Efficient Cooling Ponds: Design

The design of cooling ponds for the dissipation of waste heat from steam-electric power plants is considered from the point of view of steady-state performance, and of transient performance. Particular emphasis is put on the design of shallow ponds, as defined by classification criteria proposed earlier, which lack a predominant vertical stratification and are dominated by the throughflow hydrodynamics. Such pond types are frequently constructed by diking or excavating an offstream land area. A schematic laboratory study was performed to test the effect on pond performance of various design measures, notably internal baffle arrangements, discharge structures and a deep intake reservoir. An optimal pond design is suggested with moderate beffling (length/width ratio of 5 to 10) to prevent recirculation zones, a radial discharge structure to minimize entrance mixing and deep intake reservoir with a residence time of at least one half day to insure damping of diurnal intake temperature fluctuations.