Analysis of various models of the average diameter of phase equilibrium line R236ea

DOI: 10.17586/1606-4313-2019-18-3-87-93
UDC 536.71

Analysis of various models of the average diameter of phase equilibrium line R236ea

Rykov S.V., Kudryavtseva I.V., Rykov V.A., Sverdlov A.V. , Nurysheva M.


Abstract
The analysis of various variants of the phase equilibrium line of the refrigerant R236ea, developed in the framework of the model of the average diameter of the Wegner or [1–α]-model, [2β]-model, is performed. The peculiarity of the proposed approach is that the density of saturated steam ρ–and in all three models of average diameter fdis described by the same Clapeyron-Clausius equation, in which instead of the heat of vaporization the “apparent” heat of vaporization r*is introduced: r* = r/[1 – ρ–/ρ+] while the density of the saturated liquid ρ+is described in these models with different equations, but having the same set of terms with the same exponents. Thus, the proposed system of equations for the phase equilibrium line has a physically justified structure and makes it possible to take into account all components in the average diameter fd model, including the linear component τ= 1 – T/Tc. The listed models of average diameter were tested when calculating the phase equilibrium line R236ea in the temperature range from Ttr  (triple point) to Tc (critical point).

Keywords: line of elasticity, "apparent" heat of vaporization, R236ea, diameter of the order, average diameter, line of phase equilibrium, critical indices.


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