JP2020161362A - Fuel cell system mounted on vehicle - Google Patents

Abstract

To reduce hydrogen concentration in the exhaust-gas, even when the operation load of the fuel cell is high.SOLUTION: A fuel cell system mounted on vehicle includes fuel cells, an oxidizer gas supply pipe forming a duct of oxidant gas supplied to the fuel cells, a fuel off-gas exhaust pipeline forming a duct of fuel gas exhausted from the fuel cells, bypass piping connecting the oxidizer gas supply pipe and the fuel off-gas exhaust pipeline, and forming the duct of oxidizer gas, a hydrogen concentration detector fitted to the vehicle and detecting hydrogen concentration, and a control section executing output control of the fuel cells including control of flow quantity of the oxidizer gas supplied to the bypass piping. When the hydrogen concentration, detected by the hydrogen concentration detector, goes above a predetermined threshold level, the control section increases the flow quantity of the oxidizer gas supplied to the bypass piping more than a predetermined flow quantity, and sets the output of the fuel cells to a predetermined output limit value.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a fuel cell system mounted on a vehicle.

In the fuel cell system, since the fuel gas containing hydrogen is supplied to the anode side of the fuel cell, hydrogen may be discharged to the outside of the fuel cell system by some route. Therefore, sufficient measures are taken to prevent flammable hydrogen gas from being discharged at a high concentration. For example, in the vehicle described in Patent Document 1, when leaked hydrogen is detected from the hydrogen concentration sensor provided in the vehicle, the flow rate of the air diverted to the bypass air flow path is increased to increase the hydrogen concentration in the exhaust gas. Is diluted.

Japanese Unexamined Patent Publication No. 2012-19607

However, when the operating load of the fuel cell is high, the flow rate of the air diverted to the bypass air flow path is limited. As a result, the hydrogen concentration in the exhaust gas may not be diluted. Therefore, a technique capable of reducing the hydrogen concentration in the exhaust gas is desired even when the operating load of the fuel cell is high.

The present disclosure can be realized in the following forms.

(1) According to one form of the present disclosure, a fuel cell system mounted on a vehicle is provided. This fuel cell system includes a fuel cell, an oxidant gas supply pipe forming a flow path for an oxidant gas supplied to the fuel cell, and a fuel off gas forming a flow path for the fuel gas discharged from the fuel cell. A bypass pipe that connects the discharge pipe, the oxidant gas supply pipe, and the fuel off gas discharge pipe to form a flow path for the oxidant gas, and a hydrogen concentration detector attached to the vehicle to detect the hydrogen concentration. The control unit includes a control unit that executes output control of the fuel cell including control of the flow rate of the oxidant gas supplied to the bypass pipe, and the control unit is detected by the hydrogen concentration detection unit. When the hydrogen concentration is equal to or higher than a predetermined threshold value, the flow rate of the oxidant gas supplied to the bypass pipe is increased from the predetermined flow rate, and the output of the fuel cell is limited to a predetermined output. Set to a value.
According to this type of fuel cell system, when the hydrogen concentration detected by the hydrogen concentration detector is equal to or higher than a predetermined threshold value, the flow rate of the oxidant gas supplied to the bypass pipe is set from the predetermined flow rate. Is also increased and the output of the fuel cell is set to a predetermined output limit value. Therefore, even when the operating load of the fuel cell is high, the oxidation supplied to the bypass pipe by limiting the output of the fuel cell. The flow rate of the agent gas can be secured. As a result, the hydrogen concentration in the exhaust gas can be reduced.

The present disclosure can also be realized in various embodiments. For example, it can be realized in the form of a vehicle equipped with a fuel cell system, a control method of the fuel cell system, a method of diluting the hydrogen concentration in off-gas discharged from the fuel cell, and the like.

The explanatory view which shows the schematic structure of the vehicle which mounted the fuel cell system as one Embodiment of this disclosure. The schematic which shows the structure of the fuel cell system. The flowchart which shows the process procedure of the hydrogen concentration dilution process.

