PREMIXER INJECTOR ASSEMBLY IN GAS TURBINE ENGINE

Abstract

A premixer injector assembly in a gas turbine engine includes at least one premixer injector.The premixer injector includes a fuel tube having a fuel feed passage confined by an outer surface, a plurality of fins coupled to the fuel tube extending from the outer surface of the fuel feed passage, the outer surface of the fuel feed passage between adjacent fins having a concave shape, a plurality of mixing channels defined between adjacent fins, a plurality of fuel injection openings arranged along the fuel feed passage to direct fuel from the fuel feed passage to the mixing channels, an air tube coupled to the fuel tube to at least partially enclose the fuel tube, and a plurality of air injection openings arranged along the air tube to inject air into the mixing channels.

Description

PREMIXER INJECTOR ASSEMBLY IN GAS TURBINE ENGINE BACKGROUND OF THE INVENTION An industrial gas turbine engine typically includes a compressor section, a turbine section, and a combustion section located between them. The compressor section comprises multiple stages of rotating compressor vanes and stationary compressor blades. The combustion section typically includes multiple combustors. The turbine section comprises multiple stages of rotating turbine blades and stationary turbine blades. The gas turbine engine may include premix injectors to provide an air-fuel mixture to the combustors. These premix injectors must effectively mix the air and fuel. They may also need to dampen thermoacoustic instability. Designing premix injectors is a challenging task that requires balancing various design criteria. BRIEF DESCRIPTION OF THE INVENTION In a construction, an injector premixer assembly in a gas turbine engine, the injector premixer assembly comprises: a mixing injector having a first end and a second end opposite the first end; a fuel tube having a first plate disposed at the first end, a second plate disposed at the second end, and a fuel feed passage confined by an outer surface and extending between the first plate and the second plate; a plurality of fins coupled to the fuel tube, the plurality of fins extending from the outer surface of the fuel feed passage and extending between the first plate and the second plate, the outer surface of the fuel feed passage between adjacent fins of the plurality of fins comprising a concave shape; a plurality of mixing channels, each mixing channel of the plurality of fins;a plurality of fuel injection openings arranged along the fuel supply passage between the first plate and the second plate to direct fuel from the fuel supply passage to at least one mixing channel of the plurality of mixing channels; an air tube coupled to the fuel tube to at least partially confine the fuel tube between the first end and the second end; and a plurality of air injection openings arranged along the air tube to inject air into at least one mixing channel of the plurality of mixing channels. In another construction, a premixer injector assembly in a gas turbine engine, the premixer injector assembly comprises: a plurality of mixing injectors assembled in at least one block, each premixer injector of the plurality of premixer injectors comprising: a fuel tube having a first plate, a second plate and a fuel feed tube confined by an outer surface and extending between the first plate and the second plate;a plurality of fins attached to the fuel tube, the plurality of fins extending from the outer surface of the fuel feed passage and extending between the first plate and the second plate, the outer surface of the fuel feed passage between adjacent fins of the plurality of fins comprising a concave shape, wherein at least a portion of each fin of the plurality of fins is twisted along the fuel tube forming a helical shape; a plurality of mixing channels, each mixing channel of the plurality of fins; a plurality of fuel injection openings arranged along the fuel feed passage between the first plate and the second plate for directing fuel from the fuel feed passage to at least one mixing channel of the plurality of mixing channels;an air tube coupled to the fuel tube to at least partially confine the fuel tube; and a plurality of air injection openings arranged along the air tube to inject air into at least one mixing channel of the plurality of mixing channels. BRIEF DESCRIPTION OF THE DRAWINGS To easily identify the exposure of any particular item or act, the most significant digit or digits in a reference number refer to the figure number in which that item was first introduced. FIGURE 1 is a longitudinal cross-sectional view of a gas turbine engine taken along a plane containing a longitudinal axis or centerline. FIGURE 2 illustrates a cross-sectional view of a combustor in a combustion section. FIGURE 3 illustrates a perspective view of a premixer injector assembly. FIGURE 4 illustrates a perspective view of a premixer injector. FIGURE 5 illustrates a cross-sectional view of a fuel pipe according to FIGURE 4. FIGURE 6 illustrates a cross-sectional view of a premixing injector according to FIGURE 4. FIGURE 7 illustrates a perspective view of a premixer injector according to one modality. FIGURE 8 illustrates a cross-sectional view of a premixing injector according to FIGURE 7. FIGURE 9 illustrates a cross-sectional view of a premixer