FR3049047B1 - GAS COOLER FOR MOTOR VEHICLE. - Google Patents

Abstract

The present invention relates to a gas cooler (1) comprising: ○ a plurality of flat tubes (2) stacked and arranged parallel to one another, and in which a refrigerant fluid is able to circulate, said coolant being R744, ○ spacers (3) arranged between said flat tubes (2), said spacers (3) being adapted to be traversed by a second fluid, the tube pitch (pt) between two successive flat tubes (2) being between 6.5 and 10 mm, terminals included.

Description

Gas cooler for a motor vehicle. The invention relates to a heat exchanger, in particular for a motor vehicle, and more specifically to a gas cooler in which refrigerant fluid R744 is able to circulate.

Both heat exchangers and gas coolers generally comprise a plurality of flat tubes stacked and arranged parallel to each other, and spacers disposed between said flat tubes.

In operation, a refrigerant fluid in the gaseous state circulates in said flat tubes of the exchanger, and a second fluid, for example air, passes through said dividers arranged between said flat tubes.

The dimensions of the elements constituting a gas cooler, such as for example the pitch of flat tubes, the thickness of the flat tubes and spacers, the period of spacers, or the height of the light within the flat tubes, are generally studied to obtain a optimal efficiency and performance.

However, these gas coolers do not take into account their long-term environmental impact. Indeed, their manufacture and the recycling of materials constituents are energy consumers and therefore produce CO2. The same use in a motor vehicle affects the consumption of sedernier and thus also indirectly generates CO2 from a surplus of consumption.

One of the aims of the present invention is therefore to propose a gas cooler at least partially to the disadvantages of the prior art, in particular reducing its environmental impact.

The present invention therefore relates to a gas cooler comprising: a multiplicity of flat tubes stacked and arranged parallel to each other, and in which a refrigerant fluid is able to circulate, said coolant being R744, spacers disposed between said flat tubes; , said spacers being able to be traversed by a second fluid, the tube pitch between two successive flat tubes being between 6.5 and 10 mm, inclusive.

The gas cooler, due to its tube pitch of between 6.5 and 10 mm, has a low environmental impact.

According to one aspect of the invention, the tube pitch between two successive flat tubes is comprised between 8 and 10 mm inclusive.

According to one aspect of the invention, the tube pitch between two successive flat tubes is comprised between 8 and 9 mm inclusive.

According to another aspect of the invention, the tube pitch between two succesive tubes is 8.60 mm, with a tolerance of plus or minus 0.05 mm.

According to another aspect of the invention, the flat tubes have a width between 10 and 17 mm inclusive.

According to another aspect of the invention, the flat tubes have a thickness of between 1 and 1.25 mm inclusive.

According to another aspect of the invention, the flat tubes have a light of a height between 0.5 and 0.7 mm inclusive.

According to another aspect of the invention, the flat tubes have a flat tube wall thickness of between 0.15 and 0.4 mm inclusive.

According to another aspect of the invention, the spacers have a thickness of between 0.06 and 0.10 mm, inclusive.

According to another aspect of the invention, the spacers have a periodic profile period between 1.90 and 2.4 mm inclusive.

According to another aspect of the invention, the spacers have a height of between 7 and 10 mm inclusive.

According to another aspect of the invention, the gas cooler comprises 2 or 3 passes of refrigerant. Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings in which: FIG. 1 shows a diagrammatic representation with a view to FIG. 2 shows a diagrammatic representation in perspective of a portion of a gas cooler, FIG. 3 shows a diagrammatic representation in longitudinal section of FIG. 2, FIG. 4 shows a schematic representation of a gas cooler. FIG. 5 shows a graph of the evolution of the environmental impact of the gas cooler as a function of the pitch of tubes, FIG. 6 shows a graph of the evolution of the mass of the gas cooler and its efficiency. according to the pitch of tubes.

The identical elements in the different figures bear the same references.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply to only one embodiment. Simple features of different embodiments can also be combined to provide other embodiments.

FIG. 1 shows a schematic representation in profile of a gas cooler 1, especially for use within an air conditioning circuit of a motor vehicle. Said gas cooler 1 comprises a multiplicity of flat tubes 2 stacked and arranged parallel to each other. Inside flat cestubes 2 circulates a refrigerant, more particularly R744, between two collectors 4 placed at the ends of said flat tubes 2. Between the flat tubes 2 aredposés inserts 3. Said inserts 3 have a periodic profile and aretraversés by a second fluid, for example air. The collectors 4 comprise an inlet 4a and / or the outlet 4b of refrigerant and also one or more separators 5 defining circulation zones. In the example shown in FIG. 1, each collector 4 comprises a separator 5 so that the refrigerant fluid passes through the gas cooler to pass from the inlet 4a to the refrigerant outlet 4b. However, it is quite possible to imagine a mode of internationalational action where the refrigerant fluid makes only two passes, a single collector 4comporte then both an inlet 4a and an outlet 4b of refrigerant separated by a separator 5. The tubes plates 2 and the spacers 3 are generally made of metallic materials, for example aluminum.

The chiller 1 is characterized according to various parameters illustrated in FIGS. 2 to 4. The intervals described in the present description are intervals, the terminals of which are included, that is to say that the terminals of said intervals are included in said intervals. In addition, a tolerance quality related to the manufacturing process is to be considered for the various measurements and intervals mentioned in this description.

The gas cooler 1 has a width lt (visible in FIG. 2) of between 10 and 17 mm, in particular of the order of 12 mm. This width is particularly dictated by the requirements of car manufacturers and VDA standards.

