Power generation system exhaust cooling

Patent metadata

Field	Value
Publication number	US-2016376958-A1
Application number	US-201514753097-A
Country	US
Kind code	A1
Filing date	Jun 29, 2015
Priority date	Jun 29, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

An airflow control system for a combined cycle power generation 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; and 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; wherein the reduced temperature exhaust gas stream is provided to a heat recovery steam generator.

First claim

What is claimed is:

1 . An airflow control system for a combined cycle power generation system, comprising:
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; and 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; wherein the reduced temperature exhaust gas stream is provided to a heat recovery steam generator.

2 . The airflow control system of claim 1 , wherein the excess flow of air generated by the compressor component of the gas turbine system is about 10% to about 40% greater than a flow rate capacity of at least one of a combustor component and a turbine component of the gas turbine system.

3 . The airflow control system of claim 2 , wherein the compressor component of the gas turbine system includes at least one oversized compressor stage.

4 . The airflow control system of claim 1 , wherein the air extraction system comprises a bypass duct for diverting the bypass air around the gas turbine system into the mixing area to reduce the temperature of the exhaust gas stream.

5 . The airflow control system of claim 1 , wherein the air extraction system comprises an enclosure surrounding the gas turbine system and forming an air passage, the bypass air flowing through the air passage into the mixing area to reduce a temperature of the exhaust gas stream.

6 . The airflow control system of claim 5 , wherein the enclosure comprises a casing of the gas turbine system.

7 . The airflow control system of claim 5 , further comprising a flow directing system for directing the bypass air toward and into the exhaust gas stream in the mixing area, wherein the flow directing system comprises an inwardly curved end portion of the enclosure and/or at least one outlet guide vane.

8 . The airflow control system of claim 1 , wherein the air extraction system is configured to divert a portion of the excess flow of air into the compressor component to supercharge the gas turbine system.

9 . The airflow control system of claim 1 , further comprising a duct burner system upstream of the heat recovery steam generator for heating the reduced temperature exhaust gas stream.

10 . 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; a mixing area for receiving an exhaust gas stream produced by the gas turbine system; an air extraction system for: extracting a supply of bypass air from an excess flow of air generated by the at least one oversized compressor stage of the compressor component; and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream; a heat recovery steam generator for receiving the reduced temperature exhaust gas stream and for generating steam; and a steam turbine system for receiving the steam generated by the heat recovery steam generator.

11 . The turbomachine system of claim 10 , wherein the excess flow of air generated by the compressor component of the gas turbine system is about 10% to about 40% greater than a flow rate capacity of at least one of a combustor component and a turbine component of the gas turbine system.

12 . The turbomachine system of claim 10 , wherein the air extraction system comprises a bypass duct for diverting the bypass air around the gas turbine system into the mixing area to reduce the temperature of the exhaust gas stream.

13 . The turbomachine system of claim 10 , wherein the air extraction system comprises an enclosure surrounding the gas turbine system and forming an air passage, the bypass air flowing through the air passage into the mixing area to reduce a temperature of the exhaust gas stream.

14 . The turbomachine system of claim 13 , wherein the enclosure comprises a casing of the gas turbine system.

15 . The turbomachine system of claim 13 , further comprising a flow directing system for directing the bypass air toward and into the exhaust gas stream in the mixing area, wherein the flow directing system comprises an inwardly curved end portion of the enclosure and/or at least one outlet guide vane.

16 . The turbomachine system of claim 10 , wherein the air extraction system is configured to divert a portion of the excess flow of air into the compressor component to supercharge the gas turbine system.

17 . The turbomachine system of claim 10 , further comprising a duct burner system upstream of the heat recovery steam generator for heating the reduced temperature exhaust gas stream.

18 . A combined cycle 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; 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 a supply of bypass air from an excess flow of air generated by the at least one oversized compressor stage of the compressor component; and diverting the bypass air into the mixing area to reduce a temperature of the exhaust gas stream; a heat recovery steam generator for receiving the reduced temperature exhaust gas stream and for generating steam; and a steam turbine system for receiving the steam generated by the heat recovery steam generator.

19 . The combined cycle power generation system of claim 18 , wherein the excess flow of air generated by the compressor component of the gas turbine system is about 10% to about 40% greater than a flow rate capacity of at least one of a combustor component and a turbine component of the gas turbine system.

20 . The combined cycle power generation system of claim 18 , wherein the air extraction system comprises:
a bypass duct for diverting the bypass air around the gas turbine system into the mixing area to reduce the temperature of the exhaust gas stream in the mixing area; or an enclosure surrounding the gas turbine system and forming an air passage, the bypass air flowing through the air passage around the gas turbine system into the mixing area to reduce the temperature of the exhaust gas stream in the mixing area.

Assignees

• Gen Electric

Inventors

• Davis Jr Lewis Berkley
• Kulkarni Parag Prakash
• Reed Robert Joseph

Classifications

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title

• F02C3/04

  having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) · CPC title

• F01N3/05 Primary

  by means of air, e.g. by mixing exhaust with air (silencers working by addition of air to exhaust F01N1/14; arrangements for the supply of additional air for the thermal or catalytic conversion of noxious components of exhaust F01N3/30) · CPC title

• F05D2220/32

  in gas turbines · CPC title

• F02C6/08 Primary

  the gas being bled from the gas-turbine compressor · CPC title