| 1. |
Uthpara Perera, Kyaw Thu, Takahiko Miyazaki, Naoya Sakoda, Yukihiro Higashi, Saturation pressure measurements of the new refrigerant HFO1132(E), Proceedings of 2nd Conference on HFOs and Low GWP blends, 10.18462/iir.HFO.2021.1023, 12-19, 2021.06. |
| 2. |
Naoya Sakoda, Yukihiro Higashi, Thermodynamic properties measurements of HFO1132(E), Proceedings of 2nd IIR Conference on HFOs and Low GWP Blends, 10.18462/iir.HFO.2021.1024, 2021.06. |
| 3. |
Naoya Sakoda, Yukihiro Higashi, Ryo Akasaka, Measurements of PvT Properties, Vapor Pressures, Saturated Densities, and Critical Parameters for trans-1,1,1,4,4,4-Hexafluoro-2-nutene (R1336mzz(E)), Journal of Chemical Engineering Data, 10.1021/acs.jced.0c00848, 66, 734-739, 2021.03. |
| 4. |
Kyaw Thu, Kosei Takezato, Nobuo Takata Takahiko Miyazaki, Yukihiro Higashi, Drop-in experiments and energy assessment of HFC-32/HFO-1234yf/R744 mixture with GWP below 150 for domestic heat pumps, International Journal of Refrigeration, 10/1016/j.ijrefrig.2020.10.009, 121, 289-301, 2021.01. |
| 5. |
Kyaw Thu, Kosei Takezato, Nobuo Takata, Takahiko Miyazaki, Yukihiro Higashi, Performance evaluation of a heat pump system using an HFC32/HFO1234yf blend with GWP below 150 for heating applications, Applied Thermal Engineering, 10.1016/j.applthermaleng.2020.115952, 182, 2021.01. |
| 6. |
T. Yamada, H. Miyamoto, N. Sakoda, Y. Higashi, Vapor-Liquid Equilibrium Property Measurements for R32/R1234yf Binary Mixtures in Low R32 Concentration, International Journal of Thermophysics, 10.1007/s10765-020-02752-2, 41, 167, 1-12, 2020.10. |
| 7. |
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. |
| 8. |
Naoya Sakoda, Yukihiro Higashi, Ryo Akasaka, Measurements of Vapor Pressures for trans-1-Chloro-3,3,3-trifluoropropene (R1233zd(E)) and cis-1,1,1,4,4,4-Hexafluoro-2-butene (R1336mzz(Z)), Journal of Chemical and Engineering Data, 10.1021/acs.jced.0c00239, 65, 4285-4289, 2020.07, Vapor pressures for new low-GWP refrigerants of R1233zd(E) (trans-1-chloro-3,3,3-trifluoropropene) and R1336mzz(Z) (cis-1,1,1,4,4,4-hexafluoro-2-butene) were measured by the isochoric method. Twelve vapor-pressure measurements of R1233zd(E) were obtained at temperatures between 300 and 410 K, whereas 17 vapor-pressure measurements of R1336mzz(Z) were obtained at temperatures between 290 and 410 K. Temperature was measured with a 25 ω standard platinum resistance thermometer with an aid of ITS-90, and pressure was measured with a digital quartz pressure transducer. The experimental uncertainties in temperature and pressure are estimated to be within 5 mK and 1 kPa, respectively. The experimental data were compared with the previous experimental data and equations of state. New vapor-pressure correlations of R1233zd(E) and R1336mzz(Z) have been formulated on the basis of the data obtained.. |
| 9. |
Correlation Assessment and Temperature Dependence Check ofSurface Tension and Parachor for New Low-GWP Pure Refrigerants. |
| 10. |
Colombatantirige Uthpala Amoda Perera, Nobuo Takata, Takahiko Miyazaki, Yukihiro Higashi, Bidyut Baran Saha, Kyaw Thu, Exergy Investigation of R410A as a ‘Drop In’ Refrigerant in a Water-Cooled Mechanical Vapor Compression Cycle, Heat Transfer Engineering, 10.1080/01457632.2020.1776990, 42, 13, 1069-1086, 2021.06, The urge to replace hydrofluorocarbons which possess high global warming potentials has taken center stage in the air conditioning industry due to both international and local policies such as the Kigali Amendment and Japan’s revised Fluorinated Gas law. This has prompted the exploration of novel refrigerants as well as their mixtures to create high performance environmentally friendly alternatives. These refrigerants can be integrated into existing systems as ‘drop in’ refrigerants, which provide a simpler and low cost substitution process to replace environmentally harmful refrigerants such as R410a. R410a is currently a widely used refrigerant in air conditioning systems, but is to be phased out of use under the Kigali Amendment by the late 2040s. Thus to compare the suitability of replacing this refrigerant with environmentally friendly ‘drop in’ alternatives, a preliminary baseline investigation on a mechanical vapor compression chiller with R410a is conducted via performance and exergy indicators. The testing procedure utilized Air Conditioning, Heating and Refrigeration Standard 551/591 which revealed an optimum charge amount of 0.70 kg with a peak performance near 88% of full capacity. The heat exchanger overall heat transfer coefficients showed varying trends, whilst the exergy destruction was as expected highest for the compressor.. |
| 11. |
Kosei Takezato, Shou Senba, Takahiko Miyazaki, Nobuo Takata, Yukihiro Higashi, Kyaw Thu, Heat Pump Cycle Using Refrigerant Mixtures of HFC32 and HFO1234yf, Heat Transfer Engineering, 10.1080/01457632.2020.1776997, 42, 13, 1097-1106, 2021.06, Countermeasures for global warming have been promoted internationally. Heat pump cycles that utilize refrigerants with high global warming potential values are required to adopt the next generation refrigerants to conform to the revised Montreal Protocol. Refrigerants R410A is commonly used in the room air conditioners while it has been substituted with HFC32 in Japan; yet their global warming potential values are relatively high and are going to be phased down in the near future. On the other hand, refrigerant mixtures such as the blend of HFC32 and HFO1234yf with extremely low global warming potential can be considered as possible alternatives in compromising the flammability and the ecological tribulations. Targeting the global warming potential value of 150 or lower, the performance of HFC32/HFO1234yf (22/78 mass%) blend was evaluated using drop-in tests, and the results were compared with those of R410A and HFC32. Optimum charge amounts for these refrigerants were first evaluated, followed by the performance comparison in terms of the coefficient of performance from part- to full-load operations. The results showed that the current blend with the low global warming potential less than 150 is comparable to the targeted substitutes at part-load operations while within 83–87% of the COP using HFC32 was achievable at the full-load. The performance results from these experiments could serve as the basis for the refrigerant evaluation targeting the global warming potential 150.. |
| 12. |
Chieko Kondou, Yukihiro Higashi, Surface Tension Measurement for a New Low-GWP Refrigerant HFO-1123 by a Differential Capillary Rise Method, 日本冷凍空調学会論文集, 10.11322/tjsrae.18-31, 35, 4, 404-408, 2018.12, By a differential capillary rise method, the surface tension was measured for a new candidate of low GWP refrigerant HFO-1123. 16 points of surface tension data with a propagated uncertainty of approximately ±0.22 mN m-1 are presented in this paper. Based on the measured data, a Van der Waals type empirical correlation was proposed for HFO-1123:
σ = 61.02 (1-T/Tcrit)1.30 [mN m-1], where Tcrit is a critical temperature of 331.7 K measured by Higashi and Akasaka. This empirical correlation agrees with the measured surface tension data at temperatures from 267 K to 304 K.. |
| 13. |
C. Kondou, Y. Higashi, Surface tension measurement for a new low-GWP refrigerant HFO-1123 by a differential capillary rise method, Transactions of the Japan Society of Refrigerating and Air Conditioning Engineers, Vol.35, No.4, 403-408, 2018.12. |
| 14. |
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, 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.. |
| 15. |
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.. |
| 16. |
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, 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.. |
| 17. |
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.. |
| 18. |
Vapor-Liquid Equilibrium Measurements of Binary Refrigerant Mixtures Composed of R1123, R1234yf and R32. |
| 19. |
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, 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.. |
| 20. |
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.. |
| 21. |
N. Sakoda, Jieng Shiheng, M. Kohno, S. Koyama, Y. Higashi, Y. Takata, Vapor-liquid Equilibrium Measurements of HFO Refrigerant Mixtures, 5th IIR Conference of Thermophysical Properties and Transfer Processes of Refrigeration, Seoul, South Korea, 548-551, 2017.05. |
| 22. |
J. Steven Brown, Claudio Zilio, Ryo Akasaka, Yukihiro Higashi, Low-GWP refrigerants, Science and Technology for the Built Environment, 10.1080/23744731.2016.1230981, 22, 8, 1075-1076, 2016.11. |
| 23. |
Yukihiro Higashi, Measurements of thermodynamic properties for the 50 mass% R1234yf + 50 mass% R1234ze(E) blend, Science and Technology for the Built Environment, 10.1080/23744731.2016.1223975, 22, 8, 1185-1190, 2016.11, Copyright © 2016 ASHRAE. Measurements of pressure-density-temperature-composition properties, saturated densities, and critical parameters for the low-global warming potential refrigerant blend of the 50 mass% R1234yf (2,3,3,3-tetrafluoroprop-1-ene; CF3CF = CH2) + 50 mass% R1234ze(E) (trans-1,3,3,3-tetrafluoroprop-1-ene; CF3CH = CHF) were measured with two types of isochoric methods. As for the PρTx properties, 38 data along five isochores in one phase region were obtained by the isochoric method. This measurement was made in the range of temperatures from 340 to 430 K, of pressures from 1693 to 6774 kPa, and of densities from 100 to 900 kg·m−3. As for the saturated densities, nine saturated vapor densities and six saturated liquid densities were measured by the direct observation of meniscus disappearance. These experimental data were obtained in the temperature range from 354.62 to 374.28 K and densities between 219 and 870 kg·m−3. On the basis of the present data, the critical temperature Tc = 374.28 K, critical density ρc = 480 kg·m−3, and critical pressure Pc = 3524 kPa for the 50mass% R1234yf + 50mass% R1234ze(E) blend were determined. In addition the critical locus correlations corresponding the composition were proposed for the R1234yf + R1234ze(E) blend.. |
