FR3075348A1 - DEVICE FOR DISPENSING A REFRIGERANT FLUID FOR BEING LOOSE IN A COLLECTOR BOX OF A HEAT EXCHANGER - Google Patents

Abstract

 The invention relates to a device (10) for distributing a cooling fluid intended to be housed in a manifold of a heat exchanger comprising at least two ducts (12, 13), including an external duct (12) and a internal conduit (13), with the internal conduit (13) housed in the external conduit (12), the external conduit (12) comprising spray orifices (120i) each having an axis (120A) intersecting an axis of elongation main (12A) of the external conduit (12).  According to the invention, the internal conduit (13) comprises a single communication orifice (130), the single communication orifice (130) having an axis (130A) intersecting with a main elongation axis (13A) of the internal conduit (13).

Description

DEVICE FOR DISTRIBUTING A REFRIGERANT FLUID INTENDED TO BE ACCOMMODATED IN A HEAT EXCHANGER COLLECTOR BOX

The field of the present invention is that of heat exchangers equipping air conditioning installations for vehicles, in particular motor vehicles. The invention relates more specifically to the distribution of the coolant inside a manifold that includes such a heat exchanger and relates to a coolant distribution device, the manifold and the associated heat exchanger .

A vehicle is commonly equipped with an air conditioning installation for heat treating the passenger compartment of the vehicle. Such an installation then cooperates with a refrigerant circuit operating in a closed loop. This refrigerant circuit successively comprises, according to the direction of circulation of the refrigerant, a compressor, a condenser, a pressure reducer and at least one heat exchanger.

The heat exchanger may in particular consist of a tube exchanger in which a bundle of tubes extends between a manifold and a return box for the refrigerant. The refrigerant is admitted through an inlet mouth inside a manifold, circulates in successive paths in the tubes of the bundle between the manifold and a return box, then is evacuated from the exchanger thermal through an outlet. The outlet mouth may be formed through the manifold or through the return box.

The heat exchanger is for example a condenser, an evaporator or a liquid cooler. This heat exchanger is intended to perform a heat exchange between the refrigerant and a flow of fluid, such as outside air respectively, a flow of air circulating in the conditioning installation or a heat transfer fluid. For this, the refrigerant circulates inside the tubes of the bundle and the flow of fluid circulates between the tubes of the bundle for its cooling, the heat exchange taking place by conduction.

However, a drawback linked to such a heat exchanger lies in the heterogeneity of the supply of the tubes of the bundle. In particular, the refrigerant is admitted inside the heat exchanger in a liquid / gas two-phase state, and the difference between the physical properties of a liquid and a gas means that the liquid phase and the gas phase refrigerant tend to separate. In this way, the tubes of the bundle located closest to the inlet mouth can then be mainly supplied with liquid while the tubes of the bundle furthest from the inlet mouth can be mainly supplied with gas, or vice versa according to the arrangement of the heat exchanger.

The heterogeneity of the supply of the tubes of the bundle then generates a disparity in the heat exchange between the coolant and the flow of fluid passing through the heat exchanger, as well as a disparity in the temperature of the flow of fluid which has passed through the heat exchanger in operation. This heterogeneity complicates the thermal management of the installation which receives the heat exchanger and in the case of an evaporator implies temperature differences between two zones of the passenger compartment, while the same air flow temperature is requested .

In order to remedy such a drawback, document EP 2 392 886 proposes to house a duct provided with a plurality of orifices inside a manifold. The liquid phase refrigerant is thus sprayed through the orifices in the form of droplets over the entire length of the duct. If it improves the distribution of the fluid inside the manifold, such an arrangement can generate significant pressure drops, in particular due to the small size of each of the orifices allowing the passage of fluid, which can lead to an overhaul of the entire refrigerant circuit to supply the heat exchanger correctly.

In this context, the subject of the present invention is a device for distributing a refrigerant fluid intended to be housed in a manifold of a heat exchanger comprising at least two conduits, including an external conduit and an internal conduit, with the internal conduit housed in the external conduit, the external conduit comprising spray orifices each having an axis intersecting a main axis of elongation of the external conduit. According to the invention, the internal conduit comprises a single communication orifice, the single communication orifice having an axis intersecting with a main elongation axis of the internal conduit.

It is understood that the presence of a single orifice on the internal conduit makes it possible to introduce the fluid into a determined area of the external conduit, which makes it possible to better manage the supply of the external conduit with refrigerant. In addition, the presence of a single orifice on the internal duct makes it easier to play on the dimension of the latter and makes it possible, as a function of this dimension, to reduce the pressure losses during the passage of the internal duct.

According to one or more characteristic (s) which can be taken alone or in combination, provision may be made for:

- The spray orifices are all located in a spray zone in which they are arranged in a longitudinal series comprising a first spray orifice and a last spray orifice, the first spray orifice and the last spray orifice being each arranged at an opposite end of the longitudinal series. By longitudinal series is meant a series extending over at least part of along the lengthening axis of the conduit, here the outer conduit.

