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EP-3907388-B1 - ENGINE BLEED POWER RECOVERY SYSTEMS AND RELATED METHODS

EP3907388B1EP 3907388 B1EP3907388 B1EP 3907388B1EP-3907388-B1

Inventors

  • MACKIN, STEVE G.
  • Dirusso, Joseph Michael

Dates

Publication Date
20260506
Application Date
20210301

Claims (10)

  1. A power recovery system (202) for an aircraft engine (110) of an aircraft (100), comprising: a power recovery turbine (250) coupled to a shaft-driven device (204), wherein the shaft-driven device (204) is a core engine of the aircraft (100), the core engine including a core compressor, (216), a core turbine (226), and a core shaft (222, 224) of the aircraft engine (110), the power recovery turbine (250) being operatively coupled to the core shaft (222, 224) of the core engine (110), wherein an output shaft (304) of the power recovery turbine (250) is operatively coupled to the core shaft (222, 224) via a transmission (260), wherein the power recovery turbine (250) outputs power via the output shaft (304), which transfers to the aircraft engine (110) via the transmission (260); a bleed air valve (534, 536, 538) coupled between the power recovery turbine (250) and a bleed air source (242, 244); and a controller (500) configured to operate the bleed air valve (534, 536, 538) to allow bleed air to flow to the power recovery turbine (250) when the aircraft engine (110) operates in a predetermined mode of operation (800, 900, 1000, 1100); wherein the power recovery turbine (250) includes a variable nozzle guide vane (320), the controller (500) configured to modulate the variable nozzle guide vane (320) to regulate a discharge pressure of the bleed air at the turbine outlet (254), and wherein the transmission (260) includes a clutch (318) coupled between the power recovery turbine (250) and the core engine, the clutch (318) configured to operatively couple the output shaft (304) and the core shaft (222, 224) when the aircraft engine (110) operates in the predetermined mode of operation and operatively decouple the output shaft (304) and the core shaft (222, 224) when the aircraft engine (110) does not operate in the predetermined mode of operation.
  2. The system (202) as defined in claim 1, wherein the clutch is movable between an engaged position to rotatably couple the output shaft (304) and the core shaft (222, 224) and a disengaged position to decouple the output shaft (304) and the core shaft (222, 224), and wherein in the disengaged position, the clutch (318) prevents transfer of power from the power recovery turbine (250) to the core shaft (222, 224).
  3. The system (202) as defined in claim 2, wherein the clutch is a sprag clutch.
  4. The system (202) as defined in any of claims 1 to 3, wherein the predetermined mode of operation includes at least one of takeoff, climb, descent, landing or cruise.
  5. The system (202) as defined in any of claims 1 to 4, wherein the power recovery turbine (250) includes a turbine inlet (252) and a turbine outlet (254), the turbine inlet (252) fluidly coupled to the bleed air source (242, 244) and the turbine outlet (254) being fluidly coupled to a heat exchanger (256).
  6. The system (202) as defined in claim 1, wherein the transmission (260) includes a multi-speed gearbox (306) to reduce a speed of the output shaft (304) of the power recovery turbine (250) to a speed of the input shaft when the power recovery turbine (250) is engaged with the shaft-driven device (204).
  7. The system (202) as defined in any of claims 1 to 6, further including a precooler (256) in fluid communication with the bleed air outlet of the power recovery turbine (250).
  8. The system (202) as defined in any of claims 1 to 7, further including a bleed air valve (534, 536, 538) movable between an open position to allow bleed air to flow to the bleed air inlet of the power recovery turbine (250) and a closed position to prevent bleed air from flowing to the bleed air inlet.
  9. An aircraft (100) comprising the power recovery system (202) of any of claims 1 to 8.
  10. A method (1400) of operating a bleed air system (200) for an aircraft engine (110) of an aircraft (100), the bleed air system (200) including a power recovery system (202), the power recovery system (202) including a power recovery turbine (250) coupled to a shaft-driven device (204), a bleed air valve (534, 536, 538) coupled between the power recovery turbine (250) and a bleed air source (242, 244); and a controller (500) configured to operate the bleed air valve (534, 536, 538) to allow bleed air to flow to the power recovery turbine (250) when the aircraft engine (110) operates in a predetermined mode of operation (800, 900, 1000, 1100), said method (1400) comprising: measuring (1402) a pressure of bleed air within the bleed air system; comparing (1406) the measured bleed air pressure to a target bleed air pressure; activating (1408) the power recovery turbine (250) based on the comparison, wherein the power recovery turbine (250) includes a variable nozzle guide vane (320), the controller (500) configured to modulate the variable nozzle guide vane (320) to regulate a discharge pressure of the bleed air at the turbine outlet (254), wherein the shaft-driven device (204) is a core engine of the aircraft (100), the core engine including a core compressor, (216), a core turbine (226), and a core shaft (222, 224) of the aircraft engine (110), the power recovery turbine (250) being operatively coupled to the core shaft (222, 224) of the core engine (110), wherein an output shaft (304) of the power recovery turbine (250) is operatively coupled to the core shaft (222, 224) via a transmission (260), wherein the power recovery turbine (250) outputs power via the output shaft (304), which transfers to the aircraft engine (110) via the transmission (260), and wherein the transmission (260) includes a clutch (318) coupled between the power recovery turbine (250) and the core engine, the clutch (318) configured to operatively couple the output shaft (304) and the core shaft (222, 224) when the aircraft engine (110) operates in the predetermined mode of operation and operatively decouple the output shaft (304) and the core shaft (222, 224) when the aircraft engine (110) does not operate in the predetermined mode of operation.

