Drying device, compensation tank and battery cooling system

Abstract

The invention relates to a drying device (8) for a compensation tank (1) for a battery cooling system (3), - in which the drying device (8) has an air-permeable, bag-like housing (15) in which a drying agent is arranged, or - in which the drying device (8) has a dimensionally stable drying body (17) made of a sintered, extruded or injected drying agent. This enables a cost-effective and space-optimized design. Figure for abstract: Fig. 3

Description

Title of the invention: Drying device, compensation tank and battery cooling system

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

[0002] Electric or hybrid vehicles are attracting more and more attention from consumers due to their environmental aspects and are consequently becoming more and more widespread on the roads. In order to be able to increase both the autonomy and the performance of these electric or hybrid vehicles, it is sought to maintain a traction battery of such an electric or hybrid vehicle within an optimal temperature window for said traction battery, for which temperature regulation devices, in particular cooling devices, are used in a known manner.

[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 change in the volume of the coolant. An increase in temperature causes the coolant to expand, which, if a resulting overpressure cannot escape, could lead to a high pressure load in the compensation tank and possibly damage it, which must therefore be avoided. For this reason, compensation tanks of this type are generally connected to the environment in order to be able, if necessary, to reduce a temperature-induced pressure difference by expelling air into the environment.In order to prevent or at least reduce the unwanted emission of hydrocarbon compounds into the environment, activated carbon filters were previously provided, through which the air to be expelled into the environment passed and arranged separately from the compensation tank. When the coolant cools, it contracts, which creates a negative pressure in the compensation tank and causes fresh air to be drawn in from the environment. In order to prevent or at least reduce the unwanted moisture entering the coolant, drying cartridges were previously provided, in which a drying agent was arranged, through which the fresh air drawn in from the environment passed during the suction process and thus absorbed the moisture and dried the drawn-in fresh air.

[0004] The disadvantage of such drying devices, however, is their relatively expensive manufacture.

[0005] The present invention therefore addresses the problem that requires, for a drying device, an improved embodiment or at least an alternative embodiment, by means of which the known disadvantages of the state of the art can be overcome.

[0006] The present invention is based on the general idea of ​​constructing for the first time in a completely different manner a device for drying a compensation tank of a battery cooling system and thus being able to manufacture and install it extremely economically. The drying device according to the invention has either an air-permeable, bag-shaped housing, in which a drying agent, for example a bulk product, is arranged, or a dimensionally stable drying body made of a sintered, extruded or injected drying agent.Both the drying device comprising the bag-shaped housing and the drying agent arranged therein and the dimensionally stable drying body represent extremely economical embodiments here, which can furthermore be inserted in a form-fitting manner into associated receptacles in a tank housing of the compensation tank and thus be installed. Of course, such a dimensionally stable drying body can also be arranged in the bag-shaped housing. This also makes it possible to replace the drying device relatively simply by removing it from the tank housing and inserting a new drying device into the associated receptacle.

[0007] According to an advantageous improvement corresponding to the first alternative of the drying device according to the invention, the bag-shaped housing is made of polyester fabric. Polyester is lightweight and furthermore does not absorb moisture, so that the moisture absorption is solely due to the drying agent. The design of the bag-shaped housing made of polyester fabric offers the advantages of high strength, good machinability and weldability as well as high air permeability.

[0008] Suitably, the drying agent is arranged in the bag-shaped housing as a free-flowing bulk product. The drying device thus optimally adapts to an inner contour of the first housing in the reservoir housing of the compensation tank and can be accommodated therein in a form-fitting manner and in a fixed position. Such an embodiment also makes it possible to avoid manufacturing tolerances which can lead to an undesirable bypass flow in rigid housings.

[0009] In another advantageous embodiment, the drying agent comprises silica gel or zeolite. Silica gel is a colorless silicon dioxide of gelatinous, rubbery or solid consistency. It has a large surface area internal (approximately 600 m2 / g) and is highly hydrophilic. Zeolite can absorb up to half its own weight in moisture and thus produces heat, which can also promote drying. The use of zeolite offers a strong dehumidification effect even at low humidity, while silica gel has high water absorption and is also inexpensive.

[0010] Suitably, the non-deformable drying body made of a sintered, extruded or injected drying agent has a shape, in particular a bar shape, made in such a way as to be complementary to an inner contour of a first housing in a tank housing of a compensation tank. It is thus possible to achieve a form-fitting insertion of the drying device into the associated first housing of the tank housing, without the non-deformable, extruded, sintered or compressed drying agent requiring an additional housing, which makes it possible to reduce manufacturing costs.

