Reforming unit and fuel cell system

Abstract

Further improve combustion efficiency. [Solution] The reforming unit 10 has a combustion section 13, a reforming section 15, and a first outlet pipe 14. The combustion section 13 burns fuel off-gas in a space defined by at least a first bottom wall and a first side wall. The reforming section 15 reforms the raw fuel in a space defined by at least a first bottom wall, a first side wall, a second bottom wall, and a second side wall. The first outlet pipe 14 is provided on the first direction side of the combustion section 13. The first outlet pipe 14 discharges the combustion exhaust gas generated in the combustion section 13 from the combustion section 13.

Description

Technical Field

[0001] The present disclosure relates to a reforming unit and a fuel cell device.

Background Art

[0002] A fuel cell module has been proposed that includes a fuel cell stack, an evaporation section, and a reforming unit, and is compact as a whole while supplying sufficient heat to the reforming section and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the reforming unit described in Patent Document 1, it is required to further improve the combustion efficiency.

[0005] Therefore, an object of the present disclosure is to provide a reforming unit and a fuel cell device that improve the combustion efficiency as compared with the case where the configuration of the present disclosure is not used.

Means for Solving the Problems

[0006] The reforming unit according to the first aspect is a combustion section that burns fuel off-gas from a fuel cell within a space defined at least by a first bottom wall located on the first direction side and a first side wall erected along an edge of the first bottom wall; a reforming section that reforms raw fuel to supply fuel gas to the fuel cell within a space defined at least by the first bottom wall, the first side wall, a second bottom wall spaced apart from the first bottom wall to cover the first bottom wall, and a second side wall spaced apart from the first side wall to surround the first side wall; The system includes a first outlet pipe provided on the first direction side of the combustion section for discharging combustion exhaust gas generated in the combustion section from the combustion section.

[0007] From a second perspective, fuel cell devices are: A reforming unit comprising: a combustion section for burning fuel off-gas from a fuel cell in a space at least defined by a first bottom wall located on the first direction side and a first side wall erected along the edge of the first bottom wall; a reforming section for reforming raw fuel and supplying fuel gas to the fuel cell in a space at least defined by the first bottom wall, the first side wall, a second bottom wall covering the first bottom wall at a distance from the first bottom wall, and a second side wall surrounding the first side wall at a distance from the first side wall; and a first outlet pipe provided on the first direction side of the combustion section for discharging combustion exhaust gas generated in the combustion section from the combustion section; The reforming unit comprises the fuel cell, which is arranged perpendicular to the first direction.

[0008] From a third perspective, fuel cell devices are: A combustion section for burning fuel off-gas from a fuel cell in a space at least defined by a first bottom wall located on the first direction side and a first side wall erected along the edge of the first bottom wall; a reforming section for reforming raw fuel and supplying fuel gas to the fuel cell in a space at least defined by the first bottom wall, the first side wall, a second bottom wall covering the first bottom wall at a distance from the first bottom wall, and a second side wall surrounding the first side wall at a distance from the first side wall; and provided on the first direction side of the combustion section, A reforming unit having: a first outlet pipe for discharging combustion exhaust gas generated in the combustion section from the combustion section; a combustion exhaust gas passage having a first exhaust gas passage located circumferentially outside the second side wall, communicating with the first outlet pipe, and through which the combustion exhaust gas discharged from the combustion section flows; and an air passage located circumferentially outside the second side wall, adjacent to the first exhaust gas passage, and having a first air passage for causing air to flow in the opposite direction to the direction in which the combustion exhaust gas flows in the first exhaust gas passage; The reforming unit comprises the fuel cell, which is arranged perpendicular to the first direction. [Effects of the Invention]

[0009] According to the reforming unit and fuel cell device described above, the combustion efficiency is improved. [Brief explanation of the drawing]

[0010] [Figure 1] This diagram shows the gas supply situation between components of a fuel cell system including a reforming unit according to one embodiment. [Figure 2] This is a conceptual diagram illustrating the internal structure of the modification unit shown in Figure 1. [Figure 3] Figure 1 is a perspective view of the external appearance of the modification unit. [Figure 4] Figure 2 is an exploded perspective view of the combustion section. [Figure 5] Figure 2 is an exploded perspective view of the modified section. [Figure 6] Figure 2 is an exploded perspective view showing the combustion exhaust gas flow path. [Figure 7] This is a diagram illustrating that the first exhaust gas flow path is a meandering route. [Figure 8] Figure 2 is an exploded perspective view showing the airflow path. [Figure 9] This is an unfolded diagram illustrating that the airflow path in the area between the third and fourth side walls of Figure 8 is a meandering path. [Figure 10] Figure 2 is an exploded perspective view showing the evaporation section and other components of the reforming unit. [Figure 11] This is a partial cross-sectional view illustrating a configuration in which the evaporation section, combustion section, and reforming section are separated by a single wall. [Figure 12] Figure 1 is a diagram showing the arrangement of the reforming unit and the fuel cell in the fuel cell system. [Figure 13] This is a diagram showing an alternative arrangement of the reforming unit and fuel cell in the fuel cell system shown in Figure 1. [Figure 14] FIG. 12 is a diagram showing a modified example of the reforming unit in the fuel cell device. [Figure 15] FIG. 12 is a diagram showing another modified example of the reforming unit in the fuel cell device. [Figure 16] FIG. 12 is an arrangement diagram showing a configuration in which further components are added to the fuel cell device.

Embodiments for Carrying out the Invention

[0011] Hereinafter, embodiments of the reforming unit to which the present disclosure is applied will be described with reference to the drawings.

[0012] As shown in FIG. 1, a fuel cell device 11 including a reforming unit \ (10) according to an embodiment of the present disclosure includes a fuel cell \ (12) and a reforming unit \ (10).