injector according to one modality. FIGURE 10 illustrates a cross-sectional view of a premixer injector according to one modality. FIGURE 11 illustrates a cross-sectional view of a premixer injector according to one modality. FIGURE 12 illustrates a cross-sectional view of a premixer injector according to one modality. DETAILED DESCRIPTION OF THE INVENTION Before any of the embodiments of the invention are explained in detail, it should be understood that the invention is not limited in its application to the construction details and arrangement of components set forth in this description or illustrated in the drawings that follow. The invention is capable of other embodiments and can be practiced or carried out in various ways. It should also be understood that the phraseology and terminology used herein is for descriptive purposes and should not be considered limiting. Various technologies belonging to the systems and methods described below are referenced to the drawings, where similar reference numbers represent similar elements throughout this document. The drawings shown below, and the various methods used to describe the principles of this disclosure in this patent document, are for illustrative purposes only and should not be considered in any way as limiting the scope of the disclosure. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged apparatus. It should be understood that the functionality described as being performed by certain elements of the system can be performed by multiple elements. Similarly, for example, one element can be configured to perform the functionality described as being performed by multiple elements.The numerous innovative teachings of this application will be described with reference to non-limiting exemplary modalities. It should also be considered that the words or phrases used in this document should be interpreted broadly, unless expressly limited in certain examples. For instance, the terms “including,” “having,” and “comprising,” as well as derivatives thereof, mean inclusion without limitation. The singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the term “and / or” as used in this document refers to and encompasses each and every possible combination of one or more of the associated listed elements. The term “or” is inclusive, meaning both, unless the context clearly indicates otherwise.The phrases “associated with” and “associated with,” as well as derivatives thereof, can mean that it includes, that they are included within, interconnected with, that they contain, that they are contained within, connected to or with, coupled to or with, communicate with, cooperate with, interposed, juxtaposed, approximates, is surrounded by or with, has, has a property of, or similar. Furthermore, while multiple modalities or constructions may be described in this document, any features, methods, stages, components, etc., described in relation to one modality are equally applicable to other modalities not, conversely, to a specific statement. Also, although the terms “first,” “second,” “third,” and “fourth” may be used in this document to refer to various items, information, functions, or acts, these items, information, functions, or acts should not be limited by these terms. Furthermore, these numerical adjectives are used to distinguish different items, information, functions, or actions from one another. For example, a first item, information, function, or act may be referred to as a second item, information, function, or act, and similarly, a second item, information, function, or act may be referred to as a first item, information, function, or act, without departing from the scope of this disclosure. Furthermore, the term “adjacent to” can mean that an element is relatively close to, but not in contact with, an additional element, or that the element is in contact with the additional portion, unless the context clearly indicates otherwise. Additionally, the phrase “based on” is intended to mean “based, at least in part, on” unless clearly stated otherwise. The terms “approximately” or “substantially,” or similar terms, are intended to cover variations in a value that are within normal manufacturing tolerances in the industry for that dimension. If no industry standard is available, a 20 percent variation will fall within the meaning of these terms, unless otherwise stated. Figure 1 illustrates an example of a gas turbine engine 100 comprising a compressor section 102, a combustion section 104, and a turbine section 106 arranged along a central shaft 112. The compressor section 102 includes a plurality of compressor stages 114. Each compressor stage 114 includes a set of rotating vanes 116 and a set of stationary vanes 118 or adjustable guide vanes. A rotor 134 supports the rotating vanes 116 for rotation about the central shaft 112 during operation. In some constructions, a one-piece rotor 134 extends the length of the gas turbine engine 100 and is supported for rotation by a bearing at either end.In other constructions, the 134 rotor is assembled from many separate rotor assemblies that are attached to any of these or that may include multiple disc sections that are joined via one or a plurality of bolts. The compressor section 102 is in fluid communication with an inlet section 108 to allow the gas turbine engine 100 to draw atmospheric air into