US20120198850A1

US20120198850A1 - Gas turbine engine and fuel injection system

Info

Publication number: US20120198850A1
Application number: US13/336,276
Authority: US
Inventors: Jushan Chin; Nader K. Rizk; Thomas Richardson; Mohan K. Razdan; Duane Smith
Original assignee: Rolls Royce Corp
Current assignee: Rolls Royce Corp
Priority date: 2010-12-28
Filing date: 2011-12-23
Publication date: 2012-08-09

Abstract

One embodiment of the present invention is a unique gas turbine engine. Another embodiment is a unique fuel injection system for a gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and fuel injection systems for gas turbine engines. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims benefit of U.S. Provisional Patent Application No. 61/427,726, filed Dec. 28, 2010, entitled GAS TURBINE ENGINE AND FUEL INJECTION SYSTEM, which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to gas turbine engines, and more particularly, to fuel injection systems for gas turbine engines.

BACKGROUND

Gas turbine engines and fuel injection systems for gas turbine engines remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.

SUMMARY

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

FIG. 1 schematically illustrates some aspects of a non-limiting example of a gas turbine engine in accordance with an embodiment of the present invention.

FIG. 2 depicts some aspects of a non-limiting example of combustion system in accordance with an embodiment of the present invention.

FIG. 3 depicts some aspects of a non-limiting example of a fuel injection system in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the invention is intended by the illustration and description of certain embodiments of the invention. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as being within the scope of the present invention.
Referring to the drawings, and in particular FIG. 1, a non-limiting example of a gas turbine engine 10 in accordance with an embodiment of the present invention is depicted. In one form, engine 10 is an aircraft propulsion power plant. In other embodiments, engine 10 may be a land-based or marine engine. In one form, engine 10 is a multi-spool turbofan engine. In other embodiments, engine 10 may be a single or multi-spool turbofan, turboshaft, turbojet, turboprop gas turbine or combined cycle engine.
Gas turbine engine 10 includes a fan system 12, a compressor system 14, a diffuser 16, a combustion system 18 and a turbine system 20. Compressor system 14 is in fluid communication with fan system 12. Diffuser 16 is in fluid communication with compressor system 14. Combustion system 18 is fluidly disposed between compressor system 14 and turbine system 20. Fan system 12 includes a fan rotor system 22. In various embodiments, fan rotor system 22 includes one or more rotors (not shown) that are powered by turbine system 20 and operative to pressurize air. Compressor system 14 includes a compressor rotor system 24. In various embodiments, compressor rotor system 24 includes one or more rotors (not shown) that are powered by turbine system 20 and operative to further pressurize air received from fan system 12. Turbine system 20 includes a turbine rotor system 26. In various embodiments, turbine rotor system 26 includes one or more rotors (not shown) operative to drive fan rotor system 22 and compressor rotor system 24. Turbine rotor system 26 is driving coupled to compressor rotor system 24 and fan rotor system 22 via a shafting system 28. In various embodiments, shafting system 28 includes a plurality of shafts that may rotate at the same or different speeds and in the same or different directions. In some embodiments, only a single shaft may be employed.
During the operation of gas turbine engine 10, air is drawn into the inlet of fan system 12 and pressurized by fan system 12. Some of the air pressurized by fan system 12 is directed into compressor system 14, and the balance is directed into a bypass duct (not shown) for providing a component of the thrust output by gas turbine engine 10. Compressor system 14 further pressurizes the air received from fan system 12, which is then discharged in to diffuser 16. Diffuser 16 reduces the velocity of the pressurized air, and directs the diffused airflow into combustion system 18. Fuel is mixed with the pressurized air in combustion system 18, which is then combusted. In one form, combustion system 18 includes a combustion liner (not shown) that contains a continuous combustion process. In other embodiments, combustion system 18 may take other forms, and may be, for example, a wave rotor combustion system, a rotary valve combustion system, or a slinger combustion system, and may employ deflagration and/or detonation combustion processes. The hot gases exiting combustion system 18 are directed into turbine system 20, which extracts energy in the form of mechanical shaft power to drive fan system 12 and compressor system 14 via shafting system 28. The hot gases exiting turbine system 20 are directed into a nozzle (not shown), and provide a component of the thrust output by gas turbine engine 10.