| 24. |
Measurements of Thermodynamic Properties for the Binary R 245fa + R 134a Mixture:- 2nd Report. |
| 25. |
Measurements of Thermodynamic Properties for the Binary R 245fa + R 134a Mixture:- 1st Report. |
| 26. |
Ryo Akasaka, Yukihiro Higashi, Yasufu Yamada, Takashi Shibanuma, Thermodynamic properties of 1,1,1,2-tetrafluoroethane (R-134a) + 2,3,3,3-tetrafluoropropene (R-1234yf) mixtures: Measurements of the critical parameters and a mixture model based on the multi-fluid approximation, International Journal of Refrigeration, 10.1016/j.ijrefrig.2015.06.011, 58, 146-153, 2015.10, © 2015 Elsevier Ltd and IIR. All rights reserved. Thermodynamic properties are discussed for 1,1,1,2-tetrafluoroethane (R-134a) + 2,3,3,3-tetrafluoropropene (R-1234yf) mixtures. The critical temperatures, densities, and pressures experimentally determined are first presented with their uncertainties. Subsequently a mixture model for calculations of thermodynamic properties is formulated using the multi-fluid approximation. Comparisons to experimental data show that the mixture model calculates the vapor-liquid equilibrium and densities of the mixtures with reasonable accuracies. The critical parameters are also well represented by the mixture model.. |
| 27. |
Hironori Suzuki, Yukihiro Higashi, Takuya Yasuno, Thermoelectric properties of layered FeSi2 thermoelectric conversion module produced by Spark Plasma Sintering Method, Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy, 10.2497/jjspm.62.457, 62, 9, 457-461, 2015.09, The 5 pair layered FeSi2 thermoelectric conversion module was manufactured by sintering five layers of p type and n type powder at the same time, using SPS (spark plasma sintering) method. This process is expected to have higher reliability and shorter manufacturing time compared with conventional process which is performed by joining machined p type and n type element with the electrode. Maximum power of 32.4 mW was provided by this module under the condition of heating temperature 773 K and cooling temperature 293 K. The changes of the module shape and sintering condition greatly changed the performance of this module. By the optimization of the sintering condition and the shape, the performance of this process can be expected to be higher. To obtain the high performance it is necessary to develop the module shape which has large temperature difference with low electric resistance and sintering condition which enable low thermal conductivity with high density.. |
| 28. |
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.. |
| 29. |
Chieko Kondou, Ryuichi Nagata, Noriko Nii, Shigeru Koyama, Yukihiro Higashi, Surface tension of low GWP refrigerants R1243zf, R1234ze(Z), and R1233zd(E), International Journal of Refrigeration, 10.1016/j.ijrefrig.2015.01.005, 53, 80-89, 2015.05, Abstract The surface tension of R1243zf, R1234ze(Z), and R1233zd(E) were measured at temperatures from 270 K to 360 K by an experimental apparatus based on the differential capillary rise method. The deviation between the measured surface tension of R134a and R245fa and the calculated surface tension with REFPROP 9.1 (Lemmon et al., 2013) was ±0.13 mN m-1, which is less than the estimated propagated uncertainty in surface tension of ±0.2 mN m-1. Eleven points, thirteen points, and ten points of surface tension data were provided for R1243zf, R1234ze(Z), and R1233zd(E), respectively, in this paper. The measured data and the estimated surface tension using the methods of Miller (1963), Miqueu et al. (2000), and Di Nicola et al. (2011) agree within the standard deviation of ±0.43 mN m-1. The empirical correlations that represent the measured data within ±0.14 mN m-1 were proposed for each refrigerant.. |
| 30. |
Chieko Kondou, Ryuichi Nagata, Noriko Nii, Shigeru Koyama, Yukihiro Higashi, Surface tension of low GWP refrigerants R1243zf, R1234ze(Z), and R1233zd(E), International Journal of Refrigeration, 10.1016/j.ijrefrig.2015.01.005, 53, 80-89, 2015.05, © 2015 Elsevier Ltd and IIR. All rights reserved. Abstract The surface tension of R1243zf, R1234ze(Z), and R1233zd(E) were measured at temperatures from 270 K to 360 K by an experimental apparatus based on the differential capillary rise method. The deviation between the measured surface tension of R134a and R245fa and the calculated surface tension with REFPROP 9.1 (Lemmon et al., 2013) was ±0.13 mN m-1, which is less than the estimated propagated uncertainty in surface tension of ±0.2 mN m-1. Eleven points, thirteen points, and ten points of surface tension data were provided for R1243zf, R1234ze(Z), and R1233zd(E), respectively, in this paper. The measured data and the estimated surface tension using the methods of Miller (1963), Miqueu et al. (2000), and Di Nicola et al. (2011) agree within the standard deviation of ±0.43 mN m-1. The empirical correlations that represent the measured data within ±0.14 mN m-1 were proposed for each refrigerant.. |
| 31. |
Thermoelectric Properties of layered FeSi2 Thermoelectric Conversion Module Produced by Spark Plasma Sintering Method. |
| 32. |
Thermoelectric Properties of FeSi2 Thermoelectric Conversion Modules Sintered with Ag Joint Plates by Spark Plasma Sintering Method. |
| 33. |
Ryo Akasaka, Yukihiro Higashi, Akio Miyara, Shigeru Koyama, A fundamental equation of state for cis-1,3,3,3-tetrafluoropropene (R-1234ze(Z)), International Journal of Refrigeration, 10.1016/j.ijrefrig.2013.12.018, 44, 168-176, 2014.08, A fundamental equation of state is presented for cis-1,3,3,3- tetrafluoropropene (R-1234ze(Z)). The equation of state is expressed explicitly in the Helmholtz energy with independent variables of temperature and density. The equation of state is based on experimental data for the critical parameters, vapor pressures, densities of the liquid and vapor phases, and sound speeds in the vapor phase. All thermodynamic properties can be derived as derivatives of the Helmholtz energy. The equation is valid for temperatures from 273 K to 430 K and for pressures up to 6 MPa. The estimated uncertainties of properties calculated from the equation are 0.15% in vapor pressures, 0.4% in vapor densities, 0.2% in liquid densities, and 0.05% in the vapor phase sound speeds. The equation exhibits reasonable extrapolation behavior in regions away from the experimental data. © 2014 Elsevier Ltd and IIR. All rights reserved.. |
| 34. |
Katsuyuki Tanaka, Yukihiro Higashi, Surface Tensions of trans-1,3,3,3-Tetrafluoropropene and trans-1,3,3,3-Tetrafluoropropene+Difluoromethane Mixture, Journal of Chemical Engineering of Japan, 46, 4, 371-375, 2013.07. |
| 35. |
Ryo Akasaka, Katsuyuki Tanaka, Yukihiro Higashi, Measurements of saturated densities and critical parameters for the binary mixture of 2,3,3,3-tetrafluoropropene (R-1234yf) + difluoromethane (R-32), International Journal of Refrigeration, 10.1016/j.ijrefrig.2013.02.005, 36, 4, 1341-1346, 2013.06, The vapor-liquid coexistence curves near the critical point of the binary mixture of 2,3,3,3-tetrafluoropropene (R-1234yf) + difluoromethane (R-32) were measured by means of the visual observation of meniscus disappearance. Eleven, eighteen, and eleven saturated densities were obtained for mixtures with 50.00 mass%, 80.01 mass%, and 90.00 mass% of R-1234yf, respectively. The critical temperatures, critical densities, and critical molar volumes of the mixtures were determined from the meniscus disappearing level and the intensity of the critical opalescence. The critical pressures of the mixtures were also determined from the analysis of pρTx measurements. The composition dependence of the critical parameters was formulated with simple correlations. © 2013 Elsevier Ltd and IIR. All rights reserved.. |
| 36. |
Katsuyuki Tanaka, Yukihiro Higashi, Surface tensions of trans-1,3,3,3-tetrafluoropropene and trans-1,3,3,3-tetrafluoropropene+difluoromethane mixture, JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 10.1252/jcej.13we021, 46, 6, 371-375, 2013.06, The surface tensions of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) alone and when mixed with difluoromethane (HFC-32) were measured using the differential capillary-rise method. Twenty-three data points for HFO-1234ze(E) were obtained in the temperature range 273-333 K. Twenty-six data points for the 50.00 mass% HFO-1234ze(E)+50.00 mass% HFC-32 mixture were obtained in the temperature range from 273-323 K. The experimental uncertainty of the surface tension was estimated to be 0.2 mN m-1 for pure HFO-1234ze(E) and 0.3 mN m-1 for the fluid mixture. Based on the obtained data, the surface tension correlations for HFO-1234ze(E) and the HFO-1234ze(E)+HFC-32 mixture were formulated. The correlations can represent the data with a standard deviation of 0.06 mN m-1 for HFO-1234ze(E) and 0.18 mN m_1 for the HFO-1234ze(E)+HFC-32 mixture.. |
