# US 9,752,503 B2 · Power generation system exhaust cooling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,503 B2 - Document ID: US9752503B2 - Status: Granted - Kind: B2 - Application number: 14/753,072 - Filed: 2015-06-29 - Published: 2016-12-29 - Granted: 2017-09-05 - Earliest claimed: 2015-06-29 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Lewis Berkley Davis, Jr.; Parag Prakash Kulkarni; Robert Joseph Reed - Web page: https://patentgrep.com/patent/US9752503B2 ## CPC - F02C 7/141: of working fluid - B01D 53/9431: {Processes characterised by a specific device} - F01D 25/305: {with fluid, e.g. liquid injection} - F02C 3/04: having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) - F02C 9/18: by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} - F01N 3/2066: {Selective catalytic reduction [SCR]} - F01N 2610/02: the substance being ammonia or urea - F05D 2220/32: in gas turbines - F05D 2250/80: Size or power range of the machines - F05D 2260/201: by impingement of a fluid - F05D 2260/232: characterized by the cooling medium - F05D 2260/606: Bypassing the fluid - F05D 2270/082: with as little NOx as possible - F05D 2270/303: Temperature - F05D 2270/3061: of the working fluid - F05D 2270/3062: of the auxiliary fluid for heating or cooling purposes - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An airflow control system for a gas turbine system according to an embodiment includes: a compressor component of a gas turbine system for generating an excess flow of air; 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 compressor component of the gas turbine system to provide bypass air; and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream; and an exhaust processing system for processing the reduced temperature exhaust gas stream. ## Claims ### Claim 1 An airflow control system for a gas turbine system, comprising: a compressor component of a gas turbine system 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 a 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 compressor component of the gas turbine system to provide bypass air, and for 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 a 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 a selective catalytic reduction (SCR) system for processing the reduced temperature exhaust gas stream from the mixing area. ### Claim 2 (depends on 1) The airflow control system of claim 1, wherein the excess flow of air generated by the compressor component of the gas turbine system is 10% to 40% greater than a flow rate capacity of at least one of a combustor component and a turbine component of the gas turbine system. ### Claim 3 (depends on 2) The airflow control system of claim 2, wherein the compressor component of the gas turbine system includes at least one compressor stage for generating the excess flow of air. ### Claim 4 (depends on 1) The airflow control system of claim 1, further comprising a mixing system for mixing the bypass air with the exhaust gas stream in the mixing area. ### Claim 5 (depends on 1) The airflow control system of claim 1, further comprising a flow restriction system coupled to the bypass duct for selectively restricting the amount of bypass air flowing into the bypass duct. ### Claim 6 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. ### Claim 7 (depends on 6) The turbomachine system of claim 6, wherein the excess flow of air generated by the at least one compressor stage of the compressor component is 10% to 40% greater than a flow rate capacity of at least one of the combustor component and the turbine component of the gas turbine system. ### Claim 8 (depends on 7) The turbomachine system of claim 7, further comprising a flow restriction system coupled to the bypass duct for selectively restricting the amount of bypass air flowing into the bypass duct. ### Claim 9 (depends on 6) The turbomachine system of claim 6, further comprising a mixing system for mixing the bypass air with the exhaust gas stream in the mixing area. ### Claim 10 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. ### Claim 11 (depends on 10) The power generation system of claim 10, wherein the excess flow of air generated by the at least one compressor stage of the compressor component is 10% to 40% greater than a flow rate capacity of at least one of the combustor component and the turbine component of the gas turbine system. ### Claim 12 (depends on 10) The power generation system of claim 10, further comprising a flow restriction system coupled to the bypass duct for selectively restricting the amount of bypass air flowing into the bypass duct.