Fuel cell module

Abstract

This fuel cell module is provided with: a fuel cell stack comprising a plurality of stacked fuel cell cells; a fuel gas outlet manifold which extends in the stacking direction inside the fuel cell stack and through which the fuel gas that has passed through each of the fuel cell cells flows; an oxidant gas outlet manifold which extends in the stacking direction inside the fuel cell stack and through which the oxidant gas that has passed through each of the fuel cell cells flows; a discharge flow path that discharges the oxidant gas from the oxidant gas outlet manifold; a pressure regulating valve provided in the discharge flow path so that the pressure in the discharge flow path downstream of the pressure regulating valve is lower than the pressure in the oxidant gas outlet manifold; and a drain flow path.

Description

Technical Field

[0001] The technology disclosed in this specification relates to fuel cell modules. Background Technology

[0002] The fuel cell module disclosed in Japanese Patent Application Publication No. 2020-155212 comprises a fuel cell stack consisting of multiple stacked fuel cell cells. The fuel cell stack generates electricity by reacting fuel gas with oxidant gas. A fuel gas outlet manifold is provided inside the fuel cell stack to discharge the fuel gas that has passed through the fuel cell cells. Similarly, an oxidant gas outlet manifold is provided inside the fuel cell stack to discharge the oxidant gas that has passed through the fuel cell cells.

[0003] Inside the fuel cell stack, water (hereinafter referred to as generated water) is produced by the reaction of fuel gas and oxidant gas. The generated water is discharged to the outside of the fuel cell stack through the fuel gas outlet manifold and the oxidant gas outlet manifold.

[0004] Sometimes, fuel cell modules include a drainage path that discharges generated water from the fuel gas outlet manifold to the oxidant gas outlet manifold. This drainage path integrates the discharge routes of the generated water in both the fuel gas and oxidant gas outlet manifolds. However, this design can lead to backflow of generated water and oxidant gas within the drainage path. This specification proposes a technique to suppress backflow in the drainage path. Summary of the Invention

[0005] (Method 1)

[0006] The fuel cell module disclosed in this specification includes: a fuel cell stack consisting of multiple stacked fuel cell cells; a fuel gas outlet manifold extending inside the fuel cell stack along the stacking direction for fuel gas flowing through each fuel cell cell; an oxidant gas outlet manifold extending inside the fuel cell stack along the stacking direction for oxidant gas flowing through each fuel cell cell; a discharge path for discharging oxidant gas from the oxidant gas outlet manifold; a pressure regulating valve disposed in the discharge path to lower the pressure in the discharge path downstream of the pressure regulating valve than the pressure in the oxidant gas outlet manifold; and a drainage path for discharging water generated inside the fuel cell cells from the fuel gas outlet manifold to the discharge path downstream of the pressure regulating valve.

[0007] In the aforementioned fuel cell module, the drainage path discharges generated water from the fuel gas outlet manifold to a discharge path downstream of the pressure regulating valve. The pressure in the discharge path downstream of the pressure regulating valve is controlled by the pressure regulating valve to be lower than the pressure in the oxidant gas outlet manifold. As a result, backflow in the drainage path can be suppressed.

[0008] Following on method 1 above, the additional configuration of the fuel cell system disclosed in this specification will be described below.

[0009] (Method 2)

[0010] According to the fuel cell module described in Method 1, it further includes a gas-liquid separator. The fuel cell stack has a first end face on one side of the stacking direction and a second end face on the other side of the stacking direction. The fuel gas outlet manifold has a fuel gas outlet on the first end face, and the oxidant gas outlet manifold has an oxidant gas outlet on the second end face connected to the discharge flow path. The gas-liquid separator separates water from the fuel gas discharged from the fuel gas outlet. The drainage flow path is configured to discharge the water separated by the gas-liquid separator to the discharge flow path downstream of the pressure regulating valve. The water extends from the gas-liquid separator through the first end face and through the oxidant gas outlet manifold to the discharge flow path.

[0011] (Method 3)

[0012] According to the fuel cell module described in method 1 or 2, the fuel cell stack has a first end face on one side of the stacking direction and a second end face on the other side of the stacking direction. The fuel gas outlet manifold has a fuel gas outlet on the first end face, and the oxidant gas outlet manifold has an oxidant gas outlet on the second end face that is connected to the discharge flow path. The drainage flow path extends from the inner end of the fuel gas outlet manifold to the discharge flow path downstream of the pressure regulating valve.

