SIMPLE FUNCTIONS FOR FAST CALCULATIONS OF SELECTED THERMODYNAMIC PROPERTIES OF THE AMMONIA-WATER SYSTEM

A set of five equations describing vapour-liquid equilibrium properties of the ammonia-water system is presented. They are intended for use in the design of absorption processes. Using variable dependences of technical relevance the equations make it possible to avoid iterative evaluations. The equations were constructed by fitting critically assessed experimental data using simple functional forms. They cover the region within which absorption cycles commonly used operate most often. The enthalpy of the gas phase has been calculated in the ideal mixture approximation. The results are presented in the form of an enthalpy-concentration diagram.