Patent Application
20250018335
The present disclosure relates to an electric vehicle exhaust system.
This section provides background information related to the present disclosure which is not necessarily prior art.
Vehicles with electric propulsion systems are becoming increasingly more common. Some electrically propelled vehicles include an electric drive motor at each wheel of the vehicle, and some electrically propelled vehicles include a front electric drive motor for rotating the front wheels of the vehicle and a rear electric drive motor for rotating the rear wheels of the vehicle. In either case, the electric drive motors receive power from a battery pack that includes a plurality of battery cells therein. Example battery cells include lithium-ion battery cells and lithium-metal battery cells.
Lithium-ion and lithium-metal battery cells sometimes undergo a process called thermal runaway during failure conditions. Thermal runaway may result in a rapid increase of battery cell temperature accompanied by the release of various gases, which in some cases may be flammable. These flammable gases may be ignited by the high temperature of the battery, which may result in a fire. Accordingly, in the event of a thermal runaway, it is desirable that the vehicle include features that assist in preventing, or at least substantially minimizing, the ignition of various gases that are generated during the thermal runaway.
This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.
According to a first aspect of the present disclosure, there is provided a vehicle including a battery pack including a plurality of battery cells; a pipe in communication with the battery pack, and configured to collect a flow of gases that are generated by the plurality of battery cells; and a battery gas treatment system in communication with the pipe that is configured to treat the flow of gases that are generated by the plurality of battery cells, wherein the battery gas treatment system is configured to treat the flow of gases by at least one of cooling the flow of gases and chemically treating the flow of gases to eliminate or at least reduce a number of various chemical species from the flow of gases.
According to the first aspect, the pipe includes a jacket configured for receipt of a cooling fluid that is configured to cool the flow of gases within the pipe.
According to the first aspect, the vehicle further includes a source of the cooling fluid, wherein the source of the cooling fluid is at least one of a vehicle radiator and a container containing a cryogenic cooling fluid.
According to the first aspect, the vehicle further includes a tank configured to store a battery gas treatment fluid and a dosing device in communication with each of the tank and the pipe, wherein the dosing device is configured to inject the battery gas treatment fluid into the flow of gases within the pipe.
According to the first aspect, the vehicle further includes a mixing device located within the pipe at a location downstream from the dosing device.
According to the first aspect, the vehicle further includes a controller in communication with battery gas treatment system and a first temperature sensor, wherein the first temperature sensor is configured to generate a signal indicative of a temperature of the battery pack.
According to the first aspect, after receipt of the signal indicative of the temperature of the battery pack, the controller is configured to instruct the battery gas treatment system to treat the flow of gases.
According to the first aspect, the vehicle further includes a second temperature sensor in communication with the controller and configured to generate a signal indicative of a temperature the flow of gases travelling through the pipe.
According to the first aspect, the vehicle further includes a battery gas conversion device in communication with the pipe and configured to receive the flow of gases.
According to the first aspect, the battery gas conversion device includes a plurality of treatment zones for chemically treating the flow of gases to eliminate or at least reduce the number of various chemical species from the flow of gases.
According to the first aspect, the vehicle further includes a tank configured to store a battery gas treatment fluid and a dosing device in communication with each of the tank and the battery gas conversion device, wherein the dosing device is configured to inject the battery gas treatment fluid into the flow of gases within the battery gas conversion device.
According to a first aspect of the present disclosure, there is provided a vehicle including a battery pack including a plurality of battery cells; a pipe in communication with the battery pack, and configured to collect a flow of gases that are generated by the plurality of battery cells; a battery gas treatment system in communication with the pipe that is configured to treat the flow of gases that are generated by the plurality of battery cells; and a battery gas conversion device in communication with the pipe and configured to receive the flow of gases, wherein the battery gas treatment system is configured to treat the flow of gases by at least one of cooling the flow of gases and chemically treating the flow of gases to eliminate or at least reduce a number of various chemical species from the flow of gases; and wherein the battery gas conversion device includes a plurality of treatment zones for chemically treating the flow of gases to eliminate or at least reduce the number of various chemical species from the flow of gases.
According to the second aspect, the pipe includes a jacket configured for receipt of a cooling fluid that is configured to cool the flow of gases within the pipe.
According to the second aspect, the vehicle also includes a source of the cooling fluid, wherein the source of the cooling fluid is at least one of a vehicle radiator and a container containing a cryogenic cooling fluid.
According to the second aspect, the vehicle also includes a tank configured to store a battery gas treatment fluid, a first dosing device in communication with each of the tank and the pipe, and a second dosing device in communication with each of the tank and the battery gas conversion device, wherein the first dosing device is configured to inject the battery gas treatment fluid into the flow of gases within the pipe and the second dosing device is configured to inject the battery gas treatment fluid into the flow of gases within the battery gas conversion device.
According to the second aspect, the vehicle also includes a mixing device located within the pipe at a location downstream from the first dosing device.
According to the second aspect, the battery gas conversion device includes a plurality of treatment zones for chemically treating the flow of gases to eliminate or at least reduce the number of various chemical species from the flow of gases.
