JP4877450B2 - Fuel cell system - Google Patents

Description

The present invention relates to a fuel cell system, and more particularly, a fuel gas supplied to the fuel chamber of the fuel cell, the fuel chamber of the fuel gas through the circulation path to circulate the fuel chamber, the circulation path the fuel gas, relates to a fuel cell system for discharging to the outside through the discharge passage is opened by the opening and closing valve.

  Conventionally, in a fuel cell using a polymer electrolyte membrane, a fuel chamber and an oxygen chamber exist on both sides of the electrolyte membrane, and the fuel gas in the fuel chamber passes through the fuel electrode or the oxidizing gas (mainly outside air) in the oxygen chamber. ) Is ionized through the oxygen electrode, and the ions are taken out through the electrolyte membrane to obtain electric power.

  The fuel gas discharge port of the fuel chamber is connected to a circulation passage connected to a fuel gas supply passage for supplying fuel gas to the fuel chamber, and a hydrogen circulation solenoid valve and a circulation pump are provided in the circulation passage. . After reacting with the oxidizing gas, the fuel gas in the fuel chamber is sucked by the circulation pump with the hydrogen circulation solenoid valve opened, discharged to the circulation passage through the fuel gas discharge port, and further fueled by the circulation pump. The gas flows into the gas supply channel and flows into the fuel chamber again.

By the way, when power generation of the fuel cell system is stopped, hydrogen in the fuel cell stack is replaced with air. When the gas is replaced, if air and hydrogen are relaxedly mixed, a water generation reaction occurs locally and a local battery state is generated. As a result, the hydrogen concentration on the hydrogen electrode side decreases, and the standard electromotive voltage of the battery itself increases, and this state causes abnormal combustion of the cathode catalyst, and the durability of the fuel cell itself is significantly deteriorated. This has become a very important and serious problem as a fuel cell deterioration problem.
Therefore, the inside of the fuel cell is depressurized, the outside air is introduced into the fuel cell, and the fuel gas in the circulation path is discharged to the outside through the reduced pressure discharge path opened by the pressure reducing solenoid valve. A countermeasure against deterioration at the time of stopping has been already proposed (Patent Document 1).
JP 2004-79490 A

  However, in order to replace the gas in the fuel cell stack rapidly, it is assumed that each part of the system operates normally. If any part, especially the vacuum solenoid valve, malfunctions, Cannot be replaced rapidly.

The present invention has been made in view of the above facts, and an object thereof is to provide a fuel cell system capable of sensing the failure of the open valve.

The present invention for solving the above problems has the following configuration.
(1) a fuel cell in which a fuel chamber into which a fuel gas is introduced and an oxidizing gas chamber into which an oxidizing gas is introduced are adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidizing gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Decompression means for opening the on-off valve and driving the circulation pump to decompress the fuel chamber;
Current detecting means for detecting the driving current of the circulation pump after the opening / closing valve opening instruction every predetermined time ;
The pump drive current detected by the current detection means is not greater than or equal to a predetermined threshold before performing the process of replacing the fuel gas in the fuel chamber, which is performed when the power generation of the fuel cell is stopped, with a replacement gas. A determination means for counting the number of times continuously determined, and determining that the on- off valve is abnormal when the count reaches a predetermined value ;
A fuel cell system comprising:

(2) a fuel cell in which a fuel chamber into which fuel gas is introduced and an oxidant gas chamber into which oxidant gas is introduced are adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidant gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Decompression means for opening the on-off valve and driving the circulation pump to decompress the fuel chamber;
Pressure detecting means for detecting the pressure in the supply passage after the opening / closing valve opening instruction every predetermined time ;
The rate of change calculated from the pressure per predetermined time detected by the pressure detecting means before performing the process of replacing the fuel gas in the fuel chamber, which is executed when the power generation of the fuel cell is stopped, with a replacement gas A determination unit that counts the number of times that it is continuously determined that is not less than or equal to a threshold value, and determines that the on-off valve is abnormal when the count reaches a predetermined value ;
A fuel cell system comprising:

(3) a fuel cell in which a fuel chamber into which a fuel gas is introduced and an oxidizing gas chamber into which an oxidizing gas is introduced are adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidizing gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Decompression means for opening the on-off valve and driving the circulation pump to decompress the fuel chamber;
Current detecting means for detecting the driving current of the circulation pump after the opening / closing valve opening instruction every predetermined time ;
Pressure detecting means for detecting the pressure in the supply passage after the opening / closing valve opening instruction every predetermined time ;
Before performing the process of replacing the fuel gas in the fuel chamber, which is performed when the power generation of the fuel cell is stopped, with a replacement gas, it is continuously determined that the detected drive current of the pump is not equal to or greater than a predetermined threshold. The number of times determined is counted, and the number of times that the number of times that the count value has reached a predetermined value and the rate of change calculated from the detected pressure per predetermined time is not less than or equal to the threshold value is counted. Determining means for determining that the on-off valve is abnormal when the count reaches a predetermined value ;
A fuel cell system comprising:

(4) When the on-off valve is determined to be abnormal by the determining means, wherein said opening and closing valve is characterized, further comprising an informing means for informing an abnormal (1) through (3) The fuel cell system according to any one of the above.

According to the first aspect of the present invention, since the state of the on-off valve is determined based on the driving current of the circulation pump, it is possible to detect a malfunction of the open valve.
According to the second aspect of the present invention, since the state of the on-off valve is determined based on the pressure in the supply path, a malfunction of the open valve can be detected.
According to the third aspect of the invention, since the state of the on-off valve is determined based on the driving current of the circulation pump and the pressure in the supply path, it is possible to detect the malfunction of the open valve with higher accuracy.
According to the first to third aspects of the present invention, the state of the on-off valve is set before the process of replacing the fuel gas in the fuel chamber, which is performed when the power generation of the fuel cell is stopped, with the replacement gas. Therefore, when it is determined that there is a problem with the on-off valve, it is possible to avoid the process of replacing the fuel gas in the fuel chamber with the replacement gas, and it is possible to prevent waste of electric power.

