Abstract: A waste-heat steam generator has an exhaust gas channel in which at least one evaporator heating surface and at least one preheater heating surface are arranged. The evaporator heating surface and the preheater heating surface are connected together such that the preheater heating surface is arranged upstream of the evaporator heating surface on the feed-water side. The waste-heat steam generator also has a water separator arranged downstream of the evaporator heating surface on the feed-water side. An excess pipe length system is arranged outside of the exhaust gas channel and between the preheater heating surface and the evaporator heating surface on the feed-water side, the system being designed such that the feed water causes an overflow in a rising pipe of the excess pipe length system after completely filling the preheater heating surface and thus reaches the evaporator heating surface via a downpipe.

Abstract: A steam-temperature control device for a gas- and steam turbine plant, including a feed water line, a feed-water control valve located in the feed water line and a water injection line which branches off from the feed water line upstream of the feed-water control valve in the flow direction of said water and which opens into an injection cooler is provided. The steam-temperature control device is characterized in that a pre-heating device for the injection water is connected in the water injection line. A method for controlling the steam temperature in a gas- and steam turbine plant is also provided.

Abstract: A waste-heat steam generator has an exhaust gas channel in which at least one evaporator heating surface and at least one preheater heating surface are arranged. The evaporator heating surface and the preheater heating surface are connected together such that the preheater heating surface is arranged upstream of the evaporator heating surface on the feed-water side. The waste-heat steam generator also has a water separator arranged downstream of the evaporator heating surface on the feed-water side. An excess pipe length system is arranged outside of the exhaust gas channel and between the preheater heating surface and the evaporator heating surface on the feed-water side, the system being designed such that the feed water causes an overflow in a rising pipe of the excess pipe length system after completely filling the preheater heating surface and thus reaches the evaporator heating surface via a downpipe.

Abstract: A steam-temperature control device for a gas- and steam turbine plant, including a feed water line, a feed-water control valve located in the feed water line and a water injection line which branches off from the feed water line upstream of the feed-water control valve in the flow direction of said water and which opens into an injection cooler is provided. The steam-temperature control device is characterized in that a pre-heating device for the injection water is connected in the water injection line. A method for controlling the steam temperature in a gas- and steam turbine plant is also provided.