JP2016122571A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system capable of reducing variations in the temeperature of a stack.SOLUTION: A ventilation flue cover 22 is provided along a sidewall surface 19 of a stack, a ventilation flue 25 is formed between the stack and the ventilation flue cover, and a cooling fan for introducing air to the ventilation flue is provided. The ventilation flue is configured so that the cross-sectional area near the center in a blowing direction is smaller than the opening area of an air intake opening and an exhaust opening. The blowing speed becomes higher near the center than at the air intake opening and the exhaust opening, and the central part of the stack is cooled intensively, thus reducing variations in temperature.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel cell system.

  Conventionally, Patent Document 1 proposes a fuel cell system that cools a stack in which a plurality of single cells are stacked. In this system, air as a coolant is caused to flow through the gap between the cooling fin and the inner wall surface of the leaf spring disposed in parallel to the end face of the cooling fin, thereby cooling the stack.

JP 2013-77429 A

  However, since the unit cell has a larger area in contact with the surrounding atmosphere as it is closer to the end portion, it is easier to radiate heat, and as it is closer to the center portion, it is difficult to radiate heat. For this reason, temperature variation occurs depending on the location in the single cell. The fuel cell system described in Patent Document 1 has a structure that improves the cooling performance of the stack, but does not include means for reducing temperature variations. For this reason, the fuel cell system described in Patent Document 1 has a problem that the stack temperature varies.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fuel cell system that can reduce variations in stack temperature.

  In order to achieve this object, a fuel cell system according to claim 1 is configured by stacking a plurality of single cells in a predetermined stacking direction, and having a stack having a plurality of side wall surfaces extending along the predetermined stacking direction. A guide member that forms a ventilation path between at least one of the plurality of side wall surfaces, and a fan that introduces air into the ventilation path. An exhaust opening is provided at an end, and a cross-sectional area of a specific portion of the ventilation path located between the intake opening and the exhaust opening is smaller than an opening area of at least one of the intake opening and the exhaust opening It is comprised so that it may become.

  Further, the fuel cell system according to claim 2 is the fuel cell system according to claim 1, wherein the ventilation portion further flows from the specific portion toward at least one of the intake opening and the exhaust opening of the ventilation path. The guide member is bent so that the cross-sectional area of the road becomes large.

  Further, the fuel cell system according to claim 3 is the fuel cell system according to claim 1 or 2, wherein the single cell further extends from the specific portion toward at least one of the intake opening and the exhaust opening. The outer length in the direction orthogonal to the predetermined stacking direction and the blowing direction of the ventilation path is reduced.

  The fuel cell system according to claim 4 is the fuel cell system according to any one of claims 1 to 3, wherein the specific portion of the ventilation path is a center of the ventilation direction of the ventilation path. It is a part, The cross-sectional area of the said specific part is a minimum cross-sectional area of the said ventilation path, It is characterized by the above-mentioned.

  Further, the fuel cell system according to claim 5 is the fuel cell system according to any one of claims 1 to 4, and further from the exhaust opening than the distance from the intake opening to the specific portion. The distance to the specific part is shorter.

  The fuel cell system according to claim 6 is the fuel cell system according to any one of claims 1 to 5, wherein the single cell further includes a cooling fin, and a blowing direction of the ventilation path is It is characterized by being orthogonal to the predetermined stacking direction.

  The fuel cell system according to claim 7 is the fuel cell system according to any one of claims 1 to 6, further comprising a hydrogen storage container containing a hydrogen storage alloy therein, and the hydrogen storage system. A container is arrange | positioned in the ventilation direction of the said ventilation path in the downstream of the said exhaust opening.

  The fuel cell system according to claim 8 is the fuel cell system according to any one of claims 1 to 7, further comprising an air pump for supplying air to the stack, In the ventilation direction of the said ventilation path, it arrange | positions in the downstream of the said exhaust opening, It is characterized by the above-mentioned.

  The fuel cell system according to claim 9 is the fuel cell system according to claim 7 or 8, wherein a cross-sectional area of the ventilation path is increased from the specific portion toward the exhaust opening, A fan is disposed closer to the exhaust opening than the intake opening and is spaced outward from the stack, and the fan rotation axis moves outward from the blowing direction as it advances in the blowing direction of the ventilation path. The fan is arranged so as to be away from the vehicle.

