Showing papers by "Eric W. Lemmon published in 2015"
TL;DR: In this paper, the density, speed of sound, and vapor pressure of trans-1-chloro-3, 3,3,3-trifluoropropene, also known as R1233zd(E), were measured over the temperature range from (215 to 444) K, with pressures from (0.3 to 24.1) MPa.
Abstract: We present experimental measurements of the density, speed of sound, and vapor pressure of trans-1-chloro-3,3,3-trifluoropropene, which is also known as R1233zd(E). Densities were measured over the temperature range from (215 to 444) K, with pressures from (0.3 to 24.1) MPa. Sound speed data were measured at temperatures between (290 and 420) K, with pressures from (0.07 to 2.1) MPa. Vapor pressures span the temperature range from (280 to 438) K. The experimental data cover the saturation curve, the vapor and liquid phases, and also the vicinity of the critical point. Densities and vapor pressures were measured in a two-sinker densimeter with a magnetic suspension coupling. Sound speed data were measured with a spherical acoustic resonator. An equation of state written in terms of the Helmholtz energy was developed; it represents the present experimental data with relative root-mean-square deviations of 0.020 % for densities, 0.223 % for vapor pressures, and 0.131 % for speeds of sound.
88 citations
TL;DR: For R-227ea and 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 % as discussed by the authors.
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...
47 citations
TL;DR: In this paper, the authors report comprehensive thermodynamic property measurements of 1,1,1.2,2,4,5, 5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone.
Abstract: We report comprehensive thermodynamic property measurements of 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone. The (p, ρ, T) behavior was measured from T = (225 to 470) K with pressures up to 36 MPa with a two-sinker densimeter. These measurements include compressed-liquid states and states in the extended critical region. The vapor-phase speed of sound was measured from T = (325 to 500) K with pressures up to 1.7 MPa with a spherical acoustic resonator. The vapor pressure was measured in the spherical resonator from T = (325 to 440) K with a static technique. The density and speed of sound of the liquid was measured from T = (278 to 308) K at atmospheric pressure (p = 83 kPa) in a benchtop instrument employing a vibrating-U-tube densimeter and a time-of-flight speed-of-sound technique. These data, together with selected data from the fluid manufacturer, have been used to develop an equation of state explicit in the Helmholtz energy covering the fluid region. The equation of state represents...
34 citations
Journal Article•
TL;DR: In this paper, a new fundamental equation of state explicit in the Helmholtz energy is presented for 1,1, 1,3,3-pentafluoropropane (R-245fa), based on recent experimental data for vapor pressures, densities, and sound speeds.
Abstract: A new fundamental equation of state explicit in the Helmholtz energy is presented for 1,1,1,3,3-pentafluoropropane (R-245fa), based on recent experimental data for vapor pressures, densities, and sound speeds The functional form uses Gaussian bell-shaped terms, according to recent trends in the development of accurate equations of state The independent variables of the equation of state are temperature and density The equation is valid for temperatures between the triple point (1700 K) and 440 K, and for pressures up to 200 MPa Estimated uncertainties in this range are 01% for vapor pressures, 01% for saturated liquid densities, 01% for liquid densities below 70 MPa, 02% for densities at higher pressures, 03% for vapor densities, 03% for liquid sound speeds, and 01% for vapor sound speeds The uncertainties in the critical region are higher for all properties except vapor pressures The equation shows reasonable extrapolation behavior at extremely low and high temperatures, and at high pressures
32 citations
TL;DR: In this article, a new fundamental equation of state explicit in the Helmholtz energy is presented for 1,1, 1,3,3-pentafluoropropane (R-245fa), based on recent experimental data for vapor pressures, densities, and sound speeds.
Abstract: A new fundamental equation of state explicit in the Helmholtz energy is presented for 1,1,1,3,3-pentafluoropropane (R-245fa), based on recent experimental data for vapor pressures, densities, and sound speeds. The functional form uses Gaussian bell-shaped terms, according to recent trends in the development of accurate equations of state. The independent variables of the equation of state are temperature and density. The equation is valid for temperatures between the triple point (170.0 K) and 440 K, and for pressures up to 200 MPa. Estimated uncertainties in this range are 0.1% for vapor pressures, 0.1% for saturated liquid densities, 0.1% for liquid densities below 70 MPa, 0.2% for densities at higher pressures, 0.3% for vapor densities, 0.3% for liquid sound speeds, and 0.1% for vapor sound speeds. The uncertainties in the critical region are higher for all properties except vapor pressures. The equation shows reasonable extrapolation behavior at extremely low and high temperatures, and at high pressures.
30 citations
TL;DR: In this article, the speed of sound in liquid cyclopentane has been measured in the temperature range from (258 to 353) K at pressures up to 30 MPa (42 data points) using a pulse-echo method with a double path type sensor.
Abstract: The speed of sound in liquid cyclopentane has been measured in the temperature range from (258 to 353) K at pressures up to 30 MPa (42 data points) using a pulse-echo method with a double path type sensor. The expanded overall uncertainty (k = 2) in the speed of sound measurements is estimated to be 0.2 %. A function for the speed of sound with inputs of temperature and pressure has been fitted to the experimental results. The new speed of sound data along with available literature data were used to develop a fundamental Helmholtz equation of state for cyclopentane. Typical expanded uncertainties of properties calculated using the new equations are 0.2 % in density in the liquid phase, 1 % in heat capacity, 0.2 % in liquid-phase sound speed, and 0.5 % in vapor pressure. The equation of state is valid from the triple-point temperature, 179.7 K, to temperatures of 550 K with pressures to 250 MPa.
28 citations
31 Dec 2015
3 citations