Modeling of heat and mass transfer in parallel plate liquid-desiccant dehumidifiers

In the last few years there has been renewed interest in solar driven air-conditioning. One concept that has been investigated is the use of liquid-desiccant cooling systems. Such systems have the advantage of improved humidity control, particularly in applications with high ventilation rates. Moreover, lower regeneration temperatures can be employed, allowing for a more efficient use of heat from low temperature sources, e.g., flat plate solar collectors. In the present work, mathematical and numerical models were developed for internally cooled liquid-desiccant dehumidifiers, using three different approaches. The first approach is based on heat and mass transfer correlations. The second one numerically solves, by the finite-difference method, the differential equations for energy and species assuming a constant film thickness. The third approach introduces a variable film thickness. All approaches assume fully developed laminar flow for the liquid and air streams. The variable thickness model results closely matched the experimental data available in the literature. 2006 Elsevier Ltd. All rights reserved