阅读说明：本技术 用于飞机发动机的动力回收的系统和操作引气系统的方法 (System for power recovery of an aircraft engine and method for operating a bleed air system ) 是由 史蒂文·G·麦金 约瑟夫·迈克尔·迪鲁索 于 2021-05-06 设计创作，主要内容包括：公开了用于飞机发动机的动力回收的系统和操作引气系统的方法。用于飞机发动机(110)的示例性动力回收系统(202)包括耦接到轴驱动装置(204)的动力回收涡轮机(250)。引气阀(534、536、538)耦接在动力回收涡轮机(250)与引气源(242、244)之间。控制器(500)被配置为当飞机发动机(110)以预定的操作模式操作时操作引气阀(534、536、538)以允许引气流向动力回收涡轮机(250)。(A system for power recovery of an aircraft engine and a method of operating a bleed air system are disclosed. An exemplary power recovery system (202) for an aircraft engine (110) includes a power recovery turbine (250) coupled to a shaft drive (204). Bleed valves (534, 536, 538) are coupled between the power recovery turbine (250) and the bleed air sources (242, 244). The controller (500) is configured to operate the bleed valves (534, 536, 538) to allow bleed air to flow to the power recovery turbine (250) when the aircraft engine (110) is operating in a predetermined operating mode.)

1. System (202) for power recovery of an aircraft engine (110), comprising:

a power recovery turbine (250), the power recovery turbine (250) coupled to a shaft drive (204);

a bleed valve (534, 536, 538), the bleed valve (534, 536, 538) being coupled between the power recovery turbine (250) and a bleed air source (242, 244); and

a controller (500), the controller (500) being configured to operate the bleed valves (534, 536, 538) to allow bleed air to flow to the power recovery turbine (250) when the aircraft engine (110) is operating in a predetermined operating mode (800, 900, 1000, 1100).

2. The system (202) according to claim 1, wherein the shaft drive (204) is a core engine of the aircraft, the core engine including a core compressor (216), a core turbine (226) and a spindle (222, 224) of the aircraft engine (110), the power recovery turbine (250) being operatively coupled to the spindle (222, 224) of the core engine (110).

3. The system (202) according to claim 2, wherein an output shaft (304) of the power recovery turbine (250) is operably coupled to the spindle (222, 224) via a transmission (260).

4. The system (202) according to claim 3, wherein the transmission (260) includes a clutch (318), the clutch (318) being coupled between the power recovery turbine (250) and the core engine, the clutch (318) being configured to operably couple the output shaft (304) and the mandrels (222, 224) when the aircraft engine (110) is operating in the predetermined operating mode, and to operably decouple the output shaft (304) and the mandrels (222, 224) when the aircraft engine (110) is not operating in the predetermined operating mode.

5. The system (202) according to claim 1, wherein the shaft drive (204) is an electrical generator having an input shaft, wherein an output shaft (304) of the power recovery turbine (250) is coupled to the input shaft of the electrical generator.

6. The system (202) of claim 1, wherein the predetermined mode of operation includes at least one of take-off, climb, descent, landing, or cruise.

7. The system (202) of claim 1, wherein the power recovery turbine (250) includes a turbine inlet (252) and a turbine outlet (254), the turbine inlet (252) being fluidly coupled to the bleed air source (242, 244) and the turbine outlet (254) being fluidly coupled to a heat exchanger (256).

8. The system (202) of claim 7, wherein the power recovery turbine (250) includes variable nozzle guide vanes (320), the controller (500) configured to adjust the variable nozzle guide vanes (320) to adjust a discharge pressure of the bleed air at the turbine outlet (254).

9. The system (202) of claim 1, wherein the power recovery turbine further comprises:

a bleed air inlet (252), the bleed air inlet (252) for receiving bleed air from the bleed air source (242, 244);

a bleed air outlet (254), the bleed air outlet (254) for providing the bleed air to a downstream system (236, 240, 256); and

an output shaft (304), the output shaft (304) being operatively coupled to an input shaft (224) of a shaft drive (204) of the aircraft (110), the power recovery turbine (250) generating power in response to processing the bleed air as the bleed air flows from the bleed air inlet (252) to the bleed air outlet (254), the power recovery turbine (250) transferring the generated power to the input shaft (224) via the output shaft (304).

10. A method (1400) of operating a bleed air system, the method (1400) comprising: measuring (1402) a bleed air pressure within the bleed air system; comparing (1406) the measured bleed air pressure to a target bleed air pressure;

activating (1408) a power recovery turbine based on the comparison.

Technical Field

The present disclosure relates generally to aircraft and, more particularly, to engine bleed air power recovery systems and related methods.

Background

Commercial aircraft typically extract bleed air from the compressor of the aircraft engine to provide pressurized air for various aircraft systems. For example, commercial aircraft often employ bleed air to provide an air supply for environmental control systems to pressurize a passenger cabin of the aircraft and/or thermal anti-icing systems to provide heated air for anti-icing applications.

Disclosure of Invention

An exemplary power recovery system for an aircraft engine includes a power recovery turbine coupled to a shaft drive. A bleed air valve is coupled between the power recovery turbine and the bleed air source. The controller is configured to operate the bleed air valves to allow bleed air to flow to the power recovery turbine when the aircraft engines are operating in a predetermined mode of operation.

Another exemplary power recovery system includes a power recovery system including a power recovery turbine having: a bleed air inlet for receiving bleed air from a bleed air source; a bleed air outlet for providing bleed air to the downstream system; and an output shaft operably coupled to the input shaft of the shaft drive. A power recovery turbine generates power in response to processing the bleed air as it flows from the bleed air inlet to the bleed air outlet, the power recovery turbine transmitting the generated power to the input shaft via the output shaft.

An exemplary aircraft includes an aircraft engine having a core compressor for generating compressed air and a core turbine for driving the core compressor. The power recovery turbine is operatively coupled to the aircraft engine. The power recovery turbine has a turbine inlet in fluid communication with a bleed air supply source provided by the core compressor and a turbine outlet in fluid communication with a downstream system of the aircraft. The power recovery turbine generates power when processing bleed air from the turbine inlet to the turbine outlet and transfers the generated power to a core compressor of the aircraft engine.

The features, functions, and advantages that have been discussed can be achieved independently in various embodiments or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings.

Drawings

FIG. 1 is an illustration of an exemplary aircraft including an exemplary bleed air system having an exemplary power recovery system constructed in accordance with the teachings of the present disclosure.

FIG. 2 is a schematic illustration of an exemplary aircraft engine having an exemplary power recovery system disclosed herein.

FIG. 3 is a schematic illustration of an exemplary transmission of the exemplary power recovery system shown in FIG. 2.

FIG. 4 is a schematic illustration of an exemplary clutch of the exemplary transmission shown in FIG. 3.

Figure 5 is a schematic view of the exemplary bleed air system shown in figures 1 to 4.

Figures 6 to 11 are schematic views of the exemplary bleed air system shown in figures 1 to 5 shown in different operating modes.

FIG. 12 is a schematic illustration of an exemplary aircraft engine employing the exemplary power recovery system shown in FIGS. 1-11 as a starter.

FIG. 13 is a schematic illustration of an exemplary aircraft engine having another exemplary power recovery system disclosed herein.

Figure 14 is a flow chart representing an exemplary method that may be performed by the exemplary bleed air system shown in figures 1-13.

Figure 15 is a block diagram of an example processing platform that is configured to execute the instructions shown in figure 14 to implement the example bleed air system controller of the example bleed air system shown in figures 1 to 13.

Wherever possible, the same reference numbers will be used throughout the drawings and the accompanying written description to refer to the same or like parts. As used in this patent, stating that any component (e.g., layer, film, region or plate) is positioned (e.g., positioned, placed, arranged or formed on, etc.) on another component in any way, means that the referenced component is either in contact with the other component or that the referenced component is on the other component with one or more intervening components therebetween. The statement that any element is in contact with another element means that there are no intervening elements between the two elements.

Detailed Description

The bleed air pressure varies greatly with the operating conditions of the aircraft, such as engine speed, operating altitude, etc. In order to meet the pressure and/or temperature requirements of various aircraft systems, bleed air is typically extracted from a stage of a compressor that provides bleed air having a pressure and/or temperature that is higher than that required by the various systems that utilize the bleed air. Thus, before providing bleed air to the systems of the aircraft (e.g. the environmental control system), the pressurized bleed air is usually cooled via a heat exchanger or a pre-cooler and reduced in pressure via a pressure regulating valve. Existing aircraft bleed air systems therefore utilise pressure regulating valves and heat exchangers to reduce the bleed air to an allowable pressure and temperature compatible with the systems provided. The regulating valve may effectively limit the bleed air pressure without recovering energy from the bleed air. Thus, a large portion of the energy expended by the engine to generate bleed air is wasted when cooling the bleed air and/or reducing the pressure of the bleed air for various systems, and thus, extracting the bleed air in this manner may reduce the efficiency of the engine. This wasted energy results in greater fuel consumption.

The exemplary engine bleed air power recovery system and related methods disclosed herein provide compressed or pressurized air to various systems of an aircraft, such as an Environmental Control System (ECS), a thermal anti-icing system (e.g., a wing and/or engine anti-icing system), a pneumatic supply system (to supply pneumatics), and/or any other system of an aircraft that requires the use of compressed air.

Specifically, the example bleed air recovery system and related methods disclosed herein collect energy from extracted engine bleed air. The example bleed air recovery systems and related methods disclosed herein convert energy collected in bleed air into shaft horsepower that is fed back into an aircraft engine (e.g., a jet engine high-spool shaft). When activated, the example bleed air recovery systems and related methods disclosed herein may be used to supplement power generated by a core gas turbine engine of an aircraft (e.g., an aircraft engine). The recovered energy increases the fuel efficiency of the aircraft engine while also increasing the available thrust.

To harvest energy from the bleed air, the bleed air recovery systems and related methods disclosed herein employ a turbine that receives bleed air from an aircraft engine prior to providing the bleed air to a downstream system (e.g., a precooler, an ECS, etc.). For example, the example bleed air recovery systems and related methods disclosed herein may extract bleed air for driving a turbine (e.g., a power recovery turbine) during operation of an aircraft engine. The example turbines disclosed herein reduce one or more parameters (e.g., pressure, temperature, etc.) of the bleed air prior to providing the bleed air to the downstream system.

In some examples, the example bleed air recovery systems and related methods disclosed herein may be employed during predetermined modes of operation of the aircraft (e.g., taxiing, takeoff, climb, cruise, landing, etc.). In some examples, to activate and/or deactivate the example turbine, the example bleed air recovery systems and related methods disclosed herein may include an example control system to control the flow of bleed air to the turbine. An example control system disclosed herein includes a bleed valve coupled between a bleed air source and a turbine and a controller (e.g., communicatively and/or operatively) coupled to the bleed air valve. The control system, e.g. via a controller, may be configured to operate the bleed air valves during a predetermined mode of operation (e.g. take-off, climb, descent, landing, cruise, etc.) to direct or direct bleed air from the bleed air supply to the turbine.

In some examples, the example bleed air recovery systems and related methods disclosed herein may be used to start aircraft engines. Thus, in some cases, the starter of the aircraft engine may be replaced by the exemplary bleed air recovery system and related methods disclosed herein. Specifically, the exemplary turbomachine may be used to start (e.g., rotate) an aircraft engine. For example, a turbine (e.g., a pneumatic starter turbine) may be configured to generate a starting torque sufficient to start an aircraft engine.

Fig. 1 illustrates an exemplary aircraft 100 embodying aspects of the teachings of the present disclosure. The aircraft 100 includes a fuselage 102, a first wing 104 coupled to the fuselage 102, and a second wing 106 coupled to the fuselage 102. The fuselage 102 defines a cabin 108 that carries passengers and/or cargo. In the example shown, the aircraft 100 includes an aircraft engine 110 carried by the wings 104 and an aircraft engine 112 carried by the second wing 106. In other examples, the aircraft 100 may include only one engine, or may include more than two engines. The engines may be carried on the wings 104, 106 and/or another structure on the aircraft 100 (e.g., on the aft portion of the fuselage 102).

Fig. 2 is a partial cross-sectional view of the aircraft engine 110 shown in fig. 1. The aircraft engine 110 has an exemplary bleed air system 200, the bleed air system 200 including a power recovery system 202 according to the teachings of the present disclosure. The power recovery system 202 is configured to recover energy from the bleed air and convert the recovered energy into power (e.g., horsepower) that is delivered to the aircraft engines 110. The energy recovered by the power recovery system 202 increases the fuel efficiency of the aircraft engine 110 while also increasing thrust. In some examples, the energy extracted by the power recovery system 202 may be employed to operate (e.g., drive) an auxiliary system (e.g., a generator that generates electrical power for the auxiliary system or a device such as a pump).

