Abstract: A method of modulating a cooling supply in a gas turbine engine includes providing the engine comprising a compressor section and a turbine section and including a cooling flow circuit, the cooling flow circuit supplying a cooling air flow from a compressor cavity in the compressor section to a blade ring cavity in the turbine section, wherein the cooling flow circuit includes a main line with a full capacity valve, measuring a first pressure in the blade ring cavity, measuring a second pressure in the compressor cavity, adjusting, by a control system, the opening of the full capacity valve to control the cooling air flow through the main line in order to maintain a target pressure ratio, wherein the pressure ratio defined as a ratio of the first pressure to the second pressure. The method is performed in an ambient temperature operating range of the engine.

Abstract: A method of modulating a cooling supply in a gas turbine engine includes providing the engine comprising a compressor section and a turbine section and including a cooling flow circuit, the cooling flow circuit supplying a cooling air flow from a compressor cavity in the compressor section to a blade ring cavity in the turbine section, wherein the cooling flow circuit includes a main line with a full capacity valve, measuring a first pressure in the blade ring cavity, measuring a second pressure in the compressor cavity, adjusting, by a control system, the opening of the full capacity valve to control the cooling air flow through the main line in order to maintain a target pressure ratio, wherein the pressure ratio defined as a ratio of the first pressure to the second pressure. The method is performed in an ambient temperature operating range of the engine.

Abstract: A gas turbine and a method for operating a gas turbine having a fuel gas monitoring system are presented. The fuel gas monitoring system may provide a measurement of a parameter of a fuel gas in real time. An operation of a gas turbine may be optimized to adapt variation in hydrocarbon content of a fuel gas from the measurement. The fuel gas monitoring system may provide an optical, flow through, online monitoring of fuel gas composition.

Abstract: A starting process for a gas turbine (28) that holds the turbine speed of rotation at an ignition speed setting during an ignition window (58), with the ignition speed setting being based on ambient air conditions to achieve a specified combustor air mass flow rate (52). A fuel flow rate may be set based on the fuel type and temperature to achieve a particular air/fuel ratio in a combustor. The fuel flow rate may be adjusted during the ignition window and thereafter based on a combustor inlet air temperature (46). Completion of ignition may be determined by a reduction (68) in a blade path temperature spread (66). After ignition, fuel flow is increased to accelerate the turbine to full speed. At any point, the fuel flow may be reduced, or its increase may be slowed, to avoid exceeding a temperature limit in the turbine.

Abstract: A starting process for a gas turbine (28) that holds the turbine speed of rotation at an ignition speed setting during an ignition window (58), with the ignition speed setting being based on ambient air conditions to achieve a specified combustor air mass flow rate (52). A fuel flow rate may be set based on the fuel type and temperature to achieve a particular air/fuel ratio in a combustor. The fuel flow rate may be adjusted during the ignition window and thereafter based on a combustor inlet air temperature (46). Completion of ignition may be determined by a reduction (68) in a blade path temperature spread (66). After ignition, fuel flow is increased to accelerate the turbine to full speed. At any point, the fuel flow may be reduced, or its increase may be slowed, to avoid exceeding a temperature limit in the turbine.

Abstract: A gas turbine engine that includes a compressor, a combustion stage, a turbine assembly, a fuel gas feed system for supplying fuel gas to a combustion stage of the gas turbine, and an integrated fuel gas characterization system. The integrated fuel gas feed system can include a buffer tank. The integrated fuel gas characterization system for determining the amount of energy provided by the fuel prior to combustion of the fuel in the combustion stage. The integrated fuel gas characterization system minimizes megawatt swings by adjusting the operating parameters of the gas turbine engine based on the rate of change in fuel gas energy content. The integrated fuel gas characterization system also provides improved turbine engine start-up reliability by tuning the turbine engine operating parameters using fuel gas energy content measurements obtained prior to actual start-up.

Abstract: A power generation system. The exemplary system shown in FIGS. 1 and 2 includes a gas turbine (28), a gasifier (10) for generating gaseous fuel and a gas combustor (26) configured to receive the fuel and power the gas turbine (28). A drain collection and separation system (5) is positioned to collect gaseous fuel entrained in liquid and to separate the gaseous fuel from the liquid so the gaseous fuel can be cycled or disposed of separately from the liquid.

Abstract: A gas turbine engine that includes a compressor, a combustion stage, a turbine assembly, a fuel gas feed system for supplying fuel gas to a combustion stage of the gas turbine, an integrated fuel gas characterization system, and a buffer tank is disclosed. The integrated fuel gas characterization system may determine the heating value of the fuel and adjust engine operating parameters such as fuel flow; or steam flow or water injection, or both, input to maintain a design fuel-to-air ratio. The integrated fuel gas characterization system can minimize or eliminate megawatt load swings experienced by the gas turbine engine, extending turbine component life and reducing other operational issues, such as the risk of flashback, engine overfiring, combustion dynamics, increased emissions, and exhaust stream temperature spikes.

Abstract: A method of operating an electric power generation system (2). In one embodiment, a combustion chamber receives a combination of pressurized air (14) flow output from a compressor (12) and fuel (20) for combustion therein. The system (2) is operated at a relatively high steady state level of power output and then power is turned down by extracting a portion (34) of the pressurized air (14) flow before entry into the combustor (16). The method may further include throttling of air (14) flowing through the compressor (12) with inlet guide vanes (15). Features of the reduction in power include maintaining a characteristic combustor (16) minimum flame temperature with a volumetric percentage of NOx or CO emissions not exceeding those corresponding to the relatively high steady state operation.

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 gas turbine engine that includes a compressor, a combustion stage, a turbine assembly, a fuel gas feed system for supplying fuel gas to a combustion stage of the gas turbine, and an integrated fuel gas characterization system. The integrated fuel gas feed system can include a buffer tank. The integrated fuel gas characterization system for determining the amount of energy provided by the fuel prior to combustion of the fuel in the combustion stage. The integrated fuel gas characterization system minimizes megawatt swings by adjusting the operating parameters of the gas turbine engine based on the rate of change in fuel gas energy content. The integrated fuel gas characterization system also provides improved turbine engine start-up reliability by tuning the turbine engine operating parameters using fuel gas energy content measurements obtained prior to actual start-up.

Abstract: A power generation system. The exemplary system shown in FIGS. 1 and 2 includes a gas turbine (28), a gasifier (10) for generating gaseous fuel and a gas combustor (26) configured to receive the fuel and power the gas turbine (28). A drain collection and separation system (5) is positioned to collect gaseous fuel entrained in liquid and to separate the gaseous fuel from the liquid so the gaseous fuel can be cycled or disposed of separately from the liquid.