A. Embodiment:
A1. Vehicle configuration:
FIG. 1 is an explanatory view showing a schematic configuration of a vehicle 500 equipped with a fuel cell system as an embodiment of the present disclosure in a cross-sectional view. FIG. 1 shows a cross section of the vehicle 500 along the front FD and the rear RD at the center position of the vehicle width direction LH. The vehicle 500 is equipped with a fuel cell 10 and travels by driving a drive motor M with electric power generated by the fuel cell 10 to drive a front wheel FW and a rear wheel RW. The vehicle 500 may travel by driving either the front wheel FW or the rear wheel RW. In FIG. 1, in addition to the vehicle width direction LH, the front direction FD, and the rear direction RD, the gravity direction, that is, the vertical downward G is shown. In the following description, the front direction FD and the rear direction RD are collectively referred to as a "vehicle length direction".

The vehicle 500 is formed with a cabin 512, a tank storage chamber 513, and a battery storage chamber 511. The cabin 512 is a space on which an occupant rides, and is formed as a space extending in a direction parallel to the vehicle length direction of the vehicle 500 sandwiched between a pair of front wheel FWs and a pair of rear wheel RWs.

The tank storage chamber 513 is formed under the floor of the vehicle 500 in the rearward RD with respect to the battery storage chamber 511. The tank storage chamber 513 is formed as an underfloor space between the floor panel FP forming the floor surface of the passenger compartment 512 and the undercover 501 covering the lower part of the vehicle 500. A hydrogen gas tank 52 is placed in the tank storage chamber 513.

The battery accommodating chamber 511 is formed as a space including a region sandwiched between a pair of front wheel FWs on the front side of the passenger compartment 512. The battery accommodating chamber 511 accommodates at least some components of the fuel cell system including the fuel cell 10.

The fuel cell 10 is a polymer electrolyte fuel cell that generates electricity by receiving hydrogen gas and air as reaction gases. As the fuel cell 10, instead of the solid polymer fuel cell, any other type of fuel cell such as a solid oxide fuel cell may be adopted. The fuel off gas and oxidation off gas (hereinafter referred to as "exhaust gas") discharged from the fuel cell and the water generated by the power generation of the fuel cell are both outside the vehicle 500 (in the atmosphere) via the muffler 47. Is discharged to.

Two hydrogen concentration detection units 81 and 82 are attached to the vehicle 500. Specifically, a first hydrogen concentration detection unit 81 is installed in the battery storage chamber 511, and a second hydrogen concentration detection unit 82 is installed around the hydrogen gas tank 52 in the tank storage chamber 513. The hydrogen concentration detection units 81 and 82 detect the hydrogen concentration in the battery storage chamber 511 and the tank storage chamber 513, and transmit the detection result to the fuel cell system described later. As the hydrogen concentration detecting units 81 and 82, for example, any kind of hydrogen concentration sensor such as a gas heat conduction type hydrogen concentration sensor or a semiconductor type hydrogen concentration sensor can be adopted.

A2. Fuel cell system configuration:
FIG. 2 is a schematic view showing the configuration of the fuel cell system 100. The fuel cell system 100 is mounted on the vehicle 500 and outputs electric power that is a power source of the vehicle 500 in response to a request from the driver. The fuel cell system 100 includes a fuel cell 10, an oxidant gas supply / discharge unit 30, a fuel gas supply / discharge unit 50, and a control device 20. The fuel cell system 100 further includes a DC / DC converter 90 and a secondary battery 92.

The fuel cell 10 has a stack structure in which a plurality of cells 11 are stacked. Although not shown, each cell 11 has a membrane electrode assembly in which electrodes are arranged on both sides of the electrolyte membrane, a pair of gas diffusion layers sandwiching the membrane electrode assembly, and a pair of separators. The electric power generated by the fuel cell 10 is supplied to the load 93 of the secondary battery 92 or the drive motor M or the like via the DC / DC converter 90.

