FR3089204A1 - Air management system especially for air conditioning and defrost pack - Google Patents

Abstract

The invention relates to an air management system (10) for a DHW pack (20), comprising: - a leading edge (110, 210) of a turbomachine nacelle (100) or of an airplane wing, - an air inlet (22), for example from a DHW pack (20), characterized in that the leading edge (110) comprises an exchanger (112), the exchanger (112) being connected with the inlet d 'air (22), so that in operation, the air inlet (22) is supplied with the air from the exchanger (112). Figure for the abstract: Fig. 2

Description

Description

Title of the invention: Air management system in particular for air conditioning and defrosting pack [0001] GENERAL TECHNICAL FIELD [0002] The invention relates to the air supply of air conditioning packs, called a pack ECS (“environmental control system” which translates as an air regulation system), that is to say the systems which manage and regulate the air in the cabin, inter alia, of an aircraft, thus that the management of the anti-icing functions of the nacelle of a turbomachine (called “NAI” for “Anti-Ice Nacelle”) of the aircraft and / or of the wing tips of the latter (called “WIPS” for “Wing Ice Protection System ”or WAI for“ Wing Anti-Ice ”).

STATE OF THE ART In so-called “bleed” architectures, that is to say with an air sample at the engine (on a turbomachine, in particular at one or more compressor stages), the flow rate of the sampled air is established for various needs, including the need for renewal and conditioning of the cabin air supplied by the DHW pack, the need for anti-icing of the nacelle and the need for defrosting or anti-icing of wings and other aircraft systems.

Referring to Figure 1, the reference architecture is to take air (high and medium pressure) from the turbomachine Al, at about 250 ° C, then pass it through a precooler (air exchanger / air) A2 (called “Precooler”) where it is cooled to 175 ° C-180 ° C by air also taken from a secondary stream A3 (in the context of the turbomachine with double flow). At the outlet of the recooler A2, part of the bleed air is used to defrost the nacelle A4 (NAI function), and the other part is used to supply the pneumatic needs of the aircraft, such as defrosting WIPS of wings A5 and also the DHW pack A6, which then supplies air to cabin A7 of the aircraft. This is a parallel operation, since the air used for each of the functions (NAI, ECS, WIPS, etc.) is then evacuated to the outside, which constitutes a net loss in terms of efficiency for the turbomachine. Indeed, NAI and WIPS systems generally use Piccolo tubes which blow hot air on the surfaces to be protected against frost, which is lost.

At the inlet of the DHW system A6, the air is cooled (for example by a reverse Brayton system or by a steam condenser) to a temperature between -5 and 5 ° C.

Other more electrical technologies exist to reduce these engine air samples which adversely affect the performance of the turbomachine. These different solutions are considered separately and not with a vision of global energy integration.

Beyond ensuring an air flow for these different systems, the frost protection requires calories (thermal requirement), where the air renewal system requires a pressure level for the air taken. Today, the answer to these two needs is not decoupled, which implies significant losses in terms of packaging the sample for the needs of the aircraft.

[0008] Furthermore, future aircraft are introducing new modes of operation for turbomachines which allow them to greatly reduce their idling levels, particularly in the descent phases. However, the nacelle still needs to be protected against frost during these phases, or in operation at very low idle levels, the temperatures of the air taken from the turbomachine can no longer meet this function. One solution is to opt for electric heating mats, powered by another electrical source, which directly heat the leading edge by being placed directly on the material or in the material forming the leading edge.

Today's trend is towards electrification, without taking air from the engine to supply the DHW pack. Extra bulky and heavy air compressors are required in the aircraft.

One of the problems therefore lies in the fact that, for the DHW pack, a certain pressure is required, at a temperature not too hot, while for the NAI function, it is necessary to have a certain temperature.

DESCRIPTION OF THE INVENTION The present invention aims to respond to some of the limitations of the prior art.

In this regard, the invention provides an air management system for aircraft, comprising:

- a leading edge of a turbine engine nacelle or an aircraft wing,

- an air inlet, in which the leading edge comprises an exchanger, the exchanger being connected with the air inlet, so that in operation, the air inlet is supplied with air from the exchanger.

