JP4720148B2 - Fuel cell device - Google Patents

Description

  The present invention relates to a fuel cell device in which a fuel cell stack for generating electric power by reacting outside air introduced as an oxidizing gas with a fuel gas is housed in a case, and in particular, a high voltage fuel cell stack for automobiles or the like is placed in the case The present invention relates to a contained fuel cell device.

  Conventionally, in a fuel cell using a polymer electrolyte membrane, fuel gas or oxidizing gas is ionized on both sides of the electrolyte membrane, and the ions pass through the electrolyte membrane to cause an electrochemical reaction. If fuel gas and oxidizing gas are present with the electrolyte membrane in between, the electrochemical reaction between the two continues.

  For this reason, the fuel cell requires a gas supply device for introducing the fuel gas and the oxidizing gas. On the other hand, in order to obtain a sufficient output by the fuel cell, it is necessary to connect a plurality of unit cells composed of polymer electrolyte membranes in series, and a fuel constructed by laminating a plurality of unit cells with a separator interposed therebetween. A battery stack is used. In order to supply the oxidizing gas to each unit cell of the fuel cell stack, a gas inlet is opened for each unit cell, and a gas outlet for discharging gas is provided on the opposite side of the opening. A large number of gas inlets and outlets are arranged on substantially the entire upper and lower surfaces of the fuel cell stack.

In addition, since the fuel cell stack has a voltage of 400 V or more depending on the case in an automobile application or the like, it is necessary to insulate it so as not to conduct to the peripheral portion. Further, since water is generated by the power generation reaction in the fuel cell, it is necessary to prevent corrosion of the material by this water.
In the fuel cell stack as described above, a manifold for distributing and supplying oxidizing gas to a large number of gas inlets is placed on the upper surface of the fuel cell stack, and a tray for collecting generated water is provided on the lower surface of the fuel cell stack. In addition, an electrode for taking out the generated electric power and an insulation treatment for insulating other devices are applied.
JP 2001-313061.

In the past, air supply manifolds and exhaust ducts were installed above and below the fuel cell stack. A sufficient flat surface cannot be obtained at the top and bottom of the stacked modules, and in order to seal the portions, a liquid gasket capable of sealing a certain degree of unevenness must be used. In addition, when sealing with a liquid gasket, it is not possible to proceed to the next process until the gasket is cured.
In addition, it is necessary to separately attach an air supply manifold and an exhaust duct to the fuel cell stack, which takes time for assembly and requires airtight construction separately.

  It is an object of the present invention to provide a fuel cell device including a case that facilitates construction such as insulation and airtightness of the fuel cell stack.

The present invention for solving the above problems has the following configuration.
(1) A fuel cell stack that reacts with fuel gas to generate power by reacting with outside gas introduced from the outside air inlet formed on the upper surface and discharges it from the outside air outlet formed on the lower surface, and accommodates the fuel cell stack A fuel cell device comprising a case for
The case is
A box member having an opening for accommodating the fuel cell stack ;
A lid member fixed to the opening of the box member and closed ;
The outside air introduction outer edge to surround the opening is formed in a frame shape along the inner wall, said fuel cell stack and the interposed between the cover member inner surface Ri Do from the sealing insulating material, the fuel cell stack And a first insulating member that is inserted into the box member and fixed to the lid member to form a manifold connected to the outside air introduction port ,
Wherein formed in a frame shape outer edge shape along the inner wall so as to surround the external air outlet port, wherein the fuel cell stack and Ri Do an insulating material interposed in sealing between the box member base, wherein the fuel cell stack And a second insulating member that is inserted into the box member to connect to the outside air outlet and forms an exhaust duct .

( 2 ) The fuel cell stack case according to ( 1 ), wherein the lid member is integrally provided with an outside air flow path, and the box member is integrally provided with an exhaust flow path.
(3) The fuel cell device according to (1) or (2), wherein the fuel cell stack is arranged horizontally and cooling water is supplied to the fuel cell stack in a mist form in the manifold.
(4) The fuel cell device according to any one of (1) to (3), wherein the first insulating member and the second insulating member are made of an elastic material.