The power recovery system 202 shown in FIG. 2 is shown implemented in conjunction with the aircraft engine 110 (shown in partial cutaway view) of the aircraft 100 (FIG. 1). Systems similar to the bleed air system 200 and/or the power recovery system 202 may be implemented in connection with the aircraft engines 112 (fig. 1). Thus, in some examples, each of the aircraft engines 110, 112 includes a power recovery system 202. In some examples, each of the aircraft engines 110, 112 employs a dedicated power recovery system 202. This configuration enables the power recovery systems 202 of each of the aircraft engines 110, 112 to work together to meet the supply air requirements of the aircraft systems (e.g., ECS, auxiliary pneumatic systems, etc.) and/or to provide redundancy. In some examples, only one of the aircraft engines 110, 112 includes the power recovery system 202 disclosed herein. For the sake of brevity, only one aircraft engine 110 is described in detail.

Referring to FIG. 2, aircraft engine 110 is a turbofan engine having an engine core 204 (sometimes referred to as a gas turbine engine) and a fan 206. Engine core 204 drives fan 206 to generate thrust. The fan 206 rotates within an engine compartment 208 of the aircraft engine 110. As the fan 206 rotates, the fan 206 generates an airflow 210. A portion of fan air 210a of airflow 210 flows through a fan bypass 212 (e.g., a duct, channel, passage, nozzle duct, etc.) that bypasses engine core 204, and another portion 210b of airflow 210 is also provided to engine core 204 for combustion.

The engine core 204 operates by drawing air through a compressor intake section 214 of an engine compressor 216 (e.g., a core compressor) in the engine core 204 via a fan 206. The engine compressor 216 includes a plurality of compressor sections. For example, as shown, the engine compressor 216 is a two-shaft compressor that includes two compressors, a first or Low Pressure Compressor (LPC)218 and a second or High Pressure Compressor (HPC) 220. In the example shown, the LPC 218 provides relatively low pressure air, while the HPC 220 provides relatively high pressure air. The LPC 218 and HPC 220 are operably coupled to respective Low Pressure Compressor (LPC) shaft 222 (e.g., a first mandrel) and High Pressure Compressor (HPC) shaft 224 (e.g., a second mandrel). A turbine 226 (e.g., a core turbine) drives the fan 206 and the engine compressor 216. Specifically, the turbine 226 includes a Low Pressure (LP) turbine 228 and a High Pressure (HP) turbine 230. To drive the engine compressor 216 and the fan 206, the LPC shaft 222 is operably coupled to an LP turbine 228, and the HPC shaft 224 is operably coupled to an HP turbine 230. Thus, LPC 218 and HPC 220 are shaft-driven power plants. As used herein, a shaft driven power plant refers to a machine or device capable of absorbing power or receiving energy via an input shaft of the machine. For example, the LPC 218 includes an LPC shaft 222 (e.g., an input shaft) that receives power from an LP turbine 228, and the HPC 220 includes an HPC shaft 224 (e.g., an input shaft) that receives power from an HP turbine 230. Thus, LPC 218 and HPC are shaft driven power plants or machines that can receive power or energy. In some examples, the engine compressor 216 may include more or fewer compressor sections, each having, for example, a turbine and a shaft.

After exiting HPC 220, the high pressure air is provided to combustion chamber 232, where fuel is injected and mixed with the high pressure air and ignited in combustion chamber 232. The high energy gas flow exiting the combustor 232 turns the blades of the LP turbine 228 and the HP turbine 230, with the LP turbine 228 and the HP turbine 230 being coupled to one of the LPC shaft 222 or HPC shaft 224, respectively. The rotation of the LPC shaft 222 and the HPC shaft 224 turns the blades of the LPC 218 and the HPC 220. The heated air is discharged via nozzle 234 where it mixes with cooler temperature fan air 210a provided by fan 206 and bypasses engine core 204 (e.g., engine core) via fan bypass 212 to generate forward thrust that propels aircraft 100 (fig. 1) in a forward direction. Although in this example, the aircraft engine 110 is implemented as a turbofan engine, the power recovery system 202 may similarly be implemented in conjunction with other types of engines (e.g., turboprop engines, open-rotor engines, etc.).

In order to supply pressurized air (i.e., compressed air) to the various systems of the aircraft 100, the aircraft engine 110 of the illustrated example includes a bleed air system 200. For example, the bleed air system 200 provides supply air (e.g., pressurized, cooled, and/or heated air) to various systems including, for example, an Environmental Control System (ECS)236, a thermal anti-icing system (TAI)238 including an engine anti-icing system (EAI)238a and a wing anti-icing system (WAI)238b, and/or any other system 240 of the aircraft 100 that utilizes the pressurized, cooled, and/or heated air. For example, the ECS236 regulates cabin supply air to the cabin pressure and/or cabin temperature and supplies the regulated air to the cabin 108 of the fuselage 102 (fig. 1). In particular, the air provided by the ECS236 is used to pressurize the nacelle 108 and to provide cooled and/or heated air to adjust the temperature of the air in the nacelle 108 to a comfortable setting. The ECS236 may include one or more ECS components (e.g., an air cycle refrigeration system), receive pressurized air (e.g., pressurized and/or heated air) from the bleed air system 200, and condition or condition the air to cabin pressure and/or temperature. EAI 238a and WAI 238b utilize supply air to de-ice or prevent ice from forming on the exterior surfaces of aircraft engines 110, 112 and wings 104, 106, respectively, as shown in fig. 1. The supply air may be provided to other systems 240 including, for example, a pneumatic system or the like.

In order to provide pressurized supply air, the bleed air system 200 of the illustrated example extracts bleed air from the aircraft engines 110. For example, the bleed air system 200 extracts bleed air from dedicated compressor stages (e.g., first stage, second stage, fourth stage, etc.) of the HPC 220. Specifically, bleed air is provided from a first bleed air port 242 (e.g., a fourth stage bleed air port) of the HPC 220 and/or from a second bleed air port 244 (e.g., a tenth stage bleed air port) of the HPC 220 (e.g., a two-port mixing manifold). In some cases, the bleed air extracted from the HPC 220 may have a pressure between about 40psi and 150psi and a temperature between about 50 ° F and 700 ° F. In some examples, the bleed air system 200 extracts bleed air from the LPC 218 via the LP bleed air port. In some examples, the bleed air system 200 extracts bleed air from the first bleed air port 242, the second bleed air port 244, and/or other bleed air ports (i.e., receives mixed bleed air from the various bleed air ports and/or compressor stages).

The power recovery system 202 includes a Power Recovery (PR) turbine 250 that receives bleed air via a turbine inlet 252 (i.e., a bleed air inlet) and discharges the bleed air via a turbine outlet 254 (e.g., a bleed air outlet) to a precooler 256 (e.g., a heat exchanger). The precooler 256 receives the bleed air and provides the bleed air to downstream systems (e.g., the ECS236, other systems 240, body ducts, etc.). The precooler 256 is configured to receive fan air 210a from the fan duct 290 via a fan air inlet 292 to extract heat from the bleed air passing through the precooler 256 to reduce the temperature of the bleed air. Heated fan air exiting precooler 256 via fan air outlet 294 is exhausted via an aft vent (e.g., and used for thrust recovery).

Additionally, the power recovery system 202 extracts or collects energy from the engine bleed air. Specifically, the PR turbine 250 generates power when processing bleed air from the turbine inlet 252 to the turbine outlet 254 and transfers the generated power to the engine compressor 216 of the aircraft engine 110. For example, the PR turbine 250 extracts or collects energy by reducing one or more parameters (e.g., temperature, pressure, etc.) from the bleed air as it flows between the turbine inlet 252 and the turbine outlet 254. In some examples, the power recovery system 202 extracts energy from the bleed air during predetermined operating conditions of the aircraft 100 (e.g., taxiing, takeoff, climb, cruise, descent, landing, etc.). The energy extracted from the bleed air is converted to power (e.g., shaft horsepower) and transmitted (e.g., fed back) through the PR turbine 250 to the aircraft engines 110. In the illustrated example, shaft horsepower is transferred to the HPC shaft 224 via the PR turbine 250. However, in some examples, the energy extracted by the PR turbine 250 is fed back into the LPC shaft 222.

To operatively couple the power recovery system 202 and the aircraft engine 110, the aircraft engine 110 employs a transmission 260 (e.g., a fixed gear ratio transmission, a continuously variable transmission, etc.). In some examples, the power recovery system 202 and/or the transmission 260 provide a means for transferring energy (e.g., horsepower) to the aircraft engine 110. Transmission 260 includes a drive shaft 262, the drive shaft 262 having a first gear 264 (e.g., a bevel gear), the first gear 264 engaged (e.g., meshed) with a second gear 266 (e.g., a second bevel gear), the second gear 266 operably coupled to the HPC shaft 224 of the HPC 220.

FIG. 3 is a schematic illustration of the exemplary transmission 260 shown in FIG. 2. The power recovery system 202 is driven by bleed air 302 from the aircraft engines 110. For example, bleed air 302 flows through the PR turbine 250 to the turbine inlet 252 and via the turbine outlet 254 to the precooler 256. The PR turbine 250 converts the energy in the bleed air 302 into power (e.g., shaft horsepower) and transfers the power to the aircraft engine 110. For example, at the turbine inlet 252, the bleed air has one or more first fluid characteristics (e.g., bleed air temperature, bleed air pressure, etc.). At the turbine outlet 254, the bleed air 302 has one or more second fluid characteristics (e.g., bleed air temperature, bleed air pressure, etc.) that are different from (e.g., less than) the first fluid characteristics of the bleed air 302 at the turbine inlet 252. For example, the bleed air 302 has a first pressure and a first temperature at the turbine inlet 252 that are greater than a second pressure and a second temperature at the turbine outlet 254. Thus, as the bleed air 302 flows through the PR turbine 250 from the turbine inlet 252 to the turbine outlet 254, the PR turbine 250 reduces the pressure and temperature of the bleed air 302. Energy extracted from the bleed air 302 (e.g., from reducing the temperature and pressure of the bleed air 302) is collected or extracted by the PR turbine 250. The PR turbine 250 outputs energy (e.g., power) via a turbine output shaft 304, which turbine output shaft 304 is transmitted to the aircraft engine 110 via a transmission 260 (e.g., a continuously variable transmission). For example, turbine output shaft 304 is operably coupled to HPC shaft 224 via transmission 260. The transmission 260 is mounted between the aircraft engine 110 (e.g., HPC shaft 224) and the PR turbine 250.

The transmission 260 enables the speed of the PR turbine 250 to be varied (e.g., increased or decreased) relative to the operating speed of the aircraft engine 110 (e.g., HPC shaft 224). For example, the transmission 260 changes (e.g., increases or decreases) the speed (e.g., Revolutions Per Minute (RPM)) of the PR turbine 250 to match the speed (e.g., Revolutions Per Minute (RPM)) of the HPC shaft 224 of the aircraft engine 110. Specifically, the gearbox 306 matches the RPM of the turbine output shaft 304 and the RPM of the HPC shaft 224 to enable the PR turbine 250 to transfer torque to the HPC shaft 224.

To change the speed of the turbine output shaft 304, the transmission 260 includes a gearbox 306. For example, the gearbox 306 is a reduction gearbox or a multi-speed gearbox. The gearbox 306 is operably coupled to the PR turbine 250 and the HPC shaft 224. For example, the gearbox 306 includes a gearbox input shaft 308, the gearbox input shaft 308 operably coupled to the turbine output shaft 304 via a gear train 310. The gear train 310 of the illustrated example includes a first gear 312 (e.g., a spur gear) and a second gear 314 (e.g., a spur gear) in meshing engagement with the first gear 312. The first gear 312 is coupled (e.g., fixed or keyed) to the turbine output shaft 304 such that the first gear 312 rotates with the turbine output shaft 304. The second gear 314 is coupled (e.g., fixed or keyed) to the gearbox input shaft 308 such that the second gear 314 rotates with the gearbox input shaft 308. Thus, rotation of the turbine output shaft 304 causes rotation of the gearbox input shaft 308 via the gear train 310 (e.g., the first gear 312 and the second gear 314). In turn, the gearbox input shaft 308 causes rotation of the gearbox output shaft 316. The gearbox output shaft 316 is coupled to the drive shaft 262. First gear 264 is coupled (e.g., fixed or keyed) to drive shaft 262, drive shaft 262 is engaged (e.g., meshed) with second gear 266, and second gear 266 is operably coupled (e.g., fixed or keyed) to HPC shaft 224 of HPC 220. In the example shown, the first gear 264 and the second gear 266 are oriented substantially perpendicular to each other. As the drive shaft 262 rotates about its longitudinal axis, the first gear 264 engaged with the second gear 266 rotates the second gear 266, and thus the HPC shaft 224, about its longitudinal axis, thereby transferring power or energy (e.g., horsepower) to the aircraft engine 110.

