JP7180563B2 - fuel cell system - Google Patents

Description

The present disclosure relates to fuel cell systems.

As disclosed in Patent Document 1 below, a fuel cell system having a bypass flow path is known. This fuel cell system includes a supply channel connected to the inlet side of the fuel cell via a pressure regulating valve (also referred to as a regulating valve), and a discharge channel connected to the outlet side of the fuel cell via the pressure regulating valve. . The supply channel is connected to the compressor and the discharge channel is connected to the turbine. The pressure in the fuel cell is regulated by the pressure regulating valve on the inlet side and the pressure regulating valve on the outlet side.

The bypass flowpath bypasses a portion of the supply flowpath between the pressure regulator and the compressor to a portion of the discharge flowpath between the pressure regulator and the turbine. A bypass valve is provided in the bypass flow path. A bypass valve regulates the flow rate of the cathode gas supplied from the compressor to the turbine through the bypass passage without passing through the fuel cell. By controlling the operation of the regulating valve and the bypass valve, it is possible to efficiently recover power in the turbine while setting the pressure in the fuel cell to an appropriate value.

JP 2018-092795 A

The pressure regulating valve is composed of, for example, an electromagnetic valve, and generally utilizes pressure loss to generate a differential pressure between an upstream portion of the pressure regulating valve and a downstream portion of the pressure regulating valve. By using the pressure regulating valve, the pressure inside the fuel cell can be easily adjusted. However, if a pressure regulating valve is arranged in the exhaust path on the outlet side of the fuel cell, the pressure regulating valve causes pressure loss when adjusting the pressure in the fuel cell. becomes difficult.

An object of the present disclosure is to provide a fuel cell system that has a simple configuration and that can easily improve power recovery efficiency in a turbine as compared with the conventional one.

A fuel cell system according to the present disclosure includes a supply passage for supplying cathode gas to the fuel cell, a compressor for compressing the cathode gas and supplying it to the supply passage, and the fuel cell and the compressor in the supply passage. and an inlet valve capable of adjusting the flow rate of the cathode gas supplied to the fuel cell, a discharge passage for discharging the cathode exhaust gas from the fuel cell, a turbine wheel, and a turbine housing the turbine wheel a turbine to which cathode exhaust gas from the discharge channel is supplied into the turbine housing to generate power by the turbine wheel; and first and second connections that are communicable with each other. The first connecting portion is connected to a position between the compressor and the inlet valve in the supply flow path, and the first connecting portion is connected to a position upstream of the turbine wheel in the direction in which the cathode exhaust gas flows in the turbine housing. A bypass flow path to which a second connection part is connected, and a cathode gas flow rate provided between the first connection part and the second connection part in the bypass flow path and capable of adjusting the flow rate of the cathode gas flowing through the bypass flow path A bypass valve and a cathode exhaust gas discharged from the fuel cell and disposed upstream of the second connecting portion in a flow direction of the cathode exhaust gas discharged from the fuel cell and supplied to the turbine housing. and a variable nozzle unit capable of adjusting the flow rate.

In the fuel cell system, the variable nozzle unit may be arranged inside the turbine housing.

In the fuel cell system, the variable nozzle unit includes a frame-shaped sealing member that forms a channel inside, vanes that open and close the channel by contacting and separating from the sealing member, and pivotally supporting the vanes. The shaft extends parallel to the rotation axis of the turbine wheel, the vane has a seal surface that contacts and separates from the seal member, and the seal surface extends along the rotation axis. It may have a curved surface shape extending along the circumferential direction.

In the fuel cell system, the second connecting portion may be located between the vane and the turbine wheel when viewed along a direction parallel to the rotation axis.

In the above fuel cell system, an outlet portion of the bypass channel that forms the second connecting portion may extend substantially parallel to the rotating shaft.

In the above fuel cell system, the sealing member has an upstream portion located upstream in the direction in which the cathode exhaust gas flows, and a downstream portion located downstream of the upstream portion in the same direction. may be higher than the height position of the upstream portion in the gravity direction.

In the above fuel cell system, the vane has a closed portion, and when the vane is separated from the seal member, the closed portion is at least one of the second connection portions in the bypass flow path. part may be closed.

