Abstract:
A vehicle traction battery cooling system is provided. The battery cooling system includes a blend door movable between at least an open and a closed position to select the location of incoming air for cooling a plurality of battery cells. A controller is configured to command the door to the open position in response to detecting gases vented by the battery cells.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to cooling systems having active cabin venting for vehicle traction batteries. 
       BACKGROUND 
       [0002]    A battery may generate heat during charging and discharging, and may need to be cooled for performance, fuel economy, and battery life reasons. In addition, a battery may vent cell gases which are required to be evacuated from the passenger cabin. 
         [0003]    A battery in a hybrid electric vehicle (HEV) or an electric vehicle or any other alternative energy vehicle including a traction battery may be cooled by a separate cooling system for the battery. Other battery cooling systems may use cabin air to cool the battery or a portion of the climate control system to cool the battery. 
         [0004]    One example is of a battery cooling system is illustrated in U.S. Pat. No. 
         [0005]      8 , 047 , 318 . 
       SUMMARY 
       [0006]    In one embodiment, a vehicle traction battery cooling system is provided. The battery cooling system includes a blend door movable between at least an open and a closed position to select a source of incoming air for cooling a plurality of battery cells. A controller is configured to command the door to the open position in response to detecting gases vented by the battery cells. 
         [0007]    In another embodiment, the source of incoming air is from outside the vehicle when the door is in the open position. The source of incoming air is from a passenger cabin when the door is in the closed position. The source of incoming air is from outside the vehicle and the passenger cabin when the door is in a position between the open and closed positions. 
         [0008]    In another embodiment, the battery cooling system includes a fan located downstream of the blend door. The controller is configured to command the fan to increase speed in response to detecting gases vented by the battery cells. 
         [0009]    In another embodiment, the battery cooling system includes an air supply duct arranged to direct the incoming air to a battery chamber surrounding the battery cells. 
         [0010]    In another embodiment, the battery cooling system includes a vent tube in fluid communication with the battery chamber and extending from the battery chamber to outside the vehicle. 
         [0011]    In another embodiment, the battery cooling system includes an air puller fan in fluid communication with the battery cells arranged to pull air from the battery chamber and to direct it away from the battery chamber. 
         [0012]    In another embodiment, the controller is configured to command the air puller fan to increase speed in response to detecting gases vented by the battery cells. 
         [0013]    In another embodiment, the battery cooling system includes a climate control system in fluid communication with the battery cooling system. The climate control system includes the blend door and a climate control fan. The controller is configured to command the fan to increase speed in response to detecting gases vented by the battery cells. 
         [0014]    In one other embodiment, a vehicle control system is provided. The vehicle control system includes a vehicle traction battery and a cooling system in fluid communication with the battery. A controller is configured to command a cooling system parameter to change in response to detecting gases vented by the battery cells. 
         [0015]    In one other embodiment, a method for cooling a traction battery in a vehicle is provided. The method includes commanding a cooling system parameter to change in response to detecting gases vented by the battery cells. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  illustrates a cooling system for a traction battery in a vehicle, according to one embodiment; and 
           [0017]      FIG. 2  is a flow chart illustrating a method for cooling a traction battery with a cooling system as shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely examples of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
         [0019]      FIG. 1  illustrates a battery cooling system  10  incorporated with a climate control system  12  of a vehicle. The air distribution using the climate control system  12  can be adjusted based on the battery  14  and the passenger cabin  16  needs. 
         [0020]    The air to a battery  14  may be directed to the battery system  17  through a dedicated duct  18  or ducts. Either the same fan  20  or a second dedicated air blower may be used for the passenger cabin climate control system  12  and battery cooling system  10 . 
         [0021]    An advantage of an air cooled battery cooling system  10  can be that the location of the battery  14  within the vehicle is flexible since coolant piping does not have to be routed throughout the vehicle to a battery chamber  22 . This is especially beneficial when the battery  14  is located in an extreme rear portion of the vehicle. Instead, air ducts may be used to direct the air to the battery chamber  22 . Even if air ducts must be routed to a rear portion of the vehicle to a battery chamber, the vehicle may already include rearward air ducts to cool the rear portion of the cabin. For example, some vehicles include air ducts for the second row seat climate control. These ducts may be extended to the battery system thermal control. Even if the vehicle does not include rear air ducts, air ducts may be less expensive than refrigerant piping. 
