Abstract: Systems and methods for supplying fuel to a gas turbine are described. A fuel may be received, and one or more parameters associated with the received fuel may be determined. Based at least in part upon the determined one or more parameters, a desired pressure for removing one or more liquids from the fuel utilizing a separator may be calculated. The operation of a pressure changing device may then be controlled in order to achieve the desired pressure. In certain embodiments, the operations of the method may be performed by a controller that includes one or more computers.

Abstract: Systems and methods for supplying fuel to a gas turbine are described. A fuel may be received, and one or more parameters associated with the received fuel may be determined. Based at least in part upon the determined one or more parameters, a desired pressure for removing one or more liquids from the fuel utilizing a separator may be calculated. The operation of a pressure changing device may then be controlled in order to achieve the desired pressure. In certain embodiments, the operations of the method may be performed by a controller that includes one or more computers.

Abstract: A method and system for modulating the Modified Wobbe Index (MWI) of a fuel is provided. A variety of industrial components, which may require a gas fuel, such as but not limiting of, a heavy-duty gas turbine; an aero-derivative gas turbine; or a boiler may utilize the method and system. The method and system may provide an industrial component comprising at least one steam injection system, wherein the at least one steam injection system injects steam into at least one fuel supply line upstream of a combustion system to modulate the MWI of at least one fuel. The method and system may also determine whether the MWI of the at least one fuel is outside of a predetermined range; and utilize the at least one steam injection system to automatically inject the steam at a flowrate for adjusting the MWI of the at least one fuel.

Abstract: A system for supplying fuel to a gas turbine includes piping containing fuel at a pressure greater than approximately 500 psi. A pressure reducing valve connected downstream of the piping reduces the pressure of the fuel to less than approximately 200 psi. A heat exchanger connected downstream of the pressure reducing valve heats the wet saturated fuel or dry saturated fuel to produce a superheated fuel. A control valve connected downstream of the heat exchanger reduces the pressure of the superheated fuel to less than approximately 50 psi. A method for supplying superheated fuel to a gas turbine includes receiving fuel having a pressure greater than approximately 500 psi and reducing the pressure to less than approximately 200 psi. The method further includes separating gaseous fuel from liquid fuel, reducing the pressure of the gaseous fuel to less than approximately 50 psi, and flowing the superheated fuel to the gas turbine.

Abstract: A method and system for modulating the Modified Wobbe Index (MWI) of a fuel is provided. A variety of industrial components, which may require a gas fuel, such as but not limiting of, a heavy-duty gas turbine; an aero-derivative gas turbine; or a boiler may utilize the method and system. The method and system may provide an industrial component comprising at least one steam injection system, wherein the at least one steam injection system injects steam into at least one fuel supply line upstream of a combustion system to modulate the MWI of at least one fuel. The method and system may also determine whether the MWI of the at least one fuel is outside of a predetermined range; and utilize the at least one steam injection system to automatically inject the steam at a flowrate for adjusting the MWI of the at least one fuel.

Abstract: A method for detecting and controlling the elemental sulfur deposition on pressure reducing gas fuel control valves in cases where the sulfur deposition results from a temperature drop during expansion across the control valve, such as that encountered in gas turbine engines. The control method and algorithm according to the invention uses measured parameters of gas flow rate, pressure and temperature, combined with known pressure reducing valve characteristics to first determine whether sulfur deposition has occurred, and thereafter to calculate a valve position control parameter used to control the gas temperature upstream of the control valve, thereby maintaining the sulfur in a vapor phase through the pressure reducing process and preventing subsequent sulfur deposition on the valve and downstream piping.

Abstract: A method for operating a turbine is provided. The method includes supplying working fluid to a first flow path input and routing the fluid through a heating unit coupled in flow communication to the flow path between first flow path input and the turbine. The method also includes extracting a portion of the working fluid from first flow path at a point intermediate the heating unit and an inlet of the turbine. The method further includes re-circulating the extracted fluid through a second flow path such that the extracted fluid is discharged upstream from the heating unit.

Abstract: A method for operating a turbine is provided. The method includes supplying working fluid to a first flow path input and routing the fluid through a heating unit coupled in flow communication to the flow path between first flow path input and the turbine. The method also includes extracting a portion of the working fluid from first flow path at a point intermediate the heating unit and an inlet of the turbine. The method further includes re-circulating the extracted fluid through a second flow path such that the extracted fluid is discharged upstream from the heating unit.

Abstract: A recirculation system for circulating distillate during gas fuel operation so as to reduce or eliminate distillate carbon formation. The recirculation system keeps the distillate's temperature below the carbon formation limit by circulating the distillate back to a heat sink and/or heat exchanger. The recirculating flow also exercises the flow dividers' gears without having to perform fuel transfers. Further, the system evacuates air from the liquid fuel lines to further decrease the likelihood of carbonaceous residue forming on any interior surfaces that are actually exposed to distillate.