The oxidant gas supply / discharge unit 30 takes in air as an oxidant gas from the outside air and supplies it to the fuel cell 10, and discharges the oxidative off gas from the fuel cell 10 to the outside. The oxidant gas supply / discharge unit 30 includes an oxidant gas supply pipe 31, an air flow meter 32, an air compressor 33, a first on-off valve 34, a first pressure gauge 35, a flow dividing valve 36, and a cathode bypass pipe 37. The oxidizing off gas discharge pipe 41 and the first pressure regulating valve 42 are provided.

The oxidant gas supply pipe 31 communicates with the oxidant gas supply manifold formed inside the fuel cell 10 to form an air flow path. The air flow meter 32 is provided in the oxidant gas supply pipe 31 and measures the flow rate of the air taken in from the outside air. The air compressor 33 is provided in the oxidant gas supply pipe 31, and compresses the air taken in from the outside air and supplies it to the fuel cell 10 in response to the control signal from the control device 20. The first on-off valve 34 is provided between the air compressor 33 and the fuel cell 10 to execute and stop the supply of air from the air compressor 33 to the fuel cell 10. The first pressure gauge 35 measures the pressure at the oxidant gas inlet of the fuel cell 10 and transmits it to the control device 20.

The flow dividing valve 36 is provided at a connection point between the oxidant gas supply pipe 31 and the cathode bypass pipe 37. The shunt valve 36 adjusts the valve opening degree according to the control signal from the control device 20, so that the flow rate of the air supplied from the air compressor 33 to the fuel cell 10 and the cathode bypass pipe 37 Adjust the flow rate supplied to. The cathode bypass pipe 37 connects the oxidant gas supply pipe 31 and the oxidation off gas discharge pipe 41, and discharges at least a part of the compressed air supplied from the air compressor 33 according to the opening degree of the flow dividing valve 36. Lead to pipe 41.

The oxidation-off gas discharge pipe 41 communicates with the oxidation-off gas discharge manifold formed inside the fuel cell 10. The oxidation-off gas discharge pipe 41 discharges the oxidation-off gas discharged from each cell 11 to the outside (atmosphere) of the fuel cell system 100. In addition to air, the oxidation-off gas includes water produced by the power generation of the fuel cell 10. The first pressure regulating valve 42 adjusts the pressure of the oxidation off gas supplied to the fuel cell 10 in response to the control signal from the control device 20.

The fuel gas supply / discharge unit 50 supplies hydrogen gas as a fuel gas to the fuel cell 10 and discharges the fuel off gas from the fuel cell 10 to the outside. The fuel gas supply / discharge unit 50 includes a fuel gas supply pipe 51, a hydrogen gas tank 52, a second on-off valve 53, a second pressure regulating valve 54, an injector 55, a second pressure gauge 56, and a first fuel off-gas discharge. It includes a pipe 61, a gas-liquid separator 62, an exhaust / drain valve 63, a second fuel off-gas discharge pipe 64, a circulation pipe 65, and a hydrogen pump 66.

The fuel gas supply pipe 51 connects the hydrogen gas tank 52 and the fuel cell 10, and supplies the hydrogen gas in the hydrogen gas tank 52 and the surplus hydrogen gas sent from the hydrogen pump 66 to the fuel cell 10. The second on-off valve 53, the second pressure regulating valve 54, the injector 55, and the second pressure gauge 56 are arranged in the fuel gas supply pipe 51 from the hydrogen gas tank 52 toward the fuel cell 10 in this order.

