Numerical investigation of thermo-fluid behaviour in a channel with PCM-filled columns

Abstract

Microalgae has been identified as a potential source in the production of biofuel. Photobioreactors, which are used for microalgae production, normally experience temperature variations over the diurnal cycle due to changes in ambient conditions. Such temperature variations affect microalgae growth since microalgae are sensitive to these temperature variations. Hence, the thermal regulation of photobioreactors to minimize temperature variations will result in higher yield of microalgae. The present research is aimed to investigate a novel approach to thermally regulate photobioreactors using phase change materials (PCM) where the latent heat of the material is exploited as the energy storage mechanism. The present research uses a numerical approach to study the flow and thermal behaviors in a channel with a set of thermal energy storage columns placed at some offset from each other. The research aims to investigate the transient thermal response of the channel flow in the presence of these columns. Open source CFD software, OpenFOAM, is used to numerically simulate flow in a rectangular channel containing offset PCM columns. A parametric analysis to investigate the impact of various operating and geometric properties on the heat transfer to the PCM columns showed that geometric parameters such as the gap and blockage ratios, column aspect ratio, column shape and column arrangement in the channel influence thermal energy storage in PCM-filled columns.