FR2764680A1 - Condenser for vehicle air conditioning system. - Google Patents

Abstract

The condenser consists of horizontal tubes (3) which link compartments in two collecting boxes (2,4), a reservoir (15) and a treatment block (20) mounted above the reservoir. Fluid enters (1) a first collecting box (2) and passes to the second collecting box (4) through the tubes (3) (F1,F2,F3). The fluid then enters the reservoir (15) and is ducted (F4) from it's bottom into a treatment block (20) which is screwed into the top of the reservoir and has male and female duct joints. From the treatment block the fluid enters (19) an upper compartment of the second collecting box (4) before passing through undercooling stages (F6,F7). The fluid finally leaves the condenser through an exit pipe (5).

Description

Condenser with external processing block, in particular for a motor vehicle air conditioning circuit
The invention relates to the field of air conditioning installations, for example of a motor vehicle.

The condensers which are used in the refrigeration circuits of some of these installations usually comprise a bundle of tubes mounted between first and second manifolds communicating respectively with the circuit by an inlet manifold and an outlet manifold.

The invention relates more particularly to condensers in which the manifolds are substantially vertical, and which comprise a reservoir (or bottle) substantially parallel to the boxes and housing means for treating the fluid which circulates in the air conditioning circuit. The term “processing means” means, for example, filtration and / or drying means. The reservoir can be integrated into the second manifold, or else be joined thereto by assembly.

This integration of the processing function in the tank imposes on certain condensers a particular internal architecture, where the second manifold comprises lower and upper parts which communicate respectively by lower and upper openings with lower and upper parts of the tank, the part upper part of the second box being subdivided into a lower chamber comprising the upper opening and an upper chamber communicating with the outlet pipe.

Furthermore, when the condenser comprises a part called "sub-cooling'1, this must be placed downstream of the treatment means, so that the latter must be installed in the lower part of the tank. However, to increase the lifetime of the condenser, it is imperative that the processing means can be replaced regularly, such a replacement operation can be complex due to the architecture of the condenser.

In addition, in certain applications it is imperative that the replacement operation is carried out from the top of the tank, thanks to an upper opening. It follows that the processing means, which are usually contained in a processing block (or cartridge), must be located at a significant distance from the upper opening allowing their introduction. This therefore requires large processing blocks which reduce the efficiency of the condenser due to the reduction in the effective volume of the tank, and require that the upper opening and its seals have large dimensions.

An object of the invention is therefore to provide a condenser which does not have all or part of the aforementioned drawbacks.

To this end, the invention provides a condenser of the type defined in the introduction, in which the reservoir comprises a first orifice and a second orifice placed in its upper part, and which comprises a fluid treatment block, secured to the reservoir by means of immobilization and provided with third and fourth orifices arranged respectively to cooperate in sealing with the first and second orifices of the reservoir so that the fluid can flow from the reservoir to the block via the first and third orifices, then from the block to the upper part of the reservoir via the fourth and second orifices, before being discharged into said lower chamber of the upper part of the second manifold via its upper opening.

In this way, to replace the processing means, there is only to separate the block from the tank, which very significantly simplifies maintenance operations. In addition, the reservoir fully assumes its function because the treatment means are no longer integrated therein.

In a preferred architecture, the tank accommodates, on the one hand, a substantially horizontal partition which subdivides it into a lower chamber and an upper chamber comprising the first and second orifices, and on the other hand, a through-sealing supply conduit the horizontal partition and provided with first and second ends opening respectively at the first orifice and in the lower chamber of the tank.

Thus, the fluid which reaches the reservoir is forced to circulate in the supply duct, then in the treatment block, before being reintroduced into the sub-cooling part of the condenser (which is placed downstream of the chamber lower part of the upper part of the second manifold). The treatment of the fluid is very significantly improved.

In this embodiment, it is particularly advantageous that the first and second orifices are made in a horizontal end face of the wall delimiting the upper chamber of the tank. This makes it possible to house the treatment block above the tank. It is clear that the size of the tank can be adapted, so that the total height of the tank block assembly is substantially equal to the height of the manifolds. This allows for compact, easily implantable condensers.

Preferably, the second end of the supply conduit opens near the lower opening of the second box, so that only the fluid in the liquid phase is treated by the treatment block.

The block may be secured to the reservoir, either by an adjustable collar, or by a screw intended to pass through the block in leaktightness to cooperate with a threaded hole formed in the reservoir.

According to another characteristic of the invention, the first, second, third and fourth orifices are shaped into male or female elements, so that the first and third orifices on the one hand, and second and fourth orifices on the other hand, cooperate two by two by male-female interlocking. Preferably, each orifice shaped as a male element externally comprises at least one seal.

