EP1660812B1 - Once-through steam generator and method of operating said once-through steam generator - Google Patents

Once-through steam generator and method of operating said once-through steam generator Download PDF

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Publication number
EP1660812B1
EP1660812B1 EP04763621.2A EP04763621A EP1660812B1 EP 1660812 B1 EP1660812 B1 EP 1660812B1 EP 04763621 A EP04763621 A EP 04763621A EP 1660812 B1 EP1660812 B1 EP 1660812B1
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EP
European Patent Office
Prior art keywords
flow
heating
steam generator
gas
evaporator
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EP04763621.2A
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German (de)
French (fr)
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EP1660812A1 (en
Inventor
Joachim Franke
Rudolf Kral
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Siemens AG
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Siemens AG
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00—Methods of steam generation characterised by form of heating method
    • F22B1/02—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
    • F22B1/18—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines
    • F22B1/1807—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines using the exhaust gases of combustion engines
    • F22B1/1815—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines using the exhaust gases of combustion engines using the exhaust gases of gas-turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B29/00—Steam boilers of forced-flow type
    • F22B29/06—Steam boilers of forced-flow type of once-through type, i.e. built-up from tubes receiving water at one end and delivering superheated steam at the other end of the tubes

Definitions

  • the invention relates to a continuous-flow steam generator, in which an evaporator continuous heating surface is arranged in a throttle cable which can be flowed through in an approximately vertical heating gas direction and which comprises a number of steam generator tubes connected in parallel to flow through a flow medium.
  • a gas and steam turbine plant the heat contained in the relaxed working fluid or heating gas from the gas turbine is used to generate steam for the steam turbine.
  • the heat transfer takes place in a heat recovery steam generator connected downstream of the gas turbine, in which a number of heating surfaces are usually arranged for water preheating, steam generation and steam superheating.
  • the heating surfaces are connected in the water-steam cycle of the steam turbine.
  • the water-steam cycle usually includes several, z. B.
  • each pressure stage may have a Verdampferloom Structure.
  • gas turbine as heat recovery steam generator downstream of the steam generator come several alternative design concepts, namely the design as a continuous steam generator or the design as circulation steam generator, into consideration.
  • a continuous steam generator the heating of steam generator tubes provided as evaporator tubes leads to an evaporation of the flow medium in the steam generator tubes in a single pass.
  • the recirculated water is only partially vaporized when passing through the evaporator tubes. The water which is not evaporated is fed again to the same evaporator tubes after separation of the steam produced for further evaporation.
  • a continuous steam generator In contrast to a natural or forced circulation steam generator, a continuous steam generator is not subject to pressure limitation, so that fresh steam pressures are possible far above the critical pressure of water (P Kri ⁇ 221 bar) - where there are only slight differences in density between liquid-like and vapor-like medium.
  • a high live steam pressure promotes a high thermal efficiency and thus low CO 2 emissions of a fossil-fired power plant.
  • a continuous steam generator in comparison to a circulating steam generator a simple construction and is thus produced with very little effort.
  • the use of a designed according to the flow principle steam generator as heat recovery steam generator of a gas and steam turbine plant is therefore particularly favorable to achieve a high overall efficiency of the gas and steam turbine plant with a simple design.
  • Such continuous steam heaters are, for example, from the US 5 159 897 A , of the DE 41 26 631 A , of the DE 11 22 082 B , of the DE 29 50 622 A , of the DE 44 41 008 A , of the DE 736 611 C and the US 5 588 400 A known.
  • Such a heat recovery steam generator can be carried out particularly technically simply by the heating gas supplied to the steam generator from the gas turbine passing through the gas draft in the vertical direction, in particular from the bottom upwards.
  • two possible concepts come into consideration for the flow medium and heating gas connection of the steam generator tubes forming the evaporator flow heating surface.
  • Either the steam generator tubes laid within the gas duct are flowed through by the flow medium in a so-called crosstalk or countercurrent flow, that is to say the flow medium flows through each heating surface tube in succession following passes through the gas channel transverse to the gas flow, hence the term cross-circuit.
  • the horizontal pipe sections leading from one side of the gas channel to the other side are connected to one another via deflection pieces in such a way that they are flowed through in succession in the vertical direction counter to the flow direction of the gas Designation Countercurrent circuit.
  • This circuit will therefore be referred to below only as a countercurrent circuit. It is well known that a countercurrent evaporator heating surface is problematic in terms of flow stability. In particular, a uniform distribution of the flow to all parallel tubes of the evaporator heating requires technical effort.
  • An alternative to the countercurrent circuit is the so-called DC circuit, in which the steam generator tubes are flowed through in the cross / direct current.
  • the horizontally guided pipe sections are connected to each other via deflection pieces as in the above-described cross-flow circuit, only that they are now flowed through in the vertical direction successively in the flow direction of the gas, therefore the term DC circuit.
  • This circuit is a hybrid form of cross and DC circuit.
  • the crosscurrent character is immaterial to the following discussion. This circuit will therefore be referred to hereinafter only as a DC circuit.
  • a DC circuit requires the use of relatively large heating surfaces whose production and assembly are associated with considerable effort.
  • a steam generator which has the advantages of a continuous steam generator mentioned. Its evaporator passage heating surface is designed as a combination of countercurrent and DC circuit by having a number of tube sections in the counter-current direction, while a number of other tube sections are connected in the DC direction. By this type of interconnection, a higher degree of flow stability can be achieved than in a pure countercurrent circuit. In addition, the necessary when using a pure DC circuit high technical and apperative effort can be reduced.
  • the invention is therefore based on the object of specifying a continuous steam generator of the type mentioned above, which has a particularly high stability, especially with temperature imbalances even when exposed to comparatively large mass flow densities of the flow medium even with different heating of the steam generator tubes. Furthermore, a particularly suitable method of operating the steam generator of the type mentioned above should be specified.
  • the evaporator continuous heating surface comprising a flow medium flowing through the countercurrent to the gas flue Bank inhabitsegment whose strömungsmediumschreiber exit is seen in Walkergasraum positioned such that the operating temperature in the Verdampfer tolaufterrorism composition adjusting saturated steam temperature by less than a predetermined maximum deviation of which differs in the operating case at the position of the exit of the Schundsegments heating gas temperature.
  • the invention is based on the consideration that during the feeding of the Verdampfer,laufsammlung construction with comparatively large mass flow densities locally different heating of individual tubes could affect the flow conditions such that Shibeauchte pipes flows through less and less heated pipes of more flow medium become. More heated pipes would in this case cooled worse than less heated pipes, so that the temperature differences occurring would be amplified automatically.
  • the system should be designed to be suitable for a fundamental and global limitation of possible temperature differences. For this purpose, it is possible to use the knowledge that, at the outlet from the evaporator throughflow heating surface, the flow medium must at least have the saturated steam temperature given essentially by the pressure in the steam generator tube.
  • the flow medium can have at most the temperature which the heating gas has at the exit point of the flow medium from the evaporator throughflow heating surface.
  • the positioning of the outlet of the Verdampfer wishlaufsammlung Chemistry in relation to the temperature profile of the hot gas in the throttle cable is chosen such that a maximum deviation of about 50 ° C is maintained, so that in terms of available materials and other design parameters, a particularly high operational safety is guaranteed.
  • the evaporator continuous heating surface advantageously comprises a further heating surface segment, upstream of said heating surface segment on the flow medium side, which is advantageously arranged in front of said heating surface segment on the heating gas side.
  • the further heating surface segment upstream of the heating surface segment on the flow medium side is also advantageously designed in the manner of a countercurrent section or alternatively connected in cocurrent to the heating gas direction.
  • the steam generator is used as a heat recovery steam generator of a gas and steam turbine plant.
  • the steam generator is advantageously followed by a gas turbine on the hot gas side.
  • this circuit can be arranged expediently behind the gas turbine, an additional firing to increase the temperature of the heating gas.
  • the flow medium is guided before its exit from the evaporator continuous heating surface in countercurrent to the direction of the heating gas.
  • the steam generator tubes are thereby flowed through by the flow medium against the direction Schugasraum, ie from top to bottom.
  • the positioning of the outlet can be comparably easily varied and adapted to the temperature profile of the heating gas in the gas flue.
  • a maximum deviation of about 50 ° C is specified.
  • the evaporator system formed by the evaporator continuous heating surface 8 is acted upon by flow medium W, which evaporates in a single pass through the Verdampfer barnterrorism Chemistry 8 and discharged after exiting the Verdampfer barnterrorism Structure 8 as vapor D and is usually supplied to further overheating superheater.
  • the evaporator system formed by the evaporator continuous heating 8 is connected in the non-illustrated water-steam cycle of a steam turbine. In addition to the evaporator system are in the water-steam cycle of the steam turbine, a number of others, in FIG. 1 Not shown heating surfaces switched.
  • the heating surfaces can be, for example, superheaters, medium-pressure evaporators, low-pressure evaporators and / or preheaters.
  • the evaporator continuous heating surface 8 of the continuous steam generator 1 after FIG. 1 comprises in the manner of a tube bundle, a plurality of parallel to the flow of the flow medium W steam generator tubes 12.
  • a plurality of steam generator tubes 12 in the direction of the heating gas y is juxtaposed.
  • only one of the juxtaposed steam generator tubes 12 is visible.
  • the steam generator tubes 12 each comprise a number of horizontally flowed through pipe sections, two of which are each connected by a vertically flowed pipe section. In other words:
  • the steam generator tubes are each laid in a meandering manner within the throttle cable 6.
  • the thus juxtaposed steam generator tubes 12 is in each case a common inlet header 14 upstream of the flow medium side at its inlet 13 into the evaporator continuous heating surface 8, and a common outlet header 18 downstream of the evaporator throughflow heating surface 8 at its outlet 16.
  • the continuous-flow steam generator 1 is designed for a particularly high operational safety and for the consistent suppression of significant differences in temperature, also referred to as temperature imbalance, at the outlet 16 between adjacent steam generator tubes 12 even with a feed with comparatively high mass flow densities.
  • the evaporator throughflow heating surface 8 in its rear area seen on the flow medium side, comprises a heating surface segment 20, which is connected in countercurrent to the heating gas direction y.
  • the evaporator continuous heating surface 8 comprises, in addition to the heating surface segment 20, a further heating surface segment 22 upstream of this flow medium side.
  • This positioning is selected in the continuous steam generator 1 such that the pressure-dependent in the Verdampfer wishlaufsammlung scene 8 adjusting saturated steam temperature of the flow medium W by less than a predetermined maximum deviation of about 50 ° C of the operating case at the position or at the height of the outlet 16 of Schuvinsegments 20 prevailing heating gas temperature deviates. Since the temperature of the flow medium W at the outlet 16 must always be at least equal to the saturated steam temperature, but on the other hand can not be higher than the prevailing at this point heating gas temperature, the possible temperature differences between differently heated pipes without further countermeasures to the predetermined maximum deviation of about 50 ° C limited.
  • a particularly high flow stability with limited technical effort can also be achieved by using a combination of countercurrent circuit and DC circuit of the steam generator tubes.
  • the first heating surface segment 20 is connected to the second heating surface segment 22 by a connecting piece 24.
  • the evaporator continuous heating surface 8 comprises the further heating surface segment 22, the connecting piece 24 which is connected downstream of the flow medium side and also the flow medium side of the connecting piece 24 Downstream Walker vomsegment 20.
  • the other heating surface segment 22 is also connected in countercurrent to the direction 4 Schugasraum.
  • the occurrence of flow oscillations is reliably prevented. These occur when a different heating of individual steam generator tubes 12 greatly shifts the evaporation zone within the relevant steam generator tube 12 along the flow direction of the flow medium W.
  • Flow oscillations can be avoided in such a case, by artificially increasing the pressure loss occurring in the flow medium W as it flows through the evaporator continuous heating surface 8 by throttling at the inlet of the tubes.
  • the problem of the flow oscillations does not occur. It has been shown that the evaporation zone shifts comparatively little within the respective steam generator tube 12 in the case of deviating heating. To stabilize the flow, therefore, only a small artificial increase in the pressure loss is required.

