In-vehicle fuel cell system

Abstract

To inhibit a temperature of a fuel cell stack from being decreased by air flowing into a motor room when a vehicle travels.SOLUTION: An on-vehicle fuel cell system includes: a fuel cell stack; and a gas processing part which delivers / receives a gas to / from the fuel cell stack and has a combustor for combusting exhaust gas from the fuel cell stack. The on-vehicle fuel cell system is mounted within a motor room of a vehicle. The gas processing part is disposed at a location, which is subject to influence of convective flow generated by outside air when the vehicle travels, in the motor room. The fuel cell stack is attached to a surface opposite to the location which is subject to influence of the convective flow of the gas processing part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This invention relates to an in-vehicle fuel cell system.

Background Art

[0002] As an electric vehicle using a motor as a drive source, a fuel cell vehicle equipped with a fuel cell stack as a power source has been studied. Patent Document 1 discloses a fuel cell vehicle in which a fuel cell stack is arranged in a motor room located forward of the passenger compartment.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the fuel cell vehicle disclosed in Patent Document 1, air (traveling wind) flowing into the motor room from the front during vehicle travel directly hits the fuel cell stack. As a result, the temperature of the fuel cell stack may decrease, and there is a risk that the power generation performance may decrease. In particular, when the fuel cell stack is a solid oxide fuel cell (SOFC), since it operates at a relatively high temperature, there is a high risk that the power generation performance will decrease if it is cooled by the traveling wind.

Means for Solving the Problems

[0005] According to one aspect of the present invention, an on-board fuel cell system includes a fuel cell stack and a gas processing unit having a combustor that exchanges gas with the fuel cell stack and combusts exhaust gas from the fuel cell stack, and is mounted in a motor compartment of a vehicle. The gas processing unit is located in the motor compartment in a location that is subject to convection by outside air while the vehicle is running, and the fuel cell stack is fixed to the surface of the gas processing unit opposite the location that is subject to convection. [Effects of the Invention]

[0006] The on-board fuel cell system of the present invention can prevent the temperature of the fuel cell stack from decreasing due to air flowing in while the vehicle is running. [Brief explanation of the drawings]

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] (First embodiment) 1 is a perspective view of a motor room in which an on-board fuel cell system according to a first embodiment is mounted, with the lower left side of the figure showing the front of the vehicle and the upper right side showing the rear of the vehicle.

[0010] This figure shows a motor room 100 provided in front of the vehicle for housing a drive source. In the motor room 100, a fuel cell stack 1 (first fuel cell stack 1A, second fuel cell stack 1B), a gas processing unit 2, a high-voltage converter 3, and a drive motor 4 are arranged. The fuel cell stack 1, the gas processing unit 2, and the high-voltage converter 3 are housed in a case 5. The operations of these components will be described later with reference to FIG. 2.

[0011] A side member 6 extending in the longitudinal direction of the vehicle is provided on the side of the motor room 100. The case 5 arranged in the motor room 100 is attached to the side member 6 using a suspension device 7. Further, a front member (not shown) extending in the vehicle width direction is provided in front of the motor room 100. The motor room 100 is formed by the side member 6 and the front member.

[0012] In addition to the drive motor 4 and the case 5, steering system components such as a transaxle device and a steering device (not shown in FIG. 1) are suspended from the side member 6. Further, a low-voltage control unit (not shown in FIG. 1) for controlling auxiliary machines and air conditioning is arranged in a region in the motor room that is in contact with the passenger compartment side at the rear of the vehicle.

[0013] The rotating shaft of the drive motor 4 is mechanically connected to an axle 8 via a transmission (not shown). Thus, when the rotating shaft of the drive motor 4 rotates, the front wheels (not shown) attached to the axle 8 rotate and the vehicle travels. Note that the drive motor 4 and the axle 8 may be connected without passing through a transmission.

[0014] FIG. 2 is a side view of the motor room 100 shown in FIG. 1. The left side of the figure indicates the front of the vehicle, and the right side of the figure indicates the rear of the vehicle.

