Abstract: A method of controlling a gas turbine system (10) may include controlling an inlet guide vane position (98) to maintain a turbine (24) exhaust temperature at a corrected value that is a function of a compressor (12) inlet temperature and a turbine (24) normalized load. The method may include selecting the minimum value (138) of a part load tunable value, a part load maximum value and a fixed maximum value of a turbine (24) exhaust temperature for the corrected value. A corrected value setpoint may be determined (94) for the gas turbine system (10) operating at a part load condition where at least one of a fuel flow rate and the inlet guide vane position is controlled (98) so the corrected value does not exceed the corrected value setpoint. The corrected value may prevent a turbine (24) engine from exceeding its firing temperature during operation and ensure the engine operates within combustor dynamics and emissions limits.

Abstract: A method of controlling fuel flow to a combustor (18) of a gas turbine engine (10) during startup of the engine includes determining a relationship between Cv and valve position for a flow control valve (e.g., 24) in a fuel supply (20) to the combustor as a function of at least one real time parameter of fuel (30) in the fuel supply. The method also includes determining a value of the at least one parameter of the fuel before initiating a flow of the fuel to the combustor, and then calculating a first actual Cv value for the flow control valve at a target flow rate using the determined value of the parameter. The method then includes positioning the flow control valve to a first position corresponding to the actual Cv value based upon the determined relationship between Cv and valve position, and initiating the flow of fuel to the combustor through the flow control valve.

Abstract: A method of controlling a gas turbine system (10) may include controlling an inlet guide vane position (98) to maintain a turbine (24) exhaust temperature at a corrected value that is a function of a compressor (12) inlet temperature and a turbine (24) normalized load. The method may include selecting the minimum value (138) of a part load tunable value, a part load maximum value and a fixed maximum value of a turbine (24) exhaust temperature for the corrected value. A corrected value setpoint may be determined (94) for the gas turbine system (10) operating at a part load condition where at least one of a fuel flow rate and the inlet guide vane position is controlled (98) so the corrected value does not exceed the corrected value setpoint. The corrected value may prevent a turbine (24) engine from exceeding its firing temperature during operation and ensure the engine operates within combustor dynamics and emissions limits.

Abstract: A fuel system for a turbine engine for reducing CO emissions caused during fuel staging processes while the turbine engine operates at reduced loads. The fuel system may include a first premix injector assembly and a second premix injector assembly, each formed from one or more injectors. In at least one embodiment, the first premix injector includes four injectors assembled into two pairs, and the second premix injector includes four injectors assembled into two pairs. The two pairs of the second premix injector assembly may be positioned between the two pairs forming the first premix injector assembly, thereby reducing the interface between fueled and unfueled areas, which reduces CO emissions.

Abstract: A fuel system for a turbine engine for reducing CO emissions caused during fuel staging processes while the turbine engine operates at reduced loads. The fuel system may include a first premix injector assembly and a second premix injector assembly, each formed from one or more injectors. In at least one embodiment, the first premix injector includes four injectors assembled into two pairs, and the second premix injector includes four injectors assembled into two pairs. The two pairs of the second premix injector assembly may be positioned between the two pairs forming the first premix injector assembly, thereby reducing the interface between fueled and unfueled areas, which reduces CO emissions.

Abstract: A gas turbine engine (12) including a water injection system (56) for providing a flow of water (60) to only a pilot diffusion combustion zone (20) of a dual-mode combustor (10) and not to a pre-mixed combustion zone (18) of the combustor. The selective reduction of peak flame temperature in the pilot flame zone provides a maximum reduction in the production of oxides of nitrogen with a minimum consumption of water. The pilot fuel fraction of the combustor may be increased prior to the initiation of the pilot water injection flow. The flow rate of the pilot injection water may be varied as a function of the power level of the gas turbine, and further as a function of the humidity of the ambient air (36).

Abstract: A gas turbine engine (12) wherein combustion conditions are controlled as a function of the humidity of the ambient air (36) in order to ensure stable, emission-compliant performance over a range of ambient conditions. The pilot fuel fraction supplied to a dual mode combustor (10) may be controlled to be responsive to the relative humidity or the specific humidity of the ambient air. Humidity may be measured directly or it may be calculated as a function of other temperature and pressure measurements. A fuel system (44) is controlled by a controller (46) having as inputs the signals from one or more of a relative humidity sensor (62), a barometric pressure sensor (56), a wet bulb temperature sensor (58) and a dry bulb temperature sensor (60).

Abstract: A gas turbine engine (12) wherein combustion conditions are controlled as a function of the humidity of the ambient air (36) in order to ensure stable, emission-compliant performance over a range of ambient conditions. The pilot fuel fraction supplied to a dual mode combustor (10) may be controlled to be responsive to the relative humidity or the specific humidity of the ambient air. Humidity may be measured directly or it may be calculated as a function of other temperature and pressure measurements. A fuel system (44) is controlled by a controller (46) having as inputs the signals from one or more of a relative humidity sensor (62), a barometric pressure sensor (56), a wet bulb temperature sensor (58) and a dry bulb temperature sensor (60).

Abstract: A gas turbine engine (12) including a water injection system (56) for providing a flow of water (60) to only a pilot diffusion combustion zone (20) of a dual-mode combustor (10) and not to a pre-mixed combustion zone (18) of the combustor. The selective reduction of peak flame temperature in the pilot flame zone provides a maximum reduction in the production of oxides of nitrogen with a minimum consumption of water. The pilot fuel fraction of the combustor may be increased prior to the initiation of the pilot water injection flow. The flow rate of the pilot injection water may be varied as a function of the power level of the gas turbine, and further as a function of the humidity of the ambient air (36).