MOTOR DRIVEN CABIN AIR COMPRESSOR WITH VARIABLE DIFFUSER
An air cycle machine is provided and includes a compressor section having a variable area diffuser, a turbine section having an inlet nozzle with a variable size, a motor to drive the compressor and a common rotating shaft on which the compressor section, the turbine section and the motor are mounted, the turbine section driving rotation of the shaft to drive the compressor section with the motor.
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The subject matter disclosed herein relates to a motor driven cabin air compressor with a variable diffuser.
Aircraft environmental control systems incorporate turbomachines, commonly referred to as air cycle machines (ACMs), to help facilitate cooling and dehumidifying air for supply to a cabin of an aircraft. Air cycle machines can include two or more wheels having at least one compressor and at least one turbine disposed axially along the same shaft. On aircraft powered by gas turbine engines, the air to be conditioned in the air cycle machine is generally either compressed air bled from one or more of the compressor stages of the gas turbine engine or air diverted from another location on the aircraft. With either system, the air is passed through the compressor(s) of the air cycle machine where it is further compressed and then passed through a heat exchanger to cool the compressed air sufficiently to condense moisture therefrom. The dehumidified air continues through the environmental control system back to the turbine(s) of the air cycle machine. In the turbine(s), the air is expanded to both extract energy from the compressed air so as to drive the shaft and the compressor(s) coupled thereto and cool the air for use in the cabin as conditioned cooling air.
To meet required specifications for providing fresh air and maintain pressurization to the cabin during flight, environmental control systems on larger aircraft employ two separate (dual) air conditioning packs. Unfortunately, operating dual air conditioning packs may not be necessary or efficient in some circumstances such as when the plane is on the tarmac. In this instance and others, operating only a single air conditioning pack could accomplish the conditioning of air for the cabin.
BRIEF DESCRIPTION OF THE INVENTIONAccording to one aspect of the invention, an air cycle machine is provided and includes a compressor section having a variable area diffuser, a turbine section having an inlet nozzle with a variable size, a motor to drive the compressor and a common rotating shaft on which the compressor section, the turbine section and the motor are mounted, the turbine section driving rotation of the shaft to drive the compressor section with the motor.
According to another aspect of the invention, an air cycle machine is provided and includes a compressor section having a variable area diffuser to compress inlet air, a turbine section having an inlet nozzle with a variable size to receive the compressed air from the compressor section and to expand the air for use in an aircraft cabin, a motor to drive the compressor and a common rotating shaft on which the compressor section, the turbine section and the motor are operably mounted, the turbine section driving rotation of the shaft to provide additional drive power to the compressor section along with that of the motor.
According to yet another aspect of the invention, an air cycle machine for use in a RAM engine in an aircraft is provided and includes a compressor section having a variable area diffuser to compress RAM inlet air, a turbine section having an inlet nozzle with a variable size to receive the compressed air from the compressor section and to expand the air for use in a cabin of the aircraft, a motor to drive the compressor and a common rotating shaft on which the compressor section, the turbine section and the motor are operably mounted, the turbine section driving rotation of the shaft to provide additional drive power to the compressor section along with that of the motor.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTIONSystem air 14 is bled from one or more of the compressor stages of the gas turbine engines of the aircraft or directed from an air source at another location on the aircraft. One or more devices 16A can condition (e.g., preheat, acoustically treat) the air 14 prior to its entry into the air cycle machine 12. The air 14 enters the air cycle machine 12 at the compressor section 18 through the compressor inlet 24. The air 14 is compressed to a higher pressure by the compressor wheel 26, which is mounted on the shaft 20 for rotation about axis A. The compressed air 14 is output to the remainder of the environmental control system 10 via the compressor outlet 28. Air 14 output from the compressor section 18 is conditioned by various devices 16B to change the characteristics of the air 14 that enters the turbine section 22 via the turbine inlet 30. These devices 16B can include heat exchangers, condensers, and/or water extractors/collectors that condition the air 14 to a desired pressure and temperature.
