JP2008021485A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently start and reduce exhaust hydrogen-gas concentration even under a low temperature in a fuel cell system. <P>SOLUTION: Upon stopping the fuel cell system, it is stopped with a bypass valve in minutely open state. Upon starting the fuel cell system, the bypass valve is defrosted by a high-temperature air from an air compressor with the bypass valve in minutely open state, and while keeping the minute open state of the bypass valve, an action gas of high pressure is supplied to a cut-off valve drive part, and opening and closing operation of the cut-off valve becomes possible even in frozen state. After the cut-off valve is opened, the bypass valve is fully opened and released to the atmosphere while diluting hydrogen staying in the air-side electrode. After releasing of the hydrogen to the atmosphere, the bypass valve is fully opened to operate the fuel cell normally. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to start / stop control of a fuel cell system.

  In a fuel cell, for example, hydrogen is used as fuel and oxygen-containing air is used as an oxidant. Hydrogen is separated into hydrogen ions and electrons by the action of a catalyst on the fuel side electrode, and the hydrogen ions pass through the electrolyte membrane to the oxidant electrode. It moves, and hydrogen and the electrons and oxygen that have traveled around the external load are combined by the action of the catalyst on the oxidant side electrode to produce water. The reaction product water is discharged to the outside of the fuel cell together with air as an oxidant, but a portion of the generated water is recirculated to the fuel cell inlet by the humidification module to keep the electrolyte membrane in a humid atmosphere. Many systems are used. In such a fuel cell, during normal operation, hydrogen ions move from the fuel side electrode through the electrolyte membrane to the oxidant side electrode, but hydrogen molecules do not move to the oxidant side electrode. However, when the fuel cell is stopped, hydrogen molecules remaining in the fuel cell at the time of the stop permeate and stay in the oxidant side electrode through the electrolyte membrane (see, for example, Patent Document 1). The oxidant side electrode is connected to an exhaust pipe that discharges air or generated water as the oxidant to the outside of the fuel cell. High hydrogen is discharged from the exhaust pipe to the outside of the fuel cell when the fuel cell is started. Therefore, there is a method of providing a bypass line that bypasses the fuel cell from the air supply pipe and connects to the exhaust pipe, and at the time of starting the fuel cell, dilutes the hydrogen gas remaining in the oxygen agent side electrode and discharges it to the atmosphere. It has been proposed (see, for example, Patent Document 1).

  On the other hand, the fuel cell contains moisture in the system and in the pipe line as described above. Therefore, when the fuel cell system is stopped for a long time at a temperature below the freezing point, there is a problem that moisture freezes inside the fuel cell and the system cannot be started. For this reason, a fuel cell and a humidification module are insulated and surrounded by a heat insulating material, and a fuel cell system that can protect the system in a low temperature environment and shorten the startup time by effectively combining heating and waste heat is proposed (For example, refer to Patent Document 2).

JP 2004-172027 A JP 2003-151595 A

  However, in the prior art disclosed in Patent Document 2, since most of the fuel cell system is surrounded by a heat insulating material, the entire apparatus is enlarged, and a part other than the region surrounded by the heat insulating material, for example, Connection pipes and valves are not protected against freezing, and there is a problem that the startup of the fuel cell system may be delayed due to freezing of surrounding valves. The prior art disclosed in Patent Document 1 does not disclose the problem of freezing of the fuel cell system at low temperature, and how to start the fuel cell system by diluting hydrogen gas when freezing occurs. There is no disclosure or description of whether or not to do so.

  An object of the present invention is to provide a fuel cell system that can be efficiently started even in a low temperature state. Another object of the present invention is to provide a fuel cell system that can efficiently reduce the concentration of exhaust hydrogen gas even during startup from a low temperature state.

  A fuel cell system according to the present invention includes a fuel cell that generates electric power by an electrochemical reaction between a fuel gas and an oxidant gas, a compressor that compresses an oxidant gas supplied to the fuel cell, and an oxidation that is compressed by the compressor. A fuel cell comprising: a bypass channel for flowing the agent gas by bypassing the fuel cell; a bypass valve with an adjustable opening provided in the bypass channel; and a control unit that performs start / stop control of the fuel cell. In the system, the control unit includes fuel cell stopping means for stopping the fuel cell in a state where the opening degree of the bypass valve is set to a predetermined opening degree. Further, in the fuel cell system of the present invention, the oxidant gas supply flow path for connecting the compressor and the fuel cell and supplying the oxidant gas compressed by the compressor to the fuel cell, and the fuel cell And an oxidant gas exhaust passage for exhausting the reacted oxidant gas from the fuel cell to the atmosphere, and the fuel cell stop means further closes the shutoff valves. It is also preferable to stop the fuel cell.