Description

Die Erfindung betrifft einen Durchlaufdampferzeuger, bei dem in einem in einer annähernd vertikalen Heizgasrichtung durchströmbaren Gaszug eine Verdampferdurchlaufheizfläche angeordnet ist, die eine Anzahl von zur Durchströmung eines Strömungsmediums parallel geschalteten Dampferzeugerrohren umfasst.
Bei einer Gas- und Dampfturbinenanlage wird die im entspannten Arbeitsmittel oder Heizgas aus der Gasturbine enthaltene Wärme zur Erzeugung von Dampf für die Dampfturbine genutzt. Die Wärmeübertragung erfolgt in einem der Gasturbine nachgeschalteten Abhitzedampferzeuger, in dem üblicherweise eine Anzahl von Heizflächen zur Wasservorwärmung, zur Dampferzeugung und zur Dampfüberhitzung angeordnet sind. Die Heizflächen sind in den Wasser-Dampf-Kreislauf der Dampfturbine geschaltet. Der Wasser-Dampf-Kreislauf umfasst üblicherweise mehrere, z. B. drei, Druckstufen, wobei jede Druckstufe eine Verdampferheizfläche aufweisen kann.
Für den der Gasturbine als Abhitzedampferzeuger heizgasseitig nachgeschalteten Dampferzeuger kommen mehrere alternative Auslegungskonzepte, nämlich die Auslegung als Durchlaufdampferzeuger oder die Auslegung als Umlaufdampferzeuger, in Betracht. Bei einem Durchlaufdampferzeuger führt die Beheizung von als Verdampferrohren vorgesehenen Dampferzeugerrohren zu einer Verdampfung des Strömungsmediums in den Dampferzeugerrohren in einem einmaligen Durchlauf. Im Gegensatz dazu wird bei einem Natur- oder Zwangumlaufdampferzeuger das im Umlauf geführte Wasser bei einem Durchlauf durch die Verdampferrohre nur teilweise verdampft. Das dabei nicht verdampfte Wasser wird nach einer Abtrennung des erzeugten Dampfes für eine weitere Verdampfung den selben Verdampferrohren erneut zugeführt.The invention relates to a continuous-flow steam generator, in which an evaporator continuous heating surface is arranged in a throttle cable which can be flowed through in an approximately vertical heating gas direction and which comprises a number of steam generator tubes connected in parallel to flow through a flow medium.
In a gas and steam turbine plant, the heat contained in the relaxed working fluid or heating gas from the gas turbine is used to generate steam for the steam turbine. The heat transfer takes place in a heat recovery steam generator connected downstream of the gas turbine, in which a number of heating surfaces are usually arranged for water preheating, steam generation and steam superheating. The heating surfaces are connected in the water-steam cycle of the steam turbine. The water-steam cycle usually includes several, z. B. three, pressure levels, each pressure stage may have a Verdampferheizfläche.
For the gas turbine as heat recovery steam generator downstream of the steam generator come several alternative design concepts, namely the design as a continuous steam generator or the design as circulation steam generator, into consideration. In a continuous steam generator, the heating of steam generator tubes provided as evaporator tubes leads to an evaporation of the flow medium in the steam generator tubes in a single pass. In contrast, in a natural or forced circulation steam generator, the recirculated water is only partially vaporized when passing through the evaporator tubes. The water which is not evaporated is fed again to the same evaporator tubes after separation of the steam produced for further evaporation.

