FR2864215A1 - Hydraulic circuit unit for use in heat exchanger, has end fitting with insertion zone in which one end of tube and return zone are housed, and connection part with insertion zone in which another end of tube and connection zone are housed - Google Patents

Abstract

The unit has an end fitting (20) with an insertion zone in which an end (40) of a tube (22) and a return zone are housed in a sealed manner. A connection part (21) has an insertion zone in which an end (41) of the tube and a connection zone are housed in a tight manner. The connection zone transmits a fluid that enters in the unit to an inlet channel and transmits the fluid from an outlet channel outside the unit. An independent claim is also included for a heat exchanger including a stacking of hydraulic circuit units.

Description

Circuit element for heat exchanger

  The invention relates to a circuit element for a heat exchanger, in particular a heat exchanger for the equipment of a motor vehicle.

  More specifically, it relates to a circuit element for heat exchange between a first fluid and a second fluid.

  It also relates to heat exchangers obtained from these circuit elements.

  Exchangers commonly consist of a bundle of parallel tubes mounted between two manifolds, the tubes alternating with interleaves for example corrugated type. The first fluid circulates inside the tubes while the second fluid circulates in the space between the tubes. Heat exchange between the first fluid and the second fluid occurs at the surface of the tubes.

  However, these known exchangers have many disadvantages. With regard to the technology of tube and collector exchangers, the latter increase the size of the exchangers without increasing their performance. The collector boxes do not make it possible to improve the heat exchange and cause a loss of space.

  On the other hand, the heat exchanger must be rectangular in shape because of the presence of the collector boxes. In addition, to create passes in the exchanger, it is necessary to add and integrate additional parts, the partitions, into the collector boxes.

  The manufacture of these exchangers is also difficult because it is necessary to punch and pop the collector plates.

  FR 2834336 A proposes an exchanger that does not have such disadvantages. An exchanger according to FR 2834336 A comprises a stack of circuit elements. Each circuit element has at least one tube and at least one endpiece at one end of the tube. The tip comprises at least one communication passage that defines the path of a first fluid. This tip has a bottom to prevent the fluid from escaping in the axial direction of the tube, allowing the use of a tube having open ends. This exchanger is adapted for use with a two-channel tube but does not provide for communication between the two channels to allow a return of the first fluid at the end of the circuit element, and therefore a U-shaped circulation at the level of each circuit element of the exchanger.

  To ensure a flow of the first U fluid, it is necessary to put in communication one of the channels of the tube with the other channel of the same tube, in the vicinity of one end of the tube.

  Formed exchangers are known to allow the return of the fluid emerging from one of the channels of a tube to the other channel of the same tube, and thus a U-shaped circulation at each tube. Such circuit elements are in particular provided with a plug at one of the open ends of the tube which closes this end and which contributes to the return of the fluid.

  In this type of exchanger, it is sometimes provided a partition in the cap which delimits two compartments. When the cap is attached to the end, each compartment communicates with only one of the channels of the tube. The septum of the plug is further pierced with openings for the passage of fluid from one channel to the other channel, which allows a U-shaped circulation in the tube.

  DE 19515528 A1 proposes a circuit element comprising a two-channel flat tube having a closure plug at one end. The partition wall of the channels is pierced with small openings in the vicinity of the end provided with the closure cap. Thus the fluid flowing in one of the channels of the tube can pass into the other channel of the tube via the openings of the partition, the stopper having only a closing function.

  The passage of the fluid from one channel to the other through openings leads to overspeed and a bad distribution of the lines of currents in the width of the tube. The heat exchange surface is thus poorly exploited in the vicinity of the fluid reversal zone. In addition, the passage of the fluid through the openings may cause erosion at this zone.

  The present invention relates to a hydraulic circuit element for a heat exchanger that overcomes these disadvantages known from the prior art.

  For this purpose, the invention proposes a hydraulic circuit element, for the heat exchange between a first fluid and a second fluid, defining a path for the first fluid. The circuit element comprises at least one tube having an inlet channel and a return channel separated by a main partition, a first nozzle attached to a first open end of the tube, and a second nozzle attached to a second open end of the tube. tube. Advantageously, the first end-piece comprises an insertion zone in which the first end is housed in a sealed manner and an overturning zone delimited by a closed bottom in which the fluid which opens out from the arrival channel of the tube undergoes a reversal. to the return channel of the tube, while the second end has an insertion zone in which is sealed the second end and a connection area adapted to transmit the first fluid which enters the circuit element to the channel and to transmit the first fluid returning from the return channel to the outside of the circuit element.

