Abstract:
A cooling manifold has a plurality of pieces. The pieces extend in a circumferential direction to abutting flanges. The flanges are secured together at circumferential ends of each piece. Cooling channels are formed in between inner and outer walls. Air inlets are formed in the pieces with the air inlets delivering air in the interior. There are fingers on an outer periphery. The fingers are aligned within an air outlet. The air can be delivered into the inlet, cool the interior, and leave through the outlet extending to a main conduit. The main conduit is secured directly to an outer periphery of the cooling manifold.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application 61/765,877, filed Feb. 18, 2013. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This application relates to a turbine case cooling recovery duct for use in a gas turbine engine. 
         [0003]    Gas turbine engines are known, and typically include a fan delivering air into a compressor. Compressed air is passed downstream into a combustor where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors, driving them to rotate. 
         [0004]    A turbine case enclosing turbine rotors may become extremely hot, and thus cooling air is provided to cool the turbine case. The cooling air is then recovered after having cooled the turbine case, and redirected to a distinct location. 
         [0005]    In the prior art, a recovery duct has been connected by a plurality of fingers which extend radially outwardly from an outer periphery of the turbine case to a main duct which leads to an outlet tube. 
         [0006]    The prior art structure had a large number of pieces, and also required complex installation and maintenance procedures. 
       SUMMARY OF THE INVENTION 
       [0007]    In a featured embodiment, a turbine cooling manifold has a plurality of pieces, with each piece extending in a circumferential direction to abutting flanges. The abutting flanges are secured together at circumferential ends of each of the plurality of pieces. Cooling channels are formed between a radially inner wall and an outer wall of the cooling manifold. Air inlets are formed in at least a plurality of pieces, with air inlets delivering air into the cooling channels. Fingers on the outer wall of the cooling manifold are aligned within an air outlet, such that air can be delivered into the inlet, cool an interior of the cooling manifold in cooling channels, and leave through the outlet into the fingers, and then extend to a main conduit. The main is being secured to the outer wall of the cooling manifold. 
         [0008]    In another embodiment according to the previous embodiment, one of the plurality of pieces has an outlet connector which is connected to an outlet s-tube. 
         [0009]    In another embodiment according to any of the previous embodiments, the piece that receives the outlet connector has main conduit portions extending in both circumferential directions, and has mating flanges at each of two opposed circumferential ends attached to others of the plurality of pieces. 
         [0010]    In another embodiment according to any of the previous embodiments, the inlets include forward air inlets positioned at an axially forward end, which is actually forward of an axially forward most end of the fingers, and which deliver air into a forward portion of the interior of the cooling manifold. 
         [0011]    In another embodiment according to any of the previous embodiments, there are rear air inlets circumferentially intermediate the fingers, which deliver cooling air into a rear portion of the interior of the cooling manifold. Air entering both the forward and rear inlets cooling the interior of the cooling manifold, and then communicate with the air outlet and into the finger. 
         [0012]    In another embodiment according to any of the previous embodiments, the fingers have a radially outermost end which allows access to a bolt hole on a plate positioned radially outwardly of the main conduit. 
         [0013]    In another embodiment according to any of the previous embodiments, the outer wall of the cooling manifold forms a portion of the main conduit and fingers. 
         [0014]    In another featured embodiment, a gas turbine engine has a compressor, a combustor and a turbine section. The turbine section has turbine rotors, and a turbine casing. A cooling manifold cools the turbine casing having a plurality of pieces. Each of the pieces extends in a circumferential direction to abutting flanges. The abutting flanges are secured together at circumferential ends of each of the plurality of pieces. Cooling channels is formed between a radially inner wall and an outer wall of the cooling manifold. Air inlets are formed in at least one of the plurality of pieces. Air inlets deliver air into the cooling channels. Fingers on the outer wall of the cooling manifold are aligned within an air outlet, such that air can be delivered into the inlet, cool an interior of the cooling manifold in the cooling channels, and leave through the outlet into the fingers, and then extend to a main conduit. The main conduit is secured to the outer wall of the cooling manifold. 
         [0015]    In another embodiment according to any of the previous embodiments, one of the plurality of pieces has an outlet connector which is connected to an outlet s-tube. 
         [0016]    In another embodiment according to any of the previous embodiments, the piece which receives the outlet connector has main conduit portions extending in both circumferential directions, and has mating flanges at each of two opposed circumferential ends attached to others of the plurality of pieces. 
         [0017]    In another embodiment according to any of the previous embodiments, the inlets include forward air inlets positioned at an axially forward end, which is actually forward of an axially forward most end of the fingers, and which deliver air into a forward portion of the interior of the cooling manifold. 
