Abstract:
A novel air intake system which is suitable for at least substantially reducing the inadvertent intake of water with ambient air into an air compressor or other operational component of a fuel cell or internal combustion engine is disclosed. The air intake system typically includes an elongated air flow conduit having a downwardly-angled air inlet arm that is typically fitted with multiple louver elements and a splash shield to deflect entering water downwardly into a drain or gullet chamber. The air intake system typically further includes a mechanism for gravity-mediated draining of water from the air flow conduit to prevent entering water from being drawn into the air compressor or other component.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to air intake systems which conduct air from outside a vehicle to an engine or other operational components of the vehicle. More particularly, the present invention relates to a novel side-air intake system which includes multiple components that are designed to prevent or minimize entry of water into an air compressor of a fuel cell electric vehicle or into an internal combustion engine of a vehicle as air is drawn from outside the vehicle into the air compressor or engine.  
       BACKGROUND OF THE INVENTION  
       [0002]     Fuel cell technology has been identified as a potential alternative for the traditional internal-combustion engine conventionally used to power automobiles. It has been found that power cell plants are capable of achieving efficiencies as high as 55%, as compared to maximum efficiency of about 30% for internal combustion engines. Furthermore, fuel cell power plants produce zero tailpipe emissions and produce only heat and water as by-products.  
         [0003]     Generally, oxygen is required in fuel cells to generate electricity. For example, in fuel cells constructed with a Proton Exchange Membrane, hydrogen fuel flows into one electrode which is coated with a catalyst that strips the hydrogen into electrons and protons. Protons pass through the PEM to the other electrode. Electrons cannot pass through the PEM and must travel through an external circuit, thereby producing electricity, which drives an electric motor that powers the automobile. Oxygen flows into the other electrode, where it combines with the hydrogen to produce water vapor, which is emitted from the tailpipe of the vehicle. Individual fuel cells can be stacked together in series to generate increasingly larger quantities of electricity.  
         [0004]     Accordingly, hydrogen fuel cell-powered vehicles require a source of ambient air for the oxygen necessary to generate electrical power. During vehicle operation, ambient air is drawn through an inlet grille which is typically provided on the driver&#39;s side, lower-rear quarter panel of the vehicle. The ambient air is fed to a positive displacement air compressor, which is susceptible to liquid water that may be inadvertently drawn in with the ambient air.  
         [0005]     Accordingly, a novel air intake system is needed which is capable of at least substantially reducing the intake of water with ambient air into an air compressor or other component of a fuel cell or internal combustion engine.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention is generally directed to a novel air intake system which is suitable for at least substantially reducing the intake of water with ambient air into an air compressor or other operational component of a fuel cell or internal combustion engine. The air intake system includes a combination of multiple devices which are situated in an elongated air flow conduit to at least substantially reduce the progress of water into the operational component or components of the vehicle. The devices include an air inlet arm which is fitted with angled grill louvers to hinder the entry of water into the air flow conduit, a splash shield provided in the air inlet arm to divert from the air flow conduit water that passes beyond the grill louvers, backflow surfaces provided in the air inlet arm to facilitate the drainage of water from the air inlet arm, a vertical “head height” between the air inlet arm and a transverse segment of the air flow conduit to prevent or reduce further flow of water through the air flow conduit by gravity, a gullet chamber situated beneath the air intake arm for collecting the diverted water, and a standard air filter which absorbs any water which reaches it and is eventually dried through normal operation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The invention will now be described, by way of example, with reference to the accompanying drawings, in which:  
         [0008]      FIG. 1  is a rear, partially schematic view of an illustrative fuel cell electric vehicle (shown in phantom), more particularly illustrating a typical position of the packaged air intake system (shown in solid lines) of the present invention in the vehicle;  
         [0009]      FIG. 2  is a longitudinal sectional view of an illustrative embodiment of the air intake system of the present invention;  
         [0010]      FIG. 3  is a sectional view, taken along section lines  3 - 3  in  FIG. 2 ;  
         [0011]      FIG. 4  is a longitudinal sectional view of the air intake system of the present invention shown in  FIG. 2 , illustrating flow of air (solid arrows) through the system and blockage or deflection of water (dashed arrows) through the system during operation thereof; and  
         [0012]      FIG. 5  is an enlarged, longitudinal sectional view of the gullet chamber element of the air intake system of the present invention, more particularly illustrating drainage of accumulated water from the gullet chamber through the air inlet arm in the event of water accumulation in the gullet chamber. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]     The present invention contemplates a novel air intake system which is particularly adapted for use in a fuel cell electric vehicle to at least minimize the ingress of water with ambient air into a positive displacement air compressor which delivers compressed ambient air as an oxygen source to an electricity-generating fuel cell or cells. However, the air intake system of the present invention is equally adaptable to internal combustion engines and other systems in which air is to be delivered to a destination in a substantially water-free state.  
