Fuel cell module and fuel cell device

Abstract

To achieve the compact size.SOLUTION: A fuel cell module 10 includes a housing 11, a fuel cell stack 12, a combustor 13, and a first heat exchanger 14. The fuel cell stack 12 is housed in the housing 11. The combustor 13 combusts an unreacted fuel gas in the fuel cell stack 12. The first heat exchanger 14 is housed in the housing 11. The first heat exchanger 14 is attached to at least one of the housing 11 and the fuel cell stack 12. The first heat exchanger 14 exchanges heat between the fuel gas discharged from the fuel cell stack 12 and the fuel gas supplied to the combustor 13.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a fuel cell module and a fuel cell device. [Background technology]

[0002] A fuel cell module is known that includes a reformer, a combustor, and a fuel cell stack. The reformer reforms raw fuel gas to generate fuel gas for use in the fuel cell stack. The combustor combusts unreacted fuel gas in the fuel cells to provide the energy required for the reforming reaction in the reformer. The fuel cell stack generates electricity by electrochemically reacting the fuel gas.

[0003] The fuel cell stack contains unreacted fuel gas as well as water produced by the reaction. It has been proposed to cool a mixed gas containing unreacted fuel gas and water vapor, recover the water, and then supply the unreacted fuel gas to a combustor. In order to effectively utilize thermal energy, it has also been proposed to provide a heat exchanger that exchanges heat between the mixed gas discharged from the fuel cell stack and the fuel gas from which the water has been recovered. It has also been proposed to house this heat exchanger together with the fuel cell stack in a high-temperature housing (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-107401 A Summary of the Invention [Problem to be solved by the invention]

[0005] Placing a heat exchanger inside the high-temperature housing makes the piping complicated, which makes it difficult to reduce the size of the high-temperature housing, and as a result, makes it difficult to reduce the size of the fuel cell module.

[0006] Therefore, an object of the present disclosure is to provide a fuel cell module and a fuel cell device that can be made smaller than when the configuration of the present disclosure is not used. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, a fuel cell module according to a first aspect comprises: A housing and a fuel cell stack housed in the housing; and a combustor that combusts unreacted fuel gas in the fuel cell stack; and a first heat exchanger that is housed in the housing and attached to at least one of the housing and the fuel cell stack, and exchanges heat between the fuel gas discharged from the fuel cell stack and the fuel gas supplied to the combustor.

[0008] A fuel cell device according to a second aspect of the present invention comprises: The fuel cell module includes a housing, a fuel cell stack housed in the housing, a combustor that combusts unreacted fuel gas in the fuel cell stack, and a first heat exchanger housed in the housing and attached to at least one of the housing and the fuel cell stack and that exchanges heat between fuel gas discharged from the fuel cell stack and fuel gas supplied to the combustor, and a second heat exchanger that exchanges heat between the fuel gas discharged from the fuel cell stack and that has been heat exchanged in the first heat exchanger and a heat medium. Effect of the Invention

[0009] The fuel cell module and fuel cell device according to the present disclosure configured as described above can be made compact. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing the internal configuration of a fuel cell module according to an embodiment. [Diagram 2] FIG. 11 is a diagram showing the internal configuration of a modified example of the fuel cell module according to the embodiment. [Diagram 3] FIG. 11 is an internal configuration diagram of another modified example of the fuel cell module according to the embodiment. [Figure 4] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. [Diagram 5] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. [Figure 6] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. [Figure 7] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. [Figure 8] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. [Figure 9] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. [Figure 10] FIG. 11 is a diagram showing the arrangement of a first heat exchanger in yet another modified example of the fuel cell module according to the embodiment. [Figure 11] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. [Figure 12] FIG. 11 is an internal configuration diagram of yet another modified example of the fuel cell module according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a fuel cell module to which the present disclosure is applied will be described with reference to the drawings.

[0012] 1, a fuel cell module 10 according to a first embodiment of the present disclosure includes a housing 11, a fuel cell stack 12, a combustor 13, and a first heat exchanger 14. The fuel cell module 10 may further include a reformer 15, a second heat exchanger 16, and a gas-liquid separator 17. As described above, the second heat exchanger 16 and the gas-liquid separator 17 may be included in the fuel cell module 10, or may be included outside the fuel cell module 10, in other words, together with the fuel cell module 10, in a fuel cell device 18.