Ein Durchlaufdampferzeuger unterliegt im Gegensatz zu einem Natur- oder Zwangumlaufdampferzeuger keiner Druckbegrenzung, so dass Frischdampfdrücke weit über dem kritischen Druck von Wasser (PKri ≈ 221 bar) - wo es nur noch geringe Dichteunterschiede gibt zwischen flüssigkeitsähnlichem und dampfähnlichem Medium - möglich sind. Ein hoher Frischdampfdruck begünstigt einen hohen thermischen Wirkungsgrad und somit niedrige CO2-Emissionen eines fossilbeheizten Kraftwerks. Zudem weist ein Durchlaufdampferzeuger im Vergleich zu einem Umlaufdampferzeuger eine einfache Bauweise auf und ist somit mit besonders geringem Aufwand herstellbar. Die Verwendung eines nach dem Durchlaufprinzip ausgelegten Dampferzeugers als Abhitzedampferzeuger einer Gas- und Dampfturbinenanlage ist daher zur Erzielung eines hohen Gesamtwirkungsgrades der Gas- und Dampfturbinenanlage bei einfacher Bauweise besonders günstig.In contrast to a natural or forced circulation steam generator, a continuous steam generator is not subject to pressure limitation, so that fresh steam pressures are possible far above the critical pressure of water (P Kri ≈ 221 bar) - where there are only slight differences in density between liquid-like and vapor-like medium. A high live steam pressure promotes a high thermal efficiency and thus low CO 2 emissions of a fossil-fired power plant. In addition, a continuous steam generator in comparison to a circulating steam generator a simple construction and is thus produced with very little effort. The use of a designed according to the flow principle steam generator as heat recovery steam generator of a gas and steam turbine plant is therefore particularly favorable to achieve a high overall efficiency of the gas and steam turbine plant with a simple design.

Solche Durchlaufdampferhitzer sind bspw. aus der US 5 159 897 A , der DE 41 26 631 A , der DE 11 22 082 B , der DE 29 50 622 A , der DE 44 41 008 A , der DE 736 611 C und der US 5 588 400 A bekannt.Such continuous steam heaters are, for example, from the US 5 159 897 A , of the DE 41 26 631 A , of the DE 11 22 082 B , of the DE 29 50 622 A , of the DE 44 41 008 A , of the DE 736 611 C and the US 5 588 400 A known.

Ein solcher Abhitzedampferzeuger kann technisch besonders einfach ausgeführt werden, indem das dem Dampferzeuger von der Gasturbine zugeführte Heizgas den Gaszug in vertikaler Richtung, insbesondere von unten nach oben, durchströmt. Dabei kommen für die strömungsmedium- und heizgasseitige Verschaltung der die Verdampferdurchlaufheizfläche bildenden Dampferzeugerrohre grundsätzlich zwei mögliche Konzepte in Betracht: Entweder werden die innerhalb des Gaszuges verlegten Dampferzeugerrohre im so genannten Kreuz- oder Gegenstrom vom Strömungsmedium durchströmt, das heißt, das Strömungsmedium durchströmt jedes Heizflächenrohr in aufeinander folgenden Durchgängen durch den Gaskanal quer zur Gasströmung, deshalb die Bezeichnung Kreuzstromschaltung. Die von einer Seite des Gaskanals zur anderen Seite führenden horizontalen Rohrstücke sind über Umlenkstücke derart miteinander verbunden, dass sie in vertikaler Richtung aufeinanderfolgend entgegen der Strömungsrichtung des Gases durchströmt werden, deshalb die Bezeichnung Gegenstromschaltung. Insgesamt handelt es sich also um eine Mischform von Kreuz- und Gegenstromschaltung. Der Kreuzstromcharakter ist für die folgenden Erörterungen unwesentlich. Diese Schaltung wird deshalb im folgenden nur als Gegenstromschaltung bezeichnet. Es ist allgemein bekannt, dass eine Verdampferheizfläche in Gegenstromschaltung problematisch hinsichtlich der Stabilität der Strömung ist. Insbesondere eine gleichmäßige Verteilung der Strömung auf alle parallelen Rohre der Verdampferheizfläche erfordert technischen Aufwand.Such a heat recovery steam generator can be carried out particularly technically simply by the heating gas supplied to the steam generator from the gas turbine passing through the gas draft in the vertical direction, in particular from the bottom upwards. In principle, two possible concepts come into consideration for the flow medium and heating gas connection of the steam generator tubes forming the evaporator flow heating surface. Either the steam generator tubes laid within the gas duct are flowed through by the flow medium in a so-called crosstalk or countercurrent flow, that is to say the flow medium flows through each heating surface tube in succession following passes through the gas channel transverse to the gas flow, hence the term cross-circuit. The horizontal pipe sections leading from one side of the gas channel to the other side are connected to one another via deflection pieces in such a way that they are flowed through in succession in the vertical direction counter to the flow direction of the gas Designation Countercurrent circuit. Overall, it is a mixed form of cross and countercurrent circuit. The crosscurrent character is immaterial to the following discussion. This circuit will therefore be referred to below only as a countercurrent circuit. It is well known that a countercurrent evaporator heating surface is problematic in terms of flow stability. In particular, a uniform distribution of the flow to all parallel tubes of the evaporator heating requires technical effort.

Eine Alternative zur Gegenstromschaltung stellt die so genannte Gleichstromschaltung dar, bei der die Dampferzeugerrohre im Kreuz-/Gleichstrom durchströmt werden. Bei dieser Schaltung sind die horizontal geführten Rohrstücke wie in der vorangehend beschriebenen Kreuzstromschaltung über Umlenkstücke miteinander verbunden, nur dass sie nun in vertikaler Richtung aufeinanderfolgend in Strömungsrichtung des Gases durchströmt werden, deshalb die Bezeichnung Gleichstromschaltung. Insgesamt handelt es sich also um eine Mischform von Kreuz- und Gleichstromschaltung. Der Kreuzstromcharakter ist für die folgenden Erörterungen unwesentlich. Diese Schaltung wird deshalb im Folgenden nur als Gleichstromschaltung bezeichnet. Eine Gleichstromschaltung erfordert den Einsatz verhältnismäßig großer Heizflächen, deren Herstellung und Montage mit erheblichem Aufwand verbunden sind.An alternative to the countercurrent circuit is the so-called DC circuit, in which the steam generator tubes are flowed through in the cross / direct current. In this circuit, the horizontally guided pipe sections are connected to each other via deflection pieces as in the above-described cross-flow circuit, only that they are now flowed through in the vertical direction successively in the flow direction of the gas, therefore the term DC circuit. Overall, so it is a hybrid form of cross and DC circuit. The crosscurrent character is immaterial to the following discussion. This circuit will therefore be referred to hereinafter only as a DC circuit. A DC circuit requires the use of relatively large heating surfaces whose production and assembly are associated with considerable effort.

