Patent Abstract:
A method facilitates assembling a combustor for a gas turbine engine, wherein the combustor includes a swirler assembly. The method comprises machining material to form a domeplate, positioning a sealplate including an overhanging portion against the domeplate, securing the sealplate in position relative to the domeplate with a welding process, and welding the swirler assembly to the domeplate.

Full Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   The U.S. Government may have certain rights in this invention pursuant to contract number DAAE07-00-C-N086. 

   BACKGROUND OF THE INVENTION 
   This invention relates generally to gas turbine engines, more particularly to combustors used with gas turbine engines. 
   Known turbine engines include a compressor for compressing air which is suitably mixed with a fuel and channeled to a combustor wherein the mixture is ignited within a combustion chamber for generating hot combustion gases. More specifically, at least some known combustors include a dome assembly that channels airflow downstream and circumferentially around each fuel injector. More specifically, at least some known dome assemblies include a swirler assembly that extends upstream from a domeplate, and a baffle that extends downstream from the domeplate and into the combustion chamber. 
   Within recuperated gas turbine engines, combustor inlet temperatures may be elevated in comparison to other non-recuperated gas turbine engines, and as such, at least some dome assembly components within such engines, may be exposed to higher temperatures than other known gas turbine engine dome assemblies. As such, to facilitate withstanding exposure to the high temperatures generated within the combustion chamber, at least some known baffles are fabricated from a super alloy, such as, but not limited to Rene N5®. Although such materials are resistant to the high temperatures, such materials may be limited in their means of being coupled to the domeplate. Accordingly, known combustors including components fabricated from such super alloys are typically coupled together with an extensive brazing process. Although the brazing process is generally reliable, such processes may also be time-consuming and expensive. 
   BRIEF DESCRIPTION OF THE INVENTION 
   In one aspect, a method for assembling a combustor for a gas turbine engine is provided. The combustor includes a swirler assembly. The method comprises machining material to form a domeplate, positioning a sealplate including an overhanging portion against the domeplate, securing the sealplate in position relative to the domeplate with a welding process, and welding the swirler assembly to the domeplate. 
   In another aspect, a combustor for a gas turbine engine is provided. The combustor includes a swirler assembly and a dome assembly. The dome assembly includes a sealplate and a domeplate. The sealplate is welded to the domeplate and includes an overhang portion and an integrally-formed body. More specifically, the sealplate is welded to the domeplate such that a gap is defined between the domeplate and the sealplate overhang portion. The swirler assembly is welded to the domeplate. 
   In a further aspect, a gas turbine engine including a combustor is provided. The combustor includes a dome assembly, at least one injector, and an air swirler. The dome assembly includes a sealplate and a domeplate. The sealplate is welded to the domeplate and comprising a body and an overhang portion that extends integrally from the body. The sealplate is welded to the domeplate such that a gap is defined between the domeplate and the sealplate overhang portion. The swirler assembly is welded to the domeplate. The at least one injector is coupled to the dome assembly. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic of a gas turbine engine. 
       FIG. 2  is a cross-sectional illustration of a portion of a combustor used with the gas turbine engine shown in  FIG. 1 ; 
       FIG. 3  is an enlarged view of a portion of a dome assembly used with the combustor shown in  FIG. 2  and taken along area  3 ; and 
       FIG. 4  is an enlarged exploded view of the dome assembly shown in  FIG. 3 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a schematic illustration of a gas turbine engine  10  including a compressor  14 , and a combustor  16 . Engine  10  also includes a high pressure turbine  18  and a low pressure turbine  20 . Compressor  14  and turbine  18  are coupled by a first shaft  24 , and turbine  20  drives a second output shaft  26 . Shaft  26  provides a rotary motive force to drive a driven machine, such as, but, not limited to a gearbox, a transmission, a generator, a fan, or a pump. Engine  10  also includes a recuperator  28  that has a first fluid path  29  coupled serially between compressor  14  and combustor  16 , and a second fluid path  31  that is serially coupled between turbine  20  and ambient  35 . In one embodiment, the gas turbine engine is an LV100 engine available from General Electric Company, Cincinnati, Ohio. In the exemplary embodiment, compressor  14  is coupled by a first shaft  24  to turbine  18 , and powertrain and turbine  20  are coupled by a second shaft  26 . 
