Abstract:
The present invention provides a ventilation apparatus for a fuel cell vehicle, which can rapidly remove high-temperature air generated in the inside of a stack case by moving the same to an air cleaner using a suction pressure of air supplied for the operation of the fuel cell vehicle, reduce the risk incurred due to hydrogen leakage by moving leaking hydrogen to the air cleaner, and maintain the temperature of a fuel cell stack constant.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2007-0070582 filed Jul. 13, 2007, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    (a) Technical Field 
         [0003]    The present invention relates to a ventilation apparatus for a fuel cell vehicle. More particularly, the present invention relates to a ventilation apparatus for a fuel cell vehicle, which can rapidly remove high-temperature air generated in the inside of a stack case by moving the same to an air cleaner using a suction pressure of air supplied for the operation of the fuel cell vehicle, reduce the risk incurred due to hydrogen leakage by moving leaking hydrogen to the air cleaner, and maintain the temperature of a fuel cell stack constant. 
         [0004]    (b) Background Art 
         [0005]    In general, a fuel cell stack is a power generation device that is mounted in a hybrid electric vehicle to generate electrical power required to drive a motor, in which hydrogen, air and coolant should be continuously circulated for the operation thereof, and the electrical power generated in the fuel cell stack should be safely used. 
         [0006]    Since the fuel cell stack is mounted in the vehicle, it is necessary to ensure a stable and steady state to improve the mountability into the vehicle. Moreover, the generated electrical power should not incur a risk to the vehicle and, since the hydrogen is circulated, it is necessary to prevent explosion due to hydrogen leakage. 
         [0007]    Furthermore, in order to prevent contamination from the outside, a stack case for accommodating the fuel cell stack and maintaining an airtightness is provided on the outside of the fuel cell stack. The stack case prevents contamination by dust and moisture from the outside and also prevents problems due to condensed water generated by a change in temperature of the fuel cell stack and due to the hydrogen leakage. 
         [0008]    To provide ventilation of the stack case, conventionally, a pump is provided on the outside of the stack case so that outside air is introduced and passed through the inside of the stack case, thus removing the condensed water generated by the temperature change in the fuel cell stack. Moreover, a moisture absorbent is provided in the inside of the stack case to remove moisture. 
         [0009]    In addition, a filter is provided in the front portion of the stack case, and a fan is disposed in the rear portion thereof such that the outside air flows in the inside of the stack case by a driving force of the fan. 
         [0010]    The conventional ventilation apparatuses have drawbacks in that they need additional power to drive the pump and the fan, which may increase the overall weight of the vehicle and manufacturing cost and decrease fuel efficiency. 
         [0011]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY OF THE DISCLOSURE 
       [0012]    The present invention has been made in an effort to solve the above-described problems associated with prior art. In one aspect, the present invention provides a ventilation apparatus for a fuel cell vehicle, the ventilation apparatus comprising: a stack case for accommodating a fuel cell stack mounted in the fuel cell vehicle and generating electrical power; and an air cleaner provided on a portion of the top of the stack case for cleaning air drawn from the outside. In this case, a connection hole is provided at a position where a portion of a bottom cover of the air cleaner is in contact with a portion of the top of the stack case so as to make the air cleaner in communication with the stack case, through which connection hole air in the inside of the stack case can be moved to the air cleaner by a difference between a pressure of air introduced into the air cleaner and a pressure of the inside of the stack case. 
         [0013]    In another aspect, the present invention provides a ventilation apparatus for a fuel cell vehicle, the ventilation apparatus comprising: a stack case for accommodating a fuel cell stack mounted in the fuel cell vehicle and generating electrical power; an air cleaner provided on a portion of the top of the stack case for cleaning air drawn from the outside; and an air hose connected between the air cleaner and an air blower for supplying air to the fuel cell stack. Here, the air hose comprises a first ventilation hose, of which one end is connected to the air hose and the other end is connected to the stack case such that air in the inside of the stack case can be moved to the air hose by a difference between a pressure of air introduced through the air hose and a pressure of the inside of the stack case. 
         [0014]    In a further aspect, the present invention provides a ventilation apparatus for a fuel cell vehicle, the ventilation apparatus comprising: a stack case for accommodating a fuel cell stack mounted in the fuel cell vehicle and generating electrical power; an air discharge pipe connected to one side of the stack case for discharging air from the fuel cell stack; and a second ventilation hose, of which one end is connected to the air discharge pipe and the other end is connected to the stack case such that air in the inside of the stack case can be moved to the air discharge pipe by a difference between a pressure of air moved through the air discharge pipe and a pressure of the inside of the stack case. 
         [0015]    It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like. 
         [0016]    The above and other features and advantages of the present invention will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description, which together serve to explain by way of example the principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated the accompanying drawings which are given hereinafter by way of illustration only, and thus are not limitative of the present invention, and wherein: 
           [0018]      FIG. 1  is a diagram showing a ventilation apparatus for a fuel cell vehicle in accordance with a first preferred embodiment of the present invention; 
           [0019]      FIG. 2  is a cross-sectional view showing an assembled state of the ventilation apparatus for a fuel cell vehicle of  FIG. 1 ; 
           [0020]      FIG. 3  is a diagram showing a discharge port and an air cleaner port included in the ventilation apparatus for a fuel cell of  FIG. 1 ; 
           [0021]      FIG. 4  is a diagram showing an air cleaner provided in the ventilation apparatus for a fuel cell vehicle of  FIG. 1 ; 
           [0022]      FIG. 5  is a diagram showing a hydrogen sensor provided in the ventilation apparatus for a fuel cell vehicle of  FIG. 1 ; 
           [0023]      FIG. 6  is a diagram showing a ventilation apparatus for a fuel cell vehicle in accordance with a second preferred embodiment of the present invention; and 
           [0024]      FIG. 7  is a diagram briefly showing a ventilation apparatus for a fuel cell vehicle in accordance with a third preferred embodiment of the present invention. 
       