         [0014]     Referring initially to  FIG. 1 , an illustrative fuel cell electric vehicle  10  is indicated in phantom in rear view. The fuel cell electric vehicle  10  typically includes a chassis  12  and a cabin  14 . The vehicle  10  typically includes four wheels, including a pair of spaced-apart rear wheels  16 . The chassis  12  typically includes a rear left quarter panel  18 , a rear right quarter panel  19 , a front left quarter panel (not shown) and a front right quarter panel (not shown).  
         [0015]     An air intake system  22  according to the present invention is shown by solid lines in a typical packaged configuration in the fuel cell electric vehicle  10 . The air intake system  22  includes an elongated air flow conduit  23 , which includes an ascending air intake segment  24  having an air inlet arm  36 ; a gullet chamber  30  extending beneath the air inlet arm  36 ; a transverse segment  50  which extends generally horizontally from the air intake segment  24  and may be connected to a descending segment  54  via a flexible connector  52 ; and a filter housing  56  which is provided at the outlet end of the descending segment  54  and has a clean air outlet  64 . Preferably, the gullet chamber  30  has a water-holding capacity of at least typically about 24 oz. In the fuel cell electric vehicle  10 , the clean air outlet  64  is connected, either directly or through a connector hose  68 , to a positive displacement air compressor  66 . The air compressor  66  delivers ambient air as an oxygen source to a fuel cell or cells (not shown), which use the oxygen to generate electricity to drive the fuel cell electric vehicle  10 , as is known by those skilled in the art.  
         [0016]     As further shown in  FIG. 1 , an air inlet grille  20  is provided typically on the rear left quarter panel  18  of the chassis  12 . The air inlet arm  36  of the air intake system  22  is positioned behind the air inlet grille  20 . Accordingly, in normal operation of the fuel cell electric vehicle  10 , as hereinafter further described in detail, air is drawn through the air inlet grille  20 , air inlet arm  36  and air flow conduit  23 , respectively, and is filtered in the filter housing  56  prior to being distributed to the air compressor  66 .  
         [0017]     Referring next to  FIG. 2 , a longitudinal sectional view of the air intake system  22  is shown. The air inlet arm  36  includes multiple, elongated, parallel grill louvers  38  which extend inwardly from the wall  36   a  of the air inlet arm  36 , as shown in the cross-section of  FIG. 3 . Air flow passages  40  are defined between and separated from each other by the grill louvers  38 . As further shown in  FIG. 2 , the air inlet arm  36  extends at a downward angle from the vertical air intake segment  24 . Accordingly, because the grill louvers  38  extend generally parallel to the longitudinal axis of the air inlet arm  36 , the spaced-apart grill louvers  38  are disposed at a downward angle with respect to the air intake segment  24 . Therefore, as hereinafter further described, the downwardly-angled grill louvers  38  provide a first barrier to ingress of water to the air compressor  66  ( FIG. 1 ) and/or other operational components of the vehicle  10  as air is drawn into the air flow conduit  23  through the air inlet arm  36 .  
         [0018]     As further shown in  FIG. 2 , a splash shield  44  extends downwardly from the upper portion of the wall  36   a  of the air inlet arm  36 , into the air inlet arm  36 . The splash shield  44  is disposed in spaced-apart relationship to the downstream or outlet end of the air flow spaces  40  and partially blocks an opening  37  which establishes fluid communication between the air inlet arm  36  and the air intake segment  24 . Furthermore, the splash shield  44  is typically positioned in generally perpendicular relationship to the direction of flow of air through the air inlet arm  36 . The splash shield  44  provides a second barrier to the ingress of water into the air compressor  66  as air is drawn through the air intake system  22 .  
         [0019]     The bottom and side interior surfaces of the air inlet arm  36  define backflow surfaces  42  at the downstream or outlet end of the air flow spaces  40 . The backflow surfaces  42  define a gap distance between the outlet end of the air flow spaces  40  and the opening  37  between the air inlet arm  36  and the interior  28  of the air intake segment  24 . Accordingly, in the event that water inadvertently enters the air inlet arm  36  and collects in the descending gullet chamber  30 , the backflow surfaces  42  prevent “water lock” by facilitating the drainage of water from the gullet chamber  30  and out the air inlet arm  36 , through the air flow spaces  40 . Therefore, the backflow surfaces  42  provide a third barrier to the ingress of water to the filter housing  56  and beyond.  
         [0020]     As shown in  FIG. 2 , the air intake segment  24  of the air flow conduit  23  includes a generally cylindrical wall  26  which defines an interior  28  to accommodate upward vertical airflow. The air intake segment  24  ascends from the opening  37  at the outlet end of the air inlet arm  36 , to the transverse segment  50  of the air flow conduit  23 . Accordingly, the longitudinal extent of the air intake segment  24  defines a head height  48 , through which air (and water) must travel to reach the transverse segment  50 . The head height  48  of the air intake segment  24  utilizes gravity, or negative head pressure, to pull most of the water which inadvertently enters the interior  28  of the air intake segment  24 , downwardly into the gullet chamber  30 . Thus, the head height  48  of the air intake segment  24  provides a fourth barrier to ingress of water beyond the air intake system  22 .  
