Patent Publication Number: US-2019186381-A1

Title: Intergrated environmental control system manifold

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/118,565 filed on Aug. 12, 2016, which is National Phase Application of Patent Application PCT/US2014/056200 filed on Sep. 18, 2014, which claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 61/940,143, filed on Feb. 14, 2014, the contents each of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The subject matter of the present disclosure relates generally to gas turbine engines and, more particularly, relates to air distribution through a gas turbine engines. 
     BACKGROUND 
     Gas turbine engines may include a low pressure compressor and a high pressure compressor. In many engine configurations, a low pressure compressor case surrounds the low pressure compressor and a high pressure compressor case surrounds the high pressure compressor with a compressor intermediate case located therebetween. The area located between the low pressure compressor case and the high pressure compressor case is commonly referred to as station 2.5. Station 2.5 generally includes a 2.5 bleed path through the compressor intermediate case to allow air to bleed into the fan stream. In addition to relieving pressure when the engine is at idle or low power, the 2.5 bleed path also allows dirt particles from the low pressure compressor discharge air to exit into the fan stream, so that cleaner air passes downstream through the core engine. The 2.5 bleed path is traditionally regulated by a 2.5 bleed valve that controls the amount of bleed air flowing to the fan stream. In many configurations, the 2.5 bleed valve is located in the core compartment to facilitate maintenance. 
     An environmental control system bleed path may also be implemented in gas turbine engines. The environmental control system bleed path guides the air to the environmental control system for supplying air to the cabin of an aircraft. Conventional environmental control system bleed paths are usually sourced from the middle section of the high pressure compressor. While effective, the environmental control system air sourced from the middle section of the high pressure compressor may contain dirt particles that were not diverted through the 2.5 bleed path. However, cleaner environmental control system bleed air is desirable because this air eventually circulates throughout the aircraft cabin and is breathed in by the passengers. 
     Accordingly, there is a need to provide cleaner environmental control system bleed air into the aircraft cabin such as by sourcing this air from station 2.5 immediately downstream of the 2.5 bleed path so that there is minimal disruption to the core air flow. 
     SUMMARY 
     In accordance with an aspect of the disclosure, an intermediate case for a gas turbine engine compressor is provided. The intermediate case may include a plurality of intermediate case struts joining the intermediate case to an inner engine structure. Each strut of the plurality of intermediate case struts includes a leading edge. A turning scoop may be disposed at the leading edge of each strut of the plurality of intermediate case struts. A plurality of diffusers may extend radially outwardly from the intermediate case so that each diffuser of the plurality of diffusers may be engaged with a corresponding turning scoop. A substantially annular structural fire wall may extend radially outwardly from the intermediate case. An environmental control system manifold may be disposed on the intermediate case. The environmental control system manifold may include an exit port. 
     In accordance with another aspect of the disclosure, a non-structural fairing may extend radially outwardly from the intermediate case. The non-structural fairing may be disposed upstream of the annular structural fire wall to define a 2.5 bleed duct therebetween. 
     In accordance with yet another aspect of the disclosure, a 2.5 stability bleed valve may be in operable association with the non-structural fairing and the 2.5 bleed duct. The 2.5 stability bleed valve may be operably movable between an open and closed position. 
     In accordance with still yet another aspect of the disclosure, the 2.5 bleed duct may be arranged to the intermediate case forming a first dirt separator. 
     In further accordance with another aspect of the disclosure, the turning scoop may include an upstream-facing scoop inlet. The scoop inlet may be offset substantially radially inwardly from the intermediate case forming a second dirt separator. 
     In further accordance with yet another aspect of the disclosure, the environmental control system manifold may be asymmetrical. 
     In further accordance with still yet another aspect of the disclosure, the environmental control system manifold may be formed of a substantially annular first and second collection wall. The first collection wall may extend substantially radially outwardly from the intermediate case. The second collection wall may extend downstream substantially axially from the structural fire wall. The first and second collection walls intersect to form a smooth bend. The exit port may be disposed on the first collection wall. The second collection wall may extend a first distance from the fire wall adjacent to the exit port and tapers moving along its circumference until it reaches an area oppositely positioned across the intermediate case, where the second collection wall may extend a second distance from the fire wall that is less than the first distance. The first collection wall may extend a third distance from the intermediate case adjacent the exit port and tapers moving along its circumference until it reaches the area oppositely positioned across the intermediate case, where the first collection wall may extend a fourth distance from the intermediate case that is less than the third distance. 
