Abstract:
A vehicle cabin venting method includes cooling a vehicle battery charger by drawing outside air through a vehicle outside air vent door; and operating a hybrid vehicle battery system to establish and maintain flow of fresh air in a cabin of the vehicle by ensuring an open position of a blend door in the vehicle if the outside air vent door will not close. A vehicle cabin venting system is also disclosed.

Description:
FIELD 
       [0001]    Illustrative embodiments of the disclosure generally relate to outside air (OSA) vent systems which facilitate flow of cool outside air into the vehicle to cool a battery charger in the vehicle. More particularly, illustrative embodiments of the disclosure relate to a vehicle cabin venting method which facilitates flow of fresh air through a vehicle to prevent inflow of outside air in the event that the OSA vent system does not close. 
       BACKGROUND 
       [0002]    High voltage chargers in PHEV (plug-in hybrid elective vehicles) can become sufficiently heated to warm the cabin air inside the vehicle depending on the starting interior temperature of the vehicle. Circulating inside air to cool the charger for several hours can heat up the inside vehicle air, rendering the charger inefficient. 
         [0003]    When the charger requires cooling and the inside cabin air is above a set temperature level, introduction of outside air into the vehicle cabin through an outside air (OSA) vent system in the vehicle may facilitate cooling of the charger. In some circumstances, however, the OSA vent system may inadvertently remain open. Therefore, it may be desirable to facilitate flow of fresh air through the vehicle to prevent inflow of outside air in the event that the OSA vent system does not close. 
         [0004]    Accordingly, a vehicle cabin venting method which facilitates flow of fresh air through a vehicle to prevent inflow of outside air in the event that the OSA vent system does not close may be desirable for some applications. 
       SUMMARY 
       [0005]    Illustrative embodiments of the disclosure are generally directed to a vehicle cabin venting method which facilitates flow of fresh air through a vehicle to prevent inflow of outside air in the event that the OSA vent system does not close. An illustrative embodiment of the method includes cooling a vehicle battery charger by drawing outside air through a vehicle outside air vent door; and operating a hybrid vehicle battery system to establish and maintain flow of fresh air in a cabin of the vehicle by ensuring an open position of a blend door in the vehicle if the outside air vent door will not close. 
         [0006]    Illustrative embodiments of the method are further generally directed to a vehicle cabin venting system. An illustrative embodiment of the system includes a controller; an outside air vent door interfacing with the controller, controller detects when the vehicle outside air vent door will not close; and a blend door interfacing with the controller, the controller maintains the blend door in an open position when the vehicle outside air vent door will not close. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Illustrative embodiments of the disclosure will now be described, by way of example, with reference to the accompanying drawings, in which: 
           [0008]      FIG. 1  is a block diagram of an exemplary outside air (OSA) vent system of a vehicle in implementation of an illustrative embodiment of the vehicle cabin venting method; 
           [0009]      FIG. 2  is a top view of a vehicle illustrating normal flow of outside air into the vehicle through the OSA vent system in implementation of an illustrative embodiment of the vehicle cabin venting method; 
           [0010]      FIG. 3  is a side view of a vehicle illustrating normal flow of outside air into the vehicle through the OSA vent system in implementation of an illustrative embodiment of the vehicle cabin venting method; 
           [0011]      FIG. 4  is a top view of a vehicle illustrating maintenance of positive air pressure in the vehicle under circumstances in which the OSA vent system inadvertently remains opened in implementation of an illustrative embodiment of the vehicle cabin venting method; 
           [0012]      FIG. 5  is a side view of a vehicle illustrating maintenance of positive air pressure in the vehicle under circumstances in which the OSA vent system inadvertently remains opened in implementation of an illustrative embodiment of the vehicle cabin venting method; 
           [0013]      FIG. 6  is a flow diagram which illustrates an illustrative embodiment of the vehicle cabin venting method; 
           [0014]      FIG. 7  is a flow diagram which illustrates an exemplary control algorithm according to an illustrative embodiment of the vehicle cabin venting method; 
           [0015]      FIG. 8  is a block diagram of another exemplary outside air (OSA) vent system of a vehicle in implementation of an illustrative embodiment of the vehicle cabin venting method; and 
           [0016]      FIG. 9  is a block diagram which illustrates an illustrative embodiment of the vehicle cabin venting method. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “illustrative” is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable users skilled in the art to practice the disclosure and are not intended to limit the scope of the claims. Moreover, the illustrative embodiments described herein are not exhaustive and embodiments or implementations other than those which are described herein and which fall within the scope of the appended claims are possible. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. 
