JP2015138580A - fuel cell device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a temperature difference between a high temperature part and a low temperature part in a fuel cell stack 1.SOLUTION: Width of a passage cross section of a flat container composing an oxidant supply member 7 placed along side face parts of the fuel cell stack 1 or cell groups 1A and 1B thereof is continuously changed in a vertical direction or a lateral direction by a passage width changing member 21 or the like. Or, passage width of an exhaust passage 14 along the side face parts of the fuel cell stack 1 or passage width of an oxidant passage 17 is continuously changed in the vertical direction or the lateral direction.

Description

  The present invention relates to a fuel cell device, and more particularly to a solid oxide fuel cell device.

  A fuel cell device is the core of a fuel cell system, and is an assembly of a plurality of fuel cells that generate electricity by reacting a hydrogen-enriched fuel (including pure hydrogen) and an oxidant (generally air). A fuel cell stack, an off-gas combustion unit that burns off-gas discharged from the upper end of the fuel cell stack to maintain the fuel cell stack at a high temperature, and a housing that surrounds the fuel cell stack and the off-gas combustion unit. Composed.

  On the other hand, the oxidant supply member for supplying an oxidant to the fuel cell stack is a flat container disposed along the side surface of the fuel cell stack or a cell group constituting a part thereof, and the upper end of the flat container It has an oxidant inlet on the side and an oxidant jet on the lower end side.

  The housing has at least a side plate facing the side surface of the fuel cell stack, and has an open upper combustion chamber partition member containing the fuel cell stack and the off-gas combustion unit, and an outer side of the side plate of the combustion chamber partition member. An exhaust passage partition member that has at least a side plate to be disposed and forms an exhaust passage through which exhaust gas generated by the combustion of the off-gas flows from the top to the bottom between the side plate and the combustion chamber partition member; Oxidation that has at least a side plate disposed outside the side plate of the member and forms an oxidant flow path for flowing the oxidant to the oxidant supply member from below to the side plate of the exhaust flow path partition member And an agent flow path partition member.

  By the way, in the fuel cell device as described above, the off-gas is burned on the upper end side of the fuel cell stack, so that the temperature on the upper end side of the fuel cell stack is high and the temperature on the lower end side is low. Creates a temperature difference. In addition, since the oxidant is supplied to the lower end portion of the fuel cell stack by the oxidant supply member, the temperature at the lower end portion of the fuel cell stack is further lowered, and the temperature difference in the vertical direction is further increased.

  Therefore, in the technique described in Patent Document 1, in order to reduce the temperature difference in the vertical direction of the fuel cell, the oxidant supply member is compared with the portion corresponding to the lower end side of the fuel cell stack. In the part corresponding to the upper end part side, it is set as the structure which has high heat conductivity. Specifically, fins, dimples, and the like are provided on the upper end side of the oxidant supply member so as to promote heat exchange with the upper end side of the fuel cell stack.

Japanese Unexamined Patent Publication No. 2011-129489

However, in the technique described in Patent Document 1, a structure for increasing the thermal conductivity is provided only at a specific portion of the oxidant supply member corresponding to the upper end portion (high temperature portion) of the fuel cell stack. Fins, dimples and the like having the same shape are provided corresponding to the entire area.
For this reason, there is a limit to the uniform temperature distribution in the vertical direction. That is, a temperature distribution exists also in the “high temperature part”, and a temperature distribution exists in other than the “high temperature part”, but it has been impossible to make the temperature distribution uniform.

  In addition to the vertical direction, the fuel cell stack also has a temperature distribution in the horizontal direction (the central portion in the horizontal direction is hot and the temperature is low at the both ends), and this cannot be dealt with.

  In view of such a situation, an object of the present invention is to more effectively uniformize the temperature distribution of the fuel cell stack.

  In order to solve the above-mentioned problems, the present invention is based on the width of the cross section of the flat container of the oxidizer supply member (flow path width), the distance between the side plate of the combustion chamber partition member and the side plate of the exhaust flow path partition member. At least one of the channel width of a certain exhaust channel and the channel width of the oxidant channel, which is the distance between the side plate of the exhaust channel partition member and the side plate of the oxidant channel partition member, is a fuel cell. It is set as the structure which changes continuously at least one of the up-down direction in alignment with the side part of a stack, and the horizontal direction in alignment with the side part of a fuel cell stack.

  According to the present invention, the flow path width of the oxidizing agent or the exhaust gas is continuously changed in the vertical direction, for example, the flow path width is gradually increased from the upper end side to the lower end side, so that the flow path is increased on the upper end side. By narrowing the width to increase the flow rate of the oxidant and exhaust gas and improving the heat exchange efficiency, the heat at the upper end (high temperature part) of the fuel cell stack is relatively deprived by the oxidant and exhaust gas, The temperature distribution in the vertical direction of the fuel cell stack can be made uniform.

  In addition, the flow path width of the oxidant and exhaust gas is continuously changed in the lateral direction, for example, by gradually increasing the flow path width from the lateral central portion side to both end portions, the flow passage width is increased at the central portion side. By narrowing and increasing the flow rate of the oxidant and exhaust gas and improving the heat exchange efficiency, the heat at the lateral center (high temperature part) of the fuel cell stack is relatively deprived by the oxidant and exhaust gas, The temperature distribution in the lateral direction of the fuel cell stack can be made uniform.

1 is a schematic front view of a fuel cell device showing a first embodiment of the present invention. 1 is a schematic plan view of a fuel cell device according to a first embodiment. 1 is a schematic side view of a fuel cell device according to a first embodiment. Schematic sectional view showing structural examples 1 to 4 of the oxidant supply member The perspective view which shows the specific example of the structural examples 1 and 2 The figure which shows the temperature characteristic of the oxidizing agent in an oxidizing agent supply member A perspective view showing a specific example of Structural Example 3 A perspective view showing another specific example of Structural Example 3 A perspective view showing a specific example of Structural Example 4 Schematic plan view showing structural examples 5 to 7 of the oxidant supply member A perspective view showing a specific example of Structural Example 5 A perspective view showing a specific example of Structural Example 7 The perspective view which shows the specific example of the combination of the structural examples 1 and 2 and the structural example 5 The perspective view which shows the specific example of the combination of the structural example 4 and the structural example 7 Schematic front view of a fuel cell device showing a second embodiment of the present invention Schematic front view of a fuel cell device showing a third embodiment of the present invention Schematic plan view of the fuel cell device of the third embodiment Schematic perspective view of the channel width changing member in the third embodiment Schematic front view of a fuel cell device showing a fourth embodiment of the present invention Schematic plan view of the fuel cell device of the fourth embodiment Schematic perspective view of the channel width changing member in the fourth embodiment The schematic perspective view of the flow-path width changing member in 5th Embodiment of this invention. Schematic front view of a fuel cell device showing a sixth embodiment of the present invention Schematic plan view of a fuel cell device showing a seventh embodiment of the present invention Schematic front view of a fuel cell device showing an eighth embodiment of the present invention Schematic plan view of the fuel cell device of the eighth embodiment Schematic front view of a fuel cell device showing a ninth embodiment of the present invention Schematic plan view of the fuel cell device of the ninth embodiment Schematic perspective view of the channel width changing member in the ninth embodiment Schematic front view of a fuel cell device showing a tenth embodiment of the present invention Schematic plan view of the fuel cell device of the tenth embodiment Schematic perspective view of the channel width changing member in the tenth embodiment Schematic perspective view of a channel width changing member in an eleventh embodiment of the present invention Schematic front view of a fuel cell device showing a twelfth embodiment of the present invention Schematic plan view of a fuel cell device showing a thirteenth embodiment of the present invention Schematic front view of a fuel cell device showing a fourteenth embodiment of the present invention

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a schematic front view of a fuel cell device showing a first embodiment of the present invention, FIG. 2 is a schematic plan view of the fuel cell device same as above, and FIG. 3 is a schematic side view of the fuel cell device same as the above.

  The fuel cell device of the present embodiment is a solid oxide fuel cell (SOFC) system, and a fuel cell stack 1 that is an assembly of a plurality of fuel cells, an off-gas, in a casing (11, 12, 13). A combustion unit 3, a fuel reformer 5, and an oxidant supply member 7 are provided.

As the casing, an innermost combustion chamber partition member 11, an intermediate exhaust flow path partition member 12, and an outermost oxidant flow path partition member 13 are provided.
The combustion chamber partition member 11 has a pair of left and right side plates 11a and 11b and a bottom plate 11c in a front view, and is formed in a channel shape with an open top. A fuel cell stack 1, an off-gas combustion unit 3, a fuel reformer 5, and an oxidant supply member 7 are disposed in the combustion chamber partition member 11.
The exhaust passage partition member 12 has a pair of left and right side plates 12a, 12b, a bottom plate 12c, and a top plate 12d in a front view, and is formed in a box shape.
The oxidant flow path partition member 13 has a pair of left and right side plates 13a and 13b, a bottom plate 13c, and a top plate 13d in a front view, and is formed in a box shape.

