Abstract
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•The energy storage in a liquid suspension of Nano-Encapsulated Phase Change Materials (NEPCMs) addressed.•The NEPCM nanoparticles store latent heat energy in the liquid.•The presence of NEPCMs enhances energy storage.•The fusion temperature of particles can control the rate of energy storage/release.
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.