- The longitudinal series of spray holes is distributed in a straight line and parallel to the main extension axis of the external conduit.

- The spray holes are regularly aligned in the spray area of the external pipe.

- The axis of the single communication orifice is substantially aligned with a middle of the spraying area. Thus, it is understood that the communication orifice opens out substantially at an equal distance from the two most distant spray orifices from the external duct, that is to say at equal distance from the first spray orifice and from the last spray orifice of the longitudinal series. The term substantially means that an uncertainty of plus or minus 5% is allowed to assert that the axis of the communication orifice is aligned with the middle of the spraying area. Such centering of the communication orifice makes it possible to ensure a good distribution of the refrigerant fluid towards the spraying orifices of the external conduit, the longitudinal ends of the external conduit being also distributed with respect to one another.

- At least one of the external conduit and the internal conduit has a circular section.

- The internal conduit comprises at a first of its longitudinal ends an inlet for the admission of the refrigerant fluid inside the distribution device, the internal conduit being closed at its second longitudinal end.

- The single communication orifice has a larger dimension, measured in a plane section perpendicular to the axis of the single communication orifice, being less than or equal to a greater dimension of the internal conduit, measured in a perpendicular plane section to the main elongation axis of the internal duct.

- According to a particular embodiment, the single communication orifice has a section at least 4 millimeters in diameter.

- The communication port has a circular shape.

- The communication opening has a polygonal outline. For example, the communication port has a decagonist outline.

- The internal duct and the external duct are coaxial.

- The single communication orifice opens onto a full portion of the external conduit. By full portion of the outer conduit is meant a portion devoid of spray orifices.

- The communication opening and at least one of the spraying openings open in parallel and opposite directions.

- The communication orifice opens opposite the spray orifices. In other words, the communication orifice opens opposite a part of the opposite external conduit, if necessary diametrically opposite, to the spraying zone of the external conduit.

- The internal conduit comprises a portion of reduced thickness produced by removal of material on an external face of the internal conduit. The presence of such a reduced thickness portion makes it possible to increase the size of the communication volume extending between the internal conduit and the external conduit, which allows the refrigerant passing through the communication orifice to have more of space in order to better distribute itself along the external conduit before being evacuated by the spraying orifices.

- The removal of material forms a flat on the external face of the internal duct. By flat is meant a flat surface formed on a circular section. It will then be understood that the internal conduit is of circular section and that the external face situated on the side of the communication volume has a flat surface.

- The flat extends over at least 50% of the length of the internal duct, the length being defined as the dimension measured along the main elongation axis of the internal duct.

- The flat extends at least over a portion of the internal duct, in which the communication orifice is formed.

- The reduced thickness portion extends over a length equal to a length of the spraying area. Thus, the flat extends over a distance equal to a distance separating the first spray orifice and the last spray orifice of the longitudinal series. In other words, the reduced thickness portion extends over a longitudinal part of the dispensing device which overlaps at least partially with the spraying zone.

- The reduced thickness portion extends in a straight line along the main elongation axis of the internal duct. In other words, the reduced thickness portion is positioned in a straight line, the straight line being parallel to the main extension axis of the internal conduit.

- A greater distance separating a center of the flat and an internal face of the external conduit is between 1 to 5 millimeters.

- A smaller distance separating an external face of the internal conduit, in a distinct portion of the flat, and the internal face of the external conduit is between 0.25 and 2 millimeters.

- The reduced thickness portion of the internal conduit is produced by machining.

The invention also relates to a coolant collector box for a heat exchanger comprising a distribution chamber. The distribution chamber houses a distribution device as defined above, and the internal conduit of the distribution device comprises an inlet mouth for an admission of the refrigerant, the spray orifices being arranged so as to allow a circulation of the refrigerant. between the distribution device and the distribution chamber.

The distribution device can extend along an elongation axis of the manifold, with the internal conduit comprising at a first of its two longitudinal ends the inlet mouth for the admission of the refrigerant to the inside the internal conduit, the internal conduit being closed at a second longitudinal end.

The invention further relates to a heat exchanger comprising at least one manifold as defined in the preceding claim, as well as tubes forming a bundle of tubes extending from the manifold, characterized in that the axis of the communication orifice is parallel to the axes of the tubes of the tube bundle.