Aus der EP 0 425 717 A ist ein Dampferzeuger bekannt, der die genannten Vorteile eines Durchlaufdampferzeugers aufweist. Seine Verdampferdurchlaufheizfläche ist als Kombination von Gegenstrom- und Gleichstromschaltung ausgelegt, indem eine Anzahl von Rohrabschnitten in Gegenstromrichtung geschaltet ist, während eine Anzahl von weiteren Rohrabschnitten in Gleichstromrichtung geschaltet ist. Durch diese Art der Verschaltung kann ein höheres Maß an Strömungsstabilität erreicht werden als bei einer reinen Gegenstromschaltung. Zudem kann der bei Verwendung einer reinen Gleichstromschaltung notwendige hohe technische und apperative Aufwand verringert werden.From the EP 0 425 717 A a steam generator is known, which has the advantages of a continuous steam generator mentioned. Its evaporator passage heating surface is designed as a combination of countercurrent and DC circuit by having a number of tube sections in the counter-current direction, while a number of other tube sections are connected in the DC direction. By this type of interconnection, a higher degree of flow stability can be achieved than in a pure countercurrent circuit. In addition, the necessary when using a pure DC circuit high technical and apperative effort can be reduced.

Grundsätzlich problematisch bei Dampferzeugern in derartiger Bauweise können so genannte Temperaturschieflagen sein, also Temperaturdifferenzen an den Austritten benachbarter, strömungsmediumseitig parallel geschalteter Dampferzeugerrohre, die zu Rohrreißern oder anderen Beschädigungen führen können. Zur Vermeidung derartiger Temperaturschieflagen können Durchlaufdampferzeuger für besonders geringe Massenstromdichten des Strömungsmediums ausgelegt sein, was jedoch die Flexibilität bei der Wahl der Auslegungsparameter für den Dampferzeuger begrenzt.Fundamentally problematic in steam generators of such construction may be so-called temperature imbalances, ie temperature differences at the outlets of adjacent, flow medium side parallel connected steam generator tubes, which can lead to Rohrreißern or other damage. To avoid such temperature imbalances continuous steam generators can be designed for particularly low mass flow densities of the flow medium, but this limits the flexibility in the choice of design parameters for the steam generator.

Der Erfindung liegt daher die Aufgabe zugrunde, einen Durchlaufdampferzeuger der oben genannten Art anzugeben, der auch bei einer Beaufschlagung mit vergleichsweise großen Massenstromdichten des Strömungsmediums auch bei unterschiedlicher Beheizung der Dampferzeugerrohre eine besonders hohe Stabilität insbesondere gegenüber Temperaturschieflagen aufweist. Des Weiteren soll ein zum Betreiben dieses Dampferzeugers besonders geeignetes Verfahren der oben genannten Art angegeben werden.The invention is therefore based on the object of specifying a continuous steam generator of the type mentioned above, which has a particularly high stability, especially with temperature imbalances even when exposed to comparatively large mass flow densities of the flow medium even with different heating of the steam generator tubes. Furthermore, a particularly suitable method of operating the steam generator of the type mentioned above should be specified.

Bezüglich des Durchlaufdampferzeugers wird diese Aufgabe erfindungsgemäß gelöst, indem die Verdampferdurchlaufheizfläche ein vom Strömungsmedium im Gegenstrom zum Gaszug durchströmbares Heizflächensegment umfasst, dessen strömungsmediumseitiger Austritt in Heizgasrichtung gesehen derart positioniert ist, dass die sich im Betriebsfall in der Verdampferdurchlaufheizfläche einstellende Sattdampftemperatur um weniger als eine vorgegebene Maximalabweichung von der im Betriebsfall an der Position des Austritts des Heizflächensegments herrschenden Heizgastemperatur abweicht.With regard to the continuous-flow steam generator, this object is achieved according to the invention by the evaporator continuous heating surface comprising a flow medium flowing through the countercurrent to the gas flue Heizflächensegment whose strömungsmediumseitiger exit is seen in Heizgasrichtung positioned such that the operating temperature in the Verdampferdurchlaufheizfläche adjusting saturated steam temperature by less than a predetermined maximum deviation of which differs in the operating case at the position of the exit of the Heizflächensegments heating gas temperature.

Die Erfindung geht dabei von der Überlegung aus, dass bei der Bespeisung der Verdampferdurchlaufheizfläche mit vergleichsweise großen Massenstromdichten eine lokal unterschiedliche Beheizung einzelner Rohre die Strömungsverhältnisse derart beeinflussen könnte, dass mehrbeheizte Rohre von weniger und weniger beheizte Rohre von mehr Strömungsmedium durchströmt werden. Mehrbeheizte Rohre würden in diesem Fall schlechter gekühlt als minderbeheizte Rohre, so dass die auftretenden Temperaturdifferenzen selbsttätig verstärkt würden. Um diesem Fall auch ohne aktive Beeinflussung der Strömungsverhältnisse wirksam begegnen zu können, sollte das System für eine grundsätzliche und globale Begrenzung möglicher Temperaturunterschiede geeignet ausgelegt sein. Dazu ist die Erkenntnis nutzbar, dass am Austritt aus der Verdampferdurchlaufheizfläche das Strömungsmedium zumindest die im Wesentlichen durch den Druck im Dampferzeugerrohr gegebene Sattdampftemperatur aufweisen muss. Andererseits kann das Strömungsmedium aber maximal die Temperatur aufweisen, die das Heizgas an der Austrittsstelle des Strömungsmediums aus der Verdampferdurchlaufheizfläche hat. Durch eine geeignete Abstimmung dieser beiden das mögliche Temperaturintervall überhaupt eingrenzenden Grenztemperaturen aufeinander können somit auch die maximal möglichen Temperaturschieflagen geeignet begrenzt werden. Durch die Aufteilung der Verdampfer-Durchlaufheizfläche in ein austrittsseitiges Gegenstromsegment und ein diesem heizgas- und medienseitig vorgeschaltetes weiteres Segment ist der Austritt in Heizgasrichtung frei positionierbar, so dass ein zusätzlicher Auslegungsparameter verfügbar ist. Ein besonders geeignetes Mittel zur Abstimmung der beiden Grenztemperaturen aufeinander ist dabei die gezielte Positionierung des Austritts der Verdampferdurchlaufheizfläche in Strömungsrichtung des Heizgases gesehen.The invention is based on the consideration that during the feeding of the Verdampferdurchlaufheizfläche with comparatively large mass flow densities locally different heating of individual tubes could affect the flow conditions such that mehrbeheizte pipes flows through less and less heated pipes of more flow medium become. More heated pipes would in this case cooled worse than less heated pipes, so that the temperature differences occurring would be amplified automatically. In order to be able to counteract this case effectively even without actively influencing the flow conditions, the system should be designed to be suitable for a fundamental and global limitation of possible temperature differences. For this purpose, it is possible to use the knowledge that, at the outlet from the evaporator throughflow heating surface, the flow medium must at least have the saturated steam temperature given essentially by the pressure in the steam generator tube. On the other hand, however, the flow medium can have at most the temperature which the heating gas has at the exit point of the flow medium from the evaporator throughflow heating surface. By a suitable coordination of these two possible temperature interval limiting temperature limits on each other thus also the maximum possible temperature imbalances can be suitably limited. By dividing the evaporator Durchlaufheizfläche in an outlet-side countercurrent segment and this heizgas- and media side upstream further segment of the outlet in Heizgasrichtung is freely positioned, so that an additional design parameters is available. A particularly suitable means for matching the two limit temperatures to one another is the targeted positioning of the outlet of the evaporator continuous heating surface in the flow direction of the heating gas.

