Numerical Simulation of Thermal Process in a Phase Change Material Exposed to Solar Heating in a Tropical Region

Abstract

The capacity for phase change material (PCM) to absorb and release latent heat has led to its applications in heating/cooling strategies in solar heating systems, air-conditioning system, electronics cooling and food preservation. The use of PCM in building construction through micro/macro-encapsulation to passively cool/heat a living space has attracted a lot of experimental and simulation research work, especially after the turmoil caused due to worldwide energy crises. In this paper, the thermal behaviour of a PCM exposed to solar heating in a tropical climate is studied numerically over a 24-hour period using the ANSYS fluent Software. A grid dependency test is initially devised to establish the most appropriate grid sizes and time steps to be used for the subsequent simulations with acceptable accuracy. PCM is setup to be in contact with one side of a concrete block. The other side of the concrete is exposed directly to a typical daily solar radiation profile of a tropical region. Results, in terms of temperature distribution and liquid fraction, show that a two-layer of a commercially available PCM is sufficient to flatten the temperature fluctuations arising from solar heating in the tropical regions.