JP2009117226A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recover a pressure difference before and behind a first cut-off valve after sending a valve closing instruction to the first cut-off valve and a second cut-off valve for cutting off supply of a fuel gas. <P>SOLUTION: A fuel cell system 10 includes the first cut-off valve 34 and the second cut-off valve 42 for cutting off supply of a hydrogen gas fed from a hydrogen tank 14, a first regulator 38 for regulating pressure of the hydrogen gas, and a pressure accumulating means 50 for storing the hydrogen gas by introducing a part of the high-pressure hydrogen gas flowing a hydrogen supply passage 32 during an operation of the fuel cell system 10 and introducing the stored hydrogen gas to the hydrogen supply passage 32 after respectively sending the valve closing instructions to the first cut-off valve 34 and the second cut-off valve 42 from a ECU 66 at the time of a standstill of the fuel cell system 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention recovers the pressure difference before and after the first shut-off valve after a closing command is sent to each of the first shut-off valve and the second shut-off valve that shut off the supply of fuel gas to the fuel cell. The present invention relates to a fuel cell system capable of

  For example, a polymer electrolyte fuel cell (PEFC) employs an electrolyte membrane (electrolyte) made of a polymer ion exchange membrane. An electrolyte membrane / electrode structure having an anode and a cathode as opposite electrodes on both sides of the electrolyte membrane includes a single cell (fuel cell) sandwiched between separators, and a plurality of the single cells are stacked to form a fuel cell stack. ing.

  By the way, in the fuel cell system including the fuel cell stack, a shutoff valve for shutting off the flow of the fuel gas in the fuel gas supply channel between the fuel gas supply tank (for example, a hydrogen tank) and the fuel cell. Is disposed.

  In this case, from the viewpoint of protecting the electrolyte membrane / electrode structure, the shut-off valve remains open despite the closing command being sent to the shut-off valve when the fuel cell system is stopped. It is necessary to detect that the valve is held in a state, that is, that the valve of the shut-off valve is kept away from the valve seat for some reason (open failure).

  That is, when the open failure state of the shut-off valve continues, when the fuel cell system is stopped, one of the oxidant gas passages is open to the atmosphere and the pressure on the cathode side is reduced, while the other On the anode side, the pressure of the fuel gas remains applied, making it difficult to protect the electrolyte membrane / electrode structure, which ultimately causes deterioration of the fuel cell.

Therefore, for example, as disclosed in Patent Document 1, the present applicant can reliably detect an open failure of the shut-off valve, and even if an open failure occurs in the shut-off valve, the alternative shut-off valve The fuel cell system which can suppress deterioration of a fuel cell by operating is proposed.
JP 2007-149497 A

  The present invention has been made in connection with the above proposal. The general purpose of the present invention is to provide a close command to the first shut-off valve and the second shut-off valve for shutting off the supply of fuel gas to the fuel cell. An object of the present invention is to provide a fuel cell system capable of further improving the durability of the first shut-off valve by recovering the pressure difference before and after the first shut-off valve after being fed.

  In addition, the main object of the present invention is to perform the first failure detection processing for the first shut-off valve that shuts off the supply of fuel gas to the fuel cell, and then, due to the pressure difference before and after the first shut-off valve. An object of the present invention is to provide a fuel cell system capable of suppressing a load applied to one shut-off valve and preventing deterioration of durability of the first shut-off valve.

  To achieve the above object, the present invention provides a fuel gas supply means for supplying a fuel gas, an oxidant gas supply means for supplying an oxidant gas, and an anode from the fuel gas supply means to the anode through a fuel gas supply flow path. A fuel cell system comprising: the fuel gas to be supplied; and a fuel cell that generates electric power from the oxidant gas supplied from the oxidant supply means to the cathode through an oxidant supply flow path. A first shut-off valve capable of shutting off the supply of the fuel gas; a second shut-off valve provided downstream of the first shut-off valve in the fuel gas supply flow path; A pressure adjusting means for adjusting the pressure of the fuel gas that is provided downstream of the first shut-off valve and upstream of the second shut-off valve in the gas supply flow path and that has passed through the first shut-off valve; and the first shut-off valve valve A part of the fuel gas that is provided between the pressure adjusting means and that flows through the fuel gas supply flow path during operation of the fuel cell system is introduced and stored, and the fuel cell system is stopped. And a pressure accumulating means for deriving the stored fuel gas to the fuel gas supply channel after a closing command is sent to each of the first shut-off valve and the second shut-off valve. It is characterized by.