[0013] The orientation of the fuel cell device 18 relative to the ground surface when installed is determined. The arrangement of each component in the determined orientation relative to the ground surface will be described later.

[0014] In the fuel cell module 10, the fuel cell stack 12, the combustor 13, and the reformer 15 may be positioned so as to be aligned along a first direction. The reformer 15 may be positioned, together with the fuel cell stack 12, to sandwich the combustor 13 in the first direction. In this embodiment, in the attitude of the fuel cell device 18 determined with respect to the ground surface, the vertical upward direction may coincide with the first direction.

[0015] The housing 11 houses at least the fuel cell stack 12 and the first heat exchanger 14. The housing 11 may further house a combustor 13 and a reformer 15. The housing 11 may be formed of a metal plate. At least a part of the inner surface of the housing 11 may be flat. The entire inner wall or outer wall of the housing 11 may be covered with a thermal insulating material.

[0016] The housing 11 may be configured to include a rectangular box-shaped portion with one open side and a lid portion that covers the open side. Components and the like to be housed in the housing 11 may be installed in the housing 11 from the open side during manufacturing.

[0017] The fuel cell stack 12 may be formed by stacking a plurality of fuel cells. The fuel cell generates power through an electrochemical reaction between a fuel gas and an oxidant gas. In the fuel cell, not all of the fuel gas and oxidant gas supplied undergo an electrochemical reaction, and unreacted fuel gas and oxidant gas are discharged. In this specification, unreacted fuel gas is sometimes referred to as fuel off-gas. In this specification, unreacted oxidant gas is sometimes referred to as oxidant off-gas.

[0018] The fuel cell may have a flat shape. The flat fuel cell may be stacked. The stacking direction may be parallel to a first direction. Or, as shown in Figs. 2 and 3, the stacking direction may be perpendicular to the first direction. The stacking direction may be parallel to a second direction described below as shown in Fig. 2, or perpendicular to the second direction as shown in Fig. 3. At least a part of the outer surface of the fuel cell stack 12 may be flat.

[0019] In the fuel cell stack 12, the inlets for the fuel gas and the oxidant gas, and the outlets for the fuel gas and the oxidant gas may be provided on at least one of both end faces in the stacking direction. Both end faces in the stacking direction may form the outer surfaces of the fuel cell stack 12. At least one of the both end faces may be flat. For example, as shown in Figures 1 and 2, an inlet and an outlet for the oxidant gas may be provided on one end face in the stacking direction of the fuel cell stack 12, and an inlet and an outlet for the fuel gas may be provided on the other end face.

[0020] 3, an inlet and an outlet for oxidant gas and an inlet and an outlet for fuel gas may be provided only on one end face in the stacking direction of the fuel cell stack 12, i.e., on a single face constituting the outer face of the fuel cell stack 12. Furthermore, as shown in FIG. 4, for example, on the single face constituting the outer face of the fuel cell stack 12, an inlet 19 and an outlet 20 for fuel gas may be aligned along a first direction. Furthermore, on the single face, an inlet 21 and an outlet 22 for oxidant gas may be positioned such that a line segment connecting the inlet 19 and the outlet 20 for fuel gas intersects with a line segment connecting the inlet 21 and the outlet 22 for oxidant gas. Furthermore, on the single face, a line segment connecting the inlet 21 and the outlet 22 for oxidant gas may be parallel to the second direction.

[0021] The fuel gas inlet 19 may introduce the fuel gas supplied from the reformer 15 into each fuel cell. The oxidant gas inlet 21 may introduce the oxidant gas into each fuel cell. The oxidant gas is, for example, an oxygen-containing gas such as air, and may be introduced into the fuel cell module 10 using a blower or the like. The fuel gas outlet 20 may discharge fuel off-gas from each fuel cell. The oxidant gas outlet 22 may discharge the oxidant gas from each fuel cell.

[0022] The combustor 13 combusts the unreacted fuel gas discharged from the fuel cell stack 12 using an oxidizing gas.