The turbine inlet nozzle 32 receives air 14 entering the air cycle machine 12 through the inlet 30 and is disposed adjacent the turbine wheel 34 to direct the flow of air 14 thereto. As will be discussed subsequently, the air cycle machine 12 is configured with a valve to vary the size of turbine inlet nozzle 32 as desired to better optimize the efficiency of the environmental control system 10. In particular, the selectively variable turbine inlet nozzle 32 disclosed herein allows the power consumption of the environmental control system 10 to be reduced, for example, by operating only a single air conditioning pack to condition the cabin rather than operating two air conditioning packs in some instances.
The turbine wheel 34 is mounted on the shaft 20 to drive rotation of the shaft 20 and compressor wheel 26 about axis A. After passing through the turbine inlet nozzle 32 the air 14 is expanded to both extract energy from the air 14 so as to drive the shaft 20 and the compressor wheel 26 (in combination with a motor 38 mounted along the shaft 20 in some embodiments) and to cool the air 14 to prepare it for the cabin. After expansion, the air 14 passes through the turbine outlet 36 out of the air cycle machine 12. The air 14 can pass through one or more devices 16C (e.g., heat exchangers, compact mixers, and/or acoustic treatment devices) before reaching the cabin C at the desired temperature and pressure.
As illustrated in
The valve body 46 can be any valve commonly known in the art for selectively communicating air from two ports (two pressure sources) to a third port. The valve body 46 can be controlled to move a member between a first position that blocks a first of the three ports and allows the second and third ports to be in fluid communication, and a second position that blocks the second port and allows the first and third ports to be in fluid communication. The valve body 46 is controlled to vary the pressure in the first cavity 44 between a first pressure P1, equal to or about equal to the pressure Pt within the turbine inlet 30 (illustrated in
The second cavity 48 is defined by the shroud 42 and the poppet member 40 and is positioned radially outward of the turbine wheel 34 with respect to axis A. The poppet member 40 separates the first cavity 44 from the second cavity 48. The passage 50 through shroud 42 allows the second cavity 48 to be in fluid communication with the turbine inlet nozzle 32 immediately adjacent to the turbine wheel 34. This arrangement allows the second cavity 48 to be maintained at or about the static pressure experienced within the turbine inlet nozzle 32 immediately adjacent to the turbine wheel 34. This static pressure is lower than the pressure at the turbine inlet 30 (and selectively the pressure of the first cavity 44) but greater than the ambient pressure external to the air cycle machine 12 (and selectively the pressure of the first cavity 44), which allows for actuation of the poppet valve 40.
The poppet valve 40 includes a main body 52 that is mounted on the shroud 42 and configured to seal and separate the first cavity 44 from the second cavity 48. The main body 52 is actuated as discussed to slide relative to shroud 42. In the first position shown in
By varying the pressure of the first cavity 44 in the manner disclosed to selectively move the poppet member 40 within the turbine inlet nozzle 32, the efficiency of the environmental control system 10 can be improved. In particular, selectively moving the poppet member 40 to vary the size of the turbine inlet nozzle 32 when desired allows the power consumption of the environmental control system 10 to be reduced, for example, by operating only a single air conditioning pack to condition the cabin rather than operating both air conditioning packs.
Referring to
A shroud 336 is supported by the housing 316 and may deflect axially under load. Multiple vanes 338 are retained between the backing plate 328 and shroud 336 and, typically, a few thousandths of an inch of clearance is provided between the vane 338 and the backing plate 328 and shroud 336. In the example system shown, there are 323 vanes that are modulated between full open and 40% of full open.
The vanes 338 include an inlet end 348 and an outlet end 350. The inlet end 348 provides an adjustable throat 352, shown in
The mounting plate 330 includes a boss 342 for each vane 338. Each vane 338 includes a hole 355 for receiving a pivot pin 354. The pivot pin 354 extends through an opening in the shroud to the mounting plate 330 to secure the vane 338 between the shroud 336 and backing plate 328. An end of the pivot pin 354 is secured into the boss 342. Openings in the backing plate 328, vane 338 and shroud 336 are in a slip fit relationship relative to the pivot pin 354 to permit the shroud 336 and backing plate 328 to deflect axially without binding the vane 338.