  According to the present invention, during operation of the fuel cell system, the first shut-off valve and the second shut-off valve are each opened, and the fuel gas supply means is energized corresponding to the magnitude of the load. Thus, a predetermined amount of fuel gas and oxidant gas are supplied to the fuel cell. Therefore, the fuel gas supplied to the anode reacts with the oxidant gas supplied to the cathode to perform power generation.

  At that time, high-pressure fuel gas is supplied from the fuel gas supply means to the fuel gas supply flow path, and the fuel gas supply flow path passes through the fuel gas supply flow path with respect to the pressure accumulating means provided between the first shutoff valve and the pressure adjusting means. A part of the circulating high-pressure fuel gas is introduced and stored in the pressure accumulating means.

  On the other hand, when the fuel cell system is stopped and the valve closing command is sent to each of the first shut-off valve and the second shut-off valve, the fuel gas is supplied due to, for example, power generation consumption of the fuel cell. When the pressure on the downstream side of the first shut-off valve in the flow path decreases and a pressure difference occurs before and after the first shut-off valve, the fuel gas temporarily stored in the pressure accumulating means is supplied to the fuel gas supply flow path. Derived toward.

  Therefore, in the present invention, for example, when a pressure difference occurs between the upstream side (primary side) and the downstream side (secondary side) of the first shut-off valve, the pressure is temporarily stored in the pressure accumulating means in advance. The fuel gas is led to the downstream side of the first shut-off valve, whereby the pressure difference is relaxed and restored to a predetermined pressure.

  As a result, in the present invention, the durability of the first shut-off valve can be further improved by restoring the pressure difference before and after the first shut-off valve.

  Furthermore, the present invention provides pressure detection means for detecting the pressure of the fuel gas supply flow path between the first shutoff valve and the pressure adjusting means, and open fault detection for detecting an open fault of the first shutoff valve. And the open failure detection means is a residual fuel gas in the fuel gas supply channel after the closing command is sent to the first shutoff valve when the fuel cell system is stopped. When the fuel cell is consumed, it is preferable that an open failure of the first shutoff valve is determined based on a pressure change detected by the pressure detecting means.

  That is, when the fuel cell system is stopped and a valve closing command is sent to the first shut-off valve, an open failure detection process for detecting whether or not the first shut-off valve is securely closed is performed. Carried out. In this open failure detection process, when the pressure of the fuel gas supply flow path is detected by the pressure detecting means provided on the downstream side of the first shutoff valve, and the first shutoff valve is normally closed, the fuel gas The supply of the fuel gas from the supply means is stopped, and the fuel gas remaining in the fuel gas supply flow path before the stop is reacted with the oxidant gas remaining in the fuel cell and is consumed for power generation. The pressure on the downstream side (outlet side) of the shut-off valve decreases. The open failure detection means suitably and reliably determines whether or not the first shut-off valve is reliably closed based on such a pressure change detected by the pressure detection means.

  Even when the pressure on the downstream side of the first shutoff valve of the fuel gas supply flow path is reduced due to the power generation consumption of the fuel cell when the open failure detection processing is performed, the fuel cell is temporarily stored by the pressure accumulating means. By deriving the fuel gas to the fuel gas supply flow path, the load applied due to the pressure difference before and after the first shut-off valve is suppressed to prevent deterioration of the durability of the first shut-off valve. Can do.

  In the present invention, after a valve closing command is sent to each of the first shut-off valve and the second shut-off valve that shut off the supply of fuel gas to the fuel cell, the pressure difference before and after the first shut-off valve is recovered. Thus, a fuel cell system capable of further improving the durability of the first shutoff valve is obtained.

  Further, in the present invention, when an open failure of the first shutoff valve that shuts off the supply of fuel gas to the fuel cell is detected, the load applied due to the pressure difference before and after the first shutoff valve is suppressed. Thus, a fuel cell system capable of preventing deterioration in durability of the first shutoff valve is obtained.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a schematic configuration diagram of a fuel cell system according to an embodiment of the present invention, and FIG. 2 is an enlarged configuration diagram of a main part of FIG.