         [0018]    In another embodiment according to any of the previous embodiments, there are rear air inlets circumferentially intermediate the fingers delivering cooling air into a rear portion of the interior of the cooling manifold. Air enters both the forward and rear inlets cooling the interior of the cooling manifold, and then communicating with the air outlet and into the finger. 
         [0019]    In another embodiment according to any of the previous embodiments, the fingers have a radially outermost end which allows access to a bolt hole on a plate positioned radially outwardly of the main conduit. 
         [0020]    In another embodiment according to any of the previous embodiments, the outer wall of the cooling manifold forms a portion of the main conduit and fingers. 
         [0021]    These and other features of this application may be best understood from the following specification drawings, the following which is a brief description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  schematically shows a gas turbine engine. 
           [0023]      FIG. 2  shows an air recovery manifold. 
           [0024]      FIG. 3  is a front view of the  FIG. 2  air recovery manifold. 
           [0025]      FIG. 4A  shows a first component. 
           [0026]      FIG. 4B  shows a second component. 
           [0027]      FIG. 4C  shows a third component. 
           [0028]      FIG. 4D  shows a fourth component. 
           [0029]      FIG. 5  shows a feature of a second embodiment. 
           [0030]      FIG. 6  is a cross-sectional view. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]      FIG. 1  schematically illustrates a gas turbine engine  20 . The gas turbine engine  20  is disclosed herein as a two-spool turbofan that generally incorporates a fan section  22 , a compressor section  24 , a combustor section  26  and a turbine section  28 . Alternative engines might include an augmentor section (not shown) among other systems or features. The fan section  22  drives air along a bypass flow path B in a bypass duct defined within a nacelle  15 , while the compressor section  24  drives air along a core flow path C for compression and communication into the combustor section  26  then expansion through the turbine section  28 . Although depicted as a turbofan gas turbine engine in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures. 
         [0032]    The engine  20  generally includes a low speed spool  30  and a high speed spool  32  mounted for rotation about an engine central longitudinal axis A relative to an engine static structure  36  via several bearing systems  38 . It should be understood that various bearing systems  38  at various locations may alternatively or additionally be provided. 
         [0033]    The low speed spool  30  generally includes an inner shaft  40  that interconnects a fan  42 , a low pressure compressor  44  and a low pressure turbine  46 . The inner shaft  40  is connected to the fan  42  through a geared architecture  48  to drive the fan  42  at a lower speed than the low speed spool  30 . The high speed spool  32  includes an outer shaft  50  that interconnects a high pressure compressor  52  and high pressure turbine  54 . A combustor  56  is arranged between the high pressure compressor  52  and the high pressure turbine  54 . A mid-turbine frame  57  of the engine static structure  36  is arranged generally between the high pressure turbine  54  and the low pressure turbine  46 . The mid-turbine frame  57  further supports bearing systems  38  in the turbine section  28 . The inner shaft  40  and the outer shaft  50  are concentric and rotate via bearing systems  38  about the engine central longitudinal axis A which is collinear with their longitudinal axes. 
         [0034]    The core airflow is compressed by the low pressure compressor  44  then the high pressure compressor  52 , mixed and burned with fuel in the combustor  56 , then expanded over the high pressure turbine  54  and low pressure turbine  46 . The mid-turbine frame  57  includes airfoils  59  which are in the core airflow path. The turbines  46 ,  54  rotationally drive the respective low speed spool  30  and high speed spool  32  in response to the expansion. 
         [0035]    The engine  20  in one example is a high-bypass geared aircraft engine. In a further example, the engine  20  bypass ratio is greater than about six (6), with an example embodiment being greater than ten (10), the geared architecture  48  is an epicyclic gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about 2.3 and the low pressure turbine  46  has a pressure ratio that is greater than about five (5). In one disclosed embodiment, the engine  20  bypass ratio is greater than about ten (10:1), the fan diameter is significantly larger than that of the low pressure compressor  44 , and the low pressure turbine  46  has a pressure ratio that is greater than about five (5:1). Low pressure turbine  46  pressure ratio is pressure measured prior to inlet of low pressure turbine  46  as related to the pressure at the outlet of the low pressure turbine  46  prior to an exhaust nozzle. The geared architecture  48  may be an epicycle gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about 2.5:1. It should be understood, however, that the above parameters are only exemplary of one embodiment of a geared architecture engine and that the present invention is applicable to other gas turbine engines including direct drive turbofans. 