[0015] The fuel cell stack 1 is a stacked cell in which solid oxide fuel cell (SOFC) cells are stacked. The fuel cell stack 1 is composed of a first fuel cell stack 1A and a second fuel cell stack 1B. When there is no need to distinguish between the two in the description, it is simply referred to as the fuel cell stack 1.

[0016] In the first fuel cell stack 1A and the second fuel cell stack 1B, a plurality of fuel cell cells are stacked in the vehicle front-rear direction. The number of stacked fuel cell cells in the first fuel cell stack 1A is larger than the number of stacked fuel cell cells in the second fuel cell stack 1B. Therefore, the first fuel cell stack 1A is configured to be longer in the front-rear direction than the second fuel cell stack 1B.

[0017] In this way, for the first fuel cell stack 1A and the second fuel cell stack 1B, the one with a longer stacking direction length (vehicle front-rear direction length) is arranged above. The fuel cell stack 1 may be composed of three or more fuel cell stacks 1. In that case, the longer one is arranged above and the shorter one is arranged below.

[0018] In this way, the stacking direction coincides with the vehicle front-rear direction, the first fuel cell stack 1A with a longer stacking direction length is arranged at the upper part, and the second fuel cell stack 1B with a shorter stacking direction length is arranged at the lower part. As a result, a relatively wide space is generated in the lower part of the motor room 100, so that an arrangement area for the drive motor 4 and the like can be provided.

[0019] The electric power generated by the fuel cell stack 1 is converted into the voltage of the high-voltage system in the high-voltage converter 3 and then supplied to the drive motor 4 and a battery (not shown). The battery is provided outside the motor room 100 (for example, at the lower part of the passenger compartment where passengers are accommodated). In addition, a low-voltage converter is further provided in the motor room 100 to perform mutual voltage conversion between the high-voltage system and the low-voltage system. Thereby, electric power is supplied to the low-voltage system.

[0020] The fuel cell stack 1 generates electricity as follows using the anode gas and the cathode gas supplied via the gas processing unit 2.

[0021] A catalyst for reforming fuel is provided on the anode electrode of the fuel cell stack 1 by coating or the like. When the fuel gas before reforming is supplied to the fuel cell stack 1, the reaction of the anode gas generated by reforming proceeds at the anode electrode. Further, cathode gas (air, oxygen) is supplied to the cathode electrode of the fuel cell stack 1. Thereby, in the fuel cell stack 1, power generation is performed using the anode gas and the cathode gas.

[0022] The gas processing unit 2 includes a heater and an evaporator in the fuel gas supply system. The liquid fuel supplied from a fuel tank (not shown) is heated by the heater, and the heated liquid fuel is evaporated by the evaporator to generate fuel gas. The generated fuel gas is supplied to the anode electrode of the fuel cell stack 1. At the same time, the gas processing unit 2 includes a compressor (not shown). The air (cathode gas) taken in from the outside via a blower is supplied to the cathode electrode of the fuel cell stack 1 by the compressor. Note that the fuel tank, the compressor, etc. connected to the gas processing unit 2 are arranged on the side of the case 5.

[0023] During the power generation of the fuel cell stack 1, off-gas (fuel off-gas, air off-gas) is discharged to the gas processing unit 2. The gas processing unit 2 further includes a combustor that burns the off-gas (fuel off-gas, air off-gas) discharged from the fuel cell stack to the exhaust system. Thereby, the discharge of the unburned fuel gas contained in the off-gas to the outside is suppressed. Further, the gas processing unit 2 includes a heat exchanger, and the cathode gas supplied to the fuel cell stack 1 can be heated by heat exchange using the heat generated by the combustor.

[0024] Thus, the gas processing unit 2 includes a heater and an evaporator provided in the fuel supply system, and a combustor and a heat exchanger provided in the exhaust system. During the operation of the fuel cell stack 1, the heater and the evaporator are heated by the heat generated by the combustor. Therefore, the gas processing unit 2 is heated by the combustor that generates heat during the off-gas treatment process, and its temperature rises.