As illustrated in Figure 3, said flat tubes 2 have a height ht between 1 and 1.25 mm, preferably 1.1 mm. The flat tubes 2 may furthermore have a light 20 having a height h1 of between 0.5 and 0.7 mm, preferably 0.55 mm, with a tolerance of, for example, plus or minus 0.005 mm, and a wall thickness. flat detube 2 between 0.15 and 0.4 mm. In the example illustrated in FIG. 1, the gas cooler 1 comprises twelve flat tubes. The height ht of the flat tubes 2, the height hl of the light 20 of said flat tubes 2 as well as their number is an optimization between the manufacturing process, a limitation of the pressure drop of the refrigerant fluid inside the tubes at 100 kg / h, as well as the lowest possible pressure drop of the second fluid when it meets the sidewall of said flat tubes 2.

The flat tubes 2 have a tube pitch pt (visible in FIG. 3) of between 8 and 10 mm, more particularly between 8 and 9 mm, in particular of the order of 8.60 mm, with a tolerance for example of more or less 0.05mm.

As illustrated in FIG. 4, the spacers 3 have a thickness ei of between 0.06 and 0.10 mm, preferably 0.07 mm, with a tolerance of, for example, plus or minus 0.005 mm. Said spacers 3 also have a period pi between 1.90 and 2.4 mm, preferably 2.1 mm, with a tolerance of 0.05 mm, for example. Lapiode pi and the thickness ei of the spacers 3 are in particular defined to limit the load losses of the second fluid as it passes through said spacers 3, while enconserving good protection of said spacers against corrosion. The dividers 3 also have a height hi of between 7 and 10 mm.

The gas cooler 1, particularly because of its tube pitch pt between 8 and 10 mm, has a low environmental impact. This environmental impact is illustrated in FIG. 5 which shows a graph of the evolution of the environmental impact of a gas cooler 1 as a function of the tube pitch pt. The environmental impact is expressed in gram of CO2 per 100km and corresponds to the manufacture of said gas cooler 1, in particular the production of an ingot, extrusion, brazing, its influence on the consumption of the motor vehicle during its lifetime and its recycling. Lafigure 5 shows that, for a tube pitch of between 6.5 and 10 mm, the environmental impact is the lowest. The environmental impact is even lower for an even smaller tube pitch PT between 8 and 9 mm with an optimum of 8.60 mm, with a tolerance of, for example, plus or minus 0.05 mm.

A tube pitch of between 8 and 10 mm allows to limit the increase in the mass of the gas cooler 1 while maintaining a good efficiency. This aspect is illustrated in Figure 6 showing the evolution of the efficiency and the mass of a gas cooler 1 according to its tube pitch pt. It is observed that the more the tube pt decreases, the more the efficiency increases but also that the hardener gas 1 mass increases. Indeed, in the context of the use of R744 as a coolant, it is not possible to reduce the thickness of the flat tubes 2 below a certain threshold because its pressure is high, of the order of 150 bar, when the crossing of the gas cooler 1.

Thus, it can clearly be seen that the gas cooler 1 according to the invention allows only a good efficiency while having a limited mass, despite the fact that R744 has been used as a coolant and, above all, said gas cooler 1 has a low environmental impact.

Claims (12)

1. Gas cooler (1) comprising: a plurality of flat tubes (2) stacked and arranged parallel to each other, and in which a refrigerant fluid is able to circulate, said refrigerant fluid being R744, ° spacers (3) disposed between said flat tubes (2), said spacers (3) being adapted to be traversed by a second fluid, characterized in that the tube pitch (pt) between two successive flat tubes (2) is comprised between 6.5 and 10 mm, terminals included. 2. Gas cooler (1) according to the preceding claim, characterized inthat the tube pitch (pt) between two successive flat tubes (2) is between 8 and 10mm, inclusive terminals. 3. Gas cooler (1) according to any one of the preceding claims, characterized in that the tube pitch (pt) between two successive flat tubes (2) is comprised between 8 and 9 mm inclusive. 4. Gas cooler (1) according to any one of the preceding claims, characterized in that the tube pitch (pt) between two successive flat tubes (2) is 8.60 mm, with a tolerance of plus or minus 0 , 05 mm. 5. Gas cooler (1) according to any one of the preceding claims, characterized in that the flat tubes (2) have a width (lt) of between 10 and 17 mm inclusive. 6. Gas cooler (1) according to any one of the preceding claims, characterized in that the flat tubes (2) have a thickness (ht) of between 1 and 1, 25 mm inclusive. 7. Gas cooler (1) according to any one of the preceding claims, characterized in that the flat tubes (2) have a lumen (20) with a height (hl) of between 0.5 and 0.7 mm , terminals included. 8. Gas cooler (1) according to any one of the preceding claims, characterized in that the flat tubes (2) have a wall thickness (Et) of flat tube 2 between 0.15 and 0.4 mm, terminals included. 9. Gas cooler (1) according to any one of the preceding claims, characterized in that the spacers (3) have a thickness (ei) between0.06 and 0.10 mm inclusive. 10. Gas cooler (1) according to any one of the preceding claims, characterized in that the spacers (3) have a periodic profile period (pi) between 1.90 and 2.4 mm inclusive. 11. Gas cooler (1) according to any one of the preceding claims, characterized in that the spacers (3) have a height (hi) between 7 and 10 mm inclusive terminals. 12. Gas cooler (1) according to any one of the preceding claims, characterized in that it comprises 2 or 3 passes of refrigerant.