The modal coupling [...] for reducing combustion dynamics reduction.

[0001] The present invention relates to generally a fuel nozzle for reducing the modal coupling combustion dynamics reduction. In certain embodiments the fuel nozzle can be part of a gas turbine or another turbomachine and the method.

[0002] burner be used in the operation of industrial and commercial installations generally, order to ignite fuel and whereby flue gases to generate the high temperature and high pressure. For example, as a rule, one or more burners are gas turbines and other turbomachines on, so as to generate power or thrust. A typical gas turbine, the is used, so as to generate electric power has, at the front of an axial compressor, a turbine and a plurality of burners in the rear part in the central part. Ambient air enters the compressor as a working fluid in a, and the compressor invites increasingly with kinetic energy to the working fluid, so as to produce a compressed working fluid in a highly energy-loaded state. The compressed working fluid enters by one or more fuel nozzles from the compressor flows from and in the burners, where the compressed working fluid is mixed with fuel, before it is ignited in a combustion chamber, so as to generate combustion gases with a high temperature and under a high pressure. The combustion gases flow to the turbine, where they expand, so as to produce work. For example, the expansion in the turbine of the combustion gases can cause that rotates a shaft connected with a generator, whereby electricity is generated.

[0003] During operation it can come to instability, when excited by the combustion process are one or more acoustic fashions of the gas turbine. The excited acoustic fashions to periodic vibrations of system parameters can (e.g. speed, temperature, pressure) and processes (e.g. response rate, rate of heat transfer) lead. For example, a mechanism can occur combustion instability, when the acoustic pressure pulsations cause a variation of the mass flow at a fuel orifice, the then leads to a fluctuation of a fuel-air ratio in the flame. If the resulting variation of the fuel-air-ratio and the acoustic pressure pulsations have a particular phase behaviour (e.g. about are in phase), it may come as a result of self-excitation to a feedback. This mechanism and the resulting extent of combustion dynamics reduction depend at least in part from the delay between the time, to which the fuel is injected by the fuel nozzles, and the time from, to which the fuel is ignited and the fuel accumulation space achieved is defined as the (Tau) convection time. The longer the convection time is, the lower the frequency is the instability, and the shorter the convection time is, the higher the frequency is the instability.

[0004] combustion dynamics reduction may shorten the life of one or more burner The resultant and/or downstream arrayed components. Therefore a nozzle would be, varies the convection time , useful, so as to reduce over broad range of operating phases to promote to offer to increase the thermodynamic efficiency of the burner, a protection against accelerated wear, the stability of the flame and/or undesirable emissions.

[0005] aspects and advantages of the invention are described below in the following description or may be explained by the reaction apparently from the description or may be learned in practice of the invention.

[0006] A embodiment of the present invention is a nozzle, comprising a central body, which extends over a length extends axially along an axial centerline. A jacket circumferentially at least over a portion of the length of the central body surrounds the central body. Several walls extend radially between the central body and the jacket. Several coil turns, at least in part of the central body, the shell and the plurality of walls are defined, circumferentially along at least a portion of the length of the centerbody surrounded the middle body. spiral courses point in each coil turn in the individual fuel onfices opening a different axial position on.

[0007] The fuel collecting area within the central body can have further comprises a fuel nozzle.

[0008] The lateral surface of each of the above-mentioned plurality of walls may extend from the axially downstream fuel nozzles.

[0009] The lateral surface of each of the above-mentioned fuel nozzles can define a diameter, and the diameter decreases from the plurality of walls downstream from.

[0010] Any wall of each of the above-mentioned fuel nozzles can have an angle greater than 30 degrees with respect to the axial centerline.

[0011] Any wall of each of the above-mentioned fuel nozzles can extend axially upstream from the jacket.

[0012] each of the above-mentioned fuel nozzles by the central body can have fuel channel Each a fluid communication with another helical turn.

[0013] each of the above-mentioned fuel nozzles can have a conical fuel onfices opening The individual outer surface, extends into the individual coil turns extending radially.

