FR3097956A1 - Heat exchanger for a vehicle air conditioning installation comprising a refrigerant fluid distribution device configured to ensure the expansion of the refrigerant fluid in the heat exchanger - Google Patents

Abstract

Heat exchanger for an air conditioning installation of a vehicle comprising a device for distributing a refrigerant fluid configured to ensure the expansion of the refrigerant fluid in the heat exchanger Heat exchanger (5) comprising at least one manifold block (11) of a refrigerant fluid (FR), ensuring the circulation of the refrigerant fluid (FR), and a distribution device (25) of the refrigerant fluid (FR) which comprises a external duct (35) and an internal duct (51) each perforated with at least one orifice (29) defining a passage section (290) for the refrigerant fluid (FR), characterized in that the distribution device (25) comprises a movable obstruction member (31) moved by a means for controlling the heat exchanger (5) between two extreme obstruction positions, at least one of which is an at least partial obstruction position of at least 1 one of the orifices (29) of the dispensing device (25). Abstract figure: [Fig 7]

Description

Heat exchanger for an air conditioning installation of a vehicle comprising a device for distributing a refrigerant fluid configured to ensure the expansion of the refrigerant fluid in the heat exchanger

The field of the present invention is that of heat exchangers fitted to air conditioning installations for a vehicle, in particular an automobile. The invention relates more specifically to the methods of distributing a refrigerant fluid inside a manifold block that comprises such a heat exchanger when the latter is used as an evaporator.

A vehicle is commonly equipped with an air conditioning installation for thermally treating the air present or sent into the passenger compartment of the vehicle. In order to modify the temperature of a flow of air outside the vehicle before it is diffused into the passenger compartment, such an installation comprises a closed circuit inside which a refrigerant fluid circulates. Successively depending on the direction of circulation of the refrigerant fluid through it, the circuit essentially comprises a compressor, a condenser, an expansion valve and at least one heat exchanger used as an evaporator and crossed by the air flow for its cooling.

In such an installation, the compressor is able to bring the refrigerant fluid, which is in the gaseous state, to a high pressure. The gaseous refrigerant then circulates through the condenser, from which it emerges in a liquid state and at high pressure. In conventional air conditioning loops, the expansion valve is provided to allow expansion of the refrigerant fluid from a high pressure to a low pressure, the refrigerant fluid leaving the expansion valve being two-phase and comprising a liquid portion and a gaseous portion. This two-phase mixture is then transported into the evaporator, providing a heat exchange between the refrigerant fluid, circulating in the closed circuit, and an external fluid which passes through the heat exchanger, such as the air flow outside the vehicle, so to provide cooling of said external fluid.

The evaporator commonly comprises a bundle of tubes interposed between a manifold block and a secondary manifold block, for example a return block or a refrigerant fluid outlet block, the tube bundle forming a heat exchange surface between the refrigerant and a fluid external to the circuit which circulates between the various tubes of the bundle of the heat exchanger. The two-phase refrigerant fluid is admitted into the evaporator through an inlet mouth made in the collector block, then circulates along successive paths in the tubes of the bundle between the collector block and the secondary collector block, then is evacuated out of the heat exchanger through an outlet, which may be formed through the manifold block or through the secondary manifold block.

A problem posed lies in the fact that the refrigerant fluid is in the two-phase liquid/gaseous state when it is admitted inside the heat exchanger. Due to the difference in physical properties between the liquid and the gas, the refrigerant fluid tends to separate between its liquid phase and its gaseous phase within the manifold block. This results in heterogeneity in the supply of the tubes of the bundle with regard to the different phases of the refrigerant fluid, depending on their position relative to the inlet mouth of the refrigerant fluid inside the manifold block. More particularly, the tubes of the bundle located closest to the inlet mouth can be mainly supplied with liquid and conversely the tubes of the bundle furthest from the inlet mouth can be mainly supplied with gas, thereby affecting the performance of the heat exchanger used as an evaporator.

Additionally, this phenomenon can generate heterogeneity in the temperature of the air flow that crosses the heat exchanger in operation. This heterogeneity complicates the thermal management of the device that receives the heat exchanger and ultimately involves temperature differences between two areas of the passenger compartment, when the same air flow temperature is required.

In order to improve the distribution of the refrigerant fluid in the heat exchanger, it is known to house a conduit provided with a plurality of orifices inside the manifold block. The refrigerant in the liquid phase is thus projected through the orifices in the form of droplets over the entire length of the conduit.

The present invention falls within this context and aims to provide a heat exchanger comprising a bundle of tubes and at least one manifold block for a refrigerant fluid ensuring the circulation of the refrigerant fluid in the tubes of the bundle, the manifold block comprising a wall delimiting a first chamber into which the tubes of the bundle open, the first chamber housing a device for distributing the coolant extending along a longitudinal axis and which comprises an external duct and an internal duct each perforated with at least one orifice defining a passage section for the refrigerant fluid, characterized in that the distribution device comprises a movable obstruction member which comprises an inlet mouth allowing the admission of the refrigerant fluid into the distribution device and in that the heat exchanger comprises at least one means for controlling the movement of the obstruction member between two extreme positions, at least one of which is a position of at least partial obstruction of at least one of the orifices of the dispensing device.

In other words, the invention solves the problems previously exposed by proposing, for example, to eliminate the expansion valve, arranged upstream of the evaporator, from the refrigerant circuit of an air conditioning installation comprising the heat exchanger according to the invention and to integrate a variable expansion system throughout the manifold block located at the inlet of said heat exchanger, used as an evaporator. Thus the refrigerant enters the evaporator in liquid form and is evenly distributed in the manifold block and then in the tubes of the bundle. The heat exchanger is thus configured to ensure the expansion and then the evaporation of the refrigerant fluid. Alternatively, the heat exchanger may be intended to ensure a second expansion of the refrigerant fluid in a circuit comprising an expansion valve.

In the present invention, the manifold block ensures the entry, at the level of an inlet mouth of the distribution device, of the refrigerant fluid into the heat exchanger then its expansion along the manifold block from a first pressure to a second pressure. lower pressure. In particular, the heat exchanger is configured to ensure variable expansion of the refrigerant fluid, that is to say that the pressure drop of the refrigerant fluid can be adjusted as needed by moving the obstruction member, mobile, with respect to the internal duct and/or to the external duct, that is to say with respect to at least one fixed body, for example to adapt to a power, and therefore a flow rate of the refrigerant, which varies within the circuit. Also, the manifold block ensures the distribution of the refrigerant fluid, having a pressure lower than that of its entry into the heat exchanger, to the various tubes of the bundle extending between the manifold block and a refrigerant fluid return block.

By convention, throughout this document, the qualifier "longitudinal" applies to the direction in which the longest dimension of the dispensing device extends, the qualifier "vertical" applies to a direction substantially perpendicular to the longitudinal direction and joining between them the collector block and the secondary collector block of the heat exchanger, that is to say to the main dimension of elongation of the tubes of the bundle, and the qualifier "transverse" designates the direction perpendicular to both in the longitudinal direction and in the vertical direction.

In order to ensure the maintenance of the internal duct and/or the external duct, as well as of the obstruction member relative to each other and in the first chamber of the manifold block, the internal duct and/or the internal duct and / or the obstruction member can be mounted inside the first chamber of the collector block via at least one end piece fixed to the wall of said collector block. The obstruction member extends inside the duct(s), the obstruction member comprising the inlet mouth and can be configured to bring the refrigerant fluid into the heat exchanger. The obstruction member may, for example, have a structure that is at least partially cylindrical and/or plate-shaped at least partially matching the shape of at least one of the fixed bodies. Advantageously, the end piece can be configured to be equipped with the control means controlling the movements of the obstruction member. Also, the endpiece can be configured to receive at least one seal, such as a sealing ring, intended to prevent leaks of refrigerant fluid, for example at the connection between the inlet mouth of the organ obstruction and the supply tubing directly connected to an outlet of the condenser.

In particular, the internal duct and/or the external duct can be arranged so as to at least partially surround the obstruction member. In other words, the internal duct and/or the external duct as well as the obstruction member can be arranged so that they surround the longitudinal axis of the dispensing device. Additionally, the internal duct and/or the external duct, as well as the obstruction member can be centered on this same longitudinal axis so as to be coaxial.

