An Equation of State for Fluoroethane (R161)

Abstract

Fluoroethane (R161, C 2 H 5 F, 353-36-6) is a potential alternative refrigerant with excellent cycle performance, with zero ozone-depletion potential and low global warming potential. In this study, the thermodynamic property formulation for fluoroethane has been developed with the use of available experimental thermodynamic property data. In determining the equation of state, multiproperty fitting methods were used including single-phase pressure-density-temperature ( pρT ), vapor pressure, and saturated liquid-density data. The equation of state has been developed to conform to the Maxwell criterion for two-phase liquid-vapor equilibrium states, and is valid for temperatures from 130 K to 450 K, and pressures to 5 MPa. The extrapolation behavior of the equation of state at high temperatures and high pressures is reasonable. As there are very few compressed liquid-density experimental data published, the uncertainties in density of the equation of state are estimated to be 2.0 % in the compressed-liquid region and 0.5 % in the gas and supercritical regions. Uncertainties in vapor pressure are 0.5 % above 200 K and increase at lower temperatures. The uncertainties for all properties are higher in the critical region, except vapor pressure. Detailed comparisons between experimental and calculated data have been performed in this study.

Measurements of Gaseous Pressure-Volume-Temperature Properties for Ethyl Fluoride

“…The distributions of gaseous PVT experimental data of HFC-161 were also illustrated in Figure 2, note that the vapor pressure data of HFC-161 was given by Wu. 21 Compared with the experimental data proposed by Chen, 13 it can be observed that the present data covered a wider temperature and pressure range. Gaseous PVT properties at temperatures below 300 K were first reported in this work.…”

“…T r (= T/T c ) is the reduced temperature, where the critical temperature T c is 375.25 K for HFC-161. 21 The virial-type equation of state (EOS) for HFC-161 is available in the temperature range from 278 to 378 K and pressures from 135.08 to 4235.22 kPa. Figure 3 shows the deviation distribution of experimental and calculated pressure by eq 1 of HFC-161; the average absolute deviation of experimental data and eq 1 for pressure is 0.21%.…”

“…Figures 5 and 6 illustrate virial coefficients calculated from eq 1. a Units of B i −D i are m 3 kg −1 , (m 3 kg −1 ) 2 , and (m 3 kg −1 ) 3 , respectively. Saturated vapor densities of HFC161 were also acquired on the basis of the present experimental data and vapor pressures, 21 and their values are listed in Table 5. A temperature-dependent function was used to represent the saturated vapor densities.…”

“…where T r = T/T c , ρ = ρ/ρ c , and ρ c is the critical density (301.81 kg/m 3 ). 21 The parameters of eq 2 are listed in Table 6. Eq 2 can be used to represent the saturated vapor densities of HFC161 for temperatures from 283 to 368 K. This equation fits the saturated vapor densities well with an average absolute deviation of 0.28% and maximum absolute deviation of 0.69%.…”

Assessment of Low Global Warming Potential Refrigerants for Drop-In Replacement by Connecting their Molecular Features to Their Performance

“… Correlation for polar soft-SAFT predicted VCC values of refrigerants examined in this work and their experimental critical properties from the literature. 75 , 81 − 83 , 105 − 108 …”