Abstract: Methods for controlling a gas turbine engine are provided, where a compressor inlet temperature, ambient temperature, and relative humidity are measured. Utilizing these measurements, it is first determined whether an evaporation cooler is actively importing water content into inlet air entering the compressor. This determination is based on whether the inlet air is substantially cooler than the ambient temperature. If so, an EC correction factor is added to an inlet air temperature value (CTIM) and set as an air temperature parameter (INLETIM). Second, it is determined whether the relative humidity is greater than a predefined threshold. If so, a relative humidity (RH) correction factor is added to CTIM and set as the INLETIM. Next, the INLETIM and TTRF are located in a look-up table, and a bias value corresponding to these inputs is identified. The fuel-flow for a fuel circuit is adjusted according to the identified bias value.

Abstract: Disclosed herein is a system comprising a compressor in mechanical communication with a turbine; the compressor being operative to produce compressed air; a premixer; the premixer being operative to mix a fuel with the compressed air; a carbonator being located downstream of the premixer; the carbonator being operative to receive a mixture of carbon dioxide and syngas and to convert a metal oxide into a metal carbonate by reacting it with the carbon dioxide; a calciner; the calciner being operative to receive the metal carbonate from the carbonator; and to dissociate carbon dioxide from the metal carbonate; and a combustor; the combustor being located downstream of the carbonator; where the combustor is operative to combust syngas received from the carbonator.

Abstract: A combustor end cap assembly having an improved cooling configuration is disclosed. Embodiments of the present invention are directed towards an apparatus and method for cooling an effusion plate of the combustor end cap assembly. The combustor end cap assembly also incorporates an impingement plate having a plurality of cooling holes with the impingement plate positioned a predetermined distance from the effusion plate. The cooling fluid passes through the impingement plate and is directed towards and onto the effusion plate for cooling of the effusion plate.

Abstract: A transition duct having a thermally free aft frame and being capable of adjusting the natural frequency is disclosed. The aft frame is capable of permitting movement due to thermal gradients with the transition duct. The transition duct utilizes a spring plate located adjacent to an aft mounting bracket, where the spring plate, based on its thickness can either increase or decrease a frequency of the transition duct. Such an arrangement ensures that the transition duct natural frequency does not coincide with or cross other critical engine and/or combustor frequencies.

Abstract: Tuning processes implemented by an auto-tune controller are provided for measuring and adjusting the combustion dynamics and the emission composition of a gas turbine (GT) engine via a tuning process. Initially, the tuning process includes monitoring parameters, such as combustion dynamics and emission composition. Upon determining that one or more of the monitored parameters exceed a critical value, these “out-of-tune” parameters are compared to a scanning order table. Upon comparison, the first out-of-tune parameter that is matched within the scanning order table is addressed. The first out-of-tune parameter is then plotted as overlaid slopes on respective graphs, where the graph represents a fuel-flow split. Typically, the slopes are plotted as a particular out-of-tune parameter against a particular fuel-flow split. The slopes for each graph are considered together by taking into account the combined impact on each out-of-tune parameter when a fuel-flow split is selected for adjustment.

Abstract: A transition duct assembly with a thermally free aft frame and mounting system for use in a gas turbine engine are disclosed. The aft frame is capable of adjusting to thermal gradients while the mounting system provides for at least transverse movement of the transition duct during engine assembly. The mounting system also provides a means for raising the natural frequency of the transition duct outside of the engine's dynamic excitation ranges.

Abstract: A system and method for tuning a gas turbine combustion system having a plurality of seals positioned between the combustion system and the turbine inlet is disclosed. The system and method provide ways of permitting a predetermined amount of compressed air to bypass the combustion system and enter the turbine so as to control emissions and dynamics of the combustion system. The seals contain a plurality of holes to meter airflow passing therethrough and are positioned such that they can be removed from the engine and modified to increase or decrease the amount of air passing therethrough.

Abstract: Embodiments for an apparatus and associated method for providing a cooling fluid to a gas turbine transition duct in order to lower the effective operating temperatures of the transition duct are disclosed. The transition duct has an inner liner and an impingement sleeve positioned radially outward with a passageway formed therebetween. The impingement sleeve has a plurality of openings where a portion of the openings each have a feed tube extending through the opening and into the passageway. The feed tubes are oriented at an angle relative to the impingement sleeve, such that an inlet to the feed tube is directed generally towards an oncoming flow of cooling fluid. The feed tubes direct a portion of the cooling fluid toward the inner liner and into the passageway for cooling of the transition duct.

Abstract: Embodiments for minimizing relative thermal growth within a fuel nozzle of a gas turbine combustor are disclosed. Fuel nozzle configurations are provided in which a heating fluid is provided to one or more passages in a fuel nozzle from feed holes in the fuel nozzle base. The heating fluid passes through the fuel nozzle, thereby raising the operating temperature of portions of the fuel nozzle to reduce differences in thermal gradients within the fuel nozzle. Various fuel nozzle configurations and passageway geometries are also disclosed.