[0013] The fuel cell \ (12) may generate electricity by an electrochemical reaction using the fuel gas and air supplied from the reforming unit \ (10). The fuel cell \ (12) may be a cell stack in which fuel cells are stacked. The fuel cell \ (12) may include a plurality of cell stacks. The fuel cell \ (12) may supply the fuel offgas after the electrochemical reaction to the reforming unit \ (10). The fuel offgas includes unreacted fuel gas and oxygen-containing gas in the fuel cell \ (12).

[0014] The reforming unit \ (10) may be supplied with the raw fuel gas and water. The reforming unit \ (10) may reform the raw fuel gas using water to generate fuel gas. The reforming unit \ (10) may heat air. The fuel cell \ (12) may be supplied with the fuel gas and the heated air. The reforming unit \ (10) may burn the fuel offgas. The reforming unit \ (10) may mix a part of the fuel offgas, for example, with the raw fuel gas. The reforming unit \ (10) may use the combustion heat of the fuel offgas for heating for reforming the above-described raw fuel gas and heating air. The reforming unit \ (10) may discharge the combustion exhaust gas obtained by burning the fuel offgas.

[0015] As shown in Figure 2, the reforming unit 10 comprises a combustion section 13, a first outlet pipe 14, and a reforming section 15. The reforming unit 10 may further comprise a combustion exhaust gas passage 16, an air passage 17, and an evaporation section 18. As shown in Figure 3, the reforming unit 10 may be cylindrical overall.

[0016] As shown in Figure 4, the combustion section 13 has a combustion space defined by at least a first upper bottom wall (first bottom wall) 19 and a first side wall 20. The combustion space may be further defined by a first lower bottom wall 21. The combustion section 13 burns the fuel off-gas discharged from the fuel cell 12 within the combustion space.

[0017] The first upper bottom wall 19 is located in the combustion section 13 on the side of the first direction. The first direction is the direction that is defined to be oriented vertically upward in the installation of the fuel cell device 11, including the reforming unit 10. The first upper bottom wall 19 may be disc-shaped.

[0018] The first side wall 20 is erected along the edge of the first upper bottom wall 19. Therefore, the first side wall 20 may be cylindrical. For example, in a configuration where the first upper bottom wall 19 is disc-shaped, the first side wall 20 may be cylindrical. The first side wall 20 may have an insertion hole 24 through which the first inlet pipe 23, which will be described later, is inserted. The first inlet pipe 23 may be in close contact with the insertion hole 24 around its entire circumference.

[0019] The first lower bottom wall 21 may be provided at the end of the first side wall 20 on the side opposite to the first direction. The first lower bottom wall 21 may have the same shape as the first upper bottom wall 19.

[0020] A burner 22 facing into the combustion space may be provided in the first lower bottom wall 21. The burner 22 may burn unreacted fuel gas contained in the fuel off-gas with an oxygen-containing gas. The fuel off-gas may be supplied to the burner 22 via a first inlet pipe 23 extending in a direction perpendicular to the first direction.

[0021] For convenience, this disclosure describes a configuration in which both the fuel off-gas, in other words, the unreacted fuel gas and the unreacted oxygen-containing gas in the fuel cell 12, are supplied to the burner 22 via a single first inlet pipe 23. However, the unreacted fuel gas and the unreacted oxygen-containing gas may be supplied to the burner 22 via separate piping.

[0022] In this disclosure, a configuration is described in which a first inlet pipe 23 extending in a direction perpendicular to the first direction is applied; however, the first inlet pipe 23 may be configured to extend in the opposite direction to the first direction.

[0023] The burner 22 may have an ignition heater. Alternatively, an ignition heater may be provided separately in the combustion space from the burner 22. The ignition heater may be inserted into the combustion space, for example, from the first upper bottom wall 19 or the first side wall 20.

[0024] The first upper bottom wall 19, the first side wall 20, and the first lower bottom wall 21 may be formed from a material with high thermal conductivity, such as metal.

[0025] The first outlet pipe 14 is provided on the first direction side of the combustion section 13. The first direction side may mean the first direction side of the combustion region in the combustion section 13. The combustion region is the region in the combustion section 13 where combustion of off-gas is expected to occur. The first outlet pipe 14 may be provided, for example, on the first upper bottom wall 19. Alternatively, the first outlet pipe 14 may be provided near the first direction end of the first side wall 20. The first outlet pipe 14 discharges the combustion exhaust gas generated in the combustion section 13, specifically the combustion exhaust gas generated by combustion in the burner 22, from the combustion section 13. Therefore, the internal space of the first outlet pipe 14 and the combustion space of the combustion section 13 may be in communication.

[0026] As shown in Figure 5, the modified section 15 has a modified space defined by at least a first upper bottom wall 19, a first side wall 20, a second upper bottom wall (second bottom wall) 25, and a second side wall 26. The modified space may be further defined by a second lower bottom wall 27.

[0027] A reforming catalyst may be contained in at least a portion of the reforming space. The reforming unit 15 generates fuel gas by reforming the raw fuel using water vapor vaporized in the evaporation unit 18 (described later) within the reforming space. The reforming unit 15 supplies the fuel gas to the fuel cell 12.

[0028] The second upper base wall 25 is spaced apart from the first upper base wall 19 and covers the first upper base wall 19 from the first direction side. The wall surface of the second upper base wall 25 may be wider than that of the first upper base wall 19. The second upper base wall 25 may cover the entire first upper base wall 19 when viewed from the first direction. The second upper base wall 25 may be disc-shaped.

