FUEL CELL MODULE AND FUEL CELL DEVICE

A fuel cell module has a fuel cell stack and an oxidant gas supply plate. The fuel cell stack is arranged inside a housing. The oxidant gas supply plate is arranged adjacent to the fuel cell stack within the housing. The oxidant gas supply plate has an inner space. The oxidant gas supply plate is positioned separated away from an inner wall of the housing on the first direction side so that a space on the fuel cell stack side communicates with a space on the side opposite to the fuel cell stack side. The oxidant gas supply plate has a surface facing the fuel cell stack and a surface on the opposite side of the fuel cell stack, both being connected directly or indirectly to the housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of Japanese Patent Application No. 2021-029223 filed in Japan on Feb. 25, 2021, the entire disclosure of which being incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a fuel cell module and a fuel cell device.

BACKGROUND OF INVENTION

A fuel cell module including a plate-like member having a hollow portion inside is known for supplying an oxidant gas to a fuel cell stack (see Patent Literature 1).

CITATION LIST

Patent Literature

SUMMARY

A fuel cell module according to a first aspect includes: a housing; a fuel cell stack arranged within the housing; and an oxidant gas supply plate that is arranged adjacent to the fuel cell stack within the housing and that has an inner space for flowing an oxidant to be supplied to the fuel cell stack. The oxidant gas supply plate is positioned separated away from an inner wall of the housing on a first direction side so that a space of the oxidant gas supply plate on the fuel cell stack side communicates with a space of the fuel cell stack on the side opposite to the fuel cell stack side; the oxidant gas supply plate has a surface facing the fuel cell stack and a surface on the opposite side of the fuel cell stack, both being connected directly or indirectly to the housing.

A fuel cell device according to a second aspect includes a fuel cell module that has: a housing; a fuel cell stack arranged within the housing; and an oxidant gas supply plate that is arranged adjacent to the fuel cell stack within the housing and that has an inner space for flowing an oxidant to be supplied to the fuel cell stack, in which the oxidant gas supply plate is positioned separated away from an inner wall of the housing on a first direction side so that a space of the oxidant gas supply plate on the fuel cell stack side communicates with a space of the fuel cell stack on the side opposite to the fuel cell stack side; the oxidant gas supply plate has a surface facing the fuel cell stack and a surface on the opposite side of the fuel cell stack, both being connected directly or indirectly to the housing.

DESCRIPTION OF EMBODIMENTS

Embodiments of a fuel cell module to which the present disclosure is applied are described below with reference to the drawings.

In a first embodiment of the present disclosure, a fuel cell device including a fuel cell module may include a mechanism for adjusting the amount of fuel gas and reforming water supplied to the fuel cell module, a mechanism for cooling the off-gas discharged from the fuel cell module, and the like. As shown inFIG.1, a fuel cell module10of the first embodiment includes an oxidant gas supply plate11. The fuel cell module10may further include a fuel cell stack12, an opposite wall (first heat-insulating material)13, a first off-gas flow channel14, a reformer15, a vaporizer16, a second heat-insulating material17, an oxidant gas flow channel portion18, and a housing19.

In the fuel cell module10, the oxidant gas can be supplied to the fuel cell stack12from outside the fuel cell module10through the oxidant gas flow channel portion18and the oxidant gas supply plate11. The fuel cell module10may also discharge the gas exhausted from the fuel cell stack12from the fuel cell module10via the first off-gas flow channel14and the second off-gas flow channel, which is to be described later.

The fuel cell device including the fuel cell module10has a predetermined posture relative to the ground surface at the time of installation. In the present description, the direction of the fuel cell module10in the fuel cell device that is vertically upward in the posture predetermined with respect to the ground surface is called an upward direction (first direction). In the present description, the direction of the fuel cell module10in the fuel cell device that is vertically downward in the predetermined posture with respect to the ground surface is called a downward direction.

The oxidant gas supply plate11, as a whole, may have a plate-like shape. More specifically, the oxidant gas supply plate11, as a whole, may have a rectangular plate-like shape. As shown inFIG.2, the oxidant gas supply plate11may have an inner space IS that allows flow of the oxidant to be supplied to the fuel cell stack12. More specifically, the oxidant gas supply plate11may have a first plate portion20and a second plate portion21facing each other. The oxidant gas supply plate11may be formed by joining the outer periphery of the first plate portion20and the second plate portion21with a gap therebetween.

Since the oxidant gas supply plate11is exposed to high temperatures, it may be formed of a heat-resistant material such as a metal.

In the present description, the directions parallel to a main surface of the oxidant gas supply plate11and perpendicular to each other are called a traveling direction and a width direction. In the present description, the main surface is a surface of a thin plate that is much larger in area than the other surfaces. As described later, the oxidant gas supply plate11is arranged in the fuel cell module10so that the traveling direction is parallel to the direction in which the off-gas travels. The traveling direction and the width direction may be parallel to the sides of the main surface, which is rectangular.

As shown inFIG.3, the first plate portion20may have a supply plate inlet22. The supply plate inlet22may be positioned in the vicinity of the center of the fuel cell stack12in the stacking direction of the cells within the fuel cell module10. The supply plate inlet22may also be positioned closer to the traveling direction than the center in the traveling direction. The supply plate inlet22may also be positioned in the vicinity of the center in the width direction.

The second plate portion21may have, at a position opposite to the supply plate inlet22, a first projection35protruding to the outward side, or in other words, protruding to the side opposite to the first plate portion20. The first projection35may be recessed to the side opposite to the first plate portion20. The second plate portion21may have a supply plate outlet23. The supply plate outlet23may be arranged in the lower end portion of the side wall opposite to the fuel cell stack12. A plurality of supply plate outlets23may be provided at intervals along a direction in which the cells arranged.

The oxidant gas supply plate11may be configured so that the oxidant gas can flow in from the supply plate inlet22, flow in one direction inside, then turn back and flow out from the supply plate outlet23. More specifically, an isolating portion24provided within the oxidant gas supply plate11, as shown inFIG.4, may allow the oxidant gas to flow in one direction and then turn back. The aforesaid one direction may be, for example, a direction opposite to the traveling direction, in other words, a direction from the supply plate outlet23to the supply plate inlet22, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. Accordingly, the flow of oxidant gas entering from the supply plate inlet22becomes the counter flow of the off-gas flow in the first off-gas flow channel14, which is to be described later, until turning back.

The isolating portion24may be substantially linearly symmetrical with respect to a straight line connecting the supply plate inlet22and the supply plate outlet23, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The isolating portion24may have portions extending from the supply plate outlet23side to the supply plate inlet22side on both sides of the line segment connecting the supply plate inlet22and the supply plate outlet23, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. More specifically, the isolating portion24may be U-shaped, open on the supply plate inlet22side.

The isolating portion24may be formed by any method. As shown inFIG.2, the isolating portion24may be formed, for example, by recessing a sheet which becomes at least one of the first plate portion20and the second plate portion21, in a portion where the isolating portion24is to be formed, and joining the first plate portion20and the second plate portion21to each other. The isolating portion24may also be formed by joining a member having the above-described shape to the first plate portion20and the second plate portion21.

As shown inFIG.4, the oxidant gas supply plate11may have a heat-insulating portion25between the supply plate inlet22and the supply plate outlet23, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The heat-insulating portion25may be, for example, a hole through a portion of the isolating portion24.

As described later, the oxidant gas supply plate11may have a projection protruding from at least one of the first plate portion20to the opposite wall (first heat-insulating material)13side and the second plate portion21to the fuel cell stack12side. As shown inFIGS.2and3, for example, the oxidant gas supply plate11may have at least one first projection26protruding from the first main surface on the outer surface side of the first plate portion20.

