Compensation tank and battery cooling system

Abstract

The invention relates to a compensation tank (1) for a battery cooling system (3), - comprising a tank housing (4) made of plastic, comprising a first shell (5) and a second shell (6) connected thereto in a sealed manner, - in which a first receptacle (7) is formed in the first shell (5) and / or in the second shell (6), - comprising a drying cartridge (8) housed in a form-fitting manner in the first receptacle (7), - comprising a first valve (9) via which, in the event of excess pressure in the compensation tank (1), air (2) from the compensation tank (1) flows into the environment, - comprising a second valve (10) via which, in the event of a negative pressure in the compensation tank (1), fresh air (2a) from the environment flows into the compensation tank (1).Thus, a low-cost realization can be obtained. Figure for abstract: (Fig. 2).

Description

Title of the invention: Compensation tank and battery cooling system

[0001] The present invention relates to a compensation tank for a battery cooling system. The invention also relates to a battery cooling system comprising such a compensation tank.

[0002] Electric or hybrid vehicles are receiving increasing attention from consumers due to environmental aspects and are therefore becoming more and more widespread on the roads. In order to be able to increase both the autonomy and the performance of electric or hybrid vehicles of this type, it is sought to maintain a traction battery of such an electric or hybrid vehicle within an optimal temperature window for said traction battery, whereby temperature balancing devices, in particular cooling devices, are used in a known manner. In order to achieve particularly effective cooling, so-called immersion cooling is also used, in which a dielectric, i.e. electrically non-conductive, cooling liquid bathes each battery cell of the traction battery.

[0003] Such a battery cooling system for cooling in particular a traction battery also comprises a compensation tank in which air is stored as a compensation cushion for a temperature-induced volume change of the coolant. An increase in temperature causes the coolant to expand, which, if a resulting overpressure cannot escape, can lead to a high pressure load in the compensation tank and possibly damage it, which must therefore be avoided. Therefore, compensation tanks of this kind generally have a connection to the environment in order to possibly be able to reduce a temperature-induced pressure difference by expelling air into the environment.If the coolant cools down, it shrinks, resulting in a negative pressure in the compensation tank, which leads to fresh air being sucked in from the environment. In order to prevent or at least reduce the introduction of unwanted moisture into the coolant, sheet metal drying cartridges were previously provided in which a drying agent was arranged through which fresh air sucked in from the environment flowed during the suction process and which thus absorbed the moisture and dried the sucked in fresh air.

[0004] The disadvantage of sheet metal drying cartridges of this type, however, is that they have a housing made of sheet metal, which makes them not only heavy, but also relatively expensive. In addition, a threaded end piece had to be provided, through which the sheet metal drying cartridge was screwed onto the compensation tank. A threaded end piece of this type made of sheet metal is also expensive.

[0005] The present invention therefore aims to propose an improved or at least alternative embodiment of a compensation tank to counter the problem, by means of which the known disadvantages of the state of the art can be overcome.

[0006] This problem is solved according to the invention by the subject of independent claim 1. Advantageous embodiments are the subject of the dependent claims.

[0007] The present invention is based on the general idea of ​​not producing, as was customary up to now, a sheet metal drying cartridge having a housing made of sheet metal and not arranging it on a reservoir housing of a compensation tank, in particular for air in a battery cooling system, by means of threaded ends which are difficult and therefore expensive to manufacture, but of producing the reservoir housing of the compensation tank for air or for the coolant for a battery cooling system as an inexpensive two-shell plastic housing and of integrating a drying cartridge therein as an insert. The compensation tank then serves to buffer a volume of air due to a volume change caused by the temperature of a coolant, in particular an oil.The compensation tank according to the invention, in particular for air, for a battery cooling system, thus has the aforementioned tank housing made of plastic material and comprising a first shell and a second shell sealed thereto. A first housing is thus formed in the first shell and / or in the second shell, in which the aforementioned drying cartridge comprising a drying agent, for example zeolite or silica gel, is housed in a form-fitting manner.A first valve is also provided, via which, in the event of excess pressure in the compensation tank, air from the compensation tank can be expelled into the environment, and a second valve via which, in the event of a negative pressure in the compensation tank, fresh air from the environment can be drawn into the compensation tank. The term "fresh air" can / must refer to the surrounding air. The two-shell design of the compensation tank tank housing with the drying cartridge arranged therein and preferably not interchangeable makes it possible to create a compensation tank tank housing that is generally inexpensive and at the same time has advantages. assembly, since the drying cartridge produced as an insert only needs to be inserted in a form-fitting manner into the first receptacle of the first and / or second shell and then the two shells of the tank housing are connected to each other in a sealed manner. This also allows for a protected arrangement of the drying cartridge in the tank housing over its entire service life. Previously necessary production of the tank housing and subsequent assembly of the sheet metal drying cartridge can thus be completely eliminated.The production of the compensation tank according to the invention can thus be automated in particular, since the inner contour of the first housing, which is designed substantially complementary to an outer contour of the drying cartridge, allows the drying cartridge to be inserted into the first housing by form-fitting fit, which does not require the intervention of a worker. The arrangement of the first valve and the second valve on the tank housing allows these two valves to be replaced during periodic replacement of the drying cartridge and thus also during periodic replacement of the tank housing, which, for example, reliably prevents clogging of the valves due to excessively long use.

