Vapor-liquid critical surface of ternary difluoromethane + pentafluoroethane + 1,1,1,2-tetrafluoroethane (R-32/125/134a) mixtures

Journal Article · Wed Sep 01 04:00:00 EDT 1999 · International Journal of Thermophysics

DOI:https://doi.org/10.1023/A:1021445222925· OSTI ID:20020844

Higashi, Y

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 composition (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 {+-}10mK, {+-}5kg{center_dot}m{sup {minus}3}, and {+-}0.05%, respectively. In addition, predictive methods for the critical parameters of R-32/125/134a mixtures are discussed.

• Research Organization: Iwaki Meisei Univ., Chuodai (JP)
• OSTI ID: 20020844
• Journal Information: International Journal of Thermophysics, Journal Name: International Journal of Thermophysics Journal Issue: 5 Vol. 20; ISSN 0195-928X; ISSN IJTHDY
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
DATA COVARIANCES
DENSITY
FLUORINATED ALIPHATIC HYDROCARBONS
MATERIAL SUBSTITUTION
MIXTURES
REFRIGERANTS
THERMODYNAMIC PROPERTIES