the compressor section 102. During the operation of the gas turbine engine 100, the compressor section 102 draws atmospheric air and compresses that air for supply to the combustion section 104. The illustrated compressor section 102 is an example of a compressor section 102, other arrangements and designs being possible. In the illustrated construction, the combustion section 104 includes a plurality of separate combustors 120, each operating to mix a fuel flow with the compressed air from the compressor section 102 and burn that air-fuel mixture to produce a high-temperature, high-pressure combustion gas flow or exhaust gases 122. Of course, many arrangements of the fuel section 104 are possible. The turbine section 106 includes a plurality of turbine stages 124, with each turbine stage 124 comprising a number of rotating turbine blades 126 and a number of stationary turbine vanes 128. The turbine stages 124 are arranged to receive the exhaust gas 122 from the combustion section 104 at the turbine inlet 130 and to expand that gas to convert thermal energy and pressure into rotary or mechanical work. The turbine section 106 is connected to the compressor section 102 to drive the compressor section 102. For gas turbine engines 100 used for power generation or as power-generating machines, the turbine section 106 is also connected to a generator pump or other device to be driven. As with the compressor section 102, other designs and arrangements of the turbine section 106 are possible. An outlet portion 110 is located downstream of turbine section 106 and is arranged to receive the expanded flow of outlet gas 122 from the final turbine stage 124 in turbine section 106. The outlet portion 110 is arranged to efficiently direct the outlet gas 122 away from turbine section 106 to ensure the efficient operation of turbine section 106. Many variations and design differences are possible for the outlet portion 110. As such, the outlet portion 110 illustrated here is only one example of these variations. A control system 132 is coupled to the gas turbine engine 100 and operates to monitor various operating parameters and control various operations of the gas turbine engine 100. In preferred configurations, the control system 132 is usually microprocessor-based and includes memory and data storage devices for collecting, analyzing, and storing data. Furthermore, the control system 132 provides output data to various devices, including monitors, printers, indicators, and the like, allowing users to interface with the control system 132 and provide inputs or adjustments. In the example of a power generation system, a user can input a power output setting, and the control system 132 can adjust the various control inputs to achieve efficient power output. The 132 control system can control various operating parameters, including but not limited to variable inlet guide vane positions, fuel flow rates and pressures, engine speed, valve positions, generator load, and generator excitation. Of course, other applications may have fewer or more easily controllable devices. The 132 control system also monitors various parameters to ensure the 100 gas turbine engine is operating properly. Some of the monitored parameters include inlet air temperature, compressor outlet temperature and pressure, combustor outlet temperature, fuel flow rate, generator power output, bearing temperature, and similar parameters. Many of these measurements are displayed to the user and recorded for later review should such a review be necessary. Figure 2 illustrates a cross-sectional view of a combustor 200. The combustor 200 includes a housing 202, an inlet 204, a premixer injector assembly 206, a combustor liner 208 defining a combustor chamber 210, and a chamber outlet 212. The housing 202 confines the premixer injector assembly 206 and the combustor liner 208. The premixer injector assembly 206 is arranged in upward flow from the combustor chamber 210. The mixing injector assembly 206 includes a plurality of premixing injectors 400. The premixing injectors 400 are assembled in at least one block. As illustrated in FIGURE 2, a number of premixing injectors 400 are assembled in a primary block 214, and a remaining number of premixing injectors 400 are assembled in a secondary block 216. The primary block 214 is arranged upstream of the secondary block 216. The premixing injectors 400 are not parallel to each other. The premixing injectors 400 are angled to the general flow direction indicated by the arrow. It is understood that the 400 premixer injectors can be assembled in the primary block 214 and the secondary block 216 in other configurations, such as parallel to each other, or perpendicular to the primary block 214 or perpendicular to the secondary block 216. When the gas turbine engine 100 is running, air from the compressor section 102 enters the combustor 200 through inlet 204 and is injected into the premixer injectors 400. Fuel from a fuel source (not shown) enters the premixer injectors 400. The air and fuel are mixed in the premixer injectors 400. The air-fuel mixture enters the combustor chamber 210, as indicated by the line with the arrow, and is ignited in the combustor chamber 210. The ignited air-fuel mixture exits the combustor chamber 210 through the chamber outlet 212 and enters the turbine section 106. Figure 3 