         [0036]    A significant amount of thrust is provided by the bypass flow B due to the high bypass ratio. The fan section  22  of the engine  20  is designed for a particular flight condition—typically cruise at about 0.8 Mach and about 35,000 feet. The flight condition of 0.8 Mach and 35,000 ft, with the engine at its best fuel consumption—also known as “bucket cruise Thrust Specific Fuel Consumption (‘TSFC’)”—is the industry standard parameter of 1 bm of fuel being burned divided by 1 bf of thrust the engine produces at that minimum point. “Low fan pressure ratio” is the pressure ratio across the fan blade alone, without a Fan Exit Guide Vane (“FEGV”) system. The low fan pressure ratio as disclosed herein according to one non-limiting embodiment is less than about 1.45. “Low corrected fan tip speed” is the actual fan tip speed in ft/sec divided by an industry standard temperature correction of [(Tram ° R)/(518.7° R)] 0.5 . The “Low corrected fan tip speed” as disclosed herein according to one non-limiting embodiment is less than about 1150 ft/second. 
         [0037]      FIG. 2  shows an air recovery or turbine cooling manifold  80 , which may be utilized in the turbine section of the engine  20 , as an example. 
         [0038]    An outlet s-tube  82  communicates a main recovery duct  184  to a downstream location. A plurality of fingers  86  have inlets (See  FIG. 6 ) which communicate air outwardly of internal channels in the cooling manifold  80  into the main duct  184 , such that it may be delivered to the outlet s-tube  82 . 
         [0039]    As shown in  FIG. 3 , the main duct  184  has portions  84  and  85  extending in opposed circumferential directions from the outlet tube  82 . A clamp  88  secures the outlet tube  82  to the tube portions  84  and  85 . 
         [0040]    Clamp edges or flanges  100 ,  101 ,  102 ,  103  and  104  connect four separate pieces, as will be explained below. As can be appreciated, the tube portions  84  and  85  are secured directly to a radially outer surface  200  of the cooling manifold  80 . 
         [0041]      FIG. 4A  shows a first piece including an input  83  to connect the two portions  85  and  86  to the outlet tube  82 . There are connecting flanges  101  and  104  at edges of this first portion. A second flange  101  connects to a connecting flange  101  on a second portion  100  as shown in  FIG. 4B . Second portion  100  has fingers  86 , and a connecting flange  102  at an opposed circumferential edge. 
         [0042]    As shown in  FIG. 4C , the connecting flange  102  connects to another portion  104  which extends to a connecting flange  103 . As shown in  FIG. 4D , the connecting flange  103  connects a piece  310  to the portion  86  through another paired to connection flange  104 . The four pieces ( 85 / 86 ,  100 ,  104  and  310 ) that make up the main recovery duct  184  all include duct flow positions communicating with fingers  86 . 
         [0043]    Inlets  90  capture cooling air to be delivered into the interior of the turbine cooling manifold  80 . As can be appreciated, the four pieces shown in  FIGS. 4A-4D  are assembled together, and the outlet s-tube  82  is attached to complete the recovery tube  184 . 
         [0044]      FIG. 5  shows an embodiment wherein a finger  110  is radially lower than a main tube portion  109 . The main tube portion  109  is beneath a bolting flange  114  having bolt holes  112 . This provides additional room for the bolts to attach the cooling manifold  180  to a connecting housing. 
         [0045]    As shown in  FIG. 6 , the inlets  90  lead to air inlets  123 , as do inlets  130  which are positioned intermediate fingers, and can be seen in each of  FIGS. 4A-4D . The air entering the inlet  130  passes through a torturous path, and cools internal surfaces of the cooling manifold  80 . Similarly, the air entering the inlet  92  also cools the interior of the cooling manifold  80 . The air also cools the outer surface of a turbine case  300 . Both flows leave out of a plurality of outlets  122  leading into the fingers  110 . Notably, the fingers  86  will receive air in the same manner. The air leading through the outlets  122  into the fingers  110  passes into a chamber  120 , and eventually all reaches the outlet s-tube  82 . As shown, bolt  121  bolts the bolt flange at  114  to an adjacent housing. 
         [0046]    As can be seen at  203  in  FIG. 6 , the flow conduits found in each of the four pieces of  FIGS. 4A-4D  are connected directly to an outer periphery of the cooling manifold  80 . 
         [0047]    Air inlets  90  are positioned at an axially forward end, which is actually forward of an axially forward most end of the fingers  86  (or  110 ), and which deliver air into a forward portion of an interior of the turbine casing  80 . 
         [0048]    Rear air inlets  130  are circumferentially intermediate fingers  86 , and deliver cooling air into a rear portion of the interior of cooling manifold  80 . Air enters both the forward and rear inlets for cooling the interior of the cooling manifold  80 . Both flows then communicate with air outlets  122  and into a finger  86  (or  110 ). 
         [0049]    Fingers  110  have a radially outermost end which allows access to bolt holes  112  on a plate positioned radially outwardly of the conduit  203 . 
         [0050]    Although an embodiment of this invention has been disclosed, a worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content.