LA-2576 (RP-219) -- Enhancement of Horizontal In-Tube Condensation of R-113 PDF

This paper is the second report of a study of the augmentation of in-tube condensation. A smooth tube, the smooth tube with two different pitch twisted-tape inserts, and three internally finned tubes were tested with R-113. The twisted-tape inserts increased overall average heat transfer coefficients approximately 30% above those of the smooth tube on a nominal area basis. For the three internally finned tubes, the one with the shortest and largest number of fins had the best performance, with heat transfer coefficients increased up to 120%. Heat transfer and pressure drop correlations were developed for both augmentation techniques. These correlations provide reasonable descriptions of the present experimental results. The finned-tube correlation does not agree with the steam correlation reported previously; qualitative reasons for this behavior are given.