The spray area of the outer conduit may have a length equal to a length of the bundle of tubes.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the detailed description given below by way of indication and for example in relation to the drawings of the attached plates, in which:

FIG. 1 is a schematic representation of a circuit for circulating a refrigerant fluid participating in an air conditioning installation of a vehicle,

FIG. 2 is a sectional representation of a heat exchanger, according to the present invention, which comprises the circuit of FIG. 1,

FIG. 3 illustrates a device for distributing refrigerant, according to the present invention, capable of being arranged in a manifold of the heat exchanger of FIG. 2,

FIG. 4 illustrates an internal duct of the coolant distribution device shown in FIG. 3, the internal duct being seen at an angle making visible a portion of reduced thickness,

FIG. 5 is a side view of the coolant distribution device of FIG. 3, in which the external conduit of this distribution device has been made transparent to make the internal conduit visible in its entirety,

- Figure 6 is a perspective representation of a section of the dispensing device along its elongation axis, making in particular visible the orientation of a single communication orifice and a flat formed on the internal conduit by relative to the spray orifices arranged on the external conduit,

FIG. 7 is a sectional view of the coolant distribution device according to the present invention,

FIG. 8 is a sectional view of an alternative embodiment of the coolant distribution device according to the present invention, in which the internal duct has a constant annular section over the entire length of the duct,

- Figure 9 is a detailed view of the heat exchanger of Figure 2, in which we made more particularly visible the manifold equipped with the coolant distribution device, according to the present invention.

It should first be noted that if the figures show the invention in detail for its implementation, they can of course be used to better define the invention if necessary. Similarly, it is recalled that, for all of the figures, the same elements are designated by the same references.

FIG. 1 shows a circuit 100 of refrigerant fluid 700 intended to cooperate with an air conditioning installation for a passenger compartment of a vehicle, in particular an automobile. This circuit 100 is arranged in a closed loop inside which the refrigerant 700 circulates in a direction of circulation materialized by the arrow. In the exemplary embodiment illustrated, the circuit 100 comprises, successively in the direction of circulation of the refrigerant 700, a compressor 200, a condenser 300, an expansion member 400 and at least one heat exchanger 500. It should be noted that the condenser 300 is a heat exchanger making it possible to cool the refrigerant 700 using an outside air flow, before the expansion of the refrigerant 700. The heat exchanger 500 advantageously forms part of the air conditioning installation and takes, in this case, the form of an evaporator 600.

In order to connect the various elements making up the circuit 100, the latter includes channels as well as flow control valves. It should be noted that such a minimalist circuit 100 is given for information only and is not restrictive as to the scope of the invention with regard to the various architectures that circuit 100 can take.

The heat exchanger 500, in the form of an evaporator 600, is dedicated to cooling an air flow A circulating in the air conditioning installation. Such an air flow A is used in particular to heat treat the air in the passenger compartment of the vehicle or, for example, to cool an organ of the vehicle in operation. According to another exemplary embodiment, the heat exchanger 500 is a cooler and is dedicated to cooling a liquid making it possible to cool a member of the vehicle in operation, such as one or more batteries supplying electrical energy to a motorization electric propulsion of the vehicle.

FIG. 2 shows that the heat exchanger 500 comprises a bundle of tubes 6, or of plates, a manifold box 7 and an outlet box 9. According to this exemplary embodiment, the heat exchanger 500 also includes a box of return 8 allowing the refrigerant to circulate by forming several passages in the bundle of tubes 6 before joining the outlet box 9. The tubes of the bundle of tubes 6 extend, in this case, between the manifold 7 and the box 8. More precisely, the tubes of the bundle 6 are arranged in layers with a first layer forming a first main face of the heat exchanger 500 and a second layer forming a second main face of the heat exchanger 500. Per side main, it is understood a face of the heat exchanger 500 having one of the largest surfaces.

According to a variant embodiment not shown here, the heat exchanger 500 comprises a manifold 7 at one end of the bundle of tubes and an outlet box 9 arranged at the other end of the bundle of tubes 6.

In the description which follows, reference will be made to an orientation as a function of the longitudinal axes L, vertical V and transverse T, as defined by the trihedron L, V, T represented in FIGS. 2 to 9. The vertical axis V corresponds to the main direction of elongation of a given tube of the bundle of tubes 6 of the heat exchanger 500 and corresponds to the main direction followed by the refrigerant circulating inside the tubes of the exchanger 500. The transverse axis T, perpendicular to the vertical axis V, corresponds to the main direction followed by the fluid flow, such as the air flow A, brought to be cooled by the heat exchanger 500 crossing the bundle of tubes 6. Finally, the longitudinal axis L is perpendicular to both the vertical axis V and the transverse axis T and follows a direction of elongation of one of the boxes, whether collector, return or exit, of the heat exchanger 500. It should be noted that the choice of names for these axes is not limiting of the orientation that the heat exchanger can take in its application to a vehicle, especially automobile.

Thus, according to this standard, the manifold 7 and the return box 8 are arranged at two opposite vertical ends of the bundle of tubes 6, with the manifold 7 arranged at a first vertical end and the return box at a second vertical end. of the bundle of tubes 6. The outlet box 9 is arranged side by side of the manifold 7, along the transverse axis T, on the first vertical end of the bundle of tubes 6. Advantageously, the manifold 7 and the outlet box 9 are in one piece, that is to say they are made in one piece.

The manifold 7 defines a distribution chamber 2 which is supplied with refrigerant 700 using a dispensing device 10 housed in the manifold 7 and into which a plurality of tubes of the bundle of tubes 6 opens.

