Abstract: A system and process for restarting a turbomachine includes a shutdown cooldown protection process implemented by a plant level control system or direct control system of the turbomachine. The system and process for restarting ensure rotating components are cooled as expected prior to a unit restart. This system and process for restarting will lockout an ability to restart if an improper cooldown of rotating components is detected. If this lockout is enabled, delaying restart for the rotating components to cool naturally is needed, or the operator could decide to force cool the components.

Abstract: In a gas turbine engine that includes a compressor and a combustor, wherein the combustor includes a primary fuel injector within a fuel nozzle and a secondary fuel injector that is upstream of the fuel nozzle and configured to inject fuel into a flow annulus of the combustor, a method for detecting a flame holding condition about a fuel injector. The method may include the steps of: detecting an upstream pressure upstream of the secondary fuel injector; detecting a downstream pressure downstream of the secondary fuel injector; determining a measured pressure difference between the upstream pressure and the downstream pressure; and comparing the measured pressure difference to an expected pressure difference.

Abstract: Optical flame holding and flashback detection systems and methods are provided. Exemplary embodiments include a combustor including a combustor housing defining a combustion chamber having combustion zones, flame detectors disposed on the combustor housing and in optical communication with the combustion chamber, wherein each of the flame detectors is configured to detect an optical property related to one or more of the combustion zones.

Abstract: Systems and methods for avoidance and correction of potentially adverse combustion states such as flame holding and flashback are disclosed. According to one embodiment of the disclosure, one or more sensors acquire sensor data from one or more sensors associated with combustion. An operational limit margin (OLM) is calculated using an OLM model and based at least in part on the sensor data. A determination is made as to the presence of a potentially adverse combustion state based at least in part on the OLM and the model. Once determined, corrective action may be taken to avoid an adverse combustion event prior to occurrence of the event.

Abstract: A combustor of a turbine engine having a combustion zone defined therein is provided and includes a fuel nozzle, including two or more burners, each of the burners having a passage defined therein through which combustible materials are permitted to travel toward the combustion zone, a plurality of sensors disposed in relative association with each of the burners to respectively sense static pressures within the passages of each of the burners and to respectively issue sensed static pressure signals accordingly, and a controller, coupled to the sensors and receptive of the signals, which is configured to determine from an analysis of the signals whether any of the burners are associated with a flashback risk and to mitigate the flashback risk in accordance with the determination.

Abstract: In a gas turbine engine that includes a compressor and a combustor, wherein the combustor includes a primary fuel injector within a fuel nozzle and a secondary fuel injector that is upstream of the fuel nozzle and configured to inject fuel into a flow annulus of the combustor, a method for detecting a flame holding condition about a fuel injector. The method may include the steps of: detecting an upstream pressure upstream of the secondary fuel injector; detecting a downstream pressure downstream of the secondary fuel injector; determining a measured pressure difference between the upstream pressure and the downstream pressure; and comparing the measured pressure difference to an expected pressure difference.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for confirming ignition in a gas turbine. According to an example embodiment of the invention, a method is provided for confirming ignition associated with a gas turbine combustor. The method can include receiving one or more permissive signals associated with one or more gas flow control valves, receiving one or more fuel supply pressure signals, receiving one or more fuel igniter signals, and receiving one ore more compressor pressure discharge (CPD) signals. The method can also include determining an ignition status associated with the gas turbine combustor based at least in part on the one or more permissive signals, the one or more fuel supply pressure signals, the one or more fuel igniter signals, and a qualified change in the one or more CPD signals. The method can also include outputting an ignition status signal based on the determined ignition status.

Abstract: According to one aspect of the invention, a combustor is disclosed. The combustor can include a combustor housing, a plurality of nozzles disposed within the combustor housing, and a flame detector disposed on and in optical communication with each of the plurality of fuel nozzles, wherein each flame detector is configured to detect an optical property related to at least one of a flame holding condition and a flashback condition in a respective fuel nozzle.

Abstract: Disclosed is a method and system for determining composition of a fuel entering a combustor. The method includes determining a temperature of the fuel entering the combustor, calculating a first estimated total fuel flow utilizing fuel properties and fuel nozzle effective area (Ae), and calculating a second estimated total fuel flow utilizing an aero-thermal cycle model analysis. The first estimated total fuel flow is compared to the second estimated total fuel flow and a lower heating value of the fuel is determined from a difference between the first estimated total fuel flow and the second estimated total fuel flow. A method and system for controlling a gas turbine includes calculating effects of the fuel composition on performance of the gas turbine and comparing one or more performance parameters to one or more parameter limits. One or more machine controls of the gas turbine are changed based on the results of the comparison.

