Measurements of the Thermal Conductivity of HFC-134a in the Supercritical Region

Abstract

Measurements of the thermal conductivity of HFC-134a made in a coaxial cylinder cell operating in steady state are reported. Measurements were performed along several quasi-isotherms at temperatures ranging from the critical temperature T c (∼374 K) to T c + 150 K and in a pressure range from (0.1 to 40) MPa. Parameters of a background equation were determined from experimental data to analyze the critical enhancement of the thermal conductivity as a function of temperature and density. An analysis of the various sources of errors leads to an estimated uncertainty of the thermal conductivity data of ( 3 %.

Entropy Scaling of Thermal Conductivity: Application to Refrigerants and Their Mixtures

“…In total, 38602 experimental ( T , p , and λ) values of the pure fluids and 7621 experimental ( T , p , λ, and x ) values of the mixtures were collected from the NIST ThermoData Engine (TDE) database version 10 as well as from other publications. − These experimental data were obtained from more than 300 sources for pure fluids and more than 30 sources for mixtures, whose detailed citations are provided in the Supporting Information. The number of literature sources for each pure fluid and each mixture is listed in Tables and , respectively.…”

An Additional Condition of Efficiency of the Supercritical Fluid Extraction Process

“…Previously, this notion was predominantly used in the sense of equilibrium concentration of a solute in a liquid organic solvent. Modern technologies use promising supercritical fluid (SCF) solvents and extractants (in the dense gas state) [1-3] with an anomalous increase in the compressibility and other properties [4][5][6] in the asymptotic vicinity of the critical point (against the background of virtually incompressible solvents in the liquid state). To study, refine, and expand the classical notions of solubility, a significant research space has been formed [7].…”