Vorteilhafterweise ist die Positionierung des Austritts der Verdampferdurchlaufheizfläche in Relation zum Temperaturprofil des Heizgases im Gaszug derart gewählt, dass eine Maximalabweichung von etwa 50 °C eingehalten ist, so dass im Hinblick auf verfügbare Materialien und weitere Auslegungsparameter eine besonders hohe betriebliche Sicherheit gewährleistet ist.Advantageously, the positioning of the outlet of the Verdampferdurchlaufheizfläche in relation to the temperature profile of the hot gas in the throttle cable is chosen such that a maximum deviation of about 50 ° C is maintained, so that in terms of available materials and other design parameters, a particularly high operational safety is guaranteed.

Ein weiteres Problem bei einem Dampferzeuger der genannten Bauweise könnte die Gefährdung der Strömungsstabilität durch so genannte Strömungsoszillationen sein. Strömungsoszillationen treten auf, wenn sich bei Mehrbeheizung eines Dampferzeugerrohres das Gebiet innerhalb des Dampferzeugerrohres, in dem Verdampfung stattfindet, deutlich innerhalb des Rohres verschiebt. Die Verlagerung des Verdampfungsgebietes innerhalb eines Dampferzeugerrohres beeinflusst den Druckverlust der Strömung innerhalb der Verdampferdurchlaufheizfläche auf unerwünschte Art und Weise. Daher könnten bei einem Dampferzeuger, der derart empfindlich auf eine abweichende Beheizung der Dampferzeugerrohre reagiert, Drosseln am Eintritt aller Dampferzeugerrohre vorgesehen sein, die es erlauben, den Druckverlust der Strömung innerhalb der Verdampferdurchlaufheizfläche über einen verhältnismäßig großen Bereich hinweg zu steuern. Um auch hierfür geeignete Auslegungsparameter bereitzustellen, umfasst die Verdampferdurchlaufheizfläche vorteilhafterweise ein weiteres, dem genannten Heizflächensegment strömungsmediumseitig vorgeschaltetes Heizflächensegment, das heizgasseitig zweckmäßigerweise vor dem genannten Heizflächensegment angeordnet ist.Another problem with a steam generator of the construction mentioned could be the risk of flow stability due to so-called flow oscillations. flow oscillations occur when Mehrbestheizung a steam generator tube, the area within the steam generator tube, takes place in the evaporation significantly within the tube. The displacement of the evaporation zone within a steam generator tube undesirably affects the pressure loss of the flow within the evaporator passage heating surface. Therefore, in a steam generator that is so sensitive to differential heating of the steam generator tubes, throttles could be provided at the inlet of all steam generator tubes that allow the pressure loss of the flow within the evaporator flow heating surface to be controlled over a relatively large range. In order to also provide suitable design parameters for this purpose, the evaporator continuous heating surface advantageously comprises a further heating surface segment, upstream of said heating surface segment on the flow medium side, which is advantageously arranged in front of said heating surface segment on the heating gas side.

Das dem Heizflächensegment strömungsmediumseitig vorgeschaltete weitere Heizflächensegment ist vorteilhafterweise ebenfalls in der Art einer Gegenstromsektion ausgebildet oder alternativ im Gleichstrom zur Heizgasrichtung geschaltet.The further heating surface segment upstream of the heating surface segment on the flow medium side is also advantageously designed in the manner of a countercurrent section or alternatively connected in cocurrent to the heating gas direction.

Durch eine derartige Anordnung der Segmente im Heizgaskanal wird weitgehend der Vorteil einer reinen Gegenstromschaltung erhalten, die Wärme des Abgases effektiv auf das Strömungsmedium zu übertragen, und gleichzeitig eine hohe inhärente Sicherheit gegen schädliche Temperaturdifferenzen am strömungsmediumsseitigen Austritt erzielt.By such an arrangement of the segments in the heating gas channel is largely obtained the advantage of a pure countercurrent circuit to transfer the heat of the exhaust gas effectively to the flow medium, while achieving a high degree of inherent security against harmful temperature differences on the flow medium side outlet.

Zweckmäßigerweise wird der Dampferzeuger als Abhitzedampferzeuger einer Gas- und Dampfturbinenanlage verwendet. Dabei ist der Dampferzeuger vorteilhafterweise heizgasseitig einer Gasturbine nachgeschaltet. Bei dieser Schaltung kann zweckmäßigerweise hinter der Gasturbine eine Zusatzfeuerung zur Erhöhung der Heizgastemperatur angeordnet sein.Conveniently, the steam generator is used as a heat recovery steam generator of a gas and steam turbine plant. In this case, the steam generator is advantageously followed by a gas turbine on the hot gas side. In this circuit can be arranged expediently behind the gas turbine, an additional firing to increase the temperature of the heating gas.

Vorteilhafterweise wird das Strömungsmedium vor seinem Austritt aus der Verdampferdurchlaufheizfläche im Gegenstrom zur Heizgasrichtung geführt. In dem entsprechenden Heizflächensegment werden die Dampferzeugerrohre dabei vom Strömungsmedium entgegen der Heizgasrichtung, also von oben nach unten, durchströmt. Bei einer derartigen Bespeisung der Verdampferdurchlaufheizfläche ist die Positionierung des Austritts vergleichsweise einfach variierbar und an das Temperaturprofil des Heizgases im Gaszug anpassbar. Vorteilhafterweise wird eine Maximalabweichung von etwa 50 °C vorgegeben.Advantageously, the flow medium is guided before its exit from the evaporator continuous heating surface in countercurrent to the direction of the heating gas. In the corresponding Heizflächensegment the steam generator tubes are thereby flowed through by the flow medium against the direction Heizgasrichtung, ie from top to bottom. With such a feeding of the evaporator continuous heating surface, the positioning of the outlet can be comparably easily varied and adapted to the temperature profile of the heating gas in the gas flue. Advantageously, a maximum deviation of about 50 ° C is specified.