  The fuel cell system according to claim 10 is the fuel cell system according to any one of claims 1 to 9, wherein the fan is further disposed in the exhaust opening, and the guide member includes The ventilation port located in the center position of the ventilation direction of a ventilation path is provided, It is characterized by the above-mentioned.

  The fuel cell system according to claim 11 is the fuel cell system according to any one of claims 1 to 10, wherein the fan further includes a plurality of axial fans, and the rotation of the axial fan The direction is different from the rotation direction of the adjacent axial fans.

  According to the fuel cell system of the first aspect, the cross-sectional area of the specific portion of the ventilation path is smaller than the opening area of at least one of the intake opening and the exhaust opening. Get higher. For this reason, a part of the stack can be intensively cooled, and variations in the temperature of the stack can be reduced.

  According to the fuel cell system of the second aspect, since the guide member is bent, the sectional area of the opening is increased, so that the wind speed is reduced in the vicinity of the opening and the cooling effect is reduced. For this reason, it is possible to reduce the variation in stack temperature without overcooling the end of the stack.

  Further, according to the fuel cell system of claim 3, since the cross-sectional area of the opening is increased by reducing the outer length of the single cell in the vicinity of the opening, the wind speed is decreased in the vicinity of the opening, Cooling effect is reduced. For this reason, it is possible to reduce the variation in stack temperature without overcooling the end of the stack.

  According to the fuel cell system of the fourth aspect, the central portion of the ventilation path in the air blowing direction can be intensively cooled, and variations in the stack temperature can be reduced.

  According to the fuel cell system of the fifth aspect, the air introduced into the ventilation path absorbs heat from the stack while passing through the ventilation path, and the temperature rises as it approaches the exhaust opening. When the temperature difference between the stack and the air decreases, the cooling function decreases, but by increasing the wind speed at the exhaust opening side of the stack center, the cooling function can be compensated for and the temperature variation of the stack is reduced. can do.

  According to the fuel cell system of the sixth aspect, the cooling function can be enhanced by blowing air along the cooling fins provided in the single cell.

  According to the fuel cell system of claim 7, the hydrogen storage alloy has an endothermic reaction when hydrogen is released, but the hydrogen storage container can be heated by utilizing the exhaust heat from the stack. , Hydrogen release can be promoted.

  According to the fuel cell system of the eighth aspect, since the air pump can take in the air warmed by the exhaust heat from the stack, it is possible to stably operate the apparatus. In addition, when the heat dissipation function of the stack is high, higher-temperature air can be taken in, so that more stable operation of the apparatus is possible.

  According to the fuel cell system of claim 9, since the air heated by the exhaust heat from the stack can be widely transmitted to the hydrogen storage container and the air pump as a whole, the release of hydrogen is promoted. Thus, stable operation of the apparatus becomes possible.

  According to the fuel cell system of the tenth aspect, the air introduced into the ventilation path absorbs heat from the stack while passing through the ventilation path, and the temperature rises as it approaches the exhaust opening. When the temperature difference between the stack and the air decreases, the cooling function decreases. However, by newly sucking air from the ventilation port, the temperature rise of the air can be suppressed and the cooling function can be maintained.

  According to the fuel cell system of the eleventh aspect, the swirling flow generated from the axial fan does not collide with the swirling flow of the adjacent fans, and the blowing efficiency can be improved.

It is drawing which represented the whole fuel cell system of 1st Embodiment of this invention from the front. It is drawing which showed the detail of the fuel cell 6 of 1st Embodiment of this invention. It is drawing which cut | disconnected according to the AA line of FIG. 2, and represented the cross section seen in the arrow direction. It is drawing which cut | disconnected according to the BB line of FIG. 2, and represented the cross section seen in the arrow direction. FIG. 4 is a drawing showing a cross section of a fuel cell 6 according to a second embodiment of the present invention, corresponding to FIG. 3. It is drawing which represented the cross section of the fuel cell 6 of 3rd Embodiment of this invention, Comprising: It is drawing equivalent to FIG. It is drawing which represented the cross section of the fuel cell 6 of 4th Embodiment of this invention, Comprising: It is drawing equivalent to FIG. It is drawing which represents the cross section of the fuel cell 6 of 5th Embodiment of this invention, Comprising: It is drawing equivalent to FIG. It is the state which represented the fuel cell 6 of 6th Embodiment of this invention from the upper surface, and represented the rotation direction of six axial fans. FIG. 6 is a drawing showing a cross section of a fuel cell 6 according to a first modification of the present invention, which corresponds to FIG. 3. It is drawing which represents the cross section of the fuel cell 6 of the 2nd modification of this invention, Comprising: It is drawing equivalent to FIG. It is drawing which showed the cross section of the fuel cell 6 of the 3rd modification of this invention, Comprising: It is drawing equivalent to FIG. It is drawing which represents the cross section of the fuel cell 6 of the 4th modification of this invention, Comprising: It is drawing equivalent to FIG.

