Abstract: A gas turbine and method are disclosed by which the gas turbine can be safely operated at nominal speed with reduced margin to a surge limit of a compressor. The gas turbine, via a directly driven generator which generates alternating current with an operating frequency and which is connected in a frequency-coupled manner to an electricity grid, can deliver electric power to this grid. In the case of an underfrequency event the compressor of the gas turbine is unloaded by controlled, fast closing of the variable compressor guide vanes (VGV) and as a result maintains a sufficient margin to the surge limit of the compressor.

Abstract: The invention relates to a method of operating a gas turbine assembly, which includes a compressor, a combustor and a gas turbine. The method includes operating the gas turbine assembly at a partial load with respect to a base load of the gas turbine assembly; bypassing a portion of blow-off air from the compressor; and introducing the portion of blow-off air into an exhaust gas duct after the gas turbine. The gas turbine assembly, when operating at partial load, can maintain the air-to-fuel ratio approximately constant and hence to control the combustion flame temperature at a level where emissions are kept below the permission limit.

Abstract: Disclosed is a method for operating a gas turbine (11) comprising a compressor (14), which is equipped with variable inlet guide vanes (13) and receives at its inlet an inlet air flow, which has passed a temperature-affecting air inlet system (12a), a combustor (15, 15?) and a turbine (16, 16?). In a closed loop control scheme, a control variable indicative of the turbine outlet temperature (TAT2) is generated, and the air inlet system (12a) and/or the variable inlet guide vanes (13) are controlled in accordance with said control variable such that the turbine outlet temperature (TAT2) is kept at or above a desired setting value (TAT2min).

Abstract: The invention relates to a method for automatic closed-loop control of one or more combustion temperatures in a gas turbine installation, having the following steps: measurement of a plurality of temperatures of the working fluid of the gas turbine installation at various positions in the gas turbine installation, measurement of a plurality of pressures of the working fluid at different positions in the gas turbine installation, determination of the water content of the working fluid flowing through the gas turbine installation, taking account of the measured values, and setting of at least one combustion temperature for the gas turbine installation as a function of the determined water content.

Abstract: A method is provided for operating a gas turbine plant, in which compressed air is extracted from a compressor and for cooling is directed in an internal cooling passage through thermally loaded components to the combustion chamber and/or to the turbine, then re-cooled, and added to the compressor main flow in the compressor. At least a portion of the recirculated air is supersaturated, or partially saturated, with drops of water during or before recirculation into the compressor and a cooling mist is created. A gas turbine plant is provided with a closed cooling circuit which, for implementing the method, includes an injection arrangement for introducing water into the recirculated cooling air.

Abstract: The invention relates to a method of operating a gas turbine assembly, which includes a compressor, a combustor and a gas turbine. The method includes operating the gas turbine assembly at a partial load with respect to a base load of the gas turbine assembly; bypassing a portion of blow-off air from the compressor; and introducing the portion of blow-off air into an exhaust gas duct after the gas turbine. The gas turbine assembly, when operating at partial load, can maintain the air-to-fuel ratio approximately constant and hence to control the combustion flame temperature at a level where emissions are kept below the permission limit.

Abstract: The invention relates to a method for determining at least one firing temperature for controlling a gas turbine that comprises at least one compressor, at least one combustion chamber and at least one turbine, compressed air being drawn off at the compressor in order to cool the turbine and being fed to the turbine via at least one external cooling duct and via a control valve arranged in the cooling duct, in which method a plurality of temperatures and pressures of the working medium being measured in various positions of the gas turbine and the at least one firing temperature being derived from the measured temperatures and pressures. A more flexible and more accurate control is achieved additionally by determining the cooling air mass flow via the external cooling duct and by taking said flow into account when deriving the at least one firing temperature.

Abstract: Numerical gas turbine models permit transient modeling with high precision and at the same time numerically efficient processes for modeling a gas turbine. A gas turbine model includes a plurality of sub models. These sub models are either purely dynamic or static, which allows significant simplifications in the numerical solution of the overall model. System parts, which simulate the effects of volumes, metal masses, of actuators, and of measuring systems are regarded as dynamic. The remaining system parts are regarded as static over a time characteristic.

Abstract: Disclosed is a method for operating a gas turbine (11) comprising a compressor (14), which is equipped with variable inlet guide vanes (13) and receives at its inlet an inlet air flow, which has passed a temperature-affecting air inlet system (12a), a combustor (15, 15?) and a turbine (16, 16?). In a closed loop control scheme, a control variable indicative of the turbine outlet temperature (TAT2) is generated, and the air inlet system (12a) and/or the variable inlet guide vanes (13) are controlled in accordance with said control variable such that the turbine outlet temperature (TAT2) is kept at or above a desired setting value (TAT2min).

Abstract: A method is provided for operating a gas turbine plant, in which compressed air is extracted from a compressor and for cooling is directed in an internal cooling passage through thermally loaded components to the combustion chamber and/or to the turbine, then re-cooled, and added to the compressor main flow in the compressor. At least a portion of the recirculated air is supersaturated, or partially saturated, with drops of water during or before recirculation into the compressor and a cooling mist is created. A gas turbine plant is provided with a closed cooling circuit which, for implementing the method, includes an injection arrangement for introducing water into the recirculated cooling air.

