JP7596840B2 - Stack Manifold - Google Patents

Description

The present invention relates to a stack manifold for supplying fluid to a cell stack of a fuel cell.

As shown in Patent Document 1, the stack manifold can be attached to a cell stack of a fuel cell. The stack manifold has a housing. The housing is formed with a plurality of inlets, a distribution chamber, and a plurality of outlets. The stack manifold discharges fluid introduced from the inlet of the housing into the distribution chamber from the distribution chamber to the cell stack via the outlet.

JP 2017-117550 A

In the stack manifold of Patent Document 1, the multiple inlets are simply formed at equal intervals from one another, so when a fluid is introduced into a distribution chamber from the multiple inlets and flows to the multiple outlets, the fluid does not necessarily flow evenly through those inlets. If the fluid does not flow evenly through the multiple outlets in the stack manifold, then the discharge of the fluid from those outlets to the cell stacks will be biased.

Increasing the volume of the distribution chamber in the stack manifold makes it less likely that the flow of fluid introduced into the distribution chamber from multiple inlets will become biased within the distribution chamber. As a result, the fluid will flow more easily from the distribution chamber to multiple outlets without bias, and the discharge of the fluid from these outlets to the cell stacks will also be less likely to be biased. However, in this case, the volume of the distribution chamber must be increased, and the stack manifold will become larger.

The means for solving the above problems and their effects will be described below.
A stack manifold that solves the above problem can be attached to a cell stack formed by stacking a plurality of fuel cell units in a thickness direction. The stack manifold includes a housing in which a plurality of inlets, a distribution chamber, and a plurality of outlets are formed. The stack manifold discharges fluid introduced from the inlets into the distribution chamber from the distribution chamber through the outlet to the cell stack. The plurality of inlets are formed so that the fluid flows into the distribution chamber in mutually different directions.

According to the above configuration, since the multiple inlets have different fluid inflow directions into the distribution chamber, the fluids introduced into the distribution chamber from the multiple inlets collide with each other or with the inner wall of the housing, which tends to disturb the flow of the fluid in the distribution chamber. As a result, the flow of the fluid from the distribution chamber to the multiple outlets is less likely to become uneven, and it is possible to suppress the difficulty in discharging the fluid from the outlets to the cell stacks evenly. In addition, by disturbing the flow of the fluid in the distribution chamber, it is less likely that the flow of the fluid from the distribution chamber to the multiple outlets will become uneven, so there is no need to increase the volume of the distribution chamber to prevent such unevenness from occurring. Therefore, the stack manifold does not become larger as the distribution chamber is enlarged.

2 is a schematic diagram showing a cell stack and a stack manifold of the fuel cell of the present embodiment. 1 is a schematic diagram showing a comparative example of a stack manifold. 13 is a schematic diagram showing another example of a stack manifold.

Hereinafter, one embodiment of a stack manifold that is applied to a fuel cell will be described with reference to FIGS.
As shown in Fig. 1, a fuel cell stack 1 is formed by stacking a plurality of fuel cells 2 in the thickness direction. Fluids such as fuel gas (hydrogen, etc.), oxidizing gas (air, etc.), and coolant (cooling water, etc.) are supplied to and discharged from the cell stack 1. The fuel gas and oxidizing gas are supplied to the cell stack 1, and power is generated based on a reaction between the fuel gas and the oxidizing gas in a membrane electrode gas-diffusion assembly (MEGA) of the fuel cell 2. Heat generated during such power generation is removed by the coolant passing through the cell stack 1. As a result, the cell stack 1 is cooled.

A stack manifold 3 can be attached to the cell stack 1. This stack manifold 3 is for supplying fluids such as the above-mentioned fuel gas, oxidizing gas, and refrigerant to the cell stack 1. In this example, the stack manifold 3 supplies, for example, fuel gas to the cell stack 1. The stack manifold 3 has a housing 4. The housing 4 is formed with a plurality of inlets 5, a distribution chamber 6, and a plurality of outlets 7. The stack manifold 3 outputs the fluid (fuel gas in this example) introduced from the inlet 5 of the housing 4 to the distribution chamber 6 from the distribution chamber 6 via the outlet 7 to the cell stack 1.

The multiple outlets 7 in the stack manifold 3 are formed so that their center lines L1 are parallel to each other. The multiple inlets 5 in the stack manifold 3 are formed so that the inflow directions of the above-mentioned fluid into the distribution chamber 6 are different from each other. More specifically, the multiple inlets 5 are formed so that imaginary lines L2 extending from them toward the inside of the distribution chamber 6 intersect within the same distribution chamber 6. Furthermore, at least one of the multiple inlets 5 (all of them in this example) has a center line L3 inclined with respect to the center line L1 of the outlet 7.

Next, the operation of the stack manifold 3 of this embodiment will be described.
In a stack manifold 3 attached to a cell stack 1, the fluid is introduced into a distribution chamber 6 in a housing 4 through a plurality of inlets 5. The fluid is then discharged from the distribution chamber 6 to the cell stack 1 through a plurality of outlets 7.

