Thermodynamic Properties of R-227ea, R-365mfc, R-115, and R-13I1

Abstract

Equations of state are presented for the refrigerants 1,1,1,2,3,3,3-heptafluoropropane (R-227ea) and 1,1,1,3,3-pentafluorobutane (R-365mfc). For R-227ea, the uncertainties in densities are 0.05 % in the liquid region up to 360 K, 0.3 % in the vapor phase, and 0.5 % in the supercritical region. For vapor pressures, the uncertainties are 0.1 % above 270 K and 0.4 % between 240 K and 270 K (with the higher value at the lower temperature). The uncertainty in heat capacities is 1 % (with increasing uncertainties in the critical region and at high temperatures). For sound speeds, the uncertainties are 0.05 % in the vapor phase up to pressures of 0.5 MPa and 0.03 % in the liquid phase between 280 K and 420 K. For R-365mfc, the uncertainties in densities of the equation of state range from 0.1 % in the liquid to 1 % near the critical point, and the uncertainty in the speeds of sound is 0.05 %. The uncertainty in heat capacities is 2 %, and the uncertainty in vapor pressures is 0.25 % at temperatures between 280 K and 360 K. In the critical region, the uncertainties are higher for all properties. Equations of state for trifluoroiodomethane (R-13I1) and chloropentafluoroethane (R-115) are also given in an appendix for applications where systems using these banned substances are being upgraded or replaced with modern refrigerants, and properties of the old working fluids are needed in the design of the new system.

Models for viscosity, thermal conductivity, and surface tension of selected pure fluids as implemented in REFPROP v10.0

“…Lemmon & Span, 2015) was used to provide the density and the critical parameters. Lennard-Jones parameters were estimated with the method of Chung et al (Chung et al, 1988), with parameters as given in Table 1.…”

“…The data were converted from kinematic to dynamic viscosity using densities from the equation of state of Lemmon and Span (E.W. Lemmon & Span, 2015). The estimated uncertainty in the gas phase is 10 %, and 2 % for the saturated liquid from 253 K to 373 K, higher elsewhere.…”

Candidates to replace R-12 as a radiator gas in Cherenkov detectors

“…Therefore, any compound with vapor pressure similar to or greater than that of R-12 should be sufficiently volatile. Table 1 shows the vapor pressures computed from the best available component-specific EOS [11,13–17] for compounds considered in this work.…”

PROperties of FIre Suppressant SYstems “PROFISSY” A Spreadsheet Application for Fire-Suppressant Bottle-Filling Calculations

“…This is not sustainable for the future. NIST now has a thermophysical properties database known as REFPROP [13] with state-of-the art models for equations of state for pure fluid properties [14,15] and Helmholtz-based models for mixtures including the standards for the properties of natural gas mixtures [16]. A historical summary of the evolution of fluids used for refrigeration and the REFPROP program can be found in the review article by McLinden and Huber [17].…”