HEAT EXCHANGER EQUIPPED WITH A GUIDE FIN INTERFACE HOUSING

Abstract

HEAT EXCHANGER EQUIPPED WITH A GUIDE-FIN INTERFACE HOUSING The invention relates to a heat exchange device between two heat transfer fluids comprising: an external casing (10) defining a chamber (12) for the circulation of the heat transfer fluids; an inlet (20) and an outlet (30) of a first heat transfer fluid into the chamber; an inlet and an outlet of a second heat transfer fluid into the chamber; a heat exchanger block (14) arranged within the circulation chamber (12). The device further comprises at least one interface box (20) forming one of said fluid inlets or one of said fluid outlets, said interface box comprising a domed shell (24) provided with an inlet / outlet port (26) and an interface frame mechanically connected to said external casing. The box (20) further comprises a plurality of guide fins (22a, 22b, 22c, 22b) extending between the orifice and said interface armature. Figure for the abbreviation: Figure 3

Description

Title of the invention: HEAT EXCHANGER EQUIPPED WITH A GUIDE FIN INTERFACE HOUSING Technical field of the invention

[0001] The invention relates to a heat exchanger equipped with a fluid flow collector box and / or a fluid flow distribution box comprising fins for guiding this fluid flow. The invention relates in particular to such an exchanger intended for aeronautical use. Technological background

[0002] A heat exchanger, particularly one intended for use in an aircraft, is likely to be subjected to significant temperature gradients during its operating cycles. This is especially true for a heat exchanger intended to cool high-pressure air drawn from an aircraft propulsion engine (more commonly known as air bleed) or from an auxiliary power unit (APU).

[0003] When a heat exchanger begins to be supplied with air bleed, the temperature of the internal elements of the heat exchanger block (also called the "core") increases more rapidly than that of the adjacent elements of the heat exchanger block and its periphery. This results in temperature gradients that cause mechanical stresses, potentially leading to deformation of the heat exchanger elements (for example, rotation of the heat exchanger block's closing bars). Such deformations can even cause the failure of certain elements, manifesting as cracks or debonding of some brazed parts. These phenomena create a risk of fluid leakage inside the heat exchanger, or even to the outside.

[0004] In order to strengthen the mechanical strength of the heat exchanger and to facilitate the supply and distribution of fluid (such as air for example) to the heat exchanger, it is common to equip such a heat exchanger with a fluid flow collector box and / or a fluid flow distribution box, both mechanically connected to the exchanger block.

[0005] Throughout the following, the fluid will be referred to primarily by the term "air", it being understood that another fluid, primarily gaseous, may be used within the framework of this invention.

[0006] The distributor box is often supplied with air from a circular cross-section pipe. The distributor box delivers the received air to the heat exchanger block which presents in It generally has a parallelepiped shape and is formed, for example, by a stack of plates forming pairs of channels for the circulation of thermally interacting airflows within the heat exchanger block. The flow collector box receives the air exiting the heat exchanger block and delivers it to a duct that generally has a circular cross-section.

[0007] These changes in geometry (circular pipe to parallelepiped exchanger block and parallelepiped exchanger block to circular pipe) generate, within the collector box and the distribution box, vortices which can impact the air flow.

[0008] That being said, the manifold box and the distribution box (hereinafter referred to as interface boxes) are necessary to ensure the passage of air between the pipes and the exchanger block and to ensure the mechanical resistance to pressure and stress of the heat exchanger, which is essential in view of the constraints mentioned above.

[0009] The inventors therefore sought to propose an evolution of the heat exchanger and in particular of the interface boxes to reconcile the collection and distribution of the air flow to the exchanger with the mechanical constraints of the exchanger. Objectives of the invention

[0010] The invention aims to provide a heat exchange device that overcomes at least some of the drawbacks of known devices.

[0011] The invention also aims to provide, in at least one embodiment, such an exchange device which makes it possible to limit pressure losses.

[0012] The invention also aims to provide, in at least one embodiment, such an exchange device which can be obtained from a known exchange device, without significant structural modification.