illustrates a perspective view of a premixer injector assembly 300. The premixer injector assembly 300 includes a plurality of premixer injectors 400. As illustrated in Figure 3, the plurality of premixer injectors 400 is assembled in a single block 302. The plurality of premixer injectors 400 is parallel to each other. The plurality of premixer injectors 400 is perpendicular to each other in a single block 302. The plurality of premixer injectors 400 is arranged in the single block 302 and separated from each other. The plurality of premixer injectors 400 may be equally separated from each other. The single block 302 has a circular shape. It is understood that the single block 302 may have other geometric shapes, such as oval, square, rectangular, etc.It is also understood that the plurality of premixer injectors 400 can be assembled in the single block 302 in other configurations, such as not being parallel to each other or not being perpendicular to the single block 302, etc. The premixer injector assembly 300 shown in FIGURE 3 is easy to assemble. FIGURE 4 illustrates a perspective view of one of the 400 premixing injectors suitable for use in the arrangements illustrated in FIGURES 2-3. The premixer injector 400 has a first end 406 and a second end 408 opposite the first end 406. The premixer injector 400 includes an air tube 402 and a fuel tube 500. The air tube 402 and the fuel tube 500 extend between the first end 406 and the second end 408. The air tube 402 at least partially encloses the fuel tube 500. A portion of the fuel tube 500 extends outside the air tube 402 at the second end 408. In other embodiments, the fuel tube 500 may also be recessed within the air tube 402. The air tube 402 and the fuel tube 500 may be manufactured as two separate components. The air tube 402 and the fuel tube 500 are assembled together to form the premixer injector 400.The air tube 402 and the fuel tube 500 can be manufactured as a single component that makes up the premixer injector 400. Air tube 402 includes at least one air injection opening 404 arranged along its length and extending between the first end 406 and the second end 408. The air injection opening 404 pierces the air tube 402. The air injection opening 404 has a helical shape. The air injection opening 404 is twisted between the first end 406 and the second end 408, forming the helical shape. As shown in Figure 4, the air injection opening 404 has a uniform width between the first end 406 and the second end 408. However, the air injection openings may be narrower toward the first end 406 and narrower toward the second end 408, or vice versa. The air tube 402 may include a plurality of air injection openings 404. As illustrated in FIGURE 4, the air tube 402 includes four air injection openings 404. The air injection openings 404 are arranged in the air tube 402 and are equally spaced from each other. Each of the four air injection openings 404 is helically shaped and twisted between the first end 406 and the second end 408. The air injection openings 404 are parallel to each other. However, the air injection openings 404 may not be parallel to each other. The 402 air tube can include any number of 404 air injection openings, for example, two 404 air injection openings, three 404 air injection openings, five 404 air injection openings, six 404 air injection openings, etc. Figure 5 illustrates a cutaway view of a fuel tube 500 according to Figure 4. The fuel tube 500 includes a first plate 502 disposed at the first end 406, a second plate 504 disposed at the second end 408, and a fuel supply passage 506 extending between the first plate 502 and the second plate 504. The fuel supply passage 506 is confined by an outer surface 514. The first plate 502 has an orifice 516 for supplying fuel from a fuel source (not shown) to the fuel supply passage 506. The fuel tube 500 includes a plurality of fuel injection openings 508 arranged along the fuel feed passage 506 between the first plate 502 and the second plate 504. The fuel injection openings 508 pierce the outer surface 514 of the fuel feed passage 506 to direct fuel out of the fuel feed passage 506. The fuel tube 500 includes at least one fin 510 attached to the fuel tube 500. The fin 510 extends outward from the outer surface 514 of the fuel feed passage 506. The fin 510 extends along the fuel tube 500 between the first plate 502 and the second plate 504. The fin 510 is helically shaped. The helically shaped fin 510 is twisted between the first plate 502 and the second plate 504. The fuel tube 500 may include a plurality of fins 510. As illustrated in the cutaway view of FIGURE 5, the fuel tube 500 includes four fins 510 (three fins 510 are visible in FIGURE 5, four fins 510 are shown in FIGURE 6). The four fins 510 are arranged on the outer surface 514 of the fuel feed passage 506 and are equally spaced. Each of the four fins 510 is helically shaped and twisted between the first plate 502 and the second plate 504. The four fins 510 are parallel to each other. However, the fins 510 may not be parallel to each other. The 500 fuel tube can include any number of 510 fins, for example, two 510 fins, three 510 fins, five 510 fins, or six 510 fins, etc. A mixing channel 512 is defined between a pair of adjacent fins 510. The outer surface 514 of the fuel feed passage 506 between adjacent fins 510 