In the above fuel cell system, the vane and the shaft portion may be arranged downstream with respect to the seal member in a direction in which cathode exhaust gas flows.

In the above fuel cell system, the variable nozzle unit has vanes movable in a direction parallel to the rotation axis of the turbine wheel, and a seal member provided on the inner wall of the turbine housing, A flow rate of the cathode exhaust gas discharged from the fuel cell and supplied into the turbine housing may be adjusted by moving the vane to and from the sealing member.

According to the fuel cell system having the above configuration, it is possible to easily improve the power recovery efficiency in the turbine as compared with the conventional system.

1 is a diagram schematically showing a fuel cell system 100 according to Embodiment 1; FIG. 4 is a diagram schematically showing a fuel cell system 100a in Comparative Example 1. FIG. FIG. 10 is a diagram schematically showing a fuel cell system 100b in Comparative Example 2; FIG. 10 is a diagram showing a turbine 5 and a variable nozzle unit 11 (closed state) provided in a fuel cell system according to Embodiment 2; FIG. 8 is a perspective view showing a variable nozzle unit 11 according to Embodiment 2; FIG. 10 is a diagram showing a turbine 5 and a variable nozzle unit 11 (open state) provided in a fuel cell system according to Embodiment 2; FIG. 11 is a perspective view showing vanes 13m provided in a fuel cell system (variable nozzle unit) according to Embodiment 3; FIG. 10 is a diagram showing a turbine 5 and a variable nozzle unit 11b (closed state) provided in a fuel cell system according to Embodiment 4 of Embodiment 4; FIG. 11 is a cross-sectional view showing a turbine 5 and a variable nozzle unit 11c (closed state) provided in a fuel cell system according to Embodiment 5; FIG. 11 is a cross-sectional view showing a turbine 5 and a variable nozzle unit 11c (open state) provided in a fuel cell system according to Embodiment 5; FIG. 14 is a cross-sectional view showing a turbine 5 and a variable nozzle unit 11c (closed state) provided in a modified example of the fuel cell system according to Embodiment 5;

Embodiments will be described below with reference to the drawings. In the following description, the same reference numerals are given to the same parts and equivalent parts, and redundant description may not be repeated.

[Embodiment 1]
(Fuel cell system 100)
FIG. 1 is a diagram schematically showing a fuel cell system 100 according to Embodiment 1. FIG. The fuel cell system 100 includes a fuel cell 1, a cathode gas supply system 2 and an anode gas supply system (not shown).

The fuel cell 1 generates power by being supplied with an anode gas (hydrogen) and a cathode gas (air). The cathode gas supply system 2 includes a compressor 3, a motor 4m, a turbine 5, a supply channel 6, an inlet valve 7, a discharge channel 8, a bypass channel 9, a bypass valve 10, and a variable nozzle unit 11.

The compressor 3 has a compressor wheel 3w and a compressor housing 3h that houses the compressor wheel 3w. Cathode gas (arrow AR1) is supplied to compressor wheel 3w in compressor housing 3h through port 3s. Cathode gas is supplied to supply channel 6 through port 3d in a compressed state. The supply channel 6 connects the inlet 1a of the fuel cell 1 and the port 3d of the compressor 3, and supplies cathode gas to the fuel cell 1 (arrow AR2).

The discharge passage 8 connects the outlet 1b of the fuel cell 1 and the port 5s of the turbine 5, and discharges the cathode exhaust gas from the fuel cell 1 (arrow AR3). The turbine 5 has a turbine wheel 5w and a turbine housing 5h that houses the turbine wheel 5w. Cathode exhaust gas from the discharge passage 8 is supplied to the turbine wheel 5w in the turbine housing 5h through the port 5s and discharged from the port 5d (arrow AR4). The turbine 5 then recovers energy via the turbine wheel 5w to generate power.

The motor 4m is accommodated in the center housing 4h. Compressor wheel 3w and turbine wheel 5w are connected via shaft 4s. The energy recovered by the turbine wheel 5w is used as rotational driving force to rotate the compressor wheel 3w. The compressor wheel 3w can also be driven to rotate by the motor 4m.