[0013] The invention also aims to provide, in at least one embodiment, such a device which can exhibit better thermomechanical behavior than known exchange devices. Description of the invention

[0014] To this end, the invention relates to a heat exchange device between two heat transfer fluids comprising: - an external casing defining a chamber for the circulation of heat transfer fluids, - the entry of a first heat transfer fluid into the circulation chamber, - an outlet of said first heat transfer fluid outside of said enclosure culation, - the introduction of a second heat transfer fluid into the circulation chamber, - an outlet of said second heat transfer fluid outside the circulation enclosure, - a heat exchanger block arranged within the circulation area so as to be in fluid communication with said fluid inlets and outlets to permit the circulation of said first fluid and said second fluid in and through this exchanger block and the transfer of heat between them.

[0015] The device according to the invention is characterized in that it comprises at least one interface box forming one of said fluid inlets or one of said fluid outlets, said interface box comprising a domed envelope provided with an orifice adapted to be connected to a supply or distribution line of one of the heat transfer fluids, and an interface armature mechanically connected to said external casing, said orifice and said interface armature each extending in a plane perpendicular to a longitudinal axis which defines the main direction of circulation of the fluid flow into or out of the box, said box further comprising a plurality of heat transfer fluid guide fins which each extend between the orifice and said interface armature to ensure continuity of geometry between said line and said heat exchanger block.

[0016] The heat exchange device according to the invention thus makes it possible to limit pressure losses in the interface box equipped with guide fins by improving fluid flow through the interface box and by eliminating the abrupt change in geometry inherent in the change of cross-section between the box's supply or distribution line and the interface frame, which is mechanically connected to the heat exchanger block. In particular, the guide fins make it possible to eliminate marginal vortices that can develop due to the change in geometry of the heat transfer fluid flow through the box.

[0017] Furthermore, insofar as the box as such is not modified compared to the prior art exchangers, it can retain its mechanical resistance properties to pressure and stress.

[0018] Furthermore, the guide fins can help to absorb the mechanical stresses to which the boxes are subjected. If necessary, it is possible to design boxes that are thinner than those of the prior art, thus allowing for improved thermomechanical behavior through a reduction in thermal inertia.

[0019] The interface box can be an inlet box for the heat exchanger, in which case it is generally referred to as a distribution box or distributor. Such a box is supplied by a heat transfer fluid inlet line that opens into the box at the orifice, which is then an inlet orifice for the box. The distribution box allows the heat transfer fluid to be distributed to the heat exchanger block from the inlet orifice. The presence of guide fins in such a box provides means for directing the heat transfer fluid towards the heat exchanger block.

[0020] An interface box can also be an outlet box of the heat exchanger, in which case it is generally referred to as a collector box or manifold. Such a box is supplied by the heat exchanger block and collects the heat transfer fluid from the heat exchange matrix to supply a pipe connected to the box's orifice, which is then an outlet orifice of the box. The collector box thus allows the heat transfer fluid to be conveyed from the heat exchanger block to the outlet orifice. The presence of guide fins in such a box provides converging guidance means for the heat transfer fluid towards the box's outlet orifice.

[0021] Advantageously and according to the invention, for at least one interface box, said orifice is circular and said interface armature is rectangular with a surface area greater than the surface area of ​​said orifice, and at least one guide fin - preferably each guide fin - extends longitudinally and radially in the space of the domed envelope which is not opposite the orifice.

[0022] According to this advantageous embodiment, the orifice of the box has a circular cross-section to correspond to a pipe supplied to or feeding the orifice of the interface box, which has a circular cross-section. Furthermore, the interface frame has a rectangular cross-section to correspond to a heat exchanger block with a rectangular cross-section, such as plate heat exchangers, for example. In this case, and preferably, at least one guide fin, and preferably each fin, extends longitudinally and radially within the space of the curved casing of the box that is not opposite the orifice. This limits disruption to the flow geometry of the heat transfer fluid by not obstructing the space opposite the orifice of the box.According to this variant, the guide fin helps to maintain most of the heat transfer fluid flow in the central part of the box by preventing the fluid from flowing near the domed part of the interface box.

