Theoretical Analysis of Indirect and Direct Solar Regenerators for Liquid Desiccant Systems
Abstract
Solar liquid desiccant air-conditioning systems have recently attracted attention due to their sustainability and good energy saving potential, since only heat is required in the solution regeneration process. The solar regenerators can be classified as indirect and direct regeneration units. In the first type, the solar heat can be transferred either to the air stream via solar air collectors or a combination of solar water collectors and water-to-air heat exchangers or to the liquid desiccant via a combination of solar water collectors and water-to-solution heat exchangers before entering the regeneration chamber. In the second type, the diluted solution is exposed simultaneously to the solar radiation and the air stream within a solar collector/regenerator. A performance comparison between both types of regeneration units is presented in this paper. The simulation results demonstrate that direct solar regenerators have a high potential for enhancing the water desorption rate from a diluted solution and, consequently, the air dehumidification capacity within the absorber.