Abstract:
A combustor for a gas turbine includes a first combustor component and a second combustor component. The second combustor component is at least partially insertable into the first combustor component, and the first combustor component and second combustor component define a combustion fluid pathway. A combustor seal is located between the first combustor component and the second combustor component. The combustor seal defines at least one inner cooling pathway between the combustor seal and the second combustor component and at least one outer cooling pathway between the combustor seal and the first combustor component for cooling the first combustor component and second combustor component. A method for cooling a first combustor component and a second combustor component is also disclosed.

Description:
BACKGROUND 
       [0001]    The subject invention relates to combustors. More particularly, the subject invention relates to sealing between combustor components. 
         [0002]    Air management is an important consideration in combustor design. Air streams provide an oxidizer for a combustion process and also provide cooling to hot components of the combustor. Seals are typically provided between various components of the combustor to prevent hot combustion gas from leaking from the combustor. Seal configurations and functions are unique in a combustor. A seal providing complete sealing of flow from one area to another may not be desired, but rather a seal resulting in a small amount of cooling air “leak” may be preferred. Within combustion zones, cooling must be properly designed to provide adequate cooling for components while only minimally disturbing combustion ignition and stability. Cooling air streams “leaked” through the seal may also be directed to reducing thermal-acoustic oscillation of the combustor. 
         [0003]    These seals typically include C-Rings, fingered hula rings, cloth seals, and the like, and are subjected to high temperature and pressure as well as high gradients of pressure and temperature across the seals. Current seals can be further improved for provision of cooling flow to overcome excessive leakage around the seal at various levels of temperature and/or pressure and during temperature and/or pressure transitions, and/or wear of the seal. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0004]    A combustor for a gas turbine includes a first combustor component and a second combustor component. The second combustor component is at least partially insertable into the first combustor component, and the first combustor component and second combustor component define a combustion fluid pathway. A combustor seal is located between the first combustor component and the second combustor component. The combustor seal defines at least one inner cooling pathway between the combustor seal and the second combustor component and at least one outer cooling pathway between the combustor seal and the first combustor component for cooling the first combustor component and second combustor component. 
         [0005]    A method for cooling a first combustor component and a second combustor component includes locating a combustor seal radially between the first combustor component and the second combustor component. Cooling fluid flows through at least one inner cooling pathway defined by the combustor seal and the second combustor component. Cooling fluid also flows through at least one outer cooling pathway defined by the combustor seal and the second combustor component. The spent cooling fluid then flows into the combustion fluid. 
         [0006]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    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 objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0008]      FIG. 1  is a schematic cross-sectional view of a gas turbine; 
           [0009]      FIG. 2  is a cross-sectional view of a portion of a combustor of the gas turbine of  FIG. 1  including an embodiment of a combustor seal; 
           [0010]      FIG. 3  is a partially exploded view of the combustor seal of  FIG. 2 ; 
           [0011]      FIG. 4  is a cross-sectional view of an embodiment of a reversed seal of  FIG. 2 ; 
           [0012]      FIG. 5  is a cross-sectional view of an embodiment of a combustor seal including a coil; 
           [0013]      FIG. 6  is a plane view of the combustor seal of  FIG. 5 ; 
           [0014]      FIG. 7  is a cross-sectional view of yet another embodiment of a combustor seal; 
           [0015]      FIG. 8  is a plane view of the combustor seal of  FIG. 7 ; 
           [0016]      FIG. 9  is a cross-sectional view of an embodiment of a combustor seal having multiple wave sections; 
           [0017]      FIG. 10  is a plane view of the combustor seal of  FIG. 9 ; 
           [0018]      FIG. 11  is a cross-sectional view of a combustor seal having a mesh configuration; and 
           [0019]      FIG. 12  is a plane view of the combustor seal of  FIG. 11 . 
       
    
    
       [0020]    The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Shown in  FIG. 1  is a gas turbine  10 . The gas turbine  10  includes a compressor  12  which provides compressed fluid to a combustor  14 . Fuel is injected into the combustor  14 , mixes with the compressed air and is ignited. The hot gas products of the combustion flow to a turbine  16  which extracts work from the hot gas to drive a rotor shaft  18  which in turn drives the compressor  12 . A transition piece  20  is coupled at an upstream end  22  to the combustor  14  at a combustor liner  24  and at a downstream end  26  to an aft frame  28  of the turbine  16 . The transition piece  20  carries hot gas flow from the combustor liner  24  to the turbine  16 . The combustor  14  includes a combustor sleeve  30  spaced radially outward from the combustor liner  24  defining a combustor flow channel  32  therebetween. A combustor cap  34  is coupled to an upstream end  36  of the combustor liner  24  and includes at least one nozzle  38  disposed therein an extending into a combustion chamber  40  defined by the combustor cap  34  and the combustor liner  24 . An impingement sleeve  42  is coupled to the combustor sleeve  30  and is radially spaced from the transition piece  20  defining a transition flow channel  44  therebetween. 
