Compensation container and battery cooling system
By integrating pressure relief and negative pressure valves into the lids of the compensation container for battery cooling systems, the installation and maintenance challenges are addressed, resulting in a more accessible and cost-effective solution with extended desiccant cartridge lifespan.
Patent Information
- Application Number
- JP2024218713
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-12-15
- Filing Date
- 2024-12-13
- Publication Date
- 2025-06-26
AI Technical Summary
The existing compensation containers for battery cooling systems face challenges in the installation and replacement of pressure relief and negative pressure valves, which are typically difficult to attach to the container housing and require inaccessible inner wall access.
The solution involves integrating the pressure relief valve and negative pressure valve into two lids of the compensation container, allowing for easier installation and replacement by attaching the lids to the container housing, thus eliminating the need for direct attachment to the container housing wall.
This design simplifies the installation and maintenance of the valves, reducing costs and increasing accessibility, while also extending the lifespan of the desiccant cartridge by controlling air exchange cycles.
Smart Images
Figure 2025096249000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a compensation container for a battery cooling system. The present invention further relates to a battery cooling system provided with such a compensation container.
[0002] Electric vehicles or hybrid vehicles are increasingly attracting the attention of consumers from an environmental perspective and are accordingly becoming more widespread on the roads. In this case, in order to be able to improve both the driving range and the performance of such electric vehicles or hybrid vehicles, it is targeted to keep the traction battery of such electric vehicles or hybrid vehicles within an optimal temperature window with respect to this traction battery, and for this purpose, in a well-known form, a temperature control device, in particular a cooling device, is used. In this case, in order to achieve particularly efficient cooling, so-called immersion cooling is also used, in which a dielectric, i.e., non-conductive, cooling medium washes around the individual battery cells of the traction battery.
[0003] In this case, such a battery cooling system, especially for cooling a traction battery, also includes a compensation container in which air is held internally as a compensation cushion for volume changes of the cooling medium due to temperature. When the cooling medium expands due to a temperature increase, this would result in a high pressure load in the compensation container if the excess pressure generated at this time cannot be released, and in some cases, may damage the compensation container, so this must be avoided. For this reason, such a compensation container usually has a connection to the surroundings, whereby the pressure difference due to temperature can be reduced in some cases via the blowing out of air to the surroundings. When the cooling medium is cooled and contracts, this results in a negative pressure in the compensation container, which brings about the suction of fresh air from the surroundings. In this case, the concept of "fresh air" can mean / does mean ambient air. In order to prevent or at least reduce the introduction of undesirable moisture into the cooling medium at this time, a so-called desiccant cartridge is provided, and in this desiccant cartridge, fresh air sucked in from the surroundings during the suction process flows through, and a drying medium that absorbs moisture at this time and dries the sucked-in fresh air is arranged.
[0004] A disadvantage of such a compensation container lies particularly in the relatively difficult installation of a pressure relief valve or a negative pressure valve on the wall of the container housing of the compensation container.
[0005] Therefore, the present invention addresses the problem of providing an improved or at least one alternative embodiment for a compensation container that can overcome the disadvantages known from the prior art.
[0006] This problem is solved by the subject matter of independent claim 1 according to the present invention. Advantageous embodiments are the subject matter of the dependent claims.
[0007] Instead of arranging a pressure relief valve or a vacuum valve on the wall of the container housing of the compensation container for air in the battery cooling system as usual, the present invention incorporates these valves into two lids that are only attached to the container housing of the compensation container for the first time in the attached state, thereby greatly simplifying the valve installation, based on the general idea. In this case, the compensation container is used for buffering the air volume based on the volume change caused by the temperature of the cooling medium, especially oil. In this case, the compensation container according to the present invention for air for the battery cooling system has a container housing with a first lid having a threaded nipple, a second lid, and a desiccant cartridge that can be screwed onto the threaded nipple of the first lid. In this case, a vacuum valve is arranged in the first lid. When a negative pressure dominates inside the compensation container, fresh air can flow into the compensation container through the vacuum valve from the surroundings through the desiccant cartridge and the threaded nipple that may be formed hollow. A pressure relief valve is arranged in the second lid. When an excessive pressure dominates inside the compensation container, air can be blown out from the compensation container to the surroundings through the pressure relief valve. In this case, of course, an activated carbon filter can be further provided, so that when an excessive pressure dominates inside the container housing, the air blown out through the pressure relief valve also flows through the activated carbon filter, where hydrocarbons can be removed. A drying medium, especially a molecular sieve such as zeolite, is arranged in the desiccant cartridge. By arranging the vacuum valve in the first lid and the pressure relief valve in the second lid, these valves can be attached relatively easily before the two lids are attached to the container housing. In particular, this can eliminate the need to attach to the extremely inaccessible inner wall of the container housing. Also, this can greatly simplify the replacement of such valves during maintenance or repair.