As shown inFIG.3, the length of the first projection26in the traveling direction may be longer than its length in the width direction. The first projection26may extend in the traveling direction. The oxidant gas supply plate11may have three or more first projections26aligned along the width direction. The length in the traveling direction of the three or more first projections26may be longer as they go outward in the width direction. The first projection26may be positioned on the opposite side of the traveling direction than the center of the first main surface in the traveling direction.

The first projection26may be formed, for example, by press molding a sheet metal, which becomes the first plate portion20, into an outwardly recessed shape. The first projection26may also be formed by joining a projection member to a sheet metal, which becomes the first plate portion20.

The oxidant gas supply plate11may have a second projection27protruding from the first main surface. The second projection27may be at least higher from the first main surface than the first projection26. As described below, the oxidant gas supply plate11is arranged so that the first main surface faces the opposite wall13, and the second projection27may contact the opposite wall13.

The length of the second projection27in the width direction may be longer than the length in the traveling direction. The length of the second projection27in the width direction may be shorter than the distance between the two portions of the isolating portion24extending in the direction opposite traveling direction, at both ends of the portion of the isolating portion24extending in the width direction. The second projection27may be positioned between the first projection26and the supply plate inlet22in the traveling direction. The second projection27may be positioned at the center in the width direction. The second projection27may extend in the width direction.

The second projection27may also be formed, for example, by press molding a sheet metal, which becomes the first plate portion20, into an outwardly recessed shape. The second projection27may be formed by joining a projection member to a sheet metal, which becomes the first plate portion20.

As shown inFIG.2, the oxidant gas supply plate11may have a flow regulating portion28between the first plate portion20and the second plate portion21. The flow regulating portion28may be positioned on the side of the oxidant gas supply plate11on the traveling direction side than the second projection27, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The flow regulating portion28may be positioned on the opposite side of the traveling direction than the supply plate inlet22, when viewed from the normal direction of the main surface of the oxidant gas supply plate11.

The flow regulating portion28may regulate the flow of the oxidant gas within the oxidant gas supply plate11. More specifically, the flow regulating portion28may restrict the flow of the oxidant gas flowing from the supply plate inlet22in the opposite traveling direction. As shown inFIG.4, the flow regulating portion28may restrict the flow of the oxidant gas in the opposite traveling direction by means of a wall surface extending in the width direction. The length of the flow regulating portion28in the width direction may be the same as the length of the second projection27in the width direction. A gap may be formed between the flow regulating portion28and the isolating portion24, so that the oxidant gas flows through the gap.

The flow regulating portions28may be formed by any method. As shown inFIG.2, the flow regulating portion28may be formed, for example, by recessing a sheet which becomes at least one of the first plate portion20and the second plate portion21, in a portion where the flow regulating portion28is to be formed, and joining the first plate portion20and the second plate portion21to each other. The flow regulating portion28may also be formed by joining a member having the above-described shape to the first plate portion20and the second plate portion21.

The oxidant gas supply plate11may have an extended portion36to be fixed within the housing19. The extended portion36may be provided at the end of the oxidant gas supply plate11in the traveling direction. The extended portion36may have, when viewed from the width direction, a portion extending in the traveling direction and a portion that is bent from the aforesaid portion and extends toward the side of the second plate portion21. The extended portion36may be formed from a sheet metal, which becomes at least one of the first plate portion20and the second plate portion21.

As shown inFIG.1, the oxidant gas supply plate11may be positioned in the housing19so that the traveling direction is the downward direction.

The oxidant gas may be supplied to the fuel cell stack12from the oxidant gas supply plate11. The fuel gas may be supplied to the fuel cell stack12from the reformer15. The fuel cell stack12may be erected on a manifold37that temporarily stores the fuel gas supplied from the reformer15. The fuel cell stack12may include a plurality of stacked fuel cells. A hollow flat plate type fuel cell having a gas channel passing through the interior thereof in the vertical direction may be used as the fuel cell. The fuel cell generates electricity by an electrochemical reaction of the supplied oxidant gas and fuel gas. The fuel cell stack12discharges the gas produced by the electrochemical reaction, as well as unreacted fuel gas and oxidant gas. Hereafter, in the present description, the gas to be discharged is also referred to as off-gas.

The fuel cell stack12may be positioned adjacent to the oxidant gas supply plate11within the housing19. The fuel cell stack12may be arranged so that the side surfaces of the fuel cells face the main surface of the oxidant gas supply plate11. More specifically, the fuel cell stack12may face the main surface of the second plate portion21. The fuel cell stack12may be arranged so that the stacking direction of the fuel cells is parallel to the width direction of the oxidant gas supply plate11.

The fuel cell stack12may have an off-gas outlet flush with the distal end of the inner space IS of the oxidant gas supply plate11or on the upward direction side of the inner space IS of the oxidant gas supply plate11in the vertical direction. For example, the fuel cell stack12may have an off-gas outlet on its top surface within the fuel cell module10. The top surface of the fuel cell stack12may be located at the same position as the distal end of the oxidant gas supply plate11in the vertical direction.

The opposite wall13may be a member having a flat surface. The opposite wall13may be a flat plate member. The opposite wall13may be a heat-insulating material (first heat-insulating material). In the configuration in which the opposite wall13is a heat-insulating material, it may be located adjacent to the first off-gas flow channel in the normal direction of the main surface of the oxidant gas supply plate11.

The opposite wall13may be formed of a metal. As shown inFIG.5, the opposite wall13may be included in an off-gas channel plate38, which is to be described later. The opposite wall13may be positioned within the housing19to face the first main surface of the oxidant gas supply plate11with a gap therebetween. The opposite wall13may be positioned so that the flat surface thereof is parallel to the first plate portion20.

The off-gas channel plate38may have a flat plate portion39, a side wall portion40, and a flange portion41. The flat plate portion39may function as the opposite wall13. The flat plate portion39may be rectangular. The side wall portion40may be provided on all but a few of the outer edges of the flat plate portion39. For example, the side wall portion40may be provided on all but one of the four sides of the rectangular flat plate portion39. The side wall portion40may be vertical at the same height to the flat plate portion39. The flange portion41may be provided on the side wall portion40. The flange portion41may be brim-shaped.

The first off-gas flow channel14may be defined by the first main surface of the oxidant gas supply plate11and the opposite wall13. Thus, in the normal direction of the main surface of the oxidant gas supply plate11, the fuel cell stack12, the oxidant gas supply plate11, and the first off-gas flow channel14may be positioned in this order. Furthermore, in the aforesaid normal direction, the opposite wall13, which is the first heat-insulating material, may be located further outward from the first off-gas flow channel14. The first off-gas flow channel14may be part of the total flow channel of the off-gas that is discharged from the off-gas outlet of the fuel cell stack12and flows to the off-gas outlet of the housing19.

As described above, in the configuration in which the flat plate portion39of the off-gas channel plate38functions as the opposite wall13, the flange portion41of the off-gas channel plate38may be joined to the first main surface of the oxidant gas supply plate11, as illustrated inFIG.6. With such a configuration, the flat plate portion39can be positioned to face the first main surface of the oxidant gas supply plate11with a gap therebetween. Thus, since the flat plate portion39can function as the opposite wall13, it can define, together with the first main surface of the oxidant gas supply plate11, the first off-gas flow channel14.

The off-gas channel plate38may be positioned so that the outer edge, where the side wall portion40and the flange portion41are not provided, faces in the opposite direction of the traveling direction of the oxidant gas supply plate11. In such an arrangement, the off-gas channel plate38may be joined to the first main surface in the end portion in the traveling direction. The space between the oxidant gas supply plate11and the off-gas channel plate38may be open on the opposite side of the traveling direction. Therefore, the end of the off-gas channel plate38on the side of the direction opposite to the traveling direction may function as an off-gas inflow port.

