Aircraft incorporating a low-temperature bleed system

Abstract

An aircraft incorporating a bleed system for extracting compressed air from the aircraft main engines to be used as a source of pressurized air for the aircraft. The bleed air system includes a first pre-cooler installed at one of the main engines nacelle and coupled with the bleed duct, and adapted for cooling down the bleed air extracted from the main engine, and a second pre-cooler installed at the pylon and coupled with bleed duct and downstream the first pre-cooler. The working temperature of the aircraft bleed system is reduced, down to max 200 C., so that the dimensions of an Over Heat Detection System (OHDS) is reduced.

Claims

1. An aircraft incorporating a bleed air system for extracting compressed air from aircraft main engines to be used as a source of pressurized air for the aircraft, the bleed air system comprising a bleed air duct running from the aircraft main engines and passing through an aircraft pylon and wings; wherein the bleed air system comprises: a first pre-cooler installed at one of a main engine nacelle and coupled with the bleed air duct, and adapted for cooling down bleed air extracted from the main engine; and a second pre-cooler installed at the pylon and coupled with the bleed air duct and downstream the first pre-cooler; and wherein a wing anti-ice protection system is coupled with the bleed air duct upstream the second pre-cooler, so that pressurized air for wing anti-ice protection system can be supplied by the first pre-cooler.

2. The aircraft according to claim 1, wherein the second pre-cooler comprises an ozone converter.

3. The aircraft according to claim 1, further comprising an Over Heat Detection System for the bleed air duct, and wherein the Over Heat Detection System extends exclusively between the first and second pre-coolers.

4. The aircraft according to claim 1, further comprising air-conditioning packs coupled with the bleed air system downstream the second pre-cooler.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the disclosure herein are henceforth described with reference to the accompanying drawings, wherein:

(2) FIG. 1 is an schematic representation of a conventional bleed system of an aircraft, according to the prior art; and

(3) FIG. 2 is an schematic representation of a bleed system of an aircraft, according to the disclosure herein.

DETAILED DESCRIPTION

(4) FIG. 2 shows schematically a bleed system according to the disclosure herein installed in an aircraft, wherein a bleed air duct (1) runs from the main engines (2) and passes through the pylon (3) and wings (4) to supply pressurized air to the air-conditioning Packs and other consumers.

(5) The bleed air system comprises a main (first) pre-cooler (8) installed at one of the main engines nacelles, and coupled with the bleed duct (1) in order to cool down the bleed air extracted from the main engine. Preferably this first pre-cooler (8) is adapted to operate at a constant temperature, for example within the range 220-230 C.

(6) The first pre-cooler (8) receives through a duct (10) high-temperature and high-pressure air extracted from a main engine, which is cooled down by cold air, for example fan air received from a cold air duct (6).

(7) The bleed air system comprises a second pre-cooler (9) installed at the pylon (3) and coupled with bleed duct (1) downstream the first pre-cooler (8). Preferably, this second pre-cooler (9) integrates an ozone converter in order to reduce even more the overall weight.

(8) An Over Pressure Valve (OPV) and a Bleed Temperature Sensor (BTS), are installed at the duct (1) between the two pre-coolers (8,9).

(9) The air flow through the second pre-cooler (9) can be controlled by the FAV of the first pre-cooler (8) and through the (BTS).

(10) A Fan Air Valve (FAV) (11) can be provided to control a cold air intake at the pylon, used as a heat sink for the second pre-cooler (9).

(11) The aircraft wing anti-ice protection system (WAI) is coupled with the bleed air duct (1) upstream the second pre-cooler (9), through a WAI Valve (WAIV) so that the pressurized air for wing anti-ice protection system is supplied by the first pre-cooler (8).

(12) As shown in FIG. 2, the Over Heat Detection System (OHDS) for the bleed air system, extends only between the first and second pre-coolers (8,9), that is, there is no (OHDS) at the wing and part of the pylon.

(13) A Pack Inlet Temperature Sensor (PITS) from ATA21 can control the temperature (if too low) through the FAV of the first pre-cooler (8).

(14) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a, an or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims.