LO-2279 (RP 63) -- Flow Regimes in Horizontal Two-Phase Flow with Condensation

The flow pattern or distribution of liquid and vapor in a condenser tube depends on several parameters such as flow rate, quality, fluid properties, tube inclination, and heat transfer. Conversely, performance characteristics such as heat transfer and pressure drop depend on the type of flow pattern. A knowledge of the flow patterns in condensing two-phase flow is necessary to select appropriate heat transfer correlations or construct accurate models. The purpose of this investigation was to determine the two-phase flow regimes for the case of refrigerant condensation inside horizontal tubes.

The applicability and complexity of two-phase flow have provided the impetus for much research in this area. The volume of the more recent literature surveysl,2,3 makes this apparent. A sizeable portion of two-phase flow research has been directly or iIidirectly concerned with flow regimes in pipes.4 These flow regime investigations can be divided into many different categories. Some of the more obvious differences are the inclination of the pipe (horizontal,inclined, or vertical), the type of flow (fully developed flow or developing flow), and the heat transfer (adiabatic, boiling, or condensing). The majority of previous flow regime investigations have been studies on two-phase adiabatic " flows. Some investigations have been conducted for two- phase flow with boiling, but very few for two-phase flow with condensation.