Ehsan Izadpanah

The main goal of this work was understanding the effects of PCM container geometry on the melting and solidification rates. Then, it was followed by studying the effects of nanoparticles at different concentrations and fins attached to the inner tube of the energy storage system. Finally, the combination of nanoparticles and fins were studied in different containers and the optimal cases was reported. The container geometries included circle, horizontal ellipse, vertical ellipse, square, triangle, and downward and upward trapezes. The investigations were carried out for nanoparticle volume fractions of φnp = 0,0.02 and 0.04. The maximum improvements achieved by the combination of container geometry, nanoparticles and fins were 80% and 66% for the final melting and solidification times, respectively. The results also indicated that nanoparticles were more efficient in the melting process where a 48% improvement was observed, and adding fins mostly affected the solidification time by up to 46% which were the maximum in all the containers. Among all the cases the best performances in melting and solidification were obtained from the downward trapeze and the horizontal ellipse respectively.