Abstract:
The invention relates to a method for temporary increasing the power of a gas turbine, which is part of a combined-cycle power plant, wherein the exhaust gas of the gas turbine is used in a heat recovery steam generator to generate steam for a water/steam cycle including a steam turbine with a high pressure steam turbine, an intermediate pressure steam turbine and a low pressure steam turbine, whereby the method comprises the step of injecting steam from the water/steam cycle at a predetermined injection pressure into the gas turbine. The efficiency is improved by taking steam of a lower pressure than the predetermined injection pressure from the water/steam cycle, increasing the pressure of the steam taken from the water/steam cycle to the predetermined injection pressure by subjecting it in separate compressing means to a compression step, and injecting the compressed steam into the gas turbine.
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).