| 37. |
3成分系R‐1234ze(E)+R‐32+CO2混合冷媒の熱力学性質の測定. |
| 38. |
Measurements of Density and Isobaric Specific Heat Capacity for HFO-1234ze(E)+HFC-32 Mixtures. |
| 39. |
A Review of Study on Thermodynamic Properties of Hydrofluoroolefin Refrigerants R 1234yf and R 1234ze(E). |
| 40. |
Measurements of Density and Isobaric Specific Heat Capacity for HFO-1234ze(E)+HFC-32 Mixtures. |
| 41. |
A Review of Study on Thermodynamic Properties of Hydrofluoroolefin Refrigerants R 1234yf and R 1234ze(E). |
| 42. |
Katsuyuki Tanaka, Yukihiro Higashi, P p T property measurements for trans -1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) in the gaseous phase, Journal of Chemical and Engineering Data, 10.1021/je100707s, 55, 11, 5164-5168, 2010.11, Measurements of the PpT properties for trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) in the gaseous phase were carried out using metal bellows volumometer. A total of 204 PpT property values was obtained in the range of temperatures from (310 to 360) K, pressures from (657 to 2300) kPa, and densities from (34 to 146) kg•m-3. The sample purity was better than 99.96 % in mole fraction. The present data were compared with the existing data and equations of state. The Benedict-Webb-Rubin-Starling (BWRS) and Martin-Hou equations of state were used to correlate the present data. © 2010 American Chemical Society.. |
| 43. |
Katsuyuki Tanaka, Yukihiro Higashi, Measurements of the isobaric specific heat capacity and density for dimethyl ether in the liquid state, Journal of Chemical and Engineering Data, 10.1021/je900922x, 55, 8, 2658-2661, 2010.08, The isobaric specific heat capacity and density for dimethyl ether were measured in the temperature range from (310 to 360) K at pressures up to 5 MPa in the liquid state. Measurements were conducted by the metal-bellows calorimeter. The uncertainties of isobaric specific heat capacity and density measurements were estimated to be less than 5 % and 0.2 %, respectively. Experimental values for the isobaric specific heat capacity and density were correlated as functions of pressure and temperature. In addition, the saturated liquid isobaric specific heat capacity and saturated liquid density were obtained from extrapolation of these correlations to the vapor pressure. © 2010 American Chemical Society.. |
| 44. |
Katsuyuki Tanaka, Gen Takahashi, Yukihiro Higashi, Measurements of the isobaric specific heat capacities for trans -1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) in the liquid phase, Journal of Chemical and Engineering Data, 10.1021/je900799e, 55, 6, 2267-2270, 2010.06, The isobaric specific heat capacity of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) in the liquid phase was measured using a metal-bellows calorimeter. Twenty-six data points were obtained in the temperature range from (310 to 370) K and pressure range from (2 to 5) MPa. The relative experimental uncertainty of the isobaric specific heat capacity was estimated to be 5 %. On the basis of the present data, the correlation of the isobaric specific heat capacity in the liquid phase was formulated as functions of temperature and pressure. The heat capacities of saturated liquid were derived from this correlation by substituting the vapor pressure. © 2010 American Chemical Society.. |
| 45. |
Katsuyuki Tanaka, Gen Takahashi, Yukihiro Higashi, Measurements of the vapor pressures and p ρ T properties for trans -1,3,3,3-tetrafluoropropene (HFO-1234ze(E)), Journal of Chemical and Engineering Data, 10.1021/je900756g, 55, 6, 2169-2172, 2010.06, The vapor pressures and pρT properties for trans-1,3,3,3- tetrafluoropropene (HFO-1234ze(E)) are measured using a metal-bellows cell. As for the vapor pressure, eight data points are obtained in the temperature range from (310 to 380) K and pressure range from (703 to 3458) kPa. The data of the vapor pressure is correlated by the Wagner type equation with the absolute average deviation of 0.02 %. By extrapolating the vapor-pressure correlation to the critical temperature, the critical pressure is determined to be 3632 kPa. The acentric factor is also determined to be 0.296 by using the vapor-pressure correlation. As for the pρT properties, 26 data points are obtained in the temperature range from (310 to 370) K and pressure range from (2000 to 5000) kPa. The data of the pρT properties are correlated by the Sato equation with the absolute average deviation of 0.04 %. Seven data points of the saturated liquid density are obtained by extrapolating the correlation of the pρT properties to the vapor pressure. © 2010 American Chemical Society.. |
| 46. |
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.. |
| 47. |
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.. |
| 48. |
Yukihiro Higashi, Katsuyuki Tanaka, Tomohide Ichikawa, Critical parameters and saturated densities in the critical region for trans -1,3,3,3-Tetrafluoropropene (HFO-1234ze(E)), Journal of Chemical and Engineering Data, 10.1021/je900696z, 55, 4, 1594-1597, 2010.04, Measurements of the saturated vapor and liquid densities near the critical point for trans-1,3,3,3-tetrafluoropropene (CFH=CHCF3; HFO-1234ze(E)) were carried out in the reduced temperature range of 0.962 |
| 49. |
Katsuyuki Tanaka, Yukihiro Higashi, Measurements of the isobaric specific heat capacity for 1,1,1-trifluoroethane (R143a), pentafluoroethane (R125), and difluoromethane (R32) in the liquid phase, Journal of Chemical and Engineering Data, 10.1021/je900661c, 55, 4, 1516-1518, 2010.04, Measurements of the isobaric specific heat capacity for the hydrocarbons 1,1,1-trifluoroethane (R143a), pentafluoroethane (R125), and difluoromethane (R32) were carried out in the liquid phase at a pressure of 5 MPa by using a batch type calorimeter equipped with a metal bellows. Ten data points of the isobaric specific heat capacity for R143a, 11 data points for R125, and seven data points for R32 were obtained in the temperature range from (310 to 350) K and at a pressure of 5 MPa. The experimental uncertainties are estimated to be 5 mK for temperature, 3 kPa for pressure, and 5.2 % for isobaric specific heat capacity. The present results were compared with the literature data and the values calculated from the equation of state. The correlations of the isobaric specific heat capacity were formulated as a function of temperature at a pressure of 5 MPa. Maximum deviations of the present results from correlations were 1.4 % for R143a, 1.5 % for R125, and 0.9 % for R32, respectively. © 2009 American Chemical Society.. |
| 50. |
Katsuyuki Tanaka, Yukihiro Higashi, Ryo Akasaka, Measurements of the isobaric specific heat capacity and density for HFO-1234yf in the liquid state, Journal of Chemical and Engineering Data, 10.1021/je900515a, 55, 2, 901-903, 2010.03, The isobaric specific heat capacity and density of the HFO-1234yf (2,3,3,3-tetrafluoropropene, CH2=CFCF3) in the liquid state have been measured in the temperature range from (310 to 360) K at pressures up to 5 MPa. The uncertainties in temperature, pressure, isobaric specific heat capacity, and density measurements were estimated to be less than 5 mK, 3 kPa, 5 %, and 0.2 %, respectively. A sample with purity of 99.99 mol % or greater was used for the measurement. Experimental values for the isobaric specific heat capacity were correlated as a function of pressure along isotherms, and those for density were correlated as functions of pressure and temperature. In addition, the saturated liquid isobaric specific heat capacity and density were obtained from extrapolation of these correlations to the vapor pressure.. |
| 51. |
Ryo Akasaka, Katsuyuki Tanaka, Yukihiro Higashi, Thermodynamic property modeling for 2,3,3,3-tetrafluoropropene (HFO-1234yf), International Journal of Refrigeration, 10.1016/j.ijrefrig.2009.09.004, 33, 1, 52-60, 2010.01, This paper presents a timely and reliable equation of state for 2,3,3,3-tetrafluoropropene (HFO-1234yf) whose thermodynamic property information is strongly desired. The Patel-Teja (PT) equation of state and the extended corresponding state (ECS) model have been individually applied to property modeling for this new refrigerant. Comparisons of predicted values with the equation/model were made with the most recent experimental data. Both the PT equation of state and the ECS model can represent the vapor pressures with an accuracy of 0.2%. However, the ECS model is much better than the PT equation of state in the predictions for the liquid density and isobaric heat capacity. The uncertainties of calculated values with the ECS model are 0.5% in liquid density and 2.5% in isobaric heat capacity. The use of the ECS model is recommended for a detailed assessment of HFO-1234yf. Thermodynamic property tables and diagrams generated using the ECS model are provided.. |
| 52. |
