JP7087616B2 - Fuel cell stack - Google Patents

Description

The present invention relates to a fuel cell stack.

Solid oxide fuel cells (SOFC, hereinafter simply referred to as "SOFC") have high thermal efficiency and are capable of electrochemical reaction between fuel and air without using a noble metal catalyst. Yes, more types of fuel can be used. The SOFC has a fuel cell stack composed of a plurality of cell units including an electrolyte electrode junction that generates electricity by a supplied gas and a separator in which a flow path portion through which the gas flows is partitioned.

When starting such an SOFC, power generation starts when the threshold temperature reaches about 500 to 600 ° C. When gas is introduced into the gas flow path at the time of start-up, the temperature difference between the gas and the surroundings is large on the inlet side of the gas flow path, so that the temperature is relatively high. On the other hand, on the outlet side of the gas flow path, the temperature difference between the gas and the surroundings becomes small due to the heat being taken away on the inlet side, so that the temperature is heated to be lower than that on the upstream side. .. That is, a temperature gradient is generated along the gas flow direction, which is high on the inlet side and low on the outlet side. When such a temperature gradient occurs, SOFC does not start until the temperature on the downstream side, which is lower than the upstream side, exceeds the threshold temperature, so that there is a problem that it takes time to start.

In this regard, for example, Patent Document 1 below discloses a fuel cell stack in which a low thermal conductivity portion having a lower thermal conductivity than the downstream side is formed on the inlet side of the refrigerant. According to this configuration, the temperature gradient can be reduced.

Patent No. 4956000

However, the fuel cell stack disclosed in Patent Document 1 requires additional parts, which may increase the cost or increase the volume of the fuel cell stack.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a fuel cell stack capable of smoothing a temperature gradient without adding new parts.

The fuel cell stack according to the present invention that achieves the above object is provided between a metal support cell and a metal support cell assembly having a cell frame that holds the outer periphery of the metal support cell and the metal support cells adjacent to each other in the stacking direction. It is a fuel cell stack of a solid oxide fuel cell in which a cell unit having a separator is laminated in the stacking direction. The fuel cell stack is provided between the metal support cell and the separator, and is a main flow path through which gas can flow and a cell frame outside the width direction of the main flow path with respect to the flow direction in which the gas flows. And a bypass flow path provided between the separators and through which the gas can flow. Further, the thermal energy of the gas flowing through the bypass flow path is replenished to the gas flowing through the main flow path. Further, the bypass flow path is partitioned by the cell frame and the separator.

According to the present invention, the temperature gradient can be made gentle without adding new parts.

It is an exploded perspective view which shows the fuel cell stack which concerns on embodiment of this invention. It is an exploded perspective view of a cell unit. It is an exploded perspective view of a metal support cell assembly. It is sectional drawing which follows the 4-4 line of FIG. It is a top view which shows a part of a cell unit. It is a perspective view for demonstrating the structure of the continuous part provided in the main flow path. It is sectional drawing which follows the 7-7 line of FIG. It is sectional drawing which follows the 8-8 line of FIG. It is an image diagram which shows how the thermal energy of the gas flowing through a bypass flow path is replenished with respect to the gas flowing through a main flow path. It is a graph which shows the effect of replenishing the thermal energy of the gas flowing through a bypass flow path to the gas flowing through a main flow path. It is a figure which shows the heat transfer amount to the reaction part of the fuel cell stack which concerns on a comparative example. It is a graph which shows the time change of the temperature distribution of the fuel cell stack which concerns on a comparative example. It is a figure which shows the heat transfer amount to the reaction part of the fuel cell stack which concerns on this embodiment. It is a graph which shows the temperature distribution of the fuel cell stack which concerns on this embodiment. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 1. FIG. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 2. FIG. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 3. FIG. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 4. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 5. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 6. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 7. It is a top view which shows a part of the cell unit of the fuel cell stack which concerns on modification 8.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. The following description does not limit the technical scope and the meaning of the terms described in the claims. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

The fuel cell stack 10 according to the present embodiment will be described with reference to FIGS. 1 to 10. The fuel cell stack 10 of the present embodiment is used for a solid oxide fuel cell (SOFC: Solid Oxide Fuel Cell) using an oxide ion conductor such as stabilized zirconia as an electrolyte.

