Experimental Analysis of a Liquid Desiccant Cross Flow Plate-Type Dehumidifier for Air-Conditioning Applications
Abstract
Liquid desiccant air-conditioning systems remove the latent load directly from the air by absorbing the moisture by a strong solution of liquid desiccant. The main components of an open-loop liquid desiccant air- conditioning system are the absorber (dehumidifier) and the desorber (regenerator). The mass transfer is driven by the difference between the partial pressure of water vapor in the air stream and the vapor pressure associated with the desiccant solution. The vapor pressure above the solution decreases with increasing solution concentration and increases with increasing solution temperature. Therefore, cold and highly concentrated solution provides the best dehumidification while warm and dilute solution provides the best humidification. In the absorber, moisture absorbed from the conditioned air stream dilutes the desiccant solution by loading the desiccant with water vapor. The solution weakened by absorption of moisture is reconcentrated in the regenerator, where it is heated to elevate its water vapor pressure, the heat drives out the moisture and the strengthened solution is returned to the dehumidifier. A scavenging air stream, usually ambient air, contacts the heated solution in the regenerator. There, water evaporates from the desiccant solution into the air and the solution is reconcentrated.