[0008] According to an advantageous improvement of the compensation tank according to the invention, a second housing is provided in the first shell and / or in the second shell, in which an activated carbon cartridge is housed by form-fitting fit. An activated carbon cartridge of this type is then able to absorb pollutants, such as hydrocarbons, so that in the event of excess pressure in the compensation tank, air is expelled via the activated carbon cartridge, thereby purifying the expelled air and preventing the expulsion of hydrocarbons. The form-fitting fit of the activated carbon cartridge in the second housing of the first and / or second shell also allows the activated carbon cartridge to be inserted into the second housing, preferably in an automated manner, in a manner analogous to the drying cartridge, before the two shells are connected to each other.This also allows for a protected arrangement of the activated carbon cartridge in the tank housing.

[0009] According to an advantageous improvement of the compensation tank according to the invention, the first valve is arranged in an intermediate wall which separates the second housing from an interior space of the tank housing. Air is generally arranged in the interior space of the tank housing, which air is, depending on the temperature of the coolant, subjected to pressure or depression by expansion or contraction of said coolant. The arrangement of the first valve in the intermediate wall which separates the second housing the interior space of the tank housing allows for a direct association of the first valve with the second housing. An opening is of course provided downstream of the second housing in a wall of the tank housing towards the outside for exchange with the environment.

[0010] The second valve is then arranged in an outer wall of the tank housing, the outer wall in which the second valve is arranged separating the first housing from the environment. A suction of fresh air from the environment in the event of a negative pressure prevailing in the tank housing or in the compensation tank is therefore carried out via the second valve and the first housing in which the drying cartridge is arranged. The fresh air sucked in from the environment is thus sucked in by the drying agent of the drying cartridge and is thus dried, which in particular prevents moisture and / or water from entering the compensation tank. Too high a humidity could make the coolant electrically conductive, which, under unfavorable circumstances, in particular in the case of immersion cooling, could lead to a short circuit.

[0011] The second valve described can then also be implemented as a double valve, which also allows air to be expelled from the tank housing into the environment.

[0012] According to a particularly preferred embodiment, a spring is provided in the first or second housing, which spring pretensions the drying cartridge or the activated carbon cartridge against the tank housing. Springs of this type make it possible to achieve a reliable and fixed arrangement of the drying cartridge in the first housing and of the activated carbon cartridge in the second housing, the spring pretensioning at the same time preventing the drying cartridge and / or the activated carbon cartridge from producing rattling noises during operation, which are perceived, for example, as annoying. A spring of this type can, for example, be designed as an inexpensive coil spring, whereby the coil spring for pretensioning the drying cartridge can be arranged in the first housing in such a way that it surrounds the second valve in the outer wall of the tank housing and is thus fixed by the second valve.The spring preload also compresses the drying granules or activated carbon so that they have no room to move and can wear out / deteriorate.

[0013] According to a particularly preferred embodiment of the compensation tank according to the invention, the first shell and / or the second shell are produced in the form of plastic injection-molded parts. The production of the first and / or the second shell in the form of plastic injection-molded parts has the great advantage of being able to manufacture the tank housing and therefore the compensation tank not only with high quality, but also inexpensively.

[0014] The first shell and the second shell are welded to each other in a practical manner. By making the two shells as plastic injection-molded parts, they can be welded to each other to achieve a tight connection. Alternatively, gluing the two shells together is of course also conceivable. Alternatively, it is also conceivable, from a purely theoretical point of view, that the two shells are connected to each other by means of clip connections or screw connections, which has the great advantage that the tank housing can be opened for replacement of the drying cartridge or the activated carbon cartridge and can continue to be used after replacement of the drying cartridge or the activated carbon cartridge. In this case, a sealing gasket must still be inserted between the two shells.

[0015] According to another advantageous embodiment of the compensation tank according to the invention, the first shell and / or the second shell are made of polyoxymethylene (POM). POM is a semi-crystalline thermoplastic with high mechanical strength and stiffness and, in addition, high wear resistance and low moisture absorption, which is very advantageous, in particular when used for the compensation tank according to the invention, since in this case, water infiltration or moisture absorption increases the electrical conductivity of a dielectric coolant. Polyketones are also suitable as material for the first and / or the second shell. In order to further increase the mechanical strength and wear resistance, the plastic may have glass fibers, in particular 25% glass fibers, in particular be produced as POM GF-25.

