EP0751342B1 - Method for operating a system with a staged combustion - Google Patents

Method for operating a system with a staged combustion Download PDF

Info

Publication number
EP0751342B1
EP0751342B1 EP96810354A EP96810354A EP0751342B1 EP 0751342 B1 EP0751342 B1 EP 0751342B1 EP 96810354 A EP96810354 A EP 96810354A EP 96810354 A EP96810354 A EP 96810354A EP 0751342 B1 EP0751342 B1 EP 0751342B1
Authority
EP
European Patent Office
Prior art keywords
combustion
air
fuel
stage
flame stabilization
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP96810354A
Other languages
German (de)
French (fr)
Other versions
EP0751342A2 (en
EP0751342A3 (en
Inventor
Klaus Dr. Döbbeling
Dieter Winkler
Wolfgang Dr. Polifke
Thomas Dr. Sattelmayer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alstom SA
Original Assignee
ABB Research Ltd Switzerland
ABB Research Ltd Sweden
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ABB Research Ltd Switzerland, ABB Research Ltd Sweden filed Critical ABB Research Ltd Switzerland
Publication of EP0751342A2 publication Critical patent/EP0751342A2/en
Publication of EP0751342A3 publication Critical patent/EP0751342A3/en
Application granted granted Critical
Publication of EP0751342B1 publication Critical patent/EP0751342B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C6/00Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion
    • F23C6/04Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection
    • F23C6/042Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with fuel supply in stages