  Optional features of the circuit element 5 according to the invention, complementary or substitution, are set out below: The first end of the tube has a V shape whose tip is facing outwards.

  The connection zone comprises an auxiliary partition delimiting an arrival compartment and an exit compartment, the arrival compartment being sealingly connected to the arrival channel and the exit compartment being sealingly connected to the exit channel; .

  - The thickness of the auxiliary partition is greater than the thickness of the main partition.

  - The auxiliary partition is shaped so that the main partition comes to bear against the auxiliary partition after fixing the second end on the second end.

  The second end of the tube is V-shaped with the tip facing inwards.

  - The second end of the tube has a V shape whose tip is facing outwards.

  - Each compartment of the second nozzle comprises at least one opening.

  - Each compartment of the second nozzle comprises a pair of openings formed vis-à-vis in the main faces 35 of the second nozzle.

  - Each opening of the second nozzle is surrounded by a shaped collar adapted to the corresponding opening.

  - The outer section of one of the collars of the second nozzle, located on a main face of the second nozzle, is writable in the inner section of the collar vis-à-vis, located on the other main face of the second tip.

  The collar, located on a main face of the second endpiece, is substantially identical to the crossed collar, located on the other main face.

  - The outer section of a collar, located on a main face of the second tip, is writable in the inner section of the collar, located on the same main face of the second tip.

  - The connection piece has a symmetry along an axis which extends along the auxiliary partition.

- The tube is usually flat.

  - The lateral edges of the first nozzle each comprise an inner stop arranged so that the first end of the tube comes simultaneously bearing against these two stops, after introduction into the first nozzle.

  - The inner stops of the first nozzle are arranged near the inlet opening of the first nozzle.

  - Each main face of the first nozzle has a generally rectangular shape.

  - Each main face of the first tip has a general shape of demidisque.

  - The first end has inner walls in the form of circular arc arranged in the inner space and extending between the two main faces, these internal partitions defining runways.

  The invention furthermore proposes a heat exchanger, in particular for a motor vehicle, comprising a stack of circuit elements communicating with each other via their respective second ends.

  Optional features of the heat exchanger according to the invention, complementary or substitution, are set out below: The circuit elements are connected by interleaving the collars opposite their respective second ends, an inner collar of an element circuit penetrating the outer collar of an adjacent circuit element.

  - The section of the wall of the inner collar tapers gradually from the base of the collar and the section of the wall of the outer collar is substantially constant.

  The free end of the wall of the inner collar is curved towards the inside of the collar.

  - The free end of the wall of the outer collar is curved towards the inside of the collar.

  - The thickness of the first nozzle is less than or equal to the pitch between the respective tubes of two adjacent circuit elements.

  Other features and advantages of the invention will become apparent upon consideration of the following detailed description, and the accompanying drawings in which: - Figure 1 is a perspective view of an exchanger according to the present invention; FIG. 2 is a perspective view of a circuit element according to the present invention; Figure 3A is a perspective view showing the structure of the various components of the circuit element of Figure 2; - Figure 3B is a perspective view showing the connecting tabs between two successive first ends of the exchanger; Figure 3C is a perspective view showing the connecting tongues between two successive second ends of the exchanger; - Figure 4A is a longitudinal sectional view of a tube without V-cut; - Figures 4B and 4C are views in longitudinal section of the tube after a V-cut ends of the tube, according to various embodiments of the invention; - Figure 5A is a schematic longitudinal sectional view of a circuit element according to the invention; - Figure 5B shows a section of the tube of a circuit element according to the invention; FIG. 5C is an enlarged partial view of the circuit element of FIG. 5A; - Figures 6A to 6D are schematic longitudinal sectional views of the return plug of a circuit element according to the invention, according to various embodiments; Figure 7 is a perspective view showing the return plugs of two adjacent circuit elements according to the invention; FIG. 8 is a schematic view from above of the respective connecting pieces of two adjacent connected circuit elements; - Figure 9A shows, on a larger scale, a detail of Figure 8; and - Figure 9B shows, on a larger scale, a detail of Figure 9A.

