JP7816461B2 - fuel cell unit - Google Patents

Description

Embodiments of the present invention relate to technology for housing air-cooled fuel cell units.

Generally, a fuel cell unit is composed of a fuel cell stack in which fuel cells are stacked, and peripheral devices required for using the fuel cell stack as a power source.
Conventionally, a water-cooled fuel cell unit is housed in a predetermined case and sealed to protect it from external moisture.
However, since air-cooled fuel cell units use outside air as a reactant gas and a cooling medium, it is desirable for the fuel cell stack to be exposed to the outside air. The fuel cell stack is not housed in a single case along with the peripheral devices, but is instead placed outside the peripheral device housing case that houses the peripheral devices.

JP 2016-167463 A

Peripheral equipment for a fuel cell stack needs to be placed close to the fuel cell stack. Therefore, when operating in a humid indoor environment such as inside a room or a car, it is necessary to prevent moisture contained in the outside air introduced into the fuel cell stack from entering the peripheral equipment housing case.

However, the connection ports provided for connecting to peripheral devices are larger than the actual space for wiring to pass through in order to accommodate misalignment due to thickness tolerances in the stacking direction of the fuel cell stack, which makes sealing difficult.

The present invention was made in consideration of these circumstances, and aims to provide a fuel cell unit that can efficiently prevent the intrusion of water vapor with minimal waterproofing treatment.

A fuel cell unit according to an embodiment of the present invention comprises an air-cooled fuel cell stack in which air is supplied to stacked fuel cell cells, a voltage measurement tab protruding from the fuel cell, a cell monitoring board electrically connected to the voltage measurement tab and monitoring the output of the fuel cell, a housing for accommodating the cell monitoring board, and a first connection port provided in the housing through which the voltage measurement tab is inserted from the fuel cell stack outside the housing, the housing being partitioned by a first partition plate into a first region in which the first connection port is located and a second region in which the cell monitoring board is located, and the connection port provided in the first partition plate is sealed in order to connect the wiring connected to the voltage measurement tab to the cell monitoring board.

The present invention provides a fuel cell unit that can efficiently prevent water vapor from entering with minimal waterproofing treatment.

FIG. 2 is a perspective view of a fuel cell unit according to an embodiment of the present invention, in which a peripheral device housing case is partially transparent. FIG. 2 is a front view of the fuel cell unit according to the embodiment of the present invention, seen from the peripheral device housing section. FIG. 2 is a perspective view of the fuel cell unit of FIG. 1 in which a partition plate is further arranged. FIG. 2 is a front view of the fuel cell unit according to the embodiment of the present invention, seen from the circuit board placement area side of the peripheral device housing case. FIG. 2 is a perspective view of the fuel cell unit of FIG. 1 with a cover plate displayed;

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, a fuel cell unit 100 according to an embodiment will be outlined with reference to FIGS. 1 and 2. FIG.
FIG. 1 is a perspective view of a fuel cell unit 100 according to an embodiment, in which a peripheral device housing case 21 is partially transparent.
FIG. 2 is a front view of the fuel cell unit 100 according to the embodiment of the present invention, seen from the peripheral device housing section 20 side.
Hereinafter, the fuel cell will be referred to as an "FC (Fuel cell)", the fuel cell unit 100 will be referred to as an "FC unit 100", the fuel cell 11 will be referred to as an "FC cell 11", and the fuel cell stack 10 will be referred to as an "FC stack 10".

The FC unit 100 according to the embodiment is used, for example, in a fuel cell system mounted on a mobile body such as a fuel cell vehicle or in a stationary fuel cell system. As shown in Fig. 1, the FC unit 100 has an FC stack 10 and a peripheral device housing 20 that are, for example, perpendicular to each other and fixed to each other at their ends.
The FC stack 10 is mainly composed of a stack of several to several hundred FC cells 11 inserted into positioning pins (not shown).
In each of the drawings (FIGS. 1 to 5), only a few representative FC cells 11 are shown spaced apart so that the overall arrangement structure can be seen.