Die mit der Erfindung erzielten Vorteile bestehen insbesondere darin, dass durch die nunmehr vorgesehene, an das Temperaturprofil des Heizgases im Gaszug angepasste Positionierung des strömungsmediumseitigen Austritts der Verdampferdurchlaufheizfläche das insgesamt bei der Verdampfung des Strömungsmediums erreichbare Temperaturintervall zwischen Sattdampftemperatur des Strömungsmediums und Heizgastemperatur an der Austrittsstelle vergleichsweise eng eingegrenzt wird, so dass unabhängig von den Strömungsverhältnissen nur geringe austrittsseitige Temperaturdifferenzen möglich sind. Dadurch kann eine ausreichende Angleichung der Temperaturen des Strömungsmediums in jedem Betriebszustand sichergestellt werden. Zudem ist die Durchlaufverdampferheizfläche durch die geeignete Positionierung des strömungsmediumseitigen Eintritts der Verdampferdurchlaufheizfläche am gasseitigen Eintritt der Verdampferdurchlaufheizfläche strömungsmäßig stabiler als eine reine Gegenstromschaltung. Somit ist eine besonders hohe Strömungsstabilität und eine besonders hohe betriebliche Sicherheit für den Dampferzeuger gewährleistet. Darüber hinaus ist aber auch sichergestellt, dass die möglichen Austrittstemperaturen in ihrer absoluten Höhe begrenzt sind, so dass die durch die Materialeigenschaften vorgegebenen zulässigen Grenztemperaturen sicher unterschritten bleiben.
Ein Ausführungsbeispiel der Erfindung wird anhand einer Zeichnung näher erläutert. Darin zeigen:

FIG 1
in vereinfachter Darstellung ausschnittsweise im Längsschnitt einen Durchlaufdampferzeuger, und
FIG 2
die Verdampfungssektion des Durchlaufdampferzeugers nach FIG 1 in einer alternativen Ausführung.
Gleiche Teile sind in beiden Figuren mit denselben Bezugszeichen versehen.
Der Durchlaufdampferzeuger 1 gemäß FIG 1 ist in der Art eines Abhitzedampferzeugers einer nicht näher dargestellten Gasturbine abgasseitig nachgeschaltet. Der Durchlaufdampferzeuger 1 weist eine Umfassungswand 2 auf, die einen in einer annähernd vertikalen, durch die Pfeile 4 angedeuteten Heizgasrichtung y durchströmbaren Gaszug 6 für das Abgas aus der Gasturbine bildet. Im Gaszug 6 ist eine Anzahl von nach dem Durchlaufprinzip ausgelegten Heizflächen, insbesondere eine Verdampferdurchlaufheizfläche 8, angeordnet. Im Ausführungsbeispiel gemäß FIG 1 ist lediglich die Verdampferdurchlaufheizfläche 8 gezeigt, es kann aber auch eine größere Anzahl von Durchlaufheizflächen vorgesehen sein.The advantages achieved by the invention are in particular that by the now provided, adapted to the temperature profile of the hot gas in throttle cable positioning of the flow medium side outlet of Verdampferdurchlaufheizfläche the total achievable in the evaporation of the flow medium temperature interval between the saturated steam temperature of the flow medium and heating gas temperature at the exit point comparatively narrow is limited so that only small outlet-side temperature differences are possible, regardless of the flow conditions. As a result, a sufficient equalization of the temperatures of the flow medium can be ensured in each operating state. In addition, the flow evaporator heating surface is fluidly more stable than a pure countercurrent circuit due to the appropriate positioning of the flow medium side entrance of the evaporator flow heating surface at the gas inlet of the evaporator flow heating surface. Thus, a particularly high flow stability and a particularly high operational safety for the steam generator is guaranteed. In addition, it is also ensured that the possible outlet temperatures are limited in their absolute height, so that the safely fall below the permissible limit temperatures given by the material properties.
An embodiment of the invention will be explained in more detail with reference to a drawing. Show:
FIG. 1
in a simplified representation of a section in longitudinal section a continuous steam generator, and
FIG. 2
the evaporation section of the continuous steam generator after FIG. 1 in an alternative embodiment.
Identical parts are provided in both figures with the same reference numerals.
The continuous steam generator 1 according to FIG. 1 is downstream in the manner of a heat recovery steam generator of a gas turbine not shown exhaust. The continuous-flow steam generator 1 has a surrounding wall 2 which forms a gas duct 6 for the exhaust gas from the gas turbine which can be flowed through in an approximately vertical heating gas direction y indicated by the arrows 4. In the throttle cable 6 is a number of designed according to the flow principle heating surfaces, in particular a Verdampferdurchlaufheizfläche 8, respectively. In the embodiment according to FIG. 1 is only the evaporator continuous heating 8 shown, but it can also be provided a larger number of continuous heating.

Das aus der Verdampferdurchlaufheizfläche 8 gebildete Verdampfersystem ist mit Strömungsmedium W beaufschlagbar, das bei einmaligem Durchlauf durch die Verdampferdurchlaufheizfläche 8 verdampft und nach dem Austritt aus der Verdampferdurchlaufheizfläche 8 als Dampf D abgeführt und üblicherweise zur weiteren Überhitzung Überhitzerheizflächen zugeführt wird. Das aus der Verdampferdurchlaufheizfläche 8 gebildete Verdampfersystem ist in den nicht näher dargestellten Wasser-Dampf-Kreislauf einer Dampfturbine geschaltet. Zusätzlich zu dem Verdampfersystem sind in den Wasser-Dampf-Kreislauf der Dampfturbine eine Anzahl weiterer, in FIG 1 nicht dargestellter Heizflächen geschaltet. Bei den Heizflächen kann es sich beispielsweise um Überhitzer, Mitteldruckverdampfer, Niederdruckverdampfer und/oder um Vorwärmer handeln.The evaporator system formed by the evaporator continuous heating surface 8 is acted upon by flow medium W, which evaporates in a single pass through the Verdampferdurchlaufheizfläche 8 and discharged after exiting the Verdampferdurchlaufheizfläche 8 as vapor D and is usually supplied to further overheating superheater. The evaporator system formed by the evaporator continuous heating 8 is connected in the non-illustrated water-steam cycle of a steam turbine. In addition to the evaporator system are in the water-steam cycle of the steam turbine, a number of others, in FIG. 1 Not shown heating surfaces switched. The heating surfaces can be, for example, superheaters, medium-pressure evaporators, low-pressure evaporators and / or preheaters.

