Compensation container and battery cooling system

Abstract

The invention relates to a compensation container (1) for a battery cooling system (3), comprising: a container housing (4), which has a first cover part (5), which has a threaded connection (6), and a second cover part (11); a dryer cartridge (7) which can be screwed onto a threaded connection (6) of the first cover part (5), in which a negative pressure valve (8) is arranged, via which fresh air (2a) enters the compensation container (1) from the surroundings via the dryer cartridge (7) in the event of a negative pressure in the compensation container (1), according to the invention, an overpressure valve (9) is arranged in the second cover part (11), via which air (2) enters the surroundings from the compensation container (1) in the event of an overpressure in the compensation container (1). In this way, an easy-to-assemble and cost-effective embodiment of the compensation container (1) can be achieved.

Description

Field of the Invention

[0001] The present invention relates to a compensation container for a battery cooling system. Furthermore, the present invention relates to a battery cooling system having such a compensation container. Background Art

[0002] Due to environmental considerations, electric vehicles or hybrid vehicles are increasingly attracting the attention of consumers and are accordingly becoming increasingly common on the roads. In order to increase the range and efficiency of such electric vehicles or hybrid vehicles, it is sought to keep the traction battery of such an electric vehicle or hybrid vehicle within the optimal temperature window for the traction battery. For this purpose, temperature control devices, in particular cooling devices, are used in a known manner. Here, in order to achieve particularly efficient cooling, so-called immersion cooling is also used, in which a dielectric, i.e., non-conductive, coolant flushes around the individual battery cells of the traction battery.

[0003] Here, such a battery cooling system for cooling in particular a traction battery also includes a compensation container in which air is stored as a compensation cushion for the temperature-induced volume change of the coolant. The coolant expands due to temperature increase. If the resulting overpressure cannot be discharged, this can lead to a high pressure load in the compensation container and may damage the compensation container and therefore needs to be avoided. For this reason, this type of compensation container usually has a connection to the environment so that, if necessary, the pressure difference caused by temperature can be reduced by blowing air out into the environment. If the coolant cools, the coolant contracts, which in turn creates a negative pressure in the compensation container, which causes fresh air to be sucked in from the environment. "Fresh air" can / should be understood here as ambient air. In order to prohibit or at least reduce the entry of unwanted moisture into the coolant here, a so-called dryer cartridge is provided in which a desiccant is arranged. The desiccant is flowed through by the fresh air sucked in from the environment during the suction process and absorbs moisture here and dries the sucked-in fresh air.

[0004] The disadvantage of this type of compensation container lies in particular in the relatively difficult installation of the overpressure valve or the negative pressure valve in the wall of the container housing of the compensation container. Summary of the Invention

[0005] Therefore, the present invention studies the following problem: to provide an improved or at least an alternative embodiment for the compensation container, by means of which the disadvantages known from the prior art can be overcome.

[0006] According to the present invention, this problem is solved by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0007] The present invention is based on the following general concept: Instead of arranging an overpressure valve or a negative pressure valve in the wall of the container housing of a compensation container for air in a battery cooling system as commonly done hitherto, these valves are integrated into two cover parts which are only mounted on the container housing of the compensation container in the assembled state. Thereby, the assembly of these valves is significantly simplified. Here, the compensation container is used to buffer the air volume generated due to the volume change of the cooling medium, especially oil, caused by temperature. Here, a compensation container for a battery cooling system, especially for air, according to the present invention has the aforementioned container housing and a dryer cylinder. The container housing has a first cover part and a second cover part. The first cover part has a threaded connection. The dryer cylinder can be screwed onto the threaded connection of the first cover part. A negative pressure valve is arranged in the first cover part. In the case of negative pressure in the compensation container, fresh air can be sucked from the environment into the compensation container via the negative pressure valve through the dryer cylinder and the threaded connection, and the threaded connection can be configured hollow. An overpressure valve is arranged in the second cover part. In the case of overpressure in the compensation container, air can be blown out from the compensation container into the environment via the overpressure valve. Here, of course, an activated carbon filter can also be provided such that the air blown out via the overpressure valve in the case of overpressure in the container housing can also flow through the activated carbon filter and hydrocarbons can be removed there. A desiccant, especially a molecular sieve such as zeolite, is arranged in the dryer cylinder. By arranging the negative pressure valve in the first cover part and the overpressure valve in the second cover part, these valves can be assembled relatively easily before the two cover parts are mounted on the container housing. In particular, the assembly on the inner wall of the container housing which can only be accessed very difficultly can thereby be eliminated. Thereby, the replacement of such valves in the case of maintenance or repair can also be significantly simplified.

