Cylinder for storing coolant, and heat exchanger including such a cylinder

Abstract

The invention relates to a cylinder for storing coolant, with which a heat exchanger of an air-conditioning circuit is to be provided, said cylinder defining a first cavity (2) accommodating a desiccator, and a second cavity (3) capable of enabling fluid communication with said circuit. Said cylinder is configured such that said first (2) and second (3) cavities remain isolated from each other up to a first inner pressure threshold, and are placed in fluid communication once said second cavity (3) is subjected to a second inner pressure threshold that is greater than the first threshold. The invention also relates to a condenser provided with such a cylinder.

Claims

1. A cylinder that is a reservoir for a refrigerant for a heat exchanger of an air conditioning circuit, said cylinder comprising: a first tubular body defining a first housing accommodating a desiccant, a second tubular body defining a second housing able to allow fluid communication with said circuit, first and second lateral walls separating said first and second housings from an outside of the first and second housings, and a dividing wall isolating said first and second housings from one another, wherein said dividing wall yields under pressure and wherein said dividing wall is formed as an integral part from a same material as the first and/or the second lateral walls; at least one inlet and at least one outlet defined in said second tubular body and disposed on the same side of said dividing wall; said cylinder being configured so that said first and second housings remain isolated from one another until a first internal pressure threshold is reached, wherein said first and second housings are placed in fluidic communication once said second housing is subjected to a second internal pressure threshold higher than the first internal pressure threshold, and wherein said first and second tubular bodies each have a substantially circular cross section and each have substantially the same diameter.

2. The cylinder as claimed in claim 1, wherein said first tubular body has an open end closed by said second tubular body so that said second tubular body defines said dividing wall.

3. The cylinder as claimed in claim 2, in which the second tubular body is open at one of its ends.

4. The cylinder as claimed in claim 2, comprising a plug for closing the second tubular body, wherein said plug is brazed to said second tubular body.

5. The cylinder as claimed in claim 2, in which the second tubular body has a first thickness at the dividing wall and a higher thickness at the second lateral wall of the cylinder.

6. The cylinder as claimed in claim 2, in which said first tubular body and/or said second tubular body are formed by impact extrusion.

7. The cylinder as claimed in claim 2, comprising a bead of welding between said first tubular body and said second tubular body.

8. The cylinder as claimed in claim 1, in which said dividing wall has a thickness between 0.07 and 0.7 mm.

9. A heat exchanger comprising the cylinder as claimed in claim 1.

10. The heat exchanger as claimed in claim 9, wherein said dividing wall is burst.

11. The cylinder as claimed in claim 1, in which said dividing wall has a thickness between 0.2 and 0.5 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an exploded perspective view of an example of a cylinder according to the invention.

(2) FIG. 2 is a perspective view, on a diametral plane of section, of the cylinder of FIG. 1, illustrated assembled.

(3) FIG. 3 is a view illustrating the dividing wall of the cylinder of the preceding figures, once it has burst.

(4) FIG. 4 is a schematic view illustrating face-on one example of a condenser according to the invention.

DETAILED DESCRIPTION

(5) As illustrated in FIGS. 1 and 2, the invention relates to a cylinder 1 acting as a reservoir of refrigerant, which cylinder is intended to be fitted to a heat exchanger of an air conditioning circuit, notably a condenser.

(6) Said cylinder 1 defines a first housing 2 accommodating a desiccant, not depicted, and a second housing 3 able to allow fluid communication with said air conditioning circuit, notably via two, inlet/outlet, orifices 4, 5. Said housings 2, 3 are in the prolongation of one another along the longitudinal axis of the cylinder.

(7) According to the invention, said cylinder 1 is configured so that said first 2 and second 3 housings remain isolated from one another until a first internal pressure threshold is reached and are placed in fluidic communication once said second housing 3 is subjected to a second internal pressure threshold, higher than the first threshold.

(8) Said first internal pressure threshold corresponds, for example, to a pressure higher than the differential pressure likely to be encountered between said first housing 2, designed to be subject to phenomena of diffusion of the desiccant under the effect of the heat given off by a brazing operation in which the cylinder is involved, and said second housing 3, designed to be subjected to the brazing atmosphere.

