DENDRITIC ICE GROWTH IN SUPERCOOLED WATER INSIDE CYLINDRICAL CAPSULE

摘要

The supercooling water was studied experimentally inside cylindrical capsules used for cold storage process. The transfer fluid (TF) is a water-alcohol mixture (50% vol.), controlled by a constant temperature bath (CTB). Temperatures varying with time are measured inside and outside the capsule. Cylinder with internal diameter and thickness of 45 mm and 1.5 mm, respectively, were made in acrylic material. The water supercooling period and the nucleation temperature were investigated for different transfer Quid temperatures. The results indicate that the dendritic ice growth, for different thermocouples position, is as a function of the transfer fluid temperature. The process of nucleation varies with the transfer fluid temperature. The temperature of the phase-change material (PCM) varies during the nucleation time, and, in same cases, the dendrites disappear (formed during the nucleation time) and the solidification process continues with a smooth interface.