  A fuel cell system according to the present invention connects a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidant gas, a compressor that compresses the oxidant gas, the compressor and the fuel cell, An oxidant gas supply passage for supplying an oxidant gas compressed by the compressor to the fuel cell, and an oxidant gas exhaust connected to the fuel cell and exhausting the reacted oxidant gas from the fuel cell to the atmosphere. A shutoff valve that is provided in each of the flow path, the oxidant gas supply flow path, and the oxidant gas exhaust flow path, and is opened and closed by an open / close drive unit that uses the oxidant gas compressed by the compressor as an operating gas. An operating gas supply channel connecting the compressor and the opening / closing drive unit, an operating gas supply adjusting means provided in the operating gas supply channel, the oxidizing gas supply channel, and the oxidizing gas exhaust Flow path and A bypass passage connected to the opposite side of each shut-off valve to the fuel cell and bypassing the oxidant gas compressed by the compressor to the oxidant gas exhaust passage, and an opening provided in the bypass passage A fuel cell system including an adjustable bypass valve and a control unit that performs start / stop control of the fuel cell, wherein the control unit maintains an opening degree of the bypass valve at a predetermined opening degree, Fuel cell starting means for fully opening the bypass valve after the operating gas supply adjusting means supplies oxidant gas to the opening / closing drive section to open the shut-off valve. The control unit may further include a fuel cell stopping unit that stops the fuel cell in a state where the opening degree of the bypass valve is a predetermined opening degree.

  Furthermore, in the fuel cell system according to the present invention, the predetermined opening degree of the bypass valve is such an opening degree that the oxidant gas temperature compressed by the compressor is higher than the oxidant gas temperature during normal operation. It is also preferable that the predetermined opening degree of the bypass valve is a minimum holding opening degree of the bypass valve.

  The present invention has an effect that the fuel cell system can be efficiently started even in a low temperature state. In addition, the present invention has an effect that the exhaust hydrogen gas concentration can be efficiently reduced even at the start-up from a low temperature state.

  A preferred embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic system diagram showing an embodiment of the fuel cell system of the present invention. As shown in FIG. 1, the fuel cell system of this embodiment uses air containing oxygen as the oxidant gas and hydrogen as the fuel gas. Air, which is an oxidant gas, is sucked into the air compressor 14 from the air through the air suction line 19 via the intake flow meter 18 and the air filter, and the discharge air pressurized by the air compressor 14 is discharged from the compressor. 20 is supplied to the air supply line 21 of the fuel cell. The air that has entered the supply system is added with moisture generated by the reaction in the fuel cell 11 in the humidification module 37, becomes humid air, and is supplied to the fuel cell 11 from the air supply line 21. In the air that has entered the fuel cell from the air-side electrode 12 that is the oxidant electrode of the fuel cell 11, oxygen is reduced due to a power generation reaction with hydrogen supplied from the hydrogen system. Then, the product water as a result of the reaction increases in the air as water vapor or water droplets. The increased air moisture is discharged to the air exhaust line 23 of the fuel cell 11. The exhausted air containing a large amount of moisture is removed by the humidification module 37 so that a part of the moisture is added to the supply air. The exhaust air whose moisture content has decreased flows downstream through the exhaust pipe 23. On the other hand, between the air supply line 21 and the air exhaust line 23, the fuel cell 11 is bypassed and a part of the discharge air of the air compressor 14 is allowed to flow from the air supply line 21 to the air exhaust line 23. A bypass line 25 is provided. A bypass valve 27 whose valve opening is adjustable is attached to the bypass line 25. Exhaust gas from the air exhaust line 23 merges with the bypass air that has passed through the bypass line 25, and then is discharged from the atmospheric discharge line 24 through the silencer 53 to the atmosphere from the atmospheric discharge port 55. In the air supply line 21 and the air exhaust line 23 to the fuel cell 11, outside air enters the fuel cell 11 when the fuel cell 11 is stopped, and reacts with hydrogen remaining in the fuel cell 11. In order to prevent deterioration of the catalyst and the like, shut-off valves 29a and 29b that are closed when stopped are provided. The air supply conduit 21 is provided with an air inlet shut-off valve 29a, and the air exhaust conduit 23 is provided with an air outlet shut-off valve 29b. Each shut-off valve 29a, 29b is opened and closed by shut-off valve driving units 31a, 31b. Each shut-off valve drive unit 31a, 31b is a pneumatic drive device that opens and closes a valve by operating a diaphragm up and down with an operating gas. The working gas is air compressed by the air compressor 14. The working gas air is supplied from the working gas supply pipe 33 connected to the compressor outlet pipe 20 at the outlet of the air compressor 14 through the working gas supply pipes 33a and 33b of the shut-off valves 29a and 29b. The operating gas supply pipes 33a and 33b are provided with shut-off valve operating gas adjustment valves 35a and 35b for adjusting the supply of the operating gas to the shut-off valve driving units 31a and 31b. An air pressure adjusting valve 26 that adjusts the pressure of the air flowing in the air side electrode of the fuel cell 11 is attached to the air exhaust line 23 between the fuel cell 11 and the air outlet shutoff valve 29b. The bypass line 25 may be arranged so as to bypass the fuel cell 11 on the side opposite to the fuel cell 11 of each shut-off valve 29a, 29b. As shown in FIG. 1, the humidification module of the air supply line 21 is used. 37 may be connected to the downstream side of the humidification module of the air exhaust line 23, or downstream of the humidification module 37 of the air supply line 21 and upstream of the air inlet shut-off valve 29a. You may make it connect the humidification module upstream of the air exhaust duct 23, and the downstream of the air outlet cutoff valve 29b. Therefore, it does not include connecting the air supply pipe 21 and the air exhaust pipe 23 on the fuel cell side of the shutoff valves 29a and 29b. Each shut-off valve drive unit 31a, 31b is not limited to the diaphragm type as long as it is a pneumatic drive unit, and may be another type such as a piston type.