According to the first aspect of the invention, the fuel cell stack is covered with the case, so that it is possible to protect external impacts and the like. Since the case serves both as an air supply manifold and an exhaust duct, it is not necessary to prepare a separate manifold. The spacer ensures insulation between the case and the fuel cell stack, and physical and electrical contact between the fuel cell stack and the surroundings is suppressed by the case. The case is divided into a box member and a lid member, and the fuel cell stack is accommodated in the box member and further covered with the lid member, thereby facilitating the mounting of the case. Further, by manufacturing the box member and the lid member separately, it is possible to make a more complicated shape. For example, the lid member can integrally form the manifold, and the box member can integrate the exhaust duct. Further, since the fuel cell stack is sandwiched from above and below by the insulating member, excellent insulating properties and sufficient waterproofness to water-repellent parts can be obtained.

According to the second aspect of the present invention, the lid member can be configured to be continuous with the manifold in the outside air flow path, and the box member is formed by integrating the exhaust flow path with the exhaust duct. be able to. By doing in this way, it can be set as the structure with easy connection with an external air supply system or an exhaust system, for example.
According to the invention described in claim 3, the entire fuel cell can be uniformly cooled by supplying the cooling water in a mist form within the manifold. When the fuel cell stack is accommodated in the case 1, since the contacts and terminals with the electric cable that dislikes moisture are also disposed in the case, it is necessary to sufficiently seal the accommodating portion of the terminals. By configuring the fuel cell stack so as to be sandwiched from above and below by the first and second insulating members, excellent insulating properties and sufficient waterproofness to water-repellent parts can be obtained.
According to the fourth aspect of the present invention, when the insulating member has elasticity, the insulating member is compressed and deformed in a state where the fuel cell stack is accommodated in the case. The insulating member is deformed according to the unevenness, and the adhesion between the insulating member and the fuel cell stack 5 is increased. As a result, the airtightness between the manifold and the outside air inlet of the fuel cell stack is further improved, and the water-repellent parts are more reliably isolated from the mist.

  Next, a preferred embodiment of the present invention will be described. This embodiment is a fuel cell device mounted on an electric vehicle. FIG. 1 is a sectional side view showing a fuel cell stack 5 and a fuel cell device including the case 1 according to the present invention, FIG. 2 is a plan view of a separator 4 constituting the fuel cell stack 5, and FIG. 3 is a fuel cell stack. 5 is an enlarged view of the outside air inlet 941 provided on the upper surface of FIG. 5, and FIG. 4 is a sectional front view of the fuel cell device. The fuel cell stack 5 housed in the case 1 includes a unit cell (not shown) configured by sandwiching a polymer electrolyte membrane between a fuel electrode and an oxidation electrode, a fuel gas channel on the front and back surfaces, and an oxidizing gas. It has the laminated body which laminated | stacked alternately the separator 4 which has a convex-shaped part for forming a flow path. The electrode plate and the rigid plates 52a and 52b are stacked on both ends of the laminated body thus configured, and the rigid plates 52a and 52b on both ends are tightened by screws as fastening means. Thus, the fuel cell stack 5 is configured by compressing the stack in the stacking direction.

  FIG. 2 is a plan view of the separator 4 showing the surface on the side where the oxidizing gas flow path is formed. A plurality of convex portions 42 are arranged on the surface of the separator 4 when formed in the vertical direction, and grooves 40 are formed between the convex portions 42. When the apex portion 421 of the convex portion 42 is in contact with the oxidation electrode of the unit cell, the groove 40 and the oxidation electrode constitute a gas flow path 43 through which the oxidizing gas flows. A frame 9 is inserted between the separator 4 and the unit cell. The convex portion 42 is accommodated in the inner window 91 of the frame 9, and a step 92 formed at the edge of the inner window 91 is provided. Inside, the oxidation electrode of the unit cell is accommodated. An oxidizing gas chamber is constituted by the inner wall of the inner window 91, the groove 40 and the surface of the oxidizing electrode.

