Cooling Pond Temperature Versus Size and Water Loss

The primary cost item related to cooling ponds is land; therefore, the economic feasibility of a cooling pond system may be determined by a specific design area. As with any wet cooling device, cooling ponds incur water losses through the evaporative heat transfer process, and the value of this water should be considered in the economic evaluation of the total cooling system. Heat transfer mechanisms involved in pond cooling are considered, pointing out that back radiation, conduction–convection, and evaporation are functions of pond water surface temperature which, in turn, is subject to control through variations in plant design or operating practices. For a given waste heat load to be dissipated, higher cooling pond operating temperatures result in a smaller area requirement and less evaporative water loss. Curves are presented which show the influence of temperature on pond size and on water loss at selected locations throughout the U.S. Results of a field study, which support the general analysis, are also presented.