Description

The present disclosure relates generally to aircraft and, more particularly, to engine bleed power recovery systems and related methods. BACKGROUND Commercial aircraft typically extract bleed air from a compressor of an aircraft engine to provide pressurized air for various aircraft systems. For example, commercial aircraft often employ bleed air to provide air supply for an environmental control system to pressurize a passenger cabin of the aircraft and/or thermal anti-icing systems to provide heated air for anti-icing applications. Document US 2018/058333 A1, according to its abstract, states bleed air systems for use with aircraft and related methods are disclosed. An example apparatus includes a compressor having a compressor inlet, a compressor outlet, and a first drive shaft. The compressor outlet is to be fluidly coupled to a system of an aircraft that receives pressurized air, and the compressor inlet is to receive bleed air from a low-pressure compressor of an engine of the aircraft. The example apparatus includes a gearbox operatively coupled to the first drive shaft to drive the compressor. The gearbox is to be operatively coupled to and powered by a second drive shaft extending from the engine. The example apparatus also includes a clutch disposed between the first drive shaft and the gearbox to selectively disconnect the first drive shaft from the gearbox. Document US 2006/010875 A1, according to its abstract, states a bleed air power assist system coupled to a gas turbine engine that includes a high pressure turbine, a low pressure turbine, and an electrical generator driven by the high pressure turbine. The bleed air power assist system selectively bleeds air discharged from the high pressure turbine and supplies it to an air turbine that is also coupled to the generator. Thus, the system selectively reduces the power extracted from the high pressure turbine. This, coupled with the bleed air that is diverted from the low pressure turbine, allows the low pressure spool to run at lower speeds when high engine thrust is not needed or desired, but when the generator is still needed to supply high electrical loads. Document US 2010/314877 A1, according to its abstract, states a gas turbine engine includes a main compressor section for compressing air, a main combustor section positioned downstream of the main compressor section, a main turbine section positioned downstream of the main combustor section, and a spool extending from the main compressor section to the main turbine section. A second turbine is fluidically connected to the main compressor section by a bleed passage. An electrical generator is mechanically driven by both the spool and the second turbine. Document EP 3783212 A1 which forms prior art only under Art. 54(3) EPC, according to its abstract, states a gas turbine engine includes a compressor. A turbine is mechanically connected to the compressor by a shaft. An air-driven auxiliary turbine is in fluid communication with the compressor and is configured to receive pressurized air from the compressor. An auxiliary generator is operably connected to the auxiliary turbine. The auxiliary generator is configured to generate electrical energy in response to an operation of the auxiliary turbine. An energy storage device is in electrical communication with the auxiliary generator. Document US 5 125 597 A, according to its abstract, states that an aircraft gas turbine engine is provided with a starting air turbine that is directly connected through the starter gearbox to the high pressure, HP, shaft and is provided with an apparatus to extract excess energy from engine compressor bleed air, return it to the engine, and to Start the engine with compressed air from starting air sources, and to cool and provide compressed air for powering the Environmental Control System, ECS, and using the bleed air for cabin refreshening. The air turbine may be connected to a nacelle boundary layer bleed compressor to bleed boundary layer air from a forward portion of the nacelle to reduce nacelle surface drag. The ECS may be provided with a wing boundary layer bleed means which uses a cooling air fan in the ECS to draw cooling air through the heat exchangers in the ECS pack from the boundary layer air from a forward portion of the aircraft's wing to reduce its surface drag. SUMMARY There is provided a power recovery system for an aircraft engine of an aircraft, comprising a power recovery turbine coupled to a shaft-driven device, wherein the shaft-driven device is a core engine of the aircraft, the core engine including a core compressor, a core turbine, and a core shaft of the aircraft engine, the power recovery turbine being operatively coupled to the core shaft of the core engine, wherein an output shaft of the power recovery turbine is operatively coupled to the core shaft via a transmission, wherein the power recovery turbine outputs power via the output shaft, which transfers to the aircraft engine