Degassing system of a high-voltage storage device

Abstract

A degassing system for a high-voltage storage device of a vehicle that is at least partially electrically powered is provided, wherein the high-voltage storage device has an outlet which serves to discharge any gas escaping from the high-voltage storage device in the event of a fault, wherein an air discharge device is arranged in a first connection area adjoining the outlet, which is configured to discharge the gas from the high-voltage storage device into an outlet pipe adjoining the outlet, characterized by a second connection area provided between the outlet pipe and the first connection area, as well as a propeller arranged in the second connection area and operatively connected to the air discharge device via a shaft, which is configured to draw in ambient air from outside the high-voltage storage device and to direct it to the outlet pipe.

Description

[0001] The invention relates to the field of electromobility and in particular to the field of degassing of high-voltage storage systems for vehicles.

[0002] Thermal runaway of lithium-based high-voltage storage systems (also known as high-voltage batteries or accumulators) is a failure that can occur due to chemical processes (exothermic reactions) within the storage system. In this condition, smoke (gas) can escape from one or more cells of the lithium-based high-voltage storage system and vent outside the vehicle. The smoke can be extremely hot, reaching temperatures of several hundred to over a thousand degrees Celsius. Furthermore, the escaping gas can ignite. Thermal runaway is a safety issue that must be addressed.

[0003] From DE 10 2013 200 739 A1, for example, a battery system with a ventilation system is known, which has a fan that is arranged on a drain of the ventilation system and which serves to extract exhaust gases from the high-voltage storage device in the event of damage.

[0004] From US patent 2011 / 0159326A1, a battery system with a venting system is known, which discloses a shaft with an impeller arranged therein for gas removal and a shaft with an impeller arranged therein for providing fresh air.

[0005] Since there is still a need for improvement in the removal of gases (degassing) in the event of thermal runaway of a high-voltage storage device, it is an object of the invention to provide an improved degassing of a high-voltage storage device.

[0006] This task is solved by the features of independent claims. Advantageous embodiments are the subject of dependent claims.

[0007] A degassing system for a high-voltage storage device of a vehicle that is at least partially electrically powered is provided, wherein the high-voltage storage device has an outlet which serves to discharge any gas escaping from the high-voltage storage device in the event of a fault, wherein an air discharge device is arranged in a first connection area adjoining the outlet, which is configured to discharge the gas from the high-voltage storage device into an outlet pipe adjoining the outlet, characterized by a second connection area provided between the outlet pipe and the first connection area, as well as a propeller arranged in the second connection area and operatively connected to the air discharge device via a shaft, which is configured to draw in ambient air from outside the high-voltage storage device and to direct it to the outlet pipe.

[0008] In one embodiment, the second connection area is designed to be fluid-tight, connecting to the first connection area and the outlet pipe. This prevents uncontrolled gas leakage between the connection areas.

[0009] In one version, the second connection area is designed to have openings allowing ambient air to be drawn in. This ensures a simple air supply.

[0010] In one design, the propeller directs ambient air into the outlet pipe, allowing the ambient air to mix with the gas. This results in efficient cooling.

[0011] In one embodiment, the second connection area is designed such that a portion of it surrounds the outlet pipe, creating a cavity, and the propeller directs ambient air into this cavity. This results in efficient cooling.

[0012] In one embodiment, the air extraction device is designed as a turbine or a turbine with an electric motor connected to it. This allows the gas flow to be controlled.

[0013] In one version, the fault condition is a thermal runaway.

[0014] Also provided is a vehicle that is at least partially electrically powered, featuring a high-voltage storage system and the described degassing system.

[0015] Furthermore, a method for controlling the described degassing system is provided in order to degas a high-voltage storage device in the event of a fault, whereby the high-voltage storage device is monitored in such a way that, in the event of a fault being detected in which gas escapes from the high-voltage storage device, components of the degassing system are controlled in such a way that the escaping gas is removed from the high-voltage storage device and ambient air is directed towards the outlet pipe.