Depending on the number of components it comprises, the distribution device can be composed of a variable number of chambers. The internal duct and/or the external duct thus delimit at least one intermediate chamber in which the obstruction member extends. The obstruction member itself delimits an internal chamber communicating with the inlet mouth of the refrigerant fluid, the obstruction member having, for example, a cylindrical structure. By way of example, when the dispensing device comprises the external duct and the internal duct, arranged so as to surround the obstruction member, these each delimit an intermediate chamber while the obstruction member delimits the internal chamber, distinct from the intermediate chambers. Conversely, when the dispensing device comprises the external duct and the internal duct and the obstruction member are combined, the external duct delimits the intermediate chamber in which the obstruction member extends, which delimits the internal chamber.

The internal conduit and the external conduit each comprise at least one orifice which allows, on the one hand, the distribution of the refrigerant fluid from one chamber to another and, on the other hand, the expansion of the refrigerant fluid. In particular, at least the orifice of the internal duct can be made in a peripheral face of the internal duct while at least the orifice of the external duct can be made in a peripheral side of the external duct. Thus the heat exchanger is supplied with coolant via the distribution device, the coolant passing through the inlet mouth formed at a first longitudinal end of the obstruction member, then circulating in the internal chamber before being distributed to at least the intermediate chamber delimited by the external duct or the first chamber of the manifold block.

In the present invention, the degree of expansion of the refrigerant fluid is regulated by the position of the obstruction member relative to the orifice of at least the perforated fixed body, that is to say the orifice of the internal duct or the external duct, surrounding it, the obstruction member more or less covering said orifice. Indeed, the degree of obstruction of the orifice modifies the passage section of the refrigerant fluid through the orifice, that is to say the space left for the refrigerant fluid to circulate through at least the orifice, modifying thereby the expansion of the coolant which passes through at least the orifice of the dispensing device. By "obstruct" is thus meant that the obstruction member more or less hinders the flow of fluid to the outside of the internal chamber by variable covering of the orifice of the dispensing device, thus forming a physical barrier at the level of said orifice.

The variation of the expansion of the refrigerant fluid within the manifold block is thus ensured by the movement of the obstruction member of the distribution device, the heat exchanger being particularly configured to include the control means controlling the movement of the obstructive organ.

The movement of the obstruction member can in particular be carried out by hydraulic actuation, via the refrigerant, thermostatic fluid, or else be motorized.

According to one characteristic of the invention, the obstruction member comprises at least one means for passage of the coolant provided in a peripheral wall of the obstruction member and capable of being placed facing at least one of the orifices of the dispensing device, the displacement of the obstruction member modifying the covering of the orifice by the obstruction member so as to vary the passage section of the refrigerant fluid through said orifice.

The passage means may, for example, consist of a through opening made in the peripheral wall of the obstruction member. The displacement of the obstruction member between the two extreme positions is thus accompanied by a displacement of the passage means with respect to said orifice, the relative arrangement of the orifice and of the passage means defining the passage section of the orifice, that is to say the place left for the refrigerant fluid to circulate through the corresponding orifice. In other words, the displacement of the obstruction member in the dispensing device allows a modification of the flow section of the refrigerant fluid and therefore a modification of the degree of expansion of the refrigerant fluid flowing through the corresponding orifice.

The extreme positions can, for example, be an obstruction position, in which the obstruction member completely covers at least the orifice of the dispensing device capable of being provided opposite the passage means of the organ of obstruction, and a release position, fully uncovering said orifice.

Thus, when the dispensing device is in the position of obstruction of at least the orifice, the peripheral wall of the obstruction member forms a physical barrier covering at least the orifice of the internal duct or of the external duct. The covering of the orifice is then total, the passage section of the corresponding orifice is zero and the refrigerant fluid cannot circulate through said orifice.

When the dispensing device is in a disengaged position, the passage means for the obstruction member is arranged facing at least the orifice of the dispensing device so as to fully disengage the orifice, the section of passage of the refrigerant fluid through the corresponding orifice is maximum and the refrigerant fluid circulates through the orifice, from the internal chamber to the intermediate chamber, for example delimited by the external duct, or to the first chamber of the manifold block.

Advantageously, the obstruction member can be moved so as to adopt different intermediate positions, between the two extreme positions of the obstruction member. Each of these positions is characterized by a different degree of covering of the orifice by the peripheral wall of the obstruction member, which results in a variation of the passage section of the orifice and therefore of the degree of relaxation of the refrigerant fluid passing through said orifice. Such an effect extends to configurations in which the external duct and/or the internal duct comprise a plurality of orifices, the obstruction member then being capable of covering, at least partially, a plurality of orifices of the distribution.

It should be noted that, when the air conditioning installation is in operation, it is preferable to allow refrigerant fluid to circulate within the heat exchanger, the distribution member is then preferably provided according to the release position or according to one of the intermediate positions.

Other characteristics are likely to contribute to the variation of the expansion, that is to say the pressure drop, of the refrigerant. This is particularly the case with the number of orifices provided in the internal duct and/or the external duct of the dispensing device, the spacing separating two adjacent orifices or even the dimensions and shapes of said orifices.

Thus, the different orifices of the dispensing device can have different shapes, such as triangular, circular or parallelepipedal or, on the contrary, be identical within the same duct or the dispensing device. Also, the orifices are defined by a maximum section, for example comprised between 2 and 40 mm², and a hydraulic diameter, for example comprised between 0.2 and 1.5 mm, the various orifices of the dispensing device possibly having identical dimensions or not.

The dispensing device can also be configured so as to comprise more than two ducts each perforated with one orifice, each additional duct possibly being fixed, and/or arranged so as to surround the external duct and the internal duct and each additional duct possibly be configured to ensure an additional level of expansion of the refrigerant fluid.

According to a characteristic of the invention, the number of orifices of the internal duct is equal to or greater than the number of orifices of the external duct.

According to a first embodiment of the present invention, the dispensing device comprises the internal duct, the external duct and a cylinder, separate from said internal duct and external duct, forming the obstruction member, the internal duct surrounding the obstruction and the obstruction of at least the orifice of the internal duct being produced by a movement of the obstruction member according to a rotational movement around the longitudinal axis of the dispensing device.

In such an embodiment, the dispensing device as previously described comprises two fixed perforated bodies, the internal duct and the external duct, and a mobile member, the obstruction member. The outer conduit at least partially surrounds the inner conduit, which at least partially surrounds the obstruction member. The internal duct thus delimits a first intermediate chamber, in which the obstruction member extends, while the external duct delimits a second intermediate chamber, in which the internal duct and the obstruction member extend. The various orifices of the internal duct and external duct, as well as the means of passage of the obstruction device, ensure the circulation of the refrigerant fluid between the various chambers.

In particular, the internal duct and the obstruction member may have dimensions allowing the displacement of the obstruction member while limiting the circulation of the refrigerant fluid in the first intermediate chamber, delimited by the internal duct, so that it is minimal or zero, the coolant then flowing from the internal chamber of the obstruction member to the second intermediate chamber, delimited by the external conduit.

The internal duct and the external duct allow a gradual expansion of the refrigerant fluid, so that the pressure of the refrigerant fluid is reduced in stages or stages, passing through an intermediate stage, each stage being able, for example, to be ensured by the passage of the refrigerant fluid through one of the ducts, among the internal duct and the external duct. The internal duct and external duct are in particular respectively characterized by a total passage section, which corresponds to the sum of the passage sections of the orifices of the corresponding duct, which can be increasingly reduced in order to allow the gradual expansion of the refrigerant fluid.

Particularly, in the first embodiment, a first expansion step, resulting from the passage of the refrigerant fluid through at least the orifice of the internal duct, is variable because it depends on the positioning of the obstruction member with respect to the internal duct. . This first expansion stage can thus be regulated by the control means of the heat exchanger. Conversely, a second expansion stage, resulting from the passage of the refrigerant fluid through at least the orifice of the external duct, has a fixed degree of expansion, the passage section of at least the orifice included in the duct external being fixed.

According to a characteristic of the first embodiment, at least the orifice of the internal duct and at least the orifice of the external duct are angularly offset relative to each other around the longitudinal axis of the dispensing device. an angle between 25° and 180°.