Since the multiple inlets 5 have different directions of fluid flow into the distribution chamber 6, the fluids introduced into the distribution chamber 6 from the multiple inlets 5 tend to collide with each other or with the inner wall of the housing 4, which can easily disrupt the flow of the fluid within the distribution chamber 6. As a result, the flow of fluid from the distribution chamber 6 to the multiple outlets 7 is less likely to be biased, which can prevent the fluid from being discharged from the outlets 7 to the cell stack 1 from being unevenly distributed.

Figure 2 shows an example in which the volume of the distribution chamber 6 in the stack manifold 3 is increased to prevent bias in the flow of the fluid from the distribution chamber 6 to the multiple outlets 7. In this case, by increasing the size of the distribution chamber 6 in the direction of arrow t1, the distance from the inlet 5 to the outlet 7 becomes longer, so that bias in the flow of the fluid is less likely to occur when the fluid passes through the distribution chamber 6. However, the stack manifold 3 becomes larger in size because the volume of the distribution chamber 6 is increased.

In the stack manifold 3 of this embodiment (FIG. 1), by creating turbulence in the flow of the fluid within the distribution chamber 6, the flow of the fluid from the distribution chamber 6 to the multiple outlets 7 is less likely to become biased, so there is no need to increase the volume of the distribution chamber 6 to prevent such bias. This makes it possible to prevent the distribution chamber 6 from becoming larger in the direction of arrow t2 in FIG. 1, and to prevent the stack manifold 3 from becoming larger in size as the distribution chamber 6 is enlarged.

According to the present embodiment described above in detail, the following effects can be obtained.
(1) It is possible to prevent the occurrence of bias in the discharge of fluid from the multiple discharge ports 7 to the cell stack 1 without increasing the size of the stack manifold 3 .

(2) In the stack manifold 3, the imaginary lines L2 that are formed when the multiple inlets 5 are assumed to be extended into the distribution chamber 6 intersect within the distribution chamber 6. That is, the multiple inlets 5 are formed in the housing 4 in this manner. For this reason, the fluids introduced into the distribution chamber 6 from the multiple inlets 5 collide with each other, which efficiently disturbs the flow of the fluid within the distribution chamber 6. As a result, the flow of fluid from the distribution chamber 6 to the multiple outlets 7 is less likely to become uneven, and uneven discharge of fluid from the outlets 7 to the cell stack 1 can be suppressed.

(3) At least one of the multiple inlets 5 in the stack manifold 3 (all of them in this example) has a center line L3 that is inclined relative to the center line L1 of the outlet 7. For this reason, fluid introduced into the distribution chamber 6 from an inlet 5 having a center line L1 that is inclined relative to the center line L1 of the outlet 7 is unlikely to be discharged from the outlet 7 immediately after being introduced into the distribution chamber 6. This makes it easier for the flow of fluid to become turbulent within the distribution chamber 6. As a result, bias in the flow of fluid from the distribution chamber 6 to the multiple outlets 7 is unlikely to occur, and bias in the discharge of fluid from those outlets 7 to the cell stack 1 can be suppressed.

The above embodiment can be modified, for example, as follows: The above embodiment and the following modified examples can be combined with each other to the extent that no technical contradiction occurs.
It is not necessary that the center lines L3 of all of the multiple inlets 5 are inclined with respect to the center line L1 of the outlet 7.

The imaginary lines L2 (FIG. 1) drawn when it is assumed that the multiple inlets 5 are extended into the distribution chamber 6 do not necessarily need to intersect within the distribution chamber 6.
As shown in Fig. 3, at least one of the multiple inlets 5 (two in this example) may be formed to open toward an outlet 7 located in a portion of the multiple outlets 7 where the fluid does not flow well, for example, an outlet 7 located in a corner of the distribution chamber 6. In this case, the fluid introduced into the distribution chamber 6 from the inlet 5 that opens toward the outlet 7 located in a portion of the multiple outlets 7 where the fluid does not flow well can be made to flow toward the outlet 7 located in the portion where the fluid does not flow well. This makes it possible to prevent the occurrence of bias in the discharge of the fluid from the multiple outlets 7 to the cell stack 1. Furthermore, it is not necessary to increase the volume of the distribution chamber 6 so that such bias is unlikely to occur. This makes it possible to prevent the distribution chamber 6 from becoming larger in the direction of the arrow t2 in Fig. 3.

- The number of multiple inlets 5 may be changed as appropriate, for example to four or more.

Reference Signs List 1: cell stack 2: fuel cell 3: stack manifold 4: housing 5: inlet 6: distribution chamber 7: outlet

Claims (3)

A stack manifold that can be attached to a cell stack formed by stacking a plurality of fuel cells in a thickness direction, the stack manifold comprising a housing having a plurality of inlets, a distribution chamber, and a plurality of outlets, and that discharges a fluid introduced from the inlets into the distribution chamber from the distribution chamber through the outlets to the cell stack,
A stack manifold in which the multiple inlets are formed so that the flow directions of the fluid into the distribution chamber are different from each other , and virtual lines extending from the multiple inlets toward the distribution chamber intersect within the distribution chamber . 2. The stack manifold according to claim 1 , wherein a center line of at least one of the plurality of inlets is inclined with respect to a center line of the outlet. 3. The stack manifold according to claim 1, wherein at least one of the plurality of inlets is open toward one of the plurality of outlets that is located at a corner of the distribution chamber .