Modelling of a desiccant-coated heat and mass exchanger for airflow dehumidification

In this paper, a numerical simulation was conducted to explore the performance of a heat and mass exchanger designed for air conditioning applications. The exchanger employs a near-isothermal dehumidification, based on adsorption/desorption processes, to remove moisture from airflow. This study presents a physical and mathematical 1D-model of the device, integrating energy and mass balances. Silica Gel and Metal-Organic Frameworks (MOFs) MIL 100 are investigated as potential desiccant materials. An explicit numerical scheme based on spatial and temporal discretization is employed to solve the distributed parameters model. The results of transient adsorption and desorption processes, conducted alternatively, are presented and discussed, highlighting the promising potential of near-isothermal dehumidification in HVAC systems. The findings demonstrate that the proposed model can facilitate the effective design of desiccant devices for HVAC dehumidification. Moreover, it underscores how incorporating desiccant materials into thermally regulated heat and mass exchangers can significantly improve the energy efficiency of HVAC systems.