  As shown in FIG. 1, a fuel cell system 10 includes a fuel cell 12 and a hydrogen tank (fuel gas supply) that is filled with high-pressure hydrogen gas and supplies the hydrogen gas as fuel gas to the fuel cell 12. Means) 14, an air compressor (oxidant gas supply means) 16 for supplying air containing oxidant gas to the fuel cell 12, and unreacted hydrogen discharged from the fuel cell 10 are converted into the fuel cell. 10 and a diluter 18 for diluting with unreacted air discharged from the apparatus 10.

  The fuel cell 12 is made of, for example, a solid polymer electrolyte fuel cell (PEFC), and has an anode-side hydrogen passage 20 and a cathode-side oxygen passage 22 therein.

  The fuel cell 12 has a stack body (not shown). The stack body includes a plurality (for example, 200 to 400) of single cells (not shown), two electrode plates (terminal plates) (not shown), 2 The sheet includes an insulating plate (insulator) (not shown) and a rigid front plate and rear plate (not shown).

  The plurality of single cells are stacked in the thickness direction, and are sandwiched between the front plate and the rear plate via two electrode plates and two insulating plates. The front plate and the rear plate are fastened by fastening means such as bolts (not shown), whereby the stacked state of the single cells is maintained.

  The single cell has a MEA (Membrane Electrode Assembly) (not shown) and a plate-like anode separator and cathode separator (not shown) sandwiching the MEA.

  The MEA includes a solid polymer membrane that is a monovalent cation exchange membrane, and an anode and a cathode that sandwich the membrane. As an example, the anode is disposed in front of the solid polymer film, and the cathode is disposed behind the solid polymer film. The anode and the cathode are made of a conductive porous material such as carbon paper, and contain a catalyst (Pt, Ru, etc.) for causing an electrode reaction on the solid polymer film side.

  The anode separator is disposed on the anode side of the MEA. The cathode separator is disposed on the cathode side of the MEA. The anode separator and the cathode separator are made of metal and have conductivity. Thereby, the several single cell is connected in series.

  As shown in FIG. 1, the fuel cell 12 includes a hydrogen supply port 24 for supplying hydrogen gas, and a hydrogen exhaust for discharging exhaust gas containing unused hydrogen gas discharged from the fuel cell 12. An outlet 26, an air supply port 28 for supplying air to the fuel cell 12, and an air discharge port 30 for discharging air containing unused oxygen from the fuel cell 12 are provided. . The hydrogen supply port 24 is provided with a hydrogen supply channel 32 that functions as a fuel gas supply channel.

  The hydrogen tank 14 includes a first shut-off valve 34 which is a so-called in-tank shut-off valve (integrated shut-off valve) provided integrally with the hydrogen tank 14, and the first shut-off valve 34 is When a valve body (not shown) is seated on the seat portion, the supply of hydrogen gas from the hydrogen tank 14 is provided so as to be shut off. In the present embodiment, the first shut-off valve 34 is configured as an integral shut-off valve integrated with the hydrogen tank 14, but is not limited thereto, and is configured separately from the hydrogen tank 14. A shut-off valve may be used.

  Between the first shut-off valve 34 attached to the hydrogen tank 14 and the hydrogen supply port 24 of the fuel cell 12, a hydrogen supply flow for supplying the hydrogen gas filled in the hydrogen tank 14 to the fuel cell 12. A path 32 is provided.

  In the hydrogen supply channel 32, the pressure (high pressure) of the hydrogen gas supplied from the hydrogen tank 14 from the upstream side to the downstream side when the hydrogen tank 14 is the upstream side and the fuel cell 12 is the downstream side. Ph) for detecting a pressure sensor 36, a first regulator 38 for regulating the pressure of the hydrogen gas supplied from the hydrogen tank 14, and the pressure of the hydrogen gas regulated by the first regulator 38. The other pressure sensor 40 for detecting (intermediate pressure P2), the second shut-off valve 42 disposed downstream of the first shut-off valve 34 and shuts off the supply of hydrogen gas, and the inlet pressure of the fuel cell 12 are adjusted. A second regulator 44 that pressurizes, yet another pressure sensor 46 that detects the inlet pressure (P1) of the fuel cell 12, and a circulation channel 4 that feeds back unreacted hydrogen discharged from the fuel cell 12. And resupplying the ejector 49 is arranged respectively connected fuel cell 12 by mixing a hydrogen fed back from hydrogen and fuel cell 12 supplied from the hydrogen tank 14 to.