  The drawings contain, for the most part, elements of a certain character. They can therefore not only serve to better understand the description, but also contribute to the definition of the invention, if any.

  There is shown in Figure 1 an external perspective view of a heat exchanger according to the present invention.

  The heat exchanger 1 consists of a stack of circuit elements 2.1 to 2.n.

  Figure 2 shows a circuit element according to the invention. Each circuit element 2 comprises a tube 22, in particular a flat tube, having two open ends 40 and 41. FIG. 5B represents an example of section of the tube 22. The tube comprises two channels C1 and C2 separated by a main partition 220 Such a tube can be made by extrusion or profiling.

  The heat exchanger allows an exchange between a first fluid circulating inside the tubes and a second fluid flowing between the tubes.

  The circuit element of the invention can be used to realize different types of heat exchanger and in particular condensers for motor vehicle air conditioning installations.

  With reference to FIG. 2, a circuit element according to the present invention comprises a first end piece or return plug 20 fixed on a first end 40 and a second end piece or connecting piece 21 fixed to a second end 41 of the tube 22.

  The return plug 20 sealingly seals the first end 40. It delimits an interior space comprising a zone designed to house the first end 40 and a turning zone in which the first fluid opening from the arrival channel, for example Cl, flows in the direction of the return channel, for example C2.

  The return plug 20 thus ensures the passage of the fluid from the channel C1 of the tube 22 to the channel C2 of the same tube, which makes it possible to obtain a U-shaped circulation in each circuit element 2.

  The return plug 20 comprises a peripheral side wall, of substantially constant thickness, which fits and fits exactly the end 40 of the tube 22. The return plug 20 is shaped so that the end 40 occupies only a part of its length so as to provide a turning zone at the bottom of the cap. The first fluid which opens out from the inlet channel C1 through the end 40, with a direction of flow going from the end 41 to the end 40, thus flows into this turning zone, where it undergoes a reversal towards the return channel C2 to move in the opposite direction.

  The return plug 20 may have rounded side edges to match the shape of the tube 22. The bottom of the return plug 20 may also have a rounded shape. The rounded shape of the side edges and bottom of the return plug 20 improves the resistance of the exchanger to the high pressures of the first fluid, and facilitates flow with low pressure drops.

  According to one aspect of the invention, the end 40 of the tube 22, shown in FIG. 4B, is V-shaped. More precisely, the end 40 which is connected to the return plug 20 has a V shape. whose tip is turned outwards. The V-shape of the end 40 may be obtained by cutting into a rectangular flat tube 22 'shown in Figure 4A.

  The V-cut of the end 40 makes it possible to optimize the reversal of the fluid from the arrival channel C1 to the return channel C2 by equalizing the lengths of the lines of currents during the reversal. Indeed, in the absence of V-cut, the fluid flow lines that are closest to the longitudinal partition have the shortest path, while the current lines that are farthest from the partition have the shortest path. longest path for the fluid passing from the C1 channel to the C2 channel. Given the V-cut of the end 40, the path can be shortened by bypassing the current lines that are close to the partition. The V-cut and the plug structure contribute to the equalization of the lengths of the current lines. This equalization has the advantage of limiting the overspeeds, decreasing the pressure losses of the first fluid and equalizing the exchange coefficients on the inner wall of the tube.

  The thickness b of the return plug 20 is limited only by the pitch p between the tubes of two adjacent circuit elements, as shown in FIG. 7. It must be chosen substantially less than or equal to this pitch p to avoid hyperstatism during assembly. An exchanger according to the invention therefore makes it possible to exploit the space between two adjacent tubes to optimize the reversal of the fluid, without the bulk of the exchanger being increased. The V-shaped end of the tube 40 promotes a uniform length of the current lines, thus allowing maximum exploitation of the exchange surface of the tube.

  In short, the V-cut of the end 40 and the structure of the return plug 20 make it possible: to optimize the exchange surface on the air for a given overall size, to minimize the pressure drops of the first fluid, and minimize local overspeeds in the turning zone.

  Thus, the internal volume of the return plug 20 and its external dimensions are sufficiently small to optimize the size of the heat exchanger, and sufficiently large to optimize the reversal of the fluid.

