CH-2269 (RP-63) -- The Influence of Return Bends on the Downstream Pressure Drop and Condensation Heat Transfer in Tubes PDF

A wide variety of vapor-compression refrigeration systems utilized in industry employ condensing equipment in which the refrigerant vapor condenses while flowing inside tubes. This is the case, for example, in evaporative condensers and some water-cooled condensers of the tube-in-tube type. The present investigation is concerned with the heat transfer and pressure drop in condensers, and particularly the effect of return bends on their performance.

The purpose of this investigation was to determine whether the disturbance caused by a return bend was only a localized effect or extended over a significant length of the condenser tube, modifying the heat transfer and pressure drop.