<First Embodiment>
The fuel cell system of the present invention is installed in a traffic light, for example, and is used as an emergency power source in the event of a power failure due to a disaster or the like.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

<Overall configuration of fuel cell system>
The fuel cell system 1 includes a system housing 2. The system housing 2 includes a horizontal plate 4 and a horizontal plate 5 inside. A fuel cell 6 is disposed below the horizontal plate 4. A hydrogen storage container 7 is disposed on the horizontal plate 4. An air pump 8 is disposed on the horizontal plate 5.

<System housing>
The system housing 2 includes a door 10 that can be opened and closed on the front, and an openable lid 12 on the upper surface. The upper lid 12 includes a plurality of exhaust ports 13.

<Hydrogen storage container>
The hydrogen storage container 7 contains a hydrogen storage alloy and stores hydrogen. The hydrogen storage container 7 is connected to a hydrogen pipe 14 and supplies hydrogen to the fuel cell 6. Moreover, the hydrogen storage container 7 can be attached or detached by removing the connection with the hydrogen pipe 14, and the replacement work can be easily performed.

<Air pump>
The air pump 8 is connected to the air pipe 15 and supplies air to the fuel cell 6.

<Fuel cell>
Next, details of the fuel cell 6 will be described with reference to FIGS.

  A stack 16 is disposed inside the fuel cell 6. The stack 16 is obtained by stacking a plurality of solid polymer fuel cell single cells 17 in a predetermined stacking direction SD, and arranging one end plate 20 at each end of the stacking direction SD. The two end plates 20 pressurize each single cell 17 from both sides in the stacking direction SD and are fastened to each other by bolts (not shown).

  The single cell 17 is a unit battery configured by sandwiching a membrane / electrode assembly (MEA) between a pair of separators, and has a rectangular shape that is long in the vertical direction. The separator is provided with cooling fins 18 at the end. The side wall surface 19 is a surface formed by the tips of the cooling fins 18 of each single cell 17.

  The fuel cell 6 is fixed to the bottom surface of the system housing 2 via two end plates 20.

  A lateral guide 21 is installed before and after the end plate 20. The lateral guide 21 is fixed to the end plate 20. A ventilation path cover 22 is disposed before and after the stack 16. The ventilation path cover 22 is disposed with a gap from the side wall surface 19, and a ventilation path 25 is formed in the gap. The four corners of the ventilation path cover 22 are fixed to the lateral guide 21.

  The upper part of the ventilation path cover 22 is bent at an obtuse angle in the direction away from the side wall surface 19 upward, and the left and right ends of the upper end are fixed to the upper end of the lateral guide 21, respectively. Further, the lower portion of the ventilation path cover 22 is bent at a right angle in the direction away from the side wall surface 19, and the left and right ends of the lower end portion are respectively fixed to the lower end portion of the lateral guide 21. A central portion of the ventilation path cover 22 in the blowing direction FD is a flat surface and is disposed in parallel with the side wall surface 19.

  An intake opening 27 is formed in the lower part of the ventilation path 25. The intake opening 27 is one end of the air passage 25 and is a space formed between the lower end portion of the side wall surface 19 and the air passage cover 22. An exhaust opening 28 is formed in the upper part of the ventilation path 25. The exhaust opening 28 is a space that is the other end of the ventilation path 25 and is formed between the upper end portion of the side wall surface 19 and the ventilation path cover 22.

  The cross-sectional area of the ventilation path 25 in the blowing direction FD is larger in the intake opening 27 and the exhaust opening 28 than in the central portion of the ventilation path 25. The ventilation path 25 has the smallest cross-sectional area at the center. The central portion indicates a predetermined range near the central line.

