Isopiestic investigation and phase equilibrium of the high-efficient absorption refrigerants LiBr and SrBr2 at 288.15 K

Abstract

Isopiestic molalities and water activities for the commercial absorption refrigerants LiBr and SrBr2 at 288.15 K were accurately measured using an improved isopiestic method. And the solubilities for the absorption refrigeration systems were determined by the isothermal dissolution equilibrium method, meanwhile, the refractive indices and densities were measured. The Pitzer and HW model was used to correlate the measured water activities and solubilities, simulate the thermodynamic properties and predict the data in the phase equilibrium process for the absorption refrigeration systems, and the predicted data agreed well with the experimental solubilities. On the basis of the Pitzer ion-interaction parameters and solubility product constant (Ksp) obtained in this work, the ion-interactions between alkali metal ions with Sr2+ and phase equilibrium behaviors were illustrated on the molecular level, which could give an essential guide for the designing of absorption refrigeration system.