    
    
       [0025]    Reference numerals set forth in the Drawings includes reference to the following elements as further discussed below: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                  2: fuel cell stack 
                 100: stack case 
               
               
                   
                 200: air cleaner 
                 210: air duct 
               
               
                   
                 300: connection hole 
                 400: air hose 
               
               
                   
                 500: first ventilation hose 
                 600: air discharge pipe 
               
               
                   
                 700: second ventilation hose 
               
               
                   
                   
               
             
          
         
       
     
         [0026]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
       DETAILED DESCRIPTION 
       [0027]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the drawings attached hereinafter, wherein like reference numerals refer to like elements throughout. The embodiments are described below so as to explain the present invention by referring to the figures. 
         [0028]    Referring to  FIGS. 1 to 5 , a ventilation apparatus for a fuel cell vehicle in accordance with a first preferred embodiment of the present invention will be described in detail. 
         [0029]    The ventilation apparatus includes a stack case  100  for accommodating a fuel cell stack  2  (hereinafter referred to as a stack) mounted in the fuel cell vehicle and generating electrical power, and an air cleaner  200  provided on a portion of the top of the stack case  100  and cleaning air drawn from the outside. A connection hole  300  is provided at a position where a portion of the bottom of a lower cover of the air cleaner  200  is contact with a portion of the top of the stack case  100  such as to make the stack case  100  in communication with the air cleaner  200 . Through the connection hole  300 , air in the inside of the stack case  100  is moved to the air cleaner  200  by a difference between the pressure of air introduced into the air cleaner  200  and the pressure of the inside of the stack case  100 . 
         [0030]    It is preferable that the inside top of the stack case  100  and the top of the stack  2  are spaced apart from each other to facilitate the air flow therebetween. In particular, the stack  2  generates heat by an electrochemical reaction between hydrogen and oxygen during operation and the generated heat increases the temperature of air. The thus generated high-temperature air is moved to the space between the inside top of the stack case  100  and the top of the stack  2 . 
         [0031]    The air cleaner  200  includes a filter  10  provided on the connection hole  300  to prevent dust and moisture from being introduced into the inside of the stack case  100  during introduction of the outside air. 
         [0032]    The connection hole  300  of the air cleaner  200  may have a diameter smaller than that of the air cleanser  200 . Preferably, a tubular insertion pipe  20  may be separately disposed between the air cleaner  200  and the stack case  100 . The filter  10  may be disposed on one end of the top of the insertion pipe  20  to prevent dust and moisture from being introduced into the inside of the stack case  100 . 
         [0033]    An air duct  210  through which the outside air is introduced is provided on the air cleaner  200 . Moreover, an air cleaner port  202 , of which one end is connected to a portion of the lateral surface of the air duct  210  and the other end extends to a portion of the outside of the air duct  210 , may be provided on the air cleaner  200  so as to prevent dust and moisture contained in the air from being introduced into the inside of the stack case  100 . 
         [0034]    The air cleaner port  202  of the air cleaner  200  may be inclined in the range of 90° or less with respect to the bottom surface of the air duct  210  (see θ of  FIG. 4 ). 
         [0035]    A discharge port  110  may be provided on a portion of the outside of the stack case  100 . The discharge port  110  is connected to the air cleaner port  202  so as to discharge moisture in the air introduced through the air cleaner  200 . 
         [0036]    A hydrogen sensor  4  may be provided in the vicinity of the discharge port  110  on the stack case  100  to detect hydrogen leakage from the stack  2 . 