In the above-described arrangement with respect to the oxidant gas supply plate11, as shown inFIG.7, the flat plate portion39may extend outward, in the width direction, the area where the first projection26is located, when viewed from the normal direction of the first main surface. Since the flange portion41is provided on the outer edge of the flat plate portion39via the side wall portion40, the off-gas channel plate38may be joined to the first main surface outside the area of the first projection26in the width direction. Furthermore, in such an arrangement, the flat plate portion39may extend, when viewed from the normal direction of the first main surface, in the traveling direction from the area where at least one of the first projection26, the second projection27, the flow regulating portion28, and the supply plate inlet22is located. Thus, the off-gas channel plate38may be joined to the first main surface outside the area where at least one of the first projection26, the second projection27, the flow regulating portion28, and the supply plate inlet22is located.

In the above-described arrangement with respect to the oxidant gas supply plate11, when the traveling direction is vertically downward within the housing19, the off-gas channel plate38may extend in the same direction as the distal end of the oxidant gas supply plate11, or in a direction opposite to the traveling direction, in other words, the upward direction.

As shown inFIG.8, in the above-described arrangement with respect to the oxidant gas supply plate11, the flange portion41on the traveling direction side may extend to cover the hole-like heat-insulating portion25so as to function as a cover portion.

The flat plate portion39of the off-gas channel plate38may have, in an area facing the supply plate inlet22, a discharge hole42into which the oxidant gas flow channel portion18is to be inserted. The discharge hole42may be circular or rectangular with rounded corners. The minimum diameter of the discharge hole42may be longer than the outer diameter of the oxidant gas flow channel portion18. Since the minimum diameter of the discharge hole42is longer than the outer diameter of the oxidant gas flow channel portion18, the off-gas flowing into the first off-gas flow channel14from the off-gas inflow port can be discharged through the discharge hole42.

The reformer15may carry a catalyst inside. The reformer15may use the catalyst to generate a fuel gas to be supplied to the fuel cell stack12through a water vapor reforming reaction of raw fuel gas, such as city gas containing hydrocarbon gas. The reformer15may be located in the vicinity of the fuel cell stack12within the fuel cell module10. More specifically, the reformer15may be located above the fuel cell stack12within the fuel cell module10.

The vaporizer16may vaporize the supplied reforming water. The vaporizer16may supply the vaporized water vapor to the reformer15. The vaporizer16may be located above the fuel cell stack12within the fuel cell module10. As shown inFIG.9, the vaporizer16may be located in a second direction from the reformer15. The second direction is the direction that intersects the first direction. More specifically, the vaporizer16may be located at a different position from the reformer15, more specifically at a position different from the reformer15in the width direction, when viewed from the normal direction of the main surface of the oxidant gas supply plate11.

A reforming portion having the same function as the reformer15and a vaporizing portion having the same function as the vaporizer16may be integrated to form an integrated reformer15. In such a configuration, the vaporizing portion may be located in the second direction from the reforming portion.

As shown inFIG.1, the second heat-insulating material17may be located outside of the opposite wall body (first heat-insulating material)13in the normal direction of the main surface of the oxidant gas supply plate11. Specifically, in the fuel cell module10shown inFIG.1, the second heat-insulating material17may be located on the opposite side of the opposite wall13from the first off-gas flow channel14. The second heat-insulating material17may have a plate-like shape. The second heat-insulating material17may be in surface contact with the opposite wall13.

The second heat-insulating material17may surround the oxidant gas flow channel portion18together with the first heat-insulating material. In the first embodiment, the oxidant gas flow channel portion18may be buried in the second heat-insulating material17. The second heat-insulating material17may have a first groove29formed to conform the shape of the oxidant gas flow channel portion18. The second heat-insulating material17may have the oxidant gas flow channel portion18buried in the first groove29. The thickness and depth of the first groove29may be larger than the diameter of the oxidant gas flow channel portion18. In a state where the first heat-insulating material13is in close contact with the side surface of the second heat-insulating material17where the first groove29is provided, the first heat-insulating material13, the first groove29, and the outer peripheral surface of the oxidant gas flow channel portion18may define a second off-gas flow channel connected to the first off-gas flow channel14. The second off-gas flow channel allows the off-gas flowing out of the first off-gas flow channel14to be discharged from the fuel cell module10.

The second heat-insulating material17may have a second groove43formed to be continuous with the first groove29, as shown inFIG.10. The second groove43may be formed in an area outside of the area where the oxidant gas flow channel portion18is buried. In the state where the first heat-insulating material13is in close contact with the side surface of the second heat-insulating material17as described above, the first heat-insulating material13and the second groove43may define a third off-gas flow channel. The thickness and depth of the second groove43may be the same or different from the first groove29.

The second off-gas flow channel may be connected, via a third off-gas flow channel for example, to an off-gas treatment chamber44provided in the fuel cell module10. The off-gas treatment chamber44may be provided, for example, on the surface of the second heat-insulating material17opposite to the surface on which the first groove29is provided, and connected to the third off-gas flow channel via a communication hole45. When viewed from the normal direction of the main surface of the second heat-insulating material17, a portion of the off-gas treatment chamber44may overlap a portion of the first groove29. Between the aforesaid portion of the first groove29and the off-gas treatment chamber44, the heat-insulating material may be thinner than other portions. The off-gas treatment chamber44may be filled with a combustion catalyst that burns unreacted combustion gas in the off-gas.

A third groove46may be formed in the vicinity of the location where the first groove29and the second groove43are connected. The third groove46may be shaped to conform the shape of the portion of the oxidant gas flow channel portion18to be buried that is outside of the first groove29. The thickness and depth of the third groove46may be the same as the diameter of the oxidant gas flow channel portion18.

As shown inFIG.11, in the configuration in which the off-gas channel plate38is provided, the discharge hole42may be communicated to the second off-gas flow channel by a guide portion47, whose bottom has the same shape as the discharge hole42and which is provided at the discharge hole42. The guide portion47may be cylindrical.

In the first embodiment, the oxidant gas flow channel portion18is tubular. The oxidant gas flow channel portion18may be located outside the first off-gas flow channel14in the normal direction of the main surface of the oxidant gas supply plate11. In the first embodiment, the oxidant gas flow channel portion18may be located on the outside of the opposite wall13, in other words, on the opposite side of the opposite wall13from the first off-gas flow channel14. The oxidant gas flow channel portion18may be connected to the oxidant gas supply plate11.

The oxidant gas flow channel portion18may have a meandering shape. As shown inFIG.12, the oxidant gas flow channel portion18may have a meandering shape when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The oxidant gas flow channel portion18may have a first portion48that overlaps the off-gas treatment chamber44when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The oxidant gas flow channel portion18may have a second portion30that overlaps the reformer15and the vaporizer16, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The second portion30may extend in the width direction within the fuel cell module10. An inlet31of the oxidant gas flow channel portion18may be located on the reformer15side than the vaporizer16, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The oxidant gas flow channel portion18may have a third portion32that overlaps the first projection26, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The third portion32may extend in the width direction within the fuel cell module10. The oxidant gas flow channel portion18may have a fourth portion33that overlaps the supply plate outlet23when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The fourth portion33may be a portion of the piping extending in the width direction within the fuel cell module10. The oxidant gas flow channel portion18may have a fifth portion extending on the lower side within the fuel cell module10. The fifth portion may be the same as or different from the fourth portion.

As shown inFIG.1, the housing19may house the oxidant gas supply plate11, the fuel cell stack12, the opposite wall (first heat-insulating material)13, the reformer15, the vaporizer16, the second heat-insulating material17, and the oxidant gas flow channel portion18. The housing19may be of any shape. The housing19has, for example, a rectangular parallelopiped shape. The housing19may be formed of any material.

Within the housing19, the oxidant gas supply plate11may be separated away from the inner wall of the housing19on the upward direction (first direction) side. By being separated away from the inner wall, the space on the fuel cell stack12side of the oxidant gas supply plate11may communicate with the space on the opposite side, in other words, the space that serves as the first off-gas flow channel14. For example, with such a configuration, the off-gas discharged from the fuel cell stack12may flow into the first main surface side of the oxidant gas supply plate11from the direction opposite to the traveling direction of the oxidant gas supply plate11.

