Patent Application
20250180212
Exemplary embodiments relate to a combustor nozzle for operation in association with a combustor and gas turbine engine including the same. The combustor may use at least one of hydrogen fuel and natural gas fuel.
A gas turbine engine is a power engine that mixes air compressed by a compressor with fuel for combustion and rotates a turbine with hot gas produced by the combustion. The gas turbine engine is used to drive a generator, an aircraft, a ship, a train, etc.
The gas turbine engine typically includes a compressor, a combustor, and a turbine. The compressor sucks and compresses outside air, and then transmits the compressed air to the combustor. The combustor mixes the compressed air flowing thereinto from the compressor with fuel and burns a mixture thereof to generate high pressure and high temperature combustion gas. The combustion gas produced by the combustion is discharged to the turbine. Turbine blades in the turbine are rotated by the combustion gas, thereby generating power. The generated power is used in various fields, such as generating electric power and actuating machines.
Fuel is injected through nozzles installed in each combustor section of the combustor, and the nozzles allow for injection of gas fuel and/or liquid fuel. In recent years, it is recommended to use hydrogen fuel or fuel containing hydrogen to inhibit or reduce the emission of carbon dioxide given that hydrogen is a carbon-free fuel.
However, while use of hydrogen fuel or fuel containing hydrogen enables the desired effect of inhibiting reducing emission of carbon dioxide, problems can occur owing to the high combustion rate of hydrogen. That is, when hydrogen is introduced as a fuel, if the hydrogen is not thoroughly mixed with the compressed air generated by the compressor, the hydrogen can ignite prematurely or separately from the compressed air causing flashback in the nozzles or fuel/air mixing tubes. Such flashbacks can damage components of the gas turbine engine, and such flashbacks can lead to inefficient gas turbine engine operation owing to inconsistent energy to the gas turbine engine system. In addition, as proper pressure in the gas turbine engine system is necessary for efficient operation, premature or inefficient combustion of hydrogen fuel not properly mixed with compressed air can result in undesired pressure drops in the gas turbine engine system. Another problem owing to inefficient hydrogen fuel combustion is the production of nitrogen oxides (NOx). When air is heated to high temperatures, nitrogen which naturally occurs in air, combines with oxygen to produce NOx. Combusting hydrogen fuels mixed with compressed air when the hydrogen fuel is not properly mixed with the compressed air prior to combustion can result in over heating the compressed air which, in turn, can result in production of undesired levels of NOx.
There is a need in the art for a gas turbine engine fuel nozzle or fuel/air mixing tube in which fuels are mixed with compressed air in a manner that allows for efficient combustion of the fuels for improved gas turbine engine operation and that inhibits production of undesired byproducts.
Aspects of one or more exemplary embodiments provide a combustor nozzle that enables uniform mixing of fuel and air, a combustor, and a gas turbine engine including the same.
Additional aspects will be set forth in part in the description which follows and, in part, will become apparent from the description, or may be learned by practice of the exemplary embodiments.
According to an aspect of an exemplary embodiment, there is provided a nozzle or fuel/air mixing tube for a combustor that improves the mixing of fuels with compressed air and that enables improved combustion of fuel/air mixtures. According to one aspect of the exemplary embodiment, the nozzle comprised of a cylindrical tube is configured with an inlet formed at a longitudinal end for introduction of a first fluid (for example, compressed air) and a plurality of supply ports or passages formed on a circumferential surface of the nozzle for introduction of a second fluid (for example, hydrogen or a fuel containing hydrogen). Along an inner surface of the nozzle between the inlet and the fuel supply ports or passages, one or more fluid vortex generators in the form of wedge-shaped or three dimensional triangular shaped members are disposed. According to an aspect, as compressed air flows through the inlet, the compressed air encounters the one or more fluid vortex generators which causes the compressed air to swirl inside the nozzle resulting in an increase of turbulence in the flow of the compressed air. As fuel is then introduced into the nozzle, the fuel encounters the swirling or turbulent flow of compressed air. The swirling or turbulent air acts on the introduced fuel and causes the introduced fuel to be thoroughly mixed with the compressed air so that the fuel/air mixture will be combusted in a uniform manner reducing incidence of the above-mentioned problems associated with ill-mixed fuel/air components.
According to an aspect of another exemplary embodiment, the nozzle or fuel/air mixing tube may be configured with a plurality of other nozzles or cylindrical fuel/air mixing tubes as a multi-tube nozzle configuration. According to this aspect, each of the nozzles or fuel/air mixing tubes may include one or more fluid vortex generators inside inlets in longitudinal ends of the nozzles between the inlets and one or more fuel supply ports or passages such that compressed air passing through the inlets and encountering the one or more fluid vortex generators is swirled to produce turbulent air flow. The turbulent air flow acts to mix the compressed air with the fuel introduced through the supply ports or passages downrange from the fluid vortex generators such that the fuel and compressed air are thoroughly mixed for proper subsequent combustion.
