Fuel cell modules and fuel cell systems

Abstract

This fuel battery module comprises a fuel battery cell stack, a terminal, a bus bar, a first junction, a second junction, and a container. The terminal outputs electric power generated by the fuel battery cell stack. The bus bar is connected to the terminal. The first junction 14 joins the terminal and the bus bar. The second junction joins the bus bar to an external conductor at a different position from the terminal. The linear expansion coefficient of the first junction is equal to or less than the linear expansion coefficient of the bus bar.

Description

Cross-reference to related applications

[0001] This application claims the priority of Japanese Patent Application No. 2023-13585 filed in Japan on January 31, 2023, and incorporates the entire disclosure of the prior application herein by reference.

Technical Field

[0002] This disclosure relates to a fuel cell module and a fuel cell device.

Background Art

[0003] A fuel cell module in which a fuel cell stack is housed in a container has been proposed. In the fuel cell module, electric power is output from the fuel cell stack through a conductive portion penetrating the container (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] A fuel cell module according to a first aspect includes a fuel cell stack having a plurality of fuel cells stacked on each other, terminals for outputting electric power generated by the fuel cell stack, a bus bar connected to the terminals, a first joint portion for joining the terminals and the bus bar, a second joint portion for joining an external conductor to the bus bar at a position different from the terminals, a container for housing the fuel cell stack, the terminals, and the first joint portion, and a part of the bus bar, the linear expansion coefficient of the first joint portion is less than or equal to the linear expansion coefficient of the bus bar the law of nature, The coefficient of thermal expansion of the first joint is smaller than the coefficient of thermal expansion of the second joint. .

[0006] From a second perspective, fuel cell devices are: The fuel cell stack comprises a plurality of fuel cell cells stacked on top of each other, a terminal for outputting power generated by the fuel cell stack, a busbar connected to the terminal, a first joint for joining the terminal and the busbar, a second joint for joining an external conductor to the busbar at a position different from the terminal, and a container for housing the fuel cell stack, the terminal, the first joint, and a part of the busbar, wherein the coefficient of linear expansion of the first joint is less than or equal to the coefficient of linear expansion of the busbar. Furthermore, the coefficient of thermal expansion of the first joint is smaller than the coefficient of thermal expansion of the second joint. The system comprises a fuel cell module and an auxiliary device that provides auxiliary functions for operating the fuel cell module. [Brief explanation of the drawing]

[0007] [Figure 1] This is a side view showing the interior of the fuel cell module according to this embodiment, along with a cut-out container. [Figure 2] Figure 1 is an enlarged perspective view showing the structure near the terminal. [Figure 3] Figure 1 is a perspective view of the inside of the fuel cell module container. [Figure 4] This is a top view of the fuel cell module shown in Figure 3, with the reformer removed and the supply pipe cut at the position of the plate section in the second direction. [Modes for carrying out the invention]

[0008] Embodiments of this disclosure will be described below with reference to the drawings. In the components shown in the following drawings, the same components are denoted by the same reference numerals.

[0009] As shown in Figure 1, a fuel cell module 10 according to one embodiment of the present disclosure comprises a fuel cell stack 11, terminals 12, busbars 13, a first joint 14, a second joint 15, and a container 16. The fuel cell module 10 may further comprise an insulating section 17, a manifold 18, a supply pipe 19, and a reformer 20.

[0010] The fuel cell stack 11 may have multiple fuel cell cells 21 stacked on top of each other. The fuel cell cells 21 may be solid oxide fuel cell cells. The fuel cell cells 21 generate electricity through an electrochemical reaction between the fuel produced by the reformer 20 and an oxidizing agent such as oxygen contained in the air. The multiple fuel cell cells 21 may be connected in series, parallel, or a combination thereof.

[0011] Terminal 12 is electrically connected to the fuel cell stack 11. Terminal 12 outputs the power generated by the fuel cell stack 11. Terminal 12 may have a portion that extends in a first direction away from the fuel cell stack 11. Specifically, this portion may extend parallel to the stacking direction of the fuel cell cells 21 in the fuel cell stack 11.

[0012] As shown in Figure 2, the terminal 12 may have a flat plate portion 22. This flat plate portion 22 may be located furthest from the fuel cell stack 11 on the terminal 12. This flat plate portion 22 may be perpendicular to a second direction. The second direction is perpendicular to the first direction and is assumed to be vertically downward when the fuel cell device, including the fuel cell module 10, is installed.

