Importance of Including the Liquid Phase in Equations of State for Nonazeotropic Refrigerant Mixtures.
Importance of Including the Liquid Phase in Equations of
State for Nonazeotropic Refrigerant Mixtures.
CH-85-05 No. 3;
ASHRAE Transactions, Vol. 91, No. 1B, 260-273, January
refrigerants; equations; mixtures; liquid phases;
The recent surge of interest in nonazeotropic
refrigerant mixtures has generated a need for
correlation and prediction of liquid phase information
for mixture. We show that the ideal mixture assumption
(the linear weighting of pure liquid properties) can be
useful but can also be seriously in error when one of
the components is near its critical point, even when the
mixture is not near its own critical point. We also
suggest that using spline-fits to data in isolation is
an ineffective way of using such information. A physical
model is suggested for a mixture whose equation of state
incorporates all the departures of the mixture from
ideality, which allows small, isolated sets of data to
be used in predicting other physical properties of both
the pure fluids and their mixtures.