has a concave shape. FIGURE 6 illustrates a cutaway view of a premixer injector 400 according to FIGURE 4. The air tube 402 was cut to illustrate the fuel tube 500 arranged in the air tube 402. The fuel tube 500 includes four fins 510, each extending from the outer surface 514 of the fuel supply passage 506 to the air tube 402. Four mixing channels 512 are defined between four pairs of adjacent fins 510 and between the air tube 402 and the outer surface 514 of the fuel supply passage 506. The four mixing channels 512 are independent of each other and are separated by fins 510. The number of fins 510 and the number of mixing channels 512 are designed to meet the requirements of the particular engine in which they are used. In preferred constructions, the number of fins 510 matches the number of air injection openings 404, and the helical twist of the fins 510 matches that of the air injection openings 404. Of course, other arrangements are possible. When the gas turbine engine 100 is operating, air from the compressor section 102 enters at least one mixing channel 512 through the air injection opening 404. Fuel from the fuel feed passage 506 is directed to at least one mixing channel 512 through the fuel injection openings 508. The air and fuel are mixed in the mixing channel 512 and swirl along the helical shape of the fins 510. A swirling flow of the air-fuel mixture is induced at the second end 408 of the premixer injector 400. The strength of the swirling flow of the air-fuel mixture is defined by a tangential component of the velocity at which the air-fuel mixture exits the premixer injector 400. The strength of the swirling flow of the air-fuel mixture is controlled by an angle 512 fin propeller torsion.The swirling flow of the fuel and air mixture is discharged directly into the combustor chamber 210. When the gas turbine engine 100 is running, air may be fed unevenly to the premix injector 400. For example, air may preferentially arrive from the top of the air tube 402. The premix injector 400 is designed so that, for a given twist length of the air injection openings 404 along the air tube 402, if the twist angle of the air injection openings 404 is sufficiently high, all the mixing channels 512 are exposed to the top and below the feed side of the air injection openings 404. In this way, all the mixing channels 512 receive the same amount of air. The propeller parameters are designed to meet the swirl flow requirement of the air-fuel mixture at the combustor chamber inlet 210. The propeller parameters include propeller slope, propeller twist angle, etc. For example, the twist angle of the fin 510 between the first plate 502 and the second plate 504 can be 90°, 180°, 360°, 450°, or any other suitable angle, etc. A fin twist angle of 510 may be the same as a fin twist angle of 404. A fin slope of 510 may be the same as a fin slope of 404. It is understood that a fin twist angle of 510 may be different from a fin twist angle of 404. It is also understood that a fin slope of 510 may be different from a fin slope of 404.The fin 510 shown in FIGURE 6 has a non-zero twist angle between the first plate 502 and the second plate 504, resulting in a helical fin 510 between the first plate 502 and the second plate 504. However, the twist angle of the fin can be zero, resulting in a straight fin 510 between the first plate 502 and the second plate 504. FIGURE 7 illustrates a perspective view of another 700 premix injector. The 700 premix injector can be used instead of the 400 premix injector or can be used in conjunction with the 400 premix injector. The premixer injector 700 includes an air tube 402 and a fuel tube 500. The air tube 402 at least partially encloses the fuel tube 500. The premixer injector 700 has at least one air injection opening 404 arranged along the air tube 402 and extending between the first end 406 and the second end 408. The air injection opening 404 is straight between the first end 406 and the second end 408. Air tube 402 may include a plurality of air injection openings 404. As illustrated in FIGURE 7, air tube 402 includes four air injection openings 404 arranged along the length of the air tube 402 and extending between the first end 406 and the second end 408. The air injection openings 404 are arranged in the air tube 402 and are equally spaced. Each of the four air injection openings 404 is straight between the first end 406 and the second end 408. It is understood that air tube 402 may include any number of air injection openings 404, for example, two air injection openings 404, three air injection openings 404, five air injection openings 404, six air injection openings 404, etc. FIGURE 8 illustrates a cutaway view of a premixer injector 700 according to FIGURE 7. The fuel tube 500 includes a plurality of fuel injection openings 508 arranged along the fuel feed passage 506 between the first plate 502 and the second plate 504. The fuel injection openings 508 pierce the outer surface 514 of the fuel feed passage 506 to direct fuel out of the fuel feed passage 506. The fuel tube 500 includes at least one fin 510 attached to the fuel tube 500. The fin 510 extends outward from the outer surface 514 of the fuel supply passage 506. The fin 510 extends between the first plate 502 and the second plate 504. The fin 510 is straight between the first plate 502 and an intermediate