[0008] Advantageously, the first lid and / or the second lid is formed of metal, in particular aluminum. By using aluminum, the weight is optimized while enabling a robust construction. Furthermore, aluminum can be easily processed, for example drilled, which also provides a simple means of attaching a negative pressure valve, for example, into a hole with an internal thread.
[0009] In one advantageous refinement of the invention, the container housing is formed of metal, in particular aluminum. In this case, the container housing may be formed as an aluminum extrusion part or as a deep-drawn part made of aluminum. For example, the container housing may be formed tubular, which is exactly suitable for the extrusion process. The deep-drawing process is also suitable for the inexpensive and high-quality production of the container housing, in which case the deep-drawing provides another shaping means.
[0010] In another particularly preferred embodiment of the compensating container, the container housing is formed of plastic, in particular polyoxymethylene (POM). POM is a semi-crystalline thermoplastic resin with high mechanical strength and rigidity, as well as high wear resistance and low hygroscopicity, which is extremely advantageous especially when used for the compensating container according to the invention. This is because in this case, water storage or hygroscopicity increases the conductivity of the dielectric cooling medium. In this case, the plastic may contain glass fibers, in particular 25% glass fibers, in order to further increase the mechanical strength and wear resistance, and may in particular be formed as POM GF-25. In this case, the container housing may be formed as a plastic injection molded part. In this case, forming as a plastic injection molded part not only enables the container housing and thus the compensating container to be produced with high quality, but also brings the great advantage that it can be produced inexpensively at the same time.
[0011] Advantageously, the desiccant cartridge contains a molecular sieve, in particular zeolite. The zeolite is present, for example, in spherical form and can adsorb moisture without any other energy supply. In this case, an exothermic reaction occurs.
[0012] In another advantageous embodiment of the compensation container, the negative pressure valve opens when the negative pressure p1 is -0.3 bar ≥ p1 ≥ -0.5 bar, and in this case, the pressure relief valve can open when the overpressure p2 is 0.4 bar ≤ p2 ≤ 1.0 bar. Based on these negative pressure / overpressure values, a certain amount of overpressure / negative pressure within the container housing can be tolerated, thereby reducing the air exchange cycle and extending the lifespan of the desiccant cartridge. Generally, without such a valve, it is considered that fresh air is always sucked in from the surroundings or air is released to the surroundings, which may extremely significantly shorten the lifespan of the desiccant cartridge as well as the HC adsorber. In this case, the higher or lower the opening pressure, the shorter the cycle for replacement.
[0013] Particularly preferably, the first lid and / or the second lid are sealed to the container housing by a seal made of AEM (ethylene - acrylate - rubber) or a seal made of HNBR (hydrogenated nitrile - rubber). Furthermore, the use of various materials is possible. Acrylate - ethylene - rubber (AEM) is a polymer composed of ethylene - methyl - acrylate and a predetermined amount of monomer containing carboxylic acid groups. AEM is heat - resistant and durable against chemicals and oils. HNBR has high media durability, abrasion resistance, and good mechanical properties. Thus, both plastics are predetermined to be used as seals in the compensation container according to the present invention.
[0014] The present invention further relates to the general idea of equipping a battery cooling system with the compensation container described in the preceding paragraph, thereby transferring the advantages described for this compensation container to the battery cooling system. Specifically, the advantage of the battery cooling system equipped with the compensation container according to the present invention lies in inexpensive and simple manufacturing. This is because the pre-installation in the respective attached lids of the two valves in particular is significantly simplified. Furthermore, in order to periodically replace the desiccant cartridge, the desiccant cartridge can be easily unscrewed from the first lid and then a new one can be screwed in again.
[0015] Other important features and advantages of the present invention are apparent from the dependent claims, the drawings, and the description of the drawings based on the accompanying drawings.
