GAS TURBINE LOAD CONTROL SYSTEM

• US 20150226133A1
• Filed: 12/30/2013
• Published: 08/13/2015
• Est. Priority Date: 12/31/2012
• Status: Active Grant

• Current Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation), GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation), General Electric Company
• Inventors: Minto, Karl Dean, Thatcher, Jonathan Carl, Rittenhouse, Brian Allen, Vorel, Aaron
• Granted Patent: US 10,208,677 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E21B 43/166 Injecting a gaseous medium; Injecting a gaseous medium and a liquid medium CO2 injection E21B43/164; steam injection E21B43/24
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F02C 1/005 being recirculated
• CPC Class Codes: F02C 1/08 Semi-closed cycles
• 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 7/22 Fuel supply systems
• CPC Class Codes: F02C 9/48 Control of fuel supply conjointly with another control of the plant with nozzle section control F02K1/17
• CPC Class Codes: F02C 9/52 by bleeding or by-passing the working fluid
• CPC Class Codes: F02C 9/54 by throttling the working fluid, by adjusting vanes
• CPC Class Codes: F05D 2270/061 in particular the electrical frequency of driven generator
• CPC Class Codes: F05D 2270/304 Spool rotational speed
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]

Abstract

A gas turbine system includes a combustor configured to combust an oxidant and a fuel in the presence of an exhaust gas diluent to produce combustion products, an oxidant supply path fluidly coupled to the combustor and configured to flow the oxidant to the combustor at an oxidant flow rate, and a turbine configured to extract work from the combustion products to produce an exhaust gas used to generate the exhaust gas diluent. The turbine causes a shaft of the gas turbine system to rotate when the work is extracted from the combustion products. The system also includes an electrical generator that generates electrical power in response to rotation by the shaft, and a controller that performs load control in response to a target load by adjusting the oxidant flow rate along the oxidant flow path as a primary load control parameter.

Claims

1. A gas turbine system comprising:

a turbine combustor configured to combust a compressed oxidant and a fuel in the presence of an exhaust gas diluent generated from an exhaust gas to produce combustion products;

an oxidant supply path fluidly coupled to the turbine combustor and configured to flow the compressed oxidant to the turbine combustor at an oxidant flow rate;

a turbine configured to extract work from the combustion products to produce the exhaust gas, wherein the turbine causes a shaft of the gas turbine system to rotate when the work is extracted from the combustion products;

an electrical generator configured to generate electrical power in response to rotation by the shaft; and

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;

receive data indicative of a target load for the electrical generator; and

perform load control in response to the target load by adjusting the oxidant flow rate along the oxidant supply path as a primary load control parameter, wherein adjusting the oxidant flow rate adjusts combustion within the turbine combustor to change a rotational speed of the shaft.

2. The gas turbine system of claim 1, comprising a main oxidant compressor configured to generate the compressed oxidant along the oxidant supply path, wherein the oxidant supply path extends from the main oxidant compressor to the turbine combustor, the main oxidant compressor comprises main oxidant compressor inlet guide vanes configured to adjust an amount of oxidant received for compression to generate the compressed oxidant, and wherein the one or more processing devices are configured to execute the one or more sets of instructions to adjust a position of the inlet guide vanes to adjust the oxidant flow rate.

5. The gas turbine system of claim 1, comprising a fuel supply path fluidly coupled to the turbine combustor and configured to flow the fuel to the turbine combustor at a fuel flow rate, wherein the one or more processing devices are configured to execute the one or more sets of instructions to adjust the fuel flow rate in response to the load control in which the oxidant flow rate is adjusted.

6. The gas turbine system of claim 5, wherein the one or more processing devices are configured to execute the one or more sets of instructions to perform equivalence ratio control after performing the load control, and the equivalence ratio control adjusts the fuel flow rate in response to the adjustment in the oxidant flow rate to adjust the equivalence ratio of the fuel and the oxidant in the turbine combustor to a target equivalence ratio.

9. The gas turbine system of claim 6, comprising an exhaust gas recirculation (EGR) system, wherein the EGR system is configured to recirculate the exhaust gas along an exhaust recycle loop extending from the turbine to an exhaust gas compressor configured to supply the exhaust gas diluent to the turbine combustor, and wherein the one or more processing devices are configured to execute the one or more sets of instructions to perform exhaust recycle loop pressure control after performing the equivalence ratio control, and the exhaust recycle loop pressure control is configured to control a pressure of the exhaust gas within the exhaust recycle loop.

13. The gas turbine system of claim 9, wherein the one or more processing devices are configured to execute the one or more sets of instructions to perform turbine temperature control after performing the exhaust recycle loop pressure control, and the turbine temperature control is configured to control a turbine temperature comprising a temperature of the exhaust gas within the exhaust recycle loop, a firing temperature in the turbine, or any other temperature in the turbine combustor or turbine, or any combination thereof.

14. The gas turbine system of claim 13, comprising a recycle blower disposed along the exhaust recycle path between the turbine and the recycle compressor, wherein the turbine temperature control adjusts a vane angle of the recycle blower, a position of recycle compressor inlet guide vanes of the recycle compressor, or a combination thereof, to adjust the turbine temperature in response to a sensed pressure of the exhaust gas within the exhaust recycle loop, or in response to feedback relating to one or more operating limits of the gas turbine system, or both.

66. The gas turbine system of claim 2, comprising an oxidant vent path diverging from the oxidant supply path and fluidly coupling the oxidant supply path to an oxidant vent, and an oxidant vent control valve disposed along the oxidant vent path configured to adjust oxidant flow along the oxidant vent path, wherein the one or more processing devices are configured to execute the one or more sets of instructions to control the oxidant vent valve to adjust the oxidant flow rate.