  An outside air introduction path 94 and an outside air lead-out path 95 are formed on the back side of the frame 9 and communicate with the oxidizing gas chamber. The outside air introduction path 94 is provided with slopes 942 at both ends, and the outside air introduction port 941 is widened. The outside air lead-out path 95 is provided with slopes 952 at both ends, and the outside air lead-out opening 951 is widened. Such an outside air inlet 941 and outside air outlet 951 are formed along the end of the separator 4 to form a vertically long (slit-like) opening, and the same number of outside air as the number of separators 4 to be stacked. An inlet 941 and an outside air outlet 951 are arranged on the upper and lower surfaces of the fuel cell stack 5.

  The inner wall of the gas flow path 40 is subjected to a hydrophilic treatment. As described above, the outside air inlet 941 and the outside air outlet 951 are provided at opposing positions on the upper and lower surfaces of the fuel cell stack 5.

  FIG. 5 is a plan view of the case 1, and FIG. 6 is a plan view of the case 1 with the lid member removed. The case 1 of the present invention includes a box-shaped box member 2 and a lid member 3 covered by the opening 21 of the box member 2. A fuel cell stack 5 is accommodated in the case 1.

  The case 1 includes a box member 2 and a lid member 3 that closes the opening 21 of the box member 2. The inner space of the box member 2 serves as a housing portion 22 for housing the fuel cell stack 5. As shown in FIG. 4, the bottom portion 23 of the box member 2 has a step on the opposite end. Portions 231 and 231 are formed. The fuel cell stack 5 is placed on the step portions 231 and 231. The fuel cell stack 5 to be placed is held in the case 1 so that the orientation is horizontal. In FIG. 1, the X-axis direction is the horizontal direction, and the Y-axis direction is the vertical direction.

An exhaust passage 24 is connected to one of the end sides where the step portions 231 and 231 are not formed. The height of the step portion 231 is configured to gradually increase toward the side to which the exhaust passage 24 is connected. As a result, the bottom surface 232 of the box member 2 is directed toward the exhaust passage 24. It is configured to incline downward. By this inclination, it becomes easy to collect the water discharged from the outside air outlet 951 out of the fountain (mist) injected into the fuel cell stack 5.
The exhaust passage 24 has a configuration in which the flow passage width gradually decreases in the downstream direction, and is configured such that the width of the discharge port 242 is narrower than the width of the connection portion 241 with the box member 2. . Further, the discharge port 242 is arranged at a position higher than the connection portion 241.

  An insertion member is provided between the step portions 231 and 231 and the fuel cell stack 5 placed thereon. The insertion member 25 is made of an insulating material such as a resin. The insertion member 25 is formed in a frame shape so as to surround the lower surface of the fuel cell stack 5, and has a rectangular shape along the inner wall of the box member 2. By this insertion member 25, direct contact between the box member 2 and the fuel cell stack 5 is prevented, and electrical contact is also prevented.

  An exhaust duct 26 is configured by gaps formed between the bottom surface 232 of the box member 2 and a plurality of outside air outlets 951 provided on the lower surface of the fuel cell stack 5. The exhaust duct is connected to the exhaust passage 24. Connected.

  On the other hand, as shown in FIG. 5, the lid member 3 includes a lid body 31 having the same size and a space formed inside the lid body 31 corresponding to the opening 21 of the box member 2. The air manifold 32 is provided. The lid body 31 is sized to cover the opening 21, is configured in the same shape as the opening 21, and closes the opening 21. A flange 36 is formed on the outer peripheral end of the lid main body 31, and a flange 271 is also formed on the outer peripheral end of the opening 21 of the box member 2. By overlapping these flanges 36 and 271, the opening 21 is closed and the case 1 is assembled. The flange 36 and the flange 271 are formed with holes 361 at opposing positions, and are fastened and fixed by bolts or the like.

