Abstract: A gas and steam turbine plant includes a waste-heat steam generator disposed downstream of a gas turbine on the exhaust-gas side. The waste-heat steam generator has heating surfaces connected into a water-steam circuit of a steam turbine having a high-pressure part, a medium-pressure part and a low-pressure part. In order to achieve as high a plant efficiency as possible, a heat exchanger disposed outside the waste-heat steam generator is connected between the high-pressure part and the medium-pressure part on the primary side and between the medium-pressure part and the low-pressure part of the steam turbine on the secondary side. In a corresponding method for operating such a plant, low-pressure steam flowing to the steam turbine is heated by indirect heat exchange with medium-pressure steam flowing out of the steam turbine.

Abstract: A waste-heat steam generator of a gas-turbine and steam-turbine system. The steam-generating heat content in the expanded working medium from the gas turbine is used for the steam turbine connected into a water/steam loop. Condensed steam from the steam turbine is supplied as condensate to the water/steam loop. A partial flow is diverted from the water-steam loop for selectively preheating the condensate or the fuel with the partial flow. To achieve high efficiency, irrespective of the fuel used for the gas turbine, when oil is used as the fuel for the gas turbine, the partial flow from the water/steam loop is used for condensate preheating. When gas is used as the fuel for the gas turbine, the partial flow is used for fuel preheating. A heat exchanger for the selective preheating either of the gas-turbine fuel or of the condensate with the partial flow is provided.

Abstract: A gas and steam-turbine plant includes a waste-heat steam generator downstream of a gas turbine on the exhaust-gas side. The waste-heat steam generator has a high-pressure preheater connected into a water/steam circuit of a steam turbine having a low-pressure part. In order to achieve as high a plant efficiency as possible, a heat exchanger which is disposed outside the waste-heat steam generator has a primary-side inlet connected to an outlet of the high-pressure preheater, a primary-side outlet connected to an inlet of the high-pressure preheater and a secondary side connected into an overflow conduit opening into the low-pressure part of the steam turbine. A method for operating such a plant includes superheating low-pressure steam flowing into the steam turbine by indirect heat exchange with a part stream of preheated feed water extracted from the high-pressure preheater.

Abstract: A method for operating a gas-turbine and steam-turbine plant and a plant working according to the method, utilize exhaust gas from a gas turbine for steam generation when the plant is in operation. In order to ensure that a gas-turbine model can be freely selected, irrespective of its power rating and with a reduction in exhaust gas losses, in the case of both a new plant and a retrofitting of an already existing plant, a first part stream of exhaust gas from the gas turbine is used as combustion air for the combustion of a fossil fuel and a second part stream of exhaust gas from the gas turbine is utilized for waste-heat steam generation. At the same time, for steam generation, a combination of a fossil-fired steam generator and a waste-heat steam generator is located downstream of the gas turbine on the exhaust gas side, in each case through a part-stream conduit.

Abstract: Adequate cooling of the coolant of a gas turbine of a gas and steam turbine system is assured under all operating conditions, and especially in peak-load operation. The coolant of the gas turbine is cooled by heat exchange with a medium circulating in a separate evaporator loop connected to the steam drum. The cooling capacity is adapted to the operating state of the gas and steam turbine system. An injector connection is provided between a feedwater delivery pipe and the separate evaporator loop.

Abstract: Method for operating a gas and steam turbine system without a feedwater tank, wherein heat contained in a pressure-relieved operating fluid of a gas turbine is utilized to produce steam for a steam turbine, includes the steps of preheating condensate flowing in a water-steam loop of the steam turbine; returning a first quantitative fraction of the preheated condensate in a loop for further preheating; and evaporating a second quantitative fraction of the preheated condensate; and a device for performing the foregoing method.

Abstract: A combined gas and steam turbine system includes a steam turbine having a water/steam loop and a high-pressure stage in the water/steam loop. The high-pressure stage has a preheater and a high-pressure heater connected downstream of the preheater. A gas turbine has an exhaust gas side. A steam generator is connected downstream of the exhaust gas side of the gas turbine. The steam generator includes a firing system producing flue gases flowing in a given direction, the preheater, the high-pressure heater, an intermediate superheater connected downstream of the high-pressure stage, and a medium-pressure heater connected parallel to the high-pressure stage. The medium-pressure heater is disposed in the steam generator between the high-pressure heater and the preheater, as seen in the given flow direction of the flue gases.

Abstract: A gas and steam turbine plant includes a steam turbine having a water-steam loop. A waste heat boiler which is connected downstream of a gas turbine includes a high-pressure preheater connected in the water-steam loop, a high-pressure heater connected downstream of the high-pressure preheater, a low-pressure heater connected upstream of the high-pressure preheater, and an evaporator of a medium-pressure heater. A coal gasification plant is connected upstream of the gas turbine. An outflow line leads into the coal gasification plant and is connected to the water-steam loop downstream of the high-pressure preheater, as seen in water flow direction. A water-steam drum communicates with the outflow line and is connected to the evaporator.

Abstract: A gas and steam turbine plant has a gas turbine producing exhaust gas, a water-steam loop in which water is preheated at a given high pressure and subsequently evaporated, a steam turbine in the water-steam loop, and a steam generator through which the exhaust gas flows for generating steam for the steam turbine. The steam generator has at least one preheater connected to the water-steam loop and a high-pressure heater connected downstream of at least one preheater. The water-steam loop has a partial loop connected parallel to the at least one preheater outside the steam generator for carrying an adjustable throughput quantity. A heat exchanger is disposed in the steam generator in the vicinity of the at least one preheater for removing usable heat.