         [0022]    During operation, discharge flow  46  flows from the compressor  12  through a diffuser  48  to the impingement sleeve  42 . The discharge flow  46  proceeds through a plurality of impingement holes  50  in the impingement sleeve  42  and toward the combustor  14  in the transition flow channel  44 . The discharge flow  46  proceeds from the transition flow channel  44  and through the combustor flow channel  32  until it is finally introduced to the combustor liner  24  through the at least one nozzle  38 . In addition to providing air to the combustor  14  for the combustion process, the relatively cool discharge flow  46  further provides much needed cooling to the components exposed to hot combustion gas, for example, the combustor liner  24  and the transition piece  20 . 
         [0023]    As shown in  FIG. 2 , interfaces between adjacent components exposed to hot combustion gases, for example, the transition piece  20  and the combustor liner  24 , are configured as lap joints  56  wherein, for example, a downstream end  58  of the combustor liner  24  is configured to be insertable into the upstream end  22  of the transition piece  20 . A seal  60  is disposed radially between the overlapping portions of the transition piece  20  and the combustor liner  24  and extends perimetrically around the joint  56 . Another example of such an application is one in which the seal  60  disposed between overlapping portions of the combustor liner  24  and the combustor cap  34 . Yet another example of such application is one in which the seal  60  is disposed between overlapping portions of the combustor cap  34  and the at least one nozzle  38 . In one embodiment, the seal  60  of is configured with a wave-shaped cross section and includes two layers, an outer seal  62  and an inner seal  64 . In some embodiments, the seal  60  includes at least one support  66  comprising, for example, a weld, which secures the seal  60  to at least one of the transition piece  20  or the combustor liner  24 . 
         [0024]    Referring now to  FIG. 3 , the inner seal  64  includes at least one inner seal slot  68  disposed at an upstream inner seal end  70  and open at the upstream inner seal end  70 . The inner seal  64  further includes at least one inner seal slot  68  disposed at a downstream inner seal end  72  and open at the downstream inner seal end  72 . The at least one inner seal slot  68  may include one or more scallops  74  to reduce stress in the inner seal  64  at the inner seal slot  68 . The outer seal  62  includes a plurality of impingement holes  76  disposed at an upstream outer seal end  78 . At least one of the impingement holes  76  is located over at least one inner seal slot  68 . A wave section  80  of the outer seal  62  includes at least one wave slot  82  which may include one or more scallops  74  to reduce stress in the outer seal  62  at the wave slot  82 . 
         [0025]    Referring now to  FIG. 2 , the seal  60  is disposed between transition piece  20  and the combustor liner  24  such that the inner seal  64  contacts the combustor liner  24  at the upstream inner seal end  70  and the downstream inner seal end  72 . The outer seal  62  contacts the transition piece  20  at the wave section  80 . In operation, a portion of the flow through the transition flow channel  44  flows past an upstream end  22  of the transition piece  20  and between the transition piece  20  and combustor liner  24 . A first portion  84  of the flow proceeds through the at least one wave slot  82  thereby providing cooling to the transition piece  20 , and a second portion  86  of the flow through the inner seal slots  68  and/or the impingement holes  76  thereby providing cooling to the combustor liner  24 . While the embodiment of  FIG. 3  has two seal layers, configurations having different numbers of seal layers, for example, one layer or three layers, are contemplated within the scope of the present disclosure. 
         [0026]    In an embodiment as shown in  FIG. 4 , the seal  60  of  FIG. 2  may be reversed or flipped such that the upstream inner seal end  70  and the downstream inner seal end  72  contact the transition piece  20 , and the seal  60  contacts the combustor liner  24  at the wave section  80 . Reversal of the seal  60  as shown in  FIG. 4  can enhance cooling of the combustor liner  24  such that other cooling flows to the combustor liner  24  can be reduced or eliminated. In this embodiment, the seal  60  is fixed to the transition piece  20  so thermal expansion and/or installation displacement of the transition piece  20  will not affect the performance of the seal  60 . 
