Experimental investigation and performance analysis of a spray-type ionic liquid desiccant dehumidifier

Abstract

Ionic liquid desiccants (ILDs) have vapor pressures similar to lithium chloride and no corrosion and crystallization problems, so they are considered a promising alternative to halide salt desiccant solutions. However, the cost of ILDs is more expensive than conventional halide salts, which limits their practical application. Thus, this study developed a spray-type dehumidifier using an ionic liquid desiccant to increase dehumidification performance and reduce the required amount of ILDs. The presented dehumidifier was tested at various operating conditions. Also, a theoretical model was established to analyze heat and mass transfer coefficients of the dehumidifier. Results indicate that the increase in the flow rate ratio of solution to air benefits absorption performance, and the mass flux of solution is suggested to exceed 170 mL s−1 to avoid the occurrence of air bypass. Moreover, compared with the packed bed type, the spray type can reduce the required solution flow rate by 35 % and save power consumption by 19 % under the same moisture removal rates. The dehumidification effectiveness of the presented dehumidifier was up to 0.64 and comparable to the conventional packed bed dehumidifier using lithium chloride solutions.