Referring to FIG. 2, combustion system 18 includes a combustion liner 30 and a fuel injection system 32. Combustion liner 30 is disposed in a combustor case 34. Combustion liner 30 is operative to contain combustion processes during the operation of engine 10. Fuel injection system 32 is operative to inject fuel into combustion liner 30. In particular, fuel injection system 32 is operative to inject a fuel/air mixture into combustion liner 30, which is ignited by an igniter (not shown) to form a combustion process 36 that adds heat to the air discharged by compressor system 14. The heated air is then discharged by combustion system 18 into turbine system 20.
Referring to FIG. 3 in conjunction with FIG. 2, fuel injection system 32 includes a pilot injection module 38 and a main injection module 40. Main injection module 40 is disposed concentrically around pilot injection module 38, i.e., radially outward of pilot injection module 38. Pilot injection module 38, disposed radially inward of main injection module 40, is configured inject a pilot fuel flow 42 to generate a pilot combustion process 44. Main injection module 40 is configured to inject a main fuel flow 46 to generate a main combustion process 48 disposed around pilot combustion process 44. In one form, pilot injection module 38 and main injection module 40 are independently operable. During low power operation of engine 10, e.g., including ground idle and flight idle conditions, pilot injection module 38 is employed. Main injection module 40 is employed during high power engine 10 operation, e.g., including take-off and cruise thrust. Some operating regimes include the use of both pilot injection module 38 and main injection module 40, e.g., during transition from idle or other low power conditions to higher power conditions. In some embodiments, both main injection module 40 and pilot injection module 38 may be employed to inject fuel into combustion liner 30 during high power engine 10 operation. In other embodiments, only main injection module 40 is employed during high power engine 10 operation.
Pilot injection module 38 is fluidly coupled to a fuel supply line 50. Main injection module 40 is fluidly coupled to a fuel supply line 52. Fuel supply lines 50 and 52 are fluidly independent of each other, that is, one supply line may be pressurized to supply fuel to the corresponding injection module independent of the other fuel supply line. In one form, fuel injection system 32 is configured to selectively control fuel delivery (including fuel pressure) to fuel supply lines 50 and 52, providing independent control of pilot injection module 38 and main injection module 40 to selectively supply fuel to one or both of pilot injection module 38 and main injection module 40. In other embodiments, pilot injection module 38 and main injection module 40 may be fluidly coupled to a common fuel supply line, and may be selectively and independently operable via other means. In still other embodiments, pilot injection module 38 and main injection module 40 may not be independently operable as such. In one form, pilot injection module 38 is optimized for operation in low engine 10 power conditions, and main injection module 40 is optimized for operation in high engine 10 power conditions. In other embodiments, pilot injection module 38 and main injection module 40 may be optimized for operation at other engine 10 power conditions.
Pilot injection module 38 includes a pilot nozzle 54, a pilot swirler 56 and a discharge nozzle 58. Pilot nozzle 54 is in fluid communication with fuel supply line 50. Pilot nozzle 54 is operative to inject fuel into combustion liner 30. In one form, pilot nozzle 54 is a pressure swirl atomizer. In other embodiments, pilot nozzle 54 may take other forms. In one form, pilot swirler 56 surrounds pilot nozzle 54. In other embodiments, pilot swirler 56 may be arranged in other locations and orientations. In one form, pilot swirler 56 includes a plurality of turning vanes 60 configured to induce swirl into airflow passing through pilot swirler 56. In other embodiments, other means for inducing swirl may be employed, e.g., air injection and/or fuel injection ports configured to induce swirl.
The swirling pilot airflow from pilot swirler 56 mixes with the fuel sprayed by pilot nozzle 54. In one form, pilot injection module 38 is configured to mix pilot fuel spray and air before injection into the combustion zone. The swirl induced by pilot swirler 56 enhances the mixing of fuel and air for pilot injection module 38, e.g., relative to systems that do not employ swirlers. The amount of swirl may vary with the application. The fuel discharged from pilot nozzle 54 and the air passing through pilot swirler 56 are discharged into combustion liner 30 via discharge nozzle 58. In one form, discharge nozzle 58 is circular in shape. In other embodiments, discharge nozzle 58 may be shaped differently.
