Improved equation of state for R-134a

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

Research output: Chapter in Book/Report/Conference proceedingConference contribution

13 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
Title of host publicationASHRAE Transactions
Number of pages9
Publication statusPublished - 1994
Externally publishedYes
EventProceedings of the ASHRAE Winter Meeting - New Orleans, LA, USA
Duration: 1994 Jan 231994 Jan 26


OtherProceedings of the ASHRAE Winter Meeting
CityNew Orleans, LA, USA


ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

Cite this

Piao, C. C., Noguchi, M., Sato, H., & Watanabe, K. (1994). Improved equation of state for R-134a. In ASHRAE Transactions (1 ed., Vol. 100, pp. 358-366). ASHRAE.