[0023] Advantageously and according to the invention, for at least one interface box, at least one guide fin - preferably each guide fin - has a convex shape and extends longitudinally and radially from said orifice to said interface frame.

[0024] According to this variant, the convex shape of the guide fin ensures continuity of geometry between the orifice and the interface armature which does not generate any abrupt variation in the flow of the fluid in the interface box.

[0025] Advantageously and according to the invention, at least one interface box and said guide fins housed in this interface box are metallic and said fins are welded to the box.

[0026] According to this advantageous embodiment, the guide fins are metallic and welded into the interface box, which is itself metallic. For example, the convex fins can be stamped sheet metal welded into the interface box. which is itself made of stamped sheets.

[0027] According to another embodiment, the fins can simply be embedded between the interface box and the heat exchanger block. They are then housed in the interface box, but not fixed to the box.

[0028] Advantageously and according to the invention, for at least one interface box, at least one guide fin has a different shape from the other fins of the box.

[0029] According to this embodiment, at least one fin in the plurality of fins has a different shape from the other fins in the box. This makes it possible, for example, to limit pressure losses in the box due to a change in the geometry of the pipe connected to the box's orifice. For example, if the supply pipe to the interface box (in the case where the interface box is an inlet box in the heat exchanger) has a bend just before the inlet orifice, a fin with a specific geometry (and therefore different from the other fins) guides the airflow towards the heat exchanger block, limiting pressure losses despite the strong turbulence generated by the bend upstream of the box. This specific shape may, for example, consist of a greater or lesser curvature of the convex portion of the fin compared to the other fins in the box.

[0030] Advantageously and according to the invention, at least one guide fin - preferably each guide fin - of at least one interface box carries heat recovery elements which extend into the box so as to improve the thermomechanical behavior of said box.

[0031] According to this advantageous embodiment, the fins also carry heat recovery elements, formed, for example, by studs extending into the heat transfer fluid circulation zone. These heat recovery elements will thus be able to capture some of the heat from the heat transfer fluid circulating in the box, thereby improving the thermomechanical behavior of the box. In the case of an inlet box, this will notably help to limit the thermal inertia of the heat exchanger block arranged downstream of the box.

[0032] Advantageously and according to the invention, at least one interface box comprises four disjointed guide fins regularly distributed around said longitudinal axis.

[0033] According to this advantageous embodiment, the fins are regularly distributed around the longitudinal axis and are separated from each other so as to form passages between the fins. These passages allow the pressure forces to be transferred to the domed outer skin of the interface box, which is better suited to withstanding these stresses than the convex fins formed in the box.

[0034] Advantageously and according to the invention, the exchanger comprises at least one interface box, called a distributor box, forming said inlet of said first fluid ca- loporteur and at least one interface box, called collector box, forming said outlet of said first heat transfer fluid.

[0035] According to this variant, the heat exchanger includes one interface box as an inlet and one interface box as an outlet. It is also possible to provide a heat exchanger with four interface boxes, one for each inlet and one for each outlet. All combinations are possible depending on the requirements.

[0036] The invention also relates to a heat exchange device characterized in combination by all or part of the features mentioned above or below. List of figures

[0037] Other objects, features and advantages of the invention will become apparent from the following description, given by way of non-limiting example only, and which refers to the accompanying figures in which: • [Fig. 1] is a schematic perspective view of a heat exchanger according to one embodiment of the invention, • [Fig.2] is a schematic cross-sectional view of a prior art heat exchanger whose interface boxes lack fins for guiding the heat transfer fluid, • [Fig.3] is a schematic cross-sectional view of a heat exchanger according to a mode of realization of the invention in which the interface boxes are equipped with guide fins, • [Fig.4] is a schematic view of an interface box of a heat exchanger according to an embodiment of the invention.

[0038] Detailed description of an embodiment of the invention

[0039] In the figures, the scales and proportions are not strictly respected for the purposes of illustration and clarity.

