Aircraft air conditioning system with a cabin exhaust air turbine

Patent metadata

Field	Value
Publication number	US-11518523-B2
Application number	US-201916720577-A
Country	US
Kind code	B2
Filing date	Dec 19, 2019
Priority date	Nov 11, 2015
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

An aircraft air conditioning system comprising an ambient air line, for ambient air to flow through, connected to supply ambient air to a mixer of the aircraft air conditioning system. An ambient air compressor is arranged in the ambient air line for compressing the ambient air flowing there through. A refrigerating apparatus comprises a refrigerant circuit for a refrigerant to flow through, including a refrigerant compressor arranged in the refrigerant circuit. The refrigerant circuit is coupled thermally to the ambient air line to transfer heat from the ambient air to the refrigerant before the ambient air is supplied to the mixer. A cabin exhaust air turbine is connected to a cabin exhaust air line, is coupled to the ambient air compressor arranged in the ambient air line, and is configured to expand the cabin exhaust air flowing through the cabin exhaust air line and to drive the ambient air compressor.

First claim

What is claimed is:

1. An aircraft air conditioning system with:
a mixer,
a ram air duct,
an ambient air line configured to be flown through with ambient air and being connected to the mixer, in order to supply ambient air to the mixer,
a first ambient air compressor and a second ambient air compressor, each arranged in the ambient air line for compressing the ambient air flowing through the ambient air line,
a refrigerating apparatus, which comprises a refrigerant circuit configured to be flown through with a refrigerant, a condenser arranged in the ram air duct as well as a refrigerant compressor arranged in the refrigerant circuit, wherein the refrigerant circuit is coupled thermally to the ambient air line, in order to transfer heat from the ambient air flowing through the ambient air line to the refrigerant circulating in the refrigerant circuit before the ambient air is supplied to the mixer,
a cabin exhaust air line,
a cabin exhaust air turbine, which is connected to the cabin exhaust air line and is coupled to the first ambient air compressor arranged in the ambient air line and is configured to expand the cabin exhaust air flowing through the cabin exhaust air line and to drive the first ambient air compressor arranged in the ambient air line,
a turbine exhaust air line connected to an outlet of the cabin exhaust air turbine, wherein the turbine exhaust air line opens into the ram air duct upstream of the condenser of the refrigerating apparatus, and
a recirculation air taken from the aircraft cabin separate from the air flow in the cabin air exhaust line and thermally coupled to the refrigerating apparatus by a first evaporator,
wherein the mixer receives a first flow of the recirculation air via the first evaporator, a second flow of a bypass ambient air via a second evaporator of the refrigerating apparatus, and a third flow via a second turbine arranged on a common shaft with the second ambient air compressor, and
wherein the first ambient air compressor receives a non-compressed ambient air flow, and the second ambient air compressor is downstream from the first ambient air compressor and receives ambient air flow downstream from the ram air duct.

2. The aircraft air conditioning system according to claim 1 , wherein the ambient air line comprises a first section, in which the first ambient air compressor is arranged for compressing the ambient air flowing through the first section of the ambient air line, and in that the cabin exhaust air turbine is coupled to the first ambient air compressor and is configured to drive the first ambient air compressor.

3. The aircraft air conditioning system according to claim 2 , wherein a post-heater is arranged in the first section of the ambient air line downstream of the first ambient air compressor and is coupled thermally to the cabin exhaust air line upstream of the cabin exhaust air turbine, which post-heater is configured to transfer heat from the ambient air flowing through the ambient air line downstream of the first ambient air compressor to the cabin exhaust air flowing through the cabin exhaust air line upstream of the cabin exhaust air turbine.

4. The aircraft air conditioning system according to claim 3 , further comprising a post-heater bypass line, which branches off from the first section of the ambient air line upstream of the post-heater and opens into the first section of the ambient air line again downstream of the post-heater, wherein a post-heater bypass valve is preferably arranged in the post-heater bypass line, which post-heater bypass valve is configured to control the ambient air flow through the post-heater bypass line.

