Abstract: Methods and systems are provided for automatically tuning a combustor of a gas turbine engine during a transient period, such as when a state of the gas turbine engine is changing. Once it has been determined whether the state of the gas turbine engine is changing, it is then determined whether a lean blowout is imminent, which is based conditions being monitored. A stability bias is applied to the system if either the state is changing or if lean blowout is imminent until the lean blowout is no longer determined to be imminent. The stability bias monitors operating conditions of the gas turbine engine and determines when one of the operating conditions has overcome a threshold value. Once a threshold value is overcome, a fuel flow fraction is adjusted by a predefined increment. The application of the stability bias is gradually terminated once it is determined that the lean blowout is no longer imminent.

Abstract: The present invention discloses a fuel nozzle assembly and method for axially staging fuel injection. The fuel nozzle assembly comprises a plurality of vanes connected to a core, with an annular ring connectedly surrounding the plurality of vanes. Fuel is directed through the core and then through the vanes and is injected at different axial planes generally perpendicular to an oncoming air stream to obtain a broad spectrum of gas residence time between the point of fuel injection and the flame.

Abstract: Methods and systems for determining that a sensor, such as a pressure sensor, that provides feedback on one or more conditions of a gas turbine is deficient are provided. The amplitude of measurements from the sensor may be monitored in different frequency ranges in order to detect certain abnormal conditions of the gas turbine that require attention by the control system in one frequency range, and also, concurrently and/or separately, detect a sensor deficiency in another frequency range prior to actual failure of the sensor, at which time the failure may otherwise be noticeable in the first frequency range. This permits better detection of deficient sensors during operation of the gas turbine.

Abstract: An auto-tune controller and tuning process implemented thereby for measuring and tuning the combustion dynamics and emissions of a GT engine, relative to predetermined upper limits, are provided. Initially, the tuning process includes monitoring the combustion dynamics of a plurality of combustors and emissions for a plurality of conditions. Upon determination that one or more of the conditions exceeds a predetermined upper limit, a fuel flow split to a fuel circuit on all of the combustors on the engine is adjusted by a predetermined amount. The control system continues to monitor the combustion dynamics and to recursively adjust the fuel flow split by the predetermined amount until the combustion dynamics and/or emissions are operating within a prescribed range of the GT engine. Additionally, a method of automated extended turndown of a GT engine to find a minimum load is provided.

Abstract: The present invention discloses a novel apparatus and way for directing a supply of compressed air into a fuel nozzle assembly for mixing with a fuel source. The apparatus comprises a fuel nozzle assembly having a plurality of coaxial tubes and radially-extending swirler vanes for directing a supply of fuel to a mixing tube. Compressed air is directed to flow in a primarily axial direction by passing through a hemispherically-shaped dome portion at an air inlet region of the fuel nozzle assembly. The hemispherically-shaped dome includes a plurality of openings for directing air into the fuel nozzle assembly in a direction having a radial and axial component.

Abstract: A method for tuning a combustor of a gas turbine engine based on one or more monitored operating conditions is provided. One or more operating conditions of the gas turbine engine are monitored. The monitored operating conditions may include, for example, a low frequency tone, a high frequency tone, and a ratio of the low frequency tone to the high frequency tone. It is determined whether the ratio of the low frequency tone to the high frequency tone is within a first predefined normal range. If the ratio of the low frequency tone to the high frequency tone is within the first predefined normal range, a determination is made not to tune the gas turbine engine. But, if the ratio of the low frequency tone to the high frequency tone is not within the first predefined normal range, a determination is made to tune the gas turbine engine.

Abstract: Methods and systems for determining that a sensor, such as a pressure sensor, that provides feedback on one or more conditions of a gas turbine is deficient are provided. The amplitude of measurements from the sensor may be monitored in different frequency ranges in order to detect certain abnormal conditions of the gas turbine that require attention by the control system in one frequency range, and also, concurrently and/or separately, detect a sensor deficiency in another frequency range prior to actual failure of the sensor, at which time the failure may otherwise be noticeable in the first frequency range. This permits better detection of deficient sensors during operation of the gas turbine.

Abstract: The present invention discloses a novel apparatus and way for directing a supply of compressed air into a fuel nozzle assembly for mixing with a fuel source. The apparatus comprises a fuel nozzle assembly having one or more coaxial flow dividers and radially-extending swirler vanes for directing a supply of fuel to a mixing tube. Compressed air is directed to flow in a primarily axial direction by passing through one or more coaxial flow dividers spaced axially and radially about the air inlet region of the fuel nozzle assembly so as to form a non-uniform radial distribution of compressed air to the inlet region of the fuel nozzle assembly.

Abstract: The present invention discloses a fuel nozzle assembly and method for axially staging fuel injection. The fuel nozzle assembly comprises a plurality of vanes connected to a core, with an annular ring connectedly surrounding the plurality of vanes. Fuel is directed through the core and then through the vanes and is injected at different axial planes generally perpendicular to an oncoming air stream to obtain a broad spectrum of gas residence time between the point of fuel injection and the flame.

Abstract: The present invention discloses a novel apparatus and way for directing a supply of compressed air into a fuel nozzle assembly for mixing with a fuel source. The apparatus comprises a fuel nozzle assembly having a plurality of coaxial tubes and radially-extending swirler vanes for directing a supply of fuel to a mixing tube. Compressed air is directed to flow in a primarily axial direction by passing through a hemispherically-shaped dome portion at an air inlet region of the fuel nozzle assembly.

