Abstract: 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.

Abstract: A system for reheating a power generation system including a boiler having a waterwall and a steam drum with an input fluidly coupled to the waterwall and an auxiliary heat source to provide heated fluid. The system also includes a first flow control valve connected to the auxiliary heat source and the boiler to control a flow of heated fluid from the auxiliary heat source to the waterwall; a first isolation valve disposed at a waterwall, to isolate circulation of heated fluid from the steam drum to the waterwall; and a sensor to monitor at least one operating characteristic in the boiler. The system also includes a controller to control at least one of the flow control valve, the isolation valve, and the auxiliary heat source to control the amount of heated fluid supplied to the waterwall when the boiler is not generating steam.

Abstract: A control device includes a reception unit configured to receive a load schedule indicating a load in the future of a combined cycle plant, a steam temperature control unit configured to control a temperature of steam flowing into a steam turbine, and a fuel control unit configured to control a flow rate of fuel supplied to a gas turbine. The steam temperature control unit is configured to output a command indicating an amount of operation for decreasing the temperature of the steam to a steam temperature regulator prior to a load decrease time at which the load is to be decreased in the load schedule.

Abstract: A once-through steam generator comprises a duct having an inlet end in communication with a source of a hot gas; and a tube bundle installed in the duct and comprising multiple heat transfer tubes. The tube bundle has an economizer section, an evaporator section, and a superheater section. A steam separating device may be positioned between the evaporator section and the superheater section, wherein, as part of a wet start-up, hot water collected by the steam separating device is delivered from the steam separating device to mix with cold feedwater before it is introduced into the economizer section. A start-up module may be positioned in the duct near the inlet end, wherein, as part of a dry start-up, cold feedwater is delivered into the start-up module to generate hot water that is then mixed into the feedwater stream before it is introduced into the economizer section.

Abstract: A fluid recirculation system includes an arrangement of a flow control valve located to receive a flow of fluid from an inlet. The system further comprises an economizer inlet mixing device located to receive the flow of hotter fluid from the arrangement of the flow control valve and from a cooler feedwater stream. An economizer inlet mixing device located upstream of an economizer in a supercritical pressure boiler includes a sparger assembly through which a flow of fluid from the waterwall outlet is received, an inlet through which a flow of fluid from a feed stream is received, and a wave breaker assembly through which an outlet stream from the economizer inlet mixing device is directed.

Abstract: A device to harvest energy from lightning is disclosed. The electrical energy of the lightning may be used to heat a fluid, which may then be used to drive a turbine to produce electricity. The electricity provided by the turbine is in a form suitable to either be used or stored. The lightning strikes an antenna and is conducted through an insulated chamber where it heats the fluid.

Abstract: A method for operating a steam generator comprising a combustion chamber having a plurality of evaporator heating surfaces which are connected in parallel on the flow medium side is provided. An object is to provide a steam generator which has a particularly long service life and which is particularly reliable. For this purpose, a flow medium is introduced into an inlet of a first evaporator heating surface at a temperature which is lower than the temperature of the flow medium introduced into the inlet of a second evaporator heating surface.

Abstract: A heat exchanger apparatus for receiving water from a steam drum (1) and providing steam and heated unevaporated liquid water to the steam drum includes a first evaporator (EVAP-1) and a second evaporator (EVAP-2). The first evaporator can receive water from a steam drum via a first feed conduit (9) and the second evaporator can receive water from a second feed conduit (11). Both evaporators can output heated fluid to the steam drum via a combined evaporator output conduit (13). Each first evaporator passageway (14) only makes a single pass through a gas duct (15) having a heated gas flow (7) passing therethrough while each second evaporator passageways (24) can make one or more passes through the gas duct for transferring heat from the gas to the fluid within the evaporators. A portion of the first feed conduit can also have a pre-specified volume a pre-specified height below the first inlet (10).

Abstract: A method of controlling stress in a boiler pressure vessel comprises limiting the diameter of a drum (10) of the boiler pressure vessel and preheating at least a portion of the wall (12) of the drum (10). Limiting the diameter of the drum (10) allows pressure in the drum (10) to be increased for a given mechanical stress. Furthermore, preheating the wall (12) of the drum (10) reduces peak thermally induced stresses in a material from which the drum (10) is fabricated.

