Mixture Models for Refrigerants R-1234yf/134a, R-1234yf/1234ze(E), and R-134a/1234ze(E) and Interim Models for R-125/1234yf, R-1234ze(E)/227ea, and R-1234yf/152a

In this work, new thermodynamic models for refrigerant mixtures are provided for the binary pairs R-1234yf/134a, R-1234yf/1234ze(E), and R-134a/1234ze(E) based on new reference measurements of speed of sound, density, and bubble-point pressures. Fitting the very accurate liquid-phase speed of sound and density data reproduces the bubble-point pressures to within close to their uncertainty, yielding deviations in density less than 0.1% and speed of sound deviations less than 1% (and less than 0.1% for R-1234yf/134a). Models are also presented for the binary pairs R-125/1234yf, R-1234ze(E)/227ea, and R-1234yf/152a based solely on bubble-point measurements. (c) 2022 by the U.S. Secretary of Commerce on behalf of the United States.