Modélisation des données thermodynamiques du mélange ammoniac/eauModelling of the thermodnyamic properties of the ammonia/water mixture

The present work deals with the modeling of the thermodynamic properties of the ammonia/water mixture using the Gibbs free energy function. For the liquid phase, a three constant Margules model of the excess free enthalpy is formulated. The vapour phase is considered as a perfect mixture of real gases, each pure gas being described by a virial equation state in pressure truncated after the third term. The model developed describes with a good accuracy the mixture in the three states, subcooled liquid, superheated vapour and liquid-vapour saturation for temperatures from 200 to 500 K and pressures up to 100 bar.