Thermal Performance of a Heat Storage Module Using Calcium Chloride Hexahydrate

The thermal performance of an air-heated/cooled, phase-change, heat stoage module was tested and evaluated. The module (rated at 38.7 kWh) consist of 130 vertically oriented tubes filled with 729 kg (1607 lb) of calcium chloride hexahydrate and enclosed in a rectangular box. Heat transfer rates measured during charging and discharging decreased with time as a result of decreasing effective heat transfer area and increasing thermal resistance of the phase-change material. These two dominant effects are included in a proposed mathematical model that predicted the experimental data.