In this way, said orifices are not arranged facing each other and the coolant circulates in the second intermediate chamber, delimited by the external duct, before passing through at least the orifice of the external duct and to the first chamber of the heat exchanger.

The internal duct and the external duct can be characterized by a different arrangement of the orifice(s) that they comprise. For example, the orifices of the internal duct and/or or of the external duct can be formed so as to extend along at least one longitudinal straight line substantially parallel to the longitudinal axis of the dispensing device, the orifices of the internal duct and external duct that can be provided along a distinct number of longitudinal straight lines.

According to a characteristic of the first embodiment, the internal duct and the external duct each comprise a plurality of orifices, the orifices of the internal duct being arranged so as to form at least one row extending in a direction substantially parallel to the longitudinal axis of the dispensing device, and the orifices of the external duct being arranged along at least one straight line substantially parallel to said longitudinal axis.

In other words, the inner conduit and the outer conduit may respectively comprise at least one row and one line of ports, the inner conduit being configurable to have a plurality of rows, each extending along a direction substantially parallel to the longitudinal axis. Due to the displacement according to a rotational movement of the obstruction member and due to the arrangement of the orifices of the internal duct, the obstruction member is particularly configured so that all the orifices of the same row can present, for a defined position of the obstruction member, the same flow section of the coolant. For example, when the obstruction member is in the disengaged position, all of the orifices of the same row, included in the internal duct, are arranged opposite the passage means of the obstruction member, the all of the orifices of said row then allowing the distribution of the refrigerant fluid to the second intermediate chamber, delimited by the external duct.

According to one characteristic of the invention, at least the passage means of the obstruction member consists of a groove extending in a direction substantially parallel to the longitudinal axis of the dispensing device.

The bleeding consists of an elongated opening extending longitudinally in the peripheral wall of the obstruction member so as to simultaneously uncover all the orifices of the same row. The kerf is characterized by a width of the kerf, measured between two opposite side edges.

Advantageously, the groove can be configured so that all of the rows of orifices included in the internal duct can be released simultaneously, in particular when the obstruction member is arranged in the release position. In other words, the various rows of orifices of the internal duct are arranged so that they are included in an angular sector which originates at a point on the longitudinal axis of the dispensing device and which comprises at least the groove width. In this way, all of the orifices of the different rows of the internal duct can simultaneously allow the circulation of the refrigerant fluid from one chamber to another, here from the internal chamber, delimited by the obstruction member, towards the second chamber. intermediate, bounded by the external duct. Such an arrangement can also be reproduced when the internal duct comprises a single row of orifices.

As explained above, the obstruction member and the internal duct may have dimensions aimed at limiting the circulation of the refrigerant fluid in the first intermediate chamber, delimited by the internal duct, in order to allow the direct circulation of the refrigerant fluid from the internal chamber towards the second intermediate chamber, delimited by the external duct. Additionally, or alternatively, the groove can be delimited by a seal, said seal bordering the side edges and longitudinal end edges of the groove and the seal being in contact with an internal face of the internal duct in a manner to prevent the circulation of the refrigerant fluid in the first intermediate chamber of the internal duct.

The groove thus defines, through the peripheral wall of the obstruction member, a zone for the distribution of the refrigerant fluid delimited by the lateral edges and the longitudinal end edges. In particular, the length of the distribution zone, measured between the longitudinal end edges of the groove, is less than a length of the obstruction member, measured between the longitudinal end comprising the inlet mouth and an end opposite longitudinal.

Thus, in this first embodiment, the refrigerant can enter the heat exchanger with a high inlet pressure, in particular when the heat exchanger is directly connected to the compressor. The refrigerant fluid circulates in the obstruction member and undergoes a first expansion stage by passing through the passage means, that is to say the bleeding, and at least the orifice of the internal duct. The refrigerant fluid then circulates from the internal chamber to the second intermediate chamber, delimited by the external conduit, without the refrigerant fluid flowing into the first intermediate chamber, delimited by the internal conduit. The refrigerant then has a pressure lower than that observed when it enters the heat exchanger.

The refrigerant fluid then circulates in the second intermediate chamber then passes through at least the orifice of the external duct, towards the first chamber of the manifold block in which the distribution device extends. The refrigerant fluid, passing through the orifice of the external conduit, undergoes a second expansion stage, the refrigerant fluid circulating in the first chamber then having a pressure lower than that measured at the inlet of the refrigerant fluid in the heat exchanger and lower than that which can be observed in the second intermediate chamber of the dispensing device, which is delimited by the external duct. Then the coolant is distributed in the various tubes of the bundle of the heat exchanger, said tubes opening out into the first chamber delimited by the wall of the manifold block.

According to a second embodiment, the obstruction member and the internal duct are combined, the obstruction of at least the orifice of the external duct being achieved by a movement of the obstruction member according to a rotational movement around the longitudinal axis of the dispensing device or according to a movement in translation along said longitudinal axis.

In the second embodiment, the dispensing device comprises a fixed body, the external duct, and a mobile body, the obstruction member, formed by the internal duct. In other words, the internal duct and the organ of obstruction are confused. The external duct at least partially surrounds the obstruction member, and comprises, as previously explained, at least one orifice. The obstruction member, formed by the internal duct, also comprises at least one orifice, which forms the passage means for the obstruction member.

As specified above, the external duct delimits the intermediate chamber in which the obstruction member extends, the external duct and the obstruction member being able to be configured so as to extend in a direction substantially parallel to the longitudinal axis of the dispensing device, and more particularly, the external duct and the obstruction member being able to be centered on said longitudinal axis.

In such an embodiment, when the external duct and the obstruction member each comprise a plurality of orifices, they can be configured so as to respectively have a substantially equal number of orifices and passage means. Also, the orifices of the external duct and the passage means of the obstruction member can be adapted to have substantially identical arrangements. For example, the orifices of the external duct and the passage means of the obstruction member can be provided along longitudinal straight lines substantially parallel to the longitudinal axis of the dispensing device. Additionally, according to the second embodiment, the orifices of the external duct and the passage means of the obstruction member may have substantially identical shapes, passage sections and/or hydraulic diameters.

As previously specified, in the second embodiment the movement of the obstruction member between the extreme positions can be configured in two alternative ways. Either the movement of the obstruction member takes place by a rotational movement around the longitudinal axis of the dispensing device, or said movement takes place according to a translational movement along this same longitudinal axis.

Independently of the alternative considered for moving the obstruction member, when the dispensing device is in the disengaged position, all of the orifices of the external duct and all of the passage means of the blocking member obstruction are arranged facing each other. In other words, when the dispensing device is in the disengaged position, a longitudinal plane comprising the longitudinal axis of the dispensing device and passing through at least one middle of an orifice of the external duct passes through at least one middle of a means passage of the obstruction member disposed opposite said orifice.

When the dispensing device is in the extreme obstruction position, the obstruction member can be arranged according to two alternative configurations based on the type of displacement of the obstruction member considered.

When the obstruction member is configured to be moved according to a rotational movement, the latter can be arranged so that the longitudinal plane comprising the longitudinal axis of the dispensing device and passing through at least the middle of an orifice of the external duct does not pass through at least the means for passage of the obstruction member capable of being arranged facing said orifice when the obstruction member is arranged in the release position.

Conversely, when the obstruction member is configured to be moved according to a translational movement and when the latter is arranged in the obstruction position, at least one transverse plane, orthogonal to the longitudinal axis of the device distribution and passing through at least the middle of one of the orifices of the external duct, does not pass through the passage means of the obstruction member capable of being arranged facing said orifice when the obstruction member is moved to release position. The present invention also proposes an air conditioning installation comprising at least one compressor, one condenser and one heat exchanger as described above, used as an evaporator.

In such an installation, the compressor is capable of bringing the refrigerant fluid, which is in the gaseous state at the inlet of the compressor, to a high pressure. The hot gaseous refrigerant, leaving the compressor, then circulates through the condenser, from which it essentially emerges in a liquid state and at high pressure after having exchanged calories with air entering the vehicle and passing through the condenser. The heat exchanger, used as an evaporator according to one aspect of the invention, recovers the refrigerant fluid essentially in the liquid state so as to transfer its calories to another fluid passing through the evaporator, in particular the external air flow. Thus, within the bundle of the evaporator, a heat exchange takes place between the cold refrigerant fluid and the external fluid coming into contact with the bundle. This heat exchange causes the cooling of the external fluid and the heating of the refrigerant fluid which is then returned to the compressor of the circuit.

