Patent Application
20180163967
The present disclosure generally pertains to an injector head, and is directed toward an injector head of a gas turbine engine with integral resonators.
Gas turbine engines include compressor, combustor, and turbine sections. During operation of the gas turbine engine combustion oscillations may damage or reduce the operating life of the components of the combustor. Combustion oscillations may be the result of resonance of the fuel and/or air within the injector heads of the fuel injectors.
U.S. Pat. No. 8,789,372 to Johnson, et al. discloses a system that may include a turbine engine. The turbine engine may include a fuel nozzle. The fuel nozzle may include an air path. The fuel nozzle may also include a fuel path such that the fuel nozzle is in communication with a combustion zone of the turbine engine. Furthermore, the fuel nozzle may include a resonator. The resonator may be disposed in the fuel nozzle directly adjacent to the combustion zone.
The present disclosure is directed toward overcoming one or more of the problems discovered by the inventors or that is known in the art.
A fuel injector for a combustor of a gas turbine engine is disclosed. In one aspect of the invention, the fuel injector includes a stem, a fitting joined to the stem, a main stem fuel passage, and an injector head. The main stem fuel passage extends within the stem and fluidly connects to the fitting. The main stem fuel passage includes a main stem passage outlet. The injector head adjoins the stem distal to the fitting and adjacent to the main stem passage outlet. The injector head includes a feed air inlet, a main premix passage, a main air inlet for the main premix passage, vanes, and a main premix resonator. The feed air inlet allows compressed air to enter the injector head. The main premix passage extends through the injector head. The main air inlet is located adjacent to the feed air inlet. The vanes are located within main premix passage for swirling the compressed air that enters the main premix passage through the main air inlet. The main premix resonator is located adjacent to and downstream of the vanes, or upstream of the vanes.
In another aspect of the invention, the fuel injector includes a stem, a fitting joined to the stem, a pilot stem fuel passage, and an injector head. The pilot fuel stem passage extends within the stem and fluidly connects to the fitting. The pilot stem fuel passage includes a pilot stem passage outlet. The injector head adjoins the stem distal to the fitting. The injector head includes a feed air inlet, a pilot premix passage, a pilot fuel inlet, and a pilot fuel resonator. The feed air inlet allows compressed air to enter the injector head. The pilot premix passage provides a fuel and air mixture to the combustion chamber. The pilot fuel inlet provides the fuel to the pilot premix passage. Resonators are adjacent to the pilot fuel inlet, the pilot premix passage and the pilot air passage.
The systems and methods disclosed herein include an injector head with integral resonators. In embodiments, the injector head includes fluid passages, such as fuel passages, air passages, and mixture passages. The resonators may be positioned adjacent to transition orifices including inlets or outlets of the fluid passages that the fluids, such as fuel and air, pass through. The resonators may be radially located relative to the passage, such as a Helmholtz resonator, or may be an in-line resonator, such as a resonating cavity or a circuitous labyrinth that is in-line with the fluid passage. The radially located resonators may include a resonating cavity and a neck connecting the cavity to the fluid passage adjacent to a transition orifice. Locating the resonators adjacent to the transition orifices may minimize the resonance of the fluids within the injector head, which may reduce combustor oscillations and increase the operating life of the components in the combustor.
In addition, the disclosure may generally reference a center axis 95 of rotation of the gas turbine engine, which may be generally defined by the longitudinal axis of its shaft 120 (supported by a plurality of bearing assemblies 150). The center axis 95 may be common to or shared with various other engine concentric components. All references to radial, axial, and circumferential directions and measures refer to center axis 95, unless specified otherwise, and terms such as “inner” and “outer” generally indicate a lesser or greater radial distance from center axis 95, wherein a radial 96 may be in any direction perpendicular and radiating outward from center axis 95.
A gas turbine engine 100 includes an inlet 110, a shaft 120, a compressor 200, a combustor 300, a turbine 400, an exhaust 500, and a power output coupling 50. The gas turbine engine 100 may have a single shaft or a dual shaft configuration.