[0014] The individual fuel onfices opening each of the above-mentioned fuel nozzles can have the same distance from adjacent walls.

[0015] In an alternative embodiment, the present invention has a fuel nozzle on a central body, which extends axially along a length extending along an axial centerline. A jacket circumferentially at least over a portion of the length of the central body surrounds the central body. Several coil turns circumferentially at least along a portion of the length of the centerbody surrounded the middle body, and each of said fuel onfices opening spiral coursesconvection time points to a different in the individual.

[0016] The lateral surface of each of the above-mentioned fuel nozzles can extend from the plurality of axially downstream spiral courses.

[0017] The lateral surface of each of the above-mentioned fuel nozzles can define a diameter, and the diameter decreases from the more downstream ab spiral courses.

[0018] Each coil turn can an angle greater than each of said fuel nozzles comprise 30 degrees with respect to the axial centerline.

[0019] Each helical turn positioned axially upstream from the jacket may extend each of the above-mentioned fuel nozzles.

[0020] each of the above-mentioned fuel nozzles can have a conical fuel onfices opening The individual outer surface, extends into the individual coil turns extending radially.

[0021] The present invention can also a gas turbine comprising a compression stage, a combustion section and a turbine section downstream of the combustion section downstream of the compression stage have. A fuel nozzle is located in the combustion section, and a plurality of coil turns extend axially in the fuel nozzle. Fuel openings each have a different spiral coursesconvection time on in the individual.

[0022] The gas turbine further comprising a jacket can have, the more coil turns circumferentially surrounds the, wherein the jacket extends axially in the downstream direction from the plural spiral courses.

[0023] each of the above-mentioned types can have gas turbine further comprising a jacket The, the circumferentially surrounding said plurality of coil turns, wherein the jacket defines a diameter and the diameter of the plurality of downstream spiral courses can decrease.

[0024] each of the above-mentioned types can have gas turbine further comprising a jacket The, the circumferentially surrounding said plurality of coil turns, wherein each coil turn can axially extend from upstream from the jacket.

[0025] each of the above-mentioned gas turbines can have fuel onfices opening The individual a conical outer surface, extends into the individual coil turns extending radially.

[0026] The person skilled in the art will appreciate the features and aspects can after reading the description better this and other embodiments.

[0027] The a complete disclosure of the present invention including its receives person skilled in the art best mode and explanatory in the further description with reference to the accompanying Figures, in which:

1 a simplified lateral cross sectional view of an example for a gas turbine according to Fig. various embodiments of the present invention is;

2 a simplified lateral cross sectional view of an example for a burner according to Fig. various embodiments of the present invention is;

Fig. 3 is a perspective view of an embodiment of the present invention is according to a fuel nozzle;

4 is a lateral cross sectional view of the fuel nozzle 3 represented in Fig. Fig.; and

A lateral cross-sectional representation of an example for a helical turn and a 5 Fig. is fuel orifice, 3 and 4 are represented in Fig..

[0028] embodiments of the invention is presented in detail taken on relative now, are represented in the accompanying drawings for the one or more examples. The detailed description used figures and letters identifying, so as to be able to take on characteristics relative in the drawings. Equal or similar designations in the drawings and the description are used, to designate the same or similar parts of the invention. As used herein, the terms "first, first, first" can, "second, second, second" and "third, third, third" are used interchangeably, to distinguish one component from the other are to about Specify, and no place and no importance of the individual components. "Upstream" The terms, "downstream", "radially" and axially " denote the relative direction with respect to a fluid flow in a fluid path. "Upstream" denotes the direction, for example, from which the fluid comes, and "downstream" denotes the direction, where the fluid flows. "Radially" denotes the relative direction also is substantially perpendicular to said fluid flow, and "axially" denotes the relative direction, the is substantially parallel to the fluid flow.