Definitions

  • the present invention relates to a method of operation a system with a staged combustion system according to Preamble of claim 1.
  • the expert in the field of combustion has many Publications have meanwhile become known that a premixed combustion at very low pollutant emissions leads.
  • the NOx and CO emissions are here in the Foregrounds.
  • the premixed combustion unfolds of course, its advantages and advantages, if the fuels used belong to the class of so-called "clean fuels" belong to it are characterized in that they are not fuel-bound Nitrogen and no sulfur or Sulfur compounds include.
  • a further reduction in pollutant emissions can be achieved if the combustion in their The whole is divided, for example if the total available combustion air in partial flows is divided, these substreams, according to their Amount to be mixed with different fuel contents.
  • a premixed combustion also needs a backflow and flame stabilization Mixing zone to the inflowing fuel / air mixture by another admixture with a hot gaseous one Bring medium, for example with an exhaust gas, to ignition.
  • Numerical calculations with extensive reaction mechanisms have shown that the result of this admixture forming intensive mixing zone essential for the formation of the NOx contributes.
  • One way to weight the mixing zone to reduce NOx formation is to reduce the fuel / air mixture continue to lose weight. However, this leads Precautions with the usual burner designs resp. Firing systems regularly to extinguish the flame.
  • WO 92 16792 discloses a Heat generator with two regarding the flow to operate a series of combustion stages.
  • the first stage is with a Fuel-air mixture operated; which opposite an excess of air for the globally targeted air ratio having.
  • the resulting hot gas is in the second stage with a fuel-air mixture mixed, that relative to the total ventilation number is fuel-rich. Although thus in the second stage a mixture with the target If the total air ratio is set, the combustion with air numbers different from the total air number performed.
  • the invention seeks to remedy this.
  • the invention how it is characterized in the claims, the task lies the basis for a procedure of the type mentioned at the beginning Pollutant emissions, especially what the NOx emissions concerns to minimize.
  • the method according to the invention is for use in gas turbines with a global air ratio of Adjust combustion of 2. Particularly suitable is a procedure in which the air ratio transmits 2.4 in the first combustion stage, and the dwell time in the first stage is around 2.5 msec lies; in the second stage there is a fuel-air mixture initiated with an air ratio of 1.4. Well tolerable deviations from the specified Numerical values are +/- 25% relative.
  • a major advantage of the invention is accordingly in it see that in addition to good flame stabilization strong reduction in NOx emissions can be achieved.
  • the invention with a lean flame stabilization zone generates 50% less NOx compared to the state of the Combustion techniques belonging to technology.
  • the invention can also be easily put into practice, by staging the combustion initially with a proportional large flame stabilization zone with a lean one Fuel / air mixture is introduced. It will hot, not yet completely burned out gas after leaving this zone with the remaining slightly richer fuel / air mixture mixed, then in a second combustion stage to get to the combustion. The Combustion gases from the flame stabilization zone are still so hot that the newly entered fuel / air mixture without special flame stabilization measures ignites by itself and burns out completely.
  • Fig. 1 shows a schematic representation of a lean Mixture-stabilized flame stabilization using a tiered fuel / air guidance.
  • This stepped fuel / air guidance has the final purpose, the total air ratio of the combustion system across the various combustion stages by appropriate divisions on a predetermined Maintain level.
  • the first stage of combustion 1 operated as a flame stabilization zone.
  • the fuel / air mixture used here 3 has an air ratio that is greater than the total air ratio of the combustion system, which is the Combustion air used is consequently only one Part of the total available air flow is; within this zone is therefore a lean Fuel / air mixture 3 operated.
  • the other part of the combustion air gets a bigger fuel content, so that the fuel / air mixture that arises here 4 has an air ratio that is smaller than that said total combustion system air number; here is therefore operated with a richer fuel / air mixture.
  • What is the total air number of the combustion system concerns it is for combustion chambers of gas turbines preferably 2, with variations depending on the parameters down and up are possible.
  • a total air number of the Combustion system of 2 can be achieved if the Air ratio for the fuel / air mixture 3 for the flame stabilization zone 1 is raised to 2.4, and that for the second combustion stage 2 is still 1.4, with these air numbers from a dwell time within the flame stabilization zone 1 on the order of 2.4 msec is assumed.
  • the latter fuel / air mixture 4 with an air ratio less than the underlying total air ratio of the combustion system, is at the flame stabilization zone 1 over into the hot combustion gases 5 initiated in this zone.
  • Now for flame stabilization hot gas backmixing is no longer necessary, burns the existing mixture in a second downstream Combustion level 2 without a significant further one NOx formation.
  • this second combustion stage 2 there is therefore a perfectly premixed fuel / air mixture before, its air ratio with the underlying total air ratio of the combustion system.
  • the hot gases 6 from the second combustion stage 2 are then the working gases to apply a downstream one, for example Turbine.
  • FIG. 1a A practical embodiment variant is shown schematically in FIG the staged combustion with a large flame stabilization zone 1a.
  • the latter zone 1a is from relatively large extension and will, as above already described, operated lean.
  • the lean fuel / air mixture will be aimed for 3 in rays 3a high speed into this zone 1a injected, as shown in Fig. 2 based on the various shown arrows.
  • To achieve a strong Turbulence i.e. to achieve a fully mixed Flame stabilization zone 1a, can be a highly twisted one Flow or the use of swirl or mixing elements be provided.
  • this flame stabilization zone 1a After leaving this flame stabilization zone 1a is hot, but not yet completely burned out combustion gas 5 in a downstream second combustion stage 2a with the rest Combustion air mixed, this air with something richer fuel / air mixture operated, i.e. the air ratio is smaller than the total air ratio of the combustion system. Since the combustion gas 5 from the flame stabilization zone 1a, as already mentioned above, is sufficiently hot ignites what has been initiated in the second combustion stage Fuel / air mixture 4 by itself, without this special To have to provide flame stabilization measures.

Description

Technisches GebietTechnical field

Die vorliegende Erfindung betrifft ein Verfahren zum Betrieb einer Anlage mit einem gestuften Verbrennungssystem gemäss Oberbegriff des Anspruchs 1.The present invention relates to a method of operation a system with a staged combustion system according to Preamble of claim 1.