The FC stack 10 is constructed by sandwiching a stack of the FC cells 11 between two end plates 13 in the stacking direction, and fastening the end plates 13 together with bolts using fastening bars (not shown).
Furthermore, a current collector plate 17 equipped with a power output terminal 16 is disposed between the FC cell 11 at the endmost position in the stacking direction and the end plate 13. The current collector plate 17 collects the generated current of each FC cell 11 and outputs it from the power output terminal 16. Furthermore, an air supply fan 18 is provided on a wide surface of the FC stack 10, and air 15, which serves as both a reactant gas and a cooling medium, is supplied to the FC cells 11. Furthermore, one or more FC cells 11 are provided with a voltage measurement tab 19.

Next, the peripheral device housing section 20 will be described.
As shown in FIG. 1, the peripheral device housing 20 is configured by housing a peripheral device housing case (housing) 21, and mainly housing a cell monitoring board 24 (FIG. 4), a current sensor 25, and a main relay 26 therein.
The peripheral device housing case 21 is also provided with a plurality of connection ports (31 to 33) for connecting the devices in the peripheral device housing case 21 to external devices.

A voltage measurement tab 19 is inserted into the first connection port 31 from the FC stack 10 outside the peripheral device housing case 21. A wire 23 is connected to the inserted voltage measurement tab 19.
This wiring 23 is connected to an internal communication jack 38 of a mounting stand 27 on which the cell monitoring board 24 is mounted within the peripheral device housing 21. The cell monitoring board 24 monitors the output of the FC cell 11.

In addition, one bus bar 36 for transmitting output current is inserted into each of the two second connection ports 32 from inside the peripheral device housing case 21. This bus bar 36 is connected to the power extraction terminal 16 of the current collector plate 17.

Furthermore, a current sensor 25 is provided on one side of the bus bar 36 to measure the output current of the FC stack 10 .
A main relay 26 is provided on one side of the bus bar 36, and switches the power supply ON/OFF by opening and closing contacts. A relay box 39 that houses the main relay 26 also houses other electronic devices such as an FC converter 46 and a control device 42 that controls the FC converter 46, as appropriate.
Although the main relay 26 and the current sensor 25 are provided on different bus bars 36 in FIG. 1, they may be provided on the same bus bar 36.

Furthermore, power output jacks 30 that are connected to a power source such as a motor via an inverter or the like are inserted from outside the peripheral device housing case 21 into the two third connection ports 33 .
Furthermore, an external communication jack 29 that is connected to the control device 42 via a communication cable (not shown) is inserted into the fourth connection port 34 .

The external communication jack 29 is a jack for connecting an external communication cable for communication between the control device 42 and a control mechanism (not shown) mounted on, for example, a fuel cell vehicle.
The control device 42 and the cell monitoring board 24 are communicatively connected via a communication connector 48 .
The bus bar 36 is provided with a service plug unit 49 for blocking the output of the voltage of the FC stack 10 to the outside.

Next, the partition plates 51 and 52 that separate the interior of the peripheral device housing case 21 will be described with reference to FIGS.
FIG. 2 is a front view of the FC unit 100, as seen from the direction in which the FC stack 10 faces forward.
In FIG. 2, the narrow side of the peripheral device housing case 21 is not shown, but the first partition plate 51 and the peripheral devices therein can be seen.

As shown in Figure 2, the first partition plate 51 divides the peripheral equipment housing case 21 into a connecting area 60 in which the first connection port 31 and the second connection port 32 are located, and an equipment housing area in which the cell monitoring board 24, the current sensor 25, and the main relay 26 are located.
The first partition plate 51 is provided with a fifth connection port 35 through which a bus bar 36 connected to the power output terminal 16 is inserted into the equipment housing area.
The first partition plate 51 is also provided with a fourth connection port 34 for connecting the wiring 23 connected to the voltage measurement tab 19 to the monitoring connector 53 .

The connecting area 60 is an area that allows outside air to enter. A portion of the air 15 sent to the FC stack 10 by the air supply fan 18 enters the connecting area 60 from the first connection port 31.
It is desirable to provide a drain hole 54 in the connecting area 60, for example, at the bottom of the peripheral device housing case 21, so that if condensation occurs from the infiltrating air 15, the condensed water can be discharged through the drain hole 54.