The fuel cell stack 1 is an assembly formed by assembling a plurality of solid oxide fuel cells and electrically connecting them in series (and in parallel) on the pedestal 2 disposed at the bottom of the combustion chamber partition member 11. Is erected.
Each fuel cell is formed by laminating an anode (fuel electrode), an electrolyte made of a solid oxide, and a cathode (oxidant electrode) on the surface of a cell support extending in the vertical direction. The cell support is porous while a fuel passage is formed inside along the extending direction. Accordingly, the hydrogen-rich fuel is supplied to the anode from the inside of the cell support. An oxidizing agent (generally air) is supplied to the cathode from the outside.

The electrolyte conducts oxide ions at high temperatures. The anode reacts oxide ions with hydrogen in the fuel to generate electrons and water. The cathode reacts oxygen and electrons in the oxidant to generate oxide ions.
Therefore, the electrode reaction of the following formula (1) is caused at the cathode of each fuel cell, and the electrode reaction of the following formula (2) is caused at the anode to generate electric power.
Cathode: 1 / 2O ₂ + 2e ⁻ → O ²⁻ (electrolyte) (1)
Anode: O ²⁻ (electrolyte) + H ₂ → H ₂ O + 2e ⁻ (2)

  The fuel cell device includes a large number of fuel cells as described above, and these are electrically connected in series (and in parallel) to constitute a fuel cell stack 1 that is an assembly of fuel cells. In the present embodiment, a large number of fuel cells constituting the fuel cell stack 1 are divided into two groups, that is, a first cell group 1A and a second cell group 1B.

Here, the hydrogen-enriched fuel is supplied to the fuel cell stack 1 from the pedestal 2 side (the lower end side of the fuel cell stack 1), and the pedestal 2 has a fuel distribution function. As the hydrogen-enriched fuel, the reformed fuel is supplied from the fuel reformer 5.
The oxidant (generally air) is supplied to the fuel cell stack 1 via an oxidant supply member 7 described in detail later. In the present embodiment, the oxidant supply member 7 faces the fuel cell stack 1, that is, between the first and second cell groups 1A and 1B. In other words, the fuel cell stack 1 is divided into the first cell group 1A and the second cell group 1B by the oxidant supply member 7.

  The off-gas combustion unit 3 burns surplus hydrogen-enriched fuel in the fuel cell stack 1 (off-gas discharged as power generation unreacted gas) in the presence of surplus oxidant, and the fuel cell stack 1 and the fuel reformer 5 is maintained at a high temperature. Here, the upper end portion of the fuel cell stack 1 serves as a discharge portion for the off gas from the fuel cell stack 1, and this off gas is ignited and burned by an ignition device (not shown). Accordingly, the upper end portion side of the fuel cell stack 1 becomes the off-gas combustion portion 3. The fuel cell stack 1 is maintained in a high-temperature state capable of generating power by the combustion heat in the off-gas combustion unit 3. The high-temperature exhaust gas generated by the combustion is exhaust gas formed between the side plates 11a and 11b of the combustion chamber partition member 11 and the side plates 12a and 12b of the exhaust flow path partition member 12 from the open portion at the top of the combustion chamber partition member 11. It is discharged out of the casing through the exhaust outlet 15 via the flow path 14. The waste heat is used as appropriate.

  The fuel reformer 5 reforms the hydrogen-containing fuel by a reforming reaction using a reforming catalyst to generate a hydrogen-enriched fuel (reformed gas). For this reason, fuel is supplied to the fuel reformer 5 by a fuel pump (not shown) outside the housing.

  As the hydrogen-containing fuel (raw fuel), a hydrocarbon-based fuel is generally used. The hydrocarbon fuel here refers to a compound containing carbon and hydrogen in a molecule (may contain other elements such as oxygen) or a mixture thereof, for example, hydrocarbons, alcohols, Examples include ethers and biofuels. Specific examples of hydrocarbons include methane, ethane, propane, butane, natural gas, LPG (liquefied petroleum gas), city gas, gasoline, naphtha, kerosene, and light oil. Examples of alcohols include methanol and ethanol. Examples of ethers include dimethyl ether. Examples of biofuels include biogas, bioethanol, biodiesel, and biojet.

  The reforming method in the fuel reformer 5 is not particularly limited. For example, steam reforming (SR), partial oxidation reforming (POX), autothermal reforming (ATR), and other reforming methods can be adopted. . In the case of using steam reforming, a water vaporization unit is provided on the inlet side (or different from this) in the fuel reformer 5, and water supplied from outside the casing is vaporized to generate steam.

The fuel reformer 5 of the present embodiment is disposed above the fuel cell stack 1 in the combustion chamber partition member 11 so as to be heated by the combustion heat in the off-gas combustion unit 3.
Further, the fuel reformer 5 of the present embodiment is constituted by two cylindrical fuel reformers that are arranged in parallel with a gap therebetween because of the layout of the oxidant supply member 7. In this case, the two cylindrical fuel reformers may be connected so that the fuel flows in parallel, or may be connected so that the fuel flows back in series.
A supply pipe (not shown) for the generated reformed fuel is led out from the outlet side of the fuel reformer 5 and connected to the base (fuel distribution unit) 2 of the fuel cell stack 1.

  The oxidant supply member 7 is provided between the first and second cell groups 1 </ b> A and 1 </ b> B constituting the fuel cell stack 1 so as to supply the oxidant to the fuel cell stack 1. Consists mainly of containers. This flat container is a rectangular container having an upper surface opened and both side surfaces being flat and facing the side surface portions of the cell groups 1A and 1B.

The oxidant supply member 7 is inserted into the combustion chamber partition member 11 through a slit formed in advance on the top plate 12 d of the exhaust flow path partition member 12, and the opening on the upper end side serves as an oxidant introduction port 8. It opens in the road partition member 13 (between the exhaust flow path partition member 12 and the oxidant flow path partition member 13).
Between the exhaust flow path partition member 12 and the oxidant flow path partition member 13, an oxidant inlet 16 provided on the bottom plate 13c of the oxidant flow path partition member 13 by an oxidant pump (not shown) outside the housing. The oxidant is supplied via The oxidant flows from the bottom to the top in the oxidant flow path 17 formed between the side plates 12a and 12b of the exhaust flow path partition member 12 and the side plates 13a and 13b of the oxidant flow path partition member 13, and the oxidant It flows into the supply member 7.

On the lower end side of the oxidant supply member 7, a plurality of oxidant jets 9 are formed on both side surfaces near the bottom of the flat container constituting the oxidant supply member 7. An oxidant is supplied to each cell group 1A, 1B.
Therefore, the oxidant supply member 7 has an oxidant introduction port 8 on the upper end side of the flat container, and an oxidant jet port 9 on the lower end side. The oxidant flows in from the oxidant introduction port 8 of the oxidant supply member 7, flows from the top to the bottom in the flat container, and is ejected from the oxidant ejection port 9 to be supplied to the cathodes of the cell groups 1A and 1B. Is done.

In the fuel cell device as described above, the off-gas is combusted on the upper end side of the fuel cell stack 1, so that the temperature on the upper end side of the fuel cell stack 1 is high and the temperature on the lower end side is low. Creates a temperature difference. In addition, since the oxidant is supplied to the lower end portion side of the fuel cell stack 1 by the oxidant supply member 7, the temperature at the lower end portion of the fuel cell stack 1 is further lowered, and the temperature difference in the vertical direction is further increased.
Further, the fuel cell stack 1 has not only the vertical direction but also a temperature difference in the horizontal direction (the central portion in the horizontal direction is hot, and the heat is dissipated toward both ends). This is because both ends in the horizontal direction are easier to dissipate heat than the central part in the horizontal direction.

The flow path structure of the oxidant supply member 7 for reducing the temperature difference of the fuel cell stack 1 as described above will be described below.
FIG. 4 is a schematic cross-sectional view showing structural examples 1 to 4 of the oxidant supply member.
In the conventional example, the width (channel width) W of the cross section of the flat container of the oxidizer supply member 7 is constant from the upper end side to the lower end side of the flat container.

In the first structural example, the channel width changing member 21 is inserted and arranged in the flat container of the oxidant supply member 7 as compared with the conventional example.
The flow path width changing member 21 is inserted in the center in the width direction of the oxidant supply member 7 and divides the flow path into a flow path on the first cell group side and a flow path on the second cell group side.
The channel width changing member 21 is an isosceles triangle with a cross-sectional shape in a front view facing downward, and the channel width of each channel is narrowed on the upper end side of the flat container and widened on the lower end side. That is, the flow path width is formed so as to gradually increase from the upper end portion to the lower end portion of the flat container.