[0013] (Method 4)

[0014] According to any one of the methods 1 to 3, a drain pipe extending along the stacking direction is provided in the oxidant gas outlet manifold.

[0015] According to method 2, the drainage path of the water separated by the gas-liquid separator is extended to the discharge path through the oxidant gas outlet manifold. Therefore, the length of the drainage path can be shortened, enabling miniaturization of the fuel cell module.

[0016] According to method 3, water accumulated at the inner end of the fuel gas outlet manifold is discharged through a drain path to a discharge path downstream of the pressure regulating valve. Therefore, water is discharged from the fuel gas outlet manifold through the drain path.

[0017] According to method 4, the generated water in the oxidant gas outlet manifold can be easily discharged. Attached Figure Description

[0018] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements, wherein,

[0019] Figure 1 This is a simplified diagram of the fuel cell module in Example 1.

[0020] Figure 2 This is a simplified diagram of the fuel cell module in Example 2.

[0021] Figure 3 This is a simplified diagram of the fuel cell module in Example 3.

[0022] Figure 4 This is a simplified diagram of the fuel cell module in Example 4.

[0023] Figure 5 This is a simplified diagram of the fuel cell module in Example 5. Detailed Implementation

[0024] (Example 1)

[0025] Figure 1 The fuel cell module 100 of Embodiment 1 shown is mounted on a device powered by a fuel cell (e.g., a fuel cell vehicle). The fuel cell module 100 has a fuel cell stack 10. The fuel cell module 100 supplies electricity generated by the fuel cell stack 10 to motors, etc.

[0026] The fuel cell stack 10 includes a plurality of stacked fuel cell cells 12, end plates 14 and 16. One end of the stack of fuel cell cells 12 is covered by end plate 14, and the other end of the stack of fuel cell cells 12 is covered by end plate 16. That is, the stack of fuel cell cells 12 is sandwiched between end plates 14 and end plates 16 in the stacking direction. Furthermore, in the fuel cell stack 10 below, the end face on the end plate 14 side is referred to as the first end face 10a, and the end face on the end plate 16 side is referred to as the second end face 10b.

[0027] An oxidant gas (e.g., air) is supplied to each fuel cell cell 12 through a manifold (not shown), and a fuel gas (e.g., hydrogen) is also supplied to each fuel cell cell 12 through a manifold (not shown). Each fuel cell cell 12 generates electricity by reacting the fuel gas with the oxidant gas. Additionally, water (hereinafter referred to as generated water) is generated in each fuel cell cell 12 during this reaction. Figure 1 As shown, a fuel gas outlet manifold 20 and an oxidant gas outlet manifold 22 are provided inside the fuel cell stack 10.

[0028] A fuel gas outlet manifold 20 passes through each fuel cell cell 12 and end plate 14, extending along the stacking direction inside the fuel cell stack 10. The fuel gas outlet manifold 20 has a fuel gas outlet 20a. The fuel gas outlet 20a opens at a first end face 10a. Fuel gas passing through each fuel cell cell 12 flows in the fuel gas outlet manifold 20. The fuel cell cell 12 discharges generated water along with the fuel gas into the fuel gas outlet manifold 20. The generated water and fuel gas flow within the fuel gas outlet manifold 20 and are discharged to the outside of the fuel cell stack 10 via the fuel gas outlet 20a.

[0029] An oxidant gas outlet manifold 22 passes through each fuel cell cell 12 and end plate 16, extending along the stacking direction inside the fuel cell stack 10. The oxidant gas outlet manifold 22 has an oxidant gas outlet 22a. The oxidant gas outlet 22a opens at the second end face 10b. Oxidant gas passing through each fuel cell cell 12 flows in the oxidant gas outlet manifold 22. The fuel cell cell 12 discharges generated water along with the oxidant gas into the oxidant gas outlet manifold 22. The oxidant gas and generated water flow within the oxidant gas outlet manifold 22 toward the oxidant gas outlet 22a.