According to the fourth aspect of the present invention, when it is determined that the on-off valve is not in the normal operating state, the user is alerted that the on-off valve is not in the normal operating state.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Next, a preferred embodiment of the present invention will be described. This embodiment is a fuel cell system mounted on an electric vehicle. FIG. 1 is a block diagram showing a configuration of a fuel cell system 1 of the present invention. As shown in FIG. 1, the fuel cell system 1 is roughly configured by a fuel cell stack 100, a fuel supply system 10 including a hydrogen storage tank 11, an air supply system 12, a water supply system 50, and a load system 7. The

  The configuration of the fuel cell stack 100 will be described. The fuel cell stack 100 is configured by alternately stacking fuel cell unit cells 15 and fuel cell separators 13. 2 is an overall front view showing the fuel cell separator 13, FIG. 3 is a partial cross-sectional plan view of the fuel cell stack 100 composed of the fuel cell separator 13 (AA cross-sectional view in FIG. 2), and FIG. FIG. 5 is a partial sectional side view (BB sectional view in FIGS. 2 and 3), FIG. 5 is a partial sectional side view of the fuel cell separator 13 (CC sectional view in FIGS. 2 and 3), and FIG. FIG. 3 is an overall rear view of the fuel cell separator 13.

  The separator 13 includes current collecting members 3 and 4 for contacting the electrodes of the unit cell 15 and taking out current to the outside, and frame bodies 8 and 9 that are externally mounted on the peripheral ends of the current collecting members 3 and 4. I have. The current collecting members 3 and 4 that are current collecting plates are made of metal. The constituent metal is a metal having conductivity and corrosion resistance, and examples thereof include stainless steel, nickel alloy, titanium alloy and the like subjected to corrosion-resistant conductive treatment.

The current collecting member 3 is in contact with the fuel electrode of the unit cell 15, and the current collecting member 4 is in contact with the oxygen electrode. The current collecting member 3 is formed with a plurality of projecting convex portions 32 by pressing.
The convex portions 32 are arranged at equal intervals along the long side of the plate material in the short side direction. A hydrogen channel 301 is formed between the convex portions 32 by grooves formed between the convex portions 32 arranged along the long side (lateral direction in FIG. 2). A hydrogen flow path 302 is formed by the groove 33 formed in. The surface of the apex portion of the convex portion 32 is a contact portion 321 with which the fuel electrode contacts. Since the current collecting member 3 is a net, the fuel electrode can supply the fuel gas through the hole 320 even in the portion where the contact portion 321 contacts. In addition, hydrogen gas can flow between the hydrogen channel 301 and the hydrogen channel 302 via the holes 320.

Through holes 35 are formed at both ends of the current collecting member 3. When the separators 13 are stacked, the through holes 35 form a hydrogen supply path.
The current collecting member 4 is made of a rectangular plate material, and a plurality of convex portions 42 are formed by pressing. The convex portions 42 are continuously formed in a straight line parallel to the short sides of the plate material, and are arranged at equal intervals. A groove is formed between the convex portions 42 to form an air flow path 40 through which air flows. The surface of the apex portion of the convex portion 42 is an abutting portion 421 with which the oxygen electrode contacts. Further, the back side of the convex portion 42 is a groove-like hollow portion 41, and both ends of the hollow portion 41 are closed.

  The current collecting members 3 and 4 as described above are overlapped and fixed so that the convex portions 32 and the convex portions 42 are on the outside. At this time, the back side surface 34 of the current collecting member 3 and the back side surface 403 of the air flow path 40 are in contact with each other, so that they can be energized with each other. As shown in FIGS. 3 and 5, the air flow path 40 is overlapped with the unit cell 15, and a tubular flow path is formed by closing the groove opening 400. A part of the inner wall of 40 is composed of an oxygen electrode. Oxygen and water are supplied from the air flow path 40 to the oxygen electrode of the unit cell 15. The oxygen supplied to the oxygen electrode is oxygen contained in the air passing through the air flow path 40.

  The opening on one end side of the air flow path 40 is an introduction port 43 through which air and water flow, and the opening at the other end is a discharge port 44 through which air and water flow out. The air flow path 40 and its aggregate from the inlet 43 to the outlet 44 function as an oxygen chamber (air chamber) for supplying oxygen to the solid electrolyte membrane.

  Moreover, the opening part of the one end side of the hollow part 41 becomes the inflow opening port 45 into which air and water flow in, and the opening part of the other end becomes the outflow opening port 46 through which air and water flow out. In the above configuration, the air flow paths 40 and the hollow portions 41 are alternately arranged in parallel and are adjacent to each other with the side wall 47 interposed therebetween.

  Frame members 8 and 9 are overlaid on the current collecting members 3 and 4, respectively. As shown in FIG. 2, the frame 8 overlaid on the current collecting member 3 is configured to have the same size as the current collecting member 3, and a window 81 for accommodating the convex portion 32 is formed at the center. ing. Further, in the vicinity of both ends, a hole 83 is formed at a position matching the flow hole 35 of the current collecting member 3, and between the hole 83 and the window 81, the side in contact with the current collecting member 3 is formed. A recess is formed in the plane, and a hydrogen flow path 84 is provided. In addition, a concave portion whose contour is formed along the window 81 is formed on the plane opposite to the surface that contacts the current collecting member 3, and a storage portion 82 for storing the unit cell 15 is provided. Yes. The fuel chamber 30 is defined by the fuel electrode surface of the unit cell 15 housed in the housing portion 82, the hydrogen flow paths 301 and 302, and the window 81. Thus, the fuel chamber is provided adjacent to the fuel electrode, and the oxygen chamber is provided adjacent to the oxygen electrode.

  The frame body 9 overlaid on the current collecting member 4 is configured to have the same size as the frame body 8, and a window 91 for accommodating the convex portion 42 is formed at the center. Further, in the vicinity of both end portions, holes 93 are formed at positions corresponding to the holes 83 of the frame body 8. Grooves are formed along the pair of opposing long sides of the frame 8 on the surface of the frame 8 on which the current collecting member 4 is overlapped. By overlapping the current collecting members 3 and 4, the air flow passage 94 is formed. , 95 is configured. One end of the air flow passage 94 is connected to an opening 941 formed on the end surface on the long side of the frame body 8, and the other end is connected to the introduction port 43 of the air flow path 40.