Within the housing19, in the oxidant gas supply plate11, the second plate portion21, which is a surface facing the fuel cell stack12, and the first plate portion20, which is a surface on the opposite side of the fuel cell stack12, may be connected directly or indirectly to the housing19. In the first embodiment, the first plate portion20of the oxidant gas supply plate11is connected to the tubular oxidant gas flow channel portion18, and the inlet31of the oxidant gas flow channel portion18is connected to the housing19. In the first embodiment, with such a configuration, the oxidant gas supply plate11is indirectly connected to the housing19.

Within the housing19, a third heat-insulating material34may be provided around the inner space where the oxidant gas supply plate11, the fuel cell stack12, the reformer15, and the vaporizer16are provided, except on the side of the opposite wall13.

As shown inFIG.1, the oxidant gas supply plate11may be fixed in the housing19by piercing the extended portion36of the oxidant gas supply plate11into the third heat-insulating material34.

In the fuel cell module10of the first embodiment having the above-described configuration, the oxidant gas supply plate11is positioned to be separated away from the inner wall of the housing19on the upward direction side so that the space of the oxidant gas supply plate11on the fuel cell stack12side communicates with the space on the opposite side. With such a configuration, in the fuel cell module10, the high-temperature off-gas discharged from the fuel cell stack12flows to the first plate portion20side of the oxidant gas supply plate11. Hence, in the fuel cell module10, the oxidant gas supply plate11is heated not only by the opposing fuel cell stack12, but also by the off-gas, so that the oxidant gas flowing inside the oxidant gas supply plate11can also be heated. In the fuel cell module100, in addition to the oxidant gas supply plate11being separated away from the inner wall on the upward direction side, the second plate portion21, which is a surface facing the fuel cell stack12, and the first plate portion20, which is a surface on the opposite side of the fuel cell stack12, are connected directly or indirectly to the housing19. With such a configuration, it is easy for the fuel cell module10to release thermal stress, especially in the vertical direction of the oxidant gas supply plate11, so that deformation of the oxidant gas supply plate11con be suppressed.

In the fuel cell module10of the first embodiment, the off-gas outlet of the fuel cell stack12is located flush with the distal end of the inner space IS of the oxidant gas supply plate11or on the upward direction side of the inner space IS of the oxidant gas supply plate11in the upward direction. With such a configuration, in the fuel cell module10, the entire main surface of the oxidant gas supply plate11faces the fuel cell stack12, so that the entire main surface of the oxidant gas supply plate11can utilize the radiant heat from the fuel cell stack12.

In the fuel cell module10of the first embodiment, the oxidant gas supply plate11has the first plate portion20and the second plate portion21located opposite each other, the first plate portion20has the supply plate inlet22, the second plate portion21has the supply plate outlet23, and the supply plate inlet22is provided in the vicinity of the center of the fuel cell stack12in the stacking direction. With such a configuration, the fuel cell module10can reduce the difference in temperature distribution in the stacking direction of the fuel cell stack12.

In the fuel cell module10of the first embodiment, the oxidant gas flows into the oxidant gas supply plate11from the supply plate inlet22, flows in one direction inside the oxidant gas supply plate11, then turns back and flows out from the supply plate outlet23. With such a configuration, in the fuel cell module10, since the flow channel through which the oxidant gas passes inside the oxidant gas supply plate11is longer, the oxidant gas can be further heated.

In the fuel cell module10of the first embodiment, the supply plate inlet22and the supply plate outlet23are located at different positions when viewed from the normal direction of the main surface of the oxidant gas supply plate11, and the oxidant gas supply plate11has the heat-insulating portion25between the supply plate inlet22and the supply plate outlet23when viewed from the aforesaid normal direction. Since the oxidant gas flowing out of the supply plate outlet23is heated in the oxidant gas supply plate11, it is hotter than the oxidant gas flowing in from the supply plate inlet22. With respect to such event, with the above-described configuration, the fuel cell module10can suppress the cooling of the oxidant gas before flowing out of the supply plate outlet23by the oxidant gas flowing in from the supply plate inlet22.

The fuel cell module10of the first embodiment is further provided with a cover portion covering the hole-like heat-insulating portion25. With such a configuration, the fuel cell module10avoids the oxidant gas flowing out of the supply plate outlet23from entering the first off-gas flow channel14through the hole-like heat-insulating portion25.

In the fuel cell module10of the first embodiment, when viewed from the normal direction of the main surface of the oxidant gas supply plate11, the oxidant gas supply plate11has the isolating portion24located at least between the supply plate inlet22and the supply plate outlet23and partially partitioning the inner space into an inner space on the supply plate inlet22side and an inner space on the supply plate outlet23side, the isolating portion24being line symmetrical with respect to a straight line connecting the supply plate inlet22and the supply plate outlet23. With such a configuration, in the fuel cell module10, since the oxidant gas flows uniformly within the oxidant gas supply plate11, the oxidant gas can be heated efficiently.

The fuel cell module10of the first embodiment has portions extending from the supply plate outlet23to the supply plate inlet22side on both sides of the line segment connecting the supply plate inlet22and the supply plate outlet23, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. With such a configuration, the oxidant gas flowing in from the supply plate inlet22turns back while spreading over the entire oxidant gas supply plate11, so that the oxidant gas can be heated efficiently.

The fuel cell module10of the first embodiment is further provided with the off-gas channel plate38that defines the flow channel of the off-gas together with the oxidant gas supply plate11. With such a configuration, the fuel cell module10can perform efficient heat exchange between the oxidant gas and the off-gas in the oxidant gas supply plate11without dispersing the off-gas discharged from the fuel cell stack12to the surroundings. Thus, the fuel cell module10can further heat the oxidant gas.

In the fuel cell module10of the first embodiment, the off-gas inflow port of the off-gas channel plate38is located flush with the oxidant gas supply plate11or on the opposite side of the oxidant gas supply plate11in the traveling direction. With such a configuration, the fuel cell module10can efficiently guide the off-gas discharged from the fuel cell stack12to the first off-gas flow channel14.

In the fuel cell module10of the first embodiment, the off-gas channel plate38is joined to the first main surface outside the area of the first projection26in the width direction. With such a configuration, since the area where the first projection26is located is concentrated in the interior of the first off-gas flow channel14, the fuel cell module10can perform efficient heat exchange between the oxidant gas and the off-gas in the oxidant gas supply plate11. Thus, the fuel cell module10can further heat the oxidant gas.

In the fuel cell module10of the first embodiment, the off-gas channel plate38is joined to the first main surface outside the area of the first projection26on the traveling direction side of the flow channel of the off-gas. With such a configuration, since the area used for heat exchange between the oxidant gas and the off-gas in the oxidant gas supply plate11is large, the fuel cell module10can perform efficient heat exchange between the oxidant gas and the off-gas. Thus, the fuel cell module10can further heat the oxidant gas.

In the fuel cell module10of the first embodiment, the discharge port42and the second off-gas flow channel are communicated with each other by the guide portion47. With such a configuration, the fuel cell module10can guide the off-gas discharged from the first off-gas flow channel14, which is defined by the off-gas channel plate38, to flow into the second off-gas flow channel.

The fuel cell module10of the first embodiment is further provided with the off-gas treatment chamber44, and the second off-gas flow channel and the off-gas treatment chamber44are connected via the third off-gas flow channel. With such a configuration, the fuel cell module10can have an increased degree of freedom in design. For example, the fuel cell module10can be designed so that the distance between the connection location of the second off-gas flow channel and the third off-gas flow channel and the location where the inlet of the oxidant gas flow channel portion18is buried is reduced. Thus, in such an example, in the fuel cell module10, the oxidant gas supplied from the oxidant gas flow channel portion18is immediately heat exchanged by the off-gas flowing in the second off-gas flow channel, so that the oxidant gas flowing in the oxidant gas flow channel portion18and the off-gas can efficiently transfer heat.