According to a characteristic of the invention, the inlet mouth of the collector block of the heat exchanger is directly connected to the outlet of the condenser.

Conventionally, within an air conditioning installation, the refrigerant leaving the condenser is sent to the expansion valve which will ensure the expansion of the refrigerant fluid from a high pressure to a lower pressure. The refrigerant leaving such an expansion valve, then directed to the heat exchanger used as an evaporator, nevertheless has the disadvantage of being in a two-phase liquid/gaseous state, such a state being accompanied by heterogeneity in the distribution of the refrigerant fluid in the heat exchanger arranged downstream of the expansion valve.

According to the present invention, the air conditioning installation can be devoid of an expansion valve, and the condenser is directly connected to the heat exchanger used as an evaporator. By "directly" connected, it is meant that the inlet mouth of the heat exchanger, provided at the level of the distribution device of the collector block, is connected to the outlet of the condenser by at least one supply pipe on which no component is mounted to modify the pressure of the refrigerant fluid.

The refrigerant leaving the condenser, essentially liquid and at high pressure, thus circulates towards the heat exchanger and enters said heat exchanger through the inlet mouth of the obstruction member of the distribution device included in the manifold block of the heat exchanger, which is, as explained above, configured to ensure the expansion of the refrigerant fluid along its length. The pressure of the refrigerant fluid measured at the outlet of the condenser and that measured at the inlet of the evaporator, that is to say at the level of the inlet mouth of the obstruction member, are thus substantially equal. .

The refrigerant fluid thus enters at high pressure at the level of the inlet mouth of the obstruction member and exits from the distribution device at a pressure lower than the inlet pressure. The refrigerant thus circulates in the first chamber of the collector block in a two-phase liquid/gas state, at low pressure and cold, then is distributed in the various tubes forming the bundle of the evaporator. In such an installation, the pressure of the refrigerant fluid is thus reduced only by its circulation through the distribution device.

The heat exchanger thus advantageously combines the functions of evaporator and expansion valve, thus simplifying the assembly of the refrigerant circuit and reducing its cost while improving the performance of the heat exchanger. Advantageously, the heat exchanger according to the present invention is configured to allow variable expansion of the refrigerant fluid, the degree of expansion being, for example, dependent on the physical parameters of the circuit such as temperature or pressure.

Alternatively, a heat exchanger as described above can be integrated into a refrigerant fluid circuit comprising an expansion valve. The inlet of the heat exchanger used as an evaporator is then directly connected to the outlet of the expansion valve, the coolant, expanded, arrives at the level of the inlet of the heat exchanger in a two-phase liquid/gas state , low pressure and cold. The coolant then undergoes a second expansion within the distribution device of the heat exchanger manifold block before being distributed in the various tubes of the bundle. The refrigerant leaving the distribution device then has a temperature and a pressure lower than that measured at the outlet of the expansion valve.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the detailed description given below, and several examples of embodiment given by way of indication and not limitation with reference to the appended schematic drawings, in which:

is a schematic representation of a refrigerant circuit intended for an air conditioning installation comprising a heat exchanger according to the invention;

is a perspective view of a heat exchanger according to the invention, a manifold block of this heat exchanger being indented to make visible a distribution device;

is a schematic representation of a heat exchanger according to the invention and of the circulation of the refrigerant fluid within said heat exchanger;

is a partial cross-sectional view of the dispensing device and of a fitting holding it in the heat exchanger;

is a schematic representation of a cross-section of the dispensing device produced according to a first embodiment, arranged in a first position, said figure making visible a wall of the manifold block, an external duct, an internal duct and an obstruction member ;

is a schematic representation of a cross section of the dispensing device produced according to the first embodiment, provided in a second position;

is a schematic representation of a longitudinal section of the dispensing device according to the first embodiment;

is a perspective view of the obstruction member of the dispensing device according to the first embodiment;

is a schematic representation of the dispensing device produced according to a second embodiment;

is a schematic representation of a cross section of the dispensing device represented in FIG. 9, provided in a first position;

is a schematic representation of a cross section of the dispensing device represented in FIG. 9, provided in a second position;

is a schematic representation of a longitudinal section of the dispensing device shown in Figure 11;

It should first be noted that the figures expose the invention in detail for its implementation, but that said figures can of course be used to better define the invention, if necessary.

Furthermore, with reference to the orientations and directions defined previously, the longitudinal direction will be represented, in the figures requiring it, by the Ox axis, the vertical direction will be represented by the Oy axis, and the transverse direction will be represented by the Oz-axis. These different axes together define an orthonormal reference Oxyz shown in the different figures. In this frame, the qualifiers "high" or "upper" will be represented by the positive direction of the axis Oy, the qualifiers "low" or "lower" being represented by the negative direction of this same axis Oy.

FIG. 1 represents an air conditioning installation 1 for a vehicle, in particular an automobile, which comprises a closed circuit 2 inside which a refrigerant fluid FR circulates. In the illustrated embodiment, the air conditioning installation 1 comprises successively, in the direction S1 of circulation of the refrigerant fluid FR, a compressor 3, a condenser 4 or gas cooler and at least one heat exchanger 5. In particular, the heat exchanger 5 can be used as an evaporator, the heat exchanger 5 then being dedicated to cooling an air flow FA, external to the circuit 2, passing through it. Such an air flow FA can, for example, be exploited to heat treat the air in the passenger compartment of the vehicle.

The example given of an architecture of the air conditioning installation 1 is given by way of indication and is not restrictive as to the scope of the invention with regard to various potential architectures of said air conditioning installation. air 1.

In the refrigerant circuit 2 of the air conditioning system 1, the refrigerant FR is compressed in the compressor 3, the refrigerant FR leaving the compressor 3 in the gaseous state and brought to a high pressure. This hot gaseous refrigerant fluid FR then circulates through the condenser 4 from which it emerges in the essentially liquid state, hot, and still having a high pressure.

The present invention, as represented in FIG. 1, proposes an FR refrigerant circuit 2 devoid of an expansion valve, an outlet 401 of the condenser 4 being directly connected to the heat exchanger 5, used as an evaporator, by means of at least a pipe 6, so that when the refrigerant fluid FR enters the heat exchanger 5, it has physical properties substantially identical to those of the refrigerant fluid FR leaving the condenser 4, that is to say that it is liquid, hot and under high pressure.

In this way, the heterogeneity of the supply of the heat exchanger 5 with regard to the different phases of the refrigerant fluid FR is prevented.

Figures 1 to 3 illustrate the heat exchanger 5 and detail the circulation of the refrigerant FR within said heat exchanger 5. The heat exchanger 5 comprises a bundle 7 of tubes 9 interposed between a manifold block 11 and a secondary manifold block 13 , visible in Figure 3, the refrigerant FR. In the example shown, the secondary manifold block 13 is a return block, and will be qualified as such below, however, according to an alternative not shown, the secondary manifold block 13 can also be a refrigerant outlet block. The manifold block 11 extends in a longitudinal direction Ox substantially perpendicular to a vertical direction Oy of extension of the tubes 9 of the bundle 7. The bundle 7 thus forms a heat exchange surface between the refrigerant fluid FR, circulating in the loop circuit 2 closed, and the air flow FA external to circuit 2.

An inlet 15, connected to the pipe 6, supplies the heat exchanger 5, and more particularly the manifold block 11, with refrigerant fluid FR. The manifold block 11 comprises a wall 17 delimiting a first chamber 19 into which the various tubes 9 of the bundle 7 open. The manifold block 11 is thus configured to ensure the distribution of the refrigerant fluid FR in the various tubes 9 of the bundle 7. heat exchanger 5 further comprises an outlet mouth 21, evacuating the refrigerant fluid FR out of the heat exchanger 5. When the inlet mouth 15 and the outlet mouth 21 are connected to the manifold block 11, the heat exchanger 5 presents a circulation in "U". According to a variant, the outlet mouth 21 can be formed in the return block 13, which then implies that the heat exchanger 5 has an "I" circulation.