[0011] The present invention is further based on the general idea of ​​providing a compensation tank for compensating an air volume due to a temperature-dependent change in the volume of a cooling fluid, in particular oil, comprising a two-shell tank housing having a first housing in which the drying device according to the invention can be arranged in a form-fitting manner. The compensation tank according to the invention, in particular for air, for a battery cooling system has the aforementioned plastic tank housing having a first shell and a second shell sealed thereto.The first housing is made in the first shell and / or in the second shell, in which the drying device according to the invention is housed by form fit in accordance with one of the preceding paragraphs comprising a drying agent, for example zeolite or silica gel, while an activated carbon cartridge can be arranged in a second housing which can also be arranged in the first shell and / or in the second shell. Such an activated carbon cartridge is then capable of absorbing pollutants such as for example hydrocarbons.Furthermore, a first valve is provided, via which, in the event of excess pressure in the compensation tank, air can be expelled from the compensation tank into the environment, and a second valve is provided, via which, in the event of a negative pressure in the compensation tank, fresh air can be drawn into the compensation tank from the environment. By "fresh air" can / must be understood the ambient air. The two-shell design of the tank housing of the compensation tank with the drying device and the activated carbon cartridge arranged therein makes it possible to create a tank housing of the compensation tank which is very economical overall. while at the same time having assembly advantages, since it is sufficient to simply insert the drying device designed as an insert part into the first receptacle of the first and / or second shell and optionally the activated carbon cartridge designed as an insert part into the second receptacle of the first and / or second shell in a form-fitting manner, and then to connect the two shells of the tank housing to each other in a sealed manner. This also allows a protected arrangement of the drying device or the activated carbon cartridge in the tank housing over its entire service life. The production of the tank housing as well as the subsequent assembly of the drying cartridge or the activated carbon cartridge, which were previously necessary, can thus be completely omitted.The manufacture of the compensation tank according to the invention can even be automated in particular, since the inner contour of the first housing, which is designed to be substantially complementary to an outer contour of the drying device, and the inner contour of the second housing, which is designed to be substantially complementary to an outer contour of the activated carbon cartridge, make it possible to achieve a form-fitting insertion of the drying device into the first housing and of the activated carbon cartridge into the second housing without the need for an operator.Due to the arrangement of both the first valve and the second valve at the tank housing, these two valves can also be replaced when the drying device / activated carbon cartridge is replaced and / or when the tank housing is replaced, which, for example, reliably prevents the valves from becoming blocked due to prolonged use.

[0012] 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, depending on the temperature of the coolant, is put under pressure or under vacuum by an expansion or contraction of said coolant. By arranging the first valve in the intermediate wall which separates the second housing from the interior space of the tank housing, it is possible to achieve a direct association of the first valve with the second housing. Downstream of the second housing is certainly provided an opening in a wall of the tank housing towards the outside for exchange with the environment.

[0013] 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 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 device is arranged. The fresh air drawn in from the environment is thus drawn in by the drying agent of the drying device and thus dried, which in particular prevents moisture and / or water from being introduced into the compensation tank. Too much moisture could make the coolant electrically conductive, which, under unfavorable circumstances, in particular in the case of immersion cooling, could cause a short circuit.

[0014] The second valve described can also be designed as a double valve, which also allows air to be expelled from the tank housing into the environment.

[0015] In a particularly preferred embodiment, a spring is arranged on the activated carbon cartridge, which spring pre-tensions the activated carbon cartridge against the reservoir housing. Such a spring makes it possible to achieve a reliable and positionally fixed arrangement of the activated carbon cartridge in the second housing, the spring pre-tensioning at the same time preventing the activated carbon cartridge from producing, during operation, popping noises which are perceived as annoying, for example. Such a spring can, for example, be implemented as an inexpensive helical spring.The spring also makes it possible to pre-stress the activated carbon produced, for example, in the form of a bulk product, but also, for example, the activated carbon arranged in a bag, in particular made of polyester, in the activated carbon cartridge, since a cover can slide like a piston in a pot of the activated carbon cartridge, which allows said activated carbon to be less worn during operation.

[0016] In a particularly preferred embodiment of the compensation tank according to the invention, the first shell and / or the second shell are produced as injection-molded plastic parts. The design of the first and / or the second shell as injection-molded plastic parts has the great advantage that the tank housing and thus also the compensation tank can be manufactured not only with high quality, but also at a favorable price.

