Performance assessment of planar membrane dehumidifiers: Influence of flow configuration and wet-side conditions in crossflow design

The present study conducts an in-depth numerical examination of heat and mass transfer attributes in a crossflow planar membrane dehumidifier, emphasizing the dehumidifier's performance under various operating conditions. Using a detailed three-dimensional computational fluid dynamics (CFD) model in ANSYS Fluent, we compared three flow configurations, i.e., parallel, counterflow, and crossflow, with consistent inlet conditions with key performance metrics, dew point approach temperature (DPAT), dehumidification rate (DR), pressure loss (ΔP), and coefficient of performance (COP). The comparative analysis of airflow configurations indicates that the counterflow arrangement yields the highest dehumidification efficiency. In contrast, the crossflow design provides a more favorable trade-off between performance and pressure loss, thereby enhancing overall energy efficiency. Simulations explore the influence of inlet air temperature, relative humidity (RH), and flow rate on dehumidification performance. Results indicate that higher wet-side RH significantly enhances DR and COP, driven by an increased moisture gradient. Elevated wet-side temperatures further amplify DR and COP but also result in higher ΔP. Overall, the crossflow configuration maintained consistent and reliable performance under diverse operational scenarios, establishing it as a functional and energy-prudent approach to managing humidity and a sound choice for dehumidification.