[0040] Identical, similar or analogous elements are designated by the same references in all figures.

[0041] Figure 1 schematically illustrates, in perspective, a heat exchanger according to an embodiment of the invention comprising an external casing 10 delimiting a chamber 12 for the circulation of heat transfer fluids. The chamber 12 is visible in particular in Figure 3. The heat transfer fluids can be of any type. For example, they can be a flow of hot air, for example taken from an aircraft propulsion engine, and a flow of cold air, taken, for example, from outside the aircraft, through a dedicated scoop.

[0042] The heat exchanger further comprises an interface box 20 forming an inlet of the first heat transfer fluid (for example, a hot air stream) into the circulation chamber and an interface box 30 forming an outlet of the first heat transfer fluid. lodging outside the circulation area.

[0043] The heat exchanger also includes an interface box 40 forming an inlet for the second heat transfer fluid (for example, a flow of cold air) into the circulation chamber and an outlet for the second heat transfer fluid out of the circulation chamber. The outlet is not visible in the perspective view of [Fig. 1] as it is located on the hidden side of the perspective.

[0044] According to other embodiments, the heat exchanger may comprise a single interface box to form a fluid inlet or outlet. Any configuration is possible without altering the principle of the invention. The structure of the interface box will be described later with reference to Figures 3 and 4.

[0045] The heat exchanger also includes a parallelepiped heat exchanger block 14 arranged within the circulation chamber 12. This heat exchanger block 14 is in fluid communication with the fluid inlets and outlets and ensures heat exchange between the two fluids. This heat exchanger block is, for example, formed by a stack of parallel plates 16 that alternately delimit circulation channels for the first heat transfer fluid and the second heat transfer fluid. Thus, heat exchange can occur between the two fluids within the chamber 12 by conduction through the plates delimiting the different channels.

[0046] Fig. 4 schematically illustrates the interface box 20 which forms a fluid inlet into the enclosure 12. It should be noted, however, that according to one embodiment, the other interface boxes (if the exchanger includes several interface boxes as in Fig. 1) may include a structure identical to the interface box 20 represented by Fig. 4.

[0047] As shown in Figures 3 and 4, the interface box 20 comprises a domed casing 24 with a circular orifice 26 mechanically and fluidly connected to a cylindrical supply line 18 for the heat transfer fluid, with a circular cross-section. The interface box 20 also comprises an interface armature 28 mechanically connected to the external casing 10 and fluidly connected to the heat exchanger block 14. In other words, the interface box 20 receives the heat transfer fluid through the orifice 26 and conveys it to the interface armature 28 to supply the heat exchanger block 14.

[0048] Of course, such an interface box can also form the fluid outlet and thus be intended to receive fluid through the interface armature, from the exchanger block 14, and convey this fluid to the orifice 26, which is then an outlet orifice, connected fluidly and mechanically to a fluid distribution line.

[0049] The interface box 20 according to the embodiment of [Fig. 4] further comprises a plurality of fins 22a, 22b, 22c, 22d for guiding the heat transfer fluid. Each fin 22a, 22b, 22c, 22d extends between the orifice 26 and the interface frame 28 to ensure continuity of geometry between pipe 18 and exchanger block 14.

[0050] As shown in [Fig.4], the fins are regularly distributed around an axis, called the longitudinal axis L, which corresponds to the main direction of fluid flow through the interface box.

[0051] The fins, according to the embodiment shown in the figures, have a convex shape and extend longitudinally and radially in the space delimited by the domed envelope 24.

[0052] The fins 22a, 22b, 22c, 22d are for example formed from stamped sheets welded inside the interface box.

[0053] The guide fins 22a, 22b, 22c, 22d make it possible to suppress marginal vortices which can develop due to the disruption of the geometry of the flow of the heat transfer fluid through the box.

[0054] Fig. 2 schematically illustrates the airflow through an exchanger whose interface box 20' forming an inlet box and interface box 30' forming an outlet box are each without guide fins and Fig. 3 schematically illustrates the airflow through an exchanger according to an embodiment of the invention whose interface boxes 20 and 30 are each provided with guide fins.