  In a particular embodiment, shown in Figure 3, the return plug 20 is formed of a sheet metal strip pressed and folded to form two branches 204 corresponding to the side faces of the return plug.

  FIGS. 6A to 6D show longitudinal sectional views of various embodiments of the return plug 20. The plug may have side faces 204 in the shape of a rectangle (FIG. 6A and 6D) or in the form of a semicircle (FIG. Figure 6C and 6D). Moreover, the return plug 20 may comprise interleaved internal partitions 210 in the shape of an arc of a circle. These inner partitions extend between the two lateral faces 204 of the return plug and form tracks which guide the flow of the fluid.

  Furthermore, internal stops 202 may be provided on each of the two side edges 203 and 206 inside the return plug 20. They are located near the inlet opening 205 of the plug and are intended to define the depth of penetration of the end 40 into the return plug. They thus contribute to defining the turning zone, as can be seen in FIG. 5C.

  The connecting piece 21 shown in FIG. 2 comprises a peripheral lateral wall that comes to enclose and marry the second end 41 of the tube 22. The connecting piece 21 is shaped so that the end 41 occupies only a part of its length so that to provide a connection area at the bottom of the connection piece 21. The connection zone transmits the first fluid that arrives in the circuit element to the arrival channel Cl, and transmits the first fluid returning from the return channel C2 outside the circuit element.

  Figure 5A is a longitudinal sectional view of a circuit element 2 according to the present invention. The connecting piece 21 shown in this figure comprises two compartments, an inlet compartment C11 and an outlet compartment C21, separated by an auxiliary partition 215.

  The auxiliary partition 215 allows a separation at the level of the connection zone between the flows which flow in opposite directions respectively to the channel C1 and from the channel C2.

  The auxiliary partition 215 of the connecting piece is shaped to prolong the separation of the flows flowing in the various channels C1 and C2 beyond the end 41. The auxiliary partition 215 is in particular provided for the main partition 220 to come in support against it, after assembly of the circuit element 2. For this, the auxiliary partition 215 may have a thickness greater than the thickness of the main partition.

  The connection zone allows the communication of the circuit element 2 with the outside and in particular with an adjacent circuit element in an exchanger.

  For this, each compartment of the part 21 comprises at least one opening arranged in the connection zone. In particular, each compartment C11 (respectively C21) of the part 21 comprises a pair of openings 2120 formed opposite in the main faces 241 of the connection piece, as shown in FIG.

  Thus, as illustrated in FIG. 5A, the fluid that arrives from an adjacent circuit element in the compartment C11 through one of the openings 2120 can thus pass into the inlet channel C1 in a sealed manner (arrow 30) and the Fluid coming from the return channel C2 (arrow 34) can thus leak tightly into the compartment C21 before passing into another circuit element.

  The connection piece 21 of a circuit element thus makes it possible to ensure the entry and exit of the first fluid in the circuit element.

  According to another characteristic of the invention, the end 41 of the tube 22, shown in FIG. 4B, also has a V shape. In one embodiment, the end 41 has a V shape whose tip is turned. inwardly, i.e. the end 41 comprises a V-shaped recess. The V-shape of the end 41 may be obtained by a cut-out in the rectangular flat tube 22 'shown in FIG. in Figure 4A.

  In another embodiment, shown in Figure 4C, the second end 41 has a V-shaped whose tip is facing outwardly of the tube.

  The shape of the end 41 of the tube 22 is defined to satisfy the constraints related to the cutting of the tube, to the assembly, to the seal between the auxiliary partition 215 and the main wall of the tube 220, at the head loss. the fluid flowing in the connection piece 21, the pressure losses of the fluid at the inlet of the tube, and the equalization of the length of the current lines. along their total path between the entrance of the channel C1 and the exit of the channel C2.

  According to another aspect of the invention, the connection between two adjacent circuit elements according to the invention for use in an exchanger is made at the connection piece 21. For this, each opening 2120 of the connection piece 21 is surrounded by an outer collar 210, shown in Figure 3, of a shape adapted to the corresponding opening 2120. Each collar 210 defines the opening 2120 with which it is associated.

  The connecting piece 21 thus comprises as many collars as openings 2120 and therefore at least one collar on each of its main faces 214 and in particular two collars on each of its main faces 214.