[0025] In the gas processing unit 2, a fuel supply valve provided in the fuel path from the fuel tank and a compressor are controlled. Thereby, the supply amounts of the anode gas and the cathode gas to the fuel cell stack 1 are controlled. The control of the fuel supply valve and the compressor is performed by a controller (not shown) that controls the entire fuel cell system.

[0026] The controller controls the power generation of the fuel cell stack 1 by controlling the flow rates of the anode gas and the cathode gas supplied to the fuel cell stack 1 using the gas processing unit 2. When the state of charge (SOC) of the battery falls below the lower limit value, the controller supplies the anode gas and the cathode gas to the fuel cell stack 1 using the gas processing unit 2 to start the power generation by the fuel cell stack 1. On the other hand, when the SOC of the battery exceeds the upper limit value, the supply of the anode gas and the cathode gas of the gas processing unit 2 is stopped, and the drive of the fuel cell stack 1 is stopped. In this way, the controller controls the drive state of the fuel cell stack 1 by controlling the gas processing unit 2.

[0027] Also, as shown in this figure, two fuel cell stacks 1 (the first fuel cell stack 1A and the second fuel cell stack 1B) are connected to one gas processing unit 2. Therefore, a plurality of fuel cell stacks 1 can be operated without adding a gas processing unit 2, so that the configuration in the motor room 100 can be simplified.

[0028] As shown in the figure, the gas processing unit 2 is a rectangular structure in which various auxiliary machines through which high-pressure gas such as a combustor and a heat exchanger passes are configured as an integrated unit. The gas processing unit 2 is arranged such that a surface with a relatively large area faces the front of the vehicle. And the fuel cell stack 1 is fixed to the rear surface of the gas processing unit 2, that is, the surface facing the inside of the motor room 100. And when viewed from the front of the vehicle, the fuel cell stack 1 is arranged inside the gas processing unit 2, that is, so as not to protrude from the contour of the gas processing unit 2.

[0029] The case 5 is configured by connecting a front case 5F and a rear case 5R with their openings facing each other, and houses the fuel cell stack 1, the gas processing unit 2, and the high-voltage converter 3 inside. Specifically, the gas processing unit 2 and the high-voltage converter 3 are attached to the bottom in front of the front case 5F. A part of the fuel cell stack 1 and the high-voltage converter 3 attached to the gas processing unit 2 protrudes from the opening of the front case 5F. This configuration protruding from the front case 5F is covered by the rear case 5R.

[0030] In this way, the case 5 that houses the fuel cell stack 1, the gas processing unit 2, and the high-voltage converter 3 is configured. The case 5 is provided with holes (not shown) through which cables and pipes pass. In the following, the case 5 will be described as being configured to be airtight, but it may be configured to be able to take in outside air.

[0031] The upper surface of the case 5 is arranged below the bonnet (not shown) that covers the motor room 100, and a gap for shock absorption is formed. Since the lower surface of the case 5 is located above the lower surface of the motor room 100, collisions with road obstacles such as curbs and ruts can be avoided.

[0032] As described above, the long first fuel cell stack 1A in the stacking direction (front-rear direction) is disposed above, and the short second fuel cell stack 1B is disposed below. The end face at the rear of the vehicle of the case 5 (5R) has the lower portion 5B facing the second fuel cell stack 1B positioned more forward in the vehicle than the upper portion 5A facing the first fuel cell stack 1A. Therefore, the case 5 is configured with a large rear region in the lower portion 5B, and the drive motor 4 is provided in this region. That is, the drive motor 4 is disposed behind the lower portion of the case 5 and below the first fuel cell stack 1A.

[0033] Furthermore, a steering device 9 is provided below and in front of the vehicle of the drive motor 4. The steering device 9 is operated by a steering wheel in the vehicle interior to change the direction of the wheels attached to the axle 8. Thereby, the driver can control the traveling direction of the vehicle.

