Studies on Mathematical Models for Characterizing Plume and Drift Behavior from Cooling Towers. Volume 3. Mathematical Model for Single-Source (Single-Tower) Cooling Tower Drift Dispersion

摘要

This report presents a new salt-drift deposition model for single natural-draft cooling towers which has the advantages of improved theory and good performance with field data. Advantages to the model include: a submodel for cooling-tower plume rise which has been calibrated and validated with laboratory and field data; improved treatment of droplet evaporation which accounts for salt-concentration gradients within the drop; and an option to employ a new drop breakaway criterion which allows a more continuous transition between plume and ambient environments for the drop. The drift model performs well in terms of comparisons made of predictions to 1977 Chalk Point Dye Study data. Those data include measurements of sodium deposition flux, average diameter, number drop deposition flux, and liquid deposition flux at downwind distances of 0.5 and 1.0 km. The model is untested for distances greater than 1.0 km due to the lack of good-quality field data at those distances. The model was developed as an improvement over existing theories which are evaluated theoretically and tested with Chalk Point data in this report. Sensitivity studies are presented which provide considerable insight as to the differences among existing formulations for droplet evaporation and droplet breakaway methods. (ERA citation 06:013840)