3 is a perspective view of the FC unit 100 in FIG. 1, in which partition plates 51 and 52 are further arranged.
The side of the peripheral device housing case 21 facing the circuit board placement area 70 has a removable lid structure. In Fig. 3, the lid plate 56 (Fig. 5), which will be described in detail later, is removed. As in Fig. 2, the ceiling surface and narrow sides of the peripheral device housing case 21 are indicated by dashed lines so that the inside of the connecting area 60 and the power transmission area 80 can be seen.

4 is a front view of the FC unit 100 as seen from the circuit board placement area 70 side of the peripheral device housing case 21. FIG.
4, as in FIG. 3, the cover plate 56 of the peripheral device housing case 21 is removed to expose the board placement area 70, and the wall plate of the connecting area 60 is not shown.

The second partition plate 52 further divides the equipment housing area into a power transmission area 80 in which the current sensor 25 and the main relay 26 are arranged, and a board arrangement area 70 in which the cell monitoring board 24 is arranged.
The substrate placement area 70 is an area where the intrusion of air 15 containing water vapor is strictly prohibited.

The board placement area 70 is sealed with a sealant or the like to prevent the cell monitoring board 24 from coming into contact with moisture in the air 15 .
The partition plates 51 and 52 in the portion constituting the circuit board placement area 70 and all of the connection ports (33, 34) provided on the peripheral device housing case 21 are sealed.
It is also desirable that the contact portion between the second partition plate 52 and the first partition plate 51 and the contact portion between the second partition plate 52 and the peripheral device housing case 21 are completely sealed with a sealant or the like. Furthermore, the entire circuit board placement area 70 may be encapsulated with resin.
As will be described later, the connection ports (31 to 36) that are sealed vary depending on the shapes of the partition plates 51 and 52.

The power transmission area 80 is an area in which the intrusion of water vapor should be suppressed as much as possible. Because the degree of sealing of the power transmission area 80 can be set arbitrarily, sealing of the connection ports (35, 36, 37) provided on each surface that constitutes the power transmission area 80 is optional. However, it is preferable that these connection ports (35, 36, 37) be sealed.

Since the power transmission area 80 is separated from the connecting area 60 by the first partition plate 51, the inflow of air 15 into the power transmission area 80 is suppressed to some extent.
The power transmission region 80 may also be made of a porous membrane made of fluororesin that has breathing holes to prevent the intrusion of water vapor and allow only dry air to infiltrate.
As described above, by dividing the area into areas according to the level of waterproofing performance required, it is possible to provide appropriate waterproofing in the right places with a minimum amount of waterproofing treatment, without excess.

Next, the partition plates 51 and 52 and the cover plate 56 for improving convenience will be described with reference to FIGS.
5 is a perspective view of the FC unit 100 of FIG. 1, showing the cover plate 56. FIG.

Since the board placement area 70 requires high sealing performance, if the board placement area 70 includes various connection ports 34, 35, etc., a strict sealing process will be required. Furthermore, if the board placement area 70 is made wider, the overall size of the peripheral device housing 20 will increase. Therefore, it is desirable to make the board placement area 70 as small as possible and to design it so that it does not include the connection ports 34, 35 as much as possible.
Therefore, as shown in Figure 3, the second partition plate 52 is formed of a flat portion 58 and a storage portion 59 which has a concave shape that protrudes toward the inside of the peripheral device storage case 21 relative to the flat portion 58 and in which the cell monitoring board 24 is stored.

By forming the second partition plate 52 in this shape, the connection ports 34, 35 are not included within the board placement area 70. Furthermore, the board placement area 70 can be made as small as necessary.
Furthermore, since the cell monitoring board 24 can be arranged inward of the peripheral device housing case 21, the peripheral device housing case 21 does not expand by the amount of the cell monitoring board 24, and the entire peripheral device housing case 21 can be made compact.

A cover plate 56 that closes the opening of the storage section 59 is provided. By opening and closing the peripheral device housing case 21 with this cover plate 56, the interior of the peripheral device housing case 21 can be easily accessed.
Additionally, it is desirable to form a step 71 at the periphery of storage section 59 to accommodate the thickness of cover plate 56 so that the boundary between cover plate 56 and flat section 58 is flat. Since there is no step 71 at the boundary between cover plate 56 and flat section 58, cover plate 56 does not protrude, and peripheral device storage case 21 can be made compact.