Abstract: Some embodiments of a generator system can be used with the working fluid in a Rankine cycle. For example, the generator system can be used in a Rankine cycle to recover heat from one of a number of commercial applications and to convert that heat energy into electrical energy. In particular embodiments, the generator system may include a turbine generator apparatus to generate electrical energy and a liquid separator arranged upstream of the turbine generator apparatus.

Abstract: A generating system is presented that includes a steam generator, a separator coupled to the generator, a supply providing feed water, a start-up system coupled to and receiving the feed water, and a recirculation system coupled to the start-up system. The steam generator operates in a plurality of operating modes. In one mode the steam generator generates a flow of steam and fluid. The separator separates the flow into components of steam and fluid. The recirculation system receives the feed water from the start-up system and provides a required flow to the steam generator during at least one mode. The recirculation system includes an ejector. The ejector induces a portion of the fluid from the separator into the recirculation system, mixes the induced fluid with the feed water to provide a recirculation flow, and the recirculation system provides the required flow to the steam generator including the recirculation flow.

Abstract: A start-up system mixing element including; a body defining a cavity, a first inlet port disposed in the body and configured to provide a first fluid to the cavity, a second inlet port disposed in the body and configured to provide a second fluid to the cavity, an outlet port disposed in the body and configured to remove the first and second fluids from the cavity and an internal distribution pipe disposed in the first inlet port, wherein the internal distribution pipe is configured to provide the first fluid to the cavity via a plurality of holes directed toward a center of the cavity.

Abstract: The invention relates to a steam generator comprising a heating gas channel, which can be traversed in an approximately horizontal heating gas direction and in which at least one continuous heating surface is located, configured from a number of approximately vertical evaporator tubes, connected in parallel to allow the passage of a flow medium. The aim of the invention is to provide a method for starting a generator, which guarantees a high degree of operational safety, even for a steam generator with a particularly simple construction. According to the invention, to achieve this, at least several evaporator tubes are partially filled to a predeterminable desired level with unevaporated flow medium, prior to the impingement of the heating gas channel by a heating gas.

Abstract: The invention relates to a method of heating a liquid medium by means of a first thermal system (2, 3, 4, 7, 12, 13) and at least one second thermal system (5, 6, 6A, 15, 16) following said first thermal system (2, 3, 4, 7, 12, 13), which thermal systems each have at least one heat exchanger (2, 5) through which the medium flows, and which second thermal system (5, 6, 6A, 15, 16) is operated at a higher temperature level than the first thermal system (2, 3, 4, 7, 12, 13). The method is characterized in that, for the accelerated raising of the temperature of the medium in the first thermal system (2, 3, 4, 7, 12, 13), the direct feed of the medium to the same is reduced and in the extreme case prevented, and in that medium flowing through the first thermal system (2, 3, 4, 7, 12, 13) is directed in a circuit. The invention also relates to a plant for carrying out the method.

Abstract: A separator (8) is arranged downstream of the superheater section (4) of the once through heat recovery steam generator (1). A branch line (9) running to the separator (8) is branched off from an outflow line (5) running from the superheater section (4) to the steam turbine (6). An outflow line (11) for separated water runs from the separator (8) to the once through heat recovery steam generator (1). The steam separated in the separator (8) can flow through a bypass line (13) to the condensor/hotwell (14). For starting up the once through heat recovery steam generator (1), the latter is filled with water, the water is loop-circulated through the separator (8) and the outflow line (11) in the once through heat recovery steam generator (1) or water steam cycle and the supply of heat is initiated. In this case, the main shutoff member (7) upstream of the steam turbine (6) is closed, and the branch shutoff member (10) in the branch line (9) upstream of the separator (8) is open.

Abstract: In a once-though steam generator having a double-flue configuration, a first gas flue is followed on the fuel-gas side, by way of a horizontal gas flue, by a second gas flue. In a once-through steam generator of this type, which is to have a particularly long lifetime even in the case of frequent start-up operations, according to the invention a number of steam generator tubes, connected in parallel for a flow medium to flow through them, are connected to one another to form an evaporator heating surface which is part of a containing wall of the first gas flue. The steam generator tubes which form the evaporator heating surface opening on an exit into an outlet header which is common to them and is disposed at a lower height in comparison with the bottom edge of the horizontal gas flue and which is followed, on the flow-medium side, by a bulkhead heating surface.