[0016] The present invention is further based on the general idea of ​​equipping a battery cooling system with a compensation tank described in the preceding paragraphs and thus applying to the battery cooling system the advantages described concerning the compensation tank. Concretely, the advantages of a battery cooling system equipped with the compensation tank according to the invention lie in low-cost manufacturing, only the compensation tank having to be replaced for periodic replacement of the drying cartridge and / or the activated carbon cartridge.

[0017] Other important features and advantages of the invention will emerge from the subclaims, the diagrams and the description of the corresponding figures with the aid of the diagrams.

[0018] It is self-evident that the above-mentioned features and those which will be explained later can be used not only in the combination respectively indicated, but also in other combinations or alone, without departing from the scope of the present invention. Integral parts, mentioned above and which will be mentioned later, of a higher unit, such as a device, an apparatus or an arrangement, and which are designated separately, may constitute separate structural parts or components of said unit or be integral areas or sections of said unit, even if this is represented differently in the diagram.

[0019] Preferred embodiments of the invention are shown in the diagrams and are explained in more detail in the following description, the same reference signs referring to identical or similar or functionally identical components.

[0020] The following are shown, respectively schematically:

[0021] [Fig-1]: a view of a compensation tank according to the invention of a system of battery cooling according to the invention,

[0022] [Fig.2]: a representation identical to that of [Fig.l], but from another perspective,

[0023] [Fig.3]: an interior view of the compensation tank according to the invention,

[0024] [Fig.4]: an interior view of a compensation tank for air not covered by the invention.

[0025] According to Figures 1 to 3, a compensation tank 1 according to the invention for the air 2 of a battery cooling system 3 according to the invention has a tank housing 4 made of plastic material having a first shell 5 and a second shell 6 connected thereto. In the first shell 5 and / or in the second shell 6, a first receptacle 7 (see [Fig. 3]) is provided or formed, in which a drying cartridge 8 is arranged in a form-fitting manner. An unspecified drying agent is arranged in the drying cartridge 8. Furthermore, the compensation tank 1 according to the invention has a first valve 9 via which, in the event of excess pressure in the compensation tank 1, air 2 from the compensation tank 1 can be expelled into the environment.Fresh air 2a from the environment enters the compensation tank 1 via a second valve 10 in the event of a negative pressure in the compensation tank 1.

[0026] A second housing 11 is furthermore provided in the first shell 5 and / or in the second shell 6, second housing in which an activated carbon cartridge 12 is housed by form-fitting complementarity. The compensation tank 1 shown therefore has the tank housing 4 comprising the two housings 7, 11 which are arranged therein and in which the drying cartridge 8 or the activated carbon cartridge 12 is arranged. In the event of excess pressure in the compensation tank 1, air 2 thus flows through the first valve 9 and the activated carbon cartridge 12 arranged in the second housing 11 to the outside into the environment, the second valve 10 being able, for example, to be designed as a double valve and thus also allowing an expulsion of the air 2 from the compensation tank 1 to the outside into the environment. The expulsion of air 2 through the activated carbon cartridge 12 makes it possible, in particular, to reliably retain pollutants, such as, for example, hydrocarbons. The suction of fresh air 2a from the environment into the compensation tank 1 is carried out via the second valve 10 and the drying cartridge 8 in which the sucked-in fresh air 2a is dried.

[0027] The first valve 9 is then arranged in an intermediate wall 13 which separates the second housing 11 from the interior space 16 of the tank housing 4. The second valve 10, which can also be designed as a double valve, i.e. a valve permeable in both directions, is here arranged in an outer wall of the tank housing 4, which outer wall separates the first housing 7 from the environment. Of course, the second valve 10 described above and a further pressure relief valve can also be arranged in the outer wall of the tank housing 4, a further pressure relief valve via which air 2 from the compensation tank 1 is expelled into the environment.

[0028] If we continue to observe [Fig. 3], we can see that a spring 14 is provided in the first housing 7 and in the second housing 11 respectively, which springs pre-tension the drying cartridge 8 against the reservoir housing 4 and the activated carbon cartridge 12 also against the reservoir housing 4, here specifically against the intermediate wall 13. The two springs 14 make it possible to achieve a vibration-free and therefore rattling-free fixation of the drying cartridge 8 and the activated carbon cartridge 12 in their respective housing 7, 11. This allows in particular increased comfort of use due to reduced noise emission.