[0008] Suitably, the first cover part and / or the second cover part is / are made of metal, especially made of aluminum. By using aluminum, a weight-optimized and at the same time robust construction can be achieved. In addition, aluminum can be easily processed, for example drilled, thereby especially providing the possibility of simply fastening the negative pressure valve, for example fastening it in a drilled hole provided with an internal thread.

[0009] In an advantageous expansion scheme of the present invention, the container housing is made of metal, especially made of aluminum. Here, the container housing can be configured as an aluminum extrusion profile or as a deep-drawn part made of aluminum. For example, the container housing can be configured tubular, which is perfectly suitable for the extrusion method. The deep-drawing method is also suitable for the cost-effective and high-quality manufacture of the container housing, and deep-drawing provides additional forming possibilities.

[0010] In another particularly preferred embodiment of the compensating container, the container housing is constructed of plastic, in particular of polyoxymethylene (POM). POM is a partially crystalline thermoplastic which has high mechanical strength and stiffness and moreover has high abrasion resistance and low hygroscopicity, which is particularly advantageous especially when used for the compensating container according to the invention, since in this case water storage or moisture absorption would increase the conductivity of the dielectric coolant. In order to further increase the mechanical strength and abrasion resistance here, the plastic can have glass fibers, in particular 25% glass fibers, and can in particular be constructed as POMGF-25. Here, the container housing can also be constructed as a plastic injection molding. Here, the construction as a plastic injection molding offers the following great advantages: The container housing and thus also the compensating container can be manufactured not only with high quality but also cost-effectively.

[0011] Advantageously, the dryer cartridge has a molecular sieve, in particular zeolite. The zeolite can be present, for example, in spherical form and can absorb moisture without additional energy supply. An exothermic reaction takes place here.

[0012] In another advantageous embodiment of the compensating container, the negative pressure valve opens at a negative pressure p1 of -0.3 bar ≥ p1 ≥ -0.5 bar, wherein the overpressure valve can open at an overpressure p2 of 0.4 bar ≤ p2 ≤ 1.0 bar. By means of these negative / overpressures, a certain overpressure / negative pressure in the container housing can be tolerated, whereby the air exchange cycle can be reduced and the service life of the dryer cartridge can be extended. Generally speaking, in the absence of this type of valve, fresh air would constantly be sucked in from the environment or air would be discharged into the environment, which would extremely strongly reduce the service life of the dryer cartridge as well as of the HC absorber. Here, it applies that the higher or lower the opening pressure, the fewer exchange cycles occur.

[0013] Particularly preferably, the first cover part and / or the second cover part are sealed relative to the container housing via a seal made of AEM (ethylene acrylic rubber) or a seal made of HNBR (hydrogenated nitrile rubber). In addition, different materials can be used. Acrylic ethylene rubber (AEM) is a polymer composed of ethylene methyl acrylate and a part of monomers with carboxyl groups. AEM is heat-resistant and resistant to chemical agents and oils. HNBR has high chemical resistance, abrasion resistance and good mechanical properties. Thus, both plastics are inherently suitable for use as seals in the compensating container according to the invention.

[0014] Furthermore, the present invention is based on the following general concept: equipping the battery cooling system with the compensation container described in the above paragraph, and thereby transferring the advantages described with respect to the compensation container to the battery cooling system. Specifically, the advantage of a battery cooling system equipped with a compensation container according to the present invention lies in its easy and cost-effective manufacturing, since in particular the pre-assembly of the two valves on the respective cover parts is significantly easier. In order to regularly replace the dryer cartridge, the dryer cartridge can furthermore be easily screwed off the first cover part and a new dryer cartridge can then be screwed on again.

[0015] Other important features and advantages of the present invention result from the dependent claims, the drawings and the associated description of the drawings.

