Heat transfer and frictional pressure drop characteristics of H₂O/LiBr solution in plate heat exchangers for triple-effect absorption application

In this study, single-phase H₂O/LiBr solution heat transfer and frictional pressure drop characteristics in plate heat exchangers (PHEs) with two different chevron angles are experimentally evaluated for triple-effect H₂O/LiBr absorption chiller applications. The test PHEs are single-pass exchangers with 20 plates. Chevron angles are 78.5° and 55.7° for high- and low-theta PHEs, respectively. Heat transfer and frictional pressure drop experiments in the PHEs were conducted with LiBr concentration ranging from 50.21% to 64.92% (which is the widest concentration range for triple-effect absorption application), solution Reynolds number from 19.39 to 479.10, and Prandtl number from 3.63 to 24.40. All experiments were conducted within a ± 3% energy balance error range, and the heat transfer and frictional pressure drop correlations are developed and applicable within ± 14% and ± 6% error ranges, respectively, by considering the effect of the chevron angle. The correlations developed in this study are compared with correlations from literature. Finally, it is found that the chevron angle of the PHE does not give a significant effect on the energy savings.