JP2010135214A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid damage to a fuel cell and a system or the abnormal stoppage of the system by preventing excessive pressure generated in a cathode system. <P>SOLUTION: The system is provided with a first switching valve 36a arranged at an upstream side of the fuel cell 12, a second switching valve 36b arranged at a downstream side, and a failure detection means for detecting a failure of either or both of the first switching valve 36a and the second switching valve 36b. If either or both of the first switching valve 36a and the second switching valve 36b are in closing failures, air having excessive pressure in circulating in the cathode system 16 by being supplied from an air pump 26 is released to the outside from a relief valve 35 arranged between the air pump 26 and the first switching valve 36a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  According to the present invention, after the power generation of the fuel cell is stopped, the first on-off valve and the second on-off valve are closed to seal the cathode, and during the power generation of the fuel cell, the first on-off valve and the second on-off valve are closed. The open / close valve is opened and the cathode can be opened.

  For example, in Patent Document 1, an air inlet shut-off valve and an air outlet shut-off valve are respectively provided at the cathode inlet / outlet of the fuel cell in order to suppress cross leaks that occur when the fuel cell power generation is stopped. A fuel cell system is disclosed in which the air inlet shut-off valve and the air outlet shut-off valve are respectively closed to seal the cathode.

In the fuel cell system disclosed in Patent Document 1, a buffer tank that accumulates air compressed by an air compressor at a pressure higher than a supply pressure to the fuel cell is provided, and an atmospheric pressure chamber that communicates with the atmosphere and the buffer tank. The valve opening and closing operations of the air inlet shut-off valve and the air outlet shut-off valve are switched by the differential pressure with the pressurizing chamber pressurized by the air supplied from the air.
JP 2008-218072 A

  However, in the prior art disclosed in Patent Document 1, switching of the valve opening / closing operation of the air inlet shut-off valve and the air outlet shut-off valve is performed by the air pressure (air pressure drive) supplied from the buffer tank. When it is necessary to open each shut-off valve, such as during fuel cell power generation, if the shut-off valve fails for some reason when the shut-off valve fails, switching to the valve open state becomes difficult. The inside of the cathode system becomes excessive pressure due to the compressed air supplied from. As a result, the fuel cell and the system may be damaged or the system may be stopped abnormally due to an abnormal air pressure in the system.

  The present invention has been made in view of the above points, and can prevent the occurrence of excessive pressure in the cathode system, thereby avoiding damage to the fuel cell and system or abnormal shutdown of the system. An object is to provide a fuel cell system.

To achieve the above object, the present invention provides a fuel cell in which a fuel gas is supplied to an anode and an oxidant gas is supplied to a cathode, and an oxidant gas that supplies the oxidant gas to the fuel cell. A supply means; an oxidant gas flow path for supplying the oxidant gas to the fuel cell and discharging from the fuel cell; a first on-off valve provided on a supply side of the oxidant gas flow path; A second opening / closing valve provided on the discharge side of the oxidant gas flow path; a first opening / closing operation means for opening / closing the first opening / closing valve; and a second opening / closing operation for opening the second opening / closing valve. The cathode switch is configured to close the first opening / closing valve and the second opening / closing valve by the opening / closing operation means and the first opening / closing operation means and the second opening / closing operation means after the power generation of the fuel cell is stopped. And block the fuel Cathode blockable means for opening the cathode by opening the first open / close valve and the second open / close valve by the first open / close operation means and the second open / close operation means during power generation in the pond In a fuel cell system comprising
A failure detection unit that detects a failure of at least one of the first on-off valve and the second on-off valve and includes a relief valve disposed between the oxidant gas supply unit and the first on-off valve. When the failure detecting means detects a failure of at least one of the first on-off valve and the second on-off valve, the oxidant gas flowing through the oxidant gas flow path is externally provided by the relief valve. It is characterized in that it is released.