Stand der TechnikState of the art

Dem Fachmann auf dem Gebiet der Verbrennung ist es aus vielen Publikationen zwischenzeitlich geläufig geworden, dass eine vorgemischte Verbrennung zu sehr niedrigen Schadstoff-Emissionen führt. Dabei stehen hier die NOx- und CO-Emissionen im Vordergrunde. Allseits werden grosse Anstrengungen zu deren Minimierung unternommen. Die vorgemischte Verbrennung entfaltet freilich ihre Vorzüge und Vorteile insbesondere dann, wenn die zum Einsatz gelangenden Brennstoffe zur Klasse der sogenannten "sauberen Brennstoffe" gehören, welche dadurch charakterisiert sind, dass sie keinen brennstoffgebundenen Stickstoff und keine Schwefelanteile resp. Schwefelverbindungen beinhalten. Eine weitere Reduzierung der Schadstoff-Emissionen lässt sich erzielen, wenn die Verbrennung in ihrer Gesamtheit eine Aufteilung erfährt, beispielsweise wenn die gesamte zur Verfügung stehende Verbrennungsluft in Teilströme aufgeteilt wird, wobei diese Teilströme, entsprechend ihrer Menge, mit verschiedenen Brennstoffgehalten vermischt werden. Bei einer solchen Verbrennungstechnik ist dann des weiteren von Wichtigkeit, dass der magerste Teilstrom zur Flammenstabilisierung verwendet wird. Eine vorgemischte Verbrennung benötigt ferner zur Flammenstabilisierung eine Rückström- und Mischungszone, um das zuströmende Brennstoff/Luft-Gemisch durch eine weitere Zumischung mit einem heissen gasförmigen Medium, beispielsweise mit einem Abgas, zur Zündung zu bringen. Numerische Berechnungen mit umfangreichen Reaktionsmechanismen haben gezeigt, dass die sich aus dieser Zumischung bildende intensive Mischzone wesentlich zur Bildung der NOx beiträgt. Eine Möglichkeit, um die Gewichtung der Mischzone zur Bildung von NOx zu verringern, besteht darin, das Brennstoff/Luft-Gemisch weiter abzumagern. Indessen führt diese Vorkehrung bei den üblichen Brennerkonstruktionen resp. Brennsystemen regelmässig zum Verlöschen der Flamme.The expert in the field of combustion has many Publications have meanwhile become known that a premixed combustion at very low pollutant emissions leads. The NOx and CO emissions are here in the Foregrounds. Everyone is making great efforts Minimization undertaken. The premixed combustion unfolds of course, its advantages and advantages, if the fuels used belong to the class of so-called "clean fuels" belong to it are characterized in that they are not fuel-bound Nitrogen and no sulfur or Sulfur compounds include. A further reduction in pollutant emissions can be achieved if the combustion in their The whole is divided, for example if the total available combustion air in partial flows is divided, these substreams, according to their Amount to be mixed with different fuel contents. With such a combustion technique is then further important that the leanest partial flow for flame stabilization is used. A premixed combustion also needs a backflow and flame stabilization Mixing zone to the inflowing fuel / air mixture by another admixture with a hot gaseous one Bring medium, for example with an exhaust gas, to ignition. Numerical calculations with extensive reaction mechanisms have shown that the result of this admixture forming intensive mixing zone essential for the formation of the NOx contributes. One way to weight the mixing zone to reduce NOx formation is to reduce the fuel / air mixture continue to lose weight. However, this leads Precautions with the usual burner designs resp. Firing systems regularly to extinguish the flame.

Aus der WO 92 16792 ist bekannt, einen Wärmeerzeuger mit zwei bezüglich der strönung in Reihe geschalteten Verbrennungsstufer zu betreiben. Dabei wird die erste Stufe mit einem Brennstoff-Luft-Gemisch betrieben ; welches gegenüber der global angestrebten Luftzahl einen Luftüberschass aufweist. Das entstandene Heissgas wird in der zweiten Stufe mit einem Brennstoff-Luftgemisch vermischt, das relativ zur Gesamtlüftzahl brennstoffreich ist. Obwohl sich somit in der zweiten Stufe ein Gemisch mit der angestrebten Gesamtluftzahl einstellt, wird die Verbrennung bei von der Gesamtluftzahl verschiedenen Luftzahlen vorgenommen.WO 92 16792 discloses a Heat generator with two regarding the flow to operate a series of combustion stages. The first stage is with a Fuel-air mixture operated; which opposite an excess of air for the globally targeted air ratio having. The resulting hot gas is in the second stage with a fuel-air mixture mixed, that relative to the total ventilation number is fuel-rich. Although thus in the second stage a mixture with the target If the total air ratio is set, the combustion with air numbers different from the total air number performed.

Darstellung der ErfindungPresentation of the invention

Hier will die Erfindung Abhilfe schaffen. Der Erfindung, wie sie in den Ansprüchen gekennzeichnet ist, liegt die Aufgabe zugrunde, bei einem Verfahren der eingangs genannten Art die Schadstoff-Emissionen, insbesondere was die NOx-Emissionen betrifft, zu minimieren.The invention seeks to remedy this. The invention how it is characterized in the claims, the task lies the basis for a procedure of the type mentioned at the beginning Pollutant emissions, especially what the NOx emissions concerns to minimize.

