Method of operating an aircraft system

• US 20090117840A1
• Filed: 06/28/2006
• Published: 05/07/2009
• Est. Priority Date: 08/08/2005
• Status: Active Grant

• Current Assignee: Liebherr-Aerospace Lindenberg GmbH (Liebherr-International AG)
• Original Assignee: Liebherr-Aerospace Lindenberg GmbH (Liebherr-International AG)
• Inventors: Hirschmann, Markus, Kresser, Hubert, Sauterleute, Alfred, Lavergne, David, Hartenstein, Laurent
• Granted Patent: US 7,797,962 B2
• Time in Patent Office: Days
• US Class Current: 454/71
• CPC Class Codes: B64D 13/06 the air being conditioned pressurising B64D13/02
• CPC Class Codes: B64D 2013/0618 with arrangements for reducing or managing bleed air, using another air source, e.g. ram air
• CPC Class Codes: B64D 2013/064 comprising more than one system, e.g. dual systems
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency

Abstract

The present disclosure relates to a method of operating an aircraft system, in particular for the purpose of fresh air supply, air-conditioning and pressurization of an aircraft cabin, having a first compressed air source formed by a first compressor charged with ambient air, ram air and/or precompressed air and driven by means of at least one motor and/or of at least one turbine and whose outlet is in direct or indirect communication with an aircraft cabin, said aircraft system having at least one second compressed air source whose outlet can be connected directly or indirectly to the aircraft cabin, wherein only the first compressed air source is in communication with the aircraft cabin in a first operating mode, wherein both the first and the second compressed air sources are in communication with the aircraft cabin in a second operating mode, and wherein the selection of the operating mode depends on the pressure of the ambient air such that the first operating mode is set at a high pressure of the ambient air and the second operating mode is set at a pressure of the ambient air lower in comparison.

Claims

1. A method of operating an aircraft system for the purpose of fresh air supply, air-conditioning and pressurization of an aircraft cabin, having a first compressed air source formed by a first compressor charged with ambient air, ram air and/or precompressed air and driven by means of at least one motor and/or of at least one turbine and whose outlet is in direct or indirect communication with an aircraft cabin, said aircraft system having at least one second compressed air source whose outlet can be connected directly or indirectly to the aircraft cabin, comprising:

operating in a first operating mode where only the first compressed air source is in communication with the aircraft cabin, and operating in a second operating mode where both the first and the second compressed air sources are in communication with the aircraft cabin, wherein a selection of the operating mode depends on a pressure of the ambient air such that the first operating mode is set at a high pressure of the ambient air and the second operating mode is set at a pressure of the ambient air lower in comparison.

2. The method in accordance with claim 1, wherein the compressed air is subjected to cooling prior to entry into the aircraft cabin, with the cooling taking place by a ram air heat exchanger located in a ram air duct of the aircraft and/or by at least one turbine.

3. The method in accordance with claim 2, wherein at least one turbine is located with the first compressor on a shaft.

4. The method in accordance with claim 1, wherein, in the second operating mode, outlet air of the first compressor and at least some outlet air of the second compressed air source are mixed and the mixed air flow is subjected to cooling.

5. The method in accordance with claim 1, wherein outlet air of the first compressor is supplied at least partially to a jet pump.

6. The method in accordance with claim 1, wherein the second compressed air source is formed by one or more motorized second compressors charged with ambient air.

7. The method in accordance with claim 1, wherein the second compressed air source is made such that it provides engine bleed air.

8. The method in accordance with claim 1, wherein the aircraft system further includes a water extraction circuit downstream of the compressed air sources and upstream of the cabin as well as a turbine downstream of the water extraction circuit , the method further comprising operating in a third operating mode where both the first and the second compressed air sources are in communication with the aircraft cabin and in which the compressed air is guided around the water extraction circuit and the turbine in a partial or complete bypass.

9. The method in accordance with claim 1, wherein the air is subjected to cooling prior to the entry into the aircraft cabin, with the cooling taking place by one or more ram air heat exchangers located in a ram air duct of the aircraft and by one or more completely or partially charged turbines which are seated with the first compressor on a shaft.

10. The method in accordance with claim 1, wherein, in the first operating mode, the second compressed air source is connected such that its outlet air is supplied to a jet pump arranged in a ram air duct with at least one ram air heat exchanger.

11. The method in accordance with claim 1, wherein the second compressed air source is formed by one or more motorized second compressors charged with ambient air, with the at least one first and/or second compressors being coupled to an impeller which is arranged in the ram air duct with at least one ram air heat exchanger, the method further comprising operating the impeller in the first operating mode for the at least partial transport of air through the ram air heat exchanger.

12. The method in accordance with claim 1, wherein a switchover is made from the first to the second operating mode when a packing limit of the first compressor is reached or when a maximum motor power of the first compressor is reached.

13. The method in accordance with claim 1, wherein, in the second operating mode, the air mass supplied to the aircraft cabin is increased with respect to the first operating mode.

