JP5736996B2 - Ventilation structure of fuel cell stack - Google Patents

Description

  The present invention relates to a ventilation structure for a fuel cell stack, and more particularly to a ventilation structure for a fuel cell stack mounted on a moving body.

  When the fuel cell stack is mounted on a moving body such as a hybrid vehicle or an electric vehicle, the fuel cell stack is housed in a dedicated case and mounted at a predetermined position of the vehicle. In a fuel cell, hydrogen gas is used as a reaction gas, and even if this hydrogen leaks from the fuel cell stack, the leaked hydrogen is externally disposed so that the leaked hydrogen does not stay and the hydrogen concentration does not increase. A vent is provided for diffusion. In order to prevent water from entering the fuel cell stack, a technique for closing the vent of the storage case with a hydrogen permeable membrane has been proposed.

  Patent Document 1 listed below discloses that a case for a fuel cell including a gas permeable membrane (preferably a hydrogen permeable membrane) that does not transmit liquid but allows gas to pass is provided with a protective means for protecting the gas permeable membrane. Yes. The protection means is such that the gas that has passed through the gas permeable membrane is not retained inside, and has a strength that does not cause damage even when an external force is applied.

  Patent Document 2 discloses that a storage case for storing a fuel cell stack mounted on a vehicle includes a housing for storing the fuel cell stack, and an opening provided on the upper side of the housing. It is disclosed that the opening surface is formed so that the upstream side in the flow direction of moving wind (vehicle speed wind) generated by traveling of the vehicle is higher than the downstream side.

  FIG. 4 shows a fuel cell stack case described in Patent Document 2. The storage case 20 storing the fuel cell stack FC is fixed by a support member 80 under the vehicle floor panel FP. A predetermined clearance is secured between the floor panel FP and the storage case 20, and when the vehicle travels in the traveling direction, moving wind (vehicle speed wind) generated by the travel flows through the clearance. The storage case 20 includes a housing 30 that stores the fuel cell stack FC, and an opening 50 provided on the upper side of the housing 30. A hydrogen permeable film 40 is adhered to the entire opening surface of the opening 50, and the opening 50 is closed by the hydrogen permeable film 40. The hydrogen permeable membrane 40 is formed of a material that does not transmit water but allows gas such as hydrogen and air to pass through. In the storage case 20, the opening 50 is formed so that the upstream side in the direction of flow of the moving air is higher than the downstream side, and dust or the like is carried by the moving air and flows into the gap between the floor panel FP and the storage case 20. Even so, these are difficult to adhere to the upper surface of the hydrogen permeable membrane 40.

JP 2005-149732 A JP 2010-170923 A

  By forming the opening so that the upstream side in the flow direction of the moving wind is higher than the downstream side, dust and the like can be effectively prevented from adhering to the upper surface of the hydrogen permeable membrane, It can be assumed that the direct hitting may cause the hydrogen permeable membrane to vibrate and affect the durability of the hydrogen permeable membrane to some extent. In addition, when the mounting space is small above the opening, it is assumed that the required area of the hydrogen permeable membrane 40 cannot be secured. It is conceivable that the opening is raised from the downstream side to the upstream side, and a convex shape is formed so that the opening is lowered again toward the upstream side, but the necessary area of the hydrogen permeable membrane can be secured, but the influence of traveling wind It will not change that the part which receives directly is generated.

  It is an object of the present invention to provide a ventilation structure that can prevent the moving air from flowing into the fuel cell stack more than necessary and can effectively prevent vibration of the hydrogen permeable membrane while ensuring the ventilation of the fuel cell stack. It is to provide.

The present invention is a ventilation structure for a fuel cell stack mounted on a mobile body, and is provided in a first opening provided in a storage case that stores the fuel cell stack, and a ventilation cover that covers the first opening. , A second opening formed at a position facing the first opening, and a hydrogen permeable membrane covering the second opening, wherein the ventilation cover is substantially perpendicular to the moving direction of the moving body . Two units arranged side by side in the vehicle width direction are joined to each other, have an inclined surface with respect to a horizontal plane when viewed in the traveling direction of the moving body, and are highest at the joint portion of the two units. It is formed .

  According to the present invention, the ventilation performance of the fuel cell stack is ensured by the first opening and the second opening, and the inclined surface of the ventilation cover is formed in a direction substantially perpendicular to the moving direction of the moving body. Therefore, the inflow of the moving wind more than necessary can be suppressed. Further, according to the present invention, even when the mounting space is small above the ventilation cover, it is possible to ensure ventilation while suppressing the protrusion amount of the ventilation cover.

  Moreover, according to this invention, since a moving wind does not directly hit the inclined surface of a ventilation cover, the vibration of the ventilation cover by a moving wind is also suppressed.

