ENHANCEMENT OF HEAT TRANSFER ON PHASE CHANGE MATERIAL WITH CORRUGATED FINS

Abstract

Thermal Energy storage is a key component in any strategy aims at achieving better utilization of the available thermal energy resources. There are different technologies of thermal energy storage. Latent heat thermal energy storage (LHTES) is considered one of the most promising technologies. The main disadvantage of LHTES is the low thermal conductivity of the phase change material (PCM), where thermal energy is stored. Finned tubes are commonly used to improve the heat transfer in LHTES. This thesis studies the use of longitudinal corrugated fins in enhancing the solidification rate of PCM located in the annular area between two concentric tubes. The geometry of the corrugated fins is described in terms of the number of corrugations per fin and the height of the corrugations. The impact of both the number of corrugations per fin and the corrugation height on the solidification rate are investigated. The numerical model does not take into account the buoyancy effect, which allows the use of two-dimensional geometrical model. The results show that the use of corrugated fins reduces the solidification time by up to 35% for the studied configurations. However, the effectiveness of the corrugated fins is generally lower than the effectiveness of straight fins. The low effectiveness is attributed to the low heat transfer rate at the concave surface of the corrugated fins. Based on the results, it is recommended that the number of corrugation per fin should be kept at minimum.