     In accordance with another aspect of the disclosure, a gas turbine engine is provided. The gas turbine engine may include a compressor intermediate case. A plurality of intermediate case struts may join the compressor intermediate case to an inner engine structure. Each strut of the plurality of intermediate case struts includes a leading edge. A turning scoop may be disposed at the leading edge of each strut of the plurality of intermediate case struts. A plurality of diffusers may extend radially outwardly from the compressor intermediate case so that each diffuser of the plurality of diffusers may be engaged with a corresponding turning scoop. A substantially annular structural fire wall may extend radially outwardly from the compressor intermediate case. An environmental control system manifold may be disposed on the compressor intermediate case. The environmental control system manifold may include an exit port. 
     In accordance with still another aspect of the disclosure, a V-groove may be disposed on the structural fire wall. The V-groove securely interfaces with a core engine cowl. 
     In accordance with still yet another aspect of the disclosure, a plurality of guide vanes may be disposed upstream of each scoop inlet. 
     In accordance with another aspect of the disclosure, a method of providing cleaner environmental control system bleed air, which exits a gas turbine engine, so that there is minimal disruption to a core air flow is provided. The method entails joining a plurality of intermediate case struts between a compressor intermediate case and an inner engine structure. Each strut of the plurality of intermediate case struts includes a leading edge. Another step may be disposing a turning scoop at the leading edge of each strut of the plurality of intermediate case struts. Yet another step may be providing a plurality of diffusers extending radially outwardly from the compressor intermediate case. Each diffuser of the plurality of diffusers engages with a corresponding turning scoop. Still yet another step may be providing a substantially annular structural fire wall extending radially outwardly from the compressor intermediate case. A further step may be providing a non-structural fairing extending radially outwardly from the compressor intermediate case. The non-structural fairing is disposed upstream of the annular structural fire wall to define a 2.5 bleed duct therebetween. Still a further step may be providing an environmental control system manifold on the compressor intermediate case. The environmental control system manifold includes an exit port. 
     In accordance with yet another aspect of the disclosure, the method may include providing an upstream-facing scoop inlet onto the turning scoop so that the scoop inlet is offset substantially radially inwardly from the compressor intermediate case, forming a second dirt separator. 
     Other aspects and features of the disclosed systems and methods will be appreciated from reading the attached detailed description in conjunction with the included drawing figures. Moreover, selected aspects and features of one example embodiment may be combined with various selected aspects and features of other example embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For further understanding of the disclosed concepts and embodiments, reference may be made to the following detailed description, read in connection with the drawings, wherein like elements are numbered alike, and in which: 
         FIG. 1  is a side view of a gas turbine engine with portions sectioned and broken away to show details of the present disclosure; 
         FIG. 2  is an enlarged perspective view of an environmental control system manifold with portions sectioned and broken away to show details of the present disclosure; 
         FIG. 3  is a perspective view of an environmental control system manifold with portions sectioned and broken away to show details of the present disclosure; 
         FIG. 4  is an enlarged perspective view of an environmental control system manifold with portions sectioned and broken away to show details of the present disclosure; 
         FIG. 5  is a perspective view of an environmental control system manifold, constructed in accordance with the teachings of this disclosure; 
         FIG. 6  is plan view of an environmental control system manifold, constructed in accordance with the teaching of this disclosure; 
         FIG. 7  is a side view of an environmental control system manifold, constructed in accordance with the teachings of this disclosure; and 
         FIG. 8  is a flowchart illustrating a sample sequence of steps which may be practiced in accordance with the teachings of this disclosure. 
     
    
    
     It is to be noted that the appended drawings illustrate only typical embodiments and are therefore not to be considered limiting with respect to the scope of the disclosure or claims. Rather, the concepts of the present disclosure may apply within other equally effective embodiments. Moreover, the drawings are not necessarily to scale, emphasis generally being placed upon illustrating the principles of certain embodiments. 
     DETAILED DESCRIPTION 
     Throughout this specification the terms “downstream” and “upstream” are used with reference to the general direction of gas flow through the engine and the terms “axial”, “radial” and “circumferential” are generally used with respect to the longitudinal central engine axis. 
     Referring now to  FIG. 1 , a gas turbine engine constructed in accordance with the present disclosure is generally referred to by reference numeral  10 . The gas turbine engine  10  includes a compressor section  12 , a combustor  14  and a turbine  16 . The serial combination of the compressor section  12 , the combustor  14  and the turbine  16  is commonly referred to as a core engine  18 . The compressor section  12  includes a low pressure compressor  20  and a high pressure compressor  22 , which is downstream of the low pressure compressor  20 . The engine  10  is circumscribed about a longitudinal central axis  24 . 
