Experimental data are presented for the boiling of Refrigerant-113 and of mixtures of Refrigerant-113 and an oil (Shell Clavus-68) from horizontal electrically heated tubes. Data were obtained for both a plain tube (25.4#xA0;mm outside diameter) and a tow-finned tube having 19 fins per inch with an outside diameter of 25.4#xA0;mm and a fin route diameter of 22.2#xA0;mm. The data for the pure refrigerant boiling from the plain tube were compared with a number of previous data sets and with published correlations. The pure-refrigerant boiling data for the finned tube showed that the effect of finning decreased considerably as the heat flux was increased and that the heat flux for a given temperature difference could actually be lower with the fin tube than the plain tube for large heat fluxes. The effects of oil was to decrease the heat transfer coefficient by an amount greater than expected on the basis of its mole fraction. The presence of the oil induced a complex variation of heat transfer coefficient around the surface of the tube.
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