[0034] Of the end face at the rear of the vehicle of the case 5 (5R), the lowermost portion 5C positioned below the second fuel cell stack 1B is positioned more forward in the vehicle than the lower portion 5B facing the second fuel cell stack 1B. Therefore, a wider region is formed behind the lowermost portion 5C of the case 5, so that the steering device 9 can be disposed in this region.

[0035] Furthermore, in the motor room 100, a low-voltage control unit 10 is provided on the rear side of the vehicle. The low-voltage control unit 10 is a control unit that controls low-voltage devices such as a wiper and a hydraulic pump. And behind the low-voltage control unit 10, an upper dashboard 11 and a lower dashboard 12 that separate the motor room 100 from the vehicle interior are provided. The upper dashboard 11 and the lower dashboard 12 are made of hard plastic or the like and constitute the inner surface of the vehicle interior.

[0036] Also, an insulator 13 is provided between the low-voltage control unit 10, the upper dashboard 11, and the lower dashboard 12. The insulator 13 is made of a foaming material or the like and has heat insulation and sound insulation properties. Thereby, noise and heat generated in the motor room 100 are less likely to be transmitted into the vehicle interior.

[0037] Here, when the vehicle is running and the running wind blows into the motor room 100, the running wind blows against the surface of the case 5 where the gas treatment unit 2 is attached. Therefore, the gas treatment unit 2 is provided at a location that is easily affected by convection. And the surface of the case 5 where the running wind blows is relatively likely to have its temperature drop, but since the gas treatment unit 2 is equipped with a combustor or the like, heating control can be performed to keep the temperature constant.

[0038] Also, the fuel cell stack 1 is fixed to the rear surface of the gas treatment unit 2, that is, the surface on the opposite side of the surface of the case 5 against which the running wind blows. In this way, since the fuel cell stack 1 is provided behind the gas treatment unit 2 against which the running wind hits, the temperature of the fuel cell stack 1 is less likely to decrease. Although the case 5 is sealed, when the vehicle is running, the front surface of the case 5 (the bottom of the front case 5F) is easily cooled, so the temperature of the gas treatment unit 2 attached to the front surface of the case 5 is likely to drop. And the fuel cell stack 1 is arranged via the gas treatment unit 2 from the front surface of the case 5 against which the running wind blows, so the temperature is likely to be maintained.

[0039] In this way, the fuel cell stack 1 is fixed to the mounting surface facing the rear of the gas treatment unit 2. That is, in the gas treatment unit 2, the mounting surface of the fuel cell stack 1 faces the rear of the vehicle, and the surface on the opposite side of the mounting surface faces the front of the vehicle. In other words, since the surface on the opposite side of the mounting surface in the gas treatment unit 2 is affected by the running wind, the influence of the running wind on the fuel cell stack 1 provided on the mounting surface can be suppressed.

[0040] Note that the gas treatment unit 2 is provided with a manifold inside that branches the fuel supply paths for the anode gas and the cathode gas. On the fixing surface of the fuel cell stack 1, each of the branched supply channels is connected to the first fuel cell stack 1A and the second fuel cell stack 1B. Further, the gas treatment unit 2 is provided with a manifold inside where the off-gas flow paths discharged from the first fuel cell stack 1A and the second fuel cell stack 1B merge.

[0041] In this way, by providing a manifold that branches and combines the fuel supply path and the exhaust path of the first fuel cell stack 1A and the second fuel cell stack 1B inside the gas processing unit 2, the gas processing unit 2 can be shared for a plurality of fuel cell stacks 1. By fixing the fuel cell stack 1 to the gas processing unit 2 so that gas is directly supplied from the gas processing unit 2, the number of connection parts can be reduced. Furthermore, by directly connecting the fuel cell stack 1 to the gas processing unit 2, the surface area that can become a heat dissipation surface can be reduced, so that the temperature of the fuel cell stack 1 can be maintained and the warm-up time can be shortened.

[0042] According to the fuel cell system of the first embodiment, the gas processing unit 2 is disposed at a location affected by the convection of the outside air during the running of the vehicle, that is, in front of the motor room 100, and the fuel cell stack 1 is fixed to the rear surface of the gas processing unit 2, that is, the surface facing the motor room 100.