[0016] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures in the drawing, which shows details of the invention, and from the claims. The individual features can be implemented individually or in any combination in a variant of the invention.

[0017] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying figures. Fig. Figure 1 shows a high-voltage storage device with gas escaping from an outlet in case of a fault. Fig. Figure 2 shows a degassing system according to an embodiment of the present invention.

[0018] In the following figure descriptions, identical elements or functions are marked with the same reference symbols.

[0019] As mentioned in the introduction, in the event of a thermal runaway, gas (smoke) 3 can escape from one or more cells 1 of (especially lithium-based) high-voltage storage devices 2, which then flows out of the vehicle through the outlet 4 of the high-voltage storage device 2, as shown in Fig. Figure 1 is shown schematically. The gas 3 can be very hot. Furthermore, depending on the design of the high-voltage storage system 2, the cell type, and the cell chemistry, larger volume or mass flow rates in the range of 1000 l / s or 1 kg / s, and larger volumes / masses in the range of > 1000 l / > 0.5 kg, are to be expected.

[0020] It is important that, in the event of a thermal runaway, the gas 3 generated within the high-voltage storage unit 2 is removed from the cells 1 and from the high-voltage storage unit 2 to prevent damage to the cells 1 and / or the housing of the high-voltage storage unit 2. This process is called degassing. Each high-voltage storage unit 2 has at least one degassing outlet (hereinafter referred to as outlet 4) for venting gas 3 generated within the high-voltage storage unit 2, preferably to the outside of the vehicle.

[0021] In Fig. Figure 2 shows an embodiment that provides improved degassing in the event of a thermal runaway. Here, an air extraction device 5 is provided in the first connection area 40 of the outlet 4, which is directly adjacent to the area of ​​the high-voltage storage unit 2 in which the cells 1 are arranged. The first connection area 40 serves as an extension of the outlet 4 and thus as a housing for the air extraction device 5.

[0022] In the Fig.In the embodiment shown in Figure 2, the air extraction device 5 is designed as a turbine, which is a preferred embodiment. The turbine is accelerated by the gas 3, which flows more rapidly at the beginning of the gas discharge from the high-voltage storage device 2. As the gas flow decreases in intensity, the rotational inertia ensures that the turbine continues to rotate for some time, continuing to extract gas 3 from the high-voltage storage device 2 and thus providing further venting. The turbine can also be equipped with an electric motor (actively coupled) which, in generator mode, can provide power for emergency functions such as hazard warning lights. In motor mode, the turbine can be started prematurely by the battery management system upon detection of a potential fault, allowing the resulting gas 3 to be extracted even more quickly and completely.

[0023] Furthermore, a propeller 6 (electrically driven and controllable) is provided at a second connection area 41 following the first connection area 40. This propeller is operatively connected to the turbine via a shaft 7 and serves to draw in ambient air 8 through corresponding openings 410 in the second connection area 41. This means that the openings 410 are located in a region of the second connection area 41 that is not connected to the interior of the high-voltage storage unit 2.

[0024] A second connection area 41 is connected to an outlet pipe 10 to direct the gas 3 into a predetermined area, e.g., outside the vehicle. The propeller 6 is thus arranged between the turbine 5 and the outlet pipe 10. This allows the ambient air 8 drawn in by the propeller 6 to be directed into the outlet pipe 10, thereby cooling the gas 3 flow from the high-voltage storage unit 2 by mixing it with the gas 3. The openings 410 and the end of the outlet pipe 10 are advantageously spaced apart to prevent the gas 2 exiting the outlet pipe 10 from being drawn back in.

[0025] The second connection area 41 is configured as a housing for the propeller 6, such that a portion of it encloses the propeller 6 and provides the openings 410. The connection area 41 is connected to the outlet pipe 10 so that the gas 2 flowing out of the outlet 4 can be discharged.

[0026] In another embodiment, a further section of the connection area 41 surrounds the outlet pipe 10, creating a pipe-in-pipe system. The second connection area 41 thus forms a cavity 9 around the outlet pipe 10, into which ambient air 8 can be introduced to cool the outlet pipe 10 and thus the gas 3 contained therein from the outside (i.e., without mixing gas 3 and ambient air 8).