  According to the present invention, during the operation of the fuel cell system, at least one of the first opening / closing valve and the second opening / closing valve is closed (failure that does not switch to the valve open state while the valve body remains closed). When the failure detection means detects this, the pressure fluid in the oxidant gas passage (in the cathode system) that has become excessive due to the oxidant gas supplied from the oxidant supply means is discharged from the relief valve to the outside. Can do. As a result, in the present invention, it is possible to preferably avoid the system damage or the abnormal stop of the fuel cell system in the fuel cell and the cathode system.

  Further, according to the present invention, when a failure is detected by the failure detection means, the supply of the oxidant gas from the oxidant gas supply means is stopped, thereby rapidly increasing the pressure in the oxidant gas flow path. Can be avoided.

  According to the present invention, it is possible to obtain a fuel cell system capable of avoiding damage to the fuel cell and the system or an abnormal stop of the system by discharging excessive pressure fluid generated in the cathode system to the outside by the relief valve. it can.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is an overall configuration diagram of a fuel cell system according to a first embodiment of the present invention. In the embodiment described below, a fuel cell vehicle is described as an example. However, the present invention is not limited to this, and is applied to, for example, a ship, an aircraft, or a stationary type for business use or home use. can do.

  As shown in FIG. 1, the fuel cell system 10 according to the first embodiment includes a fuel cell 12, an anode system 14, a cathode system 16, an anode scavenging system 18, and a control system 20.

  The fuel cell 12 is composed of a polymer electrolyte fuel cell (PEFC), and is configured by laminating a plurality of single cells each having a MEA (Membrane Electrode Assembly) sandwiched between separators (not shown). Has been.

  The MEA includes an electrolyte membrane (fixed polymer membrane), a cathode and an anode that sandwich the membrane. The cathode and the anode are each composed of an electrode catalyst layer in which a catalyst such as platinum is supported on a catalyst carrier such as carbon black. Each separator has an anode channel 22 and a cathode channel 24 formed of grooves and through holes.

  In such a fuel cell 12, when hydrogen (reaction gas, fuel gas) is supplied to the anode, and when air containing oxygen (reaction gas, oxidant gas) is supplied to the cathode, it is included in the anode and cathode. An electrode reaction occurs on the catalyst, and the fuel cell 12 is ready for power generation.

  The fuel cell 12 is electrically connected to an external load (not shown). When a current is taken out by the external load, the fuel cell 12 generates power. The external load includes a traveling motor, a power storage device such as a battery or a capacitor, an air pump 26 described later, and the like.

  The anode system 14 includes a hydrogen tank 28, a shutoff valve 30, a purge valve 32, pipes a1 to a5, and the like.

  The hydrogen tank 28 is obtained by compressing high-purity hydrogen at a high pressure, and is connected to the shut-off valve 30 on the downstream side via a pipe a1. The shut-off valve 30 is composed of, for example, an electromagnetic valve, and is connected to the inlet of the anode flow path 22 of the fuel cell 12 on the downstream side via a pipe a2.

  The purge valve 32 is composed of, for example, an electromagnetic valve, and is connected to the outlet of the anode flow path 22 of the upstream fuel cell 12 via a pipe a3. Further, a pipe a4 for returning unreacted hydrogen discharged from the outlet of the anode of the fuel cell 12 to the inlet side of the anode is connected to the inlet side pipe a2 and the outlet side pipe a3.

  Note that an unillustrated ejector is provided at the junction from the pipe a4 to the pipe a2, so that the gas (hydrogen) returning from the pipe a4 is sucked by the negative pressure generated by the hydrogen flow led out from the hydrogen tank 28. It is configured. The purge valve 32 is connected to the downstream side diluter 34 via the pipe a5.

  The cathode system 16 includes an air pump (oxidant gas supply means) 26, a relief valve (failure detection means) 35, a first on-off valve 36a, a second on-off valve 36b, a back pressure valve 38, a diluter 34, piping (oxidizer). Gas flow path) c1 to c5 and the like.

  The air pump 26 is, for example, a mechanical supercharger driven by a motor (not shown), and compresses the taken outside air (air) and supplies the compressed air to the fuel cell 12.