The compressor 200 includes a compressor rotor assembly 210, compressor stationary vanes (stators) 250, and inlet guide vanes 255. The compressor rotor assembly 210 mechanically couples to shaft 120. As illustrated, the compressor rotor assembly 210 is an axial flow rotor assembly. The compressor rotor assembly 210 includes one or more compressor disk assemblies 220. Each compressor disk assembly 220 includes a compressor rotor disk that is circumferentially populated with compressor rotor blades. Stators 250 axially follow each of the compressor disk assemblies 220. Each compressor disk assembly 220 paired with the adjacent stators 250 that follow the compressor disk assembly 220 is considered a compressor stage. Compressor 200 includes multiple compressor stages. Inlet guide vanes 255 axially precede the compressor stages.
The combustor 300 includes a combustion chamber 390 and one or more fuel injectors 310. The fuel injectors 310 may be upstream of the combustion chamber 390 and may be annularly arranged about center axis 95.
The turbine 400 includes a turbine rotor assembly 410 and turbine nozzles 450. The turbine rotor assembly 410 mechanically couples to the shaft 120. In the embodiment illustrated, the turbine rotor assembly 410 is an axial flow rotor assembly. The turbine rotor assembly 410 includes one or more turbine disk assemblies 420. Each turbine disk assembly 420 includes a turbine disk that is circumferentially populated with turbine blades. Turbine nozzles 450 axially precede each of the turbine disk assemblies 420. Each turbine disk assembly 420 paired with the adjacent turbine nozzles 450 that precede the turbine disk assembly 420 is considered a turbine stage. Turbine 400 includes multiple turbine stages.
The exhaust 500 includes an exhaust diffuser 510 and an exhaust collector 520. The power output coupling 50 may be located at an end of shaft 120.
The fittings 315 supply fuel to the fuel injector 310 from a fuel source. The fuel may be a liquid or a gaseous fuel. The flange 311 may be joined to the stem 320, such as by metallurgical bonding. The flange 311 may include mounting holes 312 for securing the fuel injector 310 to the gas turbine engine 100.
The main fuel stem resonator 323 and the pilot fuel stem resonator 326 may be adjacent to the injector head 330. The main fuel stem resonator 323 and the pilot fuel stem resonator 326 along with the other resonators described herein may each be radially located relative to the passage, such as a Helmholtz resonator, or may be an in-line resonator, such as a resonating cavity or a circuitous labyrinth that is in-line with the fluid passage. The radially located resonators may include a resonating cavity and a neck connecting the cavity to the fluid passage adjacent to a transition orifice, such as an inlet or an outlet for the fluid passage. In the embodiment illustrated, the main fuel stem resonator 323 is an in-line resonator located in the path of the main fuel stem passage 321 and is adjacent to the main stem passage outlet 366 as illustrated in
Referring to
The injector body 331 may have a hollow cylinder shape. The injector body 331 may be integral to the stem 320, such as unitary with the stem 320 or joined to the stem 320. The injector body 331 may be joined to the stem 320 by a metallurgical bond. The injector barrel 332 may have a hollow cylinder shape and may axially extend from the injector body 331. The inner premix tube 340 may have a cylindrical shape and may extend within the injector body 331 and the injector barrel 332.
The inner premix tube 340 may be located inward and offset from the injector body 331 and the injector barrel 332, which may form a main premix passage 341 or a portion of the main premix passage 341. The inner premix tube 340 may be coaxial to the injector body 331 and the injector barrel 332. The inner premix tube 340 may include an inner premix tube cap 379 that may act as a heat shield for the pilot fuel air mixture that may flow there within. The inner premix tube cap 379 may include a premix tube injection opening for the pilot fuel air mixture to pass through and enter into the combustion chamber 390.
The vanes 345 may extend between the injector body 331 and the inner premix tube 340 through the main premix passage 341. The vanes 345 may cause the main air and fuel passing there through to swirl and mix prior to combustion. The vanes 345 may join the injector body 331 to the inner premix tube 340.
The pilot tube 380 may be located inward from the inner premix tube 340 and may be extend within the injector body 331 and the injector barrel 332. The pilot tube 380 may include a cylinder shape and may include a pilot tube cap 381 that is adjacent to the inner premix tube cap 379. The pilot tube cap 381 may include a pilot tube injection opening 355 that may direct the pilot fuel air mixture into the combustion chamber 390.
