TY - JOUR
T1 - Determination of Second Virial Coefficients and Virial Equations of R-32 (Difluoromethane) and R-125 (Pentafluoroethane) Based on Speed-of-Sound Measurements
AU - Hozumi, T.
AU - Ichikawa, T.
AU - Sato, H.
AU - Watanabe, K.
N1 - Funding Information:
We thank M. Harada, an undergraduate student, for valuable assistance. We are indebted to the Ministry of Education, Science and Culture, Japan, for partial financial support as a part of the Grant-in-Aid (No. 04402025). One of the authors (T.H.) is also grateful to the Research Fellowships of the Japan Society for the Promotion of Science for Young Scientists.
Publisher Copyright:
© 1999, Plenum Publishing Corporation.
PY - 1999/11
Y1 - 1999/11
N2 - The second virial coefficients, B, for difluoromethane (R-32, CH2F2) and pentafluoroethane (R-125, CF3CHF2) are derived from speed-of-sound data measured at temperatures from 273 to 343 K with an experimental uncertainty of ±0.0072%. Equations for the second virial coefficients were established, which are valid in the extensive temperature ranges from 200 to 400 K and from 240 to 440 K for R-32 and R-125, respectively. The equations were compared with theoretically derived second virial coefficient values by Yokozeki. A truncated virial equation of state was developed using the determined equation for the virial coefficients. The virial equation of state represents our speed-of-sound data and most of the vapor PρT data measured by deVries and Tillner-Roth within ±0.01 and ±0.1%, respectively.
AB - The second virial coefficients, B, for difluoromethane (R-32, CH2F2) and pentafluoroethane (R-125, CF3CHF2) are derived from speed-of-sound data measured at temperatures from 273 to 343 K with an experimental uncertainty of ±0.0072%. Equations for the second virial coefficients were established, which are valid in the extensive temperature ranges from 200 to 400 K and from 240 to 440 K for R-32 and R-125, respectively. The equations were compared with theoretically derived second virial coefficient values by Yokozeki. A truncated virial equation of state was developed using the determined equation for the virial coefficients. The virial equation of state represents our speed-of-sound data and most of the vapor PρT data measured by deVries and Tillner-Roth within ±0.01 and ±0.1%, respectively.
KW - R-125
KW - R-32
KW - alternative refrigerant
KW - equation of state
KW - hydrofluorocarbon
KW - second virial coefficient
KW - speed of sound
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U2 - 10.1023/A:1022601811779
DO - 10.1023/A:1022601811779
M3 - Article
AN - SCOPUS:0033224741
SN - 0195-928X
VL - 20
SP - 1677
EP - 1688
JO - International Journal of Thermophysics
JF - International Journal of Thermophysics
IS - 6
ER -