Main injection module 40 includes a main fuel injector 62, a main swirler 64, a deswirler 66 and a discharge nozzle 68. Main fuel injector 62 is in fluid communication with fuel supply line 52. Main fuel injector 62 is operative to inject fuel for mixing with air and combustion in combustion liner 30. In one form, main fuel injector 62 is configured to indirectly inject fuel into combustion liner 30, via swirler 64. In other embodiments, main fuel injector 62 may be configured to directly inject fuel into combustion liner 30, e.g., similar to pilot nozzle 54.
Main fuel injector 62 includes a fuel manifold 70 and plurality of main fuel nozzles 72. In one form, manifold 70 is a distribution annulus formed in main fuel injector 62 and disposed radially outward of and circumferentially around pilot injection module 38. In other embodiments, fuel manifold 70 may take other forms. Fuel manifold 70 is in fluid communication with fuel supply line 52. Fuel nozzles 72 are in fluid communication fuel manifold 70. In one form, fuel nozzles 72 are plain-jet nozzles. In other embodiments, other nozzle types may be employed in addition to or in place of plain-jet nozzles. In one form, nozzles 72 extend outward in a radial direction from manifold 70. In the example depicted in FIG. 3, nozzles 72 extend both radially outward and aft. In other embodiments, nozzles 72 may extend in other directions in addition to or in place of radial and/or aft directions. In one form, nozzles 72 are configured to discharge fuel radially outward, that is, having a radially outward flow direction component. In the example depicted in FIG. 3, nozzles 72 are configured to discharge fuel both radially outward and aft. In other embodiments, nozzles 72 may be configured to discharge fuel in other directions in addition to or in place of radial and/or aft directions. In some embodiments, some nozzles 72 may be configured to discharge fuel in one direction, whereas others may be configured to discharge fuel in one or more other directions.
Main swirler 64 is configured to induce swirl in order to enhance the mixing of fuel and air for main fuel injector 62. In one form, main swirler 64 is an axial swirler. In other embodiments, main swirler 64 may take one or more other forms. In one form, main swirler 64 includes a plurality of turning vanes 74 configured to induce swirl into airflow passing through main swirler 64. In other embodiments, other means for inducing swirl may be employed, e.g., air injection and/or fuel injection ports configured to induce swirl. In one form, nozzles 72 include discharge openings 76 disposed in main swirler 64, and are operative to inject fuel directly into main swirler 64. In other embodiments, some or all of discharge openings 76 may be disposed elsewhere.
Deswirler 66 is configured to reduce swirl induced by main swirler 64. In one form, deswirler 66 is disposed radially outward of main swirler 64. In other embodiments, deswirler 66 may be positioned in other locations and orientations. In one form, deswirler 66 includes a non-swirling air passage. In a particular form, deswirler 66 is configured to form an annular non-swirling air stream disposed around the swirling fuel and air discharged by main swirler 64, to reduce the exit swirl angle of the fuel and air discharged through discharge nozzle 68. In other embodiments, other means for reducing swirl may be employed.
Discharge nozzle 68 is operative to discharge the air fuel mixture, generated by main injection module 40, into combustion liner 30. In one form, discharge nozzle 68 is a converging nozzle. In other embodiments, discharge nozzle 68 may take other forms. In one form, discharge nozzle 68 includes contraction ramps 80 and 82 extending to and forming a throat 84. In one form, ramps 80 and 82 are conical. In other embodiments, ramps 80 and 82 may take other forms. In some embodiments, only a single contraction ramp may be employed. The air fuel mixture generated by main injection module 40 is injected into combustion liner 30 via discharge nozzle 68. In one form, discharge nozzle 68 is annular in shape, extending concentrically around pilot injection module 38 and discharge nozzle 58. In other embodiments, discharge nozzle 68 may take other forms. In one form, ramps 80 and 82 are configured to direct the air fuel mixture from main injection module 40 in a radially outward direction, that is, in a direction having a radially outward component from pilot injection module 38. In one form, discharge nozzle 68 includes a plurality of air injection openings 86 spaced apart circumferentially around the periphery of discharge nozzle 68, located aft of deswirler 66 and forward of contraction ramp 80. Air injection openings 86 are positioned to injection air into main injection module 40 upstream of discharge nozzle 68. In other embodiments, air injection openings may be disposed in other locations. Air injection openings 86 may take any convenient shape. Some embodiments may not include air injection openings 86.
Disposed between pilot nozzle 54 and main injection module 40 is a separating member 88. In one form, separating member 88 is configured as a heat shield to shield pilot nozzle 54 from heat generated during the combustion of fuel.