It is a perspective view which shows the ventilation structure of the fuel cell stack in embodiment. It is a top view which shows the ventilation structure of the fuel cell stack in embodiment. It is AA sectional drawing of FIG. It is a block diagram of a conventional apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Similar to the conventional fuel cell stack shown in FIG. 4, the fuel cell stack according to the present embodiment is housed in a housing case and fixed under a floor panel of a vehicle such as a hybrid vehicle or an electric vehicle by a support member. . Further, a predetermined clearance is secured between the floor panel and the storage case, and when the vehicle travels in the traveling direction, a moving wind generated by the travel flows through the clearance. The fuel cell stack is configured by stacking solid polymer fuel cells, and hydrogen gas and air are supplied as reaction gases.

  The storage case of the fuel cell stack has a sealing structure that seals the fuel cell stack, but an opening is formed on the upper side of the storage case, and even if hydrogen gas as a reaction gas leaks, the leaked hydrogen is stored in the storage case. It is diffused to the outside through this opening so that it does not stay inside and increase the hydrogen concentration. A hydrogen permeable film is stuck on the entire surface of the opening. The hydrogen permeable membrane is made of a material that does not transmit water but allows gas such as hydrogen and air to pass through.

  FIG. 1 shows a ventilation structure of a fuel cell stack in the present embodiment. It is the perspective view which looked at the fuel cell stack accommodated in the storage case from the upper side.

  A ventilation cover 10 is provided at the top of the storage case, and a total of four openings 12 and 14 are formed in the ventilation cover 10. A hydrogen permeable film is attached to each of the openings 12 and 14, thereby closing the opening of the storage case and the openings 12 and 14 of the ventilation cover. The ventilation cover 10 of the present embodiment includes two ventilation cover units 10a and 10b, and is configured by joining these ventilation cover units 10a and 10b. The two ventilation cover units 10a and 10b are not on the same plane, but are inclined so that the height at the joint surface is the highest. More specifically, as shown in FIG. 1, the two ventilation cover units 10a and 10b are juxtaposed in a direction substantially perpendicular to the vehicle traveling direction, and are highest at the joint between the two units 10a and 10b. Thus, it is formed so as to incline in a direction substantially perpendicular to the vehicle traveling direction (vehicle width direction of the vehicle).

  In FIG. 2, the top view which looked at the ventilation structure of the fuel cell stack in this embodiment from the upper part is shown. An opening (first opening) 16 is formed in the upper part of the storage case 15 that stores the fuel cell stack. The opening 16 has a substantially oval shape extending in the vehicle width direction of the vehicle, and a plurality of openings 16 are formed along the traveling direction of the vehicle. In the drawing, a total of four openings 16 are shown along the vehicle traveling direction, but this is of course an example and the number is not limited. The storage case 15 is made of, for example, a metal such as stainless steel or aluminum, or reinforced plastic.

  A ventilation cover 10 is provided on the upper side of the storage case 15, that is, on the side where the opening 16 is formed. The ventilation cover 10 has a rectangular planar shape, and is fixed to the storage case 15 at four corners. As shown in FIG. 1, the ventilation cover 10 is configured by joining two ventilation cover units 10a and 10b to each other, two openings 12 are formed on the ventilation cover unit 10a side, and two ventilation cover units 10b side. Two openings 14 are formed. The two openings 12 each have a rectangular planar shape and are arranged in parallel in the vehicle traveling direction. Similarly, the two openings 14 each have a rectangular planar shape, and are arranged in parallel in the vehicle traveling direction. A hydrogen permeable film is attached to all of the openings (second openings) 12 and 14. The hydrogen permeable membrane is formed of a material that does not transmit water but allows gas such as hydrogen and air to pass therethrough, for example, a porous material. An example of the material of the hydrogen permeable membrane is Poeflon (registered trademark), but is not limited thereto.

  The openings 12 and 14 are provided so as to face the opening 16 of the storage case 15, and the formation positions of the openings 12 and 14 overlap at least partly with the formation position of the opening 16, Even if part of the hydrogen leaks from the fuel cell stack, the leaked hydrogen is diffused to the outside through the opening 15 of the storage case 15 and the openings 12 and 14 of the ventilation cover 10.

  FIG. 3 shows a cross section taken along the line AA of FIG. FIG. 3 also shows a vehicle body. The fuel cell stack FC is fixed to the vehicle body 18, specifically, a floor panel with a support member. The ventilation cover 10 including the two ventilation cover units 10 a and 10 b is provided on the upper part of the storage case 15. A predetermined clearance is secured between the vehicle body 18 and the ventilation cover 10, and various wire harnesses 17 are disposed in this clearance.