The distribution device 10, which will be described in more detail below, comprises an inlet mouth 11 for an admission of the refrigerant fluid 700 into the heat exchanger 500 and in particular into the distribution device 10 which is configured to distribute the refrigerant 700 along the manifold 7.

Once the refrigerant 700 inside the heat exchanger 500, it circulates along the tubes of the tube bundle 6 so as to cool them in one or more passages using the return box 8. Next, the refrigerant 700 is evacuated from the heat exchanger 500 through an outlet 12 provided on the outlet box 9.

According to the illustrated arrangement of the heat exchanger 500, the circulation of the coolant 700 is in a "U" shape. According to an alternative embodiment, the heat exchanger 500 is multi-pass, that is to say that the return box 8 is compartmentalized so that the refrigerant 700 performs several passages on a sheet of tubes before d '' reach the second cable and the outlet box. In case the heat exchanger

500 does not have a return box 8 and instead includes the outlet box 9, the circulation of the refrigerant is done in "I".

Furthermore, in the context of its application to an air conditioning installation, the heat exchanger 500 is intended for cooling an air flow A passing through the bundle of tubes 6 in a direction transverse to their direction d 'elongation. In other words, the air flow A crosses the bundle 6 transversely to a longitudinal plane PI of the heat exchanger 500. To improve the heat exchange, the tubes of the bundle 6 comprise, for example, fins promoting the heat exchange between the air flow A and the bundle tubes 6.

The refrigerant 700 flows from the manifold 7 to a first layer of tubes of the bundle 6 dedicated to supplying the return box 8 with refrigerant 700. Then the refrigerant 700 flows from the return box 8 to the box outlet through a second ply of tubes of bundle 6. The first ply and the second ply are superposed one on the other on each side of the longitudinal plane PL

The distribution chamber 2 of the manifold 7 houses the distribution device extending along an elongation axis parallel to the direction of extension of the manifold 7. The distribution device 10 comprises at least two conduits 12, 13 , with an internal conduit 13 configured to receive the refrigerant fluid by one of its longitudinal ends forming the inlet mouth 11 and to transfer this fluid to the external conduit 12, which is configured to allow the passage of refrigerant fluid to each of the tubes of the tube bundle 6. More specifically, the internal conduit 13 is housed in the external conduit 12. Each of the conduits 12, 13 of the distribution device 10 extends along an elongation axis, respectively 12A and 13A.

More particularly, each conduit 12, 13 of the distribution device 10 extends parallel to the direction of elongation of the manifold 7, parallel to the longitudinal axis L. In other words, the axis of elongation of each of the conduits 12, 13 is parallel to the direction of elongation of the manifold 7. According to an alternative embodiment, not shown here, at least one of the conduits 12, 13 of the distribution device 10 extends from oblique to the direction of extension of the manifold 7.

According to the example illustrated, the conduits 12, 13 are coaxial, so that the elongation axes 12A, 13A are combined. In order to maintain the conduits in this position, the two conduits 12, 13 are separated from each other by means of a spacer also allowing the fixing of the distribution device 10 to the manifold 7. It could be provided as a variant, a distribution device 10 comprising more than two conduits 12, 13, it being understood that the additional conduits would be interposed between the internal conduit 13 and the external conduit 12.

FIG. 3 illustrating the dispensing device 10, shows that the external conduit 12 comprises orifices 120, called spraying ports. The spray orifices 120 each have an axis 120A intersecting with the main elongation axis 12A of the external conduit 12. Of course, when mention is made of an axis of an orifice or an opening, it is heard the axis passing through said orifice or said opening, that is to say in the main direction of the refrigerant 700 passing through this orifice or this opening. It is noted that each axis 120A of the spray orifices 120 extends perpendicular to the main elongation axis 12A of the external conduit 12.

The external conduit 12 and the internal conduit 13 are hollow so as to each define an internal volume. We then define an internal volume 15 extending in the internal conduit 13 and into which the refrigerant 700 is admitted from the inlet mouth 11 and a communication volume 14 extending in the external conduit 12 and more precisely between the internal conduit 13 and external conduit 12.

According to the example illustrated, the outer conduit 12 and the inner conduit 13 both have one end whose section is circular, the section being a section of the conduit taken in a plane transverse to the main elongation axis 12A, 13A of the conduit 12, 13. Thus, the communication volume 14 and the internal volume 15 are each delimited by at least one of the conduits 12, 13 of which at least part of the walls are rounded. Of course, other cross-sectional shapes of the conduits 12, 13 are allowed and could for example be square or rectangular.

On the external conduit 12, a spraying zone Z is defined, in which all of the spraying orifices 120 are located. The spray orifices 120 are arranged in a longitudinal series comprising a first spray orifice 120i and a last spray orifice 120n + i, the first spray orifice 120i and the last spray orifice 120n + i each being arranged at a longitudinal end opposite of the series. It will then be understood that the first spray orifice 120i and the last spray orifice 120n + i are the farthest spray orifices 120 from one another in the series. One can also define the first spray orifice 120i and the last spray orifice 120n + i as being the first and the last of the orifices to be reached by the refrigerant 700 according to the direction of circulation of this fluid along the internal conduit 13 , as shown by the arrow S.