Abstract: A system and method for improving the cooling to a portion of a combustion liner of a gas turbine combustor is disclosed. The combustion liner is cooled by supplying air through a plurality of cooling holes arranged in axially spaced rows in an upper and lower portion of the liner. The cooling holes are spaced accordingly so as to direct additional cooling flow to an area of the combustion liner not receiving sufficient flow due to maldistributions of air from the compressor discharge.

Abstract: A tuning process is provided for dynamically tuning a gas-turbine (GT) engine to correct for flashback events without directly measuring occurrences of the flashback events at the GT engine. Initially, readings are taken that measure low-frequency dynamics at the GT engine. A determination of whether flashback criteria are met by an instantaneous signal that quantifies a detected spike within the measured low-frequency dynamics is carried out, where the flashback criteria include the following: identifying the spike overcomes a multiple of an average of the low-frequency dynamics measured over a predefined period of time; and identifying the spike overcomes a preestablished minimum amplitude. Upon the spike meeting the flashback criteria, a count is added to a running record of spikes, which is compared to an alarm limit. If the alarm limit is triggered, action(s) are invoked to address the flashback events, such as adjusting fuel-flow splits of the GT engine.

Abstract: Methods and systems are provided for dynamically auto-tuning a gas turbine engine. Initially, parameters of the gas turbine engine are monitored to determine that they are within predefined upper and lower limits such that a margin exists. A first incremental adjustment of an inlet guide vane (IGV) angle is performed. If the monitored parameters are still within the predefined upper and lower limits, a second incremental adjustment of the IGV angle is performed. It is determined that the monitored parameters are still within the predefined upper and lower limits. Additionally, it is determined that a predefined value of the IGV angle has been reached such that the IGV angle is not to be further increased or decreased.

Abstract: A system and method for improving the cooling to a portion of a combustion liner of a gas turbine combustor is disclosed. The combustion liner is cooled by supplying air through a plurality of cooling holes arranged in axially spaced rows in an upper and lower portion of the liner. The cooling holes are spaced accordingly so as to direct additional cooling flow to an area of the combustion liner not receiving sufficient flow due to maldistributions of air from the compressor discharge.

Abstract: Methods and systems are provided for dynamically auto-tuning a gas turbine engine. Initially, parameters of the gas turbine engine are monitored to determine that they are within predefined upper and lower limits such that a margin exists. A first incremental adjustment of an inlet guide vane (IGV) angle is performed. If the monitored parameters are still within the predefined upper and lower limits, a second incremental adjustment of the IGV angle is performed. It is determined that the monitored parameters are still within the predefined upper and lower limits. Additionally, it is determined that a predefined value of the IGV angle has been reached such that the IGV angle is not to be further increased or decreased.

Abstract: An auto-tune controller and tuning process implemented thereby for measuring and tuning the combustion dynamics and emissions of a GT engine, relative to predetermined upper limits, are provided. Initially, the tuning process includes monitoring the combustion dynamics of a plurality of combustors and emissions for a plurality of conditions. Upon determination that one or more of the conditions exceeds a predetermined upper limit, a fuel flow split to a fuel circuit on all of the combustors on the engine is adjusted by a predetermined amount. The control system continues to monitor the combustion dynamics and to recursively adjust the fuel flow split by the predetermined amount until the combustion dynamics and/or emissions are operating within a prescribed range of the GT engine. Additionally, a method of automated extended turndown of a GT engine to find a minimum load is provided.

Abstract: A method for tuning a combustor of a gas turbine engine based on one or more monitored operating conditions is provided. One or more operating conditions of the gas turbine engine are monitored. The monitored operating conditions may include, for example, a low frequency tone, a high frequency tone, and a ratio of the low frequency tone to the high frequency tone. It is determined whether the ratio of the low frequency tone to the high frequency tone is within a first predefined normal range. If the ratio of the low frequency tone to the high frequency tone is within the first predefined normal range, a determination is made not to tune the gas turbine engine. But, if the ratio of the low frequency tone to the high frequency tone is not within the first predefined normal range, a determination is made to tune the gas turbine engine.

Abstract: Methods and systems are provided for automatically tuning a combustor of a gas turbine engine during a transient period, such as when a state of the gas turbine engine is changing. Once it has been determined whether the state of the gas turbine engine is changing, it is then determined whether a lean blowout is imminent, which is based conditions being monitored. A stability bias is applied to the system if either the state is changing or if lean blowout is imminent until the lean blowout is no longer determined to be imminent. The stability bias monitors operating conditions of the gas turbine engine and determines when one of the operating conditions has overcome a threshold value. Once a threshold value is overcome, a fuel flow fraction is adjusted by a predefined increment. The application of the stability bias is gradually terminated once it is determined that the lean blowout is no longer imminent.

Abstract: A tuning process is provided for dynamically tuning a gas-turbine (GT) engine to correct for flashback events without directly measuring occurrences of the flashback events at the GT engine. Initially, readings are taken that measure low-frequency dynamics at the GT engine. A determination of whether flashback criteria are met by an instantaneous signal that quantifies a detected spike within the measured low-frequency dynamics is carried out, where the flashback criteria include the following: identifying the spike overcomes a multiple of an average of the low-frequency dynamics measured over a predefined period of time; and identifying the spike overcomes a preestablished minimum amplitude. Upon the spike meeting the flashback criteria, a count is added to a running record of spikes, which is compared to an alarm limit. If the alarm limit is triggered, action(s) are invoked to address the flashback events, such as adjusting fuel-flow splits of the GT engine.