[0017] Suitably, the first shell and the second shell are welded together. When the two shells are made as injection-molded parts of plastic, it is advantageous to weld them together to ensure a tight connection between the two shells. Alternatively, it is of course also possible to glue the two shells together. 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 of being able to open the tank housing to replace the drying device or the activated carbon cartridge and to be able to continue to use said tank housing after replacing the drying device or the activated carbon cartridge. In this case, a sealing gasket must still be inserted between the two shells.

[0018] In 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 having high mechanical strength and stiffness and, in addition, high wear resistance and low moisture absorption, which is particularly advantageous 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. Alternatively, it is also possible to use polyketone as the plastic material for the first and / or the second shell. Polyketones (PK) are high-performance thermoplastic polymers which have high impact strength, low wear, good solvent resistance and low water absorption.Polyketone also has a high environmental compatibility. In order to further increase the mechanical strength and also the wear resistance, the plastic can have glass fibers, in particular 25% glass fibers, and be produced in particular in the form of POM GF-25.

[0019] 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 with regard to the compensation tank. Concretely, the advantages of a battery cooling system equipped with a compensation tank according to the invention lie in a low-cost manufacturing, for a possibly necessary replacement of the drying device and / or the activated carbon cartridge, only the compensation tank or, in the case of an openable tank housing, only the drying device and / or the activated carbon cartridge having to be replaced.

[0020] Other important features and advantages of the invention will emerge from the subclaims, the diagrams and the description of the figures associated with the aid of the diagrams.

[0021] It goes without saying that the above-mentioned features and those which will be explained later can be used not only in the combination indicated in each case, but also in other combinations or alone, without departing from the scope of the present invention. The elements of a higher unit, such as for example a device, apparatus or arrangement, which are mentioned above and will be mentioned later, and are designated separately, may constitute separate parts or components of this unit or be integral areas or sections of this unit, even if this is shown differently in the diagram.

[0022] 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.

[0023] We see there, respectively schematically: [Fig.l]: view of a compensation tank according to the invention of a battery cooling system according to the invention, [Fig.2]: representation identical to that of [Fig.l], but from another perspective, [Fig.3]: sectional view of a compensation tank according to the invention comprising a drying device according to the invention and an activated carbon cartridge, [Fig.4]: sectional view identical to that of [Fig.3], but with another drying device.

[0024] According to Figures 1 and 2, a compensation tank 1 according to the invention for 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 Figures 3 and 4) is provided or produced, in which a drying device 8 is arranged in a form-fitting manner.

[0025] The drying device 8 corresponding to [Fig. 3] here has an air-permeable, bag-shaped housing 15 in which a drying agent is arranged. Alternatively, the drying device 8 may also have a non-deformable drying body 17 made of a sintered, extruded or injected drying agent, as illustrated in [Fig. 4].

[0026] If [Fig. 3] is observed, a drying device 8 can be seen in which the bag-shaped housing 15 is made of polyester fabric. Certainly, other materials resistant to the coolant in the battery cooling system 3 are also conceivable. The drying agent can be arranged as a bulk product in the bag-shaped housing 15, for example in the form of silica gel or zeolite in the form of beads. The outer contour of the drying device 8 can thus optimally adapt to the inner contour of the first housing 7, which allows for a reliable and form-fitting housing. The form-fitting housing makes it possible in particular to prevent an undesired bypass flow of the fresh air 2a drawn in.

[0027] The drying agent used for the non-deformable drying device 8 corresponding to [Fig. 4] may also comprise silica gel or zeolite. According to [Fig. 4], the non-deformable drying body 17 made of pressed, sintered, extruded or injected drying agent has a bar shape.

[0028] The drying device 8 or the drying body 17 may have a shape complementary to an inner contour of the first housing 7 in the reservoir housing 4 of the compensation reservoir 1, which makes it possible to achieve a form-fitting insertion of the drying device 8 into the associated first housing 7 of the reservoir housing 4, without the non-deformable drying body 17 made of extruded, sintered or injected drying agent requiring an additional housing, which makes it possible to reduce manufacturing costs.

[0029] Furthermore, the compensation tank 1 according to the invention has a first valve 9 through 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 through a second valve 10 in the event of a negative pressure in the compensation tank 1.