In the example shown, a gear ratio is employed between the HPC shaft 224 and the PR turbine 250 to allow the rotational speed of the drive shaft 262 to match the rotational speed of the HPC shaft 224 (e.g., match RPM). For example, the gearbox 306 varies (e.g., increases or decreases) the rotational speed of the gearbox input shaft 308 based on the gear ratios of the first and second gears 264, 266 (e.g., a ratio of 2: 1 for the first and second gears 264, 266 of 1: 1, etc.) to provide a rotational speed of the gearbox output shaft 316 that matches the rotational speed of the HPC shaft 224. Accordingly, the turbine output shaft 304 rotates to provide power (e.g., horsepower) to the HPC shaft 224 via the transmission 260 (e.g., gearbox 306).

To engage and/or disengage transmission 260 from HPC shaft 224, transmission 260 includes a clutch 318. The clutch 318 moves between an engaged position to rotatably couple the turbine output shaft 304 with the HPC shaft 224 and a disengaged position to decouple the turbine output shaft 304 from the HPC shaft 224. In the disengaged position, the clutch 318 prevents power (e.g., horsepower) from being transferred from the PR turbine 250 to the HPC shaft 224. In this manner, the clutch 318 may be employed to deactivate the PR turbine 250 when power recovery is not required (e.g., during coasting). The power recovery system 202 is external with respect to the engine core 204 of the aircraft engine 110. For example, the PR turbine 250, the gearbox 306, and/or the clutch 318 are disposed within the engine compartment 208 (e.g., upper fork) of the aircraft engine 110. Further, although the second gear 266 is shown as being operably coupled to the HPC shaft 224 in the illustrated example, in other examples, the second gear 266 can be operably coupled to and driven by the LPC shaft 222 of the LPC 218 or any other drive shaft of the aircraft engine 110. In some examples, the transmission 260 (e.g., gearbox 306, turbine output shaft 304) can be operably coupled to one or more other systems used in the aircraft 100, such as, for example, an electrical generator and/or a hydraulic pump (e.g., in place of the HPC shaft 224). The gearbox 306 is a multi-speed gearbox that can be clutched out via the clutch 318, allowing for a wide range of operating conditions and/or allowing the bleed air system 200 to handle fault mode scenarios for the PR turbine 250.

The PR turbine 250 of the illustrated example is a radial inflow turbine. To account for varying inflow conditions (e.g., pressure fluctuations of the bleed air) and/or varying outflow requirements, the PR turbine 250 includes adjustable nozzles or variable inlet guide vanes 320. The variable inlet guide vanes 320 may enable the PR turbine 250 to handle a variable range of inlet conditions and outlet requirements. More specifically, in some examples, the variable inlet guide vanes 320 may be adjusted to achieve higher or lower air flow, temperature, and/or pressure at the turbine outlet 254. Thus, the turbine discharge pressure at the turbine outlet 254 is adjusted by adjusting the variable inlet guide vanes 320. In other examples, the PR turbine 250 may include movable vanes, diffuser guide vanes, vaneless diffusers, or systems with port shrouds, may be employed to account for varying inflow conditions and outflow requirements, and/or any other variable geometry feature to address varying ranges in inlet conditions and outlet requirements.

Fig. 4 is a front view of the exemplary clutch 318 shown in fig. 3. The clutch 318 of the illustrated example is a sprag clutch. The clutch 318 is a one-way mechanical clutch. The clutch 318 includes an outer race 402, an inner race 404, and sprags 406 (e.g., spring-loaded sprags) positioned circumferentially between the inner race 404 and the outer race 402. By friction, sprags 406 are operable to engage inner race 404 and outer race 402 and to disengage inner race 404 and outer race 402. For example, the gearbox output shaft 316 is coupled to the outer race 402 and the drive shaft 262 is coupled (e.g., fixed or keyed) to the inner race 404. Specifically, when the gearbox output shaft 316 rotates (e.g., in a first direction), the outer race 402 drives the inner race 404 via frictional engagement of the sprags 406, and when the gearbox output shaft 316 does not rotate, the inner race 404 may rotate freely (e.g., the outer race 402 does not drive the inner race 404). Although a wedge clutch is shown in fig. 4, the transmission 260 may employ any other suitable clutch configured to engage and disengage the turbine output shaft 304 and the HPC shaft 224. In some examples, the transmission 260 may employ an electronic clutch. In some examples, transmission 260 may employ a planetary gear system (e.g., a power split planetary gear system), a multi-speed discrete gear ratio system, a fixed gear ratio system, and/or any other suitable transmission. In some examples, the transmission 260 may include a fixed ratio gear train disposed between the turbine output shaft 304 and the drive shaft 262.

Figure 5 is a schematic view of the bleed air system 200 shown in figures 1 to 4. To provide bleed air to aircraft systems (e.g., ECS236, TAI 238, etc.), the bleed air system 200 employs a bleed air system controller 500. The bleed air system 200 includes a first TAI passage 502 and a second TAI passage 504, the first TAI passage 502 for fluidly coupling the first bleed air port 242 and the TAI 238, and the second TAI passage 504 for fluidly coupling the second bleed air port 244 and the TAI 238. In some examples, the TAI 238 receives bleed air from the first bleed air port 242 via the first TAI passage 502, receives bleed air from the second bleed air port 244 via the second TAI passage 504, and/or receives a mixture of bleed air from the first bleed air port 242 and the second bleed air port 244 via the first TAI passage 502 and the second TAI passage 504.

The power recovery system 202 includes a Low Pressure Power Recovery (LPPR) passage 506 and a High Pressure Power Recovery (HPPR) passage 508. An LPPR passageway 506 fluidly couples the first bleed air port 242 and the turbine inlet 252, and an HPPR passageway 508 fluidly couples the second bleed air port 244 and the turbine inlet 252. For example, LPPR 506 and HPPR 508 are fluidly coupled at a junction 507, and PR passage 509 fluidly couples LPPR 506 and HPPR 508 to turbine inlet 252. A Power Recovery (PR) manifold 510 fluidly couples the turbine outlet 254 and the pre-cooler 256. As used herein, a channel or manifold includes one or more pipes, conduits, hoses, and/or other fluid flow systems or devices.

To provide bleed air to the precooler 256 when the power recovery system 202 is in a deactivated state, the bleed air system 200 includes a primary manifold 512. The primary manifold 512 is fluidly coupled to the first and/or second bleed air ports 242, 244. In the example shown, the primary manifold 512 is fluidly coupled to the first bleed air port 242 via the LPPR passageway 506 and fluidly coupled to the second bleed air port 244 via the HPPR passageway 508. In some examples, the primary manifold 512 is fluidly coupled to the first and/or second bleed air ports 242, 244 via respective dedicated (e.g., isolated) passages. The primary manifold 512 is fluidly coupled to the precooler 256. In the example shown, the primary manifold 512 is fluidly coupled to the PR manifold 510 upstream of the precooler 256. In some examples, the bleed air from the primary manifold 512 may be mixed with the bleed air in the PR manifold 510 before the mixed bleed air is provided to the precooler 256.

The precooler 256 includes a precooler inlet 514 and a precooler outlet 516, the precooler inlet 514 for receiving bleed air from the PR manifold 510 and/or the primary manifold 512, the precooler outlet 516 fluidly coupled to the ECS236 via an ECS passage 518 and fluidly coupled to the other systems 240 via a secondary passage 520. To cool the bleed air flowing through the precooler 256, the bleed air is directed through the heat exchanger portion 522 of the precooler 256. The precooler 256 of the illustrated example includes a heat exchanger portion 522 between the precooler inlet 514 and the precooler outlet 516. The heat exchanger portion 522 receives bleed air from the PR manifold 510 and/or the primary manifold 512. Cooling fluid (e.g., fan air 210a) flows through the pre-cooler 256 between the cooling fluid inlet 524 and the cooling fluid outlet 526 to remove heat and, thus, cool the bleed air flowing through the heat exchanger section 522. The bleed air flowing through the heat exchanger portion 522 is fluidly isolated from the cooling fluid (i.e., the bleed air does not mix with the fan air 210 a). To provide cooling fluid to the precooler 256, the bleed air system 200 includes a fan duct 290 to direct fan air 210a from the fan 206 to the cooling fluid inlet 524.

The precooler 256 of the illustrated example includes a precooler bypass 528 to enable bleed air to bypass the precooler 256 (e.g., the heat exchanger portion 522). When flowing through the precooler bypass 528, the bleed air is not cooled. To direct the flow of bleed air between the heat exchanger portion 522 and the precooler bypass 528, the precooler 256 includes a precooler valve 530 and an actuator 532 (e.g., a linear actuator). The actuator 532 moves the precooler valve 530 to a first position to allow bleed air to flow through the heat exchanger section 522 and to block or limit bleed air flow through the precooler bypass 528 and to a second position to allow bleed air to flow through the precooler bypass 528 and to block or limit bleed air flow through the heat exchanger section 522. An exemplary heat exchanger that may implement precooler 256 is described in U.S. patent application 13/624,612, filed on 21/9/2012, which is incorporated herein by reference. In some examples, the precooler 256 may be a heat exchanger without a precooler bypass 528.

To start the aircraft engine 110, the aircraft engine 110 includes a starter 567. The starter 567 is fluidly coupled to the aircraft engine 110. An activator channel 569 fluidly couples the activator 567 with the precooler inlet 514 of the precooler 256. To start the aircraft engine 110, the auxiliary unit provides pressurized fluid (pneumatic air) to the starter passage 569 via the precooler outlet 516, through the precooler bypass 528 and the precooler inlet 514, and provides pressurized fluid (pneumatic air) to the starter passage 569. The starter valve 571 moves to an open position to allow fluid in the starter passage 569 to flow to the aircraft engine 110. After the aircraft engine 110 is started, the starter valve 571 is moved to a closed position to prevent fluid flow through the starter passage 569 to the starter 567.

During operation, the bleed air system 200 provides conditioned air to the cabin 108 of the aircraft 100 (e.g., via the ECS 236) based on the number of passengers in the cabin 108. To determine the mass flow rate of the supply air to be supplied to the cabin 108, the bleed air system controller 500 obtains, retrieves and/or receives passenger count information from, for example, the database 586 and/or the engine control system 588. The passenger number information may be manually stored in the database 586. For example, in certain aircraft, the target flow rate may be 0.55 pounds mass (lb.)/minute/passenger. The bleed system controller 500 determines the amount of pressure differential with the bleed system 200 required by the ECS236 to provide the target flow rate. The bleed system controller 500 determines which bleed port (e.g., the first bleed port 242 or the second bleed port 244) is generating sufficient pressurized bleed air to meet the target flow rate. Further, the power recovery system 202 determines, via the bleed air system controller 500, whether the pressurized bleed air is sufficient to provide the target flow rate to the ECS 236. When the pressure is insufficient, the bleed air system controller 500 deactivates the power recovery system 202. When the pressure is sufficient, the bleed air system controller 500 activates the power recovery system 202.

The bleed air system controller 500 enables the bleed air system 200 to extract bleed air from the first bleed air port 242 (e.g., during a high power setting) and from the second bleed air port 244 (e.g., during a low power setting). For example, a high power setting may occur when the aircraft engine 110 generates thrust that exceeds a thrust threshold (e.g., during takeoff, climb, cruise, descent, etc.), while a low power setting may occur when the aircraft engine 110 generates thrust that does not exceed the thrust threshold (e.g., during taxi, flight taxi, etc.). For example, during high power set operations, a parameter (e.g., pressure or temperature) of the bleed air at the first bleed air port 242 is greater than a parameter (e.g., pressure or temperature) of the bleed air at the first bleed air port 242 during low power set operations. Thus, during low power set conditions, the bleed air system 200 extracts bleed air from the second bleed air port 244 because the bleed air at the first bleed air port 242 may not be sufficient to provide target flow rate, temperature, and/or pressure bleed air to the ECS 236. During high power set conditions, the bleed air system 200 extracts bleed air from the first bleed air port 242 because the bleed air at the first bleed air port 242 is sufficient to provide a target flow rate, temperature, and/or pressure to the ECS 236. When bleed air is extracted from the first bleed air port 242, performance efficiency increases because the engine compressor 216 compresses the fan air 210b less often at the first bleed air port 242 (e.g., the fourth compression stage) than at the second bleed air port 244 (e.g., the tenth compression stage). Thus, in this example, it is more desirable to extract bleed air from the first bleed air port 242 than from the second bleed air port 244.

