Patent Publication Number: US-2017356652-A1

Title: Combustor Effusion Plate Assembly

Description:
TECHNICAL FIELD 
     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. 
     BACKGROUND OF THE INVENTION 
     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. 
     SUMMARY OF THE INVENTION 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a gas turbine engine showing a compressor, a combustor, a turbine, and a load. 
         FIG. 2  is a schematic diagram of a known combustor with an effusion plate. 
         FIG. 3  is a plan view of the effusion plate of  FIG. 2 . 
         FIG. 4  is a partial perspective view of a combustor with a fuel nozzle and an effusion plate assembly as may be described herein. 
         FIG. 5  is a perspective view of a quadrant of the effusion plate assembly of  FIG. 4 . 
         FIG. 6  is a top plan view of a cold plate of the effusion plate assembly of  FIG. 4 . 
         FIG. 7  is a top plan view of a hot plate of the effusion plate assembly of  FIG. 4 . 
         FIG. 8  is a partial cross-sectional view of the effusion plate assembly of 
         FIG. 4 . 
         FIG. 9  is a schematic diagram of an effusion hole that may be used with the effusion plate assembly. 
         FIG. 10  is a schematic diagram of an effusion hole that may be used with the effusion plate assembly. 
         FIG. 11  is a partial perspective view of an effusion plate assembly as may be described herein. 
         FIG. 12  is a further partial perspective view of the effusion plate assembly of  FIG. 11 . 
         FIG. 13  is a partial plan view of a hot plate of the effusion plate assembly of  FIG. 11 . 
         FIG. 14  is a partial plan view of the hot plate of the effusion plate assembly of  FIG. 11 . 
         FIG. 15  is a partial perspective view of an effusion plate assembly as may be described herein. 
         FIG. 16  is a sectional view of a hot plate fin of the effusion plate assembly of  FIG. 15 . 
         FIG. 17  is a plan view of a hot plate fin of the effusion plate assembly of  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, in which like numerals refer to like elements throughout the several views,  FIG. 1  shows a schematic view of gas turbine engine  10  as may be used herein. The gas turbine engine  10  may include a compressor  15 . The compressor  15  compresses an incoming flow of air  20 . The compressor  15  delivers the compressed flow of air  20  to a combustor  25 . The combustor  25  mixes the compressed flow of air  20  with a pressurized flow of fuel  30  and ignites the mixture to create a flow of combustion gases  35 . Although only a single combustor  25  is shown, the gas turbine engine  10  may include any number of the combustors  25  arranged in a circumferential array or otherwise. The flow of combustion gases  35  is delivered in turn to a turbine  40 . The flow of combustion gases  35  drives the turbine  40  so as to produce mechanical work. The mechanical work produced in the turbine  40  drives the compressor  15  via a shaft  45  and an external load  50  such as an electrical generator and the like. 
     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. 
       FIG. 2  shows an example of the combustor  25  that may be used with the gas turbine engine  10  and the like. Generally described, the combustor  25  may include an end cover  55  and a combustor cap assembly  60  at an upstream or a head end  65  thereof. The end cover  55  and the combustor cap assembly  60  may at least partially support a number of fuel nozzles  70  therein. Any number or type of the fuel nozzles  70  may be used herein. 
     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  FIG. 3 , the combustor cap assembly  60  may include an effusion plate  90 . The effusion plate  90  may be positioned at an upstream end of the combustion chamber  80  and about a downstream end of the fuel nozzles  70 . The effusion plate  90  may be substantially circular in shape. The effusion plate  90  may include a number of fuel nozzle ports  92  for the fuel nozzles  70  to extend therethrough. Any number of the fuel nozzle ports  92  may be used herein. The effusion plate  90  also may include a number of effusion cooling holes  94 . Any number of the effusion cooling holes  94  may be used herein in any suitable size, shape, or configuration. The effusion cooling holes  94  allow for effusion cooling during the combustion of the fuel and air in the adjacent combustion chamber  80 . The effusion plate  90  thus may function as a radiation shield for the combustor cap assembly  60 . The combustor  25  and the combustor components described herein are for the purpose of example only. Many other types of combustors and combustor components may be known. 
       FIGS. 4-8  show examples of a portion of a combustor  100  as may be described herein. Specifically, portions of a combustor cap assembly  110  are shown. The combustor cap assembly  110  may include a number of fuel nozzles  120 . Any number and type of the fuel nozzles  120  may be used herein in any suitable size, shape, or configuration. 
     The combustor cap assembly  110  also may include an effusion plate assembly  130 . Specifically, quadrants of the effusion plate assembly  130  are shown in  FIGS. 5-7 . The effusion plate assembly  130  may include a cold plate  140  positioned at an upstream or a cold end thereof. The cold plate  140  may include a number of cold plate fuel nozzle ports  150  extending therethrough. Any number of the cold plate fuel nozzle ports  150  may be used herein in any suitable size, shape, or configuration. The cold plate  140  also may include a number of cold plate cooling air holes  160  extending therethrough. Any number of the cold plate cooling air holes  160  may be used herein in any suitable size, shape, or configuration. 
     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  FIG. 8 , the flow of air  20  may flow towards the effusion plate assembly  130 . The flow of air  20  may pass through the cold plate cooling air holes  160 , swirl about the hot plate fins  190 , and flow through the hot plate effusion holes  230  so as to provide effusion cooling to the hot plate  170  and the surrounding components. The use of the hot plate fins  190  increases the overall cooling surface area about the cold side end and adds structural stiffness to the overall effusion plate assembly  130 . The cold plate cooling air holes  160  form a film of cooling air. Likewise, secondary flows about the hot plate fins  190  increase overall cooling effectiveness. Specifically, the hot plate fins  190  increase conduction cooling effectiveness. Increased cooling thus may provide increased overall component lifetime. 
       FIG. 9  shows a further embodiment of an effusion hole  250  that may be used with the effusion plate assembly  130  or otherwise. When manufactured, the effusion hole  250  generally includes a largely circular shape  260 . Over time and use, however, the effusion hole  250  may deform to a substantially elliptical shape  270 . This deformation to the elliptical shape  270  may promote the formation of cracks  280  and the like at the smaller radii ends thereof. 
       FIG. 10  thus shows a further embodiment of an effusion hole  290  as may be used herein. The effusion hole  290  may be manufactured with a substantially elliptical shape  300 . Over time and use, the elliptical shape  300  may deform into a substantially circular shape  310 . The circular shape  310  may resist the formation of cracks and the like given the larger and substantially uniform radii. Other components and other configurations may be used herein. 
       FIGS. 11-14  show a further embodiment of an effusion plate assembly  320  as may be described herein. The effusion plate assembly  320  may include a cold plate  330  at the upstream or the cold end thereof. The cold plate  330  may include any number of cold plate fuel nozzle ports (not shown). The cold plate  330  also may include a number of cold plate cooling air holes  340 . Any number of the cold plate cooling air holes  340  may be used herein in any suitable size, shape, or configuration. 
     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. 
       FIGS. 15-17  show a further embodiment of an effusion plate assembly  410  as may be described herein. The effusion plate assembly  410  may include a cold plate  420  at the upstream or the cold end thereof. The cold plate  420  may include any number of cold plate fuel nozzle ports  430 . The cold plate  420  also may include a number of cold plate cooling air holes  440 . Any number of the cold plate cooling air holes  440  may be used herein in any suitable size, shape, or configuration. 
     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.