Abstract:
A turbomachine combustor includes a combustor body extending from a head end to a discharge end. The combustor body includes a combustor liner defining a combustion chamber. A combustor sleeve surrounds the combustor liner. The combustor sleeve is spaced from the combustor liner forming a passage. The combustor sleeve includes at least one opening. A baffle is arranged in the passage. The baffle includes a curvilinear surface extending from the combustor sleeve across the at least one opening toward the head end of the combustor body. The baffle is configured and disposed to compress a fluid flow passing through the passage toward the head end.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a turbomachine combustor including a combustor sleeve baffle. 
         [0002]    Turbomachines include a compressor portion linked to a turbine portion through a common compressor/turbine shaft and a combustor assembly. An inlet airflow is passed through an air intake toward the compressor portion. In the compressor portion, the inlet airflow is compressed through a number of sequential stages toward the combustor assembly. In the combustor assembly, the compressed airflow mixes with a fuel to form a combustible mixture. The combustible mixture is combusted in the combustor assembly to form hot gases. The hot gases are guided along a hot gas path of the turbine portion through a transition piece. The hot gases expand along a hot gas path through a number of turbine stages acting upon turbine bucket airfoils mounted on wheels to create work that is output, for example, to power a generator. A portion of the compressed air is passed through various components of the turbomachine for cooling purposes. In some case, air for cooling is passed through a combustor sleeve that surrounds the combustor. The air for cooling may enter the combustor as part of the combustible mixture. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    According to an aspect of an exemplary embodiment, a turbomachine combustor includes a combustor body extending from a head end to a discharge end. The combustor body includes a combustor liner defining a combustion chamber. A combustor sleeve surrounds the combustor liner. The combustor sleeve is spaced from the combustor liner forming a passage. The combustor sleeve includes at least one opening. A baffle is arranged in the passage. The baffle includes a curvilinear surface extending from the combustor sleeve across the at least one opening toward the head end of the combustor body. The baffle is configured and disposed to compress a fluid flow passing through the passage toward the head end. 
         [0004]    According to another aspect of an exemplary embodiment, a turbomachine includes a compressor portion, a turbine portion operatively connected to the compressor portion, and a combustor assembly fluidically connected to the compressor portion and the turbine portion. The combustor assembly includes at least one combustor having a combustor body extending from a head end to a discharge end. The combustor body includes a combustor liner defining a combustion chamber. A combustor sleeve surrounds the combustor liner. The combustor sleeve is spaced from the combustor liner forming a passage. The combustor sleeve includes at least one opening. A baffle is arranged in the passage. The baffle includes a curvilinear surface extending from the combustor sleeve across the at least one opening toward the head end of the combustor body. The baffle is configured and disposed to compress a fluid flow passing through the passage toward the head end. 
         [0005]    According to yet another aspect of an exemplary embodiment, a method of passing air through a combustor includes a passage defined between a combustor liner and a combustor sleeve including guiding a first airflow through the passage toward a head end of the combustor, passing the first airflow over a baffle, compressing the first airflow between the baffle and the combustor liner, introducing a second airflow into the first airflow downstream of the baffle, and merging the first airflow and the second airflow creating a substantially turbulent free airflow. 
         [0006]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF 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 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 representation of a turbomachine system including a turbomachine having a combustor provided with a combustor sleeve baffle, in accordance with an exemplary embodiment; 
           [0009]      FIG. 2  is a cross-sectional view of the combustor of  FIG. 1 ; 
           [0010]      FIG. 3  is a cross-sectional view of a portion of the combustor of  FIG. 2 ; 
           [0011]      FIG. 4  is a cross-sectional view of the baffle of  FIG. 1 ; 
           [0012]      FIG. 5  is a cross-sectional view of the baffle of  FIG. 4  rotated circumferentially illustrating holes an a curvilinear surface of the baffle; 
           [0013]      FIG. 6  is a partial perspective view of the baffle of  FIG. 1 ; and 
           [0014]      FIG. 7  is a cross-sectional view of the baffle, in accordance with another aspect of an exemplary embodiment. 
       
    
    
       [0015]    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 
       [0016]    With reference to  FIGS. 1-4 , a turbomachine system, in accordance with an exemplary embodiment, is indicated generally at  2 , in  FIG. 1 . Turbomachine system  2  includes a turbomachine  3  having a compressor portion  4  operatively connected to a turbine portion  6  through a shaft  8 . Compressor portion  4  is fluidically connected to turbine portion  6  through a combustor assembly  10  having at least one combustor  14 . In the exemplary embodiment shown, turbomachine system  2  includes a driven load/component  20  operatively connected to turbomachine  3 . Driven component  20  may take on a variety of forms including generators, pumps, and the load. Driven load may also take the form of a mode of transportation driven by turbomachine  3 . Turbomachine system  2  is also shown to include an air intake system  24  fluidically connected to compressor portion  4 . 
