Abstract
An advanced cylindrical tower-style thermal storage tank has been developed which features simultaneous storage of warm water and ice within a single unit employing ice-freezing coils. The tank, made of steel sheets, was installed at a new office building. By making use of thermal stratification, the principle of the tank's system is that it can simultaneously store warm water in its upper section, and ice, with a higher latent heating rate, in its lower section. To prevent warm and cold water from intermixing in the tank, a trap shaped density-stabilizing unit is installed in the middle of the tank. In the demonstration test we collected operational data from this novel thermal storage system for heating and cooling, by combining the tank and heat recovery heat pump during winter. The operational status of thermal storage and discharge was examined to analyze the nighttime peak-shifting factor, thermal storage efficiency, and energy conservation effects. The test results revealed that the tower-style thermal storage tank was capable for both practical and commercial use in buildings.