For the convenience of the following description, the XYZ Cartesian coordinate system is shown in the figure. The X-axis and the Y-axis indicate horizontal axes, and the Z-axis indicates an axis parallel to the vertical direction (corresponding to the stacking direction).

FIG. 1 is an exploded perspective view showing a fuel cell stack 10 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the cell unit 100. FIG. 3 is an exploded perspective view of the metal support cell assembly 110. FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. FIG. 5 is a top view showing a part of the cell unit 100. FIG. 6 is a perspective view for explaining the configuration of the continuous portion R3 provided in the main flow path R1. FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. FIG. 8 is a cross-sectional view taken along the line 8-8 of FIG. In FIG. 5, for the sake of easy understanding, the current collector auxiliary layer 130 is omitted. FIG. 9 is an image diagram showing how the heat energy of the gas flowing through the bypass flow path R2 is replenished to the gas flowing through the main flow path R1. FIG. 10 is a graph showing the effect of replenishing the thermal energy of the gas flowing through the bypass flow path R2 with respect to the gas flowing through the main flow path R1.

Generally, the fuel cell stack 10 is a separator provided between a metal support cell assembly 110 having a cell frame 113 holding a metal support cell 110M and a cell frame 113 that holds the outer periphery of the metal support cell 110M, and a metal support cell 110M adjacent to each other in the Z direction. The cell unit 100 having 120 and 120 is laminated in the Z direction. Further, the fuel cell stack 10 is provided between the metal support cell 110M and the separator 120, and has a main flow path R1 through which gas can flow and a width direction (Y) with respect to the flow direction (X direction) in which the gas of the main flow path R1 flows. Directional) Outside, with a bypass flow path R2 provided between the cell frame 113 and the separator 120 through which gas can flow. The thermal energy of the gas flowing through the bypass flow path R2 is replenished to the gas flowing through the main flow path R1.

As shown in FIG. 1, the fuel cell stack 10 is configured by stacking a plurality of cell units 100 in the vertical direction.

(Cell unit 100)
As shown in FIG. 2, the cell unit 100 includes a separator 120 that partitions a main flow path R1 for gas to flow between the metal support cell assembly 110 and the electrolyte electrode junction 111, and a current collector auxiliary layer 130. And are stacked in order. A contact material for conducting conduction contact between the metal support cell assembly 110 and the current collector auxiliary layer 130 may be arranged, or the current collector auxiliary layer 130 may be omitted.

The cell unit 100 includes a manifold portion 150 for supplying and discharging an anode gas (see FIG. 1), and a plurality of sealing portions 160 (see FIG. 1) that seal around the manifold portion 150 to limit the flow of gas. (See FIG. 2), and further. In the present embodiment, the fuel cell stack 10 is configured as an open cathode structure in which the cathode gas freely flows outside the cell unit 100 (the portion surrounded by the broken line in FIGS. 2 and 3).

As shown in FIGS. 2 and 3, the metal support cell assembly 110 includes a plurality of metal support cells (Metal-Supported Cell: MSC) 110M arranged side by side along the longitudinal direction Y (two in the present embodiment). It has a cell frame 113 that holds the outer periphery of the metal support cell 110M.

As shown in FIGS. 3 and 4, the metal support cell 110M has an electrolyte electrode junction 111 having an electrolyte 111E sandwiched between an anode 111A and a cathode 111C from both sides, and an electrolyte electrode junction 111 from one side in the vertical direction. It has a metal support portion 112 made of metal to support. The metal support cell 110M is superior in mechanical strength, rapid startability and the like as compared with the electrolyte-supported cell and the electrode-supported cell.

(Electrolyte electrode joint 111)
As shown in FIGS. 3 and 4, the electrolyte electrode junction 111 is configured by sandwiching the electrolyte 111E from both sides between the anode 111A and the cathode 111C.

The electrolyte 111E allows oxide ions to pass from the cathode 111C toward the anode 111A. The electrolyte 111E allows oxide ions to pass through but does not allow gas and electrons to pass through. Examples of the material for forming the electrolyte 111E include solid oxide ceramics such as stabilized zirconia doped with yttria, neodymium oxide, samarium, gadolinium, scandium and the like.

The anode 111A is a fuel electrode, and reacts an anode gas (for example, hydrogen) with an oxide ion to generate an oxide of the anode gas and extract electrons. The anode 111A has resistance to a reducing atmosphere, allows the anode gas to permeate, has high electrical (electron and ion) conductivity, and has a catalytic action of reacting the anode gas with oxide ions. Examples of the material for forming the anode 111A include a mixture of a metal such as nickel and an oxide ion conductor such as yttria-stabilized zirconia.

