화학공학소재연구정보센터
Heat Transfer Engineering, Vol.30, No.4, 302-308, 2009
Influence of Isotherm Shape over Desiccant Cooling Cycle Performance
The interest in desiccant cooling cycles has been continuously growing in the last years, driven by its simplicity and flexibility of arrangements, as well as the claim for environmentally sound acclimatization techniques. Accordingly, the present work aims at developing and solving a numerical model that is able to represent the conjugated heat and mass transfer within a desiccant material. A mathematical model is constructed based on a number of simplifying assumptions, so as to achieve a relative mathematical simplicity while retaining physical reasoning. Heat and mass balances are applied to elementary control volumes, resulting in a system of four partial differential equations that account for the temperature and humidity content within the air flow channel and the sorbent layer, respectively, as well as an algebraic equation, which stands for the adsorption isotherm. Three different desiccant materials are represented by a generalized adsorption isotherm, which is characterized by a single parameter. The model is solved using a fully implicit finite-volume discretization technique. The results showed that a balance between the properties of commercially available adsorptive materials is desirable if the coefficient of performance is to be maximized.