In the fuel cell module10of the first embodiment, the second off-gas flow channel and the third off-gas flow channel have the same thickness and depth. With such a configuration, since the wall from the second off-gas flow channel to the third off-gas flow channel is continuous, the fuel cell module10can flow the off-gas uniformly. Further, with such a configuration, the fuel cell module10can be manufactured in a concise manner and with a reduced manufacturing cost.

In the fuel cell module10of the first embodiment, the oxidant gas flow channel portion18has a first portion48that overlaps the off-gas treatment chamber44when viewed from the normal direction of the main surface of the oxidant gas supply plate11. With such a configuration, the fuel cell module10can efficiently transfer heat generated by combustion of unreacted combustion gas in the off-gas treatment chamber44to the oxidant gas flowing in the oxidant gas flow channel portion18.

In the fuel cell module10of the first embodiment, the oxidant gas flow channel portion18has the fifth portion extending in the lower side in the fuel cell module10. With such a configuration, since the center of gravity of the oxidant gas flow channel portion18is located on the lower side in the vertical direction, the fuel cell module10can be stabilized. In a second embodiment of the present disclosure, a fuel cell module will be described below. The second embodiment differs from the first embodiment in the configuration of the oxidant gas supply plate, the first off-gas flow channel, the second heat-insulating material, the oxidant gas flow channel portion and the like. The following is a description of the second embodiment focusing on matters different from the first embodiment Note that components having the same functions and structures as those of the first embodiment will be denoted by the same reference signs.

As shown inFIG.13, similar to the first embodiment, a fuel cell module100of the second embodiment may include an oxidant gas supply plate110, a fuel cell stack12, a first heat-insulating material130, a first off-gas flow channel140, a reformer15, a vaporizer16, a second heat-insulating material170, an oxidant gas flow channel portion180, and a housing19. Unlike the first embodiment, the fuel cell module100may further include an exhaust gas lead-out portion, which is to be described later. The structures and the functions of the fuel cell stack12, the reformer15, the vaporizer16, and the housing19are the same as in the first embodiment.

Similar to the first embodiment, in the fuel cell module100, the oxidant gas can be supplied to the fuel cell stack12from outside the fuel cell module100via the oxidant gas flow channel portion180and the oxidant gas supply plate110. The fuel cell module100can also discharge, via the first off-gas flow channel140, the gas discharged by the fuel cell stack12from the fuel cell module100.

As shown inFIG.14, similar to the first embodiment, the oxidant gas supply plate110, as a whole, may have a rectangular plate-like shape. Similar to the first embodiment, the oxidant gas supply plate110may have an inner space IS that allows flow of the oxidant to be supplied to the fuel cell stack12. More specifically, as shown inFIGS.15and16, similar to the first embodiment, the oxidant gas supply plate110may have a first plate portion200and a second plate portion210facing each other. Similar to the first embodiment, the oxidant gas supply plate110may be formed by joining the outer periphery of the first plate portion200and the second plate portion210with a gap therebetween.

Similar to the first embodiment, the oxidant gas supply plate110may be formed of a heat-resistant material such as a metal.

As shown inFIG.15, the first plate portion200may have a supply plate inlet220. The supply plate inlet220may be positioned in the vicinity of the center of the fuel cell stack12in the stacking direction of the cells within the fuel cell module100. The supply plate inlet220may be provided in a portion opposite the upward direction side (first direction side) end portion of the fuel cell stack12, within the fuel cell module100. Note that the upward direction side end portion includes the position up to ⅓ of the length in the upward direction from the upper end of the fuel cell stack12.

The second plate portion210may have, at a location opposite the supply plate inlet220, a third projection350that is recessed to the side opposite to the first plate portion200. As shown inFIG.16, at least a part of the inner wall surface around an axis parallel to the normal direction of the main surface of the second plate portion210in the third projection350may be inclined in the aforesaid normal direction to face toward the first plate portion200. As shown inFIG.15, the second plate portion210may have a supply plate outlet230, similar to the first embodiment.

The oxidant gas supply plate110may have at least one flow regulating portion280between the supply plate inlet220and the supply plate outlet23, when viewed from the normal direction of the main surface of the oxidant gas supply plate11. The flow regulating portion280may be provided on at least one of the first plate portion200and the second plate portion210. In one example, the flow regulating portion280is provided on both the first plate portion200and the second plate portion210in the same shape and opposite each other. The flow regulating portion280may rise from at least one of the first plate portion200and the second plate portion210to the other.

The flow regulating portion280may include at least one first flow regulating portion281and at least one second flow regulating portion282. The rising of the first flow regulating portion281from at least one of the first plate portion200and the second plate portion210to the other may be in contact with the aforesaid other. The second flow regulating portion282may have a gap in the facing direction between the first plate portion200and the second plate portion210while rising from at least one of the first plate portion200and the second plate portion210to the other. Since the second flow regulating portion282is part of the first plate portion200and the second plate portion210, in a configuration in which the second flow regulating portion282is provided on both the first plate portion200and the second plate portion210, there is a gap between the second flow regulating portions282facing each other. In the following description, when describing matters common to the first flow regulating portion281and the second flow regulating portion282, they are simply referred to as the flow regulating portion280.

The flow regulating portion280may be shaped to extend at least in a direction that intersects the direction from the supply plate inlet220to the supply plate outlet23. At least some of a plurality of flow regulating portions280may be curved in the direction from the supply plate outlet230to the supply plate inlet220, when viewed from the normal direction of the main surface of the oxidant gas supply plate110. For example, the first flow regulating portion281proximate to the supply plate inlet220may be curved in the direction from the supply plate outlet230to the supply plate inlet220, when viewed from the normal direction of the main surface of the oxidant gas supply plate110. The plurality of flow regulating portions280may be located so as to be aligned in the direction from the supply plate inlet220to the supply plate outlet230. The flow regulating portions280adjacent to each other in the aforesaid direction may have portions that do not overlap each other in the width direction.

The flow regulating portion280may regulate the flow of oxidant gas from the supply plate inlet220to the supply plate outlet230within the oxidant gas supply plate110. The first flow regulating portion281may regulate the flow of the oxidant gas so that the oxidant gas avoids the first flow regulating portion281in the flow of the oxidant gas from the supply plate inlet220to the supply plate outlet230. The second flow regulating portion282may regulate the flow of the oxidant gas flowing from the supply plate inlet220to the supply plate outlet230so that the oxidant gas becomes a flow that flows through the gap between the second flow regulating portion282and a flow that avoids the second flow regulating portion282. With such a configuration, the flow regulating portion280may disperse the oxidant gas in multiple directions parallel to the main surface of the second plate portion210.

The second plate portion210may have a plurality of support portions650. The plurality of support portions650may be located side by side in the width direction. The support portion650may support heat-insulating material sandwiched between the fuel cell stack12and the oxidant gas supply plate110in the fuel cell module100. The support portion650may be a projection protruding from the second plate portion210toward the fuel cell stack12.

As shown inFIG.17, within the fuel cell module100, in the upward direction (first direction) and in the width direction perpendicular to the normal direction of the main surface of the oxidant gas supply plate110, a width w1of the inner space IS of the oxidant gas supply plate110on the upward direction side may be larger than a width w2of the inner space IS of the oxidant gas supply plate110on the downward direction side. Furthermore, the width w2on the upward direction side of the inner space IS may be longer than the width of the opposing fuel cell stack12. The width w2on the downward direction side of the inner space IS may also be the same as the width of the opposing fuel cell stack12.