[0023] The first heat exchanger 14 is attached to at least one of the housing 11 and the fuel cell stack 12. For example, as shown in Figs. 1 to 4, the first heat exchanger 14 may be attached to the fuel cell stack 12. Alternatively, as shown in Figs. 5 to 7, the first heat exchanger 14 may be attached to the housing 11. Alternatively, as shown in Fig. 8, the high-temperature side heat exchange section 23 and the low-temperature side heat exchange section 24 constituting the first heat exchanger 14 may be attached to the fuel cell stack 12 and the housing 11, respectively. At least a part of the outer surface of the first heat exchanger 14 may be flat. The first heat exchanger 14 may be attached in a state of surface contact with the flat surface on the outer surface of at least one of the housing 11 and the fuel cell stack 12.

[0024] 1 to 4, the first heat exchanger 14 may be attached to an end surface in the stacking direction of the fuel cell stack 12. The first heat exchanger 14 may be attached directly to the fuel cell stack 12, or may be attached via a thermal insulator.

[0025] In a configuration in which the first heat exchanger 14 is provided on an end face of the fuel cell stack 12, the height of the first heat exchanger 14 from the end face may be lower than the height of the piping provided on the end face. The height from the end face is the distance between the end face and the part of the object (piping, first heat exchanger 14) that is furthest from the end face in the normal direction of the end face. For example, in a configuration in which the piping provided on the end face of the fuel cell stack 12 is bent, the height of the first heat exchanger 14 from the end face may be lower than the part where the distance between the piping and the end face is the greatest within the range of the end face of the fuel cell stack 12. Also, in this configuration, the height of the first heat exchanger 14 from the end face may be lower than the part where the distance between at least some of the piping and the end face is the greatest, and other parts of the piping may be lower than the height of the first heat exchanger 14 from the end face. Furthermore, the piping may include a joint. At the end face of the fuel cell stack 12, the inlets 19, 21 or the outlets 20, 22 for the fuel gas or oxidant gas may be connected to piping using, for example, a joint or the like. The joint has a minimum height, and the height of the first heat exchanger 14 is less than the minimum height.

[0026] In a configuration in which the first heat exchanger 14 is attached to a plane that constitutes the outer surface of the fuel cell stack 12, the entire first heat exchanger 14 may overlap the fuel cell stack 12 when viewed from the normal direction of the plane. Alternatively, in a configuration in which the first heat exchanger 14 is attached to a plane that constitutes the outer surface of the fuel cell stack 12, only a portion of the first heat exchanger 14 may overlap the fuel cell stack 12 when viewed from the normal direction of the plane, as shown in Fig. 9.

[0027] As shown in FIG. 10, the first heat exchanger 14 may be located between the fuel cell stack 12 and the combustor 13, and attached to an end surface of the fuel cell stack 12 in the stacking direction.

[0028] 11 and 12, the first heat exchanger 14 may be attached to the housing 11 in a direction perpendicular to the stacking direction of the fuel cell stack 12, which is arranged so that the stacking direction is parallel to the first direction. The first heat exchanger 14 may be connected to a fuel gas outlet 20 in the fuel cell stack 12 by a first flow path 25. The fuel gas outlet 20 may be provided on an end face on the combustor 13 side. At least a part of the first flow path 25 may be located between the fuel cell stack 12 and the combustor 13. As shown in FIG. 12, the first flow path 25 may be located on the side of a reformer 26, which will be described later, in the second direction.

[0029] The first heat exchanger 14 exchanges heat between the fuel gas discharged from the fuel cell stack 12 and the fuel gas supplied to the combustor 13. The fuel gas discharged from the fuel cell stack 12 may be the fuel gas at which heat exchange is first performed after being discharged from the fuel cell stack 12. The fuel gas supplied to the combustor 13 may be the fuel gas from which at least a portion of the water vapor contained in the fuel gas has been removed, as described below, from the fuel gas discharged from the fuel cell stack 12 and having flowed through the first heat exchanger 14.

