Comparison of Experimental Measurements of Local Flow Boiling Heat Transfer Coefficients for R11 and R123.
Comparison of Experimental Measurements of Local Flow
Boiling Heat Transfer Coefficients for R11 and R123.
(6181 K)
Kedzierski, M. A.; Didion, D. A.
ASME/JSME Thermal Engineering Proceedings. Vol. 3.
1991, 243-250 pp, 1991.
Keywords:
refrigerants; heat transfer; ozone; trichloroethylene;
dichlorotrifluoroethane; flow boiling heat transfer;
tests; thermodynamics
Abstract:
This paper presents a comparison of the measured
horizontal, smooth-tube, flow boiling heat transfer
coefficient of R11 to that of its proposed ozone safe
replacement R123. The fluid properties of R11 and R123
are similar. The flow boiling data for the two fluids
are similar for the convective region. However, the
heat transfer coefficient for R11 in the nucleate flow
boiling region was consistently observed to be, on
average, 8.5% to 33% larger than that for R123. The
influence of Reynolds number and heat flux on the heat
transfer-thermodynamic quality relationship is also
presented. Predictions of the heat transfer coefficient
with two open literature flow boiling correlations were
compared to the measured data. The heat transfer
coefficients predicted with the correlations were, on
average, from 13% to 57% greater than the measured heat
transfer coefficients. Not until recently has there
been sufficient thermodynamic or transport data for R123
to perform an accurate heat transfer analysis for that
fluid. Great care was taken to ensure that the most
carefully measured property data were used for this
analysis. For the convenience of the reader, both the
R123 and R11 property data used in this study are
presented.