According to an aspect of another exemplary embodiment, there is provided a combustor including a burner having a plurality of nozzles for injecting fuel and air, and a combustion chamber for burning a mixture of the fuel and the air therein from which combustion gas may be transmitted to a turbine. According to this aspect each of the nozzles or fuel/air mixing tubes may include one or more fluid vortex generators inside inlets in longitudinal ends of the nozzles between the inlets and one or more fuel supply ports or passages such that compressed air passing through the inlets and encountering the one or more fluid vortex generators is swirled to produce turbulent air flow. The turbulent air flow acts to mix the compressed air with the fuel introduced through the supply ports or passages downrange from the fluid vortex generators such that the fuel and compressed air are thoroughly and uniformly mixed for proper subsequent combustion. According still to this aspect, a plurality of such configured nozzles may be combined to form a multi-tube nozzle configuration for efficient mixing of fuel and compressed air for combustion in a combustion chamber of the combustor.
According to an aspect of a further exemplary embodiment, there is provided a gas turbine engine including a compressor configured to compress air introduced thereinto from the outside, a combustor configured to mix fuel with the air compressed by the compressor for combustion, and a turbine having a plurality of turbine blades rotated by combustion gas produced by the combustion in the combustor. The combustor includes a burner having a plurality of nozzles for injecting the fuel and the air, and a combustion chamber for burning a mixture of the fuel and the air therein from which combustion gas may be transmitted to the turbine. According to this aspect, each of the nozzles or fuel/air mixing tubes may include one or more fluid vortex generators inside inlets in longitudinal ends of the nozzles between the inlets and one or more fuel supply ports or passages such that compressed air passing through the inlets and encountering the one or more fluid vortex generators is swirled to produce turbulent air flow. The turbulent air flow acts to mix the compressed air with the fuel introduced through the supply ports or passages downrange from the fluid vortex generators such that the fuel and compressed air are thoroughly and uniformly mixed for proper subsequent combustion. According still to this aspect, a plurality of such configured nozzles may be combined to form a multi-tube nozzle configuration for efficient mixing of fuel and compressed air for combustion in a combustion chamber of the combustor of the gas turbine engine.
It is to be understood that both the foregoing general description and the following detailed description of exemplary embodiments are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed.
The above and other aspects will become more apparent from the following description of the exemplary embodiments with reference to the accompanying drawings, in which:
Various modifications and different embodiments will be described below in detail with reference to the accompanying drawings so that those skilled in the art can carry out the disclosure. It should be understood, however, that the present disclosure is not intended to be limited to the specific embodiments, but the present disclosure includes modifications, equivalents or replacements that fall within the spirit and scope of the disclosure as defined in the following claims.
The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. In the disclosure, terms such as “comprises”, “includes”, or “have/has” should be construed as designating that there are such features, integers, steps, operations, components, parts, and/or combinations thereof, not to exclude the presence or possibility of adding of one or more of other features, integers, steps, operations, components, parts, and/or combinations thereof.
Exemplary embodiments will be described below in detail with reference to the accompanying drawings. It should be noted that like reference numerals refer to like parts throughout various drawings and exemplary embodiments. In certain embodiments, a detailed description of functions and configurations well known in the art may be omitted to avoid obscuring appreciation of the disclosure by those skilled in the art. For the same reason, some components may be exaggerated, omitted, or schematically illustrated in the accompanying drawings.
Hereinafter, a gas turbine engine according to an exemplary embodiment will be described.
The gas turbine engine 100 using the above Brayton cycle may include a compressor 110, a combustor 120, and a turbine 130, as illustrated in
Referring still to
The compressor 110 may be designed as a centrifugal compressor or an axial compressor. In general, the centrifugal compressor is applied to a small gas turbine engine, whereas the multistage axial compressor is applied to the large gas turbine engine 100 as illustrated in
A plurality of compressor vanes 113, 114 may be formed in a multistage manner and mounted in a compressor casing 115. The compressor vanes 114 guide the compressed air, which flows from front-stage compressor blades 113, to rear-stage compressor blades 114. In an exemplary embodiment, at least some of the plurality of compressor vanes 114 may be mounted so as to be rotatable within a fixed range for regulating the inflow rate of air or the like.
The compressor 110 may be driven by some of the power output from the turbine 130. To this end, the rotary shaft of the compressor 110 may be directly connected to the rotary shaft of the turbine 130, as illustrated in
The turbine 130 includes a plurality of rotor disks 131, a plurality of turbine blades radially arranged on each of the rotor disks 131, and a plurality of turbine vanes (not shown). Each of the rotor disks 131 has a substantially disk shape and has a plurality of grooves formed on the outer peripheral portion thereof. The grooves are each formed to have a curved surface so that the turbine blades are inserted into the grooves, and the turbine vanes are mounted in a turbine casing. The turbine vanes are fixed so as not to rotate and serve to guide the direction of flow of the combustion gas that has passed through the turbine blades. The turbine blades generate rotational force while rotating by the combustion gas.
