Influence of structural parameters on dehumidification efficiency of cross-flow elliptic membrane modules

Abstract Membrane technology presents an energy-efficient alternative to traditional dehumidification methods, such as refrigeration-based systems. This research introduces a novel approach by developing membranes with elliptical cross-section, optimizing surface area for mass transfer of water vapor without significantly increasing module volume. The flow and mass transfer characteristics of humid air across the elliptical fiber membrane bundles were investigated by numerical simulations. A comparative analysis was conducted to evaluate the dehumidification performance enhancement of elliptical fiber membranes relative to circular fiber membranes. The results indicate that the dehumidification amount of the elliptical fiber membrane module increased up to 40% compared to that of circular fiber membrane module. Additionally, the interaction effects of structural parameters, including the fiber axial ratio and inter-fiber spacing, on the dehumidification performance and flow resistance of the elliptical membrane module were explored. The membrane module with a S a - S b of 2.0-2.0 and a fiber axial ratio of 0.5 exhibited optimal dehumidification performance and flow resistance, with the highest dehumidification amount per unit pressure drop of 0.786 g·kg −1 ·Pa −1 . This demonstrates that a wide, long flow channel increases the contact time between wet air and the membrane surface, reduces the formation of flow vortices, and enhances the dehumidification efficiency. These findings provide essential theoretical insights for the design and performance prediction of elliptical membrane modules.