  An upper cover 24 is disposed above the stack 16. The upper cover 24 has a thin plate shape and is bent at both ends. Both ends are fixed to the upper end of the lateral guide 21 together with the ventilation path cover 22. The upper cover 24 has a central plane arranged parallel to the top surface of the stack 16, and the plane is provided with six openings of 3 rows × 2 rows, and six cooling fans 26 are arranged in accordance with the opening positions. Arranged.

  The six cooling fans 26 are all the same type of axial flow fans, the blowing direction is all upward, and the rotation directions of the wings are all the same direction. The cooling fan 26 sucks air in the ventilation path 25 from the exhaust opening 28, whereby air is introduced from the intake opening 27 to the ventilation path 25.

  A lateral cover 23 is disposed between the upper cover 24 and the end plate 20. The lateral cover 23 is fixed to the upper surface of the end plate 20 and closes the gap between the upper cover 24 and the end plate 20.

  The fuel cell system 1 is connected to a separate power control device (not shown). The power control device includes a secondary battery, a CPU, various control circuits, and the like, and controls the entire fuel cell system 1.

  Next, operation | movement of the fuel cell system 1 of this embodiment is demonstrated.

  The fuel cell system according to the present invention is used as an emergency power source at the time of a power failure due to, for example, a disaster. When the commercial power supply is shut off, the valve operation is performed by the power of the secondary battery, and the hydrogen storage container 7 supplies hydrogen to the stack 16 through the hydrogen pipe 14. Further, the air pump 8 operates to suck air and supply air to the stack 16 through the air pipe 15.

  The stack 16 generates electricity using hydrogen and oxygen in the air as fuel, and supplies electricity to the power control device. The stack 16 generates heat as power is generated.

  When the temperature of the stack 16 rises, the cooling fan 26 operates and sucks air in the ventilation path 25 from the exhaust opening 28 to introduce air into the ventilation path 25 from the intake opening 27 and cool the stack 16. The cooling fan 26 is desirably operated after the temperature of the stack 16 has become sufficiently high, and the operating temperature is preferably 45 ° C. or higher. When the operating temperature becomes lower than the predetermined temperature range, the cooling fan 26 can be stopped. Further, the rotational speed and the air volume of the cooling fan 26 may be adjusted according to the operating temperature.

  The temperature of the stack 16 is measured using a thermometer or the like, and the result is transmitted to the power control device, whereby the operation of the cooling fan 26 can be controlled.

  When the cooling fan 26 operates, air is introduced from the intake opening 27 and blown to the ventilation path 25. Since the cross-sectional area of the ventilation path 25 in the blowing direction FD is smaller in the central portion than in the intake opening 27 and the exhaust opening 28, the blowing speed is increased in the central portion. For this reason, the amount of heat radiation in the center portion is larger than that of the lower end portion and the upper end portion of the single cell 17 and the center portion is intensively cooled, so that variations in the temperature of the entire stack 16 can be reduced.

  When air passes through the ventilation path 25, heat from the stack 16 is transmitted and the temperature of the air rises. The air discharged from the exhaust opening 28 rises by the operation of the cooling fan 26 and is transmitted to the hydrogen storage container 7 to heat the hydrogen storage container 7. When the hydrogen storage container 7 is heated, hydrogen can be effectively released and supplied to the stack 16. Further, the air discharged from the exhaust opening 28 is transmitted to the air pump 8. As the temperature of the air supplied to the stack 16 increases, the air humidification performance increases and the performance of the fuel cell improves. After the hydrogen storage container 7 and the air pump 8 are heated, the air is exhausted out of the fuel cell system 1 through the exhaust port 13.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the shape of the ventilation path cover 22a and the shape of the single cell 17a are different from those of the first embodiment. In the first embodiment, since the upper end portion and the lower end portion of the ventilation path cover 22 are bent outward in the direction away from the side wall surface 19, the cross-sectional area of the ventilation path 25 is changed. Then, the cross-sectional area changes as the length of the single cell 17a changes. Since the configuration excluding the single cell 17a and the ventilation path cover 22a and the operation of the fuel cell system 1 are the same as those in the first embodiment, detailed description thereof is omitted.

  The ventilation path cover 22a has a thin plate shape and is disposed with a gap from the side wall surface 19, and a ventilation path 25 is formed in the gap.