         [0027]    In another embodiment as shown in  FIG. 5 , the seal  60  comprises a coil  88  disposed radially between the transition piece  20  and the combustor liner  24  and contacting both the transition piece  20  and combustor liner  24 . The coil  88  extends perimetrically around the joint  56  and is secured to at least one of the transition piece  20  or the combustor liner  24  by at least one support  66 . A sleeve  90 , which is shown with annular cross-section, is located inside the coil  88 . The coil  88  and the sleeve  90  are configured to allow the flow to proceed between coil windings  92  as shown in  FIG. 6 . Referring again to  FIG. 5 , the first portion  84  proceeds between coil windings  92  to provide cooling to the transition piece  20 , and the second portion  86  proceeds between coil windings  92  to provide cooling to the combustor liner  24 , while the sleeve  90  provides sealing to prevent undesired outflow of hot gas from the transition piece  20 . 
         [0028]    In another embodiment shown in  FIG. 7 , the seal  60  comprises a solid or tubular rod  94  disposed radially between the transition piece  20  and the combustor liner  24  and contacting both the transition piece  20  and the combustor liner  24 . The rod  94  extends perimetrically around the joint  56  and is secured to at least one of the transition piece  20  or the combustor liner  24  by at least one support  66 . A plurality of cooling slots  96  are disposed in the rod  94  as shown in  FIG. 8  to provide cooling flow to the transition piece  20  and the combustor liner  24 . The cooling slots  96  shown in  FIG. 8  are disposed substantially axially in the rod  94 , but it is to be appreciated that cooling slots  96  disposed in other angular directions are contemplated within the scope of the present disclosure. 
         [0029]    Another alternative embodiment of a seal  60  is illustrated in  FIG. 9 . The seal  60  comprises at least one seal layer  98  having a upstream seal end  100 , a seal downstream end  102 , and a plurality of wave sections  104  disposed therebetween. The seal layer  98  extends perimetrically around the joint  56  and is secured to at least one of the transition piece  20  or the combustor liner  24  by at least one support  66  and includes at least one end slot  106  disposed at each seal end  100 ,  102 . Each wave section  104  contacts one of the transition piece  20  or the combustor liner  24  and includes at least one wave slot  82  as shown in  FIG. 10 . The at least one wave slot  82  may include one or more scallops  74  to reduce stress in the seal layer  98  at the wave slot  82 . Referring again to  FIG. 9 , the first portion  84  proceeds through the wave slots  82  to provide cooling to the transition piece  20 , and the second portion  86  proceeds through the end slots  106  disposed at the seal upstream end  100 , through the wave slots  82  and through the end slots  106  disposed at the seal downstream end  102  to provide cooling to the combustor liner  24 . While the embodiment shown in  FIG. 9  includes three wave sections  104 , and seal ends  100 ,  102  which contact the combustor liner  24 , other quantities of wave sections  104  and other orientations of seal ends  100 ,  102  are contemplated by the present disclosure. 
         [0030]    Yet another embodiment of a seal  60  is illustrated in  FIG. 11 . The seal  60  of this embodiment comprises a multi-layer mesh. The mesh in  FIG. 11  has an inner mesh layer  108  and an outer mesh layer  110 . The inner mesh layer  108  is formed from a plurality of, for example, inner wires  112  arranged to define a plurality of inner mesh channels  114 . Similarly, the outer mesh layer  110  is formed from a plurality of, for example, outer wires  116  arranged to define a plurality of outer mesh channels  118 . As shown in  FIG. 12 , the inner mesh layer  108  and the outer mesh layer  110  are configured such that a channel angle  120  exists between the inner mesh channels  114  and the outer mesh channels  118 . The channel angle  120  of  FIG. 12  is substantially 90 degrees, but it is to be appreciated that other channel angles  120  are contemplated depending on desired cooling effects. To provide cooling, the first portion  84  proceeds through the outer mesh channels  118  to provide cooling to the transition piece  20 , and the second portion  86  proceeds through the inner mesh channels  114  to provide cooling to the combustor liner  24 . 
         [0031]    While the embodiments above describe seals  60  disposed between a transition piece  20  and a combustor liner  24 , the seal  60  can be utilized at other locations in the combustor  14  or gas turbine  10 , for example, between the transition piece  20  and the aft frame  28  or between the combustor liner  24  and the combustor cap  34 . 
         [0032]    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.