Abstract: A method for determining when a combustor is experiencing hardware damage includes sensing acoustic vibrations of a plurality of combustor cans, determining a center frequency for each acoustic tone of the sensed acoustic vibrations within a predetermined frequency range, and indicating an alarm when a center frequency of one or more of the combustor cans changes in a different manner compared to a representative center frequency of the plurality of combustor cans.

Abstract: A method for determining a lean blow out condition for a combustor. In an exemplary embodiment, the method includes determining acoustical frequency data for the combustor, determining a combustor flame temperature based on the acoustical frequency data, determining an existing fuel/air ratio in the combustor based on the combustor flame temperature, and comparing the existing fuel/ratio to a lean blow out fuel/air ratio. A lean blow out condition for the combustor is indicated when the existing fuel/air ratio is about equal to the lean blow out fuel/air ratio.

Abstract: A method of determining the temperature inside a combustion liner without making a direct measurement of the actual temperature. The technique is based on a measurement of the frequency of one of the transverse acoustic modes occurring inside the combustion chamber. The frequency is determined from the transverse geometric dimensions of the combustion chamber and the speed of sound in the gas inside the combustion chamber. The speed of sound in the gas is known from thermodynamics to be a function of gas temperature and gas properties. Thus, from a measurement of the resonant frequency and knowing the combustor dimensions and gas properties, the temperature can be determined with accuracy.

Abstract: In a gas turbine having a compressor, a combustor and a turbine, a gaseous fuel supply coupled to provide gaseous fuel to the combustor, a liquid fuel supply coupled to provide liquid fuel to the combustor via nozzle assembly. The nozzle assembly includes a plurality of passageways for flowing a fluid into the combustor, one of the passageways being an atomizing air passageway conduit interconnecting the atomizing air passageway to one of the plurality of passageways to enable fluid flow therebetween, while not allowing the flow of fluid back into the atomizing air passageway. High pressure air from the atomizing air passageway is diverted into one of the plurality of passageways via the conduit to protect the nozzle from ingestion of hot combustor gases, thus eliminating a need for a dedicated air purge system for that one of the plurality of passageways.