[0030] In a configuration in which the first heat exchanger 14 has the high-temperature side heat exchange section 23 and the low-temperature side heat exchange section 24, the fuel gas discharged from the fuel cell stack 12 may pass through the high-temperature side heat exchange section 23 and the low-temperature side heat exchange section 24 in that order. In other words, the fuel gas discharged from the fuel cell stack 12 may be heat exchanged in the low-temperature side heat exchange section 24 after being heat exchanged in the high-temperature side heat exchange section 23. In addition, in a configuration in which the first heat exchanger 14 has the high-temperature side heat exchange section 23 and the low-temperature side heat exchange section 24, the fuel gas supplied to the combustor 13 may be supplied to the combustor 13 after passing through the low-temperature side heat exchange section 24 and the high-temperature side heat exchange section 23 in that order. In other words, the fuel gas supplied to the combustor 13 may be heat exchanged in the low-temperature side heat exchange section 24 and then in the high-temperature side heat exchange section 23 before being supplied to the combustor 13.

[0031] The first heat exchanger 14 may be located on the opposite side to the open face of the housing 11 described above.

[0032] The reformer 15 may have at least a reforming section 26. The reformer 15 may be heated by the combustor 13. The reformer 15 may further have a vaporization section 27. The reforming section 26 and the vaporization section 27 may be aligned in a second direction intersecting the first direction. The second direction is a direction perpendicular to the first direction.

[0033] The reforming unit 26 contains a reforming catalyst. The reforming unit 26 generates a fuel gas containing hydrogen by reforming the raw fuel gas using steam. The raw fuel gas and steam may be supplied to the reforming unit 26 via a vaporization unit 27. The vaporization unit 27 may vaporize water to supply the steam to the reforming unit 26. The raw fuel gas is, for example, a light hydrocarbon gas such as city gas. The raw fuel gas may be desulfurized by a desulfurizer 28 before being supplied to the reformer 15.

[0034] The second heat exchanger 16 may exchange heat between the fuel gas discharged from the fuel cell stack 12 and having been heat exchanged in the first heat exchanger 14 and a heat medium. The heat medium is, for example, water.

[0035] The second heat exchanger 16 may be located together with the first heat exchanger 14 in a normal direction of a portion of the outer surface of the fuel cell stack 12. At least a portion of the second heat exchanger 16 may overlap the first heat exchanger 14 when viewed from the normal direction.

[0036] The gas-liquid separator 17 may separate the liquid liquefied by cooling in the second heat exchanger 16 from the fuel gas. The fuel gas contains water vapor, and the liquid liquefied by cooling is, for example, water. The fuel gas from which the water vapor has been removed may be sent to the combustor 13 after heat exchange in the first heat exchanger 14. A portion of the fuel gas from which the water vapor has been removed may be sent to a recycle flow path 29 directly or via the first heat exchanger 14. The recycle flow path 29 may supply the fuel gas from which the water vapor has been removed to the fuel cell stack 12.

[0037] The fuel cell module 10 of the present embodiment configured as described above includes a housing 11, a fuel cell stack 12 housed in the housing 11, a combustor 13 that combusts unreacted fuel gas in the fuel cell stack 12, and a first heat exchanger 14 housed in the housing 11 and attached to at least one of the housing 11 and the fuel cell stack 12, and that exchanges heat between the fuel gas discharged from the fuel cell stack 12 and the fuel gas supplied to the combustor 13. With this configuration, the fuel cell module 10 can omit piping between the first heat exchanger 14 and at least one of the housing 11 and the fuel cell stack 12. Therefore, the fuel cell module 10 can be made smaller by the amount that piping can be omitted within the housing 11.

[0038] Moreover, in the fuel cell module 10, the fuel cell stack 12 is formed by stacking a plurality of fuel cells, and the first heat exchanger 14 is attached to an end face in the stacking direction of the fuel cell stack 12. With such a configuration, the fuel cell module 10 can directly conduct Joule heat generated in the fuel cell module 10 to the outer surface of the first heat exchanger 14. Therefore, the fuel cell module 10 can effectively utilize the Joule heat generated in the fuel cell stack 12. Furthermore, the fuel cell module 10 can reinforce the fuel cell stack 12 with the first heat exchanger 14.

[0039] Furthermore, in the fuel cell module 10, the height of the first heat exchanger 14 from the end face is lower than the height of the piping provided on the end face of the fuel cell stack 12. With this configuration, the fuel cell module 10 can be made compact.