[0030] A drain pipe 30 is provided inside the oxidant gas outlet manifold 22. The drain pipe 30 is a pipe thinner than the oxidant gas outlet manifold 22 and is open at both ends. The drain pipe 30 extends from the inner end (i.e., the first end face 10a side) of the oxidant gas outlet manifold 22 to the oxidant gas outlet 22a. That is, the drain pipe 30 extends along the stacking direction of the fuel cell cell 12. If generated water accumulates at the inner end of the oxidant gas outlet manifold 22, the generated water is discharged to the oxidant gas outlet 22a through the drain pipe 30. Therefore, the drain pipe 30 facilitates the discharge of generated water within the oxidant gas outlet manifold 22.

[0031] The fuel cell module 100 has a discharge path 24. The upstream end of the discharge path 24 is connected to an oxidant gas outlet 22a. Oxidant gas and generated water flowing in the oxidant gas outlet manifold 22 are discharged to the outside of the fuel cell module 10 via the discharge path 24. A pressure regulating valve 26 is provided in the discharge path 24. The fuel cell module 100 has a control device 40. The control device 40 controls the pressure regulating valve 26 in such a way that the pressure in the discharge path 24 downstream of the pressure regulating valve 26 is lower than the pressure in the oxidant gas outlet manifold 22.

[0032] The fuel cell module 100 has a drain flow path 32. The drain flow path 32 is narrower than both the fuel gas outlet manifold 20 and the oxidant gas outlet manifold 22. The upstream end of the drain flow path 32 is connected to the inner end (i.e., the second end face 10b side) of the oxidant gas outlet manifold 22. The drain flow path 32 extends through the end plate 16 to the discharge flow path 24. The downstream end of the drain flow path 32 is connected to the discharge flow path 24 downstream of the pressure regulating valve 26. A valve 34 is provided in the drain flow path 32. The valve 34 opens and closes the flow path of the drain flow path 32. If generated water accumulates at the inner end of the fuel gas outlet manifold 20 when the valve 34 is open, the generated water is discharged through the drain flow path 32 to the discharge flow path 24. The drain flow path 32 facilitates the discharge of generated water from the fuel gas outlet manifold 20.

[0033] During the operation of the fuel cell module 100, as described above, fuel gas and generated water are discharged from the fuel gas outlet manifold 20 to the outside of the fuel cell stack 10 via the fuel gas outlet 20a, and oxidant gas and generated water are discharged from the oxidant gas outlet manifold 22 to the outside of the fuel cell stack 10 via the discharge path 24. Furthermore, during the operation of the fuel cell module 100, valve 34 is controlled to be in the open state. Therefore, if generated water accumulates in the fuel gas outlet manifold 20, the generated water in the fuel gas outlet manifold 20 is discharged to the discharge path 24 via the drain path 32. At this time, the pressure in the discharge path 24, which is downstream of the pressure regulating valve 26, is controlled to be lower than the pressure in the oxidant gas outlet manifold 22 by the pressure regulating valve 26, thus the pressure at the outlet of the drain path 32 is low. Therefore, it is possible to prevent oxidant gas and generated water from flowing back from the discharge path 24 to the drain path 32. Therefore, the generated water in the fuel gas outlet manifold 20 is appropriately discharged to the discharge path 24.

[0034] (Example 2)

[0035] Figure 2 This refers to the fuel cell module 102 of Example 2. Furthermore, in... Figure 2 In the middle, to and Figure 1The common parts are labeled with the same reference numerals. The fuel cell module 102 of Embodiment 2 differs from Embodiment 1 in that it does not have a drainage path 32, and it has a drainage pipe 44, a gas-liquid separator 42, and a drainage path 36. Otherwise, the fuel cell module 102 of Embodiment 2 is the same as that of Embodiment 1.

[0036] A gas-liquid separator 42 is disposed next to end plate 14. The gas-liquid separator 42 is connected to fuel gas outlet 20a. The generated water and fuel gas discharged from each fuel cell cell 12 flow within the fuel gas outlet manifold 20 and are discharged to the gas-liquid separator 42 via the fuel gas outlet 20a. The gas-liquid separator 42 separates fuel gas from the generated water. The fuel gas separated from the generated water is then supplied to the fuel cell stack 10 again via a fuel gas supply path (not shown).