According to Structural Example 1, the flow path width is continuously varied in the vertical direction, and the flow path width is gradually increased from the upper end portion to the lower end portion side. The heat exchange efficiency can be increased and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack, which is the high temperature side, by the oxidant. On the lower end side, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away excessively by the oxidant from the lower end side of the fuel cell stack on the low temperature side. As a result, the temperature difference between the high temperature portion on the upper end side and the low temperature portion on the lower end side of the fuel cell stack can be reduced, and the temperature distribution in the vertical direction of the fuel cell stack can be made smooth and uniform as a whole.
Moreover, according to the structural example 1, in order to change the flow path width, the outer shape is changed by using the flow path width changing member 21 inserted and arranged in the flat container of the oxidant supply member 7. There is an advantage that it can be implemented.

  Specifically, the structure example 1 can be realized by an assembly structure as shown in FIG. 5, for example. There may be a gap between the lower end of the flow path width changing member 21 and the bottom of the flat container, or they may be in contact with each other. Further, a flat portion for abutment may be formed at the lower end portion of the flow path width changing member 21.

Structure example 2 is basically the same as structure example 1, but the oxidizer supply member 7 is wider than the conventional example and structure example 1. Corresponding to the widening of the oxidant supply member 7, the flow path width changing member 21 is also widened.
By widening the oxidant supply member 7, the space between the cell groups 1A, 1B and the oxidant supply member 7 can be reduced, and the oxidant supplied to the cell groups 1A, 1B and the oxidant supply member 7 can be reduced. The heat exchange with the oxidizing agent is further improved. The distance between the cell groups 1A and 1B is substantially constant from the viewpoint of compactness and manufacturing.
However, if the width of the oxidant supply member 7 is simply widened, the flow rate of the oxidant inside the oxidant supply member 7 is lowered, and the thermal conductivity is lowered. Arranging also has an advantage of suppressing a decrease in the internal gas flow rate.

In Structural Example 3, the flow path width is formed so as to narrow again after gradually increasing from the upper end portion to the lower end portion side of the flat container. For this reason, the flow path width changing member 23 of Structural Example 3 has a cross-sectional shape in a front view in which relatively small isosceles triangles are connected to the apex side of the downward isosceles triangles.
The reason for this will be described.
6, the horizontal axis indicates the distance from the oxidant inlet in the oxidant flow path in the oxidant supply member, and the vertical axis indicates the temperature of the oxidant in the oxidant supply member and the temperature of the fuel cell stack. Is shown.
As can be seen, on the lower end side of the oxidant supply member, the temperature of the oxidant exceeds the temperature of the fuel cell stack. For this reason, it is desirable to increase the heat exchange efficiency on the lower end portion side of the oxidant supply member so as to apply the heat of the oxidant to the fuel cell stack. Therefore, on the lower end side of the oxidant supply member, the heat exchange efficiency is improved by gradually narrowing the flow path width and increasing the flow rate of the oxidant.

  Specifically, the structural example 3 can be realized by an assembly structure as shown in FIG. 7 or FIG. In FIG. 7, the upper portion 23a and the lower portion 23b of the flow path width changing member 23 are integrated with the insertion side member. In FIG. 8, the upper part 23a of the flow path width changing member 23 is an insertion side member, and the lower part 23b of the flow path width changing member 23 is formed at the bottom of the flat container. In FIG. 8, there may be a gap between the upper part 23a and the lower part 23b of the flow path width changing member 23, or they may be in contact with each other.

In Structural Example 4, the wall (side surface) of the flat container of the oxidant supply member 7 is inclined to form the inclined surface 24 in order to make the flow path widths different. Specifically, the both sides of the oxidant supply member 7 are inclined outward as they go downward, so that the flow path width gradually increases from the upper end to the lower end of the flat container.
Even in this case, the flow path width is continuously changed in the vertical direction, and the flow path width is gradually increased from the upper end portion to the lower end portion side. The flow rate can be increased and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack, which is the high temperature side, by the oxidant. On the lower end side, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away excessively by the oxidant from the lower end side of the fuel cell stack on the low temperature side. As a result, the temperature distribution in the vertical direction of the fuel cell stack can be made uniform.
Moreover, according to the structural example 4, in order to make a flow path width different, the structure which inclines the wall part of the flat container of the oxidizing agent supply member 7 has the advantage that it can implement, without increasing a number of parts. is there.

  Specifically, the structure example 4 can be realized as shown in FIG. 9, for example. Here, on the lower end portion side of the oxidant supply member 7, the wall portion of the flat container is not inclined but is vertical. This is to keep the ejection direction horizontal (perpendicular to the side surface of the fuel cell stack) without tilting the formation surface of the oxidant ejection port 9.

  In the structural examples 1 to 4, the flow paths corresponding to the left and right cell groups 1A and 1B are formed symmetrically in the oxidant supply member 7, but the left and right flow paths are formed differently. Also good. For example, when the fuel reformer 5 is a folded type and the water vaporization unit is disposed on one upstream side, the lower cell group of the water vaporization unit has a lower temperature than the other cell groups. In such a case, it is possible to further promote the uniformity of the temperature distribution by appropriately changing the channel width on the left and right.

Next, a structural example in which the width of the flow path cross section (flow path width) of the flat container of the oxidant supply member 7 is continuously changed in the horizontal direction of the flat container will be described.
FIG. 10 is a schematic plan view showing structural examples 5 to 7 of the oxidant supply member.

In Structural Example 5, the flow path width changing member 25 is inserted and arranged in the flat container of the oxidant supply member 7.
The flow path width changing member 25 is inserted in the center in the width direction of the oxidant supply member 7 and divides the flow path into a flow path on the first cell group side and a flow path on the second cell group side.
The flow path width changing member 25 has a rhombic cross-sectional shape in plan view, and the flow path width of each flow path is narrowed at the center in the horizontal direction of the flat container and wide at both ends in the horizontal direction. That is, the flow path width is formed so as to gradually become wider in the lateral direction of the flat container from the central portion to both end portions.

According to Structural Example 5, the flow path width is continuously varied in the lateral direction, and the flow path width is gradually increased from the lateral center part to both end sides, thereby reducing the flow path width on the lateral center part side. Thus, the flow rate of the oxidant can be increased and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the laterally central portion of the fuel cell stack on the high temperature side by the oxidant. At both lateral ends, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the oxidant from both sides in the lateral direction of the fuel cell stack on the low temperature side. As a result, the temperature difference between the high temperature portion at the lateral center portion of the fuel cell stack and the low temperature portion at both lateral end portions can be reduced, and the temperature distribution in the lateral direction of the fuel cell stack can be made smooth and uniform overall. .
Specifically, the structural example 5 can be realized by an assembly structure as shown in FIG. 11, for example.

  The structural example 6 is based on the structural example 5 and is formed asymmetrically in the front-rear and left-right directions by changing the shape of the flow path width changing member 26. That is, in the structural example 5, the two flow paths corresponding to the cell groups 1A and 1B are formed symmetrically with respect to each other (front and rear symmetry), and the respective flow paths are formed symmetrically with each other. On the other hand, in the structural example 6, all are asymmetric. This is for the purpose of optimizing the channel width in accordance with the actual position of the high temperature portion when the position of the high temperature portion changes due to the arrangement of the water vaporization portion described above.

In the structural example 7, the wall portion (side surface) of the flat container of the oxidant supply member 7 is inclined in the horizontal direction to form the inclined surface 27 in order to vary the flow path width in the horizontal direction. Specifically, the both side surfaces of the oxidant supply member 9 are inclined inwardly from the lateral end portions to the lateral end portions, and the flow path width is gradually increased from the lateral center portion of the flat container to the both end sides. Like to do.
Even in this case, the flow path width is continuously varied in the lateral direction, and the flow path width is gradually increased from the lateral center part to both end sides, thereby reducing the flow path width on the lateral center part side. Thus, the flow rate of the oxidant can be increased and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the laterally central portion of the fuel cell stack on the high temperature side by the oxidant. At both lateral ends, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the oxidant from both sides in the lateral direction of the fuel cell stack on the low temperature side. As a result, the temperature distribution in the lateral direction of the fuel cell stack can be made uniform.

  Specifically, the structural example 7 can be realized as shown in FIG. 12, for example. Here, on the lower end side of the oxidant supply member 7, the wall portion of the flat container is flattened without being inclined. This is to keep the forming direction of the oxidant jet port 9 from being inclined and to keep the jet direction proper (perpendicular to the side surface of the fuel cell stack).