The second on-off valve 53 opens and closes in response to a control signal from the control device 20, and controls the inflow of hydrogen gas from the hydrogen gas tank 52 to the injector 55. When the fuel cell system 100 is stopped, the second on-off valve 53 is closed. The second pressure regulating valve 54 adjusts the pressure of the hydrogen gas supplied to the injector 55 to a predetermined pressure in response to the control signal from the control device 20. The injector 55 supplies hydrogen gas to the fuel cell 10 and supplies hydrogen gas to the fuel cell 10 by opening and closing the valve according to the drive cycle and the opening / closing time set by the control device 20 in response to the control signal from the control device 20. adjust. The second pressure gauge 56 measures the pressure at the hydrogen gas inlet of the fuel cell 10 and transmits it to the control device 20.

The first fuel off-gas discharge pipe 61 connects the fuel-off gas discharge manifold formed inside the fuel cell 10 and the gas-liquid separator 62. The first fuel off-gas discharge pipe 61 is a flow path for discharging fuel-off gas from the fuel cell 10. The fuel off gas includes hydrogen gas and nitrogen gas that were not used in the power generation reaction, and water produced by the power generation of the fuel cell 10. The first fuel off gas discharge pipe 61 guides the fuel off gas to the gas-liquid separator 62.

The gas-liquid separator 62 is connected between the first fuel off-gas discharge pipe 61 and the circulation pipe 65. The gas-liquid separator 62 separates hydrogen gas and water contained in the fuel off gas in the first fuel off gas discharge pipe 61, and causes the gas containing the hydrogen gas to flow into the circulation pipe 65.

The circulation pipe 65 is connected to the fuel gas supply pipe 51 on the downstream side of the injector 55. A hydrogen pump 66 driven in response to a control signal from the control device 20 is arranged in the circulation pipe 65. The hydrogen pump 66 sends the gas (gas containing hydrogen gas) separated by the gas-liquid separator 62 to the fuel gas supply pipe 51. In the fuel cell system 100, a gas containing hydrogen gas contained in the fuel off gas is circulated and supplied to the fuel cell 10 again to improve the utilization efficiency of hydrogen gas.

The exhaust drain valve 63 is an on-off valve provided in the lower part of the gas-liquid separator 62. The exhaust / drain valve 63 opens / closes in response to a control signal from the control device 20, and removes impurity gases such as nitrogen gas contained in the water and fuel off gas separated by the gas / liquid separator 62 into the second fuel off gas discharge pipe. Discharge to 64.

The second fuel off-gas discharge pipe 64 connects the lower part of the exhaust drain valve 63 and the oxidation off-gas discharge pipe 41. The second fuel off-gas discharge pipe 64 communicates with the oxidation-off gas discharge pipe 41, and discharges the water and the fuel-off gas discharged from the exhaust drain valve 63 to the oxidation-off gas discharge pipe 41. The fuel off gas that has flowed into the oxidation off gas discharge pipe 41 through the second fuel off gas discharge pipe 64 is sent to the outside (atmosphere) of the fuel cell system 100 via the muffler 47 due to the force of the oxidation off gas flowing in the oxidation off gas discharge pipe 41. Is discharged to.

The DC / DC converter 90 boosts the output voltage of the fuel cell 10 in response to a control signal from the control device 20. A current sensor 95 for measuring the output current value of the fuel cell 10 is provided between the fuel cell 10 and the DC / DC converter 90. The secondary battery 92 stores the electric power generated by the fuel cell 10 and functions together with the fuel cell 10 as a power supply source in the fuel cell system 100. The electric power of the secondary battery 92 is supplied to the air compressor 33, the hydrogen pump 66, various valves, and the like. The secondary battery 92 is composed of a chargeable / dischargeable lithium ion battery. The secondary battery 92 may be composed of any other type of battery such as a lead storage battery, a nickel cadmium battery, and a nickel hydrogen battery.

The control device 20 controls the entire fuel cell system 100. The control device 20 includes a CPU 21 and a memory 25. The CPU 21 functions as the control unit 22 by executing a control program stored in the memory 25 in advance.

