Field Experience in Fog Power Augmentation of Frame 9E Gas Turbine

Inlet air cooling by water fogging became very popular in recent years, because it is relatively simple and inexpensive technique for gas turbine power augmentation. Large experience established general practices of design, operation and maintenance of the fog systems. Nevertheless, fog systems could require some tuning to a specific gas turbine configuration and site conditions. Israel Electric Corporation (IEC) has implemented eight fog systems on 120–150 MW gas turbines, and each system was initially tuned to provide higher effectiveness. During hot weather conditions, noticeable additional power was obtained, which was very helpful to meet peak electricity demand. Based on these positive results, an additional six fog systems were installed on Frame 9E gas turbines. Initial operation of new fog systems revealed some unexpected problems. IEC undertook a thorough study of the problems including computational fluid dynamics (CFD) analysis of the inlet duct air flow. On the basis of the study results, significant modifications of the fog systems were carried out. Field tests of the modified systems showed that all goals of the modifications were successfully achieved.