Abstract: A combustor of a turbine engine having a combustion zone defined therein is provided and includes a fuel nozzle, including two or more burners, each of the burners having a passage defined therein through which combustible materials are permitted to travel toward the combustion zone, a plurality of sensors disposed in relative association with each of the burners to respectively sense static pressures within the passages of each of the burners and to respectively issue sensed static pressure signals accordingly, and a controller, coupled to the sensors and receptive of the signals, which is configured to determine from an analysis of the signals whether any of the burners are associated with a flashback risk and to mitigate the flashback risk in accordance with the determination.

Abstract: A method and system for reducing the amount of nitrogen oxides (NOx) in a combustion gas waste stream by (1) analyzing the waste stream to determine the amount of NOx; (2) determining the stoichiometric amount of ammonia required to reduce the NOx concentration down to a required level or less; (3) determining the flow rate profile of NOx components across the combustion gas waste stream upstream of an ammonia injection grid; (4) selecting specific locations within the ammonia injection grid to activate ammonia valves; (5) injecting controlled amounts of ammonia vapor into the gas stream at grid locations corresponding to the location of NOx in the gas stream; and (6) treating the gas stream using a selective catalytic reduction unit to reduce the amount of NOx down to acceptable levels.

Abstract: Optical flame holding and flashback detection systems and methods are provided. Exemplary embodiments include a combustor including a combustor housing defining a combustion chamber having combustion zones, flame detectors disposed on the combustor housing and in optical communication with the combustion chamber, wherein each of the flame detectors is configured to detect an optical property related to one or more of the combustion zones.

Abstract: Disclosed is a method and system for determining composition of a fuel entering a combustor. The method includes determining a temperature of the fuel entering the combustor, calculating a first estimated total fuel flow utilizing fuel properties and fuel nozzle effective area (Ae), and calculating a second estimated total fuel flow utilizing an aero-thermal cycle model analysis. The first estimated total fuel flow is compared to the second estimated total fuel flow and a lower heating value of the fuel is determined from a difference between the first estimated total fuel flow and the second estimated total fuel flow. A method and system for controlling a gas turbine includes calculating effects of the fuel composition on performance of the gas turbine and comparing one or more performance parameters to one or more parameter limits. One or more machine controls of the gas turbine are changed based on the results of the comparison.

Abstract: Disclosed is a method and system for determining composition of a fuel entering a combustor. The method includes determining a temperature of the fuel entering the combustor, calculating a first estimated total fuel flow utilizing fuel properties and fuel nozzle effective area (Ae), and calculating a second estimated total fuel flow utilizing an aero-thermal cycle model analysis. The first estimated total fuel flow is compared to the second estimated total fuel flow and a lower heating value of the fuel is determined from a difference between the first estimated total fuel flow and the second estimated total fuel flow. A method and system for controlling a gas turbine includes calculating effects of the fuel composition on performance of the gas turbine and comparing one or more performance parameters to one or more parameter limits. One or more machine controls of the gas turbine are changed based on the results of the comparison.

Abstract: Disclosed is a method and system for controlling a combustor of a gas turbine utilizing fuel nozzle equivalence ratio. The equivalence ratio of at least one fuel nozzle of the combustor, the combustor having at least one fuel nozzle disposed in at least one combustor can, is measured. The measured equivalence ratio is compared to a threshold value for lean blowout. The fuel flow from the at least one nozzle is modified thereby adjusting the equivalence ratio to prevent lean blowout.

Abstract: Disclosed is a method and system for determining composition of a fuel entering a combustor. The method includes determining a temperature of the fuel entering the combustor, calculating a first estimated total fuel flow utilizing fuel properties and fuel nozzle effective area (Ae), and calculating a second estimated total fuel flow utilizing an aero-thermal cycle model analysis. The first estimated total fuel flow is compared to the second estimated total fuel flow and a lower heating value of the fuel is determined from a difference between the first estimated total fuel flow and the second estimated total fuel flow. A method and system for controlling a gas turbine includes calculating effects of the fuel composition on performance of the gas turbine and comparing one or more performance parameters to one or more parameter limits. One or more machine controls of the gas turbine are changed based on the results of the comparison.

Abstract: The systems and method may include receiving a plurality of measured tuning inputs associated with an operating parameter of an engine, providing a plurality of parameter estimation modules that utilize one or more component performance maps having adjustable knobs to generate model outputs, where each parameter estimation module is configured independently of a respective one of the operating parameters of the engine, and where each parameter estimation module generates the model outputs based upon fundamental inputs associated with the engine. The systems and methods may further include calculating residual values for each parameter estimation module, adjusting knobs of each parameter estimation module, and determining that a sensor associated with a measured tuning input or a fundamental input is faulty based at least in part upon values of the knobs and residual values.