The spraying zone Z extends over a length LZ, measured along the main elongation axis 12A of the external conduit 12. The medium M of this length LZ, makes it possible to define a central part C of the spraying zone Z, the central part covering an interval of plus or minus 5% of the length LZ around the middle M.

It should be noted that according to the illustrated embodiment, the spray orifices 120 are regularly spaced in the spray zone Z of the external conduit 12. More precisely, the spray orifices 120 are rectilinearly disposed along the axis d main elongation 12A of the external conduit 12, at regular intervals. In other words, the spray orifices 120 are positioned in a straight line, the straight line being parallel with the main elongation axis 12A of the external conduit 12, with a constant pitch between two successive spray orifices. According to an alternative embodiment, the spray orifices 120 are arranged in the form of a helix rotating around the main elongation axis 12A of the external conduit 12.

It should be noted that in the example illustrated, the external conduit 12 comprises a single row of spray orifices 120. According to an alternative embodiment, the external conduit 12 comprises several parallel rows of spray orifices 120. It is then understood that, in this variant not shown here, the spraying zone Z comprises two first spraying orifices 120i and two last spraying orifices 120n + i.

FIG. 3 also shows that the internal conduit 13 protrudes longitudinally from the external conduit 12, here on the side of the inlet mouth. As can be seen in FIG. 5, the external conduit 12 and the internal conduit 13 have an identical length, the length being measured along their main elongation axis 12A, 13A. It should be noted that the dispensing device 10 comprises two support elements, one of the supports 123 of which is partially visible in FIG. 6, arranged at each of its longitudinal ends and which allow both to position the external conduit 12 longitudinally offset from the internal conduit 13 and to keep them coaxial. A first support element is disposed at the longitudinal end opposite that of the inlet mouth 11, and this support element, if necessary in two parts, is configured to close each of the conduits and prevent the leakage of fluid by this longitudinal end. A second support element is arranged at the longitudinal end comprising the inlet mouth, this second fixing element being drilled to allow passage to this fluid inlet. The second support element can also be equipped with a means for angular positioning of one or other of the conduits, to ensure, for example by cooperation of a slot arranged in this second support element and d 'A rib arranged on the periphery of one or the other of the conduits, the correct position of the orifices as they are the subject of the present invention, either relative to each other or relative to the bundle of tubes.

Figure 4 shows the internal conduit 13 in isolation, comprising the inlet mouth 11 disposed at a longitudinal end of the internal conduit 13. In other words, the internal conduit 13 is open at one of its two longitudinal ends so as to form the inlet mouth 11 for the admission of the coolant 700 into the distribution device 10.

According to the invention, the internal conduit 13 comprises a single orifice 130, called a communication orifice, the axis 130A of which intersects the main elongation axis 13A of the internal conduit 13. More precisely, the axis 130A of the communication orifice 130 is perpendicular to the main elongation axis 13A of the internal conduit 13. The fluid brought into the internal conduit 13 via the inlet mouth 11 circulates along the conduit and passes through this communication orifice 130 for entering the external conduit 12.

The presence of a single communication orifice 130 on the internal conduit 13, that is to say of a single orifice allowing the passage of the internal conduit to the external conduit, makes it possible to access the refrigerant fluid 700 at a precise point of the external conduit 12, which makes it possible to control the distribution of this refrigerant fluid along the external conduit, and in particular to avoid that the fluid circulates from one longitudinal end of the conduit to the other. The uniqueness of this communication orifice also makes it possible to play on the dimension thereof, and in particular to provide it large enough to minimize the pressure losses. It is understood that these two points make it possible to facilitate the development of the distribution device 10 in its application to a heat exchanger 500 and this regardless of the size of the heat exchanger 500 on which the distribution device 10 is mounted .

Advantageously, the communication orifice 130 opens onto a portion of the external conduit 12 devoid of spraying orifices 120. Thus, the communication orifice 130 is disposed opposite a solid part of the external conduit 12. By solid part, it is understood a part of the external conduit 12 devoid of spray orifices 120. Thus, the communication orifice 130 is not disposed facing the spray zone Z.

Preferably, the communication orifice 130 is arranged in such a way that the refrigerant fluid 700 circulates in an opposite direction with respect to the direction of circulation of the refrigerant fluid 700 passing through the spray orifices 120. In other words, the communication orifice 130 has an axis 130A parallel to the axes 120A of the spray orifices 120, while opening in an opposite direction. In the case where the conduits 12, 13 are coaxial and circular, it can be said that the communication orifice 130 is located opposite a part of the external conduit 12, which is diametrically opposite to the spray orifices 120. In the case where the conduits have a shape other than circular, it can be said that the communication orifice 130 is located opposite a part of the external conduit 12, which is symmetrically opposite to the spray orifices 120. Such a position of the orifice of communication 130 with respect to the spray orifices 120 makes it possible to force the gas phase to entrain the liquid phase in the direction of the spray orifices 120.