The cathode 111C is an oxidant electrode, and reacts electrons with a cathode gas (for example, oxygen contained in air) to convert oxygen molecules into oxide ions. The cathode 111C has resistance to an oxidizing atmosphere, allows the cathode gas to pass through, has high electrical (electron and ion) conductivity, and has a catalytic action of converting oxygen molecules into oxide ions. Examples of the material for forming the cathode 111C include oxides made of lanthanum, strontium, manganese, cobalt and the like.

(Metal support unit 112)
As shown in FIGS. 3 and 4, the metal support portion 112 supports the electrolyte electrode joint 111 from the side of the anode 111A. The metal support portion 112 is a porous metal having gas permeability and electron conductivity. Examples of the material for forming the metal support portion 112 include corrosion-resistant alloys containing nickel and chromium, corrosion-resistant steel, and stainless steel.

(Cell frame 113)
As shown in FIGS. 3 and 4, the cell frame 113 holds the metal support cell 110M from the surroundings. The cell frame 113 has a plurality of (two in this embodiment) openings 113H arranged side by side along the longitudinal direction Y. A metal support cell 110M is arranged in the opening 113H of the cell frame 113. The outer circumference of the metal support cell 110M is joined to the inner edge of the opening 113H of the cell frame 113. Examples of the material for forming the cell frame 113 include a metal having an insulating surface.

As shown in FIG. 3, the cell frame 113 includes an anode gas first inlet 113a, an anode gas second inlet 113b, an anode gas third inlet 113c, an anode gas first outlet 113d, and an anode through which the anode gas flows. It has a gas second outlet 113e.

(Separator 120)
As shown in FIG. 2, the separator 120 is arranged between the metal support cells 110M adjacent to each other in the Z direction. As shown in FIGS. 5 to 8, the separator 120 is provided with a main flow path R1 through which gas flows between the separator 120 and the metal support cell 110M. Further, as shown in FIGS. 5 to 8, the separator 120 is provided with a bypass flow path R2 through which gas can flow between the separator 120 and the cell frame 113. The detailed configuration of the main flow path R1 and the bypass flow path R2 will be described later. Examples of the material for forming the separator 120 include metal.

As shown in FIG. 2, the separator 120 includes an anode gas first inlet 120a, an anode gas second inlet 120b, an anode gas third inlet 120c, an anode gas first outlet 120d, and an anode gas. It has a second outlet 120e.

(Current collector auxiliary layer 130)
As shown in FIGS. 7 and 8, the current collector auxiliary layer 130 is arranged between the metal support cell 110M and the separator 120, and the surface pressure is equalized while forming a space through which gas passes, and the metal support cell 110M is formed. Assists in electrical contact between the separator 120 and the separator 120. Examples of the current collecting auxiliary layer 130 include a wire mesh-like expanded metal. Further, if the present characteristics and functions can be provided by other elements, the current collecting auxiliary layer 130 can be omitted.

(Manifold part 150)
The manifold portion 150 shown in FIG. 1 is composed of the anode gas outflow ports 113a, 113b, 113c, 113d, 113e of the cell frame 113 shown in FIG. 2 and the anode gas outflow ports 120a, 120b, 120c, 120d, 120e of the separator 120. Will be done.

(Seal part 160)
The sealing portion 160 is formed of a material having heat resistance and sealing properties. Examples of such a material include thermiculite (registered trademark) whose main raw material is vermiculite (vermiculite). Alternatively, it is also possible to use a seal made of a glass component.

Hereinafter, the configurations of the main flow path R1 and the bypass flow path R2 will be described in detail with reference to FIGS. 5 to 10. As shown in FIG. 9, the thermal energy of the gas flowing through the bypass flow path R2 is supplied to the gas flowing through the main flow path R1 (see the dotted line arrow in FIG. 9). Therefore, it is supplied to the low temperature portion as the bypass flow of the bypass flow path R2 so as to be covered with the circle portion in FIG.

(Main flow path R1)
As shown in FIG. 5, the main flow path R1 is formed in a substantially linear shape so that the uneven shape extends in the Y direction. As a result, the flow direction of the gas flowing along the main flow path R1 is the X direction.

As shown in FIGS. 7 and 8, the main flow path R1 is formed between the separator 120 and the metal support cell 110M.