Dies wird erreicht, indem das Verlöschen der Flamme bei einer Abmagerung des Brennstoff/Luft-Gemisches in der ersten Verbrennungsstufe, im folgenden auch Flammenstabilisierungszone genannt, durch eine Vergrösserung und Intensivierung der Mischung in ebendieser Zone verhindert wird.This is achieved by extinguishing the flame at a Emaciation of the fuel / air mixture in the first combustion stage, hereinafter also the flame stabilization zone called, by an enlargement and intensification of the Mixing in this zone is prevented.

Des weiteren, damit das gesamtheitliche Brennstoff/Luft-Gemisch mit einer festgelegten Gesamtluftzahl des Verbrennungssystems innerhalb der zweiten Verbrennungsstufe erhalten bleibt, wird ein Teil der Verbrennungsluft mit einem grösserem Brennstoffgehalt an der Flammenstabilisierungszone vorbei in das heisse Verbrennungsgas geleitet. Da jetzt zur Flammenstabilisierung keine Heissgas-Rückvermischung mehr erforderlich ist, verbrennt die Mischung nunmehr ohne nennenswerte weitere NOx-Bildung. Dieses an sich aus der WO 92 16 792 bekannte Verfahren ist erfindungsgemäss für den Einsatz in Gasturbinen mit einer globalen Luftzahl der Verbrennung von 2 anzupassen. Besonders geeignet ist dabei ein Verfahren, bei dem die Luftzahl in der ersten Verbrennungsstufe 2,4 berträgt, und die Verweilzeitin der ersten Stufe bei rund 2,5 msec liegt; in der zweiten Stufe wird dann ein Brennstoff-Luft-Gemisch mit einer Luftzahl von 1,4 eingeleitet. Gut tolemeirbare Abweichungen von den spezifizierten Zahlenwerten liegen von +/- 25% relativ.Furthermore, the overall fuel / air mixture with a fixed total air ratio of the combustion system obtained within the second combustion stage remains, a part of the combustion air with a larger Fuel content past the flame stabilization zone passed into the hot combustion gas. Now for flame stabilization hot gas backmixing no longer required the mixture now burns without significant further NOx formation. This is known from WO 92 16 792 The method according to the invention is for use in gas turbines with a global air ratio of Adjust combustion of 2. Particularly suitable is a procedure in which the air ratio transmits 2.4 in the first combustion stage, and the dwell time in the first stage is around 2.5 msec lies; in the second stage there is a fuel-air mixture initiated with an air ratio of 1.4. Well tolerable deviations from the specified Numerical values are +/- 25% relative.

Was die Luftzahl, die in der Literatur oft mit dem griechischen Buchstabe "Lambda" gekennzeichnet wird, betrifft, so ist zu sagen, dass diese eine Zahl wiedergibt, welche aus dem tatsächlichen Luft/Brennstoff-Verhältnis zum stöchiometrischen Luft/Brennstoff-Verhältnis resultiert.As for the air number, which in literature is often associated with the Greek Letter "Lambda" is marked, so is to be said that this represents a number which results from the actual air / fuel ratio to stoichiometric Air / fuel ratio results.

Ein wesentlicher Vorteil der Erfindung ist demnach darin zu sehen, dass nebst einer guten Flammenstabilisierung eine kräftige Reduktion der NOx-Emissionen erzielt werden kann. Die Erfindung mit mager betriebener Flammenstabilisierungszone erzeugt 50% weniger NOx gegenüber der zum Stand der Technik gehörenden Verbrennungstechniken.A major advantage of the invention is accordingly in it see that in addition to good flame stabilization strong reduction in NOx emissions can be achieved. The invention with a lean flame stabilization zone generates 50% less NOx compared to the state of the Combustion techniques belonging to technology.

Die Erfindung lässt sich auch einfach praktisch umsetzen, indem die gestufte Verbrennung zunächst mit einer verhältnismässig grosse Flammenstabilisierungszone mit einem mageren Brennstoff/Luft-Gemisch eingeleitet wird. Dabei wird das heisse, noch nicht vollständig ausgebrannte Gas nach Verlassen dieser Zone mit dem restlichen etwas fetteren Brennstoff/Luft-Gemisch vermischt, um dann anschliessend in einer zweiten Verbrennungsstufe zur Verbrennung zu gelangen. Die Verbrennungsgase aus der Flammenstabilisierungszone sind immer noch so heiss, dass das neu eingegebene Brennstoff/Luft-Gemisch ohne spezielle Flammenstabilierungsmassnahmen von selbst zündet und vollständig ausbrennt. The invention can also be easily put into practice, by staging the combustion initially with a proportional large flame stabilization zone with a lean one Fuel / air mixture is introduced. It will hot, not yet completely burned out gas after leaving this zone with the remaining slightly richer fuel / air mixture mixed, then in a second combustion stage to get to the combustion. The Combustion gases from the flame stabilization zone are still so hot that the newly entered fuel / air mixture without special flame stabilization measures ignites by itself and burns out completely.