  The ventilation path cover 22 a is fixed to the upper end portion of the lateral guide 21 at both left and right ends of the upper end portion. Further, the left and right ends of the lower end are fixed to the lower end of the lateral guide 21, respectively.

  As for the single cell 17a, the length of the external shape orthogonal to the lamination direction SD and the ventilation direction FD becomes small toward the upper end part from the center part of the ventilation direction FD. Further, the length of the outer shape perpendicular to the stacking direction SD and the blowing direction FD becomes smaller from the central portion toward the lower end portion. Each single cell 17 a includes a cooling fin 18, and the side wall surface 19 is a plane formed by the tips of the cooling fins 18.

  The side wall surface 19 includes a side surface parallel to the ventilation path cover 22a, a slope connecting the side surface and the top surface, and a slope connecting the side surface and the bottom surface.

  Even in this case, the temperature variation of the entire stack 16 can be reduced as in the first embodiment.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the shape of the ventilation path cover 22b differs from 1st Embodiment. Since the configuration excluding the ventilation path cover 22b and the operation of the fuel cell system 1 are the same as those in the first embodiment, detailed description thereof is omitted.

  The end of the ventilation path cover 22b is bent at an obtuse angle in the direction away from the side wall surface 19 upward, and the left and right ends of the upper end are fixed to the upper end of the lateral guide 21, respectively. Further, the lower portion of the ventilation path cover 22b is bent at a larger angle than the upper portion in the direction away from the side wall surface 19 in the downward direction, and the left and right ends of the lower end portion are fixed to the lower end portion of the lateral guide 21, respectively. The distance from the lower end of the single cell 17 to the bent position at the lower part of the ventilation path cover 22b is longer than the distance from the upper end of the single cell 17 to the bent position at the upper part of the ventilation path cover 22b. The central portion of the ventilation path cover 22 b in the blowing direction FD is a flat surface and is disposed in parallel with the side wall surface 19.

  When the cooling fan 26 operates, air is sucked from the intake opening 27 and blown to the ventilation path 25. Since the cross-sectional area of the ventilation path 25 decreases from the intake opening 27 toward the central portion in the air blowing direction FD, the air blowing speed is increased, and the heat radiation amount in the central portion is larger than the lower end portion of the single cell 17. In addition, since the cross-sectional area of the ventilation path 25 increases from the central portion of the ventilation path 25 toward the exhaust opening 28, the air blowing speed is reduced, and the heat dissipation amount in the central area is larger than the upper end of the single cell 17.

  The air introduced into the ventilation path 25 absorbs heat from the stack 16 while passing through the ventilation path 25, and the temperature rises as it approaches the exhaust opening 28. When the temperature of the air rises, the temperature difference between the stack 16 and the air decreases, and the cooling function deteriorates. However, in this embodiment, the center of the range where the wind speed is fastest in the blowing direction FD of the ventilation path 25 is the stack 16. Therefore, it is possible to compensate for the deterioration of the cooling function and to reduce the temperature variation of the entire stack 16.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the shape of the upper cover 24a and the arrangement direction of the cooling fan 26 are different from those of the first embodiment. Since the configuration excluding the upper cover 24a and the cooling fan 26 and the operation of the fuel cell system 1 are the same as those in the first embodiment, detailed description thereof is omitted.

  An upper cover 24 a is disposed above the stack 16. The upper cover 24 a has a mountain shape with two slopes, and both ends are fixed to the upper end of the lateral guide 21 together with the ventilation path cover 22. The upper cover 24 a is provided with three openings on the slope, and six cooling fans 26 are arranged along the slope so that the rotation axis is away from the stack 16 according to the opening position. .

  The six cooling fans 26 are all the same type of axial fans, and the rotation directions of the wings are all in the same direction. The cooling fan 26 blows air upward in a direction away from the stack 16, and air is introduced into the ventilation path 25.

  Even in this case, the temperature variation of the entire stack 16 can be reduced as in the first embodiment.

  Further, by directing the axial direction of the cooling fan 26 outward, the air that has passed through the ventilation passage 25 flows upward while flowing outward, and the hydrogen storage container 7 and the air pump 8 are connected to the whole. Can be heated widely.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the shape of the ventilation path cover 22c differs from 1st Embodiment. Since the configuration excluding the ventilation path cover 22c and the operation of the fuel cell system 1 are the same as those in the first embodiment, detailed description thereof will be omitted.

