Thermodynamic properties of refrigerant trans-1,3,3,3-tetrafluoropropene: method for constructing the fundamental equation of state and calculation of thermodynamic tables

Abstract

A new environmentally friendly fourth-generation refrigerant trans-1,3,3,3-tetrafluoropropene R1234ze(E) is considered as an alternative to R134a refrigerant in chillers and heat pumps, as well as R22 refrigerant in air conditioning systems. A technique has been developed for constructing a unified fundamental equation of state of liquid and gas, implemented for trans-1,3,3,3-tetrafluoropropene. The proposed fundamental equation in the vicinity of the critical point satisfies the requirements of the scale theory for asymmetric systems, and in the region of rarefied gas it is reduced to the virial equation of state. Based on this fundamental equation, tables of standard reference data on pressure, density, enthalpy, isobaric and isochoric heat capacities, entropy, heat of vaporization, and speed of sound, trans-1,3,3,3-tetrafluoropropene in the region of state parameters in the temperature ranges 169–420 K and pressure 0.1–100 MPa were calculated. A number of statistical characteristics have been calculated – absolute mean deviation, systematic deviation, standard deviation, root mean square deviation, which characterize the accuracy of the proposed fundamental equation in describing the experimental values of equilibrium properties obtained in generally recognized international thermophysical centers. It has been established that the values of these statistical characteristics are significantly less than the values of the corresponding characteristics of international fundamental equations given in the literature when describing thermal and caloric experimental data of trans-1,3,3,3-tetrafluoropropene. The estimated expanded uncertainties of the tabulated data obtained based on the proposed fundamental equation were 0.26 % for density, 0.57 % for pressure, 1.7 and 1.2 % for isochoric and isobaric heat capacities, 0.38 % for speed of sound. The results obtained allow us to conclude that the proposed unified fundamental equation of state adequately conveys the thermodynamic characteristics of trans-1,3,3,3-tetrafluoropropene in the specified range of temperatures and pressures.