         [0022]    In some embodiments of the disclosure, the battery  14  may be cooled with cabin  16  air when the climate control system  12  for the cabin  16  is turned off. In this case, more air may be needed since the passenger cabin  16  air temperature may be relatively warm. The cooled air directly from the passenger cabin  16  may require the air flow to the battery  14  to be greater. In this case, a separate door  26  may be needed in the battery system  17 . In another embodiment, dedicated ducts from the climate control system  12  to the battery chamber  22  are not required. 
         [0023]    The battery  14  can be cooled with outside air  28  when the climate control system  12  is turned off and it is undesirable to use the passenger cabin  16  air. In this case, a blend door  30  door is required to switch the air between the climate control system  12 , the passenger cabin  16 , and outside air  28 . 
         [0024]    An entry duct  32  may receive air from outside vehicle  28 , cabin air from the vehicle cabin  16 , or some combination thereof based on the position of the blend door  30 . The entry duct  32  directs this air to the fan  20 . The climate control system fan  20  may then direct the air over a heat exchanger  36  to cool the air. The cooled air exits the heat exchanger  36  and enters a duct system  40 . 
         [0025]    The duct system  40  may direct air into either or both of the battery duct  18  or the cabin ducts  42 . The cabin ducts  42  fluidly connect the duct system  40  with cabin air vents  44 . The battery duct  18  fluidly connects battery chamber  22  with the duct system  40 . Air cooled by heat exchanger  36  may be used to cool one or both of battery  14  and vehicle cabin  16 . 
         [0026]    A fan  46  located downstream of the battery system  17  pulls air from within battery chamber  22  and directs it into vehicle trunk or rear air extractors  48 . In another embodiment, a fan may be a pusher type cooling fan. The pusher type cooling fan pulls in air from the cabin or outside of the vehicle and then pushes cooling air into the battery chamber  22  and eventually to the atmosphere outside the vehicle through rear air extractors  48  or the vent tube  50 . 
         [0027]    The battery cooling system  10  is in electrical communication with a vehicle communication network  60 . The vehicle network  60  may continuously broadcast data and information to the vehicle-based systems, such as a climate control module  64 , a vehicle controller  68  or an information display system  70 . The vehicle network  60  may be a controlled area network (CAN) bus used to pass data to and from the vehicle systems (or components thereof). 
         [0028]    Although the vehicle network  60  is shown with a single vehicle controller  64 , the vehicle network  60  may be connected to multiple controllers or control system that may be used to control multiple vehicle systems. 
         [0029]    The controller area network (CAN)  60  may allow the controller  64  to communicate with the climate control system  12  and the battery system  17 . Just as the climate control system  12  includes a controller  64 , the battery system may have its own controller. Some or all of these various controllers can make up a control system. Although illustrated and described in the context of a battery electric vehicle (BEV), it is understood that embodiments of the present application may be implemented on other types of vehicles, such as those powered by an engine in combination with an electric motor. 
         [0030]    In addition to the foregoing, the vehicle network  60  may be in communication with an information display system  70 . The display system  70  can provide relevant vehicle information to the driver of the vehicle. For example, the information display system  70  can indicate various battery system characteristics, such as state-of-charge or venting status. 
         [0031]    The information display system  70  may be disposed within a dashboard of the vehicle, such as in an instrument panel or center console area. The information display system  70  may include a touch screen, buttons for receiving and effectuating driver input associated with selected areas of the information display system  70 , such as the climate control system  12  or the battery cooling system  10 . 
         [0032]    The battery cooling system  10  can also include a sensor  80  or battery monitoring system that monitors the battery conditions and manages temperature and state-of-charge or venting of each of the battery cells, for example. 
         [0033]    The sensor  80  may be positioned in the battery chamber  22  or adjacent the battery cells  14  for detecting battery cell venting. Typically, the battery cells  14  do not vent gases. However, in some circumstances or conditions, the battery cells  14  may be required to vent gases. During battery cell venting, the sensor  80  or battery monitoring system be adapted to detect the vented gases. The sensor  80  may be any suitable sensor for detecting venting gases. Alternatively, an alternate detection mechanism may be used to determine if the battery cells  14  vented gases. In another embodiment, the sensor  80  or battery monitoring system can be configured to detect conditions that would include a likelihood of the battery cells 14  venting gases. 