  The first opening / closing valve 36a is provided on the oxidant gas supply side, is connected to the upstream air pump 26 via a pipe c1, and is connected to the cathode flow path 24 of the downstream fuel cell 12 via a pipe c2. Connected to the entrance. The second opening / closing valve 36b is provided on the oxidant gas discharge side, is connected to the outlet of the cathode flow path 24 of the upstream fuel cell 12 via the pipe c3, and is connected to the downstream side via the pipe c4. A back pressure valve 34 is connected.

  Since the first on-off valve 36a and the second on-off valve 36b are normally closed and have the same configuration, the configuration of the first on-off valve 36a will be described in detail below, and the second on-off valve 36b The description of is omitted.

  As shown in FIG. 2, the first open / close valve 36a includes a valve housing 42 in which an inlet port 40a into which a fluid is introduced and an outlet port 40b into which the fluid is led out are formed, and a chamber of the valve housing 42. 44, a valve body 46 that switches between a communication state and a non-communication state of the inlet port 40a and the outlet port 40b, a spring member 50 that presses the valve body 46 toward the seating portion 48, and the valve body A valve drive mechanism 52 (opening / closing operation means) that displaces the valve body 46 along a direction in which the valve 46 is separated from the seating portion 48 and a direction in which the seat 46 is seated.

  As shown in FIG. 1, a pipe c1 communicating with the air pump 26 is connected to the inlet port 40a of the valve housing 42, and the fuel cell 12 is connected to the outlet port 40b. A pipe c2 communicating with the cathode channel 24 is connected. The second open / close valve 36b is connected to a pipe c3 that communicates with the cathode flow path 24 of the fuel cell 12 with respect to the inlet port 40a of the valve housing 42, and communicates with the back pressure valve 38 with respect to the outlet port 40b. Pipe c4 is connected. In this case, the positions of the inlet port 40a and the outlet port 40b are reversed in the first on-off valve 36a and the second on-off valve 36b.

  The valve body 46 includes a valve portion 46a formed in a disc shape and a rod portion 46b connected to the center of the valve portion 46a. A seating portion of the valve housing 42 is provided on the lower surface of the valve portion 46a. A valve packing 46c that abuts 48 and exhibits a sealing function is mounted.

  The valve drive mechanism 52 is exposed from, for example, a rotation drive source 56 formed of an electric drive means such as a stepping motor, a pinion 58 connected to the rotation drive shaft 56a (motor shaft) of the rotation drive source 56, and the valve housing 42. And a rack portion 60 that is provided on the outer peripheral surface of the rod portion 46 b of the valve body 46 that engages with the pinion 58. The rotational drive source 56 is fixed by a fixing member (not shown) connected to the valve housing 42.

  In this case, the rotational drive source 56 is rotationally driven and the rotational motion of the rotational drive shaft 56 a is transmitted to the pinion 58, and the rotational motion of the pinion 58 is caused by the linear action of the valve body 46 by the meshing action of the pinion 58 and the rack portion 60. It is converted into motion (lifting motion). As a result, the valve body 46 is seated on the seat portion 48 and closes the outlet port 40b, whereby the communication between the inlet port 40a and the outlet port 40b is shut off (see the solid line in FIG. 2). On the other hand, when the valve body 46 is separated from the seating portion 48, the valve is in an open state in which the inlet port 40a and the outlet port 40b communicate with each other through the chamber 44 in the valve housing 42 (see the two-dot chain line in FIG. 2). ).

  The rotational drive source 56 of the valve drive mechanism 52 is driven by, for example, electric power of a low voltage battery (not shown) provided separately from the high voltage battery. Further, the first opening / closing valve 36a and the second opening / closing valve 36b are not limited to the normally closed type as described above. For example, the valve is opened during power generation of the fuel cell 12, and the fuel cell 12 A normally open type on-off valve in which the valve is closed via the valve drive mechanism 52 when the cathode is blocked after the power generation is stopped, and the valve closed state is held by a fixing member (or lock mechanism) not shown. It is good.