[0016] It should be understood that the features mentioned above and those to be described below can be used not only in the combinations given accordingly, but also in other combinations or individually, without departing from the framework of the present invention. The separately marked components mentioned above and still to be mentioned below of a superior unit (such as a device, an apparatus or a component) can form separate members or parts of the unit or can be regions or sections that form the unit as a whole, even if this is shown otherwise in the drawings.

[0017] Preferred embodiments of the present invention are shown in the drawings and are explained in more detail in the following description, where the same reference numerals refer to the same or similar or functionally identical components. Description of the Drawings

[0018] The drawings schematically show respectively:

[0019] Figure 1 A cross-sectional view of a compensation container according to the present invention of a battery cooling system according to the present invention,

[0020] Figure 2 Showing Figure 1 detail schematic view A in

[0021] Figure 3 Showing Figure 1 detail schematic view B in

[0022] Figure 4 A cross-sectional view of the overpressure valve is shown. Detailed Description of the Invention

[0023] According to Figures 1 to 3, the compensation container 1 for the air 2 of the battery cooling system 3 according to the present invention has a container housing 4 made of plastic, the container housing having a first cover member 5 and a second cover member 11, the first cover member having a threaded connection 6. A dryer cartridge 7 is also provided, which is screwed onto the threaded connection 6 of the first cover member 5. Here, a negative pressure valve 8 is arranged in the first cover member 5. In the case where there is a negative pressure in the compensation container 1, fresh air 2a enters the compensation container 1 from the environment via the negative pressure valve through the dryer cartridge 7 and the threaded connection 6. Thereby, the sucked fresh air 2a can be dried.

[0024] An overpressure valve 9 is arranged in the second cover member 11 (see also Figure 4 ), in the case where there is an overpressure in the compensation container 1 or the container housing 4 of the compensation container, air 2 can be blown out of the compensation container 1 into the environment via the overpressure valve.

[0025] The dryer cartridge 7 can be replaced by easily unscrewing or screwing it onto the threaded connection 6. The dryer cartridge 7 can have molecular sieves, especially zeolites, or other desiccants.

[0026] By integrating the two valves 8, 9 onto the respective cover members 5, 11, it is possible to dispense with the difficult and thus expensive installation of the valves 8, 9 into the wall of the container housing 4 of the compensation container 1. Thereby, the container housing 4 can be constructed very easily, for example as a tube. By arranging the negative pressure valve 8 in the first cover member 5 and the overpressure valve 9 in the second cover member 11, the replacement of such valves 8, 9 can also be significantly simplified in the case of maintenance or repair, because the valves 8, 9 are significantly more accessible when the cover members 5, 11 are removed from the container housing 4. Here, the compensation container 1 is used to buffer the air volume generated due to the temperature-induced volume change of the cooling medium, especially oil.

[0027] The first cover member 5 and / or the second cover member 11 can be constructed of metal, especially of aluminum, wherein by using aluminum, a weight-optimized and at the same time robust structural form can be achieved. In addition, aluminum enables the manufacture of a stable threaded connection 6 via which the dryer cartridge 7 can be reliably fixed. Of course, it is also possible to consider constructing the cover members 5, 11 of plastic, especially as plastic injection molded parts.

[0028] The container housing 4 can also be constructed of metal, especially of aluminum, wherein in this case, the container housing 4 can be constructed as an aluminum extrusion profile or an aluminum deep-drawn part. Thereby, high-quality and cost-effective production can be achieved. The deep-drawing method is also suitable for manufacturing the container housing 4.

[0029] The fastening of the cover parts 5, 11 to the container housing 4 can be achieved via adhesion or screwing, wherein, in particular, screwing enables particularly easy maintenance or repair.

[0030] The container housing 4 can be constructed of plastic, in particular polyoxymethylene (POM), like the cover parts 5, 11. POM has high mechanical strength and stiffness, and in addition has high wear resistance and low hygroscopicity, which is particularly advantageous especially when used for the compensation container 1 according to the invention, because in this case, water storage or moisture absorption increases the conductivity of the dielectric coolant. Polyketone is also suitable for this. To increase strength and / or wear resistance, glass fibers, in particular 25% glass fibers, can be embedded in the plastic base layer. The container housing 4 can also be constructed as a plastic injection molding, which offers the great advantage of high-quality and cost-effective manufacturing and enables shapes that cannot be achieved, for example, by extrusion.