         [0018]    Referring initially to  FIGS. 1-5 , a vehicle  100  in implementation of an illustrative embodiment of the vehicle cabin venting method is shown. The vehicle  100  may have a vehicle front end  101 , a vehicle rear end  102 , a vehicle cabin  103  and a vehicle dashboard  104  in the vehicle cabin  103 . A recirculation or blend door  108  may be included in the vehicle dashboard  104 . Responsive to operation of the vehicle climate control fan (not shown), the recirculation door  108  may facilitate selective introduction of outside air  109  ( FIG. 4 ) into the vehicle cabin  103  or recirculation of inside air  134  in the vehicle cabin  103 , such as in the conventional manner. In exemplary operation, the recirculation door  108  is closed during hot humid weather when the operator of the vehicle  100  selects the “Max A/C” setting on the vehicle climate control system, thereby recirculating cabin air to reduce the heat load on the evaporator and cool the vehicle cabin  103  more quickly. As shown in  FIGS. 3 and 4 , a battery cooling fan  130  may circulate battery cooling air  131  from inside the vehicle cabin  103  through a vehicle battery  122  ( FIG. 1 ). 
         [0019]    An outside air (OSA) vent system  112  may be provided at the vehicle rear end  102  of the vehicle  100 . As shown in  FIG. 1 , the OSA vent system  112  may include an OSA vent door  113  which is selectively opened and closed by operation of a OSA vent door actuator  114 . A fan inlet duct  115  may lead from the OSA vent door  113 . An OSA fan  116  may be provided in the fan inlet duct  115 . A fan outlet duct  117  may lead from the OSA fan  116 . A battery charger  120  for a vehicle battery  122  is disposed in thermally conductive contact with the fan outlet duct  117 . As shown in  FIGS. 2-5 , an air extractor  132  may be provided at the vehicle rear end  102  of the vehicle  100  to extract inside air  134  from the vehicle cabin  103 . 
         [0020]    The outside air vent system  112  may be configured to maintain the OSA vent door  113  in a closed configuration unless the battery charger  120  requires cooling and the temperature of the vehicle cabin  103  exceeds a predetermined set temperature. As shown in  FIG. 1 , upon opening of the OSA vent door  113  by the OSA vent door actuator  114 , the OSA fan  116  draws outside air  118  through the fan inlet duct  115  and the fan outlet duct  117  and into the vehicle cabin  103 . As shown in  FIGS. 2 and 3 , the inflowing outside air  118  cools the battery charger  120  to within a target temperature range which ensures optimal operation of the battery charger  120 . Upon cooling of the battery charger  120  to within the target temperature range, the OSA vent door actuator  114  may close the OSA vent door  113  and further operation of the OSA fan  116  may be terminated. Throughout operation of the outside air vent system  112 , the recirculation door  108  may remain closed to facilitate recirculation of air in the vehicle cabin  103 . The air extractor  132  may remove inside air  134  from the vehicle cabin  103 . 
         [0021]    According to the vehicle cabin venting method, the Battery Energy Control Module (BECM) of the vehicle  100  may be configured to operate the recirculation door  108  and the vehicle climate control fan (not shown) in an error mitigation strategy in the event that the OSA vent door  113  inadvertently does not close after cooling of the battery charger  120 . The error mitigation strategy maintains flow of fresh air  126  in the vehicle cabin  103  and causes the recirculation door  108  to open if it is closed and prevents the recirculation door  108  from closing if it is open, and operates the vehicle climate control fan (not shown). Accordingly, as shown in  FIGS. 4 and 5 , the vehicle climate control fan (not shown) is operated to blow fresh inflowing outside air  109  into the vehicle cabin  103  through the open recirculation door  108 . The inflowing outside air  109  maintains flow of fresh air  126  in the vehicle cabin  103 , facilitating flow of inside air  134  from the vehicle cabin  103  through the OSA vent door  113 . The flow of fresh air  126  in the vehicle cabin  103  prevents exhaust as well as hot and humid air from entering the vehicle cabin  103  from the rear area of the vehicle  100  through the OSA vent door  113 . Since the need to cool the battery charger  120  and operate the vehicle climate control in the “Max A/C” setting on the vehicle climate control system may be likely to occur under the same hot environmental conditions, the probability of the OSA vent door  113  being opened and the recirculation door  108  being closed may be high. 
