||Ryo Akasaka, Yukihiro Higashi, Naoya Sakoda, Sho Fukuda, Eric W. Lemmon, Thermodynamic properties of trifluoroethene (R1123): (p, r, T) behavior and fundamental equation of state, International Journal of Refrigeration, 10.1016/j.ijrefrig.2020.07.011, 119, 457-467, 2020.07.
||Yukihiro Higashi, Naoya Sakoda, Measurements of PvT Properties, Saturated Densities, and Critical Parameters for 3,3,3-Trifluoropropene (HFO1243zf), Journal of Chemical and Engineering Data, 10.1021/acs.jced.8b00452, 63, 10, 3818-3822, 2018.10, © 2018 American Chemical Society. Measurements of PvT properties, saturated densities, and critical parameters were carried out for a low-GWP refrigerant: 3,3,3-trifluoropropene (HFO1243zf, CF3CH=CH2). Seventy-five PvT property data points along seven isochores around the critical point were obtained in the temperature range from 328 to 430 K, in the density range between 50 and 899 kg m-3, and at pressures up to 6.9 MPa by the isochoric method. Fourteen saturated densities were obtained by the observation of meniscus disappearance in the critical region. On the basis of these measurements, the critical parameters of Tc = 376.93 ± 0.01 K and ρc = 414 ± 3 kg m-3 were determined. The present results are compared to an available equation of state..
||Yukihiro Higashi, Naoya Sakoda, Md Amirul Islam, Yasuyuki Takata, Shigeru Koyama, Ryo Akasaka, Measurements of Saturation Pressures for Trifluoroethene (R1123) and 3,3,3-Trifluoropropene (R1243zf), Journal of Chemical and Engineering Data, 10.1021/acs.jced.7b00818, 63, 2, 417-421, 2018.02, © 2018 American Chemical Society. Saturation pressures for new low global warming potential refrigerants trifluoroethene (R1123, CF2= CHF) and 3,3,3-trifluoropropene (R1243zf, CF3CH=CH2) were measured by the isochoric method for temperatures between 278 and 377 K. Temperature was measured with a 25 standard platinum resistance thermometer on ITS-90. Pressure was measured with a digital quartz pressure transducer. The experimental uncertainties in temperature and pressure are estimated to be 5 mK and 1 kPa (k = 2), respectively. New saturation-pressure correlations for the refrigerants have been formulated based on the present saturation-pressure data. The critical pressures of R1123 and R1243zf were also determined..
||Naoya Sakoda, Jiang Shiheng, Masamichi Kohno, Shigeru Koyama, Yukihiro Higashi, Yasuyuki Takata, Gaseous PVT Property Measurements of cis-1,3,3,3-Tetrafluoropropene, Journal of Chemical and Engineering Data, 10.1021/acs.jced.7b00263, 62, 7, 2178-2182, 2017.07, © 2017 American Chemical Society. PVT properties in the vapor phase of cis-1,3,3,3-tetrafluoropropene (R1234ze(Z)) were measured by a multiple expansion method in the temperature range from 353 to 413 K and at pressures up to 2.7 MPa. Thirty data along four isotherms are obtained in the temperatures between 353 and 413 K. The vapor pressures at the temperatures were also measured by adding a sample of R1234ze(Z) to a sample cell at the vapor-liquid equilibrium conditions. The uncertainties in temperature and pressure measurements are estimated to be within 6 mK and 0.3 kPa, respectively. The expanded uncertainty in density measurement is estimated within no greater than 0.12% (k = 2). The obtained PVT properties and vapor pressures are compared with the existing equation of state..
||Yukihiro Higashi, Shugo Hayasaka, Chihiro Shirai, Ryo Akasaka, Measurements of PρT properties, vapor pressures, saturated densities, and critical parameters for R 1234ze(Z) and R 245fa, International Journal of Refrigeration, 10.1016/j.ijrefrig.2014.12.007, 52, 100-108, 2015.05, © 2014 Elsevier Ltd and IIR. All rights reserved. Abstract Pressure-density-temperature (PρT) properties, vapor pressures, and saturated liquid and vapor densities for refrigerants R 1234ze(Z) (cis-1,3,3,3-tetrafluoroprop-1-ene; CF3CHCHF) and R 245fa (1,1,1,3,3-pentafluoropropane; C3H3F5) were measured with two types of isochoric methods. Pressure was measured with a digital quartz pressure transducer. Temperature was measured with 25 Ω standard platinum resistance thermometer on the ITS-90 temperature scale. Density was calculated from the mass of sample and the inner volume of pressure vessel. By using the present vapor pressure data, new vapor pressure correlations for R 1234ze(Z) and R 245fa have been formulated. In addition, the critical temperature Tc, critical density ρc, and critical pressure Pcwere directly determined on the basis of direct observation of the meniscus disappearance..
||Katsuyuki Tanaka, Yukihiro Higashi, Thermodynamic properties of HFO-1234yf (2,3,3,3-tetrafluoropropene), International Journal of Refrigeration, 10.1016/j.ijrefrig.2009.10.003, 33, 3, 474-479, 2010.05, Measurements of the thermodynamic properties of HFO-1234yf were conducted. The critical temperature TC, critical density ρC, and critical pressure PC, were measured by the visual observation of the meniscus disappearance, and were determined to be 367.85 ± 0.01 K, 478 ± 3 kg/m3, and 3382 ± 3 kPa, respectively. Vapor pressures were measured by a batch-type calorimeter with a metal-bellows in the temperature range from 310 K to 360 K and correlated by the Wagner-type equation. Surface tensions were measured by the differential capillary-rise method in the temperature range from 273 K to 340 K and correlated by the van der-Waals type equation. The acentric factor was determined to be 0.280 with the vapor pressure correlation. Based on the critical parameters and acentric factor, saturated vapor and liquid densities were estimated by the Peng-Robinson equation and the Hankinson-Thomson equation, respectively. The heat of vaporization was also calculated from the Clausius-Clapeyron equation. © 2009 Elsevier Ltd and IIR..