This results in a very significant improvement in the tightness of the reservoir, due to the reduced dimensions of the seals at the orifices allowing the passage of the fluid.

According to yet another characteristic of the invention, the treatment block comprises a cavity supplied with fluid by the third orifice and subdivided into at least one treatment chamber and one evacuation chamber.

Advantageously, this cavity houses an evacuation channel provided with ends opening respectively into the evacuation chamber and at the level of the fourth orifice, so that the treated fluid is injected directly from the evacuation chamber into the upper chamber of the reservoir. which communicates through the second opening with the lower chamber of the upper part of the second manifold.

The cavity can accommodate desiccation means and / or filtration means, such as for example one or more impurity filter (s).

In the description which follows, given by way of example, reference is made to the appended drawings, in which - FIGS. 1A and 1B illustrate respectively in front and top views a condenser according to the invention; - Figure 2 illustrates, in a cross-sectional view along the axis II-II of Figure 1B, the second manifold assembled with a tank-processing block couple in a first embodiment; - Figure 3 illustrates, in a cross-sectional view along the axis III-III of Figure 2, the tank-processing block couple of the first embodiment; - Figure 4 details the processing block of Figure 3; - Figure 5 illustrates, in a cross-sectional view along the axis II-II of Figure 1B, the second manifold assembled with a tank-processing block couple in a second embodiment; - Figure 6 illustrates, in a cross-sectional view along the axis VI-VI of Figure 5, the tank-processing block couple of the second embodiment; - Figure 7 details the processing block of Figure 6; and - Figures 8 and 9 are variants of the processing block of Figure 7.

First of all, reference is made to FIG. 1 to describe a preferred embodiment of a condenser according to the invention, intended to operate in an air conditioning installation, for example of a motor vehicle.

Such a condenser is integrated in an air conditioning circuit which supplies it with refrigerant brought to a given temperature T, and to which it delivers the cooled and condensed fluid at a temperature Ts called sub-cooling temperature.

To do this, the condenser comprises an inlet pipe 1, connected to an upstream part of the air conditioning circuit (not shown in the figures), which opens into a first manifold 2 communicating via a beam of tube 3 with a second manifold 4 into which there opens an outlet pipe 5 connected to an upstream part of the air conditioning circuit.

The first 2 and second 4 manifolds are parallel to each other and intended to be installed in the engine compartment of the vehicle in a substantially vertical direction.

The first manifold 2 is subdivided by means of two intermediate horizontal partitions 6 into first 7, second 8 and third 9 chambers. The inlet tube 1 opens into the second chamber 8. The three chambers 7 to 9 of the first manifold 2 define three parts called respectively upper, intermediate and lower.

The second manifold 4 is subdivided by means of three horizontal partitions 10 into first 11, second 12, third 13 and fourth 14 chambers. The outlet pipe 5 opens into the fourth chamber 14.

The second 12 and first 11 chambers of the second manifold 4 respectively delimit intermediate and lower parts 11. The third 13 and fourth 14 chambers of this same second manifold 4 together delimit an upper part subdivided into two subparties called respectively lower (third room 13) and superior (fourth room 14).

The intermediate and lower parts of the condenser comprising the second 8 and third 9 chambers of the first manifold 2, the first 11 and second 12 chambers of the second manifold 4, as well as the tubes which connect the aforementioned chambers, form the cooling and condensing part of the condenser. The first chamber 7 of the first manifold 2 and the third 13 and fourth 14 chambers of the second manifold 4, as well as the tubes which connect the aforementioned chambers constitute the sub-cooling part of the condenser. In other words, in the cooling and condensing part, the fluid which arrives via the inlet pipe 1 at a temperature T sees its temperature lowered at a condensing temperature Tc (arrows
F0 to F3), while in the sub-cooling part, the fluid arriving at the temperature Tc sees its temperature lowered by at least 10 to a temperature Ts (arrows F6 to F7), before being reinjected into the downstream part of the air conditioning system via outlet pipe 5 (arrow F8).

Due to its condensation in the condenser, the refrigerant arrives in the first chamber 11 of the lower part of the second manifold 4 in the form of a mixture of gaseous and liquid phases which it is necessary to separate so that only the liquid fluid is reinjected into the downstream part of the air conditioning circuit. To do this, the condenser comprises a reservoir (or bottle) 15 which communicates by lower parts 16 and upper 17 respectively with the first 11 and third 13 chambers of the second manifold by first (or lower) 18 and second (or upper) 19 openings, respectively.

The condenser according to the invention also comprises a treatment block 20, to which we will return in more detail later, intended to treat by desiccation and / or filtration the fluid in liquid form which is collected in the reservoir 15. In the example illustrated , the processing block 20 is placed above the tank 15, their cumulative height being substantially equal to that of the second manifold 4, so that the condenser is as compact as possible (of course, other configurations are possible in the scope of the invention).