   In operation, air flows through high pressure compressor  14 . The highly compressed air is delivered to recouperator  28  where hot exhaust gases from turbine  20  transfer heat to the compressed air. The heated compressed air is delivered to combustor  16 . Airflow from combustor  16  drives turbines  18  and  20  and passes through recouperator  28  before exiting gas turbine engine  10 . In the exemplary embodiment, during operation, air flows through compressor  14 , and the highly compressed recuperated air is delivered to combustor  16 . 
     FIG. 2  is a cross-sectional illustration of a portion of combustor  16 .  FIG. 3  is an enlarged view of a portion of a dome assembly  38  used with combustor  16  and  FIG. 4  is an enlarged exploded view of dome assembly  38 . Combustor  16  also includes an annular outer liner  40 , an outer support  42 , an annular inner liner  44 , an inner support  46 , and a dome  48  that extends between outer and inner liners  40  and  44 , respectively. 
   Outer liner  40  and inner liner  44  extend downstream from dome  48  and define a combustion chamber  54  therebetween. Combustion chamber  54  is annular and is spaced radially between liners  40  and  44 . Outer support  42  is coupled to outer liner  40  and extends downstream from dome  48 . Moreover, outer support  42  is spaced radially outward from outer liner  40  such that an outer cooling passageway  58  is defined therebetween. Inner support  46  also is coupled to, and extends downstream from, dome  48 . Inner support  46  is spaced radially inward from inner liner  44  such that an inner cooling passageway  60  is defined therebetween. 
   Outer support  42  and inner support  46  are spaced radially within a combustor casing  62 . Combustor casing  62  is generally annular and extends around combustor  16 . More specifically, outer support  42  and combustor casing  62  define an outer passageway  66  and inner support  46  and combustor casing  62  define an inner passageway  68 . Outer and inner liners  40  and  44  extend to a turbine nozzle  69  that is downstream from liners  40  and  44 . 
   Combustor dome assembly  38  includes an annular domeplate  72 , a swirler assembly  74 , and a baffle  76 . Domeplate  72  is coupled to an upstream end  78  and  80  of outer and inner liners  40  and  44 , respectively, such that domeplate  72  defines an upstream end  82  of combustion chamber  54 . In the exemplary embodiment, inner support  46  is formed integrally with domeplate  72 , and outer support  42  is coupled to domeplate  72  by at least one coupling member  84 . 
   Domeplate  72  includes an opening  90  extending therethrough from an upstream side  92  to a downstream side  94  of domeplate  72 . More specifically, within domeplate downstream side  94 , opening  90  is defined by a chamfered edge  100  that circumscribes opening  90  and facilitates providing clearance for other combustor components, as described in more detail below. Within domeplate upstream side  92 , opening  90  is defined by a counter-bored edge  102  that circumscribes opening  90  and defines a seat  104  within domeplate upstream side  92 . 
   In the exemplary embodiment, opening  90  is substantially circular and is oriented substantially concentrically with respect to a combustor center longitudinal axis of symmetry  110  extending through combustor  16 . Accordingly, opening  90  has a diameter D 1  measured across opening  90 , and a diameter D 2  measured with respect to an outer edge  112  of seat  104 . Seat diameter D 2  is larger than opening diameter D 1 . 
   A plurality of cooling openings  114  extend through domeplate  72  between upstream and downstream sides  92  and  94 , respectively. Openings  114  facilitate channeling cooling air through domeplate  72  to facilitate impingement cooling of baffle  76 . 