Die Verdampferdurchlaufheizfläche 8 des Durchlaufdampferzeugers 1 nach FIG 1 umfasst in der Art eines Rohrbündels eine Mehrzahl von zur Durchströmung des Strömungsmediums W parallel geschalteten Dampferzeugerrohren 12. Dabei ist jeweils eine Mehrzahl von Dampferzeugerrohren 12 in Heizgasrichtung y gesehen nebeneinander angeordnet. Dabei ist jeweils lediglich eines der so nebeneinander angeordneten Dampferzeugerrohre 12 sichtbar. Die Dampferzeugerrohre 12 umfassen jeweils eine Anzahl von waagerecht durchströmten Rohrstücken, von denen jeweils zwei durch ein senkrecht durchströmtes Rohrstück verbunden sind. Mit anderen Worten: Die Dampferzeugerrohre sind jeweils mäanderartig innerhalb des Gaszuges 6 verlegt. Den so nebeneinander angeordneten Dampferzeugerrohren 12 ist dabei strömungsmediumseitig an ihrem Eintritt 13 in die Verdampferdurchlaufheizfläche 8 jeweils ein gemeinsamer Eintrittssammler 14 vor- und an ihrem Austritt 16 aus der Verdampferdurchlaufheizfläche 8 ein gemeinsamer Austrittssammler 18 nachgeschaltet.The evaporator continuous heating surface 8 of the continuous steam generator 1 after FIG. 1 comprises in the manner of a tube bundle, a plurality of parallel to the flow of the flow medium W steam generator tubes 12. In each case, a plurality of steam generator tubes 12 in the direction of the heating gas y is juxtaposed. In each case, only one of the juxtaposed steam generator tubes 12 is visible. The steam generator tubes 12 each comprise a number of horizontally flowed through pipe sections, two of which are each connected by a vertically flowed pipe section. In other words: The steam generator tubes are each laid in a meandering manner within the throttle cable 6. The thus juxtaposed steam generator tubes 12 is in each case a common inlet header 14 upstream of the flow medium side at its inlet 13 into the evaporator continuous heating surface 8, and a common outlet header 18 downstream of the evaporator throughflow heating surface 8 at its outlet 16.

Der Durchlaufdampferzeuger 1 ist für eine besonders hohe betriebliche Sicherheit und zur konsequenten Unterdrückung von auch als Temperaturschieflage bezeichneten signifikanten Temperaturunterschieden am Austritt 16 zwischen benachbarten Dampferzeugerrohren 12 selbst bei einer Bespeisung mit vergleichsweise hohen Massenstromdichten ausgelegt. Dazu umfasst die Verdampferdurchlaufheizfläche 8 in ihrem strömungsmediumseitig gesehen hinteren Bereich ein Heizflächensegment 20, das im Gegenstrom zur Heizgasrichtung y geschaltet ist. Weiterhin umfasst die Verdampferdurchlaufheizfläche 8 zusätzlich zum Heizflächensegment 20 ein diesem strömungsmediumseitig vorgeschaltetes weiteres Heizflächensegment 22. Durch diese Schaltung ist die Positionierung des Austritts 16 in Heizgasrichtung y gesehen wählbar. Diese Positionierung ist beim Durchlaufdampferzeuger 1 derart gewählt, dass die sich im Betriebsfall druckabhängig in der Verdampferdurchlaufheizfläche 8 einstellende Sattdampftemperatur des Strömungsmediums W um weniger als eine vorgegebene Maximalabweichung von etwa 50 °C von der im Betriebsfall an der Position oder auf der Höhe des Austritts 16 des Heizflächensegments 20 herrschenden Heizgastemperatur abweicht. Da die Temperatur des Strömungsmediums W am Austritt 16 immer mindestens gleich der Sattdampftemperatur sein muss, andererseits aber nicht höher als die an dieser Stelle herrschende Heizgastemperatur sein kann, sind die möglichen Temperaturdifferenzen zwischen unterschiedlich beheizten Rohren auch ohne weitere Gegenmaßnahmen auf die vorgegebene Maximalabweichung von etwa 50 °C begrenzt.The continuous-flow steam generator 1 is designed for a particularly high operational safety and for the consistent suppression of significant differences in temperature, also referred to as temperature imbalance, at the outlet 16 between adjacent steam generator tubes 12 even with a feed with comparatively high mass flow densities. For this purpose, the evaporator throughflow heating surface 8, in its rear area seen on the flow medium side, comprises a heating surface segment 20, which is connected in countercurrent to the heating gas direction y. Furthermore, the evaporator continuous heating surface 8 comprises, in addition to the heating surface segment 20, a further heating surface segment 22 upstream of this flow medium side. By means of this circuit, the positioning of the outlet 16 in heating gas direction y can be selected. This positioning is selected in the continuous steam generator 1 such that the pressure-dependent in the Verdampferdurchlaufheizfläche 8 adjusting saturated steam temperature of the flow medium W by less than a predetermined maximum deviation of about 50 ° C of the operating case at the position or at the height of the outlet 16 of Heizflächensegments 20 prevailing heating gas temperature deviates. Since the temperature of the flow medium W at the outlet 16 must always be at least equal to the saturated steam temperature, but on the other hand can not be higher than the prevailing at this point heating gas temperature, the possible temperature differences between differently heated pipes without further countermeasures to the predetermined maximum deviation of about 50 ° C limited.

Eine besonders hohe Strömungsstabilität bei gleichzeitig begrenztem technischen Aufwand lässt sich zudem durch die Verwendung einer Kombination aus Gegenstromschaltung und Gleichstromschaltung der Dampferzeugerrohre erzielen. Das erste Heizflächensegment 20 ist dabei mit dem zweiten Heizflächensegment 22 durch ein Verbindungsstück 24 verbunden. Die Verdampferdurchlaufheizfläche 8 umfasst das weitere Heizflächensegment 22, das diesem strömungsmediumseitig nachgeschaltete Verbindungsstück 24 sowie das dem Verbindungsstück 24 strömungsmediumseitig nachgeschaltete Heizflächensegment 20. Im Ausführungsbeispiel nach FIG 1 ist das weitere Heizflächensegment 22 ebenfalls im Gegenstrom zur Heizgasrichtung 4 geschaltet.A particularly high flow stability with limited technical effort can also be achieved by using a combination of countercurrent circuit and DC circuit of the steam generator tubes. The first heating surface segment 20 is connected to the second heating surface segment 22 by a connecting piece 24. The evaporator continuous heating surface 8 comprises the further heating surface segment 22, the connecting piece 24 which is connected downstream of the flow medium side and also the flow medium side of the connecting piece 24 Downstream Heizflächensegment 20. In the embodiment according to FIG. 1 the other heating surface segment 22 is also connected in countercurrent to the direction 4 Heizgasrichtung.

Wie sich herausgestellt hat, weist sowohl die in FIG 1 dargestellte als auch die in FIG 2 dargestellte alternative Schaltung der Verdampferdurchlaufheizfläche 8 eine besonders große Strömungsstabilität auf. Insbesondere wird auch das Auftreten von Strömungsoszillationen sicher verhindert. Diese treten auf, wenn eine abweichende Beheizung einzelner Dampferzeugerrohre 12 das Verdampfungsgebiet innerhalb des betreffenden Dampferzeugerrohres 12 stark entlang der Strömungsrichtung des Strömungsmediums W verschiebt. Strömungsoszillationen können in einem solchen Fall vermieden werden, indem der beim Durchströmen der Verdampferdurchlaufheizfläche 8 auftretende Druckverlust im Strömungsmedium W durch Drosseln am Eintritt der Rohre künstlich erhöht wird. Bei den in FIG 1 und 2 dargestellten Schaltungen tritt das Problem der Strömungsoszillationen jedoch nicht auf. Es hat sich gezeigt, dass sich das Verdampfungsgebiet bei einer abweichenden Beheizung nur vergleichsweise wenig innerhalb des jeweiligen Dampferzeugerrohres 12 verschiebt. Zur Stabilisierung der Strömung ist daher lediglich eine geringe künstliche Erhöhung des Druckverlustes erforderlich.As it turned out, both the in FIG. 1 presented as well as the in FIG. 2 illustrated alternative circuit of the evaporator continuous heating surface 8 a particularly high flow stability. In particular, the occurrence of flow oscillations is reliably prevented. These occur when a different heating of individual steam generator tubes 12 greatly shifts the evaporation zone within the relevant steam generator tube 12 along the flow direction of the flow medium W. Flow oscillations can be avoided in such a case, by artificially increasing the pressure loss occurring in the flow medium W as it flows through the evaporator continuous heating surface 8 by throttling at the inlet of the tubes. At the in 1 and 2 however, the problem of the flow oscillations does not occur. It has been shown that the evaporation zone shifts comparatively little within the respective steam generator tube 12 in the case of deviating heating. To stabilize the flow, therefore, only a small artificial increase in the pressure loss is required.

