JP2017134929A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system capable of properly detecting hydrogen while discharging hydrogen leaked from one of a fuel tank, a fuel cell and piping from a housing.SOLUTION: Fuel tanks 4, a fuel cell 5 and piping 6 are housed together in a housing 2. The housing 2 includes: a side plate 11; and a ceiling board 12 which is provided on the top surface of the side plate 11 and inclined upward toward the other end 11b from one end 11a of the top surface of the side plate 11 and in which, between an inner peripheral surface 12a of an upper end 12A in an inclination direction and the top surface of the other end 11b of the side plate 11, an opening 13 is formed communicating the inside and the outside of the housing 2. Hydrogen detection sensors 8A, 8B are installed on the inner peripheral surface 12a of the upper end 12A in the inclination direction of the ceiling board 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel cell system that generates power using hydrogen as a raw material.

  A fuel cell generates electric power by supplying oxygen-containing air and hydrogen, and drives an electric motor using the generated electric power to drive an automobile such as a vehicle. A fuel cell system including a fuel cell mainly includes a fuel tank in which hydrogen is stored, a fuel supply pipe for supplying hydrogen from the fuel tank to the fuel cell, and the like.

  Since hydrogen is flammable, a fuel cell system mounted on a vehicle such as an automobile is provided with a hydrogen detection sensor for detecting hydrogen leakage. As a conventional fuel cell system equipped with a hydrogen detection sensor, a fuel cell case for storing a fuel cell stack is provided, and a collection part for collecting hydrogen lighter than air is formed on the upper part of the fuel cell case. One in which a hydrogen detection sensor for detecting hydrogen is attached to a collection part is known (see, for example, Patent Document 1).

JP 2002-367648 A

  However, in the fuel cell system described in Patent Document 1, only the fuel cell stack is accommodated inside the fuel cell case. Thereby, only hydrogen leaking from the fuel cell stack can be detected by the hydrogen detection sensor, and hydrogen leaking from the hydrogen tank connected to the fuel cell and the pipe connecting the hydrogen tank and the fuel cell stack is detected. I can't.

  Further, the fuel cell case is a sealed space, and hydrogen filled in the fuel cell case cannot be discharged from the fuel cell case to the outside, and there is a possibility that the hydrogen concentration inside the fuel cell case becomes high.

  An object of the present invention is to provide a fuel cell system capable of accurately detecting hydrogen while discharging hydrogen leaked from any one of a fuel tank, a fuel cell, and piping from a casing.

  The present invention connects a fuel tank in which hydrogen is stored, a fuel cell that generates power by reacting hydrogen and oxygen, the fuel tank and the fuel cell, and the hydrogen stored in the fuel tank is A fuel cell system comprising: a pipe that supplies fuel cells; a plurality of hydrogen detection sensors that detect hydrogen; and a control unit that controls operation of the fuel cell based on detection information from the hydrogen detection sensors. A housing in which the fuel tank, the fuel cell, and the piping are accommodated, the housing being provided on a side plate and an upper surface of the side plate, from one end of the upper surface of the side plate toward the other end. And a ceiling plate in which an opening is formed between the inner peripheral surface of the upper end portion in the tilt direction and the upper surface of the other end portion of the side plate so as to communicate the inside and the outside of the housing. The upper end of the ceiling panel in the inclined direction The face, the plurality of hydrogen detecting sensor is arranged.

  According to the present invention, hydrogen can be accurately detected while discharging hydrogen leaking from any of the fuel tank, the fuel cell, and the piping from the casing.

FIG. 1 is a front view of a fuel cell system according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a flowchart of a system control process executed by the fuel cell system according to the embodiment of the present invention. FIG. 4 is a timing chart showing the relationship between the magnitude of the hydrogen concentration and the ON / OFF of the power supply in the fuel cell system according to one embodiment of the present invention. FIG. 5 is a flowchart of another system control process executed by the fuel cell system according to the embodiment of the present invention. FIG. 6 shows the relationship between the magnitude of the hydrogen concentration of the fuel cell system according to one embodiment of the present invention, the magnitude of the difference between the maximum value and the minimum value of the output value of the hydrogen detection sensor, and the ON / OFF of the power source. It is a timing chart which shows.

Hereinafter, a fuel cell system according to an embodiment of the present invention will be described with reference to the drawings.
1 to 6 are diagrams showing a fuel cell system according to an embodiment of the present invention.

First, the configuration will be described.
The fuel cell system 1 is mounted on, for example, an electric vehicle using a motor as a drive source. 1 and 2, the fuel cell system 1 includes a housing 2 and a control device 3. The housing 2 accommodates three fuel tanks 4, a fuel cell 5, a pipe 6, control valves 7A to 7C, and a pair of hydrogen detection sensors 8A and 8B.

