RP-221 -- Heat Transfer and Pressure Drop in Condensing and Evaporating Multicomponent Flow PDF

The objectives of this study are
(a) To perform experimental measurements of local convective heat transfer coefficient in horizontal tube flow during condensation and evaporation of Freon refrigerant R-12, in the presence of small amounts of a miscible oil.
(b) To perform experimental measurements of pressure drop under the same conditions.
(c) To develop correlations to predict heat transfer and pressure, and to compare these correlations to the experimental data.
(d) To develop flow maps to predict the flow pattern behavior in the presence of oil contamination.
(e) To improve understanding of the behavior of two-component two-phase flow, specifically the effect of a second non-volatile liquid component on a condensing or evaporating fluid.

The refrigerant R-12 was selected because it is completely miscible in oil. The more common R-22 is only partially miscible and this would add an additional complication to an already difficult problem. Constant wall temperature condltions are simulated as nearly as possible by the double pipe heat exchanger configuration. The fluid in the annulus is water. Local measurements of heat transfer are reported over a wide range of flow patterns.