[0013] The terminal 12 may be made of a material that is heat-resistant, elastic, and conductive. The terminal 12 may be made of a material that contains a magnetic material. Specifically, the terminal 12 may be made of ferritic stainless steel.

[0014] The bus bar 13 is connected to the terminal 12. The bus bar 13 may be generally rod-shaped. The bus bar 13 may have a flat plate-shaped portion 23 and a columnar portion 24. The flat plate-shaped portion 23 may be joined so as to be parallel to the axial direction of the columnar portion 24.

[0015] The bus bar 13 may be connected to the terminal 12 at the flat plate-shaped portion 23. Specifically, the bus bar 13 may be connected to the terminal 12 such that the flat plate-shaped portion 22 of the terminal 12 and the flat plate-shaped portion 23 of the bus bar 13 are in surface contact. The bus bar 13 may be connected to the terminal 12 so as to extend in the first direction.

[0016] A male screw may be formed at the opposite end of the flat plate-shaped portion 23 of the bus bar 13.

[0017] The linear expansion coefficient of the bus bar 13 may be closer to the linear expansion coefficient of the terminal 12 than the linear expansion coefficient of the second joint portion 15. The fact that the linear expansion coefficients are close means that the difference in the linear expansion coefficients is small. The bus bar 13 may be made of a material containing a magnetic material. The material of the bus bar 13 may be the same as that of the terminal 12. The bus bar 13 may be made of ferritic stainless steel or austenitic stainless steel.

[0018] The first joint portion 14 joins the terminal 12 and the bus bar 13. The first joint portion 14 may join the terminal 12 and the bus bar 13 detachably. The first joint portion 14 may be joined by fastening so as to sandwich both the terminal 12 and the bus bar 13. To explain, the first joint portion 14 can maintain the coupled state of the terminal 12 and the bus bar 13, and the coupled state may be released by removing the first joint portion 14.

[0019] The first joint 14 may be, for example, a combination of a bolt and a nut. The first joint 14 being a bolt and a nut joins the terminal 12 and the bus bar 13 by fastening the nut in a state where the bolt is inserted through holes drilled in the flat plate-like portion 22 and the flat plate-like portion 23. The first joint 14 may be a mechanical joining tool other than a combination of a bolt and a nut, such as a clip, for example.

[0020] The linear expansion coefficient of the first joint 14 is equal to or less than the linear expansion coefficient of the bus bar 13. Further, the linear expansion coefficient of the first joint 14 may be smaller than the linear expansion coefficient of the second joint 15. The linear expansion coefficient of the first joint 14 may be closer to the linear expansion coefficient of the terminal 12 than the linear expansion coefficient of the second joint 15. The linear expansion coefficient of the first joint 14 may be closer to the linear expansion coefficient of the terminal 12 than the linear expansion coefficient of the bus bar 13.

[0021] The first joint 14 may be made of a material excellent in corrosion resistance, heat resistance, and workability. The first joint 14 may be made of a material containing a magnetic material. The material of the first joint 14 may be the same as or different from that of the terminal 12. Specifically, the first joint 14 may be made of a ferritic stainless steel.

[0022] The second joint 15 joins an external conductor to the bus bar 13 at a position different from the terminal 12. A position different from the terminal 12 is, for example, near the opposite end of the terminal 12 in the first direction. The external conductor is, for example, a conducting wire of a device into which the power output from the fuel cell stack 11 such as a power conversion device is input.

[0023] The second joint 15 may join the bus bar 13 and the external conductor in a detachable manner. To explain, the first joint 14 can maintain the coupled state of the bus bar 13 and the external conductor, and the coupled state may be released by removing the second joint 15.

[0024] The second joint 15 may be a nut in a configuration where a male thread is formed on the cylindrical portion 24. The second joint 15 may be a mechanical fastener other than a nut.

[0025] The second joint 15 may be made of a material with high heat resistance, corrosion resistance, and strength. The second joint 15 may be made of an oxidation-resistant metal. The coefficient of thermal expansion of the second joint 15 is different from that of the first joint 14. The coefficient of thermal expansion of the second joint 15 may be greater than that of the first joint 14. The second joint 15 may be made of austenitic stainless steel.