Embodiments of the present invention include a gas turbine engine, comprising: a compressor system; a turbine system; and a combustion system fluidly disposed between the compressor system and the turbine system, the combustion system including a combustion liner and a fuel injection system operative to inject fuel into the combustion liner, wherein the fuel injection system includes: a pilot injection module having a pilot nozzle and a pilot swirler for the pilot nozzle, wherein the pilot swirler is operative to induce swirl to enhance mixing of fuel and air for the pilot injection module; and a main injection module disposed radially outward of the pilot injection module, wherein the main injection module includes a main fuel injector; a main swirler; and a deswirler, wherein the main fuel injector includes a plurality of nozzles operative to discharge fuel radially outward; wherein the main swirler is operative to induce swirl to enhance mixing of fuel and air for the main fuel injector; and wherein the deswirler is operative to reduce swirl induced by the main swirler.
In a refinement, the deswirler is located radially outward of the main swirler.
In another refinement, the main fuel injector includes a plurality of plain-jet nozzles.
In yet another refinement, the engine further comprises a main fuel manifold, wherein at least one of the plain-jet nozzles extends outward in a radial direction from the main fuel manifold.
In still another refinement, at least one of the plain-jet nozzles has a discharge opening disposed in the main swirler.
In yet still another refinement, the engine further comprises a first fuel supply line; and a second fuel supply line that is fluidly independent of the first fuel supply line, wherein the pilot nozzle is fluidly coupled to the first fuel supply line; and wherein the main fuel injector is fluidly coupled to the second fuel supply line.
In a further refinement, the fuel injection system is configured to selectively supply fuel to one or both of the pilot injection module and the main injection module.
Embodiments of the present invention include a fuel injection system for a gas turbine engine, comprising: a main injection module including a plurality of plain-jet nozzles; a main swirler; and a deswirler; wherein at least one of the plain-jet nozzles is operative to discharge fuel radially outward; wherein the main swirler is operative to induce swirl to enhance mixing of fuel and air for the main injection module; and wherein the deswirler is operative to reduce swirl induced by the main swirler; and a pilot injection module disposed radially inward of the main injection module, wherein the pilot injection module includes a pilot nozzle and a pilot swirler for the pilot nozzle, wherein the pilot swirler is operative to induce swirl to enhance mixing of fuel and air for the pilot injection module.
In a refinement, the deswirler includes a non-swirling air passage.
In another refinement, the main injection module includes an annular discharge nozzle for discharging a fuel air mixture.
In yet another refinement, the main injection module includes a discharge nozzle for discharging a fuel air mixture, further comprising a plurality of air injection openings positioned to inject air into the main injection module upstream of the discharge nozzle.
In still another refinement, the system further comprises a ramp configured to direct an air fuel mixture from the main injection module in a radially outward direction.
In yet still another refinement, the ramp is conical.
In a further refinement, the system further comprises a separating member disposed around the pilot nozzle and positioned between the pilot nozzle and the main injection module.
In a yet further refinement, the separating member is configured to shield the pilot nozzle from combustion heat.
In a still further refinement, the at least one of the plain-jet nozzles is configured to inject fuel directly into the main swirler.
Embodiments of the present invention include a fuel injection system for a gas turbine engine, comprising: a pilot injection module having a pilot nozzle operative to produce a pilot combustion zone; and a main injection module having a fuel distribution manifold; a plurality of main nozzles extending from the fuel distribution manifold for injecting fuel; a main swirler; and a deswirler, wherein the main swirler is operative to induce swirl into fuel and air in the main injection module; and wherein the deswirler is operative to reduce swirl induced by the main swirler.
In a refinement, the system further comprises a heat shield disposed around the pilot injection module and positioned between the pilot injection module and the main injection module.
In another refinement, the main nozzles are plain-jet nozzles oriented with a directional component extending radially outward of the pilot nozzle.
In still another refinement, the main injection module is configured to produce a main combustion zone disposed radially outward of the pilot combustion zone.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.