As is better illustrated, in particular in FIGS. 2 to 4, the reservoir 15 comprises in its upper part 17 first 21 and second 22 orifices which cooperate respectively with third 23 and fourth 24 orifices formed in the lower part of the treatment block 20.

In the example illustrated in FIGS. 2 to 4, the orifices of the reservoir 15 and of the treatment block 20 cooperate between them by a male-female type interlocking. To do this, the first orifice 21, here of the male type, is fitted inside the third orifice 23, here of the female type, while the fourth orifice 24, here of the male type, is fitted into the second orifice 22, here female type.

The joining of the processing block 20 and the reservoir 15 is ensured in this first embodiment by immobilization means comprising a screw 25 provided with an external thread 26 and passing through the processing block 20 projecting at the bottom between the third 23 and fourth 24 orifices, and a hole 27 provided with an internal thread 28 homologous to the external thread 26 of the screw 25, formed in an upper end horizontal wall 29 obstructing the upper end of the reservoir 15. Thus, once the four holes fitted two by two, all that remains is to screw the threaded end of the screw 25 into the threaded hole 27, until the block 20 and the reservoir 15 are tightly joined, leaktight.

In the reservoir 15, the fluid which is in the gas phase is placed above the fluid which is in the liquid phase. It is therefore advantageous to only take from the reservoir the fluid which is in its lower part 16. To do this, a supply conduit 30 is provided, a first lower end 31 of which opens into the lower part 16 of the reservoir, preferably near the first opening 18 of the second manifold 4, and a second upper end 32 which opens at the first orifice 21. Here, the first orifice 21 and the second upper end 32 form the same shaped element.

Preferably (see FIG. 6), the treatment block is produced in the form of a rigid cartridge delimited by an aluminum wall, for example, and containing on the one hand a desiccant 61 (approximately 50 g) and a filter of impurities 63 (intended to intercept impurities larger than about 50 Hm) enclosed between two grids 62.

To prevent the fluid treated by the treatment block 20 from falling, at least in part, into the lower part 16 of the reservoir 15, said reservoir comprises in its upper part 17 a horizontal partition 33 which subdivides it into two upper chambers 40 and lower 60, the upper chamber 40 communicating with the third chamber 13 of the second manifold 4 via the second opening 19.

Advantageously, to constrain all of the liquid fluid to be treated inside the treatment block 20, the latter comprises a cavity 34 subdivided into at least one treatment chamber 35 and a discharge chamber 36, placed above the treatment chamber 35, as well as an evacuation channel 37, a first upper end of which opens into the evacuation chamber 36, while a second lower end opens at the fourth orifice 24. Here, the fourth orifice 24 and the lower end of the discharge channel 37 are combined to form the same shaped element.

In this way, the fluid which reaches the lower part 16 of the reservoir 15 through the first opening 18 of the first chamber 11 of the second manifold 4 penetrates along arrow F4 inside the supply conduit 30, reaches the level of the third orifice 23 of the treatment block 20, passes through the treatment chamber 35, opens into the evacuation chamber 36, then enters the evacuation channel 37 which routes it into the chamber 40 (arrow F5). When it reaches chamber 40, it borrows the second opening 19, opens into the third chamber 13 of the second manifold 4, then following the arrows F6 and F7 (see FIG. 1A) cools down in the upper part of the front condenser to be evacuated from the fourth chamber 14 of the second manifold 4 by the outlet pipe 5 (arrow F8).

Reference is now made to FIGS. 5 to 7 to describe a second embodiment of the tank-processing block pair, according to the invention.

The main difference between this second embodiment and the first embodiment (described with reference to FIGS. 2 to 4) relates to the means for immobilizing the treatment block 20 on the reservoir 15. Instead of a screwing device , an adjustable collar 50 is used which is intended to hold the upper faces 29 of the reservoir 15 and lower 51 of the treatment block 20 tightly against one another, which have peripheral edges suitable for this purpose.

All the other elements are substantially identical and bear identical reference numbers. In addition, but this can also be envisaged in the first embodiment of the tank-processing block couple, O-rings 52 around the shaped parts delimiting the orifices in the form of male elements (here the first orifice 21 of the reservoir 15 and the fourth orifice 24 of the treatment block 20, which are fitted respectively in the orifices in the form of female elements 23 and 22.

As illustrated in FIGS. 8 and 9, the orifices of the reservoir and of the treatment block intended to be nested one inside the other can be produced differently from what has been described previously. In fact, all combinations of male and / or female elements can be considered. Thus, in FIG. 8, the processing block 20 comprises third 23 and fourth 24 orifices in the form of male elements intended to cooperate with a reservoir provided with first (21) and second (22) orifices in the form of female elements. Conversely, in FIG. 9 is illustrated a processing block 20 provided with third 23 and fourth 24 orifices in the form of female elements intended to cooperate with first (21) and second (22) orifices of the reservoir 15.