Vorteilhafte und zweckmässige Weiterbildungen der erfindungsgemässen Aufgabenlösung sind in den weiteren Ansprüchen gekennzeichnet.Advantageous and expedient developments of the inventive Task solutions are in the further claims characterized.

Im folgenden werden, anhand der Zeichnung, Ausführungsbeispiele der Erfindung näher erläutert. Alle für das unmittelbare Verständnis der Erfindung nicht erforderlichen Elemente sind weggelassen worden. Die Strömungsrichtung der Medien ist mit Pfeilen angegeben. Gleiche Elemente sind in den verschieden Figuren mit den gleichen Bezugszeichen versehen.In the following, based on the drawing, exemplary embodiments the invention explained in more detail. All for the immediate Understanding the invention does not require elements have been left out. The direction of flow of the media is indicated by arrows. The same elements are different in the Figures with the same reference numerals.

Kurze Beschreibung der ZeichnungBrief description of the drawing

Es zeigt:

Fig. 1
eine schematische Darstellung einer mageren Flammenstabilisierung mit gestufter Brennstoff/Luft-Führung und
Fig. 2
eine schematisch dargestellte Ausführungsvariante einer gestuften Verbrennung mit einer grossen Flammenstabilisierungszone.
It shows:
Fig. 1
a schematic representation of a lean flame stabilization with stepped fuel / air guidance and
Fig. 2
a schematically illustrated embodiment of a staged combustion with a large flame stabilization zone.

Wege zur Ausführung der Erfindung, gewerbliche VerwendbarkeitWAYS OF CARRYING OUT THE INVENTION, INDUSTRIAL APPLICABILITY