[0026] As shown in Figure 1, the container 16 houses the fuel cell cell stack 11, the terminals 12, and the first joint 14. The container 16 also houses a portion of the busbar 13. The container 16 may further house a portion of the insulating section 17, the manifold 18, the supply pipe 19, and the reformer 20.

[0027] The insulating portion 17 may be provided on the busbar 13. The insulating portion 17 may electrically insulate the busbar 13 and the container 16. Therefore, the insulating portion 17 may be interposed in the entire area between the busbar 13 and the container 16. Specifically, the insulating portion 17 may be cylindrical and provided along the first direction by being inserted through the cylindrical portion 24 of the busbar 13. The length L1 of the insulating portion 17 in the first direction may be greater than 1 / 2 and 3 / 4 of the length L2 of the busbar 13 along the first direction. The length of the busbar 13 is the length from the tip of the cylindrical portion to just before the second joint 15.

[0028] The insulating portion 17 may be fixed to the container 16 while penetrating the container 16. Specifically, the insulating portion 17 may be fixed by fitting into a hole drilled in the container 16.

[0029] The insulating portion 17 may be made of an insulating material. Furthermore, the coefficient of thermal expansion of the insulating portion 17 may be smaller than that of the busbar 13. Specifically, the insulating portion 17 may be made of a ceramic material such as alumina or steatite.

[0030] The manifold 18 may fix one end of the fuel cell 21. Specifically, the manifold 18 may fix the end of the fuel cell 21 on the first direction side. The manifold 18 may supply gas to each fuel cell 21. Specifically, the manifold 18 may supply fuel gas to each fuel cell 21. Specifically, as shown in Figure 3, the manifold 18 may have a box portion 25 and a plate portion 26.

[0031] The box portion 25 may have a defined interior cavity. A fuel cell cell 21 may be inserted through one side of the box portion 25. Gas flowing into the interior cavity of the box portion 25 from the supply pipe 19 may be supplied to each fuel cell cell 21. As shown in Figure 4, the box portion 25 may be a rounded rectangle with the longer side in the first direction when viewed in the second direction.

[0032] The plate portion 26 may protrude from the outer wall surface of the box portion 25. The plate portion 26 may be located on the side where the supply pipe 19 is provided in the first direction. The plate portion 26 may protrude from the corner of the box portion 25 when viewed in the second direction. Specifically, the plate portion 26 may protrude from both corners of the box portion 25 when viewed in the second direction, on the side where the supply pipe 19 is provided in the first direction. A fan-shaped notch may be formed in one corner of the plate portion 26. The plate portion 26 may be perpendicular to the second direction.

[0033] The supply pipe 19 may supply gas to the manifold 18. Specifically, the interior of the supply pipe 19 may communicate with the interior of the box portion 25 of the manifold 18. As shown in Figure 1, the supply pipe 19 may have a straight portion 27 extending along a second direction and a U-shaped curved portion 28 that is continuous with the end of the straight portion 27 on the second direction side. The curved portion 28 may be connected to the bottom surface of the box portion 25 on the second direction side.

[0034] The supply pipe 19 may be joined to the manifold 18 at a location different from the point of communication with the box portion 25. The supply pipe 19 may be joined to the manifold 18 only in a portion of the entire circumference of the shaft. More specifically, the supply pipe 19 may be joined to the outer edge of the plate portion 26 of the manifold 18. Even more specifically, the supply pipe 19 may be joined to the corner of the plate portion 26. In a configuration in which a fan-shaped notch is formed at the corner of the plate portion 26, the supply pipe 19 may be joined within the notch.

[0035] The reformer 20 may generate hydrogen, which is the fuel gas for the fuel cell cell 21, by reforming light hydrocarbons such as city gas. The reformer 20 may be located on the side opposite to the second direction relative to the fuel cell cell stack 11. The fuel gas may be supplied to the reformer 20 via the supply pipe 19.

