Evaluation of Air -- Water Flow in an Evaporative Condenser

Evaporative condensers present a hard problem fornumerical modeling because of the complex phenomena of heatand mass transfer outside of the bundle tubes in turbulent flows. The goal of this work is to study the air and water behavior inside an evaporative condenser operating with ammonia as the refrigerant fluid. A commercial CFD software package (FLUENT) is employed to predict the two-phase flow of air and water droplets in this equipment. The air flow is modeled as a continuous phase using the Eulerian approach while the droplets water flow is modeled as a disperse phase with Lagrangian approach. The coupling between pressure and velocity fields is performed by the SIMPLE algorithm. The pressure, velocity and temperature fields are used to perform qualitative analyses toidentify functional aspects of the condenser, while thetemperature and the relative humidity evolution contributed to verify the agreement between the results obtained with the numerical model and those presented by equipmentmanufacturer.