Florida Power & Light (FPL) is pursuing through the Florida Department of Environmental Protection the air permitting needed for a major upgrade of its gas-fired Sanford Power Plant in Volusia County.
The department on June 21 put the draft air permit approval out for comment. FPL is a unit of NextEra Energy (NYSE: NEE).
This existing facility consists of eight combined-cycle combustion turbines (250 MW each), designated as Units 4A, 4B, 4C, 4D, 5A, 5B, 5C and 5D. This May 4 application is for a minor source air construction permit. The permit is for improving the performance of the existing General Electric (GE) Model MS7241FA (7FA.04) combustion turbines (CTs) associated with Units 4A, 4B, 4C, 4D, 5A, 5B, 5C and 5D with GE 7FA.05 and dry low-NOX (DLN) 2.6+ components. The resulting performance is referred to as a “7FA.05 hybrid CT.”
The purpose of the project is to improve the performance of the GE turbines by installing 7FA.05 and DLN 2.6+ components in the GE Model MS7241 turbines. In 2011, FDEP authorized improvements to these turbines for replacing the original 7FA.03 components with 7F.04 components during the normal maintenance cycle. This replacement of 7FA.03 components with 7FA.04 components involved the installation of new hot gas path components, new combustion liners and flow sleeves, and new control software to increase firing temperature and resulted in higher efficiency and provided approximately a 4.5% increase in output power per turbine with an approximate 2.5% decrease in heat rate (heat input/output power) per turbine.
After recognizing the benefits of 7FA.04 improvements over those of just replacing components parts of the 7FA.03, FPL now plans to further improve the efficiency by replacing the 7FA.04 components with 7FA.05 and DLN 2.6+ components during the normal schedule maintenance. FPL also proposes to install GE’s DLN 2.6+ plus system software.
The installation of 7FA.05 components and DLN 2.6+ will provide about a 11.2% increase in output power per turbine with an approximate 1% decrease in heat rate (heat input/output power) per turbine at ambient temperature of 75°F. The 7FA.05 and DLN 2.6+ components have a projected design heat input capacity approximately 9.7% higher than the 7FA.04 at 75°F. As a result, there will be an expected increase in the design fuel flow for the units compared to the same turbine inlet temperature based on manufacturer information. As part of this project the applicant requested changes to the heat input for the baseload and High-Temperature Peaking Mode (HTPM) for the 7FA.05 DLN 2.6+ hybrid CTs.