A fuel injector assembly for a gas turbine engine includes a centerbody extended along a lengthwise direction, the centerbody defining a first fuel nozzle, and an annular shroud defining a second fuel nozzle directly surrounding the centerbody and extended along the lengthwise direction. A passage is defined through the annular shroud and extended generally along the lengthwise direction. The passage defines an exit opening disposed at a downstream end adjacent to the combustion chamber and in fluid communication therewith. The annular shroud defines a fuel inlet opening disposed at an upstream end of the passage. The annular shroud defines an air inlet opening in fluid communication with the passage. The air inlet opening is disposed between the fuel inlet opening and the exit opening.

The gas turbine combustor and the operation method thereof are designed to minimize visualization of exhaust gas from the gas turbine upon switching of the gas turbine fuel from the oil fuel to the gas fuel. Upon switching of the combustion by the pilot burner from the oil burning to the gas burning, the gas fuel is supplied to the main burners so as to start the gas burning. Then the gas fuel is supplied to the pilot burner to start the gas burning.

An ignition system includes a pulverized fuel pipe receiving a mixture of pulverized fuel and primary air for injection into a combustion chamber for combustion, and an igniter received within the pulverized fuel pipe for igniting the mixture. The igniter is axially movable within the pulverized fuel pipe.

A burner assembly having a blower housing, a blower to supply air to the burner assembly, a blast tube having a longitudinal axis, a fuel source to supply fuel to the burner assembly, a center tube that is substantially parallel to the longitudinal axis and conveys air and fuel to a center tube burner end opening, a plurality of premix tubes, each of which is substantially parallel to the longitudinal axis and conveys air and fuel to a premix tube burner end opening, a diffuser that is disposed in the center tube near the center tube burner end opening, a nozzle that is disposed in the center tube substantially perpendicular to the diffuser. The center tube air and fuel mixture is fuel rich and the premix tubes air and fuel mixture is fuel lean. A method for burning the center tube air and fuel mixture and the premix tubes mixtures.

Sparkless igniters for pilot services comprising hot surface igniter elements, and methods for operating these igniters without the use of flame rods or thermocouples. The electrical resistance of the hot surface igniter element is measured and used to control the operation of the igniters using a suitable burner management system. The measured electrical resistance may also be manipulated to yield a control parameter for use in the burner management system. The igniters are designed to prevent quenching of the hot surface elements by the fuel-air mixture. The igniters optionally permit easy swap out of hot surface igniter elements.

According to embodiments, burner systems include a distal flame holder and distal pilot burner formed at least partially from shared structure.

The present disclosure is directed to a fuel injector assembly and a gas turbine engine including the fuel injector assembly. The fuel injector assembly includes a centerbody extended along a lengthwise direction. The centerbody defines a first fuel nozzle. An annular shroud defining a second fuel nozzle surrounds the centerbody and is extended along the lengthwise direction. A passage is defined through the annular shroud and extended generally along the lengthwise direction. The passage defines an exit opening disposed at a downstream end adjacent to the combustion chamber and in fluid communication therewith. The annular shroud defines a fuel inlet opening disposed at an upstream end of the passage. The annular shroud further defines an air inlet opening in fluid communication with the passage. The air inlet opening is disposed between the fuel inlet opening and the exit opening.

A combustion system includes an electrically actuated flame location control mechanism.

A combustion system includes an electrically actuated flame location control mechanism.

A modulating burner apparatus includes a burner and a blower placed upstream of the burner. A venturi is placed upstream of the blower. A damper valve is placed upstream of the venturi. The damper valve has an open position and a restricted position. A smaller gas valve and a larger gas valve are communicated with the venturi. A controller is operably associated with the system to select a position of the damper valve and to select the appropriate one of the gas valves so as to provide a low output operation mode and a high output operation mode, which in combination provide an overall turndown ratio of at least 25:1.