As previously explained, in the circuit 2 according to the invention, the refrigerant fluid FR enters the heat exchanger 5, more precisely into the manifold block 11, presenting a pressure substantially equal to that observed at the level of the outlet 401 of the condenser 4. Nevertheless, so that the heat exchanger 5 can perform its evaporator function optimally, it is necessary that the refrigerant fluid FR, when it circulates in the tubes 9 forming the bundle 7 of the heat exchanger 5 , has a pressure lower than that measured at the outlet 401 of the condenser 4. The heat exchanger 5 according to the invention is thus configured to achieve the expansion of the refrigerant fluid FR in the manifold block 11, between the inlet mouth 15 of the heat exchanger 5 and a vertical end of the tubes 9 of the bundle 7, passing through the wall 17 of the manifold block to extend into the first chamber 19 of the manifold block 11.

In order to ensure the expansion of the refrigerant fluid FR, the manifold block 11 of the heat exchanger 5 comprises a device 25 for distributing the refrigerant fluid FR extending along a longitudinal axis 100 and disposed in the first chamber 19. distribution 25 is particularly configured to comprise at least one fixed body 27, perforated with at least one circular orifice 29 for the passage of the refrigerant fluid FR, and a movable member, called an obstruction member, the movement of which is controlled by a means of control 33 of the heat exchanger 5. The configuration of the distribution device 25 and the movements of the obstruction member within the distribution device 25 will be further detailed below.

In this way, the collector block 11 ensures the entry, at the level of the inlet mouth 15, of the liquid refrigerant FR into the heat exchanger 5 then its expansion, along the distribution device 25, from a first pressure to a second pressure which is lower. The refrigerant FR leaving the distribution device 25 then circulates in the first chamber 19 with a view to its distribution in the tubes 9 of the bundle 7, the refrigerant FR then having the second pressure, lower than that measured at its entry into the heat exchanger 5, the second pressure being compatible with the evaporator function of heat exchanger 5.

The expanded FR refrigerant fluid can then circulate along successive paths in the tubes 9 of the bundle 7, between the collector block 11 and the return block 13, the heat exchange between the FR refrigerant fluid and the flow to be cooled, here the flow air FA, causing the evaporation of the refrigerant FR. At the outlet of the heat exchanger 5, the refrigerant FR is in the gaseous state and at a pressure lower than that observed at the inlet of the heat exchanger 5 and the refrigerant FR is again sent to the compressor. 3.

The expansion of the refrigerant fluid FR is thus carried out between the inlet mouth 15 of the refrigerant fluid FR in the heat exchanger 5 and the vertical ends of the tubes 9 of the bundle 7 opening into the first chamber 19 of the manifold block 11, the loss of charge of the refrigerant fluid FR can be regulated by the displacement of the obstruction member of the distribution device 25 by the control means 33. The displacement of the obstruction member can in particular be adapted according to certain parameters of the circuit, such as as the temperature, pressure or flow rate of the refrigerant.

For example, when the air conditioning installation 1 is operating at a higher power and the refrigerant fluid FR has a high flow rate, the obstruction member of the heat exchanger 5 is moved so as to cause a degree of expansion, that is to say a pressure drop, of the refrigerant greater than when the air conditioning installation 1 operates at a lower power and therefore that the refrigerant FR circulates at a lower flow rate.

The heat exchanger can then be configured so that the displacement of the obstruction member results from a hydraulic drive, via the refrigerant fluid or else from a motorized drive, via an electric motor. As illustrated in Figure 2, the control means 33 may in particular comprise a thermostatic valve 33.

According to an alternative not shown, the heat exchanger 5 can be integrated into a circuit 2 of refrigerant fluid FR comprising an expansion valve. The inlet 15 of the heat exchanger 5 is then directly connected to an outlet of the expansion valve, for example by means of a tube. The refrigerant FR leaving the expansion valve then arrives at the level of the inlet 15 of the heat exchanger 5 in a two-phase liquid/gas state, at reduced pressure and cold. The FR refrigerant fluid undergoes a second expansion within the distribution device 25 of the manifold block 11 and the distribution device 25 contributes to the homogenized distribution of the two-phase FR refrigerant fluid within the manifold block 11 by allowing the circulation of the FR refrigerant fluid at the within the obstruction member then through at least the perforated body 27 before being distributed in the various tubes 9 of the bundle 7.

FIG. 4 represents an assembled dispensing device 25 . The dispensing device 25 comprises a first perforated body 27, formed, in the example shown, by an outer duct 35 extending in the direction defined by the longitudinal axis 100 of the dispensing device 25 and being centered on said axis. The outer duct 35 has a cylindrical structure, delimiting an intermediate chamber in which extends the obstruction member 31, represented by dotted lines, of the dispensing device 25. The outer duct 35 comprises a peripheral flank 39 comprising a plurality of circular orifice 29 for the passage of the refrigerant fluid FR, as well as a first longitudinal termination 40, open, allowing the insertion of the obstruction member 31, and a second longitudinal termination 41, opposite the first longitudinal termination 40 and closed.

In the example illustrated, the outer duct 35 comprises a plurality of orifices 29, arranged along a straight line substantially parallel to the longitudinal axis 100 of the dispensing device 25. When the dispensing device 25 is assembled in the block collector 11 of the heat exchanger 5, these orifices 29 allow the passage of the refrigerant fluid FR from the intermediate chamber, delimited by the outer conduit 35, towards the first chamber of the collector block.

Maintaining the dispensing device 25 in the first chamber 19 of the manifold block 11 is ensured by an end piece 43, secured to the first longitudinal termination 40 of the outer duct 35 of the dispensing device 25 and secured to the manifold block. The end piece 43 comprises, for example, two through-holes. A first hole 45 receives the obstruction member 31 which comprises, at a first longitudinal end 46, the inlet 15 supplying the heat exchanger 5, and more particularly the distribution device 25, with refrigerant FR. The first longitudinal end 46 and/or the first hole 45 are configured to cooperate with at least the pipe connecting the heat exchanger 5 to the refrigerant circuit FR, for example at the outlet of the condenser. A second hole 47 of the end piece 43 includes the outlet mouth 21 of the heat exchanger 5, the second hole 47 being, for example, configured to receive at least one pipe for evacuating the refrigerant fluid FR to the compressor of the circuit .

The obstruction member 31, movable, is thus inserted into the first hole 45 of the end piece 43 so as to pass through said end piece 43. The end piece 43 can particularly be configured to include or carry the piloting means, not illustrated , controlling the movement of the obstruction member 31 between two extreme positions, at least one of which is a position of at least partial obstruction of at least one of the orifices 29 of the dispensing device 25.

Conversely, the outer conduit 35 is held on an outer portion of the endpiece 43, in a fixed manner, for example by brazing or by snap-fastening. The dispensing device 25 may also comprise at least one additional perforated body, such as a plate or a duct, not shown, formed within the intermediate chamber delimited by the outer duct 35, said additional perforated body being able to be brazed onto a internal surface of the peripheral side 39 of the external duct 35 or even fixed on the end piece 43.

FIGS. 5 to 8 illustrate the relative arrangement of the various components of the dispensing device 25 when the latter is produced according to a first embodiment, FIGS. to the longitudinal axis 100 of the dispensing device 25, as shown in Figure 4, the transverse plane 500 passing through an orifice 29 of the outer conduit 35.

The dispensing device 25 according to the first embodiment comprises the outer duct 35, delimiting the intermediate chamber hereinafter called the second intermediate chamber 53, a second fixed perforated body 27, formed by an internal duct 51 comprising a plurality of orifices 29 , and the mobile obstruction member 31 . In the example illustrated, the outer conduit 35, the inner conduit 51 and the obstruction member 31 have cylindrical structures, and are coaxial, each being centered on the longitudinal axis 100 of the dispensing device 25.

The outer duct 35, as previously explained, comprises a peripheral side 39 in which a plurality of orifices 29 are made. In the example shown, the orifices 29 of the outer duct 35 are arranged along a straight line substantially parallel to the longitudinal axis 100 of the dispensing device 25.

The internal duct 51 is arranged in the second intermediate chamber 53, delimited by the external duct 35, and extends in a direction defined by the longitudinal axis 100 of the dispensing device 25. In particular, the internal duct 51 is centered on said longitudinal axis 100, a peripheral face 55 of the internal duct 51 delimiting a first intermediate chamber 59 and surrounding the obstruction member 31 of the dispensing device 25.

