EXCHANGER ASSEMBLY COMPRISING AN INSULATING AIR GAP, AND ASSOCIATED AIR CONDITIONING SYSTEM

Abstract

Heat exchanger assembly comprising a ram air flow channel (14) extending in a longitudinal direction, and characterized in that said assembly comprises: at least two separate heat exchangers (12a, 12b) that are adjacent in a transverse direction perpendicular to the longitudinal direction, are arranged in the ram air flow channel (14), and are configured such that the ram air passing through said channel (14) forms a cold pass of each heat exchanger (12a, 12b) by passing through said heat exchanger (12a, 12b) in said longitudinal direction, each heat exchanger (12a, 12b) also being configured for the passage therethrough of a fluid that is intended to be cooled and that forms a hot pass (20a, 20b); and an air passage which is provided between the heat exchangers and forms a thermally insulating air gap (18) between said exchangers (12a, 12b), and through which the ram air flows, said air passage extending in said longitudinal direction of said ram air flow channel (14).

Claims

1. A heat exchanger assembly comprising a ram air flow channel extending in a longitudinal direction, wherein said assembly comprises: at least two separate heat exchangers that are adjacent in a transverse direction perpendicular to the longitudinal direction, are arranged in the ram air flow channel, and are configured such that the ram air passing through said channel forms a cold pass of each heat exchanger by passing through said heat exchanger in said longitudinal direction, each heat exchanger also being configured for the passage therethrough of a fluid that is intended to be cooled and that forms a hot pass; and an air passage which is provided between the heat exchangers and forms a thermally insulating air gap between said exchangers, and through which the ram air flows, said air passage extending in said longitudinal direction of said ram air flow channel.

2. The assembly according to claim 1, wherein at least two heat exchangers of the exchangers of the assembly are produced in the same mold.

3. The assembly according to claim 1, wherein the fluid forming the hot pass of each exchanger is air.

4. The assembly according to claim 1, wherein the distance between the two exchangers, in the transverse direction, is between 1 mm and 10 mm, preferably between 3 mm and 6 mm.

5. An air conditioning system for an aircraft, wherein said system comprises a heat exchanger assembly comprising: a ram air flow channel extending in a longitudinal direction; at least two separate heat exchangers that are adjacent in a transverse direction perpendicular to the longitudinal direction, are arranged in the ram air flow channel, and are configured such that the ram air passing through said channel forms a cold pass of each heat exchanger by passing through said heat exchanger in said longitudinal direction, each heat exchanger also being configured for the passage therethrough of a fluid that is intended to be cooled and that forms a hot pass; and an air passage which is provided between the heat exchangers and forms a thermally insulating air gap between said exchangers, and through which the ram air flows, said air passage extending in said longitudinal direction of said ram air flow channel.

6. The air conditioning system according to claim 5, wherein a first exchanger of the assembly forms a primary exchanger of the air conditioning system, cooling the intake air and transmitting the air thus cooled to an inlet of a compressor of the air conditioning system, and in that a second exchanger of the assembly forms a main exchanger of the air conditioning system, cooling the air leaving said compressor.

7. The air conditioning system according to claim 5, wherein said system comprises a turbine engine comprising a transmission shaft, said transmission shaft being rotated by the turbine engine and driving a fan configured to supply the ram air passing through the ram air flow channel.

8. An aircraft, comprising an air conditioning system comprising a heat exchanger assembly comprising: a ram air flow channel extending in a longitudinal direction; at least two separate heat exchangers that are adjacent in a transverse direction perpendicular to the longitudinal direction, are arranged in the ram air flow channel, and are configured such that the ram air passing through said channel forms a cold pass of each heat exchanger by passing through said heat exchanger in said longitudinal direction, each heat exchanger also being configured for the passage therethrough of a fluid that is intended to be cooled and that forms a hot pass; and an air passage which is provided between the heat exchangers and forms a thermally insulating air gap between said exchangers, and through which the ram air flows, said air passage extending in said longitudinal direction of said ram air flow channel.

Description

LIST OF FIGURES

[0035] Further aims, features and advantages of the invention will become apparent upon reading the following description, which is provided solely by way of non-limiting example, and which refers to the accompanying figures, in which:

[0036] FIG. 1 is a schematic perspective view of a heat exchanger assembly according to one embodiment of the invention; and

[0037] FIG. 2 is a schematic simplified view of an air conditioning system according to one embodiment of the invention.

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION

[0038] For the sake of illustration and clarity, scales and proportions are not strictly adhered to in the figures.

[0039] Moreover, identical, similar or analogous elements are denoted using the same reference signs throughout the figures.