Ryo Akasaka, Katsuyuki Tanaka, Yukihiro Higashi, Thermodynamic property modeling for 2,3,3,3-tetrafluoropropene (HFO-1234yf), International Journal of Refrigeration, 10.1016/j.ijrefrig.2009.09.004, 33, 1, 52-60, 2010.01, This paper presents a timely and reliable equation of state for 2,3,3,3-tetrafluoropropene (HFO-1234yf) whose thermodynamic property information is strongly desired. The Patel-Teja (PT) equation of state and the extended corresponding state (ECS) model have been individually applied to property modeling for this new refrigerant. Comparisons of predicted values with the equation/model were made with the most recent experimental data. Both the PT equation of state and the ECS model can represent the vapor pressures with an accuracy of 0.2%. However, the ECS model is much better than the PT equation of state in the predictions for the liquid density and isobaric heat capacity. The uncertainties of calculated values with the ECS model are 0.5% in liquid density and 2.5% in isobaric heat capacity. The use of the ECS model is recommended for a detailed assessment of HFO-1234yf. Thermodynamic property tables and diagrams generated using the ECS model are provided. © 2009 Elsevier Ltd and IIR.. |
| 53. |
Katsuyuki Tanaka, Takuya Yasuno, Yukihiro Higashi, Shunichi Okuzaki, Tatsuo Katakura, Development of temperature-change sensor by thermoelectric elements and its response evaluation on dropping into water, Heat Transfer - Asian Research, 10.1002/htj.20268, 38, 8, 507-519, 2009.12, A temperature-change sensor by thermoelectric elements that is directly connected to a p-type element and an n-type element was developed. A β-FeSi2 thermo-electric semiconductor made by a spark plasma sintering method was used as a prototype sensor. Evaluation of this thermoelectric temperature-change sensor was carried out by measuring its electromotive force when it was dropped into a thermo-stated water bath. It was confirmed that there existed a correlation between the temperature difference and the electromotive force of the sensor, i.e., approximately 5 mV of electromotive force was generated at a temperature difference of 30 K. In addition, the dependence of electromotive force on the size and properties of the thermoelectric elements was evaluated by carrying out FEM analysis. © 2009 Wiley Periodicals, Inc.. |
| 54. |
K. Tanaka, T. Yasuno, Y. Higashi, S. Okuzaki, T. Katakura, Development of temperature-change sensor by thermoelectric elements and its response evaluation on dropping into water, Heat Transfer – Asian Research, Vol.38, No.8, 507-519, 2009.08. |
| 55. |
Katsuyuki Tanaka, Yukihiro Higashi, Measurements of the surface tension for the R290 + R32 mixture, Journal of Chemical and Engineering Data, 10.1021/je800756r, 54, 6, 1656-1659, 2009.06, There were no data of the surface tension for the R290 + R32 mixture which is expected as one of the new refrigerant mixtures, and its prediction is considered to be difficult because it is a mixture of a very polar molecule with a nonpolar molecule. In this work, the surface tension measurements for the R290 + R32 mixture were carried out by the differential capillary-rise method modified for measuring mixtures. Thirtyone, thirty-five, and thirty-three data points were obtained with changing the composition of the mixture at T = 280 K, 290 K, and 300 K, respectively. The experimental uncertainties of temperature and surface tension are estimated to be within 20 mK and 0.2 mN·m -1, respectively. The excess molar surface tension is also calculated by the present data, and its uncertainty was estimated to be 0.3 mN·m-1. The excess molar surface tension was correlated as a function of composition. The deviation of the present data from the present correlation was within the experimental uncertainty. © 2009 American Chemical Society.. |
| 56. |
Katsuyuki Tanaka, Yukihiro Higashi, Ryo Akasaka, Yohei Kayukawa, Kenich Fujii, Measurements of the vapor - Liquid equilibrium for the CO2 + R290 mixture, Journal of Chemical and Engineering Data, 10.1021/je800938s, 54, 3, 1029-1033, 2009.03, Vapor - liquid equilibrium (VLE) of the CO2 + R290 mixture has been measured by the recirculation method. Thirty-three data sets of VLE measurements were obtained in the temperature range between (260 and 290) K and in the pressure range between (408 and 4710) kPa. The experimental uncertainties of the temperature, pressure, and composition measurements are estimated to be within 3 mK, 3 kPa, and 0.11 %, respectively. The present data were compared with the calculation by the REFPROP and correlated well by two cubic equations of state, i.e., the Peng - Robinson equation and the Soave - Redlich - Kwong equation. © 2009 American Chemical Society.. |
| 57. |
K. Tanaka, Y. Higashi, Calorimeter for measuring the isobaric specific heat capacity of natural refrigerants, 8th IIR Gustav Lorentzen Conference on Natural Working Fluids, Copenhagen, CD-ROM
, 2008.05. |
| 58. |
Katsuyuki Tanaka, Yukihiro Higashi, Measurements of the surface tension for R290, R600a and R290/R600a mixture, International Journal of Refrigeration, 10.1016/j.ijrefrig.2007.04.002, 30, 8, 1368-1373, 2007.12, The surface tensions of R290, R600a and R290/R600a mixture have been measured by the modified differential capillary-rise method. Twenty-two data points for R290 and 21 data points for R600a were obtained in the temperature range between 273 K and 354 K, and 43 data points for R290/R600a mixture on three isotherms of 278 K, 300 K and 320 K were obtained. The experimental uncertainties of temperature and surface tension are estimated to be within 20 mK and 0.2 mN m-1, respectively. Surface tension correlations as a function of temperature for pure R290 and R600a were formulated in the temperature range between 253 K and critical temperature, and the correlation as a function of the composition for R290/R600a mixture was discussed at 278 K, 300 K and 320 K. It is found that the surface tension for R290/R600a mixture can be reproduced by the simple mixing rule by mole fraction with the correlations of both pure components. © 2007 Elsevier Ltd and IIR.. |
| 59. |
Ryo Akasaka, Yukihiro Higashi, Katsuyuki Tanaka, Yohei Kayukawa, Kenichi Fujii, Vapor-liquid equilibrium measurements and correlations for the binary mixture of difluoromethane + isobutane and the ternary mixture of propane + isobutane + difluoromethane, Fluid Phase Equilibria, 10.1016/j.fluid.2007.06.029, 261, 1-2, 286-291, 2007.12, Hydrocarbons such as propane (R-290), n-butane (R-600), and isobutane (R-600a) are expected candidates for CFC, HCFC, and HFC alternative working fluids for refrigerators and heat pump systems. Hydrocarbons (HCs) are environmentally acceptable refrigerants; however, most HCs have the problem of flammability. In order to maintain the safety of home refrigerators and air-conditioners, mixing a small amount of HFCs with HCs may be effective. In our previous study, the vapor-liquid equilibrium (VLE) measurements for the binary mixtures of R-290 + R-600a and the difluoromethane (R-32) + R-290 have already been performed. This study measured the VLEs of the binary mixture of R-32 + R-600a and the ternary mixture of R-290 + R-600a + R-32. Based on the experimental data, the VLEs for three binary mixtures were correlated by using the cubic equations of state with the conventional mixing rule, and the appropriate binary interaction parameters were determined for each binary mixture. For the R-290 + R-600a and R-32 + R-290 mixtures, the correlations were successful. For the R-32 + R-600a mixture, however, because of a relatively high nonideality, the accuracy of correlation was less than that for the other two mixtures. By applying the mixing rule based on the excess Gibbs free energy model, the accuracy was well improved. Moreover, by using the binary interaction parameters for each binary mixture the prediction of the VLE for the R-290 + R-600a + R-32 mixture was tested, and predicted bubble-point pressures were compared with the experimental values. The accuracy of this prediction was at similar level to the VLE correlation for the R-32 + R-600a mixture. © 2007 Elsevier B.V. All rights reserved.. |
| 60. |
K. Tanaka, Y. Higashi , Measurements of the surface tension for R290, R600a and R290/R600a mixture, International Journal of Refrigeration, Vol.30, No.8, 1368-1373, 2007.08. |
| 61. |
R. Akasaka, Y. Higashi, K. Tanaka, Y. Kayukawa, K. Fujii, Vapor-liquid equilibrium measurements and correlations for the binary mixture of difluoromethane+isobutane and the ternary mixture of propane+isobutane+difluoromethane, Fluid Phase Equilibria, Vol.261, 286-291, 2007.05. |
| 62. |
Katsuyuki Tanaka, Yukihiro Higashi, Surface tension of 1,1,1,2,2,3,3,4,4-nonafluorohexane and 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, kagaku kogaku ronbunshu, 10.1252/kakoronbunshu.33.1, 33, 1, 1-5, 2007.04, The surface tensions of 1,1,1,2,2,3,3,4,4-nonafluorohexane (CF 3CF2CF2CF2CH2CH 3) and 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoro-ethyl ether (CHF 2CF2OCH2CF3), which are potential alternatives to HCFC solvents, were measured by the differential capillary-rise method. 20 data points for 1,1,1,2,2,3,3,4,4-nonafluorohexane and 17 data points for 1,1,2,2-tetrafluoroethyl-2,2,2,-trifluoroethyl ether were obtained in the temperature range of 289-348 K. The experimental uncertainties of temperature and surface tension measurements were estimated to be within 20 mK and 0.14 mN·m-1, respectively. Surface tension correlations for 1,1,1,2,2,3,3,4,4-nonafluorohexane and 1,1,2,2-tetrafluoroethyl-2,2,2- trifluoroethyl ether were formulated and were found to reproduce the present data within the limits of experimental uncertainty.. |
| 63. |
K. Tanaka, Y. Higashi, Surface tension for 1,1,1,2,2,3,3,4,4-Nonafluorohexane and 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 化学工学論文集, Vol.33, No.1, 1-5, 2007.01. |
| 64. |
