WO2013009211A1

WO2013009211A1 - Fuel cooled combustor

Info

Publication number: WO2013009211A1
Application number: PCT/RU2011/000514
Authority: WO
Inventors: Sergey Maskhutovich KHAYRULIN; Borys Borysovych SHERSHNYOV; Roy Marshall Washam; Paula ZELESNIK
Original assignee: General Electric Company
Priority date: 2011-07-14
Filing date: 2011-07-14
Publication date: 2013-01-17
Also published as: EP2732212A1; CN103703317B; CN103703317A

Abstract

The present application provides a combustor for use with a gas turbine engine and a flow of fuel. The combustor may include a combustion surface and a fuel pathway positioned within the combustion surface such that the flow of fuel through the fuel pathway heat treats the combustion surface.

Description

FUEL COOLED COMBUSTOR

TECHNICAL FIELD

[0101] The present application relates generally to gas turbine engines and more particularly relates to a gas turbine combustor that is at least partially cooled with a flow of fuel.

BACKGROUND OF THE INVENTION [0102] In general, gas turbine engines combust a fuel-air mixture to form a high temperature combustion gas stream. The high temperature combustion gas stream is channeled to a turbine via a hot gas path. The turbine converts the thermal energy from the high temperature combustion gas stream to mechanical energy so as to rotate a turbine shaft. The gas turbine engine may be used in a variety of applications, such as for providing power to a pump or an electrical generator and the like. Other types of gas turbine engine configurations may be used.

[0103] Operational efficiency of a gas turbine engine generally increases as the temperature of the combustion gas stream increases. Higher gas stream temperatures, however, may produce higher levels of nitrogen oxide ("ΝΟχ"), an emission that is subject to both federal and state regulation in the US and subject to similar types of regulations abroad. A balance thus exists between operating the gas turbine in an efficient temperature range while also ensuring that the output of ΝΟχ and other types of emissions remain below the mandated levels.

[0104] The fuel-air mixture may be combusted in a combustor. The combustor is generally cooled via a cooling air flow. This cooling air flow, however, may not take part in the fuel-air mixing process for efficient combustion. A deficiency in the amount of air neidfidJhrJemiud- k^mxture operation thus may exist with rising gas turbine parameters. Moreover, rising temperatures also may cause ΝΟχ emissions to rise to unacceptable levels. [0105] There is therefore a desire for an improved combustor and combustor cooling methods. Such a combustor and cooling methods should permit increased gas turbine parameters and performance while limiting ΝΟχ emissions to within mandated levels.

SUMMARY OF THE INVENTION

[0106] The present application thus provides a combustor for use with a gas turbine engine and a flow of fuel. The combustor may include a combustion surface and a fuel pathway positioned within the combustion surface such that the flow of fuel through the fuel pathway heat treats the combustion surface.

[0107] The present application further provides a method of operating a combustor on a flow of fuel and a flow of air. The method may include the steps of providing the flow of fuel and the flow of air to a fuel circuit, flowing the flow of fuel through a pathway extending along the fuel circuit, heat treating the fuel circuit with the flow of fuel, mixing the flow of fuel and the flow of air after the cooling step, and combusting the flow of fuel and the flow of air downstream of the fuel circuit.

[0108] The present application further provides for a combustor for use with a gas turbine engine and a flow of fuel. The combustor may include a number of fuel circuits, a number of combustion surfaces with the fuel circuits including one or more of the combustion surfaces, and a number of fuel pathways with one or more of the fuel pathways positioned within one or more of the combustion surfaces. The flow of fuel through the fuel pathways cools one or more of the combustion surfaces.

[0109] These and other features and improvements of the present application will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Fig. 1 is a schematic view of a gas turbine engine as may be used with the combustor described herein.

[0111] Fig. 2 is a schematic view of a nested combustor. [0112] Fig. 3 is a side cross-sectional view of a combustor as may be described herein.

[0113] Fig. 4 is a side cross-sectional view of an alternative embodiment of a combustor as may be described herein.

DETAILED DESCRIPTION

[0114] Referring now to the drawings, in which like numbers refer to like elements throughout the several views, Fig. 1 shows a schematic view of a gas turbine engine 10. As is described above, the gas turbine engine 10 may include a compressor 20 to compress an incoming flow of air. The compressor 20 delivers the compressed flow of air to a combustor 30. The combustor 30 mixes the compressed flow of air with a compressed flow of fuel and ignites the mixture. Although only a single combustor 30 is shown, the gas turbine engine 10 may include any number of combustors 30. The hot combustion gases are in turn delivered to a turbine 40. The hot combustion gases drive the turbine 40 so as to produce mechanical work. The mechanical work produced by the turbine 40 drives the compressor 20 and an external load 50 such as an electrical generator and the like.

