SYSTEM AND METHOD FOR A GAS TURBINE ENGINE

• US 20150308293A1
• Filed: 11/25/2014
• Published: 10/29/2015
• Est. Priority Date: 12/04/2013
• Status: Active Grant

• Current Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation), GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation), General Electric Company
• Inventors: Huntington, Richard A., Dhanuka, Sulabh K.
• Granted Patent: US 9,752,458 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 25/30 Exhaust heads, chambers, or the like
• CPC Class Codes: F01D 25/305 with fluid, e.g. liquid injection
• CPC Class Codes: F02C 3/34 with recycling of part of the working fluid, i.e. semi-closed cycles with combustion products in the closed part of the cycle
• CPC Class Codes: F02C 6/00 Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use
• CPC Class Codes: F02C 6/18 using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10
• CPC Class Codes: F02C 9/28 Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed F02C9/30 - F02C9/38, F02C9/44 take precedence
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F05D 2270/08 to produce clean exhaust gases
• CPC Class Codes: F05D 2270/303 Temperature
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A system includes a gas turbine engine configured to combust an oxidant and a fuel to generate an exhaust gas, a catalyst bed configured to treat a portion of the exhaust gas from the gas turbine engine to generate a treated exhaust gas, a differential temperature monitor configured to monitor a differential temperature between a first temperature of the portion of exhaust gas upstream of the catalyst bed and a second temperature of the treated exhaust gas downstream of the catalyst bed, and an oxidant-to-fuel ratio system configured to adjust a parameter to maintain an efficacy of the catalyst bed based at least in part on the differential temperature in order to maintain a target equivalence ratio.

Claims

1. A system, comprising:

a gas turbine engine configured to combust an oxidant and a fuel to generate an exhaust gas;

a catalyst bed configured to treat at least a portion of the exhaust gas from the gas turbine engine to generate a treated exhaust gas;

a differential temperature monitor configured to monitor a differential temperature between a first temperature of the portion of exhaust gas upstream of the catalyst bed and a second temperature of the treated exhaust gas downstream of the catalyst bed; and

an oxidant-to-fuel ratio system configured to adjust a parameter to maintain an efficacy of the catalyst bed based at least in part on the differential temperature in order to maintain a target equivalence ratio.

2. The system of claim 1, wherein the parameter comprises at least one of an oxidant flow rate of the oxidant, a fuel flow rate of the fuel, an exhaust gas flow rate of the portion of exhaust gas, a recycle flow rate of exhaust gas recycled to the gas turbine engine, a temperature of the catalyst bed, a pressure of the catalyst bed, or a diluent flow rate of diluent to the catalyst bed, or any combination thereof.

3. The system of claim 1, wherein the first temperature is measured at an inlet of the catalyst bed and the second temperature is measured at an outlet of the catalyst bed.

4. The system of claim 1, comprising a plurality of catalyst beds, wherein the first temperature is measured at an inlet of one of the plurality of catalyst beds and the second temperature is measured at an outlet of one of the plurality of catalyst beds.

5. The system of claim 1, wherein the oxidant-to-fuel ratio system is configured to maintain the differential temperature between approximately zero degrees Celsius to 400 degrees Celsius.

6. The system of claim 1, wherein the oxidant-to-fuel ratio system is configured to maintain the target equivalence ratio is between approximately 0.95 to 1.05.

7. The system of claim 1, comprising a heat recovery steam generator (HRSG) having the catalyst bed, wherein the HRSG is configured to generate steam using the portion of exhaust gas or the treated exhaust gas.

8. The system of claim 1, comprising a product conditioner having the catalyst bed, wherein the product conditioner is configured to treat the portion of exhaust gas.

9. The system of claim 8, wherein the product conditioner comprises a plurality of catalyst beds.

10. The system of claim 9, wherein the plurality of catalyst beds comprises a first catalyst bed disposed upstream of a second catalyst bed, wherein the system comprises an oxidant injection system configured to inject a catalyst bed oxidant downstream of the first catalyst bed, and wherein the first catalyst bed comprises a NO_X catalyst configured to reduce a concentration of NO_X in the portion of exhaust gas.

11. The system of claim 1, comprising an oxidant injection system configured to inject a catalyst bed oxidant upstream of the catalyst bed, or an oxidant fuel injection system configured to inject an oxidation fuel upstream of the catalyst bed, or any combination thereof.

12. The system of claim 11, comprising a localized differential temperature monitor configured to monitor a localized differential temperature between the first temperature of the portion of exhaust gas and a localized outlet temperature of the treated exhaust gas downstream of an injection point of the catalyst bed oxidant, oxidation fuel, or any combination thereof, wherein the oxidant-to-fuel ratio system is configured to adjust at least one of the oxidant flow rate, or the fuel flow rate, or any combination thereof, based at least in part on a comparison of the localized differential temperature with the differential temperature.