[0040] FIG. 1 illustrates a heat exchanger assembly 10 according to one embodiment of the invention.

[0041] The heat exchanger comprises at least two adjacent heat exchangers, in this case a first heat exchanger 12a and a second heat exchanger 12b, which exchangers are arranged in a ram air flow channel 14. The exchangers are advantageously produced in the same mold.

[0042] The ram air flow channel 14 extends in a longitudinal direction, which corresponds to the direction of flow of the ram air passing through said channel 14, as shown schematically by arrows 16a to 16f and arrow 18, which represent the flow of the ram air through the channel 14.

[0043] The heat exchangers 12a, 12b are thus adjacent in a transverse direction (not shown) perpendicular to the longitudinal direction.

[0044] The ram air forms a cold pass of each of the heat exchangers. In the schematic form of FIG. 1, a first part of the ram air represented by the arrows 16a, 16b, 16c forms the cold pass of the first heat exchanger 12a, and a second part of the ram air represented by the arrows 16d, 16e, 16f forms the cold pass of the second heat exchanger 12b.

[0045] This ram air forming the cold pass of the heat exchangers 12a, 12b allows a fluid forming a hot pass of each exchanger to be cooled: the first heat exchanger 12a comprises a first circuit 20a for the flow of a first fluid forming a hot pass of said first heat exchanger 12a, and second heat exchanger 12b comprises a second circuit 20b for the flow of a second fluid forming a hot pass of said second heat exchanger 12b.

[0046] The distance between the heat exchangers 12a, 12b allows an air passage to be formed between the heat exchangers, forming, when the ram air passes therethrough, a thermally insulating air gap 18 between said exchangers. The arrow representing the ram air gap 18 is thicker than the arrows 16a to 16f only for reasons of clarity, and the thickness of said arrow does not presume any particular characteristic of the ram air forming the air gap 18 relative to the ram air forming a cold pass of the heat exchangers 12a, 12b.

[0047] The presence of the air gap 18 makes it possible to prevent thermal bridges between the heat exchangers 12a and 12b, that is to say the transmission of heat from one heat exchanger to another. When the two fluids forming the hot pass of one and the other of the exchangers have very different temperatures, the thermal bridges could cause the exchangers to malfunction, in particular the coldest fluid could be heated by the ram air cooling the hottest fluid. Thus, the thermally insulating air gap 18 makes it possible to ensure correct operation of the two heat exchangers 12a, 12b.

[0048] The heat exchanger assembly 10 is particularly suitable for use in an air conditioning system for an aircraft, one embodiment of which is shown with reference to FIG. 2.

[0049] The heat exchanger assembly 10 comprises, in the same way as above, two heat exchangers 12a and 12b arranged in the ram air flow channel 14. The ram air forms a first cold pass 16ac of the first heat exchanger 12a (corresponding to the arrows 16a to 16c in FIG. 1), and a second cold pass 16df of the second heat exchanger 12b (corresponding to the arrows 16d to 16f of FIG. 1). The insulating blade 18 passes through the channel 14 between the two heat exchangers 12a, 12b in the longitudinal direction.

[0050] In this embodiment, the first exchanger 12a is a primary heat exchanger, often referred to as a PHX. The first exchanger 12a receives air 22 that is bled, for example, from the engines of the aircraft or taken in from outside the aircraft and then compressed. This intake air 22 forms the hot pass of the first exchanger 12a.

[0051] The air 24 cooled in the first exchanger is transmitted to the compressor 26 of a turbine engine 28, in order to be compressed therein. The turbine engine 28 further comprises a turbine 30, and a fan 32, both connected to each other and to the compressor by a transmission shaft 34. The turbine engine 28 can also comprise an electric motor (not shown), to form a motorized turbine engine.

[0052] The air 36 compressed by the compressor 26 forms the hot pass of the second heat exchanger 12b. The second heat exchanger 12b thus forms a main heat exchanger, often referred to as an MHX.

[0053] The air 38 cooled by the second heat exchanger 12b is transmitted to the air conditioning pack 40 which treats this air in order for said air to be conditioned before being transmitted to a cabin 100 of the aircraft. In particular, this treatment by the air conditioning pack 40 can comprise passage through the turbine 30 for air expansion and cooling, thus supplying energy to the turbine engine 28 for the rotation thereof.

[0054] The rotation of the transmission shaft 34 of the turbine engine, due to the recovery of energy by the turbine 30, by an electric motor or by any other means, operates the fan 32, allowing the formation of the ram air forming both the cold passes 16ac, 16df of the heat exchangers 12a, 12b, and at the same time the thermally insulating air gap 18.