[0031] In the dryer drum 7, a molecular sieve, in particular zeolite, can be arranged as a desiccant.

[0032] The negative pressure valve 8 can be opened at a negative pressure p1 of -0.3 bar ≥ p1 ≥ -0.5 bar, while the overpressure valve can be opened at an overpressure p2 of 0.4 bar ≤ p2 ≤ 1.0 bar. With these negative / overpressures, a certain overpressure / negative pressure in the container housing can be tolerated, whereby the air exchange cycle can be reduced and the service life of the dryer drum 7 can be extended.

[0033] To reliably seal the interior space of the container housing 4, the first cover part 5 and / or the second cover part 11 is sealed relative to the container housing 4 via a seal 10 made of AEM (ethylene acrylic rubber) or HNBR (hydrogenated nitrile rubber). AEM is resistant to heat, chemical agents, and oils. HNBR has high chemical resistance, wear resistance, and good mechanical properties.

[0034] Figure 4 The illustrated overpressure valve 9 has a valve body 12 pre-tensioned by a spring 13, which rests tightly on the associated valve seat 14 for closing the overpressure valve 9. The overpressure valve 9 is sealed relative to the second cover 7 by means of an O-ring seal 15. Here, of course, it is clear that Figure 4 The illustrated overpressure valve 9 can also be used as the negative pressure valve 8 in the same, just inverted construction. The overpressure valve 9 or the negative pressure valve 8 can also prevent an inadmissible pressure increase / decrease in the coolant circuit. In addition, a diaphragm 16 can be arranged on the negative pressure valve 8 or the overpressure valve 9, which prevents the undesired intrusion of surge water.

[0035] Thanks to the compensating container 1, the battery cooling system 3 can also be produced easily and cost-effectively, especially since the pre-assembly of the two valves 8, 9 on the respectively assigned cover parts 5, 11 is significantly easier. In order to replace the dryer cartridge 7 regularly, the dryer cartridge can moreover be easily unscrewed from the first cover part 5 and a new dryer cartridge can then be screwed on again.

Claims

1. A compensating container (1) for a battery cooling system (3), comprising: - a container housing (4) having a first cover (5) and a second cover (11), the first cover having a threaded connection (6); a dryer cartridge (7) which can be screwed onto the threaded connection (6) of the first cover (5), -in, A negative pressure valve (8) is arranged in the first cover (5), and when negative pressure exists in the compensation container (1), fresh air (2a) enters the compensation container (1) from the environment via the negative pressure valve via the dryer cylinder (7). wherein an overpressure valve (9) is arranged in the second cover (11), through which, in the event of an overpressure in the compensating container (1), air (2) passes from the compensating container (1) into the environment.

2. The compensating container according to claim 1, It is characterized in that The first cover part (5) and / or the second cover part (11) are made of metal, in particular of aluminum.

3. The compensating container according to claim 2, It is characterized in that The container housing (4) is made of metal, in particular of aluminum.

4. The compensating container according to claim 3, It is characterized in that The container housing (4) is designed as an aluminum extruded profile or an aluminum deep-drawn part.

5. The compensating container according to claim 1 or 2, It is characterized in that The container housing (4) is made of plastic, in particular polyoxymethylene (POM) or polyketone.

6. The compensating container according to claim 5, It is characterized in that The plastic has glass fibers, in particular a glass fiber content of 25%.

7. The compensating container according to any one of the preceding claims, It is characterized in that The dryer cartridge (7) contains a molecular sieve, in particular a zeolite.

8. The compensating container according to any one of the preceding claims, It is characterized in that - the negative pressure valve (8) opens at a negative pressure p1 of -0.3 bar ≥ p1 ≥ -0.5 bar, and / or The overpressure valve (9) opens at an overpressure p2 of 0.4 bar ≤ p2 ≤ 1.0 bar.

9. The compensating container according to claim 1, It is characterized in that - the first cover (5) is sealed relative to the container housing (4) via a seal (10) made of AEM (ethylene acrylate rubber) or HNBR (hydrogenated nitrile rubber), and / or The second cover (11) is sealed relative to the container housing (4) via a seal (10) made of AEM (ethylene acrylate rubber) or HNBR (hydrogenated nitrile butadiene rubber).

10. A battery cooling system (3) having a compensating container (1) according to any one of the preceding claims.

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