  Figure 8 is a schematic top view showing the connection between two adjacent circuit elements 2 and 2 'according to the invention. The connections between the two adjacent circuit elements 2 and 2 'are made thanks to the collars 210.

  Indeed, a collar 210A 'of a circuit element is shaped so that it can be inserted into the neck opposite 210D of an adjacent circuit element 2, while remaining held in it after insertion.

  In particular, the outer section of one of the collars, for example the collar 210A ', of a circuit element 2' is writable in the internal section of the collar 210D facing an adjacent circuit element 2. Thus, the collar 210A 'can be inserted into the neck 210D while remaining in the collar 210D, after insertion.

  The connection between the circuit element 2 and the adjacent circuit element 2 'can therefore be achieved by inserting the collars having a smaller outer section 210C, 210A', called inner collars, in the opposite collars having an internal section. larger respectively 210D ', 210D, said outer collets.

  Each connection piece 21 of a circuit element may comprise both outer collars and inner collets.

  In particular, the collar, for example the collar 210A, which is on a main face F1 of the connecting piece 21 of a circuit element, is an inner collar while the neck opposite 210D which is on the other main face F2 of the connecting piece 21 of the same circuit element is an outer collar.

  In addition, the collar, for example the collar 210A, which is on a main face Fi of the connecting piece 21, is identical to the "crossed" collar 210C, which is on the other main face F2 of the piece of connection 21, opposite the collar 210A.

  In addition, the collar, for example the collar 210A, which is on a main face F1 of the connection piece 21, is an inner collar while the collar 210B, which is on the same main face F1 of the piece of connection 21 is an outer collar.

  In this case, the connecting piece may have symmetry with respect to an axis which extends along the auxiliary partition 215.

  FIG. 9A is an enlarged view of the portion designated by the reference numeral 400 in FIG. 8. It shows the connection between a collar of the circuit element 2 and the collar opposite the adjacent circuit element 2 ', and more specifically, the insertion of the inner collar 210A 'of the adjacent circuit element 2' into the outer collar 210D of the circuit element 2.

  According to a particular embodiment of the invention, the section of the wall of the inner collar 210A ', denoted by reference 2100' in FIG. 9A, tapers gradually and slightly as one moves away from the base of the collar. On the other hand, the section of the wall of the outer collar 210D, represented by the reference 2100 in FIG. 9A, is substantially constant. The slight narrowing of the wall of the inner collar 210A 'allows easy introduction into the inner collar while ensuring a good contact at the end of the race.

  Figure 9B is an enlarged view of the free end 402 of the wall 2100 'of the inner collar 210A' shown in Figure 9A. According to a complementary feature of the invention, the free end 402 of the wall of an inner collar 210A 'is curved inwards to further facilitate the introduction of the inner collar into the outer collar 210D opposite.

  Similarly, the free end 402 of the wall of an outer collar 210 D is bent inwards so that the outer edge 2102 of the free end 402 of the outer collar 210D rests against the wall 2100 'of the collar. 210A 'interior, after connection. This bending of the free end of the outer collar ensures a good contact after insertion.

  The connection of the circuit elements according to the invention also makes it possible to eliminate the side plates which are conventionally brazed on the bundle of stacked tubes.

  In a particular embodiment, the connecting piece 21 consists of a strip of sheet metal pressed and folded to form two branches 214, shown in FIG.

  FIG. 3 shows a perspective view of the various components of a circuit element 2 of a heat exchanger according to the invention, at a particular stage of their manufacture. The connecting piece 21 may be made by stamping and folding a metal strip, preferably aluminum, to form two branches 214.

  The stamping can make it possible to perform beforehand the openings 210 of the connection area and the collars 2120. The sheet metal strip is then folded so as to bring the two branches 214, which constitute the respective main faces of the connection piece.

  The connecting piece 21 and the return plug 20 are then assembled, for example by fitting or crimping on the tube 22 before soldering.

  When such circuit elements are used in an exchanger according to the present invention, in particular the exchanger shown in FIG. 1, the connection part 21 allows the arrival of the first fluid in each circuit element and the output of the first fluid of each circuit element.

  With reference to FIG. 1, the first fluid arrives in the circuit element 2.1 of the exchanger 1 via an inlet pipe, as represented by the arrow 50, and leaves the heat exchanger via an outlet pipe connected to the circuit element 2.1, as represented by the arrow 52.

