Abstract: A combustor for a gas turbine having primary and secondary combustion zones. The combustor has a centrally disposed dual fuel nozzle that can supply a fuel rich mixture of either liquid or gaseous fuel to the primary combustion zone. The combustor also has primary gas fuel spray pegs for supplying a lean mixture of gaseous fuel to the primary combustion zone via a first annular pre-mixing passage and secondary dual fuel spray bars for supplying a lean mixture of either gaseous or liquid fuel to the secondary combustion zone via a second annular pre-mixing passage. The dual fuel spray bars are aerodynamically shaped and have passages for distributing gas and liquid fuel to a number of fuel discharge ports. The gas fuel discharge ports are formed in two rows on either side of the spray bar. The liquid fuel discharge ports are formed by a row of spray nozzles arranged along the downstream edge of the spray bar.

Abstract: A combustor for a gas turbine having primary and secondary combustion zones. The combustor has primary gas fuel spray pegs for supplying a lean mixture of gaseous fuel to the primary combustion zone via a first annular pre-mixing passage and secondary fuel spray bars for supplying a lean mixture of fuel to the secondary combustion zone via a second annular pre-mixing passage. The fuel spray bars are aerodynamically shaped and a row of fuel discharge ports are formed on opposing sides of the spray bar. A pair of mixing fins project outwardly from the spray bar sides. The fins create turbulence in the air flow that ensures adequate mixing of the fuel and air. The fins have sufficient height and are displaced sufficiently far from the fuel discharge ports so that although the turbulence has not dissipated by the time the air flow reaches the fuel discharge ports, the zone of recirculation located downstream from the fins does not extend to the fuel discharge ports.

Abstract: A combustor for a gas turbine having a centrally located fuel nozzle and inner, middle and outer concentric cylindrical liners, the inner liner enclosing a primary combustion zone. The combustor has an air inlet that forms two passages, each of which has a circumferential array of individually rotatable swirl vanes. The swirl vanes are mounted on axially oriented primary fuel pegs that extend through the air inlet passages. The middle and outer liners form an outer annular passage in which radially oriented secondary fuel pegs are disposed. The middle and inner liners form an inner annular passage that is supplied with cooling air. A perforated circumferentially extending baffle is locating in the inner annular passage and directs the cooling air to flow over the inner liner.

Abstract: A combustor for a gas turbine having primary and secondary combustion zones. The combustor has a centrally disposed dual fuel nozzle that can supply a fuel rich mixture of either liquid and gaseous fuel to the primary combustion zone. The combustor also has primary gas fuel spray bars for supplying a lean mixture of gaseous fuel to the primary combustion zone via a first annular pre-mixing passage and secondary gas fuel spray bars for supplying a lean mixture of gaseous fuel to the secondary combustion zone via a second annular pre-mixing passage. In addition, the combustor also has a plurality of liquid fuel spray nozzles for introducing a lean mixture of liquid fuel into the secondary combustion zone via the second annular pre-mixing passage. The liquid fuel spray nozzles are disposed in fan shaped channels that are arranged in a circumferential array and that are connected to the second annular pre-mixing passage.

Abstract: An ultra-low NOx gas turbine combustor having a dual fuel capability. The combustor has a pre-mixing zone and a downstream combustion zone. The pre-mixing zone has three concentric annular passages that surround a central diffusion-type dual fuel nozzle. A gas fuel manifold distributes gas fuel around the inner and outer passages. A plurality of dual fuel nozzles are disposed in the middle passage to distribute either gas or oil fuel around the middle passage. The distribution of fuel around the passages allows the formation of lean fuel/air ratios, thereby lowering NOx formation. In addition, swirl vanes are arrayed around the inner and outer passages and around each of the fuel nozzles. A step increase in the flow area in going from the pre-mixing zone to the combustion zone creates vortices that tend to anchor the flame.

Abstract: 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).