Abstract: A method for detecting and controlling the elemental sulfur deposition on pressure reducing gas fuel control valves in cases where the sulfur deposition results from a temperature drop during expansion across the control valve, such as that encountered in gas turbine engines. The control method and algorithm according to the invention uses measured parameters of gas flow rate, pressure and temperature, combined with known pressure reducing valve characteristics to first determine whether sulfur deposition has occurred, and thereafter to calculate a valve position control parameter used to control the gas temperature upstream of the control valve, thereby maintaining the sulfur in a vapor phase through the pressure reducing process and preventing subsequent sulfur deposition on the valve and downstream piping.

Abstract: A solid fuel, pressurized fluidized bed combustion system for a gas turbine engine includes a carbonizer outside of the engine for gasifying coal to a low Btu fuel gas in a first fraction of compressor discharge, a pressurized fluidized bed outside of the engine for combusting the char residue from the carbonizer in a second fraction of compressor discharge to produce low temperature vitiated air, and a fuel-rich, fuel-lean staged topping combustor inside the engine in a compressed air plenum thereof. Diversion of less than 100% of compressor discharge outside the engine minimizes the expense of fabricating and maintaining conduits for transferring high pressure and high temperature gas and incorporation of the topping combustor in the compressed air plenum of the engine minimizes the expense of modifying otherwise conventional gas turbine engines for solid fuel, pressurized fluidized bed combustion.

Abstract: An external combustion system for a stationary gas turbine engine includes a rich zone combustor, a water or steam quench stage, a lean zone combustor and a dilution stage. Fuel such as natural gas or liquid hydrocarbon, which forms no ash or slag, burns in a primary air supply in the rich zone combustor at an equivalence ratio exceeding 1 which inhibits rapid formation of of oxides of nitrogen. The effluent from the rich zone combustor is a stream of combustible gas including carbon monoxide and hydrogen. The combustible gas stream is quenched in the quench stage and mixed with a secondary supply of compressed air in the lean zone combustor. The combustible gas ignites spontaneously in the lean zone combustor and burns at an equivalence ratio of less than 1 and at a temperature below the range characterized by rapid formation of oxides of nitrogen.

Abstract: In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature.

Abstract: A catalytic combustor comprises a pilot zone having means to introduce fuel therein; upstream of said pilot zone and communicating therewith a catalytically supported thermal combustion zone comprising a plurality of catalytically supported thermal combustion sections each comprising a solid oxidation catalyst, means for introducing air into said section and means to introduce fuel into said section; and means to control the rate of fuel flow in each of the means to introduce fuel into a catalytically supported thermal combustion section and the means to introduce fuel into the pilot zone. The combustor is operated by staging the fuel supply in order to maximize the amount of combustion in the catalytically supported thermal combustion zone and minimize NOx emissions under all load conditions.

Abstract: The quantity of NOx emissions generated by a combined gas turbine-steam boiler power plant is controlled by recycling a controlled amount of the steam boiler exhaust gas to the air compressor of the gas turbine such that the recycled gases constitutes up to about 30% of the fluid flowing through the air compressor and by cooling the recycled steam boiler exhaust gases to about the desired gas turbine compressor inlet temperature prior to its introduction into the air compressor.

Abstract: The NOx emissions of a stationary gas turbine are reduced by concentrating a NOx suppressant in the reaction zone of the gas turbine combustor by dividing the flow of air to the reaction zone and the dilution zone of the combustor by means of an air flow splitter and by taking advantage of the radially stratified compressor flow. The air flow to the two zones is preferably separated by a common flow shield.

Abstract: An improved dual stage-dual mode combustor capable of reduced emissions of nitrogen oxide from a combustion turbine is disclosed. The combustor includes two combustion chambers separated by a throat region. Fuel is initially introduced and ignited in the first chamber. Thereafter, fuel is introduced near the downstream end of the first chamber for ignition and burning in the second chamber. Burning in the first chamber is extinguished by shifting the fuel flow to burning in the second chamber and after termination of the flame in the first chamber, fuel is reintroduced into the first chamber for premixing only with burning in the second chamber. By selectively controlling the percentage of fuel introduced into the first stage, low emissions of nitrogen oxide are realized.

Abstract: A combustion system for gas turbines is disclosed which is capable of burning gaseous and liquid fuels. Excess air injected into the reaction zone of the combustor produces either a fuel-lean or fuel-rich mixture which lowers the temperature at which combustion occurs and thereby reduces the amount of nitrogen oxides in the turbine exhaust. Efficient combustion is maintained across a wide range of turbine loads by means of a control mechanism disposed externally of the combustor, which directs the airflow from the compressor to the reaction zone and to the downstream dilution zone respectively in a manner which permits variable, inverse proportioning of the air supplied to these zones. The variation in the pressure drop across the combustor is maintained within acceptable limits throughout the full load range.

Abstract: A fuel nozzle for use with gas turbines includes a centrally disposed orifice for discharging fuel into a combustion chamber. A first annular passage surrounds the fuel orifice and discharges primary air adjacent the exit of the fuel orifice for effecting atomization of the fuel and mixture of the air with the fuel to provide a fuel/air spray having a predetermined spray angle. A second annular passage for supplying secondary air is provided surrounding the first passage. This second passage is formed to supply air in a manner which creates a relatively low pressure substantially at the base of the fuel/air spray. When operating at the low fuel flow rates corresponding to low loads, air is supplied only through the first air passage and a relatively narrow spray angle, with a substantial concentration of fuel, is achieved.