As shown in FIG. 8, the main flow path R1 has a continuous portion R3 that is spatially continuous with respect to the main flow paths R1 adjacent to each other in the Y direction. When viewed from the Z direction, the continuous portion R3 is configured to be inclined toward the lower side in the distribution direction (lower side in FIG. 5) as shown in FIG. According to this configuration, the gas flowing through the bypass flow path R2 easily joins the main flow path R1, so that the thermal energy of the gas flowing through the bypass flow path R2 is suitably supplied to the gas flowing through the main flow path R1. can do.

As shown in FIG. 6, the continuous portion R3 is formed at a position where the convex portion 121 of the separator 120 forming the main flow path R1 is not partially formed along the X direction.

(Bypass flow path R2)
As shown in FIG. 5, the bypass flow path R2 is provided outside the Y direction (width direction with respect to the distribution direction) of the main flow path R1. Further, as shown in FIGS. 7 and 8, the bypass flow path R2 is provided between the cell frame 113 and the separator 120.

As shown in FIG. 5, the bypass flow path R2 is formed in a fan shape along the outer side of the circular manifold portion 150 on the upstream side in the distribution direction (X direction), and is formed in a fan shape on the downstream side in the distribution direction. , Is formed along the downward direction in the X direction. In the present embodiment, the bypass flow path R2 is formed so that the widths in the Y direction are the same along the downstream in the X direction.

As shown in FIGS. 7 and 8, the height H2 of the bypass flow path R2 is higher than the height H1 of the main flow path R1. According to this configuration, the amount of gas flowing in the bypass flow path R2 is larger than that in the main flow path R1, and the thermal energy of the gas flowing through the bypass flow path R2 is transferred to the gas flowing through the main flow path R1. Can be suitably replenished.

Further, as shown in FIGS. 7 and 8, the Z direction of the bypass flow path R2 is partitioned by the cell frame 113 and the separator 120. On the other hand, the Z direction of the main flow path R1 is partitioned by the metal support cell 110M and the separator 120, as shown in FIGS. 7 and 8. That is, the thickness of the member forming the Z direction of the bypass flow path R2 is thinner than the thickness of the member forming the Z direction of the main flow path R1. According to this configuration, since the bypass flow path R2 has a lower heat capacity than the main flow path R1, the heat loss in the bypass flow path R2 can be reduced. Therefore, the thermal energy of the gas flowing through the bypass flow path R2 can be suitably replenished to the gas flowing through the main flow path R1.

Further, as shown in FIGS. 7 and 8, the Y direction of the bypass flow path R2 is partitioned by the outer frame portion 122 of the separator 120. The outer frame portion 122 has a hollow shape. According to this configuration, the heat capacity in the outer frame portion 122 can be reduced as compared with the configuration in which the outer frame portion has a solid shape. Therefore, the heat loss in the bypass flow path R2 can be reduced. It should be noted that the present invention also includes a configuration in which the outer frame portion has a solid shape.

In the present embodiment, the outer frame portion 122 is integrally configured with the separator 120, but may be configured as a separate body.

Next, with reference to FIGS. 11 to 14, the operation and effect of the fuel cell stack 10 according to the present embodiment will be described while comparing with the fuel cell stack according to the comparative example. Here, the fuel cell stack according to the comparative example is a fuel cell stack in which only the main flow path R1 is provided without the bypass flow path R2. FIG. 11 is a diagram showing the amount of heat transferred to the reaction section of the fuel cell stack according to the comparative example. FIG. 12 is a graph showing the time change of the temperature distribution of the fuel cell stack according to the comparative example. FIG. 13 is a diagram showing the amount of heat transferred to the reaction section of the fuel cell stack 10 according to the present embodiment. FIG. 14 is a graph showing the temperature distribution of the fuel cell stack according to the present embodiment.

First, with reference to FIGS. 11 and 12, the supply of heat to the reaction unit of the fuel cell stack according to the comparative example will be described. Here, the reaction portion is virtually divided into three regions Ra, Rb, and Rc.