  The ventilation cover units 10a and 10b are arranged side by side in the vehicle width direction of the vehicle and are inclined so as to be highest at the center. The inclination angle θ is 5 ° or more, for example, 8 °.

  In this way, the ventilation cover 10 is formed with an inclined surface, and the inclination direction is not the vehicle traveling direction but the vehicle width direction of the vehicle substantially perpendicular to the vehicle traveling direction. The moving wind accompanying the traveling of the vehicle does not flow in through the openings 12, 14, 16 more than necessary. In addition, since the inclination direction of the ventilation cover 10 is the vehicle width direction of the vehicle, the moving air does not directly hit the inclined surface, the vibration of the ventilation cover 10 due to the moving air is suppressed, and the durability of the ventilation cover 10 is maintained. You can also

  Further, since the inclined surface of the ventilation cover 10 is formed in the vehicle width direction of the vehicle, there is an advantage that water does not collect on the upper surface of the ventilation cover 10 even when the vehicle is traveling on an uphill road.

  Moreover, since the ventilation cover 10 in this embodiment is not comprised from a single member, but is comprised by joining two ventilation cover units 10a and 10b, the height of an upper direction can be suppressed. This means that a clearance between the vehicle body 18 and the ventilation cover 10 can be ensured, and the arrangement area of the wire harness 17 can be ensured reliably.

  In this embodiment, the hydrogen permeable membrane is attached to the surface of the ventilation cover 10 and is attached to the vehicle body 18 side in FIG. 3, thereby preventing water from accumulating on the hydrogen permeable membrane. Can do.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation is possible.

  For example, the opening 16 in the present embodiment has an elliptical shape, and a plurality of openings 16 are provided along the traveling direction of the vehicle. In other words, the opening 16 is formed in a slit shape, which ensures the ventilation of the fuel cell stack. This is because the strength of the storage cover 15 is maintained. Therefore, an opening having an arbitrary shape can be provided as long as the strength of the storage cover 15 can be maintained.

  In the present embodiment, the inclination angle θ (see FIG. 3) of the ventilation cover 10 is set to 5 ° or more. However, as the inclination angle θ increases, the effect of preventing the retention of water or the like increases. The height of 10 also increases and the clearance with the vehicle body 18 is compressed. Therefore, the inclination angle θ is preferably set to an appropriate value considering both. Of course, when it is not necessary to arrange the wire harness 17 in the clearance, such consideration is unnecessary.

  In addition, the inclination angle θ in the present embodiment is the same in the two ventilation cover units 10a and 10b. However, the inclination angle θ is not necessarily the same, and an asymmetric inclined surface in which one inclination angle is larger than the other inclination angle. It may be formed.

  In addition, “substantially vertical” in the present embodiment does not mean a vertical in a strict sense, but also includes a vertical within a predetermined tolerance range. In this sense, not only when the inclined surface of the ventilation cover 10 forms 90 ° with respect to the traveling direction of the vehicle, but also within a range of 90 ° ± α (α is a predetermined tolerance, for example, set to 10 °). If it is within, it can be said to be substantially vertical.

  Furthermore, in the present embodiment, the configuration in which the fuel cell stack is disposed under the floor panel of the vehicle has been described. However, the fuel cell stack may be mounted at other positions, for example, a vehicle engine using a conventional gasoline engine as a power source. It may be mounted in a space (engine compartment) corresponding to a room, or may be a center tunnel, a trunk, or the like. When mounted in the center tunnel, the vehicle body 18 in FIG. 3 corresponds to the center tunnel, and the wire harness 17 is disposed in the center tunnel. It will be understood that the height of the center tunnel is limited, and in this sense, the inclination angle θ of the ventilation cover 10 is limited within a certain range.

  DESCRIPTION OF SYMBOLS 10 Ventilation cover, 10a Ventilation cover unit, 10b Ventilation cover unit, 12, 14 Opening part (opening part of ventilation cover), 15 Storage case, 16 Opening part (opening part of storage case), 17 Wire harness, 18 Vehicle body, FC fuel cell stack.

Claims (1)

A fuel cell stack ventilation structure mounted on a moving body,
A first opening provided in a storage case for storing the fuel cell stack;
A second opening provided in a ventilation cover covering the first opening, and formed at a position facing the first opening;
A hydrogen permeable membrane covering the second opening;
With
The ventilation cover is formed by joining two units arranged in parallel in the vehicle width direction substantially perpendicular to the traveling direction of the moving body, and has an inclined surface with respect to a horizontal plane in the traveling direction view of the moving body. And a ventilation structure for a fuel cell stack, wherein the ventilation structure is formed so as to be highest at a joint portion of the two units .

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