The control unit 22 executes output control of the fuel cell 10. Specifically, the control unit 22 is electrically connected to the control device 20 such as the air compressor 33 and the hydrogen pump 66 based on the output request from the load 93 of the drive motor M or the like to the fuel cell system 100. Controls the drive and stop of each component. Further, the control unit 22 determines the flow rate of the air supplied to the fuel cell 10 and the flow rate of the air supplied to the cathode bypass pipe 37 by adjusting the valve opening degree of the flow dividing valve 36, the valve opening time, and the like. To control the output of the fuel cell 10.

In the present embodiment, the first fuel off-gas discharge pipe 61 and the second fuel off-gas discharge pipe 64 correspond to the subordinate concept of the fuel-off gas discharge pipe in the means for solving the problem. The cathode bypass pipe 37 corresponds to a subordinate concept of the bypass pipe in the means for solving the problem.

A3. Hydrogen concentration dilution treatment:
First, the outline of the hydrogen concentration dilution treatment shown in FIG. 3 will be described. In the hydrogen concentration dilution treatment, when the hydrogen concentration detected by the hydrogen concentration detection units 81 and 82 is equal to or higher than the predetermined hydrogen concentration, hydrogen in the exhaust gas is increased by increasing the flow rate of the air supplied to the cathode bypass pipe 37. Reduce the concentration. Here, when the vehicle 500 enters a flooded passage, a snowy road, or the like, the exhaust port of the muffler 47 is blocked, and the exhaust gas enters the tank accommodating chamber 513, the battery accommodating chamber 511, or the like through the gap of the undercover 501. There is a risk of intrusion. Further, in this case, since the vehicle 500 runs on a rough road such as a flooded road, the output requirement for the fuel cell system 100 increases, and the operating load of the fuel cell 10 increases. As a result, the flow rate of air supplied to the cathode bypass pipe 37 may be limited. Therefore, in the hydrogen concentration dilution treatment of the present embodiment, when the hydrogen concentration exceeds a predetermined threshold value (first threshold value described later), the output of the fuel cell 10 is set to a predetermined output limit value. Even when the operating load of the fuel cell 10 is high, the flow rate of air required to reduce the hydrogen concentration is secured. The details will be described below.

FIG. 3 is a flowchart showing a processing procedure of the hydrogen concentration dilution treatment. In the fuel cell system 100, when a signal indicating that the ignition switch has been switched from off to on is input from a higher-level ECU (Electronic Control Unit) that controls the entire vehicle 500, the hydrogen concentration dilution process is started. The hydrogen concentration dilution process is performed until the ignition switch is switched from on to off. The control unit 22 executes normal control (step S105). In normal control, the supply amounts of fuel gas and air are controlled according to the output request to the fuel cell system 100, and a predetermined flow rate of air is supplied to the cathode bypass pipe 37. Specifically, the control unit 22 sets the opening degree of the flow dividing valve 36 to an opening degree at which the flow rate of the air flowing from the oxidant gas supply pipe 31 into the cathode bypass pipe 37 becomes a predetermined flow rate. The control unit 22 drives the air compressor 33 to send air to the fuel cell 10 and the cathode bypass pipe 37. The above-mentioned predetermined flow rate can be arbitrarily determined by an experiment or the like, and is stored in the memory 25 in advance.

The control unit 22 determines whether or not the vehicle speed is 5 km / h or more (step S110). Specifically, the control unit 22 acquires the speed of the vehicle 500 from the vehicle speed sensor mounted on the vehicle 500, and determines whether or not the acquired speed is 5 km / h or more. In the present embodiment, it is determined whether or not the vehicle speed is 5 km / h or more for the following reasons. The inventors of the present disclosure have found that when the vehicle speed is less than 5 km / h, the hydrogen concentration in the exhaust gas does not increase because the operating load of the fuel cell 10 is low. Therefore, when the vehicle speed is less than 5 km / h, each process described later is not executed. The vehicle speed may be any speed in the range of 1 km / h to 10 km / h instead of 5 km / h.

