Figure 2-.7. Absorption refrigerated inlet cooling system.
systems ahead of the mechanical inlet refrigeration system should be con-sidered as seen in Figure 2-38. This may notalways be intuitive, since evaporative cooling is an adiabatic process that occurs at constant enthalpy.When water is evaporated into an airstream, any reduction in sensible heat is accompanied by an increase in the latent heat of the air stream (the heat in the air stream being used to effect a phase change in the water from liquid tothe vapor phase). lf fog is applied in front of a chillingcoil, the temperaturewill be decreased when the fog evaporates, but since the chiller coil will haveto work harder to remove the evaporated water from the airsteam, the result would yield no thermodynamic advantage.
To maximi.e theeffect, the chiller must be designed in such a manner that in combination with evaporative cooling the maximum reduction in tem-perature is achieved. This can be done by designing a slightly undersi.edchiller, which is not capable of bringing the air temperature down to the ambient dew point temperature; but in conjunction with evaporative coolingthe same effect can be achieved, thus taking the advantage of evaporative cooling to reduce the load of refrigeration.
Generator
Water
Steam
Thermal Energy Storage Systems
These systems are usually designed to operate the refrigeration system at off-peak hours and then use the refrigerated media at peak hours. The refrigerated media in most cases is ice and the gas turbine air is then passedthrough themedia, which lowers it inlet temperature as seen in Figure 2-39. The si.e of the refrigeration system is greatly reduced as it can operate for8-10 hours at off-peak conditions to make theice, which is thenstored, and air passed through it at peak operating hours that may only be for about 4-6 hours.
The cost for such a system runs about .90-.110jkW. And have been successfully employed for gas turbines producing 100-200 MW.
Injection of CompressedAir,Steam, or Water for Increasing .o.er
Mid-Compressor Flashing of Water.ln this system, the water is injected into the mid-stages of the compressor to cool the air and approach an
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