Equation of state for fluid mixtures based on the principle of corresponding states with a two‐fluid model: Application to fluid mixtures of water + ammonia

We propose an equation of state for fluid mixtures of water + ammonia which is expressed in Helmholtz free energy as a function of temperature, molar volume, and mole fraction. IAPWS Formulation 1995 for water and the equation of state by Tillner‐Roth and colleagues for ammonia should be used for each pure component with the present equation. We applied the principle of corresponding states with a two‐fluid model to the present equation for fluid mixtures. On comparison with experimental data, the uncertainty in property calculations by the present equation was evaluated: within ±0.03 · x for bubble point curve, within ±0.04 · x for dew point curve, within ±0.02 · ρ^L for saturated liquid density, and within ±0.02 · ρ for PVTX properties. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 131(4): 320–330, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10023