Inadequacy of plume rise information to predict the ground level pollutant concentration in vicinity of small cooling towers

Abstract

Dispersion of pollutant emitted from cooling towers is investigated to discover the pollution concentration distribution at the ground level. The objective is to find the proper arrangement of the cooling towers leading to a lesser concentration of pollutant on the ground. This can be very useful for sustainable development of areas in vicinity of the towers. Comprehensive plume rise data available in the literature has greatly helped to understand how an exhaust plume disperses in a cross wind. In this article, it is shown that the concentration of pollutant on the ground deduced from the plume rise behavior differs from what obtained via direct calculation. The maximum concentration of pollutant on the ground is found to occur once towers are placed in tandem. That is in contrast with what is inferred from the behavior of plume rise. For side by side towers, the plume rise occurs at a lower altitude which can mislead one to conclude that more pollutant would reach the ground surface. The evolution of vortices is employed to explain such discrepancy between the results of direct calculation and those deduced from the plume rise behavior. Similar discussions are presented for square and diamond configurations of multi-flue sources.