Of course, these variants also apply to the first embodiment of the tank-processing block pair.

The invention is not limited to the embodiments described above, only by way of example, but it extends to other variants which a person skilled in the art may develop within the scope of the claims below.

Thus, in the foregoing, a preferred embodiment has been described in which the treatment block was placed above the tank, the cumulative height of this block and of the tank being substantially equal to the height of the manifolds, so as to form a compact condenser. However, it is possible to envisage a vertical extension tank substantially equal to that of the manifolds, for example.

Furthermore, the treatment unit can be located at a location other than the top of the tank. Indeed, it could be secured to the tank on a lateral face of it, at its upper part.

Finally, in simplified variants of the treatment block, it can be envisaged that the cavity is entirely filled with treatment means, and that consequently there is no evacuation chamber or evacuation conduit.

Claims (12)

Claims 1. Condenser for a refrigeration circuit traversed by a refrigerant, of the type comprising a bundle of tubes (3) mounted between first (2) and second (4) manifolds extending in a substantially vertical direction and communicating respectively with said circuit by an inlet pipe (1) and an outlet pipe (5), the second box (4) comprising lower and upper parts communicating respectively by lower (18) and upper (19) openings with lower parts (16) and upper (17) of a tank (15) substantially parallel to the boxes, said upper part of the second box being subdivided into a lower chamber (13) comprising the upper opening (19) and an upper chamber (14 ) which communicates with said outlet pipe (5),  characterized in that the reservoir (15) comprises a first orifice (21) and a second orifice (22) placed in its upper part (17), and in that it comprises a fluid treatment block (20) suitable for be secured to the tank by immobilization means (50; 25,27) and provided with third (23) and fourth (24) orifices arranged respectively to cooperate with the first (21) and second (22) tank openings (15) so that the fluid can flow from said reservoir to said block via the first (21) and third (23) orifices, then from the block to the upper part (17) of the reservoir (15) via the fourth (24) and second (22) orifices, before being discharged into said lower chamber (13) from the upper part of the second manifold (4) via its upper opening (19). 2. Condenser according to claim 1, characterized in that the reservoir (15) houses, on the one hand, a substantially horizontal partition (33) which subdivides it into a lower chamber (60) and an upper chamber (40) comprising the first (21) and second (22) orifices, and on the other hand, a supply duct (30) sealingly passing through said horizontal partition (33) and provided with first (31) and second (32) ends opening respectively at level of the first orifice (21) and in the lower chamber (60) of said reservoir (15). 3. Condenser according to claim 2, characterized in that the first (21) and second (22) orifices are produced in a horizontal end face (29) of the wall defining the upper chamber (40) of the reservoir (15) , so that the block (20) is housed above said tank. 4. Condenser according to one of claims 2 and 3, characterized in that the second end (32) of the supply duct (30) opens near the lower opening (18) of the second box (4). 5. Condenser according to one of claims 1 to 4, characterized in that the immobilization means comprise an adjustable collar (50) suitable for securing the region of the block (20) which comprises said third (23) and fourth (24 ) ports in the region of the reservoir (15) which includes said first (21) and second (22) ports. 6. Condenser according to one of claims 1 to 4, characterized in that the immobilization means comprise a screw (25) provided with an external thread (26) and intended to pass through said block (20) sealingly protruding therefrom in the region comprising said third (23) and fourth (24) ports, and a hole (27) formed in the region of the reservoir (15) which includes said first (21) and second (22) ports and provided with an internal thread (28) homologous to the external thread (26) to allow the block and the tank to be secured. 7. Condenser according to one of claims 1 to 6, characterized in that the first (21), second (22), third (23) and fourth (24) orifices are shaped as male or female elements, so that said first and third orifices on the one hand, and second and fourth orifices on the other hand, cooperate two by two by male-female interlocking. 8. Condenser according to claim 7, characterized in that each orifice shaped as a male element externally comprises at least one seal (52). 9. Condenser according to one of claims 1 to 8, characterized in that the block (20) comprises a cavity (34) supplied with fluid by the third orifice (23) and subdivided into at least one treatment chamber (35) and an evacuation chamber (36). 10. Condenser according to claim 9, characterized in that the cavity (34) houses an evacuation channel (37) provided with ends opening respectively into the evacuation chamber (36) and at the level of the fourth orifice (24) . 11. Condenser according to one of claims 9 and 10, characterized in that the cavity (34) houses desiccation means (61). 12. Condenser according to one of claims 9 to 11, characterized in that the cavity (34) houses filtration means (63).