point 802. The fin 510 is twisted between the intermediate point 802 and the second plate 504, thereby forming a helical shape. The intermediate point 802 is defined between the first plate 502 and the second plate 504. The intermediate point 802 may be located near the second plate 504. The propeller parameters are designed to meet the swirl flow requirement of the air-fuel mixture at the combustor inlet 200. For example, the twist angle of the fin 510 between the midpoint 802 and the second plate 504 can be 45°, 90°, 180°, 270° or any suitable angles, etc. The fuel tube 500 may include a plurality of fins 510. As illustrated in the cutaway view of FIGURE 8, the fuel tube 500 includes four fins 510. The four fins 510 are arranged on the outer surface 514 of the fuel feed passage 506 and are equally spaced from each other. Each of the four fins 510 is straight between the first plate 502 and the midpoint 802 and twisted between the midpoint 802 and the second plate 504. It is understood that the fuel tube 500 may include any number of fins 510, for example, two fins 510, three fins 510, five fins 510, or six fins 510, etc. A mixing channel 512 is defined between a pair of adjacent fins 510. The outer surface between adjacent fins 510 has a concave shape. The concave shape includes a continuous curve that intersects tangentially with each fin 510 of the adjacent fins 510 that define the mixing channel 512. In another construction, the concave shape includes a single continuous curve that extends from one fin tip 510 to the tip of an adjacent fin 510 (e.g., a hyperbola). As illustrated in the cutaway view of FIGURE 8, four mixing channels 512 are defined between four pairs of adjacent fins 510 and between the air tube 402 and the outer surface 514 of the fuel feed passage 506. The four mixing channels 512 are independent of each other and are separated by fins 510.The number of fins 510 and the number of mixing channels 512 are designed to meet the mixture requirement at the inlet of the combustor chamber 210. FIGURE 9 illustrates a cross-sectional view of a 900 premixer injector. The arrangement of the 900 premixer injector illustrated in FIGURE 9 can be used in the 400 premixer injector or the 700 premixer injector. Each air injection opening 404 is positioned between a pair of adjacent fins 510. The injection opening 404 is positioned along the center of one of the mixing channels 512 defined by the pair of adjacent fins 510. However, the air injection opening 404 may be positioned off-center from the mixing channel 512. For example, the air injection opening 404 may be positioned along the edge of a fin 510 of the pair of adjacent fins 510. Figure 9 shows that the air injection opening 404 has a uniform width from an outer surface of the air tube 402 to an inner surface of the air tube 402. However, the air injection opening 404 may have a fillet on the outer surface of the air tube 402. The air injection opening 404 may be tapered from the outer surface of the air tube 402 to the inner surface of the air tube 402.Air enters each mixing channel 512 through an air injection opening 404. Fuel enters each mixing channel 512 of the fuel supply passage 506 through two fuel injection openings 508. As illustrated in FIGURE 9, the fuel injection openings 508 are drilled through the outer surface 514 of the fuel supply passage 506 in radial directions. However, it is understood that other arrangements are possible. Air strikes the outer surface 514 of the fuel feed passage 506 and creates a pair of counter-rotating vortices in each mixing channel 512. The pair of counter-rotating vortices mixes with the fuel in each mixing channel 512. The air and fuel are effectively mixed in the mixing channel 512. The air-fuel mixture is discharged directly into the combustor chamber 210 with a swirl induced by the helical fins 510. A pair of counter-rotating vortices is created in each mixing channel 512. The outer surface 514 of the fuel feed passage 506, where the air impinges, has a concave shape. The concave incident surface allows for a stable flow configuration of the pair of counter-rotating vortices. FIGURE 10 illustrates a cross-sectional view of a 1000 premix injector. The arrangement of the 1000 premix injector illustrated in FIGURE 10 can be used in the 400 premix injector or the 700 premix injector. Each air injection opening 404 is positioned along each fin 510 and bisected by each fin 510. Air enters two adjacent mixing channels 512 through a bisected air injection opening 404. Of course, when this arrangement is in use, the air injection openings 404 are somewhat larger than those illustrated in the arrangement of Figure 9, and the fin 510 effectively blocks a portion of the air injection opening 404. Fuel enters each mixing channel 512 of the fuel feed passage 506 through at least one fuel injection opening 508. A pair of counter-rotating vortices is created in each mixing channel 512. Figure 10 shows that each air injection opening 404 is positioned along each fin 510 and bisected by each fin 510.However, it should be understood that each air injection opening 404 is positioned along an alternate fin 510 and bisected by the alternate fin 510. FIGURE 11 illustrates a cross-sectional view of a premixer injector 1100. The arrangement of the premixer injector 1100 illustrated in FIGURE 11 can