[0016] It is self-evident that the features described above and the features described hereinafter can be used not only in the combinations described, but also in other combinations or alone, without departing from the framework of the present invention. For example, the above-described components and the components described hereinafter, which are separately described as higher-level aggregates such as devices, facilities, or units, may form separate components or components of this aggregate, even if they are shown differently in the drawings, or may be an integrated area or section of this aggregate.
[0017] Preferred embodiments of the present invention are illustrated and will be described in more detail in the following description. In this case, the same reference signs relate to the same, or similar, or functionally identical components.
Brief Description of the Drawings
[0018]
Figure 1
Figure 2
Figure 3
Figure 4
[0019] Corresponding to FIGS. 1 to 3, the compensation container 1 according to the present invention for the air 2 of the battery cooling system 3 according to the present invention has a container housing 4 made of plastic provided with a first lid 5 having a threaded nipple 6 and a second lid 11. Similarly, a desiccant cartridge 7 screwed onto the threaded nipple 6 of the first lid 5 is also provided. In this case, a negative pressure valve 8 is disposed in the first lid 5, and when the negative pressure dominates inside the compensation container 1, fresh air 2a flows into the compensation container 1 from the surroundings through the negative pressure valve 8 via the desiccant cartridge 7 and the threaded nipple 6. Thereby, the sucked fresh air 2a can be dried.
[0020] A pressure relief valve 9 is disposed in the second lid 11 (see also FIG. 4), and when the overpressure dominates inside the compensation container 1 or its container housing 4, the air 2 can be blown out from the compensation container 1 to the surroundings through the pressure relief valve 9.
[0021] The desiccant cartridge 7 can be replaced by simply unscrewing it from the threaded nipple 6 or by simply screwing it onto the threaded nipple 6. The desiccant cartridge 7 may contain a molecular sieve, particularly zeolite, or another drying medium.
[0022] By incorporating the two valves 8, 9 into the respective attached covers 5, 11, it is possible to avoid the difficult and thus costly attachment of the valves 8, 9 to the wall of the container housing 4 of the compensation container 1. Thereby, the container housing 4 can be formed extremely simply, for example as a tube. By arranging the negative pressure valve 8 in the first cover 5 and the pressure relief valve 9 in the second cover 11, the replacement of such valves 8, 9 during maintenance or repair can also be made significantly easier. This is because the valves 8, 9 are extremely easily accessible when the covers 5, 11 are removed from the container housing 4. In this case, the compensation container 1 is used for buffering the air volume based on the volume change caused by the temperature of the cooling medium, especially oil.
[0023] The first cover 5 and / or the second cover 11 may be formed from metal, especially aluminum. In this case, by using aluminum, the weight is optimized and at the same time a robust structural form becomes possible. Aluminum also enables the production of a stable threaded nipple 6 that can securely position the desiccant cartridge 7. Of course, it is also conceivable to form the covers 5, 11 from plastic, especially as plastic injection molded parts.
[0024] The container housing 4 may likewise be formed from metal, especially aluminum. In this case, the container housing 4 may be formed as an aluminum extrusion part or as an aluminum deep drawing part. Thereby, high-quality and more cost-effective production can be enabled. The deep drawing method is also suitable for the production of the container housing 4.
[0025] The attachment of the covers 5, 11 to the container housing 4 may be effected via adhesion or screw fastening. In this case, screw fastening in particular enables particularly easy maintenance or repair.
[0026] The container housing 4 may also be formed from plastic, in particular polyoxymethylene (POM), similar to the lids 5, 11. POM has high mechanical strength and rigidity, as well as high wear resistance and low hygroscopicity, which is extremely advantageous especially when used in the compensation container 1 according to the present invention. This is because in this case, water storage or hygroscopicity increases the conductivity of the dielectric cooling medium. For this purpose, polyketone is also suitable. In order to increase the strength and / or wear resistance, glass fibers, especially 25% glass fibers, may be embedded in the plastic matrix. The container housing 4 may be formed as a plastic injection molded part, which brings great advantages of high-quality and low-cost manufacturing, and at the same time enables shapes that cannot be obtained by, for example, extrusion molding.
[0027] In the desiccant cartridge 7, a molecular sieve, especially zeolite, may be arranged as the drying medium.