The internal duct 51 comprises a plurality of orifices 29, which are arranged so as to form a plurality of rows 57 substantially parallel to each other and each extending in a direction substantially parallel to the longitudinal axis 100. In the example illustrated , the internal duct 51 comprises three rows 57. The orifices 29 of the internal duct 51 and the orifices 29 of the external duct 35 can be angularly offset relative to each other around the longitudinal axis 100 of the dispensing device 25 at an angle between 25° and 180°. For example, as shown, the internal duct 51 and the external duct 35 can be arranged so that the orifice 29 of the external duct 35 and an orifice 29 of the central row 57 of the internal duct 51 are angularly offset by 180° around the longitudinal axis 100 of the dispensing device 25.

The obstruction member 31 comprises a peripheral wall 61 in which is disposed a passage means 63, such as can be seen in Figures 5 to 8, and more particularly in Figure 8. In the first mode of embodiment, the passage means 63 is a groove 65 forming an elongated opening extending in a direction substantially parallel to the longitudinal axis 100 of the dispensing device 25. Advantageously, the groove 65 is framed by a seal 67 bordering longitudinal end edges 69 and lateral edges 70 delimiting the groove 65. The groove 65 extends over a length, called the length of the groove 650, measured between the longitudinal end edges 69 of the groove 65, according to a direction substantially parallel to the longitudinal axis 100. The length of the groove 650 is less than a length of the obstruction member 310, measured between its longitudinal ends 46 and in a direction parallel to the longitudinal axis 100 of the distribution 25.

The obstruction member 31 and the internal conduit 51 have dimensions allowing the displacement of the obstruction member 31 towards a position of at least partial obstruction of at least one of the orifices 29 of the internal conduit 51. The clearance between the obstruction member 31 and the internal duct 51, characterized by a transverse distance 590 measured between an internal face 71 of the internal duct and the obstruction member 31, is minimal in order to limit the flow of fluid refrigerant FR in the first intermediate chamber 59 delimited by the internal duct 51. Similarly, the seal 67, bordering the groove 65, is in contact with the internal face 71 of the internal duct 51 in order to prevent the circulation of the refrigerant FR between the obstruction member 31 and the internal duct 51. The seal 67 thus limits the circulation zone of the refrigerant fluid FR in the first intermediate chamber 59, housing the obstruction member 31, the bleeding 65 and the seal 67 thus defining a distribution zone 73 of the refrigerant fluid FR within the distribution device 25. In particular, the orifices 29 of the internal duct 51 and/or of the external duct 35 can be arranged so as to be in next to said distribution zone 73 of the obstruction member 31.

Thus, in the transverse plane 500 of the cup as represented in FIGS. 5 and 6, the obstruction member 31 comprises the groove 65, which forms a continuous opening on the distribution zone 73. The distribution zone 73, bordered by the seal 67 and partly defined by a width of the groove 65, measured between the opposite side edges 70, is included in an angular sector 151. Said angular sector 151 is measured between two half-lines emerging from the same point of the longitudinal axis 100 of the dispensing device 25, included in the transverse plane 500, and passing through two closest points respectively included in the seal 67 bordering the lateral edges 70, opposite, of the groove 65.

The obstruction member 31 is surrounded by the internal duct 51 which delimits the first intermediate chamber 59. The internal duct comprises a plurality of orifices 29 arranged in different rows 57, here three in number. The rows 57 of the internal duct 51 are particularly provided so as to be included in the angular sector 151 defined by the width of the groove 65, in order to allow the simultaneous release of the different rows 57 of the internal duct 51 when the groove 65 of the obstruction member 31 is provided opposite said rows 57.

The orifices 29 of the rows 57 of the internal duct 51 are characterized by a passage section 290 of the refrigerant fluid FR, corresponding to the space left for the refrigerant fluid FR to circulate, said passage section 290 being reduced with respect to the distribution zone 73 delimited by the groove 65. Also, the internal duct 51 is characterized by a total passage section of the internal duct, equal to the sum of the passage sections 290 of the orifices 29 of the internal duct 51, less than the distribution zone 73, ensuring thus a first step of expansion of the refrigerant fluid FR, even when all of the orifices 29 of the internal duct 51 are cleared by the obstruction member 31 to allow passage of the refrigerant fluid.

The external duct 35 surrounds the internal duct 51 and the obstruction member 31, the external duct 35 comprising, in the example illustrated, a single line of orifices 29, substantially parallel to the longitudinal axis 100 of the dispensing device 25 The external duct 35 thus comprises a number of orifices 29 that is less than the number of orifices 29 of the internal duct 51, and is characterized by a total passage section of the external duct, corresponding to the sum of all the passage sections 351 of the orifices 29 of the external duct 35, less than the total passage section of the internal duct 51 evaluated when all of the orifices 29 of the internal duct 51 are cleared by the obstruction member 31.

The circulation of the refrigerant fluid FR through the orifices 29 of the outer conduit 35 thus provides a second stage of expansion of said refrigerant fluid, which is fixed since the passage section 351 of each orifice 29 of the outer conduit 35 cannot be modified.

The dispensing device 25 according to the first embodiment thus allows a gradual expansion of the refrigerant fluid FR. It should be noted that such a gradual expansion can result from a reduction in the number of orifices 29 observed between the internal duct 51 and the external duct 35, from a reduction in the dimensions of said orifices 29, from a reduction in the total flow section of the coolant between the internal conduit 51 and the external conduit 35 or a combination of these different characteristics.

Thus, the refrigerant FR, entering the heat exchanger 5 through the inlet 15 of the obstruction member 31, circulates in an internal chamber 75, delimited by the peripheral wall 61 of the obstruction member 31 then, depending on the position of the obstruction member 31, is distributed, or not, in the second intermediate chamber 53 of the distribution device 25.

In the first embodiment, the control means allows the displacement, by hydraulic, mechanical or electrical drive, of the obstruction member 31 according to a rotational movement M1 around the longitudinal axis 100, towards one of the extreme positions. The extreme positions adopted by the obstruction member 31 can in particular be an obstruction position, in which the peripheral wall 61 of the obstruction member 31 completely covers the orifices 29 of the internal duct 51 in order to hinder the circulation refrigerant fluid FR to the second intermediate chamber 53, and a release position, completely releasing said orifices 29 from the internal duct 51 by positioning the passage means 63, here the groove 65, opposite the orifices 29 of the internal duct 51 in order to allow the circulation of the refrigerant fluid from one chamber to another. Also, the obstruction member 31 can be arranged in any intermediate position, between these two extreme positions, the different intermediate positions being characterized by a variable degree of covering of the different orifices 29 of the internal duct 51 by the peripheral wall 61 of the obstruction member 31 resulting in a modification of the passage section 290 of the orifices 29 of the internal duct 51. This results in a modification of the total passage section of the internal duct and therefore a modification of the degree of expansion of the fluid FR refrigerant passing through said ports 29.

It should nevertheless be noted that, when the air conditioning installation is in operation, it is preferable to allow refrigerant fluid FR to circulate within the heat exchanger, the distribution member is then preferably provided according to the position relief or according to one of the intermediate positions.

Figures 5 and 6 illustrate some of the different positions of the obstruction member 31 allowing the distribution and expansion of the refrigerant fluid FR in the manifold block 11. Figures 5 and 6 are thus distinguished from each other by the position of the obstruction member 31 with respect to the orifices 29 of the internal duct 51 and by the degree of expansion of the refrigerant fluid FR which results therefrom. Figure 5 thus details the release position, while Figure 6 shows an example of an intermediate position, between the two extreme positions.

When it is in the obstruction position, not shown, the peripheral wall 61 of the obstruction member 31 covers all of the orifices 29 of the different rows 57 of the internal conduit 51, hindering the circulation of the refrigerant fluid FR towards the first chamber 19 of the collector block 11.

Conversely, when the obstruction member 31 is in the released position, as shown in Figure 5, all of the orifices 29 of the rows 57 of the internal duct 51 are arranged opposite the passage means 63, that is to say the groove 65, the obstruction member 31. The refrigerant FR can then circulate through all the orifices 29 of the internal conduit 51 from the internal chamber 75 to the second intermediate chamber 53, delimited by the external duct 35, the circulation of the refrigerant fluid FR in the first intermediate chamber 59, delimited by the internal duct 51, being limited by the presence of the seal 67.