  Hydrogen gas as fuel gas is stored in a hydrogen gas tank 41. Hydrogen is supplied from a hydrogen gas tank 41 to a hydrogen side electrode 13 which is a fuel side electrode of the fuel cell through a hydrogen supply line 43. A part of the hydrogen supplied to the fuel cell 11 is consumed by reacting with oxygen in the air that is an oxidant supplied to the air side electrode 12, but the hydrogen that has not been consumed is discharged from the hydrogen side electrode 13. After that, it is pressurized again by the hydrogen circulation pump 47 provided in the hydrogen circulation line 45 and supplied to the hydrogen side electrode 13 of the fuel cell 11. The hydrogen content consumed by the power generation is replenished from the hydrogen gas tank 41 through the hydrogen supply line 43. The amount of hydrogen gas to be replenished is adjusted by a hydrogen gas supply control valve 44. Since the hydrogen system is a circulation system, the impurities generated by the reaction in the circulating hydrogen gas and impurities contained in the hydrogen gas from the beginning are concentrated when operated for a long time. Therefore, when such impurities have been concentrated to some extent, a predetermined amount of hydrogen gas is released from the hydrogen exhaust pipe 46 to the outside air. In this case, the high-concentration hydrogen gas is mixed with the exhaust air by the mixer 49 so as not to be directly released into the atmosphere, and the concentration is lowered before being discharged into the atmosphere.

  The fuel cell 11 is housed in a fuel cell case 71 in order to protect it and to prevent deterioration due to a decrease in internal temperature during stoppage at a low temperature. The fuel cell case 71 houses not only the main body of the fuel cell 11 but also the air pressure control valve 26 directly related to the control of the fuel cell, a hydrogen system control valve (not shown), and the like.

  Each instrument, control valve, fuel cell, air compressor, circulation pump motor, etc. are all connected to the control unit 61, and the measured value from each instrument is input to the control unit 61. A valve opening command and a motor rotation speed command are output to control the entire fuel cell system 10. The control unit 61 includes a CPU and a storage unit, and may be configured to perform overall control by software, or may be configured to perform control by combining electric circuits. The controller 61 may be input with data from the vehicle such as the running state of the vehicle and the addition of necessary requirements.

