Experimental performance of a finned spherical container in cold thermal storage for tropical buildings.

The heating and cooling of buildings consume almost 40% of global energy consumption. Cooling building spaces require more input energy compared to heating in tropical buildings. The power tariff varies according to the base and peak demands. This research mainly minimizes peak electricity demand by operating cold thermal storage using deionized water as a phase change material (PCM). The experimental work investigates the partial charging of deionized water in an internally finned stainless steel spherical container immersed in a constant temperature bath. Encapsulated PCM is tested with constant bath temperatures of - 6 ℃, - 9 ℃, and - 12 ℃. Radial copper fins with a diameter of 3 mm are attached inside the container. The selected fin lengths are 7.5 mm, 13.5 mm, and 19.5 mm. The fin length of 13.5 mm is significantly reducing the freezing period. An effective reduction in the charging duration of 52% is observed at - 6 ℃ bath temperature. Partial charging is recommended by incorporating twice the amount of PCM in the design stage and utilizing 50% freezing during operation to achieve up to 52% energy savings. Therefore, the current findings help design effective cold storage for large-scale air-conditioning in buildings.