Patent Application
20130031905
The subject matter disclosed herein relates to a fuel nozzle and, more particularly, to a fuel nozzle with liquid fuel staging and partial mixing.
In gas turbine engines, liquid and gaseous fuels are mixed with air and other combustible materials and injected as a mixture into a combustor where combustion occurs to produce high energy fluids from which power and electricity can be generated. Often, this mixing occurs upstream from the combustion zone of the combustor in, for example, pre-mixing passages. The liquid and gaseous fuels are injected into these pre-mixing passages from internal plenums within fuel nozzles that are often provided in a complex arrangement.
The complex arrangement of the plenums within fuel nozzles require that the liquid and gaseous fuels follow complicated routes from the internal plenums to the pre-mixing passages and do not allow for certain types of liquid fuel staging or additional forms of partial mixing.
According to one aspect of the invention, a fuel nozzle is provided and includes a nozzle body defining first and second interior regions for providing a supply of first and second fluids, a collar defining a third interior region and radial slots permitting radial ingress of a third fluid to the third interior region and a nozzle tip interposed between the nozzle body and the collar. The nozzle tip defines an annular slot, first discrete passageways by which the first fluid is communicated from the first interior region to the annular slot, second discrete passageways by which the first fluid is communicated from the annular slot to the radial slots, and third discrete passageways by which the second fluid is communicated from the second interior region to the radial slots.
According to another aspect of the invention, a fuel nozzle is provided and includes a nozzle body defining first and second interior regions for providing a supply of first and second fluids, a collar defining a third interior region and radial slots permitting radial ingress of a third fluid to the third interior region, the collar including swirler vanes disposed in each of the radial slots to impart a swirling effect to the third fluid and a nozzle tip interposed between the nozzle body and the collar. The nozzle tip defines an annular slot, first discrete passageways by which the first fluid is communicated from the first interior region to the annular slot, second discrete passageways extending through corresponding ones of the swirler vanes by which the first fluid is communicated to the radial slots, and third discrete passageways by which the second fluid is communicated from the second interior region to the radial slots.
According to yet another aspect of the invention, a method of assembling a nozzle tip of a fuel nozzle for interposition between a nozzle body defining first and second interior regions for providing a supply of first and second fluids and a collar defining a third interior region and radial slots permitting radial ingress of a third fluid to the third interior region is provided. The method includes forming an annular slot within the nozzle tip, machining first discrete passageways into the nozzle tip such that the first fluid is able to be communicated from the first interior region to the annular slot, machining second discrete passageways into the nozzle tip such that the first fluid able to be communicated from the annular slot to the radial slots and machining third discrete passageways into the nozzle tip such that the second fluid is able to be communicated from the second interior region to the radial slots.
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
In accordance with embodiments, the first fluid may include liquid fuel, the second fluid may include gas, such as natural gas, propane, etc., and the third fluid may include air, such as compressor discharge air provided from a compressor of the exemplary gas turbine engine. It is to be understood however, that other fluids may be provided by or to the first, second and third interior regions 21, 22, 31 in accordance with various applications of the description provided herein. In accordance with an aspect, the first fluid, such as the liquid fuel, may also be provided to the interior region 31 from a center body liquid fuel supply section of the nozzle body 20 via a central injector during start up operations and/or other low flow conditions.
The nozzle tip 40 is operably interposed between the nozzle body 20 and the collar 30. In particular, the nozzle tip 40 may be an annular body and may be affixed to an aft end of the nozzle body 20 and welded or brazed to a forward end of the collar 30. The nozzle tip 40 is formed to define an annular slot 41, first discrete passageways 42, second discrete passageways 43 and third discrete passageways 44. The annular slot 41 is formed as an annular slot within the annular body of the nozzle tip 40 whereas the first and second discrete passageways 42, 43 are formed as circumferentially discrete passageways through the annular body of the nozzle tip 40. A number and respective positions of the first and second discrete passageways 42, 43 may correspond with each other and with the radial slots 32 of the collar 30. That is, for each radial slot 32 defined within the collar 30, a first discrete passageway 42 and a second discrete passageway 43 may be defined through the nozzle tip 40.
In accordance with embodiments, the first discrete passageways 42 extend axially from the first interior region 21 along first sections 421 and radially from the first sections 421 to the annular slot 41 along second sections 422. The second sections 422 may be oriented with only radial components or at an angle with radial and axial components. In either case, the first fluid may be communicated from the first interior region 21 to the annular slot 41 via the first sections 421 and the second sections 422. The second discrete passageways 43 extend axially and radially from the annular slot 41 to a location just downstream from the radial slots 32 along main sections 431. As such, the first fluid may be communicated from the annular slot 41 to the location just downstream from the radial slots 32 and into the third interior region 31. The third discrete passageways 44 extend axially and radially from the second interior region 22 to a location just downstream from the radial slots 32 along axial sections 444. As such, the second fluid may be communicated from the second interior region 22 to the location just downstream from the radial slots 32 and into the third interior region 31.
In accordance with an aspect, the fuel nozzle 10 may further include deformable seals 50. The deformable seals 50 are formed of compliant material and may be disposed at interfaces between the first interior region 21 and each of the first discrete passageways 42. The deformable seals 50 therefore account for at least axial, radial and/or circumferential differential thermal growth between the nozzle body 20 and the nozzle tip 40 such that leakage of the first fluid is prevented.
In the assembly of the fuel nozzle 10, the nozzle tip 40 is formed by, for example, casting, machining, forging or another similar process or processes. The annular slot 41 may be formed by similar process or processes. The first, second and third passageways 42, 43, 44, however, can be machined into the nozzle tip 40. Generally, such machining is performed along substantially straight lines with the result being that at least the second sections 422 will extend from an exterior surface of the nozzle tip 40, past the first sections 421 and into the annular slot 41. First plugs 60 may, therefore, be provided in the second sections 422 to prevent leakage of the first fluid from the first discrete passageways 42 to an exterior of the nozzle tip 40. In addition, since the annular slot 41 can be open to the second interior region 22, a second plug 70 may be provided to prevent leakage of the first fluid from the annular slot 41 to the second interior region 22 and to prevent leakage of the second fluid from the second interior regions 22 to the annular slot 41. A periphery of the second plug 70 may be welded or otherwise sealed to the nozzle tip 40 such that any leakage across the second plug in either direction is prevented.
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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.