  In this case, the first regulator 38 is provided on the downstream side of the first cutoff valve 34 and the upstream side of the second cutoff valve 42, and pressure adjusting means for adjusting the pressure of the hydrogen gas that has passed through the first cutoff valve 34. It functions as.

  A pressure accumulating means 50 is provided between the first shutoff valve 34 and the first regulator 38 via a communication passage 48 communicating with the hydrogen supply flow path 32. The pressure accumulating means 50 is constituted by, for example, a small-capacity buffer tank that temporarily stores part of the high-pressure hydrogen gas that is supplied from the hydrogen tank 14 and flows through the hydrogen supply passage 32. One end of the pressure accumulating means is provided with an orifice 52 connected to the communication passage 48 and having a predetermined orifice diameter. Hydrogen gas that has flowed in through the orifice 52 flows into the space 53 in the pressure accumulating means 50. It is stored in.

  The orifice diameter is larger than the hydrogen gas consumption amount consumed by the fuel cell 12 remaining in the hydrogen supply passage 32 when an open failure of the first shut-off valve 34 described later is detected. The supply flow rate (derived flow rate) is set to be small, and the orifice diameter is set so as not to affect the determination of an open failure (decrease in a predetermined value described later).

  Hydrogen gas supplied from the hydrogen tank 14 flows through the hydrogen supply channel 32 and is supplied to the fuel cell 12 through the hydrogen supply port 24. Exhaust gas containing unreacted hydrogen gas that has not been used in the fuel cell 12 is discharged from the hydrogen discharge port 26 to the hydrogen discharge passage 54.

  The hydrogen discharge flow path 54 includes a hydrogen purge valve 56 that purges water accumulated in the anode of the fuel cell 12 and fuel gas including nitrogen gas that has permeated the electrolyte membrane from the cathode and mixed into the anode to the diluter 18 side. And a drain valve 58 for opening and closing a conduit for discharging drain accumulated in a catch tank (not shown) having a function of separating hydrogen gas containing water discharged from the fuel cell 12 into hydrogen and water, respectively. It is done.

  An air compressor 16 that supplies compressed air to the fuel cell 12 is connected to an air supply channel (oxidant gas supply channel) 60 that communicates with the air supply port 28 of the fuel cell 12. An air discharge channel 62 is provided between the air discharge port 30 of the fuel cell 12 and the diluter 18.

  The diluter 18 dilutes the exhaust gas discharged from the hydrogen purge valve 56 and the drain valve 58 with the oxidant gas flowing in through the air discharge flow path 62, and the diluted gas is discharged from the exhaust flow. It is discharged outside through the path 64.

  Further, the fuel cell system 10 is provided with an ECU 66, and an ignition switch 68 for starting or stopping the fuel cell system 10 is electrically connected to the ECU 66.

  The ECU 66 outputs control signals to various devices of the fuel cell system 10, mainly the air compressor 16, the first shut-off valve 34, the second shut-off valve 42, the purge valve 56, and the drain valve 58. And all operations of the fuel cell system 10 are controlled.

  In this case, the ECU 66 is constituted by a computer, such as detection signals corresponding to the pressures Ph, P2, P1 from the plurality of pressure sensors 36, 40, 46, start / stop signals by the on / off operation of the ignition switch 68, and the like. Various processing functions are realized by controlling the various devices by executing programs stored in a memory based on various input signals. Further, as will be described later, the ECU 66 functions as an open failure detection means for detecting an open failure of the first shutoff valve 34 based on a detection signal from the pressure sensor 36.

  The fuel cell system 10 according to the present embodiment is basically configured as described above. Next, the operation will be described with reference to the flowchart of FIG. 3 and the time chart of FIG.

  When the ECU 66 detects an ON operation (start signal) of the ignition switch 68 (step S1 → YES), the fuel cell system 10 is activated and a normal power generation operation is performed (step S2). When the ECU 66 does not detect the ON operation of the ignition switch 68 in step 1 (step S1 → NO), the closed loop including step S1 is circulated until it is detected.

