The thermal conductivity of liquid 1,1,1,2-tetrafluoroethane (HFC 134a)

“…Data sets of the thermal conductivity of R-32 [4][5][6][7][8][9][10][11][12][13][14], R-125 [4,7,8,10,[12][13][14][15][16][17][18][19][20][21][22][23], R-134a [7,11,15,[24][25][26][27][28][29][30][31][32][33], and R-143a [13,14,30,34,35] considered in the present formulation are listed in Tables I to IV. Experimental data for R-32 are also shown in Fig.…”

Section: Available Experimental Datamentioning

confidence: 99%

Equations for the Thermal Conductivity of R-32, R-125, R-134a, and R-143a

2005

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At present hydrofluorocarbons (HFCs) such as R32, R-125, R-134a, and R-143a are widely used, and it is required to obtain accurate information of thermophysical properties, especially of the thermal conductivity of HFCs. In this paper new thermal conductivity equations for R-32, R-125, R134a, and R143a are proposed, applicable over a wide range of temperature and pressure including the critical region based on existing experimental data, and the reliability of the present equations is summarized. The problem that the thermal conductivity calculated from the thermal diffusivity in the critical region differs depending on the equation of state is also discussed.

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“…The second apparatus allowed studies at cryogenic temperatures, to measure liquefied gases, like argon and methane [6][7][8][9], and permitted measurements of a wide range of refrigerant liquids [10][11][12][13] that were environmentally acceptable. The need for accurate data on electrically conducting liquids justified the construction of the third apparatus, applied to the measurement of the thermal conductivity of water, and aqueous solutions of inorganic salts [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

A New Instrument for the Measurement of the Thermal Conductivity of Fluids

et al. 2006

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The transient hot-wire technique is at present the best technique for obtaining standard reference data for the thermal conductivity of fluids. It is an absolute technique, with a working equation and a complete set of corrections reflecting departures from the ideal model, where the principal variables are measured with a high degree of accuracy. It is possible to evaluate the uncertainty of the experimental thermal conductivity data obtained using the best metrological recommendations. The liquids proposed by IUPAC (toluene, benzene, and water) as primary standards were measured with this technique with an uncertainty of 1% or better (95% confidence level). Pure gases and gaseous mixtures were also extensively studied. It is the purpose of this paper to report on a new instrument, developed in Lisbon, for the measurement of the thermal conductivity of gases and liquids, covering temperature and pressure ranges that contain the near-critical region. The performance of the instrument for pressures up to 15 MPa was tested with gaseous argon, and measurements on dry air (Synthetic gas mixture, with molar composition certified by Linde AG, Wiesbaden, Germany, Ar -0.00920; O 2 -0.20966; N 2 -0.78114), from room temperature to 473 K and pressures up to 10 MPa are also reported. The estimated uncertainty is 1%.

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The thermal conductivity of liquid 1,1,1,2-tetrafluoroethane (HFC 134a)

Cited by 21 publications

References 7 publications

A multiparameter thermal conductivity equation for R134a with an optimized functional form

A multiparameter thermal conductivity equation for R134a with an optimized functional form

Equations for the Thermal Conductivity of R-32, R-125, R-134a, and R-143a

A New Instrument for the Measurement of the Thermal Conductivity of Fluids

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