|Figure 1: Oswald Generating Station|
This means the seven combustion turbines (CTs), or fewer, provide steam to one or both steam turbines, depending on the current power demand. The plant is not configured for the CTs to operate in simple cycle mode.
The plant is designed to supply approximately 75 MW to 510 MW of power during high electrical demand hours of each day, usually between the hours of 7:00 a.m. and 11:00 p.m., and ramp down to approximately 75 MW during off-peak hours. This daily load cycling results in reduced power production each day during hours when there is less demand for the power.
The six LM combustion turbines are equipped with steam injection for emission control of oxides of nitrogen (NOx). The Title V Air Permit limits the six LMs to a three- hour rolling average of 25 ppm and a yearly average of 22 ppm NOx corrected to 15% oxygen (O2). The 7EA combustion turbine utilizes dry low NOX (DLN) burners for NOx control. The 7EA is limited to a three-hour rolling average of 9 ppm NOx corrected to 15% O2.