As shown inFIG.13, the oxidant gas supply plate110may be positioned within the housing19so that the direction from the supply plate inlet220to the supply plate outlet230is the downward direction.

Similar to the first embodiment, the fuel cell stack12may be supplied with oxidant gas from the oxidant gas supply plate110.

Similar to the first embodiment, the fuel cell stack12may be positioned adjacent to the oxidant gas supply plate110within the housing19. Similar to the first embodiment, the fuel cell stack12may be arranged so that the side surfaces of the fuel cells face the main surface of the oxidant gas supply plate110. More specifically, similar to the first embodiment, the fuel cell stack12may face the main surface of the second plate portion210. Similar to the first embodiment, the fuel cell stack12may be arranged so that the stacking direction of the fuel cells is parallel to the width direction of the oxidant gas supply plate110.

Unlike the first embodiment, the fuel cell stack12may have an off-gas outlet on the downward direction side (the side opposite the first direction) from the distal end of the inner space IS of the oxidant gas supply plate11in the vertical direction. For example, the top of the fuel cell stack12may be located on the downward direction side from the distal end of the oxidant gas supply plate11in the vertical direction.

Unlike the first embodiment, the first heat-insulating material130may be located between the oxidant gas supply plate110and the first off-gas flow channel140in the normal direction of the main surface of the oxidant gas supply plate110. The first heat-insulating material130may have a rectangular plate-like shape. The first heat-insulating material130may be sized to cover the fuel cell stack12, the oxidant gas supply plate110, the reformer15, and the vaporizer16within the fuel cell module100.

The first heat-insulating material130, together with other heat-insulating materials, may define an inner space that houses the oxidant gas supply plate110, the fuel cell stack12, the reformer15, and the vaporizer16. An exhaust gas lead-out portion490may be provided in the aforesaid inner space. The first heat-insulating material130may be disposed in contact with a first off-gas flow channel portion510, which will be described later, and the oxidant gas supply plate110. As shown inFIG.18, the exhaust gas lead-out portion490may be, for example, a cutout portion formed by cutting out a part of the first heat-insulating material130. The exhaust gas lead-out portion490is a path for leading the off-gas out to the first off-gas flow channel140. The exhaust gas lead-out portion490is, in other words, an off-gas discharge port of the fuel cell stack12.

In the flow of the off-gas discharged from the fuel cell stack12to the reformer15side, the exhaust gas lead-out portion490may allow the off-gas to flow in a direction opposite to the second direction, in other words, in a direction from the vaporizer16side to the reformer15side. For example, such a function can be achieved by forming the exhaust gas lead-out portion490in the direction opposite to the second direction on the upward direction side of the inner space above.

In the flow of the off-gas discharged from the fuel cell stack12toward the reformer15side, the exhaust gas lead-out portion490may cause the off-gas to flow toward the center of the housing19in the second direction. For example, such a function can be achieved by forming the exhaust gas lead-out portion490in the vicinity of the center, in the second direction, of the inner space on the upward direction side, as shown inFIG.19.

As described above, the configuration in which the exhaust gas lead-out portion490, which is a cutout, is provided on the opposite side of the second direction or in the vicinity of the center in the second direction is described as an example, but the exhaust gas lead-out portion490is not limited to be provided in the vicinity of the end portion in the direction opposite to the second direction or in the vicinity of the center in the second direction, but may be provided in the vicinity of the end portion on the second direction side or provided over the entire second direction.

Furthermore, the exhaust gas lead-out portion490may be formed by cutting out a part of an area in the fuel cell module100that contains the supply plate inlet220, when viewed from the normal direction of the main surface of the oxidant gas supply plate110. In other words, the cutout area may be cut in a size so that there is a gap between the cutout and the outer peripheral surface of a communication pipe500that communicates the supply plate inlet220and the oxidant gas flow channel portion180. The off-gas discharged from the fuel cell stack12can be avoided from flowing below the cutout by the first heat-insulating material130.

As shown inFIG.13, the communication pipe500that communicates the supply plate inlet220and the oxidant gas flow channel portion180may be inserted in the first heat-insulating material130within the fuel cell module100.

As shown inFIG.18, in the configuration in which the exhaust gas lead-out portion490and the supply plate inlet220do not overlap when viewed from the normal direction of the main surface of the oxidant gas supply plate110, the off-gas discharged from the fuel cell stack12may flow into the first off-gas flow channel140via the flow channel defined by the exhaust gas lead-out portion490. As shown inFIG.19, in the configuration in which the exhaust gas lead-out portion490and the supply plate inlet220overlap when viewed from the aforesaid normal direction, the off-gas discharged from the fuel cell stack12flows into the first off-gas flow channel140via the flow channel defined by the exhaust gas lead-out portion490and the outer peripheral surface of the communication pipe500.

As shown inFIG.20, in the configuration in which the exhaust gas lead-out portion490and the supply plate inlet220overlap when viewed from the normal direction, the supply plate inlet220, or in other words, the communication pipe500may be deviated from the center of the exhaust gas lead-out portion490in a direction perpendicular to the upward direction (first direction) and the normal direction of the main surface of the oxidant gas supply plate110. In the configuration in which the communication pipe500is deviated from the center of the exhaust gas lead-out portion490, the exhaust gas lead-out portion490may extend from the center to the second direction or the opposite direction.

As shown inFIGS.19and20, in the configuration in which the exhaust gas lead-out portion490and the supply plate inlet220overlap when viewed from the normal direction, the cutout, which is the exhaust gas lead-out portion490, may pass through the first heat-insulating material130in the thickness direction, as shown inFIG.21. The cutout may be part of the oxidant gas supply plate110side in the thickness direction of the first heat-insulating material130and not pass through the first heat-insulating material130, as shown inFIG.22.

As shown inFIG.23, in the second embodiment, the first off-gas flow channel140may be defined by the first off-gas flow channel portion510and a partition plate520. In other words, the first off-gas flow channel portion510and the partition plate520may define a part of the first off-gas flow channel140. The first off-gas flow channel portion510may have a first groove portion530formed by recessing a part of flat plate into a path-like shape. The first off-gas flow channel portion510may be joined to one surface of the partition plate520. More specifically, the partition plate520may be joined to cover the first groove portion530.

The first off-gas flow channel portion510may be arranged so that the flat plate-like portion is parallel to the main surface of the oxidant gas supply plate110. The first groove portion530may have a portion that overlaps a part of the exhaust gas lead-out portion490within the fuel cell module100, when viewed from the normal direction of the main surface. The first groove portion530may be shaped such that the aforesaid portion is one end of the path-like shape. The first groove portion530may include, for example, a U-shape portion. The U-shaped portion may open on the upward direction side and the both leg portions of the U-shaped portion may extend substantially parallel to each other in the upward direction. A communication hole540may be formed in the vicinity of the aforesaid portion of the first groove portion530.

For example, in the configuration in which the exhaust gas lead-out portion490is located in the direction opposite to the second direction as shown inFIG.18, the communication hole540may be formed in the end portion of the leg portion of the U-shaped first groove portion530in the direction opposite to the second direction, as shown inFIG.23. In the configuration in which the exhaust gas lead-out portion490is located in the vicinity of the center in the second direction as shown inFIG.19, the communication hole540may be formed in a portion extending in the second direction from the leg portion of the U-shaped portion of first groove portion530located in the direction opposite to the second direction, as shown inFIG.24. Furthermore, in the aforesaid configuration, the communication pipe500may be located within the communication hole540when viewed from the normal direction of the main surface of the oxidant gas supply plate110. In other words, the communication pipe500may be inserted through the communication hole540.

The communication hole540may be connected to the exhaust gas lead-out portion490. By connecting the communication hole540and the exhaust gas lead-out portion490, the inner space formed by the joining of the first off-gas flow channel portion510and the partition plate520, in other words, the first off-gas flow channel140may communicate with the flow channel defined by the exhaust gas lead-out portion490. The first groove portion530may communicate, at the other end, with a discharge portion670having a discharge port550. The discharge port550may discharge the off-gas from the fuel cell module100.

