Experimental Characterization of a Three-Dimensional-Printed Adiabatic Desorber for Absorption Chillers

Abstract

Absorption chillers are bulkier and more expensive than vapor compression chillers (especially for the low-capacity applications). One of the stumbling blocks is their on-demand fabrication and the complexity of their sorption elements (multifunctional exchangers with coupled heat and mass transfers). Adiabatic sorption exchangers (i.e., absorbers and desorbers) have recently been studied with a focus on enhancing the mass transfer phenomenon and allowing for the heat transfer to be performed in compact mass-manufactured heat exchangers. The present work provides the experimental characterization, by a concept of mass effectiveness, of a three-dimensional-printed adiabatic falling film mass exchanger for absorption chillers operating in desorption mode with the H2O-LiBr working fluid. The impact of four parameters was analyzed: the operating pressure, the solution mass flow rate, the solution concentration, and the solution equilibrium deviation temperature. For the tested experimental domain, the desorber can provide an equivalent cooling capacity (in a single-stage chiller) of between 0.32 and 4.74 kW with an effectiveness in the range of 69.5–100%. The presented desorber showed very good performances while having the advantages of a negligible solution pressure drop, high robustness, as well as easy and potential low-cost manufacture.