Y. Higashi, Critical parameters for 2-Methylpropane (R600a), Journal of Chemical and Engineering Data, Vol.51, No.2, 406-408, 2006.04. |
| 65. |
K. Tanaka, Y. Higashi, Measurements of the surface tension for the R290 + R600a mixtures, 3rd Asian Conference on Refrigeration and Air-Conditioning, 667-670, Gyeongju, Korea (2006), 2006.03. |
| 66. |
Yukihiro Higashi, Critical parameters for 2-methylpropane (R600a), Journal of Chemical and Engineering Data, 10.1021/je050328d, 51, 2, 406-408, 2006.03, Measurements of the vapor-liquid coexistence curve near the critical point for 2-methylpropane (isobutane; R600a) were carried out in the reduced temperature range of 0.957 |
| 67. |
Yukihiro Higashi, Surface tension measurements of fluids under high pressures, Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu, 15, 3, 218-223, 2005.10, In this paper, the simple and useful procedures of the surface tension measurement are reported. The principles and calculation methods as well as the experimental technique are also represented with respect to the typical methods, i.e., Wilhelmy method, ring method, capillary rise method, and so on. Especially, the differential capillary rise method, which is adopted by the author for the surface tension measurements under high pressures are explained in detail.. |
| 68. |
Y. Higashi, Composition dependence of the critical parameters for the binary mixtures of R32+R290, R32+R600a, and R290+R600a system, Thermophysical Properties and Transport Processes of Refrigerants, 153-159, Vicenza, Italy (2005), 2005.09. |
| 69. |
Yohei Kayukawa, Kenichi Fiyii, Yukihiro Higashi, Vapor-liquid equilibrium (VLB) properties for the binary systems propane (1) + re-butane (2) and propane (1) + isobutane (3), Journal of Chemical and Engineering Data, 10.1021/je0496701, 50, 2, 579-582, 2005.03, PTxy data (bubble-point and dew-point pressures at a specific composition) for two binary systems, propane (1) + n-butane (2) and propane (1) + isobutane (3), are presented in this paper. These binary systems are under consideration for use as a refrigerant for a Lorentz cycle. A recirculation method along with the aid of a new composition measurement system was employed. The experimental uncertainty is 3 mK for temperature, 0.027% + 1.04 kPa for pressure, and 0.11 mol % for composition. A total of 60 data points were obtained in the temperature range of (270 to 310) K for propane (1) + n-butane (2) and (260 to 320) K for propane (1) + isobutane (3). Comparisons of the present data with available mixture thermodynamic models and other experimental data are discussed in this paper. © 2005 American Chemical Society.. |
| 70. |
Y. Kayukawa, K. Fujii, Y. Higashi, Vapor-liquid equilibrium (VLE) properties for the binary systems propane (1) + n-butane (2) and propane (1) + isobutane (2), Journal of Chemical and Engineering Data, Vol.50, No.2, 579-582, 2005.02. |
| 71. |
Yukihiro Higashi, Experimental determination of the critical locus for the difluoromethane (R32) and propane (R290) system, Fluid Phase Equilibria, 10.1016/j.fluid.2004.02.004, 219, 1, 99-103, 2004.05, Vapor-liquid coexistence curves in the critical region for binary difluoromethane (R32) + propane (R290) mixtures have been measured by visual observation of the meniscus disappearance. Twelve and 15 data of saturated vapor and liquid densities for 70mass% R32 and 90mass% R32, respectively, have been obtained in the temperature range of 316K |
| 72. |
Vapor-Liquid Equilibrium Measurements of the Binary R32+R125 Refrigerant Mixture. |
| 73. |
S. Shimawaki, K. Fujii, Y. Higashi, Precise measurements of the vapor-liquid equilibria(VLE) of HFC-32/134a mixtures using a new apparatus, International Journal of Thermophysics, Vol.23, No.8, 801-808, 2002.08. |
| 74. |
S. Shimawaki, K. Fujii, Y. Higashi, Precise Measurements of the Vapor-Liquid Equilibria (VLE) of HFC-32/134a Mixtures Using a New Apparatus, International Journal of Thermophysics, 10.1023/A:1015407205188, 23, 3, 801-808, 2002.05, A new apparatus for precise measurements of the vapor-liquid equilibria of mixtures by the circulation method has been developed. This apparatus has two special components: a high-stability temperature control system and a helium pressurization system. The temperature in the liquid bath surrounding the sample cell is kept constant within ±0.5 mK. The helium pressurization system increases the pressure of the sampled mixture when measuring the compositions at low temperatures by gas chromatography. With these components, the uncertainty in measuring the vapor-liquid equilibria has been reduced. Using this apparatus, the vapor-liquid equilibria of HFC-32/134a mixtures were measured in a temperature range of 263.15 to 293.15 K. These results are in good agreement with the calculated results from REFPROP (Ver. 6.0.1) with a relative pressure difference of about 2%.. |
| 75. |
Current Information on the Properties of Hydrofluorocarbons(HFCs) and Other Pure Refrigerants. |
| 76. |
Y. Higashi, Vapor-liquid critical surface of the ternary difluoromethane + pentafluoroethane + 1,1,1,2-tetrafluoroethane (R32/125/134a) mixture, International Journal of Thermophysics, Vol.20, No.5, 1483-1495, 1999.09. |
| 77. |
Yukihiro Higashi, Vapor-liquid equilibrium, coexistence curve, and critical locus for pentafluoroethane + 1,1,1,2-tetrafluoroethane (R125/R134a), Journal of Chemical and Engineering Data, 10.1021/je980265h, 44, 2, 328-332, 1999.03, The vapor-liquid equilibrium for pentafluoroethane (R125) + 1,1,1,2-tetrafluoroethane (R134a) was measured along four isotherms between 283 K and 313 K. The vapor-liquid coexistence curve at constant composition near the mixture critical point was measured by the observation of the meniscus disappearance. The critical temperatures and critical densities of the 0.2670 and 0.6648 mole fraction of R125 were determined from the saturation densities along the coexistence curve in the critical region. In addition, the critical locus for the R125/R134a mixture is correlated as a function of composition.. |
| 78. |
Yukihiro Higashi, Vapor-liquid equilibrium, coexistence curve, and critical locus for pentafluoroethane + 1,1,1-trifluoroethane (R125/R143a), Journal of Chemical and Engineering Data, 10.1021/je980266+, 44, 2, 333-337, 1999.03, The vapor-liquid equilibrium for pentafluoroethane (R125) + 1,1,1-trifluoroethane (R143a) was measured by the static method in the temperature range between 273.15 K and 313.15 K. The vapor-liquid coexistence curve near the critical point was measured by observation of the meniscus disappearance. The critical temperatures and critical densities of the 0.4118 and 0.6208 mole fraction of R125 were determined from the saturation densities along the coexistence curve in the critical region. In addition, the critical locus for the R125/R143a mixture is correlated as a function of composition.. |
| 79. |
Y. Higashi, Vapor-liquid equilibria for the binary difluoromethane (R-32) + propane (R-290) mixture, International Journal of Thermophysics, Vol.20, No.2, 507-518, 1999.03. |
| 80. |
Y. Higashi, Vapor-liquid equilibrium, coexistence curve, and critical locus for pentafluoroethane + 1,1,1,2-tetrafluoroethane (R125/R134a), Journal of Chemical and Engineering Data, Vol.44, No.2, 328-332, 1999.02. |
| 81. |
Y. Higashi, Vapor-liquid equilibrium, coexistence curve, and critical locus for pentafluoroethane + 1,1,1-trifluoroethane (R125/R143a), Journal of Chemical and Engineering Data, Vol.44, No.2, 333-337, 1999.02. |
| 82. |
M. Okada, T. Shibata, Y. Sato, Y. Higashi, Surface tension of HFC refrigerant mixtures, International Journal of Thermophysics, 10.1023/A:1021482231102, 20, 1, 119-127, 1999.01, The surface tension of several refrigerant mixtures was measured and correlated. The measurements were conducted using the differential capillary rise method (DCRM) under conditions of coexistence of the sample liquid and its saturated vapor in equilibrium. The temperature range covered was from 273 to 323 K. The resulting data were represented by a mixing rule using mass friction based on the van der Waals correlation.. |
| 83. |
Y. Higashi, Vapor-liquid equilibria for the binary difluoromethane (R-32) + propane (R-290) mixture, International Journal of Thermophysics, 10.1023/A:1022653020420, 20, 2, 507-518, 1999.01, The vapor-liquid equilibrium of the mixture composed of difluoromethane (R-32) and propane (R-290) was studied in the temperature range between 273.15 and 313.15 K. The experimental uncertainties of temperature, pressure, and composition measurements were estimated to be within ± 10 mK, ± 3 kPa, and ± 0.4 mol%, respectively. Comparisons between the present data and available experimental data were made using the Helmholtz free energy mixture model (HMM) adopted in the thermophysical properties program package, REFPROP 6.0, as a baseline. In addition, the existence of an azeotrope and the determination of new adjustable parameters for HMM for the R-32 + R-290 mixture are discussed.. |
| 84. |
