R513A
R513A (also known as Opteon XP10) is an azeotropic mixture consisting of 56 weight% R1234yf and 44% R134a. It has a molar mass of 108.4 kg/kmol. Although it is a mixture, R513A exhibits no temperature glide between saturated liquid and vapor and therefore can be modeled as a pseudo pure fluid in the manner described by
E. Lemmon
"Pseudo-Pure Fluid Equations of State for the Refrigerant Blends R-410A, R-404A,R-507A, and R-407C"
International Journal of Thermophysics, Vol. 24, No. 4, July 2003
The model provided by EES was generated by fitting mixture data from the REFPROP program to a fundamental equation of state for a pure fluid. The model is applicable for temperatures between 240 K and 420 K with pressures up to 20 MPa. The reference state is saturated liquid at 0 C for which specific enthalpy and entropy are 200 kJ/kg and 1.0 kJ/kg-K, respectively.
Transport properties were fitted to data provided by the manufacturer, available at https://www.chemours.com/Refrigerants/en_US/products/Opteon/Stationary_Refrigeration/products/Opteon_XP10.html.
The data provided by EES should be considered as approximate. Use of REFPROP property data (with the EES_REFPROP interface) is recommended for applications requiring high accuracy.