An inlet valve 7 is provided between the fuel cell 1 and the compressor 3 in the supply channel 6 . The inlet valve 7 is composed of, for example, a pressure regulating valve, more specifically an electromagnetic valve, and can adjust the flow rate of the cathode gas supplied to the fuel cell 1 .

The bypass channel 9 has a first connection portion 9a and a second connection portion 9b that can communicate with each other. A first connection 9 a of the bypass channel 9 is connected to a position in the supply channel 6 between the compressor 3 and the inlet valve 7 . The second connecting portion 9b of the bypass flow path 9 is connected to a position upstream of the turbine wheel 5w in the direction in which the cathode exhaust gas flows inside the turbine housing 5h.

In FIG. 1, the second connection portion 9b is provided so as to pass through a wall portion of the turbine housing 5h on the far side from the center housing 4h. The second connecting portion 9b may be provided so as to penetrate a wall portion of the turbine housing 5h on the side closer to the center housing 4h.

The bypass flow path 9 bypasses the fuel cell 1 and supplies the cathode gas discharged from the compressor 3 to the turbine 5 . A bypass valve 10 is provided between the first connection portion 9 a and the second connection portion 9 b in the bypass flow path 9 . The bypass valve 10 can adjust the flow rate of the cathode gas flowing through the bypass channel 9 .

Here, in the fuel cell system 100a of Comparative Example 1 (FIG. 2), a pressure regulating valve 11a composed of an electromagnetic valve or the like is employed on the outlet side of the fuel cell 1. As shown in FIG. On the other hand, in this embodiment, the variable nozzle unit 11 is adopted on the outlet side of the fuel cell 1 (FIG. 1). A second connecting portion 9b of the bypass flow path 9 is provided between the variable nozzle unit 11 and the turbine wheel 5w in the direction in which the cathode exhaust gas flows.

The variable nozzle unit 11 converts pressure energy of fluid passing through the variable nozzle unit 11 into velocity energy. The variable nozzle unit 11 is arranged upstream of the position of the second connecting portion 9b of the bypass channel 9 in the direction in which the cathode exhaust gas discharged from the fuel cell 1 flows. The variable nozzle unit 11 can adjust the flow rate of the cathode exhaust gas discharged from the fuel cell 1 and supplied into the turbine housing 5h.

The variable nozzle unit 11 of the present embodiment further blocks or substantially blocks the flow of fluid from the upstream portion of the variable nozzle unit 11 to the downstream portion of the variable nozzle unit 11 in the direction in which the cathode exhaust gas flows. It is possible. The variable nozzle unit 11 can also block or substantially block the flow of fluid in the opposite direction.

(action and effect)
For example, when the bypass valve 10 is opened and the inlet valve 7 and the variable nozzle unit 11 are closed, the cathode gas discharged from the compressor 3 is supplied to the turbine 5 through the bypass passage 9 without passing through the fuel cell 1. be. The cathode gas is discharged from port 5d with energy recovered by turbine wheel 5w.

Even in the case of Comparative Example 1 (FIG. 2), when the bypass valve 10 is opened and the inlet valve 7 and the pressure regulating valve 11a are closed, the cathode gas discharged from the compressor 3 bypasses the fuel cell 1 without passing through it. It is supplied to turbine 5 through flow path 9 . Fuel cell system 100 in Embodiment 1 can perform the same operation by bypass flow path 9 and variable nozzle unit 11 .

By closing the inlet valve 7 and the variable nozzle unit 11 when the operation is stopped, it is possible to cut off or substantially cut off the input/output of the fluid to the fuel cell 1 via the inlet portion 1a and the outlet portion 1b. becomes.

When the variable nozzle unit 11 is opened, the cathode exhaust gas passes through the variable nozzle unit 11, thereby converting the pressure energy of the cathode exhaust gas into velocity energy. A differential pressure is generated between the upstream side and the downstream side of the variable nozzle unit 11 . By controlling the degree of opening of each of the inlet valve 7, the bypass valve 10 and the variable nozzle unit 11, the pressure inside the fuel cell 1 can be set to an appropriate value. The conversion efficiency of the variable nozzle unit 11 can be easily made higher than that of the pressure regulating valve 11a (FIG. 2) in Comparative Example 1, and the amount of regeneration can be increased.

