Prediction and Measurement of Apparent Heat Transfer Coefficient by Condensation in Finned-Tube Heat Exchangers

The apparent heat transfer coefficient by condensation in finned-tube heat exchangers is determined experimentally and numerically in this paper. The film method is used to predict the partial or total condensation of the water vapor contained in the humid air over the smooth or finned tube-heat recuperators. Based on this method, a computer code is developed here. The mathematical formulation is validated by our experimental results, using tube bundles in staggered and aligned arrangements. The determination of the fin portion, which functions in wet regime, is carried out by the prediction of thermal field over a circular fin. The condensation of the water vapor contained in the humid air is done preferentially with the last rows of the heat exchanger. The heat flux is predicted in a range of 20% and 5% in wet and dry regimes, respectively. The apparent heat transfer coefficient by condensation can exceed 10 times the value of the air-side heat transfer coefficient in dry regime.