be used in the premixer injector 400 or the premixer injector 700. Each air injection opening 404 is positioned between a pair of adjacent fins 512. The air injection opening 404 is positioned along the center of each mixing channel 512, defined by the pair of adjacent fins 510. However, the injection opening 404 may be positioned off-center from the mixing channel 512. Air enters each mixing channel 512 through an air injection opening 404. Fuel enters each mixing channel 512 from the fuel supply passage 506 through at least one fuel injection opening 508. A pair of counter-rotating vortices is created in each mixing channel 512. FIGURE 12 illustrates a cross-sectional view of a 1200 premixer injector. The arrangement of the 1200 premixer injector can be used in the 400 premixer injector or the 700 premixer injector. Each air injection opening 404 is positioned along each fin 510 and bisected by each fin 510. Air enters two adjacent mixing channels 512 through a bisected air injection opening 404. Fuel enters each mixing channel 512 from the fuel feed passage 506 through two fuel injection openings 508. A pair of counter-rotating vortices is created in each mixing channel 512. The configurations of the 900, 1000, 1100, or 1200 premix injector can be combined with different configurations of these. The 400 or 700 premix injector can be used with any configuration of the 900, 1000, 1100, or 1200 premix injector, or any other configuration thereof. The 400 or 700 premix injectors effectively and rapidly mix the upward-flowing air and fuel from the combustor chamber 210 by means of a pair of stable, counter-rotating vortices created in each mixing channel 512. This pair of stable, counter-rotating vortices is created by the concave outer surface 514 of the fuel feed passage 506. The efficiently mixed air and fuel provide a uniform mixture composition to the combustor chamber 210. The 400 or 700 premix injector is robust against uneven air feeds, ensuring uniform mixing of the composition throughout the mixing channels 512. This uniform air-fuel composition reduces nitrogen oxide emissions from the combustor chamber 210. The 400 or 700 premix injectors induce a swirling flow of the air-fuel mixture at the second end 408 of the 400 or 700 premix injector to stabilize the flames in the combustor chamber 210. The swirling flow of the air-fuel mixture is induced by helically shaped fins 510, which can eliminate the need to position swirling bodies protruding downward from the fuel injection openings 508. The 400 or 700 premix injector provides a mixing channel. The 512 has an aerodynamic property that reduces low-speed zones in the 512 mixing channel due to boundary layers, wakes from protruding eddy-forming bodies, etc., thus reducing the occurrence of flashbacks and auto-ignition. The 400 or 700 premix injector provides a robust, anchored flame with vortex breaking for flame stability and reduction capability. The air injection openings 404 and the fuel injection openings 508 of the premixer injector 400 or premixer injector 700 are arranged and distributed along the premixer injector 400 or premixer injector 700. Air progressively enters the mixing channels 512 through the air injection openings 404 to dampen fluctuations in the fuel-air ratio at the outlet of the premixer injector 400 or premixer injector 700, which reduces thermoacoustic instability in the combustion chamber 210. In this way, fuel-air ratio (FAR) dampening is achieved. The 400 or 700 premix injector can use either gaseous or liquid fuel. The 400 or 700 premix injector can be fitted with a diesel rail for direct injection of liquid fuel into the 210 combustor chamber, enabling dual dry-liquid fuel operation.The premixer injector 400 or premixer injector 700 can accommodate a variety of liquid fuel injectors, such as direct downflow jets across the premixer injector 400 or premixer injector 700, or jets near the outlet of the premixer injector 400 or premixer injector 700 to conceal the liquid injection orifices from the flames to reduce radiation heating or coking, or pressure swirl atomizers, or any other configurations small enough to be integrated within the tip of the premixer injector 400 or premixer injector 700. Liquid fuel can be injected into a portion of the fuel tube 500 in an upward flow to obtain premixed flames directly into the combustor chamber 210. The 400 or 700 premix injector is easy to manufacture and assemble. It can be scaled numerically, geometrically, or both for use in different gas turbine engines, creating a shared component base and reducing costs. Although an exemplary form of the present disclosure has been described in detail, those experts in the technique will understand that various changes, substitutions, variations, and improvements disclosed in this document can be made without departing from the spirit and scope of the disclosure in its broadest form. None of the descriptions in this application should be read as implying that any particular element, step, act, or function is an essential element that must be included within the scope of the claim: the scope of the patentable subject matter is defined only by the permitted claims. Furthermore, none of these claims purports to invoke a claimed construction of means plus function unless the exact words “means to” are followed by a participle.