The total passage section of the internal duct 51, that is to say the sum of the passage sections 290 of the various orifices 29 of the internal duct 51, is then maximum. As previously explained, this total passage section of the internal duct 51 is less than the distribution zone 73 defined by the groove 65, so that the refrigerant fluid FR undergoes a first expansion by crossing said orifices 29.

In the intermediate position shown in Figure 6, the peripheral wall 61 of the obstruction member 31 completely covers the orifice 29 of one of the rows of the internal conduit 51 and reduces the passage section 290 of the refrigerant fluid FR to through the orifice 29 of another row 57. The same is true for each orifice, not visible, included in one of these two rows 57 which are then respectively covered or partially covered by the peripheral wall 61 of the obstruction member 31, insofar as the side edges 70 of the groove 65 extend parallel to each other and to the longitudinal axis 100. The orifice 29 of the third row 57, like any orifice included in the third row , is uncovered and allows the circulation of the refrigerant fluid FR without hindrance. In this intermediate position, the total flow section of the coolant through the internal conduit 51 is thus reduced by half compared to the release position shown in Figure 5.

In FIG. 7, representing a section taken at the level of a longitudinal plane 600 orthogonal to the longitudinal axis 100 of the dispensing device 25, as shown in FIG. 4, the longitudinal plane 600 passing through an orifice 29 of the external duct 35, it can be observed that the refrigerant fluid FR enters the heat exchanger 5 through the inlet mouth, arranged at the level of the longitudinal end of the obstruction member 31 included in the distribution device 25, the fluid FR refrigerant then having a high inlet pressure. The refrigerant FR circulates in the internal chamber 75, delimited by the peripheral wall 61 of the obstruction member 31 then circulates according to the path as previously exposed, that is to say that, when the distribution device 25 is in the release position or in one of the intermediate positions, the refrigerant fluid FR passes through the passage means 63, that is to say the groove 65, and through at least one of the orifices 29, completely or partially uncovered, of the internal duct 51, arranged opposite the bleeding 65.

The refrigerant fluid FR thus circulates from the internal chamber 75, delimited by the obstruction member 31, towards the second intermediate chamber 53, delimited by the peripheral flank 39 of the external conduit 35, undergoing the first stage of expansion by passing through the internal conduit 51. The coolant fluid observed in the second intermediate chamber 53 then has a lower pressure than that observed in the internal chamber 75 or at the inlet of the fluid into the heat exchanger 5, at the level of the inlet mouth .

The refrigerant FR then circulates in the second intermediate chamber 53, delimited by the external conduit 35, then passes through the orifices 29 of the external conduit 35 towards the first chamber 19, in which the distribution device 25 extends. through the orifices 29 of the external conduit 35, the refrigerant FR undergoes the second expansion stage, the refrigerant FR circulating in the first chamber 19 having a pressure lower than that observed at the inlet of the fluid in the heat exchanger 5 and to that observed in the second intermediate chamber 53 of the dispensing device 25.

Then the refrigerant fluid FR circulating in the first chamber 19, relaxed, and is distributed in the vertical ends 23 of the various tubes 9 of the bundle 7 of the heat exchanger, said tubes 9 passing through the wall 17 of the collector block and extending partially in the first chamber 19. In particular, according to the example of FIG. 8, the orifices 29 of the outer duct 35 are oriented diametrically opposite the vertical ends 23 of the tubes 9 of the bundle 7, with respect to the longitudinal axis 100 of the dispensing device 25.

The refrigerant FR thus undergoes a gradual expansion, carried out in two stages. The first expansion, depending on the positioning of the obstruction member 31 relative to the internal duct 51, is variable, that is to say it can be regulated by the control means of the heat exchanger 5 according to demand, for example to adapt to specific conditions relating to the environment of the circuit of the air conditioning installation or of the heat exchanger 5. The second expansion, on the other hand, is fixed, the passage section orifices 29 of the outer duct 35 cannot be modified in the first embodiment.

FIGS. 9 to 12 illustrate a dispensing device 25 produced according to a second embodiment. According to the second embodiment, the dispensing device 25 comprises the external duct 35, fixed, and the obstruction member 31, mobile. The second embodiment differs from the first embodiment in that the internal duct 51 and the obstruction member 31 are combined, that is to say that unlike the first embodiment, formed of two bodies 27 fixed and a movable member, the second embodiment comprises a fixed body 27, the outer conduit 35, and a movable member. In particular, in the example illustrated, the outer duct 35 and the obstruction member 31 have cylindrical structures and both extend in a direction defined by the longitudinal axis 100 of the dispensing device 25.

As previously explained, the outer duct 35 comprises the peripheral side 39 in which several circular orifices 29 are formed, said orifices 29 being particularly arranged along a straight line substantially parallel to the longitudinal axis 100 of the dispensing device 25. orifices 29 are regularly arranged, that is to say at regular intervals, each orifice 29 being separated from the adjacent orifice 29 by a spacing 350 measured between two closest points respectively included in the borders 79 of two adjacent orifices 29 of the external duct 35. In addition, the orifices 29 of the external duct 35 have substantially identical dimensions, the orifices 29 of the external duct 35 being characterized by a first passage section 351.

The peripheral flank 39 delimits an intermediate chamber 37, in which the obstruction member 31 extends. The second embodiment thus also differs from the first embodiment in that the dispensing device 25 comprises a single intermediate chamber 37. Specifically, the obstruction member 31 and the outer conduit 35 may be centered on the longitudinal axis 100 of the dispensing device 25, the outer conduit 35 and the obstruction member 31 then being coaxial.

The obstruction member 31 comprises the peripheral wall 61 in which the passage means 63 are formed. In the example illustrated, the passage means 63 are circular orifices having an arrangement, shape and dimensions substantially identical to those observed in the outer conduit 35, that is to say that the passage means 63 are arranged along a straight line substantially parallel to the longitudinal axis 100 of the dispensing device 25. As a result, the passage means 63 are regularly arranged, each passage means 63 being separated from the adjacent passage means 63 by a gap 312 substantially equal to the spacing 350 measured between two adjacent orifices 29 of the external conduit 35. Also, the passage means 63 are respectively characterized by a second passage section 316, substantially equal to the first passage section 351 of the orifices 29 of the external conduit 35.

The obstruction member 31 and the outer conduit 35 have dimensions allowing the displacement of the obstruction member 31 inside the outer conduit 35 and between the extreme positions of which at least one is a position of at least partial obstruction of the orifices 29 of the outer conduit 35. The clearance existing between the obstruction member 31 and the outer conduit 35, characterized by a transverse distance 595 measured between an inner surface 83 of the outer conduit 35 and the obstruction 31, can, as illustrated, be minimal in order to limit the circulation of the refrigerant fluid FR in the intermediate chamber 37.

In the second embodiment, the obstruction member 31 is controlled by the control means so that the peripheral wall 61 of the obstruction member 31 provides full or partial coverage of the orifices 29 of the external duct. 35. The drive of the obstruction member 31 can be hydraulic, via the coolant fluid, mechanical or electrical, the distribution device 25 being able to be configured according to two variants: a first variant, represented in FIGS. 9 to 12, in which the movement of the obstruction member 31 is carried out according to a translational movement T1 along the longitudinal axis 100 of the dispensing device 25, and a second variant, not shown, in which the obstruction member 31 is moved according to a rotational movement around the longitudinal axis 100 of the dispensing device 25.

As previously explained, the obstruction member 31 is thus controlled between two extreme positions, for example between an obstruction position and a position of clearance of the orifices 29 of the external conduit 35, the obstruction member 31 also being able to be arranged in one or more intermediate positions, between said extreme positions.

According to the variant shown, in which the obstruction member 31 is moved according to a translational movement T1 along the longitudinal axis 100, the orifices 29 of the external duct 35 and the passage means 63 of the obstruction 31 are arranged, independently of the position of the dispensing device 25, so that the longitudinal plane 600 passes through the middle of each of the orifices 29 of the external duct 35 and through the middle of each of the passage means 63 of the organ obstruction 31.

