The present disclosure relates to combustion systems for gas turbine engines and, in particular, low net-swirl configurations for a combustor.
Gas turbine engines, such as those used to power modern aircraft, to power sea vessels, to generate electrical power, and in industrial applications, include a compressor for pressurizing a supply of air, a combustor for burning a fuel in the presence of the pressurized air, and a turbine for extracting energy from the resultant combustion gases. Generally, the compressor, combustor, and turbine are disposed about a central engine axis with the compressor disposed axially upstream or forward of the combustor and the turbine disposed axially downstream of the combustor. In operation of a gas turbine engine, fuel is injected into and combusted in the combustor with compressed air from the compressor thereby generating high-temperature combustion exhaust gases, which may contain pollutant gases or smoke.
Accordingly, there is a desire to provide configurations that improve fuel and air mixing within combustors. There is also a desire to improve the configurations of gas turbine engines and combustor assemblies to reduce unwanted pollutant emission such as NOx and smoke.
Disclosed and claimed herein are swirlers and swirler configurations for combustors of gas turbine engines. One embodiment is directed to a swirler including an inner passage for receiving a fuel injector and a plurality of outer passages concentrically arranged around the inner passage. The plurality of outer passages include an outer vane assembly including a plurality of vane elements arranged at a first angle and a first middle vane assembly include a plurality of vane elements arranged at a second angle. The outer vane assembly is concentrically arranged around the first middle vane assembly, and the outer vane assembly and first middle vane assembly are configured to produce a low net-swirl to control the penetration depth of a fuel air mixture for the fuel injector.
In one embodiment, the swirler is configured to generate an air and fuel mixture downstream of a combustor pilot flow and improve premixing of the fuel air mixture.
In one embodiment, vanes of the outer vane assembly are angled within the range of +45 to +60 degrees.
In one embodiment, vanes of the outer vane assembly are arranged and configured to handle within 50 to 70 percent of the airflow received by the swirler.
In one embodiment, vanes of the first middle vane assembly are angled within the range of 0 to −25 degrees.
In one embodiment, vanes of the first middle vane assembly are arranged and configured to handle within 20 to 40 percent of the airflow received by the swirler.
In one embodiment, the penetration depth relates to the penetration depth within a combustor cavity.
In one embodiment, the swirler generates a low net-swirl by co-swirling airflow associated with the outer vane assembly and first middle vane assembly.
In one embodiment, the swirler includes a second middle vane assembly include a plurality of vane elements arranged at a third angle, and wherein the first middle vane assembly is arranged concentrically around the first middle vane assembly.
In one embodiment, vanes of the outer vane assembly are angled in a direction opposite to vanes of the first middle vane assembly.
Another embodiment is directed to a swirler including an inner passage for receiving a fuel injector and a plurality of outer passages concentrically arranged around the inner passage. The plurality of outer passages include an outer vane assembly including a plurality of vane elements arranged at a first angle, a first middle vane assembly include a plurality of vane elements arranged at a second angle, and a second middle vane assembly include a plurality of vane elements arranged at a third angle. The first middle vane assembly is concentrically arranged around the second middle vane assembly. The outer vane assembly is concentrically arranged around the first middle vane assembly and second middle assembly, and wherein the outer vane assembly, first middle vane assembly and second middle vane assembly are configured to produce a low net-swirl to control the penetration depth of a fuel air mixture for the fuel injector.
In one embodiment, the swirler is configured to generate an air and fuel mixture downstream of a combustor pilot flow and improve premixing of the fuel air mixture.
In one embodiment, vanes of the outer vane assembly are angled within the range of +45 to +60 degrees.
In one embodiment, vanes of the outer vane assembly are arranged and configured to handle within 45 to 65 percent of the airflow received by the swirler.
In one embodiment, vanes of the first middle vane assembly are angled within the range of −10 to −30 degrees and vanes of the second middle assembly are angled within the range of +10 to +30 degrees.