In step S110 described above, when it is determined that the vehicle speed is 5 km / h or more (step S110: YES), the control unit 22 determines whether or not the hydrogen concentration is equal to or higher than the first threshold value (step S115). Specifically, the control unit 22 continuously acquires the hydrogen concentration detected by the two hydrogen concentration detection units 81 and 82. Then, the control unit 22 continuously determines whether the hydrogen concentration acquired from the hydrogen concentration detection unit of any one of the two hydrogen concentration detection units 81 and 82 is continuously equal to or higher than the first threshold value for a predetermined time. Judge whether or not. In the present embodiment, the predetermined time is set to 1 second. The first threshold value is set to 1%. The predetermined time may be any time in the range of 0.1 seconds to 3.0 seconds instead of 1 second. Further, the first threshold value may be any concentration in the range of 0.3% to 3.0% instead of 1%. The first threshold corresponds to a predetermined subordinate concept of the threshold in the means for solving the problem.

In step S115 described above, the hydrogen concentration continuously acquired for a predetermined time is used for determining the hydrogen concentration for the following reasons. First, as will be described later, when it is determined that the hydrogen concentration is equal to or higher than the first threshold value and the process of increasing the flow rate of the air supplied to the cathode bypass pipe 37 is executed, the rotation speed of the air compressor 33 and the rotation speed of the air compressor 33 are increased. It is considered that the intake / delivery pressure of air and the like increase, and the driving noise and vibration of the air compressor 33 increase accordingly. As a result, the occupants of the vehicle 500 may feel uncomfortable or uncomfortable. Therefore, by accurately determining the hydrogen concentration, it is possible to prevent the process of increasing the flow rate of the air supplied to the cathode bypass pipe 37 from being frequently executed. Secondly, when the vehicle 500 is stopped in a closed space such as a garage and the operation of the fuel cell 10 is started in a low temperature environment such as below freezing point, the hydrogen concentration detection units 81 and 82 have a hydrogen concentration equal to or higher than the first threshold value. May be detected. In this case, since it is considered that the hydrogen concentration equal to or higher than the first threshold value is not continuously detected for a predetermined time, a process of increasing the flow rate of the air supplied to the cathode bypass pipe 37 is executed. There is no need. Therefore, by accurately determining the hydrogen concentration, a process of increasing the flow rate of the air supplied to the cathode bypass pipe 37 is executed only when necessary.

When it is determined in step S115 above that the hydrogen concentration is equal to or higher than the first threshold value (step S115: YES), the control unit 22 increases the flow rate of air supplied to the cathode bypass pipe 37 (step S120). .. Specifically, the control unit 22 supplies air to the cathode bypass pipe 37 at a flow rate increased by 1000 [NL / min] with respect to the predetermined flow rate in the above-mentioned normal control (step S105). The control unit 22 increases the flow rate of air supplied to the cathode bypass pipe 37 by controlling the rotation speed of the air compressor 33 and the valve opening degree of the flow dividing valve 36. The flow rate to be increased may be a flow rate sufficient to reduce the hydrogen concentration, and is 100 [NL / min] to 3000 [NL / min], preferably 500 [NL / min] to 1000 [NL / min]. It may be any flow rate in the range of [min].

The control unit 22 sets the output of the fuel cell 10 to the output limit value (step S125). Specifically, the control unit 22 sets the output limit value of the fuel cell 10 to a current value of about 80% of the maximum current value of the fuel cell 10, preferably a current value of about 60% of the maximum current value. ..

The control unit 22 determines whether or not the hydrogen concentration is equal to or lower than the second threshold value (step S130). Specifically, the control unit 22 continuously acquires the hydrogen concentration detected by the two hydrogen concentration detection units 81 and 82, as in step S115 described above. Then, the control unit 22 continuously determines whether or not the hydrogen concentration acquired by the two hydrogen concentration detection units 81 and 82 is continuously equal to or lower than the second threshold value for a predetermined time. In step S130, the predetermined time is set to 5 seconds. The second threshold value is set to 0.5%. The predetermined time may be any time of 60 minutes or less instead of 5 seconds. Further, the second threshold value may be any other value as long as it is smaller than the first threshold value used in step S115 described above instead of 0.5%.