  The upstream air flow passage 94 has an end inner wall that is a tapered surface 942 so that the cross-sectional area gradually decreases from the opening 941 side to the air flow path 40 side, and is injected from an air manifold 54 described later. It is easy to take in mist water. On the other hand, one end of the downstream air flow passage 95 is connected to the outlet 44 of the air flow path 40, and the other end is connected to an opening 951 formed on the long side end surface of the frame 8. The air flow passage 95 has an end inner wall as a tapered surface 952 so that the cross-sectional area gradually decreases from the opening 951 side toward the air flow path 40 side. Even when the fuel cell stack 100 is tilted, the tapered surface 952 maintains the discharge of water. In addition, a concave portion having a contour formed along the window 91 is formed on the plane opposite to the surface of the frame body 9 that contacts the current collecting member 4, and the storage unit in which the unit cell 15 is stored. 92 is provided.

  FIG. 7 is an enlarged cross-sectional view of the unit cell 15. The unit cell 15 includes a solid polymer electrolyte membrane 15a, and an oxygen electrode 15b and a fuel electrode 15c that are oxidant electrodes stacked on both side surfaces of the solid polymer electrolyte membrane 15a, respectively. The membrane 15a is sandwiched between the oxygen electrode 15b and the fuel electrode 15c. The solid polymer electrolyte membrane 15 a is formed in a size that matches the storage portions 82 and 92, and the oxygen electrode 15 b and the fuel electrode 15 c are formed in a size that matches the windows 91 and 81. Since the thickness of the unit cell 15 is extremely thin compared to the thicknesses of the frame bodies 8 and 9 and the current collecting members 3 and 4, the unit cell 15 is shown as an integral member in the drawing.

The inner wall of the air flow path 40 is subjected to hydrophilic treatment. The surface treatment may be performed so that the contact angle between the inner wall surface and water is 40 ° or less, preferably 30 ° or less. As the treatment method, a method of applying a hydrophilic treatment agent to the surface is taken. Examples of the treating agent to be applied include polyacrylamide, polyurethane resin, titanium oxide (TiO ₂ ), and the like.

  The separators 13 are configured by holding the current collecting members 3 and 4 by the frames 8 and 9 configured as described above, and the fuel cell stack 100 is configured by alternately stacking the separators 13 and the unit cells 15. . FIG. 8 is a partial plan view of the fuel cell stack 100. A large number of inlets 43 are opened on the upper surface of the fuel cell stack 100. As will be described later, air flows into the inlet 43 from the air manifold 54, and is a water injection means within the air manifold 54. Water sprayed from the nozzle 55 flows in simultaneously. The air and water flowing in from the introduction port 43 cool the current collecting members 3 and 4 by latent heat cooling.

Next, the configuration of the fuel cell system shown in FIG. 1 will be described.
The configuration of the fuel supply system 10 will be described. A hydrogen storage tank 11 that is a fuel gas cylinder is connected to a gas inlet 201BIN of the fuel cell stack 100 via fuel gas supply channels 201A and 201B. The fuel gas supply channel 201A includes a hydrogen source solenoid valve 18, a primary sensor S0, a regulator 19, a secondary pressure sensor S1, a hydrogen start solenoid valve 20 and a hydrogen pressure regulating valve 21 connected in parallel, a gas supply valve 22, a tertiary pressure. The sensor S2 is provided in order, and the fuel gas supply channel 201A is connected to the fuel gas supply channel 201B. The fuel gas supply flow path 201B is provided with a lily valve 31, and the fuel gas supply flow path 201B is connected to the gas intake port 201BIN of the fuel cell stack 100. One end of the gas discharge channel 202 is connected to the gas discharge port 202OUT of the fuel cell stack 100, and the other end is connected to the trap 24 to which the level sensor S11 is attached. One end of the circulation flow path 204 and one end of the gas outlet path 203 are connected to the trap 24. The other end of the gas lead-out path 203 is connected to a decompression discharge path 205 and is finally connected to an air discharge path 124 described later. An exhaust solenoid valve 27 is provided in the gas outlet passage 203.

The other end of the circulation channel 204 is connected to the outside air inflow channel 206. The circulation flow path 204 is provided with a circulation pump 25 and a circulation electromagnetic valve 26, and one end of a decompression discharge path 205 is connected between the circulation pump 25 and the circulation electromagnetic valve 26. The other end of the reduced pressure discharge path 205 opens to the air discharge path 124, and a reduced pressure electromagnetic valve 23 is provided in the reduced pressure discharge path 205. The other end of the outside air inflow path 206 opens to the outside, and the filter 29 and the outside air introduction electromagnetic valve 28 are provided in this order from the opening side. The circulation pump 25 is provided with a drive current detection sensor S10 that detects a drive current of the circulation pump.
A gas circulation path is formed by the fuel gas supply channel 201, the gas discharge channel 202, the circulation channel 204, and the outside air introduction electromagnetic valve 28.

  Next, the air supply system 12 will be described. The air supply system 12 includes an air introduction path 123, an air manifold 54, and an air discharge path 124. In the air introduction path 123, a filter 121, an outside air temperature sensor S6, an air fan 122, a heater H, an air inlet temperature sensor S5, and an air manifold 54 are provided in this order along the inflow direction. In the air manifold 54, a nozzle 55 for injecting cooling water is provided. The air manifold 54 divides and flows the air into the inlet 43 of the fuel cell stack 100.

  The air discharge path 124 is connected to the outlet 44 of the fuel cell stack 100, joins the air flowing out from the outlet 44, and guides it to the outside. The air exhaust path 124 is provided with a condenser 51 to which a fan is attached and a condenser exhaust temperature sensor S10, and then a filter 125 is connected thereto. The condenser 51 separates air and moisture. The water supplied from the nozzle 55 is also collected here. An exhaust temperature sensor S9 is provided in the air discharge path 124, and the temperature of the fuel cell stack 100 is indirectly detected.

  Next, the water supply system will be described. The water supply system 50 includes a water tank 53 that is a water storage means, a water conduit 52 that guides the water collected by the condenser 51 to the water tank 53, and a water supply passage 56 that guides the water in the water tank 53 to the nozzle 55. A collection pump 62 is provided in the water conduit 52. In the water supply path 56, a filter 64, a supply pump 61 that is water supply means, and a water supply electromagnetic valve 63 are provided in this order. An outside air intake passage 54 is connected to the water supply passage 56, and an outside air intake electromagnetic valve 65 is provided in the introduction passage 54. The water tank 53 is provided with a water temperature sensor S7 and a tank water level sensor S8 which is a storage amount detection means. The condenser 51, the water conduit 52, and the recovery pump 62 constitute water recovery means.

