The subject matter disclosed herein generally relates to turbine engines and, more particularly, to a fuel injection assembly for use in a turbine engine.
At least some known turbine engines are used in cogeneration facilities and power plants. Such engines may have high specific work and power per unit mass flow requirements. Such turbine engines may include at least one combustor that includes a plurality of fuel nozzles that may be coupled within a combustor. Compressed air flows through and past the nozzles to reach a combustion zone within the combustor. As the air travels through and past the fuel nozzles, fuel is injected into the airflow, and the air and the fuel mix together to produce a fuel-air mixture which is ignited in the combustion zone of the combustor. To increase the operating efficiency, at least some known turbine engines, such as gas turbine engines, operate with increased combustion temperatures. In at least some known gas turbine engines, engine efficiency increases as combustion gas temperatures increase.
However, operating with higher temperatures may also increase the generation of polluting emissions, such as oxides of nitrogen (NOX). In an attempt to reduce the generation of such emissions, at least some known turbine engines include improved combustion system designs. For example, many combustion systems may use premixing technology that includes tube assemblies or micro-mixers that facilitate mixing substances, such as diluents, gases, and/or air with fuel to generate a fuel mixture for combustion. Premixing technology may also include a process known as hydrogen doping. In a hydrogen doping process, hydrogen gas (H2) is mixed with fuel such that a fuel and hydrogen gas mixture is channeled to fuel nozzles. Hydrogen doping has been shown to reduce emission levels and helps reduce a combustor lean blow out (LBO).
However, micro-mixers that are symmetrically installed in a combustor and/or operating with high hydrogen gas levels may induce a screech tone frequency of greater than 1 kHz as the fuel is evenly dispersed within the micro-mixers.
Further, a screech frequency range greater than 1 kHz may result from a flame interaction between adjacent nozzles. Screech excitation induces mechanical vibrations throughout the combustion assembly and associated hardware components. Moreover, vibrations that are induced into the combustion system may increase the wear of the combustor and associated components, and/or may shorten the useful life of the combustion system.
In one embodiment, a fuel injection assembly for use in a turbine engine is provided. The fuel injection assembly includes a plurality of tube assemblies wherein each of the plurality of tube assemblies includes a plurality of tubes. At least one injection system is coupled to at least one tube assembly of the plurality of tube assemblies. The injection system includes a fuel delivery pipe and a fluid supply member coupled to the fuel delivery pipe, wherein the fluid supply member is positioned a predefined distance upstream from the tube assembly and includes at least one first portion having an annular end portion. The annular end portion includes at least one opening for delivering fluid toward the tube assembly for reducing dynamic pressure oscillations and/or the temperature within a combustor during operation of the turbine engine.
In another embodiment, a turbine engine is provided. The turbine engine includes a compressor and a combustion assembly coupled downstream from the compressor. The combustion assembly includes at least one combustor that includes at least one fuel injection assembly. The fuel injection assembly includes a plurality of tube assemblies wherein each of the plurality of tube assemblies includes a plurality of tubes. At least one injection system is coupled to at least one tube assembly of the plurality of tube assemblies. The injection system includes a fuel delivery pipe and a fluid supply member coupled to the fuel delivery pipe, wherein the fluid supply member is positioned a predefined distance upstream from the tube assembly and includes at least one first portion having an annular end portion. The annular end portion includes at least one opening for delivering fluid toward the tube assembly for reducing dynamic pressure oscillations and/or the temperature within the combustor during operation of the turbine engine.
In yet another embodiment, a method of assembling a fuel injection assembly for use with a turbine engine is provided. A plurality of tube assemblies are provided. Each of the plurality of tube assemblies includes a plurality of tubes. At least one injection system is coupled to at least one tube assembly of the plurality of tube assemblies. The injection system includes a fuel delivery pipe and a fluid supply member coupled to the fuel delivery pipe, wherein the fluid supply member includes at least one first portion having an annular end portion, and the annular end portion includes at least one opening for delivering fluid toward the tube assembly for reducing dynamic pressure oscillations and/or the temperature within the combustor during operation of the turbine engine. The fluid supply member is positioned a distance upstream from the tube assembly.
