Thermal conductivity of a wide range of alternative refrigerants measured with an improved guarded hot-plate apparatus
- Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)
The thermal conductivity of the refrigerants R22, R123, R134a, R142b, R143a, and R152a has been determined as a function of temperature in the range from 300 to 460 K. Measurements were carried out at atmospheric pressure with an improved guarded hot-plate apparatus. The width of the instrument`s gas layer and the temperature difference across the metering section were varied to detect any stray heat transfer. Radiation correction factors were derived from IR absorption spectra. The uncertainty of the measurements is estimated to be 2% at a standard deviation of less than 0.1%. Our data sets are compared with corresponding hot wire results. In contrast to the generally preferred hot wire technique, with its possible electrical and chemical interactions between the wire and the polar refrigerant, there are no such difficulties using a guarded hot-plate apparatus. Our data sets may thus contribute to the discussions on discrepancies in thermal conductivity values from various authors using hot wire as one particular method.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 123376
- Report Number(s):
- CONF-940633-; ISSN 0195-928X; TRN: 95:024315
- Journal Information:
- International Journal of Thermophysics, Vol. 16, Issue 5; Conference: 12. symposium on thermophysical properties, Boulder, CO (United States), 19-24 Jun 1994; Other Information: PBD: Sep 1995
- Country of Publication:
- United States
- Language:
- English
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