5. The aircraft air conditioning system according to claim 1 , further comprising a controller, which is configured to control the operation of the cabin exhaust air turbine in dependence on the flight altitude of an aircraft equipped with the aircraft air conditioning system.

6. The aircraft air conditioning system according to claim 5 , wherein the controller is configured to operate the cabin exhaust air turbine when an aircraft equipped with the aircraft air conditioning system is flying at a flight altitude of at least 6000 m.

7. A method for operating an aircraft air conditioning system, comprising:
conducting ambient air through an ambient air line, which is connected to a mixer of the aircraft air conditioning system, in order to supply ambient air to the mixer,
compressing the ambient air flowing through the ambient air line in a first ambient air compressor and a second ambient air compressor arranged in the ambient air line, wherein the first ambient air compressor receives a non-compressed ambient air flow, and the second ambient air compressor is downstream from the first ambient air compressor and receives ambient air flow downstream from a ram air duct,
providing a refrigerating apparatus, which comprises a refrigerant circuit configured to be flown through with a refrigerant, a condenser configured to be arranged in the ram air duct as well as a refrigerant compressor arranged in the refrigerant circuit,
thermal coupling of the refrigerant circuit of the refrigerating apparatus to the ambient air line, in order to transfer heat from the ambient air flowing through the ambient air line to the refrigerant circulating in the refrigerant circuit before the ambient air is supplied to the mixer,
providing a cabin exhaust air turbine, which is connected to a cabin exhaust air line and is coupled to the first ambient air compressor arranged in the ambient air line, expands the cabin exhaust air flowing through the cabin exhaust air line and drives the first ambient air compressor arranged in the ambient air line,
conducting turbine exhaust air, which flows through a turbine exhaust air line connected to an outlet of the cabin exhaust air turbine, into the ram air duct, wherein the turbine exhaust air line opens into the ram air duct upstream of the condenser of the refrigerating apparatus,
conducting a recirculation air to the mixer, the recirculation air taken from the aircraft cabin separate from the air flow in the cabin air exhaust line, the recirculation air thermally coupled to the refrigerating apparatus by a first evaporator,
conducting a bypass ambient air via a second evaporator of the refrigerating apparatus to the mixer, and
conducting a flow of air to the mixer via a second turbine arranged on a common shaft with the second ambient air compressor,
wherein the mixer receives a first flow of the recirculation air, a second flow of the bypass ambient air, and a third flow of the flow of air via the second turbine.

8. The method according to claim 7 , wherein the ambient air line comprises a first section, in which the first ambient air compressor is arranged for compressing the ambient air flowing through the first section of the ambient air line, and in that the cabin exhaust air turbine is coupled to the first ambient air compressor and drives the first ambient air compressor.

9. The method according to claim 8 , wherein in the first section of the ambient air line downstream of the first ambient air compressor, a post-heater is arranged, which is coupled thermally to the cabin exhaust air line upstream of the cabin exhaust air turbine and transfers heat from the ambient air flowing through the ambient air line downstream of the first ambient air compressor to the cabin exhaust air flowing through the cabin exhaust air line upstream of the cabin exhaust air turbine.

10. The method according to claim 9 , further comprising a post-heater bypass line, which branches off from the first section of the ambient air line upstream of the post-heater and opens into the first section of the ambient air

Assignees

• Airbus Operations Gmbh

Inventors

• Bammann Holger
• Klimpel Frank

Classifications

• B64D2013/0648

  with energy recovery means, e.g. using turbines · CPC title

• B64D13/08 Primary

  the air being heated or cooled · CPC title

• B64D2013/0688

  with means for recirculating cabin air · CPC title

• B64D13/06 Primary

  the air being conditioned (pressurising B64D13/02) · CPC title

• B64D2013/0618

  with arrangements for reducing or managing bleed air, using another air source, e.g. ram air · CPC title