To control the flow of bleed air within the bleed air system 200 and/or to the power recovery system 202, the bleed air system 200 includes one or more control valves 534 and 550. For example, to control the flow of bleed air from the first bleed port 242 to the TAI 238 and the turbine inlet 252 via the LPPR passage 506, the bleed air system 200 includes a first control valve 534 (e.g., an Intermediate Pressure Check Valve (IPCV)). A second control valve 536 (e.g., a High Pressure Shut Off Valve (HPSOV)) controls bleed air flow from the second bleed air port 244 to the turbine inlet 252 via the HPPR passage 508. In the example shown, the second control valve 536 includes a sense line 536a to measure the pressure of the fluid downstream of the second control valve 536. In this manner, the second control valve 536 may adjust the pressure of the bleed air downstream of the second control valve 536 (e.g., at the outlet of the second control valve 536) based on a desired preset pressure value (e.g., a set point). The preset pressure value may be set mechanically and/or may be provided by the bleed air system controller 500 via a signal (e.g. an analogue signal). To control the flow of bleed air from the LPPR passage 506 and/or the HPPR passage 508 to the turbine inlet 252, the power recovery system 202 includes a third control valve 538 (e.g., a stop valve (SOV)). The third control valve 538 provides a bleed control valve to control the flow of bleed air to the turbine inlet 252.

To bypass the PR turbine 250 and control the flow of bleed air to the precooler 256 via the primary manifold 512, the bleed air system 200 includes a fourth control valve 540 (e.g., a pressure regulating shutoff valve (PRSOV)). For example, the fourth control valve 540 enables bleed air to bypass the PR turbine 250 when use of the PR turbine 250 is not needed or desired. For example, if the pressure of the bleed air from the first bleed air port 242 is insufficient to meet the pressure requirements of the ECS236, the bleed air may bypass the PR turbine 250 such that a pressure drop across the PR turbine 250 is not achieved. In the example shown, the fourth control valve 540 includes a sense line 540a to sense the fluid pressure in the primary manifold 512 downstream of the fourth control valve 540. In this manner, the fourth control valve 540 may adjust the pressure downstream of the fourth control valve 540 (e.g., at the outlet of the fourth control valve 540) based on a desired preset value (e.g., a set point). The preset values may be set mechanically and/or may be provided by the bleed air system controller 500 via signals (e.g. analog signals).

The bleed air system 200 includes a fifth control valve 542 (e.g., a low stage ice protection valve) to control the flow of bleed air to the TAI 238, a sixth control valve 546 to control the flow of bleed air to the ECS236, and a seventh control valve 548 to control the flow of bleed air to the other systems 240. In order to control the flow of cooling fluid between the cooling fluid inlet 524 and the cooling fluid outlet 526 of the precooler 256, the bleed air system 200 comprises a fan valve 550.

Each of the control valves 534 and 550 operates independently of the other valves and may operate between an open position (e.g., a fully open position or state) that allows fluid flow through the respective control valve 534 and 550 and a closed position (e.g., a fully closed position or state) that prevents or limits fluid flow through the respective control valve 534 and 550. The control valves 534-550 may include a Pressure Regulating Valve (PRV), a pressure regulating cut-off valve (PRSOV), a cut-off valve (SOV), a high pressure cut-off valve (HPSOV), an Intermediate Pressure Check Valve (IPCV), an anti-reflux valve, a multi-flow reversing valve, a three-way valve, a four-way valve, etc., and/or any other air control device. In some examples, the bleed air system 200 may include more or less than the number of control valves 534, 550, channels 502, 518, 520, and/or manifolds 510, 512 disclosed herein. For example, although the control valve 534 and 550, the channels 502 and 508, 518, 520 and/or the manifold 510 and 512 are shown in FIG. 5. One or more additional valves, passages and/or manifolds may be incorporated into the bleed air system 200.

To measure a parameter or characteristic of the bleed air, the bleed air system 200 includes one or more sensors 552 and 566 (e.g., temperature sensors, pressure sensors, flow sensors, humidity sensors, etc.). For example, the bleed air system 200 includes one or more sensors 552 and 566 to measure the temperature, pressure, flow rate, and/or any other parameter or characteristic of the bleed air system 200. For example, one or more sensors 552 are coupled to the LPPR passageway 506 to measure the pressure and/or flow of bleed air flowing to the turbine inlet 252 via the LPPR passageway 506 and/or the HPPR passageway 508. One or more sensors 554 are coupled near the turbine inlet 252 to measure the temperature of the bleed air at the turbine inlet 252. One or more sensors 556 are coupled to the PR manifold 510 to measure the pressure of the bleed air exiting the turbine outlet 254 before the bleed air flows to the precooler 256. One or more sensors 558 are coupled to the PR manifold 510 to measure the temperature of the bleed air exiting the turbine outlet 254. One or more sensors 560 are coupled near the precooler inlet 514 (downstream of the primary manifold 512) to measure the pressure of the bleed air entering the precooler inlet 514. One or more sensors 562 are coupled near the precooler inlet 514 (downstream of the primary manifold 512) to measure the temperature of the bleed air entering the precooler inlet 514. One or more sensors 564 are coupled near the precooler outlet 516 (downstream of the precooler outlet 516) to measure the pressure of the bleed air exiting the precooler outlet 516. One or more sensors 566 are coupled near the precooler outlet 516 (downstream of the precooler outlet 516) to measure the temperature of the bleed air exiting the precooler outlet 516. Additional sensors may be provided at various other locations to similarly measure one or more parameters of the supply air at various points in the bleed air system 200.

To control the operation of the power recovery system 202, the bleed air system 200 includes a bleed air system controller 500. The bleed air system controller 500 may be implemented by a controller or processor, such as the processor 1512 of the processor platform 1500 disclosed in connection with fig. 15. The bleed air system controller 500 is communicatively coupled to one or more control valves 538, 550, one or more sensors 552, 566 of the PR turbine 250, the variable inlet guide vanes 320 (fig. 3), the gearbox 306, the clutch 318, the actuator 532, and/or any other device that controls various devices of the bleed air system 200 and/or the power recovery system 202 and/or monitors various parameters (e.g., mass flow rate, pressure, temperature, etc.).

In the example shown, the bleed air system controller 500 includes a bleed air regulator 570, a power recovery determiner 572, a power recovery operator 574, a valve operator 576, a precooler operator 578, an input/output (I/O) module 580, and a comparator 582 communicatively coupled via a bus 584. In the example shown, the bleed air system controller 500 is communicatively coupled to an engine control system 588, which engine control system 588 receives or determines operating parameters and/or flight conditions including, for example, altitude, air speed, throttle lever position, air pressure, air temperature, humidity, engine speed, air density, passenger count, engine speed (RPM), HP axle RPM, LP axle RPM, high power setting conditions, low power setting conditions, and/or other parameters. The database 586, communicatively coupled to the bleed air system controller 500, includes PR turbine map data, thresholds (e.g., bleed air pressure threshold, turbine outlet temperature and/or pressure threshold, precooler inlet temperature and/or pressure threshold, turbine inlet temperature and/or pressure threshold, HP spool RMP threshold or range, precooler outlet temperature and/or pressure threshold, etc.).

The I/O module 580 receives signals from one or more of the sensors 552 and 566, and the sensors 552 and 566 measure one or more parameters of the bleed air system 200. The comparator 582 may be operable to compare the measured values of the parameters provided by the one or more sensors 552 and 566 to one or more thresholds or threshold ranges (e.g., stored in the database 586 accessible by the bleed air system controller 500). Based on whether the parameters satisfy the threshold or threshold range, the valve operator 576 may operate one or more of the valves 534 and 548 to provide bleed air having desired parameters (e.g., pressure and/or temperature) to the ECS236, TAI 238, and/or other systems 240. Additionally, the valve operator 576 may operate the fan valve 550 to control the flow of cooling fluid through the pre-cooler 256. For example, valve operator 576 controls the operational state of valve 536 and 550. For example, any of the valves 536 and 550 may be operable between an open state (e.g., a fully open position) and a closed state (e.g., a fully closed position) and any state or position therebetween (e.g., a semi-open position) to control fluid flow through the respective TAI passages 502 and 504, the LPPR passage 506, the HPPR passage 508, the primary manifold 512, the ECS passage 518, the secondary passage 520, the PR turbine 250, and so forth.

In the example shown, the first control valve 534 is a check valve. Thus, the valve operator 576 does not control the operation of the first control valve 534. For example, the first control valve 534 is a one-way spring-loaded check valve that operates based on a pressure differential across the check valve. If the pressure downstream of the first control valve 534 is less than the pressure of the bleed air at the first bleed air port 242, the first control valve 534 moves to an open position to allow bleed air from the first bleed air port 242 to flow to the LPPR duct 506. If the pressure downstream of the first control valve 534 is greater than the pressure of the bleed air at the first bleed port 242 (e.g., when the second bleed port 244 is open), the first control valve 534 moves to a closed position to prevent bleed air from the first bleed port 242 from flowing to the LPPR duct 506. However, in some examples, the first control valve 534 may be a shut-off valve controlled by the valve operator 576 between an open position, a closed position, and/or one or more intermediate positions between the open position and the closed position.

During operation, the bleed air regulator 570 determines whether the pressure of bleed air flowing from the first bleed air port 242 through the first control valve 534 is sufficient to provide a target flow rate and/or pressure to the ECS 236. For example, the bleed air regulator 570 receives one or more parameters from the engine control system 588 and/or one or more sensors 552 and 566 via the I/O module 580 to determine whether to obtain bleed air at the first bleed air port 242 based on the temperature and/or pressure of the bleed air at the first bleed air port 242 or the temperature and/or pressure of the bleed air at the second bleed air port 244. In some examples, the bleed air regulator 570 determines whether the aircraft engine 110 is at a high power setting (e.g., based on altitude (e.g., cruise), angle of attack or thrust (e.g., take-off, climb, descent, or landing)) or a low power setting (e.g., based on altitude, thrust, taxi, fly-idle, etc.).

In the example shown, a sensor 552 (e.g., an intermediate pressure sensor) measures the pressure of the bleed air in the LPPR duct 506 and provides a signal to the bleed air system controller 500. The bleed air regulator 570 determines, via the comparator 582, whether the pressure is greater than a pressure threshold (e.g., 40psi) retrieved from the database 586 and/or the engine control system 588. If the measured pressure is greater than the pressure threshold, the bleed air regulator 570 commands the second control valve 536 (e.g., via the valve operator 576) to move to the closed position. When the second control valve 536 is closed, the pressure differential across the first control valve 534 causes the first control valve 534 to move to the open position to allow bleed air to flow from the first bleed port 242 to the LPPR duct 506. If the pressure measured by the sensor 552 is greater than the pressure threshold, the bleed air regulator 570 commands the second control valve 536 (e.g., via the valve operator 576) to move to the open position. When the second control valve 536 is open, the pressure differential across the first control valve 534 causes the first control valve 534 to move to the closed position to prevent bleed air from flowing from the first bleed port 242 to the LPPR duct 506.

The power recovery determiner 572 obtains, collects, and/or otherwise receives flight condition and/or aircraft engine operating condition information from the bleed air regulator 570 and/or the engine control system 588. For example, the power recovery determiner 572 receives pressure values and/or temperature values and/or target flow rates of the bleed air, target pressures and/or target temperatures from one or more sensors 552 and 566 via the I/O module 580 for use by the ECS236, other systems 240, and/or the like. Additionally, the power recovery determiner 572 receives, retrieves, and/or otherwise obtains PR turbine performance mapping information from the database 586 and/or receives, retrieves, and/or otherwise obtains a speed (e.g., RPM) of the HPC shaft 224.

