Power generation system exhaust cooling

A turbomachine system, comprising:

• a gas turbine system including a compressor component, a combustor component, and a turbine component, wherein the compressor component of the gas turbine system includes at least one oversized compressor stage for generating a combined flow of air flowing through an air intake section of the gas turbine system, the combined flow of air including an operational flow of air supplied to the combustor component of the gas turbine system and an excess flow of air;
• a plurality of inlet guide vanes in the air intake section upstream from the compressor component, the combined flow of air passing through the inlet guide vanes, the inlet guide vanes controlling the combined flow of air passing through the air intake section to the compressor component;
• a mixing area for receiving an exhaust gas stream produced by the gas turbine system;
• an air extraction system for extracting at least a portion of the excess flow of air generated by the at least one oversized compressor stage of the compressor component to provide bypass air;
• and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream, the air extraction system including an air splitting system comprising:
• an outer bypass duct for diverting the bypass air around the combustor and turbine of the gas turbine system into the mixing area to reduce the temperature of the exhaust gas stream in the mixing area, wherein the outer bypass duct comprises an arrangement of axially extending ducts, the axially extending ducts arrayed circumferentially around the gas turbine system to surround the combustor and turbine:
• and
• an inner passage for directing any non-extracted portion of the excess flow of air into the combustor of the gas turbine system to supercharge the gas turbine system;
• and
• an exhaust processing system for processing the reduced temperature exhaust gas stream, wherein the exhaust processing system comprises a selective catalytic reduction (SCR) system.

A power generation system, comprising:

• a gas turbine system including a compressor component, a combustor component, and a turbine component, wherein the compressor component of the gas turbine system includes at least one oversized compressor stage for generating a combined flow of air flowing through an air intake section of the gas turbine system, the combined flow of air including an operational flow of air supplied to the combustor component of the gas turbine system and an excess flow of air;
• a plurality of inlet guide vanes in the air intake section upstream from the compressor component, the combined flow of air passing through the inlet guide vanes, the inlet guide vanes controlling the combined flow of air passing through the air intake section to the compressor component;
• a shaft driven by the turbine component;
• an electrical generator coupled to the shaft for generating electricity;
• a mixing area for receiving an exhaust gas stream produced by the gas turbine system;
• an air extraction system for extracting at least a portion of the excess flow of air generated by the at least one compressor stage of the compressor component to provide bypass air;
• and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream, the air extraction system including an air splitting system comprising:
• an outer bypass duct for diverting the bypass air around the combustor and turbine of the gas turbine system into the mixing area to reduce the temperature of the exhaust gas stream in the mixing area, wherein the outer bypass duct comprises an arrangement of axially extending ducts, the axially extending ducts arrayed circumferentially around the gas turbine system to surround the combustor and turbine:
• and
• an inner passage for directing any non-extracted portion of the excess flow of air into the combustor of the gas turbine system to supercharge the gas turbine system;
• and
• an exhaust processing system for processing the reduced temperature exhaust gas stream, wherein the exhaust processing system comprises a selective catalytic reduction (SCR) system.