  In addition to this, the water collecting means is provided on the lower side of the fuel cell stack 100, and is provided in a water receiving tray as a water receiving and collecting means for receiving water injected from the nozzle 55, water generated by the fuel cell stack 100, and the like. A configuration for collecting the accumulated water may be added. When the condenser 51 is not provided, the water is collected by the water receiving tray. Further, by disposing the condenser 51, the water receiving tray, and the like in the vertical direction with respect to the water tank 53, the water can be collected by gravity. In this case, the recovery pump 62 is not required, but an electromagnetic on-off valve is provided in place of the recovery pump in order to control the water recovery operation by the switching means.

  A load system 7 is connected to the fuel cell stack 100, and electric power output from the fuel cell stack 100 is supplied to the load system 7. The electrodes of the fuel cell stack 100 are connected to relays 72 and 72 via a wiring 71, and the relays 72 and 72 are further connected to a motor 74 via an inverter 73. In addition, an auxiliary power source 76 is connected to the inverter 73 via an output control device 75.

The load system 7 is provided with a voltage sensor S4 for detecting the output voltage of the fuel cell stack 100 and a current sensor S3 for detecting the output current.
As shown in FIG. 9, the control system of the fuel cell system 1 receives the detection values of the sensors S0 to S10, the regulator 19, the solenoid valves 18, 20, 22 to 24, 26 to 28, 63, 65, Each pump 25, 62, 61, nozzle 55, fan 122, heater H, inverter 73, and control device (ECU) 200 for controlling the output control device 75 are provided. An ignition switch (not shown) is connected to the control device 200, and an instruction signal for driving or stopping the motor 74 is input.

Next, the principle of detecting the state of the pressure reducing electromagnetic valve 23 in the present embodiment will be described.
In the fuel cell system control operation when the fuel cell system enters the stop operation, the hydrogen source solenoid valve 18, the gas supply valve 22, the circulation solenoid valve 26, and the exhaust solenoid valve 27 that were opened during the steady power generation operation are closed. Then, the pressure reducing solenoid valve 23 is opened. Then, the pressure of the hydrogen system in the fuel cell stack is reduced using the suction operation of the circulation pump 25. When the pressure reaches a level at which the volume in the stack and the fuel gas supply channel 201B can be replaced, the outside air introduction electromagnetic valve 28 is opened, and air is instantaneously caused to flow into the fuel cell stack under a negative pressure. Thereby, hydrogen can be instantaneously replaced with outside air. In this case, the voltage of the fuel cell instantaneously decreases exponentially with time.

  However, various problems occur when the pressure reducing solenoid valve 23 does not open due to some trouble. In the conventional system, the failure detection of the pressure reducing electromagnetic valve 23 could not be detected until the abnormal processing due to the time regulation exceeding the operation in which the pressure reducing electromagnetic valve 23 is opened and the circulation pump 25 is used to make the negative pressure in the stack. The abnormality detection in this case corresponds to a malfunction event in which the capacity of the circulation pump 25 is insufficient or a gas leak in the stack occurs, and does not detect a failure of the pressure reducing solenoid valve 23 alone.

  When a malfunction occurs in the pressure reducing solenoid valve 23, the remaining hydrogen that does not work during this time is trapped in the stack, which cross leaks over time and generates an abnormal potential by mixing the cell anode and cathode gases, causing the fuel cell There is a possibility of causing a deterioration reaction, which is dangerous. In addition, continuing to take measures against deterioration without recognizing that a failure has occurred leads to wasteful consumption of capacitor power serving as a power source for the auxiliary fuel cell system.

In order to solve such a problem, it is very important to find an early detection method in which the pressure reducing electromagnetic valve 23 is not opened.
Therefore, the present inventor has found the operating characteristics of the circulation pump 25 that is seen when the fuel cell system enters the power generation stop operation, and whether or not a malfunction has occurred in the circulation pump 25 by using this characteristic. I found out as follows.

  That is, as shown in FIG. 10, when the decompression solenoid valve 23 is normally opened by the opening instruction (time t1) of the decompression solenoid valve 23 during the power generation stop operation of the fuel cell system, the fuel gas supply channel 201B Since the differential pressure between the air pressure and the outside air pressure is generated, the work of the circulation pump 25 increases instantaneously near the time t1 explosively. As a result, it can be seen that the drive current (Pump Current) Z of the circulation pump 25 is increased. Therefore, the drive current (Pump Current) Z of the circulation pump 25 from when the power generation stop operation of the fuel cell system is started and the decompression solenoid valve 23 is instructed to open changes rapidly as shown in FIG. That is, when a predetermined value (a predetermined threshold value I0 described later) becomes equal to or greater than a predetermined time, it can be determined that the pressure reducing electromagnetic valve 23 has been normally opened, and conversely, the driving current (Pump Current) of the circulation pump 25 If Z does not change rapidly, that is, if it remains below a predetermined value (predetermined threshold I0 described later) after a certain period of time, it can be determined that a malfunction has occurred in the pressure reducing solenoid valve 23. .

  Therefore, in the present embodiment, based on the above-described principle that it is possible to determine whether a malfunction has occurred in the pressure reducing electromagnetic valve 23 based on the driving current of the circulation pump 25 detected by the driving current detection sensor S10. The malfunction of the pressure reducing solenoid valve 23 is determined as follows.

  FIG. 11 shows a flowchart of the decompression solenoid valve state detection processing program showing the state detection process of the decompression solenoid valve 23. The decompression solenoid valve state detection processing program is repeatedly executed every predetermined time from when the decompression solenoid valve 23 is instructed to be opened.

  When the decompression solenoid valve state detection processing program starts, variables K and C used in the program are initialized to 0 in step 522. In this program, the state of the pressure reducing electromagnetic valve 23 is determined a plurality of times, and C is a variable for counting the number of determinations. Further, in this program, even if the state of the pressure reducing electromagnetic valve 23 is determined to be abnormal, it is finally concluded that the state of the pressure reducing electromagnetic valve 23 is abnormal when it is continuously determined to be abnormal for a predetermined number of times. And K is a variable for counting the number of times that the state of the pressure reducing electromagnetic valve 23 is continuously determined to be abnormal.