Based on the parameter and/or condition information received, retrieved, and/or otherwise obtained (e.g., pressure of the bleed air, temperature of the bleed air, target flow rate, turbine map, HP shaft RPM, etc.), the power recovery determiner 572 determines whether the PR turbine 250 is capable of extracting energy from the bleed air and adding power (e.g., horsepower 575) to the HPC shaft 224. For example, the PR turbine 250 reduces the pressure and/or temperature of the bleed air as it flows through the PR turbine 250. The power recovery determiner 572 may determine to deactivate the power recovery system 202 if the resulting pressure, temperature, and/or flow rate at the turbine outlet 254 is insufficient to meet the requirements of the ECS236 or other system 240.

For example, the power recovery determiner 572 determines whether one or more parameters of the bleed air system 200 (e.g., a target pressure, a target temperature, a target flow rate, a HP shaft RPM, etc.) may be achieved based on one or more parameters of the bleed air at the turbine inlet 252 and, consequently, one or more parameters of the bleed air at the turbine outlet 254. For example, after processing the bleed air via the PR turbine 250 to extract energy, the power recovery determiner 572 determines whether one or more parameters of the bleed air extracted from the first bleed air port 242 or the second bleed air port 244 are sufficient to achieve a target temperature, target pressure, target flow rate, etc. of the bleed air at the turbine outlet 254 (e.g., for the pre-cooler inlet 514 and/or the pre-cooler outlet 516). For example, after recovering energy from the bleed air by processing the bleed air through the PR turbine 250, the power recovery determiner 572 determines whether the pressure of the bleed air at the turbine inlet 252 is sufficient to provide the target pressure at the turbine outlet 254. In some examples, the power recovery determiner 572 determines whether the temperature of the bleed air at the turbine inlet 252 is sufficient to provide the target temperature at the turbine outlet 254. In some examples, the power recovery determiner 572 determines whether the temperature of the bleed air at the turbine inlet 252 is sufficient to provide the target temperature at the precooler inlet 514 by mixing the bleed air at the turbine outlet 254 (e.g., which may be below the target temperature at the precooler 256) with the bleed air from the primary manifold 512 before the bleed air flows to the precooler inlet 514. In some examples, the power recovery determiner 572 determines whether to activate the PR turbine 250 based on the speed (e.g., RPM) of the HPC shaft 224 and/or the speed (e.g., RPM) of the drive shaft 262. If the power recovery determiner 572 determines that the operating parameters of the bleed air are sufficient to activate the power recovery system 202, the power recovery determiner 572 commands the valve operator 576 to operate one or more of the valves 536-550. When the power recovery system is activated, the power recovery operator 574 compares the speed (e.g., RPM) of the HPC shaft 224 to the speed (e.g., RPM) of the drive shaft 262. Based on the fixed gear ratio between the first gear 264 and the second gear 266, the power recovery operator 574 controls the gearbox 306 to enable the drive shaft 262 to operate at a speed that matches the speed of the HPC shaft 224 based on the fixed ratio of the first gear 264 and the second gear 266.

Further, when the power recovery system 202 is activated, the valve operator 576 commands or otherwise moves the third control valve 538 to an open position and the power recovery determiner 572 commands the power recovery operator 574 to operate the PR turbine 250. For example, the power recovery operator 574 operates or adjusts the variable inlet guide vanes 320 (fig. 3) (e.g., turbine nozzle) of the turbine inlet 252 to engage the clutch 318 (fig. 3) and enable the PR turbine 250 to transfer horsepower 575 to the HPC shaft 224 via the transmission 260. After the clutch 318 is engaged, the power recovery operator 574 commands or otherwise causes the variable inlet guide vanes 320 to adjust (e.g., increase or decrease the resolver position) to affect the mass flow rate (which is based on the pressure differential of the bleed air flowing between the turbine inlet 252 and the turbine outlet 254 required to achieve the target flow rate, target pressure, target temperature for use by the ECS236 or other system 240), the target speed (e.g., RPM) of the drive shaft 262 based on the speed (e.g., RPM) and/or gear ratio of the HPC shaft 224, etc.).

If the power recovery determiner 572 determines that the power recovery system 202 should be deactivated, the bleed air regulator 570 commands or otherwise causes the valve operator 576 to control the third control valve 538 to a closed position and the fourth control valve 540 to an open position to flow bleed air to the precooler inlet 514 via the primary manifold 512.

Regardless of whether the power recovery system 202 is activated or deactivated, the precooler operator 578 determines whether the temperature of the bleed air at the precooler outlet 516 is greater than a predetermined maximum threshold and/or within a predetermined threshold range. The precooler operator 578 controls the precooler valve 530 via the actuator 532 and the fan valve 550 to cool the bleed air via the precooler 256 or controls the precooler valve 530 via the actuator 532 to allow the bleed air to flow through the precooler bypass 528 without cooling.

Although an exemplary manner of implementing the bleed air system controller 500 is shown in fig. 5, one or more of the elements, processes and/or devices shown in fig. 5 may be combined, divided, rearranged, omitted, eliminated and/or implemented in any other way. Further, the bleed air regulator 570, the power recovery determiner 572, the valve operator 576, the pre-cooler operator 578, the input/output (I/O) module 580, the comparator 582, and/or, more generally, the example bleed air system controller 500 shown in fig. 5 may be implemented via hardware, software, firmware, and/or any combination of hardware, software, and/or firmware. Thus, for example, any of the bleed air regulator 570, the power recovery determiner 572, the valve operator 576, the precooler operator 578, the input/output (I/O) module 580, the comparator 582, and/or, more generally, the example bleed air system controller 500 shown in fig. 5 may be implemented via one or more analog or digital circuits, logic circuits, programmable processors, programmable controllers, Graphics Processing Units (GPUs), Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Programmable Logic Devices (PLDs), and/or Field Programmable Logic Devices (FPLDs). When any of the apparatus or system aspects of this patent are read to encompass pure software and/or firmware implementations, at least one of the bleed air regulator 570, the power recovery determiner 572, the valve operator 576, the pre-cooler operator 578, the input/output (I/O) module 580, the comparator 582 is hereby expressly defined to include a non-transitory computer readable storage device or storage disk such as a memory, a Digital Versatile Disk (DVD), a Compact Disk (CD), a blu-ray disk, etc., including software and/or firmware. Further, the example bleed air system controller 500 shown in fig. 5 may include one or more elements, processes and/or devices in addition to or instead of those shown in fig. 5, and/or may include one or all of more than any of the elements, processes and devices shown. As used herein, the phrase "in communication," including variations thereof, encompasses direct communication and/or indirect communication through one or more intermediate components and does not require direct physical (e.g., wired) communication and/or continuous communication, but additionally includes selective communication at periodic intervals, scheduled intervals, aperiodic intervals, and/or one-time events.

Figure 6 is a schematic view of the bleed air system 200 shown in figures 1 to 5 in a first mode of operation 600. In the first operating mode 600, the aircraft engine 110 is at a low power setting 602 and the ambient air temperature is less than an ambient temperature threshold (e.g., 75 degrees fahrenheit). For example, in the first operating mode 600, the aircraft 100 is in a taxi mode, an idle mode, and/or a fly-idle mode. In the first mode of operation 600, the power recovery system 202 is in the deactivated state 604 and power (e.g., horsepower 575) is not generated by the PR turbine 250.

In the first mode of operation 600, bleed air flows from the second bleed air port 244 through the HPPR passage 508 and the main manifold 512 and to the precooler inlet 514. For example, the bleed system controller 500 moves the second and fourth control valves 536, 540 to the open position to provide bleed air from the second bleed ports 244 to the pre-cooler inlets 514 via the HPPR passage 508 and the primary manifold 512. The first control valve 534 limits or prevents bleed air from entering the LPPR duct 506 from the first bleed air port 242 and the third control valve 538 is in a closed position to prevent bleed air from flowing to the PR turbine 250. Bleed air flows to the ECS236 through the precooler bypass 528.

For example, in the first mode of operation 600, the bleed air regulator 570 determines that the aircraft 100 is at the low power setting 602 based on information received, retrieved, and/or otherwise obtained from the engine control system 588. In addition, the power recovery determiner 572 receives, retrieves, or otherwise obtains a measured pressure of the bleed air in the LPPR channel 506 via the sensor 552 and compares the measured pressure to a pressure threshold obtained from the database 586 (e.g., via the comparator 582). In some examples, the bleed air regulator 570 determines that the aircraft engine 110 is at the low power setting 602 by comparing the speed of the HPC shaft 224 (e.g., RPM) to a low power setting RPM threshold (e.g., an RPM range or a table stored in the database 586). Because the aircraft engine 110 is at the low power setting 602, the power recovery determiner 572 determines that the measured pressure does not exceed a pressure threshold (e.g., 40 psi). In response to determining that the aircraft engines 110 are at the low power setting 602, the bleed air regulator 570 commands the valve operator 576 to open the second control valve 536 and open the fourth control valve 540 to allow bleed air from the second bleed air port 244 to flow to the pre-cooler 256 via the HPPR passage 508 and the primary manifold 512.

In addition, the power recovery determiner 572 determines to move the power recovery system 202 to the deactivated state 604. To deactivate the power recovery system 202, the power recovery determiner 572 commands the valve operator 576 to move the third control valve 538 to a closed position to prevent bleed air from flowing through the PR turbine 250. In addition, the precooler operator 578 receives, retrieves, and/or otherwise obtains a measured temperature of the bleed air at the precooler inlet 514 via the sensor 562 and a target temperature of the ECS236 via the database 586. The pre-cooler operator 578 compares the measured temperature to the target temperature. In this example, the precooler operators 578 determine that the measured temperature does not exceed the target temperature and command or otherwise cause the actuators 532 to move the precooler valves 530 to the second position to enable bleed air to flow through their precooler bypasses 528.

Figure 7 is a schematic view of the bleed air system 200 shown in figures 1 to 5 in a second mode of operation 700. In the second operating mode 700, the aircraft engine 110 is operating in the low power setting 602 and the ambient air temperature is greater than an ambient temperature threshold (e.g., 75 degrees fahrenheit). In contrast to the example of fig. 6, the bleed air is cooled (e.g., the temperature of the bleed air is reduced) via the precooler 256. For example, the precooler operator 578 determines that the measured temperature from the sensor 562 at the precooler inlet 514 exceeds the target temperature at the precooler outlet 516. To activate the precooler 256, the precooler operator 578 commands or otherwise causes the actuator 532 to move the precooler valve 530 to the first position to enable flow of bleed air through the heat exchanger section 522. In addition, the precooler operator 578 commands or otherwise causes the valve operator 576 to open the fan valve 550 to allow fan air 210a (fig. 2) to flow from the cooling fluid inlet 524 to the cooling fluid outlet 526 to cool the bleed air flowing through the heat exchanger section 522. The precooler operator 578 receives the second measured temperature from the sensor 566 downstream from the precooler outlet 516 and compares the second measured temperature to the target temperature. The precooler operator 578 or the valve operator 576 adjusts (e.g., opens and/or closes) the fan valve 550 to adjust the second measured temperature downstream from the precooler outlet 516 to the target temperature.

Figure 8 is a schematic view of the bleed air system 200 shown in figures 1 to 5 in a third mode of operation 800. In the third operating mode 800, the aircraft engine 110 is at a high power setting 802 and the ambient air temperature is less than an ambient temperature threshold (e.g., 75 degrees fahrenheit). For example, the third mode of operation 800 may occur during takeoff, cruise, and/or landing. In the third operating mode 800, the power recovery system 202 is in the active state 804, and the PR turbine 250 extracts power (e.g., horsepower 575) from the bleed air.

In the third mode of operation 800, bleed air flows from the first bleed air port 242 to the PR turbine 250. The PR turbine 250 expands the bleed air as it flows between the turbine inlet 252 and the turbine outlet 254. During this expansion, as the bleed air flows through the PR turbine 250, the pressure and/or temperature of the bleed air is reduced. The PR turbine 250 converts the energy into power and transfers the converted energy to the HPC shaft 224 via the transmission 260. Bleed air at the turbine outlet 254 flows via the PR manifold 510 to the precooler 256.

To provide bleed air from the first bleed port 242 to the turbine inlet 252 via the LPPR passage 506, the bleed air system controller 500 moves the second and fourth control valves 536, 540 to a closed position to prevent bleed air from flowing from the second bleed port 244 to the turbine inlet 252 via the HPPR passage 508 or through the primary manifold 512. The first control valve 534 moves to an open position to allow bleed air from the first bleed air port 242 to flow to the PR turbine 250 based on a pressure differential across the first control valve 534. Bleed air flows to the ECS236 through the precooler bypass 528.