Y. Higashi, Vapor-liquid critical surface of ternary difluoromethane+pentafluoroethane+1,1,1,2-tetrafluoroethane (R-32/125/134a) mixtures, International Journal of Thermophysics, 10.1023/A:1021445222925, 20, 5, 1483-1495, 1999.01, The plane of vapor-liquid criticality for ternary refrigerant mixtures of difluoromethane (R-32)+pentafluoroethane (R-125)+1,1,1,2-tetrafluoroethane (R-134a) was determined from data on the vapor-liquid coexistence curve near the mixture critical points. The compositions (mass percentage) of the mixtures studied were 23% R-32+25% R-125+52% R-134a (R-407C), 25% R-32+15% R-125+60% R-134a (R-407E), and 20% R-32+40% R-125+40% R-134a (R-407A). The critical temperature of each mixture was determined by observation of the disappearance of the meniscus. The critical density of each mixture was determined on the basis of meniscus disappearance level and the intensity of the critical opalescence. The uncertainties of the temperature, density, and composition measurements are estimated as ±10 mK, ±5 kg·m-3, and ±0.05%, respectively. In addition, predictive methods for the critical parameters of R-32/125/134a mixtures are discussed.. |
| 85. |
Y. Higashi, Vapor-liquid equilibria for the binary difluoromethane (R-32) + propane (R-290) mixture, International Journal of Thermophysics, 10.1023/A:1022653020420, 20, 2, 507-518, 1999.01, The vapor-liquid equilibrium of the mixture composed of difluoromethane (R-32) and propane (R-290) was studied in the temperature range between 273.15 and 313.15 K. The experimental uncertainties of temperature, pressure, and composition measurements were estimated to be within ± 10 mK, ± 3 kPa, and ± 0.4 mol%, respectively. Comparisons between the present data and available experimental data were made using the Helmholtz free energy mixture model (HMM) adopted in the thermophysical properties program package, REFPROP 6.0, as a baseline. In addition, the existence of an azeotrope and the determination of new adjustable parameters for HMM for the R-32 + R-290 mixture are discussed.. |
| 86. |
Apparatus of the vapor-pressure measurements for natural refrigerants. |
| 87. |
Y. Higashi, Vapor-liquid equilibrium, coexistence curve and critical locus for Difluoromethane + Pentafluoroethane (R-32 + R-125), Journal of Chemical and Engineering Data, Vol.42, No.6, 1269-1273, 1997.11. |
| 88. |
Y. Higashi, T. Shibata, M. Okada, Surface tension for 1,1,1-trifluoroethane(R-143a), 1,1,1,2-tetrafluoroethane (R-134a), 1,1- dichloro-2,2,3,3,3-pentafluorpropane(R-225ca) and 1,3- dichloro- 1,2,2,3,3 – pentafluoropropane(R-225cb), Journal of Chemical and Engineering Data, Vol.42, No.3, 438-440, 1997.03. |
| 89. |
Yukihiro Higashi, Takahide Shibata, Masaaki Okada, Surface tension for 1,1,1-trifluoroethane (R-143a), 1,1,1,2-tetrafluoroethane (R-134a), 1,1-dichloro-2,2,3,3,3-pentafluoropropane (R-225ca), and 1,3-dichloro-1,2,2,3,3-pentafluoropropane (R-225cb), Journal of Chemical and Engineering Data, 10.1021/je960274v, 42, 3, 438-440, 1997.01, The surface tensions for 1,1,1-trifluoroethane (R-143a), 1,1,1,2-tetrafluoroethane (R-134a), 1,1-dichloro-2,2,3,3,3-pentafluoropropane (R-225ca), and 1,3-dichloro-1,2,2,3,3-pentafluoropropane (R-225cb) have been measured by the differential capillary rise method. The results were obtained in the temperature range between 273 K and 343 K. The experimental uncertainties of temperature and surface tension are estimated to be within ±20 mK and ±0.15 mN·m-1, respectively. A correlation for the surface tension as a function of temperature is presented.. |
| 90. |
Yukihiro Higashi, Vapor-liquid equilibrium, coexistence curve, and critical locus for difluoromethane + pentafluoroethane (R-32 + R-125), Journal of Chemical and Engineering Data, 10.1021/je9701083, 42, 6, 1269-1273, 1997.01, The vapor-liquid equilibrium for difluomethane + pentafluoroethane (R-32 + R-125) was measured by the static method in the temperature range between 283 K and 313 K. The vapor-liquid coexistence curve near the critical point was measured by the observation of the meniscus disappearance. The critical temperatures and critical densities of a 30 mass % R-32 and a 60 mass % R-32 mixture were determined on the basis of the saturation densities along the coexistence curve in the critical region. In addition, the critical locus for the R-32 + R-125 mixture is correlated as the function of composition.. |
| 91. |
Yukihiro Higashi, Takeaki Ikeda, Critical parameters for 1,1,1-trifluoroethane (R-143a), Fluid Phase Equilibria, 10.1016/s0378-3812(96)03089-0, 125, 1-2, 139-147, 1996.10, Measurements of the vapor-liquid coexistence curve near the critical point were carried out for 1,1,1-trifluoroethane (R-143a) in the reduced temperature range of 0.97 |
| 92. |
Y. Higashi, T. Ikeda, Critical parameters for 1,1,1-trifluoroethane (R-143a), Fluid Phase Equilibria, Vol.125, 139-147, 1996.07. |
| 93. |
Y. Higashi, Vapor-liquid equilibrium, coexistence curve and critical locus for Binary HFC-32/HFC-134a mixture, International Journal of Thermophysics, Vol.16, No.5, 1175-1184, 1995.09. |
| 94. |
Y. Higashi, Vapor-liquid equilibrium, coexistence curve, and critical locus for binary HFC-32/HFC-134a mixture, International Journal of Thermophysics, 10.1007/BF02081285, 16, 5, 1175-1184, 1995.09, Two kinds of equilibrium measurements of binary R-32/134a mixtures were carried out. The vapor-liquid equilibria were measured by the static method in the temperature range between 283 and 313 K. On the basis of the present experimental data, the temperature dependence of the binary interaction parameter k12 for two equations of state, namely, the Soave-Redlich-Kwong equation and Carnahan-Starling-De Santis equation, was discussed. The vapor-liquid coexistence curve near the critical point was also measured by the observation of meniscus disappearance. The critical temperatures and critical densities of 30 and 70 wt% R-32 mixtures were determined on the basis of the saturation densities along the coexistence curve in the critical region. In addition, a correlation of the critical locus for this mixture is proposed as a function of composition. © 1995 Plenum Publishing Corporation.. |
| 95. |
M. Okada, Y. Higashi, Experimental surface tension for HFC-32, HCFC-124, HFC-125, HCFC-141b and HFC-152a, International Journal of Thermophysics, Vol.16, No.3, 791-800, 1995.05. |
| 96. |
M. Okada, Y. Higashi, Experimental surface tensions for HFC-32, HCFC-124, HFC-125, HCFC-141b, HCFC-142b, and HFC-152a, International Journal of Thermophysics, 10.1007/BF01438864, 16, 3, 791-800, 1995.05, The surface tension of six alternative refrigerants, i.e., HFC-32 (CH, F, ). HCFC-124 (CHClFCF,), HFC-125 (CHF2CF3). HCFC-14lb ICH,CCI,F). HCFC-142b (CH3CCIF2), and HFC-152a (CH3CHF2), has been measured in the present study. The measurements were conducted under equilibrium conditions between the liquid and its saturated vapor. The differential capillary-rise method (DORM) used two glass capillaries, with inner radii of 0.3034 ± 0.0002 and 0.5717 ±0.0002 mm, respectively. Temperatures in the range from 270 to 340 K were considered. The accuracy of surface tension measurements is estimated to be within ±0.2 mN · m-1. The temperatures are accurate to within ±20 mK. The temperature dependence of the resultant data were successfully represented by van der Waals' correlations to within ±(1.1 mN m-1 for each substance. Available surface tension data are compared with the present data. © 1995 Plenum Publishing Corporation.. |
| 97. |
Y. Higashi, Critical parameters for HFC134a, HFC32 and HFC125, International Journal of Refrigeration, Vol.17, No.8, 524-531, 1994.08. |
| 98. |
Masaaki Okada, Yukihiro Higashi, Surface Tension Measurements of Fluids under High Pressure, The Review of High Pressure Science and Technology, 10.4131/jshpreview.3.324, 3, 4, 324-331, 1994.01, Surface tension measurements of fluids under high pressure is described here. A topic focused on is the fluorocarbon refrigerants and alternative refrigerants, since the authors have much experience for these fluids. The principle and the experimental apparatus of capillary rise method is briefly explained, since this method is widely utilized to measure the surface tension under high pressure. This article introduces the summary of the experimental results and correlations for surface tension of HCFCs and HFCs which are the candidate fluids for alternative refrigerants.. |
| 99. |
Y. Higashi, Critical parameters for HFC134a, HFC32 and HFC125, International Journal of Refrigeration, 10.1016/0140-7007(94)90028-0, 17, 8, 524-531, 1994, The vapour-liquid coexistence curves near the critical point for HFC134a (CF3CH2F: 1,1,1,2-tetrafluoroethane), HFC32 (CH2F2: difluoromethane) and HFC125 (CHF2CF3: pentafluoroethane) have been measured by visual observation of the meniscus disappearance. Three sets of 17 experimental results for the saturated liquid or vapour densities for HFC134a, HFC32 and HFC125 have been obtained in the reduced temperature range T/Tc > 0.96 and in the reduced density range 0.4 c -3 and ± 9 kPa, respectively.. |
| 100. |
T. Kamimura, A. Iso, Y. Higashi, M. Uematsu, K. Watanabe, Apparatus for measurements of PVT properties and their derivatives for fluids and fluid mixtures with a metal bellows as a variable-volume vessel, Review of Scientific Instruments, 10.1063/1.1141059, 60, 9, 3055-3061, 1989.12, A new apparatus for measurements of PVT properties and their derivatives with a metal bellows was designed for fluids and fluid mixtures of a fixed composition for pressures up to 20 MPa in the range of temperatures from room-temperature condition to 473 K. The apparatus, procedures, and results of calibrations are described. The capabilities of the apparatus are illustrated by means of the vapor-pressure measurements for chlorodifluoromethane and the PVT measurements of sulfur hexafluoride. Temperatures were set and kept constant at the values desired within ±3 mK and pressures within ±2 kPa. It was shown that density derivatives with respect to pressure at constant temperature and those with respect to temperature at constant pressure may both obtain from the experimental results.. |