[0040] Furthermore, in the fuel cell module 10, a fuel gas inlet 19 and outlet 20 and an oxidant gas inlet 21 and outlet 22 are provided on a single plane constituting the outer surface of the fuel cell stack 12, and the fuel gas inlet 19 and outlet 20 are aligned along a first direction in which the fuel cell stack 12 and the combustor 13 are aligned, and intersect with a line segment connecting the inlet 19 and outlet 20 and a line segment connecting the oxidant gas inlet 21 and outlet 22. With this configuration, the fuel cell module 10 is less likely to cause interference with piping connected to the fuel cell stack 12, improving the ease of piping connection work.

[0041] Furthermore, in the fuel cell module 10, the first heat exchanger 14 is attached to a plane that constitutes the outer surface of the fuel cell stack 12, and when viewed from the normal direction of the plane, the entire first heat exchanger 14 overlaps the fuel cell stack 12. With this configuration, the fuel cell module 10 maximizes the contact area between the fuel cell stack 12 and the first heat exchanger 14, so that the Joule heat generated in the fuel cell stack 12 can be more effectively utilized by the first heat exchanger 14.

[0042] Furthermore, in the fuel cell module 10, the first heat exchanger 14 is attached to a plane that constitutes the outer surface of the fuel cell stack 12, and only a portion of the first heat exchanger 14 overlaps with the fuel cell stack 12 when viewed from the normal direction of the plane. With this configuration, in the region of the fuel cell module 10 that does not overlap with the fuel cell stack 12 when viewed from the normal direction, no heat transfer due to surface contact occurs, which can promote a decrease in the temperature of the fuel gas that is a fluid within the first heat exchanger 14. Therefore, when utilizing the heat of the fuel gas discharged from the fuel cell stack 12 and passed through the first heat exchanger 14, the fuel cell module 10 can suppress the occurrence of bumping or the like of the heat medium that exchanges heat with the fuel gas.

[0043] Furthermore, in the fuel cell module 10, at least a portion of the first flow path 25 connecting the fuel gas outlet 20 in the fuel cell stack 12 and the first heat exchanger 14 is located between the fuel cell stack 12 and the combustor 13. With this configuration, the fuel cell module 10 can heat the fuel gas by the fuel cell stack 12 and the combustor 13, which have a higher temperature than the fuel cell stack 12, and then exchange the fuel gas in the first heat exchanger 14. Therefore, the fuel cell module 10 can effectively utilize the thermal energy generated in the fuel cell module 10.

[0044] The fuel cell module 10 further includes a reformer 15 that is positioned along the first direction to sandwich the combustor 13 together with the fuel cell stack 12 and is heated by the combustor 13. The reformer 15 has a reforming section 26 that generates fuel gas by reforming raw fuel gas and a vaporizing section 27 that vaporizes water to supply steam to the reforming section 26, which are aligned in a second direction intersecting the first direction, and the first flow path 25 is positioned on the reforming section 26 side in the second direction. The amount of heat absorbed in the vaporizing section 27 is greater than the amount of heat absorbed in the reforming section 26. Therefore, the temperature of the combustor 13 on the vaporizing section 27 side is lower than the temperature of the combustor 13 on the reforming section 26 side. In response to such an event, the fuel cell module 10 having the above-mentioned configuration can improve the heating effect of the fuel gas before it reaches the first heat exchanger 14.

[0045] Furthermore, in the fuel cell module 10, the first heat exchanger 14 exchanges heat in a high-temperature side heat exchange section 23 and a low-temperature side heat exchange section 24 attached to the fuel cell stack 12, and the fuel gas supplied to the combustor 13 is supplied to the combustor 13 after heat exchange in the low-temperature side heat exchange section 24 and then heat exchange in the high-temperature side heat exchange section 23. With this configuration, in the fuel cell module 10, no heat transfer occurs due to surface contact with the fuel cell stack 12 in the low-temperature side heat exchange section 24, and this can promote a decrease in the temperature of the fuel gas, which is a fluid in the low-temperature side heat exchange section 24. Therefore, when utilizing the heat of the fuel gas discharged from the fuel cell stack 12 and passing through the first heat exchanger 14, the fuel cell module 10 can suppress the occurrence of bumping or the like of the heat medium that exchanges heat with the fuel gas.

