Abstract: A gas turbine and steam turbine installation has a waste-heat steam generator whose heating surfaces are connected into the water/steam cycle of the steam turbine. A gasification device is connected upstream of the gas turbine in order to provide an integrated gasification of a fossil fuel. Reliable operation of a saturator which is connected into a fuel line is ensured independently of the operating condition of the gasification device. For this purpose, a saturator-water heat exchanger connected with its secondary side into the saturator cycle is supplied, on its primary side, with feed water extracted from the water/steam cycle of the steam turbine. Thus it is possible to heat the feed water cooled in the saturator-water heat exchanger through the use of a partial flow of compressed air, and it is possible to supply the partial flow of compressed air to an air separation unit connected upstream of the gasification device.

Abstract: In a gas and steam turbine plant with a waste-heat steam generator, a fuel gasification device is located upstream of the combustion chamber of the gas turbine via a fuel line. The after-heat steam generator is located downstream of the gas turbine on the flue-gas side and the heating surfaces of which are connected into the water/steam circuit of the steam turbine for the integrated gasification of a fossil fuel. For especially high plant efficiency, a heat exchanger is connected on the primary side into the fuel line between the gasification device and a saturator. In addition to a mixing device for admixing nitrogen, the heat exchanger likewise is connected on the secondary side into the fuel line between the saturator and the combustion chamber.