| 101. |
T. Kamimura, A. Iso, Y. Higashi, M. Uematsu, K. Watanabe, Apparatus for measurements of PVT properties and their derivatives for fluids and fluid mixtures with a metal bellows as a variable-volume vessel, Review of Scientific Instruments, Vol.60, No.9, 3055-3061, 1989.09. |
| 102. |
Y. Higashi, Y. Kabata, M. Uematsu, K. Watanabe, Measurements of the Vapor-Liquid Coexistence Curve for the R 13B1 + R 114 System in the Critical Region, Journal of Chemical and Engineering Data, 10.1021/je00051a009, 33, 1, 23-26, 1988.09, Measurements of the vapor-liquid coexistence curve in the critical region for the refrigerant mixture of bromotrHIuoromethane (CBrF3, R 13B1) and 1,2-dlchloro-1,1,2,2-tetrafluoroethane (CCIF2CCIF2, R 114) were made by visual observation of the disappearance of the meniscus at the vapor-liquid Interface within an optical cell. Eighteen saturated-vapor densities and 21 saturated-liquid densities for four different compositions of 25, 50, 70, and 80 wt % R 13B1 between 345 and 406 K were obtained in the range of densities 356-1166 kg/m3. The experimental error of temperature, density, and mass fraction was estimated within ±15 mK, ±0.5%, and ±0.05%, respectively. On the basis of these measurements, the critical curve of the R 13B1 + R 114 system is determined and compared with several predictive methods. In addition, new correlation so as to represent the composition dependence of the critical parameters for the R 13B1 + R 114 system is proposed. © 1988, American Chemical Society. All rights reserved.. |
| 103. |
Y HIGASHI, M UEMATSU, K WATANABE, CORRELATION OF THE CRITICAL CURVE FOR BINARY REFRIGERANT MIXTURES, JSME INTERNATIONAL JOURNAL SERIES II-FLUIDS ENGINEERING HEAT TRANSFER POWER COMBUSTION THERMOPHYSICAL PROPERTIES, 10.1299/jsmeb1988.31.3_573, 31, 3, 573-580, 1988.08. |
| 104. |
M ASHIZAWA, Y HIGASHI, M UEMATSU, K WATANABE, A PROPOSAL FOR A GENERALIZED CORRELATION OF VAPOR-PRESSURES OF REFRIGERANTS, JSME INTERNATIONAL JOURNAL SERIES II-FLUIDS ENGINEERING HEAT TRANSFER POWER COMBUSTION THERMOPHYSICAL PROPERTIES, 31, 3, 565-572, 1988.08. |
| 105. |
Y. Higashi, Y. Kabata, M. Uematsu, K. Watanabe, Measurements of the vapor-liquid coexistence curve for the R13B1 + R114 system in the critical region, Journal of Chemical and Engineering Data, Vol.33, No.1, 23-26, 1988.01. |
| 106. |
Yukihiro Higashi, Masami Ashizawa, Masahiko Uematsu, Koichi Watanabe, A proposal for generalized correlation of vapor pressures of refrigerants, JSME International Journal, 31, 3, 565-572, 1988. |
| 107. |
Yukihiro Higashi, Masahiko Uematsu, Koichi Watanabe, Correlation of the critical curve for binary refrigerant mixtures, JSME International Journal, 31, 3, 573-580, 1988. |
| 108. |
MEASUREMENT OF VAPOR PRESSURE, VAPOR-LIQUID COEXISTENCE CURVE AND CRITICAL PARAMETERS OF REFRIGERANT 152a.
Forty-four vapor pressures of Refrigerant 152a (CH//3CHF//2: 1,1-difluoroethane) between 273 K and 386 K have been measured in the range of pressures from 0. 26 MPa to 4. 48 MPa. Ten saturated liquid densities and eleven saturated vapor densities near the critical point have also been measured in the range of temperatures from 370 K to the critical temperature which corresponds to a density variation of 153 kg multiplied by (times) m** minus **3 to 635 kg multiplied by (times) m** minus **3. The experimental uncertainties of temperature, pressure and density measurements have been estimated within 10 mK, 0. 8 kPa and 0. 55%, respectively. On the basis of these results, the critical temperature, critical pressure and critical density of R 152a have been determined to be 386. 44 K, 4. 519 8 MPa and 368 kg multiplied by (times) m** minus 3, respectively, in consideration of the meniscus disappearing level as well as the intensity of the critical opalescence.. |
| 109. |
Yukihiro Higashi, Masami Ashizawa, Yasuo Kabata, Toshiaki Majima, Masahiko Uematsu, Koichi Watanabe, MEASUREMENT OF VAPOR PRESSURE, VAPOR-LIQUID COEXISTENCE CURVE AND CRITICAL PARAMETERS OF REFRIGERANT 152a., JSME international journal, 10.1299/jsme1987.30.1106, 30, 265, 1106-1112, 1987.01, Forty-four vapor pressures of Refrigerant 152a (CH//3CHF//2: 1,1-difluoroethane) between 273 K and 386 K have been measured in the range of pressures from 0. 26 MPa to 4. 48 MPa. Ten saturated liquid densities and eleven saturated vapor densities near the critical point have also been measured in the range of temperatures from 370 K to the critical temperature which corresponds to a density variation of 153 kg multiplied by (times) m** minus **3 to 635 kg multiplied by (times) m** minus **3. The experimental uncertainties of temperature, pressure and density measurements have been estimated within 10 mK, 0. 8 kPa and 0. 55%, respectively. On the basis of these results, the critical temperature, critical pressure and critical density of R 152a have been determined to be 386. 44 K, 4. 519 8 MPa and 368 kg multiplied by (times) m** minus 3, respectively, in consideration of the meniscus disappearing level as well as the intensity of the critical opalescence.. |
| 110. |
Yukihiro Higashi, Masami Ashizawa, Yasuo Kabata, Toshiaki Majima, Masahiko Uematsu, Koichi Watanabe, Measurements of vapor pressure, vapor-liquid coexistence curve and critical parameters of refrigerant 152a, Transactions of the Japan Society of Mechanical Engineers Series B, 10.1299/kikaib.53.1379, 53, 488, 1379-1385, 1987.01, Forty-four vapor pressures of Refrigerant 152 a (CH3 CHF2 : 1, 1-difluoroethane) between 273 and 386 K were measured in the range of pressures from 0.26 to 4.48 MPa. Ten saturated liquid densities and eleven saturated vapor densities near the critical point were also measured in the range of temperatures from 370 K to the critical temperature which corresponds to a density variation of 153 to 635 kg·m-3. The experimental uncertainties of temperature, pressure and density measurements were estimated within ±10 mK, ±0.8 kPa and ±0. 55 %, respectively. On the basis of these results, the critical temperature, critical pressure and critical density of R 152 a were determined to be 386.44 K, 4.5198 MPa and 368 kg·m-3, respectively, in consideration of the meniscus disappearing level as well as the intensity of the critical opalescence. In addition, the correlation of vapor pressure and that of the vapor-liquid coexistence curve were also proposed.. |
| 111. |
Y. Higashi, M. Uematsu, K. Watanabe, Measurements of the vapor-liquid coexistence curve and the critical locus for several refrigerant mixtures, International Journal of Thermophysics, 10.1007/BF00503796, 7, 1, 29-40, 1986.01, Measurements of the vapor-liquid coexistence curve in the critical region for the systems of binary refrigerant mixture, i.e., Refrigerant 22 + Refrigerant 114 and Refrigerant 13B1 + Refrigerant 114, have been made by visual observation of the meniscus at the vapor-liquid interface within an optical cell. The experimental uncertainty of the temperature, density, and mass fraction is estimated within 15 mK, 0.5%, and 0.05%, respectively. The critical locus for these mixtures has been determined taking into consideration the disappearing meniscus level and the intensity of the critical opalescence. In accordance with the previous results of the Refrigerant 12 + Refrigerant 22 system, the coexistence curve for binary refrigerant mixtures is discussed. The composition dependence of the critical parameters for refrigerant mixtures is also discussed and compared with that of several predictive methods. © 1986 Plenum Publishing Corporation.. |
| 112. |
Y. Higashi, M. Uematsu, K. Watanabe, Measurements of the vapor-liquid coexistence curve and the critical locus for several refrigerant mixtures, International Journal of Thermophysics, 10.1007/BF00503796, 7, 1, 29-40, 1986.01, Measurements of the vapor-liquid coexistence curve in the critical region for the systems of binary refrigerant mixture, i.e., Refrigerant 22 + Refrigerant 114 and Refrigerant 13B1 + Refrigerant 114, have been made by visual observation of the meniscus at the vapor-liquid interface within an optical cell. The experimental uncertainty of the temperature, density, and mass fraction is estimated within 15 mK, 0.5%, and 0.05%, respectively. The critical locus for these mixtures has been determined taking into consideration the disappearing meniscus level and the intensity of the critical opalescence. In accordance with the previous results of the Refrigerant 12 + Refrigerant 22 system, the coexistence curve for binary refrigerant mixtures is discussed. The composition dependence of the critical parameters for refrigerant mixtures is also discussed and compared with that of several predictive methods.. |
| 113. |
