R-245fa phase equilibrium line modeling method

DOI: 10.17586/1606-4313-2021-20-3-65-74
UDC 536.71

R-245fa phase equilibrium line modeling method

Rykov S.V. , Kudryavtseva I.V. , Popov Petr V., Nurysheva M.

For citation: Rykov S.V., Kudryavtseva I.V., Popov P.V., Nurysheva M. R-245fa phase equilibrium line modeling method. Journal of International Academy of Refrigeration. 2021. No 3. p. 65-74. DOI: 10.17586/1606-4313-2021-20-3-65-74

A critical analysis of the available information on the density  and pressure ps of the R-245fa refrigerant on the line of phase equilibrium (LPE) has been carried out and a mathematical model of LPE has been proposed that transmits this information within the limits of its uncertainty. The LPE model was developed within the framework of the Clapeyron-Clausius and Mendeleev-Clapeyron equations, the model [2β, 1 – α] of the average diameter fd:, where αand β are the critical indices; τ= T/Tc – 1, and the equation of the "apparent" heat of vaporization, developed within the framework of the large-scale theory. It is shown that in the temperature range from Tt = 171.05K to the critical temperature Tc = 427.01  K, the proposed LPE model transmits data on  and psof R-245fa within the limits of their experimental uncertainty; the RSM (Root-mean square deviation) values are given, which for the most reliable data were compiled by: Feng et al. (2010), RSM(ps) = 0,063%; Wang et al. (2004), RSM(ps) = 0,021%; Semenyuk Yu.V. et al. (2006), RSM(p+) = 0,087%. It is shown that the combined use of the parameter, the Mendeleev-Clapeyron equation and the Clapeyron equation can significantly increase the reliability of the calculated information about the density ρ–  in the vicinity of the triple point.

Keywords: R-245fa, line of phase equilibrium, уравнение Clapeyron-Clausius equation, vaporization heat, hydrofluorocarbons, technogenic safety.

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