Whatever the size of the heat exchanger 500 and therefore of the internal duct 13, the communication orifice 130 is positioned so as to lead to the central part C of the external duct 12, that is to say on a part equidistant from the first spray opening 120i and the last spray opening 120n + i. As has been said previously, the spraying zone Z comprises a central part C extending from the medium M to more or less 5% of the length LZ of this spraying zone, the medium M being located equidistant from the first orifice spray

120i and the last spray port 120n + i. Thus, it is ensured that the refrigerant 700 circulating in the internal conduit 13 opens substantially in the middle of the spraying zone Z, which makes it possible to supply the spray orifices 120 of the external conduit 12 in a homogeneous manner, the term substantially meaning that the communication orifice 130 opens in the middle M, where at least in the central part C framing this medium M in the proportions mentioned above.

According to the example illustrated in FIG. 4, the communication orifice 130 has a circular or oblong outline. Of course, other forms of orifice are possible, such as a communication orifice having a polygon-shaped outline, for example a decagon. In all cases of shapes, it should be noted that the communication orifice 130 has a larger dimension, such as a diameter or a diagonal, measured in a plane section perpendicular to its axis 130A, which is less than or equal to a section of the internal conduit 13. By section of the internal conduit 13, it is understood the largest dimension of the internal conduit 13 measured in a planar section perpendicular to the main elongation axis 13A of the internal conduit 13, such as a diameter or a diagonal. Furthermore, it should be noted that the largest dimension, in particular the minimum diameter, of the communication orifice can be equal to twice the equivalent dimension of a spray orifice.

According to the example illustrated, the internal conduit 13 has an external diameter of 6 millimeters and an internal diameter of 4 millimeters, and the communication orifice 130 has a diameter, or a larger dimension, equal to 4 millimeters. The fact that the communication orifice 130 has a diameter substantially equal to the diameter of the internal conduit 13 makes it possible to ensure a control of the pressure losses when the fluid passes between the inlet mouth, consisting of a single orifice of given diameter arranged at one end of the device, and the external duct, along which the refrigerant 700 is caused to be distributed in order to pass through each of the spray orifices 120 in a homogeneous manner. The central position of the communication orifice allows a homogeneous supply of that the refrigerant 700 entering the external conduit 12 is evenly distributed towards one or the other of the longitudinal ends of the distribution device.

It should be noted from the above that theoretically, the optimal position of the communication orifice 130 is such that it is strictly plumb with the middle

M of the spraying zone Z. However, it may be desired to offset the longitudinal position of this communication orifice, advantageously in correspondence with the central portion C surrounding this medium M, if a pressure imbalance is noted between the inlet and the coolant outlet in the heat exchanger.

For example, if the geometry of the outlet box 9 is such that the pressure at the outlet of this outlet box is lower than at its opposite end, it is necessary to move the communication orifice 130 towards the end opposite to the inlet mouth 11. In fact, in the outlet box, the refrigerant is in the gas state and therefore capable of experiencing high speeds), so that the geometric singularities in this outlet box generate pressure losses and therefore a pressure difference. This pressure difference is reflected in the manifold 7 by a stronger suction of the coolant in the tubes closest to the outlet end, which means that less coolant passes through the last tubes. Shifting the communication port 130 towards the bottom partially compensates for this phenomenon.

FIG. 4 also illustrates that the internal conduit 13 comprises a portion of reduced thickness 16, that is to say that at least part of the internal conduit 13 has undergone removal of material. This removal of material is carried out on the external face of the internal conduit 13, that is to say on the face of the internal conduit 13 situated on the side of the communication volume 14. This portion of reduced thickness 16 makes it possible to increase the communication volume 14 in comparison with an internal conduit 13 not comprising a reduced thickness portion 16. The increase in communication volume 14 makes it possible to improve the homogenization of the liquid phase and of the gas phase of the refrigerant 700 when this fluid, leaving the internal conduit 13, circulates along the external conduit 12 before reaching the spray orifices 120, as will be described later.

The reduced thickness portion 16 of the internal conduit 13 is for example formed by machining the tube forming the internal conduit. According to the example illustrated, the reduced thickness portion 16 is in the form of a flat 17. By flat is meant a flat surface formed on a circular section. It should be noted that the flat 17 extends in the example illustrated over at least 50% of a length of the internal conduit 13. The flat 17 preferably extends in a straight line and parallel to the axis d main elongation 13A of the internal duct 13. In addition, the communication orifice 130 is arranged so as to pass through the flat part 17. In other words, the flat part 17 extends over at least part of the internal duct 13, in which the communication port 130 is provided.