[0043] In such a configuration, the fuel cell stack 1 is fixed to the rear surface of the gas processing unit 2, that is, the surface on the opposite side of the surface where the running wind blows. Therefore, since the fuel cell stack 1 is disposed behind the gas processing unit 2 attached to the case 5 where the running wind directly blows, it is hardly affected by the running wind. As a result, the temperature of the fuel cell stack 1 is easily maintained, and a decrease in power generation performance can be suppressed. In particular, when the fuel cell stack 1 is a SOFC, since it operates at a relatively high temperature, there is a high possibility that the power generation performance will be affected if it is cooled by the running wind. However, by suppressing the influence of the running wind as in this embodiment, it becomes easier to maintain the power generation performance of the fuel cell stack 1.

[0044] On the other hand, inside the motor room 100, since the gas processing unit 2 is easily affected by the convection of the running wind, the temperature is relatively likely to drop. However, since the gas processing unit 2 is provided with a configuration for performing heat generation processes such as a combustor and a heat exchanger, even if the temperature drops, the combustor can be operated to heat it to a predetermined temperature.

[0045] In this embodiment, the fuel cell stack 1 and the gas processing unit 2 are housed in a sealed case 5. However, in the case of the case 5, since the front surface where the traveling wind blows is easily cooled, the temperature of the gas processing unit 2 tends to decrease. However, the temperature of the fuel cell stack 1 disposed behind the gas processing unit 2 is easily maintained. Note that when the case 5 is not sealed, the front surface of the gas processing unit 2 directly hit by the traveling wind is more easily cooled. Even in such a case, the fuel cell stack 1 is not directly hit by the traveling wind, so the temperature hardly decreases. As a result, the temperature of the fuel cell stack 1 is easily maintained, and a decrease in power generation performance can be suppressed.

[0046] According to the fuel cell system of the first embodiment, the fuel cell stack 1 is disposed on the opposite side of the passenger compartment in the motor room 100. The fuel cell stack 1 becomes relatively hot during driving. Therefore, by disposing the fuel cell stack 1 forward away from the passenger compartment in the motor room 100 and further providing an insulator 13 between the fuel cell stack 1 and the passenger compartment, an increase in the temperature of the passenger compartment can be suppressed. Note that when the low-voltage control unit 10 is provided near the passenger compartment, an increase in the temperature of the low-voltage control unit 10 is suppressed, so heat damage can be reduced.

[0047] According to the fuel cell system of the first embodiment, the motor room 100 where the fuel cell stack 1 and the gas processing unit 2 are provided is disposed in the front of the vehicle, and traveling wind flows into the motor room 100 from the front of the vehicle when the vehicle is running. In such a configuration, by providing the gas processing unit 2 at a place where the traveling wind in the front blows, the traveling wind easily hits and the temperature of the gas processing unit 2 easily decreases. On the other hand, since the fuel cell stack 1 is fixed to the rear surface of the gas processing unit 2, it is hardly affected by the traveling wind, and a decrease in the temperature of the fuel cell stack 1 can be suppressed.

[0048] According to the fuel cell system of the first embodiment, when viewed from the front of the vehicle, the fuel cell stack 1 is disposed inside the gas processing unit 2 so as not to protrude from the contour of the gas processing unit 2. With such a configuration, the fuel cell stack 1 is disposed at a position where the traveling wind is blocked by the gas processing unit 2. For example, when the case 5 does not exist, the traveling wind is blocked by the gas processing unit 2, so that the traveling wind does not directly hit the fuel cell stack 1. Therefore, a temperature drop of the fuel cell stack 1 can be suppressed.

[0049] According to the fuel cell system of the first embodiment, the fuel cell stack 1 is composed of two first fuel cell stacks 1A and a second fuel cell stack 1B having different lengths in the longitudinal direction of the vehicle, which is the stacking direction. The relatively long first fuel cell stack 1A is disposed at the upper part, and the relatively short second fuel cell stack 1B is disposed at the lower part.

