Fluid Properties at Gas Turbine Inlet Due to Fogging Considering Evaporation and Condensation Phenomena as Well as Icing Risk

Abstract

This study reports on numerically calculated thermophysical properties of air entering a gas turbine compressor after passing through an intake duct affected by different cooling techniques. Case of reference is unaffected ambient air (referenced to as unaffected) passing the intake duct. Furthermore, ambient air cooled down to wet bulb temperature by (overspray) fogging (referenced to as wet) was considered. The third case shows air cooled down to the same temperature as it was reached in the wet case but by using chillers (referenced to as chilled). Equilibrium and nonequilibrium properties according to the occurring evaporation and condensation phenomena were compared. Equilibrium conditions seem to have a reduced inlet icing risk for the wet case compared to the chilled case. However, comparing the wet case to the unaffected case showed a higher icing risk for the wet case at low ambient relative humidity. In contrast to equilibrium conditions, a consideration of nonequilibrium conditions resulted in an increased icing risk due to almost negligible condensation rates.