Performance predication of desiccant coated heat exchangers using different composite desiccant materials.

A DCHE (desiccant coated heat exchanger) is a novel solid desiccant cooling component with desiccant coated onto the surface of a fin-tube heat exchanger. It can handle sensible and latent load simultaneously by carrying away released adsorption heat in dehumidification process. In the study, composite desiccants are fabricated by impregnating LiCl into pores of six different porous hosts, respectively. Due to impregnated salt, composite desiccants have smaller surface area and pore volume. Sorption isotherms were measured and simulated based on Polanyi potential theory. Water sorption isotherms showed that most composite samples possessed enhanced sorption quantity than their pure hosts except that from microporous silica gel. TGA-DSC simultaneous thermal analysis was investigated and results indicate the existence of salt hydrate. Finally, to predict dehumidification performance of composite desiccants in DCHE systems, a mathematical model is built based on fitting equations of sorption isotherms.