3-4. -4. (canceled)

7-8. -8. (canceled)

10-12. -12. (canceled)

15. A system, comprising one or more tangible, non-transitory, machine readable media collectively storing one or more sets of instructions executable by one or more processing devices to:

receive a load reference indicative of a target loading for a gas turbine system;

determine an oxidant flow rate associated with the target loading, wherein the oxidant flow rate corresponds to a flow of a compressed oxidant along an oxidant supply path from a main oxidant compression system to a turbine combustor of the gas turbine system;

generate one or more oxidant flow control signals for input to the main oxidant compression system to cause the main oxidant compression system to adjust the flow of the compressed oxidant to the oxidant flow rate associated with the target loading;

determine a fuel flow rate based on the oxidant flow rate associated with the target loading, wherein the fuel flow rate corresponds to a flow of a fuel along a fuel supply path to the turbine combustor; and

generate one or more fuel flow control signals for input to a fuel flow control system, wherein the one or more fuel flow control signals are configured to cause the fuel flow control system to adjust the flow of the fuel to enable combustion at a target equivalence ratio between the fuel and the oxidant in the presence of an exhaust gas diluent within the turbine combustor.

16. The system of claim 15, wherein the one or more oxidant flow control signals are configured to cause a positional adjustment of one or more main oxidant compressor inlet guide vanes of a main oxidant compressor of the main oxidant compression system.

19. The system of claim 15, wherein the one or more fuel flow control signals are configured to cause a change in a position of one or more fuel flow control valves of the fuel flow control system.

20. The system of claim 15, wherein the one or more sets of instructions are executable by one or more processing devices to perform an exhaust gas recirculation loop pressure control routine, wherein the exhaust gas recirculation loop pressure control routine is configured to control a pressure of an exhaust gas flowing through an exhaust recirculation path in response to a target pressure for the exhaust gas, or a sensed pressure of the exhaust gas, or feedback related to a flow rate of the exhaust gas flowing through the exhaust recirculation path, or any combination thereof, and wherein the exhaust recirculation path extends from a turbine of the gas turbine system to a recycle compressor configured to produce the exhaust gas diluent.

21. The system of claim 20, wherein the exhaust gas recirculation loop pressure control routine comprises controlling a flow of the exhaust gas diluent from the recycle compressor as an exhaust purge flow to a product compressor configured to compress the exhaust purge flow into a product gas.

22. The system of claim 21, wherein the exhaust gas recirculation loop pressure control routine comprises controlling the flow of the exhaust purge flow along an exhaust purge flow path extending from the recycle compressor to the product compressor by adjusting a purge vent flow control device positioned along a purge vent path diverging from the exhaust purge flow path, or a flow control device positioned along the exhaust purge flow path, or both.

23. The system of claim 20, wherein the one or more sets of instructions are executable by one or more processing devices to perform a turbine temperature control routine, wherein the turbine temperature control routine is configured to control a turbine temperature comprising a temperature of the exhaust gas flowing through the exhaust recirculation path, a firing temperature in the turbine, or any other temperature in the turbine combustor or turbine, or any combination thereof.

24. The system of claim 23, wherein the turbine temperature control routine controls the turbine temperature by adjusting a position of recycle compressor inlet guide vanes of the recycle compressor.

67. The system of claim 15, wherein the one or more oxidant flow control signals are configured to cause a positional adjustment of an oxidant vent control valve disposed along an oxidant vent path diverging from the oxidant supply path and to an oxidant vent.

17-18. -18. (canceled)

25-59. -59. (canceled)

60. A method of operating a gas turbine system, comprising:

receiving a load reference indicative of a target loading for a gas turbine system;

flowing a compressed oxidant along an oxidant supply path from a main oxidant compression system to a turbine combustor of the gas turbine system at an oxidant flow rate associated with the target loading; and

flowing a fuel along a fuel supply path to the turbine combustor at a fuel flow rate, wherein the fuel flow rate is determined based on the oxidant flow rate associated with the target loading, or equivalence ratio feedback obtained downstream of the turbine combustor, or both, and wherein the fuel flow rate enables combustion at a target equivalence ratio between the fuel and the oxidant in the presence of an exhaust gas diluent within the turbine combustor.

61. The method of claim 60, wherein flowing the compressed oxidant at the oxidant flow rate comprises adjusting the oxidant flow rate by adjusting respective positions of one or more main oxidant compressor inlet guide vanes of a main oxidant compressor of the main oxidant compression system.

62. The method of claim 60, comprising controlling a turbine temperature after the oxidant flow rate and fuel flow rate are established, wherein controlling the turbine temperature comprises controlling a temperature of exhaust gas flowing along an exhaust recirculation path extending from a turbine that receives combustion products from the turbine combustor and to an exhaust gas compressor that compresses the exhaust gas to produce the exhaust gas diluent, controlling a firing temperature of a turbine, or controlling any other temperature in the turbine combustor or turbine, or any combination thereof.

63. The method of claim 62, wherein controlling turbine temperatures comprises controlling the temperature of exhaust gas flowing along the exhaust recirculation path.

64. The method of claim 62, wherein controlling turbine temperatures comprises controlling the firing temperature of the turbine.

65. The method of claim 62, comprising controlling a pressure of the exhaust gas flowing along the exhaust recirculation path after the oxidant flow rate and fuel flow rate are established, and at substantially the same time as controlling the turbine temperature.