  The fuel tank 4 includes, for example, a liner (not shown) configured to be hollow so that a storage space is formed therein, and a reinforcing layer that covers the outer surface of the liner, and the storage space is filled with high-pressure hydrogen. ing. The fuel tank 4 can be replenished with hydrogen gas from, for example, a hydrogen supply station installed at a gas station or the like.

  The fuel cell 5 generates power by an electrochemical reaction between the anode gas and the cathode gas. The fuel cell 5 includes an electrolyte membrane, and is configured as a stack in which a plurality of cells (not shown) formed by sandwiching an electrolyte membrane from both sides of an anode electrode (not shown) and a cathode electrode (not shown) are stacked.

  In the fuel cell 5, hydrogen as an anode gas is supplied to the anode electrode and air containing oxygen as the cathode gas is supplied to the cathode electrode, so that hydrogen ions generated by the catalytic reaction at the anode electrode permeate the electrolyte. Then, it moves to the cathode electrode and generates electricity by electrochemical reaction with oxygen at the cathode electrode.

  The fuel cell 5 supplies electric power generated by a chemical reaction to a traveling motor (not shown) or a battery (not shown) via an inverter (not shown).

  The pipe 6 connects the fuel tank 4 and the fuel cell 5, and supplies hydrogen stored in the fuel tank 4 to the anode electrode of the fuel cell 5. The control valves 7A to 7C are provided in the fuel tanks 4 respectively, adjust the amount of hydrogen supplied from the respective fuel tanks 4 to the fuel cells 5, or close the outlets of the respective fuel tanks 4 to fuel tanks. 4 stops supplying hydrogen of the fuel cell 5.

  Air is fed into the cathode electrode of the fuel cell 5 through an oxygen pipe (not shown). This oxygen pipe extends from the inside of the housing 2 to the outside of the housing 2, and sends air containing oxygen taken from the outside to the cathode electrode of the fuel cell 5.

  Hydrogen detection sensors 8 </ b> A and 8 </ b> B detect the concentration of hydrogen leaked from any of the fuel tank 4, the fuel cell 5, and the pipe 6 inside the housing 2, and output the detection result to the control device 3. The control device 3 of the present embodiment constitutes a control unit of the present invention.

  The hydrogen detection sensors 8A and 8B include, for example, a detection element (not shown) to which a catalyst such as platinum is attached and a temperature compensation element (not shown) to which the catalyst is not attached, and when leaked hydrogen comes into contact with the catalyst, Due to the combustion of the catalyst, the temperature of the detection element rises above the temperature compensation element, so that a difference occurs in the electrical resistance value between the detection element and the temperature compensation element, and the hydrogen concentration is detected based on the electrical resistance value.

  The configuration of the hydrogen detection sensors 8A and 8B is not limited to the catalytic combustion type, and may be any type of semiconductor type, solid electrolyte type, thermoelectric type, optical type, etc., and is not particularly limited. .

  The control device 3 is composed of a microcomputer, and variably controls the control valves 7A to 7C according to the driving state of the vehicle. Further, the control device 3 closes the control valves 7A to 7C based on the detection information of the hydrogen detection sensors 8A and 8B and stops supplying hydrogen from the fuel tank 4 to the fuel cell 5.

The housing 2 includes a rectangular bottom plate 10, a rectangular parallelepiped side plate 11 extending upward from an outer peripheral end of the bottom plate 10, and a rectangular ceiling plate 12 provided on the upper surface of the side plate 11.
The ceiling plate 12 is inclined upward from one end portion 11a on the upper surface of the side plate toward the other end portion 11b. An opening 13 is formed between the inner peripheral surface 12a of the upper end portion 12A in the inclined direction of the ceiling plate 12 and the upper surface of the other end portion 11b of the side plate 11. Is communicated.

  The hydrogen detection sensors 8A and 8B are provided on the inner peripheral surface 12a of the upper end portion 12A in the inclination direction of the ceiling board 12, and are separated from each other in the width direction of the upper end portion 12A.

  Each fuel tank 4 is provided with a pressure sensor (not shown), and the detection result of the pressure sensor is output to the control device 3. The control device 3 estimates the amount of hydrogen stored in the fuel tank 4 based on detection information from the pressure sensor.

  When the detection result of the pressure sensor exceeds a predetermined threshold value, the control device 3 opens one of the control valves 7A to 7C and opens one of the control valves 7A to 7C. Hydrogen is supplied from the tank 4 to the fuel cell 5.

  When the detection result of the pressure sensor falls below a predetermined threshold value, the control device 3 determines that the amount of hydrogen in the fuel tank 4 having the pressure sensor cannot be secured to the fuel cell 5. To do.

  The control device 3 closes any one of the control valves 7A to 7C of the fuel tank 4 in which the amount of hydrogen is reduced, and when the detection result of the pressure sensor exceeds a threshold value, any of the control valves 7A to 7C of the fuel tank 4 One is opened, and hydrogen is supplied to the fuel cell 5 from the fuel tank 4 in which any one of the control valves 7A to 7C is opened.