  The upper part of the ventilation path cover 22c is bent at an obtuse angle in the direction away from the side wall surface 19 upward, and the left and right ends of the upper end are fixed to the upper end of the lateral guide 21, respectively. Further, the lower portion of the ventilation path cover 22c is bent at a right angle in the direction away from the side wall surface 19, and the left and right ends of the lower end are fixed to the lower end of the lateral guide 21, respectively. The central portion of the ventilation path cover 22 c in the blowing direction FD is a flat surface and is disposed in parallel with the side wall surface 19. The ventilation path cover 22 c includes a ventilation port 29 in the central portion of the ventilation path 25 in the blowing direction FD. There may be one or more ventilation ports 29, and it is desirable to provide a filter or the like to prevent foreign matter from entering the ventilation path 25. Further, the position of the ventilation port 29 may be a central point or a vicinity including the central point.

  When the cooling fan 26 operates, air is sucked from the intake opening 27 and blown to the ventilation path 25. Since the cross-sectional area of the ventilation path 25 decreases from the air intake opening 27 toward the center in the air blowing direction FD, the air blowing speed is increased, and the heat dissipation amount in the central portion is larger than the lower end portion of the single cell 17. Further, since the cross-sectional area of the ventilation path 25 increases from the center of the ventilation path 25 toward the exhaust opening 28, the air blowing speed is reduced, and the amount of heat radiation at the center is greater than the upper end of the single cell 17.

  Further, the air introduced into the ventilation path 25 absorbs heat from the stack 16 while passing through the ventilation path 25, and the temperature rises as it approaches the exhaust opening 28. When the temperature of the air rises, the temperature difference between the stack 16 and the air decreases and the cooling function decreases, but in this embodiment, air is newly sucked from the ventilation port 29 to suppress the temperature rise. For this reason, variation in temperature of the entire stack 16 can be reduced.

<Sixth Embodiment>
Next, a sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the rotation directions of the two types of cooling fans 26a and 26b are different from those of the first embodiment. Since the configuration excluding the cooling fans 26a and 26b and the operation of the fuel cell system 1 are the same as those in the first embodiment, detailed description thereof is omitted.

  The upper cover 24 includes three cooling fans 26a and three cooling fans 26b whose wing directions are opposite to those of the cooling fans 26a. The cooling fan 26a and the cooling fan 26b are installed alternately. The cooling fan 26a and the cooling fan 26b are all directed upward in the blowing direction, but the rotation direction RD is opposite because the direction of the wings is opposite.

  The axial fan generates a swirl flow, but the adjacent swirl flows are prevented from colliding with each other by alternately arranging the rotation direction with the adjacent fans. For this reason, ventilation efficiency increases and a cooling function can be improved.

  As mentioned above, although this embodiment was described, this invention is not limited to the said embodiment, A various change is possible. Below, the example of the change which can be added to the said embodiment is demonstrated.

  For example, as illustrated in FIG. 10, the ventilation path cover 22 d may be bent in a curved line in a direction in which the upper end portion and the lower end portion are separated from the side wall surface 19. Also in this case, similarly to the above, the ventilation path 25 has a small cross-sectional area near the center of the blowing direction FD, and the wind speed is increased. For this reason, the central part of the single cell 17 can be intensively cooled, and variations in the temperature of the entire stack 16 can be reduced. Further, as shown in FIG. 11, the ventilation path cover 22 e may be bent at a right angle in a stepped manner in a direction in which the upper end portion and the lower end portion are separated from the side wall surface 19. In this case, the same effect as described above is obtained.

  For example, as shown in FIG. 12, the single cell 17 b has a length that is perpendicular to the stacking direction SD and the air blowing direction FD from the center to the upper end in the air blowing direction FD so as to draw a curve. The length perpendicular to the stacking direction SD and the blowing direction FD may be reduced from the part toward the lower end so as to draw a curve. Each single cell 17 b includes a cooling fin 18, and the side wall surface 19 is a curved surface formed by the tips of the cooling fins 18. Also in this case, similarly to the above, the ventilation path 25 has a small cross-sectional area near the center of the blowing direction FD, and the wind speed is increased. For this reason, the central portion of the single cell can be intensively cooled, and variations in the temperature of the entire stack 16 can be reduced. Further, as shown in FIG. 13, the single cell 17c has a length that is perpendicular to the stacking direction SD and the blowing direction FD in a stepwise manner from the central portion to the upper end portion in the blowing direction FD, and from the central portion to the lower end. The length perpendicular to the stacking direction SD and the blowing direction FD may be reduced stepwise toward the part. In this case, the same effect as described above is obtained.