Fig. 1 zeigt eine schematische Darstellung einer mageren mischungsstabilisierten Flammenstabilisierung anhand einer gestuften Brennstoff/Luft-Führung. Diese gestufte Brennstoff/Luft-Führung hat den finalen Zweck, die Gesamtluftzahl des Verbrennungssystems über die verschiedenen Verbrennungsstufen durch entsprechende Aufteilungen auf einem vorbestimmten Niveau zu erhalten. Zu diesem Zweck wird die erste Verbrennungsstufe 1 als Flammenstabilisierungszone betrieben. Das hier zum Einsatz gelangenden Brennstoff/Luft-Gemisch 3 weist eine Luftzahl auf, die grösser als die Gesamtluftzahl des Verbrennungssystems ist, wobei es sich bei dieser zum Einsatz gelangenden Verbrennungsluft folgerichtig nur um eine Teilmenge des ganzen zur Verfügung stehenden Luftstromes handelt; innerhalb dieser Zone wird also mit einem mageren Brennstoff/Luft-Gemisch 3 operiert. Der weitere Teil der Verbrennungsluft erhält einen grösseren Brennstoffgehalt, dergestalt, dass sich das hier einstellende Brennstoff/Luft-Gemisch 4 eine Luftzahl aufweist, die kleiner als die genannte Gesamtluftzahl des Verbrennungssystems ist; hier wird demnach mit einem fetteren Brennstoff/Luft-Gemisch operiert. Was die Gesamtluftzahl des Verbrennungssystems betrifft, so beträgt sie für Brennkammern von Gasturbinen vorzugsweise 2, wobei, je nach Parametern, Variationen nach unten und nach oben möglich sind. Eine Gesamtluftzahl des Verbrennungssystems von 2 lässt sich erreichen, wenn die Luftzahl beim Brennstoff/Luft-Gemisch 3 für die Flammenstabilisierungszone 1 auf 2.4 angehoben wird, und diejenige für die zweite Verbrennungsstufe 2 noch 1,4 beträgt, wobei bei diesen Luftzahlen von einer Verweilzeit innerhalb der Flammenstabilisierungszone 1 in der Grössenordnung von 2,4 msec ausgegangen wird. Das letztgenannte Brennstoff/Luft-Gemisch 4, mit einer Luftzahl kleiner als die zugrundegelegte Gesamtluftzahl des Verbrennungssystems, wird an der Flammenstabilisierungszone 1 vorbei in die heissen Verbrennungsgase 5 aus ebendieser Zone eingeleitet. Da jetzt zur Flammenstabilisierung keine Heissgasrückmischung mehr erforderlich ist, verbrennt die so vorhandene Mischung in einer zweiten nachgeschalteten Verbrennungsstufe 2 ohne eine nennenswerte weitere Bildung von NOx. In dieser zweiten Verbrennungsstufe 2 herrscht sonach ein perfekt vorgemischtes Brennstoff/Luft-Gemisch vor, dessen Luftzahl mit der zugrundegelegten Gesamtluftzahl des Verbrennungssystems übereinstimmt. Bei einer solchen Schaltung kann man davon ausgehen, dass die NOx-Emissionen demgemäss, also aufgrund der mager betriebenen Stabilisierungszone, nur noch 50% dessen ausmachen, was mit herkömmlichen mehrstufigen Verbrennungssystemen erreichbar ist. Die Heissgase 6 aus der zweiten Verbrennungsstufe 2 sind dann die Arbeitsgase zur Beaufschlagung beispielsweise einer nachgeschalteten Turbine.Fig. 1 shows a schematic representation of a lean Mixture-stabilized flame stabilization using a tiered fuel / air guidance. This stepped fuel / air guidance has the final purpose, the total air ratio of the combustion system across the various combustion stages by appropriate divisions on a predetermined Maintain level. For this purpose, the first stage of combustion 1 operated as a flame stabilization zone. The fuel / air mixture used here 3 has an air ratio that is greater than the total air ratio of the combustion system, which is the Combustion air used is consequently only one Part of the total available air flow is; within this zone is therefore a lean Fuel / air mixture 3 operated. The other part of the combustion air gets a bigger fuel content, so that the fuel / air mixture that arises here 4 has an air ratio that is smaller than that said total combustion system air number; here is therefore operated with a richer fuel / air mixture. What is the total air number of the combustion system concerns, it is for combustion chambers of gas turbines preferably 2, with variations depending on the parameters down and up are possible. A total air number of the Combustion system of 2 can be achieved if the Air ratio for the fuel / air mixture 3 for the flame stabilization zone 1 is raised to 2.4, and that for the second combustion stage 2 is still 1.4, with these air numbers from a dwell time within the flame stabilization zone 1 on the order of 2.4 msec is assumed. The latter fuel / air mixture 4, with an air ratio less than the underlying total air ratio of the combustion system, is at the flame stabilization zone 1 over into the hot combustion gases 5 initiated in this zone. Now for flame stabilization hot gas backmixing is no longer necessary, burns the existing mixture in a second downstream Combustion level 2 without a significant further one NOx formation. In this second combustion stage 2 there is therefore a perfectly premixed fuel / air mixture before, its air ratio with the underlying total air ratio of the combustion system. At a Such a circuit can be assumed to have NOx emissions accordingly, i.e. due to the lean stabilization zone, only make up 50% of what is conventional multi-stage combustion systems is achievable. The hot gases 6 from the second combustion stage 2 are then the working gases to apply a downstream one, for example Turbine.

