Sanjeev Jolly, P.E.
Joseph Nitzken, P.E.
Caldwell Energy & Environmental, Inc.
Louisville, Kentucky, USA
Cooling the inlet air utilizing water spray system can increase the performance of a combustion turbine during hot weather. In a direct spray system, water is added to the sir stream in the form of fine droplets. As the droplets absorb the latent heat of vaporization, heat is removed from the air stream thereby reducing it’s temperature. the objective of this paper is to discuss a direct spray system for cooling inlet air for Florida Power & Light’s Westinghouse 501 B5 combustion turbine at the Putnam plant. The fogging is done in multiple stages – an external zone and an internal zone to control the humidity to a precise level. An overspray zone has been added for additional power augmentation. The water is sprayed into the incoming air stream through impingement nozzles placed at the cross-section of the incoming air. The size of the water droplets varies with the nozzle dimensions and water pressure. It is important to limit the size of the water droplets in order to allow for vaporization of water in a relatively short distance, thus minimizing water carryover and droplet agglomeration. Therefore selection of the nozzle type, their arrangement and placement, and the water discharge pressure is very important to control the stringent compressor inlet air requirements. These design requirements and actual cooling system performance are discussed in detail in this paper.