Thus, the heat of the air entering the exchanger defrosts the leading edge and the induced cooling of this air reduces the temperature of the air entering the air inlet, this air inlet being for example that of a DHW air conditioning pack.

The air management system advantageously comprises a sample of engine air, configured to sample a flow of air in a turbomachine, said sample of engine air being connected to the exchanger to supply it with air, so that the engine air intake, the exchanger and the air conditioning pack air intake

DHW is pneumatically arranged in series in this order.

The removal of engine air is for example carried out at a compression stage corresponding to a pressure between 1 and 5 bars, preferably between 1 and 2 bars (for so-called “more electric” packs) or at a pressure between 4 and 5 bars (for so-called “pneumatic” packs). The location of the engine air intake depends on the type of DHW pack used, more electric or pneumatic (which does not require all the same pressures and / or temperatures). The use of a DHW pack technology mixing electric and pneumatic allows compression corresponding to a pressure ranging from 1 to 5 bars.

In this description, the term "more electric DHW pack" means a pack which always requires a sample of air from the engine and which conditions it to meet cabin needs thanks to electrical energy. There are all-electric DHW packs which do not require air to be drawn from the engine but only operate with air taken directly from outside the aircraft.

The system may also include a precooler connected to the exchanger, so that the precooler, the exchanger and the DHW pack air inlet are pneumatically arranged in series in this order.

The exchanger is preferably an air-air exchanger, configured to allow heat exchange with a free air flow via the leading edge to be defrosted. This exchanger can be surface.

Finally, in one embodiment, the system includes a heat source configured to heat the air circulating in the exchanger. This heat source is preferably electric (for example one or more electric mats formed of resistors, positioned in or around an air duct carrying the air flow intended for the exchanger). This heat supply may be necessary when the engine air sampling is carried out at a low pressure, therefore at a low temperature, insufficient to defrost the nacelle.

The heat source can be positioned upstream of the exchanger, in the direction of air flow.

The invention further relates to an assembly comprising a system as described above and a DHW air conditioning pack supplied by the air inlet of the DHW air conditioning pack.

In one embodiment, the DHW air conditioning pack is a pneumatic pack, for example of the reverse Brayton type. In another embodiment, the DHW air conditioning pack is a more electric pack, for example with vapor compression, that is to say an electric pack using nevertheless a drawing of engine air.

Finally, the invention relates to a turbomachine comprising:

- an air management system as described above,

- a nacelle including the leading edge,

- a compression stage at which the engine air intake is located, in which the engine air intake, the exchanger and the air inlet are pneumatically arranged in series.

BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics, objects and advantages of the invention will emerge from the description which follows, which is purely illustrative and not limiting, and which should be read with reference to the appended drawings, in which:

[Fig.l]

Figure 1 schematically illustrates a state-of-the-art air management architecture, [0026] [fig.2]

FIG. 2 schematically illustrates an air management architecture according to an embodiment of the invention, [0027] [fig.3]

FIG. 3 schematically illustrates an exchanger usable in the context of FIG. 2.

Description of the embodiments A management system 10 for air conditioning pack 20 or also environmental control system pack (translation of ECS in French - it will also be called ECS pack 20 thereafter) d 'an aircraft will now be described, with reference to Figure 2. This management system 10 involves a turbomachine 1, including its nacelle 100 and / or a wing of the aircraft.

The description will be made for a management system 10 applied to a leading edge 110 of the nacelle 100 of the turbomachine 1. However, it is applicable for a leading edge of an aircraft wing (not illustrated). ), subject naturally to the implementation of suitable pneumatic ducts, in particular with a closed circulation of hot air.

The air management system 10 for DHW pack 20 therefore includes a leading edge 110 of the nacelle 100 of the turbomachine, as well as an air inlet 22 of DHW pack 20. The DHW pack 20, arranged downstream (in the direction of air flow) of the air management system 10, is an element known to aircraft, as explained in the introduction. It includes various elements (compressors, turbines, valves, exchangers, etc.) and will therefore not be detailed here.

