Systems and methods to respond to grid overfrequency events for a stoichiometric exhaust recirculation gas turbine
First Claim
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1. A method, comprising:
- combusting a fuel and an oxidant in a combustor of an exhaust gas recirculation (EGR) gas turbine system that produces electrical power and provides a portion of the electrical power to an electrical grid;
controlling, via one or more processors, one or more parameters of the EGR gas turbine system to decrease the portion of the electrical power provided to the electrical grid in response to an over-frequency event associated with the electrical grid, wherein controlling the one or more parameters comprises decreasing a flow rate of fuel to the combustor in response to the over-frequency event; and
decreasing a concentration and/or flow rate of oxidant in the combustor in response to the over-frequency event, wherein the EGR gas turbine system comprises a shaft coupled to an electric generator, and wherein a droop governor control is applied to control the electric generator, wherein a flow rate of the oxidant is decreased by an air stroke reference (ASR) from a higher flow rate to a lower flow rate subsequent to the over-frequency event.
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Abstract
A method includes combusting a fuel and an oxidant in a combustor of an exhaust gas recirculation (EGR) gas turbine system that produces electrical power and provides a portion of the electrical power to an electrical grid. The method further includes controlling, via one or more processors, one or more parameters of the EGR gas turbine system to decrease the portion of the electrical power provided to the electrical grid in response to an over-frequency event associated with the electrical grid, wherein controlling the one or more parameters comprises decreasing a flow rate of fuel to the combustor in response to the over-frequency event.
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Citations
15 Claims
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1. A method, comprising:
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combusting a fuel and an oxidant in a combustor of an exhaust gas recirculation (EGR) gas turbine system that produces electrical power and provides a portion of the electrical power to an electrical grid; controlling, via one or more processors, one or more parameters of the EGR gas turbine system to decrease the portion of the electrical power provided to the electrical grid in response to an over-frequency event associated with the electrical grid, wherein controlling the one or more parameters comprises decreasing a flow rate of fuel to the combustor in response to the over-frequency event; and decreasing a concentration and/or flow rate of oxidant in the combustor in response to the over-frequency event, wherein the EGR gas turbine system comprises a shaft coupled to an electric generator, and wherein a droop governor control is applied to control the electric generator, wherein a flow rate of the oxidant is decreased by an air stroke reference (ASR) from a higher flow rate to a lower flow rate subsequent to the over-frequency event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system, comprising:
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an exhaust gas recirculation (EGR) gas turbine system, comprising; a combustor configured to receive and combust a fuel with an oxidant; a turbine driven by combustion products from the combustor; a generator driven via a shaft of the turbine, wherein the generator is configured to generate electrical power and to export a portion of the electrical power to an electrical grid; a control system comprising one or more processors, the control system comprising; a droop governor control system configured to control the electrical power; and an equivalence ratio control system configured to control one or more parameters of the EGR gas turbine system to decrease the portion of the electrical power exported to the electrical grid in response to an over-frequency event, wherein the equivalence ratio control system is configured to provide control signals to decrease a flow rate of fuel to the combustor in response to the over-frequency event when the EGR gas turbine system is operating in stoichiometric mode; and at least one oxidant compressor disposed upstream of the combustor and configured to receive an inlet flow comprising an oxidant flow and a recirculated exhaust gas flow, wherein the equivalence ratio control system is configured to provide control signals to a control valve to decrease a ratio of the oxidant flow to the recirculated exhaust gas flow by reducing the recirculated exhaust gas flow in response to the over-frequency event. - View Dependent Claims (10, 11, 12, 13)
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14. A non-transitory, computer readable medium storing instructions executable by one or more processors, the instructions including comprising:
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instructions, that when executed by the one or more processors, cause the one or more processors to determine that an over-frequency event is occurring in an electrical grid coupled to an EGR gas turbine system; instructions, that when executed by the one or more processors, cause the one or more processors to decrease a flow rate of fuel to a combustor of the EGR gas turbine system in response to the over-frequency event; and instructions, that when executed by the one or more processors, cause the one or more processors to decrease a flow rate of oxidant to the combustor after decreasing the flow rate of fuel to the combustor, wherein the EGR gas turbine system is operating in a stoichiometric combustion mode;
wherein the instructions to decrease the flow rate of oxidant to the combustor comprise instructions, that when executed by the one or more processors, cause the one or more processors to modulate one or more of;
an inlet guide vane position, a variable stator vane position, a speed, an inlet throttle valve position, a discharge throttle valve position, or a recycle valve position of at least one oxidant compressor disposed upstream of the combustor in response to the over-frequency event. - View Dependent Claims (15)
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Specification