Abstract
The percentage of sensible heat to the total heat charged in the spherical ice storage capsule exceeds 20% depending on charging and discharging conditions. It is necessary to consider the change of sensible heat of water and ice to predict charging and discharging characteristics of the spherical ice storage capsule with high accuracy. In this paper, measurements of the temperature distributions of the water inside of the spherical capsule were conducted by changing heating and cooling rates. The flow of the water inside of the spherical capsule changes its direction at the water mean temperature around 4℃. Heat transfer continues even though the flow in the spherical capsule stops. The experimental equation concerning the heat transfer rates inside of the spherical capsule was obtained. The simple method to calculate the heat flow rate in an unsteady-state heat conduction of a spherical body was shown to estimate the change of sensible heat of the ice inside of the spherical ice storage capsule. Finally, considering sensible heat of water and ice, the method to calculate charging and discharging characteristics of the spherical ice storage capsule was shown and the calculated results were examined.