[0029] In a configuration in which a first outflow pipe 14 is provided in a first upper bottom wall 19, a through hole 28 may be formed in the second upper bottom wall 25. The through hole 28 may be formed at the same position as the first outflow pipe 14 when viewed from the first direction. The inner diameter of the through hole 28 may be the same as the outer diameter of the first outflow pipe 14. The first outflow pipe 14 may reach the through hole 28. The first outflow pipe 14 may be in close contact with the through hole 28 around its entire circumference. In a configuration in which a first outflow pipe 14 is provided in a first side wall 20, the through hole 28 may be formed in the second side wall 26 instead of the second upper bottom wall 19.

[0030] The second side wall 26 surrounds the first side wall 20, with a gap between them. The second side wall 26 may be erected along the edge of the second upper base wall 25. Therefore, the second side wall 26 may be cylindrical. For example, in a configuration where the second upper base wall 25 is disc-shaped, the second side wall 26 may be cylindrical.

[0031] A second outflow pipe 30 may be provided near the end of the second side wall 26 on the first direction side. The second outflow pipe 30 may extend in a direction perpendicular to the first direction. A first inflow pipe 23 may be inserted through the second side wall 26 near the end on the opposite side of the first direction.

[0032] The second lower bottom wall 27 may be provided at the end of the second side wall 26 on the side opposite to the first direction. The second lower bottom wall 27 may be in close contact with the first lower bottom wall 21. Alternatively, the second lower bottom wall 27 may also serve as the first lower bottom wall 21. In other words, a combustion space may be formed by bringing the end face of the first side wall 20 on the side opposite to the first direction into close contact with the second lower bottom wall 27, without providing the first lower bottom wall 21.

[0033] The second lower bottom wall 27 may have the same shape as the second upper bottom wall 25. A through hole 29 may be formed in the second lower bottom wall 27. The through hole 29 may be located away from the combustion section 13 when viewed from the first direction. In a configuration in which the second exhaust gas flow path, described later, is located between the reforming section 15 and the evaporation section 18, a second inlet pipe 31 extending in the opposite direction to the first direction may be provided in the second lower bottom wall 27. The inner circumferential surface of the second inlet pipe 31 may be continuous with the inner circumferential surface of the through hole 29 all around.

[0034] The second upper bottom wall 25, the second side wall 26, and the second lower bottom wall 27 may be formed from a material with high thermal conductivity, such as metal.

[0035] In the configuration described above, steam and raw fuel gas flowing in from the through-hole 29 may flow into the reforming section 15. The fuel gas generated by the reforming of the raw fuel gas by the steam reforming reaction may be discharged along with excess steam through the second outlet pipe 30.

[0036] The combustion exhaust gas passage 16 may be connected to the first outlet pipe 14. Therefore, the combustion exhaust gas passage 16 may be connected to the combustion space via the first outlet pipe 14. Furthermore, the combustion exhaust gas passage 16 may be connected to a third outlet pipe, which will be described later. Combustion exhaust gas discharged from the combustion section 13 may flow through the combustion exhaust gas passage 16.

[0037] The combustion exhaust gas passage 16 may have at least a first exhaust gas passage. The combustion exhaust gas passage 16 may further have at least one of a second exhaust gas passage and a third exhaust gas passage. The first exhaust gas passage may communicate with the second exhaust gas passage and the third exhaust gas passage.

[0038] The first exhaust gas passage may be located circumferentially outside the second side wall 26. The second exhaust gas passage may be located on the opposite side of the first direction from both the combustion section 13 and the reforming section 15. The second exhaust gas passage may extend along the wall surfaces of the combustion section 13 and the reforming section 15 on the opposite side of the first direction. In other words, the second exhaust gas passage may extend along the first lower bottom wall 21 and the second lower bottom wall 27. The third exhaust gas passage may be located on the first side from the reforming section 15.

[0039] In a configuration where the first outlet pipe 14 is provided in the first upper bottom wall 19, the combustion exhaust gas passage 16 may have a third exhaust gas passage. In a configuration where the first outlet pipe 14 is provided in the first side wall 20 and a through hole 28 is formed in the second side wall 26, the third exhaust gas passage does not need to be present.

[0040] The first exhaust gas passage may be located inside or outside the air passage 17. In this embodiment, a configuration in which a portion of the first exhaust gas passage is located inside the air passage 17 is described.

[0041] As shown in Figure 6, the first exhaust gas passage may be defined by the second side wall 26 and the third side wall 32. The second exhaust gas passage may be defined by at least the third lower bottom wall 33. In a configuration where the second exhaust gas passage is located between the reforming section 15 and the evaporation section 18 (described later), the second exhaust gas passage may be further defined by the second lower bottom wall 27. In a configuration where the second exhaust gas passage is located on the opposite side of the first direction from the evaporation section 18, the second exhaust gas passage may be further defined by the side wall of the evaporation section 18 on the opposite side of the first direction. The third exhaust gas passage may be defined by the second upper bottom wall 25 and the third upper bottom wall 34.

[0042] The third side wall 32 may be spaced apart from the second side wall 26 and surround the second side wall 26. The third side wall 32 may be erected along the edge of the third upper bottom wall 34. Therefore, the third side wall 32 may be cylindrical. For example, in a configuration where the third upper bottom wall 34 is disc-shaped, the third side wall 32 may be cylindrical.

[0043] As shown in Figure 7, a meandering path may be formed by separating the space defined by the first exhaust gas flow path, or in other words, the second side wall 26 and the third side wall 32, with the inner wall iw1.

[0044] A first inlet pipe 23 may be inserted through the third side wall 32 near the end on the side opposite to the first direction. A second outlet pipe 30 may also be inserted through the third side wall 32 near the end on the side facing the first direction. In a configuration where the combustion exhaust gas passage 16 does not have a second exhaust gas passage, a third outlet pipe 35 may be provided in the third side wall 32.

