Patent Application
20130067921
The subject matter disclosed herein relates to a fuel injector and, more particularly, to a fuel injector for a staged combustion process.
In gas turbine engines, combustible materials are combusted in a combustor and the high energy fluids produced by the combustion are directed to a turbine via a transition piece. In the turbine, the high energy fluids aerodynamically interact with and drive rotation of turbine blades in order to generate electricity. The high energy fluids are then transmitted to further power generation systems or exhausted as emissions along with certain pollutants, such as oxides of nitrogen (NOx) and carbon monoxide (CO). These pollutants are produced due to non-ideal consumption of the combustible materials.
Recently, efforts have been undertaken to achieve more ideal consumption of the combustible materials to thereby reduce the amounts of pollutants in the emissions. These efforts include the development of fuel injection whereby combustible materials are injected into the transition piece to mix with the main flow of high energy fluid moving through the transition piece toward the turbine. This leads to increased temperature and energy of the high energy fluids and more ideal consumption of fuel, which correspondingly reduces the pollutant emissions.
According to one aspect of the invention, a fuel injector is provided and includes a member defining a flowpath through which a first fluid flows, the flowpath having a cross-section with transverse elongate and short axes, a head defining a plenum storing a supply of a second fluid and a system fluidly coupled to the flowpath and the plenum to inject the second fluid from the plenum and into the flowpath at first and second locations along the elongate axis. The injected second fluid is formed into jets at the first and second locations, the first fluid entrains the jets such that the injected second fluid flows through the flowpath and mixes with the first fluid, and the short axis has a sufficient dimension such that the jets remain spaced from a sidewall of the member
According to another aspect of the invention, a portion of a gas turbine engine is provided and includes a vessel including a liner defining an interior through which a main flow travels and a flow sleeve disposed about the liner to define a space through which a liner flow travels and a fuel injector to injector fuel and air into the main flow. The fuel injector includes a member traversing the space and defining an elongate flowpath through which the fuel and air flow toward the main flow. The member includes an outer surface having an elongate shape and is disposed in the space at an angle with respect to the liner flow.
According to yet another aspect of the invention, a portion of a gas turbine engine is provided and includes a vessel including a liner defining an interior through which a main flow travels and a flow sleeve disposed about the liner to define a space through which a liner flow travels and a fuel injector. The fuel injector includes a member traversing the space and defining a flowpath through which a first fluid flows, the flowpath having a cross-section with transverse elongate and short axes, the elongate axis being angled with respect to the liner flow, a head defining a plenum storing a supply of a second fluid and a system fluidly coupled to the flowpath and the plenum to inject the second fluid from the plenum and into the flowpath at first and second locations along the elongate axis. The injected second fluid is formed into jets at the first and second locations, the first fluid entrains the jets such that the injected second fluid flows through the flowpath toward the main flow and mixes with the first fluid, and the short axis has a sufficient dimension such that the jets remain spaced from a sidewall of the member.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
With reference to
The fuel injector 30 includes a member 40 disposed to traverse the annular space 25 in a substantially radial direction. The member 40 includes a sidewall 50. The sidewall 50 defines a flowpath 51 through which a first fluid 52, such as air or CDC air, flows in the radial direction. The flowpath 51 has an elongate cross-sectional shape that is characterized with an elongate axis 53, which may be oriented transversely with respect to the liner flow 26, and a short axis 54, which is shorter than and oriented transversely with respect to the elongate axis 53. The elongate axis 53 may form an angle of 0 degrees or 90 degrees with a predominant travel direction of the liner flow 26 or, in accordance with further embodiments, the elongate axis 53 may form an angle between 0 and 90 degrees with the predominant travel direction of the liner flow 26. The elongate cross-sectional shape of the flowpath 51 may be an elliptical shape, a rectangular shape, a super-elliptical shape or another similar shape with possibly aerodynamic edges.
The fuel injector 30 is disposed such that an inlet 510 of the flowpath 51 is proximate to the flow sleeve 22 and an outlet 511 is proximate to the liner 21 whereby the first fluid 52 enters the flowpath 51 at the inlet 510 and flows toward the outlet 511 and then into the main flow 24. The fuel injector 30 may further include a head 60 and a foot 70. The head 60 is connected to the member 40 proximate to the inlet 510 and may be supportively coupled to the flow sleeve 22 or integrally formed with the flow sleeve 22. The head 60 is formed to define a plenum 61 therein, which is configured to store or to be supplied with a supply of a second fluid 62, such as fuel or late lean injection (LLI) fuel. The foot 70 is connected to the member 40 proximate to the outlet 511 and may be supportively coupled to the liner 21 or integrally formed with the liner 21. In particular, the liner 21 may be formed to define an aperture having a shape corresponding to a shape of the foot 70 whereby the foot 70 is installed into the aperture with little to no clearance. In accordance with embodiments, the foot 70 may be dropped in and welded to the liner 21 at the aperture and/or a seal may be provided between the liner 21 and the foot 70.
The fuel injector 30 further includes an injection system 80. The injection system 80 is disposed at or proximate to the inlet 510 of the flowpath 51 and fluidly coupled to the plenum 61. The injection system 80 is thereby configured to inject the second fluid 62 from the plenum 61 and into the flowpath 51. This injection may occur at least at first and second injection locations 81 and 82, which are arrayed with respect to one another in a direction extending along the elongate axis 53. Upon injection, the injected second fluid 62 is formed, due to a pressure thereof and the influence of the first fluid 52, into jets at the first and second locations 81 and 82. The first fluid 52 entrains these jets such that the injected second fluid 62 flows through the flowpath 51 toward the main flow 24 while mixing with the first fluid 52. The distance between the first and second locations 81 and 82 is sufficient to prevent the jets from interfering with each other and.
With reference to
Thus, the first and second fluids 52 and 62 may be injected into the main flow 24 at the axial location of the fuel injector 30, which may be downstream from the combustor of a gas turbine engine. In such a case, the injection of the first and second fluids 52 and 62 forms a secondary stage of combustion that will tend to increase an energy of the main flow 24 and reduce emissions of pollutants, such as oxides of nitrogen (NOx).
Referring to
With reference back to
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While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
