Experimental study on heat/mass transfer and pressure drop of plate heat exchanger desorber for compact and efficient absorption cooling

Abstract

Plate heat exchanger (PHE) desorber has the potential to improve the compactness and efficiency in absorption cooling. However, there is little research on empirical correlations to accurately describe the desorption process in PHE desorbers. In this study, we experimentally evaluated the heat/mass transfer processes and pressure drop characteristics of H2O/LiBr in a PHE desorber. The PHE is arranged with single-pass and counter flow, with a chevron angle of 60°, length of 278 mm, width of 75 mm, and corrugation height of 8 mm. H2O/LiBr is used as the working fluid with mass concentrations ranging between 50 wt% and 60 wt%, and inlet temperatures ranging between 60°C and 80°C. The experimental results show that Nusselt number (Nu) and Sherwood number (Sh) are increased with Reynolds number (Re) and inlet temperature but decreased with the inlet concentration. Friction factor (f) decreases with Re and inlet temperature but increases with the inlet concentration. Based on the experimental data, empirical correlations of Nu, Sh, and f for a single-effect H2O/LiBr PHE desorber are developed. They show comparable accuracies to correlations in the literature and can facilitate the evaluation and design of compact and efficient absorption cooling applications.