New Helmholtz Equation of State for HFO-1234ze(E) with Comprehensive Assessment

Two issues of energy and environment cannot be separated in energy utilization systems. Using the working fluids in the thermal systems has to be highly attained due to these fluids may affect to the energy efficiency, global warming, and ozone depletion. Trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) was developed to address the issue. This fluid can replace the use of R-134a which is available in commercial market. Reliable thermodynamic equation of state (EOS) for HFO-1234ze(E) plays important role on optimization and design of refrigeration and thermal power systems. Helmholtz EOS is used as base of mathematical model because it is able to easily derive all thermodynamic properties and reliable to represent for a wide range of fluid phase. A new EOS was developed with a genetic algorithm combined with regression. The EOS represents thermodynamic properties of HFO-1234ze(E) with average absolute deviation (AAD) of 0.043% for the ideal gas isobaric specific heat, 0.084% for the liquid density, 0.39% for the vapor density, 0.096% for the vapor pressure, 0.11% and 1.0% for the saturated liquid and vapor densities. The caloric properties can be represented within AAD of 13%, 1.5%, and 5.4% for the isochoric, isobaric, and saturated specific heats, respectively, and the ADD of the speed of sound is 0.12% for liquid phase and 0.063% for vapor phase. The EOS also has proper behavior of the second and third virial coefficients and has proper extrapolation trend for the caloric and PVT properties. The EOS can be applied for temperature up to 600 K and pressure up to 100 MPa. (C) 2020 Elsevier B.V. All rights reserved.