The injector body 331, the injector barrel 332, the inner premix tube 340, the vanes 345, and the pilot tube 380 may be integral, such as unitary, joined together by metallurgical bonds, or combinations thereof.
Referring to
The feed air resonators 335 may be adjacent to the feed air inlet 333 and may be located outward from the feed air inlet 333. The feed air resonators may be radial resonators and may be Helmholtz resonators. Each feed air resonator 335 may include a feed air resonator cavity 337 and a feed air resonator neck 336. In the embodiment illustrated, the feed air resonator cavity 337 is a cylindrical cavity extending axially into the injector body 331 adjacent to the feed air inlet 333.
The main air inlet 334 may be an annular plate extending between the injector body 331 and the inner premix tube 340 adjacent to the feed air inlet 333. The main air inlet 334 may include main air inlet passages 342 that control the amount of air that enters the main premix passage 341. The secondary air inlet 350 may be located inward from the main air inlet 334 and may provide air for the pilot air and for cooling air.
Referring to
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The pilot fuel tubing 317 may include a pilot fuel tubing outlet 338 adjacent to the pilot tube 380. The injector head 330 may also include a pilot premix passage 354, a pilot fuel inlet 353, and a pilot fuel resonator 339. The pilot premix passage 354 may be inward from the main premix passage 341, may be coaxial to the pilot tube 380, and may provide a fuel and air mixture to the combustion chamber 390. The pilot fuel inlet 353 may provide and direct pilot fuel into the pilot premix passage 354 at an end distal to the pilot tube cap 381 and to the pilot tube injection opening 355.
The pilot fuel resonator 339 may be in-line with the pilot fuel inlet 353. The pilot fuel resonator 339 may be adjacent to the pilot fuel tubing outlet 338 and to the pilot fuel inlet 353. In the embodiment illustrated, the pilot fuel resonator 339 includes a circuitous labyrinth passage that delivers pilot fuel from the pilot fuel tubing outlet 338 to the pilot fuel inlet 353, where the pilot fuel tubing outlet 338 acts as an inlet to the pilot fuel resonator 339 and the pilot fuel inlet 353 acts as an outlet to the pilot fuel resonator 339. The circuitous labyrinth passage may be configured to primarily flow in an axial, circumferential, or radial direction. In the embodiment illustrated the circuitous labyrinth includes annular passages connected by radial passages. The annular passages may extend completely around the axis of the injector head 330 or may be annular sectors.
The injector head 330 may also include a pilot air inlet 352, a pilot air resonator 351, and a pilot air resonator inlet 375, which may be formed in the pilot tube 380. The pilot air inlet 352 may be located in the pilot tube 380 adjacent to the pilot fuel inlet 353. The pilot air resonator 351 may be an in-line resonator adjacent to the pilot air inlet 352 and to the secondary air inlet 350. In the embodiment illustrated, the pilot air resonator 351 includes a circuitous labyrinth passage that delivers the pilot air from the secondary air inlet 350 to the pilot premix passage 354. The circuitous labyrinth passage may be configured to primarily flow in an axial, circumferential, or radial direction. In the embodiment illustrated the circuitous labyrinth includes annular passages connected by radial passages. The annular passages may extend completely around the axis of the injector head 330 or may be annular sectors.
The pilot air resonator inlet 375 may direct air into the pilot air resonator 351 from the secondary air inlet 350. In some embodiments, the pilot air resonator inlet 375 may be adjacent to the feed air inlet 333 and may direct air directly from the feed air inlet 333 into the pilot air resonator 351.
The pilot premix resonator 385 may also be located within the centerbody 384 and may be located adjacent to the pilot fuel inlet 353 and the pilot air inlet 352. In the embodiment illustrated, the pilot premix resonator 385 includes a pilot premix cavity 386 and a pilot premix neck 387. The pilot premix neck 387 fluidly connects the pilot premix cavity 386 to the pilot premix passage 354. The pilot premix neck 386 may be located and may fluidly connect to the pilot premix passage 354 adjacent to the pilot fuel inlet 353 and the pilot air inlet 352.