  The relief valve 35 is disposed in a pipe c1 between the air pump 26 and the first opening / closing valve 36a, and is constituted by a known direct acting relief valve. The relief valve 35 includes, for example, a valve member (including a ball) (not shown) that is pressed against the valve seat by the spring force of the adjustment spring inside a substantially cylindrical valve body. In this case, the pressure fluid introduced from an inlet port (not shown) of the valve body (air flowing through the pipe c1) presses the valve member in the direction away from the valve seat, and the pressure of the pressure fluid is adjusted by the spring of the adjustment spring. By overcoming the force, the valve member is separated from the valve seat, and the pressure fluid is discharged (relieved) from a relief port (not shown).

  The relief valve 35 includes, for example, a Hall element that detects the magnetic field strength of a permanent magnet attached to the valve member using the Hall effect, and the position for detecting the position of the valve member. A detection sensor (failure detection means) 37 is provided. The position detection sensor 37 derives a detection signal to the ECU 100 described later when the valve member is separated from the valve seat and is in a relief state.

  The back pressure valve 38 is disposed on the downstream side of the second opening / closing valve 36 b and has a function of adjusting the pressure of the cathode of the fuel cell 12. The back pressure valve 38 is configured by a butterfly valve (normally open type) that can adjust the valve opening degree by a valve opening signal from the ECU 100 described later. Further, the back pressure valve 38 is connected to the diluter 34 via the pipe c5.

  The diluter 34 dilutes the unconsumed hydrogen discharged from the purge valve 32 with the cathode off-gas discharged from the cathode and discharges it outside the vehicle. The cathode system 16 is provided with a humidifier (not shown) for humidifying the air supplied from the air pump 26 in the pipe c1.

  The anode scavenging system 18 includes an air introduction pipe 70, an air introduction valve 72, an air lead-out pipe 74, an air lead-out valve 76, and the like.

  The air introduction pipe 70 constitutes a flow path for introducing air (scavenging gas, oxidant gas) from the air pump 26 to the anode, the upstream end is connected to the pipe c1, and the downstream end is the pipe a2. Connected with. The air introduction valve 72 is provided on the flow path of the air introduction pipe 70 and is opened by the ECU 100 during anode scavenging after the fuel cell 12 stops generating power.

  The air outlet piping 74 constitutes a flow path for returning air (scavenging gas) discharged from the anode to the cathode system 16, the upstream end is connected to the piping a <b> 3, and the downstream end is the back pressure valve 38. It is connected to the downstream pipe c5. The air outlet valve 76 is provided on the flow path of the air outlet pipe 74 and is opened by the ECU 100 during anode scavenging.

  The control system 20 includes an ECU (failure detection means) 100 (Electronic Control Unit), and the ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. Further, the ECU 100 controls the opening / closing of the shut-off valve 30, the purge valve 32, the air introduction valve 72, and the air lead-out valve 76, and drives and controls the valve drive mechanism 52, whereby the first on-off valve 36a and the second on-off valve 36a. Switching control is performed between the valve closed state and the valve closed state of the on-off valve 36b. Further, the ECU 100 controls the rotational speed of the motor of the air pump 26 to control the air flow rate (air pressure) supplied from the air pump 26 to the fuel cell 12 and adjusts the valve opening of the back pressure valve 38.

  The fuel cell system 10 according to the first embodiment is basically configured as described above. Next, the function and effect will be described.

  First, the case where the ignition switch of the fuel cell vehicle is turned off (IG-OFF) and the power generation of the fuel cell 12 is stopped will be described.

  When the ignition switch is turned off (IG-OFF) by the driver, the shutoff valve 30 is closed by the control signal from the ECU 100, the supply of hydrogen to the fuel cell 12 side is stopped, and the air pump 26 The driving of a motor (not shown) is stopped, and the supply of air to the fuel cell 12 side is stopped. Further, when the power generation of the fuel cell 12 is stopped, the first opening / closing valve 36a and the second opening / closing valve 36b are closed, and the cathode of the fuel cell 12 is blocked.

  In other words, when power generation of the fuel cell 12 is stopped, when the first on-off valve 36a and the second on-off valve 36b are, for example, normally closed valves, as shown by the solid line in FIG. The valve body 46 is pressed against the seat portion 48 by 50 spring force. Accordingly, the first on-off valve 36a and the second on-off valve 36b are in a valve-closed state in which the communication between the inlet port 40a and the outlet port 40b is blocked. At that time, the rotational drive source 56 of the valve drive mechanism 52 is in a non-energized state.