The exemplary apparatus, systems, and methods described herein overcome at least some known disadvantages associated with at least some known combustion systems of turbine engines that induce vibrational energy therein and/or operate with high temperatures. The embodiments described herein provide a fuel injection assembly that may be used with turbine engines to facilitate substantially reducing the dynamic pressure oscillations and/or locally peak temperature within a combustor. The fuel injection assembly includes a plurality of tube assemblies wherein each of the plurality of tube assemblies includes a plurality of tubes. At least one injection system is coupled to at least one tube assembly of the plurality of tube assemblies. The injection system includes a fuel delivery pipe and a fluid supply member coupled to the fuel delivery pipe, wherein the fluid supply member is positioned a distance upstream from the tube assembly. The fluid supply member includes at least one first portion that includes at least one opening for delivering fluid toward the tube assembly for reducing dynamic pressure oscillations and/or locally peak temperature within a combustor during operation of the turbine engine. By delivering the fluid toward at least one of the tube assemblies, flame interactions within the tube assembly and/or between adjacent tube assemblies may be prevented by making uneven fuel distribution and diluting some portion of the fuel in the tube assembly, and the dynamic pressure oscillations and/or locally peak temperature may be reduced therein.
Moreover, in the exemplary embodiment, turbine engine 100 includes an intake section 112, a compressor section 114 coupled downstream from intake section 112, a combustor section 116 coupled downstream from compressor section 114, a turbine section 118 coupled downstream from combustor section 116, and an exhaust section 120. Turbine section 118 is coupled to compressor section 114 via a rotor shaft 122. In the exemplary embodiment, combustor section 116 includes a plurality of combustors 124. Combustor section 116 is coupled to compressor section 114 such that each combustor 124 is positioned in flow communication with the compressor section 114. A fuel injection assembly 126 is coupled within each combustor 124. Turbine section 118 is coupled to compressor section 114 and to a load 128 such as, but not limited to, an electrical generator and/or a mechanical drive application. In the exemplary embodiment, each compressor section 114 and turbine section 118 includes at least one rotor disk assembly 130 that is coupled to a rotor shaft 122 to form a rotor assembly 132.
During operation, intake section 112 channels air toward compressor section 114 wherein the air is compressed to a higher pressure and temperature prior to being discharged toward combustor section 116. The compressed air is mixed with fuel and other fluids that are provided by each fuel injection assembly 126 and ignited to generate combustion gases that are channeled toward turbine section 118. More specifically, each fuel injection assembly 126 injects fuel, such as natural gas and/or fuel oil, air, diluents, and/or inert gases, such as Nitrogen gas (N2), into respective combustors 124, and into the air flow. The fuel mixture is ignited to generate high temperature combustion gases that are channeled toward turbine section 118. Turbine section 118 converts the thermal energy from the gas stream to mechanical rotational energy, as the combustion gases impart rotational energy to turbine section 118 and to rotor assembly 132. As described in more detail below, by having each fuel injection assembly 126 inject the fuel with air, diluents, and/or inert gases into respective combustors 124, dynamic pressure oscillations and locally peak temperature may be reduced within each combustor 124.
Fuel injection assembly 126 also includes at least one injection system 206. More specifically, in the exemplary embodiment, each tube assembly 202 is coupled to one injection system 206, and
In the exemplary embodiment, fluid supply member 210 includes at least one first portion 211 extending from a second portion 212. A fluid source 215 is coupled to fluid supply member 210. More specifically, in the exemplary embodiment, fluid source 215 is coupled to second portion 212. Fluid source 215 may include an inert gas, air, and/or a diluent, such as Nitrogen gas (N2), Carbon Dioxide (CO2), fuel, and/or steam that may be used for reducing the probability of flameholding in fluid supply member 210. Fluid source may also include a fuel, such as a low reactive fuel, in fluid supply member 210. In the exemplary embodiment, fluid supply member second portion 212 has a substantially cylindrical shape such that fluid supply member second portion 212 substantially circumscribes a portion of fuel delivery pipe, and second portion 212 extends through end cover 140. Alternatively, fluid supply member second portion 212 may have any other shape that enables fuel injection assembly 126 and/or turbine engine 100 to function as described herein.