[0046] In this configuration, the high-temperature side heat exchanger 23 attached to the fuel cell stack 12 may exchange heat between the fuel gas discharged from the fuel cell stack 12 and the fuel gas supplied to the combustor 13, while the low-temperature side heat exchanger 24 attached to the housing 11 may exchange heat between the fuel gas after heat exchange in the high-temperature side heat exchanger 23 and the water supplied to the vaporization section 27. With this configuration, it is possible to more effectively promote a decrease in the temperature of the fuel gas, which is the fluid within the low-temperature side heat exchanger 24, and also to more efficiently vaporize the water, thereby reducing the problem of the vaporization section 27 taking away heat from the surroundings.

[0047] Moreover, in the fuel cell module 10, the first heat exchanger 14 is attached to the fuel cell stack 12 via a thermal insulating material. With this configuration, the fuel cell module 10 can promote a decrease in the temperature of the fuel gas, which is a fluid in the low-temperature side heat exchange section 24. Therefore, when utilizing the heat of the fuel gas discharged from the fuel cell stack 12 and passed through the first heat exchanger 14, the fuel cell module 10 can suppress the occurrence of bumping and the like of the heat medium that exchanges heat with the fuel gas.

[0048] Furthermore, in the fuel cell module 10, the first heat exchanger 14 is located between the fuel cell stack 12 and the combustor 13. With this configuration, the fuel cell module 10 can suppress heat dissipation from the first heat exchanger 14 by the combustor 13 and the fuel cell stack 12, which have a higher temperature than the fuel cell stack 12. Therefore, the fuel cell module 10 can effectively utilize the thermal energy generated in the fuel cell module 10.

[0049] The fuel cell device 18 configured as above includes the fuel cell module 10 and the second heat exchanger 16 that exchanges heat with a heat medium for the fuel gas discharged from the fuel cell stack 12 and having been heat exchanged in the first heat exchanger 14. With this configuration, the fuel cell device 18 can recover heat at high temperatures using the heat medium.

[0050] In the fuel cell device 18, the first heat exchanger 14 and the second heat exchanger 16 are positioned in the normal direction of a portion of the outer surface of the fuel cell stack 12, and at least a portion of the second heat exchanger 16 overlaps with the first heat exchanger 14 when viewed from the normal direction. With this configuration, the fuel cell device 18 can increase the size of the first heat exchanger 14 and the second heat exchanger 16 in the normal direction while reducing the size of the fuel cell device 18 in the normal direction, compared to a configuration in which the second heat exchanger 16 is positioned offset from the first heat exchanger 14 in the normal direction. Therefore, the fuel cell device 18 can increase the effective areas of the first heat exchanger 14 and the second heat exchanger 16.

[0051] In one embodiment, (1) the fuel cell module comprises: A housing and a fuel cell stack housed in the housing; and a combustor that combusts unreacted fuel gas in the fuel cell stack; and a first heat exchanger that is housed in the housing and attached to at least one of the housing and the fuel cell stack, and exchanges heat between the fuel gas discharged from the fuel cell stack and the fuel gas supplied to the combustor.

[0052] (2) In the fuel cell module described above in (1), The fuel cell stack is formed by stacking a plurality of fuel cells, The first heat exchanger is attached to an end surface of the fuel cell stack in the stacking direction.

[0053] (3) In the fuel cell module described in (2) above, The height of the first heat exchanger from the end face of the fuel cell stack is lower than the height of a pipe provided on the end face of the fuel cell stack from the end face.

[0054] (4) In any one of the fuel cell modules (1) to (3), a fuel gas inlet and an outlet, and an oxidant gas inlet and an outlet are provided on a single plane constituting an outer surface of the fuel cell stack; the fuel gas inlet and outlet are aligned along a first direction in which the fuel cell stack and the combustor are aligned, A line segment connecting the inlet and the outlet intersects with a line segment connecting the inlet and the outlet for the oxidant gas.

[0055] (5) In any one of the fuel cell modules (1) to (4), the first heat exchanger is attached to a flat surface that constitutes an outer surface of the fuel cell stack, When viewed from the normal direction of the plane, the first heat exchanger is entirely overlapped with the fuel cell stack.