         [0022]    Referring next to  FIG. 6 , a flow diagram  600  which illustrates an illustrative embodiment of the vehicle cabin venting method is shown. Normal operation of a recirculation door and outside air vent system is shown in blocks  602 - 618 . Mitigating operation of the recirculation door and outside air vent system is shown in blocks  620 - 628 . In block  602 , charging of the vehicle battery by operation of the battery charger may be initiated. In block  604 , a charger fan which cools the charger may be started. In block  606 , a determination may be made as to whether the temperature of the vehicle cabin exceeds a predetermined set temperature. If yes, then the OSA vent door of the outside air vent system may be opened to cool the vehicle cabin interior. If no, then a determination may be made as to whether charging of the vehicle battery is complete. 
         [0023]    Upon charging of the vehicle battery in block  610 , the OSA vent door may be closed in block  612 . In block  614 , verification may be made as to whether the OSA vent door is closed. If the OSA vent door is closed in block  614 , then the OSA vent door is powered down in block  618 . If the OSA vent door is not closed in block  614 , then an error flag is set in block  616  and the OSA vent door is powered down in block  618 . 
         [0024]    In the event that the OSA vent door is closed in block  614  and the error flag is set in block  616 , mitigating operation of the recirculation door and outside air vent system is carried out in blocks  620 - 628 . In block  620 , the vehicle is keyed on. In block  622 , the OSA error flag which was set in block  616  is checked. In block  624 , verification may be made as to whether the OSA error flag was set. If yes, then in block  626 , a command may be transmitted to the vehicle climate control system to inhibit closure and open the front recirculation door if closed. Accordingly, fresh air flows through the vehicle cabin such that air is not able to enter the cabin interior through the open OSA vent door. If the OSA error flag was not set in block  624 , then normal operation of the recirculation door may be carried out in block  628 . 
         [0025]    Referring next to  FIG. 7 , a flow diagram  700  which illustrates an exemplary control algorithm according to an illustrative embodiment of the vehicle cabin venting method is shown. The method may start at block  702 . At block  704 , a BECM (Battery Energy Control Module) may monitor the position of the OSA vent door. At block  706 , a determination may be made as to whether the OSA vent door is open or the position of the OSA door is undetermined. If the outcome of the query at block  706  reveals that the OSA vent door is not open, then the method may end at block  708 . 
         [0026]    If the outcome of the query at block  706  reveals that the OSA vent door is either open or undetermined, then at block  710  a message may be transmitted from an HV (Hybrid Vehicle) battery system to open a blend door and operate a climate control fan. The method may return to block  704 , where the method may be repeated. 
         [0027]    Referring next to  FIG. 8 , a block diagram  812  of another exemplary outside air (OSA) vent system of a vehicle in implementation of an illustrative embodiment of the vehicle cabin venting method is shown. The OSA vent system  812  may include an OSA vent door  813  which is selectively opened and closed by operation of a OSA vent door actuator  814 . A fan inlet duct  815  may lead from the OSA vent door  813 . An OSA fan  816  may be provided in the fan inlet duct  815 . A fan outlet duct  817  may lead from the OSA fan  816 . A battery charger  820  for a vehicle battery  822  is disposed in thermally conductive contact with the fan outlet duct  817 . When the OSA vent door actuator  814  opens the OSA vent door  813 , the OSA fan  816  draws outside air  818  from outside the vehicle through the fan inlet duct  815  and the fan outlet duct  817 , respectively, to cool the battery charger  820 . A portion of the outside air  818  may be directed beyond the battery charger  820  toward a second row seat  814  of the vehicle. 
         [0028]    Referring next to  FIG. 9 , a block diagram  900  which illustrates an illustrative embodiment of the vehicle cabin venting method is shown. According to the method, an OSA vent door actuator  902  opens an OSA vent door in a vehicle to cool a battery charger. A BECM (Battery Energy Control Module) detects that the actuator is stuck in an open position or that the position of the actuator cannot be determined  904 . An HV (Hybrid Vehicle) battery system  906  transmits a message, via a CAN (Controller Area Network)  908 , to a climate control module  910  to open a blend door and turn the climate control fan of the vehicle on. The climate control module  910  transmits a signal  912  which opens the blend door  914 . Consequently, the fresh air  916  flows through the open blend door  914  to a climate control fan  920  in the vehicle. 
         [0029]    The climate control module  910  additionally transmits a signal  918  which operates the climate control fan  920  of the vehicle. The climate control fan  920  blows fresh air  922  from the open blend door  914  into the cabin area  924  of the vehicle. Fresh air  926  may flow from the cabin area  924  through the rear air extractors  928  at the rear of the vehicle. Fresh air  930  may also flow from the cabin area  924  through the fresh air ducts  932  at the rear of the vehicle. 
         [0030]    Although the embodiments of this disclosure have been described with respect to certain exemplary embodiments, it is to be understood that the specific embodiments are for purposes of illustration and not limitation, as other variations will occur to those of skill in the art.