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Acoustic determination of thermophysical properties and critical parameters for R404A and critical line of x CO2+(1− x) R404A
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Advisor(s)
Abstract(s)
The thermophysical properties and critical parameters for the alternative refrigerant R404A (52 wt % of 1,1,1-
trifluoroethane (R143a) + 44 wt % of pentafluoroethane (R125) + 4 wt % of 1,1,1,2-tetrafluoroethane (R134a))
were investigated using two different acoustic techniques. The critical behavior of the system xCO2 +
(1 - x)R404A was also investigated. Experimental data of speed of sound in liquid R404A from 258 K to
338 K and pressures up to 65 MPa were measured using a pulse-echo method. Derived thermodynamic properties
are calculated, combining our experimental data with density and isobaric heat capacity values published by
other authors. Measurements of the critical temperature Tc and pressure pc on (R404A) and mixtures of xCO2 +
(1 - x)R404A were performed using another simple ultrasonic time-delay technique. The binary critical line was
determined over the whole composition range showing that this system deviates only slightly from ideality since
the critical line is a continuous line. The Peng-Robinson equation of state with conventional mixing and combining
rules was used to correlate the binary experimental data.
Description
Keywords
R404A xCO2 + (1 - x)R404A Acoustic determination Thermophysical properties Critical parameters . Faculdade de Ciências Exatas e da Engenharia
Citation
Esperança, J. M., Pires, P. F., Guedes, H. J., Ribeiro, N., Costa, T., & Aguiar-Ricardo, A. (2006). Acoustic determination of thermophysical properties and critical parameters for R404A and critical line of x CO2+(1− x) R404A. Journal of Chemical & Engineering Data, 51(3), 1148-1155. https://doi.org/10.1021/je0600707
Publisher
American Chemical Society