[0030] In the first shell 5 and / or in the second shell 6, a second housing 11 is furthermore provided, in which an activated carbon cartridge 12 (see also Figures 3 and 4) is housed in a form-fitting manner. The compensation tank 1 shown thus has the tank housing 4 with the two housings 7, 11 arranged therein and in which the drying device 8 or the activated carbon cartridge 12 is arranged. In the event of excess pressure in the compensation tank 1, the air 2 therefore flows out into the environment through the first valve 9 and the activated carbon cartridge 12 arranged in the second housing 11. 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 device 8 in which the sucked-in fresh air 2a is dried.

[0031] The first valve 9 is for this purpose 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 for this purpose arranged in an outer wall of the tank housing 4, which outer wall separates the first housing 7 from the environment. Certainly, the second valve 10 described above and a further pressure relief valve, via which an expulsion of air 2 from the compensation tank 1 into the environment is carried out, can also be arranged in the outer wall of the tank housing 4.

[0032] If we continue to observe Figures 3 and 4, we can see that a spring 14 is arranged on the activated carbon cartridge 12, which spring prestresses the activated carbon cartridge 12 against the reservoir housing 4, here specifically against the intermediate wall 13. The spring 14 makes it possible to obtain a vibration-free and therefore rattling-free fixing of the activated carbon cartridge 12 in the second housing 11. This makes it possible in particular to improve user comfort due to the reduction in noise.

[0033] The first shell 5 and / or the second shell 6 can be produced as injection-molded parts made of plastic, which not only allows high-quality production, but also inexpensive production. 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 reservoir housing 4 to replace the drying device 8 or the activated carbon cartridge 12 and to be able to continue to use said reservoir housing after the drying device 8 or the activated carbon cartridge 12 has been replaced.

[0034] The first shell 5 and / or the second shell 6 can be made of polyoxymethylene (POM) or polyketone, i.e. a plastic material with high strength and low moisture absorption, which is particularly advantageous for a compensation tank 1 for air 2 of a battery cooling system 3. In order to be able to further increase the strength and also the wear resistance of the tank housing 4, the plastic material of the two shells 5, 6 can be reinforced with fibers, in particular glass fibers. Preferably, the first shell 5 and / or the second shell 6 have glass fibers, in particular a proportion of 25% of glass fibers in the plastic material.

[0035] All things considered, the drying device 8 according to the invention, 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 economical and space-optimized solution.

Claims

Claims

1. Drying device (8) for a compensation tank (1) for a battery cooling system (3), - in which the drying device (8) has an air-permeable, bag-shaped housing (15) in which a drying agent is arranged, or - in which the drying device (8) has a dimensionally stable drying body (17) made of a sintered, extruded or injected drying agent.

2. Drying device according to claim 1, first alternative, characterized in that the bag-shaped housing (15) is made of polyester fabric.

3. Drying device according to claim 1, first alternative, characterized in that the drying agent is arranged as a bulk product in the bag-shaped housing (15).

4. Drying device according to claim 1, second alternative, characterized in that the drying body (17) has a bar shape.

5. Drying device according to one of the preceding claims, characterized in that the drying agent comprises silica gel or zeolite.

6. 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 device (8) according to one of the preceding claims 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), air (2) enters the environment, compensation (1), fresh air (2a) from the environment arrives in the compensation tank (1).

7. Compensation tank according to claim 6, characterized in that - a second housing (11) is formed in the first shell (5) and / or in the second shell (6), - an activated carbon cartridge (12) is housed by form-fitting complementarity in the second housing (11).

8. Compensation tank according to claim 6 or 7, characterized in that the first valve (9) is arranged in an intermediate wall (13) which separates the second housing (11) from an interior space (16) of the tank housing (4).

9. Compensation tank according to one of claims 6 to 8, characterized in that the first shell (5) and / or the second shell (6) are produced as injection-molded plastic parts.

10. Compensation tank according to one of claims 6 to 9, characterized in that the first shell (5) and the second shell (6) are welded, clipped, screwed or glued to each other.

11. Compensation tank according to one of claims 6 to 10, characterized in that the first shell (5) and / or the second shell (6) are made of polyoxymethylene (POM) or polyketone.

12. Compensation tank according to one of claims 6 to 11, characterized in that the first shell (5) and / or the second shell (6) have glass fibers, in particular a proportion of 25% of glass fibers in the plastic material.

13. Compensation tank according to one of claims 6 to 12, 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.

14. Battery cooling system (3) comprising a compensation tank (1) according to one of claims 6 to 13.

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