Investigation of combined heat and mass transfer from a wet heat exchanger. Part 1: Formulation of an approximate heat/mass transfer model for calculating the performance of heat exchangers in dry/wet operation

An approximate analytical model that may be used to calculate the rates of heat transfer and evaporation from the surface of a wet finned heat exchanger is described. The model is analogous to the conventional expression for convective heat transfer. The driving potential, however, is an enthalpy difference instead of a temperature difference. The overall heat transfer coefficient can be computed in the usual manner using a simple transformation of variables. The value of the model is that wet heat exchanger performance can be estimated accurately using dry performance data.