Abstract: A method is provided for operating a gas turbine, which especially feeds power to a local isolated power supply network, and which comprises a compressor for compressing combustion air which is drawn in from the environment, a combustion chamber for combusting supplied fuel by the compressed combustion air, a turbine which is driven by the hot gas from the combustion chamber, and a generator, which is driven by the turbine, for generating electric power. With such a method, an improvement of controlling is achieved by one or more parameters of the gas turbine being measured or determined, by the effective thermal output power of the gas turbine being calculated from the measured or determined parameters, and by the calculated effective thermal output power being used for controlling the gas turbine.

Abstract: Numerical gas turbine models permit transient modeling with high precision and at the same time numerically efficient processes for modeling a gas turbine. A gas turbine model includes a plurality of sub models. These sub models are either purely dynamic or static, which allows significant simplifications in the numerical solution of the overall model. System parts, which simulate the effects of volumes, metal masses, of actuators, and of measuring systems are regarded as dynamic. The remaining system parts are regarded as static over a time characteristic.

Abstract: A gas turbine and method are disclosed by which the gas turbine can be safely operated at nominal speed with reduced margin to a surge limit of a compressor. The gas turbine, via a directly driven generator which generates alternating current with an operating frequency and which is connected in a frequency-coupled manner to an electricity grid, can deliver electric power to this grid. In the case of an underfrequency event the compressor of the gas turbine is unloaded by controlled, fast closing of the variable compressor guide vanes (VGV) and as a result maintains a sufficient margin to the surge limit of the compressor.

Abstract: In a method for operating a gas turbine plant (10) with a compressor (11) for the compression of combustion air sucked in from the surroundings, with a combustion chamber (15) for generating hot gas by the combustion of a fuel with compressed combustion air, and with a turbine (12), in which the hot gas from the combustion chamber (15) is expanded so as to perform work, temperatures and pressures are measured at various points in the gas turbine plant (10), and a combustion chamber exit temperature is derived from the measured temperatures and pressures and used for controlling the gas turbine plant (10). Improved temperature determination is achieved in that the composition of the gas, in particular the water content in the exhaust gas of the turbine (12), is determined, and in that the specific water content in the exhaust gas of the turbine (12) is taken into account in deriving the combustion chamber exit temperature.

Abstract: The invention relates to a method for automatic closed-loop control of one or more combustion temperatures in a gas turbine installation, having the following steps: measurement of a plurality of temperatures of the working fluid of the gas turbine installation at various positions in the gas turbine installation, measurement of a plurality of pressures of the working fluid at different positions in the gas turbine installation, determination of the water content of the working fluid flowing through the gas turbine installation, taking account of the measured values, and setting of at least one combustion temperature for the gas turbine installation as a function of the determined water content.

Abstract: The invention relates to a method for determination of a temperature, mass-averaged over a flow cross-section, of a gas flow in a gas turbine or the like, particularly during partial load operation of the gas turbine. The invention also relates to a control apparatus, which can be operated using the method according to the invention, for controlling a gas turbine installation. The method according to the invention comprising the steps of the temperature value of the gas flow being detected by a sensor or sensors at at least one position in the gas flow in the area of the flow cross-section, of determination of a correction value for correction of the temperature value for compensation for non-uniformities in the temperature profile of the gas flow across the flow cross-section as a function of at least one operating-point-specific parameter, and of correcting the temperature value, which is recorded by a sensor or sensors, by the correction value.

Abstract: A method is provided for operating a gas turbine, which especially feeds power to a local isolated power supply network, and which comprises a compressor for compressing combustion air which is drawn in from the environment, a combustion chamber for combusting supplied fuel by the compressed combustion air, a turbine which is driven by the hot gas from the combustion chamber, and a generator, which is driven by the turbine, for generating electric power. With such a method, an improvement of controlling is achieved by one or more parameters of the gas turbine being measured or determined, by the effective thermal output power of the gas turbine being calculated from the measured or determined parameters, and by the calculated effective thermal output power being used for controlling the gas turbine.

Abstract: In a method for operating a gas turbine plant (10) with a compressor (11) for the compression of combustion air sucked in from the surroundings, with a combustion chamber (15) for generating hot gas by the combustion of a fuel with compressed combustion air, and with a turbine (12), in which the hot gas from the combustion chamber (15) is expanded so as to perform work, temperatures and pressures are measured at various points in the gas turbine plant (10), and a combustion chamber exit temperature is derived from the measured temperatures and pressures and used for controlling the gas turbine plant (10). Improved temperature determination is achieved in that the composition of the gas, in particular the water content in the exhaust gas of the turbine (12), is determined, and in that the specific water content in the exhaust gas of the turbine (12) is taken into account in deriving the combustion chamber exit temperature.

Abstract: The invention relates to a method for determination of a temperature, mass-averaged over a flow cross-section, of a gas flow in a gas turbine or the like, particularly during partial load operation of the gas turbine. The invention also relates to a control apparatus, which can be operated using the method according to the invention, for controlling a gas turbine installation. The method according to the invention comprising the steps of the temperature value of the gas flow being detected by a sensor or sensors at at least one position in the gas flow in the area of the flow cross-section, of determination of a correction value for correction of the temperature value for compensation for non-uniformities in the temperature profile of the gas flow across the flow cross-section as a function of at least one operating-point-specific parameter, and of correcting the temperature value, which is recorded by a sensor or sensors, by the correction value.