That is, the pressure loss that can occur when the pressure is adjusted by the variable nozzle unit 11 is smaller than the pressure loss that can occur when the pressure is adjusted using the pressure regulating valve 11a. The cathode exhaust gas is supplied to the turbine wheel 5w while having more kinetic energy. Therefore, according to the present embodiment, it is possible to easily improve the power recovery efficiency in the turbine 5 compared to the conventional configuration and the configuration of Comparative Example 1, and the power consumption in the vehicle or the like in which the fuel cell system 100 is mounted. Efficiency can be improved.

According to the fuel cell system 100, the variable nozzle unit 11 is arranged upstream of the position of the second connecting portion 9b of the bypass channel 9 in the direction in which the cathode exhaust gas discharged from the fuel cell 1 flows. By closing the inlet valve 7 and the variable nozzle unit 11, the inlet portion 1a and the outlet portion 1b of the fuel cell 1 can be closed.

Here, in the fuel cell system 100b of Comparative Example 2 (FIG. 3), the second connecting portion 9b of the bypass channel 9 is located between the outlet portion 1b of the fuel cell 1 in the exhaust channel 8 and the port 5s of the turbine 5. connected to the part of In order to close the inlet portion 1a and the outlet portion 1b of the fuel cell 1, that is, to bring the fuel cell 1 into a closed state, not only the inlet valve 7 and the variable nozzle unit 11 but also the bypass valve 10 are closed. should also be closed.

In the fuel cell system 100 of Embodiment 1, the closed state of the fuel cell 1 can be realized by closing the inlet valve 7 and the variable nozzle unit 11 . In the case of Comparative Example 2, in order to obtain the closed state of the fuel cell 1, the closing performance of the inlet valve 7, the variable nozzle unit 11 and the bypass valve 10 must be ensured. In the first embodiment, the bypass valve 10 is not required to have high closing performance as compared with the second comparative example, so that the system can be constructed at a low cost.

In the fuel cell system 100 of Embodiment 1, when the fuel cell is closed, both the bypass channel 9 and the discharge channel 8 need to be closed. can be closed.

In the fuel cell system 100, the variable nozzle unit 11 is arranged inside the turbine housing 5h. The distance between the variable nozzle unit 11 and the turbine wheel 5w is shorter than when the variable nozzle unit 11 is arranged outside the turbine housing 5h. Immediately after the pressure energy of the cathode exhaust gas is converted into velocity energy by the variable nozzle unit 11, the cathode exhaust gas is imparted to the turbine wheel 5w with more kinetic energy.

[Embodiment 2]
FIG. 4 is a diagram showing the turbine 5 and the variable nozzle unit 11 provided in the fuel cell system according to Embodiment 2. The turbine housing extends along a direction parallel to the rotation axis 5c of the turbine wheel 5w (shaft 4s). It shows how each element in 5h is viewed. FIG. 5 is a perspective view showing the variable nozzle unit 11 according to Embodiment 2. FIG.

As in the case shown in FIG. 1, the second connecting portion 9b is provided so as to penetrate the wall portion of the turbine housing 5h on the far side from the center housing 4h (FIG. 1). Therefore, the second connecting portion 9b is illustrated in FIG. 4 using a dashed line for convenience. The second connecting portion 9b may be provided so as to penetrate a wall portion of the turbine housing 5h on the side closer to the center housing 4h.

The variable nozzle unit 11 has a seal member 12 , vanes 13 and a shaft portion 14 . The sealing member 12 has a frame-like shape and forms a flow path 12r inside. The seal member 12 has an upstream portion 12a, a downstream portion 12c, and intermediate portions 12b and 12d (FIG. 5). The upstream portion 12a is located on the upstream side in the direction in which the cathode exhaust gas flows, and the downstream portion 12c is located on the downstream side of the upstream portion 12a in the same direction (see FIG. 4).

The vane 13 has a plate-like shape. An upstream end of the vane 13 is pivotally supported by the shaft portion 14 . The shaft portion 14 is connected to the drive source 15 . The shaft portion 14 is driven by the drive source 15, and the vane 13 rotates integrally with the shaft portion 14 (arrow DR in FIG. 5).

