Optimized geometric designs of desiccant wheels with metal-organic frameworks considering dehumidification capacity and energy

With the increasing demand for handling dehumidification loads and energy savings in air-conditioning systems, solid-desiccant dehumidification systems have been implemented in passive and zero-energy buildings. Although novel metal-organic frameworks (MOFs) have been introduced to improve the performance of desiccant wheels, previous studies have mainly focused on silica gel-based desiccant rotors (DRs). This study aimed to optimize the geometric design of MOF DRs to achieve enhanced dehumidification and energy performance. A numerical model for estimating the performance characteristics of MOF DRs was developed using the adsorption isotherm curves measured in this study. The numerical model was validated by comparing the predictions with the experimental data. The dehumidification and energy performance of the MOF DRs were analyzed in terms of the coating amount, channel pitch, rotor thickness, and process-regeneration area ratio. Accordingly, the optimized geometric designs of the MOF DRs were determined to achieve the maximum dehumidification capacity and minimum energy consumption. Compared to the baseline MOF DR, the capacity-optimized MOF DR exhibited a 47.4 % higher moisture removal capacity, whereas the energy-optimized MOF DR exhibited a 48.6 % lower sensible energy ratio.