[0045] The third lower bottom wall 33 may be provided at the end of the third side wall 32 on the side opposite to the first direction. The third lower bottom wall 33 may cover the second lower bottom wall 27. The wall surface of the third lower bottom wall 33 may be wider than the second upper bottom wall 25. The third upper bottom wall 34 may cover the entire second upper bottom wall 25 when viewed from the first direction. The third upper bottom wall 34 may be disc-shaped.

[0046] The third lower bottom wall 33 may be located at a distance from the second lower bottom wall 27 in a configuration in which the combustion exhaust gas passage 16 has a second exhaust gas passage between the reforming section 15 and the evaporation section 18. In a configuration in which the combustion exhaust gas passage 16 does not have a second exhaust gas passage, or in a configuration in which the second exhaust gas passage is located on the opposite side of the first direction from the evaporation section 18, the second lower bottom wall 27 may be in close contact with the third lower bottom wall 33. Alternatively, the third lower bottom wall 33 may also serve as the second lower bottom wall 27. In other words, a reforming space may be formed by bringing the end face of the second side wall 26 on the opposite side of the first direction into close contact with the third lower bottom wall 33 without providing a second lower bottom wall 27.

[0047] In a configuration in which the combustion exhaust gas passage 16 has a second exhaust gas passage, a third outlet pipe 35 extending in the opposite direction to the first direction may be provided in the third lower bottom wall 33. A through hole 36 may be formed in the third lower bottom wall 33 at the same position as the through hole 29 of the reforming section 15 when viewed from the first direction. In a configuration in which a second inlet pipe 31 is provided in the second lower bottom wall 27, the second inlet pipe 31 may reach the through hole 36. The second inlet pipe 31 may be in close contact with the through hole 36 around its entire circumference.

[0048] The third upper bottom wall 34 may cover the second upper bottom wall 25. The third upper bottom wall 34 may have the same shape as the third lower bottom wall 33. In a configuration where the combustion exhaust gas passage 16 has a third exhaust gas passage, the third upper bottom wall 34 may be located at a distance from the second upper bottom wall 25. In a configuration where the combustion exhaust gas passage 16 does not have a third exhaust gas passage, the second upper bottom wall 25 may be in close contact with the third upper bottom wall 34. Alternatively, the third upper bottom wall 34 may also serve as the second upper bottom wall 25. In other words, the combustion exhaust gas passage 16 may be defined by bringing the end face of the second side wall 26 on the first direction side into close contact with the third upper bottom wall 34 without providing a second upper bottom wall 25.

[0049] The third side wall 32, the third lower bottom wall 33, and the third upper bottom wall 34 may be formed from a material with high thermal conductivity, such as metal.

[0050] With the configuration described above, combustion exhaust gas flows into the combustion exhaust gas flow path 16 via the first outlet pipe 14. The combustion exhaust gas flowing into the combustion exhaust gas flow path 16 may be discharged from the combustion exhaust gas flow path 16 via the third outlet pipe 35.

[0051] The air passage 17 may be connected to a fourth inlet pipe and a fourth outlet pipe, which will be described later. The air passage 17 may allow air to flow from the fourth inlet pipe to the fourth outlet pipe.

[0052] The air passage 17 may have at least a first air passage. The air passage 17 may further have a second air passage. The first air passage may communicate with the second air passage.

[0053] The first air passage may be located circumferentially outside the second side wall 26. The first air passage may be adjacent to the first exhaust gas passage. The second air passage may be located on the first direction side from the reforming section 15. The first air passage may cause air to flow in the opposite direction to the direction in which the combustion exhaust gas flows in the first exhaust gas passage.

[0054] The first air passage may be located outside or inside the combustion exhaust gas passage 16. In this embodiment, as described above, a configuration in which a portion of the first air passage is located outside the combustion exhaust gas passage 16 is described.

[0055] As shown in Figure 8, the first air passage may be defined by at least the third side wall 32 and the fourth side wall 37. The second air passage may be defined by the third upper bottom wall 34 and the fourth upper bottom wall 38. The entire surface of the third lower bottom wall 33 on the opposite side of the first direction and the end face of the fourth side wall 37 on the opposite side of the first direction may be covered by the fourth lower bottom wall 39.

[0056] The fourth side wall 37 may surround the third side wall 32 at a distance from it. The fourth side wall 37 may be erected along the edge of the fourth upper bottom wall 38. Therefore, the fourth side wall 37 may be cylindrical. For example, in a configuration where the fourth upper bottom wall 38 is disc-shaped, the fourth side wall 37 may be cylindrical.

[0057] As shown in Figure 9, a meandering path may be formed by separating the space defined by the first air passage, or in other words, the third side wall 32 and the fourth side wall 37, with the inner wall iw2. The meandering first air passage may have approximately the same shape as the meandering first exhaust gas passage when viewed from a direction perpendicular to the fourth side wall 37.

[0058] As shown in Figure 8, a fourth inlet pipe 40 may be provided in the fourth side wall 37. The fourth inlet pipe 40 may extend in a direction perpendicular to the first direction. The fourth inlet pipe 40 may be provided near the end on the opposite side of the first direction. Air may be supplied to the air passage 17 from the fourth inlet pipe 40.

[0059] A first inlet pipe 23 may be inserted through the fourth side wall 37 near the end on the side opposite to the first direction. A second outlet pipe 30 may also be inserted through the fourth side wall 37 near the end on the side facing the first direction.

[0060] The wall surface of the fourth upper bottom wall 38 may be wider than that of the third upper bottom wall 34. The fourth upper bottom wall 38 may cover the entire third upper bottom wall 34 when viewed from the first direction. The fourth upper bottom wall 38 may be disc-shaped. In a configuration where the air passage 17 has a second air passage, the fourth upper bottom wall 38 may be positioned at a distance from the third upper bottom wall 34. In a configuration where the air passage 17 does not have a second air passage, the fourth upper bottom wall 38 may be in close contact with the third upper bottom wall 34. Alternatively, the fourth upper bottom wall 38 may also serve as the third upper bottom wall 34. In other words, the air passage 17 may be defined by bringing the end face of the third side wall 32 on the first direction side into close contact with the fourth upper bottom wall 38, without providing a third upper bottom wall 34.