Abstract: Embodiments for an apparatus and associated method for reducing the residence time in a gas turbine combustor are disclosed. The embodiments of the present invention comprise a fuel nozzle that extends to a downstream plane of an end cap for a combustion liner where the axial distance of the premixer is reduced, however the swirl for mixing the fuel and air, is increased. As a result, the mixing of the fuel and air is essentially unchanged, thereby allowing higher air pressures and operating temperatures within the premixer without inducing auto-ignition.

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: Methods for controlling a gas turbine engine are provided, where a compressor inlet temperature, ambient temperature, and relative humidity are measured. Utilizing these measurements, it is first determined whether an evaporation cooler is actively importing water content into inlet air entering the compressor. This determination is based on whether the inlet air is substantially cooler than the ambient temperature. If so, an EC correction factor is added to an inlet air temperature value (CTIM) and set as an air temperature parameter (INLETIM). Second, it is determined whether the relative humidity is greater than a predefined threshold. If so, a relative humidity (RH) correction factor is added to CTIM and set as the INLETIM. Next, the INLETIM and TTRF are located in a look-up table, and a bias value corresponding to these inputs is identified. The fuel-flow for a fuel circuit is adjusted according to the identified bias value.

Abstract: Tuning processes implemented by an auto-tune controller are provided for measuring and adjusting the combustion dynamics and the emission composition of a gas turbine (GT) engine via a tuning process. Initially, the tuning process includes monitoring parameters, such as combustion dynamics and emission composition. Upon determining that one or more of the monitored parameters exceed a critical value, these “out-of-tune” parameters are compared to a scanning order table. Upon comparison, the first out-of-tune parameter that is matched within the scanning order table is addressed. The first out-of-tune parameter is then plotted as overlaid slopes on respective graphs, where the graph represents a fuel-flow split. Typically, the slopes are plotted as a particular out-of-tune parameter against a particular fuel-flow split. The slopes for each graph are considered together by taking into account the combined impact on each out-of-tune parameter when a fuel-flow split is selected for adjustment.

Abstract: A system and way for controlling a gas turbine engine in the event of a partial or full load rejection from a generator is disclosed. Upon detection of a partial or full load rejection, the fuel flow of the combustor is directed to a secondary circuit of a secondary fuel nozzle to maintain a flame in a downstream chamber of the combustor. By maintaining the flame in the downstream chamber while the engine speed is controlled, the recovery process to a load condition avoids use of spark ignition system and flame detectors in the upstream chamber.

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: A gas turbine combustor having a self-purging pilot fuel injection system and method of operation thereof is disclosed. The pilot fuel injection system comprises a radial inflow swirler, a generally axially extending centerbody, and at least one fuel injection source. In operation a fluid containing at least air passes along the centerbody outer surface clearing any remaining fuel from proximate the fuel injection source so as to prevent flame attachment proximate the fuel injection source.

Abstract: A fuel supply system and method thereof that utilizes an off-gas in addition to the primary fuel to lower the emissions of a gas turbine combustion system is disclosed. The fuel supply system apparatus comprises a fuel gas supply conduit and an off-gas supply conduit in fluid communication with the fuel gas supply conduit such that the flow of an off-gas to the fuel gas supply conduit can be regulated as required by the operator to the desired fuel nozzle(s). The fuel gas supply preferably operates with natural gas and the off-gas supply preferably comprises the constituents hydrogen and methane.

Abstract: A combustor end cap assembly having an improved cooling configuration is disclosed. Embodiments of the present invention are directed towards an apparatus and method for cooling an effusion plate of the combustor end cap assembly. The combustor end cap assembly also incorporates an impingement plate having a plurality of cooling holes with the impingement plate positioned a predetermined distance from the effusion plate. The cooling fluid passes through the impingement plate and is directed towards and onto the effusion plate for cooling of the effusion plate.

Abstract: A transition duct having a thermally free aft frame and being capable of adjusting the natural frequency is disclosed. The aft frame is capable of permitting movement due to thermal gradients with the transition duct. The transition duct utilizes a spring plate located adjacent to an aft mounting bracket, where the spring plate, based on its thickness can either increase or decrease a frequency of the transition duct. Such an arrangement ensures that the transition duct natural frequency does not coincide with or cross other critical engine and/or combustor frequencies.

Abstract: Embodiments for minimizing relative thermal growth within a fuel nozzle of a gas turbine combustor are disclosed. Fuel nozzle configurations are provided in which a heating fluid is provided to one or more passages in a fuel nozzle from feed holes in the fuel nozzle base. The heating fluid passes through the fuel nozzle, thereby raising the operating temperature of portions of the fuel nozzle to reduce differences in thermal gradients within the fuel nozzle. Various fuel nozzle configurations and passageway geometries are also disclosed.