Melting characteristics of a phase change material mixed with nano particles of cobalt oxide bounded in a trapezoidal structure

Abstract

A novel trapezoidal design for storage of heat energy through melting of phase-change material (PCM) is investigated. Latent heat thermal energy storage system (LHTES) is a promising option to diminish mis-match between energy consumption and supply. For this purpose, Paraffin: Rubitherm-35 (RT35) material is successively melted in aluminum structure which is heated from one side and the other sides are kept adiabatic. Melting of PCM is observed experimentally and melt fronts are photographed for various time lengths. The fluid-solid module in COMSOL Multiphysics 5.4 has been utilized. The transient heat conduction with enthalpy function is hired. Simulations are carried out for enhancement of thermal conductivity through addition of nano-entities of cobalt oxide Co3O4. The melting time is notably reduced with inclusion of nano-entities to enhance thermal conductivity. The time spans for melt start and total melt in case of pure PCM are 375 and 4500 (s) respectively whereas for the nano mix case, these are 150 and 3000 s. Thus 33% shorter time length is noticed for charging of the PCM trapezoidal matrix with nano entities of Co3O4 are mixed. The results from simulation and lab observations depict similar patterns and are in quite close comparison.