[0061] A fourth outflow pipe 41 may be provided in the fourth upper bottom wall 38. The fourth outflow pipe 41 may extend in the first direction. The fourth outflow pipe 41 may be positioned so as to overlap at least a portion of the first outflow pipe 14 when viewed in the axial direction of the first outflow pipe 14, in other words, when viewed from the first direction.

[0062] The fourth lower bottom wall 39 may have the same shape as the fourth upper bottom wall 38. The third lower bottom wall 33 and the fourth side wall 37 may be in close contact with the fourth lower bottom wall 39. Alternatively, the fourth lower bottom wall 39 may also serve as the third lower bottom wall 38. In other words, the air passage 17 may be defined by bringing the end face of the third side wall 32 on the opposite side of the first direction into close contact with the fourth lower bottom wall 39, without providing the third lower bottom wall 38.

[0063] A through-hole 42 may be formed in the fourth lower bottom wall 39 at the same position as the through-hole 36 of the third lower bottom wall 33 when viewed from the first direction. The inner circumferential surface of the through-hole 42 in the fourth lower bottom wall 39 may be continuous with the inner circumferential surface of the through-hole 36 of the third lower bottom wall 33 all around. A through-hole 43 may be formed in the fourth lower bottom wall 41 for inserting the third outflow pipe 35. The third outflow pipe 35 may be in close contact with the through-hole 43 all around.

[0064] With the above configuration, the air passage 17 can allow air flowing in from the fourth inlet pipe 40 to the fourth outlet pipe 41. The air flowing out from the fourth outlet pipe 41 is supplied to the fuel cell 12 as described above. Furthermore, with the above configuration, the air passage 17 exchanges heat with the combustion exhaust gas flowing through the combustion exhaust gas passage 16.

[0065] The fourth side wall 37, the fourth upper bottom wall 38, and the third lower bottom wall 39 may be formed from a material with high thermal conductivity, such as metal.

[0066] As shown in Figure 2, the evaporation section 18 may vaporize the incoming water. The evaporation section 18 may supply the vaporized water to the reforming section 15. As shown in Figure 10, an internal space is may be formed in the evaporation section 18. The evaporation section 18 may obtain the heat necessary to vaporize the water flowing into the internal space is from the combustion section 13 and the combustion exhaust gas flow path 16.

[0067] The evaporation section 18 may be positioned on the opposite side of the first direction from the combustion section 13, so as to be able to transfer heat from the combustion section 13. Specifically, being positioned so as to be able to transfer heat means that it may be in direct or indirect contact with the combustion section 13 via a heat-conducting member, or it may be positioned in close proximity to the combustion section 13. At least a portion of the evaporation section 18 may be positioned so as to overlap the reforming section 15 when viewed from the first direction. This portion may be positioned on the opposite side of the first direction from the reforming section 15.

[0068] For example, the evaporation section 18 may be positioned to contact the combustion section 13 without being separated by a second exhaust gas passage. Alternatively, the evaporation section 18 may be positioned to contact the reforming section 15 without being separated by a second exhaust gas passage. Specifically, in a configuration where the combustion exhaust gas passage 16 does not have a second exhaust gas passage, the evaporation section 18 may be positioned to contact both the combustion section 13 and the reforming section 15. Or, the second exhaust gas passage may be positioned on the opposite side of the first direction from the evaporation section 18.

[0069] In a configuration where the evaporation section 18 faces the combustion section 13 and the reforming section 15 without a second exhaust gas passage in between, an insulating material may be placed between the evaporation section 18 and the reforming section 15. However, an insulating material does not need to be placed between the evaporation section 18 and the combustion section 13. With this configuration, the evaporation section 18 can be heated by the heat of the combustion section 13 while preventing the heat required for the reforming section 15 from being taken away by the evaporation section 18.

[0070] In a configuration in which the evaporation section 18 is in contact with the combustion section 13 and the reforming section 15, as shown in Figure 11, the wall 48 separating the evaporation section 18 from the combustion section 13 and the reforming section 15 may be a single wall. In other words, a single wall 48 may function as the wall on the first direction side of the evaporation section 18, as well as the first lower bottom wall 21 and the second lower bottom wall 27. In this configuration, through holes 49 may be formed in the wall 48 separating the reforming section 15 and the evaporation section 18. Water vaporized in the evaporation section 18 may be supplied to the reforming section 15 through these through holes 49.

[0071] Alternatively, for example, the evaporation section 18 may be located together with the combustion section 13 and the reforming section 15, straddling a second exhaust gas flow path in the first direction. The evaporation section 18 may be in contact with the second exhaust gas flow path. In this configuration as well, heat from the combustion section 13 is conducted to the evaporation section 18 via the second lower bottom wall 27 and the third lower bottom wall 33 that define the second exhaust gas flow path, and the combustion exhaust gas flowing within the second exhaust gas flow path.

[0072] The evaporation section 18 may have the same shape as the fourth lower bottom wall 39 when viewed from the first direction. The evaporation section 18 may have a through hole 43 that communicates with the internal space is at the same position as the through hole 42 of the fourth lower bottom wall 39 when viewed from the first direction. The inner circumferential surface of the through hole 43 of the evaporation section 18 may be continuous with the inner circumferential surface of the through hole 42 of the fourth lower bottom wall 39 all around.

