General Electric Company

Jeffery Allan Lovett

Wolfgang Daum

Robert J Dunki-Jacobs

Emily Yixie Shu

Steven George Goebel

Louis Jacob Petrucco

Dale M Brown

Masayoshi Kuwata

Warren James Mick

Sanjay M Correa

Anil Gulati

Richard J Borkowicz

John Henry Bowen

Daniel Michael Popa

Dale Marius Brown

David T Foss

An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.

Fiber optic sensors for gas turbine control

A combustor comprises an outer combustor casing defining a plurality of circumferentially adjoining combustion chambers. Each combustion chamber comprises a dome at an upstream end and an outlet at a downstream end. A plurality of pre-mixers are joined to the combustor dome of each respective combustion chamber. The pre-mixers comprise a duct having an inlet at one end for receiving compressed air, an outlet at an opposite end disposed in flow communication with the combustion chamber and a swirler disposed in the duct adjacent the duct inlet for swirling air channeled therethrough. A fuel injector is provided for injecting fuel into the pre-mixer ducts and for mixing with the air in the ducts for flow into the combustion chamber to generate a combustion flame at the duct outlets. A portion of the pre-mixers comprise an altered flameholding capability so as to distribute the resulting combustion flames from the respective portion of the pre-mixers axially downstream with respect to the non-altered pre-mixers so as to reduce the dynamic pressure amplitude of the combustion flames.

Combustors with improved dynamics

A low NOx combustor and method improve dynamic stability of a combustion flame fed by a fuel and air mixture. The combustor includes a chamber having a dome at one end thereof to which are joined a plurality of premixers. Each premixer includes a duct with a swirler therein for swirling air, and a plurality of fuel injectors for injecting fuel into the swirled air for flow into the combustion chamber to generate a combustion flame therein. The fuel injectors are axially staged at different axial distances from the dome to uncouple the fuel from combustion to reduce dynamic pressure amplitude of the combustion flame.

Dynamically uncoupled low nox combustor with axial fuel staging in

The instant invention is directed in general to combustors for gas turbines and, more specifically, to a hybrid can-annular combustor for axial staging in low NOx Combustion. In a preferred embodiment, the instant invention uses premixing stages at different axial positions to carry out axial staging of the heat release for increased operability, where the combustor has a first premixing means for injecting a fuel-air mixture into a can-type configuration for providing the advantages of a can-type combustor for low-load and/or low-temperature conditions and a second premixing means for injecting a fuel-air mixture into an annular-type configuration for providing the advantages of an annular-type combustor for high load and/or high temperature conditions.

Hybrid can-annular combustor for axial staging in low NOx combustors

Dynamically uncoupled low NOx combustor having multiple premixers with

This invention relates to low NOx combustor burners of the type that employ an irregular edge at the edge of the center hub of the combustor burner. Such structures of this type, generally, reduce the strength of combustion instabilities by disrupting the coherent vortices shed from the center hub section of the burner.

Fuel nozzle for low-NOx combustor burners

A system and method periodically sample a fluid stream in a conduit for undergoing analysis thereof. A sampling tube having a probe is joined to the conduit for removing samples from the stream flowing therethrough. An analyzer is joined to the sampling tube for analyzing the removed samples. A solenoid valve is disposed in the tube for controlling flow of the samples to the analyzer. A dynamic pressure transducer is joined to the conduit so that a specific dynamic pressure reference frequency of the stream in the conduit may be locked-on to and used for periodically switching the solenoid valve open and closed for intermittently removing stream samples from the conduit at the reference frequency for channeling to the analyzer periodic stream samples at a sampling frequency corresponding to the reference frequency. In a preferred embodiment, the solenoid valve is switched open at a specific sampling phase in the sampling frequency, which phase may be indexed for obtaining different periodic samples at the sampling frequency for measuring periodic and short duration concentration fluctuations.

Phase resolved sampling system

Combustion-induced instabilities are minimized in gas turbine combustors with a plurality of flameholders disposed on the center hub of each fuel nozzle. The flameholders are streamlined bluffbodies oriented at an angle with respect to the longitudinal axis of the center hub which roughly matches the swirl angle of the fuel nozzle swirl vanes. The flameholders have streamlined upstream faces and flat downstream faces. The flat faces are preferably flush with the bluff end of the center hub. The flameholders, which are equally spaced about the circumference of the center hub, preferably block about 30-50% of the annular cross-sectional area in each burner. Thus, an array of additional flame sheets is produced in each burner without destroying the swirl. These additional flame sheets effectively increase early fuel consumption so that heat release in the main combustion chamber is decreased, thereby reducing combustion instabilities.

Bluffbody flameholders for low emission gas turbine combustors

A fuel nozzle for gas turbine combustors reduces combustion instabilities by injecting purge air into the combustor angularly instead of axially. The fuel nozzle has a substantially cylindrical body with a number of internal passages. One of the passages provides premix gas fuel to a plurality of fuel injectors attached to the fuel nozzle. The remaining passages can be for diffusion gas, atomizing air and liquid fuel. One or more of the remaining passages is connected to a respective group of discharge orifices formed in the cylindrical side surface of the nozzle body. During low NO.sub.x operation, premix gas is introduced through the fuel injectors, and the remaining passages are all purged with air to prevent the ingress of flame gases from the combustion chamber. The resulting jets of air emitted from discharge orifices formed in the side surface will disrupt or break-up spanwise vortices shed from the bluff end of the fuel nozzle, thereby reducing combustion instabilities. These air jets are preferably discharged at an angle of about 45 degrees to the longitudinal axis of the fuel nozzle. The orifices can be rectangular, circular or triangular in shape.

Multi-stage fuel nozzle for reducing combustion instabilities in low NOX

In a gas turbine (10), a plurality of combustors (14), each having a plurality of fuel nozzles (32) arranged about a longitudinal axis of the combustor, and a single combustion zone (70), each fuel nozzle having a diffusion passage (74) and a premix passage (60), the premix passage communicating with a plurality of premix fuel distribution tubes (66) located within a dedicated premix tube (46) adapted to mix the premix fuel and combustion air prior to entry into the single combustion zone (70) located downstream of the premix tube (46).

Growing community of inventors

Scotia, NY, United States of America

Jeffery Allan Lovett