[0055] Figure 2 shows the presence of significant vortices in the inlet interface box 20' and residual vortices in the outlet interface box 30'.

[0056] In [Fig. 3], the inlet interface box 20 and outlet interface box 30 are equipped with guide fins, which guide the airflow between the circular cross-section inlet orifice and the parallelepiped-shaped heat exchanger block. The fins thus guide the airflow, eliminating the abrupt change in geometry inherent in the change of cross-section between the box's supply or distribution line and the interface frame, which is mechanically connected to the heat exchanger block.

[0057] According to an embodiment not shown in the figures, at least one guide fin further carries heat recovery elements that extend into the box so as to improve the thermomechanical behavior of the box. These heat recovery elements are, for example, studs carried by the fin that extend into the fluid flow. These studs thus make it possible to capture some of the heat from the fluid circulating in the interface box at the point of contact with the fins.

[0058] A heat exchange device can be used for various applications, including, but not limited to, an air conditioning system for a transport vehicle such as an aircraft.

Claims

Demands

1. A heat exchange device between two heat transfer fluids comprising: • an external casing (10) delimiting a chamber (12) for the circulation of the heat transfer fluids, • an inlet (20) of a first heat transfer fluid into the circulation chamber, • an outlet (30) of said first heat transfer fluid out of said circulation chamber, • an inlet (40) of a second heat transfer fluid into the circulation chamber, • an outlet of said second heat transfer fluid out of the circulation chamber, • a heat exchanger block (14) arranged in the circulation chamber (12) so as to be in fluid communication with said fluid inlets and outlets to allow the circulation of said first fluid and said second fluid in and through this heat exchanger block and the transfer of heat between them, characterized in that it comprises at least one interface box (20,30) forming one of said fluid inlets or outlets, said interface box (20) comprising a domed casing (24) provided with an orifice (26) adapted for connection to a supply line (18) or distribution line for one of the heat transfer fluids, and an interface frame (28) mechanically connected to said external casing (10), said orifice (26) and said interface frame (28) each extending in a plane perpendicular to a longitudinal axis (L) which defines the principal direction of fluid flow at the inlet or outlet of the box, said box (20) further comprising a plurality of heat transfer fluid guiding fins (22a, 22b, 22c, 22d) each extending between said orifice (26) and said interface frame (28) to ensure geometric continuity between said line (18) and said heat exchanger block (14).,

2. Device according to claim 1, characterized in that for at least one interface box (20), said orifice (26) is circular and said the interface armature (28) is rectangular with a surface area greater than the surface of said orifice, and in that at least one guide fin (22a, 22b, 22c, 22d) - preferably each guide fin - extends longitudinally and radially in the space of the domed envelope (24) which is not opposite the orifice (26).

3. Device according to any one of claims 1 or 2, characterized in that for at least one interface box (20), at least one guide fin - preferably each guide fin - has a convex shape and extends longitudinally and radially from said orifice (26) to said interface frame (28).

4. Device according to any one of claims 1 to 3, characterized in that at least one interface box (20) and said guide fins (22a, 22b, 22c, 22d) housed in this interface box are metallic and in that said fins are welded to the box.

5. Device according to any one of claims 1 to 4, characterized in that for at least one interface box (20), at least one guide fin (22a, 22b, 22c, 22d) has a different shape from the other guide fins.

6. Device according to any one of claims 1 to 5, characterized in that at least one guide fin (22a, 22d, 22c, 22d) - preferably each guide fin - of at least one interface box (20) carries heat recovery elements which extend into the box so as to improve the thermomechanical behavior of said box.

7. Device according to any one of claims 1 to 6, characterized in that at least one interface box (20) comprises four disjoint fins (22a, 22b, 22c, 22d) regularly distributed around said longitudinal axis.

8. Device according to any one of claims 1 to 7, characterized in that it comprises at least one interface box (20), referred to as distributor box, forming said inlet of said first heat transfer fluid and at least one interface box (30), referred to as collector box, forming said outlet of said first heat transfer fluid.