[0037] A drain pipe 44 is disposed within the fuel gas outlet manifold 20. The drain pipe 44 is thinner than the fuel gas outlet manifold 20 and is open at both ends. The drain pipe 44 extends from the inner end (i.e., the second end face 10b side) of the fuel gas outlet manifold 20 to the fuel gas outlet 20a. That is, the drain pipe 44 extends along the stacking direction of the fuel cell cell 12. If generated water accumulates at the inner end of the fuel gas outlet manifold 20, the generated water flows within the drain pipe 44 and is discharged to the gas-liquid separator 42 via the fuel gas outlet 20a. Within the fuel gas outlet manifold 20, the drain pipe 44 facilitates the discharge of generated water.

[0038] The fuel cell module 102 has a drainage path 36 formed by a thin tube. The drainage path 36 is narrower than the fuel gas outlet manifold 20 and the oxidant gas outlet manifold 22. The upstream end of the drainage path 36 is connected to the gas-liquid separator 42. The drainage path 36 extends from the gas-liquid separator 42 through the first end face 10a and into the oxidant gas outlet manifold 22. The drainage path 36 extends inside the oxidant gas outlet manifold 22 to the oxidant gas outlet 22a. The drainage path 36 is led outward from the discharge path 24. The downstream end of the drainage path 36 is connected to the discharge path 24 downstream of the pressure regulating valve 26. A valve 38 is provided in the drainage path 36. The valve 38 opens and closes the drainage path 36. When the valve 38 is open, the generated water separated from the fuel gas by the gas-liquid separator 42 is discharged through the drainage path 36 to the discharge path 24.

[0039] In the operation of the fuel cell module 102 of Example 2, as in Example 1, oxidant gas and generated water are discharged from the oxidant gas outlet manifold 22 to the outside of the fuel cell stack 10 via the discharge path 24. Additionally, in the operation of the fuel cell module 102, as described above, fuel gas and generated water are discharged from the fuel gas outlet manifold 20 to the gas-liquid separator 42. Furthermore, in the operation of the fuel cell module 102, valve 38 is controlled to be in the open state. Therefore, the generated water in the gas-liquid separator 42 is discharged to the discharge path 24 via the drain path 36. That is, the drain path 36 discharges the generated water generated in the fuel cell cell 12 from the fuel gas outlet manifold 20 to the discharge path 24, which is downstream of the pressure regulating valve 26. Because the pressure in the discharge path 24, which is downstream of the pressure regulating valve 26, is controlled by the pressure regulating valve 26 to be lower than the pressure in the oxidant gas outlet manifold 22, the pressure at the outlet of the drain path 36 is low. Therefore, it will prevent oxidant gas and generated water from flowing back from the discharge path 24 to the drainage path 36.

[0040] In Embodiment 2, as described above, the drainage path 36 is provided within the oxidant gas outlet manifold 22. With this configuration, compared to providing the drainage path 36 externally to the fuel cell stack 10, the path length of the drainage path 36 can be shortened, enabling miniaturization of the fuel cell module 102.

[0041] (Example 3)

[0042] Figure 3 The pressure regulating valve of the fuel cell module 103 in Embodiment 3 is different from that in Embodiment 2. Additionally, the downstream configuration of the drainage path 36 in Embodiment 3 is different from that in Embodiment 2. The other components of the fuel cell module 103 in Embodiment 3 are the same as those in Embodiment 2.

[0043] In Embodiment 3, the fuel cell module 103 includes a pressure regulating valve 50. The pressure regulating valve 50 is a butterfly valve with a valve body 52. ​​The pressure regulating valve 50 is housed within a housing 54. A downstream portion of the drain flow path 36 extends through the housing 54 to the discharge flow path 24. In Embodiment 3, the downstream end of the drain flow path 36 is also connected to the discharge flow path 24 at a position downstream of the pressure regulating valve. Therefore, backflow in the drain flow path 36 can be prevented, and generated water can be discharged through the drain flow path 36.

