Numerical Investigation of Flow and Thermal Behavior in Channels with PCM-filled Thermal Energy Storage Columns for Potential Application in Photobioreactors
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. The thermal regulation of photobioreactors to minimize temperature variations will result in a higher yield of microalgae, which are sensitive to such variations. 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. The present research uses a numerical approach to study the flow and thermal behaviors in a rectangular channel with PCM-filled thermal energy storage columns. An open source CFD software, OpenFOAM, is used to numerically simulate the problem. The results show 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 the PCM-filled columns. The results also show that the thermal response of the channel flow, when there is a gradual change in the flow temperature, is influenced by the flow parameters such as the mass flow rate and the rate at which the flow temperature varies.