         [0037]    The inside of the air cleaner  200  is divided into a dirty area  203  corresponding to a lower portion and a clean area  204  corresponding to an upper portion with respect to an air cleaner filter  205  provided therein. The dirty area  203  is connected to the connection hole  300  disposed between the air cleaner  200  and the stack case  100 . 
         [0038]    Referring to  FIG. 6 , the ventilation apparatus for a fuel cell vehicle in accordance with a second preferred embodiment of the present invention will be described. 
         [0039]    The ventilation apparatus includes a stack case  100  for accommodating a stack  2  mounted in the fuel cell vehicle and generating electrical power, an air cleaner  200  provided on a portion of the top of the stack case  100  and cleaning air drawn from the outside, and an air hose  400  connected between the air cleaner  200  and an air blower  3  (shown in  FIG. 1 ) for supplying air to the stack  2 . At least one first ventilation hose  500  is provided. One end of the first ventilation hose  500  is connected to the air hose  400  and the other end thereof is connected to a portion of the stack case  100  such that air in the inside of the stack case  100  can be moved to the air hose  400  by a difference between the pressure of air introduced through the air hose  400  and the pressure of the inside of the stack case  100 . 
         [0040]    As shown in  FIG. 6 , a filter  10 ′ may be provided inside the stack case  100  to remove contaminants contained in the air in the stack case  100  before being moved through the air hose  400 . 
         [0041]    Referring to  FIG. 7 , a ventilation apparatus for a fuel cell vehicle in accordance with a third preferred embodiment of the present invention will be described. 
         [0042]    The ventilation apparatus includes a stack case  100  for accommodating a stack  2  mounted in the fuel cell vehicle and generating electrical power, an air discharge pipe  600  connected to a portion of one side of the stack case  100  for discharging air from the stack  2 , and a second ventilation hose  700 , of which one end is connected to a portion of the air discharge pipe  600  and the other end is connected to a portion of the stack case  100  such that air in the inside of the stack case  100  can be moved to the air discharge pipe  600  by a difference between the pressure of air moved through the air discharge pipe  600  and the pressure of the inside of the stack case  100 . 
         [0043]    Hereinafter, operation modes of the above-described ventilation apparatuses will be described. 
         [0044]    Operation mode of the ventilation apparatus for a fuel cell vehicle in accordance with the first preferred embodiment of the present invention will be described with reference to  FIGS. 1 to 5 . 
         [0045]    When the fuel cell vehicle is turned on, outside air is introduced through the air duct  210  of the air cleaner  200  by the operation of the air blower  3 . While the outside air passes through the air duct  210 , the dirty area  203 , and the air cleaner filter  205 , contaminants contained in the outside air are filtered, and the thus purified air is supplied to the clean area  204 . 
         [0046]    At this time, there occurs a difference between the pressure of air introduced into the air cleaner  200  and the pressure of the inside of the stack case  100 . The pressure difference according to the operation of the air blower  3  is varied according to revolutions per minute (RPM) of the air blower  3 , and a negative pressure is generated in the dirty area  203  of the air cleaner  200 . 
         [0047]    As above, the air in the inside of the stack case  100  is moved to the dirty area  203  through the connection hole  300  as shown by arrows in  FIG. 1  by the difference in pressure between the air cleaner  200  and the stack case  100 , and then supplied to the stack  2  by way of the air cleaner filter  205  and the clean area  204  by the operation of the air blower  3 . 
         [0048]    Referring to  FIG. 2 , the filter  10  disposed on the top of the insertion pipe  20  prevents moisture from being introduced into the stack  2  through the air cleaner  200  during the stop of the fuel cell vehicle or in case of rain. 
         [0049]    Referring to  FIGS. 3 and 4 , the outside air introduced through the air duct  210  of the air cleaner  200  may contain dust and moisture. The dust and moisture are moved through the air cleaner port  202  and discharged to the outside of the air cleaner  200 . The air cleaner port  202  may be variously inclined with an angle value of θ. The angle value of θ may be in the range of 90° or less. 