[0029] Each example is given for explaining the invention, but not to limit the invention. Indeed, it will be obvious for a person skilled in the art that modifications and variations can be made to the present invention, without depart from their range or idea. For example features can, are described as part of one embodiment, the illustrated or, alternatively, be used, to give still another embodiment. Such modifications and variations is to cover the present invention therefore, lie in the range of the attached claims and their equivalents the.

[0030] Miscellaneous embodiments of the present invention include a fuel nozzle for reducing the modal coupling a combustion dynamics reduction. The fuel nozzle has generally a plurality of coil turns on, the extend axially in the fuel nozzle has, wherein each helical turn at least one fuel orifice. In certain embodiments the fuel nozzle can comprise: a central body, a jacket, the circumferentially surrounding at least a portion of the central body, and/or more walls, the extend radially between the central body and the sheath, at least in part to define the coil turns. Any fuel orifice can have a different axial position in the respective spiral courses , so that each has a different fuel orifice convection time. The different amplitude relationshipconvection times the frequency and/or the change between the nozzles and/or to the burners, whereby the coherence of the combustion system as a whole is reduced in size reduced, what any couplings between the fuel nozzles and/or burners. As used herein, means the strength of the linear relationship between two coherence (or more) dynamic signals, the strongly influenced by the degree of mutual frequency overlap is. The ability of the various embodiments of the present invention can therefore to generate burner sound , a vibration response in downstream components, reduce. Although embodiments of the present invention for the purposes of the explanation described in the context of the combustion dynamics reduction within a gas turbine engine are generally, a person skilled in the art will readily recognize that embodiments of the present invention can be applied to a gas turbine combustion dynamics reduction on each are limited and not, when is otherwise expressly indicated in the claims.

[0031] Now is made to the drawings reference, wherein same reference numbers in all Figures same elements describe, and a simplified lateral cross sectional view of an example for a gas turbine 1 where Fig. 10 is, in the various embodiments of the present invention may be embodied. As represented, the gas turbine 12 can generally an inlet portion 10, a compression section 14, a combustion section 16, a turbine section 18 and 20 have an exit portion. The inlet section 12 can have a series of filtering fluid conditioning devices 22 and one or more 24, so as to cool to dehumidify to heat to condition a working fluid to wet (e.g. air) enters 28 to clean, in the gas turbine 10, , , , , and/or otherwise. The purified and conditioned working fluid flows to a compressor 28 30 32 14 28 a closes the working fluid in the compression section. A compressor housing, during alternating stages of rotating blades 34 and stationary guide plates 28 increasingly accelerate and deflect the working fluid 36, 38 so as to generate a continuous flow of compressed working fluid at a higher temperature and a higher pressure.

[0032] the main bulk of the compressed working fluid flows by a 40 38 42 discharge opening collecting area to one or more burners in the combustion portion 16 of the compressor. A fuel source 44, 42 in fluid communication with the individual burners is the, fuel to the individual burners 42 provides for example blast furnace gas are. Possible fuels, coke oven gas, natural gas, methane, vaporized liquefied natural gas (LNG), hydrogen, syngas, butane, propane, olefins, diesel, petroleum distillates and combinations thereof. The compressed working fluid is mixed with the fuel and ignited 38, about 46 with a higher temperature and a higher pressure to generate combustion gases.

[0033] The combustion gases in the turbine section 48 by a turbine 46 hot gas way 18 along a flow, where they expand, so as to produce work. By alternating stages of stationary nozzles 46 can the combustion gases 50 Exact rotor blades 48 and 52 flow in the turbine. The stationary nozzles 52 50 46 on the next stage of rotor blades for directing the combustion gases, and the combustion gases expand from 46, when they flow over the rotor blades 52, thereby causing that the rotor blades 52 rotate. The rotor blades can be connected to a shaft 52 54, the drives is connected to the compressor 30, the compressor 54 so that the rotation of the shaft 30, so as to generate the compressed working fluid 38. Alternatively or in addition thereto the shaft 56 54 can be connected with a generator, to generate electricity. Exhaust gases flow from the turbine section 20 through the discharge section 58 18, before they are released into the environment.