Next, an example of a structure in which the width of the channel cross section (channel width) of the flat container of the oxidizer supply member 7 is continuously changed in the vertical direction of the flat container and continuously changed in the horizontal direction of the flat container. To do.
Such a structural example can be realized by combining the structural examples 1 to 4 in FIG. 4 and the structural examples 5 to 7 in FIG. 10.

FIG. 13 is a perspective view showing a specific example of a combination of Structural Examples 1 and 2 and Structural Example 5.
The flow path width changing member 31 in this combination example has a rhombus cross-sectional shape on the upper end side and a linear cross-sectional shape on the lower end side, and the cross-sectional shape continuously changes in these intermediate portions. ing.
According to this, the width (channel width) of the flow path cross section of the flat container of the oxidizer supply member 7 gradually increases from the upper end portion to the lower end side of the flat container, and from the central portion in the lateral direction of the flat container. It gradually widens toward both ends.
Therefore, the flow path width of the portion corresponding to the upper end portion side and the lateral center portion side of the fuel cell stack is narrowed to increase the flow rate of the oxidant at the portion, and improve the heat exchange efficiency at the portion. Can do. Therefore, the temperature difference between the vertical direction and the horizontal direction of the fuel cell stack can be reduced.

FIG. 14 is a perspective view showing a specific example of a combination of Structural Example 4 and Structural Example 7.
The inclined surface 32 of the side surface portion of the oxidant supply member 7 in this combination example is inclined inward from the lower end portion side toward the upper end portion side, and is inclined inward from the lateral end portions toward the center portion. Yes.
According to this, the width (channel width) of the flow path cross section of the flat container of the oxidizer supply member 7 gradually increases from the upper end portion to the lower end side of the flat container, and from the central portion in the lateral direction of the flat container. It gradually widens toward both ends.
Therefore, the flow path width of the portion corresponding to the upper end portion side and the lateral center portion side of the fuel cell stack is narrowed to increase the flow rate of the oxidant at the portion, and improve the heat exchange efficiency at the portion. Can do. Therefore, the temperature difference between the vertical direction and the horizontal direction of the fuel cell stack can be reduced.

  In addition, although only the typical combination example was demonstrated here, the structural examples 1-4 of FIG. 4 (and its modification) and the structural examples 5-7 of FIG. 10 (and its modification) can be combined suitably. Needless to say.

Next, a second embodiment of the present invention will be described.
FIG. 15 is a schematic front view of a fuel cell device showing a second embodiment of the present invention.
In this embodiment, the oxidant supply member 7 is provided in two parts, and is disposed along both the left and right side portions so as to sandwich the fuel cell stack 1 that is an assembly of a plurality of fuel cells. ing.
Even in such an arrangement, the width of the cross section of the flat container (flow path width) of each oxidant supply member 7 is continuously varied in at least one of the vertical direction and the horizontal direction of the flat container, The temperature difference in the vertical direction and / or the horizontal direction of the fuel cell stack 1 can be reduced. The power generation efficiency and the like can be improved by making the temperature distribution of the fuel cell stack 1 uniform. Note that the flow path width changing member 21 ′ used in FIG. 15 is a right-angled triangle whose sectional shape when viewed from the front is downward.

In the first and second embodiments (FIGS. 1 to 15) described above, the flat container of the oxidant supply member 7 so as to reduce the temperature difference between the high temperature part and the low temperature part according to the temperature distribution of the fuel cell stack 1. In general, since the upper end portion side and the lateral center portion side of the fuel cell stack 1 are at a high temperature, the flow passage width is set so as to reduce the temperature difference accordingly.
In these implementations, in order to obtain a higher effect, when the temperature distribution of the fuel cell stack 1 is made uniform, the actual temperature distribution of the fuel cell stack 1 during rated operation of the fuel cell device is measured, and according to this, It is desirable to set the channel width.
That is, the width of the channel cross-section (channel width) of the flat container of the oxidant supply member 7 is such that the higher the temperature, the narrower the higher the temperature, the narrower the temperature in the vertical direction in the fuel cell stack 1 during rated operation. To be different.
Further, the width of the flow path cross section (flow path width) of the flat container of the oxidant supply member 7 is such that the higher the temperature portion, the narrower the temperature in the horizontal direction in the fuel cell stack 1 during rated operation. To be different.

In the first embodiment (FIG. 1), the fuel cell stack 1 is divided into two cell groups, and the oxidant supply member 7 is disposed between them. However, the fuel cell stack 1 is divided into three cells. You may divide into groups and arrange | position the oxidizing agent supply member 7 between each.
In the second embodiment (FIG. 15), the two oxidant supply members 7 are arranged on both sides of the fuel cell stack 1, but in addition, the fuel cell stack 1 is divided into two cell groups. It may be divided and the oxidant supply member 7 may be disposed between them.

  Next, embodiments (third to eighth embodiments) in which the structure of the exhaust passage 14 is improved in order to reduce the temperature difference of the fuel cell stack 1 will be described.

The exhaust passage 14 is formed between the side plates 11a and 11b of the combustion chamber partitioning member 11 and the side plates 12a and 12b of the exhaust passage partitioning member 12, and exhaust gas from the combustion of the offgas in the offgas combustion unit 3 from above. Distribute down.
Conventionally, the flow path width of the exhaust flow path 14 (the width of the cross section of the flow path; the distance between the side plates 11a and 11b and the side plates 12a and 12b) is set to the side plates 11a, 11b, 12a, and 12b that are the exhaust gas flow direction. It is constant from the upper end side to the lower end side in the vertical direction along. Further, the horizontal direction along the side plates 11a, 11b, 12a, and 12b perpendicular to the flow direction of the exhaust gas is constant from the center side to both end sides.
In contrast to such a conventional structure, in the third to eighth embodiments of the present invention, the flow passage width of the exhaust flow passage 14 is continuously varied in at least one of the vertical direction and the horizontal direction.

FIG. 16 is a schematic front view of a fuel cell device showing a third embodiment, and FIG. 17 is a schematic plan view of the same.
In the third embodiment (FIGS. 16 and 17), the flow passage width changing member is provided in the exhaust passage 14 between the side plates 11a and 11b of the combustion chamber partition member 11 and the side plates 12a and 12b of the exhaust passage partition member 12. 41 is inserted and arranged. FIG. 18 is a schematic perspective view of the flow path width changing member 41.

The flow path width changing member 41 is attached to the side plates 12a, 12b of the outer exhaust flow path partition member 12, and the flow width is changed between the side plates 11a, 11b of the inner combustion chamber partition member 11. A flow path 14 is formed.
The flow path width changing member 41 is a right-angled triangle whose front sectional view is downward, and the flow path width of the exhaust flow path 14 is narrowed on the upper end side and widened on the lower end side. That is, the channel width is formed so as to gradually increase from the upper end side to the lower end side of the exhaust channel 14.

According to this embodiment, the flow path width of the exhaust flow path 14 is continuously changed in the vertical direction, and in particular, the flow path from the upper end side to the lower end side corresponding to the vertical part of the fuel cell stack 1. By gradually widening the width, it is possible to narrow the flow path width on the upper end side, increase the flow rate of the exhaust gas, and improve the heat exchange efficiency. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack 1 on the high temperature side by the exhaust gas. On the lower end side, the flow path width can be widened to reduce the flow rate of the exhaust gas, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the exhaust gas from the lower end side of the fuel cell stack 1 on the low temperature side. As a result, the temperature difference between the high temperature part on the upper end side and the low temperature part on the lower end side of the fuel cell stack 1 can be reduced, and the temperature distribution in the vertical direction of the fuel cell stack 1 can be made smooth overall.
In addition, according to the present embodiment, in order to vary the flow path width, by using the flow path width changing member 41 inserted and arranged in the exhaust flow path 14, without changing the housing shape, There is an advantage that it can be implemented.

  In the present embodiment, the exhaust flow path 14 (and the flow path width changing member 41) corresponding to one side surface (the first cell group 1A side) of the fuel cell stack 1 and the other side surface of the fuel cell stack 1 are used. The exhaust channel 14 (and the channel width changing member 41) corresponding to the portion (second cell group 1B side) is formed symmetrically. However, the left and right exhaust passages 14 may be formed different from each other. For example, when the fuel reformer 5 is a folded type and the water vaporization unit is disposed on one upstream side, the lower cell group of the water vaporization unit has a lower temperature than the other cell groups. In such a case, it is possible to further promote the homogenization of the temperature distribution by appropriately varying the channel width on the left and right. The same applies to the following embodiments.