Meanwhile, the combustor 120 may mix the compressed air, which is supplied from the outlet of the compressor 110, with fuel for isobaric combustion to produce combustion gas with high energy. That is, the combustor 120 mixes the compressed air, which is supplied from the outlet of the compressor 110, with fuel for isobaric combustion to produce combustion gas with high energy. The combustor 120 is disposed downstream of the compressor 110 and includes a plurality of burners 200 arranged annularly around a central axis of the gas turbine engine 100.
Referring now to
The gas turbine engine may use gas fuel containing hydrogen and/or natural gas, liquid fuel, or composite fuel as a combination thereof, which is the fuel fluid in the present exemplary embodiment. For the gas turbine engine, it is important to make a combustion environment for reducing an amount of emission such as carbon monoxide or nitrogen oxide that is subject to legal regulations. Accordingly, premixed combustion has been increasingly used in recent years in that it enables uniform combustion to reduce emission by lowering a combustion temperature even though it is relatively difficult to control the premixed combustion.
In the case of premixed combustion, after the compressed air introduced from the compressor 110 is mixed with fuel in the nozzle 300, the mixture thereof enters the combustion chamber 240. When combustion is stable after premixed gas is initially ignited by an igniter, the combustion is maintained by the supply of fuel and air.
The duct assembly 220 includes the combustion chamber 240, which is a space for combustion, and further includes a liner 250 and a transition piece 260.
The liner 250 may be disposed downstream of the nozzle 300 and may have a double structure of an inner liner 251 and an outer liner 252. That is, the liner 250 may have a double structure in which the inner liner 251 is surrounded by the outer liner 252. In this case, the inner liner 251 may be a hollow tubular member, and the inside of the inner liner 251 defines the combustion chamber 240. The inner liner 251 may be cooled by the compressed air penetrating into an annular space inside the outer liner 252 through a compressed air inlet hole H.
The transition piece 260 may be positioned downstream of the liner 250, which allows combustion gas produced in the combustion chamber 240 to be released at high speed to the turbine. The transition piece 260 may have a double structure of an inner transition piece 261 and an outer transition piece 262. That is, the transition piece 260 may have a double structure in which the inner transition piece 261 is surrounded by the outer transition piece 262. Like the inner liner 251, the inner transition piece 261 may also be a hollow tubular member. The inner transition piece 261 may have a diameter that gradually decreases from the liner 250 toward the turbine 130. In this case, the inner liner 251 and the inner transition piece 261 may be coupled to each other by a plate spring seal (not shown). The respective ends of the inner liner 251 and the inner transition piece 261 are fixed to the combustor 120 and the turbine, and the plate spring seal has a structure that accommodates an extension in length and diameter due to thermal expansion. As a result, the inner liner 251 and the inner transition piece 261 may be supported.
The outer liner 252 and the outer transition piece 262 may surround the inner liner 251 and the inner transition piece 261, respectively. Compressed air may penetrate into an annular space between the inner liner 251 and the outer liner 252 and an annular space between the inner transition piece 261 and the outer transition piece 262 through the compressed air inlet hole H (the illustrated aspect includes a plurality of holes H). The inner liner 251 and the inner transition piece 261 may be cooled by the compressed air penetrating into the annular spaces.
Meanwhile, the high-temperature and high-pressure combustion gas produced in the combustor 200 is supplied to the turbine 130 through the liner 250 and the transition piece 260. In the turbine 130, the combustion gas applies impingement or reaction force to the turbine blades radially disposed on the rotary shaft of the turbine 130 while expanding adiabatically, so that the thermal energy of the combustion gas is converted into mechanical energy for rotating the rotary shaft. Some of the mechanical energy obtained from the turbine 130 is supplied as energy required to compress air in the compressor, and the rest is utilized as effective energy, such as for driving the power generator to generate electric power.