  When the output value output from the hydrogen detection sensors 8A and 8B exceeds a predetermined threshold value, the control device 3 closes one of the opened control valves 7A to 7C and stops the operation of the fuel cell 5. To do.

Next, the operation will be described.
The fuel tank 4, the fuel cell 5, and the pipe 6 according to the present embodiment are housed together in the housing 2. The housing 2 is provided on the side plate 11 and the upper surface of the side plate 11, and is inclined upward from one end portion 11a of the upper surface of the side plate 11 toward the other end portion 11b, and the inner peripheral surface 12a of the upper end portion 12A in the inclined direction. An opening 13 is formed between the upper surface of the other end portion 11b of the side plate 11 to communicate the inside and the outside of the housing 2, and the ceiling plate 12 is provided. The inner periphery of the upper end portion 12A in the inclined direction of the ceiling plate 12 Hydrogen detection sensors 8A and 8B are installed on the surface 12a.
Thereby, when hydrogen leaks from at least one of the fuel tank 4, the fuel cell 5 and the pipe 6, the hydrogen rises toward the opening 13 along the inner peripheral surface 12 a of the ceiling plate 12.

  Hydrogen flowing out of the housing 2 from the opening 13 is detected by the hydrogen detection sensors 8A and 8B, and information detected by the hydrogen detection sensors 8A and 8B is output to the control device 3.

  As a result, while the hydrogen leaking from any of the fuel tank 4, the fuel cell 5 and the pipe 6 is discharged from the casing 2, the hydrogen detection sensors 8A and 8B installed at the optimum positions of the casing 2 can accurately detect the hydrogen. It is possible to prevent hydrogen from staying inside the housing 2 while detecting the above.

  System control processing will be described based on the flowchart shown in FIG. 3 and the time chart shown in FIG. Note that the flowchart shown in FIG. 3 is a flowchart of a system control process executed by the control device 3.

  In FIG. 3, the control device 3 starts measuring hydrogen by the hydrogen detection sensors 8A and 8B (step S1). Next, the control device 3 determines whether or not the output values of the hydrogen detection sensors 8A and 8B exceed a predetermined threshold A based on the detection information from the hydrogen detection sensors 8A and 8B (step S2).

  In step S2, when it is determined that the output values of the hydrogen detection sensors 8A and 8B are equal to or less than the threshold value A, the control device 3 continues the operation of the fuel cell 5 (step S3), and the process proceeds to step S1. To return.

On the other hand, when the control device 3 determines in step S2 that the output value of any of the hydrogen detection sensors 8A and 8B exceeds the threshold value A, the power source of the fuel cell system 1 is turned on as shown in FIG. By turning it off, the operation of the fuel cell 5 is stopped (step S4), and the current process is terminated. When the operation of the fuel cell 5 is stopped, the driver may be notified by a lamp, a buzzer, or the like.
When the power supply of the fuel cell system 1 is turned off, any of the currently opened control valves 7A to 7C is closed, and hydrogen is not supplied from the fuel tank 4 to the fuel cell 5.

  Thus, according to the fuel cell system 1 of the present embodiment, the control device 3 operates the fuel cell 5 when the output values output from the hydrogen detection sensors 8A and 8B exceed a predetermined threshold A. Therefore, hydrogen can be prevented from leaking excessively from the housing 2 and the safety of the fuel cell system 1 can be improved.

Further, according to the fuel cell system 1 of the present embodiment, since the pair of hydrogen detection sensors 8A and 8B are installed on the inner peripheral surface 12a of the upper end portion 12A in the inclination direction of the ceiling plate 12, the optimum housing 2 is provided. Hydrogen detection sensors 8A and 8B can be installed at the positions.
Thereby, hydrogen leaking from any one of the fuel tank 4, the fuel cell 5, and the pipe 6 can be detected more accurately.

  Note that the control device 3 determines that the difference between the maximum value and the minimum value of the output values output from the hydrogen detection sensors 8A and 8B exceeds a predetermined determination value, and a certain time elapses after the determination value is exceeded. The operation of the fuel cell 5 may be stopped by closing any of the opened control valves 7A to 7C.

  This system control processing will be described based on the flowchart shown in FIG. 5 and the time chart shown in FIG. Note that the flowchart shown in FIG. 5 is a flowchart of a system control process executed by the control device 3.

  In FIG. 5, the control device 3 starts measuring hydrogen by the hydrogen detection sensors 8A and 8B (step S11). Next, as shown in FIG. 6, the control device 3 determines in advance the difference between the maximum value max and the minimum value min of the output values of the hydrogen detection sensors 8A, 8B based on the detection information from the hydrogen detection sensors 8A, 8B. It is determined whether or not the time that exceeds the determined determination value B and exceeds the determined value B has passed a predetermined time t (step S12).