  In the fuel cell system 10 of the present embodiment, the air compressor 14 is a scroll type. The scroll type air compressor 14 is a kind of positive displacement type air compressor, and the air flow rate can be adjusted mainly by adjusting the rotation speed. FIG. 2 shows the relationship between the discharge air flow rate and the discharge pressure of the air compressor 14. As shown in this figure, the air compressor 14 has a characteristic that the discharge pressure is high when the discharge air flow rate is small, and the discharge pressure decreases as the discharge flow rate increases. During normal operation of the fuel cell system 10, the air flow rate is adjusted by adjusting the rotational speed of the air compressor 14, and the pressure is adjusted by the air pressure control valve 26 at the outlet of the air side electrode 12 of the fuel cell 11. . As long as the air compressor 14 can supply air of the required pressure and flow rate to the air-side electrode 12 of the fuel cell 11, the air compressor 14 is not limited to the scroll type but may be a screw type or a centrifugal type blower.

  The stop operation and start operation in the low temperature state of the fuel cell system 10 of the present embodiment described above will be described with reference to FIG. Even in a low temperature state, the fuel cell system 10 is maintained at an appropriate operating temperature by the reaction heat from the fuel cell 11 during normal operation. In a normal operation state, the output of the fuel cell 11 is controlled by controlling the flow rates of hydrogen, which is a fuel gas, and air, which is an oxidant gas, according to a required output from the vehicle. Both the air inlet shut-off valve 29a and the air outlet shut-off valve 29b of the air side electrode 12 can supply and exhaust air, which is an oxidant gas, to the fuel cell 11 in an open state. The supplied air pressure is controlled by the air pressure control valve 26 according to a command from the control unit 61, and the air flow rate is controlled by adjusting the rotational speed of the air compressor 14 according to a command from the control unit 61. During the operation of the fuel cell 11, a part of the water generated by the power generation reaction is circulated to the supply air by the humidification module 37, and the air on the inlet side of the air side electrode 12 is also moistened. Further, the air flowing through the air exhaust line 23 between the fuel cell 11 and the humidifying module 37 is also moistened by the generated water, and the air flowing through the air exhaust line 23 at the outlet of the humidifying module 37 is also humid. Although it is lower than the inlet side of the humidification module 37, air in a wet state flows. During normal operation, the bypass valve 27 is fully closed, and all the air compressed by the air compressor 14 is supplied to the air side electrode 12 of the fuel cell 11. Since the downstream side of the bypass valve 27 is connected to the air exhaust pipe 23 through which humid air flows, the inside of the bypass valve 27 is in contact with the humid air. The humid air is discharged from the atmospheric discharge line 24 through the silencer 53 to the atmosphere from the atmospheric discharge port 55.

  When the vehicle stops and the fuel cell 11 also stops, the air inlet and outlet shutoff valves 29a and 29b of the air side electrode 12 are fully closed so that air does not enter the air side electrode 12 of the fuel cell 11 during the stop. Become. The opening degree of the bypass valve 27 is set to a predetermined minute opening degree. The minute opening is a minimum holding opening of the bypass valve, for example, 3 to 5% opening. Depending on the type of valve, it may be about 10%. Since the operation is stopped at a low temperature, the temperature of the entire fuel cell system 10 starts to decrease immediately after the fuel cell system 10 is stopped. And the apparatus which contact | connects the humid air which is not accommodated in the fuel cell case 71 starts freezing as temperature falls. Then, the valve bodies of the air inlet and outlet shut-off valves 29a and 29b and the bypass valve 27 are frozen for a short period of time, and the space between the valve stem and the valve body is frozen. The valve becomes inoperable. On the other hand, the air pressure control valve 26 housed in the fuel cell case 71 does not freeze when the fuel cell 11 is stopped overnight because of the residual heat of the fuel cell 11. Further, when the fuel cell 11 is stopped, hydrogen remaining in the hydrogen side electrode 13 of the fuel cell 11 at the time of stopping permeates the electrolyte membrane and gradually stays in the air side electrode 12.

  Thus, the fuel cell 11 is started in a state where the above-mentioned valves are frozen and do not operate, and hydrogen permeated from the hydrogen side electrode is retained in the air side electrode 12. At the time of stop, since the bypass valve 27 is stopped in the slightly open state, it is in the slightly open state even after freezing. On the other hand, the shutoff valves 29a and 29b at the air inlet and outlet of the air side electrode 12 of the fuel cell 11 are frozen in the fully closed state, so that air cannot be supplied to the air side electrode 12 of the fuel cell. Yes. In this state, when the fuel cell 11 is started, the air compressor 14 is first started by a command from the control unit 61. Since each shut-off valve 29a, 29b is in a closed state, the discharge air of the air compressor 14 flows from the bypass valve 27, which is frozen in a slightly open state, to the air exhaust line 23, and further to the atmospheric discharge line. 24 is emitted from the atmosphere discharge port 55 to the atmosphere via the silencer 53. Here, when the rotation speed of the air compressor 14 is increased, the discharge pressure of the air compressor 14 increases and the discharge air temperature also increases due to the compression. For example, when the discharge air pressure is about 100 kPa, the discharge air temperature of the air compressor 14 is about 70 ° C. The air of about 70 ° C. flows into the bypass valve that is in a slightly open state, and warms and thaws the valve body and the valve stem. As a result, the bypass valve 27 becomes operable.

