Patent Application
20140331681
The subject matter disclosed herein relates to turbine systems, and more particularly to a wake manipulating structure for such turbine systems.
Combustor arrangements are often of a reverse-flow configuration and include a liner formed of sheet metal. The sheet metal and an outer boundary component form a path for air received from the compressor outlet to flow in a direction toward a head end of the combustor, where the air is then turned into nozzles and mixed with fuel in a combustor chamber. Various components that serve structural and functional benefits may be located along the airflow path. These components result in wake regions located proximate a downstream side of the components. These wake regions lead to pressure drops and non-uniform airflow as the air is provided to the nozzles at the head end, thereby leading to undesirable effects such as increased NOx emission and less efficient overall operation.
According to one aspect of the invention, a wake manipulating structure for a turbine system includes a combustor liner defining a combustor chamber. Also included is an airflow path located along an outer surface of the combustor liner. Further included is a wake generating component disposed in the airflow path and proximate the combustor liner, wherein the wake generating component generates a wake region located downstream of the wake generating component. Yet further included is a venturi structure disposed in the airflow path and comprising at least one inlet hole and at least one outlet hole, the at least one outlet hole circumferentially aligned with the wake generating component at an axially downstream location of the wake generating component.
According to another aspect of the invention, a wake manipulating structure for a turbine system includes a combustor liner defining a combustor chamber. Also included is an airflow path located along an outer surface of the combustor liner. Further included is a wake generating component disposed in the airflow path and proximate the combustor liner, wherein the wake generating component generates a wake region located downstream of the wake generating component. Yet further included is a venturi structure disposed in the airflow path and comprising at least one slot circumferentially aligned with the wake generating component at an axially downstream location of the wake generating component.
According to yet another aspect of the invention, a wake manipulating structure for a turbine system includes an airflow path located along an outer surface of a combustor liner. Also included is a wake generating component disposed in the airflow path and proximate the combustor liner, wherein the wake generating component generates a wake region located downstream of the wake generating component. Further included is a first venturi section disposed in the airflow path. Yet further included is a second venturi section disposed downstream of the first venturi section.
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.
Referring to
In operation, air flows into the compressor 12 and is compressed into a high pressure gas. The high pressure gas is supplied to the combustor assembly 14 and mixed with fuel, for example natural gas, fuel oil, process gas and/or synthetic gas (syngas), in the combustor chamber 18. The fuel/air or combustible mixture ignites to form a high pressure, high temperature combustion gas stream. In any event, the combustor assembly 14 channels the combustion gas stream to the turbine 24 which converts thermal energy to mechanical, rotational energy.
Referring now to
The combustor assembly 14 is defined by a combustor liner 32 which is at least partially surrounded at a radially outward location by an outer boundary component 34, such as a flow sleeve, for example. Specifically, the combustor liner 32 includes an inner surface 36 and an outer surface 38, where the inner surface 36 defines the combustor chamber 18. An airflow path 40 formed between the outer surface 38 of the combustor liner 32 and the outer boundary component 34 provides a region for an airstream to flow therein toward nozzles of the combustor assembly 14. Although illustrated and previously described as having the flow sleeve surrounding the combustor liner 32, it is contemplated that only the combustor liner 32 is present, with the outer boundary component 34 comprising an outer casing or the like. Disposed within, or partially protruding into, the airflow path 40 is at least one wake generating component 42. The wake generating component 42 generically refers to any structural member and may provide various structural and/or functional benefits to the gas turbine engine 10. For example, the wake generating component 42 comprises a fuel injector extending radially inwardly through the combustor liner 32, a tube such as a cross-fire tube that fluidly couples adjacent combustor chambers, cameras, a spark plug, or a flame detector, etc. The preceding list is merely exemplary and it is to be understood that the wake generating component 42 may refer to any structural member disposed in the airflow path 40.
As air flowing within the airflow path 40 encounters the wake generating component 42, a wake region 44 is generated downstream of the wake generating component 42. Specifically, the wake region 44 may extend from immediately adjacent a downstream end of the wake generating component 42 to locations proximate the downstream end of the wake generating component 42. Various embodiments described herein reduce the wake region 44 by imposing an energizing effect on a mass of air around the wake generating component 42 to fill in the wake region 44. Specifically, the embodiments described below result in a venturi effect on air 46 flowing with the airflow path 40.
Referring to
The venturi structure 52 may be formed of numerous suitable materials, including sheet metal and includes a convergent portion 54, as well as a divergent portion 56. More specifically, the airflow path 40 includes a region of converging airflow and diverging airflow that is formed by inclusion of the convergent portion 54 and the divergent portion 56, respectively. As the air 46 travels along the convergent portion 54, the velocity increases and an associated pressure drop is imposed in this region due to the restriction of cross-sectional area proximate the convergent portion 54. Extending through the convergent portion 54 is at least one, but typically a plurality of inlet holes 58 for the air 46 to enter. The plurality of inlet holes 58 are located in position(s) circumferentially offset from the wake generating component 42, but typically relatively aligned in an axial plane. Axial flow in these circumferential locations is relatively strong and uniform, such that drawing of air in these locations is acceptable. Extending through the divergent portion 56 is at least one, but typically a plurality of outlet holes 60. The plurality of outlet holes 60 is circumferentially aligned with the wake generating component 42 and located axially downstream of the wake generating component 42. The plurality of outlet holes 60 is located in-line with, and downstream of, the wake generating component 42 in the wake region 44 to provide a suction side for the air that is ingested into the plurality of inlet holes 58 to be drawn to.
In operation, the air 46 flows into the plurality of inlet holes 58 at regions not circumferentially aligned with the wake generating component 42 and is routed axially downstream and circumferentially to the plurality of outlet holes 60 in order to energize and “fill-in” the wake region 44 located axially downstream of the wake generating component 42.
Referring now to
The wake manipulating structure 70 includes a venturi structure 72 that includes a convergent portion 74 and a divergent portion 76 that extend circumferentially around the combustor liner 32 to impose a converging and diverging section along the airflow path 40, as described in detail above regarding the first embodiment. However, the venturi structure 72 of the second embodiment of the wake manipulating structure 70 does not extend continuously around the combustor liner 32. Rather, at least one slot 78 is included in locations circumferentially aligned with, and axially downstream of, the wake generating component 42. The at least one slot 78 is formed of numerous geometries, including circular or rectangular, for example, and allows low velocity recirculation of air through low resistance provided by the at least one slot 78. The wake region 44 proximate the at least one slot 78 is energized as flow of the air 46 enters the at least one slot 78 from relatively circumferential directions of flow of the air 46. Specifically, a relatively low pressure drop draws the air toward the at least one slot 78 from the side in a circumferential manner to assist with energizing the wake region 44.
As shown in
Referring now to
Advantageously, airflow uniformity is increased as the airflow is routed to the head end nozzles, which promotes increased overall efficiency of the gas turbine engine 10, as well as reduced NOx emission by making flow uniform and equally dividing the air into downstream fuel nozzles. This is accomplished with a lower pressure drop than other systems require and improves cooling of the combustor liner 32 by increasing the heat transfer coefficient in the vicinity of the wake generating component 42.
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.