  The last circuit element 2.n of the stack is connected on one side to the adjacent circuit element 2 (n-i) and is free on the other side. The main face of the connecting piece 21 which is located on the free side of the circuit element 2.n has no opening while the other main face has two openings, each being arranged in one of the compartments C11 or C21.

  The other circuit elements each have two pairs of openings. Each pair comprises two openings formed vis-a-vis in the main faces of the connection piece, at one of the compartments C11 or C21.

  In the example shown in perspective in FIG. 1, the first fluid arrives in the exchanger via the inlet compartment C11 of the circuit element 2.1, as shown by the arrow 50. The successive arrival compartments C11 of the connecting pieces 21 of the circuit elements 2.1 to 2.n form a fluid inlet passage. The first fluid that arrives in the exchanger flows along this arrival passage to flow into each circuit element 2.1 to 2.n.

  The first fluid arrives in a circuit element 2.i by its arrival compartment C11. It flows into the arrival channel Cl of the tube 22. It then flows along the channel Cl, from top to bottom, until it reaches the return plug 20 in which it undergoes a reversal towards the channel C2, shown schematically by the arrow 54. It then flows in the return channel C2, from bottom to top, until it arrives in the outlet compartment C21 of the connection piece 21.

  The first fluid thus carries out a U-shaped circulation in parallel in all the tubes 22.

  The successive output compartments C21 of the connecting pieces 21 of the circuit elements 2.1 to 2.n form a fluid outlet passage. The first fluid that opens out of the outlet compartment C21 of each circuit element flows in this outlet passage towards the outlet of the exchanger.

  When the first fluid circulating in the outlet compartment C21 reaches the level of the first circuit element 2.1, it emerges from the exchanger, as represented by the arrow 52.

  In addition, corrugated inserts 6 may be arranged between the circuit elements 2.1 to 2.n of the exchanger 1 as shown schematically in FIG. 1 to improve the exchange with the second fluid.

  It is possible to use a production station to produce the tubes, a press to produce the connection piece and the return plug and an automatic machine to fix the connection piece and the return plug on the tubes and thus to make a circuit element according to the invention. The assembly of the exchanger can be performed by superimposing the circuit elements thus produced with possibly interposed corrugated spacers 6. The assembly can then be assembled by brazing.

  It is possible to obtain several connection pieces 21 (respectively several return plugs 20) in one strike. In this case, it may be advantageous to keep between these parts a connecting tab 2041 shown in Figure 3B, respectively a connecting tab 2101 shown in Figure 3C, to secure them together. The parts 20 and 21 thus obtained allow the manufacture of several exchangers mechanically secured to each other. The separation of these exchangers takes place at the end of manufacture, by cutting tabs 2041 and 2101. The reduction in the number of parts handled during manufacture reduces the manufacturing cost of these exchangers.

  The exchanger according to the invention makes it possible to replace certain machined components of the prior art, such as the collector, with a less expensive modular structure. It also makes it possible to simplify assembly and manufacture of the exchanger.

  Obviously, the invention is not limited to the exchanger described above. It is possible in particular to use flat tubes of different lengths and thus produce non-rectangular exchangers whose shape can be adapted to the size of the vehicle. In addition, the number of circuit elements can be chosen according to the desired exchange performance.

Claims (26)