Claims

1. A premixer injector assembly in a gas turbine engine, the premixer injector assembly is characterized in that it comprises: the premixer injector having a first end and a second end opposite the first end; a fuel tube having a first plate disposed at the first end, a second plate disposed at the second end, and a fuel feed passage confined by an outer surface and extending between the first plate and the second plate; a plurality of fins coupled to the fuel tube, the plurality of fins extending from the outer surface of the fuel feed passage and extending between the first plate and the second plate, the outer surface of the fuel feed passage between adjacent fins of the plurality of fins comprising a concave shape;a plurality of mixing channels, each mixing channel of the plurality of mixing channels being defined between a pair of adjacent fins of the plurality of fins; a plurality of fuel injection openings arranged along the fuel feed passage between the first plate and the second plate to direct fuel from the fuel feed passage to at least one mixing channel of the plurality of mixing channels; an air tube coupled to the fuel tube to at least partially confine the fuel tube between the first end and the second end; and a plurality of air injection openings arranged along the air tube to inject air into at least one mixing channel of the plurality of mixing channels.

2. The premixer injector assembly according to claim 1, characterized in that the concave shape comprises a continuous curve that intersects each fin tangentially with the adjacent fins.

3. The premixer injector assembly according to claim 1, characterized in that each fin of the plurality of fins is twisted between the first plate and the second plate.

4. The premixer injector assembly according to claim 1, characterized in that each air injection opening of the plurality of air injection openings is twisted between the first end and the second end.

5. The premixer injector assembly according to claim 1, characterized in that each fin of the plurality of fins comprises a straight shape between the first plate to an intermediate point and is twisted between the intermediate point and the second plate.

6. The premixer injector assembly according to claim 1, characterized in that each air injection opening of the plurality of injection openings is twisted between the first end and the second end.

7. The premixer injector assembly according to claim 1, characterized in that each air injection opening of the plurality of air injection openings is positioned between two adjacent fins of the plurality of fins.

8. The premixer injector assembly according to claim 1, characterized in that each air injection opening of the plurality of injection openings is positioned along a fin of the plurality of fins.

9. The premixer injector assembly according to claim 1, characterized in that the plurality of fuel injection openings directs fuel to each mixing channel of the plurality of mixing channels, and wherein the plurality of air injection openings injects air into each mixing channel of the plurality of mixing channels.

10. A premixer injector assembly in a gas turbine engine, the premixer injector assembly is characterized in that it comprises: a plurality of premixer injectors assembled in at least one block, each premixer injector of the plurality of premixer injectors comprising: a fuel tube having a first plate, a second plate, and a fuel feed passage confined by an outer surface and extending between the first plate and the second plate;a plurality of fins coupled to the fuel tube, the plurality of fins extending from the outer surface of the fuel feed passage and extending between the first plate and the second plate, the outer surface of the fuel feed passage between adjacent fins of the plurality of fins comprising a concave shape, wherein at least a portion of each fin of the plurality of fins is twisted along the fuel tube forming a helical shape; a plurality of mixing channels, each mixing channel of the plurality of mixing channels being defined between a pair of adjacent fins of the plurality of fins;a plurality of fuel injection openings arranged along the fuel feed passage between the first plate and the second plate to direct fuel from the fuel feed passage to at least one mixing channel of the plurality of mixing channels; an air tube coupled to the fuel tube to at least partially confine the fuel tube; and a plurality of air injection openings arranged along the air tube to inject air into at least one mixing channel of the plurality of mixing channels.

11. The premixer injector assembly according to claim 10, characterized in that the concave shape comprises a continuous curve that intersects each fin tangentially with the adjacent fins.

12. The premixer injector assembly according to claim 10, characterized in that each fin of the plurality of fins is twisted between the first plate and the second plate.

13. The premixer injector assembly according to claim 10, characterized in that each air injection opening of the plurality of air injection openings is twisted between the first end and the second end.

14. The premixer injector assembly according to claim 10, characterized in that each fin of the plurality of fins comprises a straight shape between the first plate to an intermediate point and is twisted between the intermediate point and the second plate.

15. The premixer injector assembly according to claim 10, characterized in that each air injection opening of the plurality of injection openings is twisted between the first end and the second end.

16. The premixer injector assembly according to claim 10, characterized in that each air injection opening of the plurality of air injection openings is positioned between two adjacent fins of the plurality of fins.

17. The premixer injector assembly according to claim 10, characterized in that each air injection opening of the plurality of injection openings is positioned along a fin of the plurality of fins.

18. The premixer injector assembly according to claim 10, characterized in that the plurality of fuel injection openings directs fuel to each mixing channel of the plurality of mixing channels, and wherein the plurality of air injection openings injects air into each mixing channel of the plurality of mixing channels.

19. The premixer injector assembly according to claim 10, characterized in that the plurality of premixer injectors is all assembled in a single block.

20. The premixer injector assembly according to claim 10, characterized in that a first quantity of the plurality of premixer injectors is assembled in a primary block and a second quantity of the plurality of premixer injectors is assembled in a secondary block.

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