In step 524, the variable C is incremented by 1. In step 526, the drive current I of the circulation pump 25 detected by the drive current detection sensor S10 is fetched. In step 528, the drive current I of the circulation pump 25 is set to a predetermined threshold value I0. It is determined whether or not this is the case.
Here, the threshold value I0 exceeds the fluctuation amount of the driving current from the value of the driving current of the circulation pump 25 obtained from the experiment described with reference to FIG. Value.

If it is determined that the drive current I of the circulation pump 25 is equal to or greater than the predetermined threshold value I0 (step 528: Y), it can be determined that the pressure reducing solenoid valve 23 has operated normally. In step 530, the variable K is initialized to zero. In step 536, it is determined whether or not the variable C has reached the planned total number of determinations C0. The planned total number of determinations C0 is as follows. That is, as described above, the drive current (Pump Current) Z of the circulation pump 25 from when the decompression electromagnetic valve 23 is instructed to open changes rapidly as shown in FIG. If the pressure later becomes a predetermined value (a predetermined threshold I0 described later) or more, it can be determined that the pressure reducing electromagnetic valve 23 is normally opened. Also. As described above, this program is repeatedly executed every predetermined time. The number is larger than the number obtained by dividing the predetermined time from the predetermined time.
If the variable C is not the planned total number of determinations C0, the process returns to step 524 and the above processing (steps 524 to 536) is repeated.

On the other hand, if it is determined in step 528 that the drive current I of the circulation pump 25 is less than the predetermined threshold value I0 (step 528: N 2 ), it can be determined that the pressure reducing solenoid valve 23 is not operating normally, and the pressure reducing electromagnetic valve In order to continuously count that the valve 23 is not operating normally, in step 532, the variable K is incremented by 1, and in step 534, it is determined whether or not the variable K has reached a predetermined value Kn. If the variable K is not the predetermined value Kn, it is not counted continuously that the pressure reducing solenoid valve 23 is not operating normally, so the routine proceeds to step 536.

  However, when the variable K becomes the predetermined value Kn, since the predetermined value is continuously counted that the pressure reducing solenoid valve 23 is not operating normally, in step 538, the abnormal stop mode (for example, the circulation pump 25) is counted. To stop the fuel cell safely.

  If the variable C reaches the planned total number of determinations C0 in step 536, the pressure reduction electromagnetic valve 23 operates normally while the state of the pressure reduction electromagnetic valve 23 is determined as the total number of determinations C0. Since the predetermined value is not counted continuously, it can be determined that the state of the pressure reducing electromagnetic valve 23 is normal, and thus this program is terminated.

As described above, according to the present embodiment, it is possible to determine whether a malfunction has occurred in the pressure reducing electromagnetic valve 23 based on the drive current of the circulation pump 25, and to easily determine the state of the pressure reducing electromagnetic valve 23. it can.
Further, since the malfunction of the pressure reducing solenoid valve 23 is determined every predetermined time from when the opening instruction of the pressure reducing solenoid valve 23 is given, this allows early detection of an abnormality in the pressure reducing solenoid valve 23 and the fuel cell resulting therefrom. Can predict the danger.

  In the above-described embodiment, when an abnormality is detected, the abnormal stop mode is executed, a warning lamp is further provided, the warning lamp is lit, a display is provided, and the pressure reducing electromagnetic valve 23 is provided on the display. A warning may be displayed that a failure has occurred, or a speaker may be provided, and a voice may be sent to notify that a failure has occurred in the pressure reducing electromagnetic valve 23 via the speaker. As a result, the user can be alerted.

Next, a second embodiment of the present invention will be described. Since this embodiment has the same configuration as the first embodiment described above, the description thereof will be omitted and the operation will be described.
In the present embodiment, whether or not a malfunction has occurred in the pressure reducing electromagnetic valve 23 is determined based on the pressure in the fuel gas supply channel 201B detected by the sensor S2 (third pressure (3rd Pressure) N). However, the principle will be described below.

  That is, as shown in FIG. 10, when the decompression solenoid valve 23 is normally opened by the opening instruction (time t1) of the decompression solenoid valve 23 during the power generation stop operation of the fuel cell system, the fuel gas supply channel 201B Since the differential pressure between the air pressure and the outside air pressure is generated, the work of the circulation pump 25 increases instantaneously near the time t1 explosively. As a result, the pressure N in the fuel gas supply channel 201B decreases rapidly. Accordingly, the pressure N in the fuel gas supply channel 201B from when the power generation stop operation of the fuel cell system is entered and the decompression electromagnetic valve 23 is instructed to open is rapidly decreased (changed) as shown in FIG. When the rate ΔP 0), it can be determined that the pressure reducing solenoid valve 23 has been normally opened. Conversely, when the pressure N in the fuel gas supply channel 201 B has not decreased sharply, the pressure reducing solenoid valve 23, it can be determined that a problem has occurred.

  Therefore, in the present embodiment, based on the above-described principle that it is possible to determine whether or not a malfunction has occurred in the pressure reducing electromagnetic valve 23 based on the pressure N in the fuel gas supply channel 201B detected by the sensor S2. The malfunction of the pressure reducing solenoid valve 23 is determined as follows.

  FIG. 12 shows a flowchart of a decompression solenoid valve state detection processing program showing a process of sensing the state of the decompression solenoid valve 23 based on the pressure in the fuel gas supply channel 201B. The decompression solenoid valve state detection processing program is repeatedly executed every predetermined time from when the decompression solenoid valve 23 is instructed to be opened.

  When the decompression solenoid valve state detection processing program starts, variables L and M used in the program are initialized to 0 in step 620. In this program, the state of the pressure reducing solenoid valve 23 is determined a plurality of times, and M is a variable for counting the number of determinations. Further, in this program, even if the state of the pressure reducing electromagnetic valve 23 is determined to be abnormal, it is finally concluded that the state of the pressure reducing electromagnetic valve 23 is abnormal when it is continuously determined to be abnormal for a predetermined number of times. L is a variable for counting the number of times that the state of the pressure reducing electromagnetic valve 23 is continuously determined to be abnormal.