[0073] The evaporation section 18 may be provided with a fifth inlet pipe 44 that communicates with the internal space is. The fifth inlet pipe 44 may be provided so as to extend in the opposite direction to the first direction or in a direction perpendicular to the first direction. The fifth inlet pipe 44 may be located away from the through hole 43. Located away from the first direction means, for example, that the fifth inlet pipe 44 and the through hole 43 may be located in the opposite direction to the center of the internal space is as viewed from the first direction. The fifth inlet pipe 44 may also be located near the third outlet pipe 35.

[0074] The evaporation section 18 may have an insertion hole 45 formed along the first direction through which a third outlet pipe 35 is inserted. The third outlet pipe 35 may be in close contact with the insertion hole 45 around its entire circumference.

[0075] As shown in Figure 11, in the fuel cell device 11, the fuel cell 12 may be positioned close to the reforming unit 10 in a direction perpendicular to the first direction. Alternatively, as shown in Figure 12, in the fuel cell device 11, the fuel cell 12 may be positioned in the opposite direction to the first direction from the reforming unit 10. In the configuration where the fuel cell 12 is positioned in the opposite direction to the first direction, it is preferable that the first inlet pipe 23 extends in that opposite direction from the surface of the reforming unit 10 on the side opposite to the first direction. In the fuel cell device 11, the reforming unit 10 and the fuel cell 12 may be aligned in a direction perpendicular to the stacking direction of the cell stack of the fuel cell 12.

[0076] As shown in Figure 13, in a configuration in which the fuel cell 12 is positioned perpendicular to the first direction from the reforming unit 10, the supply and discharge of gas in the fuel cell 12 may be performed from the surface on the first direction side and the surface on the opposite side of the first direction. The gas is fuel gas, heated air, or fuel off-gas. Alternatively, as shown in Figure 14, in a configuration in which the fuel cell 12 is positioned perpendicular to the first direction from the reforming unit 10, the supply and discharge of gas in the fuel cell 12 may be performed from the surface on the side perpendicular to the first direction. In the above configuration, the fourth outlet pipe 41 for discharging heated air from the reforming unit 10 may be provided on the surface perpendicular to the first direction, in other words, on the fourth side wall 37.

[0077] As shown in Figure 15, the fuel cell device 11 may include a housing container 46 and a condenser 47. The housing container 46 may house the reforming unit 10 and the fuel cell 12. The condenser 47 may be located on the opposite side of the first direction from the reforming unit 10. When viewed from the first direction, the condenser 47 may be positioned overlapping with a third outlet pipe 35 that extends along the first direction. The condenser 47 may use the combustion exhaust gas discharged from the reforming unit 10 to exchange heat with a heat transfer medium. The heat transfer medium is, for example, water. In such a configuration, the piping that sends the combustion exhaust gas from the reforming unit 10 to the heat exchanger 62 can be shortened, thus reducing heat loss. Furthermore, such a configuration allows the fuel cell device 11 to be miniaturized.

[0078] The reforming unit 10 of this embodiment, having the configuration described above, comprises: a combustion section 13 that burns fuel off-gas from the fuel cell 12 in a space defined at least by a first bottom wall 19 located on the first direction side and a first side wall 20 erected along the edge of the first bottom wall 19; a reforming section 15 that reforms raw fuel and supplies fuel gas to the fuel cell 12 in a space defined at least by the first bottom wall 19, the first side wall 20, a second bottom wall 25 that covers the first bottom wall 19 at a distance from the first bottom wall 19 and a second side wall 26 that surrounds the first side wall 20 at a distance from the first side wall 20; and a first outlet pipe 14 provided on the first direction side of the combustion section 13 and for discharging combustion exhaust gas generated in the combustion section 13 from the combustion section 13. With this configuration, the reforming unit 10 suppresses the accumulation of high-temperature combustion off-gas in the combustion section 13 compared to a configuration in which the outlet is located on the opposite side of the first direction, thereby improving combustion efficiency. Therefore, the reforming unit 10 improves reforming efficiency.

[0079] Furthermore, the reforming unit 10 includes a combustion exhaust gas passage 16 located circumferentially outside the second side wall 26, communicating with the first outlet pipe 14, through which combustion exhaust gas discharged from the combustion section 13 flows, and an air passage 17 located adjacent to the first exhaust gas passage circumferentially outside the second side wall 26, and having a first air passage that causes air to flow in the opposite direction to the direction in which the combustion exhaust gas flows in the first exhaust gas passage. With this configuration, the reforming unit 10 can effectively heat the air because there is a portion where the combustion exhaust gas flows in opposition to the air. Therefore, the reforming unit 10 improves power generation efficiency. In addition, with the above configuration, the reforming unit 10 can be miniaturized while effectively heating the air.

[0080] Furthermore, in the reforming unit 10, the first outlet pipe 14 and the fourth outlet pipe 41 of the air passage 17 are positioned so that at least a portion of them overlap when viewed from the axial direction of the first outlet pipe 14. With this configuration, the reforming unit 10 causes the air in the air passage to flow toward the point where the combustion exhaust gas flows into the combustion exhaust gas passage 16. Therefore, in the reforming unit 10, the combustion exhaust gas becomes a counterflow against the air at that point, so the air can be heated effectively. Consequently, the reforming unit 10 improves the power generation efficiency.

[0081] Furthermore, the reforming unit 10 is positioned on the opposite side of the first direction from the combustion section 13, capable of transferring heat from the combustion section 13, and includes an evaporation section 18 that vaporizes water and supplies it to the reforming section 15. With this configuration, the reforming unit 10 can use the heat generated in the combustion section 13 to vaporize water.