13. The system of claim 11, comprising a gas composition sensor disposed downstream of the catalyst bed, wherein the gas composition sensor is configured to sense a gas concentration of at least one of oxygen, carbon monoxide, hydrogen, nitrogen oxides, or unburned hydrocarbons, or any combination thereof, and wherein the oxidant injection system is configured to adjust a catalyst bed oxidant flow rate of the catalyst bed oxidant, or a catalyst bed fuel flow rate of the oxidation fuel, or any combination thereof, based at least in part on the gas concentration.

14. The system of claim 11, comprising an oxidant compressor configured to provide the oxidant to the gas turbine engine and the catalyst bed oxidant upstream of the catalyst bed.

15. The system of claim 1, comprising an oxidant-to-fuel sensor configured to sense an oxidant-to-fuel ratio of the exhaust gas, wherein the oxidant-to-fuel ratio system is configured to adjust at least one of the oxidant flow rate of the oxidant, or the fuel flow rate of the fuel, or any combination thereof, based at least in part on the oxidant-to-fuel ratio.

16. The system of claim 1, wherein the gas turbine engine is a stoichiometric exhaust gas recirculation (SEGR) gas turbine engine.

17. The system of claim 16, comprising an exhaust gas extraction system coupled to the gas turbine engine, and a hydrocarbon production system coupled to the exhaust gas extraction system.

18. A method, comprising:

combusting an oxidant and a fuel in a gas turbine engine to generate an exhaust gas;

treating a portion of the exhaust gas from the gas turbine engine in a catalyst bed to generate a treated exhaust gas;

monitoring a differential temperature between a first temperature of the portion of exhaust gas upstream of the catalyst bed and a second temperature of the treated exhaust gas downstream of the catalyst bed using a differential temperature monitor; and

adjusting a parameter to maintain an efficacy of the catalyst bed based at least in part on the differential temperature in order to maintain a target equivalence ratio using an oxidant-to-fuel ratio system.

19. The method of claim 18, wherein the parameter comprises at least one of an oxidant flow rate of the oxidant, a fuel flow rate of the fuel, an exhaust gas flow rate of the portion of exhaust gas, a recycle flow rate of exhaust gas recycled to the gas turbine engine, a temperature of the catalyst bed, a pressure of the catalyst bed, or a diluent flow rate of diluent to the catalyst bed, or any combination thereof.

20. The method of claim 19, comprising at least one of adjusting the oxidant flow rate using an oxidant compressor, adjusting the oxidant flow rate by adjusting a speed of the oxidant compressor, adjusting the oxidant flow rate using an inlet guide vane of the oxidant compressor, adjusting the oxidant flow rate using an inlet control valve of the oxidant compressor, adjusting the oxidant flow rate using an outlet control valve of the oxidant compressor, adjusting a recycle of oxidant from the oxidant compressor, or adjusting a blow-off of oxidant from the oxidant compressor, or any combination thereof.

21. The method of claim 18, comprising injecting a catalyst bed oxidant upstream of the catalyst bed using an oxidant injection system, or injecting an oxidation fuel upstream of the catalyst bed using an oxidant fuel injection system, or any combination thereof.

22. The method of claim 21, comprising:

monitoring a localized differential temperature between the inlet temperature of the exhaust gas and a localized outlet temperature of the treated exhaust gas downstream of an injection point of the catalyst bed oxidant, oxidation fuel, or any combination thereof, using a localized differential temperature monitor; and

adjusting at least one of the oxidant flow rate of the oxidant, or the fuel flow rate of the fuel, or any combination thereof, based at least in part on a comparison of the localized differential temperature with the differential temperature.

23. A system, comprising:

a controller, comprising;

one or more tangible, non-transitory, machine-readable media collectively storing one or more sets of instructions; and

one or more processing devices configured to execute the one or more sets of instructions to;

combust an oxidant and a fuel in a gas turbine engine to generate an exhaust gas;

treat a portion of the exhaust gas from the gas turbine engine in a catalyst bed to generate a treated exhaust gas

monitor a differential temperature between an inlet temperature of the exhaust gas upstream of the catalyst bed and an outlet temperature of the treated exhaust gas downstream of the catalyst bed using a differential temperature monitor;

transmit a differential temperature signal from the differential temperature monitor to a control system; and

adjust a parameter to maintain an efficacy of the catalyst bed based at least in part on the differential temperature in order to maintain a target equivalence ratio.

24. The system of claim 23, wherein the one or more processing devices are configured to execute the one or more sets of instructions to:

monitor a localized differential temperature between the first temperature of the portion of exhaust gas and a localized outlet temperature of the treated exhaust gas downstream of an injection point configured to inject a catalyst bed oxidant, or an oxidation fuel, or any combination thereof, upstream of the catalyst bed, and

adjust at least one of the oxidant flow rate, or the fuel flow rate, or any combination thereof, based at least in part on a comparison of the localized differential temperature with the differential temperature.

25. The system of claim 24, wherein the one or more processing devices are configured to execute the one or more sets of instructions to increase the oxidant flow rate, decrease the fuel flow rate, or any combination thereof, when the localized temperature differential is greater than the differential temperature, and to decrease the oxidant flow rate, increase the fuel flow rate, or any combination thereof, when the differential temperature is greater than the localized temperature differential.