         [0017]    Air enters air inlet system  24  and flows to compressor portion  4 . The air is compressed and passed to combustor assembly  10 . A portion of the air is passed into turbine portion  6  for cooling. In combustor assembly  10  the air is mixed with a fuel and or diluents to form a combustible mixture. The combustible mixture is combusted forming hot gases that pass from combustor assembly  10  to turbine portion  6 . The hot gases expand through turbine portion  6  which converts thermal energy from the hot gases into mechanical energy that drives driven component  20 . The hot gases pass from turbine portion  6  to an exhaust system (not shown). 
         [0018]    As best shown in  FIGS. 2-3 , combustor  14  includes a combustor body  34  having a head end  36  and a discharge end  38  that is coupled to turbine portion  6  via a transition piece  42 . Head end  36  houses a plurality of nozzles  46 . Combustor  14  also includes a combustor liner  50  arranged within combustor body  34 . Combustor liner  50  defines a combustion chamber  54 . The combustible mixture is delivered into combustion chamber  54  and combusted to form the hot gases delivered to turbine portion  6  via transition piece  42 . Combustor  14  also includes a combustor sleeve  60  that circumscribes combustor liner  50 . Combustor sleeve  60  is spaced from combustor liner  50  forming a passage  64 . Passage  64  delivers an airflow from compressor portion  4  along combustor liner  50  toward head end  36  of combustor  14 . A plurality of openings, one of which is shown at  68 , extend through, and circumferentially about, combustor sleeve  60 . As will be detailed more fully below, openings  68  deliver an airflow into passage  64 . 
         [0019]    In accordance with an exemplary embodiment, combustor  14  includes a baffle  80  arranged in passage  64 . Baffle  80  is arranged downstream from any obstacles that may be present in passage  64 . With this arrangement, air passing over baffle  80  has a substantially unobstructed flow path to head end  36 . As shown in  FIG. 4 , baffle  80  extends from a first end  83  coupled to combustor sleeve  60  to a second, cantilevered end  84  through a curvilinear surface  86 . Curvilinear surface  86  extends across openings  68  and converges toward combustor liner  50 . Air flowing through passage  64  downstream of baffle  80  may be turbulent and circumferentially and radially non-uniform as a result of interaction with various components such as injectors, cross-fire tubes, spark plugs, and the like such as shown at  88 . The air reaches baffle  80  and is compressed between combustor liner  50  and curvilinear surface  86  reducing turbulence and/or reducing recirculation thereby enhancing circumferential uniformity. Additional air enters passage  64  through openings  68  and mixes with the air flowing across baffle  80 . In accordance with an aspect of an exemplary embodiment, about 15% to about 30% of an overall airflow passing through passage  64  downstream of baffle  80  enters through openings  68 . The addition of air through openings  68  further reduces turbulence in the airflow passing to head end  36 . Reducing turbulence in the airflow passing to head end  36  enhances performance of combustor  14 . 
         [0020]    The reduction of turbulence in passage  64  resulting from compressing the air between combustion liner  50  and curvilinear surface  86  also improves heat transfer from a hot side of the combustion liner  50  to air passing over the combustion liner  50  thereby prolonging an overall service life and reliability of combustor assembly  10 . Performance improvements may also be realized by a reduction in pressure losses and by a reduction of NOx emissions. More specifically, improving uniformity will lead to each nozzle  46  receiving a substantially identical (by volume) air flow and thus create a more uniform air/flow mixture for combustion. Uniformity of the air/fuel mixtures leads to more complete combustion and improved flameholding resulting in a reduction in emissions such as NOx. 
         [0021]    In accordance with an aspect of an exemplary embodiment illustrated in  FIG. 5 , baffle  80  includes an opening  90  shown in the form of holes, two of which are shown at  93  and  94 , formed in curvilinear surface  86 . Holes  93  and  94  may be formed in curvilinear surface  86  between adjacent ones of openings  68 . The incorporation of holes  93  and  94  enables additional air to flow through baffle  80  in areas in which openings  68  may not be present. In accordance with another aspect of an exemplary embodiment illustrated in  FIG. 6 , baffle  80  is shown to include an opening  98 . Opening  98  takes the form of an interruption or discontinuity  100  in baffle  80 . In a manner similar to that discussed above, opening  98  enables additional air to flow through baffle  80  in areas in which openings  68  may not be present. 
         [0022]    At this point it should be understood that the exemplary embodiments describe a baffle arranged in an annular passage of a reverse flow combustor. The baffle conditions a turbulent airflow passing along the combustor toward the head end. More specifically, the baffle compresses the airflow against the combustor liner to reduce air recirculation leading to enhanced flow uniformity. In this manner, the exemplary embodiments reduce impingement pressure losses for air coming through openings in the baffle to enhance combustion properties of the combustor. It should also be understood that baffle  80  may include a divergent portion  160  that may further enhance flow uniformity in passage  64 , as shown in  FIG. 7 . Divergent portion  160  may diverge from second end  84  at an angle of less than 5 degrees. Of course the angle of divergent portion  160  may also be greater than 5 degrees. 
         [0023]    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.