Abstract: Methods and apparatus for control of NOx in catalytic combustion systems, and more particularly to control of thermal or/and prompt NOx produced during combustion of liquid or gaseous fuels in the combustor sections of catalytic combustor-type gas turbines, by controlled injection of water in liquid or vapor form at selected locations, orientations, amounts, rates, temperatures, phases, forms and manners in the compressor and combustor sections of gas turbines. The ratio of thermal NOx ppm reduction to water addition, in weight %, is on the order of 4-20, with % NOx reduction on the order of up to about 50-80% and NOx of below 2 ppm. Liquid water, steam or superheated steam can be used to reduce NOx in combustion systems operating at reaction zone temperatures above 900° C., preferably 1400° C. to 1700° C. The amount of water added is sufficient to provide a concentration of water in the range of from about 0.

Abstract: An aspirating or suction pyrometer for measuring hot combustion gases. A thermocouple in the pyrometer has a temperature sensitive junction formed of platinum alloys. The thermocouple junction is insulated and is encased within a platinum alloy sheath. The sheathed thermocouple is mounted within inner and outer tubular radiation shields. These shields are formed of a platinum alloy having a radiation emissivity substantially the same as the thermocouple. The shields block radiated heat from the flame and combustion chamber from being transferred to the thermocouple. The radiation shields do not themselves radiate heat to the thermocouple because the shields and thermocouple are at the same temperature and formed of substantially the same noble alloys.

Abstract: The burner assembly includes a flow body 12 having a central liquid fuel injection nozzle 14, inner and outer concentric passages 24 and 26, respectively, and a flow duct comprising a venturi downstream of the liquid injection nozzle. The inner passage 24 communicates air and gaseous fuel into the flow duct 16. Swirlers 30 and 38 are provided at the exit ends of the inner and outer passages, respectively, to create counterrotating flows which form a shear layer at the exit of the burner assembly body. The extent of the flow duct 16 facilitates liquid fuel atomization and vaporization, while affording sufficient time for gaseous fuel/air pre-mixing. The arrangement creates a recirculation zone 40 and a shear layer 42 at the exhaust of the burner assembly body which affords flame stabilization.

Abstract: A poppet valve system for controlling the air distribution within the combustor of a gas turbine. The cylindrical combustor includes a concentric combustion lining where air and fuel are mixed and burned near a flame holder, and a dilution air manifold that injects dilution air into the combustion lining downstream of the flame holder. Air enters the dilution air manifold and the liner mixing zone through openings that can be closed by poppet valves. Each poppet valve is operated to close either an opening in the combustion liner to the mixing zone or a corresponding opening in the dilution air manifold. The volume of air mixing with fuel in the mixing zone is controlled by operation of the poppet valves.