Complex heat and mass coupleding transfer phenomena exist in a solid dehumidification cycle

where the adsorption heat released by the desiccant during the adsorption stage will reduce dehumidification performance

while ideal isothermal dehumidification can eliminate this negative effect. To investigate the mass transfer characteristics of the silica gel desiccant coating under an isothermal dehumidification process

the heat and mass transfer was decoupled

and a two-dimensional conjugated heat and mass transfer numerical model validated by the isothermal dehumidification experimental results of isothermal dehumidification was developed. Simulations were conducted to study the impact of air velocity and desiccant layer thickness on the movement of matter. These two factors

namely

air velocity and desiccant layer thickness

affect the resistance of matter mass transfer on both the air and solid sides. The results show that an increase in air velocity strengthens the air-side mass transfer capacity

resulting in a relatively stronger effect of the solid-side mass transfer resistance on the total mass transfer process. As a result

both Sh and 〖Bi〗_m increased during the adsorption and desorption processes. As the thickness of the desiccant layer increased

the solid-side mass transfer resistance increased

thereby reducing Sh and increasing 〖Bi〗_m for the adsorption and desorption processes. In particular

both air-side and solid-side mass transfer resistances should be accounted for in the numerical modeling of the dehumidification cycle for desiccant coatings usually requires the simultaneous effects of air- and solid-side mass transfer resistances.