Potential weather modification from cooling tower effluents at conceptual power parks

Abstract

A numerical model for multiple plumes is developed to study the enhanced convection of merged plumes from a cluster of cooling towers at a conceptual power park. The model is based on the equations of motion for a quasi incompressible fluid derived from the laws governing the change of momentum, the first law of thermodynamics, and the conservation of mass. The microphysical processes are simplified in the model by a parameterization approach similar to the work of Kessler (1969) with the assumption that the droplet size distributions in the cooling tower plume are the same as those of cooling tower drift measured near the top of cooling towers. The numerical model is employed to simulate the merged plume convection from clusters of (up to 40) natural draft cooling towers, where each tower serves to dissipate 2400 MW of waste heat. It was found that the plume rise from 40 towers is predicted to be approximately 360% and 130% of that from a single tower for an average July afternoon and average January morning sounding, respectively, taken in the Louisiana area if the towers are arranged in a near square grid and spaced at 300 m apart. However, it is not uncommon to predict an induced convective cloud developing over 4000 m in height from more than 5 towers in a group for an individual afternoon sounding in the southeastern United States. Comparison of the predicted precipitation using Kessler's microphysical parameterization with Marshall and Palmer's (1948) drop size distribution and the similar approach with available observed droplet size distribution from cooling tower drift is also made. The model predictions are in good agreement with observations at existing power plants up to 3000 MWe generating capacity.