[0027] The ambient air 8 drawn in by the propeller 6 can therefore only be directed into the outlet pipe 10 in order to cool the gas flow of gas 3 from the high-voltage storage unit 2 by mixing it with the gas 3. Alternatively, the ambient air 8 can only be directed into the cavity 9 (if a corresponding guidance system is present), or into both the outlet pipe 10 and the cavity 9, depending on the design of the degassing system.

[0028] The air extraction device 5 is not limited to a turbine with or without an electric motor. It can also be designed as a fan or other suitable device to extract the gas 3 from the high-voltage storage device 2.

[0029] All components used to provide the degassing system, in particular the air discharge device 5, the propeller 6, the connection areas 40, 41 and the outlet pipe 10, are made of a temperature-resistant material designed for the specified requirements. The preferred material is a steel alloy or another temperature-resistant alloy or ceramic or a ceramic-metal alloy.

[0030] The degassing system is used in vehicles that are at least partially electrically powered, i.e., in vehicles where a high-voltage storage system 2 is provided to power a drive component. The high-voltage storage system 2 can advantageously consist of several lithium-based cells 1.

[0031] Furthermore, a battery management system is provided which, in the event of a fault detection, can initiate measures to rectify the fault and / or warn a user. In the event of thermal runaway, the battery management system can control the air discharge device 5 (if a controllable component such as an electric motor is present) and the propeller 6 to facilitate degassing.

Claims

[1] Degassing system of a high-voltage storage device of a vehicle that is at least partially electrically powered, wherein the high-voltage storage device has an outlet (4) which serves to discharge a gas (3) escaping from the high-voltage storage device (2) in the event of a fault, wherein an air discharge device (5) is arranged in a first connection area (40) adjoining the outlet (4), which is configured to discharge the gas (3) from the high-voltage storage device (2) into an outlet pipe (10) adjoining the outlet (4), wherein a second connection area (41) is further arranged between the outlet pipe (10) and the first connection area (40), and a propeller (6) arranged in the second connection area (41) and operatively connected to the air discharge device (5) via a shaft (7), which is configured to draw in ambient air (8) from outside the high-voltage storage device (2) and to the outlet pipe (10). lead, characterized by, that the second connection area (41) is formed such that a part of it surrounds the outlet pipe (10) in such a way that a cavity (9) is formed, and that the propeller (6) directs the ambient air (8) into the cavity (9). [2] Degassing system according to claim 1, wherein the second connection area (41) is fluid-tightly connected to the first connection area (40) and the outlet pipe (10). [3] Degassing system according to claim 1 or 2, wherein the second connection area (41) has openings (410) such that ambient air (8) can be drawn in through the openings (410). [4] Degassing system according to one of the preceding claims, wherein the propeller (6) directs the ambient air (8) into the outlet pipe (10) so that the ambient air (8) mixes with the gas (3). [5] Degassing system according to one of the preceding claims, wherein the air removal device (5) is formed as a turbine or a turbine with an electric motor connected thereto. [6] Degassing system according to any of the preceding claims, wherein the fault condition is thermal runaway. [7] At least partially electrically powered vehicle comprising a high-voltage storage device (2) and a degassing system according to any of the preceding claims. [8] At least partially electrically powered vehicle according to claim 7, further comprising a battery management system which is configured to control the degassing system in such a way that the gas (3) escaping in the event of a fault is removed from the high-voltage storage (2) and ambient air (8) is supplied to the outlet pipe (10). [9] Method for controlling a degassing system according to one of claims 1 to 6 to degas a high-voltage storage device (2) in the event of a fault, wherein the high-voltage storage device (2) is monitored in such a way that, upon detection of a fault in which gas (3) escapes from the high-voltage storage device (2), components of the degassing system are controlled in such a way that the escaping gas (3) is removed from the high-voltage storage device (2) and ambient air (8) is directed towards the outlet pipe (10).

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