         [0021]     A tapered drain  32  is provided in the bottom of the gullet chamber  30 . A drain conduit  34  may extend from the bottom end of the drain  32 . As shown in  FIG. 1 , the open-ended drain conduit  34  may terminate at the bottom of the chassis  12  of the vehicle  10  to drain water from the gullet chamber  30  and onto the pavement (not shown). Alternatively, a collection receptacle (not shown) may be provided at the bottom end of the drain conduit  34  to collect water as it is drained from the gullet chamber  30 , in which case the collection receptacle may be periodically emptied. The drain  32  provides a fifth barrier to ingress of water beyond the air intake system  22 .  
         [0022]     As shown in  FIG. 2 , the filter housing  56  is provided at the downstream or outlet end of the descending segment  54  of the air flow conduit  23 . The filter housing  56  includes a pre-filtered air chamber  58 , a standard air filter  60  and a clean air chamber  62 . The clean air outlet  64  extends downwardly from the clean air chamber  62  of the filter housing  56 .  
         [0023]     It will be appreciated by those skilled in the art that any water which remains in the air flowing through the air flow conduit  23 , beyond the descending segment  54  must pass through the filter  60 , which removes most or all of the remaining water from the flowing air. During the course of normal operation, the air flowing through the air filter  60  will dry the water trapped therein. Therefore, the air filter  60  provides a sixth barrier to the ingress of water beyond the air intake system  22  to the air compressor  66 .  
         [0024]     Referring next to  FIGS. 4 and 5 , in operation of the air intake system  22 , pre-filtered ambient air  70  is drawn through the air inlet grille  20  ( FIG. 1 ) of the vehicle  10 , into the air inlet arm  36 ; through the air intake segment  24 , transverse segment  50  and descending segment  54 , respectively, of the air flow conduit  23 ; and through the filter  60  in the filter housing  56 , where dust, dirt and other particulate material is removed from the pre-filtered air  70 . Filtered air  70   a  emerges from the air filter  60  and flows from the clean air chamber  62  through the clean air outlet  64 , and finally, is distributed to the air compressor  66 .  
         [0025]     As further shown in  FIG. 4 , during operation of the air intake system  22 , water  72  may be inadvertently splashed through or otherwise enter the air inlet grille  20  ( FIG. 1 ) and enter the air inlet arm  36  with the pre-filtered air  70 . Accordingly, the multiple, parallel grill louvers  38  in the air inlet arm  36  act as a first barrier to the progression of the water  72  beyond the air intake system  22 . The grill louvers  38  therefore deflect much of the splashed water  72  back out of the air inlet arm  36  and through the air inlet grille  20 .  
         [0026]     In the event that some of the water  72  progresses through the air flow spaces  40  and beyond the grill louvers  38  inside the air inlet arm  36 , the splash shield  44  in the air inlet arm  36  deflects much or all of the water  72  downwardly into the gullet chamber  30 . The water  72  is drained from the drain  32  and through the drain conduit  34 . In the event that some of the water  72  progresses beyond the splash shield  44  and into the interior  28  of the air intake segment  24 , gravity pulls most or all of the water  72  downwardly into the gullet chamber  30  and out the drain  32  and drain conduit  34 , due to the head height  48  ( FIG. 2 ) of the air intake segment  24 .  
         [0027]     As shown in  FIG. 5 , under some circumstances the drain  32  and/or drain conduit  34  may become plugged or blocked with debris (not shown). In that case, water  72  deflected by the splash shield  44  and pulled by gravity from the air intake segment  24  may accumulate in the gullet chamber  30 . Accordingly, when the accumulated water  72   a  reaches the level of the opening  37  at the air inlet arm  36 , the water  72  flows down the interior backflow surfaces  42  of the air inlet arm  36 , through the air flow spaces  40  and out of the air inlet arm  36 .  
         [0028]     As the pre-filtered air  70  flows through the air flow conduit  23 , some small droplets of the water  70  may be carried by the flowing pre-filtered air  70  upwardly through the air intake segment  24 , horizontally through the transverse segment  50  and downwardly into the filter housing  56  through the descending segment  54 . Accordingly, the pre-filtered air  70  carries the water  72  through the air filter  60 , which removes most or all of the remaining water  72  from the pre-filtered air  70 . Therefore, the filtered air  70   a  emerges from the air filter  60  and enters the clean air chamber  62  in a substantially dry, water-free state. Accordingly, water is substantially incapable of entering and interfering with operation of the air compressor  66  and/or other operational components of the vehicle  1 .  
         [0029]     While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications can be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.