As described above, with the fuel cell unit 100 according to this embodiment, by applying appropriate waterproofing treatment to each of the separated areas (60, 70, 80), it is possible to efficiently suppress the amount of water vapor that penetrates with minimal waterproofing treatment.

In addition, peripheral devices such as the cell monitoring board 24, current sensor 25, and main relay 26 can be pre-assembled on the partition plates 51 and 52 and then placed inside the peripheral device housing case 21. This improves assembly work efficiency compared to assembling peripheral devices one by one inside the peripheral device housing case 21, which has limited work space.

Although an embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention.
The embodiments may be embodied in various other forms, and various omissions, substitutions, modifications, and combinations may be made without departing from the spirit of the invention. The embodiments and their modifications are included in the scope of the inventions and their equivalents as defined in the claims, as well as in the scope and spirit of the inventions.

For example, the fuel cell stack and the peripheral device housing do not have to be connected perpendicularly or end-to-end, but may be arranged in a straight line, or the fuel cell stack may be placed on the peripheral device housing.
In addition, in an environment where wind from traveling can be utilized, such as in a vehicle, an air supply fan does not need to be provided.

10...Fuel cell stack (FC stack), 11...FC cell, 13...End plate, 5...Air, 16...Power output terminal, 17...Current collector plate, 18...Air supply fan, 19...Voltage measurement tab, 20...Peripheral device housing, 21...Peripheral device housing case, 23...Wiring, 24...Cell monitoring board, 25...Current sensor, 26...Main relay, 27...Installation stand, 29...External communication jack, 30...Power output jack, 31...First connection port, 32...Second connection port, 33...Third connection port, 34...Fourth connection port, 3 5...Fifth connection port, 36...Bus bar, 38...Internal communication jack, 39...Relay box, 42...Control device, 46...FC converter, 48...Communication connector, 49...Service plug unit, 51...First partition plate (partition plate), 52...Second partition plate (partition plate), 53...Monitoring connector, 54...Drain hole, 56...Cover plate, 58...Flat portion, 59...Storage section, 60...Connecting area, 70...Platform placement area, 71...Step, 72...Rear panel, 80...Power transmission area, 100...Fuel cell unit (FC unit).

Claims (5)

an air-cooled fuel cell stack in which air is supplied to stacked fuel cell cells;
a voltage measurement tab protruding from the fuel cell;
a cell monitoring board electrically connected to the voltage measurement tab to monitor the output of the fuel cell;
a housing for accommodating the cell monitoring board;
a first connection port provided in the housing and into which the voltage measurement tab is inserted from the fuel cell stack outside the housing;
The housing is partitioned by a first partition plate into a first area in which the first connection port is arranged and a second area in which the cell monitoring board is arranged,
A fuel cell unit characterized in that a connection port provided in the first partition plate for connecting wiring connected to the voltage measurement tab to the cell monitoring board is sealed. a power output terminal protruding from a current collector plate of the fuel cell stack;
a current sensor connected in series to the power output terminal for measuring an output current;
a second connection port provided on the housing and into which the power output terminal is inserted,
the second connection port is disposed in the first region in which the first connection port is disposed,
The fuel cell unit according to claim 1 , wherein the current sensor is disposed in the second region where the cell monitoring board is disposed. A main relay is provided to switch the supply of output power ON/OFF.
3. The fuel cell unit according to claim 1, wherein the main relay is disposed in the second area where the cell monitoring board is disposed. a second partition plate that partitions the second area in which the cell monitoring board is arranged;
The second partition plate is
A flat portion and
4. The fuel cell unit according to claim 1, further comprising: a storage section having a recessed shape that protrudes inward from the flat section of the housing, and in which the cell monitoring board is stored. a cover plate that closes the opening of the storage section;
5. The fuel cell unit according to claim 4, further comprising: a step provided on the periphery of the storage section so that a boundary line between the cover plate and the flat section is flat.