[0044] (Example 4)

[0045] In the above-described embodiment 3, the downstream portion of the drainage path 36 extends through the housing 54 to the discharge path 24. In contrast, as... Figure 4As shown, in the fuel cell module 104 of Example 4, the drain path 36 extends from the gas-liquid separator 42 through the oxidant gas outlet manifold 22 and the valve body 52 to the discharge path 24. In Example 4, the downstream end of the drain path 36 is also connected to the discharge path 24 at a position downstream of the pressure regulating valve. Therefore, backflow in the drain path 36 can be prevented, and generated water can be discharged through the drain path 36.

[0046] (Example 5)

[0047] Figure 5 The fuel cell module 105 of Embodiment 5 shown is a combination of the configurations of Embodiments 1 and 2. Furthermore, in this case, the drain pipe 44 may not be provided.

[0048] In Examples 1-5, the fuel gas outlet 20a is open at the first end face 10a. However, the fuel gas outlet 20a may also be open at the second end face 10b. Additionally, in Examples 1 and 2, the oxidant gas outlet 22a is open at the second end face 10b. However, the oxidant gas outlet 22a may also be open at the first end face 10a.

[0049] In Examples 1-5, a drain pipe 30 is provided inside the oxidant gas outlet manifold 22. However, the drain pipe 30 may not be provided inside the oxidant gas outlet manifold 22.

[0050] In embodiments 2 to 4, a drain pipe 44 is provided inside the fuel gas outlet manifold 20. However, the drain pipe 44 may not be provided inside the fuel gas outlet manifold 20.

[0051] In embodiments 1 and 5, the drain passage 32 has a valve 34. However, the drain passage 32 may also not have a valve 34. In this case, the drain passage 32 may always be open.

[0052] In embodiments 2-5, the drain passage 36 includes a valve 38. However, the drain passage 36 may also be without a valve 38. In this case, the drain passage 36 may always be open.

[0053] The embodiments have been described in detail above, but these are merely illustrative and do not limit the technical solutions. The technology described in the technical solutions includes various modifications and alterations to the specific examples illustrated above. The technical elements described in this specification or drawings exert their technical usefulness individually or in various combinations, and are not limited to the combinations described in the technical solutions at the time of application. Furthermore, the technology illustrated in this specification or drawings simultaneously achieves multiple objectives, and achieving one of these objectives is itself technically useful.

Claims

1. A fuel cell module, characterized in that, The fuel cell module includes: A fuel cell stack consists of multiple stacked fuel cell cells; A fuel gas outlet manifold extends inside the fuel cell stack along the stacking direction to supply fuel gas flow through each fuel cell cell; An oxidant gas outlet manifold extends inside the fuel cell stack along the stacking direction to supply oxidant gas flow through each fuel cell cell; The oxidant gas is discharged from the oxidant gas outlet manifold through the discharge flow path. A pressure regulating valve is provided in the discharge flow path to make the pressure in the discharge flow path downstream of the pressure regulating valve lower than the pressure in the oxidant gas outlet manifold. as well as The drainage path discharges water generated within the fuel cell from the fuel gas outlet manifold to the discharge path downstream of the pressure regulating valve.

2. The fuel cell module according to claim 1, characterized in that, The fuel cell module also includes a gas-liquid separator. The fuel cell stack has a first end face on one side of the stacking direction and a second end face on the other side of the stacking direction. The fuel gas outlet manifold has a fuel gas discharge port on the first end face. The oxidant gas outlet manifold has an oxidant gas outlet on the second end face that is connected to the discharge flow path. The gas-liquid separator separates water from the fuel gas discharged from the fuel gas outlet. The drainage path is configured to discharge the water separated by the gas-liquid separator to the discharge path downstream of the pressure regulating valve, extending from the gas-liquid separator through the first end face and through the oxidant gas outlet manifold to the discharge path.

3. The fuel cell module according to claim 1, characterized in that, The fuel cell stack has a first end face on one side of the stacking direction and a second end face on the other side of the stacking direction. The fuel gas outlet manifold has a fuel gas discharge port on the first end face. The oxidant gas outlet manifold has an oxidant gas outlet on the second end face that is connected to the discharge flow path. The drainage path extends from the inner end of the fuel gas outlet manifold to the discharge path downstream of the pressure regulating valve.

4. The fuel cell module according to any one of claims 1 to 3, characterized in that, A drain pipe extending along the stacking direction is provided inside the oxidant gas outlet manifold.

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