  On the other hand, the shutoff valves 29a and 29b attached to the air supply pipe 21 and the air exhaust pipe 23 through which the heated air does not flow remain in a frozen state, and air cannot be vented to the fuel cell 11. It has become. However, since the bypass valve 27 is held in the slightly opened state, the discharge pressure of the air compressor 14 is held at about 100 kPa, for example, as described above. This compressor discharge pressure is applied to the working gas supply pipe 33 of each drive part 31a, 31b of each shut-off valve 29a, 29b. Since the shut-off valve operating gas control valves 35a and 35b are not in an environment where wet air enters, the fuel cell 11 is not frozen for about one night, and can be opened and closed by a command from the control unit 61. It has become. Moreover, since each shut-off valve 29a, 29b has a pneumatic drive unit, a large driving force can be generated when the driving gas pressure is high. For example, in this embodiment, since the diaphragm has a size that can generate a sufficiently large driving force to open the valve even in a frozen state in the shut-off valve driving unit if the pressure is about 100 kPa, Even when the shutoff valves 29a and 29b are frozen, the opening / closing operation can be performed.

  Therefore, when the fuel cell 11 is started, the air compressor 14 is operated with the opening of the bypass valve 27 slightly opened, and the discharge pressure is increased to, for example, about 100 kPa. Then, the shut-off valve operating gas regulating valves 35a and 35b are opened by a command from the control unit 61, and the operating gas at the pressure is supplied from the working gas supply pipe 33 to the drive units 31a and 31b of the shut-off valves 29a and 29b. Supply. Thus, the frozen shut-off valves 29a and 29b are opened. When the shutoff valves 29a and 29b are opened, the air can flow into the air side electrode 12 of the fuel cell 11.

  With the shut-off valves 29a and 29b opened, the air pressure of the air-side electrode 12 is adjusted by the air pressure control valve 26 that is housed in the fuel cell case 71 and is not frozen. It will be in the state which can start and start electric power generation. However, while the fuel cell 11 is stopped, as described above, residual hydrogen permeates and stays from the hydrogen side electrode 13 to the air side electrode 12, so that the air pressure is adjusted by the air pressure control valve 26. Before starting power generation, it is necessary to dilute the remaining hydrogen and discharge it. Therefore, the flow rate of the air flowing from the air exhaust line 23 to the atmospheric discharge line 24 is increased from the minute opening degree to the full opening degree of the bypass valve 27 that has already been thawed by the inflow of hot air. Then, the air pressure control valve 26 of the fuel cell 11 is controlled by the control unit 61 in a state where the air flow rate is large, and air is gradually introduced into the air side electrode 12. Then, hydrogen staying in the air side electrode 12 of the fuel cell 11 is gradually discharged from the air exhaust pipe 23. The hydrogen discharged to the air exhaust line 23 is diluted by a large amount of air flowing through the fully open bypass valve 27 and is discharged from the atmospheric discharge line 24 through the silencer 53 to the atmosphere. In this way, even when the fuel cell 11 is started, the concentration of discharged hydrogen can be lowered, so that the influence on the environment can be reduced.

  As described above, when the bypass valve 27 is fully opened to allow a large amount of air to flow into the bypass pipe 25, the discharge pressure of the air compressor 14 is small as shown in the flow characteristics of the air compressor 14 in FIG. Compared to the time of, for example, it is reduced to about 40 kPa. However, since the shut-off valves 29a and 29b are already open, a high air pressure is not required as the operating gas of the shut-off valves 29a and 29b, and even if the pressure is low, the fuel cell 11 Since the pressure is sufficient to discharge the hydrogen staying at the air side electrode 12, the hydrogen staying at the air side electrode 12 can be diluted and discharged without any problem.