[0034] Distillers 42 may include to each type of burner is known in the art, and the present invention is not limited to any particular burner construction , as long as in claims otherwise expressly specified. 2 is a simplified cross-sectional representation of an example for a burner is Fig. 42 according to various embodiments of the lateral present invention. As in Fig. 2 represented, a burner housing 60 and an end cap 62 can be combined, to enclose the compressed working fluid flows 38, 42 to the burner the,. A 64 can extend radially beyond at least a portion of the burner cap assembly 42, and one or more fuel nozzles may be arranged radially beyond the cap assembly 64 66, 70 to provide fuel to a combustion chamber downstream of the cap assembly 64. A insert 70 circumferentially surrounded at least a portion of the combustion chamber 72 can, and a 70 72 the combustion chamber downstream of the insert 74 transition channel can connect to the inlet of the turbine 48. 74 78 76 with flow passages impact casetransition channel can circumferentially surrounded the A, and 72 a 80 aircraft can be circumferentially surrounded flow case. In this way the compressed working fluid can enter in the 76 78 38 by the flow holesimpact case , 74 and 82 by an annular channel to flow outside the transition channel 72 of the insert. If the compressed working fluid reaches the end cover 38 62, the compressed working fluid flows through the fuel nozzles 38 the direction and changes into the combustion chamber 66 and 70.

[0035] 3 is a perspective view of an example for a fuel nozzle 66 Fig. within the range of various embodiments of the present invention is a lateral cross sectional view of 3 represented in 4 and Fig. Fig. 3 and 4 66. As in Fig. represented fuel nozzle, the fuel nozzle can have a central body 66 90, 92 94 extends across a length along an axial centerline of the fuel nozzle 66. The central body 62 with said end cover 90 can be connected and/or extend therethrough, so as to establish fluid communication from the end cap 62, 64 and into the combustion chamber by the cap assembly 70. For example, the central body can have one or more 90 fluid collecting area , the fuel, diluent and/or other additives into the combustion chamber 62 to pass from the end cover 70. The special embodiment, 3 and 4 is represented in Fig., extends axially within a 96 94 90 along the length of the centerbody fuel collecting area , so as to supply fuel through the fuel nozzle 66.

[0036] The fuel nozzle 100 may also have a jacket 66, the surrounding 90 94 of the central body over at least a portion of the length the middle body 90 circumferentially. The jacket 102 104 100 a diameter defined within the shell 90 can extend radially between the centerbody. Several walls 100 and the jacket. In this way the central body can 90, the jacket and the walls together, at least in part, a plurality of coil turns 104 100 106 define, at least along a portion of the length 94 90 the the middle body 90 of the centerbody surrounded circumferentially. The coil turns on the compressed working fluid 106 swirl 38, the flows through the fuel nozzle 66. The special embodiment, 3 and 4 is represented in Fig., 104 and/or each coil turn can extend themselves each wall 100 from axially upstream from the jacket 106, so that the compressed working fluid can be received or collected in the fuel nozzle 66 38. Alternatively or in addition thereto, can extend from the walls 104 and/or the the sheath 100 106 axially downstream spiral courses , and the diameter of the shell 102 104 100 106 spiral courses can decrease from the walls and/or the downstream, so as to strengthen the compressed working fluid enters a persistent vortex 38 enters, from the fuel nozzle into the combustion chamber 66 and 70,.

[0037] The number and the helix angles of the walls 104 and 106 may vary the coil turns, so as to change the strength of the overall and/or the mixture lengthwithdrawal eddy. The special embodiment, 3 and 4 are represented in Fig., for example, has twelve walls 66 on the fuel nozzle 104, 106 form the twelve coil turns, at an angle of about 90 degrees around the central body 50 which are disposed around. In other embodiments, the lie in the range of the present invention, the number may vary between 3 and 15 or more of the walls, and may vary between about 10 degrees and about 80 degrees the pitch angle. However, not on any particular number of walls the embodiments are of the present invention 104 and/or 106 and/or helix angles spiral courses limited, as long as is otherwise expressly indicated in the claims.