The shroud 336 is shown broken along planes J, K and L in
With reference to
As shown in
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Claims
1. An air cycle machine, comprising:
- a compressor section having a variable area diffuser;
- a turbine section having an inlet nozzle with a variable size;
- a motor to drive the compressor; and
- a common rotating shaft on which the compressor section, the turbine section and the motor are mounted,
- the turbine section driving rotation of the shaft to drive the compressor section with the motor.
2. The air cycle machine according to claim 1, wherein the compressor section, the turbine section and the motor are each supported on air bearings.
3. The air cycle machine according to claim 1, wherein the variable size of the inlet nozzle is set according to operation of a predefined number of packs.
4. The air cycle machine according to claim 1, wherein the motor comprises an integrally cooled motor.
5. The air cycle machine according to claim 4, further comprising a heat exchanger coupled to the motor.
6. The air cycle machine according to claim 5, wherein a first cooling flow is tapped from an inlet of the compressor section and exited downstream form the heat exchanger.
7. The air cycle machine according to claim 5, wherein a second cooling flow is tapped from an outlet of the compressor section for air bearing cooling.
8. An air cycle machine, comprising:
- a compressor section having a variable area diffuser to compress inlet air;
- a turbine section having an inlet nozzle with a variable size to receive the compressed air from the compressor section and to expand the air for use in an aircraft cabin;
- a motor to drive the compressor; and
- a common rotating shaft on which the compressor section, the turbine section and the motor are operably mounted,
- the turbine section driving rotation of the shaft to provide additional drive power to the compressor section along with that of the motor.
9. The air cycle machine according to claim 8, wherein the compressor section, the turbine section and the motor are each supported on air bearings.
10. The air cycle machine according to claim 8, wherein the variable size of the inlet nozzle is set according to operation of a predefined number of packs.
11. The air cycle machine according to claim 8, wherein the motor comprises an integrally cooled motor.
12. The air cycle machine according to claim 11, further comprising a heat exchanger coupled to the motor.
13. The air cycle machine according to claim 12, wherein a first cooling flow is tapped from an inlet of the compressor section and exited downstream form the heat exchanger.
14. The air cycle machine according to claim 12, wherein a second cooling flow is tapped from an outlet of the compressor section for air bearing cooling.
15. An air cycle machine for use in a RAM engine in an aircraft, comprising:
- a compressor section having a variable area diffuser to compress RAM inlet air;
- a turbine section having an inlet nozzle with a variable size to receive the compressed air from the compressor section and to expand the air for use in a cabin of the aircraft;
- a motor to drive the compressor; and
- a common rotating shaft on which the compressor section, the turbine section and the motor are operably mounted,
- the turbine section driving rotation of the shaft to provide additional drive power to the compressor section along with that of the motor.
16. The air cycle machine according to claim 15, wherein the compressor section, the turbine section and the motor are each supported on air bearings.
17. The air cycle machine according to claim 15, wherein the variable size of the inlet nozzle is set according to operation of a predefined number of packs.
18. The air cycle machine according to claim 15, wherein the motor comprises an integrally cooled motor.
19. The air cycle machine according to claim 18, further comprising a heat exchanger coupled to the motor.
20. The air cycle machine according to claim 19, wherein a first cooling flow is tapped from an inlet of the compressor section and exited downstream form the heat exchanger and a second cooling flow is tapped from an outlet of the compressor section for air bearing cooling.
Type: Application
Filed: Nov 4, 2010
Publication Date: May 10, 2012
Applicant: HAMILTON SUNDSTRAND CORPORATION (Windsor Locks, CT)
Inventors: Craig M. Beers (Wethersfield, CT), Christopher McAuliffe (Windsor, CT)
Application Number: 12/939,740
International Classification: F04D 29/46 (20060101);