Patent Application
20170356652
The present application and the resultant patent relate generally to gas turbine engines and more particularly relate to an effusion plate assembly for a gas turbine combustor with an improved cooling flow for overall increased component lifetime and reliability.
The operational efficiency and the overall power output of a gas turbine engine generally increases as the temperature of the hot combustion gas stream increases. Higher combustion gas stream temperatures, however, may produce higher levels of nitrogen oxides (“NOx”) and other types or regulated emissions. A balancing act thus exists between the benefits of operating the gas turbine engine in an efficient high temperature range while also ensuring that the output of nitrogen oxides and other types of regulated emissions remain below mandated levels.
Several types of known gas turbine engine designs, such as those using Dry Low NOx (“DLN”) combustors, generally premix the flow of fuel and the flow of air to reduce peak flame temperatures and, hence, overall NOx emission. DLN combustion systems utilize fuel delivery systems that typically include multi-nozzle, premixed combustors. DLN combustor designs utilize lean premixed combustion to achieve low NOx emissions without using diluents such as water or steam. Lean premixed combustion involves premixing the fuel and air upstream of the combustor flame zone and operation near the lean flammability limit of the fuel to keep peak flame temperatures and NOx production low.
Even with reduced peak flame temperatures, the components along the hot gas path of the combustor face high temperatures and otherwise overall harsh operating conditions. For example, combustor effusion plates used about a combustion chamber often sustain damage such as cracks or fractures over time due to the combustion conditions. Specifically, thermal gradients and vibrations due to combustion tones and the like may promote such effusion plate cracks or other types of damage. The time and costs involved in repairing these effusion plates may be significant.
The present application and the resultant patent thus provide a combustor for a gas turbine engine. The combustor may include a number of fuel nozzles and an effusion plate assembly positioned about the fuel nozzles. The effusion plate assembly may include a cold pate, a hot plate, and a number of swirl inducing structures extending therebetween.
The present application and the resultant patent further provide a method of manufacturing an effusion plate assembly. The method may include the steps of forming a cold plate with a number of cold plate cooling air holes and forming a hot plate with a number of swirl inducing structures extending towards the cold plate cooling air holes and a number of effusion holes. The forming steps may use an additive manufacturing process. The step of forming a number of effusion holes may include forming a number of elliptical effusion holes.
The present application and the resultant patent further provide a combustor for a gas turbine engine. The combustor may include a number of fuel nozzles and an effusion plate assembly positioned about the fuel nozzles. The effusion plate assembly may include a cold pate, a hot plate with a number of hot plate effusion holes, and a number of fins extending therebetween.
These and other features and improvements of the present application and the resultant patent will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.
Referring now to the drawings, in which like numerals refer to like elements throughout the several views,
The gas turbine engine 10 may use natural gas, liquid fuels, various types of syngas, and/or other types of fuels and blends thereof. 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 also may be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment also may be used herein together.
The combustor 25 may include a combustor liner 72 disposed within a flow sleeve 74. The arrangement of the liner 72 and the flow sleeve 74 may be substantially concentric so as to define an annular flow path 76 therebetween. The flow sleeve 74 may include a number of flow sleeve inlets 78 extending therethrough. The flow sleeve inlet 78 may provide a pathway for at least a portion of the flow of air 20 from the compressor 15 or elsewhere. The combustor liner 72 may define a combustion chamber 80 for the combustion of the flow of air 20 and the flow of fuel 30 downstream of the fuel nozzles 70. The aft end of the combustor may include a transition piece 85. The transition piece 85 may be positioned adjacent to the turbine 40 so as to direct the flow of combustion gases 35 thereto.
As is shown in
The combustor cap assembly 110 also may include an effusion plate assembly 130. Specifically, quadrants of the effusion plate assembly 130 are shown in
The effusion plate assembly 130 also may include an effusion plate or a hot plate 170. The hot plate 170 may be positioned downstream of and spaced apart from the cold plate 140 at a downstream or a hot end thereof facing the hot combustion gases 35. The hot plate 170 may include any number of hot plate fuel nozzle ports 170 extending therethrough. Any number of the hot plate fuel nozzle ports 170 may be used herein in any suitable size, shape, or configuration.