According to the second aspect, the vehicle also includes a controller in communication with battery gas treatment system and a first temperature sensor, wherein the first temperature sensor is configured to generate a signal indicative of a temperature of the battery pack.
According to the second aspect, after receipt of the signal indicative of the temperature of the battery pack, wherein the controller is configured to instruct the battery gas treatment system to treat the flow of gases.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings. The example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
Still referring to
While not required, it should also be understood that vehicle 10 may also include an internal combustion engine (ICE) 20 such that vehicle 10 may be a hybrid electric vehicle. In the event that vehicle 10 is a hybrid electric vehicle including ICE 20, vehicle 10 may also include a heat exchanger or radiator 22 for cooling ICE 20 during operation thereof. Vehicle 10 may include a controller 24 that may communicate with battery pack 12, electric drive module(s) 18, and an electronic control unit (ECU) 26 of ICE 20.
As noted above, battery cells 14 may sometimes undergo a process called thermal runaway during failure conditions of the battery cell(s) 14. Thermal runaway may result in a rapid increase of battery cell temperature accompanied by the release of various gases, which in some cases may be flammable. Example gases that may be released during a thermal runaway event include hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), and various hydrocarbons including, but not limited to, methane, ethane, ethylene, acetylene, propane, cyclopropane, and butane. As these gases are released and the temperature of battery pack 12 increases, the pressure within battery pack 12 also increases. Housing 16 of battery pack 12, therefore, includes a plurality of vents 28 that permit the pressure and gases to escape housing 16. Vents 28 may each include a valve 30 that may be a one-way valve and opens upon a predetermine pressure threshold being generated within housing 16. For example, if the pressure within housing 16 reaches 100 millibars the valves 30 may open and permit the gases within housing 16 to exit the battery pack 12. Vents 28 may be in communication with various conduits 27, which direct the gases generated during the thermal runaway event to the vents 28 to be expelled from battery pack 12.
While housing 16 may include vents 28 including valves 30 for releasing the gases from battery pack 12, the gases released from battery pack 12 may collect beneath the vehicle 10. If the gases are at a sufficient temperature, the gases may combust after exiting battery pack 12 at a location beneath vehicle 10. If this occurs, there is the potential for other features of the vehicle 10 to also combust including, for example, the tires (not shown) of the vehicle 10, hoses (not shown), vehicle brakes (not shown) and other features. In order to prevent, or at least substantially minimize, the gases from collecting beneath vehicle 10, it should be understood that battery pack 12 may also include a manifold 32 attached to housing 16 of battery pack 12 and in communication with vents 28 that collect the gases that are generated during the thermal runaway event. Manifold 32, in turn, is connected to a pipe 34 that communicates the gases to the atmosphere. Notably, pipe 34 communicates the gases in a direction away from underneath vehicle 10 (e.g., toward a rear of the vehicle) such that pipe 34 is similar to a tailpipe.
When a thermal runaway event occurs, the gases generated during failure of batteries 14 will enter the various conduits 27 and travel in a direction toward vents 28. As the pressure increases in battery pack 12 and reaches the predetermined threshold (e.g., 100 millibars), valves 30 will open and permit the gases to enter and collect in manifold 32 before entering pipe 34 and being directed to the atmosphere at location away from underneath vehicle 10. While it is beneficial to direct the gases away from vehicle 10, it should be understood that the gases generated during the thermal runaway event may still be hazardous to occupants of the vehicle or any person located proximate to vehicle 10 during the thermal runaway event. Accordingly, the present disclosure provides a battery gas treatment system 36 having various components that are configured to treat the gases such that the gases are less hazardous.
Battery gas treatment system 36 is configured to cool the gas flow generated during the thermal runaway event as well as chemically treat the various chemical species present in the gas flow. The gas flow can be cooled in different ways, dependent on the type of vehicle 10. For example, if vehicle 10 is a hybrid electric vehicle including ICE 20 and radiator 22, a first coolant line 38 may direct coolant of radiator 22 to a jacket 40 that surrounds pipe 34. Coolant in first coolant line 38 may be drawn to jacket 40 using a pump 42. After circulating in jacket 40, the coolant may be directed back to radiator 22 using a second coolant line 44. As the gas flow travels through pipe 34, the gas flow will exchange heat with the coolant located in jacket 40 and be cooled.
As illustrated in
While the above description is directed to a vehicle 10 including ICE 20 and radiator 22, it should be understood that even if vehicle 10 does not include ICE 20, vehicle 10 may still include radiator 22 for the purpose of heating/cooling a cabin (not shown) of vehicle 10. Accordingly, even if vehicle 10 does not include ICE 20 (i.e., is not a hybrid vehicle), the above configuration is also equally applicable to vehicles 10 that include battery pack 12 and radiator 22.