In the present embodiment, the shaft portion 14 extends parallel to the rotation axis 5c of the turbine wheel 5w (FIG. 4), and the vane 13 has a seal surface 13s that contacts and separates from the seal member 12. As shown in FIG. The seal surface 13s extends in a direction parallel to the rotating shaft 5c of the turbine wheel 5w and has a curved shape extending along the circumferential direction of the rotating shaft 5c. 13 s of seal surfaces are arrange|positioned so that it may become substantially parallel to the shape of the internal peripheral surface of the turbine housing 5h.

According to the variable nozzle unit 11 having the configuration described above, the flow path 12r is opened and closed by the sealing surface 13s of the vane 13 coming into contact with and separating from the sealing member 12. As shown in FIG. The variable nozzle unit 11 blocks or substantially blocks, with less leakage, the flow of fluid from the upstream portion of the variable nozzle unit 11 to the downstream portion of the variable nozzle unit 11 in the flow direction of the cathode exhaust gas. It is possible to The variable nozzle unit 11 can also block or substantially block the flow of fluid in the opposite direction.

As shown in FIG. 4, the vane 13 and the shaft portion 14 are preferably arranged downstream with respect to the sealing member 12 in the direction in which the cathode exhaust gas flows. Compared to the case where the vane 13 and the shaft portion 14 are arranged on the upstream side with respect to the seal member 12 , it becomes easier to form a sealed state or a substantially sealed state by the vane 13 and the seal member 12 .

As shown in FIG. 6, the sealing surface 13s of the vane 13 has a curved shape extending along the circumferential direction of the rotating shaft 5c of the turbine wheel 5w. When the variable nozzle unit 11 is open, that is, when the vane 13 is separated from the seal member 12, the variable nozzle unit 11 smoothly guides the cathode exhaust gas from the exhaust passage 8 toward the turbine wheel 5w. The cathode exhaust gas guided by the variable nozzle unit 11 can flow tangentially to the rotating direction of the turbine wheel 5w, and as a result, the turbine 5 can convert fluid pressure energy into velocity energy with high conversion efficiency. It becomes possible.

As shown in FIG. 4, when viewed along a direction parallel to the rotation axis 5c of the turbine wheel 5w, the second connecting portion 9b of the bypass flow path 9 is positioned between the vane 13 and the turbine wheel 5w. I hope you are. Fluid flows through the turbine housing 5h to rotate the turbine wheel 5w. Turbulence in the fluid can reduce the kinetic energy imparted from the fluid to the turbine wheel 5w. According to the above configuration, the second connection portion 9b is easily covered with the vanes 13, and the influence of the cathode gas from the second connection portion 9b on the fluid that directly contributes to the rotation of the turbine wheel 5w is reduced. It becomes possible.

In the configuration shown in FIG. 4, the second connecting portion 9b is positioned between the vane 13 and the turbine wheel 5w in the radial direction of the turbine wheel 5w. The second connecting portion 9b may be provided at the position P1 or the position P2 shown in FIG. Even when the second connection portion 9b is provided at the position shown in FIG. In the direction of flow, the variable nozzle unit 11 is located upstream of the second connection portion 9b, and the turbine wheel 5w is located downstream of the second connection portion 9b.

As shown in FIG. 1, the outlet portion of the bypass flow path 9 forming the second connecting portion 9b preferably extends substantially parallel to the rotation axis 5c of the turbine wheel 5w. The above configuration also makes it possible to reduce the influence of the cathode gas from the second connection portion 9b on the fluid that directly contributes to the rotation of the turbine wheel 5w.

[Embodiment 3]
FIG. 7 is a perspective view showing vanes 13m provided in the fuel cell system (variable nozzle unit) according to the third embodiment. The vane 13m has a portion that forms the sealing surface 13s and a bulging portion 13t that bulges from the portion, and exhibits a substantially L-shaped cross-sectional shape as a whole. The surface of the bulging portion 13t constitutes the closing portion 13c. The closing portion 13c preferably closes at least a portion of the second connecting portion 9b in the bypass flow path 9 in a state where the vane 13 is separated from the sealing member 12 (see FIG. 5, etc.).