  In the normal power generation operation of the fuel cell system 10, the first shut-off valve 34 and the second shut-off valve 42 are each opened, and the air compressor 16 is operated in accordance with the magnitude of the load of a running motor (not shown). By driving, air containing a predetermined amount of oxidant gas is supplied to the fuel cell 12. The hydrogen supplied to the anode and the oxygen supplied to the cathode react to generate a power generation action. The hydrogen is supplied from the hydrogen tank 14 to the fuel cell 12 so as to make up for the consumed amount.

  When the fuel cell system 10 is in a normal power generation operation, high-pressure hydrogen gas is supplied from the hydrogen tank 14 to the hydrogen supply passage 32, and enters the hydrogen supply passage 32 between the first cutoff valve 34 and the first regulator 38. A part of the high-pressure hydrogen gas flowing through the hydrogen supply flow path 32 is introduced into the pressure accumulating means 50 that communicates via the communication passage 48, and is stored in the space 53 of the pressure accumulating means 50 (step). S3).

  The amount of high-pressure hydrogen gas introduced into the space 53 of the pressure accumulating means 50 is set by the orifice diameter of the orifice 52 facing the communication path 48. Further, the inflow action of hydrogen gas into the pressure accumulating means 50 of hydrogen gas is caused by a pressure difference between the pressure of the hydrogen gas flowing through the hydrogen supply channel 32 and the pressure of the space 53 of the pressure accumulating means 50.

  When the ECU 66 detects an off operation (stop signal) of the ignition switch 68 during the normal power generation operation of the fuel cell system 10 (step S4 → YES), the fuel cell system 10 is stopped. That is, the ECU 66 outputs a deactivation signal to the air compressor 16 to stop the driving of the air compressor 16 and to shut off the supply of hydrogen gas from the hydrogen tank 14 to the first shutoff valve 34. Then, a valve closing command is sent so as to be (step S5). Note that if the ECU 66 does not detect an off operation (stop signal) of the ignition switch 68 during the normal power generation operation of the fuel cell system 10 (step S4 → NO), the process returns to step S2.

  Subsequently, the ECU 66 performs an open failure detection process for detecting whether or not the first shut-off valve 34 to which the valve closing command has been sent has been reliably closed (step S6). This open failure detection process is performed by the ECU 66 monitoring a temporal change (pressure change) of the high pressure Ph detected by the pressure sensor 36 provided on the outlet side (secondary side) of the first cutoff valve 34. . Note that during the open failure detection process, the valve closing command has not yet been sent to the second shutoff valve 42, and the second shutoff valve 42 is in the open state as in the normal power generation operation.

  When the first shut-off valve 34 is normally closed, as shown in FIG. 4, after the valve close command is sent to the first shut-off valve 34, it is detected by the pressure sensor 36. High pressure Ph gradually decreases. This is because when the first shut-off valve 34 is shut off and the supply of hydrogen gas from the hydrogen tank 14 is stopped, the hydrogen gas remaining in the hydrogen supply passage 32 before the stop remains in the fuel cell 12. This is because the pressure on the downstream side (outlet side) of the first shut-off valve 34 decreases because the power is consumed by reacting with the oxidant gas. At this time, the hydrogen stored in the space 53 of the pressure accumulating means 50 flows out, but the orifice 52 provided in the pressure accumulating means 50 becomes a flow path resistance, and the hydrogen outflow amount is very small. This does not affect the failure determination in step S6a described later.

  Therefore, as shown in FIG. 4, when the high pressure Ph detected by the pressure sensor 36 decreases by a predetermined value, the ECU 66 determines that the first shut-off valve 34 has closed normally (step S6a → NO), A valve closing command is sent to the second shutoff valve 42 (step S7). If step S6a → YES (failure), the failure is notified (step S9).

  In this way, after the closing commands are sent to the first cutoff valve 34 and the second cutoff valve 42, respectively, and the first cutoff valve 34 and the second cutoff valve 42 are closed (see FIG. 4). ), As described above, the pressure downstream of the first shutoff valve 34 of the hydrogen supply flow path 32 is reduced by the power generation consumption of the fuel cell 12, so that it is temporarily stored in the space 53 by the pressure accumulating means 50. The hydrogen gas thus discharged is led out to the hydrogen supply flow path 32 through the communication path 48 (step S8). Here, since the second shut-off valve 42 is in the closed state in step S7, the pressure between the first shut-off valve 34 and the second shut-off valve 42 starts to increase due to the hydrogen gas derived from the pressure accumulating means 50.