  In step 622, the variable M is incremented by 1. In step 624, the pressure P in the fuel gas supply channel 201B detected by the sensor S2 is taken in. In step 626, the rate of change ΔP of the pressure P is calculated. In the present embodiment, in the processing loop (steps 622 to 636), the pressure P detected by executing the previous program loop is subtracted from the pressure P1 detected this time, and this subtraction value is used as the program. Is calculated by dividing by the predetermined time repeatedly executed. That is, the change rate ΔP is a negative value in the normal state, and the change rate ΔP0 that is a threshold value is naturally a negative value.

In step 628, it is determined whether or not the change rate ΔP of the pressure P is equal to or less than the change rate ΔP0 obtained in the above experiment (or whether or not the absolute value is ΔP ≧ ΔP0).
If it is determined that the rate of change ΔP of the pressure P is equal to or less than the rate of change ΔP0 obtained in the above experiment, it can be determined that the pressure reducing solenoid valve 23 has operated normally. In step 630, the variable L is initialized to zero. In step 636, it is determined whether or not the variable M has reached the planned total number of determinations M0.

If the variable M is not the planned total number of determinations M0, the process returns to step 622 and the above processing loop (steps 622 to 636) is repeated.
On the other hand, if it is determined in step 628 that the rate of change ΔP of the pressure P is not less than the rate of change ΔP 0 obtained in the above-described experiment, it can be determined that the pressure reducing solenoid valve 23 is not operating normally, In order to continuously count that the valve 23 is not operating normally, in Step 632, the variable L is incremented by 1, and in Step 634, it is determined whether or not the variable L has reached a predetermined value Ln. If the variable L is not equal to the predetermined value Ln, the fact that the pressure-reducing solenoid valve 23 is not operating normally has not been counted continuously, and the routine proceeds to step 536.

  However, when the variable L becomes the predetermined value Ln, since the predetermined value is continuously counted that the pressure reducing electromagnetic valve 23 is not operating normally, in step 638, an abnormal stop mode (for example, the circulation pump 25) is counted. To stop the fuel cell safely.

  When the variable M reaches the planned total number of determinations M0 in step 636, the pressure reducing solenoid valve 23 operates normally while the state of the pressure reducing solenoid valve 23 is determined as the total number of determinations M0. Since the predetermined value is not counted continuously, it can be determined that the state of the pressure reducing electromagnetic valve 23 is normal, and thus this program is terminated.

As described above, according to the present embodiment, it is possible to determine whether or not a malfunction has occurred in the pressure reducing electromagnetic valve 23 based on the pressure in the fuel gas supply flow path 201B, and to easily determine the state of the pressure reducing electromagnetic valve 23. can do.
In addition, since the malfunction of the pressure reducing solenoid valve 23 is determined every predetermined time (10 milliseconds) from when the opening instruction of the pressure reducing solenoid valve 23 is issued, this enables early detection of an abnormality in the pressure reducing solenoid valve 23, This makes it possible to predict the danger of fuel cells caused by

  In the above-described embodiment, when an abnormality is detected, the abnormal stop mode is executed, a warning lamp is further provided, the warning lamp is lit, a display is provided, and the pressure reducing electromagnetic valve 23 is provided on the display. A warning may be displayed that a failure has occurred, or a speaker may be provided, and a voice may be sent to notify that a failure has occurred in the pressure reducing electromagnetic valve 23 via the speaker. As a result, the user can be alerted.

Next, a third embodiment of the present invention will be described. Since the present embodiment has the same configuration as that of the first embodiment described above, the description thereof will be omitted and the operation will be described.
FIG. 13 shows a flowchart of the decompression solenoid valve state detection processing program showing the process of sensing the state of the decompression solenoid valve 23. The decompression solenoid valve state detection processing program is repeatedly executed every predetermined time from when the decompression solenoid valve 23 is instructed to be opened.

  In step 722, flags F and G are set to zero. Note that the flag F is determined when an abnormality of the pressure reducing electromagnetic valve 23 is determined in a process of determining an abnormality of the pressure reducing electromagnetic valve 23 based on the drive current of the circulation pump 25 (drive current abnormality determining process) as described later. Is set to 1. The flag G is determined when an abnormality of the pressure reducing electromagnetic valve 23 is determined in a process of determining an abnormality of the pressure reducing electromagnetic valve 23 based on the pressure in the fuel gas supply channel 201B (pressure abnormality determining process) as will be described later. Is set to 1.

  In step 724, drive current abnormality determination processing is executed. The drive current abnormality determination process executes steps 522 to 536 other than step 536 in the above-described pressure-reducing solenoid valve state detection process program (see FIG. 11) of the first embodiment described above, and the determination of step 534. Is affirmative, the flag F is set to 1.

Next, in step 726, based on the set state (1 or 0) of the flag F, it is determined whether or not the pressure in the fuel gas supply channel 201B is normal. If normal (F = 0), Exit this program.
When the drive current of the circulation pump 25 is not normal (F = 1), the pressure abnormality determination process is executed in step 728 in this embodiment instead of immediately shifting to the abnormal stop mode. In the pressure abnormality determination process, steps 620 to 636 other than step 638 are executed in the decompression solenoid valve state detection processing program (see FIG. 12) of the second embodiment described above, and the determination in step 634 is performed. If the determination is affirmative, the flag G is set to 1.

Next, in step 730, based on the set state (1 or 0) of the flag G, it is determined whether or not the pressure in the fuel gas supply channel 201B is normal. If normal (F = 0), Exit this program.
On the other hand, when the pressure in the fuel gas supply channel 201B is not normal (G = 1), it is determined that the drive current of the circulation pump 25 is abnormal for the first time, that is, in the fuel gas supply channel 201B. If the pressure is determined to be abnormal, the process proceeds to an abnormal stop mode at step 732.

