Battery arrangement

Abstract

A battery arrangement (20) comprising a battery (30) and a cooling system (22), in which the battery (30) comprises a battery housing (64) with a fluid line (66), in which the cooling system (22) comprises a cooling circuit (42) and an expansion tank (46), in which the fluid line (66) forms part of the cooling circuit (42), in which the expansion tank (46) is connected to the cooling circuit (42), has a fluid space (51) and is designed to change the volume of the fluid space (51) depending on a change in the volume of a coolant (43) in the cooling circuit (42), in which the expansion tank (46) comprises an expansion tank housing (47), a separating element (48) and a sealing element (50), in which the separating element (48) is displaceable relative to the expansion tank housing (47), and in which the sealing element (50) is arranged between the separating element (48) and the expansion tank housing (47),to create a seal in this area.

Description

[0001] The invention relates to a battery arrangement.

[0002] DE 10 2021 006 067 A1 shows an expansion tank for a battery cooling system, in which an expansion tank has a housing and a flexible, fluid-tight shell.

[0003] DE 10 2015 200 700 A1 shows an expansion tank for a directly cooled battery, in which an equalizing device has a receiving volume limited by a diaphragm bellows.

[0004] DE 10 2021 115 321 A1 shows a pressure compensation device for a component with a closed interior, a housing, a movable element arranged therein, wherein the component is designed to be exposed on one side to a pressure prevailing in the interior and on the opposite side to an external pressure outside the component, wherein the movable element is adjustable over a structurally predetermined path.

[0005] EP 2 290 729 A1 shows an energy storage device with an energy storage housing and a volume compensation device in the form of a bellows, a rolling diaphragm or a bladder accumulator.

[0006] DE 10 2019 214 755 A1 shows a pressure equalization device for a battery.

[0007] DE 30 01 989 A1 shows an expansion vessel for a heating or cooling system in which the expansion vessel has a membrane for separating a water space from a gas space.

[0008] DE 10 2018 215 477 A1 shows a battery system with a battery module, with a housing and with a coolant circuit which has a pressure equalization unit.

[0009] DE 10 2013 215 699 A1 shows a battery with a tightly sealable battery housing, and the battery housing has a pressure equalization system.

[0010] It is therefore an object of the invention to provide a new battery arrangement.

[0011] This problem is solved by the subject matter of claim 1.

[0012] A battery arrangement comprises a battery and a cooling system, in which the battery has a battery housing with a fluid line, in which the cooling system has a cooling circuit and an expansion tank, in which the fluid line forms part of the cooling circuit, in which the expansion tank is connected to the cooling circuit, has a fluid space and is designed to change the volume of the fluid space depending on a change in the volume of a coolant in the cooling circuit, in which the expansion tank has an expansion tank housing, a separating element and a sealing element, in which the separating element is displaceable relative to the expansion tank housing, and in which the sealing element is provided between the separating element and the expansion tank housing in order to effect a seal in this area.With such cooling, temperature-dependent volume fluctuations of the coolant can occur, and the movable separating element enables a compact expansion tank.

[0013] According to a preferred embodiment, the battery comprises battery cells, and the battery cells are located at least partially in the cooling circuit to enable direct cooling of the battery. Direct cooling is particularly effective, but significant volume changes occur.

[0014] According to a preferred embodiment, the battery is designed to generate an alternating voltage which lies in a range between 30 V and 1,500 V, preferably between 300 V and 1,300 V. In such high-voltage batteries, a lot of heat energy can occur, and the expansion tank can be used particularly effectively in this case.

[0015] According to a preferred embodiment, the battery is designed to generate a direct voltage which lies in a range between 60 V and 1,900 V, preferably in a range between 300 V and 1,600 V. In such high-voltage batteries, a lot of heat energy can occur, and the expansion tank can be used particularly effectively in this case.

[0016] According to a preferred embodiment, the expansion tank is connected to the cooling circuit in an area outside the battery. This allows the battery to be designed relatively compactly, and a suitable location with good cooling options can be selected for the expansion tank.

