The Oklahoma Department of Environmental Quality went out for comment June 9 on a renewal of the Title V air permit for Green Country Energy LLC‘s power plant, located at Jenks in Tulsa County.
This facility began operations in February 2002. It consists of three combined cycle gas turbines, each with a heat recovery steam generator (equipped with duct burners) powering a steam turbine. There are two operating scenarios; combustion turbines (CTs) operating with duct burners and CTs operating without duct burners.
The DEQ noted that there is another application under review for this facility for a Tier I construction permit in which the applicant has requested authorization to make modifications to the facility:
- Install the General Electric OpFlex modification, which involves both new process control software and replacement or modification to some components of the turbine gas path. This upgrade will increase the nominal heat input rating of each turbine from 1940 MMBTUH to 2010 MMBTUH, and also improve turbine efficiency, enabling the facility to recover generating capacity that has been lost since it commenced operation.
- Install additional duct burners to increase duct firing capacity for each heat recovery steam generator (HRSG) from 265 MMBTUH to 325 MMBUTH. The facility has requested a new permit limit such that the additional duct firing capacity be utilized not more than 2,500 hours per year for each turbine, based on historical data on utilization of duct burners.
The plant operates three combined-cycle gas turbines firing only natural gas. Maximum total combined rating of the entire facility is 800 MWe. The gas turbines are GE Model PG7241FA, each with a nominal output of 194.4 MWe at base conditions of zero degrees F, with a nominal higher heat value (HHV) input of 1,940 MMBTUH. The combustion turbines and duct burners are authorized to operate continuously, or 8,760 hours per year.