         [0034]    The sensor  80 , or any suitable detection mechanism, provides a signal to the vehicle network  60  when/if the battery cell  14  venting occurs, or is likely to occur. In response to the vented gas signal, the battery cooling system  10  commands a change in a cooling system parameter in order to direct the vent gases outside the vehicle, or prevent the vented gases from entering the passenger compartment. This may be particularly important in vehicles where the battery system  17  is located in the passenger cabin  16 , as opposed to a separate compartment like the trunk. 
         [0035]    A battery cooling system  10  command to change a cooling system parameter may automatically override any driver inputs. Alternatively, the battery cooling system  10  may provide a message on the information display system  70  requesting that the driver change a system parameter manually. 
         [0036]    The climate control module  64  may change a cooling system parameter by commanding the blend door  30  to an open position based on the battery cell venting signal. In a fully open position, blend door  30  solely receives fresh air from outside the vehicle  28 . In contrast, in a fully closed position, the blend door  30  solely receives cabin air from the passenger cabin  16 . In an intermediate open position, the blend door  30  receives a combination of air from outside the vehicle air  28  from inside the passenger cabin  16  air. 
         [0037]    The climate control module  64  may also automatically change a cooling system parameter by commanding a cooling fan to increase speed based on the battery cell venting gases input. The climate control module  64  may increase the speed of the climate control fan  20  that is upstream of the battery chamber  22 . By increasing the speed of the fan  20 , more air is pushed through the duct system  40  and subsequently through the battery system duct  18  and battery chamber  22 . Air that is pushed from the battery chamber  22  can then be evacuated to the atmosphere outside  28  the vehicle through the vent tube  50 . 
         [0038]    Alternatively, the climate control module  64  may increase the speed of the battery fan  46 . By increasing the speed of the battery fan  46 , more air is pulled from the battery chamber  22  in order to evacuate vented gases to the atmosphere outside  28  the vehicle through the vent tube  50  or the rear air extractors  48 . 
         [0039]      FIG. 2  illustrates a flow chart  200  depicting a method for cooling a traction battery  14  with a battery cooling system  10  as shown in  FIG. 1 . As those of ordinary skill in the art will understand, the functions represented by the flowchart may be performed by hardware and/or software. Depending on the particular processing strategy, such as event driven, interrupt driven, etc., the various functions may be performed in an order or sequence other than that illustrated in  FIG. 2 . Likewise, one or more steps or functions may be repeatedly performed although not explicitly illustrated. Similarly, one or more of the steps or functions illustrated may be omitted in some applications or implementations. In one embodiment, the functions illustrated are primarily implemented by software instructions, code, or control logic stored in a computer-readable storage medium and executed by a microprocessor based computer or controller to control operation of the vehicle, such as the battery cooling system or the climate control controller, illustrated in  FIG. 1 . 
         [0040]    Initially, a controller monitors the battery system in order to detect any battery cell venting, as represented by block  210 . As discussed above, the system may include a sensor or another suitable detection mechanism for monitoring for venting gases. 
         [0041]    The controller determines if/when battery cell venting occurs based on an input signal, as represented by block  212 . If the input signal indicates battery cell venting, the controller provides a signal to the climate control system and battery cooling system to change a system parameter, as represented by block  214 . 
         [0042]    In response to the change parameter signal from block  214 , the controller commands the blend door to open to an open position, as represented by block  216 . In an open position, the blend door directs air from outside the vehicle into the climate control system and subsequently into the battery system and passenger cabin. The blend door may move to a fully open position so that the blend door only directs outside air into the cooling system. Alternatively, the blend door may move to an intermediate open position which directs a combination of outside air and cabin air into the cooling system. 
         [0043]    In response to the change parameter signal from block  214 , the controller can also command a fan to increase speed. The controller may command a climate control fan to increase speed, as represented by block  218 . The climate control fan may be a fan in the climate control system which may be located upstream of the battery system. The controller may also command a battery fan to increase speed. The battery fan may be in the battery system which may be located downstream of the battery cells and battery chamber. 
         [0044]    In response to the change parameter signal from block  214 , the controller can change one or more battery cooling system parameters, climate control system parameters, or any combination thereof The combined battery cooling system parameters direct the venting gases to outside the vehicle, represented by block  222 . 
         [0045]    While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.