  As described above, in this embodiment, when the drive current of the circulation pump 25 is determined to be abnormal, and the pressure in the fuel gas supply flow path 201B is determined to be abnormal, the pressure reducing solenoid valve 23 is determined to be abnormal. Thus, since the operation shifts to the abnormal stop mode, erroneous determination is suppressed and abnormality of the pressure reducing electromagnetic valve 23 can be determined with higher accuracy. Also, when the tertiary pressure sensor S2 fails, it is determined in the actual stop operation that the pressure reducing solenoid valve 23 is opened as controlled and falls to the atmospheric pressure level, but is normal. I can't. In this case, in the present embodiment, it can be determined whether it is a malfunction of the tertiary pressure sensor S2 or a malfunction of the pressure reducing electromagnetic valve 23.

In addition, in this embodiment, if it is not normal in step 726, step 732 is executed. If it is normal, step 728 is executed. If it is normal in step 730, the process is executed. If the process ends (end) and is abnormal, step 732 may be implemented. In this case, if either the driving current of the circulation pump 25 or the pressure in the fuel gas supply flow path 201B is determined to be abnormal, the abnormality of the pressure reducing electromagnetic valve 23 can be determined, and the sensitivity It is possible to perform abnormality determination well.
Further, since the malfunction of the pressure reducing solenoid valve 23 is determined every predetermined time from when the opening instruction of the pressure reducing solenoid valve 23 is given, this allows early detection of an abnormality in the pressure reducing solenoid valve 23 and the fuel cell resulting therefrom. Can predict the danger.

Further, in the above-described embodiment, when an abnormality is detected, the abnormal stop mode is executed and a warning lamp is further provided, the warning lamp is turned on, a display is provided, and the pressure reducing electromagnetic valve 23 is provided on the display. A warning may be displayed that a failure has occurred, or a speaker may be provided, and a voice may be sent to notify that a failure has occurred in the pressure reducing electromagnetic valve 23 via the speaker. As a result, the user can be alerted.
In the present embodiment, steps 724 and 726 and steps 728 and 730 may be interchanged.

Furthermore, as another embodiment, when the stop operation is started normally and the pressure reducing solenoid valve 23 is opened, the inside of the fuel gas supply flow path 201B (tertiary pressure region) instantaneously drops to the atmospheric pressure level. To do. Therefore, when the output value of the tertiary pressure sensor S2 decreases to the atmospheric pressure value within a predetermined time, it can be determined that the pressure reducing electromagnetic valve 23 is normal. In this case, the present embodiment is configured by a timer that measures the elapsed time from the opening operation with the threshold value P0 being atmospheric pressure, and a determination unit that determines whether the threshold value P0 is within a predetermined time. This predetermined time is a sufficiently short time to determine that the pressure is decreasing rapidly.
This specification discloses the following matters.
(1) a fuel cell in which a fuel chamber into which a fuel gas is introduced and an oxidizing gas chamber into which an oxidizing gas is introduced are adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidizing gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Current detecting means for detecting a driving current of the circulation pump;
Determination means for determining the state of the on-off valve based on the drive current of the pump detected by the current detection means;
A fuel cell system comprising:
(2) a fuel cell in which a fuel chamber into which fuel gas is introduced and an oxidant gas chamber into which oxidant gas is introduced are adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidant gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Pressure detecting means for detecting the pressure in the supply path;
Determination means for determining the state of the on-off valve based on the pressure in the supply path detected by the pressure detection means;
A fuel cell system comprising:
(3) a fuel cell in which a fuel chamber into which a fuel gas is introduced and an oxidizing gas chamber into which an oxidizing gas is introduced are adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidizing gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Current detecting means for detecting a driving current of the circulation pump;
Pressure detecting means for detecting the pressure in the supply path;
Determination means for determining the state of the on-off valve based on the detected drive current of the pump and the detected pressure in the supply path;
A fuel cell system comprising:
(4) Furthermore, the determination means determines the state of the on-off valve before performing the process of replacing the fuel gas in the fuel chamber, which is executed when the power generation of the fuel cell is stopped, with a replacement gas. The fuel cell system according to any one of (1) to (3), wherein the fuel cell system is characterized.
(5) The apparatus further comprises notification means for notifying that the on-off valve is not in a normal operating state when the determining means determines that the on-off valve is not in a normal operating state. (1) The fuel cell system according to any one of (4).
(6) A fuel chamber into which the fuel gas is introduced and an oxidizing gas chamber into which the oxidizing gas is introduced are adjacent to each other via an electrolyte layer, and the fuel chamber in the fuel cell that generates power by the reaction between the fuel gas and the oxidizing gas is disposed in the fuel chamber. Fuel gas is supplied via a supply path, and the fuel gas in the fuel chamber is circulated to the fuel chamber via a circulation path and a supply path by a circulation pump, and the fuel gas in the circulation path is opened by an on-off valve. A failure determination method for an open valve in a fuel cell system that discharges to the outside through a discharge path,
Detecting the drive current of the circulation pump;
Based on the detected driving current of the pump, the state of the on-off valve is determined.
The failure determination method of the open valve characterized by the above-mentioned.
(7) A fuel chamber into which fuel gas is introduced and an oxidizing gas chamber into which oxidizing gas is introduced are adjacent to each other via an electrolyte layer, and the fuel chamber in the fuel cell that generates power by reaction between the fuel gas and the oxidizing gas is disposed in the fuel chamber. Fuel gas is supplied via a supply path, and the fuel gas in the fuel chamber is circulated to the fuel chamber via a circulation path and a supply path by a circulation pump, and the fuel gas in the circulation path is opened by an on-off valve. A failure determination method for an open valve in a fuel cell system that discharges to the outside through a discharge path,
Detecting the pressure in the supply path;
Based on the detected pressure in the supply passage, the state of the on-off valve is determined.
The failure determination method of the open valve characterized by the above-mentioned.
(8) The fuel chamber in the fuel cell in which the fuel chamber into which the fuel gas is introduced and the oxidizing gas chamber into which the oxidizing gas is introduced are adjacent to each other via the electrolyte layer and power is generated by the reaction between the fuel gas and the oxidizing gas. Fuel gas is supplied via a supply path, and the fuel gas in the fuel chamber is circulated to the fuel chamber via a circulation path and a supply path by a circulation pump, and the fuel gas in the circulation path is opened by an on-off valve. A failure determination method for an open valve in a fuel cell system that discharges to the outside through a discharge path,
Detecting the driving current of the circulation pump and detecting the pressure in the supply path;
Based on the detected driving current of the pump and the detected pressure in the supply passage, the state of the on-off valve is determined.
The failure determination method of the open valve characterized by the above-mentioned.
According to the configuration described in (1) above, since the state of the on-off valve is determined based on the drive current of the circulation pump, it is possible to detect a malfunction of the open valve.
According to the configuration described in (2) above, since the state of the on-off valve is determined based on the pressure in the supply path, a malfunction of the open valve can be detected.
According to the configuration described in (3) above, since the state of the on-off valve is determined based on the drive current of the circulation pump and the pressure in the supply path, it is possible to detect the malfunction of the open valve more accurately.
According to the configuration described in (4) above, the state of the on-off valve is determined before performing the process of replacing the fuel gas in the fuel chamber, which is executed when the power generation of the fuel cell is stopped, with the replacement gas. When it is determined that there is a problem with the on-off valve, it is possible not to perform the process of replacing the fuel gas in the fuel chamber with the replacement gas, and it is possible to prevent waste of electric power.
According to the configuration described in the above (5), when it is determined that the on-off valve is not in a normal operation state, the user is alerted that the on-off valve is not in a normal operation state, so that the user can be alerted. .
According to the configuration described in (6) above, since the state of the on-off valve is determined based on the driving current of the circulation pump, it is possible to detect a malfunction of the open valve.
According to the configuration described in (7) above, since the state of the on-off valve is determined based on the pressure in the supply path, a malfunction of the open valve can be detected.
According to the configuration described in (8) above, since the state of the on-off valve is determined based on the driving current of the circulation pump and the pressure in the supply path, the malfunction of the open valve can be detected with higher accuracy.

