Abstract: Disclosed is a mixing hole arrangement for improving homogeneity of an air and fuel mixture in a combustor, the mixing hole arrangement comprising a plurality of mixing holes defined by a liner, wherein at least one of the plurality of mixing holes is a mixing hole that is at least one of sized and positioned to impede penetration of a fluid flow into a primary mixing zone located in a head end of the combustor.

Abstract: A gas turbine comprises a plurality of target exhaust temperature determination modules, the plurality of target exhaust temperature modules comprising a nitrogen oxide (NOx) compliance module configured to determine an exhaust temperature at which an exhaust of the gas turbine complies with a maximum permitted level of NOx; at least one bias module, the at least one bias module configured to apply a bias to an output of at least one of the plurality of target exhaust temperature determination modules; and a controller configured to operate the gas turbine to produce the exhaust temperature determined by the NOx compliance module.

Abstract: A combustor includes a burner tube that receives fuel for combustion from a fuel delivery system. An axial swirler is installed in the burner tube. The burner tube is flared downstream of the swirler. The structure provides for improved combustion stability while extending lean blowout and low frequency dynamics margins, which in turn serve to further reduce NOx emissions.

Abstract: A combustor assembly for use in a gas turbine engine and method of assembly is described. The combustor assembly includes a combustor liner having a slot that at least partially circumscribes the combustor liner. The slot is defined adjacent to a venturi throat region defined within the liner. The combustor assembly also includes a restrictor plate having at least one aperture defined therein. The restrictor plate is removably coupled within the combustor assembly such that the restrictor plate is inserted within the slot and extends at least partially across the venturi throat region.

Abstract: A combustor includes a primary combustion chamber and a secondary combustion chamber, one or more primary nozzles disposed in the primary combustion chamber and providing fuel to the primary combustion chamber, a centerbody assembly, a venturi disposed downstream of the centerbody assembly, and a secondary fuel nozzle housed within the centerbody assembly and extending towards the venturi and providing fuel to the secondary combustion chamber. The secondary fuel nozzle includes a fuel passage and an air passage, and a swirler positioned around the fuel passage and having one or more vanes projecting radially within the air passage, each vane having a trailing edge arranged at a swirl angle relative to a longitudinal axis of the secondary fuel nozzle, the swirl angle is greater than 45°.

Abstract: A method for determining a target exhaust temperature for a gas turbine including: determining a target exhaust temperature based on a compressor pressure condition; determining a temperature adjustment to the target exhaust temperature based on at least one parameter of a group of parameters consisting of specific humidity, compressor inlet pressure loss and turbine exhaust back pressure; and adjusting the target exhaust temperature by applying the temperature adjustment.

Abstract: A gas turbine combustor is presented, which includes a combustion chamber that is positioned downstream of a premixing chamber. The premixing chamber includes at least one opening for ingesting air. At least one primary fuel nozzle is disposed to discharge fuel into the premixing chamber. The fuel discharged from the primary fuel nozzle mixes with the ingested air in the premixing chamber to provide a fuel air mix. A secondary fuel nozzle is disposed proximate the combustion chamber to discharge fuel at the combustion chamber. A stabilizer is disposed at the secondary fuel nozzle so as to be positioned in close proximity to a flame when fuel at the secondary fuel nozzle is ignited. The stabilizer is composed of a material having the ability to absorb heat from a heat flux generated within the combustor and maintaining a temperature sufficient to sustain ignition of the flame. A method of stabilizing a flame in a gas turbine combustor is also presented.

Abstract: Disclosed is a leakage reducing venturi for a dry low nitric oxides (NOx) emissions combustor, the venturi including a substantially annular outer liner, a substantially annular inner liner, a venturi channel defined by the annular inner liner and the annular outer liner, the venturi channel including a forward end and an aft end, a forward weld disposed in proximity to the forward end of the venturi channel, the forward weld being configured to connect the annular outer liner with the annular inner liner, and an aft weld disposed in proximity to the aft end of the venturi channel, the aft weld being configured to connect the annular outer liner with the annular inner liner.

Abstract: A dry low nitric oxides (NOx) emissions combustor includes a premixing chamber for mixing fuel and cooling gas and a combustion chamber positioned downstream of the premixing chamber for the combustion of pre-mixed fuel and cooling gas. The combustor further includes a venturi having generally annular walls including converging and diverging wall portions that define a constricted portion and positioned between the premixing chamber and the combustion chamber through which the premixed fuel and air pass to the combustion chamber. The walls defining a passage for cooling gas flow extending axially along the combustion chamber and having an exit for flowing cooling gas to the combustion chamber. A plurality of inlets at the converging and diverging wall portions ingest cooling gas into the passage to produce an impingement cooling effect. A plurality of tubulators disposed downstream of the inlets interact with the cooling gas to produce a turbulated cooling effect.

Abstract: A method of assembling a turbine engine includes defining a first chamber and defining a second chamber. The method also includes forming at least one venturi device oriented with a predetermined venturi step angle greater than approximately 48°. The method further includes coupling the first chamber in flow communication with the second chamber via the venturi device therebetween.

Abstract: A double wall venturi chamber having a converging section, a diverging section and a cylindrical section wherein said chamber defines a venturi zone in which compressed air, fuel and combustion products flow downstream through converging section, diverging section and cylindrical section, and has a cooling gas passage between the walls of the venturi chamber, a least one cooling gas inlet in an outlet wall of the venturi chamber, and at least one cooling gas outlet in an inner wall of the venturi chamber, wherein said cooling gas outlet is in at least one of the diverging and the cylindrical section, and the outlet is downstream of the at least one cooling gas inlet and upstream of an axial end of the chamber.

Abstract: A transition piece body, having an inlet end for receiving combustion products from a turbine combustor and an outlet end for flowing the gaseous products into a first stage nozzle, has dilution holes in zones respectively adjacent the transition piece body inlet and outlet ends. The volume of dilution air flowing into the gas stream is substantially equal at the inlet and outlet ends of the transition piece. The locations and sizes of the openings are given in the respective X, Y, Z coordinates and hole diameters in Table I. The X and Y coordinates lie in the circular plane of the transition body at its inlet end and the Z coordinates extend in the direction of gas flow from the origin.

Abstract: Disclosed is a mixing hole arrangement for improving homogeneity of an air and fuel mixture in a combustor, the mixing hole arrangement comprising a plurality of mixing holes defined by a liner, wherein at least one of the plurality of mixing holes is a mixing hole that is at least one of sized and positioned to impede penetration of a fluid flow into a primary mixing zone located in a head end of the combustor.

Abstract: A method for determining a target exhaust temperature for a gas turbine including: determining a target exhaust temperature based on a compressor pressure condition; determining a temperature adjustment to the target exhaust temperature based on at least one parameter of a group of parameters consisting of specific humidity, compressor inlet pressure loss and turbine exhaust back pressure; and adjusting the target exhaust temperature by applying the temperature adjustment.