Numerical investigation of mass transfer characteristics for the desiccant-coated dehumidification wheel in a dehumidification process

Desiccant dehumidification systems provide an environment-friendly and energy-saving option for air humidity regulation. The dehumidification wheel as the key component occurring mass transfer process determines the dehumidification performance of the systems. In this study, a two-dimension numerical model was developed to conduct parameter studies on the mass transfer characteristics of dehumidification process for the desiccant coated dehumidification wheel. The mass transfer coefficient K-d and K-total, the integral-average of mass transfer coefficient (K) over bar (d,eff) and (K) over bar (total,eff) determined by the effective adsorption time (t(eff)) and the dimensionless parameter chi(t) were introduced to evaluate the mass transfer performance. Effects of main operational and structural parameters on the mass transfer performance were analyzed and discussed. The results show that these evaluation indices significantly depend on the various parameters, and the preferable dehumidification channel shape is related to cycle time. Research efforts have been made to obtain a correlation for the mass transfer coefficient, which provides an effective tool to predict the dehumidification characteristics of the dehumidification systems