Improved equation of state for R-134a

C. C. Piao, M. Noguchi, H. Sato, K. Watanabe

Research output: Contribution to journalConference articlepeer-review

12 Citations (Scopus)


An 18-coefficient, modified Benedict-Webb-Rubin equation of state for R-134a (1,1,1,2-tetrafluoroethane) has been developed. New correlations of vapor pressure and saturated liquid density are also presented. The temperature scale in this paper is given in the new International Temperature Scale of 1990 (ITS-90). This equation of state has been developed based on the experimental data of PVT properties, saturation properties, and isochoric heat capacities by using a least-squares fitting. The experimental data of isobaric heat capacities, speed of sound, and second virial coefficients were also taken into consideration as secondary data. This equation of state is effective both in the super-heated gaseous phase and the compressed liquid phase at pressures up to 70 MPa, densities to 1,600 kg/m3, and temperatures from 180 K to 500 K.

Original languageEnglish
Pages (from-to)358-366
Number of pages9
JournalASHRAE Transactions
Issue number1
Publication statusPublished - 1994 Dec 1
EventProceedings of the ASHRAE Winter Meeting - New Orleans, LA, USA
Duration: 1994 Jan 231994 Jan 26

ASJC Scopus subject areas

  • Building and Construction
  • Mechanical Engineering


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