Next, a fourth embodiment of the present invention will be described.
FIG. 19 is a schematic front view of a fuel cell device showing a fourth embodiment of the present invention, and FIG. 20 is a schematic plan view of the same fuel cell device.
In the present embodiment, a flow path width changing member 42 is inserted and disposed in the exhaust flow path 14 between the side plates 11 a and 11 b of the combustion chamber partition member 11 and the side plates 12 a and 12 b of the exhaust flow path partition member 12. FIG. 21 is a schematic perspective view of the flow path width changing member 42.

The flow path width changing member 42 is attached to the side plates 12a, 12b of the outer exhaust flow path partition member 12, and the flow width is changed between the side plates 11a, 11b of the inner combustion chamber partition member 11. A flow path 14 is formed.
The channel width changing member 42 is an isosceles triangle whose cross-sectional shape when viewed from above is an inward isosceles triangle, and the channel width of the exhaust channel 14 is narrowed on the laterally central portion side and widened on both ends. That is, the channel width is formed so as to gradually increase from the lateral center portion side of the exhaust channel 14 to both end portions.

  According to the present embodiment, the flow passage width of the exhaust passage 14 is continuously varied in the lateral direction, and particularly from the lateral central portion side to the both end portions in correspondence with the lateral portion of the fuel cell stack 1. By gradually widening the flow path width, the flow path width can be narrowed on the side in the lateral direction to increase the flow rate of the exhaust gas, and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the lateral center portion of the fuel cell stack 1 on the high temperature side by the exhaust gas. At both lateral ends, the flow path width can be widened to reduce the exhaust gas flow velocity, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away excessively from the lateral end portions of the fuel cell stack 1 on the low temperature side. As a result, the temperature difference between the high temperature portion on the lateral center side of the fuel cell stack 1 and the low temperature portion on both lateral ends is reduced, and the temperature distribution in the lateral direction of the fuel cell stack 1 is generally smooth and uniform. Can be

  In the present embodiment, the exhaust flow path 14 (and the flow path width changing member 42) is formed symmetrically in the horizontal direction, and the horizontal center position has the minimum width. This is based on the premise that the central position in the horizontal direction is the highest temperature part (maximum temperature part). However, the position of the highest temperature part may shift from the horizontal center position due to the arrangement of the water vaporization part described above. In such a case, it is desirable to set the position of the minimum width in accordance with the position of the highest temperature part. Therefore, the channel width of the exhaust channel 14 does not necessarily have to be symmetrical in the lateral direction. The same applies to the following embodiments.

Next, a fifth embodiment of the present invention will be described.
FIG. 22 is a schematic perspective view of the flow path width changing member 43 in the fifth embodiment. The schematic front view of the fuel cell device in this case is the same as FIG. 16, and the schematic plan view is the same as FIG.
The flow path width changing member 43 of the present embodiment has an isosceles triangle cross-sectional shape on the upper end side and a linear cross-sectional shape on the lower end side so that the cross-sectional shape continuously changes at these intermediate portions. It has become.

According to this, the flow passage width of the exhaust flow passage 14 gradually increases from the upper end portion side to the lower end portion side of the exhaust flow passage 14, and gradually from the central portion side to both end portions in the lateral direction of the exhaust flow passage 14. Become wider.
Therefore, the flow path width of the part corresponding to the upper end part side and the lateral center part side of the fuel cell stack 1 is narrowed to increase the flow rate of the exhaust gas at the part and improve the heat exchange efficiency at the part. be able to. Therefore, the temperature difference between the vertical direction and the horizontal direction of the fuel cell stack 1 can be reduced.

Next, a sixth embodiment of the present invention will be described.
FIG. 23 is a schematic front view of a fuel cell device showing a sixth embodiment of the present invention.
In the present embodiment, the side plates 11a and 11b of the combustion chamber partition member 11 are inclined in order to vary the flow passage width of the exhaust flow passage 14 in the vertical direction. Specifically, the side plates 11a and 11b of the combustion chamber partitioning member 11 are inclined outward as they go upward, the flow path width is narrowed on the upper end side, and gradually widened from the upper end side to the lower end side. ing.

Even in this case, the flow path width of the exhaust flow path 14 is continuously varied in the vertical direction, and in particular, the flow path width from the upper end side to the lower end side corresponding to the vertical part of the fuel cell stack 1. By gradually widening, the flow width of the exhaust gas can be increased by narrowing the flow path width on the upper end side, and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack 1 on the high temperature side by the exhaust gas. On the lower end side, the flow path width can be widened to reduce the flow rate of the exhaust gas, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the exhaust gas from the lower end side of the fuel cell stack 1 on the low temperature side. As a result, the temperature distribution in the vertical direction of the fuel cell stack 1 can be made uniform.
Further, according to the present embodiment, the side plates 11a and 11b of the combustion chamber partitioning member 11 constituting the exhaust passage 14 are inclined in order to make the passage widths different, thereby increasing the number of parts. There is an advantage that can be implemented.

  In addition to the configuration in which the side plates 11a and 11b of the combustion chamber partition member 11 are tilted (upper side is tilted outward), or in place of the configuration, the side plates 12a and 12b of the exhaust flow path partition member 12 are tilted (the upper side is tilted). It is good also as a structure made to incline inward.

Next, a seventh embodiment of the present invention will be described.
FIG. 24 is a schematic plan view of a fuel cell device showing a seventh embodiment of the present invention.
In the present embodiment, the side plates 11a and 11b of the combustion chamber partition member 11 and the side plates 12a and 12b of the exhaust channel partition member 12 are inclined in the lateral direction in order to vary the width of the exhaust channel 14 in the lateral direction. It has been made. Specifically, the side plates 11a and 11b of the combustion chamber partition member 11 are inclined in a mountain shape outwardly with the central portion in the horizontal direction as a ridgeline, and the side plates 12a and 12b of the exhaust flow path partition member 12 are centered in the horizontal direction. The part is inclined inwardly as a ridgeline. As a result, the flow passage width of the exhaust passage 14 between the side plates 11a, 11b and the side plates 12a, 12b is narrowed at the central portion in the horizontal direction and gradually widened from the central portion in the horizontal direction toward both end portions.

Even in this case, the flow passage width of the exhaust flow passage 14 is continuously changed in the lateral direction, and in particular, the flow passage from the lateral central portion to the both end portions in correspondence with the lateral portion of the fuel cell stack 1. By gradually widening the width, the flow width of the exhaust gas can be increased by narrowing the flow path width on the laterally central portion side, and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the lateral center portion of the fuel cell stack 1 on the high temperature side by the exhaust gas. At both lateral ends, the flow path width can be widened to reduce the exhaust gas flow velocity, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away excessively from the lateral end portions of the fuel cell stack 1 on the low temperature side. As a result, the temperature distribution in the lateral direction of the fuel cell stack 1 can be made uniform.
Here, both the side plates 11a and 11b of the combustion chamber partitioning member 11 and the side plates 12a and 12b of the exhaust passage partitioning member 12 are inclined in a mountain shape, but either one may be inclined.

  The sixth embodiment (FIG. 23) and the seventh embodiment (FIG. 24) are combined, and the side plates 11a and 11b of the combustion chamber partition member 11 and / or the side plates 12a and 12b of the exhaust flow path partition member 12 are combined. The temperature distribution in the vertical and horizontal directions of the fuel cell stack 1 may be made uniform by varying the flow channel width of the exhaust flow channel 14 in the vertical and horizontal directions by an inclined structure.

Next, an eighth embodiment of the present invention will be described.
FIG. 25 is a schematic front view of a fuel cell device showing an eighth embodiment of the present invention, and FIG. 26 is a schematic plan view of the same fuel cell device.
In this embodiment, the site | part by the side of the upper end part of the side wall 11a, 11b of the combustion chamber division member 11 and a horizontal direction center part side is bulged outside.
Even with such a configuration, the flow passage width of the portion of the exhaust passage 14 corresponding to the high temperature portion on the upper end portion side and the laterally central portion side of the fuel cell stack 1 is narrowed, and the flow rate of the exhaust gas in that portion is reduced. By raising the temperature, the temperature distribution of the fuel cell stack 1 can be made uniform.

In the third to eighth embodiments (FIGS. 16 to 26), the flow path width of the exhaust flow path 14 is reduced so as to reduce the temperature difference between the high temperature part and the low temperature part according to the temperature distribution of the fuel cell stack 1. In general, the upper end portion side and the lateral center portion side of the fuel cell stack 1 are at a high temperature, and accordingly, the flow path width is set so as to reduce the temperature difference.
In these implementations, in order to obtain a higher effect, when the temperature distribution of the fuel cell stack 1 is made uniform, the actual temperature distribution of the fuel cell stack 1 during rated operation of the fuel cell device is measured, and according to this, It is desirable to set the channel width.
That is, the flow path width of the exhaust flow path 14 is varied in the vertical direction so as to become narrower as the temperature increases, according to the vertical temperature distribution in the fuel cell stack 1 during rated operation.
Further, the flow path width of the exhaust flow path 14 is varied in the lateral direction so as to become narrower as the temperature increases, according to the temperature distribution in the lateral direction in the fuel cell stack 1 during rated operation.