  Preferably, the cathode of the fuel cell 12 is blocked by the first opening / closing valve 36a and the second opening / closing valve 36b, so that new air flows into the cathode flow path 24 when the fuel cell 12 stops generating power. Thus, the occurrence of cross leak can be prevented and the performance degradation of the fuel cell 12 can be prevented.

  Next, when the ignition switch of the fuel cell vehicle is turned on (IG-ON) by the driver and the fuel cell system 10 is in operation, the ECU 100 sets the first on-off valve 36a and the second on-off valve 36b. The respective valves are opened to release the blocked state of the cathode, the shut-off valve 30 is opened to supply hydrogen from the hydrogen tank 28 to the anode, and the air pump 26 is driven to air ( Air) is supplied, and the fuel cell 12 generates power.

  During the operation of the fuel cell system 10, the air introduction valve 72 and the air lead-out valve 76 are closed, the purge valve 32 is appropriately opened, and the pipes a2, a3, a4 and the anode Impurities such as nitrogen and generated water accumulated in the anode circulation system composed of the flow path 22 are discharged. Nitrogen and produced water permeate the anode from the cathode through the electrolyte membrane.

  Here, during the operation of the fuel cell system 10, one or both of the first on-off valve 36a and the second on-off valve 36b are closed due to some cause (the valve body 46 is held in the valve closed state). The following describes the case of a failure that does not switch from the valve closed state to the valve open state.

  When only the first opening / closing valve 36a disposed on the upstream side of the fuel cell 12 is closed, the air in the pipe c1 upstream of the first opening / closing valve 36a is caused by the air pressure supplied from the air pump 26. Pressure increases. When the air pressure in the pipe c1 reaches a predetermined pressure, the valve member of the relief valve 35 is separated from the valve seat by overcoming the spring force of the adjustment spring, and the air having increased air pressure is released to the outside from the relief port. can do.

  The “predetermined pressure” is set by the spring force (spring constant) of an adjusting spring that is disposed inside the valve body of the relief valve 35 and presses the valve member. Further, an adjustment knob (not shown) provided in the relief valve 35 may be rotated to adjust the spring force of the adjustment spring to a desired value.

  When only the second opening / closing valve 36b disposed on the downstream side of the fuel cell 12 is closed, the air pressure supplied from the air pump 26 causes the inside of the pipe c3 upstream of the second opening / closing valve 36b. , The air pressure in the cathode flow path 24 of the fuel cell 12, the air pressure in the pipe c2, and the air pressure in the pipe c1 respectively increase. Therefore, when the air pressure in the pipe c1 reaches a predetermined pressure, the valve portion of the relief valve 35 is separated from the valve seat by overcoming the spring force of the adjustment spring, and the increased air pressure is externally supplied from the relief port. Can be released. When only the second opening / closing valve 36b disposed downstream of the fuel cell 12 is closed, the predetermined pressure is set to a pressure (withstand pressure) that does not damage the fuel cell 12 and the pipes c1 to c3. It should be set.

  When both the first opening / closing valve 36a and the second opening / closing valve 36b disposed on the upstream side of the fuel cell 12 are closed, the air pump 26 is similar to the closing failure of only the first opening / closing valve 36a. The air pressure in the pipe c1 on the upstream side of the first opening / closing valve 36a is increased by the air pressure supplied from. Therefore, when the air pressure in the pipe c1 reaches a predetermined pressure, the valve portion of the relief valve 35 is separated from the valve seat by overcoming the spring force of the adjustment spring, and the increased air pressure is externally supplied from the relief port. Can be released.

  At that time, when a detection signal that detects that the valve member is separated from the valve seat is input from the position detection sensor 37 that detects the position of the valve member of the relief valve 35, the ECU 100 sends a control signal to the air pump 26. The rotational speed of the air pump 26 is controlled to reduce the air pressure (air flow rate) supplied from the air pump 26, or the rotation of the motor of the air pump 26 is stopped and the air from the air pump 26 is stopped. Stop supplying. By stopping the supply of air from the air pump 26, a sudden increase in air pressure in the cathode system 16 can be avoided.