[0082] Furthermore, in the reforming unit 10, at least a portion of the evaporation section 18 is positioned on the opposite side of the reforming section 15 from the first direction, so as viewed from the first direction, it overlaps with the reforming section 15. With this configuration, the reforming unit 10 causes the raw fuel gas to flow from the evaporation section 18 towards the reforming section 15 in the first direction, thereby promoting mixing by increasing the flow velocity and generating turbulence as the raw fuel gas and water vapor rise due to heat. Therefore, the reforming unit 10 can uniformly mix the raw fuel gas and water vapor. Also, with this configuration, the reforming unit 10 can uniformly transfer the heat generated in the combustion section 13 to the raw fuel gas and water vapor. Therefore, the reforming unit 10 improves the reforming efficiency.

[0083] Furthermore, in the reforming unit 10, the reforming section 15 and the evaporation section 18 are separated by a wall with through-holes formed in part of it, and the water vaporized in the evaporation section 18 is supplied to the reforming section 15 through these through-holes. With this configuration, the reforming unit 10 can eliminate the need for piping to flow water vapor from the reforming section 15 to the evaporation section 18, thereby reducing pressure loss and making the overall unit more compact.

[0084] Furthermore, in the reforming unit 10, the second exhaust gas flow path included in the combustion exhaust gas flow path 16 is located on the opposite side of the first direction from both the combustion section 13 and the reforming section 15, extends along the walls on the opposite side of the first direction from both the combustion section 13 and the reforming section 15, and contacts the evaporation section 18. With this configuration, the reforming unit 10 can heat the evaporation section 18 using the heat of the combustion exhaust gas as well.

[0085] Furthermore, in the reforming unit 10, the second exhaust gas passage is located between the combustion section 13 and the reforming section 15 and the evaporation section 18. With this configuration, the reforming unit 10 can suppress sudden boiling in the evaporation section 18 caused by the transfer of high-temperature heat generated in the combustion section 13 to the evaporation section 18.

[0086] Furthermore, in the reforming unit 10, the second exhaust gas flow path is located on the opposite side of the direction from the evaporation section 18 to the first direction. With this configuration, the reforming unit 10 can heat the evaporation section 18 with both the heat generated in the combustion section 13 and the combustion exhaust gas flowing through the combustion exhaust gas flow path. Therefore, the reforming unit 10 can promote the vaporization of water in the evaporation section 18. As a result, the reforming unit 10 can improve the reforming efficiency.

[0087] Furthermore, the fuel cell device 11 of this embodiment comprises a reforming unit 10 and a fuel cell 12 arranged perpendicular to the first direction from the reforming unit 10. With this configuration, the fuel cell device 11 can be adjacent to the fuel cell 12 with the heat-generating combustion section 13 interposed between it and the heat-absorbing reforming section 15, thus reducing the thermal impact on the fuel cell 12 while bringing the reforming unit 10 and the fuel cell 12 closer together. Therefore, the fuel cell device 11 can be made smaller overall.

[0088] Furthermore, the fuel cell device 11 of this embodiment comprises a reforming unit 10 and a fuel cell 12 arranged in the opposite direction from the reforming unit 10 to the first direction. With this configuration, the fuel cell device 11 can be adjacent to the fuel cell 12 with a heat-generating combustion section 13 interposed between it and an evaporation section 18 that causes heat absorption. This allows the reforming unit 10 and the fuel cell 12 to be brought closer together while reducing the thermal impact on the fuel cell 12. Therefore, the fuel cell device 11 can be made smaller overall.

[0089] In one embodiment, (1) the modification unit is A combustion section for burning fuel off-gas from a fuel cell is provided within a space defined at least by a first bottom wall located on the first directional side and a first side wall erected along the edge of the first bottom wall. A reforming unit that reforms raw fuel and supplies fuel gas to the fuel cell within a space defined by at least the first bottom wall, the first side wall, the second bottom wall that covers the first bottom wall at a distance from the first bottom wall, and the second side wall that surrounds the first side wall at a distance from the first side wall, The system includes a first outlet pipe provided on the first direction side of the combustion section for discharging combustion exhaust gas generated in the combustion section from the combustion section.

[0090] (2) The modification unit in (1) above is A first exhaust gas passage is located circumferentially outside the second side wall, communicates with the first outlet pipe, and is a combustion exhaust gas passage through which the combustion exhaust gas discharged from the combustion section flows, The invention further comprises an air passage located outside the second side wall, adjacent to the first exhaust gas passage along the circumferential direction, and having a first air passage that causes air to flow in the opposite direction to the direction in which the combustion exhaust gas flows in the first exhaust gas passage.

[0091] (3) In the modification unit described in (2) above, The first outlet pipe and the fourth outlet pipe of the air passage are positioned so that at least a portion of them overlap when viewed from the axial direction of the first outlet pipe.

[0092] (4) The modification unit described in (2) or (3) above is The system further includes an evaporation section located on the opposite side of the first direction from the combustion section, capable of transferring heat from the combustion section, and which vaporizes water and supplies it to the reforming section.

[0093] (5) In the modification unit described in (4) above, At least a portion of the evaporation section is located on the side opposite to the first direction from the modifying section, such that it overlaps with the modifying section when viewed from the first direction.

[0094] (6) In the modification unit described in (5) above, The modification section and the evaporation section are separated by a wall body in which through holes are formed in part. Through the through-hole, the water vaporized in the evaporation section is supplied to the modification section.

[0095] (7) In any of the modification units described in (4) to (6) above, The second exhaust gas passage included in the combustion exhaust gas passage is located on the opposite side of the first direction from both the combustion section and the reforming section, extends along the wall surface on the opposite side of the first direction from both the combustion section and the reforming section, and is in contact with the evaporation section.

[0096] (8) In the modification unit described in (7) above, The second exhaust gas passage is located between the combustion section, the reforming section, and the evaporation section.

[0097] (9) In the modification unit described in (7) above, The second exhaust gas flow path is located on the opposite side from the evaporation section in the direction of the first flow path.

[0098] (10) Fuel cell devices are A modification unit of any of the above (1) to (9), The reforming unit comprises the fuel cell, which is arranged perpendicular to the first direction.