In the third operating mode 800, the bleed air regulator 570 determines that the aircraft 100 is in the high power setting 802 based on information received, retrieved, and/or otherwise obtained from the engine control system 588. For example, the bleed air regulator 570 determines that the aircraft engine 110 is in the high power setting mode by comparing the speed (e.g., RPM) of the HPC shaft 224 to a high power setting RPM threshold (e.g., an RPM range or table stored in the database 586). In some examples, the engine control system 588 receives pressure values of bleed air in the engine compressor 216 and determines a selection between the first bleed air port 242 or the second bleed air port 244 based on the measured pressure values. In response to determining that the aircraft engines 110 are at the high power setting 802, the bleed air regulator 570 commands the valve operator 576 to close the second control valve 536 (reducing the pressure in the LPPR duct 506) to enable the first control valve 534 to open and allow bleed air from the first bleed air port 242 to flow to the LPPR duct 506.

In some examples, the power recovery determiner 572 receives, retrieves, or otherwise obtains a measured pressure of the bleed air in the LPPR channel 506 via the sensor 552 and compares the measured pressure to a pressure threshold, a target pressure, etc. obtained from the database 586 (e.g., via the comparator 582). When the aircraft engine 110 is operating in the high power setting 802, the power recovery determiner 572 determines that the measured pressure exceeds a pressure threshold (e.g., 40psi) and thus determines to activate the power recovery system 202. To activate the power recovery system 202, the power recovery determiner 572 commands the valve operator 576 to open the third control valve 538.

The power recovery operator 574 measures the pressure of the bleed air at the turbine inlet 252 and the pressure of the bleed air at the turbine outlet 254 and adjusts the variable inlet guide vanes 320 of the PR turbine 250 to adjust (e.g., increase or decrease) the output power to the HPC shaft 224. Furthermore, the power recovery determiner 572 and/or the power recovery operator 574 receive the pressure and/or temperature values of the bleed air from the sensors 560, 562 at the precooler inlet 514. If the pressure and/or temperature at the precooler inlet 514 exceeds the precooler inlet pressure threshold and/or the precooler inlet temperature threshold (e.g., retrieved from the database 586), the valve operator 576 moves the fourth control valve 540 to the closed position to prevent bleed air from flowing through the primary manifold 512. If the pressure and/or temperature at the precooler inlet 514 does not exceed the precooler inlet pressure threshold and/or the precooler inlet temperature threshold (e.g., retrieved from the database 586), the valve operator 576 moves the fourth control valve 540 to the open position to flow all of the bleed air through the primary manifold 512.

In addition, the precooler operator 578 receives, retrieves, and/or otherwise obtains a measured temperature of the bleed air at the precooler outlet 516 via the sensor 566, and a target temperature of the ECS236 via the database 586. The pre-cooler operator 578 compares the measured temperature to the target temperature. In this example, the precooler operator 578 determines that the measured temperature does not exceed the target temperature and commands or otherwise causes the actuator 532 to move the precooler valve 530 to the second position to enable bleed air to flow through the precooler bypass 528.

Figure 9 is a schematic view of the bleed air system 200 shown in figures 1 to 5 in a fourth mode of operation 900. In the fourth operating mode 900, the aircraft engine 110 is operating in the high power setting 802 and the ambient air temperature is greater than an ambient temperature threshold (e.g., 75 degrees fahrenheit). The fourth mode of operation 900 is substantially similar to the third mode of operation 800, except that the bleed air is cooled (e.g., the temperature of the bleed air is reduced) via the precooler 256. For example, the precooler operator 578 determines that the measured temperature from the sensor 566 at the precooler outlet 516 exceeds the target temperature. To activate the precooler 256, the precooler operator 578 commands or otherwise causes the actuator 532 to move the precooler valve 530 to the first position to enable flow of bleed air through the heat exchanger section 522. In addition, the precooler operator 578 commands or otherwise causes the valve operator 576 to open the fan valve 550 to allow fan air 210a (fig. 2) to flow from the cooling fluid inlet 524 to the cooling fluid outlet 526 to cool the bleed air flowing through the heat exchanger section 522. The pre-cooler operator 578 receives the downstream measured temperature from the sensor 566 downstream of the pre-cooler outlet 516 and compares the downstream measured temperature to a target temperature. The precooler operator 578 or the valve operator 576 adjusts (e.g., opens and/or closes) the fan valve 550 to adjust the measured temperature downstream from the precooler outlet 516 to the target temperature.

Figure 10 is a schematic view of the bleed air system 200 shown in figures 1 to 5 in a fifth mode of operation 1000. In the fifth operating mode 1000, the aircraft engine 110 is operating in a medium power setting 1002 (e.g., between the low power setting and/or the high power setting 802) and the ambient air temperature is less than an ambient temperature threshold (e.g., 75 degrees fahrenheit). The fifth operating mode 1000 is substantially similar to the third operating mode 800, except that the bleed air exiting the turbine outlet 254 mixes with the bleed air flowing through the primary manifold 512. For example, the bleed air provided by the turbine outlet 254 mixes with the bleed air provided by the primary manifold 512 to increase a parameter (e.g., pressure or temperature) of the bleed air before flowing to the precooler inlet 514. For example, the power recovery operator 574 determines that the measured pressure or temperature from the sensors 560, 562 at the precooler inlet 514 does not exceed the target pressure or temperature at the precooler outlet 516. For example, during the medium power setting 1002, the pressure exiting the turbine outlet 254 may be too low and/or the temperature of the bleed air exiting the turbine outlet 254 may be too cold. To activate the flow of bleed air through the primary manifold 512, the valve operator 576 commands or otherwise moves the fourth control valve 540 to an open position to allow fluid to pass through the primary manifold 512.

Figure 11 is a schematic view of the bleed air system 200 shown in figures 1 to 5 in a sixth mode of operation 1100. In the sixth operating mode 1100, the aircraft engine 110 is in the low power setting 602, and the power recovery system 202 is in the active state 804, and power (e.g., horsepower 575) is generated by the PR turbine 250. For example, in the sixth mode of operation 1100, the power recovery system 202 receives bleed air from the second bleed air port 244. For example, bleed air flows from the second bleed air port 244 to the turbine inlet 252 via the HPPR passage 508.

To provide bleed air from the second bleed air port 244 to the turbine inlet 252 via the HPPR passage 508, the bleed air system controller 500 moves the second and third control valves 536, 538 to an open position. The bleed air system controller 500 moves the first and fourth control valves 534, 540 to the closed position to prevent bleed air from flowing from the first bleed port 242 to the turbine inlet 252 via the LPPR passage 506 or to prevent bleed air from flowing through the primary manifold 512.

For example, in the sixth mode of operation 1100, the bleed air regulator 570 determines that the aircraft 100 is at the low power setting 602 based on information received, retrieved, and/or otherwise obtained from the engine control system 588. In response to determining that the aircraft engines 110 are at the low power setting 602, the bleed air regulator 570 commands the valve operator 576 to open the second control valve 536 to allow bleed air from the second bleed air port 244 to flow to the HPPR passage 508.

Further, the power recovery determiner 572 receives, retrieves, or otherwise obtains the measured pressure and/or measured temperature of the bleed air in the HPPR passage 508 via the sensors 552, 554 and compares the measured pressure to a pressure threshold and/or the measured temperature to a temperature threshold obtained from the database 586 (e.g., via the comparator 582). If the power recovery determiner 572 determines that the measured pressure exceeds a pressure threshold (e.g., 40psi) and/or the measured temperature exceeds a temperature threshold, the power recovery determiner 572 determines to activate the power recovery system 202 and commands the valve operator 576 to open the third control valve 538.

The power recovery operator 574 measures the pressure of the bleed air at the turbine inlet 252 and the pressure of the bleed air at the turbine outlet 254. If the change in pressure is greater than the delta pressure threshold retrieved from the database 586, the power recovery operator 574 adjusts the variable inlet guide vanes 320 of the PR turbine 250 to increase the power to the HPC shaft 224. Furthermore, the power recovery determiner 572 and/or the power recovery operator 574 receive the pressure and/or temperature values of the bleed air from the sensors 560, 562 at the precooler inlet 514. If the pressure at the precooler inlet 514 is greater than the precooler inlet pressure threshold (e.g., retrieved from the database 586), the valve operator 576 moves the fourth control valve 540 to the closed position to prevent bleed air from flowing through the primary manifold 512. If the pressure at the precooler inlet 514 is less than the precooler inlet pressure threshold (e.g., retrieved from the database 586), the valve operator 576 moves the fourth control valve 540 to the open position to allow bleed air to flow through the primary manifold 512.

In addition, the precooler operator 578 receives, retrieves, and/or otherwise obtains a measured temperature of the bleed air at the precooler inlet 514 via the sensor 562 and a target temperature of the ECS236 via the database 586. The pre-cooler operator 578 compares the measured temperature to the target temperature. The precooler operator 578 commands or otherwise causes the actuator 532 to move the precooler valve 530 to the first position to enable bleed air to flow through the heat exchanger section 522 and causes the valve operator 576 to open the fan valve 550 when the measured temperature exceeds the target temperature. The precooler operator 578 commands or otherwise causes the actuator 532 to move the precooler valve 530 to the second position such that bleed air can flow through the precooler bypass 528 when the measured temperature does not exceed the target temperature.

FIG. 12 is a schematic illustration of an aircraft engine 110 employing a power recovery system as a starter 1200. For example, the starter 567 of the aircraft engine 110 shown in fig. 5 can be omitted or replaced with the power recovery system 202. In some examples, the power recovery system 202 may provide a starter backup system for the starter 567 shown in fig. 5. To employ the power recovery system 202 as the starter 1200, pressurized fluid is provided at the precooler outlet 516 via an auxiliary unit (e.g., external to the aircraft 100). The pressurized fluid flows to the precooler inlet 514 (e.g., via a precooler bypass 528) and to the turbine outlet 254 via the PR manifold 510. The fluid flows through the PR turbine 250 and exits via an exhaust port 1202 controlled by an exhaust valve 1204 (e.g., a shut-off valve). When the exhaust valve 1204 is in an open position, the exhaust port 1202 provides a secondary outlet to allow airflow in the PR turbine 250 to exhaust through the exhaust port 1202. When the PR turbine 250 operates as a starter, the first, second, third, and fourth control valves 534, 536, 538, and 540, respectively, are in a closed position.

Fig. 13 is a schematic illustration of an aircraft engine 110 and a bleed air system 1302 implemented with another exemplary power recovery system 1304 disclosed herein. The components of the example aircraft engine 1300, bleed air system 1302, and power recovery system 1032 are substantially similar or identical to those of the example aircraft engine 110, bleed air system 200, and power recovery system 200 described above in connection with fig. 1-12, and components having functions substantially similar or identical to those of the components will not be described in detail below. Instead, the interested reader is referred to the corresponding description above. To facilitate this process, similar reference numbers will be used for similar structures. For example, the aircraft engine 1300 is substantially identical to the aircraft engine 110 and includes the fan 206, the first bleed port 242, the second bleed port 244, the ECS236, the TAI 238, the precooler 256, and the like.

For example, the bleed air system 1300 may be substantially identical to the bleed air system 200 and include a first TAI passage 502, a second TAI passage 504, a Low Pressure Power Recovery (LPPR) passage 506, a High Pressure Power Recovery (HPPR) passage 508, a PR passage 509, a Power Recovery (PR) manifold 510, a primary manifold 512, a precooler inlet 514, a precooler outlet 516, a first control valve 534, a second control valve 536, a third control valve 538, a fourth control valve 540, a fifth control valve 542, a sixth control valve 546, a seventh control valve 548, one or more sensors 552 and 566, a bleed air system controller 500, the bleed air system controller 500 includes a bleed air regulator 570, a power recovery determiner 572, a power recovery operator 574, a valve operator 576, a precooler operator 578, an input/output (I/O) module 580, and a comparator 582 communicatively coupled via a bus 584 or the like.

