Condensation of HCFC123 in bundles of horizontal finned tubes: Effects of fin geometry and tube arrangement

Experiments were conducted to obtain row-by-row heat transfer data during condensation of downward-flowing HCFC123 vapour in staggered bundles of horizontal two-dimensional fin tubes. Two conventional low-fin tubes and two finned tubes with fin shapes close to a new class of high performance fin were tested. The heat transfer characteristics were compared with previous results for in-line bundles of the same test tubes. The decrease in heat transfer due to condensate inundation was less significant for the staggered tube bundle. The highest heat transfer performance was provided by the staggered bundle of one of the newly developed finned tubes. Comparison was also made with theoretical predictions for stagnant vapour and predictions of empirical equations for bundles of smooth tubes. The theoretical predictions compared well with experimental data at a low vapour velocity and low-to-medium condensate inundation rates.