[0115] The gas turbine engine 10 may use natural gas, various types of syngas, and other types of fuels. The gas turbine engine 10 may be a 9FBA Heavy Duty gas turbine engine offered by General Electric Company of Schenectady, New York. The gas turbine engine 10 may have other configurations and may use other types of components. Other types of gas turbine engines also may be used herein. Multiple gas turbine engines 10, other types of turbines, and other types of power generation equipment may be used herein together.

[0116] Fig. 2 shows a schematic view of a nested combustor 100. The nested combustor 100 provides for axially staged fuel injection. The nested combustor 100 thus includes a first fuel circuit 1 10. The first fuel circuit 1 10 includes a center nozzle 120 surrounded by a first fuel circuit swirler 130. A flow of fuel 140 may pass through both the center nozzle 120 and the first fuel circuit swirler 130. Likewise, a flow of air 150 may pass through the first fuel circuit swirler 130. The flow of fuel 140 and the flow of air 150 mix downstream of the center nozzle 120 and are ignited A shear layer or a recirculation zone 160 may be formed downstream of the center nozzle 120 via the mixed flows 140, 150. Other configurations may be used herein.

[0117] A second fuel circuit 170 may be formed around the first fuel circuit 110. The second fuel circuit 170 may be formed between a first fuel circuit shell 180 and a second fuel circuit shell 190. A second fuel circuit swirler 200 may be positioned therebetween. As above, the flow of fuel 140 and the flow of air 150 may pass through the second fuel circuit swirler 200 for mixing therewith. A second fuel circuit shear layer 210 may be created downstream of the second fuel circuit swirler 200 via the mixed flows 140, 150. Other configurations may be used herein.

[0118] A third fuel circuit 220 may surround the second fuel circuit 170. The third fuel circuit 220 may be formed between the second fuel circuit shell 190 and a third fuel circuit shell 230. A third fuel circuit swirler 240 may be positioned therebetween. The flow of fuel 140 and the flow of air 150 may mix therein. A third fuel circuit shear layer 250 also may be formed downstream thereof via the mixed flows 140, 150. Other configurations may be used herein. The nested combustor 100 may have any number of fuel circuits herein.

[0119] At high temperature operation, all three fuel circuits 1 10, 170, 220 may be in operation. During mid-load operation, the first fuel circuit 170 and the second fuel circuit 170 may be active while the third fuel circuit 220 and the flow of air 150 therethrough may be largely uninvolved in the combustion process. During low load operation, only the first fuel circuit 1 10 may be in operation. The second and third fuel circuits 170, 220 and the flow of air 150 therethrough may be largely uninvolved in the combustion process.

[0120] Fig. 3 shows portions of a combustor 300 as may be described herein.

The combustor 300 may use the fuel circuits 1 10, 170, 220 largely as described above. In this example, the center nozzle 120 may include a center nozzle fuel path 310. The center nozzle fuel path 310 may extend along the length of the center nozzle 310 and end about the first fuel circuit swirler 130. The first fuel circuit shell 180 also may include a first fuel circuit shell path 320 extending therethrough. The first fuel circuit shell path 320 also may extend along the length of the first fuel circuit shell 180 and end about the first fuel circuit swirler 130. The second fuel circuit shell 190 may include a second fuel circuit shell path 330. The second fuel circuit shell path 330 also may extend the length of the second fuel circuit shell 190 and end about the second fuel circuit swirler 200. Other configurations may be used herein.

(0121] The fuel circuit shell paths 310, 320, 330 thus provide heat treatment about the center fuel nozzle 120, the first circuit shell 180, and the second circuit shell 190. Specifically, the fuel circuit shell paths 310, 320, 330 provide impingement cooling. The fuel paths 310, 320, 330 also may include ribbing 340 therein so as to promote a more turbulent flow therethrough. Given that the flow of fuel 140 may be used for cooling purposes, the fuel circuit shell paths 310, 320, 330 only cool those surfaces of the combustor 300 where combustion occurs, i.e. , a number of combustion surfaces 350. The zones or surfaces that are not participating in combustion may continue to be cooled by the flow of air 150. As such, the coolant flow is always proportional to the hot zone wall area and the flame temperature.

[0122] Fig. 4 shows a further embodiment of a combustor 360 as may be described herein. The combustor 360 maybe largely identical to the combustor 300 described above except that a flow of liquid fuel 370 and a flow of a diluent 380 may be used. The liquid fuel flow 370 may flow through the center nozzle 120, the second fuel circuit shell path 330, and the third fuel circuit swirler 240. The flow of the diluent 360 may pass through the center nozzle fuel path 310 and the first fuel circuit shell path 320. Other configurations and other types of fuels may be used herein.

