Performance Of A Cool Thermal Store Filled With Balls Containing Water

Abstract

A cool thermal storage (CTS) system can be integrated with an A/C system in order to reduce power consumption during a period of high demand. Investigator conducted experiments to investigate the performance of a CTS during charging and discharging processes. The rectangular 1.65 m3 CTS enclosed 1080 plastic balls, with each having a diameter of 11 cm and Vi full of water. All balls were immersed totally in a 40% ethylene glycol solution. The solution circulated through the store during charging and discharging processes at a speed of 0.417 kg/sec by entering the store at the top and leaving at the bottom. A chiller was used to charge the store with cool energy and an electric heater was used to discharge it. Temperatures of selected balls at different locations and temperatures of entering and leaving solution were recorded. A sharp drop in temperature of balls was observed generally during the first four hours of every charging process, followed by a gradual but slow decrease in temperature. Temperature inside some balls reached-6 to-8°C. It increased to 3°C after one and half-hours of a discharging process. Ball temperatures generally remained constant at around 3.5"C during most of a discharging process. Experiments reveal that CTS has a potential of handling a cooling load.