A gas turbine combustion instability control device has a combustion unit provided with a hollow combustion chamber, a gas turbine connected to the inside of the combustion chamber and a dynamic pressure sensor which is provided to the inside of the combustion chamber and measures the combustion dynamics of the inside of the combustion chamber; a diagnosis module which processes combustion dynamic pressure signals (p) according to the combustion dynamics measured by the dynamic pressure sensor to calculate the kurtosis value (k) of the dynamic pressure signals, and compares the same with a kurtosis reference value (k.sub.th) to evaluate the combustion instability; and a combustion control unit for controlling the operation of the combustion part according to the determination of the diagnosis module.

Provided are more efficient techniques for operating gas turbine systems. In one embodiment a gas turbine system comprises an oxidant system, a fuel system, a control system, and a number of combustors adapted to receive and combust an oxidant from the oxidant system and a fuel from the fuel system to produce an exhaust gas. The gas turbine system also includes a number of oxidant-flow adjustment devices, each of which are operatively associated with one of the combustors, wherein an oxidant-flow adjustment device is configured to independently regulate an oxidant flow rate into the associated combustor. An exhaust sensor is in communication with the control system. The exhaust sensor is adapted to measure at least one parameter of the exhaust gas, and the control system is configured to independently adjust each of the oxidant-flow adjustment devices based, at least in part, on the parameter measured by the exhaust sensor.

A system includes a gas turbine system having a first compressor, a combustor, and a turbine, where the first compressor provides a first portion of a discharge air directly to the combustor. The system includes a fluid circuit which receives a fluid comprising a second portion of the discharge air from the first compressor or a combustible fluid and provides the second portion of the discharge air to fuel at a location upstream of the combustor to alter a chemical and physical characteristic of the fuel in an air-fuel mixture that is provided to the combustor.

A system includes a control system. The control system includes a coherence derivation system configured to derive a coherence between respective outputs of each of a plurality of combustors coupled to a gas turbine system, and a phase derivation system configured to derive a phase difference between the respective outputs of each of the plurality of combustors coupled to the gas turbine system. The control system is configured to derive an indication of an impending lean blowout (LBO) or an actual LBO of at least one of the plurality of combustors based at least in part on the coherence derivation, the phase derivation, or a combination thereof.

In one embodiment, a system includes a turbine combustor having a combustor liner disposed about a combustion chamber, a head end upstream of the combustion chamber relative to a downstream direction of a flow of combustion gases through the combustion chamber, a flow sleeve disposed at an offset about the combustor liner to define a passage, and a barrier within the passage. The head end is configured to direct an oxidant flow and a first fuel flow toward the combustion chamber. The passage is configured to direct a gas flow toward the head end and to direct a portion of the oxidant flow toward a turbine end of the turbine combustor. The gas flow includes a substantially inert gas. The barrier is configured to block the portion of the oxidant flow toward the turbine end and to block the gas flow toward the head end within the passage.

Provided are more efficient techniques for operating gas turbine systems. In one embodiment a gas turbine system comprises an oxidant system, a fuel system, a control system, and a number of combustors adapted to receive and combust an oxidant from the oxidant system and a fuel from the fuel system to produce an exhaust gas. The gas turbine system also includes a number of oxidant-flow adjustment devices, each of which are operatively associated with one of the combustors, wherein an oxidant-flow adjustment device is configured to independently regulate an oxidant flow rate into the associated combustor. An exhaust sensor is in communication with the control system. The exhaust sensor is adapted to measure at least one parameter of the exhaust gas, and the control system is configured to independently adjust each of the oxidant-flow adjustment devices based, at least in part, on the parameter measured by the exhaust sensor.

A computer system includes a processor controls the computer system to perform a computer-implemented method of determining a minimum humidity required for formation and persistence of contrails produced by an engine of an aircraft. The computer-implemented method includes determining engine performance model parameters of the engine at desired operating conditions with zero humidity; determining additional energy flow out of the engine; and determining an exhaust plume temperature scaling factor. The method further comprises determining a contrail engine efficiency parameter (noverall_) based on additional energy flow out of the engine and the exhaust plume temperature scaling factor; and generating an improved Schmidt-Appleman equation based on the contrail engine efficiency parameter (noverall_). The method further includes determining an improved mixing line slope based on the improved Schmidt-Appleman equation; and determining the minimum humidity required for formation and persistence of contrails produced by the engine based on the improved mixing line slope.

Systems and methods for frequency separation in a gas turbine engine are provided herein. The systems and methods for frequency separation in a gas turbine engine may include determining a hot gas path natural frequency, determining a combustion dynamic frequency, and modifying a compressor discharge temperature to separate the combustion dynamic frequency from the hot gas path natural frequency. Specifically, the compressor discharge temperature may be modified by adjusting the inlet guide vanes of the compressor or by adjusting a temperature of air entering the compressor.

Methods and a sensor module for use in controlling operation of a gas turbine system are provided herein. The sensor module is coupled within a combustion system and is configured to obtain an aspirated exhaust sample of exhaust flowing through an exhaust duct. The exhaust is generated by the combustion system. The aspirated exhaust sample is analyzed to determine a plurality of exhaust parameters. The sensor module also controls at least one combustion system parameter in a closed loop emission control (CLEC) system based on at least one of the plurality of exhaust parameters.

A system and method for operating a gas turbine include a controller that determines, for at least one combustion instability, a frequency; a quantification of the frequency or a quantification of the frequency through time; and, optionally, a phase and/or an amplitude. The logic also causes the controller to compare the frequency, the quantification of the frequency or the quantification of the frequency through time, the phase, and/or the amplitude of the at least one combustion instability to an associated predetermined limit. When the frequency is actionable relative to its predetermined limit and one of the quantification of the frequency or the quantification of the frequency through time is actionable relative to its respective predetermined limit, at least one parameter of the gas turbine is adjusted. The quantification of the frequency is one of the standard deviation, the coefficient of variation, the index of dispersion, and the variance.