  As a result, the pressure difference generated by the open failure detection process before and after the first shut-off valve 34, that is, between the upstream side (primary side) and the downstream side (secondary side) of the first shut-off valve 34 is the accumulator 50. By recovering the pressure on the downstream side of the first shut-off valve 34 that has been reduced and reduced by the hydrogen gas derived from the gas, the durability of the first shut-off valve 34 can be further improved.

  After the first shut-off valve 34 is closed in step S5, the supply amount of the hydrogen gas led out from the pressure accumulating means 50 to the hydrogen supply flow path 34 is the same as the hydrogen gas remaining in the hydrogen supply flow path 32. The orifice diameter of the orifice 52 is set so as to be smaller than the consumption consumed by the reaction with the oxidant gas remaining in the gas generator 12. Influencing the determination of whether or not the first shut-off valve 34 has an open failure at the time of failure detection is avoided. Further, after the second shutoff valve 42 is closed in step S7, the hydrogen gas derived from the pressure accumulating means 50 is supplied to the fuel cell 12 with the hydrogen shutoff valve 32 shut off by the second shutoff valve 44. The pressure rises because it is not done.

  In this embodiment, the process of recovering the pressure on the downstream side of the first shut-off valve 34 by the hydrogen gas derived from the pressure accumulating means 50 after the open fault detection process is performed. There is no need for the ECU 66 to determine that the first shut-off valve 34 has failed, and it is only necessary for the pressure accumulation means 50 to perform a recovery process after the ECU 66 has finished checking whether the first shut-off valve 34 is open or not.

  When the open failure detection process is performed when the fuel cell system 10 is stopped, the pressure on the downstream side of the first shutoff valve 34 in the hydrogen supply flow path 32 decreases due to the power generation consumption of the fuel cell 12, and the upstream of the first shutoff valve 34. In this embodiment, the high-pressure hydrogen gas stored in the pressure accumulating means 50 is supplied to the hydrogen supply passage 32 on the downstream side of the first shut-off valve 34. By deriving, the pressure difference can be recovered.

  If the pressure difference is left until the next activation of the fuel cell system 10, an excessive load is applied to a valve body (seat surface) (not shown) of the first shut-off valve 34, and the first shut-off valve 34 is applied. However, in this embodiment, the durability of the first shut-off valve 34 is deteriorated by allowing the pressure difference to be recovered relatively quickly before the next activation without leaving the pressure difference as it is. This can be suitably avoided to obtain desired durability performance (desired seat force of the valve body with respect to the seating portion).

  In the present embodiment, the high-pressure hydrogen gas temporarily stored in the space 53 of the pressure accumulating means 50 is caused by the pressure difference between the hydrogen supply channel 32 and the pressure accumulating means 50 when the pressure is reduced due to power generation consumption. Thus, it is only naturally derived toward the hydrogen supply flow path 32 side, and no control of the ECU 66 or the like is required, and the pressure difference between the upstream side and the downstream side of the first shut-off valve 34 is reduced. There is no reversal.

  Next, the principal part structure of the fuel cell system 10a which concerns on other embodiment of this invention is shown in FIG. A fuel cell system 10a according to another embodiment is different from the above-described embodiment in that an electromagnetic valve 70 is provided instead of the orifice 52 attached to the pressure accumulating means 50. The other components are the same as those of the fuel cell system 10 shown in FIG. 1, and thus illustration and description thereof are omitted.

  The electromagnetic valve 70 has a valve body (not shown) that is turned on / off by an urging signal / deactivation signal output from the ECU 66, and controls the opening and closing of a passage (not shown) that communicates with the communication passage 48 by the valve body. Yes. Further, the pressure accumulating means 50 is provided with a pressure sensor 72 for detecting the pressure in the space 53, and a detection signal (P3) from the pressure sensor 72 is output to the ECU 66.

  In this other embodiment, the ECU 66 monitors the pressure Ph on the hydrogen supply flow path 32 side and the pressure P3 on the pressure accumulating means 50 side, respectively, and appropriately outputs an energization signal / deactivation signal from the ECU 66, whereby the first The pressure of the hydrogen gas flowing through the hydrogen supply channel 32 on the downstream side of the shutoff valve 34 can be suitably controlled.

