Transient CFD Analysis of Macro-Encapsulated Latent Heat Thermal Energy Storage Containers Incorporated within Solar Air Heater

Abstract

The present work addresses the computational analysis on the cluster of discrete macro-encapsulated (rectangular containers) phase change material (paraffin wax) incorporated in the airflow pathway of a solar air heater. Transient, three-dimensional, pressure-based, Newtonian, viscous-laminar solver with user-defined function aids to investigate the melting and solidification characteristics of the phase change material. The study highlights to determine the influence of critical factors like heat input, flow velocity, melting temperature, and quantity of wax on the phase change characteristics. Additionally, this study aims to investigate the behavior among the discrete multiple energy storage capsules on the phase change response depending upon its relative position inside the heater. The computational findings pointed out that in the charging mode; the flow velocity is not as authoritative as that of the heat input, melting temperature, and quantity of wax. However, the flow velocity is critical during the heat retrieval from the phase change material. A crucial observation regarding the energy storage integrated into the collector was that the paraffin wax melted faster at a lower velocity. The results concluded that an excellent agreement between all the above-listed factors would facilitate the integration of phase change material inside solar air heaters more meaningful.