  Next, embodiments in which the structure of the oxidant channel 17 is improved in order to reduce the temperature difference of the fuel cell stack 1 (ninth to thirteenth embodiments) will be described.

The oxidant flow path 17 is formed between the side plates 12a and 12b of the exhaust flow path partition member 12 and the side plates 13a and 13b of the oxidant flow path partition member 13, and distributes the oxidant from the bottom to the top.
Conventionally, the channel width of the oxidant channel 17 (the width of the channel cross section; the distance between the side plates 12a, 12b and the side plates 13a, 13b) is the side plate 12a, 12b, 13a, which is the flow direction of the oxidant gas. It is constant from the upper end side to the lower end side in the vertical direction along 13b. Further, the horizontal direction along the side plates 12a, 12b, 13a, and 13b perpendicular to the flow direction of the oxidant gas is constant from the center side to both end sides.
In contrast to such a conventional structure, in the ninth to thirteenth embodiments of the present invention, the channel width of the oxidant channel 17 is continuously varied in at least one of the vertical direction and the horizontal direction.

FIG. 27 is a schematic front view of a fuel cell device showing a ninth embodiment, and FIG. 28 is a schematic plan view of the same.
In the ninth embodiment (FIGS. 27 and 28), the oxidant flow path 17 between the side plates 12a and 12b of the exhaust flow path partition member 12 and the side plates 13a and 13b of the oxidant flow path partition member 13 has a flow path. A width changing member 51 is inserted and arranged. FIG. 29 is a schematic perspective view of the flow path width changing member 51.

The channel width changing member 51 is attached to the side plates 13a and 13b of the outer oxidant channel partition member 13, and the channel width is changed between the side plates 12a and 12b of the inner exhaust channel partition member 12. The exhaust passage 17 is formed.
The flow path width changing member 51 is a right-angled triangle whose front sectional view is downward, and the flow path width of the exhaust flow path 17 is narrowed on the upper end side and widened on the lower end side. That is, the channel width is formed so as to gradually increase from the upper end side to the lower end side of the oxidant channel 17.

According to the present embodiment, the channel width of the oxidant channel 17 is continuously varied in the vertical direction, and in particular, the flow from the upper end side to the lower end side in correspondence with the vertical part of the fuel cell stack 1. By gradually widening the channel width, the channel width can be narrowed on the upper end side to increase the flow rate of the oxidant and improve the heat exchange efficiency. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack 1 which is the high temperature side by the oxidant. On the lower end side, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the oxidant from the lower end side of the fuel cell stack 1 that is on the low temperature side. As a result, the temperature difference between the high temperature part on the upper end side and the low temperature part on the lower end side of the fuel cell stack 1 can be reduced, and the temperature distribution in the vertical direction of the fuel cell stack 1 can be made smooth overall. However, heat exchange between the oxidant flowing through the oxidant flow path 17 and the fuel cell stack 1 is performed via the exhaust gas flowing through the exhaust flow path 14.
Moreover, according to this embodiment, in order to make a flow path width different, it is set as the structure using the flow path width changing member 51 inserted and arrange | positioned in the oxidizing agent flow path 17, without changing a housing | casing shape. There is an advantage that can be implemented.

  In the present embodiment, the oxidant channel 17 (and the channel width changing member 21) corresponding to one side surface (cell group 1A side) of the fuel cell stack 1 and the other side surface of the fuel cell stack 1 are provided. The oxidant flow path 17 (and the flow path width changing member 21) corresponding to the (cell group 1B side) was formed symmetrically. However, the left and right oxidant channels 17 may be formed differently. For example, when the fuel reformer 5 is a folded type and the water vaporization unit is disposed on one upstream side, the lower cell group of the water vaporization unit has a lower temperature than the other cell groups. In such a case, it is possible to further promote the homogenization of the temperature distribution by appropriately varying the channel width on the left and right. The same applies to the following embodiments.

Next, a tenth embodiment of the present invention will be described.
FIG. 30 is a schematic front view of a fuel cell device showing a tenth embodiment of the present invention, and FIG. 31 is a schematic plan view of the same fuel cell device.
In the present embodiment, the channel width changing member 52 is inserted and disposed in the oxidant channel 17 between the side plates 12 a and 12 b of the exhaust channel partition member 12 and the side plates 13 a and 13 b of the oxidant channel partition member 13. It is. FIG. 32 is a schematic perspective view of the flow path width changing member 52.

The channel width changing member 52 is attached to the side plates 13 a and 13 b of the outer oxidant channel partition member 13, and the channel width is changed between the side plates 12 a and 12 b of the inner exhaust channel partition member 12. An oxidant flow path 17 is formed.
The channel width changing member 52 is an isosceles triangle whose cross-sectional shape in plan view is inward, and the channel width of the oxidant channel 17 is narrowed at the center in the lateral direction and wide at both ends. That is, the channel width is formed so as to gradually increase from the lateral center portion side of the oxidant channel 17 to both end portions.

  According to the present embodiment, the channel width of the oxidant channel 17 is continuously varied in the lateral direction, and in particular corresponding to the lateral part of the fuel cell stack 1, from the lateral center side to the both end sides. By gradually increasing the width of the flow path, the flow width of the oxidant can be increased by narrowing the width of the flow path on the laterally central portion side, and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the lateral center portion of the fuel cell stack 1 on the high temperature side by the oxidant. At both lateral ends, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent the heat from being taken away excessively by the oxidant from the both ends in the lateral direction of the fuel cell stack 1 on the low temperature side. As a result, the temperature difference between the high temperature portion on the lateral center side of the fuel cell stack 1 and the low temperature portion on both lateral ends is reduced, and the temperature distribution in the lateral direction of the fuel cell stack 1 is generally smooth and uniform. Can be

  In this embodiment, the oxidant flow path 17 (and the flow path width changing member 52) are formed symmetrically in the horizontal direction, and the horizontal center position has the minimum width. This is based on the premise that the central position in the horizontal direction is the highest temperature part (maximum temperature part). However, the position of the highest temperature part may shift from the horizontal center position due to the arrangement of the water vaporization part described above. In such a case, it is desirable to set the position of the minimum width in accordance with the position of the highest temperature part. Therefore, the channel width of the oxidant channel 17 is not necessarily symmetrical with respect to the lateral direction. The same applies to the following embodiments.

Next, an eleventh embodiment of the present invention will be described.
FIG. 33 is a schematic perspective view of the flow path width changing member 53 in the eleventh embodiment. The schematic front view of the fuel cell device in this case is the same as FIG. 27, and the schematic plan view is the same as FIG.
The flow path width changing member 53 of the present embodiment has an isosceles triangle cross-sectional shape on the upper end side and a linear cross-sectional shape on the lower end side so that the cross-sectional shape continuously changes at these intermediate portions. It has become.

According to this, the channel width of the oxidant channel 17 gradually increases from the upper end side to the lower end side of the oxidant channel 17, and both ends from the center side in the lateral direction of the oxidant channel 17. Widen gradually to the side.
Therefore, the flow path width of the portion corresponding to the upper end portion side and the laterally central portion side of the fuel cell stack 1 is narrowed to increase the flow rate of the oxidant at the portion and improve the heat exchange efficiency at the portion. be able to. Therefore, the temperature difference between the vertical direction and the horizontal direction of the fuel cell stack 1 can be reduced.

Next, a twelfth embodiment of the present invention will be described.
FIG. 34 is a schematic front view of a fuel cell device showing a twelfth embodiment of the present invention.
In the present embodiment, the side plates 12a and 12b of the exhaust flow path partition member 12 are inclined in order to vary the flow path width of the oxidant flow path 17 in the vertical direction. Specifically, the side plates 12a and 12b of the exhaust flow path partitioning member 12 are inclined outwardly toward the upper side, the flow width of the oxidant flow path 17 is narrowed on the upper end side, and the upper end side to the lower end part. It gradually increases to the side.

Even in this case, the flow path width of the oxidant flow path 17 is continuously varied in the vertical direction, and in particular, the flow path from the upper end side to the lower end side in correspondence with the vertical portion of the fuel cell stack 1. By gradually widening the width, the flow width of the oxidant can be increased by narrowing the channel width on the upper end side, and the heat exchange efficiency can be improved. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack 1 which is the high temperature side by the oxidant. On the lower end side, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the oxidant from the lower end side of the fuel cell stack 1 that is on the low temperature side. As a result, the temperature distribution in the vertical direction of the fuel cell stack 1 can be made uniform.
In addition, according to the present embodiment, in order to make the flow path widths different, the side plates 12a and 12b of the exhaust flow path drawing member 12 constituting the oxidant flow path 17 are inclined to increase the number of parts. There is an advantage that it can be implemented.