When the gas having the calorific value Q0 flows into the main flow path R1, the calorific value Qt1 is deprived in the region Ra on the upstream side of the main flow path R1. Then, the gas that has passed through the region Ra has a calorific value Q1 = Q0-Qt1 and moves to the downstream side. Then, the heat quantity Qt2 is deprived in the region Rb located on the downstream side of the region Ra. Then, the gas that has passed through the region Rb has a calorific value Q2 = Q1-Qt2 and moves to the downstream side. Then, in the region Rc located on the downstream side of the region Rb, the heat quantity Qt3 is deprived. Then, the gas that has passed through the region Rc has a calorific value Q3 = Q2-Qt3 and moves to the downstream side.

At this time, the magnitude relationship between the amount of heat Qt1 deprived in the region Ra, the amount of heat Qt2 deprived in the region Rb, and the amount of heat Qt3 deprived in the region Rc is Qt1> Qt2> Qt3.

As described above, in the fuel cell stack according to the comparative example, as shown in FIG. 12, a gas temperature gradient is generated in which the temperature on the upstream side is high and the temperature on the downstream side is low. When such a temperature gradient occurs, it is necessary to continue flowing gas until the downstream side, which has a lower temperature than the upstream side, exceeds the threshold temperature, and it takes time to start SOFC.

On the other hand, in the fuel cell stack 10 according to the present embodiment, as shown in FIG. 13, when the gas having the calorific value Qall flows into the fuel cell stack 10, the calorific value Q0 first flows into the main flow path R1. And the amount of heat Qb flowing into the bypass flow path R2 is distributed. The heat amount Q0 that has flowed into the main flow path R1 is deprived of the heat amount Qt1 in the region Ra that is the diffuser portion. Then, the gas from which the calorific value Qt1 has been deprived moves to the downstream side with the calorific value Q1 = Q0-Qt1. Here, the amount of heat of only Qb1 is replenished from the bypass flow path R2, and the amount of heat of only Q1'= Q1 + Qb1 is provided and moves to the downstream side. Then, the heat quantity Qt2 is deprived in the region Rb located on the downstream side of the region Ra. Then, the gas from which the calorific value Qt2 has been deprived moves to the downstream side with the calorific value Q2 = Q1'-Qt2. Here, the amount of heat of only Qb2 is supplied from the bypass flow path R2, and the amount of heat of only Q2'= Q2 + Qb2 is provided and the heat is moved to the downstream side. Then, in the region Rc located on the downstream side of the region Rb, the heat quantity Qt3 is deprived. Then, the gas from which the calorific value Qt3 has been deprived moves to the downstream side with the calorific value Q3 = Q2'-Qt3.

As shown in FIG. 14, the fuel cell stack according to the comparative example shown by the dotted line has a large temperature gradient. On the other hand, according to the fuel cell stack 10 according to the present embodiment shown by the solid line, the heat energy of the gas flowing through the bypass flow path R2 is replenished to the gas flowing through the main flow path R1, so that the temperature is increased. The gradient is gentle with respect to the comparative example. Therefore, it becomes easier to reach the threshold temperature as compared with the comparative example, and the time until activation can be shortened.

As described above, the fuel cell stack 10 according to the present embodiment has a metal support cell assembly 110 having a cell frame 113 that holds the outer periphery of the metal support cell 110M and the metal support cell 110M, and a metal support adjacent to each other in the Z direction. It is a fuel cell stack 10 of a solid oxide fuel cell in which a cell unit 100 having a separator 120 provided between cells 110M is laminated in the Z direction. The fuel cell stack 10 is provided between the metal support cell 110M and the separator 120, and is outward in the width direction with respect to the main flow path R1 through which the gas can flow and the flow direction in which the gas of the main flow path R1 flows, and is a cell frame. It has a bypass flow path R2 provided between the 113 and the separator 120 through which gas can flow. Further, the thermal energy of the gas flowing through the bypass flow path R2 is replenished to the gas flowing through the main flow path R1. According to the fuel cell stack 10 configured in this way, the heat energy of the gas flowing through the bypass flow path R2 is replenished to the gas flowing through the main flow path R1, so that the bypass flow path R2 is not provided. Compared with, the temperature gradient becomes gentle. Therefore, it becomes easier to reach the threshold temperature as compared with the comparative example, and the time until activation can be shortened. Therefore, the temperature gradient can be smoothed without adding new parts.

Further, the bypass flow path R2 has a longer length in the Z direction than the main flow path R1. According to the fuel cell stack 10 configured in this way, the amount of gas flowing in the bypass flow path R2 is larger than that in the main flow path R1, and the thermal energy of the gas flowing through the bypass flow path R2 is mainly used. The gas flowing through the road R1 can be suitably replenished.