For example, the power recovery system 1304 is substantially similar to the power recovery system 202 shown in fig. 2-12 and includes a Power Recovery (PR) turbine 250 that receives bleed air via a turbine inlet 252 (i.e., a bleed air inlet) and discharges the bleed air to a pre-cooler 256 (e.g., a heat exchanger) via a turbine outlet 254 (e.g., a bleed air outlet). An LPPR passageway 506 fluidly couples the first bleed air port 242 with the turbine inlet 252 and an HPPR passageway 508 fluidly couples the second bleed air port 244 with the turbine inlet 252. PR passages 509 fluidly couple LPPR 506 and HPPR 508 to turbine inlet 252. A Power Recovery (PR) manifold 510 fluidly couples the turbine outlet 254 and the pre-cooler 256. The primary manifold 512 is fluidly coupled to the first bleed port 242 via the LPPR passageway 506 and fluidly coupled to the second bleed port 244 via the HPPR passageway 508. The precooler 256 includes a precooler inlet 514 and a precooler outlet 516, the precooler inlet 514 for receiving bleed air from the PR manifold 510 and/or the primary manifold 512, the precooler outlet 516 fluidly coupled to the ECS236 via an ECS passage 518 and fluidly coupled to the other systems 240 via a secondary passage 520.

The PR turbine 250 of the power recovery system 1304 is operably (e.g., mechanically) coupled to an auxiliary power plant or machine 1306. The auxiliary power device 1306 is a shaft drive or a machine. In other words, the auxiliary power device 1306 absorbs the power supplied via the input shaft of the power absorber. The PR output shaft 304 (fig. 3) transmits power to an input shaft 1308 (e.g., a driven shaft, a generator shaft, etc.) of an auxiliary power device 1306. In other words, the input shaft 1308 receives power from the output shaft 304 of the PR turbine 250 (e.g., when the power recovery system 1304 is in an active state). The PR turbine 250 may be operably coupled to an auxiliary device 1306 via a transmission 1310. For example, the transmission 1310 may include a gearbox (e.g., gearbox 306 shown in fig. 3), a gear train (e.g., gear train 310 shown in fig. 3), a clutch (e.g., clutch 318 shown in fig. 3), and/or any other transmission (e.g., a fixed ratio transmission, a continuously variable transmission, etc.). The auxiliary power device 1306 may include, for example, a generator (e.g., a generator or alternator for generating electrical power), a compressor, a turbine, an Auxiliary Power Unit (APU), and/or any other shaft drive device that may receive or use energy from the PR turbine 250. The auxiliary power device 1306 may be located in the engine compartment of the aircraft engine 1300, the wing box of a wing, the fuselage of an aircraft, and/or any other location. The LPPR 506, HPPR 508, PR channel 509, and Power Recovery (PR) manifold 510 may be routed to the location of the PR turbine 250.

In operation, the operation of the aircraft engine 1300, the bleed air system 1302 and the power recovery system 1304 is substantially similar to the operation of the aircraft engine 110, the bleed air system 200 and the power recovery system 202 shown in fig. 1 to 12. For example, the power recovery system 1304 extracts or collects energy from the engine bleed air via the controller 500 of the bleed air system 1302. Specifically, the PR turbine 250 generates power while processing bleed air from the turbine inlet 252 to the turbine outlet 254 and transfers the generated power to an auxiliary power unit 1302 of an aircraft (e.g., the aircraft 100 shown in fig. 1). For example, the PR turbine 250 extracts or collects energy by reducing one or more parameters (e.g., temperature, pressure, etc.) of the bleed air as it flows between the turbine inlet 252 and the turbine outlet 254. Energy extracted from the bleed air is converted to power (e.g., shaft horsepower) and transmitted (e.g., fed back) through the PR turbine 250 to the auxiliary power plant 1306. In some examples, the power recovery system 1304 extracts energy from the bleed air during predetermined operating conditions of the aircraft (e.g., taxiing, takeoff, climb, cruise, descent, landing, etc.). Without further details of the operation of the bleed air system 1304, the interested reader is referred to the description of fig. 1 to 12 and 14.

The foregoing examples of the power recovery systems 202 and 1304 may be employed with aircraft and/or aircraft engines. While each of the exemplary power recovery systems disclosed above has certain features, it should be understood that the specific features of one example need not be dedicated to that example. Rather, any of the features described above and/or depicted in the drawings may be combined with any of the examples in addition to or in place of any other features of those examples. Features of one example are not mutually exclusive of features of another example. Rather, the scope of the present disclosure encompasses any combination of any feature. For example, an aircraft engine may employ one or more power recovery systems 202 and 1304. In some examples, the aircraft engine may employ the power recovery system 202 and the power recovery system 1304. In some examples, the aircraft engine 1300 may be used as a starter (e.g., the starter 1200 shown in fig. 12).

Fig. 14 is a flow chart representing an exemplary method 1400, which exemplary method 1400 may be implemented with the bleed air system 200 shown in fig. 2, the bleed air system 1302 shown in fig. 13, and/or a control system such as the bleed air system controller 500 shown in fig. 5-13. For purposes of discussion, the exemplary method 1400 shown in fig. 14 is described in connection with the bleed air system 200 shown in fig. 2-12, the bleed air system 1302 shown in fig. 13, and the bleed air system controller 500 shown in fig. 5-13. In this manner, each of the example operations of the example method 1400 shown in fig. 14 is an example manner of carrying out the corresponding one or more operations performed by the one or more blocks of the example bleed air system controller 500 shown in fig. 5-13. In this example, the method may be implemented using machine readable instructions comprising a program for execution by a processor, such as processor 1500 shown in fig. 15. The machine readable instructions may be one or more executable programs or portions of executable programs for execution by a computer processor, such as the processor 1512 shown in the exemplary processor platform 1500 discussed below in connection with fig. 15. The program may be presented in software stored on a non-transitory computer readable storage medium such as a CD-ROM, floppy disk, hard drive, DVD, blu-ray disk, or memory associated with the processor 1512, but the entire program and/or parts thereof could alternatively be executed by a device other than the processor 1512 and/or presented in firmware or dedicated hardware. Further, although the example program is described with reference to the flowchart shown in fig. 14, many other methods of implementing the example bleed air system controller 500 may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined. Additionally or alternatively, any or all of the blocks may be implemented by one or more hardware circuits (e.g., discrete and/or integrated analog and/or digital circuits, FPGAs, ASICs, comparators, operational amplifiers (op-amps), logic circuitry, etc.) configured to perform the respective operations without the execution of software or firmware.

The machine-readable instructions described herein may be stored in one or more of a compressed format, an encrypted format, a fragmented format, a compiled format, an executable format, a packaged format, and the like. The machine-readable instructions described herein may be stored as data (e.g., portions of instructions, code, representations of code, etc.) that may be used to create, fabricate, and/or produce machine-executable instructions. For example, the machine-readable instructions may be segmented and stored on one or more storage devices and/or computing devices (e.g., servers). The machine-readable instructions may require one or more of installation, modification, adaptation, updating, combining, supplementing, configuring, decrypting, decompressing, unpacking, distributing, redistributing, compiling, etc., in order for them to be directly readable, interpretable, and/or executable by the computing device and/or other machine. For example, machine-readable instructions may be stored in multiple parts that are separately compressed, encrypted, and stored on separate computing devices, where the parts, when decrypted, decompressed, and combined, form a set of executable instructions that implement a program such as that described herein.

In another example, machine-readable instructions may be stored in a state in which the machine-readable instructions can be read by a computer, but require the addition of libraries (e.g., Dynamic Link Libraries (DLLs)), Software Development Kits (SDKs), Application Programming Interfaces (APIs), and the like, in order to execute the instructions on a particular computing device or other device. In another example, machine readable instructions (e.g., storage settings, data entry, logging network addresses, etc.) may need to be configured before the machine readable instructions and/or corresponding program can be executed in whole or in part. Accordingly, the disclosed machine readable instructions and/or corresponding programs are intended to encompass such machine readable instructions and/or programs regardless of the particular format or state of the machine readable instructions and/or programs as stored or otherwise in rest or in transit.

The machine-readable instructions described herein may be represented by any past, present, or future instruction language, scripting language, programming language, or the like. For example, the machine-readable instructions may be represented using any one of the following languages: C. c + +, Java, C #, Perl, Python, JavaScript, HyperText markup language (HTML), Structured Query Language (SQL), Swift, and the like.

As described above, the example method illustrated in fig. 13 may be implemented using executable instructions (e.g., computer and/or machine readable instructions) stored on a non-transitory computer and/or machine readable medium such as a hard disk drive, a flash memory, a read-only memory, an optical disk, a digital versatile disk, a cache, a random-access memory, and/or any other storage device or storage disk, where information is stored for any period of time (e.g., for extended periods of time, permanently, brief instances, for temporarily buffering, and/or for caching of the information). As used herein, the term non-transitory computer readable medium is expressly defined to include any type of computer readable storage and/or storage disk and to exclude propagating signals and to exclude transmission media.

Turning in detail to fig. 14, the bleed air system controller 500 monitors, receives and/or otherwise obtains a measured pressure of the bleed air in the bleed air system 200 (block 1402). For example, to monitor system parameters, the bleed air system controller 500 receives one or more signals from the sensors 552 via the I/O module 580.

The bleed air system controller 500 retrieves, receives, and/or otherwise obtains the target pressure (block 1404). For example, the bleed air regulator 570 retrieves the target pressure from the database 586.

The bleed air system controller 500 determines whether to activate the power recovery system 202 based on the measured pressure and the target pressure (block 1406). In some examples, to determine whether to activate the power recovery system 202, the power recovery determiner 572 determines, via the comparator 582, whether the measured pressure is greater than the target pressure to determine whether the PR turbine 250 is capable of adding power (e.g., horsepower 575) to the HPC shaft 224 (block 1404). For example, the power recovery determiner 572 determines whether the PR turbine 250 is capable of adding power to the HPC shaft 224 and achieving a minimum ECS pressure based on the turbine performance map (e.g., retrieved from the database 586), the measured speed (e.g., RPM) of the HPC shaft 224, and the measured pressure from the sensor 552. In some examples, the PR turbine 250 determines a pressure differential between the pressure at the turbine inlet 252 and the pressure at the turbine outlet 254 to determine whether the pressure differential is sufficient to provide the required mass flow rate to the ECS 236. In some examples, to determine whether to activate the power recovery system 1304, the power recovery determiner 572 determines whether the measured pressure is greater than a target pressure via the comparator 582 to determine whether the PR turbine 250 is capable of adding power (e.g., horsepower 575) to the auxiliary power device 1306 (block 1404). For example, the power recovery determiner 572 determines whether the PR turbine 250 is capable of adding power to the auxiliary power device 1306 and achieves a minimum ECS pressure based on the turbine performance map (e.g., retrieved from the database 586) and the measured pressure from the sensor 552. In some examples, to determine whether to activate the power recovery system 202 or the power recovery system 1304, the power recovery determiner 572 determines whether the PR turbine 250 is capable of providing the minimum ECS pressure based on the turbine performance map (e.g., retrieved from the database 586) and the measured pressure from the sensor 552.

If the bleed air system controller 500 determines not to activate the power recovery system 202 or the power recovery system 1302 (block 1408), the bleed air system controller 500 prevents bleed air from flowing to the PR turbine 250 (block 1408). For example, the power recovery determiner 572 and/or the valve operator 576 moves the third control valve 538 to the closed position. In some examples, the power recovery determiner 572 determines not to activate the power recovery system 202 in response to determining that the PR turbine 250 is unable to add power to the HPC shaft 224 or the auxiliary power device 1306. In some examples, if the PR turbine 250 is unable to provide the minimum ECS pressure based on the turbine performance map (e.g., retrieved from the database 586) and the measured pressure from the sensor 552, the power recovery determiner 572 determines not to activate the power recovery system 202 or the power recovery system 1304.

If, at block 1408, the bleed air system controller 500 determines that the power recovery system 202 or the power recovery system 1304 is activated, the bleed air system controller 500 allows bleed air to flow to the PR turbine 250 (block 1410). For example, the power recovery determiner 572 and/or the valve operator 576 moves the third control valve 538 to an open position to allow bleed air to flow to the turbine inlet 252. In some examples, the power recovery determiner 572 determines to activate the power recovery system 202 in response to determining that the PR turbine 250 may add power to the HPC shaft 224. In some examples, the power recovery determiner 572 determines to activate the power recovery system 1304 in response to determining that the PR turbine 250 may add power to the auxiliary power device 1306.

The bleed air system controller 500 engages the clutch 318 (block 1412). For example, the power recovery operator 574 adjusts (e.g., adjusts) the variable inlet guide vanes 320 to increase the output speed of the PR turbine 250 to engage the clutch 318.

