### Abstract

The second virial coefficients, B, for difluoromethane (R-32, CH_{2}F_{2}) and pentafluoroethane (R-125, CF_{3}CHF_{2}) 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.

Original language | English |
---|---|

Pages (from-to) | 1677-1688 |

Number of pages | 12 |

Journal | International Journal of Thermophysics |

Volume | 20 |

Issue number | 6 |

DOIs | |

Publication status | Published - 2014 |

### Fingerprint

### Keywords

- alternative refrigerant
- equation of state
- hydrofluorocarbon
- R-125
- R-32
- second virial coefficient
- speed of sound

### ASJC Scopus subject areas

- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Mechanics of Materials
- Computational Mechanics
- Fluid Flow and Transfer Processes
- Physics and Astronomy (miscellaneous)

### Cite this

*International Journal of Thermophysics*,

*20*(6), 1677-1688. https://doi.org/10.1023/A:1022601811779

**Determination of Second Virial Coefficients and Virial Equations of R-32 (Difluoromethane) and R-125 (Pentafluoroethane) Based on Speed-of-Sound Measurements.** / Hozumi, T.; Ichikawa, T.; Sato, H.; Watanabe, K.

Research output: Contribution to journal › Article

*International Journal of Thermophysics*, vol. 20, no. 6, pp. 1677-1688. https://doi.org/10.1023/A:1022601811779

}

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.

PY - 2014

Y1 - 2014

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 - alternative refrigerant

KW - equation of state

KW - hydrofluorocarbon

KW - R-125

KW - R-32

KW - second virial coefficient

KW - speed of sound

UR - http://www.scopus.com/inward/record.url?scp=0033224741&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033224741&partnerID=8YFLogxK

U2 - 10.1023/A:1022601811779

DO - 10.1023/A:1022601811779

M3 - Article

AN - SCOPUS:0033224741

VL - 20

SP - 1677

EP - 1688

JO - International Journal of Thermophysics

JF - International Journal of Thermophysics

SN - 0195-928X

IS - 6

ER -