The leading edge 110 of the nacelle 100 comprises an exchanger 112 connected (by a pipe) to the air inlet 22 of DHW packs 20. This exchanger 112 receives hot air from a sample of engine air 12 (via a pipe), and exchanges with the cold air in contact with the leading edge 110. The heat of the air circulating in the exchanger 112 makes it possible to heat the leading edge 110 and therefore to allow a defrost, while the outside air makes it possible to cool the hot air circulating in the exchanger 112. It is therefore an air-air exchanger, preferably surface. This exchanger 112 is part of an NAI device.

Thus, at the outlet of the exchanger 112, the air has been cooled, which means that the air arriving at the air inlet 22 of the DHW pack 20 is cooler.

For example, under certain flight conditions and certain phases of the mission, the air entering the exchanger 112 is at 180 ° C and it comes out between 110 ° and 140 ° C. Then, the DHW pack is requested to ultimately condition the cabin air. Consequently, there is a difference of 70 ° to 40 ° C compared to an air management system without exchanger 112. Thus, the ECS 20 pack works on a lower temperature difference: it can therefore be undersized compared to the ECS packs of the prior art and it consumes less. We thus gain in compactness (volume, mass, etc.), energy, with all the positive consequences that this can have on an aircraft (more space, less weight, etc.).

Upstream of the exchanger 112, the air management system 10 comprises the removal of engine air 12 from the turbomachine 1, configured to take a flow of air which will supply the exchanger 112, then in downstream the air management system 10, then downstream the DHW pack 20. This removal of engine air 12 is done at a compression stage. Depending on the type of DHW pack used, the location of the engine air intake 12 varies.

The engine air intake 12, the exchanger 112 and the air inlet 22 of the DHW pack 20 are arranged in series: the air passes successively (in this order) through these three elements.

There are two main types of DHW packs: the pneumatic pack, called classic, which generally works with a reverse Brayton system, and the electric pack, whose development is more recent, which generally works with vapor compression. These two packs do not require the same air supplies. In particular, the pneumatic pack needs a pressure at the air inlet 22 of the DHW pack 20 of between 4 and 5 bars when the more electric pack needs a lower operating pressure.

It is recalled that what is meant by "DHW plus electric pack", a pack which always requires a sample of air from the engine and which conditions it to meet cabin needs thanks to electrical energy. There are all-electric DHW packs which do not require air to be drawn from the engine but only operate with air taken directly from outside the aircraft. We can also speak of semi-electric DHW packs.

Depending on the pressure requirement, the location of the engine air sample 12 differs: the higher the pressure, the more the sample is taken in high compression stages.

Depending on the temperatures of the air taken from the turbomachine, a precooler 14 (pre-cooler, but the English term is commonly used) is provided, to lower the temperature to less than 180 ° C (in accordance with regulations) . It is positioned downstream of the engine air intake 12 and upstream of the exchanger 112. This precooler 14 is standard and will not be detailed.

In the case of a more electric DHW pack, the precooler 14 can be bypassed when the operating conditions mean that the temperature of the engine air intake 12 is less than 180 ° C. A bypass circuit 16 is therefore provided, which bypasses the precooler 14 and connects the engine air intake 12 to the exchanger 112 of the leading edge 110 of the nacelle 100.

This bypass circuit 16 can also be provided in the case of a pneumatic DHW pack, to adapt to the different operational modes.

In the case of a more electric DHW pack, there are known NAI functions, that is to say defrosting of the nacelle, fully electric. In the context of this description, the NAI function is provided by the exchanger 112. However (and even in the case of a pneumatic DHW pack), the temperature of the air taken off may not be sufficient to ensure the defrost (especially during certain flight phases). To this end, it is proposed to provide a hot source 30 configured to heat the air passing through the exchanger 112. The hot source 30 is preferably electric. The electrical hot source 30 may include a set of electrical resistors. The electric hot source 30 may have the form of one or more electric mats, arranged in a pipe 32 conveying air. This pipe 32 can be part of the exchanger 112 or else be upstream of the latter (as illustrated in FIG. 2). Different arrangements of the electric hot source 30 are possible, in order to homogenize as much as possible the diffusion of heat in the pipe 32.

