Experimental study on silica gel-LiCl composite desiccants for desiccant coated heat exchanger

Desiccant coated aluminum-fin is an important part in desiccant coated heat exchanger (DCHE). It will affect the overall performance of this novel solid desiccant component. In the paper, different silica gel-LiCl composite desiccant coated aluminum sheets were fabricated and some key parameters were studied. Nitrogen adsorption suggested that texture properties of composite desiccants were different from silica gel due to impregnated salt and combined action of silica sol and silica gel. The highest thermal conductivity of composite sheets was 5.8 Wm(-1)K(-1), which is twice of silica gel coated one. Sorption kinetics indicated that composite sheets exhibited higher dynamic sorption quantities and faster sorption rates. Sorption isotherms were also obtained and fitted with Dubinin -Astakhov equation. Besides, dehumidification capacity of composite DCHE was tested and compared with silica gel one. Results indicated that enhanced dehumidification capacity can be achieved with use of composite desiccant in the DCHE system. (C) 2014 Elsevier Ltd and IIR. All rights reserved.