Solidification characteristics of phase change material in a rectangular finned spherical capsule

This work investigates the solidification characteristics of deionized water in a stainless steel spherical capsule fitted with rectangular fins immersed in a constant temperature bath. Experiments are carried at three different bath temperatures (-6,-9, and -12 degrees C). Four rectangular fins of size 20.6mm length, width 10.6 mm, and 1mm thick made of copper are fixed on the inner surface of the spherical capsule. Results indicated that fin had a significant reduction in total solidification time. A reduction of 13% in total solidification duration is achieved at -9 and -12 degrees C. However a decrease of 87-90 % in freezing duration is observed while considering 50% of PCM mass at bath temperatures of -6 degrees C,-9 degrees C, and -12 degrees C. It is concluded that fins can be employed in CTES systems at lower bath temperatures to achieve expected energy savings of 9-12% under the partial charging method.