[0099] (11) Fuel cell devices are A modification unit of any of the above (4) to (9), The system comprises the fuel cell, which is positioned in the opposite direction to the first direction from the reforming unit.

[0100] The diagrams illustrating the embodiments described herein are schematic. Dimensions and proportions shown in the drawings do not necessarily correspond to actual dimensions.

[0101] While embodiments relating to this 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 this disclosure. Therefore, it should be noted that these modifications or alterations are within the scope of this disclosure. For example, the functions and other elements included in each component can be rearranged in a logically consistent manner, and multiple components can be combined into one or separated.

[0102] All of the constituent elements described in this disclosure, and / or all of the disclosed methods or steps of processing, can be combined in any combination except for any combination in which these features are mutually exclusive. Furthermore, each of the features described in this disclosure can be replaced by an alternative feature that works for the same, equivalent, or similar purpose, unless expressly disregarded. Thus, unless expressly disregarded, each of the disclosed features is merely an example of a comprehensive set of identical or equivalent features.

[0103] Furthermore, the embodiments relating to this disclosure are not limited to any specific configuration of the embodiments described above. The embodiments relating to this disclosure can be extended to all novel features or combinations thereof described herein, or all novel methods or processing steps or combinations thereof described herein.

[0104] In this disclosure, the designations "First," "Second," etc., are identifiers used to distinguish the configurations. Configurations distinguished by the designations "First," "Second," etc., in this disclosure may have their numbers swapped. For example, the first upper base wall may swap the identifiers "First" and "Second" with the second upper base wall. The swapping of identifiers occurs simultaneously. The configurations remain distinguishable even after the swapping of identifiers. Identifiers may be deleted. Configurations from which identifiers have been deleted are distinguished by codes. The designations "First," "Second," etc., in this disclosure should not be used alone to interpret the order of the configurations or to justify the existence of smaller numbered identifiers. [Explanation of Symbols]

[0105] 10 Modification Units 11 Fuel cell device 12 Fuel Cell 13 Combustion section 14. First outflow pipe 15 Modification section 16 Combustion exhaust gas flow path 17 Airflow channel 18 Evaporation section 19. First upper base wall 20 First side wall 21. First lower bottom wall 22 burners 23 First inlet pipe 24 Through hole 25. Second upper bottom wall 26 Second side wall 27. Second lower bottom wall 28 Through holes 29 Through hole 30 Second outflow pipe 31 Second inlet pipe 32 Third side wall 33 Third lower bottom wall 34. Third upper bottom wall 35 Third outflow pipe 36 Through holes 37. Fourth side wall 38. Fourth upper bottom wall 39. Fourth lower bottom wall 40. Fourth inlet pipe 41. Fourth outflow pipe 42 Through hole 43 Through hole 44. Fifth inlet pipe 45 Through hole 46 Storage containers 47 Condenser 48 Wall 49 Through hole is internal space iw1 inner wall iw2 inner wall

Claims

1. A combustion section for burning fuel off-gas from a fuel cell is provided within a space defined at least by a first bottom wall located on the first direction side and a first side wall erected along the edge of the first bottom wall. A reforming unit that reforms raw fuel and supplies fuel gas to the fuel cell within a space defined by at least the first bottom wall, the first side wall, the second bottom wall that covers the first bottom wall at a distance from the first bottom wall, and the second side wall that surrounds the first side wall at a distance from the first side wall, The combustion section is provided on the first direction side and includes a first outlet pipe that discharges combustion exhaust gas generated in the combustion section from the combustion section. Modification unit.

2. In the modification unit according to claim 1, A first exhaust gas passage is located circumferentially outside the second side wall, communicates with the first outlet pipe, and is a combustion exhaust gas passage through which the combustion exhaust gas discharged from the combustion section flows, The present invention further comprises an air passage located outside the second side wall, adjacent to the first exhaust gas passage along the circumferential direction, and having a first air passage that causes air to flow in the opposite direction to the direction in which the combustion exhaust gas flows in the first exhaust gas passage. Modification unit.

3. In the modification unit according to claim 2, The first outlet pipe and the fourth outlet pipe of the air passage are positioned so that at least a portion of them overlap when viewed from the axial direction of the first outlet pipe. Modification unit.

4. In the modification unit according to claim 2 or 3, The evaporator is located on the opposite side of the first direction from the combustion section, capable of transferring heat from the combustion section, and further comprises an evaporation section that vaporizes water and supplies it to the modification section. Modification unit.

5. In the modification unit according to claim 4, At least a portion of the evaporation section is located on the opposite side of the first direction from the modifying section, such that it overlaps with the modifying section when viewed from the first direction. Modification unit.

6. In the modification unit according to claim 5, The modification section and the evaporation section are separated by a wall body in which through holes are formed in part. Through the through-hole, the water vaporized in the evaporation section is supplied to the modification section. Modification unit.

7. In the modification unit according to claim 4, The second exhaust gas passage included in the combustion exhaust gas passage is located on the opposite side of the first direction from both the combustion section and the reforming section, extends along the wall surface on the opposite side of the first direction from both the combustion section and the reforming section, and is in contact with the evaporation section. Modification unit.

8. In the modification unit according to claim 7, The second exhaust gas passage is located between the combustion section and the reforming section and the evaporation section. Modification unit.

9. In the modification unit according to claim 7, The second exhaust gas flow path is located on the opposite side from the first direction from the evaporation section. Modification unit.

10. A modification unit according to any one of claims 1 to 3, The reforming unit comprises the fuel cell arranged in a direction perpendicular to the first direction. Fuel cell device.

11. The modification unit according to claim 4, The reforming unit comprises the fuel cell arranged in the opposite direction to the first direction. Fuel cell device.

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