   An annular sealplate  120  including a seated end  122 , an overhang portion  124 , and a body  126  extending therebetween is coupled to domeplate  72 . In the exemplary embodiment, sealplate  120  is fabricated from Hast-X® and is welded to domeplate  72 . Sealplate  120  is toroidal such that an opening  128  is defined therethrough. Sealplate seated end  122  has an outer diameter D 3  measured with respect to an outer edge  130  of seated end  122 , and an inner diameter D 4  measured with respect to an inner wall  132  of sealplate  120  that defines opening  128 . Seated end outer diameter D 3  is slightly smaller than domeplate seat diameter D 2 . Accordingly, domeplate seat  104  is sized to receive sealplate seated end  122  therein such that sealing contact is facilitated between domeplate seat  104  and sealplate seated end  122  when sealplate  120  is coupled to domeplate  72 . More specifically, when sealplate  120  is coupled to domeplate  72 , sealplate  120  is substantially concentrically aligned with respect to domeplate  72  and axis of symmetry  110 , such that sealplate body  126  is generally parallel to axis of symmetry  110 . 
   In the exemplary embodiment, sealplate overhang portion  124  extends substantially perpendicularly outward from body  126 . Overhang portion  124  has a thickness T 1  measured between an upstream side  129  of sealplate  120  and a downstream side  131  of overhang portion  124 . Overhang portion thickness T 1  is thinner than a thickness T 2  of body  126  measured between upstream side  129  and seated end  122 . Accordingly, when sealplate  120  is coupled to domeplate  72 , a gap  136  is defined between sealplate overhang portion  124  and domeplate  72 , or more specifically, between overhang portion downstream side  131  and domeplate upstream side  92 . Domeplate cooling openings  114  are in flow communication with gap  136 , such that cooling air directed into gap  136  during operation is channeled into domeplate cooling openings  114  to facilitate impingement cooling of baffle  76 . 
   Baffle  76  is coupled to sealplate  120  and extends divergently downstream from domeplate  72  into combustion chamber  54 . In the exemplary embodiment, baffle  76  is fabricated from Rene N5® and is coupled to sealplate  120  through a brazing process. More specifically, baffle  76  is coupled circumferentially against sealplate inner wall  132 , and accordingly is coupled radially inward from sealplate  120  within domeplate opening  90 . A radially outer surface  140  of baffle  76  defines an outer diameter D 6  of an upstream end  142  of baffle  76 . Baffle outer diameter D 6  is slightly smaller than sealplate opening diameter D 4 . In the exemplary embodiment, a radially inner surface or flowpath surface  144  of baffle  76  is coated with a layer of thermal barrier coating (TBC). 
   Swirler assembly  74  is coupled to sealplate  120  such that swirler assembly  74  is substantially concentrically aligned with respect to sealplate  120 . Swirler assembly  74  includes a secondary swirler  150 , a primary swirler  152 , and a swirler retainer  154 . Primary swirler  152  is retained against secondary swirler  152  by swirler retainer  154  such that primary swirler  152  is aligned substantially concentrically with respect to secondary swirler  150 , but is free to move to accommodate thermal and mechanical stresses between fuel injector  182  and swirler assembly  74 . More specifically, in the exemplary embodiment, swirler retainer  152  is welded to secondary swirler  150 . 
   Secondary swirler  150  includes a substantially cylindrical body  162  and an attachment flange  164  that extends radially outwardly from body  162 . More specifically, in the exemplary embodiment, attachment flange  164  extends substantially perpendicularly from body  162  such that an annular shoulder  166  is defined between a radially outer surface  170  of body  162  and flange  164 . Body outer surface  170  defines an outer diameter D 7  for swirler  150  that is slightly smaller than an inner diameter D 8  defined by baffle flowpath surface  144 . Accordingly, flange  164  is coupled to sealplate overhang portion  124  in substantial sealing contact. In the exemplary embodiment, flange  164  is welded to sealplate overhang portion  124 . 