[0017] The expansion tank has a first chamber on the side of the separating element facing away from the fluid chamber. Such a first chamber allows for a defined movement of the separating element, and the first chamber can also be protected, for example, by a filter.

[0018] The first chamber has a fluid opening and is in fluid communication with the surroundings of the expansion tank via the fluid opening to enable pressure equalization. This allows for a reduction in the maximum pressures occurring in the cooling circuit.

[0019] The fluid opening has a moisture filter to prevent or at least reduce the ingress of moisture into the first chamber. This advantageously reduces the risk of moisture penetrating the coolant and the associated deterioration of the electrical insulation.

[0020] According to a preferred embodiment, the sealing element is designed to seal the area between the separating element and the expansion tank housing against the passage of moisture from the first chamber into the fluid chamber. This advantageously reduces the risk of moisture entering the coolant and the associated deterioration of the electrical insulation.

[0021] According to a preferred embodiment, the sealing element has a contact surface that is in contact with the expansion tank housing but is not rigidly connected thereto, and in which the contact surface is designed to also perform a displacement relative to the expansion tank housing upon displacement of the separating element relative to the expansion tank housing. Such a contact surface enables a good seal, and a sealing element fixed on both sides between the separating element and the expansion tank housing is not necessary.

[0022] According to a preferred embodiment, the separating element has a plate-shaped section or a spherical section. A plate-shaped section allows for easy formation of the separating element. A spherical section reduces the risk of the separating element becoming jammed.

[0023] According to a preferred embodiment, the separating element is rigid. This allows for a largely constant pressure in the area of ​​the sealing element.

[0024] According to a preferred embodiment, a sliding guide is provided between the separating element and the expansion tank housing, in particular with a piston rod or with a wall of the separating element extending in the direction of displacement of the separating element. This reduces the risk of the separating element becoming jammed.

[0025] According to a preferred embodiment, the cooling circuit comprises a pump and a heat exchanger.

[0026] A coolant is provided in the cooling circuit. The coolant is a dielectric coolant to reduce the risk of short circuits.

[0027] According to a preferred embodiment, a vehicle has such a battery arrangement. This enables a powerful battery arrangement in a vehicle.

[0028] Further details and advantageous developments of the invention will become apparent from the exemplary embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, as well as from the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the present invention. It shows: Fig. 1 shows a schematic representation of a vehicle with a battery arrangement and with an expansion tank, Fig. 2 shows a schematic representation of another embodiment of the expansion tank of Fig. 1, Fig. 3 shows a schematic representation of another embodiment of the expansion tank of Fig. 1, and Fig. 4 shows a schematic representation of another embodiment of the expansion tank of Fig. 1.

[0029] In the following, identical or functionally identical parts are provided with the same reference symbols and are usually described only once. The description builds on each figure to avoid unnecessary repetition.

[0030] Fig. 1 shows a schematic representation of a vehicle 10 with a battery arrangement 20.

[0031] The battery assembly 20 has a cooling system 22 and a battery 30.

[0032] The battery 30 has a battery housing 64 with a fluid line 66.

[0033] In the exemplary embodiment, the fluid line 66 is connected to a heat exchanger 34 via a fluid line 32, the heat exchanger 34 is connected to a pump 38 via a fluid line 36, and the pump 38 is connected to the battery 30 via a fluid line 40. This enables a cooling circuit 42, wherein the flow sequence of the heat exchanger 34, the pump 38, and the battery 30 can also be interchanged individually or as a whole.

[0034] A coolant 43 is preferably provided in the cooling circuit 42 to enable good heat transfer.

[0035] In the exemplary embodiment, an expansion tank 46 is in fluid communication with the fluid line 36 via a fluid line 44.

[0036] The expansion tank 46 is connected to the cooling circuit 42 in an area outside the battery 30. This enables a compact design of the battery 30.

[0037] The fluid line 66 forms part of the cooling circuit 42. The battery 30 has battery cells 62, and the battery cells 62 are located at least partially, at least in regions, in the cooling circuit 42 to enable direct cooling of the battery 30.

