POWER AUGMENTATION STUDY OF AN EXISTING COMBINED CYCLE POWER PLANT BY OVERSPRAY INLET FOGGING

With increasing demand for power and with shortages envisioned especially during the peak load times during the summer, there is a need to boost gas turbine power. In Taiwan, most of gas turbines operate with combined cycle for base load. Only a small portion of gas turbines operates with simple cycle for peak load. To prevent the electric shortage due to derating of power plants in hot days, the power augmentation strategies for combined cycles need to be studied in advance. As a solution, our objective is to add an overspray inlet fogging system into an existing gas turbine-based combined cycle power plant (CCPP) to study the effects. Simulation runs were made for adding an overspray inlet fogging system to the CCPP under various ambient conditions. The overspray percentage effects on the CCPP thermodynamic performance are also included in this paper. Results demonstrated that the CCPP net power augmentation depends on the percentage of overspray under site average ambient conditions. This paper also included CCPP performance parametric studies in order to propose overspray inlet fogging guidelines for combined cycle power augmentation.