claims   1. Hydraulic circuit element (2), for heat exchange between a first fluid and a second fluid, defines a path for the first fluid, the circuit element comprising at least one tube (22) having an inlet channel and a return channel separated by a main partition (220), a first nozzle (20) fixed on one open end (40) of the tube, and a second nozzle (21) fixed on a second end ( 41) open of the tube (22), characterized by first end insertion and a reversal zone, delimited by a closed bottom, in which the fluid which opens out from the inlet channel of the tube undergoes a return to the return channel of the tube , and in that the second endpiece comprises an insertion zone in which the second end is housed in a sealed manner and a connection zone suitable for transmitting the first fluid which enters the circuit element to the arrival channel and to forward the first fluid returning from the return channel to the outside of the circuit element.   2. Circuit element according to claim 1, characterized in that the first end of the tube has a V shape whose tip is facing outwards.   3. Circuit element according to one of claims 1 and 2, characterized in that the connection zone comprises an auxiliary partition (215) delimiting an inlet compartment (C11) and an outlet compartment (C21), the compartment inlet (C11) being sealingly connected to the inlet channel (C1) and the outlet compartment (C21) being sealingly connected to the outlet channel (C2).   4. Circuit element according to claim 3, characterized in that the thickness of the auxiliary partition (215) is greater than the thickness of the main partition (220).   in that the first nozzle comprises a zone in which the 5. Circuit element according to one of claims 3 and 4, characterized in that the auxiliary partition (215) is shaped so that the main partition comes into abutment against the auxiliary partition (215) after fixing the second endpiece (21). on the second end (41).   6. Circuit element according to one of claims 1 to 5, characterized in that the second end (41) of the tube (22) has a V shape whose tip is facing inwards.   7. Circuit element according to one of claims 1 to 5, characterized in that the second end (41) of the tube (22) has a V-shaped whose tip is facing outwards.   8. Circuit element according to one of claims 1 to 7, characterized in that each compartment of the second nozzle comprises at least one opening.   9. A circuit element according to claim 8, characterized in that each compartment of the second endpiece comprises a pair of openings (2120) formed vis-a-vis in the main faces (214) of the second endpiece (21).   10. Circuit element according to one of claims 8 and 9, characterized in that each opening of the second nozzle is surrounded by a collar (210) of shape adapted to the corresponding opening.   11. Circuit element according to claim 10, characterized in that the outer section of one of the collars (210D) of the second end, located on a main face (F1) of the second endpiece (21), is writable in the section internal collar (210A) vis-à-vis, located on the other main face (F2) of the second tip.   12. Circuit element according to one of claims 10 and 11, characterized in that the collar (210D), located a main face (F1) of the second endpiece, is substantially identical to the crossed collar (210B), located on the other main face (F2).   13. Circuit element according to one of claims 10 to 12, characterized in that the outer section of a collar (210D), located on a main face (F1) of the second endpiece (21), is writable in the section internal collar (210C), located on the same main face (F1) of the second tip.   14. Circuit element according to claim 13, characterized in that the connecting piece has a symmetry along an axis which extends along the auxiliary partition (215).   15. Circuit element according to one of the preceding claims, characterized in that said tube (22) is generally flat.   16. A circuit element according to one of the preceding claims, characterized in that the lateral edges of the first endpiece (20) each comprise an inner abutment (202) arranged so that the first end of the tube comes simultaneously in abutment against these two stops, after introduction into the first endpiece (20).   17. Circuit element according to claim 16, characterized in that the inner stops (202) of the first nozzle (20) are arranged near the inlet opening (205) of the first nozzle (20). 18. Circuit element according to one of the preceding claims, characterized in that each main face of the first endpiece (20) has a generally rectangular shape.   19. Circuit element according to one of claims 1 to 17, characterized in that each main face of the first nozzle (21) has a generally half-disk shape.   20. A circuit element according to one of the preceding claims, characterized in that the first endpiece comprises inner walls (201) in the form of an arc of a circle arranged in said interior space and extending between the two main faces (204). ), these internal partitions delimiting runways.   21. Heat exchanger, in particular for a motor vehicle, comprising a stack of circuit elements (2) according to one of the preceding claims communicating with each other via their respective second ends (21).   22. Heat exchanger according to claim 21, characterized in that the circuit elements (20) are connected by nesting the flanges opposite their respective second end pieces (24), an inner collar of a penetrating circuit element. in the outer collar of an adjacent circuit element.   23. Heat exchanger according to claim 22, characterized in that the section of the wall of the inner collar (210A ') narrows gradually from the base of the collar and in that the section of the wall of the outer collar. (210D) is substantially constant.   24. Heat exchanger according to one of claims 22 and 23, characterized in that the free end (402) of the wall (2100 ') of the inner collar (210D) is curved towards the inside of the collar.   25. Heat exchanger according to one of claims 22 to 24, characterized in that the free end (402) of the wall (2100) of the outer collar (210D) is curved towards the inside of the collar.   26. Heat exchanger according to one of claims 21 to 25, characterized in that the thickness of the first nozzle is less than or equal to the pitch between the respective tubes of two adjacent circuit elements.