Further, the bypass flow path R2 is partitioned by the cell frame 113 and the separator 120. According to the fuel cell stack 10 configured in this way, the bypass flow path R2 has a lower heat capacity than the main flow path R1, so that the heat loss in the bypass flow path R2 can be reduced. Therefore, the thermal energy of the gas flowing through the bypass flow path R2 can be suitably replenished to the gas flowing through the main flow path R1.

Further, an outer frame portion 122 forming the bypass flow path R2 is provided outside the bypass flow path R2 in the width direction, and the outer frame portion 122 has a hollow shape. According to the fuel cell stack 10 configured in this way, the heat capacity in the outer frame portion 122 can be reduced as compared with the configuration in which the outer frame portion has a solid shape. Therefore, the heat loss in the bypass flow path R2 can be reduced.

Further, the main flow path R1 has a continuous portion R3 that is spatially continuous with respect to the main flow paths R1 adjacent to each other in the width direction. According to the fuel cell stack 10 configured as described above, the thermal energy of the gas flowing through the bypass flow path R2 can be suitably supplied to the gas flowing through the main flow path R1 via the continuous portion R3. can.

Further, the continuous portion R3 is configured to be inclined toward the downstream side in the distribution direction with respect to the Y direction. According to this configuration, the gas flowing through the bypass flow path R2 easily joins the main flow path R1, so that the thermal energy of the gas flowing through the bypass flow path R2 is suitably supplied to the gas flowing through the main flow path R1. can do.

Although the fuel cell stack 10 according to the present invention has been described above through the embodiments, the present invention is not limited to the contents described in the embodiments, and may be appropriately modified based on the description of the scope of claims. Is possible.

For example, in the above-described embodiment, the bypass flow path R2 is configured so that the width in the Y direction is constant along the distribution direction, as shown in FIG. However, as shown in FIG. 15, the bypass flow path R4 may be configured so that the flow path width becomes smaller toward the downstream side in the flow direction (X direction). According to this configuration, the inflow amount from the bypass flow path R4 to the main flow path R1 is larger than that of the fuel cell stack 10 according to the above-described embodiment. Therefore, the thermal energy of the gas flowing through the bypass flow path R4 can be suitably replenished to the gas flowing through the main flow path R1.

Further, as shown in FIG. 16, the bypass flow path R5 may have a pressure loss portion 90 protruding in the Z direction. The pressure loss portion 90 is provided on the downstream side in the flow direction with respect to the merging portion D where the bypass flow path R5 merges with the main flow path R1. According to this configuration, the inflow amount from the bypass flow path R5 to the main flow path R1 is larger than that of the fuel cell stack 10 according to the above-described embodiment. Therefore, the thermal energy of the gas flowing through the bypass flow path R5 can be suitably replenished to the gas flowing through the main flow path R1. Further, it is preferable that the pressure loss portion 90 is provided at the most downstream position of the bypass flow path R5. According to this configuration, the thermal energy of the gas flowing through the bypass flow path R5 can be more preferably supplied to the gas flowing through the main flow path R1.

Further, in the above-described embodiment, the continuous portion R3 is configured to be inclined toward the lower side in the distribution direction as shown in FIG. 5 when viewed from the Z direction. However, the continuous portion R31 may be configured along the Y direction as shown in FIG. 17 when viewed from the Z direction. Further, as shown in FIG. 18, both the continuous portion R3 and the continuous portion R31 may be provided.

Further, in the above-described embodiment, the main flow path R1 has a configuration in which the pressure loss is the same on the upstream side and the downstream side. However, the main flow paths R11, R12, R13, and R14 may be configured so that the pressure loss on the downstream side is smaller than that on the upstream side. For example, as shown in FIGS. 19 and 20, the main flow paths R11 and R12 are configured so that the pressure loss on the downstream side is smaller than that on the upstream side by making the pitches different from each other on the upstream side and the downstream side. Can be done. Further, as shown in FIGS. 21 and 22, the protrusions 80 may be arranged on the downstream side of the main flow paths R13 and R14 so that the pressure loss is smaller than that on the upstream side. In this way, by configuring the downstream side so that the pressure loss is smaller than that on the upstream side, the pressure loss is smaller on the downstream side of the main flow paths R11, R12, R13, and R14, so that the bypass flow path R2 is more preferable. The thermal energy of the gas flowing through the main flow paths R11, R12, R13, and R14 can be suitably replenished to the gas flowing through the main flow paths R11, R12, R13, and R14. Further, as shown in FIGS. 20 and 22, the main flow paths R12 and R14 can be configured so that the pressure loss decreases inward in the Y direction. According to this configuration, the heat energy from the bypass flow path R2 can be replenished to the center in the Y direction on the downstream side of the main flow paths R12 and R14.

