Empirical Analysis of the Dehumidification Performance of a Packed-Bed Counter-Flow Liquid Desiccant Dehumidifier

Abstract

Recently, liquid desiccant system integrated with a ventilation system such as a dedicated outdoor air system (DOAS) has been attracting increasing research attention due to its energy saving potentials in controlling latent loads from indoor air in hot and humid climate. This study experimentally investigates the dehumidification performance of a packed bed counter-flow type liquid desiccant system using structured packing material with a specific surface area (229 m2m-3). In this study, lithium chloride aqueous solution was used as the desiccant solution and CELdek structured packing was selected. The enthalpy efficiency, dehumidification efficiency, and moisture removal rate were adopted as the dehumidification performance indices. To investigate the impact of air and solution conditions on the three indices, five parameters were measured: the liquid to gas ratio, the inlet air temperature and humidity ratio, and the solution temperature and concentration. Experimental results show that the dehumidification efficiency and enthalpy efficiency varied from 24.32% to 73.45% and from 30.91% to 68.31%, respectively under experimental inlet conditions. Similarly, the range of the moisture removal rate varied from 0.43 g/s to 0.93 g/s. The characteristics of the dehumidification performance in various inlet air and desiccant solution conditions are presented in this paper