(9) Said second internal pressure threshold corresponds, for example, to a pressure-test pressure such as the pressure used for the helium leak tests carried out on condensers.

(10) During brazing, the desiccant therefore remains confined in the first housing 2. After the pressure test, it is, by contrast, in the fluid circuit, the latter being able to pass from said second housing 3 to said first housing 2.

(11) Said cylinder 1 notably comprises walls 6, 7, referred to as lateral walls, separating said first 1 and second 2 housings from the outside, and a dividing wall 8, isolating said first 1 and said second 2 housing from one another. Said dividing wall 8 is designed to yield under pressure, as will be expanded upon in conjunction with FIG. 3.

(12) Said dividing wall is, for example, formed as an integral part from the same material as one 6 and/or the other 7 of said lateral walls. This then yields a cylinder that is particularly simple, with no added-on component for defining the solution that allows the desiccant to be kept isolated during brazing.

(13) Said dividing wall 8 has, for example, a thickness comprised between 0.07 and 0.7 mm, notably between 0.2 and 0.5 mm.

(14) On that subject, said cylinder may be made of metal, for example of aluminum or aluminum alloys.

(15) Said cylinder 1 notably comprises a first tubular body 9 defining said first housing 2 and a second body 10 defining said second housing 3. Said first tubular body 9 has an open end 11 closed by said second body 10 so that said second body 10 defines said dividing wall 8.

(16) The second body 10 may likewise be tubular in shape, open at one 12 of its ends. The cylinder 1 may incidentally comprise a plug 13 that closes the second body 10, and is brazed to said second body 10 at said open end 12 thereof.

(17) Said second body 10 has said inlet/outlet orifices 4, 5 for the fluid. In this instance they are situated on the lateral wall 7 thereof. A filter, not depicted, may be placed inside said second body 10, between said orifices 4, 5.

(18) The second body 10 may have at least two different thicknesses; a first thickness like the one mentioned above at the dividing wall 8, and a greater thickness at its lateral wall 7. This may be a thickness of 1 to 2 mm, notably 1.5 mm, the thickness of the dividing wall 8 then, for example, being 0.4 mm.

(19) The first 9 and second 10 bodies are of substantially circular cross section here and have substantially the same diameter. They are formed, for example, by impact extrusion. They may be connected by a bead of welding 14, obtained using TIG, MIG, laser or some other welding method.

(20) As illustrated in FIG. 3, said dividing wall 8, having been subjected to a pressure that exceeds the second pressure threshold, has burst. This figure shows how material has been torn away creating a passage orifice 15 in said dividing wall 8, allowing the first housing 2 and the second housing 3 to communicate. It will thus be appreciated that before said second pressure threshold is applied, the first housing 2 is isolated and protected from diffusion originating from the desiccant whereas, after said second pressure threshold or a higher pressure has been applied, said first housing 2 is connected to the second housing 3 by the creation of said passage orifice 15 between said housings 2, 3.

(21) As illustrated in FIG. 4, the invention also relates to a heat exchanger, notably a condenser, equipped with a cylinder 1 as described hereinabove.

(22) It comprises a core bundle 30 of tubes 20 for the circulation of the fluid and of inserted spaces 21 situated between the tubes 20. It further comprises headers 22 into which the tubes 20 open via their ends 20a. The headers 20 here are fitted with inlet/outlet flanges 23, 24.

(23) The cylinder 1 is situated parallel to one of the headers 22. The condenser allows fluid to circulate between the cylinder 1 and the adjacent header 22, for example via inlet/outlet orifices 4, 5 of said cylinder 1 such that the condenser here offers a supercooling pass.

(24) In the preassembled condenser prior to brazing, the dividing wall 8 of the cylinder 1 is fluidtight. It is configured to remain fluidtight during brazing. It is also configured to be burst after brazing, for example under the effect of a pressure test at the pressure of said condenser. It thereby allows the first and second housings 2, 3 of said cylinder 1 to be placed in communication.