The hot plate 170 also may include a number of swirl inducing structures 185. In this example, the swirl inducing structures 185 may include a number of hot plate fins 190. The hot plate fins 190 may have a substantial conical shape 200. Any number of the hot plate fins 190 may be used herein in any suitable size, shape, or configuration. In this example, the hot plate fins 190 may include a base 210 extending from the hot plate 170 and an apex 220 extending towards the cold plate cooling air holes 160. Other suitable shapes, sizes, and configurations may be used herein. Hot plate fins 190 of differing sizes, shapes, and configurations may be used herein together on the same hot plate 170. The hot plate 170 also may include a number of hot plate effusion holes 230 extending therethrough. Any number of the hot plate effusion holes 230 may be used herein in any suitable size, shape, or configuration. A number of the hot plate effusion holes 230 may surround each of the hot plate fins 190. Other positions also may be used herein. Other components and other configurations may be used herein.
As is shown in
The effusion plate assembly 320 also may include a hot plate 350 at the downstream or the hot end thereof. The hot plate 350 may include any number of hot plate fuel nozzle ports (not shown). The hot plate 350 may include a number of hot plate effusion holes 360. Any number of the hot plate effusion holes 360 may be used herein in any suitable size, shape, or configuration. The hot plate effusion holes 360 may have a filleted shape 370 in whole or in part. Each of the hot plate effusion holes 360 may be surrounded by one or more swirl inducing structures 380. In this example, the swirl inducing structures 380 may include a number of semi-circular structures 390 positioned around and leading to the hot plate effusion holes 360. The hot plate effusion holes 360 with the filleted shape 370 and the semi-circular structures 390 may promote a swirling flow 400 passing through the hot plate effusion holes 360.
In use, cooling air 20 enters the effusion plate assembly 320 via the cold plate cooling air holes 340 of the cold plate 330. The cooling airflow thus impinges on the backside of the hot plate 350. After the cooling air impinges on the back of the hot plate 350, the air flow enters the swirl inducing structures 380 so as to cool the hot plate 350 and to develop swirl 400 therein. The cooling air develops such swirl 400 so as to create a film on the downstream side of the hot plate 350 after exiting the hot plate effusion holes 360 so as to provide improved cooling. The hot plate effusion holes 360 may have the filleted design 370 at the outlet thereof so as to further encourage the development of swirl therein. Other components and other configurations may be used herein.
The effusion plate assembly 320 and the swirl inducing structures 380 in particular, may be produced in a Direct Metal Laser Melting (“DMLM”) manufacturing process. Such a DMLM manufacturing process or other types of additive or three dimensional printing processes provide the ability to produce complicated three dimensional features herein. For example, the shape of the swirl inducing structures 380 may provide for the improved swirling flow therein. A thermal barrier coating and the like also may be applied to the hot plate 350. Any overspray extending through the hot plate effusion holes 360 thus may be applied to the cold plate 330. The hot plate effusion holes 360 are sufficiently large to allow the spray to flow therethrough without clogging. Other components and other configurations may be used herein.
The effusion plate assembly 410 also may include a hot plate 450 at the downstream or the hot end thereof. The hot plate 450 may include any number of hot plate fuel nozzle ports 460. The hot plate 450 also may include also may include a number of swirl inducing structures 470. In this example, the swirl inducing structures 470 may include a number of hot plate fins 480. The hot plate fins 480 may be offset from the cold plate cooling air holes 440. The hot plate fins 480 may have a substantially cylindrical shape 490 and may extend from the hot plate 450 to the cold plate 420. The hot plate fins 480 also may have a substantially hollow shape with one or more cooling air entry holes 500 leading to a central air passage 510 and an effusion hole 520. The effusion hole 520 may have a chamfered shape 530 on the hot side thereof. Any number of the hot plate fins 480 may be used herein in any suitable size, shape, or configuration. Other suitable shapes, sizes, and configurations may be used herein. Hot plate fins 480 of differing sizes, shapes, and configurations may be used herein together on the same hot plate 450. Other components and other configurations may be used herein.
In use, cooling air 20 enters the effusion plate assembly 410 via the cold plate cooling air holes 440 of the cold plate 420. The cooling airflow thus impinges in part on the backside of the hot plate 450 while a portion of the cooling air flow enters the hot plate fins 480 via the cooling entry holes 500, passes through the central air passage 510, and exits along the hot side of the hot plate 450 through the effusion holes 520 to provide film cooling. The positioning of the cooling entry holes 500 creates swirl 540 within the central air passage 510. The swirling air flow thus exits the effusion holes 520 so as to provide the film cooling on the hot plate 450. The chamfered shape 530 of the effusion holes 520 at the outlet thereof further encourage the development of swirl therein. Other components and other configurations may be used herein.
It should be apparent that the foregoing relates only to certain embodiments of the present application and the resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.