[0036] The fuel cell module 10 of this embodiment, configured as described above, comprises a fuel cell cell stack 11 having a plurality of fuel cell cells 21 stacked on top of each other, a terminal 12 for outputting power generated by the fuel cell cell stack 11, a busbar 13 connected to the terminal 12, a first joint 14 for joining the terminal 12 and the busbar 13, a second joint 15 for joining an external conductor to the busbar 13 at a position different from the terminal 12, and a container 16 that houses the fuel cell stack 11, the terminal 12, the first joint 14, and a part of the busbar 13, wherein the coefficient of linear expansion of the first joint 14 is less than or equal to the coefficient of linear expansion of the busbar 13. The temperature inside the container 16 during power generation is higher than when it is stopped. Therefore, temperature changes occur in the first joint 14 and the busbar 13 when switching between power generation and power generation stoppage. In response to such phenomena, the fuel cell module 10 having the above-described configuration can reduce the gap that occurs between the first joint 14 and the busbar 13 even when temperature changes occur in the first joint 14 and the busbar 13. In this way, the fuel cell module 10 improves the connection between the terminals 12 and the busbar 13, which are multiple components that constitute a conductor for outputting power from the fuel cell stack 11.

[0037] Furthermore, in the fuel cell module 10, the coefficient of linear expansion of the first joint 14 is smaller than that of the second joint 15. Since the first joint 14 is closer to the fuel cell stack 11 than the second joint 15, it is expected to be exposed to a higher temperature atmosphere than the second joint 15. On the other hand, since the second joint 15 is expected to be connected to external wiring, etc., it may be subjected to tensile stress. In response to such assumptions, the fuel cell module 10 having the above configuration can further mitigate tensile stress because the second joint 15 is more easily deformed than the first joint 14.

[0038] Furthermore, in the fuel cell module 10, the coefficient of linear expansion of the first joint 14 is closer to the coefficient of linear expansion of the terminal 12 than the coefficient of linear expansion of the second joint 15. With this configuration, the fuel cell module 10 reduces the difference in the degree of expansion and contraction between the terminal 12 and the first joint 14 due to temperature changes. Therefore, by reducing the difference in the degree of expansion and contraction, the fuel cell module 10 reduces the possibility of peeling of the oxide film on the surface of the first joint 14, etc., and thus can reduce the increase in resistance due to the peeling of the oxide film.

[0039] Furthermore, in the fuel cell module 10, the terminals 12 and the first joint 14 are made of ferritic stainless steel. With this configuration, the fuel cell module 10 can use the magnetic force emitted by the ferritic stainless steel to fix the first joint 14 during the joining process of the terminals 12 and the busbar 13 by the first joint 14. Therefore, the fuel cell module 10 facilitates the joining process. In addition, since the thermal expansion coefficient of ferritic stainless steel is relatively small, the fuel cell module 10 can reduce the gap that occurs between the terminals 12 and the first joint 14, which are exposed to a high-temperature atmosphere closer to the fuel cell stack 11.

[0040] Furthermore, in the fuel cell module 10, the second joint 15 is made of austenitic stainless steel. With this configuration, the fuel cell module 10 can mitigate tensile stress applied from external wiring, etc., because austenitic stainless steel has a relatively large coefficient of thermal expansion.

[0041] Furthermore, in the fuel cell module 10, the coefficient of thermal expansion of the first joint 14 is closer to the coefficient of thermal expansion of the terminal 12 than that of the busbar 13. The first joint 14 and the terminal 12 are generally closer to the fuel cell stack 11 than the busbar 13 and are exposed to a high-temperature atmosphere. In response to such phenomena, the fuel cell module 10 having the above configuration can reduce the gap that occurs between the terminal 12 and the first joint 14, which are exposed to a high-temperature atmosphere.

[0042] Furthermore, the fuel cell module 10 includes an insulating portion 17 that has a coefficient of thermal expansion smaller than that of the busbar 13, is provided on the busbar 13 along a first direction and fixed in a state that it penetrates the container 16, and electrically insulates the busbar 13 and the container 16. Since the insulating portion 17 is in contact with the busbar 13, it expands and contracts due to the repeated power generation and shutdown of the fuel cell cell stack 11. Therefore, the insulating portion 17 applies stress to the container 16 due to its expansion and contraction. In response to such phenomena, the fuel cell module 10 having the above configuration can mitigate the stress applied to the container 16 because the insulating portion 17 has a smaller coefficient of thermal expansion than the busbar 13. In addition, in the fuel cell module 10, the length L1 of the insulating portion 17 in the first direction is greater than 1 / 2 and less than or equal to 3 / 4 of the length L2 of the busbar 13. With this configuration, the fuel cell module 10 can increase the certainty that the insulating portion 17 is interposed between the busbar 13 and the container 16 by setting a lower limit value for the length L1 of the insulating portion 17 in the first direction. Therefore, the fuel cell module 10 can fully exert a stress-relieving effect on the container 16. Furthermore, the fuel cell module 10 can ensure that the busbar 13 has a portion that connects to the external conductor by defining an upper limit value for the length L1 of the insulating portion 17 in the first direction.