[0056] (6) In any one of the fuel cell modules (1) to (4), the first heat exchanger is attached to a flat surface that constitutes an outer surface of the fuel cell stack, When viewed from the normal direction of the plane, only a portion of the first heat exchanger overlaps with the fuel cell stack.

[0057] (7) In the fuel cell module described in (1) above, At least a portion of a first flow passage connecting a fuel gas outlet in the fuel cell stack and the first heat exchanger is located between the fuel cell stack and the combustor.

[0058] (8) In the fuel cell module of (7) above, a reformer located along a first direction so as to sandwich the combustor together with the fuel cell stack, and heated by the combustor; the reformer has a reforming section that generates the fuel gas by reforming a raw fuel gas and a vaporization section that vaporizes water to supply water vapor to the reforming section, the reforming section and the vaporization section being aligned in a second direction intersecting the first direction; The first flow path is located on the reforming section side in the second direction.

[0059] (9) In any one of the fuel cell modules (1) to (8), The fuel gas supplied to the combustor is fuel gas from which at least a portion of the water vapor contained in the fuel gas discharged from the fuel cell stack has been removed.

[0060] (10) In any one of the fuel cell modules (1) to (9), the first heat exchanger includes a high-temperature side heat exchange unit attached to the fuel cell stack and a low-temperature side heat exchange unit attached to the housing, the fuel gas discharged from the fuel cell stack is heat exchanged in the high-temperature side heat exchange section, and then heat exchanged in the low-temperature side heat exchange section; The fuel gas supplied to the combustor is subjected to heat exchange in the low-temperature side heat exchange section, and then to heat exchange in the high-temperature side heat exchange section, and then is supplied to the combustor.

[0061] (11) In any one of the fuel cell modules (1) to (10), The first heat exchanger is attached to the fuel cell stack with a thermal insulator interposed therebetween.

[0062] (12) In any one of the fuel cell modules (1) to (11), The first heat exchanger is located between the fuel cell stack and the combustor.

[0063] (13) A fuel cell device comprising: a fuel cell module according to any one of (1) to (12) above; and a second heat exchanger that exchanges heat between the fuel gas discharged from the fuel cell stack and having been heat exchanged in the first heat exchanger and a heat medium.

[0064] (14) In the fuel cell device according to (13), the first heat exchanger and the second heat exchanger are located in a normal direction of a part of an outer surface of the fuel cell stack, At least a portion of the second heat exchanger overlaps with the first heat exchanger when viewed from the normal direction.

[0065] The drawings for explaining the embodiments according to the present disclosure are schematic, and the dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones.

[0066] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions, etc. included in each component, etc. can be rearranged so as not to cause logical inconsistencies, and multiple components, etc. can be combined into one or divided.

[0067] All of the features described in this disclosure and / or all steps of any method or process disclosed herein may be combined in any combination except those combinations in which the features are mutually exclusive. Also, each feature described in this disclosure may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly denied. Thus, unless expressly denied, each disclosed feature is only one example of a generic series of the same or equivalent features.

[0068] Furthermore, the embodiments of the present disclosure are not limited to any of the specific configurations of the embodiments described above, but rather extend to any novel feature or combination of features described herein, or any novel method or process step or combination of features described herein.

[0069] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. Configurations distinguished by descriptions such as "first" and "second" in this disclosure may have their numbers exchanged. For example, a first heat exchanger may have its identifiers "first" and "second" exchanged with a second heat exchanger. The exchange of identifiers is performed simultaneously. The configurations remain distinguished even after the identifiers are exchanged. Identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a symbol. Descriptions of identifiers such as "first" and "second" in this disclosure alone should not be used to interpret the order of the configurations or to justify the existence of an identifier with a smaller number. [Explanation of symbols]

[0070] 10 Fuel Cell Module 11. Cabinet 12 Fuel cell stack 13 Combustor 14 First heat exchanger 15 Reformer 16 Second heat exchanger 17 Gas-liquid separator 18 Fuel cell equipment 19 Fuel gas inlet 20 Fuel gas outlet 21 Oxidant gas inlet 22 Oxidant gas outlet 23 High temperature side heat exchange section 24 Low temperature side heat exchange section 25 First Channel 26 Modification Section 27 Evaporation section 28 Desulfurizer 29 Recycle Channel

Claims

1. A housing and a fuel cell stack housed in the housing; and a combustor that combusts unreacted fuel gas in the fuel cell stack; a first heat exchanger that is housed in the housing and attached to at least one of the housing and the fuel cell stack, and exchanges heat between a fuel gas discharged from the fuel cell stack and a fuel gas supplied to the combustor. Fuel cell module.