Referring to
In the embodiment illustrated, the injector head 330 includes a first cooling resonator 359, a second cooling resonator 362, and a third cooling resonator 364. The first cooling resonator 359 may include a first cooling resonator cavity 361 and a first cooling resonator neck 360. The first cooling resonator cavity 361 may be outward from the cooling passage 356. The first cooling resonator neck 360 may connect the first cooling resonator cavity 361 adjacent to the cooling passage inlet 357.
The second cooling resonator 362 and the third cooling resonator 364 may be in-line resonators that are at the downstream end of the cooling passage 356 adjacent to the pilot tube cap 381. The injector head 330 may further include first cooling passage holes 358, second cooling passage holes 363, and cooling impingement holes 365. The first cooling passage holes 358 may pass through standoffs 382 to form the inlet to the second cooling resonator 362. The second cooling passage holes 363 may pass through standoffs 382 to form the outlet of the second cooling resonator 362 and the inlet to the third cooling resonator 364. The cooling impingement holes 365 may form the outlet of the third cooling resonator 364 and to the cooling passage 356 to direct the air into the pilot tube cap 381.
Gas turbine engines may be suited for any number of industrial applications such as various aspects of the oil and gas industry (including transmission, gathering, storage, withdrawal, and lifting of oil and natural gas), the power generation industry, cogeneration, aerospace, and other transportation industries.
Referring to
Once compressed air 10 leaves the compressor 200, it enters the combustor 300, where it is diffused and fuel is added. Air 10 and fuel are injected into the combustion chamber 390 and combusted. An air and fuel mixture is supplied via fuel injector 310. Energy is extracted from the combustion reaction via the turbine 400 by each stage of the series of turbine disk assemblies 420. Exhaust gas 90 may then be diffused in exhaust diffuser 510, collected and redirected. Exhaust gas 90 exits the system via an exhaust collector 520 and may be further processed (e.g., to reduce harmful emissions, and/or to recover heat from the exhaust gas 90).
Resonance between the combustor heat release process (“flame”) and passages in the fuel injector 310 may result in combustor dynamic pressure oscillations. These passages may include fuel passages, air passages, and fuel/air mixture passages, such as the passages described herein. Fluidly connecting resonators to these passages in the fuel injector 310 may counteract the resonance between unsteady heat release and the passages and may reduce or prevent combustor oscillations.
In particular, connecting the resonators to the passages adjacent to a transition orifice, such as an inlet or an outlet to the passages, within the injector head 330 may place the resonator adjacent to an antinode of a linked resonance between the flame and the passages, which may increase the overall effectiveness of the resonators and further reduce combustor oscillations. Counteracting and reducing combustor oscillations may increase the durability and operating life of the combustor 300 and the various components of the combustor 300.
In some embodiments, the in-line resonators, such as the main fuel stem resonator 323, the pilot fuel resonator 339, and the pilot air resonator 351 may be low pass filters that are configured to filter out vibrations within a low pass frequency range. However, in some embodiments, the resonators are used as band-stop filters, targeting a frequency associated with a mode shape and diminishing it.
The preceding detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. The described embodiments are not limited to use in conjunction with a particular type of gas turbine engine or a particular combustor. Hence, although the present disclosure, for convenience of explanation, depicts and describes particular embodiments of the fuel injector and resonators for a combustor, it will be appreciated that the fuel injector and resonators in accordance with this disclosure can be implemented in various other configurations, can be used with various other types of combustors and gas turbine engines, and can be used in other types of machines. Further, the resonators may be used in conjunction with pilot or main passages for air, fuel, or a mixture thereof and can be used with passages for gas or liquid fuel. Any explanation in connection with one embodiment applies to similar features of other embodiments, and elements of multiple embodiments can be combined to form other embodiments. Furthermore, there is no intention to be bound by any theory presented in the preceding background or detailed description. It is also understood that the illustrations may include exaggerated dimensions to better illustrate the referenced items shown, and are not consider limiting unless expressly stated as such.