1 is a block diagram showing a fuel cell system 1 of the present invention. It is a whole front view which shows the separator for fuel cells. It is a fragmentary sectional top view (AA sectional view) of the fuel cell stack comprised with the fuel cell separator. It is a partial section side view (BB sectional view) of a fuel cell stack constituted with a fuel cell separator. It is a partial cross section side view (CC sectional view) of a fuel cell separator. 1 is an overall rear view of a fuel cell separator. It is sectional drawing of a unit cell. It is a partial top view of a fuel cell stack. 2 is a block diagram of a control system of the fuel cell system 1. FIG. It is a graph which compares the drive current of a circulation pump with the output current of a secondary pressure sensor and a tertiary pressure sensor when a pressure-reducing solenoid valve operates normally, and shows it. It is a flowchart which shows the state detection process program of the pressure reduction solenoid valve in 1st Embodiment. It is a flowchart which shows the state detection process program of the pressure-reducing solenoid valve in 2nd Embodiment. It is a flowchart which shows the state detection process program of the pressure reduction solenoid valve in 3rd Embodiment.

Explanation of symbols

1 Fuel cell system 11 Hydrogen storage tank (supply means)
100 Fuel cell stack (fuel cell)
201A, 201B Fuel gas supply channel (supply channel)
204 Circulation channel (circulation channel)
25 Circulating pump 23 Pressure reducing solenoid valve (open / close valve)
S2 Tertiary pressure sensor (pressure detection means)
S10 Drive current detection sensor (current detection means)
200 Control device (judgment means)

Claims (4)

A fuel cell in which a fuel chamber into which fuel gas is introduced and an oxidant gas chamber into which oxidant gas is introduced are disposed adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidant gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Decompression means for opening the on-off valve and driving the circulation pump to decompress the fuel chamber;
Current detecting means for detecting the driving current of the circulation pump after the opening / closing valve opening instruction every predetermined time ;
The pump drive current detected by the current detection means is not greater than or equal to a predetermined threshold before performing the process of replacing the fuel gas in the fuel chamber, which is performed when the power generation of the fuel cell is stopped, with a replacement gas. A determination means for counting the number of times continuously determined, and determining that the on- off valve is abnormal when the count reaches a predetermined value ;
A fuel cell system comprising: A fuel cell in which a fuel chamber into which fuel gas is introduced and an oxidant gas chamber into which oxidant gas is introduced are disposed adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidant gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Decompression means for opening the on-off valve and driving the circulation pump to decompress the fuel chamber;
Pressure detecting means for detecting the pressure in the supply passage after the opening / closing valve opening instruction every predetermined time ;
The rate of change calculated from the pressure per predetermined time detected by the pressure detecting means before performing the process of replacing the fuel gas in the fuel chamber, which is executed when the power generation of the fuel cell is stopped, with a replacement gas A determination unit that counts the number of times that it is continuously determined that is not less than or equal to a threshold value, and determines that the on-off valve is abnormal when the count reaches a predetermined value ;
A fuel cell system comprising: A fuel cell in which a fuel chamber into which fuel gas is introduced and an oxidant gas chamber into which oxidant gas is introduced are disposed adjacent to each other via an electrolyte layer, and power is generated by a reaction between the fuel gas and the oxidant gas;
A supply path connected to the fuel chamber for supplying fuel gas;
A circulation path connected to the supply path for circulating the fuel gas in the fuel chamber to the fuel chamber via the supply path;
A circulation pump that is provided in the circulation path and circulates the fuel gas in the fuel chamber to the supply path through the circulation path;
A discharge path connected to the circulation path for discharging the fuel gas in the circulation path to the outside;
An on-off valve for opening and closing the discharge path;
Decompression means for opening the on-off valve and driving the circulation pump to decompress the fuel chamber;
Current detecting means for detecting the driving current of the circulation pump after the opening / closing valve opening instruction every predetermined time ;
Pressure detecting means for detecting the pressure in the supply passage after the opening / closing valve opening instruction every predetermined time ;
Before performing the process of replacing the fuel gas in the fuel chamber, which is performed when the power generation of the fuel cell is stopped, with a replacement gas, it is continuously determined that the detected drive current of the pump is not equal to or greater than a predetermined threshold. Counts the number of times determined, and counts the number of times when the number of determinations is a predetermined value, and the rate of change calculated from the detected pressure per predetermined time is not less than or equal to a threshold value. Determining means for determining that the on-off valve is abnormal when the count reaches a predetermined value ;
A fuel cell system comprising: When the on-off valve is determined to be abnormal by the determining means, any one of claims 1 to 3, characterized in that further comprising informing means for informing that the on-off valve has abnormality The fuel cell system described in 1.

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