Performance evaluation of phase change materials an assorted technological approach

Abstract

The phase change materials (PCM) is useful for energy storage by the virtue of their latent heat. Sustainable development can be achieved with this technology in load levelling of power grid and waste heat recovery. In this work, three PCMs (Fructose, Magnesium chloride hexahydrate and Sorbitol) were studied in Solidification tester in large scale (~10 kg) to find the optimum flow rate in discharging phase using energy and exergy analysis. CFD analysis on the three chosen PCM in a heat exchanger was simulated to develop Nusselt number correlations with Stefan number, Archimedes number and Prandtl number for both charging and discharging cycle. Five soft computing models were trained and tested with an objective of virtual replication of the heat storage and retrieval process. From the experiment, it was found that the PCMs rate of cooling and the mass flow rate of the heat transfer fluid are not proportional to each other. The optimum flow rate for the material based on the energy and exergy analysis for PCMs are 1500, 1000 and 2000 lit/hr respectively. The conventional material problems were not witnessed in the experiment owing to the larger material size. Hence the importance must be given to the material property improvement in the future. The developed Nusselt number correlations for the CFD analysis are verified against the experimental results and it agrees quite well. Among the various soft computing models, Catboost model performed well for all the three PCMs in both charging and discharging cycle. newline