Referring back to
Turning to
Referring to
The nozzle 300 may also include one or more outer nozzles 318 arranged radially around the central nozzle 310. For example, the illustrated nozzle 300 includes five outer nozzles 318 that may be independently operated based upon a desired power output from the gas turbine engine 100 (e.g., operating two of the outer nozzles 318 may produce 40% load output). Each of the outer nozzles 318 may include a housing 320 that is coupled to one or more of an adjacent housing or the central nozzle 310. Each of the outer nozzles 318 may also include a fuel supply tube 322. The fuel supply tube 322 may extend upstream from the housing 320 to the end cover 231 to receive fuel from a fuel source. Contained within the housing 320 is a plurality of mixing tubes 324. Each of the mixing tubes 324 includes a first opening 326 (best seen in
Referring to
The one or more fluid vortex generators 332 may comprise wedge-shaped members. As illustrated in
Fuel is then introduced into the mixing tube 324 through the intermediate openings 330, the fuel encounters the swirling or turbulent flow of compressed air 360. The swirling or turbulent air 360 acts on the introduced fuel and causes the introduced fuel to be thoroughly mixed with the compressed air so that the fuel/air mixture will be combusted in a more uniform manner.
As should be appreciated and as will be discussed below the fluid vortex generators illustrated herein (
Referring then to
Referring still to
In recent years, it is recommended to use hydrogen fuel or fuel containing hydrogen to inhibit or reduce the emission of carbon dioxide given that hydrogen is a carbon-free fuel. However, while use of hydrogen fuel or fuel containing hydrogen enables the desired effect of inhibiting reducing emission of carbon dioxide, problems can occur owing to the high combustion rate of hydrogen. That is, when hydrogen is introduced as a fuel, if the hydrogen is not thoroughly mixed with the compressed air generated by the compressor, the hydrogen can ignite prematurely or separately from the compressed air causing flashback in the nozzles or fuel/air mixing tubes. Such flashbacks can damage components of the gas turbine engine, and such flashbacks can lead to inefficient gas turbine engine operation owing to inconsistent energy to the gas turbine engine system. Another problem owing to inefficient hydrogen fuel combustion is the production of nitrogen oxides (NOx). When air is heated to high temperatures, nitrogen which naturally occurs in air, combines with oxygen to produce NOx. Combusting hydrogen fuels mixed with compressed air when the hydrogen fuel is not properly mixed with the compressed air prior to combustion can result in over heating the compressed air which, in turn, can result in production of undesired levels of NOx.
As will be discussed below, by controlling the size, shape, and orientation of the fluid vortex generators 332, the relative spacing of the fuel input from the air input in the mixing tube 324, hydrogen fuel (e.g, hydrogen, hydrogen blends, fuels containing hydrogen) can be mixed with compressed air in a manner that allows for efficient combustion of the fuels for improved gas turbine operation and that inhibits production of undesired byproducts (e.g., CO2, NOx, etc.).
In the illustrated aspect shown in
Each of these parameters for the fluid vortex generators 332 affects the swirling effect applied to compressed air as it passes over the fluid vortex generators 332 through the mixing tube 324. Thus, each of these parameters may be modified to produce desired impact on the flow of compressed air passing through the mixing tube 324 for optimizing mixture of compressed air with fuel (e.g., hydrogen).
According to one embodiment, the distance (e.g., distance 406) of the intermediate openings 330 from the first opening 326 of the mixing tube 324 may be set at a minimum of one times (1D) the diameter (e.g., diameter 402) of the first opening 326 of the mixing tube 324 to a maximum of two times (2D) the diameter (e.g., diameter 402). That is, the distance 406 on the core 400 is proportional to the diameter 402 of the longitudinal end 408 of the core 400.
The height of the fluid vortex generators 332 is also proportional to the diameter of the mixing tube 324. In aspects, the height may be set at a minimum of 0.1 times (0.1D) the diameter (e.g., diameter 402) of the first opening 326 of the mixing tube 324 to a maximum of 0.3 times (0.3D) the diameter (e.g., diameter 402) of the first opening 326 of the mixing tube 324.
The wedge angle may be set at a minimum of fifteen (15) degrees to a maximum of forty-five (45) degrees relative to the direction of air flow. The angle of attack may be set at a minimum of zero (0) degrees to a maximum of forty-five (45) degrees. The clocking configuration of the intermediate openings 330 may be set at a minimum of zero (0) degrees to a maximum of ninety (90) degrees relative to the fluid vortex generators 332 (e.g., the intermediate openings 330 may be circumferentially aligned with the fluid vortex generators 332 in an axial direction, or may be offset therefrom up to ninety (90) degrees).
In addition, the velocity of compressed air through the mixing tube 324 may be set at a minimum of 80 meters per second to a maximum of 120 meters per second, in accordance with some embodiments. As should be appreciated, these configuration parameters for the fluid vortex generators 332, and intermediate openings 330 are example parameters for the mixing tube 324, but these parameters are not limiting of many different parameters that may be set to achieve desired swirling of compressed air by the fluid vortex generators 332 to thoroughly mix entering compressed air with entering fuel.
While one or more exemplary embodiments have been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that various variations and modifications may be made by adding, changing, or removing components without departing from the spirit and scope of the disclosure as defined in the appended claims, and these variations and modifications fall within the spirit and scope of the disclosure as defined in the appended claims.