[0029] The first shell 5 and / or the second shell 6 can then be produced as plastic injection-molded parts, which not only allows for high-quality but also inexpensive manufacturing. The two shells 5, 6 can be welded or glued to each other, but it is also conceivable, from a purely theoretical point of view, that the two shells 5, 6 are connected to each other by means of clip connections or screw connections, which has the great advantage of being able to open the tank housing 4 for replacement of the drying cartridge 8 or the activated carbon cartridge 12 and to be able to continue to be used after replacing the drying cartridge 8 or the activated carbon cartridge 12.

[0030] The first shell 5 and / or the second shell 6 can then be made of polyoxymethylene (POM), i.e. a plastic material with high strength and low moisture absorption, which is very advantageous, in particular for a compensation tank 1 for the air 2 of a battery cooling system 3. In order to further increase the strength and robustness to wear of the tank housing 4, the plastic material of the two shells 5, 6 can be reinforced with fibers, in particular glass fibers.

[0031] All things considered, the compensation tank 1 according to the invention and the battery cooling system 3 according to the invention make it possible to create an extremely inexpensive solution compared to a sheet metal drying cartridge comprising a sheet metal housing.

[0032] Hereinafter, it is also appropriate to briefly describe the embodiment of a compensation tank 1' not covered by the invention, in accordance with [Fig. 4], the same reference signs being used in [Fig. 4] for the same structural parts, but respectively with an apostrophe.

[0033] According to [Fig. 4], a compensation tank 1' not covered by the invention has a tank housing 4' made of aluminum, also having a drying cartridge 8' and an activated carbon cartridge 12', a first valve 9' being arranged in the area of ​​the activated carbon cartridge 12', so that in the event of excess pressure prevailing in the tank housing 4', air 2' can be expelled into the environment via the first valve 9' and the activated carbon cartridge 12'. Fresh air 2a' from the environment can be sucked in via a second valve 10' in the event of a negative pressure prevailing in the tank housing 4'. The sucked in fresh air 2a' then flows through the drying cartridge 8'.

[0034] In [Fig. 4], the reservoir housing 4' is at least partially made of an extruded aluminum profile, which is sealed on the longitudinal end side by two end caps 15' also made of aluminum. The end caps 15' are fixed, for example removably, to the reservoir housing 4', which allows replacement of the drying cartridge 8' and / or the activated carbon cartridge 12' without replacing the reservoir housing 4', only by removing the end caps 15' and subsequently replacing the end caps 15'. The drying cartridge 8' or the activated carbon cartridge 12' is pre-tensioned against the reservoir housing 4' by means of corresponding springs 14' and is thus held without rattling.

Claims

Claims

1. Compensation tank (1) for a battery cooling system (3), - comprising a tank housing (4) made of plastic, comprising a first shell (5) and a second shell (6) connected thereto, - in which a first receptacle (7) is formed in the first shell (5) and / or in the second shell (6), - comprising a drying cartridge (8) housed in a form-fitting manner in the first receptacle (7), - comprising a first valve (9) via which, in the event of excess pressure in the compensation tank (1), air (2) from the compensation tank (1) enters the environment, - comprising a second valve (10) via which, in the event of a negative pressure in the compensation tank (1), fresh air (2a) from the environment enters the compensation tank (1).

2. Compensation tank according to claim 1, characterized in that - a second receptacle (11) is formed in the first shell (5) and / or in the second shell (6), - an activated carbon cartridge (12) is received in a form-fitting manner in the second receptacle (11). 3 Compensation tank according to claim 2, characterized in that the first valve (9) is arranged in an intermediate wall (13) which separates the second receptacle (11) from an interior space (16) of the tank housing (4). 4 Compensation tank according to claim 2 or 3, characterized in that a spring (14) is provided, which pre-tensions the drying cartridge (8) or the activated carbon cartridge (12) against the tank housing (4). 5 Compensation tank according to one of the preceding claims, characterized in that the first shell (5) and / or the second shell (6) are produced as plastic injection-molded parts. 6 Compensation tank according to one of the preceding claims, characterized in that the first shell (5) and the second shell (6) are welded, clipped, screwed or glued to each other. 7 Compensation tank according to one of the preceding claims, characterized in that the first shell (5) and / or the second shell (6) are made of polyoxymethylene (POM) or polyketone. 8 Compensation tank according to one of the preceding claims, characterized in that the first shell (5) and / or the second shell (6) have glass fibers, in particular a proportion of glass fibers of 25% in the plastic material. 9 Compensation tank according to one of the preceding claims, characterized in that the second valve (10) is arranged in an outer wall of the tank housing (4), which outer wall separates the first housing (7) from the environment. 10 Battery cooling system (3) comprising a compensation tank (1) according to one of the preceding claims.

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