  The side wall surface 19 is a surface including the tips of the cooling fins 18 and may be a flat surface, a curved surface, or an uneven surface.

  The cooling fan may be an axial fan installed on the intake opening side. Even in this case, air is introduced into the ventilation path by sending air from the intake opening. Alternatively, it may be an axial fan installed in both the intake opening and the exhaust opening. Even in this case, air is introduced into the ventilation path, and the same effect as described above is obtained.

  The cooling fan may be a centrifugal fan installed on the intake opening side or the exhaust opening side or both. Even in this case, air is introduced into the ventilation path, and the same effect as described above is obtained.

  The single cell 17 may be arranged in a direction in which the stacking direction SD and the blowing direction FD are parallel to each other. Even in this case, the same effect as described above can be obtained.

DESCRIPTION OF SYMBOLS 1 Fuel cell system 2 System housing 6 Fuel cell 7 Hydrogen storage container 8 Air pump 16 Stack 17 Single cell 19 Side wall surface 20 End plate 22 Ventilation path cover 24 Upper cover 25 Ventilation path 26 Cooling fan 27 Intake opening 28 Exhaust opening SD Lamination Direction FD Air blowing direction RD Rotation direction

Claims (11)

A stack having a plurality of single cells stacked in a predetermined stacking direction and having a plurality of side wall surfaces extending along the predetermined stacking direction;
A guide member that forms a ventilation path between at least one of the plurality of side wall surfaces;
A fan for introducing air into the ventilation path,
The ventilation path has an intake opening at one end and an exhaust opening at the other end,
A cross-sectional area of a specific portion of the ventilation path located between the intake opening and the exhaust opening is configured to be smaller than an opening area of at least one of the intake opening and the exhaust opening. A fuel cell system.   2. The guide member according to claim 1, wherein the guide member is bent toward at least one of the intake opening and the exhaust opening of the ventilation path so that a cross-sectional area of the ventilation path is increased from the specific portion. The fuel cell system described.   From the specific portion toward at least one of the intake opening and the exhaust opening, the single cell has a reduced outer length in a direction perpendicular to the predetermined stacking direction and the blowing direction of the ventilation path. The fuel cell system according to claim 1 or 2.   The said specific part of the said ventilation path is a center part of the ventilation direction of the said ventilation path, The cross-sectional area of the said specific part is the minimum cross-sectional area of the said ventilation path, The any one of Claims 1-3 characterized by the above-mentioned. 2. The fuel cell system according to item 1.   The fuel cell system according to any one of claims 1 to 4, wherein a distance from the exhaust opening to the specific portion is shorter than a distance from the intake opening to the specific portion. The single cell comprises cooling fins;
The fuel cell system according to any one of claims 1 to 5, wherein a blowing direction of the ventilation path is orthogonal to the predetermined stacking direction. It has a hydrogen storage container that contains a hydrogen storage alloy inside,
The fuel cell system according to any one of claims 1 to 6, wherein the hydrogen storage container is disposed on the downstream side of the exhaust opening in the blowing direction of the ventilation path. An air pump for supplying air to the stack;
The fuel cell system according to any one of claims 1 to 7, wherein the air pump is disposed on the downstream side of the exhaust opening in a blowing direction of the ventilation path. The cross-sectional area of the ventilation path increases from the specific portion toward the exhaust opening,
The fan is disposed at a position closer to the exhaust opening than the intake opening, and is disposed away from the stack;
9. The fuel cell system according to claim 7, wherein the fan is disposed so as to move away from the blowing direction as the rotation axis of the fan advances in the blowing direction of the ventilation path. The fan is disposed in the exhaust opening;
The fuel cell system according to any one of claims 1 to 9, wherein the guide member is provided with a ventilation port located at a central position in a ventilation direction of the ventilation path. The fan includes a plurality of axial fans,
The fuel cell system according to any one of claims 1 to 10, wherein a rotation direction of the axial fan is different from a rotation direction of the adjacent axial fans.

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