[0050] With such a configuration, a large accommodation area is provided at the lower part in the motor room 100. Specifically, among the end faces at the rear of the vehicle of the case 5 (5R), the lower part 5B facing the second fuel cell stack 1B is located further forward in the vehicle than the upper part 5A facing the first fuel cell stack 1A. Therefore, the rear area of the case 5 becomes wider as it is lower. Therefore, the drive motor 4 can be disposed in the rear area of the lower part 5B.

[0051] Furthermore, among the end faces at the rear of the vehicle of the case 5 (5R), the lowermost part 5C located below the second fuel cell stack 1B is located further forward in the vehicle than the lower part 5B facing the second fuel cell stack 1B. Therefore, a wider area is formed behind the lowermost part 5C of the case 5, so that the steering device 9 can be disposed in the rear area of the lowermost part 5C.

[0052] In this way, the first fuel cell stack 1A and the second fuel cell stack 1B having different lengths are arranged with the longer one above and the shorter one below. As a result, a larger area can be provided at the lower part behind the fuel cell stack 1 in the motor room 100, so that the layout property can be improved. In particular, relatively large components such as the drive motor 4 and the steering device 9 can be easily arranged in such an area.

[0053] According to the fuel cell system of the first embodiment, the fuel cell stack 1 composed of the first fuel cell stack 1A and the second fuel cell stack 1B is further provided at a distance from the lower surface of the motor room 100. And, other components such as the high-voltage converter 3 can be accommodated below the separated fuel cell stack 1. Furthermore, since the fuel cell stack 1 is arranged above, the area at the lower rear of the fuel cell stack 1 becomes wider, and the layout efficiency of the motor room 100 can be improved.

[0054] (Second Embodiment) In the first embodiment, an example in which the motor room 100 where the fuel cell stack 1 and the like are arranged is provided in front of the vehicle has been described, but the present invention is not limited to this. In the present embodiment, an example in which the motor room 100 is provided at the rear of the vehicle will be described.

[0055] FIG. 3 is a view showing the motor room 100 of the second embodiment. As shown in this figure, the motor room 100 is provided under the rear dashboard 21 at the rear of the vehicle. The rear dashboard 21 is attached under the floor at the rear of the passenger compartment and constitutes the bottom of the rear trunk room. The rear dashboard 21 rises along the back of the rear seat toward the rear and then extends rearward along the bottom of the trunk room.

[0056] The gas treatment unit 2 is disposed at the rear in the motor room 100 such that the relatively large surface of the rectangular structure faces the rear of the vehicle. The fuel cell stack 1 is fixed to the front surface of the gas treatment unit 2, that is, the surface facing the inside of the motor room 100. Although the case 5 is not shown in this embodiment, the fuel cell stack 1 and the gas treatment unit 2 may be provided in the case 5.

[0057] Here, when the vehicle is running, the running wind generated flows along the outer body surface on the side surface of the vehicle, and convection occurs on the rear surface. Therefore, since the rear surface of the gas treatment unit 2 is hit by the convection, the gas treatment unit 2 is provided at a location where it is affected by the convection, and the temperature of the gas treatment unit 2 is likely to decrease.

[0058] As described above, the fuel cell stack 1 is fixed to the mounting surface facing the front of the gas treatment unit 2. That is, in the gas treatment unit 2, the mounting surface of the fuel cell stack 1 faces the front of the vehicle, and the surface on the opposite side of the mounting surface faces the rear of the vehicle. In other words, since the surface on the opposite side of the mounting surface in the gas treatment unit 2 is affected by the running wind, the influence of the running wind on the fuel cell stack 1 provided on the mounting surface can be suppressed.

[0059] Regarding the fuel cell stack , the long first fuel cell stack 1A in the stacking direction (front-rear direction) is disposed below, and the short second fuel cell stack 1B is disposed above. As a result, the ridge line connecting the front end of the second fuel cell stack 1B and the front end of the first fuel cell stack 1A is substantially equal to the inclination of the rear seat in the passenger compartment, so that the layout of the motor room 100 can be efficiently performed.