  In addition to the configuration in which the side plates 12a and 12b of the exhaust flow path partition member 12 are inclined (the upper side is inclined outward), or in place of the configuration, the side plates 13a and 13b of the oxidant flow path partition member 13 are inclined ( The upper side may be inclined inward).

Next, a thirteenth embodiment of the present invention will be described.
FIG. 35 is a schematic plan view of a fuel cell device showing a thirteenth embodiment of the present invention.
In the present embodiment, the side plates 12a and 12b of the exhaust channel partition member 12 and the side plates 13a and 13b of the oxidant channel partition member 13 are laterally arranged to vary the channel width of the oxidant channel 17 in the lateral direction. It is inclined in the direction. Specifically, the side plates 12a and 12b of the exhaust flow path partition member 12 are inclined outwardly in a mountain shape with the laterally central portion as a ridgeline. The side plates 13a and 13b of the oxidant flow path dividing member 13 are inclined inwardly with a central portion in the horizontal direction as a ridgeline. As a result, the channel width of the oxidant channel 17 between the side plates 12a, 12b and the side plates 13a, 13b is narrowed at the central portion in the lateral direction, and gradually widened from the central portion in the lateral direction toward both end portions. .

Even in this case, the flow width of the oxidant flow path 17 is continuously varied in the lateral direction, and in particular, the flow from the central portion in the lateral direction to the both end sides in correspondence with the lateral portions of the fuel cell stack 1. By gradually widening the channel width, the channel width can be narrowed on the laterally central portion side to increase the flow rate of the oxidant and improve the heat exchange efficiency. That is, heat can be sufficiently removed from the lateral center portion of the fuel cell stack 1 on the high temperature side by the oxidant. At both lateral ends, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent the heat from being taken away excessively by the oxidant from the both ends in the lateral direction of the fuel cell stack 1 on the low temperature side. As a result, the temperature distribution in the lateral direction of the fuel cell stack 1 can be made uniform.
Here, both the side plates 12a and 12b of the exhaust passage partition member 12 and the side plates 13a and 13b of the oxidant passage partition member 13 are inclined in a mountain shape, but either one may be inclined. Good.

  The twelfth embodiment (FIG. 34) and the thirteenth embodiment (FIG. 35) are combined, and the side plates 12a and 12b of the exhaust flow path partition member 12 and / or the side plate 13a of the oxidant flow path partition member 13 are combined. By the inclined structure of 13b, the channel width of the oxidant channel 17 may be varied in the vertical direction and the horizontal direction so that the temperature distribution in the vertical direction and the horizontal direction of the fuel cell stack 1 can be made uniform.

In the ninth to thirteenth embodiments (FIGS. 27 to 35), the flow path of the oxidant flow path 17 is reduced in accordance with the temperature distribution of the fuel cell stack 1 so as to reduce the temperature difference between the high temperature portion and the low temperature portion. The width is set, and generally the upper end portion side and the lateral center portion side of the fuel cell stack 1 are at a high temperature. Therefore, the flow passage width is set so as to reduce the temperature difference accordingly.
In these implementations, in order to obtain a higher effect, when the temperature distribution of the fuel cell stack 1 is made uniform, the actual temperature distribution of the fuel cell stack 1 during rated operation of the fuel cell device is measured, and according to this, It is desirable to set the channel width.
That is, the flow path width of the oxidant flow path 17 is varied in the vertical direction so as to become narrower as the temperature increases, according to the vertical temperature distribution in the fuel cell stack 1 during rated operation.
Further, the channel width of the oxidant channel 17 is varied in the lateral direction so as to become narrower as the temperature increases, according to the temperature distribution in the lateral direction in the fuel cell stack 1 during rated operation.

  Next, an embodiment in which the flow path structure of the oxidant supply member 7, the flow path structure of the exhaust flow path 14, and the flow path structure of the oxidant flow path 17 are improved in order to reduce the temperature difference of the fuel cell stack 1. (14th Embodiment) is demonstrated.

FIG. 36 is a schematic front view of a fuel cell device showing a fourteenth embodiment of the present invention.
In the present embodiment, the temperature distribution of the fuel cell stack 1 is set by combining the flow path structure of the oxidant supply member 7, the flow path structure of the exhaust flow path 14, and the flow path structure of the oxidant flow path 17. Further homogenization is attempted.

The side plates 7a and 7b, which constitute a flat container of the oxidant supply member 7 and are opposed to the side surfaces of the cell groups 1A and 1B of the fuel cell stack 1, are inclined inward as they go upward. The channel width (distance between the side plates 7a and 7b) of the oxidant channel 10 formed therebetween is narrowed on the upper end side, and gradually becomes wider from the upper end side to the lower end side.
By doing so, the flow path width of the oxidant flow path 10 in the oxidant supply member 7 is continuously varied in the vertical direction, in particular, the upper end portion corresponding to the vertical position of the fuel cell stack 1. By gradually widening the flow path width from the side to the lower end part side, the flow path width can be narrowed on the upper end part side to increase the flow rate of the oxidant and improve the heat exchange efficiency. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack 1 which is the high temperature side by the oxidant. On the lower end side, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the oxidant from the lower end side of the fuel cell stack 1 that is on the low temperature side. As a result, the temperature distribution in the vertical direction of the fuel cell stack 1 can be made uniform.

Further, the side plates 11a, 11b of the combustion chamber partition member 11 are inclined outward as they go upward, and formed between the side plates 11a, 11b of the combustion chamber partition member 11 and the side plates 12a, 12b of the exhaust flow path partition member 12. The exhaust passage 14 is made narrower at the upper end side and gradually becomes wider from the upper end side to the lower end side.
In this way, the flow path width of the exhaust flow path 14 is continuously varied in the vertical direction, and in particular, the flow path from the upper end side to the lower end side corresponding to the vertical part of the fuel cell stack 1. By gradually widening the width, it is possible to narrow the flow path width on the upper end side, increase the flow rate of the exhaust gas, and improve the heat exchange efficiency. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack 1 on the high temperature side by the exhaust gas. On the lower end side, the flow path width can be widened to reduce the flow rate of the exhaust gas, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the exhaust gas from the lower end side of the fuel cell stack 1 on the low temperature side. As a result, the temperature distribution in the vertical direction of the fuel cell stack 1 can be made uniform.

Further, the side plates 13a and 13b of the oxidant flow path partition member 13 are inclined inward as they go upward, and the side plates 12a and 12b of the exhaust flow path partition member 12 and the side plates 13a and 13b of the oxidant flow path partition member 13 The channel width of the oxidant channel 17 formed between the upper end portion and the lower end portion is narrowed on the upper end side and gradually increased from the upper end side to the lower end side.
In this way, the flow path width of the oxidant flow path 17 is continuously varied in the vertical direction, and in particular, the flow from the upper end side to the lower end side corresponding to the vertical part of the fuel cell stack 1. By gradually widening the channel width, the channel width can be narrowed on the upper end side to increase the flow rate of the oxidant and improve the heat exchange efficiency. That is, heat can be sufficiently removed from the upper end side of the fuel cell stack 1 which is the high temperature side by the oxidant. On the lower end side, the flow path width can be widened to reduce the flow rate of the oxidant, thereby reducing the heat exchange efficiency. That is, it is possible to prevent heat from being taken away by the oxidant from the lower end side of the fuel cell stack 1 that is on the low temperature side. As a result, the temperature distribution in the vertical direction of the fuel cell stack 1 can be made uniform.

Therefore, in this embodiment, the temperature distribution in the vertical direction of the fuel cell stack 1 is determined by the combination of the flow path structure of the oxidant supply member 7, the flow path structure of the exhaust flow path 14 and the flow path structure of the oxidant flow path 17. Can be achieved.
In the combination structure described here, the channel width is changed by the inclined structure of the side plate, but the channel width may be changed by inserting and arranging the channel width changing member in the channel. . In addition, although an example in which the temperature distribution in the vertical direction is made uniform has been described here, it is needless to say that a combination structure may be adopted in order to make the temperature distribution in the horizontal direction uniform. Further, any two of the channel structure of the oxidant supply member 7, the channel structure of the exhaust channel 14, and the channel structure of the oxidant channel 17 may be combined.