In one embodiment, vanes of the first middle vane assembly are arranged and configured to handle within 15 to 25 percent of the airflow received by the swirler wherein vanes of the second middle vane assembly are arranged and configured to handle within 15 to 25 percent of the airflow received by the swirler.
In one embodiment, the penetration depth relates to the penetration depth within a combustor cavity.
In one embodiment, the swirler generates a low net-swirl by co-swirling airflow associated with the outer vane assembly and first middle vane assembly.
In one embodiment, the swirler includes a second middle vane assembly include a plurality of vane elements arranged at a third angle, and wherein the first middle vane assembly is arranged concentrically around the first middle vane assembly.
In one embodiment, vanes of the outer vane assembly and second middle vane assembly are angled in a direction opposite to vanes of the first middle vane assembly
Other aspects, features, and techniques will be apparent to one skilled in the relevant art in view of the following detailed description of the embodiments.
The features, objects, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:
One aspect of this disclosure relates to configurations for a gas turbine engine and in particular a swirler for a combustor. According to one embodiment, a swirler configuration can include two or more outer passages with vane elements configured to provide a fuel-air mixture with low net-swirl. Based on the amount of swirl, the penetration depth of the fuel-air mixture may be controlled to in order to increase the efficiency of fuel burn within the combustor. According to one or more embodiments,
As used herein, the terms “a” or “an” shall mean one or more than one. The term “plurality” shall mean two or more than two. The term “another” is defined as a second or more. The terms “including” and/or “having” are open ended (e.g., comprising). The term “or” as used herein is to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” means “any of the following: A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
Reference throughout this document to “one embodiment,” “certain embodiments,” “an embodiment,” or similar term means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of such phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner on one or more embodiments without limitation.
Referring now to the figures,
According to one embodiment, swirler 120 may include a plurality of passages 125 to provide low net-swirl and as a result control the penetration depth and improve premixing of fuel-air mixture 130. By controlling the penetration depth of fuel-air mixture 130, swirler can provide a fuel-air mixture that improves the fuel burning ability of fuel-air mixture 130 by pilot fuel-air mixture 115. In that fashion, NOx (e.g., nitric oxide and nitrogen dioxide) emissions of the combustor 105 and gas turbine engine 100 may be reduced.
Swirler 120 may be configured for one or more fuel injectors to control the penetration of a fuel air mixture and to control premixing of the fuel air mixture. According to one embodiment, swirler 120 improves fuel and air mixing within combustor 105 due to premixing. In addition, swirler 120 reduces unwanted pollutant emission such as NOx and smoke by controlling the penetration depth of the fuel air mixture and by combustion of substantially all fuel.
Swirl passages include outer passages concentrically arranged around the inner passage 205, wherein the plurality of outer passages include an outer vane assembly 225 and first middle vane assembly 230. Outer vane assembly 225 includes a plurality of vane elements arranged at a first angle. First middle vane assembly 230 includes a plurality of vane elements arranged at a second angle. As shown in
According to one embodiment, a fuel injector within inner passage 205 may spray fuel axially as shown by 235. Axial fuel spray 235 is mixed with air output by outer vane assembly 225 and first middle vane assembly 230 as fuel-air mixture 240. Fuel-air mixture may be characterized as having a low net-swirl that allows for the penetration depth of fuel-air mixture 240 to be controlled with respect to an annular structure of a combustor.
Air flow output by inner passage 255 and inner passage 255 co-swirls in fuel spray location 260 and joins airflow of inner passage 255 at exit 261 of the swirler.
Air flow output by inner passage 275 and inners passage 272, 273 co-swirls in fuel spray location 280 and joins airflow of inner passage 275 at exit 281 of the swirler.
While this disclosure has been particularly shown and described with references to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the claimed embodiments.
This invention was made with Government support under contract number NNC13TA45T awarded by the National Aeronautics and Space Administration (NASA). The Government has certain rights in the invention.