FIG. 5 shows that the flat 17 extends over a length L17 equal to the length LZ of the spraying zone Z. In other words, the flat 17 extends over a distance L17 equal to the length LZ separating the first orifice of spray 120i and the last spray port 120n + i of the longitudinal series of spray ports 120. Thus, the reduced thickness portion 16 extends over a longitudinal part of the dispensing device 10 which overlaps at least partially with the spray zone Z in which all the spray orifices 120 are formed. More generally, it can be said that the reduced thickness portion 16 and the spray orifices 120 are at least partially superimposed in the dispensing device 10. In the example illustrated, the reduced thickness portion 16 and the zone spray carrying these spray orifices are arranged in vertical overlap of one another.

This vertical overlap is accompanied in the example illustrated by a particular arrangement of the flat 17, and of the communication orifice 130, of the internal conduit 13 and of the spraying orifices 120 of the external conduit 12. The internal conduit 13 is thus disposed in the outer conduit 12 so that the portion of reduced thickness 16 is turned towards a portion of the outer conduit 12 devoid of spray orifices 120. In FIG. 5, it is thus notable that the portion of thickness reduced 16 is not disposed opposite the spray zone Z. Such an arrangement of the reduced thickness portion 16 relative to the spray orifices 120 makes it possible to provide a large communication volume 14 in part of the external conduit 12 devoid of spray orifices 120, and more particularly in a part of the external conduit opposite, and if necessary diametrically opposite, to that in which are arranged the spray orifices, as can be seen in particular in FIG. 6. In this way, a space for accumulation of the liquid phase of refrigerant 700 is generated. In fact, the refrigerant 700 can penetrate the device. distribution in a two-phase state and still be in this state at the outlet of the communication orifice 130, and the liquid phase contained in the two-phase mixture of coolant 700, denser than the gas phase, tends to rest in the space d accumulation partly defined by the reduced thickness portion 16, in particular under the effect of gravity.

The purpose of the space created by the flat 17 is to promote the longitudinal distribution of the two-phase refrigerant, this by reducing the pressure drop, by increasing the passage section, along the flat, compared to the pressure drop observed. in the rest of the volume between the external conduit 12 and the internal conduit 13

Advantageously, the communication orifice 130 has an axis 130A parallel to the earth's gravity and the flat 17 has a flat surface extending perpendicular to the earth's gravity.

So that the volume in which the liquid phase accumulates is as large as possible, the spray orifices 120 have axes 120A perpendicular to the flat face formed by the removal of material. In other words, the spray orifices 120 have axes 120A perpendicular to the plane in which the flat 17 extends.

FIG. 7 shows a cross-sectional view of the dispensing device 10, in the spraying zone Z. The two conduits 12, 13 being coaxial, it can be seen that the presence of the reduced thickness 16 with the removal of material located on the external face of the internal conduit 13, that is to say the face facing the external conduit 12, generates a difference in distance between different parts of the internal conduit 13 and the external conduit

12.

More precisely, with the presence of the flat 17 on the internal conduit 13, there is a smallest radial distance W1 and a greatest radial distance W2, it being understood that the radial distances are measured for a given section, perpendicular to the main elongation axis 13A of the internal conduit 13, on a straight line passing through the common center of the internal conduit and the external conduit. The smallest radial distance W1 corresponds to the distance between the external face of the internal duct 13 in a separate portion of the flat 17 and the internal face of the external duct 12. Conversely, the largest radial distance W2 corresponds to the distance between the center of the flat 17 and the internal face of the external conduit 12.

Depending on the size of the distribution device 10, the smallest distance W1 can reach a maximum value of 0.25 millimeter to 2 millimeters, while the largest distance W2 can reach a maximum value of 1 to 5 millimeters. Of course, the largest distance W2 is, in any case, greater than the smallest distance Wl. Thus, it is understood that from one distribution device 10 to another, the communication volume 14 can be more or less large as a function of these distances W1, W2.

It should be noted that other embodiments can be envisaged to achieve the largest possible volume in which the liquid phase accumulates. By way of nonlimiting examples, it may be provided that instead of having a tube on which material has just been removed, the volume W2 is created by a specific shape of the internal conduit in a closed half-cylinder whose thickness remains constant, which has the advantage of reducing the mass as much as possible while retaining the mechanical properties of the part, or provision may be made to offset the internal cylindrical conduit relative to the axis of the external cylindrical conduit.

FIG. 8 illustrates an alternative embodiment, in which the internal duct 13 does not include a portion of reduced thickness as previously described. The internal conduit 13 and the external conduit 12 are coaxial and conform to the description above, differing from the embodiment previously described in that the internal conduit 13 has a constant section over the entire length and around the entire periphery of the conduit.

FIG. 9 illustrates the application of the distribution device 10 comprising an internal conduit 13 with flat 17 in a manifold box 7 of an evaporator 600. The distribution device is placed coaxially with the manifold box 7, so that that the main axis of elongation of the internal conduit 13 is coincident with the axis of the manifold 7.