[0038] The expansion tank 46 has an expansion tank housing 47, a separating element 48 and a sealing element 50. The separating element 48 separates the expansion tank into a fluid chamber 51 and a chamber 52, wherein the fluid chamber 51 is connected to the cooling circuit 41 and the chamber 52 is provided on the side of the separating element 48 facing away from the fluid chamber 51.

[0039] The separating element 48 is displaceable relative to the expansion tank housing 47 along a displacement direction 90 and enables a change in the volume of the cooling circuit 22. This is particularly advantageous for coolants 43 whose density is highly temperature-dependent. This is the case, for example, with dielectric coolants 43. Dielectric coolants are advantageously used for cooling electrical and electronic components because they are electrically non-conductive, thus reducing the risk of a short circuit.

[0040] In a closed system with a fixed total volume, significant pressure changes may occur. This pressure change can be significantly reduced with the expansion tank 46.

[0041] In the exemplary embodiment, the separating element 48 is rigid. This enables a good seal between the separating element 48 and the expansion tank housing 47.

[0042] In the exemplary embodiment, the separating element 48 has a plate-shaped section 81. This allows even large surfaces to be separated.

[0043] The sealing element 50 is provided between the separating element 48 and the expansion tank housing 47 in order to effect a seal in this area.

[0044] Examples of the sealing element 50 are a piston seal, a mechanical seal or a hydraulic seal.

[0045] The sealing element 50 has a contact surface 53 which is in contact with the expansion tank housing 47 but is not firmly connected thereto.

[0046] The contact surface 53 is designed to also carry out a displacement relative to the expansion tank housing 47 when the separating element is displaced relative to the expansion tank housing 47.

[0047] Chamber 52 has a fluid opening 54 and is in fluid communication with the surroundings 60 of the expansion tank 46 via the fluid opening 54 to enable pressure equalization. A gas 55, preferably air, is located in chamber 52.

[0048] The fluid opening 54 preferably has a moisture filter 56 to prevent or at least reduce the entry of moisture into the space 52.

[0049] The sealing element 50 is designed to seal the area between the separating element 48 and the expansion tank housing 47 against the passage of moisture from the first space 52 into the fluid space 51.

[0050] High-voltage batteries 30 in particular are subject to large temperature fluctuations, and they require efficient cooling. Direct cooling, in which the coolant 43 flows directly around the battery cells 62, is very effective for cooling the battery 30.

[0051] According to one embodiment, the battery 30 is preferably designed to generate an alternating voltage which lies in a range between 30 V and 1,500 V, preferably in a range between 300 V and 1,300 V.

[0052] According to a further embodiment, the battery 30 is preferably designed to generate a direct voltage which lies in a range between 60 V and 1,900 V, preferably in a range between 300 V and 1,600 V.

[0053] Such batteries 30 allow for a comparatively low current intensity even at high electrical power levels due to the high voltage, and can therefore be designed with a comparatively small cable diameter. This leads to a reduction in volume and weight.

[0054] The possibility of pressure equalization by moving the separating element 48 reduces the maximum pressure occurring in the system. This allows for a reduction in the material thickness of the cooling circuit 42.

[0055] The provision of the sealing elements 50 prevents or at least reduces the ingress of moisture or water via the space 52. The provision of the filter 56 further increases safety, since less moisture or water is present in the space 52 than without the filter 56.

[0056] Fig. 2 shows a schematic representation of another embodiment of the expansion tank 46 of Fig. 1. The expansion tank 46 has a sliding guide 95 between the separating element 48 and the expansion tank housing 47.

[0057] In the exemplary embodiment, the sliding guide 95 is designed as a wall 91 of the separating element 48 extending in the direction of displacement 90, wherein the wall 91 preferably protrudes beyond the plate of the separating element 48 in the direction of displacement. This reduces the risk of the separating element 48 becoming jammed.

[0058] Fig. 3 shows a schematic representation of another embodiment of the expansion tank 46 of Fig. 1. The expansion tank 46 has a sliding guide 95 between the separating element 48 and the expansion tank housing 47.

[0059] In the exemplary embodiment, the sliding guide 95 has a piston rod 92 connected to the separating element 48, which is guided in a piston rod guide 93. This prevents the separating element 48 from tilting.