In a state in which a large amount of cathode exhaust gas is supplied into the turbine housing 5h, the presence of the second connection portion 9b and the supply of fluid from the second connection portion 9b cause turbulence in the cathode exhaust gas within the turbine housing 5h. can be. According to the above configuration, part or most of the bypass passage 9 is blocked by the blocking portion 13c when the variable nozzle unit is opened to some extent, so that it is possible to suppress the occurrence of turbulence in the cathode exhaust gas in the turbine housing 5h. .

[Embodiment 4]
FIG. 8 is a diagram showing the turbine 5 and the variable nozzle unit 11b (closed state) provided in the fuel cell system according to the fourth embodiment.

In the variable nozzle unit 11b, the seal member 12 has an upstream portion 12a located upstream in the direction in which the cathode exhaust gas flows, and a downstream portion 12c located downstream of the upstream portion 12a in the same direction. The height position of the downstream portion 12c in the direction of gravity is higher than the height position of the upstream portion 12a in the direction of gravity.

When the moisture accumulated near the downstream portion 12c freezes, the vane 13 and the seal member 12 are stuck together, making it difficult for the vane 13 to open and close the variable nozzle unit 11 (flow path 12r). According to the above configuration, the height position of the downstream portion 12c in the direction of gravity is higher than the height position of the upstream portion 12a in the direction of gravity. along the surface of the upstream portion 12a. It is possible to suppress the occurrence of freezing in a narrow range near the downstream portion 12c.

[Embodiment 5]
FIG. 9 is a cross-sectional view showing the turbine 5 and the variable nozzle unit 11c (closed state) provided in the fuel cell system according to the fifth embodiment. In Embodiment 5, a partition wall 17 is provided on the side opposite to the port 5d when viewed from the turbine wheel 5w (that is, on the side of the motor 4m). The partition 17 has a disk-like shape, and the partition 17 is provided with a recess forming portion 19 . The recess forming portion 19 forms a recess that is recessed on the side of the motor 4m.

A shaft portion 14 of the variable nozzle unit 11 c is arranged so as to pass through the recess forming portion 19 . The shaft portion 14 is axially movable by a drive source 15 . The variable nozzle unit 11c has a vane 13 movable in a direction parallel to the rotating shaft 5c of the turbine wheel 5w, and a seal member 12 provided on the inner wall 5u of the turbine housing 5h. When the vane 13 is in contact with the seal member 12, the communication between the space located on the turbine wheel 5w side with respect to the variable nozzle unit 11c and the space 5e on the opposite side is blocked or substantially blocked. .

FIG. 10 is a cross-sectional view showing the turbine 5 and the variable nozzle unit 11c (open state) provided in the fuel cell system according to the fifth embodiment. The movement of the vane 13 to and from the sealing member 12 adjusts the flow rate of the cathode exhaust gas (AR5 shown in FIG. 10) discharged from the fuel cell and supplied into the turbine housing 5h.

In the above configuration, the second connection portion 9b of the bypass flow path 9 is preferably connected to the recessed space inside the recessed portion 19 . Even when the second connection portion 9b is provided at this position, the variable nozzle unit 11 is positioned upstream of the second connection portion 9b in the direction in which the cathode exhaust gas discharged from the fuel cell 1 flows. The wheel 5w is positioned downstream of the second connecting portion 9b.

(Modification of Embodiment 5)
As shown in FIG. 11, a partition wall 5v may be provided inside the turbine housing 5h. The partition wall 5v constitutes an inner wall 5u of the turbine housing 5h, and a seal member 12 is provided on the inner wall 5u. The partition wall 5v allows communication between the second connecting portion 9b of the bypass flow path 9 and the space in the turbine housing 5h where the turbine wheel 5w is arranged. This configuration also provides the same actions and effects as the above-described embodiment.

In the fifth embodiment and its modification, the vane 13 is not only movable in the axial direction, but may also rotate around the shaft portion 14 in the same manner as in the first to fourth embodiments. That is, the technical ideas disclosed in the fifth embodiment and its modifications can be implemented in combination with the first to fourth embodiments.

Although the embodiments have been described above, the above disclosure is illustrative in all respects and is not restrictive. The technical scope of the present invention is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope of equivalence to the scope of claims.