Note that the external conduit 12 is arranged in the manifold 7 so that the spray orifices 120 open opposite the zone of the external conduit into which the tubes of the bundle of tubes opens 6. In an arrangement such as illustrated in FIG. 9, in which the bundles of tubes are arranged vertically under the manifold 7, the external conduit 12 is arranged so that the spray orifices open out on top of this external conduit 12.

Preferably, the spray orifices 120 are arranged so that the refrigerant 700 circulates in a direction opposite to the direction of circulation of the refrigerant 700 flowing along the bundle of tubes 6. In other words, the orifices spray 120 each have an axis 120A parallel to the axes 6A of the tubes, while opening opposite these tubes, the manifold participating in guiding the fluid in the tube at the outlet of the spray orifice. In the case where the external conduit 12 is circular, it can be said that the spray orifices 120 are located opposite a part of the manifold 7, which is diametrically opposite to the bundle of tubes 6. Such a position of the orifices of spraying 120 relative to the bundle of tubes 6 makes it possible to improve the vaporization of the refrigerant fluid 700 before it flows along the tubes.

It should be noted that the spraying orifices 120 are all distributed along the bundle of tubes 6. In other words, the spraying zone Z has a length LZ equal to the length of the bundle of tubes 6, the length of the bundle of tubes 6 being measured along the longitudinal axis L, parallel to the main elongation axis 12A of the external conduit 12. Thus, it can also be said that the flat 17 has a length L17 equal to the length of the bundle of tubes 6. It can also be said that the communication orifice 130 is aligned with the middle of the bundle of tubes 6.

Whatever the variant of embodiment chosen, the invention makes it possible to provide a device for distributing the coolant offering low pressure drops for a homogeneous distribution of the coolant in a manifold of a heat exchanger. The installation of a single communication orifice in the distribution device makes it possible to obtain an efficient heat exchanger in which the fluid distribution device meets these two criteria.

The invention cannot however be limited to the means and configurations described and illustrated, and it also applies to all means, or all configurations, equivalent (s) and to all combinations of such means and / or configurations. Indeed, if the invention has been described and illustrated according to different alternative embodiments each implementing a particular arrangement separately, it goes without saying that these arrangements presented can be combined without harming the invention.

Claims (10)

1. A device (10) for distributing a coolant (700) intended to be housed in a manifold (7) of a heat exchanger (500, 600) comprising at least two conduits (12, 13), of which an outer conduit (12) and an inner conduit (13), with the inner conduit (13) housed in the outer conduit (12), the outer conduit (12) comprising spray orifices (120) each having an axis (120A ) intersecting a main elongation axis (12A) of the external conduit (12), characterized in that the internal conduit (13) comprises a single communication orifice (130), the single communication orifice (130) having a axis (130A) intersecting a main elongation axis (13A) of the internal conduit (13). 2. Dispensing device according to claim 1, characterized in that the spray orifices (120) are all located in a spray zone (Z) in which they are arranged in a longitudinal series comprising a first spray orifice (120i) and a last spray orifice (120n + i), the first spray orifice (120i) and the last spray orifice (120n + i) each being arranged at an opposite end of the longitudinal series. 3. Dispensing device according to claim 2, characterized in that the axis (130A) of the single communication orifice (130) is substantially aligned with a medium (M) of the spraying zone (Z). 4. Dispensing device according to one of the preceding claims, characterized in that the single communication orifice (130) has a larger dimension, measured in a plane section perpendicular to the axis (130A) of the single orifice communication (130), being less than or equal to a larger dimension of the internal conduit (13), measured in a plane section perpendicular to the main elongation axis (13 A) of the internal conduit (13). 5. Dispensing device according to any one of the preceding claims, characterized in that the single communication orifice (130) opens onto a solid portion of the external conduit (12). 6. Dispensing device according to any one of the preceding claims, characterized in that the internal duct (13) comprises a portion of reduced thickness (16) produced by removing material from an external face of the internal duct (13) . 7. Dispensing device according to the preceding claim, characterized in that the removal of material forms a flat (17) on the external face of the internal duct (13). 8. Dispensing device according to one of claims 6 or 7, taken in combination with claim 2, characterized in that the reduced thickness portion (16) extends over a length (L17) equal to a length ( LZ) of the spray area (Z). 9. Collecting box (7) of coolant (700) for heat exchanger (500, 600) comprising a distribution chamber (2) characterized in that the distribution chamber (2) houses a distribution device (10) such as defined in any one of the preceding claims, and characterized in that the internal conduit (13) of the distribution device (10) comprises an inlet mouth (11) for an admission of the refrigerant fluid (700), the orifices spraying device (120) being arranged so as to allow a circulation of the refrigerant fluid (700) between the distribution device (10) and the distribution chamber (2). 10. Heat exchanger (500, 600) comprising at least one manifold (7) as defined in the preceding claim, as well as tubes forming a bundle of tubes (6) extending from the manifold (7 ), characterized in that the axis (130A) of the communication orifice (130) is parallel to the axes of the tubes of the tube bundle (6).