mesh generation tools and FLUENT software. Paraffin wax was selected as the PCM and three types of nanoparticles: Alumina (Al2O3), Copper oxide (CuO) and Zinc Oxide (ZnO) were added to form nanoparticles enhanced phase change material. This paper focus on the melting rate and energy stored of phase change material in a 100mm x 100mm square enclosure. The effect of heat source orientation and the mass fraction of nanoparticles dispersed in phase change material were also investigated. Enthalpy porosity method was applied in this numerical study. Results shown that melting rate only can improved by adding low volume fraction of nanoparticles (2% wt). The overall melting rate of phase change material heated from the vertical side is higher than that heated from below. Besides, the energy Stored during the melting of phase change material heated from vertical side is greater and faster compared with heated from bottom. Al2O3 was the best enhancing nanomaterial among those three nanoparticles as it shown the fastest melting rate and highest amount of energy stored (207287 J).