[0123] The use of the fuel circuit shell paths 310, 320, 330 for heat treatment thus provides for increased cooling performance while allowing the use of the flow of air 150 to be dedicated to lean fuel-air mixture preparation. As such, gas turbine parameters may be increased without appreciable growth of ΝΟχ emissions or wall temperatures. Almost all of the air flow thus may be used for lean air-fuel mixture preparation. Better control of the fuel-air ratios with emissions compliance at turn down also may be provided. Acoustic behavior and dynamics may be mitigated by axial staging ot the heat release, multiple flame stabilization structures, and fuel heating to increase fuel injection pressure ratio before combustion. Fuel flexibility also may be provided in that less flammable fuels may be piloted by a strong center flame. Lower energy content fuel may provide more fuel coolant flow. [0124] It should be apparent that the foregoing relates only to certain embodiments of the present application and that numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.

PARTS LIST

10 gas turbine engine

20 compressor

30 combustor

40 turbine

50 load

100 nested combustor

1 10 first fuel circuit

120 center nozzle

130 first fuel circuit swirler

140 flow of fuel

150 flow of air

160 recirculation zone

170 second fuel circuit

180 first fuel circuit shell

190 second fuel circuit shell

200 second fuel circuit swirler

210 second fuel circuit shear layer

220 third fuel circuit

230 third fuel circuit shell

240 third fuel circuit swirler

250 third fuel circuit shear layer

300 combustor

310 center nozzle fuel path

320 first fuel circuit shell path

330 second fuel circuit shell path

34U ribbing

350 combustion surfaces

360 combustor

370 flow of liquid fuel

380 flow of diluent

Claims

We claim: 1. A combustor for use with a gas turbine engine and a flow of fuel, comprising:

a combustion surface; and

a fuel pathway positioned within the combustion surface;

wherein the flow of fuel through the fuel pathway heat treats the combustion surface.

2. The combustor of claim 1, wherein the flow of fuel through the fuel pathway cools the combustion surface.

3. The combustor of claim 1, further comprising a fuel circuit and wherein the fuel circuit comprises the combustion surface thereon and the fuel pathway therein.

4. The combustor of claim 3, further comprising a plurality of fuel circuits, a plurality of combustion surfaces, and a plurality of fuel pathways.

5. The combustor of claim 3, wherein the fuel circuit comprises a center nozzle and wherein the fuel pathway comprises a center nozzle fuel path therethrough.

6. The combustor of claim 3, wherein the fuel circuit comprises a first fuel circuit shell and wherein the fuel pathway comprises a first fuel circuit shell path therethrough.

7. The combustor of claim 3, wherein the fuel circuit comprises a second fuel circuit shell and wherein the fuel pathway comprises a second fuel circuit shell path therethrough.

8. The combustor of claim 3, wherein the fuel circuit comprises a swirler therein for mixing the flow of fuel and a flow of air.

9. The combustor of claim 1, wherein the fuel pathway comprises ribbing therein.

10. The combustor of claim 1, wherein the flow of fuel comprises a flow of a liquid fuel and a flow of a diluent.

1 1. A method of operating a combustor on a flow of fuel and a flow of air, comprising:

providing the flow of fuel and the flow of air to a fuel circuit;

flowing the flow of fuel through a pathway extending along the fuel circuit; heat treating the fuel circuit with the flow of fuel;

mixing the flow of fuel and the flow of air after the heat treating step; and combusting the flow of fuel and the flow of air downstream of the fuel circuit.

12. The method of claim 1 1, further comprising a plurality of fuel circuits and further comprising providing the flow of air only to one or more of the plurality of fuel circuits.

13. The method of claim 1 1, wherein the step of heat treating the fuel circuit comprises further warming the flow of fuel.

14. The method of claim 1 1, wherein the step of heat treating the fuel circuit comprises impingement cooling.

15. The method of claim 1 1, wherein the step of heat treating the fuel circuit comprises cooling one or more combustion surfaces of the fuel circuit.

16. A combustor for use with a gas turbine engine and a flow of fuel, comprising:

a plurality of fuel circuits;

a plurality of combustion surfaces with the plurality of fuel circuits comprising one or more of the plurality of combustion surfaces; and

a plurality of fuel pathways with one or more of the plurality of fuel pathways positioned within one or more of the plurality of combustion surfaces;

wherein the flow of fuel through the plurality of fuel pathways cools one or more of the plurality of combustion surfaces.

17. The combustor of claim 16, wherein the plurality of fuel circuits comprises a center nozzle and wherein the plurality of fuel pathways comprises a center nozzle fuel path therethrough.

18. The combustor of claim 17, wherein the plurality of fuel circuits comprises a first fuel circuit shell and wherein the plurality of fuel pathways comprises a first fuel circuit shell path therethrough.

19. The combustor of claim 18, wherein the plurality of fuel circuits comprises a second fuel circuit shell and wherein the plurality of fuel pathways comprises a second fuel circuit shell path therethrough.

20. The combustor of claim 16, wherein one or more of the plurality of fuel pathways comprise ribbing therein.