Further, in the above-described embodiment, the gas flowing through the main flow path R1 is heated by supplying the heat energy of the gas flowing through the bypass flow path R2 to the gas flowing through the main flow path R1. However, the gas flowing through the main flow path R1 may be cooled by supplying the negative heat energy of the gas flowing through the bypass flow path R2 to the gas flowing through the main flow path R1.

10 Fuel cell stack,
90 pressure loss part,
100 cell unit,
110 Metal Support Cell Assembly,
110M metal support cell,
111 Electrolyte electrode junction,
112 Metal support part,
120 separator,
122 outer frame,
D confluence,
R1, R11, R12, R13, R14, main flow path,
R2, R4, R5 bypass flow path,
R3, R31 continuous part.

Claims (10)

A metal support cell assembly having a metal support cell and a cell frame that holds the outer circumference of the metal support cell, and
A fuel cell stack of a solid oxide fuel cell in which cell units having a separator provided between the metal support cells adjacent to each other in the stacking direction are laminated in the stacking direction.
A main flow path provided between the metal support cell and the separator and through which gas can flow,
It has a bypass flow path provided between the cell frame and the separator and through which the gas can flow, which is outside the width direction of the main flow path with respect to the flow direction in which the gas flows.
The thermal energy of the gas flowing through the bypass flow path is replenished with respect to the gas flowing through the main flow path.
The bypass flow path is a fuel cell stack formed by the cell frame and the separator . A metal support cell assembly having a metal support cell and a cell frame that holds the outer circumference of the metal support cell, and
A fuel cell stack of a solid oxide fuel cell in which cell units having a separator provided between the metal support cells adjacent to each other in the stacking direction are laminated in the stacking direction.
A main flow path provided between the metal support cell and the separator and through which gas can flow,
It has a bypass flow path provided between the cell frame and the separator and through which the gas can flow, which is outside the width direction of the main flow path with respect to the flow direction in which the gas flows.
The thermal energy of the gas flowing through the bypass flow path is replenished with respect to the gas flowing through the main flow path.
The bypass flow path is a fuel cell stack configured so that the flow path width becomes smaller toward the downstream side in the distribution direction . The fuel according to claim 2 , wherein the bypass flow path has a pressure loss portion that causes a pressure loss at least on the downstream side in the flow direction of the confluence portion where the bypass flow path merges with the main flow path. Battery stack. The fuel cell stack according to claim 3 , wherein the pressure loss portion is provided at the most downstream position of the bypass flow path. A metal support cell assembly having a metal support cell and a cell frame that holds the outer circumference of the metal support cell, and
A fuel cell stack of a solid oxide fuel cell in which cell units having a separator provided between the metal support cells adjacent to each other in the stacking direction are laminated in the stacking direction.
A main flow path provided between the metal support cell and the separator and through which gas can flow,
It has a bypass flow path provided between the cell frame and the separator and through which the gas can flow, which is outside the width direction of the main flow path with respect to the flow direction in which the gas flows.
The thermal energy of the gas flowing through the bypass flow path is replenished with respect to the gas flowing through the main flow path.
The main flow path is a fuel cell stack configured so that the pressure loss decreases inward in the width direction . The fuel cell stack according to any one of claims 1 to 5 , wherein the bypass flow path has a longer length in the stacking direction than the main flow path. An outer frame portion forming the bypass flow path is provided on the outer side of the bypass flow path in the width direction.
The fuel cell stack according to any one of claims 1 to 6, wherein the outer frame portion has a hollow shape. The fuel cell stack according to any one of claims 1 to 7, wherein the main flow path has a continuous portion spatially continuous with respect to the main flow path adjacent to the main flow path in the width direction. The fuel cell stack according to claim 8, wherein the continuous portion is configured to be inclined toward the downstream side in the distribution direction with respect to the width direction. The fuel cell stack according to any one of claims 1 to 9, wherein the main flow path is configured such that the pressure loss on the downstream side is smaller than that on the upstream side.

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