Patent ID: 6912855
Filing Date: 2005-07-05
Classification: F01K

Abstract:
1. A control method for a combined gas and steam turbine installation, having a gas turbine part and steam part with at least one pressure stage whose working steam is generated by at least one waste-heat boiler fed with waste heat from the gas turbine part and whose control valve passage cross section is adjusted by a control system, whose required value is controlled by use of a control parameter, relating to power, of the pressure stage, comprising: operating the pressure stage with a control valve throttled in such a way that a frequency-support power reserve is built up which, in the case of under-frequency, is used for frequency maintenance by a required value correction being formed which is determined by the amount by which the frequency is too low, wherein the required value correction corresponds to an increased passage cross section relative to the throttled condition of the control valve and acts, using an applied signal decaying with time, on the passage cross section of the control valve; and dimensioning the signal decaying with time in such a way that, taking account of the response behavior of the gas and steam turbine installation to the increased passage cross section, a stable operating condition is ensured despite required value correction.