     A core engine case  26  surrounds the core engine  18 . The core engine case  26  is formed, in part, from a low pressure compressor case  28 , which mainly surrounds the low pressure compressor  20 , and a high pressure compressor case  30 , which mainly surrounds the high pressure compressor  22 . A compressor intermediate case  32  is located between the low pressure compressor case  28  and the high pressure compressor case  30 , joining the cases  28 ,  30  together. Alternatively, the high pressure compressor case  30  and the compressor intermediate case  32  may form a single case. 
     Air enters the compressor section  12  at the compressor inlet  34  and is pressurized. The pressurized air then enters the combustor  14 . In the combustor  14 , the air mixes with jet fuel and is burned, generating hot combustion gases that flow downstream to the turbine  16 . The turbine  16  extracts energy from the hot combustion gases to drive the compressor section  12  and a fan  36 , which includes a plurality of airfoils  38  (one shown in  FIG. 1 ). As the turbine  16  drives the fan  36 , the airfoils  38  rotate so as to take in more ambient air. This process accelerates the ambient air  40  to provide the majority of the useful thrust produced by the engine  10 . Generally, in some modern gas turbine engines, the fan  36  has a much greater diameter than the core engine  18 . Because of this, the ambient air flow  40  through the fan  36  can be 5-10 times higher, or more, than the core air flow  42  through the core engine  18 . The ratio of flow through the fan  36  relative to flow through the core engine  18  is known as the bypass ratio. 
     The fan  36  and the core engine cowl  44 , which surrounds the core engine  18 , are surrounded by a fan cowl  46  forming part of a nacelle  48 . A core compartment  50  is functionally defined by the area between core engine case  26  and the core engine cowl  44 . A fan duct  52  is functionally defined by the area between the core engine cowl  44  and the nacelle  48 . The fan duct  52  is substantially annular in shape so that it can accommodate the air flow produced by the fan  36 . This air flow  40  travels the length of the fan duct  52  and exits downstream at a fan nozzle  54 . A tail cone  56  may be provided at the core engine exhaust nozzle  58  to smooth the discharge of excess hot combustion gases that were not used by the turbine  16  to drive the compressor section  12  and the fan  36 . 
     As best seen in  FIGS. 2-7 , a structural fire wall  60  extends radially outwardly from the compressor intermediate case  32  to the core engine cowl  44  (shown in  FIG. 1 ). The structural fire wall  60  may be substantially annular and includes a V-groove  62  disposed along its outer rim adjacent to the core engine cowl  44 . The V-groove  62  securely interfaces with the core engine cowl  44 . The V-groove is designed to support the core engine cowl  44 . 
     A non-structural fairing wall  64  also extends radially outwardly from the compressor intermediate case  32 , at a location upstream of the structural fire wall  60 , to the core engine cowl  44 . The non-structural fairing wall  64  is offset axially from the structural fire wall so that a 2.5 bleed duct  66  is defined therebetween. The compressor intermediate case  32  is arranged at this location to allow portions of the core air flow  42  (also known at this location as the low pressure compressor discharge air) flowing from the low pressure compressor  20  to flow into the 2.5 bleed duct  66 . The fairing wall  64  provides the core air flow  42  with a bleed air path  68 . The bleed air path  68  receives the air flow from the low pressure compressor  20  and flows through the 2.5 bleed duct  66  into the fan duct  52  to join the air flow  40  (also commonly referred to as the fan stream). 
     A 2.5 stability bleed valve  70  is substantially annular and is in operable association with the fairing wall  64  and the 2.5 bleed duct  66 . The 2.5 stability bleed valve  70  is operably movable between an open position (as shown in  FIGS. 2-4 ) and a closed position to control the air flow through the 2.5 bleed duct  66 . In the closed position, the 2.5 stability bleed valve  70  prevents any core air flow  42  from flowing into the 2.5 bleed duct  66 . In the open position, the stability bleed valve  70  relieves the engine bleed pressure through the bleed air path  68 . The position of the 2.5 stability bleed valve  70  may vary between the open and closed position to provide the desired amount of air flow through the 2.5 bleed duct  66 . The 2.5 stability bleed valve  70  may be actuated in response to a controller, such as a full authority digital engine control (FADEC). 
     The 2.5 bleed duct  66  is arranged to the compressor intermediate case  32  forming a first dirt separator  72 . During operation, dirt particles moving through the core air flow  42  gather along the compressor intermediate case  32 . When the 2.5 stability bleed valve  70  is in the open position, or in a variable position between the opened and closed position, the dirt particles will pass into the bleed air path  68  and exit into the air flow  40 , allowing cleaner air to pass downstream toward the high pressure compressor  22 . 