The hot source 30 is supplied by different means or a combination between these different means: direct or indirect mechanical sampling (generator, auxiliary expansion turbine, etc.), or even by a secondary electrical source.

The activation and stopping of the hot source 30 are controlled by a control unit, which can take into account different data: air temperature at bleeding, angular speed of the compressor, altitude, outside temperature, Mach , humidity, etc.

The hot source 30 can be bypassed by a bypass line 34.

It is thus possible to decouple the need for temperature and the need for pressure:

we take what is needed in terms of flow and pressure by removing engine air 12 and the question of temperature, if the latter is not sufficient, is managed by the hot spring 30.

Referring to Figure 3, an exchanger 112 in a leading edge 110 of a nacelle 100 is illustrated. The exchanger 112 is formed by an external skin 114, in contact with the outside air, and an internal skin 116, in contact with the primary / secondary flow. Between these two skins, cavities are defined for the circulation of air from the engine air sample 12. This type of exchanger is known in applications other than wings or nacelles. It will not be detailed here.

As indicated above, the air management system for DHW pack 20 can use an exchanger in the leading edge of an aircraft wing or any other surface of the aircraft requiring an anti-corrosion system. icing / defrosting like air inlets. The aircraft wing can support the turbomachine 1 or not support it (turbomachine 1 attached to the rear fuselage).

Claims (1)

Claims [Claim 1] Air management system (10) for aircraft, comprising: - a leading edge (110, 210) of a turbomachine nacelle (100) or of an aircraft wing, - an air inlet (22), characterized in that the leading edge (110) comprises an exchanger (112), the exchanger (112) being connected with the air inlet (22), so that in operation, the inlet of air (22) is supplied with air from the exchanger (112). [Claim 2] The system of claim 1, further comprising an engine air intake (12), configured to draw an air flow in a turbomachine, said engine air intake (12) being connected to the exchanger (112) for supply it with air, so that the engine air intake (12), the exchanger (112) and the air inlet (22) are pneumatically arranged in series in this order. [Claim 3] System according to claim 2, in which the engine air sampling (12) is carried out at a compression stage corresponding to a pressure between 1 and 5 bars, preferably at a pressure between 1 and 2 bars or between 4 and 5 bars. [Claim 4] System according to any one of claims 1 to 3, further comprising a precooler (14) connected to the exchanger (112), so that the precooler (14), the exchanger (112) and the inlet of air (22) are pneumatically arranged in series in this order. [Claim 5] System according to any one of Claims 1 to 4, in which the exchanger (112) is an air-air exchanger, preferably areal, configured to allow heat exchange with a free flow of air via the leading edge (110). [Claim 6] System according to any one of claims 1 to 5, comprising a heat source (30), preferably electric, configured to heat the air circulating in the exchanger (112). [Claim 7] The system of claim 6, wherein the heat source (30) is positioned upstream of the exchanger (112). [Claim 8] The system of claim 6 or 7, wherein the heat source (30) comprises one or more electric mats formed of resistors, positioned in or around an air duct (32) carrying the air flow intended for the 'exchanger (112). [Claim 9] Assembly comprising a system (10) according to any one of the vendications 1 to 8 and an air conditioning pack (ECS, 20) supplied by the air inlet (22), the air conditioning pack (ECS, 20) being for example a pneumatic pack, for example example of the reverse Brayton system type, or a more electric pack, for example with vapor compression. [Claim 10] Turbomachine (1) comprising: - an air management system (10) according to any one of claims 1 to 8, - a nacelle (100) comprising the leading edge (110), - a compression stage (2) at which the engine air intake (12) is located, in which the engine air intake (12), the exchanger (112) and the air inlet (20 ) are pneumatically arranged in series.