In a plurality of portions in the first off-gas flow channel portion510that extend along the first direction and are located at different positions in a direction intersecting the first direction, for example, in the width direction, the width of the portion on the discharge port550side where the off-gas is discharged from the fuel cell module100may be narrower than the width of the portion on the inlet side where the off-gas discharged from the fuel cell stack12flows in. More specifically, in the U-shaped portion of the first groove portion530of the first off-gas flow channel portion510, the width of the leg portion on the discharge port550side may be narrower than the width of the leg portion on the communication hole540side. Furthermore, in the first off-gas flow channel portion510, the width of the leg portion on the side of the communication hole540may be narrower than the width of the portion on the side of the discharge port550. Furthermore, the width of the portion connecting both leg portions of the U-shaped portion of the first groove portion530may be narrower than the width of the leg portion on the communication hole540side and the width of the leg portion on the discharge port550side.

The portion of the first off-gas flow channel portion510on the off-gas inflow side (on the communication hole540side), specifically the leg portion, may be filled with a pretreatment material. The pretreatment material may adsorb Si contained in the off-gas as it flows in contact with the off-gas. The portion of the first off-gas flow channel portion510on the discharge port550side, specifically the leg portion, may be filled with a combustion catalyst. The combustion catalyst may burn the combustible gases such as hydrogen and carbon monoxide contained in the off-gas. In the first off-gas flow channel portion510, the combustion catalyst may be located on the second direction side within the fuel cell module100.

The first off-gas flow channel portion510may have an oxidant gas introducing portion560. The oxidant gas introducing portion560may be a pipe, or may be groove-shaped by recessing the flat plate of the first off-gas flow channel portion510in the same direction as the first groove portion530. The oxidant gas introducing portion560may be joined to the partition plate520to cover the groove. When joined to the partition plate520, the oxidant gas introducing portion560may not be in communication with the first groove portion530. The oxidant gas introducing portion560may communicate with an oxidant gas flow channel, which is to be described later, via a first through-hole570formed in the partition plate520.

One end of the oxidant gas introducing portion560may function as an oxidant gas introducing port580. The oxidant gas introducing port580may introduce the oxidant gas to be supplied to the fuel cell stack12into the fuel cell module100via the oxidant gas flow channel. The oxidant gas introducing portion560may be located in the vicinity of the discharge port550. The oxidant gas introducing portion560may be separate from the first off-gas flow channel portion510. In the configuration in which the oxidant gas introducing portion560is separate from the first off-gas flow channel portion510, the oxidant gas introducing portion560may be located on the surface of the partition plate520to which the first off-gas flow channel portion510is joined.

The oxidant gas introducing port580may be located on the upward direction (first direction) side from the discharge port550within the fuel cell module100.

As shown inFIG.25, the first off-gas flow channel portion510may have an extension portion590that branches in the vicinity of the discharge port550and extends toward the vicinity of the oxidant gas introducing portion560. More specifically, the extension portion590branches from the first groove portion530. The extension portion590may be groove-shaped, similar to the first groove portion530. The groove in the extension portion590may communicate with the first groove portion530.

As shown inFIG.13, the second heat-insulating material170is located outside the first heat-insulating material130in the normal direction of the oxidant gas supply plate110, similar to the first embodiment. In other words, the second heat-insulating material170may be located further away from the oxidant gas supply plate110than the first heat-insulating material130. The second heat-insulating material170may be located circumferentially around the first off-gas flow channel140and the oxidant gas flow channel portion18with a straight line parallel to the normal of the main surface of the oxidant gas supply plate110as an axis. The second heat-insulating material170may have a frame-like shape with a rectangular hollowed-out interior and may be constituted by combining a plurality of heat-insulating materials. The second heat-insulating material170may be arranged so that the end surface along the axial direction is in surface contact with the main surface of the first heat-insulating material130.

The oxidant gas flow channel portion180may be joined to the other side of the partition plate520to which the first off-gas flow channel portion510is joined. The oxidant gas flow channel portion180may be positioned to overlap the first off-gas flow channel portion510when viewed from the normal direction of the main surface of the partition plate520. The oxidant gas flow channel may be defined by joining the oxidant gas flow channel portion180to the partition plate520. More specifically, the oxidant gas flow channel may be defined by joining the oxidant gas flow channel portion180to the partition plate520to cover a second groove portion600, which is obtained by recessing a part of the flat plate into a path-like shape. The recessed depth of the second groove portion600may be shallower than the recessed depth of the first groove portion530.

The oxidant gas flow channel portion180may be arranged so that the flat plate portion is parallel to the main surface of the oxidant gas supply plate110. A part of the oxidant gas flow channel portion180may overlap the entire area of the first off-gas flow channel portion510within the fuel cell module100, when viewed from the normal direction of the main surface of the partition plate520. More specifically, a part of the second groove portion600may overlap the entire area of the first groove portion530, when viewed from the aforesaid normal direction. The oxidant gas flow channel portion180may overlap the extension portion590when viewed from the aforesaid normal direction.

The second groove portion600may have a part overlapping the entire supply plate inlet220within the fuel cell module100, when viewed from the normal direction of the aforesaid main surface. The second groove portion600may be shaped such the aforesaid part is one end of the path-like shape. The aforesaid part may communicate with the inner space IS of the oxidant gas supply plate110via the communication pipe500and the supply plate inlet220. The second groove portion600may have a part overlapping the oxidant gas introducing portion560at the other end of the path-like shape within the fuel cell module100. The aforesaid may communicate, via the first through-hole570, with the space defined by the oxidant gas introducing portion560. The second groove portion600may include, for example, a U-shaped portion.

The partition plate520may have a second through-hole610through which the communication pipe500passes.

The partition plate520may have a cutout620. Within the fuel cell module100, the cutout620may be located at least partially in an area other than the area where it overlaps the first off-gas flow channel140and the second groove portion600that defines the oxidant gas flow channel, when viewed from the normal direction of the main surface of the partition plate520. More specifically, the cutout620may be located at least partially in an area other than the area where it overlaps the first groove portion530and the second groove portion600, when viewed from the aforesaid normal direction. The cutout620may also be provided along the first off-gas flow channel140, in the central portion of the U-shape of first off-gas flow channel140, more specifically, of the first groove portion530. The cutout620may be provided around the first off-gas flow channel140and the second groove portion600that defines the oxidant gas flow channel.

The partition plate520may have a raised portion630protruding into the first groove portion530within the fuel cell module100in the area overlapping both the first groove portion530and the second groove portion600, when viewed from the normal direction of the main surface of the partition plate520. With such a configuration, the heat exchange efficiency between the first off-gas flow channel portion510and the oxidant gas flow channel portion180can be improved.

Similar to the first embodiment, a third heat-insulating material340may be provided around the inner space within the housing19where the oxidant gas supply plate110, the fuel cell stack12, the reformer15, and the vaporizer16are provided, except for the portion where the first heat-insulating material130is provided.

The third heat-insulating material34may have a portion extending along the upward direction (first direction) on the opposite side of the oxidant gas supply plate110of the fuel cell stack12. In the aforesaid portion, a recessed portion640may be formed in the vicinity of the location of the reformer15in the upward direction, when viewed from the fuel cell stack12side. A gap may be provided between the recessed portion640and the reformer15.

