Siemens Aktiengesellschaft

Siemens Energy Global Gmbh & Co. Kg

Fuchs Petrolub Se

Frank Thomas

Jan Brückner

Martin Effert

Joachim Franke

Rudolf Kral

Tobias Schulze

Joachim Brodesser

Bernd Weissenberger

Gerhard Schlund

Holger Schmidt

Gerhard Zimmermann

Axel Butterlin

Andre Schrief

Jürgen Birnbaum

Antje Burgemeister

Zsuzsa Preitl

Peter Gottfried

Jan Brueckner

A method for operating a forced-flow steam generator constructed as a waste-heat steam generator having a pre-heater, including pre-heater heating surfaces, and having an evaporator including evaporator heating surfaces connected downstream on the flow medium side of the pre-heater heating surfaces. A device for adjusting a feed water mass flow has a set point for the feed water mass flow. During the creation of the set point for the feed water mass flow, a waste-heat flow transferred to a fluid in the evaporator heating surfaces is determined, and mass storage and energy storage in the fluid in the evaporator heating surfaces is detected during non-steady-state plant operation. A behaviour over time of a mass storage in the evaporator is coupled with a behaviour over time of a mass storage in the pre-heater, wherein scaling is carried out with a ratio of the density changes in the evaporator and pre-heater.

Feedwater control for a forced-flow waste-heat steam generator

A method for the short-term adjustment of the output of a steam turbine of a combined-cycle power plant, includes: opening, respectively closing, a backed-up turbine valve of a pressure stage, according to a required change in output; comparing a desired pressure with a pressure measurement upstream of the turbine valve to measure pressure of steam mass flow flowing into the pressure stage; and opening, respectively closing, a feed line for introducing a variable proportion of water into the steam mass flow as soon as the pressure falls below or exceeds the desired pressure; the variable proportion of water is introduced into the steam mass flow until an adjusted desired steam temperature is reached, which is determined from the difference between a basic specified desired steam temperature and the default value of a controller which operates at least proportionally and evaluates the difference between the pressure measurement and the desired pressure.

Method for the short-term adjustment of the output of a combined-cycle power plant steam turbine, for primary frequency control

A vertical heat recovery steam generator, the low-pressure stages of which are designed as a once-through system, having a condensate preheater with at least one condensate preheater heating surface, through which a flow medium flows and which is disposed in a hot gas channel through which hot gas flows, a low-pressure preheater with at least one low-pressure preheater heating surface through which the flow medium flows and which is disposed in the hot gas channel, and a low-pressure evaporator with at least one low-pressure evaporator heating surface through which the flow medium flows and which is disposed in the hot gas channel. The flow medium flows successively through the at least one low-pressure preheater heating surface and the at least one low-pressure evaporator heating surface in one pass and without additional pressure compensation.

Vertical heat recovery steam generator

A method for operating a waste heat steam generator, in particular one designed according to the forced flow principle, having an evaporator, through which a flow medium flows; an economizer having a number of economizer heating surfaces, and having a bypass line, which on the flow medium side is connected in parallel to a number of economizer heating surfaces. A variable that is characteristic of the heat energy supplied to the waste heat steam generator for controlling or regulating the flow rate of the bypass line is used, wherein the regulating or controlling of the flow rate of the flow medium through the bypass line takes place at the inlet of the evaporator subject to a supercooling target value. The regulating or controlling of the flow rate of the flow medium through the bypass line also takes place at the outlet of the evaporator subject to an overheating target value.

Method for operating a waste heat steam generator

A method for flexible operation of a power plant having a recovery steam generator having heat exchanger stages for generating live steam and/or reheater steam for a steam turbine from an exhaust flow of a gas turbine, wherein auxiliary firing is arranged in a flue gas channel of the recovery steam generator in the region of the heat exchanger stages. In order to regulate the live steam and/or the reheater steam, at least one injection cooling device is brought online directly upon using the auxiliary firing.

Method for flexible operation of a power plant

A method for flexibly operating a nuclear power plant with a waste heat steam generator that operates according to the forced-flow principle and that has heating surfaces of different stages of the waste heat steam generator, the heating surfaces being arranged in the flue gas channel, is provided. In order to increase the output, a mass flow of the feedwater flowing through the heating surfaces is increased while almost simultaneously activating a supplementary firing arranged in the flue gas channel of the waste heat steam generator.

Method for the flexible operation of a power plant

A combined cycle gas turbine plant and a corresponding method for operating such a combined cycle gas turbine plant, in which, during load operation of the combined cycle gas turbine plant, a water mass flow which is supplied according to the forced-flow principle to a waste heat steam generator is adjusted such that the evaporator heating surface of the medium pressure stage is oversupplied and thus a defined amount of excess water, which is heated in the evaporator heating surface but not vaporized, is discharged via the water-steam separator to a heat exchanger circuit for preheating fuel for the gas turbine.

