Aircraft air conditioning system with an electrically driven ambient air compressor and method for operating such an aircraft air conditioning system

Patent metadata

Field	Value
Publication number	US-10202197-B2
Application number	US-201715465242-A
Country	US
Kind code	B2
Filing date	Mar 21, 2017
Priority date	Mar 24, 2016
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

An aircraft air conditioning system comprising an ambient air supply line with a first end connected to an ambient air inlet and a second end connected to a mixing chamber. A first electrically driven ambient air compressor in the ambient air supply line compresses the ambient air flowing therethrough. A first ambient air branch line branches off from the ambient air supply line upstream of the first ambient air compressor and rejoins the supply line downstream of the air compressor. A second ambient air compressor in the first ambient air branch line compresses the ambient air flowing therethrough. A cabin exhaust air line has a first end connected to an air conditioned aircraft area. A cabin exhaust air turbine in the exhaust air line is driven by the exhaust air flowing through the cabin exhaust air line and is coupled to drive the second ambient air compressor.

First claim

The invention claimed is:

1. An aircraft air conditioning system, comprising:
an ambient air supply line configured to have ambient air flow therethrough and comprising a first end connected to an ambient air inlet and a second end connected to a mixing chamber of the aircraft air conditioning system,
a first ambient air compressor, arranged in the ambient air supply line and being configured to compress the ambient air flowing through the ambient air supply line,
an electrically driven air cycle machine, configured to drive the first ambient air compressor,
a first ambient air branch line, branching off from the ambient air supply line upstream of the first ambient air compressor and rejoining the ambient air supply line downstream of the first ambient air compressor,
a second ambient air compressor, arranged in the first ambient air branch line and being configured to compress the ambient air flowing through the first ambient air branch line,
a cabin exhaust air line configured to have cabin exhaust air flow therethrough and having a first end connectable to an aircraft area to be air conditioned,
a cabin exhaust air turbine, arranged in the cabin exhaust air line and being configured to be driven by the cabin exhaust air flowing through the cabin exhaust air line and being coupled to the second ambient air compressor to drive the second ambient air compressor, and
a cabin exhaust air reheater, arranged in the cabin exhaust air line upstream of the cabin exhaust air turbine and being thermally coupled to a second ambient air branch line, branching off from the ambient air supply line downstream of the first ambient air compressor and the second ambient air compressor and rejoining the ambient air supply line downstream of the cabin exhaust air reheater, to transfer heat from the compressed ambient air flowing through the second ambient air branch line to the cabin exhaust air flow flowing through the cabin exhaust air line.

2. The aircraft air conditioning system according to claim 1 , wherein a second end of the cabin exhaust air line opens into a ram air duct, wherein the second end of the cabin exhaust air line is connected to an ejector arranged in the ram air duct, wherein the ejector is configured to eject the cabin exhaust air flowing through the cabin exhaust air line into the ram air duct.

3. The aircraft air conditioning system according to claim 1 , further comprising:
a connection line, branching off from the ambient air supply line downstream of the first ambient air compressor and joining the first ambient air branch line upstream of the second ambient air compressor,
an ambient air supply control valve, configured to control the flow of ambient air through the connection line and the first ambient air branch line, and
an electronic controller, configured to control the operation of the ambient air supply control valve in such a way that ambient air flows through the first ambient air compressor and the second ambient air compressor, either in parallel or in series, as a function of the operating state of the aircraft air conditioning system.

4. The aircraft air conditioning system according to claim 3 , wherein at least one of
the electronic controller is configured to control the operation of the ambient air supply control valve and the operation of a cabin exhaust air control valve arranged in the cabin exhaust air line downstream of the cabin exhaust air turbine in a synchronized manner as a function of an ambient air requirement of the aircraft air conditioning system, or
a heat exchanger is arranged in the connection line, wherein the heat exchanger is configured to cool the ambient air flowing through the connection line downstream of the first ambient air compressor before it is supplied to the second ambient air compressor.

5. The aircraft air conditioning system according to claim 1 , further comprising:
a compressor air recirculation line, branching off from the ambient air supply line downstream of the first ambient air compressor and rejoining the ambient air supply line upstream of the first ambient air compressor, and
a compressor air recirculation valve, arranged in the compressor air recirculation line and being configured to control a flow of compressed ambient air emerging from the first ambient air compressor through the compressor air recirculation line back into the ambient air supply line downstream of the first ambient air compressor.

6. The aircraft air conditioning system according to claim 1 ,
wherein a bypass valve is arranged in the second ambient air branch line to control the flow of compressed ambient air through the second ambient air branch line.

7. The aircraft air conditioning system according to claim 2 , further comprising:
at least one of
an ambient air cooler arranged in the ambient air supply line downstream of the first ambient air compressor and the second ambient air compressor, wherein the ambient air cooler is thermally coupled to the ram air duct, to transfer heat from the compressed ambient air flowing through the ambient air supply line to a ram air flow flowing through the ram air duct, or
an ambient air reheater arranged in the ambient air supply line, downstream of the ambient air cooler,

a condenser arranged in the ambient air supply line, downstream of the ambient air reheater,
a water separator arranged in the ambient air supply line, downstream of the condenser, and
an ambient air turbine arranged in the ambient air supply line, downstream of the water separator, wherein the ambient air turbine is coupled to the first ambient air compressor to drive the first ambient air compressor.

8. The aircraft air conditioning system according to claim 7 , wherein at least one of
the ambient air reheater is thermally coupled to a section of the ambient air supply line which is arranged downstream of the water separator, to transfer heat from the ambient air flow that flows through the section of the ambient air supply line which is arranged downstream of the water separator to the ambient air flow flowing through the ambient air reheater, or
the condenser is thermally coupled to a section of the ambient air supply line which is arranged downstream of the ambient air turbine to transfer heat from the ambient air flow flowing through the condenser to the ambient air flow that flows through the section of the ambient air supply line which is arranged downstream of the ambient air turbine.

9. The aircraft air conditioning system according to claim 7 , further comprising at least one of:
a ventilation line, which branches off from the ambient air supply line upstream of the ambient air turbine and upstream of the ambient air reheater and rejoins the ambient air supply line downstream of the ambient air turbine, wherein a ventilation valve is arranged in the ventilation line and is configured to control the flow of ambient air through the ventilation line,
a trim air line, which branches off from the ambient air supply line between the first ambient air compressor and the ambient air cooler and rejoins the ambient air supply line downstream of the ambient air turbine, wherein a trim air valve is arranged in the trim air line and is configured to control the flow of hot compressed ambient air through the trim air line,
an emergency ventilation line, which connects the ambient air inlet to the mixing chamber of the aircraft air conditioning system, wherein an emergency ventilation valve is arranged in the emergency ventilation line and is configured to control the flow of ambient air through the emergency ventilation line, and
a further trim air line branching off from the trim air line, which further trim air line is connectable to an aircraft area to be h

Assignees

• Airbus Operations Gmbh

Inventors

• Bammann Holger
• Klimpel Frank
• Giese Tim

Classifications

• B64D13/08 Primary

  the air being heated or cooled · CPC title

• B64D13/04

  Automatic control of pressure · CPC title

• B64D2013/064

  comprising more than one system, e.g. dual systems · CPC title

• B64D2013/0618

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

• B64D13/02

  the air being pressurised · CPC title