[0060] Fig. 4 shows a schematic representation of another embodiment of the expansion tank 46 of Fig. 1. The expansion tank 46 has a separating element 48 with a spherical section 82. The separating element 48 can move within the expansion tank housing 47 and forms a seal against it. A layer serving as a sealing element 50 is provided on the inside of the expansion tank housing 47. The sealing element 50 is, for example, a plastic such as Teflon or polyethylene, which enables a good seal while simultaneously allowing the sealing element 50 to be moved.

[0061] In the examples of Fig. 1 to Fig. 3, the sealing element 50 is firmly connected to the separating element 48, and in the embodiment of Fig. 4, the sealing element 50 is firmly connected to the expansion tank housing 47.

[0062] Naturally, various variations and modifications are possible within the scope of the present invention.

Claims

[1] Battery arrangement (20) comprising a battery (30) and a cooling system (22), in which the battery (30) comprises a battery housing (64) with a fluid line (66), in which the cooling system (22) comprises a cooling circuit (42) and an expansion tank (46), in which a dielectric coolant (43) is provided in the cooling circuit (42), in which the fluid line (66) forms part of the cooling circuit (42), in which the expansion tank (46) is connected to the cooling circuit (42), has a fluid space (51) and is designed to change the volume of the fluid space (51) depending on a change in the volume of a coolant (43) in the cooling circuit (42), in which the expansion tank (46) comprises an expansion tank housing (47), a separating element (48) and a sealing element (50), in which the separating element (48) is arranged relative to the expansion tank housing (47) is movable,and in which the sealing element (50) is provided between the separating element (48) and the expansion tank housing (47) in order to effect a seal in this area, wherein the compensating tank (46) has a first space (52) on the side of the separating element (48) facing away from the fluid space (51), wherein the first space (52) has a fluid opening (54) and is in fluid communication with the environment (60) of the expansion tank (46) via the fluid opening (54) to enable pressure equalization, and wherein the fluid opening (54) has a moisture filter (56) to prevent or at least reduce the entry of moisture into the first space (52). [2] Battery arrangement (20) according to claim 1, wherein the battery (30) has battery cells (62), and wherein the battery cells (62) are at least partially located in the cooling circuit (42) in order to enable direct cooling of the battery (30). [3] Battery arrangement (20) according to one of the preceding claims, in which the battery (30) is designed to generate an alternating voltage which lies in a range between 30 V and 1,500 V, preferably between 300 V and 1,300 V. [4] Battery arrangement (20) according to one of the preceding claims, in which the battery (30) is designed to generate a direct voltage which lies in a range between 60 V and 1,900 V, preferably in a range between 300 V and 1,600 V. [5] Battery arrangement (20) according to one of the preceding claims, in which the expansion tank (46) is connected to the cooling circuit (42) in a region outside the battery (30). [6] Battery arrangement (20) according to one of the preceding claims, in which the sealing element (50) is designed to seal the area between the separating element (48) and the expansion tank housing (47) against the passage of moisture from the first space (52) into the fluid space (51). [7] Battery arrangement (20) according to one of the preceding claims, in which the sealing element (50) has a contact surface (53) which is in contact with the expansion tank housing (47) but is not firmly connected thereto, and in which the contact surface (53) is designed to also carry out a displacement relative to the expansion tank housing (47) when the separating element (48) is displaced relative to the expansion tank housing (47). [8] Battery arrangement (20) according to one of the preceding claims, wherein the separating element (48) has a plate-shaped portion (81) or a spherical portion (82). [9] Battery arrangement (20) according to one of the preceding claims, in which the separating element (48) is rigid. [10] Battery arrangement (20) according to one of the preceding claims, in which a sliding guide (95) is provided between the separating element (48) and the expansion tank housing (47), in particular with a piston rod (92) or with a wall (91) of the separating element (48) extending in the direction of displacement (90) of the separating element (48). [11] Battery arrangement (20) according to one of the preceding claims, in which the cooling circuit (42) comprises a pump (38) and a heat exchanger (34).

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