[0038] 3 and 4 is represented in Fig. As, each helical turn has at least one fuel orifice 106 108 on, 90 and 96 through the central body for providing fluid communication from the set up in each individual coil turn fuel collecting area 106. The fuel onfices opening 108 allow, 109 106 inject the fuel into each individual fuel channel 38 to swirl and with the compressed working fluid, to achieve a thorough mixing of the fuel and the compressed working fluid 38 to strengthen 109, before these the combustion chamber 70. The convection time (Tau) is associated with the individual fuel onfices opening 108 is directly proportional to the distance, the covers 109 the fuel, before it reaches the combustion chamber 70. This distance is in turn a function of the pitch angle (i.e. the length) of each helical turn 108 106 and the axial position of the individual fuel onfices opening 66 in the fuel nozzle shorter convection time reduced in that the dimension of the mixing between the fuel. A 109 and the compressed working fluid 38, the flow through the coil turns 106. Longer convection time 109 and the compressed working fluid between the fuel mixing reinforced 38, but also can increase the reactivity of the fuel can lead 109 and create conditions, the cause premature ignition, before the fuel reaches the combustion chamber 109 70.

[0039] The special embodiment, 3 and 4 is represented in Fig., each individual fuel orifice 108 106 faces a different axial position in the respective helical turn on, which generates a corresponding different convection time for each fuel orifice 108. The different convection times lead to a corresponding different frequency for each coil turn 108. Whereas as a consequence, the frequencies, 66 are generated by the fuel nozzle, and have smaller amplitudes to diffuse, similar to white noise, whereby the conditions, the lead to instability, are reduced.

[0040] 5 is a lateral cross-sectional representation of an example for a helical turn and Fig. a fuel orifice, 3 and 4 are represented in Fig.. As represented, the fuel orifice 104 and 108 can be located equidistant from adjacent walls 110 has a conical [...][...] can, the 106 extends radially into each helical turn. 110 106 and the conical outer surface the helical turn the combination can therefore a double vortex of the compressed working fluid 38, flows through the coil turns the generate 106, , whereby the mixing with the fuel 109, 106 is injected into the coil turn is reinforced. In specific embodiments the fuel onfices opening 106 108 can be angled in a compound angle in the helical turn. Alternatively or in addition thereto the coil turns have turbulators can 106, 109 to break up the laminar flow from the fuel by the fuel nozzle 38 and compressed working fluid 66.

[0041] The various embodiments, with respect to FIG. 1-5 are described and represented, can offer one or more of the following advantages over present-day burners 42. Specifically more diffuse and smaller amplitudes with the reduce the frequencies, are associated with the 106 spiral courses , the conditions, the lead to instability, whereby the consistency and/or modal coupling is reduced combustion dynamics reduction. The embodiments described herein can increase the various thermodynamic efficiency therefore, the stability of the flame and/or undesirable emissions over a wide range of operating phases promote reduce, without impact on the life in the downstream arrayed components hot gas way.

[0042] This description used examples, in order to describe the invention to include implement, including of the best manner for their execution, and around the person skilled in the art in the situation, the invention into practice, including the preparation and use of devices and systems and the execution contained Method. The Sperkhios scope of the invention is defined by the claims and may include other examples, the may be obvious to someone skilled in the art. These other examples should lie in the range of claims, if they have structural elements, the have not differ from the text of the claims, or if they equivalent structural elements, the differ from the text of the claims will be insignificant.

[0043] A fuel nozzle has a central body on, which extends axially along a length extending along an axial centerline. A jacket circumferentially at least over a portion of the length of the central body surrounds the central body. Several coil turns circumferentially at least along a portion of the length of the centerbody surrounded the middle body, and each of said fuel onfices opening spiral coursesconvection time points to a different in the individual.