Thermal behavior and energy storage of a suspension of nano-encapsulated phase change materials in an enclosure

The energy storage capability of a suspension of Nano-Encapsulated Phase Change Material (NEPCM) nanoparticles was addressed in an enclosure during the charging and discharging process. The nanoparticles contain a Phase Change Material (PCM) core, which are capable to absorb a notable quantity of thermal energy on melting. There is a heat pipe in the cavity at the bottom corner, which is enhanced by a layer of metallic matrix. The natural convection flow occurs due to a temperature gradient during the charging or discharging process. The particles of NEPCM move with the natural convection flow and contribute to heat transfer & storage of thermal energy. The regulating equations for the heat transfer & flow of the NEPCM suspension were established & converted in the non-dimensional type. The finite element method (FEM) was utilized in resolving the equations. The results show that there was a rise in the rate of heat transfer & storage of total energy with a rise in nanoparticles volume fraction. The decrease of the Stefan number from 0.2 to 0.6 increases the total stored energy by 25%. The fusion temperature is another important parameter in which its behavior depends on the charging or discharging process.