Aus Fig. 2 geht schematisch eine praktische Ausführungsvariante der gestuften Verbrennung mit einer grossen Flammenstabilisierungszone 1a hervor. Die letztgenannte Zone 1a ist von verhältnismässig grosser Ausdehnung und wird, wie oben bereits beschrieben, mager betrieben. Zur Erzeugung einer starken Verwirbelung in dieser Flammenstabilisierungszone 1a zu erreichen, womit die Eigenschaften eines idealen Rührreaktors angestrebt werden, wird das magere Brennstoff/Luft-Gemisch 3 in Strahlen 3a hoher Geschwindigkeit in diese Zone 1a eingedüst, wie dies aus Fig. 2 anhand der verschiedentlich dargestellten Pfeilen hervorgeht. Zum Erzielen einer starken Verwirbelung, d.h. zum Erreichen einer vollständig gemischten Flammenstabilisierungszone 1a, kann hierein eine stark verdrallte Strömung oder auch der Einsatz von Drall- oder Mischelementen vorgesehen werden. Nach Verlassen dieser Flammenstabilisierungszone 1a wird das heisse, jedoch noch nicht vollständig ausgebrannte Verbrennungsgas 5 in einer nachgeschalteten zweiten Verbrennungsstufe 2a mit der restlichen Verbrennungsluft vermischt, wobei diese Luft mit einem etwas fetteren Brennstoff/Luft-Gemisch operiert, d.h. die Luftzahl ist hier kleiner als die Gesamtluftzahl des Verbrennungssystems. Da das Verbrennungsgas 5 aus der Flammenstabilisierungszone 1a, wie oben bereits erwähnt, genügend heiss ist, zündet das in die zweite Verbrennungsstufe eingeleitete Brennstoff/Luft-Gemisch 4 von selbst, ohne hierzu spezielle Flammenstabilisierungsmassnahmen vorsehen zu müssen. A practical embodiment variant is shown schematically in FIG the staged combustion with a large flame stabilization zone 1a. The latter zone 1a is from relatively large extension and will, as above already described, operated lean. To generate a strong turbulence in this flame stabilization zone 1a to achieve what the properties of an ideal stirred reactor the lean fuel / air mixture will be aimed for 3 in rays 3a high speed into this zone 1a injected, as shown in Fig. 2 based on the various shown arrows. To achieve a strong Turbulence, i.e. to achieve a fully mixed Flame stabilization zone 1a, can be a highly twisted one Flow or the use of swirl or mixing elements be provided. After leaving this flame stabilization zone 1a is hot, but not yet completely burned out combustion gas 5 in a downstream second combustion stage 2a with the rest Combustion air mixed, this air with something richer fuel / air mixture operated, i.e. the air ratio is smaller than the total air ratio of the combustion system. Since the combustion gas 5 from the flame stabilization zone 1a, as already mentioned above, is sufficiently hot ignites what has been initiated in the second combustion stage Fuel / air mixture 4 by itself, without this special To have to provide flame stabilization measures.

BezugszeichenlisteReference list

11
Erste Verbrennungsstufe, FlammenstabilisierungszoneFirst combustion stage, flame stabilization zone
1a1a
FlammenstabilisierungszoneFlame stabilization zone
22nd
Zweite VerbrennunsstufeSecond stage of combustion
2a2a
Zweite VerbrennungsstufeSecond stage of combustion
33rd
Mageres Brennstoff/Luft-GemischLean fuel / air mixture
3a3a
Stahlen des Gemisches 3 in die FlammenstabilisierungszoneStealing the mixture 3 in the flame stabilization zone
44th
Fetteres Brennstoff/Luft-GemischFatter fuel / air mixture
55
Heisse VerbrennungsgaseHot combustion gases
66
Heissgase zur Beaufschlagung einer StrömungsmaschineHot gases to act on a turbomachine

Claims (1)

  1. Method of operating a plant with a graduated combustion system, the plant essentially comprising a first combustion stage (1) and at least one second downstream combustion stage (6), being the first combustion stage (1, 1a) operated with a fuel/air mixture (3) whose air coefficient is kept larger than the overall air coefficient of the combustion system, and that [sic] the hot combustion gases (5) from the first combustion stage (1, 1a) being mixed with a fuel/air mixture (4) whose air coefficient is kept smaller than the overall air coefficient of the combustion systems characterized in that the fuel/air mixture (3) for the first combustion stage (1, 1a), given a dwell time within this first combustion stage of 2.4 msec +/- 25%, burns with an air coefficient of 2.4 +/- 25%, and in that the fuel/air mixture (4) directed into the hot combustion gases (5) has an air coefficient of 1.4 +/- 25%.
EP96810354A 1995-06-26 1996-05-31 Method for operating a system with a staged combustion Expired - Lifetime EP0751342B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19523093A DE19523093A1 (en) 1995-06-26 1995-06-26 Method for operating a plant with a staged combustion system
DE19523093 1995-06-26

Publications (3)

Publication Number Publication Date
EP0751342A2 EP0751342A2 (en) 1997-01-02
EP0751342A3 EP0751342A3 (en) 1998-05-20
EP0751342B1 true EP0751342B1 (en) 2001-12-19

Family

ID=7765230

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96810354A Expired - Lifetime EP0751342B1 (en) 1995-06-26 1996-05-31 Method for operating a system with a staged combustion

Country Status (4)