  Further, after the detection signal from the position detection sensor 37 is input, the ECU 100 detects the valve opening degree of the back pressure valve 38 and controls the pressure of the valve body of the back pressure valve 38 from the fully opened state to the closed side. When it is determined that the valve body (butterfly valve) is fully open, a valve opening signal for opening the valve body (butterfly valve) is output to the back pressure valve 38. Therefore, the valve body of the back pressure valve 38 is fully opened to reduce the back pressure of the cathode, thereby contributing to suppressing a sudden increase in air pressure in the cathode system 16. .

  As described above, in the present embodiment, when one or both of the first opening / closing valve 36a and the second opening / closing valve 36b are closed due to some cause during the operation of the fuel cell system 10, the air pump 26 The pressure fluid in the cathode system 16 that has become excessive due to the supplied air can be discharged from the relief valve 35 to the outside. As a result, in this embodiment, it is possible to favorably avoid system breakage or abnormal stop of the fuel cell system 10 in the fuel cell 12 and the cathode system 16.

  Next, FIG. 3 shows an overall configuration diagram of the fuel cell system according to the second embodiment of the present invention. In the following embodiment, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the fuel cell system 10a according to the second embodiment, as shown in FIG. 3, the opening degree of the valve body 46 of the first on-off valve 36a and the second on-off valve 36b is detected, and the detection signal is The first embodiment is provided with a valve opening sensor (failure detection means) 39 for outputting to the ECU 100 and a solenoid portion 35a for driving the valve member of the relief valve 35 by a drive signal from the ECU 100. Is different.

  That is, the ECU 100 determines whether the first opening / closing valve 36a or the second opening / closing valve 36a or the second opening / closing valve 36a or the second opening / closing valve 36a is detected by a detection signal from the valve opening degree sensor 39 that detects the opening degree of the valve body 46 of the first opening / closing valve 36a. When it is determined that one or both of the open / close valves 36b have failed, a drive signal is output to the solenoid portion 35a of the relief valve 35. In the relief valve 35, the coil of the solenoid part 35a is excited to attract the valve member, and the valve member is separated from the valve seat. Therefore, the pressure fluid in the cathode system 16 that has become excessive pressure due to the air supplied from the air pump 26 can be discharged from the relief valve 35 to the outside. As a result, in this embodiment, it is possible to favorably avoid system breakage or abnormal stop of the fuel cell system 10 in the fuel cell 12 and the cathode system 16.

  In this case, as in the first embodiment, the ECU 100 controls the rotational speed of the air pump 26 and the valve opening degree of the back pressure valve 38.

Next, FIG. 4 shows an overall configuration diagram of a fuel cell system according to a third embodiment of the present invention.
In the fuel cell system 10b according to the third embodiment, as shown in FIG. 4, instead of the valve opening sensor 39, a pressure is applied between the first on-off valve 36a and the cathode inlet of the fuel cell 12. A second embodiment is provided in that a detection sensor (failure detection means) 41 is provided, the pressure of the air flowing through the pipe c2 upstream of the cathode inlet of the fuel cell 12 is detected, and the detection signal is output to the ECU 100. Is different.

  That is, the ECU 100 detects one of the first on-off valve 36a and the second on-off valve 36b or the same depending on the detection signal from the pressure detection sensor 41 that detects the air pressure upstream of the cathode system 16 of the fuel cell 12. When it is determined that both of them have failed, a drive signal is output to the solenoid portion 35a of the relief valve 35. In this case, the ECU 100 obtains a reference pressure corresponding to the current operating state of the fuel cell system 10 from a table or the like (not shown) from the rotational speed information of the motor of the air pump 26, the valve opening information of the back pressure valve 38, and the like. Is compared with the actual air pressure detected by the pressure detection sensor 41, and it is determined that a closed failure has occurred. For example, when the upstream side first opening / closing valve 36a fails to close, it is determined that the closing failure occurs when the actual air pressure is lower than the reference pressure, while the downstream side second opening / closing valve 36b. Is closed, it is determined that the closed failure occurs when the actual pressure exceeds the reference pressure.