Claims

1. A gas turbine engine, comprising:

a compressor system;

a turbine system; and

a combustion system fluidly disposed between the compressor system and the turbine system, the combustion system including a combustion liner and a fuel injection system operative to inject fuel into the combustion liner, wherein the fuel injection system includes:

a pilot injection module having a pilot nozzle and a pilot swirler for the pilot nozzle, wherein the pilot swirler is operative to induce swirl to enhance mixing of fuel and air for the pilot injection module; and

a main injection module disposed radially outward of the pilot injection module, wherein the main injection module includes a main fuel injector; a main swirler; and a deswirler, wherein the main fuel injector includes a plurality of nozzles operative to discharge fuel radially outward; wherein the main swirler is operative to induce swirl to enhance mixing of fuel and air for the main fuel injector; and wherein the deswirler is operative to reduce swirl induced by the main swirler.

2. The gas turbine engine of claim 1, wherein the deswirler is located radially outward of the main swirler.

3. The gas turbine engine of claim 1, wherein the main fuel injector includes a plurality of plain-jet nozzles.

4. The gas turbine engine of claim 3, further comprising a main fuel manifold, wherein at least one of the plain-jet nozzles extends outward in a radial direction from the main fuel manifold.

5. The gas turbine engine of claim 3, wherein at least one of the plain-jet nozzles has a discharge opening disposed in the main swirler.

6. The gas turbine engine of claim 1, further comprising a first fuel supply line; and a second fuel supply line that is fluidly independent of the first fuel supply line, wherein the pilot nozzle is fluidly coupled to the first fuel supply line; and wherein the main fuel injector is fluidly coupled to the second fuel supply line.

7. The gas turbine engine of claim 1, wherein the fuel injection system is configured to selectively supply fuel to one or both of the pilot injection module and the main injection module.

8. A fuel injection system for a gas turbine engine, comprising:

a main injection module including a plurality of plain-jet nozzles; a main swirler;

and a deswirler; wherein at least one of the plain-jet nozzles is operative to discharge fuel radially outward; wherein the main swirler is operative to induce swirl to enhance mixing of fuel and air for the main injection module; and wherein the deswirler is operative to reduce swirl induced by the main swirler; and

a pilot injection module disposed radially inward of the main injection module, wherein the pilot injection module includes a pilot nozzle and a pilot swirler for the pilot nozzle, wherein the pilot swirler is operative to induce swirl to enhance mixing of fuel and air for the pilot injection module.

9. The fuel injection system of claim 8, wherein the deswirler includes a non-swirling air passage.

10. The fuel injection system of claim 8, wherein the main injection module includes an annular discharge nozzle for discharging a fuel air mixture.

11. The fuel injection system of claim 8, wherein the main injection module includes a discharge nozzle for discharging a fuel air mixture, further comprising a plurality of air injection openings positioned to inject air into the main injection module upstream of the discharge nozzle.

12. The fuel injection system of claim 8, further comprising a ramp configured to direct an air fuel mixture from the main injection module in a radially outward direction.

13. The fuel injection system of claim 12, wherein the ramp is conical.

14. The fuel injection system of claim 8, further comprising a separating member disposed around the pilot nozzle and positioned between the pilot nozzle and the main injection module.

15. The fuel injection system of claim 14, wherein the separating member is configured to shield the pilot nozzle from combustion heat.

16. The fuel injection system of claim 8, wherein the at least one of the plain-jet nozzles is configured to inject fuel directly into the main swirler.

17. A fuel injection system for a gas turbine engine, comprising:

a pilot injection module having a pilot nozzle operative to produce a pilot combustion zone; and

a main injection module having a fuel distribution manifold; a plurality of main nozzles extending from the fuel distribution manifold for injecting fuel; a main swirler; and a deswirler, wherein the main swirler is operative to induce swirl into fuel and air in the main injection module; and wherein the deswirler is operative to reduce swirl induced by the main swirler.

18. The fuel injection system of claim 17, further comprising a heat shield disposed around the pilot injection module and positioned between the pilot injection module and the main injection module.

19. The fuel injection system of claim 17, wherein the main nozzles are plain-jet nozzles oriented with a directional component extending radially outward of the pilot nozzle.

20. The fuel injection system of claim 17, wherein the main injection module is configured to produce a main combustion zone disposed radially outward of the pilot combustion zone.