Mathematical Modeling of Cooling-Tower Plumes

摘要

The vast majority of mathematical models used to predict plume rise from natural-draft (NDCT) and mechanical-draft (MDCT) cooling towers employ the integral approach. The following significant areas of controversy exist in the theoretical development of such models: assumptions needed to assure the proper balance between buoyancy and momentum transfer mechanisms; treatment of tower downwash; treatment of thermodynamics; treatment of atmospheric diffusion; and proper method for merging of plumes. The most successful models employ assumptions which appear physically reasonable with calibration of unknown coefficients with field and/or laboratory data. Such models are capable of predicting visible plume rise within a factor of 2 and visible plume length within a factor of 2.5 for 50 to 75% of most new field cases. Such accuracy is sufficient for most design and environmental impact evaluations. Only the ANL and KUMULUS Models of this better-performing group are sufficiently general, however, to handle any configuration of NDCTs and MDCTs. (ERA citation 08:021679)