Abstarct: Dry cooling of power plants may be an attractive alternative to wet cooling, particularly where water conservation and environmental protection pose critical sitting issues. However, dry cooling technology may be unable to maintain design plant output during the hottest periods of the year, which are often periods of peak system demand. Depending on the meteorology at the site and the choice of design point, a plant can experience capacity reductions of up to 10 to 20% on the steam side alone because of increased turbine backpressure. For combined cycle plants, the gas-turbine side suffers simultaneous capacity reductions from increased ambient temperatures as well. One approach to alleviate this condition is the use of some water to supplement or enhance dry system (air cooled condenser) performance for these brief hot periods. A number of approaches have been considered to accomplish this. They are reviewed in Section 1 of this project. One approach—inlet air spray cooling, which sprays a small amount of water into the inlet air stream where it evaporates and cools the air—was selected for detailed analysis in this study. The numerical analysis was carried out to study the 3- D heat transfer and flow in elliptic finned tube heat exchanger of Air-cooled condenser. Numerical simulation was performed by 3-D laminar analysis with conjugated heat transfer and fluid flow. The numerical results (with and without spray) for the temperature, pressure, Nusselt number and fanning friction factor at various inlet frontal velocities (1~5 m/s) are shown and compared with the available experimental data. the experimental and numerical results show that an inlet spray cooling system can significantly enhance performance of an ACC at a dry-cooled power plant, while maintaining acceptable water use and reasonable cost, minimizing energy requirements and complexity, and avoiding unacceptable O&M requirements or environmental impacts.