COMPARISON OF THE ENERGY STORAGE POTENTIAL OF DIFFERENT ABSORPTION MODES FOR AIR DEHUMIDIFICATION IN LIQUID DESICCANT COOLING SYSTEMS

摘要

Liquid Desiccant Cooling Systems (LDCS) have a signifi- cant potential for replacing conventional vapor compression cooling systems in hot and humid areas. They require elec- tricity only as auxiliary energy and are driven by low- temperature heat that solar thermal collectors can provide. As solar energy is a discontinuous energy source, a storage system bridges the mismatch between energy demand and supply. The performance of this storage system is decisive for the total costs of the solar air-conditioning systems. In LDCS, the liquid desiccant itself can serve as storage me- dium that stores solar energy thermochemically. This is very efficient for storing energy for dehumidification demands. This study compares the energy storage potential of two alternative absorption modes in LDCS. They differ in the mass flow ratio of liquid desiccant to air and in the absorp- tion device. The analysis was performed for reference con- ditions for supply air and return air and two sets of ambient temperature and humidity conditions, representing moderate and tropical climates. The simulation shows that the absorp- tion mode is decisive for the energy storage potential. It further proves that the difference in performance of both systems increases with an increasing outside air humidity.