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

Abstract

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.

Authors:
Publication Date:
Research Org.:
Iwaki Meisei Univ., Chuodai (JP)
OSTI Identifier:
20020844
Resource Type:
Journal Article
Journal Name:
International Journal of Thermophysics
Additional Journal Information:
Journal Volume: 20; Journal Issue: 5; Other Information: PBD: Sep 1999; Journal ID: ISSN 0195-928X
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; MIXTURES; REFRIGERANTS; MATERIAL SUBSTITUTION; FLUORINATED ALIPHATIC HYDROCARBONS; THERMODYNAMIC PROPERTIES; DATA COVARIANCES; DENSITY

Citation Formats

Higashi, Y. Vapor-liquid critical surface of ternary difluoromethane + pentafluoroethane + 1,1,1,2-tetrafluoroethane (R-32/125/134a) mixtures. United States: N. p., 1999. Web. doi:10.1023/A:1021445222925.
Higashi, Y. Vapor-liquid critical surface of ternary difluoromethane + pentafluoroethane + 1,1,1,2-tetrafluoroethane (R-32/125/134a) mixtures. United States. doi:10.1023/A:1021445222925.
Higashi, Y. Wed . "Vapor-liquid critical surface of ternary difluoromethane + pentafluoroethane + 1,1,1,2-tetrafluoroethane (R-32/125/134a) mixtures". United States. doi:10.1023/A:1021445222925.
@article{osti_20020844,
title = {Vapor-liquid critical surface of ternary difluoromethane + pentafluoroethane + 1,1,1,2-tetrafluoroethane (R-32/125/134a) mixtures},
author = {Higashi, Y.},
abstractNote = {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.},
doi = {10.1023/A:1021445222925},
journal = {International Journal of Thermophysics},
issn = {0195-928X},
number = 5,
volume = 20,
place = {United States},
year = {1999},
month = {9}
}