[0028] The negative pressure valve 8 can open when the negative pressure p1 is -0.3 bar ≥ p1 ≥ -0.5 bar, while the pressure relief valve 9 can open when the overpressure p2 is 0.4 bar ≤ p2 ≤ 1.0 bar. Based on these negative / overpressures, a certain degree of overpressure / negative pressure in the container housing can be tolerated, thereby reducing the air exchange cycle and extending the life of the desiccant cartridge 7.
[0029] In order to be able to reliably seal the inner chamber of the container housing 4, the first lid 5 and / or the second lid 11 are sealed to the container housing 4 by a seal 10 made of AEM (ethylene - acrylate - rubber) or HNBR (hydrogenated nitrile - rubber). AEM is durable against heat, chemicals, and oil. HNBR has high media durability, wear resistance, and good mechanical properties.
[0030] The pressure relief valve 9 shown in Fig. 4 has a valve body 12 preloaded by a spring 13, and the valve body 12 is in close contact with an attached valve seat 14 to close the pressure relief valve 9. The pressure relief valve 9 is sealed against the second lid 11 by an O-ring seal 15. In this case, it is of course obvious that the pressure relief valve 9 shown in Fig. 4 can also be used as a negative pressure valve 8 in the opposite manner in the same configuration. The pressure relief valve 9 or the negative pressure valve 8 can also prevent unacceptable pressure increases / pressure drops in the coolant circuit. The negative pressure valve 8 or the pressure relief valve 9 may further be provided with a diaphragm 16 to prevent the ingress of unwanted splash water.
[0031] The compensation container 1 significantly simplifies the pre-installation of the two valves 8, 9, in particular at their respective attached lids 5, 11, so that the battery cooling system 3 can also be manufactured inexpensively and simply. Furthermore, in order to periodically replace the desiccant cartridge 7, the desiccant cartridge 7 can be easily unscrewed from the first lid 5 and then a new one can be screwed in again.
Claims
1. A compensation container (1) for a battery cooling system (3), comprising: A container housing (4) with a first lid (5) and a second lid (11) having a threaded nipple (6); a desiccant cartridge (7) that can be screwed onto the threaded nipple (6) of the first lid (5); Equipped with A negative pressure valve (8) is disposed in the first lid (5), and when negative pressure prevails in the compensation container (1), fresh air (2a) flows from the surroundings through the desiccant cartridge (7) into the compensation container (1) via the negative pressure valve (8); a pressure relief valve (9) is arranged in the second lid (11), through which air (2) leaves the compensation container (1) to the surroundings in the event of excessive pressure prevailing in the compensation container (1); Compensation container (1).
2. 2. The compensation container according to claim 1, wherein the first lid (5) and / or the second lid (11) are made from metal, in particular from aluminum.
3. 3. The compensation vessel according to claim 2, wherein the vessel housing (4) is made from metal, in particular from aluminum.
4. 4. The compensation vessel according to claim 3, wherein the vessel housing (4) is formed as an aluminum extrusion part or as an aluminum deep-drawn part.
5. 3. Compensation vessel according to claim 1 or 2, characterized in that the vessel housing (4) is made from plastic, in particular from polyoxymethylene (POM) or polyketone.
6. 6. The compensation container according to claim 5, wherein the plastic contains glass fibres, in particular a glass fibre content of 25%.
7. 7. Compensation vessel according to any one of claims 1 to 6, wherein the desiccant cartridge (7) contains a molecular sieve, in particular a zeolite.
8. The negative pressure valve (8) is １ is -0.3 bar ≧ p １ open if ≧−0.5 bar, and / or The pressure relief valve (9) prevents excess pressure p ２ 0.4 bar≦p ２ Open if ≦1.0 bar; A compensation vessel according to any one of claims 1 to 7.
9. said first lid (5) is sealed to said container housing (4) by a seal (10) made of AEM (Ethylene-Acrylate-Rubber) or HNBR (Hydrogenated Nitrile-Rubber); and / or said second lid (11) is sealed to said container housing (4) by a seal (10) made of AEM (Ethylene-Acrylate-Rubber) or HNBR (Hydrogenated Nitrile-Rubber); A compensation vessel according to any one of claims 1 to 8.
10. A battery cooling system (3) comprising a compensation container (1) according to any one of claims 1 to 9.