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Isochoric Heat Capacity Measurements for Binary Refrigerant Mixtures Containing Difluoromethane (R32), Pentafluoroethane (R125), 1,1,1,2-Tetrafluoroethane (R134a), and Trifluoroethane (R143a) From 200 to 345 K at Pressures ato 35 Mpa

Published

Author(s)

Joe W. Magee

Abstract

Molar heat capacities at constant volume Cv were measured for binary refrigerant mixtures with an adiabatic colorimeter with gravimetric determinations of the amount of substance. Temperatures ranged from 200 to 345 K, while pressures extended up to 35 Mpa. Measurements were conducted on liquid samples with equimolar compositions for the following binary systems: R32/R134a, R32/R125, R125/R134a, and R125/R143a. The uncertainty is 0.002 K for the temperature rise and is 0.2% for the change-of-volume work, which is the principal source of uncertainty. The expanded relative uncertainty (with a coverage factor k=2 and thus a two-standard deviation estimate) for Cv is estimated to be 0.7%.
Citation
International Journal of Thermophysics
Volume
21
Issue
No. 1

Keywords

1, 1, 1, 2-tetrafluoroethane, binary mixtures, difluoromethane, heat capacity, pentafluoroethane, R125, R134a, R143a, R32

Citation

Magee, J. (1999), Isochoric Heat Capacity Measurements for Binary Refrigerant Mixtures Containing Difluoromethane (R32), Pentafluoroethane (R125), 1,1,1,2-Tetrafluoroethane (R134a), and Trifluoroethane (R143a) From 200 to 345 K at Pressures ato 35 Mpa, International Journal of Thermophysics (Accessed July 17, 2024)

Issues

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Created June 1, 1999, Updated February 17, 2017