  In this way, when the ECU 100 determines that one or both of the first on-off valve 36a and the second on-off valve 36b has failed, the relief valve 35 is energized by the coil of the solenoid unit 35a. The member is sucked and the valve member is separated from the valve seat. Therefore, the pressure fluid in the cathode system 16 that has become excessive pressure due to the air supplied from the air pump 26 can be discharged from the relief valve 35 to the outside. As a result, in this embodiment, it is possible to favorably avoid system breakage or abnormal stop of the fuel cell system 10 in the fuel cell 12 and the cathode system 16.

  In this case, as in the first embodiment, the ECU 100 controls the rotational speed of the air pump 26 and the valve opening degree of the back pressure valve 38.

Next, FIG. 5 shows an overall configuration diagram of a fuel cell system according to a fourth embodiment of the present invention.
In the fuel cell system 10c according to the fourth embodiment, as shown in FIG. 5, a valve opening sensor 39 that detects the valve opening of the valve body 46 of the first opening / closing valve 36a and the second opening / closing valve 36b. And a pressure detection sensor 41 disposed between the first opening / closing valve 36 a and the cathode inlet of the fuel cell 12, and different in that each detection signal is output to the ECU 100.

  In this case, the ECU 100 takes an AND based on both the detection signal output from the valve opening sensor 39 and the detection signal output from the pressure detection sensor 41, whereby the first opening / closing valve 36a and the second opening / closing valve 36a. It is possible to reliably and accurately detect the closing failure of one or both of the open / close valves 36b.

1 is an overall configuration diagram of a fuel cell system according to a first embodiment of the present invention. It is a schematic longitudinal cross-sectional view of the 1st on-off valve and the 2nd on-off valve which comprise the said fuel cell system. It is a whole block diagram of the fuel cell system which concerns on 2nd Embodiment of this invention. It is a whole block diagram of the fuel cell system which concerns on 3rd Embodiment of this invention. It is a whole block diagram of the fuel cell system which concerns on 4th Embodiment of this invention.

Explanation of symbols

10, 10a to 10c Fuel cell system 12 Fuel cell 16 Cathode system 24 Cathode flow channel 26 Air pump (oxidant gas supply means)
35 Relief valve (Failure detection means)
36a First open / close valve 36b Second open / close valve 37 Position detection sensor (failure detection means)
39 Valve opening sensor (failure detection means)
41 Pressure detection sensor (failure detection means)
46 valve body 52 valve drive mechanism (first and second opening / closing operation means)
100 ECU (cathode blockable means, failure detection means)
c1 to c5 piping (oxidant gas flow path)

Claims (2)

A fuel cell in which fuel gas is supplied to the anode and oxidant gas is supplied to the cathode; and
Oxidant gas supply means for supplying the oxidant gas to the fuel cell;
Supplying the oxidant gas to the fuel cell and discharging the oxidant gas from the fuel cell;
A first on-off valve provided on the supply side of the oxidant gas flow path;
A second on-off valve provided on the discharge side of the oxidant gas flow path;
First opening / closing operation means for opening / closing the first opening / closing valve;
Second opening / closing operation means for opening / closing the second opening / closing valve;
After the power generation of the fuel cell is stopped, the first opening / closing operation means and the second opening / closing operation means close the first opening / closing valve and the second opening / closing valve to close the cathode, and During the power generation of the fuel cell, the first open / close operation means and the second open / close operation means open the cathode by closing the first open / close valve and the second open / close valve. Possible means,
In a fuel cell system comprising:
A failure detection unit that detects a failure of at least one of the first on-off valve and the second on-off valve and includes a relief valve disposed between the oxidant gas supply unit and the first on-off valve. With
When at least one failure of the first on-off valve and the second on-off valve is detected by the failure detecting means, the oxidant gas flowing through the oxidant gas flow path is released to the outside by the relief valve. A fuel cell system. The fuel cell system according to claim 1, wherein
When a failure is detected by the failure detection means, supply of the oxidant gas from the oxidant gas supply means is stopped.

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