Similar to the first embodiment, in the fuel cell module100of the second embodiment with the above-described configuration, the oxidant gas supply plate110is positioned to be separated away from the inner wall of the housing19on the upward direction side, and the second plate portion21, which is a surface facing the fuel cell stack12, and the first plate portion20, which is a surface on the opposite side of the fuel cell stack12, are connected directly or indirectly to the housing19so that the space of the oxidant gas supply plate110on the fuel cell stack12side communicates with the space on the opposite side. Thus, similar to the first embodiment, in the fuel cell module100, the oxidant gas supply plate110is heated not only by the opposing fuel cell stack12, but also by the off-gas, so that the oxidant gas flowing inside the oxidant gas supply plate110can also be heated. Similar to the first embodiment, it is also easy for the fuel cell module100to release thermal stress, especially in the vertical direction of the oxidant gas supply plate11, so that deformation of the oxidant gas supply plate11can be suppressed.

In the fuel cell module100of the second embodiment, the off-gas outlet in the fuel cell stack12is located on the opposite side of the first direction than the distal end of the inner space IS of the oxidant gas supply plate110. With such a configuration, the fuel cell module100can absorb more combustion heat generated in the fuel cell stack12by the oxidant gas in the oxidant gas supply plate110. Thus, the fuel cell module100can improve power generation efficiency.

Similar to the first embodiment, in the fuel cell module100of the second embodiment, the oxidant gas supply plate110has the first plate portion200and the second plate portion210located opposite each other, the first plate portion200has the supply plate inlet220, the second plate portion210has the supply plate outlet230, and the supply plate inlet220is provided in the vicinity of the center of the fuel cell stack12in the stacking direction. With such a configuration, the fuel cell module100can also reduce difference in temperature distribution in the stacking direction of the fuel cell stack12.

The fuel cell module100of the second embodiment is provided, between the supply plate inlet220and the supply plate outlet230, with a flow regulating portion280in at least one of the first plate portion200and the second plate portion210that rises from the one to the other and at least extends, when viewed from the normal direction of the main surface of the oxidant gas supply plate110, in a direction intersecting the direction from the supply plate inlet220to the supply plate outlet230. With such a configuration, the fuel cell module100has the effect of spreading the oxidant gas in the direction intersecting the direction from the supply plate inlet220to the supply plate outlet230.

In the fuel cell module100of the second embodiment, the flow regulating portion280has at least one first flow regulating portion281in at least one of the first plate portion200and the second plate portion210that rises from the one to the other and contacts the other, and the first flow regulating portion281proximate to the supply plate inlet220is curved in a direction from the supply plate outlet230to the supply plate inlet220, when viewed from the normal direction of the main surface of the oxidant gas supply plate110. With such a configuration, the fuel cell module100can allow oxidant gas flowing from the supply plate inlet220into the oxidant gas supply plate110to stay in the opposite direction from the supply plate outlet230. Therefore, the fuel cell module100can effectively absorb the heat generated in the fuel cell stack12by the oxidant gas.

In the fuel cell module100of the second embodiment, the flow regulating portion280has the second flow regulating portion282in at least one of the first plate portion200and the second plate portion210, the second flow regulating portion282having a gap in the facing direction between the first plate portion200and the second plate portion210while rising from the one to the other. With such a configuration, the fuel cell module100can spread the oxidant gas flowing in from the supply plate inlet220over the entire oxidant gas supply plate110, and since the second flow regulating portion282has a gap, thermal deformation of the oxidant gas supply plate110can be suppressed.

In the second embodiment of the fuel cell module100, the portion of the second plate portion210opposite the supply plate inlet220is recessed to the side opposite to the first plate portion200. With such a configuration, the fuel cell module100can reduce the pressure loss when the oxidant gas flowing into the oxidant gas supply plate110impacts the inner wall of the second plate portion210.

The fuel cell module100of the second embodiment is provided with the exhaust gas lead-out portion490that, in the flow of the off-gas discharged from the fuel cell stack12toward the reformer15side, causes the off-gas to flow toward the center of the housing19in the second direction. With such a configuration, the fuel cell module100can discharge the off-gas uniformly from both sides in the second direction within the housing19.

The fuel cell module100of the second embodiment is provided with the exhaust gas lead-out portion490that, in the flow of the off-gas discharged from the fuel cell stack12toward the reformer15side, causes the off-gas to flow toward the opposite side of the second direction. With such a configuration, the fuel cell module100can increase the outlet temperature of the reformer15by the high-temperature off-gas. Thus, the fuel cell module100can improve the power generation efficiency of the fuel cell stack12.

The fuel cell module100of the second embodiment is further provided with the heat-insulating material340that extends along the second direction on the opposite side of the oxidant gas supply plate110of the fuel cell stack12, and in which the recessed portion640is formed in the vicinity of the location of the reformer15in the first direction when viewed from the fuel cell stack12side, the reformer15having a gap with the recessed portion640. With such a configuration, in the fuel cell module100, since the off-gas can stay in the recessed portion640, the temperature of the reformer15can be increased. Thus, the fuel cell module100can improve the power generation efficiency of the fuel cell stack12.

In the fuel cell module100of the second embodiment, the width of the inner space IS of the oxidant gas supply plate110on the first direction side in the width direction is longer than the width on the side opposite to the first direction. With such a configuration, the fuel cell module100causes the first direction side of the oxidant gas supply plate110to face the first direction side of the fuel cell stack12where the temperature is higher, thus maintaining a larger area facing the fuel cell stack12and slowing the flow of the oxidant gas in the inner space IS; therefore, the efficiency of heat exchange can be improved. In addition, in the fuel cell module100having the above-described configuration, since the area facing the fuel cell stack12, in the opposite side of the first direction of the fuel cell stack12where the temperature is relatively low, is small, the decrease in heat of the heated oxidant gas can be suppressed.

In the fuel cell module100of the second embodiment, the width of the inner space IS in the first direction side is longer than the width of the fuel cell stack12. With such a configuration, the fuel cell module100can increase the heat exchanged between the heat emitted by the fuel cell stack12and the oxidant gas in the inner space IS of the oxidant gas supply plate110. In the fuel cell module100, the width of the inner space IS in the opposite side of the first direction is the same as the width of the fuel cell stack12. With such a configuration, the fuel cell module100can homogenize the supply of oxidant gas to the fuel cell stack12via the supply plate outlet230in the second direction, while reducing the heat loss of the oxidant gas.

Although the embodiments according to the present disclosure have been described based on the drawings and the examples, it is to be noted that various changes and modifications may be made easily by those who are ordinarily skilled in the art based on the present disclosure. Thus, it is to be noted that such changes and modifications are included in the scope of the present disclosure. For example, functions and the like included in each component, each step or the like can be rearranged without logical inconsistency, and a plurality of components, steps or the like can be combined into one or divided. Although the embodiment according to the present disclosure has been described focusing on the device, the embodiment according to the present disclosure can also be realized as a method including steps executed by each component of the device. The embodiments according to the present disclosure can also be realized as a method and a program executed by a processor included in the device, or a storage medium on which a program is recorded. It is to be understood that the scope of the present disclosure includes these as well.

For example, in the first embodiment, the flange portion41on the traveling direction side of the off-gas channel plate38functions as a cover portion, but the hole-like heat-insulating portion25may be covered by a cover portion that is separate from the off-gas channel plate38.

Further, in the second embodiment, the structure of the oxidant gas supply plate110is not limited to the above, but may have a fourth projection660that rises on the fuel cell stack12side within the fuel cell module100, as shown inFIG.26, for example.

The descriptions such as “first” and “second” in the present disclosure are identifiers for distinguishing corresponding configurations. Configurations distinguished by the descriptions such as “first” and “second” in the disclosure can exchange numbers in the corresponding configurations. For example, a first camera can exchange “first” and “second”, which are identifiers, with a second camera. The exchange of identifiers takes place at the same time. Even after exchanging identifiers, the corresponding configuration is distinguished. The identifier may be deleted. The configuration with the identifier deleted is distinguished by a reference sign. It may not be used as a basis for interpreting the order of the corresponding configurations and the existence of identifiers with lower numbers, based on the description of identifiers such as “first” and “second” in this disclosure.

REFERENCE SIGNS