Abstract: A gas and steam turbine plant includes a steam turbine having a water-steam loop. A waste heat boiler which is connected downstream of a gas turbine includes a high-pressure preheater connected in the water-steam loop, a high-pressure heater connected downstream of the high-pressure preheater, a low-pressure heater connected upstream of the high-pressure preheater, and an evaporator of a medium-pressure heater. A coal gasification plant is connected upstream of the gas turbine. An outflow line leads into the coal gasification plant and is connected to the water-steam loop downstream of the high-pressure preheater, as seen in water flow direction. A water-steam drum communicates with the outflow line and is connected to the evaporator. A method for operating the plant includes generating steam for the steam turbine with working fluid expanded in the gas turbine.

Abstract: A combined gas and steam turbine plant includes a coal gasification system having a heat exchanger device and preferably a gas scrubber connected downstream of the heat exchanger device. A gas turbine part is connected downstream of the coal gasification system and has an exhaust gas turbine. A steam generator system receives exhaust gas from the exhaust gas turbine and has an economizer heating surface, an evaporator heating surface, and superheater heating surfaces. A steam turbine part is connected to the steam generator system and has a high-pressure feedwater system. The heat exchanger device of the coal gasification system is connected in such a way that it directly transfers or gives up thermal energy for feedwater heating or steam generation to the high-pressure feedwater system of the steam turbine part.

Abstract: In plants for generating steam using waste heat, the heat in the hot waste gases flowing through the steam generator must be utilized with maximum efficiency. To this end, the feed water is branched into two streams, one of which flows into the high-pressure heating surfaces and the other into the heating surfaces of the medium-pressure evaporator. The division of the two streams is controlled as a function of the quality of the steam, so that the steam in the heating surfaces of the intermediate superheater is heated to the same temperature as the steam in the heating surfaces of the high-pressure superheater. The invention is particularly useful in combined gas and steam turbine power plants.

Abstract: A gas and steam turbine power plant has a gas turbine with a gas side, a waste heat steam generator having a steam side and being connected downstream of the gas side of the gas turbine, and a steam turbine connected to the steam side of the waste heat steam generator. A super-charged, coal-fired steam generator has an exhaust gas vent line connected to the gas turbine. The coal-fired steam generator includes at least one substoichiometrically operated fluidized bed furnace system, an integrated dust separator connected downstream of the at least one fluidized bed furnace system, and a steam generator slag tap or wet tap furnace having burners with a gas side connected downstream of the dust separator.

Abstract: According to a process for the combustion of organic substances, such as domestic or industrial waste and the like, in a fluidized incineration bed (1) at a mean combustion temperature of 800.degree. C., the flue gased emitted by the fluidized bed (1) are heated with the associated flue dust to a temperature of at least 900.degree. C., preferably 1000.degree. C. to 1200.degree. C., in a subsequent combustion zone (23), in order to destroy toxic substances are burnt. To this effect, the flue gases are introduced in the incinerating chamber of an industrial furnace, for example a steam generator (2) of a coal-operated power plant. By connecting in the gas supply line a fluidized bed (1) upstream of a steam generator (2) fired with coal, a substantial reduction in NOx formation is achieved.

Abstract: A combustion chamber with a fluidized bed furnace having a nozzle plate, a fuel feed above the nozzle plate, a primary air feed below the nozzle plate, an exhaust gas channel at an upper end of the combustion chamber, and heat-exchanging heating surfaces includes a cylindrical combustion chamber wall disposed vertically upright and having, in an upper region thereof, a plurality of secondary air nozzles disposed tangentially as well as downwardly inclined to the cylindrical wall for separating and returning unspent solid particles into a lower region of the fluidized bed, a device for directing a flow of gas and particles vertically upwardly in a central region of the combustion chamber and spirally downwardly along the cylindrical wall, and a device for impressing an upwardly increasing rotary flow about an axis of symmetry of the combustion chamber upon the gas flow.

Abstract: Waste heat steam generator for hot, dust-loaded gases under overpressure, with a gas feedline, with a gas exhaust line as well as with heat exchanger elements through which a coolant flows. The gas feedline is conducted inside a gas exhaust line, which opens from above into heat exchanger space which is concentrically arranged in a pressure vessel. The heat exchanger space is open at the lower end and in it the heat exchanger elements are supported. The space between the containment walls of the heat exchanger space and the pressure vessel wall at the upper end of the pressure vessel is connected to the gas exhaust line. The pressure vessel bottom in the form of a funnel is connected to an ash removal device. The containment walls of the heat exchanger space are provided with heat exchanger tubes.

Abstract: Combined gas-steam power plant, including a device for carrying out a gasification reaction at overpressure between oxygen and fuel fed to the gasification device, a heat exchanger and a charged steam generator disposed down stream of the gasification device in flow direction of fuel gas generated by the gasification device, a gas turbine receiving a flue gas stream from the steam generator, an air decomposition device having a first outlet line carrying oxygen to the gasification device and a second outlet line carrying nitrogen through the heat exchanger to the gas stream between the steam generator and gas turbine.