Another configuration that can be used to cool the gas flow generated during the thermal runaway event is one that includes a separate source of cooling fluid. As illustrated in
Similar to the above-described cooling system using radiator 22, if first temperature sensor 46 generates a signal indicative of a temperature to controller 24 that indicates a thermal runaway event may be occurring, controller 24 may be configured to instruct pump 54 to begin operation and begin drawing coolant from coolant source 50 to jacket 40 to cool the gas flow generated by the thermal runaway event. If temperatures detected by second temperature sensor 48 are not commensurate with a desired reduction in temperature, controller 24 may instruct pump 54 to increase speed to draw additional coolant to jacket 40 to further lower the temperature of the gas flow in pipe 34. While not illustrated in
As noted above, battery gas treatment system 36 may also include components to chemically treat the various chemical species located in the gas flow generated during the thermal runaway event. In this regard, gas treatment system 36 may include a tank 58 that stores a battery exhaust gas treatment fluid and a dosing device 60 (e.g., injector) that doses the battery exhaust gas treatment fluid into the gas flow located in pipe 34. A connection line 62 communicates the battery exhaust gas treatment fluid stored in tank 58 to dosing device 60.
Dosing device 60 is in communication with controller 24. Upon receipt of a signal from temperature sensor 46 that a thermal runaway event may be occurring, controller 24 can instruct dosing device 60 to begin dosing the battery exhaust gas treatment fluid into the gas flow located in pipe 34. To assist with intermixing of the battery exhaust gas treatment fluid with the battery gases located in pipe 34, pipe 34 may include a mixing device 64. Mixing device 64 may be a static mixing device having a plurality of vanes 66 that are configured to swirl the gas flow and battery exhaust gas treatment fluid as it travels through pipe 34, which results in improved intermixing of the battery gas exhaust gas treatment fluid and the battery gases located in pipe 34.
As the battery exhaust gas treatment fluid intermixes with the battery gases within pipe 34, the battery exhaust gases may be cooled. In this regard, battery exhaust gas treatment fluid is preferably a liquid and as the liquid intermixes with the hot battery gases, the liquid may undergo phase change to gas. In addition, battery exhaust gas treatment fluid may also react with various chemical species of the battery gases and cause the chemical species to either non-hazardous or less hazardous chemical species. Battery exhaust gas treatment fluid may include at least one of water or other liquid that can cool the battery exhaust gases during intermixing and due to evaporation of the battery exhaust treatment fluid, and a liquid that includes chemical species such as KOH (potassium hydroxide), NaOH (sodium hydroxide), and monoethanolamine (MEA) for reacting with the chemical species of the battery gases to reduce the corrosive nature of the battery gases and/or reduce combustibility of the battery gases. For example, battery exhaust gas treatment fluid may include chemical species that oxidize H2 and CO to H2O and CO2, respectively, which are less hazardous (i.e., less combustible, and poisonous, respectively). Preferably, the battery exhaust gas treatment fluid is non-toxic.
Now referring to
Now referring to
In the illustrated embodiment, first treatment zone 108 may be located proximate inlet 105 and is configured to remove or least reduce hydrogen gas (H2) from the battery exhaust gas flow. In this regard, first treatment zone 108 may include a plurality of titanium hydride plates that are configured to absorb H2 from the battery exhaust gas flow. While titanium hydride is a material preferable to absorb the H2 from the battery exhaust gas flow, it should be understood that other metal hydrides such as magnesium hydride and sodium aluminum hydride may also be used in place of or in addition to titanium hydride.
In the illustrated embodiment, second treatment zone 110 and third treatment zone 112 may be located downstream from first treatment zone 108. It should be understood, however, that each or one of these zones may be located upstream from first treatment zone 108. In any event, second treatment zone 108 and third treatment zone 112 collectively work to remove or at least reduce amounts of CO and CO2 present in the battery exhaust gas flow.
More particularly, second treatment zone 110 may include beds or grids coated with catalysts such as platinum, palladium, rhodium, or other precious metals that facilitate the conversion of CO to CO2. Similarly, third treatment zone 112 may include beds or grids coated with catalysts such as nickel, iron, and cobalt that are configured to absorb the CO2 generated in the second treatment zone 110 as well as generated by batteries 14 during the thermal runaway event. In addition, as shown in
Fourth treatment zone 114 and fifth treatment zone 116 may include materials that are effective at reacting with methane (CH4) to remove and or reduce the amount thereof in the battery exhaust gas flow. For example, fourth treatment zone 114 may include beds or grids coated with activated carbon that assist with absorbing the methane. Fifth treatment zone 116 may include grid(s) formed of steel, polymer, ceramic, or glass that help collect droplets of the battery exhaust gas treatment fluid for reaction with the methane. As noted above, the battery exhaust gas treatment fluid may contain MEA, which is effective at absorbing methane.
After passing through conversion device 102, the treated battery exhaust gas flow will exit conversion device and enter pipe 24 to be expelled to the atmosphere. Inasmuch as the battery exhaust gas flow has been cooled and treated to eliminate or at least reduce various chemical species from the battery exhaust gas flow, the treated exhaust gas battery flow will be less hazardous to the environment and less hazardous to any persons that may near vehicle 10 during the thermal runaway event.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