[0043] Furthermore, the fuel cell module 10 comprises a manifold 18 and a supply pipe 19 that supplies gas to the manifold 18, with the supply pipe 19 joined to the manifold 18 only in a portion of its circumferential direction. Preferably, the supply pipe 19 is supported at many points within the container 16. Therefore, it is conceivable that it is supported at points other than the supply points on the manifold 18. In the case of support by the manifold 18, it is conceivable that the supply pipe 19 penetrates the manifold 18 and is joined by welding or the like over the entire circumferential area of ​​the inner circumferential surface of the through hole in the manifold 18 and the outer circumferential surface of the supply pipe 19. On the other hand, in the fuel cell module 10 having the above configuration, since the supply pipe 19 is joined to the manifold 18 only in a portion of its circumferential direction, the stress concentrated at the joint between the supply pipe 19 and the manifold 18 during temperature changes due to power generation and power generation stoppage can be relieved. Therefore, the fuel cell module 10 can reduce the possibility of the supply pipe 19 separating from the manifold 18 by relieving stress.

[0044] Furthermore, in the fuel cell module 10, the manifold 18 has a box portion 25 and a plate portion 26, and the supply pipe 19 is joined to the outer edge of the plate portion 26. As described above, in a configuration in which the supply pipe 19 penetrates the manifold 18 and is joined over the entire circumferential area of ​​the inner circumferential surface of the through-hole of the manifold 18 and the outer circumferential surface of the supply pipe 19, the manifold 18 needs to have an area wider than the size of the through-hole, in addition to the area that supports the fuel cell stack 11 when viewed in the second direction. On the other hand, the fuel cell module 10 having the above configuration does not need to secure an area wider than the size of the through-hole, so the manifold 18 can be miniaturized when viewed in the second direction. Therefore, the fuel cell module 10 as a whole can be miniaturized.

[0045] Furthermore, in the fuel cell module 10, the supply pipe 19 is joined to the corner of the plate portion 26. With this configuration, the fuel cell module 10 can be positioned such that, when viewed in the second direction, the connection point between the supply pipe 19 and the box portion 25 is separated from the connection point between the supply pipe 19 and the plate portion 26. Therefore, the radius of curvature of the curved portion 28 of the supply pipe 19 can be increased, thereby reducing the bending stress on the curved portion 28.

[0046] Furthermore, in the fuel cell module 10, the coefficient of linear expansion of the second joint 15 is greater than that of the first joint 14. Since the second joint 15 is connected to the external conductor, it is frequently subjected to tensile stress from the external conductor. In response to such phenomena, the fuel cell module 10 having the above configuration can alleviate this tensile stress because the second joint 15 is easily deformable.

[0047] In one embodiment, (1) the fuel cell module is A fuel cell cell stack having multiple fuel cell cells stacked on top of each other, A terminal for outputting the electricity generated by the fuel cell stack, A busbar connected to the aforementioned terminal, A first joint for joining the terminal and the busbar, A second joint for joining an external conductor to the busbar at a position different from the aforementioned terminal, The fuel cell cell stack, the terminals, the first joint, and a container for housing a part of the busbar are provided. The coefficient of thermal expansion of the first joint is less than or equal to the coefficient of thermal expansion of the busbar.

[0048] (2) In the fuel cell module described in (1) above, The coefficient of thermal expansion of the first joint is smaller than the coefficient of thermal expansion of the second joint.

[0049] (3) In the fuel cell module described in (1) or (2) above, The coefficient of thermal expansion of the first joint is closer to the coefficient of thermal expansion of the terminal than the coefficient of thermal expansion of the second joint.

[0050] (4) In the fuel cell modules described in (1) to (3) above, The terminal and the first joint are made of ferritic stainless steel. The second joint is made of austenitic stainless steel.

[0051] (5) In the fuel cell modules described in (1) to (4) above, The coefficient of thermal expansion of the first joint is closer to the coefficient of thermal expansion of the terminal than the coefficient of thermal expansion of the busbar.