  In the assembled case 1, an insertion member 32 is inserted between the lid member 3 and the fuel cell stack 5. As shown in FIG. 6, the insertion member 33 is formed in a frame shape so as to surround a plurality of outside air inlets 941 provided on the upper surface of the fuel cell stack 5, and the outer edge shape is the same as that of the lid main body 31. It has a rectangular shape along the inner wall. The insertion member 33 prevents direct contact between the lid member 3 and the fuel cell stack 5, and also prevents electrical contact. Moreover, it has the effect | action which guides the external air which flowed in from the outside to the external air introduction port 941, without escaping elsewhere.

  One end of the air manifold 32 is connected to the outside air introduction path 34. As shown in FIGS. 1 and 5, the outside air introduction path 34 has a connection portion 341 at one end connected to the air manifold 32 and an outside air inlet 342 at the other end. The width of the flow path gradually increases toward the manifold 32.

  The outside air flow path that continues from the outside air introduction path 34 to the air manifold 32 allows the outside air to flow linearly from the outside air inlet 342 to each outside air introduction port 941 of the fuel cell stack 5 (inside the outside air flow path). The flow line of the flowing gas is configured to be a straight line or close to a straight line). That is, the top plate continuing from the outside air inlet 342 to the air manifold 32 is a flat plate, and is a straight line in a side view as shown in FIG.

  In such a configuration, the air as the oxidizing gas introduced from the outside air introduction path 34 flows into the oxidizing gas chamber from the outside air introduction port 941 and further flows out from the outside air outlet 951 to the exhaust duct 26 in the case 1. To do. Further, the air in the exhaust duct 26 is exhausted from the exhaust port 242 through the exhaust passage 24.

  In this embodiment, the gap 220 formed between the fuel cell stack 5 and the side wall 27 of the case 1 may be filled with, for example, a foamed urethane resin. In this case, further sealing performance can be exhibited, and leakage of the introduced outside air, leakage of generated water and direct jet water, and the like can be more reliably prevented. Furthermore, positioning of the fuel cell stack 5 in the case 1 can be performed more reliably.

  According to the configuration of the present invention as described above, the fuel cell stack 5 configured by stacking the separator 4, the frame body 9, and the like cannot obtain a sufficient plane on the upper and lower surfaces. Therefore, in order to seal the upper and lower surfaces, a liquid gasket that can seal a certain degree of unevenness must be used. According to the case 1 of the present invention, since the entire fuel cell stack 5 is covered with the case, it is not necessary to directly seal the upper and lower surfaces. Further, since the seal structure of the box member 2 and the lid member 3 is a seal between the flat surfaces of the flange 271 and the flange 36, it is possible to use a seal material 37 such as a rubber packing or an O-ring that requires a flat surface, Diversification of the seal structure is achieved.

  In this case structure, the outside air inlet 342 is disposed on one side (right side in FIG. 1) and the outlet 242 is disposed on the other side (left side in FIG. 1) with the fuel cell stack 5 interposed therebetween. As a result, the air flow in the case 1 is less likely to be uneven, and the cooling water can be uniformly distributed in the air manifold 32 by being applied to a fuel cell system that supplies the cooling water together with the outside air. The entire fuel cell can be cooled uniformly. In addition, since the long side of the slit-shaped outside air introduction port 941 is arranged so as to be parallel to the flow of the outside air flowing in from the outside air intake port 342 (along the outside air flow), the outside air is smooth. It can flow into each outside air introduction port 941, and can suppress generation of pressure loss.