         [0050]    The air cleaner port  202  is connected to the discharge port  110  provided on the stack case  100  so as to discharge dust and moisture introduced through the air duct  210  to the outside of the stack case  100 . 
         [0051]    Referring to  FIG. 5 , hydrogen gas may leak from the stack  2  accommodated in the stack case  100  due to a broken separator (not shown) or an aging gasket (not shown). Like this, in the event that the hydrogen gas leaks, the hydrogen sensor  4  provided in the vicinity of the discharge port  110  detects the hydrogen leakage and transmits a detection signal to a controller (not shown). Then, the controller operates a warning light (not shown) to provide a warning signal to a driver or controls the fuel cell vehicle to be stopped. 
         [0052]    Next, operation mode of the ventilation apparatus for a fuel cell vehicle in accordance with the second preferred embodiment of the present invention will be described with reference to  FIG. 6 . 
         [0053]    When the outside air moved through the air cleaner  200  and the air hose  400  passes through the area where the first ventilation hose  500  is provided, a negative pressure is generated around the first ventilation hose  500 . As a result, the high-temperature air generated in the inside of the stack case  100  is introduced into the air hose  400  through the first ventilation hose  500  and then filtered by the filter  10 ′ provided to remove contaminants which may remain in the inside of the stack case  100  such that the thus purified air is moved to the air hose  400 . Like this, the air moved to the air hose  400  is humidified by a humidifier  5  by the operation of the air blower  3  and then supplied to the stack  2 . The higher the speed of the vehicle is, the more the amount of air introduced from the stack case  100  into the air hose  400  through the first ventilation hose  500  is. The air introduced from the stack case  100  is of high temperature. As above, the high-temperature air introduced into the air hose  400  is humidified by the humidifier  5  and recirculated to the stack. Moreover, the air hose  400  is connected to the clean area of the air cleaner  200 . A plurality of first ventilation hoses  500  may be provided according to engine displacement and the number thereof is not particularly limited. 
         [0054]    Lastly, operation mode of the ventilation apparatus for a fuel cell vehicle in accordance with the third preferred embodiment of the present invention will be described with reference to  FIG. 7 . 
         [0055]    The stack case  100  may be provided in various positions according to the layout of the vehicle. In general, the stack case  100  may be provided on an engine room (not shown); however, in the case where it is provided on the bottom of the vehicle, the second ventilation hose  700  may be disposed between the air discharge pipe  600  and the stack case  100  in a state that the air cleaner  200  is positioned on the engine room. 
         [0056]    In this case, the diameter of the second ventilation hose  700  is smaller than that of the air discharge pipe  600  such that the high-temperature air in the inside of the stack case  100  can be discharged to the outside by a difference between the pressure of air discharged through the air discharge pipe  600  and the pressure of the inside of the stack case  100  as shown by arrows in the figure. 
         [0057]    Accordingly, it is possible to prevent the stack  2  from being damaged or malfunctioning which may be caused by the high-temperature heat generated in the stack  2 . Moreover, the high-temperature air generated in the stack  2  is continuously recirculated or discharged to the outside of the stack case  100 , thus ensuring a stable running of the travel. 
         [0058]    As described above, the ventilation apparatuses for a fuel cell vehicle in accordance with the present invention provides various effects including the following. 
         [0059]    The high-temperature air generated in the fuel cell stack is reused or stably recirculated to maintain the temperature of the fuel cell stack constant, thus providing a stable power generation and ensuring safety of the vehicle against the leakage of hydrogen gas. 
         [0060]    Moreover, it is possible to prevent contaminants contained in the outside air from being supplied to the stack, thus increasing the durability of the fuel cell stack, and minimizing the damage of the separator and gasket provided in the fuel cell stack. As a result, the durability of the fuel cell vehicle is increased. 
         [0061]    The invention has been described in detail with reference to preferred embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.