Computational Dynamic Modeling of Thin Film Evaporators and Condensers

Abstract

The steady and dynamic behavior of thin film evaporators and condensers are simulated with a general thin film heat exchanger model. The dynamics of the gravity-controlled falling laminar film on horizontal and vertical tubes are studied in detail. For a first approximation or for a slow transient a single-lumped model can be used. For a refined simulation or for a severe transient a grouped model is proposed. The grouped model preserves the important feature of delay-time and wave-distortion of a transient, which was observed in a separate precise analysis [9]. The thin film heat exchanger models are used in the dynamic simulation computer programs ODSP3 and OSCAR which were established for OTEC systems. Typical results are presented to demonstrate the capability of the model.