  Specifically, during normal power generation operation of the fuel cell system 10a, an energizing signal is output from the ECU 66 to open the electromagnetic valve 70, and high-pressure hydrogen gas is stored in the space 53 of the pressure accumulating means 50. In this case, the ECU 66 monitors the pressure Ph on the hydrogen supply flow path 32 side and the pressure P3 on the pressure accumulation means 50 side, respectively, and when the pressure in the space 53 of the pressure accumulation means 50 reaches a predetermined pressure, the ECU 66 A deactivation signal is output to close the electromagnetic valve 70.

  On the other hand, when the fuel cell system 10a with the ignition switch 68 turned off is stopped and the hydrogen gas stored in the space 53 of the pressure accumulating means 50 is led out to the hydrogen supply passage 32, the hydrogen supply passage The first cutoff valve 34 is controlled by opening and closing a passage (not shown) of the electromagnetic valve 70 communicating with the communication passage 48 by appropriately outputting an urging signal / deactivation signal from the ECU 66 while monitoring the pressure Ph on the 32 side. It is possible to suitably control the pressure of the hydrogen gas flowing through the downstream hydrogen supply passage 32.

  Since the pressure of the hydrogen gas stored in the space 53 of the pressure accumulating means 50 can be maintained at a relatively high pressure by such pressure control of the electromagnetic valve 70, the storage capacity can be reduced to reduce the size of the pressure accumulating means 50. Weight reduction can be achieved.

1 is a schematic configuration diagram of a fuel cell system according to an embodiment of the present invention. It is a principal part enlarged view of the pressure accumulation means which comprises the fuel cell system shown in FIG. It is a flowchart with which operation | movement description of the open failure detection process of a 1st cutoff valve is provided. 2 is a time chart for explaining the operation of the fuel cell system shown in FIG. 1. It is a principal part block diagram of the fuel cell system which concerns on other embodiment of this invention.

Explanation of symbols

10, 10a Fuel cell system 12 Fuel cell 14 Hydrogen tank (fuel gas supply means)
16 Air compressor (oxidant supply means)
32 Hydrogen supply channel (fuel gas supply channel)
34 First shut-off valve 36 Pressure sensor (pressure detection means)
38 First regulator (pressure adjusting means)
42 Second shut-off valve 50 Pressure accumulating means 60 Air supply flow path (oxidant supply flow path)
66 ECU (open failure detection means)

Claims (2)

Fuel gas supply means for supplying fuel gas, oxidant gas supply means for supplying oxidant gas, and the fuel gas and oxidant supply means supplied from the fuel gas supply means to the anode through a fuel gas supply channel A fuel cell system that generates power with the oxidant gas supplied to the cathode from the oxidant supply flow path,
A first shutoff valve capable of shutting off the supply of the fuel gas from the fuel gas supply means;
A second shut-off valve that is provided in the fuel gas supply channel on the downstream side of the first shut-off valve and shuts off the supply of the fuel gas;
Pressure adjusting means for adjusting the pressure of the fuel gas that has been provided in the fuel gas supply flow path downstream of the first shutoff valve and upstream of the second shutoff valve, and passed through the first shutoff valve;
A part of the fuel gas that is provided between the first shut-off valve and the pressure adjusting means and that flows through the fuel gas supply channel during operation of the fuel cell system is introduced and stored, and the fuel cell The stored fuel gas is led out to the fuel gas supply flow path after the valve closing command is sent to the first shut-off valve and the second shut-off valve, respectively, when the system is stopped. Pressure accumulation means;
A fuel cell system comprising: The fuel cell system according to claim 1, wherein
Pressure detecting means for detecting the pressure of the fuel gas supply channel between the first shutoff valve and the pressure adjusting means;
An open failure detecting means for detecting an open failure of the first shutoff valve;
The open failure detecting means is configured to stop the fuel gas in the fuel gas supply flow path in the fuel cell after the valve closing command is sent to the first shutoff valve when the fuel cell system is stopped. A fuel cell system, wherein when the battery is consumed, an open failure of the first shut-off valve is determined based on a pressure change detected by the pressure detecting means.

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