When it is determined in step S130 described above that the hydrogen concentration is not equal to or less than the second threshold value (step S130: NO), the above steps S120 to S130 are executed until it is determined that the hydrogen concentration is not equal to or less than the second threshold value. Will be done. On the other hand, when it is determined that the hydrogen concentration is equal to or lower than the second threshold value (step S130: YES), the process returns to step S105 described above, and normal control is executed.

According to the fuel cell system 100 of the embodiment having the above configuration, the flow rate of air supplied to the cathode bypass pipe 37 when the hydrogen concentration detected by the hydrogen concentration detecting units 81 and 82 is equal to or higher than the first threshold value. Is increased from a predetermined flow rate and the output of the fuel cell 10 is set to the output limit value. Therefore, even when the operating load of the fuel cell 10 is high, the cathode is formed by limiting the output of the fuel cell 10. The flow rate of the air supplied to the bypass pipe 37 can be secured. As a result, the hydrogen concentration in the exhaust gas can be reduced.

The present disclosure is not limited to the above-described embodiment, and can be realized by various configurations within a range not deviating from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the column of the outline of the invention may be used to solve some or all of the above-mentioned problems, or one of the above-mentioned effects. It is possible to replace or combine as appropriate to achieve a part or all. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

10 ... fuel cell, 11 ... cell, 20 ... control device, 21 ... CPU, 22 ... control unit, 25 ... memory, 30 ... oxidant gas supply / discharge unit, 31 ... oxidant gas supply pipe, 32 ... air flow meter, 33 ... air compressor, 34 ... first on-off valve, 35 ... first pressure gauge, 36 ... divergence valve, 37 ... cathode bypass pipe, 41 ... oxide off gas discharge pipe, 42 ... first pressure regulating valve, 47 ... muffler, 50 ... fuel Gas supply / discharge unit, 51 ... fuel gas supply pipe, 52 ... hydrogen gas tank, 53 ... second on-off valve, 54 ... second pressure regulating valve, 55 ... injector, 56 ... second pressure gauge, 61 ... first fuel off gas discharge pipe , 62 ... Gas-liquid separator, 63 ... Exhaust / drain valve, 64 ... Second fuel off gas discharge pipe, 65 ... Circulation pipe, 66 ... Hydrogen pump, 81, 82 ... Hydrogen concentration detector, 90 ... DC / DC converter, 92 ... Secondary battery, 93 ... Load, 95 ... Current sensor, 100 ... Fuel cell system, 500 ... Vehicle, 501 ... Undercover, 511 ... Battery storage room, 512 ... Guest room, 513 ... Tank storage room, FD ... Forward direction, FP ... Floor panel, FW ... Front wheel, G ... Vertically downward, LH ... Vehicle width direction, M ... Drive motor, RD ... Rear direction, RW ... Rear wheel

Claims (1)

A fuel cell system installed in a vehicle
With a fuel cell
An oxidant gas supply pipe that forms a flow path for the oxidant gas supplied to the fuel cell,
A fuel off-gas discharge pipe that forms a flow path for fuel gas discharged from the fuel cell,
A bypass pipe that connects the oxidant gas supply pipe and the fuel off gas discharge pipe to form a flow path for the oxidant gas, and
A hydrogen concentration detector that is attached to the vehicle and detects the hydrogen concentration,
A control unit that executes output control of the fuel cell including control of the flow rate of the oxidant gas supplied to the bypass pipe.
With
When the hydrogen concentration detected by the hydrogen concentration detecting unit is equal to or higher than a predetermined threshold value, the control unit causes the flow rate of the oxidant gas supplied to the bypass pipe to be higher than the predetermined flow rate. Increase and set the output of the fuel cell to a predetermined output limit value,
Fuel cell system.

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