Claims (1)

  1. Continuous-flow steam generator (1), wherein an evaporator throughflow heating surface (8) is disposed in a gas duct (6) through which heating gas can flow in an approximately vertical direction (y), said evaporator throughflow heating surface comprising a number of steam generating pipes (12) connected in parallel for a flow medium (W) to flow through and comprising the heating surface segment (20), through which the flow medium (W) can flow in a counterflow relative to the gas duct (6), and a further heating-surface segment (22) connected upstream on the flow-medium side and on the heating-gas side of the heating-surface segment (20),
    characterised in that
    the flow-medium-side outlet (16) of the heating-surface segment (20), viewed in the direction (y) of the heating gas, is positioned such that the saturated-steam temperature which is adjusted during operation in the evaporator throughflow heating surface (8) deviates by less than a predetermined maximum amount of at most 70°C from the heating-gas temperature prevailing during operation at the position of the outlet (16) of the heating-surface segment (20).
EP04763621.2A 2003-09-03 2004-07-29 Once-through steam generator and method of operating said once-through steam generator Not-in-force EP1660812B1 (en)

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EP03020021A EP1512905A1 (en) 2003-09-03 2003-09-03 Once-through steam generator and method of operating said once-through steam generator
EP04763621.2A EP1660812B1 (en) 2003-09-03 2004-07-29 Once-through steam generator and method of operating said once-through steam generator
PCT/EP2004/008526 WO2005028955A1 (en) 2003-09-03 2004-07-29 Continuous steam generator and method for operating said continuous steam generator

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EP1660812A1 EP1660812A1 (en) 2006-05-31
EP1660812B1 true EP1660812B1 (en) 2018-10-17

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EP (2) EP1512905A1 (en)
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WO (1) WO2005028955A1 (en)
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Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2065641A3 (en) * 2007-11-28 2010-06-09 Siemens Aktiengesellschaft Method for operating a continuous flow steam generator and once-through steam generator
EP2194320A1 (en) * 2008-06-12 2010-06-09 Siemens Aktiengesellschaft Method for operating a once-through steam generator and once-through steam generator
DE102009012321A1 (en) * 2009-03-09 2010-09-16 Siemens Aktiengesellschaft Flow evaporator
IT1395108B1 (en) 2009-07-28 2012-09-05 Itea Spa BOILER
RU2473838C1 (en) * 2011-07-20 2013-01-27 Открытое акционерное общество "Всероссийский дважды ордена Трудового Красного Знамени теплотехнический научно-исследовательский институт" Evaporating surface of heating in straight-flow waste heat boiler with partitioned coil packages
JP6187879B2 (en) * 2013-01-10 2017-08-30 パナソニックＩｐマネジメント株式会社 Rankine cycle device and cogeneration system
EP2770171A1 (en) 2013-02-22 2014-08-27 Alstom Technology Ltd Method for providing a frequency response for a combined cycle power plant
DE102016102777A1 (en) * 2016-02-17 2017-08-17 Netzsch Trockenmahltechnik Gmbh Method and apparatus for generating superheated steam from a working fluid
CN111059517A (en) * 2019-11-07 2020-04-24 宋阳 Flue gas waste heat steam injection boiler and system for producing high-pressure saturated steam
CN114017761A (en) * 2021-10-13 2022-02-08 广东美的厨房电器制造有限公司 Steam generator and cooking equipment

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE736611C (en) * 1940-10-01 1943-06-23 Duerrwerke Ag Forced-through steam generator with a superheater connected directly to the evaporation heating surface
DE1122082B (en) * 1957-12-13 1962-01-18 Ver Kesselwerke Ag Forced once-through steam generator
GB1037995A (en) * 1962-06-15 1966-08-03 Babcock & Wilcox Ltd Improvements in or relating to tubulous vapour generators of the forced flow, once through type
US4072182A (en) * 1977-01-05 1978-02-07 International Power Technology, Inc. Pressure staged heat exchanger
DE2950622A1 (en) * 1979-12-15 1981-10-08 Evt Energie- Und Verfahrenstechnik Gmbh, 7000 Stuttgart Operating process for forced circulation boiler - involves measures to maximise water content on shut-down in boiler with radiant contact evaporators in parallel
DE58909259D1 (en) * 1989-10-30 1995-06-29 Siemens Ag Continuous steam generator.
AT394627B (en) * 1990-08-27 1992-05-25 Sgp Va Energie Umwelt METHOD FOR STARTING A HEAT EXCHANGER SYSTEM FOR STEAM GENERATION AND A HEAT EXCHANGER SYSTEM FOR STEAM GENERATION
DE4126631C2 (en) * 1991-08-12 1995-09-14 Siemens Ag Gas-fired heat recovery steam generator
DE4142376A1 (en) * 1991-12-20 1993-06-24 Siemens Ag FOSSIL FIRED CONTINUOUS STEAM GENERATOR
DE4303613C2 (en) * 1993-02-09 1998-12-17 Steinmueller Gmbh L & C Process for generating steam in a once-through steam generator
DE4441008A1 (en) * 1994-11-17 1996-05-23 Siemens Ag Plant for steam generation according to the natural circulation principle and method for initiating water circulation in such a plant
UA42888C2 (en) * 1997-06-30 2001-11-15 Сіменс Акціенгезелльшафт Waste-heat steam generator
US5924389A (en) * 1998-04-03 1999-07-20 Combustion Engineering, Inc. Heat recovery steam generator
US6092490A (en) * 1998-04-03 2000-07-25 Combustion Engineering, Inc. Heat recovery steam generator
DE10127830B4 (en) * 2001-06-08 2007-01-11 Siemens Ag steam generator

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

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AU2004274583B2 (en) 2009-05-14
AU2004274583A1 (en) 2005-03-31
US7383791B2 (en) 2008-06-10
BRPI0413202A (en) 2006-10-03
US20070034167A1 (en) 2007-02-15
JP2007504425A (en) 2007-03-01
UA87280C2 (en) 2009-07-10
TW200516218A (en) 2005-05-16
CN100420900C (en) 2008-09-24
CA2537464C (en) 2012-10-09
EP1660812A1 (en) 2006-05-31
CN1853072A (en) 2006-10-25
JP4489773B2 (en) 2010-06-23
CA2537464A1 (en) 2005-03-31
RU2006110527A (en) 2007-10-10
EP1512905A1 (en) 2005-03-09
WO2005028955A1 (en) 2005-03-31
ZA200601455B (en) 2007-04-25
RU2351843C2 (en) 2009-04-10
TWI263013B (en) 2006-10-01

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