14. The method in accordance with claim 1, wherein the outlet of the first compressor and/or of the compressors of the second compressed air source and/or of a further compressed air source are connected to the respective compressor inlets for the purpose of producing a recirculation flow.

15. The method in accordance with claim 1, wherein the outlet air of the first compressor and/or of the compressors is supplied to the second compressed air source and/or to a further compressed air source via a jet pump into a ram air duct of the aircraft or to further consumers of the aircraft.

16. The method in accordance with claim 15, wherein the further consumers are selected from the group OBOGS, OBIGGS, WAI (wing anti-ice), supplemental cooling/heating or wherein the outlet air is utilized for the start of an engine or auxiliary engine.

17. The method in accordance with claim 1, wherein the aircraft air-conditioning system has a turbine which is in communication with the outlet of the compressed air sources, the method further comprising changing a cross-sectional surface of the turbine by means of a turbine guide apparatus to increase the transmission of the aircraft air-conditioning system.

18. The method in accordance with claim 8, wherein the compressed air in the circuit is supplied via the compressors to the first compressed air source and/or to a further compressed air source for increasing air temperature.

19. The method in accordance with claim 1, wherein a restriction of the outlet lines of the compressors of the first compressed air source and/or of the further compressed air source takes place for increasing air temperature.

20. The method in accordance with claim 1, wherein a ram air amount guided through a ram air duct of the aircraft is reduced for increasing air temperature.

21. The method in accordance with claim 20, wherein a ram air duct inlet can be closed at least partly by a flap or valve which is controlled via an actuator.

23. The method in accordance with claim 1, wherein the aircraft system further has a first air-conditioning system and a second air-conditioning system, with the second compressed air source being formed by a motorized compressor charged with ambient air, ram air or precompressed air or by an engine bleed air source, with the second compressed air source being switched in to both air-conditioning systems with a lower mass flow in the second operating mode and with the second compressed air source being switched in to both air-conditioning systems with a mass flow higher in comparison in a further operating mode.

22. The method in accordance with claim I wherein the aircraft system further has a first air-conditioning system and a second air-conditioning system, with the second compressed air source being formed by two, or more than two, motorized compressors charged with ambient air, ram air or precompressed air or by two, or more than two, engine bleed sources, with one of the second compressed air sources being switched in to both air-conditioning systems in the second operating mode and with the second compressed air sources being switched in to a respective one of the two air-conditioning systems in a further operating mode.

24. A system for an aircraft, the system for the purpose of fresh air supply, air-conditioning and pressurization of an aircraft cabin, comprising:

a first compressed air source formed by a first compressor charged with ambient air, ram air and/or precompressed air and driven by at least one motor and/or at least one turbine and whose outlet is in direct or indirect communication with an aircraft cabin,

at least one second compressed air source whose outlet can be connected directly or indirectly to the aircraft cabin, wherein only the first compressed air source is in communication with the aircraft cabin in a first operating mode, wherein both the first and the second compressed air sources are in communication with the aircraft cabin in a second operating mode, and wherein the second operating mode includes a higher ambient pressure than the first operating mode.

25. The system in accordance with claim 24, further comprising further compressed air sources, in addition to the first and second compressed air sources, whose outlets can be connected directly or indirectly to the aircraft cabin.

26. The system in accordance with claim 24, wherein the first compressed air source and the at least one second compressed air source are connected in parallel.

27. The system in accordance with claim 24, further comprising a jet pump and/or a fan for cooling the at least one motor driving the compressor or compressors.

28. The system in accordance with claim 24, further comprising one or more fans for the cooling of the motor or motors driving the compressors and/or of a ram air heat exchanger or exchangers which are not coupled to the compressor or compressors.

29. The system in accordance with claim 28, wherein the compressed air is subjected to cooling prior to entry into the aircraft cabin, with the cooling taking place by a ram air heat exchanger located in a ram air duct of the aircraft and/or by at least one turbine, and wherein the ram air duct comprises one or more partition walls extending in the flow direction at least sectionally which divide the ram air duct into at least two sections, with a jet pump communicating with the second compressed air source or an impeller coupled to the second compressor being arranged in the first section and with the second section forming a bypass of the first section for the air flowing through the ram air duct.

30. The system in accordance with claim 29, further comprising a further section in the ram air duct in which a jet pump and/or a fan is/are arranged for the purpose of motor cooling.

31. The system in accordance with claim 24, wherein the outlet air of the first compressor and of the at least one further compressed air source are combined at a mixing point, with the mixing point being formed by a chamber, in particular by a chamber for the conversion of ozone and/or hydrocarbons.

32. The system in accordance with claim 24 further comprising a line connecting the inlet line of the ram air heat exchanger to the outlet of the turbine in which a valve (TCV:

temperature control valve) is arranged and, a common control unit for the TCV valve and for the turbine guide apparatus.