Film Condensation of R-113 on In-Line Bundles of Horizontal Finned Tubes

Abstract

Film condensation of R-113 on in-line bundles of horizontal finned tubes with vertical vapor downflow was experimentally investigated. Two tubes with flat-sided annular fins and four tubes with three-dimensional fins were tested. The test sections were 3×15 tube bundles with and without two rows of inundation tubes at the top. Heat transfer measurements were carried out on a row-by-row basis. The heat transfer enhancement due to vapor shear was much less for a finned tube bundle than for a smooth tube bundle. The decrease in heat transfer due to condensate inundation was more marked for a three-dimensional fin tube than for a flat-sided fin tube. The predictions of the previous theoretical model for a bundle of flat-sided fin tubes agreed well with the measured data for low vapor velocity and a small to medium condensate inundation rate. Among the six tubes tested, the highest heat transfer performance was provided by the flat-sided fin tube with fin dimensions close to the theoretically determined optimum values.

Falling-film evaporation on horizontal tubes—a critical review

“…For the three test fluids, the jet-sheet mode began at KZ0.32, and a complete sheet was observed when K reached from 0.37 to 0.47. In a similar report for R-113 on finned tubes, Honda et al [53] found a significant increase in Re for transition from the jet mode to the sheet mode with a downward-flowing vapor. However, for three-dimensional fins this effect was dramatically reduced due to the promotion of the liquid distribution by the surface structure.…”

Reasons for drop in shell-and-tube condenser performance when replacing R22 with zeotropic mixtures. Part 1. Analysis of experimental findings

“…A number of researchers [10 -15] have studied the performance of the Beatty and Katz model. However, [12,14,15] have observed that the model overpredicts or underpredicts the heat transfer performance depending on the fluid and geometry of fins. Errors increase at higher fin density and for fluids having higher surface tension.…”

Condensation of pure refrigerants R12, R134a and their mixtures on a horizontal tube with capillary structure: An experimental study

“…In experiments, either the heat transfer was measured using single tubes [25, 26, 31-34, 36, 37, 42, 43, 46, 51, 54, 55, 57, 58] and tube bundles [12,20,22,28,45,[47][48][49][50]56], or capillary phenomena and condensate retention in the lower bottom tube region [31][32][33][34]37] were analysed. As was to be expected, flooding of the lower tube portion is influenced by fin geometry and physical properties of condensate.…”