Abstract: Systems and methods for dual-fuel operation of a gas turbine combustor are provided. An exemplary gas turbine combustor may comprise one or more components, such as a cylindrical combustion liner, a flow sleeve, a main mixer, a radial inflow swirler, a combustor dome, and a fuel cartridge assembly, one or more of which may be configured to supply either a gaseous or a liquid fuel to the combustion liner, depending on whether gaseous fuel operation or liquid fuel operation of the combustor is desired.

Abstract: Gas turbine combustion systems and fuel cartridge assemblies are provided. An exemplary combustion system may comprise a combustor including one or more components, such as a cylindrical combustion liner, a flow sleeve, a main mixer, a radial inflow swirler, a combustor dome, and a fuel cartridge assembly. An exemplary fuel cartridge assembly may comprise first and second fuel manifolds which are connected to respective fuel circuits which supply fuel, such as liquid fuel, through a plurality of fuel passages within the fuel cartridge assembly or to other locations within an associated combustor. The fuel cartridge assembly may further include a plurality of fuel injector tips located at a tip plate of the fuel cartridge assembly through which fuel may be supplied to an associated combustor.

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 novel and improved apparatus and method for reducing the emissions of a gas turbine combustion system. More specifically, a combustion system is provided having a first combustion chamber and a premixer positioned proximate an outlet end of a combustion liner for mixing a second fuel/air mixture with hot combustion gases and burning the subsequent mixture to achieve reduced emissions levels. The premixer is positioned generally about the combustion liner and includes a plurality of channels and fuel injectors for introducing a fuel/air mixture, induced with a swirl, into a second, axially staged combustor.

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 are provided for ensuring non-excessive variation of a gradient of an applied split bias versus firing temperature of a gas turbine engine. It is determined that an incremental split bias step is to be taken, and a current firing temperature of the gas turbine engine is identified on a graph. A first difference between a split schedule and an applied schedule gradient is calculated using lower firing temperatures than the current firing temperature, and a second difference is calculated using higher firing temperatures. If the first difference exceeds a predetermined limit, the incremental split bias step is not allowed at a lower firing temperature, and similarly, if the second difference exceeds a predetermined limit, the incremental split bias step is not allowed at a higher firing temperature.

Abstract: Gas turbine combustion systems and fuel cartridge assemblies are provided. An exemplary combustion system may comprise a combustor including one or more components, such as a cylindrical combustion liner, a flow sleeve, a main mixer, a radial inflow swirler, a combustor dome, and a fuel cartridge assembly. An exemplary fuel cartridge assembly may comprise first and second fuel manifolds which are connected to respective fuel circuits which supply fuel, such as liquid fuel, through a plurality of fuel passages within the fuel cartridge assembly or to other locations within an associated combustor. The fuel cartridge assembly may further include a plurality of fuel injector tips located at a tip plate of the fuel cartridge assembly through which fuel may be supplied to an associated combustor.

Abstract: Gas turbine combustion systems and fuel cartridge assemblies are provided. An exemplary combustion system may comprise a combustor including a cylindrical combustion liner, a flow sleeve, a main mixer, a radial inflow swirler, a combustor dome, and a fuel cartridge assembly. An exemplary combustor and/or fuel cartridge assembly may comprise first and second fuel circuits or manifolds. Methods and systems are also provided for staging and controlling a flow of fuel and/or water through different fuel circuits and pilot injectors, to allow purging and ignition using different fuel circuits, pilot injectors, and fuel sources.

Abstract: Systems and methods for dual-fuel operation of a gas turbine combustor are provided. An exemplary gas turbine combustor may comprise one or more components, such as a cylindrical combustion liner, a flow sleeve, a main mixer, a radial inflow swirler, a combustor dome, and a fuel cartridge assembly, one or more of which may be configured to supply either a gaseous or a liquid fuel to the combustion liner, depending on whether gaseous fuel operation or liquid fuel operation of the combustor is desired.

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: The present invention discloses a novel and improved apparatus and method for reducing the emissions of a gas turbine combustion system. More specifically, a combustion system is provided having a first combustion chamber and a premixer positioned proximate an outlet end of a combustion liner for mixing a second fuel/air mixture with hot combustion gases and burning the subsequent mixture to achieve reduced emissions levels. The premixer is positioned generally about the combustion liner and includes a plurality of channels and fuel injectors for introducing a fuel/air mixture, induced with a swirl, into a second, axially staged combustor.

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.

Abstract: Methods are provided for ensuring non-excessive variation of a gradient of an applied split bias versus firing temperature of a gas turbine engine. It is determined that an incremental split bias step is to be taken, and a current firing temperature of the gas turbine engine is identified on a graph. A first difference between a split schedule and an applied schedule gradient is calculated using lower firing temperatures than the current firing temperature, and a second difference is calculated using higher firing temperatures. If the first difference exceeds a predetermined limit, the incremental split bias step is not allowed at a lower firing temperature, and similarly, if the second difference exceeds a predetermined limit, the incremental split bias step is not allowed at a higher firing temperature.

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.

Abstract: A tuning process is provided for monitoring fuel properties of a fuel being consumed by a gas turbine (GT) engine, and for dynamically tuning the GT engine as a function of changes to the monitored fuel properties. Initially, readings are taken from the GT engine during a reference calibration, or commissioning, and utilized to calculate an initial-pressure-drop reference value. The tuning process during commercial operation takes post-calibration readings from the GT engine to calculate a fuel property parameter, which represents a heating value of the fuel. Specifically, the fuel property parameter is calculated by deriving a corrected-pressure-drop dynamic value as a function of pressure and temperature readings of the fuel at a point upstream of a combustor and pressure drops across fuel nozzles that introduce the fuel into the combustor, and solving a ratio of the dynamic value and the reference value.

Abstract: An indirect-fired gas turbine power plant comprises a compressor; a turbine mechanically coupled to the compressor; a furnace; a heat exchanger inside the furnace and fluidly coupled at an inlet end to the compressor and at an outlet end to the turbine; and means for forming a gas barrier around a portion of the heat exchanger to impede combustion products from contacting the heat exchanger. Such means can be a plurality of gas discharge manifolds located around a portion of the heat exchanger. The manifolds can be coupled to heated working gas exhausted by the turbine.