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Equation of State for the Thermodynamic Properties of trans-1,3,3,3-Tetrafluoropropene [R1234ze(E)]



Monika Thol, Eric Lemmon


An equation of state for the calculation of the thermodynamic properties of the hydrofluoro-olefin (HFO) refrigerant R-1234ze(E) is presented. The equation of state (EOS) is expressed in terms of the Helmholtz energy as a function of temperature and density. The formulation can be used for the calculation of all thermodynamic properties through the use of derivatives of the Helmholtz energy. Comparisons to experimental data are given to establish the uncertainty of the EOS. The equation of state is valid from the triple point (169 K) to 420 K, with pressures to 100 MPa. The uncertainty in density in the liquid and vapor phases is 0.1 % from 200 K to 420 K at all pressures. The uncertainty increases outside of this temperature region and in the critical region. In the gaseous phase, speeds of sound can be calculated with an uncertainty of 0.05 %. In the liquid phase, the uncertainty in speed of sound increases to 0.1 %. The estimated uncertainty for liquid heat capacities is 5 %. The uncertainty in vapor pressure is 0.1 %.
International Journal of Thermophysics


equation of state, Helmholtz energy, R1234ze(E), thermodynamic properties


Thol, M. and Lemmon, E. (2016), Equation of State for the Thermodynamic Properties of trans-1,3,3,3-Tetrafluoropropene [R1234ze(E)], International Journal of Thermophysics, [online], (Accessed July 15, 2024)


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Created January 24, 2016, Updated October 12, 2021