2. 2. The fuel cell module according to claim 1, The fuel cell stack is formed by stacking a plurality of fuel cells, The first heat exchanger is attached to an end surface in a stacking direction of the fuel cell stack. Fuel cell module.

3. 3. The fuel cell module according to claim 2, The height of the first heat exchanger from the end surface of the fuel cell stack is lower than the height of a pipe provided on the end surface of the fuel cell stack from the end surface. Fuel cell module.

4. 4. The fuel cell module according to claim 1, a fuel gas inlet and an outlet, and an oxidant gas inlet and an outlet are provided on a single plane constituting an outer surface of the fuel cell stack; the fuel gas inlet and outlet are aligned along a first direction in which the fuel cell stack and the combustor are aligned, A line segment connecting the inlet and the outlet intersects with a line segment connecting the inlet and the outlet of the oxidant gas. Fuel cell module.

5. 4. The fuel cell module according to claim 1, the first heat exchanger is attached to a flat surface that constitutes an outer surface of the fuel cell stack, When viewed from the normal direction of the plane, the first heat exchanger is entirely overlapped with the fuel cell stack. Fuel cell module.

6. 4. The fuel cell module according to claim 1, the first heat exchanger is attached to a flat surface that constitutes an outer surface of the fuel cell stack, When viewed from the normal direction of the plane, only a portion of the first heat exchanger overlaps with the fuel cell stack. Fuel cell module.

7. 2. The fuel cell module according to claim 1, At least a portion of a first flow passage connecting a fuel gas outlet in the fuel cell stack and the first heat exchanger is located between the fuel cell stack and the combustor. Fuel cell module.

8. 8. The fuel cell module according to claim 7, a reformer located along a first direction to sandwich the combustor together with the fuel cell stack, and heated by the combustor; the reformer has a reforming section which generates the fuel gas by reforming a raw fuel gas, and a vaporization section which vaporizes water to supply water vapor to the reforming section, the reforming section and the vaporization section being aligned in a second direction intersecting the first direction; The first flow path is located on the reforming unit side in the second direction. Fuel cell module.

9. 4. The fuel cell module according to claim 1, The fuel gas supplied to the combustor is fuel gas from which at least a portion of the water vapor contained in the fuel gas discharged from the fuel cell stack has been removed. Fuel cell module.

10. 4. The fuel cell module according to claim 1, the first heat exchanger includes a high-temperature side heat exchange unit attached to the fuel cell stack and a low-temperature side heat exchange unit attached to the housing, the fuel gas discharged from the fuel cell stack is heat exchanged in the high-temperature side heat exchange section, and then heat exchanged in the low-temperature side heat exchange section; The fuel gas supplied to the combustor is subjected to heat exchange in the low-temperature side heat exchange section, and then to heat exchange in the high-temperature side heat exchange section before being supplied to the combustor. Fuel cell module.

11. 4. The fuel cell module according to claim 1, The first heat exchanger is attached to the fuel cell stack via a thermal insulator. Fuel cell module.

12. 4. The fuel cell module according to claim 1, The first heat exchanger is located between the fuel cell stack and the combustor. Fuel cell module.

13. A fuel cell module according to any one of claims 1 to 3; a second heat exchanger that exchanges heat between the fuel gas discharged from the fuel cell stack and the fuel gas that has been heat exchanged in the first heat exchanger and a heat medium. Fuel cell device.

14. 14. The fuel cell device according to claim 13, the first heat exchanger and the second heat exchanger are located in a normal direction of a part of an outer surface of the fuel cell stack, At least a portion of the second heat exchanger overlaps with the first heat exchanger when viewed from the normal direction. Fuel cell device.

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