   Fuel is supplied to combustor  16  through a fuel injection assembly  180  that includes a plurality of circumferentially-spaced fuel nozzles  182  that extend into swirler assembly  74  into combustion chamber  54 . More specifically, fuel injection assembly  180  is coupled to combustor  16  such that each fuel nozzle  182  is substantially concentrically aligned with respect to dome assembly  38 , and such that nozzle  182  is configured to discharge downstream through swirler assembly  74  into combustion chamber  54 . When fuel nozzle  182  is coupled to combustor  16 , nozzle  182  circumferentially contacts primary swirler  152  to facilitate minimizing leakage to combustion chamber  54  between nozzle  82  and swirler assembly  74 . 
   During assembly of combustor  16 , initially domeplate  72  is machined from a near net shape forging. Opening  90  is then cut into domeplate  72  such that chamfered edge  100  is formed along domeplate downstream side  94 . Edge  100  facilitates providing clearance for baffle  76  and sealplate welds. Domeplate upstream side  92  is then counter-bored to form edge  102  such that seat  104  circumscribes opening  90 . 
   Sealplate seated end  122  is then inserted within domeplate seat  72  such that substantially circumferential sealing contact is created between sealplate  120  and domeplate  72  within seat  104 . Accordingly, seat  104  aligns sealplate  120  with respect to domeplate  72  to facilitate minimizing leakage between domeplate  72  and sealplate  120 . Moreover, because sealplate  120  is aligned with respect to domeplate  72  through seat  104 , seat  104  also facilitates proper alignment between swirler assembly  74  and fuel injectors  182 , and between baffle  76  and domeplate  72 . 
   After sealplate  120  has been welded to domeplate  72 , baffle  76  is then tack welded in position against sealplate  120 . More specifically, tack welding baffle  76  to sealplate  120  facilitates ensuring sealplate  120  and baffle  76  form a pre-determined dimensionally controlled assembly. Although, the tack welds provide secondary baffle retention, baffle  76  is primarily secured to sealplate  120  through a brazing process. Moreover, to facilitate the brazing process, during assembly of combustor  16 , in the exemplary embodiment, baffle surface  140  is pre-sintered with braze tape adjacent baffle upstream end  142 . 
   Swirler assembly  74  is then tack welded to sealplate  120 . More specifically, swirler assembly  74  is tack welded to sealplate overhang portion  124  such that secondary swirler flange  164  is against sealplate overhang portion  124  in substantial sealing contact. 
   In the exemplary embodiment, a plurality of dome assemblies  38  formed as described above, are equally spaced around combustor domed end  48 . Moreover, such assemblies  38  facilitate providing predetermined dimensional stack control of combustor dome assembly  38  to ensure combustor  16  satisfies pre-determined combustor performance requirements for pattern factor, profile factor, emissions control, starting, and useful life. Moreover, because a plurality of components are welded together, rather than coupled through an expensive brazing operation, dome assembly  38  facilitates reducing assembly costs compared to at least some other known combustor dome assemblies. 
   The above-described combustor dome assemblies provide a cost-effective and reliable means for operating a combustor. More specifically, each assembly includes a domeplate opening that is defined by a chamfered edge and an opposite counter-bored edge. The counter-bored edge facilitates aligning the sealplate relative to the domeplate such that leakage between the sealplate and domeplate is facilitated to be minimized. In addition, the counter-bored edge also facilitates aligning each swirler assembly relative to each fuel injector. As a result, a combustor assembly is provided which satisfies pre-determined combustor performance requirements while maintaining pre-determined operational requirements. 
   An exemplary embodiment of a combustor dome assembly is described above in detail. The combustor dome assembly components illustrated are not limited to the specific embodiments described herein, but rather, components of each dome assembly may be utilized independently and separately from other components described herein. For example, the dome assembly components described above may also be used in combination with other engine combustion systems. 
   While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.

Technology Classification (CPC): 8