When the dispensing device 25 is in the released position, as shown in Figure 10, the orifices 29 of the outer duct 35 and the passage means 63 of the obstruction member 31 are arranged facing each other. In other words, the transverse plane 500 passes through the middle of one of the orifices 29 of the outer duct 35 and also passes through the middle of one of the passage means 63 of the obstruction member 31. In addition, the orifices 29 and passage means 63, as illustrated, are characterized by substantially identical dimensions, shapes and arrangement.

Conversely, when the obstruction member 31 is in the obstruction position, as shown in FIG. 11, the transverse plane 500 passes through the middle of one of the orifices 29 of the external duct 35 but does not pass not through the passage means 63 of the obstruction member 31 configured to be arranged facing said orifice 29 when the obstruction member 31 is moved into the release position. The passage means 63 of the obstruction member 31 are then opposite the peripheral side 39 of the outer conduit 35 and the orifices 29 of the outer conduit 35 are arranged opposite the peripheral wall 61 of the obstruction member 31 The circulation of the refrigerant FR cannot take place from the internal chamber 75, delimited by the obstruction member 31, towards the first chamber 19 of the manifold block 11, in which the distribution device 25 extends.

As explained for the first embodiment, it should be noted that the obstruction position is described here for explanatory purposes, the obstruction member 31 being preferably formed according to the release position or according to one of the intermediate positions in order to allow the circulation of the refrigerant fluid FR in the heat exchanger when the air conditioning installation is in operation.

It is observed in the example of intermediate position illustrated in FIG. 12, that the transverse plane 500, passing through the middle of one of the orifices 29 of the external duct 35, does not pass through the middle of the passage means 63 of the obstruction member 31 but passes through any points of the passage means 63.

In the second embodiment, the refrigerant fluid FR enters the heat exchanger 5 through the inlet mouth, disposed at the level of the longitudinal end of the obstruction member 31 of the distribution device 25, the refrigerant fluid FR then having a high inlet pressure, substantially equal to that measured at the outlet of the condenser. The refrigerant fluid FR circulates in the internal chamber 75, delimited by the peripheral wall 61 of the obstruction member 31 then, when the dispensing device 25 is in the disengaged position or in one of the intermediate positions, the refrigerant fluid FR passes through the passage means 63 and through the orifices 29 of the external conduit 35, or through a first passage section 351 reduced by said orifices 29. The refrigerant fluid FR thus circulates from the internal chamber 75 to the first chamber 19 , in which the dispensing member 25 extends, without circulating in the whole of the intermediate chamber 37, delimited by the outer duct 35.

In this way, the refrigerant fluid FR, passing through the orifices 29 of the external conduit 35, undergoes an expansion, that is to say that the refrigerant fluid FR circulating in the first chamber 19 has a pressure lower than that measured. in the internal chamber 75 or at the inlet of the refrigerant fluid in the heat exchanger 5, at the level of the inlet mouth.

Thus, in the second embodiment, the refrigerant fluid FR thus undergoes an expansion in one step. This expansion, depending on the positioning of the obstruction member 31 relative to the external duct 35, is variable, that is to say it can be regulated by the control means of the heat exchanger 5 according to the asked.

As for the first embodiment, the refrigerant fluid FR circulating in the first chamber 19 is then distributed in the vertical ends 23 of the various tubes 9 of the bundle 7 of the heat exchanger 5, said tubes 9 opening into the first chamber 19 delimited by the wall of the manifold block 11. According to the example of FIG. 12, the orifices 29 of the outer duct 35 are oriented diametrically opposite the vertical ends 23 of the tubes 9 of the bundle 7, with respect to the longitudinal axis 100 of the distribution device 25, the tubes 9 of the bundle 7 passing through the wall 17 of the manifold block 11 to extend inside the first chamber 19.

It is understood on reading the foregoing that the present invention proposes a heat exchanger, intended to be used as an evaporator, the heat exchanger being configured to ensure the expansion of the refrigerant fluid FR. The heat exchanger comprises a manifold block which comprises a distribution device configured to ensure the expansion of the refrigerant fluid FR between the inlet of the fluid into the heat exchanger, at the level of an inlet mouth, and the distribution of the fluid FR refrigerant in a heat exchanger tube bundle. The dispensing device comprises, for this purpose, a combination of at least one fixed body perforated with at least one orifice, for example a duct, and of a mobile obstruction member, the movement of which is controlled by a means for controlling the heat exchanger between two extreme positions, at least one of which is a position of at least partial obstruction of at least one of the orifices of the dispensing device.

The invention cannot however be limited to the means and configurations described and illustrated here, and it also extends to any equivalent means or configuration and to any technical combination operating such means. In particular, the number, dimensions, shape and arrangement of the orifices or of the passage means may be modified without harming the invention, insofar as the distribution device of the manifold block, ultimately, fulfills the same features than those described in this document.

Claims (10)

Heat exchanger (5) comprising a bundle (7) of tubes (9) and at least one manifold block (11) for a refrigerant fluid (FR) ensuring the circulation of the refrigerant fluid (FR) in the tubes (9) of the bundle (7), the manifold block (11) comprising a wall (17) delimiting a first chamber (19) into which the tubes (9) of the bundle (7) open, the first chamber (19) housing a distribution device (25 ) of the refrigerant fluid (FR) extending along a longitudinal axis (100) and which comprises an outer conduit (35) and an inner conduit (51) each perforated with at least one orifice (29) defining a passage section ( 290, 351) of the refrigerant fluid (FR), characterized in that the distribution device (25) comprises a movable obstruction member (31) which comprises an inlet mouth (15) allowing the admission of the refrigerant fluid ( FR) in the dispensing device (25) and in that the heat exchanger (5) comprises at least one means (33) for controlling the displacement of the obstruction member (31) between two extreme positions of which at least one is a position of at least partial obstruction of at least one of the orifices (29) of the dispensing device (25). Heat exchanger (5) according to claim 1, in which at least one passage means (63) of the refrigerant fluid FR is provided in a peripheral wall (61) of the obstruction member (31) and adapted to be arranged in facing at least one of the orifices (29) of the dispensing device (25), the movement of the obstruction member (31) modifying the covering of the orifice (29) by the obstruction member (31) so as to vary the passage section (290, 351) of the refrigerant fluid FR through said orifice (29). Heat exchanger (5) according to Claim 1 or 2, in which the number of orifices (29) of the internal duct (51) is equal to or greater than the number of orifices (29) of the external duct (35). Heat exchanger (5) according to any one of the preceding claims, in which the distribution device (25) comprises the internal duct (51), the external duct (35) and a cylinder, separate from the said internal duct (51) and external (35), forming the obstruction member (31), the internal duct (51) surrounding the obstruction member (31) and the obstruction of at least the orifice (29) of the internal duct ( 51) being carried out by a movement of the obstruction member (31) according to a rotational movement around the longitudinal axis (100) of the dispensing device (25). Heat exchanger (5) according to the preceding claim, in which at least the orifice (29) of the internal duct (51) and at least the orifice (29) of the external duct (35) are angularly offset from each other the other around the longitudinal axis (100) of the dispensing device (25) by an angle comprised between 25° and 180°. Heat exchanger (5) according to Claim 4 or 5, in which the internal duct (51) and the external duct (35) each comprise a plurality of orifices (29), the orifices (29) of the internal duct (51) being arranged so as to form at least one row (57) extending in a direction substantially parallel to the longitudinal axis (100) of the dispensing device (25), and the orifices (29) of the external duct (35) being arranged along at least one line substantially parallel to said longitudinal axis (100). Heat exchanger (5) according to any one of Claims 4 to 6, in which at least the passage means (63) of the obstruction member (31) consists of a groove (65) extending in a direction substantially parallel to the longitudinal axis (100) of the dispensing device (25). Heat exchanger (5) according to any one of Claims 1 to 3, in which the obstruction member (31) and the internal duct (51) coincide, the obstruction of at least the orifice (29) of the external duct (35) being produced by a displacement of the obstruction member (31) according to a rotational movement around the longitudinal axis (100) of the dispensing device (25) or according to a translational movement along said longitudinal axis (100). Air conditioning installation (1) comprising at least one compressor (3), one condenser (4) and one heat exchanger (5), according to any one of the preceding claims, used as an evaporator. Air conditioning installation (1) according to the preceding claim, in which the inlet (15) of the manifold block (11) of the heat exchanger (5) is directly connected to an outlet (21) of the condenser ( 4).