Method and apparatus for controlling the injection of water into the flue gas path of a gas / steam turbine facility

摘要

A method for operating a gas and steam turbine installation, wherein the heat contained in the expanded flue gas of the gas turbine is used to generate steam for the steam turbine. If a critical operating state arises, the temperature of the expanded flue gas is reduced by introducing water into the expanded flue gas in the flue gas duct between the gas turbine and the waste-heat steam generator connected downstream with regard to flow, wherein the amount of water to be introduced is determined in dependence on the flue gas temperature. The flue gas temperature is measured before water is introduced into the flue gas, an average combustion temperature of the combustion chamber of the gas turbine is determined from the flue gas temperature, and the amount of water to be introduced is set on the basis of the combustion temperature.