  Furthermore, since the outside air inlet 342 is disposed above the outside air inlet 941 of the fuel cell stack 5, the outflow of the direct fountain water to the outside of the case 1 can be suppressed. Further, since the discharge port 242 is disposed above the outside air outlet 951 of the fuel cell stack 5, the outflow of water (mist) in the exhaust gas to the outside of the case 1 can be reduced and the condenser provided at the discharge port 242 can be reduced. The fallen condensed water can be collected in the case 1.

  When the fuel cell stack 5 is accommodated in the case 1, since the contacts and terminals with the electrical cable that dislikes moisture are also disposed in the case 1, it is necessary to sufficiently seal the terminal accommodating portion. By configuring the fuel cell stack 5 so as to be sandwiched from above and below by the resinous insertion members 25 and 33 via urethane, excellent insulation and sufficient waterproofness to water-repellent parts can be obtained.

  Further, when the insertion members 25 and 33 have elasticity, the insertion members 25 and 33 are compressed and deformed in a state where the fuel cell stack 5 is accommodated in the case 1. The insertion members 25 and 33 are deformed according to the unevenness of the surface, and the adhesion between the insertion members 25 and 33 and the fuel cell stack 5 is increased. Thereby, the airtightness between the air manifold 32 and the outside air introduction port 941 of the fuel cell stack 5 is further improved, and isolation of the water-repellent parts from the mist is further ensured.

Further, if the amount of deformation of the insertion members 25 and 33 is such that the deformation of the insertion members 25 and 33 can be further elastically deformed while the fuel cell stack 5 is housed in the case 1, It also functions as a cushioning material that protects the fuel cell stack 5.
The case 1 may be made of a metal such as aluminum or a resin.

It is a cross-sectional side view which shows the case of a fuel cell stack. It is a top view of the separator which comprises a fuel cell stack. It is an enlarged view of the external air inlet provided in the upper surface of the fuel cell stack. It is a section front view of a case. It is a top view of a case. It is a top view of a case in the state where a lid member was removed.

Explanation of symbols

1: Case 2: Box member 21: Opening portion 22: Housing portion 23: Bottom portion 231: Step portion 232: Bottom surface 24: Exhaust flow path 25: Insertion member 3: Lid member 31: Lid body 32: Air manifold 33: Medium Insertion member 34: Outside air introduction path 342: Outside air inlet 343: Guide surface 4: Separator 40: Groove 42: Convex portion 421: Apex portion 43: Gas flow path 47: Inner wall 5: Fuel cell stack 941: Outside air introduction port 951 : Outside air outlet

Claims (4)

A fuel cell stack that reacts with the fuel gas to generate power by reacting with the outside gas introduced from the outside air inlet formed on the upper surface and discharges it from the outside air outlet formed on the lower surface; and a case for housing the fuel cell stack; In a fuel cell device comprising:
The case is
A box member having an opening for accommodating the fuel cell stack ;
A lid member fixed to the opening of the box member and closed ;
The outside air introduction outer edge to surround the opening is formed in a frame shape along the inner wall, said fuel cell stack and the interposed between the cover member inner surface Ri Do from the sealing insulating material, the fuel cell stack And a first insulating member that is inserted into the box member and fixed to the lid member to form a manifold connected to the outside air introduction port ,
Wherein formed in a frame shape outer edge shape along the inner wall so as to surround the external air outlet port, wherein the fuel cell stack and Ri Do an insulating material interposed in sealing between the box member base, wherein the fuel cell stack And a second insulating member that is inserted into the box member to connect to the outside air outlet and forms an exhaust duct . The lid member is integrally provided with an outside air flow path having an outside air intake above the manifold, and the box member is integrally provided with an exhaust flow path having a discharge port above the exhaust duct. The fuel cell device according to claim 1. The fuel cell device according to claim 1 or 2, wherein the cooling water is supplied to the fuel cell stack in a mist form in the manifold. The fuel cell device according to any one of claims 1 to 3, wherein the first insulating member and the second insulating member are made of an elastic material.

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