1 fuel cell, 1a inlet, 1b outlet, 2 cathode gas supply system, 3 compressor, 3d, 3s, 5d, 5s port, 3h compressor housing, 3w compressor wheel, 4h center housing, 4m motor, 4s shaft, 5 turbine , 5c rotating shaft, 5e space, 5h turbine housing, 5u inner wall, 5v partition wall, 5w turbine wheel, 6 supply channel, 7 inlet valve, 8 discharge channel, 9 bypass channel, 9a first connection part, 9b second 2 connection part 10 bypass valve 11, 11b, 11c variable nozzle unit 11a pressure regulating valve 12 sealing member 12a upstream part 12b, 12d intermediate part 12c downstream part 12r flow path 13, 13m vane 13c blockage Part 13s Sealing surface 13t Swelling part 14 Shaft part 15 Drive source 17 Partition wall 19 Recess formation part 100, 100a, 100b Fuel cell system AR1, AR2, AR3, AR4, DR Arrow P1, P2 position.

Claims (9)

a fuel cell;
a supply channel for supplying a cathode gas to the fuel cell;
a compressor that compresses the cathode gas and supplies it to the supply channel;
an inlet valve provided between the fuel cell and the compressor in the supply flow path and capable of adjusting the flow rate of the cathode gas supplied to the fuel cell;
a discharge channel for discharging cathode exhaust gas from the fuel cell;
a turbine having a turbine wheel and a turbine housing containing the turbine wheel, wherein cathode exhaust gas from the discharge passage is fed into the turbine housing to generate power by the turbine wheel;
a first connection and a second connection in communication with each other, the first connection being connected to a position between the compressor and the inlet valve in the supply flow path; a bypass flow path to which the second connecting portion is connected at a position upstream of the turbine wheel in the direction in which the cathode exhaust gas flows;
a bypass valve provided between the first connection portion and the second connection portion in the bypass flow channel and capable of adjusting the flow rate of the cathode gas flowing through the bypass flow channel;
The cathode exhaust gas discharged from the fuel cell is arranged upstream of the position of the second connecting portion in the flow direction of the cathode exhaust gas, and the flow rate of the cathode exhaust gas discharged from the fuel cell and supplied into the turbine housing can be adjusted. and a variable nozzle unit,
fuel cell system. The variable nozzle unit is arranged inside the turbine housing,
The fuel cell system according to claim 1. The variable nozzle unit has a frame-shaped sealing member that forms a flow path inside, vanes that open and close the flow path by contacting and separating from the sealing member, and a shaft that supports the vanes,
The shaft portion extends parallel to the rotation axis of the turbine wheel,
The vane has a sealing surface that contacts and separates from the sealing member,
The sealing surface has a curved surface shape extending along the circumferential direction of the rotating shaft,
3. The fuel cell system according to claim 2. when viewed along a direction parallel to the axis of rotation, the second connection is located between the vane and the turbine wheel;
4. The fuel cell system according to claim 3. an outlet portion of the bypass channel forming the second connecting portion extends substantially parallel to the rotation axis;
5. The fuel cell system according to claim 3 or 4. The seal member has an upstream portion positioned upstream in a direction in which the cathode exhaust gas flows, and a downstream portion positioned downstream of the upstream portion in the same direction,
the height position of the downstream portion in the direction of gravity is higher than the height position of the upstream portion in the direction of gravity;
The fuel cell system according to any one of claims 3 to 5. The vane has a blockage,
In a state in which the vane is separated from the seal member, the blocking portion blocks at least a portion of the second connection portion in the bypass flow path,
The fuel cell system according to any one of claims 3 to 6. The vane and the shaft are arranged downstream with respect to the sealing member in the direction in which the cathode exhaust gas flows,
The fuel cell system according to any one of claims 3 to 7. The variable nozzle unit is
vanes movable in a direction parallel to the axis of rotation of the turbine wheel;
a sealing member provided on the inner wall of the turbine housing;
The movement of the vane to and from the sealing member adjusts the flow rate of the cathode exhaust gas discharged from the fuel cell and supplied into the turbine housing.
3. The fuel cell system according to claim 2.

Images