  In step S12, the control device 3 determines that the difference between the maximum value max and the minimum value min of the output values of the hydrogen detection sensors 8A and 8B exceeds a predetermined determination value B, and the time exceeding the determination value B is a fixed time. If it is determined that t has elapsed, as shown in FIG. 6, the fuel cell system 1 is turned off to stop the operation of the fuel cell 5 (step S15), and the current process is performed. finish. In this case, the operation of the fuel cell 5 is stopped even if the output values of the hydrogen detection sensors 8A and 8B do not exceed the threshold value A.

When the operation of the fuel cell 5 is stopped, the driver may be notified by a lamp, a buzzer, or the like.
When the power supply of the fuel cell system 1 is turned off, any of the currently opened control valves 7A to 7C is closed, and hydrogen is not supplied from the fuel tank 4 to the fuel cell 5.

  In step S12, the control device 3 determines that the difference between the maximum value max and the minimum value min of the output values of the hydrogen detection sensors 8A and 8B does not exceed the predetermined determination value B or exceeds the determination value B. If it is determined that the predetermined time t has not elapsed, it is determined whether or not the output values of the hydrogen detection sensors 8A and 8B have exceeded a predetermined threshold A (step S13).

  In step S13, when it is determined that the output values of the hydrogen detection sensors 8A and 8B are equal to or less than the threshold value A, the control device 3 continues the operation of the fuel cell 5 (step S14), and the process proceeds to step S11. To return.

  In step S13, when it is determined that the output values of the hydrogen detection sensors 8A and 8B exceed the threshold value A, the control device 3 turns off the power supply of the fuel cell system 1 as shown in FIG. Thus, the operation of the fuel cell 5 is stopped (step S15), and the current process is terminated.

  As described above, in the fuel cell system of the present embodiment, the control device 3 causes the difference between the maximum value and the minimum value of the output values output from the hydrogen detection sensors 8A and 8B to exceed a predetermined determination value, When the time exceeding the determination value elapses for a certain time, one of the opened control valves 7A to 7C may be closed to stop the operation of the fuel cell 5.

In this way, the failure of the hydrogen detection sensors 8A and 8B can be detected and the operation of the fuel cell 5 can be stopped immediately, and the safety of the fuel cell system 1 can be improved more effectively.
In addition to this, an initial check and a disconnection check when the fuel cell system 1 is powered on can be performed.

  Further, since the operation of the fuel cell 5 is not stopped when the difference between the maximum value and the minimum value of the output values output from the hydrogen detection sensors 8A and 8B does not exceed a predetermined determination value, the hydrogen detection sensor It is possible to prevent the operation of the fuel cell 5 from being stopped due to the malfunction of 8A and 8B. For this reason, it can prevent that the reliability of the fuel cell system 1 falls.

  In addition, although the fuel cell system 1 of this Embodiment is mounted in the vehicle, it is applicable to moving bodies, such as an aircraft, a ship, and a robot, It is not limited to these.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 2 ... Housing | casing, 3 ... Control apparatus (control part), 4 ... Fuel tank, 5 ... Fuel cell, 6 ... Piping, 8A, 8B. .. Hydrogen detection sensor, 11 ... side plate, 11a ... one end, 11b ... other end, 12 ... ceiling plate, 12A ... upper end, 12a ... inner peripheral surface, 13 ... opening

Claims (3)

A fuel tank in which hydrogen is stored, a fuel cell that generates electricity by reaction of hydrogen and oxygen, the fuel tank and the fuel cell are connected, and hydrogen stored in the fuel tank is supplied to the fuel cell A fuel cell system comprising: a pipe to be operated; a plurality of hydrogen detection sensors for detecting hydrogen; and a control unit for controlling operation of the fuel cell based on detection information from the hydrogen detection sensor,
A housing in which the fuel tank, the fuel cell, and the pipe are accommodated;
The housing is provided on a side plate and an upper surface of the side plate, and is inclined upward from one end portion of the upper surface of the side plate toward the other end portion. A ceiling plate in which an opening communicating the inside and the outside of the housing is formed between the upper surface of the unit,
The fuel cell system, wherein the plurality of hydrogen detection sensors are installed on an inner peripheral surface of an upper end portion in an inclination direction of the ceiling board.   2. The fuel cell system according to claim 1, wherein the control unit stops the operation of the fuel cell when output values output from the plurality of hydrogen detection sensors exceed a predetermined threshold value. .   The control unit, when the difference between the maximum value and the minimum value of the output value output from the plurality of hydrogen detection sensors exceeds a predetermined determination value, and when the time exceeding the determination value has elapsed for a certain period of time, The fuel cell system according to claim 1, wherein the operation of the fuel cell is stopped.

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