Combined cycle gas turbine plant comprising a waste heat steam generator and fuel preheating step

A control method for operating a heat recovery steam generator having a flue gas channel in which an evaporator, having at least two evaporator heating surfaces arranged successively in the flue gas channel and at least one intermediate heating surface arranged between the evaporator heating surfaces, is provided, the method including determining a characteristic value characteristic of the heat absorption in the evaporator for the evaporator heating surfaces, additionally determining for the at least one intermediate heating surface, an additional characteristic value for the heat absorption of the intermediate heating surface, and subtracting this additional characteristic value from the characteristic value characteristic of the heat absorption in the evaporator.

Control method for operating a heat recovery steam generator

A method for starting a continuous steam generator is provided. The steam generator includes a combustion chamber provided with a plurality of burners, a water-steam separation device that is mounted downstream of evaporator tubes of the water-steam separation device on a flow-medium side. The amount of water flowing into the water-steam separation device during a starting process is kept to a minimum. The firing power of at least one of the burners is adjusted in accordance with a filling level characteristic value of the water-steam separation device.

Method for starting a continuous steam generator

A method for operating a waste heat steam generator including an evaporator, an economizer having a number of economizer heating surfaces, and a bypass line connected on the flow medium side in parallel with a number of economizer heating surfaces is provided. The method makes possible higher operational safety and reliability in the control of the waste heat steam generator. For this purpose, a parameter that is characteristic of the thermal energy fed to the waste heat steam generator is used to control or regulate the flow rate of the by-pass line.

A once-through steam generator includes a combustion chamber, the walls of which comprise vertically arranged evaporator pipes connected to one another in gas-tight fashion by pipe webs, through which evaporator pipes flows a flow medium from bottom to top. The evaporator pipes are combined by upstream inlet collectors to form more intensely and less intensely heated pipe groups. A feed water supply is assigned to respective inlet collectors. At least one regulating valve regulates throttling of the mass flow of the flow medium into the evaporator pipes. To determine a control variable for the regulating valve, temperature measurement device measures outlet temperatures of the flow medium exiting the evaporator pipes. Each of the more intensely and less intensely heated pipe groups is assigned to one of the inlet collectors and to an outlet collector, and each of the outlet collectors has one of the temperature measurement devices.

Once-through steam generator

A method for operating a directly heated, solar-thermal steam generator is provided. As per the method, a nominal value {dot over (M)}for the supply water mass flow {dot over (M)} is conducted to an apparatus for adjusting the supply water mass flow {dot over (M)} wherein, at the adjustment of the nominal value {dot over (M)}for the supply water mass flow {dot over (M)}, account is taken of a correction value K, by which the thermal effects of storage or withdrawal of thermal energy in an evaporator are corrected.

Method for operating a directly heated, solar-thermal steam generator

A method for operating a recirculating waste heat steam generator is provided, in which in a pressure stage of the recirculating waste heat steam generator, the feed water mass flow is guided on the basis of a specified desired value in order to control the water level in a drum. The method should give a recirculating waste heat steam generator a particularly high degree of efficiency and simultaneously a particularly high level of operational flexibility. For this purpose the thermal input introduced into an evaporator of the pressure stage is used as input variable in the determination of the desired value.

Method for operating a recirculating waste heat steam generator

A fossil-fired steam generator for a steam power station includes a number of economizer, evaporator and superheater heating surfaces forming a flow path through which a flow medium flows in a plurality of pressure stages. In a high-pressure stage, an overflow line is connected to the flow path on its inlet side and leads to an injection valve disposed upstream in the flow path from a superheater heating surface in a medium-pressure stage on the flow medium side. The overflow line has two supply lines of which a first supply line branches off on the flow medium side upstream from a high-pressure preheater and a second supply line branches off on the flow medium side downstream from the high-pressure preheater.

Fossil-fired steam generator

A method for operating a once-through steam generator including an evaporator heating surface is provided. A target value for the supply water mass flow is fed to a device for setting the supply water mass flow, which is predefined using the ratio of the heat flow currently being transferred in the evaporator heating surface from the hot gas to the flow medium to a target enthalpy increase predefined with respect to the desired live steam condition of the flow medium in the evaporator heating surface. A forced-flow steam generator used for carrying out the method is also provided. The heat flow transferred from the hot gas to the flow medium is ascertained for this purpose allowing for a specific temperature value characteristic of the current temperature of the hot gas at the evaporator inlet and a specific mass flow value characteristic for the current mass flow of the hot gas.

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Erlangen, Germany

Frank Thomas