The bleed air system controller 500 determines the turbine discharge pressure at the turbine outlet 254 (block 1414). For example, the power recovery determiner 572 compares the measured pressure of the bleed air from the sensor 556 to a target pressure retrieved from the database 586. Based on the comparison between the measured pressure and the target pressure, the bleed air system controller 500 determines whether the turbine discharge pressure is within a threshold range of the target pressure (block 1416). If at block 1416, the discharge pressure is within the threshold range at block 1416, the power recovery operator 574 adjusts (e.g., increases or decreases) the output torque of the PR turbine 250 by adjusting (e.g., increasing or decreasing) the variable inlet guide vanes 320 (block 1418).

If, at block 1416, the bleed air system controller 500 determines that the turbine discharge pressure is not within the threshold range of the target pressure, the bleed air system controller 500 determines if the power recovery turbine discharge temperature at the turbine outlet 254 exceeds a maximum temperature threshold (block 1420). For example, the bleed air system 200 measures the discharge temperature of the bleed air at the turbine outlet 254 and compares the measured temperature to a maximum temperature threshold or range via the comparator 582.

The bleed air system controller 500 determines if the turbine discharge temperature exceeds a maximum temperature threshold (block 1422). If at block 1422 the bleed air system controller 500 determines that the turbine discharge temperature exceeds the maximum temperature threshold, the bleed air system controller 500 activates the precooler 256 (block 1424). For example, the precooler operator 578 measures the temperature of the bleed air at the precooler outlet 516 via the sensor 566 and compares the measured temperature to a target temperature or range. For example, the precooler operator 578 and/or the valve operator 576 causes the actuator 532 to move the precooler valve 530 to the first position to allow bleed air to flow through the heat exchanger section 522 and command the fan valve 550 to move to the open position to allow cooling fluid passing through the precooler 256 to flow between the cooling fluid inlet 524 and the cooling fluid outlet 526. For example, the precooler operator 578 adjusts the fan valve 550 so that the bleed air at the precooler outlet 516 is within the target temperature threshold.

If at block 1422 the bleed air system controller 500 determines that the turbine discharge temperature does not exceed the maximum temperature threshold, the bleed air system controller 500 determines if the discharge temperature is below the minimum temperature threshold (block 1426). If the discharge temperature is not below the minimum temperature threshold at block 1426, the bleed air system controller 500 flows bleed air through the pre-cooler bypass 528 (block 1428). If at block 1426 the bleed air system controller 500 determines that the turbine exhaust temperature is below the minimum temperature threshold, the bleed air system controller 500 disables the power recovery system 202 (block 1430). For example, the power recovery operator 574 moves the third control valve 538 to a closed position to prevent bleed air from flowing to the turbine inlet 252.

In some examples, the bleed air system controller 500 determines whether to insist on and/or otherwise continue monitoring the power recovery system 202 or the power recovery system 1304 (block 1432). For example, if the aircraft engine 110 is running, etc., the bleed air system controller 500 may determine to discontinue monitoring the power recovery system 202 or the power recovery system 1304 based on user input, receiving continuous communications (e.g., communicating heartbeat signals, sensor information, etc.) from sensors communicatively coupled to the bleed air system 200.

Fig. 15 is a block diagram of an example processor platform 1500, the example processor platform 1500 being configured to execute the instructions shown in fig. 13 to implement the bleed air system controller 500 shown in fig. 15. The processor platform 1500 may be, for example, a server, a personal computer, a workstation, a self-learning machine (e.g., a neural network), a mobile device (e.g., a cell phone, a smart phone), or any other type of computing device.

The processor platform 1500 of the illustrated example includes a processor 1512. The processor 1512 of the illustrated example is hardware. For example, the processor 1512 may be implemented by one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any desired family or manufacturer. The hardware processor may be a semiconductor-based (e.g., silicon-based) device. In this example, the processor implements a bleed air regulator 570, a power recovery determiner 572, a power recovery operator 574, a valve operator 576, a pre-cooler operator 578, a comparator 582, and an I/O module 580.

The processor 1512 of the illustrated example includes local memory 1513 (e.g., a cache). The processor 1512 of the depicted example communicates with main memory, including a volatile memory 1514 and a non-volatile memory 1516, over a bus 1518. The volatile memory 1514 may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM),Dynamic random access memoryAnd/or any other type of random access memory device. The non-volatile memory 1516 may be implemented by flash memory and/or any other desired type of memory device. Access to the main memory 1514, 1516 is controlled by a memory controller.

The processor platform 1500 of the illustrated example also includes interface circuitry 1520. Interface circuit 1520 may be implemented by any type of interface standard, such as an Ethernet interface, Universal Serial Bus (USB), or a USB interface,Interface, Near Field Communication (NFC) interface, and/or PCI express interface。

In the example shown, one or more input devices 1522 are connected to the interface circuit 1520. The input device 1522 allows a user to enter data and/or commands into the processor 1512. The input device may be implemented by, for example, a keyboard, buttons, a mouse, a touch screen, a touch pad, a track ball, an isopoint, and/or a voice recognition system.

One or more output devices 1524 are also connected to the interface circuit 1520 of the illustrated example. The output devices 1524 may be implemented, for example, by display devices (e.g., Light Emitting Diodes (LEDs), Organic Light Emitting Diodes (OLEDs), Liquid Crystal Displays (LCDs), cathode ray tube displays (CRTs), in-place switch (IPS) displays, touch screens, etc.), tactile output devices, and/or speakers. Thus, the interface circuitry 1520 of the illustrated example typically includes a graphics driver card, a graphics driver chip, and/or a graphics driver processor.

The interface circuit 1520 of the illustrated example also includes communication devices, such as transmitters, receivers, transceivers, modems, residential gateways, wireless access points, and/or network interfaces to facilitate the exchange of data with external machines (e.g., any kind of computing device) via the network 1526. The communication may be via, for example, an ethernet connection, a Digital Subscriber Line (DSL) connection, a telephone line connection, a coaxial cable system, a satellite system, a field line wireless system, a cellular telephone system, etc.

The processor platform 1500 of the illustrated example also includes one or more mass storage devices 1528 for storing software and/or data. Examples of such mass storage devices 1528 include floppy disk drives, hard disk drives, optical disk drives, blu-ray disk drives, Redundant Array of Independent Disks (RAID) systems, and Digital Versatile Disk (DVD) drives.

The machine-executable instructions (coded instructions) 1532 shown in fig. 15 may be stored in mass storage device 1528, volatile memory 1514, non-volatile memory 1516, and/or on a removable non-transitory computer-readable storage medium such as a CD or DVD.

The terms "including" and "comprising" (and all forms and tenses thereof) are used herein as open-ended terms. Thus, whenever a claim recites "comprising" or "comprising" in any form (e.g., including, comprising, including, having, etc.) as a preface or in any kind of claim recitation, it is to be understood that additional elements, terms, etc. may be present without departing from the scope of the corresponding claim or recitation. As used herein, the phrase "at least" when used as a transitional term in, for example, the preamble of a technical solution is open-ended in the same way that the terms "comprising" and "including" are open-ended. When used, for example, in a form such as A, B and/or C, the term "and/or" refers to any combination or subset of A, B, C, such as (1) a alone, (2) B alone, (3) C alone, (4) a and B, (5) a and C, (6) B and C, and (7) a and B and C. As used herein in the context of describing structures, components, items, objects, and/or things, the phrase "at least one of a and B" is intended to refer to embodiments that include (1) at least one a, (2) at least one B, and (3) any one of at least one a and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects, and/or things, the phrase "at least one of a or B" is intended to refer to embodiments that include any of (1) at least one a, (2) at least one B, and (3) at least one a and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities, and/or steps, the phrase "at least one of a and B" is intended to refer to embodiments that include any of (1) at least one a, (2) at least one B, and (3) at least one a and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities, and/or steps, the phrase "at least one of a or B" is intended to refer to embodiments that include (1) at least one a, (2) at least one B, and (3) any one of at least one a and at least one B.

As used herein, singular references (e.g., "a," "an," "first," "second," etc.) do not exclude a plurality. As used herein, the term "a" or "an" entity refers to one or more of that entity. The terms "a" (or "an)", "one or more" and "at least one" are used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements or method acts may be implemented by e.g. a single unit or processor. Additionally, although individual features may be included in different examples or aspects, these features may be combined, and the inclusion in different examples or aspects does not imply that a combination of features is not feasible and/or advantageous.

At least some of the foregoing examples include one or more features and/or advantages, including, but not limited to, the following:

in some examples, a power recovery system for an aircraft engine includes a power recovery turbine coupled to a shaft drive. A bleed air valve coupled between the power recovery turbine and the bleed air source. A controller configured to operate the bleed air valve to allow bleed air to flow to the power recovery turbine when the aircraft engine is operating in a predetermined mode of operation.

In some examples, the shaft drive is a core engine of an aircraft, the core engine including a core compressor, a core turbine, and a spindle, the power recovery turbine being operatively coupled to the spindle of the core engine.

In some examples, an output shaft of the power recovery turbine is operably coupled to the spindle via a transmission.

In some examples, the transmission includes a clutch coupled between the power recovery turbine and the core engine, the clutch configured to operably couple the output shaft and the spindle when the aircraft engine is operating in the predetermined operating mode and to operably decouple the output shaft and the spindle when the aircraft engine is not operating in the predetermined operating mode.

In some examples, the shaft drive is an electrical generator having an input shaft, wherein the output shaft of the power recovery turbine is coupled to the input shaft of the electrical generator.

In some examples, the predetermined mode of operation includes at least one of takeoff, climb, descent, landing, or cruise.

In some examples, the power recovery turbine includes a turbine inlet and a turbine outlet, the turbine inlet fluidly coupled to the bleed air source and the turbine outlet fluidly coupled to the heat exchanger.

In some examples, the power recovery turbine includes a variable nozzle guide vane, and the controller is configured to adjust the variable nozzle guide vane to adjust a discharge pressure of the bleed air at the turbine outlet.

In some examples, the power recovery system includes a power recovery turbine having: a bleed air inlet that receives bleed air from a bleed air source; a bleed air outlet for providing bleed air to the downstream system; and an output shaft operably coupled to an input shaft of a shaft drive of the aircraft. A power recovery turbine generates power in response to treating the bleed air as it flows from the bleed air inlet to the bleed air outlet, the power recovery turbine transmitting the generated power to the input shaft via the output shaft.

In some examples, a transmission for coupling an output shaft of the power recovery turbine with an input shaft of the shaft drive.

In some examples, the transmission includes a clutch to engage an output shaft of the power recovery turbine with an input shaft of the shaft drive and to disengage the output shaft of the power recovery turbine from the input shaft of the shaft drive.

In some examples, the transmission includes a multi-speed gearbox that reduces the speed of the output shaft of the power recovery turbine to the speed of the input shaft when the power recovery turbine is engaged with the shaft drive.

In some examples, the precooler is in fluid communication with a bleed air outlet of the power recovery turbine.

In some examples, the bleed valve is movable between an open position that allows bleed air to flow to a bleed air inlet of the power recovery turbine and a closed position that prevents bleed air from flowing to the bleed air inlet.

In some examples, a controller for controlling operation of the bleed valve between the open and closed positions.

In some examples, the power recovery turbine includes a variable nozzle guide vane, wherein the discharge pressure of the bleed air at the bleed air outlet is adjusted by adjusting the variable nozzle guide vane.

An exemplary aircraft includes an aircraft engine having a core compressor that generates compressed air and a core turbine that drives the core compressor. The power recovery turbine is operatively coupled to the aircraft engine. The power recovery turbine has a turbine inlet in fluid communication with a bleed air supply source provided by the core compressor and a turbine outlet in fluid communication with a downstream system of the aircraft. A power recovery turbine that generates power when processing bleed air from the turbine inlet to the turbine outlet and transfers the generated power to a core compressor of the aircraft engine.

In some examples, the power recovery turbine is located within an aircraft engine.

In some examples, the precooler is located upstream of the power recovery turbine.

In some examples, a bleed air control valve is used to control the flow of bleed air from the bleed air supply to the turbine inlet.

In some examples, a controller is communicatively coupled to the bleed control valve, the controller configured to move the bleed control valve between an open position that allows bleed air to flow to the turbine inlet and a closed position that prevents bleed air from flowing to the turbine inlet.

In some examples, the power recovery turbine includes variable nozzle guide vanes, wherein the discharge pressure of the bleed air at the turbine outlet is adjusted by adjusting the variable nozzle guide vanes.

In some examples, the power recovery turbine may be mechanically or operatively coupled to the shaft drive power plant to receive power generated by the power recovery turbine to drive the input shaft of the power plant.

Although certain example methods, apparatus, and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.