An experimental apparatus was developed to investigate the supercooling phenomenon of pure water inside cylindrical capsules used for cold storage process. The Phase Change Material (PCM) used was distilled water. The external coolant material was a water-alcohol mixture (50% vol.), controlled by a constant temperature bath (CTB) in four fixed values (-4 °C, -6 °C, -8 °C, and -10 °C). Temperatures varying with time were measured inside and outside the capsule. Cylindrical capsules with internal diameter of 30 mm, 45 mm, and 80 mm, with 1.5 mm wall thickness were made in aluminum, bronze or acrylic materials. The Cooling Rate (CR) was investigated for different positions on the internal wall of the capsule, for different external coolant temperatures (Tc), different capsules diameters and different materials. The results showed that the cooling rate is a strong function of the angular position on the internal wall, the coolant temperature, the capsule material, and the capsule's diameter.
Bibliographical noteFunding Information:
This paper was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq of Brazil. The authors also wish to thank the agreement between Pontifical Catholic University of Rio de Janeiro, Brazil and San Pablo Catholic University, Peru for motivating this research.
- Phase change
- Thermal storage