Fluid supply member second portion 212 extends downstream from end cover 140 to fluid supply member first portion 211. In the exemplary embodiment, a first end portion 216 of each fluid supply member first portion 211 extends from fluid supply member second portion 212. A second end portion 217 of each fluid supply member first portion 211 extends substantially radially outwardly from first end 216 of fluid supply member first end portion 211. In the exemplary embodiment, fluid supply member 210 is positioned a distance 220 upstream from tube assembly 202. Moreover, in the exemplary embodiment, distance 220 between each fluid supply member 210 and respective tube assembly 202 are substantially different from each other. Alternatively, distance 220 between each fluid supply member 210 and respective tube assembly 202 may be substantially the same or vary in any other suitable arrangement. More specifically, each first end portion 216 and second end portion 217 is positioned distance 220 upstream from tube assembly. In the exemplary embodiment, first portion 211 also includes at least one opening (not shown in
Fuel delivery pipe 208 in the exemplary embodiment includes a first end portion 221 that is coupled to tube assembly 202, a middle portion 222, and a second end portion 223 that is coupled to a fuel source (not shown). In the exemplary embodiment, fuel delivery pipe 208 has a substantially cylindrical shape. Alternatively, fuel delivery pipe 208 may have any other shape and/or size that enables fuel injection assembly 126 and/or turbine engine 100 to function as described herein.
In the exemplary embodiment, second end portion 217 includes an exterior surface 306 and an opposing interior surface 307, wherein openings 302 extend from exterior surface 306 to interior surface 307 for delivering fluid toward tube assembly 202. In the exemplary embodiment, openings 302 channel fluid in an outwardly direction from fluid supply member 210, as shown by arrows 310, and openings 302 may also channel fluid in toward fluid supply member 210, as shown by arrows 312. Alternatively, openings 302 may channel fluid in any other direction that enables fuel injection assembly 126 (shown in
During operation, fuel is channeled through fuel delivery pipe 208 (shown in
In the exemplary embodiment, second end portion 504 has an exterior surface 508 and an opposing interior surface 510, wherein at least one opening 512 extends from exterior surface 508 to interior surface 510 for delivering fluid toward tube assembly 202 (shown in
Referring to
As compared to known apparatus and systems that are used with turbine engines, the above-described fuel injection assembly may be used with turbine engines to facilitate substantially reducing the dynamic pressure oscillations and/or reducing locally peak temperature, such as a locally peak temperature, within a combustor. The fuel injection assembly includes a plurality of tube assemblies wherein each of the plurality of tube assemblies includes a plurality of tubes. At least one injection system is coupled to at least one tube assembly of the plurality of tube assemblies. The injection system includes a fuel delivery pipe and a fluid supply member coupled to the fuel delivery pipe, wherein the fluid supply member is positioned a distance upstream from the tube assembly. The fluid supply member includes at least one first portion that includes at least one opening for delivering fluid toward the tube assembly for reducing dynamic pressure oscillations and/or locally peak temperature within a combustor during operation of the turbine engine. By delivering the fluid toward at least one of the tube assemblies, flame interactions within the tube assembly and/or between adjacent tube assemblies may be prevented by making uneven fuel distribution and diluting some portion of the fuel in the tube assembly, and the dynamic pressure oscillations and/or locally peak temperature may be reduced therein.
Exemplary embodiments of a fuel injection assembly and method of assembling same are described above in detail. The fuel injection assembly and method of assembling same are not limited to the specific embodiments described herein, but rather, components of the fuel injection assembly and/or steps of the injection assembly may be utilized independently and separately from other components and/or steps described herein. For example, the fuel injection assembly may also be used in combination with other machines and methods, and is not limited to practice with only a turbine engine as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other systems.
Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
This invention was made with Government support under Contract No. DE-FC26-05NT42643, awarded by the Department of Energy (DOE), and the Government has certain rights in this invention.