[0060] According to the fuel cell system of the second embodiment, the gas treatment unit 2 is disposed at a location in the motor room 100 where it is affected by the running wind at the rear of the vehicle, and the fuel cell stack 1 is fixed to the front surface of the gas treatment unit 2, that is, the surface on the side opposite to the side affected by the running wind.

[0061] In such a configuration, the fuel cell stack 1 is fixed to the front surface of the gas processing unit 2, that is, the surface on the side opposite to the side affected by the traveling wind, so that the temperature drop of the fuel cell stack 1 can be prevented and the decrease in power generation performance can be suppressed. Also, in the motor room 100, since the gas processing unit 2 is easily affected by the convection of the traveling wind, its temperature is relatively likely to drop, but since it is equipped with a combustor, it can be easily heated to a predetermined temperature.

[0062] Furthermore, the height levels of the fuel cell stack 1 and the gas processing unit 2 become substantially equal. As a result, the upper surface of the motor room 100 becomes lower, and the upper luggage space can be enlarged. When an object collides with the rear of the vehicle, since the relatively strong gas processing unit 2 faces outward, the impact applied to the fuel cell stack 1 can be reduced.

[0063] According to the fuel cell system of the second embodiment, regarding the fuel cell stack 1, the long first fuel cell stack 1A in the stacking direction (front-rear direction) is arranged below, and the short second fuel cell stack 1B is arranged above. As a result, the ridge line connecting the front end of the second fuel cell stack 1B and the front end of the first fuel cell stack 1A is substantially equal to the inclination of the back of the rear seat in the passenger compartment, so that the layout property of the motor room 100 can be improved. Also, the first fuel cell stack 1A located below is relatively large and has a large heat generation amount, and the second fuel cell stack 1B located above is relatively small and has a small heat generation amount. Therefore, heat generation in places close to the passenger compartment and the luggage room can be suppressed, and the comfort in the passenger compartment can be improved.

[0064] (Third Embodiment) In the third embodiment, another example in which the motor room 100 is provided at the rear of the vehicle will be described.

[0065] FIG. 4 is a view showing the motor room 100 of the third embodiment. As shown in this figure, the motor room 100 is provided under the rear dashboard 21 at the rear of the vehicle.

[0066] The gas processing unit 2 is disposed below in the motor room 100 such that a relatively large surface of the rectangular structure faces downward of the vehicle. And the fuel cell stack 1 is fixed to the upper surface of the gas processing unit 2, that is, the surface facing the motor room 100.

[0067] Here, when the vehicle is running, the running wind flows along the outer surface of the body on the side surface of the vehicle. Since the lower part of the motor room 100 has a non-smooth surface unlike the body, the running wind generates convection on the lower surface of the gas processing unit 2. Therefore, the gas processing unit 2 is provided at a location affected by the convection.

[0068] Also, regarding the fuel cell stack 1, the first fuel cell stack 1A having a long length in the stacking direction (front-rear direction) is disposed at the rear, and the short second fuel cell stack 1B is disposed at the front. As a result, since the ridge line connecting the upper end of the second fuel cell stack 1B and the upper end of the first fuel cell stack 1A is substantially equal to the inclination of the rear seat in the vehicle interior, the layout of the motor room 100 can be efficiently performed.

[0069] Thus, the fuel cell stack 1 is fixed to the mounting surface facing upward of the gas processing unit 2. That is, in the gas processing unit 2, the mounting surface of the fuel cell stack 1 faces upward of the vehicle, and the surface on the opposite side of the mounting surface faces downward of the vehicle. In other words, since the surface on the opposite side of the mounting surface in the gas processing unit 2 is affected by the running wind, the influence of the running wind on the fuel cell stack 1 provided on the mounting surface can be suppressed.

[0070] According to the fuel cell system of the third embodiment, the gas processing unit 2 is disposed at a location affected by the running wind below the vehicle in the motor room 100, and the fuel cell stack 1 is fixed to the upper surface of the gas processing unit 2, that is, the surface on the side opposite to the side affected by the running wind.