     A plurality of intermediate case struts  74  extend substantially radially inwardly from the compressor intermediate case  32 . As a non-limiting example, the plurality of intermediate case struts  74  may include 8 struts, but more or less struts also fit within the scope of the disclosure. The plurality of intermediate case struts  74  joins the compressor intermediate case  32  to an inner engine structure  76  and carries the loads between the inner engine structure  76  and the compressor intermediate case  32 . The plurality of intermediate case struts  74  is circumferentially spaced apart from one another in such a way so that the majority of the core air flow  42  flows from the low pressure compressor  20  around the struts  74  to the high pressure compressor  22 . Each strut of the plurality of intermediate case struts  74  includes an upstream leading edge  78 . 
     A turning scoop  80  is disposed on the leading edge  78  of each strut of the plurality of intermediate case struts  74 . The turning scoop  80  is hollowed and includes a scoop inlet  81  that faces upstream to capture a portion of the core air flow  42  flowing from the low pressure compressor  20 . Because the turning scoop  80  is substantially curved, the turning scoop  80  radially turns the portion of core air flow  42  approximately 90 degrees into a corresponding diffuser  82 , which is disposed on the surface of the compressor intermediate case  32  that faces the core compartment  50 . The turning scoop  80  engages with the corresponding diffuser  82  so that the portion of core air flow  42  flows continuously through the turning scoop  80  into the diffuser  82 . The scoop inlet  81  may be offset substantially radially inwardly from the compressor intermediate case  32 , to form a second dirt separator  83 , so that any dirt particles that bypassed the first dirt separator  72  will pass along the compressor intermediate case  32  and avoid passing into the scoop inlet  81 . The second dirt separator  83  facilitates in supplying cleaner air to the environmental control system. A plurality of guide vanes  84  may be disposed upstream of each scoop inlet  81  to remove the swirl from the core air flow  42  before it passes into the turning scoop  80 . 
     The portion of the core air flow  42  that exits the diffuser  82  feeds into an asymmetrical environmental control system manifold  85 , which contains the air for distribution, through an exit port  86 , to the environmental control system of an aircraft. As best seen in  FIGS. 5-7 , the environmental control system manifold  85  is formed of a first collection wall  88  and a second collection wall  90 . The first collection wall  88  is substantially annular and extends substantially radially outwardly from the compressor intermediate case  32 . The second collection wall  90  is also substantially annular and extends downstream substantially axially from the structural fire wall  60 . The first collection wall  88  and the second collection wall  90  intersect to form a smooth bend so that the first and second collection walls  88 ,  90 , the structural fire wall  60  and the compressor intermediate case  32  form an air collection chamber  92  of the environmental control system manifold  85 . 
     The exit port  86  is disposed on the first collection wall  88  and includes an annular rim  94 , which extends substantially axially downstream. The exit port  86  may engage a tubing or a piping  95  that transfers the exit air to the environmental control system of the aircraft. Accordingly, the exit port  86  is positioned to accommodate easy attachment of the tubing or piping  95 . The exit port  86  may also transfer the exit air to a turbo-compressor. 
     Furthermore, as best seen in  FIG. 7 , the downstream extension from the structural fire wall  60  of the second collection wall  90  gradually tapers such that the second collection wall  90  extends a first distance  96  from the fire wall  60  adjacent to the exit port  86  and tapers moving along its circumference until it reaches the area oppositely positioned across the compressor intermediate case  32 , where the second collection wall  90  extends a second distance  98  from the fire wall  60  that is less than the first distance  96 . In a similar manner, the first collection wall  88  gradually tapers such that the first collection wall  88  extends a third distance  100  from the compressor intermediate case  32  adjacent the exit port  86  and tapers moving along its circumference until it reaches the area oppositely positioned across the compressor intermediate case  32 , where the first collection wall  88  extends a fourth distance  102  from the compressor intermediate case  32  that is less than the third distance  100 . This asymmetrical configuration of the environmental control system manifold  85  is designed to maintain a balanced air pressure within the collection chamber  92  and prevent an over pressure scenario from occurring. 