  In the above-described embodiment, a hydrocarbon-based fuel is used as the hydrogen-containing fuel, and the fuel reformer 5 reforms the fuel into a hydrogen-rich reformed fuel (hydrogen-enriched fuel). However, an organic hydride is used as the hydrogen-containing fuel, the fuel reformer 5 is replaced with a dehydrogenation reaction type, and a hydrogen-rich gas (hydrogen-enriched fuel) generated by the dehydrogenation reaction of the organic hydride is used as a fuel cell. It may be supplied to the anode of the stack 1. It is also possible to use pure hydrogen as the hydrogen-enriched fuel. In this case, the fuel reformer 5 can be omitted, and the hydrogen-enriched fuel can be directly supplied to the anode of the fuel cell stack 1 from a hydrogen tank or the like outside the housing.

  In the above embodiment, the fuel cell stack 1, which is an assembly of a plurality of fuel cells, is divided into two cell groups 1A, 1B, and the oxidant supply member 7 is disposed between them. The division form of the cell group is not limited to this. Moreover, it is good also as a single group, without dividing | segmenting (refer FIG. 15). The layout and number of the oxidant supply member 7 and the fuel reformer 5 are appropriately changed according to the form of the assembly.

  Thus, the illustrated embodiments are merely illustrative of the present invention, and the present invention is not limited to those directly illustrated by the described embodiments, and various modifications made by those skilled in the art within the scope of the claims. Needless to say, it includes improvements and changes.

1 Fuel cell stack (an assembly of multiple fuel cells)
1A, 1B Cell group 2 Pedestal 3 Off-gas combustion section 5 Fuel reformer 7 Oxidant supply member 8 Oxidant inlet 9 Oxidant outlet 11 Combustion chamber partition members 11a, 11b Side plate 12 Exhaust flow path partition members 12a, 12b Side plate 13 Oxidant channel partition members 13a, 13b Side plate 14 Exhaust channel 15 Exhaust outlet 16 Oxidant inlet 17 Oxidant channels 21, 21 ', 23 (23a, 23b) Channel width changing member 24 Inclined surfaces 25, 26 Flow Road width changing member 27 Inclined surface 31 Channel width changing member 32 Inclined surfaces 41, 42, 43 Channel width changing members 51, 52, 53 Channel width changing member

Claims (23)

A fuel cell stack that is an assembly of a plurality of fuel cells that generate electricity by reacting a hydrogen-rich fuel with an oxidant;
An off-gas combustion unit that burns off-gas discharged from an upper end of the fuel cell stack to maintain the fuel cell stack in a high temperature state;
In order to supply the oxidant to the fuel cell stack, the fuel cell stack is composed of a flat container arranged along a side surface of a cell group constituting the fuel cell stack or a part thereof, and the oxidant is introduced into the upper end side of the flat container An oxidizer supply member having a mouth and having an oxidizer jet on the lower end side;
An upper open combustion chamber partition member having at least a side plate facing a side surface portion of the fuel cell stack and containing the fuel cell stack and the off-gas combustion portion;
An exhaust passage that has at least a side plate disposed outside the side plate of the combustion chamber partition member and circulates the exhaust gas generated by the combustion of the off-gas from the top to the bottom is formed between the side plate and the side plate of the combustion chamber partition member. An exhaust passage partition member;
An oxidant that has at least a side plate disposed on the outer side of the side plate of the exhaust flow path partition member and causes the oxidant to the oxidant supply member to flow between the side plate of the exhaust flow path partition member from the bottom to the top An oxidant flow path partition member forming a flow path;
Comprising
The width of the cross-section of the flat container of the oxidant supply member, the width of the exhaust flow path that is the distance between the side plate of the combustion chamber partition member and the side plate of the exhaust flow path partition member, and the exhaust flow At least one of the channel widths of the oxidant channel, which is the distance between the side plate of the path partition member and the side plate of the oxidant channel partition member,
The fuel cell apparatus is characterized by being continuously different in at least one of a vertical direction along the side surface portion of the fuel cell stack and a lateral direction along the side surface portion of the fuel cell stack.   2. The fuel cell device according to claim 1, wherein a width of a cross section of the flat container of the oxidizer supply member is continuously varied in at least one of a vertical direction and a horizontal direction of the flat container.   3. The fuel cell device according to claim 2, wherein the width of the cross section of the flow path of the flat container of the oxidant supply member is formed so as to gradually increase from the upper end portion to the lower end portion side of the flat container.   The width of the flow path cross section of the flat container of the oxidant supply member is formed so as to become narrow again after gradually increasing from the upper end portion to the lower end portion side of the flat container. Fuel cell device.   The width of the cross section of the flat container of the flattened container of the oxidant supply member is formed so as to gradually increase from the central part to the both end parts in the lateral direction of the flat container. The fuel cell device according to any one of the above.   The width of the cross section of the flow path of the flat container of the oxidant supply member is varied in the vertical direction so that the higher the temperature, the narrower the higher temperature portion according to the vertical temperature distribution in the fuel cell stack during rated operation. The fuel cell device according to claim 2.   The width of the cross section of the flow path of the flat container of the oxidizer supply member is varied in the lateral direction so as to become narrower as the high-temperature portion follows the lateral temperature distribution in the fuel cell stack during rated operation. The fuel cell device according to claim 2 or 6.   The flow path width changing member inserted and disposed in the flat container of the oxidant supply member is provided in order to vary the width of the flow path cross section of the flat container of the oxidant supply member. The fuel cell device according to claim 7.   The wall portion of the flat container of the oxidant supply member is inclined to vary the width of the cross-sectional width of the flat container of the oxidant supply member. The fuel cell device according to claim 1.   The flow path width of the exhaust flow path, which is the distance between the side plate of the combustion chamber partition member and the side plate of the exhaust flow path partition member, is the vertical direction along the side plate, which is the flow direction of exhaust gas, 2. The fuel cell device according to claim 1, wherein the fuel cell device is continuously varied in at least one of the lateral directions along the side plate perpendicular to the flow direction.   The exhaust passage has a flow passage width that is formed so as to gradually increase in the vertical direction from the upper end side to the lower end side corresponding to the vertical portion of the fuel cell stack. The fuel cell device according to claim 10.   The exhaust passage has a flow passage width that is formed so as to gradually increase in the lateral direction from the central portion side to both end portions in correspondence with the lateral portion of the fuel cell stack. 12. A fuel cell device according to claim 10 or claim 11.   The flow path width of the exhaust flow path is varied in the vertical direction so as to become narrower as the high-temperature portion follows the temperature distribution in the vertical direction of the fuel cell stack during rated operation. 10. The fuel cell device according to 10.   The flow path width of the exhaust flow path is varied in the lateral direction so as to become narrower as the temperature increases in accordance with the temperature distribution in the lateral direction in the fuel cell stack during rated operation. The fuel cell device according to claim 10 or claim 13.   The flow path width changing member inserted and arranged in the exhaust flow path is provided in order to make the flow path width of the exhaust flow path different. 15. The fuel cell device according to the description.   The at least one side plate of the combustion chamber partition member and the exhaust flow path partition member constituting the exhaust flow path is inclined in order to make the flow path width of the exhaust flow path different. Item 15. The fuel cell device according to any one of Items 14.   The flow path width of the oxidant flow path, which is the distance between the side plate of the exhaust flow path partition member and the side plate of the oxidant flow path partition member, is the vertical direction along the side plate that is the flow direction of the oxidant, and 2. The fuel cell device according to claim 1, wherein the fuel cell device is continuously varied in at least one of the lateral directions along the side plate orthogonal to the flow direction of the oxidant.   The channel width of the oxidant channel is formed so as to gradually widen from the upper end side to the lower end side in the vertical direction corresponding to the vertical part of the fuel cell stack. The fuel cell device according to claim 17.   The channel width of the oxidant channel is formed so as to gradually widen from the center side to both end sides in the lateral direction, corresponding to the lateral part of the fuel cell stack. The fuel cell device according to claim 17 or claim 18.   The flow path width of the oxidant flow path is varied in the vertical direction so as to become narrower as the high-temperature portion follows the vertical temperature distribution in the fuel cell stack during rated operation. Item 18. The fuel cell device according to Item 17.   The flow path width of the oxidant flow path is varied in the lateral direction so as to become narrower as the high-temperature portion follows the lateral temperature distribution in the fuel cell stack during rated operation. Item 21. The fuel cell device according to item 20 or item 20.   The flow path width changing member inserted and arranged in the oxidant flow path is provided in order to make the flow path widths of the oxidant flow paths different from each other. The fuel cell device described in 1.   In order to make the channel width of the oxidant channel different, at least one side plate of the exhaust channel partition member and the oxidant channel partition member constituting the oxidant channel is inclined. Item 20. The fuel cell device according to any one of items 17 to 21.