[0071] In such a configuration, the fuel cell stack 1 is provided on the upper surface of the gas processing unit 2, that is, the surface opposite to the side affected by the running wind, which can prevent the temperature of the fuel cell stack 1 from decreasing and suppress the decrease in power generation performance. In the motor room 100, since the gas processing unit 2 is easily affected by the convection of the running wind, its temperature is relatively likely to drop. However, since it is equipped with a combustor, it can be heated to a predetermined temperature. Further, when an object collides from below the vehicle, since the relatively strong gas processing unit 2 faces outward, the impact applied to the fuel cell stack 1 can be reduced.

[0072] As described above, the embodiments of the present invention have been described. However, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Explanation of Reference Numerals

[0073] 1 Fuel cell stack, 2 Gas processing unit, 3 High-voltage converter, 4 Drive motor, 5 Case, 6 Side member, 7 Suspension device, 8 Axle, 9 Steering device, 10 Low-voltage control unit, 11 Upper dashboard, 12 Lower dashboard, 13 Insulator, 21 Rear dashboard, 100 Motor room

Claims

1. An in-vehicle fuel cell system mounted in a motor room of a vehicle, comprising: a fuel cell stack; and a gas processing unit that exchanges gas with the fuel cell stack and has a combustor that burns exhaust gas from the fuel cell stack, wherein the gas processing unit is disposed in the motor room at a location affected by convection by outside air during running of the vehicle, the fuel cell stack is closely fixed to a surface on the opposite side of the location affected by the convection of the gas processing unit, An in-vehicle fuel cell system.

2. The in-vehicle fuel cell system according to claim 1, wherein the motor room is disposed in front of a passenger compartment in which a passenger of the vehicle is accommodated, the gas processing unit is disposed in the motor room at a position where running wind from the front of the vehicle blows, the fuel cell stack is fixed to a rear surface of the gas processing unit. An in-vehicle fuel cell system.

3. The in-vehicle fuel cell system according to claim 2, wherein the gas processing unit and the fuel cell stack are disposed in front of the motor room away from the passenger compartment. An in-vehicle fuel cell system.

4. The in-vehicle fuel cell system according to claim 3, wherein the fuel cell stack is disposed inside the gas processing unit when viewed from the front of the vehicle. An in-vehicle fuel cell system.

5. The in-vehicle fuel cell system according to claim 3 or 4, wherein the fuel cell stack includes a plurality of fuel cell stacks having different lengths in the front-rear direction of the vehicle, the longer the fuel cell stack is in the front-rear direction, the higher it is disposed. An in-vehicle fuel cell system.

6. The in-vehicle fuel cell system according to claim 5, wherein a motor serving as a drive source of the vehicle provided in the motor room is disposed behind the fuel cell stack and below a fuel cell stack that is long in the front-rear direction and disposed at an upper portion. An in-vehicle fuel cell system.

7. The in-vehicle fuel cell system according to claim 5 or 6, wherein a power control unit that controls power output from the fuel cell stack is provided below the fuel cell stack. An in-vehicle fuel cell system.

8. The in-vehicle fuel cell system according to claim 1, wherein the motor room is disposed behind a passenger compartment in which a passenger of the vehicle is accommodated, The gas treatment unit is disposed at the rear part of the motor room, The fuel cell stack is fixed to the front side of the gas treatment unit, and it is an in-vehicle fuel cell system.

9. In the in-vehicle fuel cell system according to Claim 8, The fuel cell stack includes a plurality of fuel cell stacks having different lengths in the longitudinal direction of the vehicle, In the in-vehicle fuel cell system, each of the plurality of fuel cell stacks is disposed lower as it is longer in the longitudinal direction.

10. In the in-vehicle fuel cell system according to Claim 1, The motor room is disposed behind the passenger compartment in which the passengers of the vehicle are accommodated, The gas treatment unit is disposed below the motor room, The fuel cell stack is closely fixed to the upper surface of the gas treatment unit, and it is an in-vehicle fuel cell system.

Images