[0052] (6) The fuel cell modules described in (1) through (5) above are: The invention further comprises an insulating portion having a coefficient of linear expansion smaller than that of the busbar, provided on the busbar along a first direction away from the fuel cell stack, having a length L1 in the first direction greater than 1 / 2 and less than or equal to 3 / 4 of the length L2 of the busbar, fixed in a state that penetrates the container, and electrically insulating the busbar and the container.

[0053] (7) The fuel cell modules described in (1) through (6) above are: A manifold that fixes one end of the fuel cell and supplies gas to the fuel cell, The manifold further comprises a supply pipe for supplying gas to the manifold, The supply pipe is joined to the manifold only in a portion of its circumferential direction.

[0054] (8) In the fuel cell module described in (7) above, The manifold has a box portion with a defined interior space through which the supply pipe communicates, and a plate portion that protrudes from the outer wall surface of the box portion. The supply pipe is joined to the outer edge of the plate portion.

[0055] (9) In the fuel cell module described in (8) above, The supply pipe is joined to the corner of the plate portion.

[0056] In one embodiment, (10) the fuel cell device is The system comprises the fuel cell modules described in (1) to (9) above, and an auxiliary device that provides an auxiliary function for operating the fuel cell modules.

[0057] The diagrams illustrating the embodiments described herein are schematic. Dimensions and proportions shown in the drawings do not necessarily correspond to actual dimensions.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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 joint may swap the identifiers "First" and "Second" with the second joint. 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]

[0062] 10 Fuel Cell Modules 11 Fuel cell stack 12 terminals 13 Bus Bar 14. First joint 15. Second joint 16 Container 17 Insulation 18 Manifold 19 Supply pipe 20 Reformer 21 fuel cell cells 22 Flat portion 23 Flat portion 24 Cylindrical part 25 Hakobe 26 Board part 27. Straight section 28 Curved section

Claims

1. A fuel cell cell stack having multiple fuel cell cells stacked on top of each other, A terminal for outputting the electricity generated by the fuel cell stack, A busbar connected to the aforementioned terminal, A first joint for joining the terminal and the busbar, A second joint for joining an external conductor to the busbar at a position different from the aforementioned terminal, The fuel cell cell stack, the terminals, the first joint, and a container for housing a part of the busbar are provided. The coefficient of linear expansion of the first joint is less than or equal to the coefficient of linear expansion of the busbar. The coefficient of thermal expansion of the first joint is smaller than the coefficient of thermal expansion of the second joint. Fuel cell module.

2. In the fuel cell module according to claim 1, The coefficient of thermal expansion of the first joint is closer to the coefficient of thermal expansion of the terminal than the coefficient of thermal expansion of the second joint.

3. In the fuel cell module according to claim 1, The terminal and the first joint are made of ferritic stainless steel. The second joint is made of austenitic stainless steel. Fuel cell module.

4. In the fuel cell module according to claim 1, The coefficient of thermal expansion of the first joint is closer to the coefficient of thermal expansion of the terminal than the coefficient of thermal expansion of the busbar. Fuel cell module.

5. In the fuel cell module according to any one of claims 1 to 4, A fuel cell module further comprising an insulating portion having a coefficient of linear expansion smaller than that of the busbar, provided on the busbar along a first direction away from the fuel cell cell stack, having a length in the first direction greater than 1 / 2 and less than or equal to 3 / 4 of the length of the busbar, fixed in a state penetrating the container, and electrically insulating the busbar and the container.

6. In the fuel cell module according to any one of claims 1 to 4, A manifold that fixes one end of the fuel cell and supplies gas to the fuel cell, The manifold further comprises a supply pipe for supplying gas to the manifold, The supply pipe is joined to the manifold only in a portion of its circumference. Fuel cell module.

7. In the fuel cell module according to claim 6, The manifold has a box portion with a defined interior space through which the supply pipe communicates, and a plate portion that protrudes from the outer wall surface of the box portion. The supply pipe is joined to the outer edge of the plate portion. Fuel cell module.

8. In the fuel cell module according to claim 7, The supply pipe is joined to the corner of the plate portion. Fuel cell module.

9. A fuel cell device comprising a fuel cell module according to any one of claims 1 to 4, and an auxiliary device having an auxiliary function for operating the fuel cell module.

Images