Patent Application
20140165577
Embodiments of the present application relate generally to gas turbine engines and more particularly to combustor assemblies including late lean injection (LLI) premixing.
In gas turbine engines, mixtures of fuel and gas are combusted within a combustor disposed upstream from a transition piece and a turbine. The combustor produces high energy fluids from which mechanical energy can be derived for the generation of power and electricity. The high energy fluids are continually reused until significant levels of power generation cannot be derived at which point they are exhausted into the atmosphere. This exhaust often includes pollutants produced during the combustion, such as nitrous oxides (NOx) and carbon monoxide (CO).
Efforts have been expended to reduce the amount of pollutants produced by the combustion processes and include the development of LLI. LLI involves the injection of combustible materials into the flow of the high energy fluids at a location downstream from the normal combustion zone in the combustor. This downstream location could be defined as a section of the combustor liner or at a section of the transition piece. In any case, the combustible materials injected at this location increase the temperature and energy of the high energy fluids and lead to an increased consumption of CO with little to no significant increase in NOx for reasonable levels of LLI fuel flow.
Some or all of the above needs and/or problems may be addressed by certain embodiments of the present application. According to one embodiment, there is disclosed a LLI combustor assembly. The LLI combustor assembly may include a first interior in which a first fuel supplied thereto is combustible. The LLI combustor assembly may also include a flow sleeve annulus including a second interior in which a second fuel supplied thereto is combustible. The flow sleeve annulus may fluidly couple the first interior and the second interior. The LLI combustor assembly may also include at least one fuel injector disposed about the second interior. The at least one fuel injector may be configured to supply the second fuel to the second interior. The LLI combustor assembly may also include at least one elongate premixing conduit disposed about the flow sleeve annulus and in fluid communication with the at least one fuel injector. In this manner, the at least one elongate premixing conduit may be in fluid communication with a compressor discharge air and the second fuel such that the compressor discharge air and the second fuel are premixed within the elongate premixing conduit before entering the second interior by way of the at least one fuel injector.
According to another embodiment, there is disclosed a gas turbine engine assembly. The gas turbine engine assembly may include a combustor having a first interior in which a first fuel supplied thereto is combustible. The gas turbine engine assembly may also include a turbine that receives the products of at least the combustion of the first fuel. The gas turbine engine assembly may also include a flow sleeve annulus including a second interior in which a second fuel supplied thereto and the products of the combustion of the first fuel are combustible. The flow sleeve annulus may fluidly couple the combustor and the turbine. The gas turbine engine assembly may also include at least one fuel injector disposed about the second interior and configured to supply the second fuel to the second interior. The gas turbine engine assembly may also include at least one elongate premixing conduit disposed about the flow sleeve annulus and in fluid communication with the at least one fuel injector. In this manner, the at least one elongate premixing conduit may be in fluid communication with a compressor discharge air and the second fuel such that the compressor discharge air and the second fuel are premixed within the elongate premixing conduit before entering the second interior by way of the at least one fuel injector.
Further, according to another embodiment, there is disclosed a method for facilitating LLI. The method may include providing a first fuel to a first interior of a combustor. The method may also include providing a second fuel to at least one elongate premixing conduit disposed about a flow sleeve annulus. The method may also include providing compressor discharge air to the at least one elongate premixing conduit. The method may also include premixing the second fuel with the compressor discharge air within the at least one elongate premixing conduit. The method may also include injecting the premixed second fuel/compressor discharge air into a second interior of the combustor with at least one fuel injector.
Other embodiments, aspects, and features of the invention will become apparent to those skilled in the art from the following detailed description, the accompanying drawings, and the appended claims.
Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
Illustrative embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments are shown. The present application may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like numbers refer to like elements throughout.
Illustrative embodiments are directed to, among other things, a combustor assembly including LLI premixing.
The gas turbine engine 10 may use natural gas, various types of syngas, and/or other types of fuels. The gas turbine engine 10 may be any one of a number of different gas turbine engines offered by General Electric Company of Schenectady, N.Y., including, but not limited to, those such as a 7 or a 9 series heavy duty gas turbine engine and the like. The gas turbine engine 10 may have different configurations and may use other types of components.
Other types of gas turbine engines may also be used herein. Moreover, multiple gas turbine engines, other types of turbines, and other types of power generation equipment may be used herein together.
Still referring to
In one embodiment, one or more fuel injectors 214 may be structurally supported by the flow sleeve annulus 210. The fuel injectors 214 may be disposed about the second interior 202 and may be configured to supply the second fuel 215 (having been mixed with air) to the second interior 206. The fuel injectors 214 may be disposed about the second interior 206 in any one of a single axial stage, multiple axial stages, a single axial circumferential stage, multiple axial circumferential stages, or the like. In this manner, the fuel injectors 214 may supply the second fuel 215 to the second interior 206 in a direction that is substantially traverse to a predominant flow of the flow sleeve annulus 210. Any number, type, or arrangement of fuel injector nozzles 214 may be used.
In certain aspects, at least one elongate premixing conduit 208 may be disposed about the flow sleeve annulus 210. The elongate premixing conduit 208 may include any passageway, channel, slot, duct, or the like that facilitates the mixing of fuel and air. For example, in some instances, the elongate premixing conduit 208 may be formed between an inner and outer wall of the flow sleeve annulus 210 and may extend wholly or partially along the axial length of the flow sleeve annulus 210.
In an embodiment, the elongate premixing conduit 208 may be in fluid communication with the fuel injectors 214, a compressor discharge air 216, and the second fuel 215. In this manner, the compressor discharge air 216 and the second fuel 215 may be premixed within the elongate premixing conduit 208 before entering the second interior 206 by way of the fuel injectors 214. For example, the fuel manifold 220 may be in fluid communication with the elongate premixing conduit 208 via the fuel conduit 221 for supplying the second fuel 215 to the elongate premixing conduit 208, as denoted by the dotted line 222. Compressor discharge air 216 may enter the elongate premixing conduit 208 at inlet 218 such that the second fuel 215 and the compressor discharge air 216 may be premixed within the elongate premixing conduit 208 thereby forming an air/fuel mixture as denoted by dashed line 224. Accordingly, in this embodiment, a portion of the axial length of the flow sleeve annulus 210 may be utilized to premix the second fuel 215 with the compressor discharge air 216. The premixed air/fuel mixture may then be directed into the second interior 206 by the fuel injector nozzles 214.
The second fuel 215 and the compressor discharge air 216 may be supplied to the elongate premixing conduit 208 by any number of circuit arrangements. For example, the LLI combustor assembly 200 may include one or more fuel conduits 221 (or feeds) in fluid communication with the elongate premixing conduit 208 and/or one or more compressor discharge air inlets 218 (or feeds) in fluid communication with the elongate premixing conduit 208. In this manner, any number or combination of conduits or passageways may be used to supply the fuel 215 and/or air 216 to the elongate premixing conduits 208. Moreover, any number or combination of elongate premixing conduits 208 may be used.
The transition piece 212 may also include a similar configuration for facilitating LLI premixing. That is, the transition piece may include any number or combination of fuel manifolds, fuel conduits, air inlets, elongate premixing conduits, fuel injectors, or the like disposed about the transition piece 212 in a similar fashion to the flow sleeve annulus 210 described above.
Although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments.
