Comparative analysis of solid and perforated fins for thermal enhancement of a latent heat storage unit positioned at various inclinations

Abstract

ABSTRACT Augmentation of the charging/discharging rate of the latent heat storage unit (LHSU) is one of the challenges in the design and development of the energy storage unit. Natural convection plays a pivotal role in this aspect which gets influenced by the inclination at which LHSU is placed. Employing radial fins enhance the heat transfer rate but there is a possibility of suppressing the natural convection. Providing perforations on the fins could assist the melted PCM to flow freely upwards and hence can overcome the issue of attenuation of natural convection. However, the orientation of LHSU may alter the influence of perforations. Hence in the current study, a comparative analysis on the thermal performance of a LHSU with solid and perforated fins at different orientations is presented. Experiments are carried out for both melting and solidification processes. It is observed that irrespective of the type of fin, orientation has a significant effect on the melting process. Regardless to the type of fin, total melting time is found to be 48% lesser in the vertical configuration in comparison with horizontal configuration. The considered design of perforations is found to be more effective in a vertical configuration as they increased the energy storage rate in the initial stages of melting. At other orientations, perforations do not have an ample effect. Fin effectiveness is observed to be 5% more in the case of solid fins in comparison with perforated fins at all the orientations. For the solidification process, orientation and perforations have negligible effect as the discharging process is conduction dominant. Exergy efficiency is noticed to be higher for vertically oriented LHSU in both the types fins during the charging process. During solidification of PCM, exergy efficiency is noticed to be same at all the orientations irrespective of the type of fin.