     During operation of the engine  10 , the core air flow  42  enters the compressor inlet  34  and flows into the low pressure compressor  20 . The core air flow  42  passes through the low pressure compressor  20  and into the compressor intermediate case  32 . As the core air flow  42  enters the compressor intermediate case  32 , the core air flow  42  may be diverted so that it splits into at least 3 different paths. The core air flow  42  may pass through the 2.5 bleed duct  66  when the 2.5 stability bleed valve  70  is in the open position, or in a variable position between the opened and closed position, and exit into the air flow  40 . Accordingly, the dirt particles flowing from the low pressure compressor  20  along the wall of the compressor intermediate case  32  will also flow out through the 2.5 bleed duct  66  and exit into the air flow  40 . Alternatively, when the 2.5 stability bleed valve  70  is in the closed position the core air flow  42  will be prevented from flowing into the 2.5 bleed duct  66 . 
     Further, portions of the core air flow  42  pass into each of the turning scoops  80  located on each leading edge  78  of each strut of the plurality of intermediate case struts  74 , regardless of whether the 2.5 stability bleed valve  70  is in the open or closed position. Because the scoop inlet  81  is offset substantially radially inwardly from the compressor intermediate case  32  to form a second dirt separator  83 , the portions of the core air flow  42  through the turning scoops  80  are much cleaner air. The curved structure of each turning scoop  80  radially turns the core air flow  42  approximately 90 degrees allowing the core air flow  42  to pass into corresponding diffusers  82 , which slow down the core air flow  42  before entering into the environmental control system manifold  85 . The core air flow  42  that is collected in the collection chamber  92  of the environmental control system manifold  85  then flows through the exit port  86  and to the environmental control system of the aircraft. 
     The majority of the core air flow  42 , which does not pass into the 2.5 bleed duct  66  or the turning scoops  80 , travels between each strut of the plurality of intermediate case struts  74  and toward the high pressure compressor  22 . 
       FIG. 8  illustrates a flowchart  800  of a sample sequence of steps which may be performed to of provide cleaner environmental control system bleed air, which exits a gas turbine engine, so that there is minimal disruption to a core air flow. Box  810  shows the step of joining a plurality of intermediate case struts between a compressor intermediate case and an inner engine structure. Each strut of the plurality of intermediate case struts includes a leading edge. Another step, as illustrated in box  812 , is disposing a turning scoop at the leading edge of each strut of the plurality of intermediate case struts. Box  814  illustrates the step of providing a plurality of diffusers extending radially outwardly from the compressor intermediate case. Each diffuser of the plurality of diffusers engages with a corresponding turning scoop. Yet another step, as shown in box  816 , is providing a substantially annular structural fire wall extending radially outwardly from the compressor intermediate case. 
     As shown in box  818 , another step is providing a non-structural fairing extending radially outwardly from the compressor intermediate case. The non-structural fairing is disposed upstream of the annular structural fire wall to define a 2.5 bleed duct therebetween. Box  820  illustrates the step of providing an environmental control system manifold on the compressor intermediate case. The environmental control system manifold includes an exit port. Another step may be providing an upstream-facing scoop inlet onto the turning scoop so that the scoop inlet is offset substantially radially inwardly from the compressor intermediate case, forming a second dirt separator. The environmental control system manifold may be asymmetrical so that the environmental control system manifold is formed of a substantially annular first and second collection wall. The first collection wall may extend substantially radially outwardly from the compressor intermediate case while the second collection wall may extend downstream substantially axially from the structural fire wall. The first and second collection walls intersect to form a smooth bend. The exit port may be disposed on the first collection wall. The second collection wall may extend a first distance from the fire wall adjacent to the exit port and tapers moving along its circumference until it reaches an area oppositely positioned across the compressor intermediate case, where the second collection wall may extend a second distance from the fire wall that is less than the first distance. The first collection wall may extend a third distance from the compressor intermediate case adjacent the exit port and tapers moving along its circumference until it reaches the area oppositely positioned across the compressor intermediate case, where the first collection wall may extend a fourth distance from the compressor intermediate case that is less than the third distance. 
     While the present disclosure has shown and described details of exemplary embodiments, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the disclosure as defined by claims supported by the written description and drawings. Further, where these exemplary embodiments (and other related derivations) are described with reference to a certain number of elements it will be understood that other exemplary embodiments may be practiced utilizing either less than or more than the certain number of elements. 
     INDUSTRIAL APPLICABILITY 
     Based on the foregoing, it can be seen that the present disclosure sets forth an environmental control system manifold integrated with the station 2.5 compressor intermediate case. The teachings of this disclosure can be employed to provide cleaner air to the environmental control system of an aircraft. Moreover, through the novel teachings set forth above, the cleaner air can be provided with minimal disruption to the core air flow. Furthermore, the present disclosure provides a structural fire wall having a V-groove that can support the core engine cowl.