Thermal Cycle Arrangements for Power Plants Employing Dry Cooling Towers

The use of dry cooling towers with air as the cooling medium will become more prevalent in the not-too-distant future as water quantities available for consumption in evaporative cooling processes for steam-electric generating plants become limited. Special considerations for designing either fossil-fueled or nuclear-fueled plants are required due to significant differences in turbine exhaust pressures which result in sizable capability losses. Those design considerations affecting turbine thermal cycles for steam-electric generating plants employing dry cooling towers are discussed in this paper. Effects on major plant components, such as turbine exhaust end sizes, cycle parameters and steam conditions, and the extent of feedwater heating within the regenerative cycle are discussed. Plant siting constraint considerations and general economic appraisals of fossil-fueled and nuclear-fueled cycles are summarized.