Country Link
US (1) US5918457A (en)
EP (1) EP0751342B1 (en)
JP (1) JPH0914604A (en)
DE (2) DE19523093A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10100730C2 (en) * 2001-01-10 2002-11-07 Bosch Gmbh Robert Gas burner for a water heater
DE10112864A1 (en) * 2001-03-16 2002-09-19 Alstom Switzerland Ltd Process for igniting a thermal turbomachine
US6868676B1 (en) 2002-12-20 2005-03-22 General Electric Company Turbine containing system and an injector therefor
US7886545B2 (en) * 2007-04-27 2011-02-15 General Electric Company Methods and systems to facilitate reducing NOx emissions in combustion systems
US20100095649A1 (en) * 2008-10-20 2010-04-22 General Electric Company Staged combustion systems and methods
US9551492B2 (en) * 2012-11-30 2017-01-24 General Electric Company Gas turbine engine system and an associated method thereof

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0816531B2 (en) * 1987-04-03 1996-02-21 株式会社日立製作所 Gas turbine combustor
US4910957A (en) * 1988-07-13 1990-03-27 Prutech Ii Staged lean premix low nox hot wall gas turbine combustor with improved turndown capability
US5013236A (en) * 1989-05-22 1991-05-07 Institute Of Gas Technology Ultra-low pollutant emission combustion process and apparatus
JPH06509158A (en) * 1991-03-15 1994-10-13 ラジアン コーポレーション Combustion device and method in porous matrix element
US5271729A (en) * 1991-11-21 1993-12-21 Selas Corporation Of America Inspirated staged combustion burner

Also Published As

Publication number Publication date
JPH0914604A (en) 1997-01-17
DE19523093A1 (en) 1997-01-02
US5918457A (en) 1999-07-06
EP0751342A2 (en) 1997-01-02
EP0751342A3 (en) 1998-05-20
DE59608478D1 (en) 2002-01-31

Similar Documents

Publication Publication Date Title
DE60011541T2 (en) Method and apparatus for NOx reduction
EP0767345B1 (en) Process for operating a power plant
DE60105093T2 (en) Fuel dilution method and apparatus for NOx reduction
EP0274630B1 (en) Arrangement for a burner
DE3432971C2 (en)
DE69828916T2 (en) Low emission combustion system for gas turbine engines
EP0713058B1 (en) Multi-stage combustion chamber
DE3439595A1 (en) METHOD AND DEVICE FOR REDUCING THE NITROGEN OXIDE EMISSIONS OF A GAS FUEL BURNER
DE69917395T2 (en) Combustion process for burning a fuel
DE4446842B4 (en) Method and device for feeding a gaseous fuel into a premix burner
DE69923797T2 (en) METHOD FOR OPERATING A TANGENTIAL IGNITION SYSTEM
EP0095788A1 (en) Gas turbine combustion chamber and method of operating it
DE19614001A1 (en) Combustion chamber
CH699911B1 (en) Combustion chamber and method for mixing a compressed air stream.
EP1235033B1 (en) Annular combustor and method of operating the same
WO2003098110A1 (en) Premix burner
EP1439349A1 (en) Combustion method and burner for carrying out the method
EP0816759B1 (en) Premix burner and method of operating the burner
EP0751342B1 (en) Method for operating a system with a staged combustion
DE102005061486B4 (en) Method for operating a combustion chamber of a gas turbine
CH698404A2 (en) Lean blowout Auslöschschutz by controlling the nozzle-equivalence ratios.
DE3606625A1 (en) Pilot burner with low NOx emission for furnace installations, in particular of gas turbine installations, and method of operating it
DE19545311B4 (en) Method for operating a combustion chamber equipped with premix burners
EP0602396B1 (en) Method of operating a heat generator
DE2705647A1 (en) BURNERS FOR GAS OR LIQUID FUEL

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB IT NL

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB IT NL

17P Request for examination filed

Effective date: 19981118

17Q First examination report despatched

Effective date: 20000406

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

RTI1 Title (correction)

Free format text: METHOD FOR OPERATING A SYSTEM WITH A STAGED COMBUSTION

RTI1 Title (correction)

Free format text: METHOD FOR OPERATING A SYSTEM WITH A STAGED COMBUSTION

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT NL

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: ALSTOM

REF Corresponds to:

Ref document number: 59608478

Country of ref document: DE

Date of ref document: 20020131

NLT2 Nl: modifications (of names), taken from the european patent patent bulletin

Owner name: ALSTOM

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20020402

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20040427

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20040429

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20040510

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20040512

Year of fee payment: 9

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050531

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20051201

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20051201

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20050531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060131

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20051201

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20060131