Liquid Density of Pure Alkanes and Halogenated Alkanes in a Corresponding States Format (original) (raw)
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Fluid Phase Equilibria, 1999
Ž. Fourteen correlations and four equations of state EOS have been used to predict the liquid density of 15 w refrigerants. Overall, Hankinson and Thomson correlation R.W. Hankinson, G.H. Thomson, AIChE J., 26 Ž. x 1979 653-663 with an average of absolute percent deviation of 0.381 is the best for the prediction of liquid Ž. w density of the refrigerants. The Chain of Rotator Group Contribution CORGC equation of state J.D. Pults, Ž .
Liquid Density of Alkanes and Halogenated Alkanes Mixtures in a Corresponding States Format
1998
The Corresponding States (CS) density models for mixture proposed here, one for saturated and one for compressed liquid, are analytically similar to the pure fluid liquid density exposed in the former paper, but now with critical constants and 8,, replacing wm , as from the mixing rules. The mixing rules present two adjustable interaction coefficients for each binary pair, but they are set to unity making the two models completely predictive: both in fact do not preliminarily require any density data for the mixture of interest. To improve the prediction accuracy a correlative mode is here proposed in which the om parameter is substituted with a 8,, (x) function which parameters are regressed from saturated liquid data, when available, for the binary mixture of interest. The two models are validated with mixtures experimental data for the families of alkanes and hydrofluoroalkanes (HFC) and the prediction accuracy obtained is significatively better with respect to the existing predictive liquid density models for mixtures. The result is particularly useful for the studies about the new generation refrigerants applications.
An analytical equation of state for some liquid refrigerants
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A correlation of densities of liquid polar and nonpolar refrigerants from critical temperature
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International Journal of Refrigeration, 1985
able ~'2. However, a generalized design procedure would require temperature dependence of liquid viscosity coefficients. The most common one is the Andrade equation relating the natural logarithm of viscosity coefficient and the inverse temperature. This equation is not exact over the entire liquid range although it is a good approximation below the normal boiling point. Based on the theory of corresponding states, several empirical correlations have been proposed for monoatomic and diatomic liquefied Volume 8 Number
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International Journal of Refrigeration-revue Internationale Du Froid, 2007
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Science and Technology of Environmental Protection, 2002
Vapor-liquid equilibrium, thermodynamic and volumetric properties were predicted for three pure hydrofluorocarbons (R32, R125 and R134a) as well as for binary mixtures of these refrigerants. Three cubic equations of state GEOS3C, SRK (Soave-Redlich-Kwong) and PR (Peng-Robinson) were used. A wide comparison with literature experimental data was made. For the binary refrigerant mixtures, classical van der Waals mixing rules without interaction parameters were used. The GEOS3C equation, with three parameters estimated by matching several points on the saturation curve (vapor pressure and corresponding liquid volumes), compares favorably to other equations in literature, resting simple enough for applications.