Koichi Watanabe, Yukihiro Higashi, THERMOPHYSICAL PROPERTIES OF NONAZEOTROPIC REFRIGERANT BLENDS., Unknown Journal, 1986, This paper presents an overview of the thermophysical properties of nonazeotropic refrigerant blends (NARBs) which have been considered prospective especially for the advanced vapor-compression heat pump systems. After introducing some general backgrounds on the thermodynamic behaviors of NARBs, the current state of the art for the thermophysical properties research on NARBs is reviewed. The emphasis, however, is given not only to the systematic studies of thermodynamic properties of NARBs by the group of the present authors at Keio University, Yokohama, but also to the experimental results of non-equilibrium properties recently published in Japan. The paper concludes the importance of thermophysical properties research on refrigerant mixtures under the extended ranges of parameters so as to provide more accurate and concrete criteria to the selection of the optimum blend for various industrial applications.. |
| 114. |
Y. Higashi, M. Uematsu, K. Watanabe, Measurements of the vapor-liquid coexistence curve and determination of the critical parameters for Refrigerant R 114, Bulletin of the JSME, Vol.28, No.246, 2968-2973, 1985.11. |
| 115. |
Y. Higashi, M. Uematsu, K. Watanabe, Measurements of the vapor-liquid coexistence curve and determination of the critical parameters for Refrigerant R 13B1, Bulletin of the JSME, Vol.28, No.245, 2660-2666, 1985.09. |
| 116. |
Yukihiro Higashi, Masahiko Uematsu, Koichi Watanbe, MEASUREMENTS OF THE VAPOR-LIQUID COEXISTENCE CURVE AND DETERMINATION OF THE CRITICAL PARAMETERS FOR REFRIGERANT 114., Bulletin of the JSME, 10.1299/jsme1958.28.2968, 28, 246, 2968-2973, 1985.01, Measurements of the vapor-liquid coexistence curve in the critical region for Refrigerant 114 (C//2Cl//2F//4) were made by visual observation of the disppearance of a meniscus at the vapor-liquid interface within an optical cell. Twenty-three saturated densities between 410 K and the critical temperature were obtained in the density range 290 to 894 kg/m**3. The experimental uncertainties of temperature and density were estimated within plus or minus 15 mK and plus or minus 0. 5 %, respectively. On the basis of these results, the critical temperature ** TAU //c and the critical density ** rho //c for R 114 were determined to be 418. 78 K and 576 kg/m**3, respectively, in consideration of the disappearing meniscus level as well as the intensity of the critical opalescence.. |
| 117. |
Yukihiro Higashi, Masahiko Uematsu, Koichi Watanabe, MEASUREMENTS OF THE VAPOR-LIQUID COEXISTENCE CURVE AND DETERMINATION OF THE CRITICAL PARAMETERS FOR REFRIGERANT 13B1., Bulletin of the JSME, 10.1299/jsme1958.28.2660, 28, 245, 2660-2666, 1985.01, Measurements of the vapor-liquid coexistence curve in the critical region for Refrigerant 13B1 (CBrF//3) were made by visual observation of the disappearance of the meniscus at the vapor-liquid interface within an optical cell. Twenty-two saturated densities for temperatures between 332 and 340 K were obtained in the range of densities 376 to 1108 kg/m**3. Based upon the results along the coexistence curve, the critical temperature T//c, the critical density P//c and the critical pressure P//c for R 13B1 were determined to be 340. 08 K, 764 kg/m**3 and 3. 956 MPa, respectively, in consideration of the disappearing meniscus level as well as the intensity of the critical opalescence. In addition, the critical exponent beta was determined to be 0. 340 and the correlation of the vapor-liquid coexistence curve for R 13B1 was established.. |
| 118. |
Yukihiro Higashi, Masahiko Uematsu, Koichi Watanabe, Measurements of the Vapor-Liquid Coexistence Curve and Determination of the Critical Parameters for R 114, Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, 10.1299/kikaib.51.1327, 51, 464, 1327-1333, 1985.01, The measurements of the vapor-liquid coexistence curve in the critical region for R 114 (C2Cl2F4) were made by visual observation of the disappearance of the meniscus at the vapor-liquid interface within an optical cell. Twenty-three saturated densities between 410 K and critical temperature were obtained in the range of densities 290 to 894 kg/m3. The experimental errors of temperature and density were estimated within ±15mK and ±0.5%, respectively. On the basis of these results, the critical temperature Tc and the critical density ρc for R 114 were determined to be 418.78 K and 576 kg/m3, respectively, in consideration of the disappearing meniscus level as well as the intensity of the critical opalescence. The critical pressure Pc for R 114 was calculated to be 3.252 MPa by the available vapor-pressure correlation with the present value of Tc. In addition, the critical exponent β and the law of rectilinear diameter near the critical point were also discussed.. |
| 119. |
Y. Higashi, M. Uematsu, K. Watanabe, Determination of the vapor-liquid coexistence curve and the critical parameters for refrigerant 502, International Journal of Thermophysics, 10.1007/BF00505495, 5, 2, 117-129, 1984.06, The vapor-liquid coexistence curve for refrigerant 502 (R 502) near the critical point has been determined by visual observation of the disappearance of the meniscus. Twenty-six saturated densities between 262 and 899 kg· m-3 have been obtained within an experimental error in temperature and density of ± 10 mK and ± 0.5%, respectively. Using these results along the vapor-liquid coexistence curve, the critical parameters, i.e., the critical temperature Tc=355.37 ±0.01 K and the critical density ρc=555±3kg · m-3, have been determined based on the disappearance of the meniscus level as well as on the intensity of the critical opalescence. A critical pressure Pc=4.070±0.002 MPa has been calculated from the existing vapor-pressure correlation using the present Tcvalue. In addition, the critical exponent β along the coexistence curve and the law of rectilinear diameter near the critical point are discussed. © 1984 Plenum Publishing Corporation.. |
| 120. |
Y. Higashi, M. Uematsu, K. Watanabe, Determination of the vapor-liquid coexistence curve and the critical parameters for refrigerant 502, International Journal of Thermophysics, 10.1007/BF00505495, 5, 2, 117-129, 1984.06, The vapor-liquid coexistence curve for refrigerant 502 (R 502) near the critical point has been determined by visual observation of the disappearance of the meniscus. Twenty-six saturated densities between 262 and 899 kg· m-3 have been obtained within an experimental error in temperature and density of ± 10 mK and ± 0.5%, respectively. Using these results along the vapor-liquid coexistence curve, the critical parameters, i.e., the critical temperature Tc=355.37 ±0.01 K and the critical density ρc=555±3kg · m-3, have been determined based on the disappearance of the meniscus level as well as on the intensity of the critical opalescence. A critical pressure Pc=4.070±0.002 MPa has been calculated from the existing vapor-pressure correlation using the present Tcvalue. In addition, the critical exponent β along the coexistence curve and the law of rectilinear diameter near the critical point are discussed.. |
| 121. |
Yuklhlro Higashi, Shlro Okazaki, Yoshinori Takalshl, Masahlko Uematsu, Kolchl Watanabe, Measurements of the Vapor-Liquid Coexistence Curve for the Binary R12 + R22 System in the Critical Region, Journal of Chemical and Engineering Data, 10.1021/je00035a012, 29, 1, 31-36, 1984.04, Measurements of the vapor-liquid coexistence curve In the critical region for the binary dichlorodlfluoromethane (CCI2F2, R12) + chlorodlfluoromethane (CHCIF2, R22) system were made by visual observation of the disappearance of the meniscus at the vapor-liquid Interface within an optical cell. Fifty-one saturated-vapor densities and thirty-seven saturated-liquid densities for seven different compositions of 0, 10, 20, 30, 50, 75, and 100 wt % R22 between 355 and 385 K (T, > 0.98) were obtained In the range of densities 280-892 kg/m3 (0.5 |
| 122. |
Yuklhlro Higashi, Shlro Okazaki, Yoshinori Takalshl, Masahlko Uematsu, Kolchl Watanabe, Measurements of the Vapor-Liquid Coexistence Curve for the Binary R12 + R22 System in the Critical Region, Journal of Chemical and Engineering Data, 10.1021/je00035a012, 29, 1, 31-36, 1984.04, Measurements of the vapor-liquid coexistence curve In the critical region for the binary dichlorodlfluoromethane (CCI2F2, R12) + chlorodlfluoromethane (CHCIF2, R22) system were made by visual observation of the disappearance of the meniscus at the vapor-liquid Interface within an optical cell. Fifty-one saturated-vapor densities and thirty-seven saturated-liquid densities for seven different compositions of 0, 10, 20, 30, 50, 75, and 100 wt % R22 between 355 and 385 K (T, > 0.98) were obtained In the range of densities 280-892 kg/m3 (0.5 |
| 123. |
S. Okazaki, Yukihiro Higashi, Y. Takaishi, M. Uematsu, K. Watanabe, Procedures for determining the critical parameters of fluids, Review of Scientific Instruments, 10.1063/1.1137208, 54, 1, 21-25, 1983.12, An apparatus and procedures to determine the critical parameters and the vapor-liquid coexistence curve in the critical region by observing the disappearance of the vapor-liquid interface are described. The apparatus has the advantage of measuring the saturated vapor and liquid densities with only a single filling of the sample, and the procedures are applicable not only to pure fluids but also to mixtures. Three densities of liquid and eight of vapor on the coexistence curve for trifluoromethane are obtained, and the critical temperature, density, and pressure are also determined.. |
| 124. |
S. Okazaki, Y. Higashi, Y. Takaishi, M. Uematsu, K. Watanabe
, Procedures for determining the critical parameters of fluids, Review of Scientific Instruments, Vol.54, No.1, 21-25, 1983.01. |