  After performing the operation of discharging the hydrogen accumulated in the air-side electrode 12 as described above for a predetermined time, the bypass valve 27 is fully closed. As a result, the air pressure of the air side electrode 12 is adjusted by the air pressure control valve 26, and the air flow rate is in a state where a normal operation in which the air flow rate is adjusted by controlling the rotational speed of the air compressor 14 can be performed. Thereafter, the output of the fuel cell 11 rises according to the load demand.

  In the above-described embodiment, by keeping the bypass valve 27 at a very small opening degree, the operating gas pressure supplied to each drive unit 31a, 31b of each shut-off valve 29a, 29b is increased, and the shut-off valves 26a, 29b in the frozen state are raised. As described above, the air compressor 14 is started at an opening that can maintain the opening of the bypass valve 27 so that the discharge air temperature of the air compressor 14 is higher than that during normal operation. 27, the bypass valve 27 is throttled to increase the operating gas pressure supplied to the drive units 31a and 31b of the shut-off valves 29a and 29b, so that the frozen shut-off valves 26a and 29b are The valve may be opened. In this case, if the opening degree of the bypass valve 27 is a valve opening degree that can defrost the bypass valve 27 by making the discharge temperature of the air compressor 14 higher than the discharge air temperature during normal operation, The predetermined opening is not limited to the minimum valve opening. For example, the opening may be 20 to 30%. Further, in the present embodiment, it has been described that the bypass valve 27 is fully opened when discharging the hydrogen remaining in the air-side electrode 12, but the valve is opened to the extent that it can be discharged to the atmosphere even if it is not fully opened. The degree of hydrogen may be set and purged with hydrogen.

  As described above, in the present embodiment, the outlet of the air compressor 14 is stopped by slightly opening the bypass valve 27 even in a low temperature state in which peripheral devices not stored in the fuel cell case 71 are frozen. The temperature and pressure can be started at a high state, and the bypass valve 27 can be thawed with high-temperature air at an early stage to enable the opening / closing operation. Further, by enabling the operation of the bypass valve 27, there is an effect that the residual hydrogen remaining in the air side electrode 12 can be diluted and discharged. Furthermore, since it can be started in a state where the outlet pressure of the air compressor 14 is kept high, it is possible to supply a high drive pressure to each drive unit 31a, 31b of each shut-off valve 29a, 29b, and each shut-off valve 29a even in a frozen state. , 29b can be opened. As a result, even if the bypass valve 27 and the shut-off valves 29a and 29b are in a frozen state, the fuel cell system can be efficiently started, and the startup is effective even from a low temperature state. In addition, there is an effect that the concentration of discharged hydrogen gas can be reduced.

1 is a system diagram of an embodiment of a fuel cell system according to the present invention. It is a graph which shows the flow characteristic of the air compressor used for the fuel cell system concerning the present invention. 3 is a timing chart showing operations at the time of stopping and starting the fuel cell system according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Fuel cell system, 11 Fuel cell, 12 Air side electrode, 13 Hydrogen side electrode, 14 Air compressor, 18 Intake flow meter, 19 Air suction line, 20 Compressor discharge line, 21 Air supply line, 23 Air Exhaust pipe, 24 Atmospheric discharge pipe, 25 Bypass pipe, 26 Air pressure control valve, 27 Bypass valve, 29a, 29b Air outlet shut-off valve, 31a, 31b Shut-off valve drive unit, 33, 33a, 33b Working gas supply pipe Passage, 35a, 35b shutoff valve operating gas control valve, 37 humidification module, 41 hydrogen gas tank, 43 hydrogen supply line, 44 hydrogen gas supply control valve, 45 hydrogen circulation line, 46 hydrogen exhaust line, 47 hydrogen circulation pump, 49 Mixer, 53 Silencer, 55 Air outlet, 61 Control unit, 71 Fuel cell case.

Claims (6)

A fuel cell that generates electricity by an electrochemical reaction between a fuel gas and an oxidant gas;
A compressor for compressing an oxidant gas supplied to the fuel cell;
A bypass passage for flowing the oxidant gas compressed by the compressor, bypassing the fuel cell;
A bypass valve provided in the bypass passage and adjustable in opening;
A control unit for performing start-stop control of the fuel cell;
A fuel cell system comprising:
The controller is configured to stop the fuel cell in a state where the opening of the bypass valve is a predetermined opening;
A fuel cell system comprising: The fuel cell system according to claim 1, wherein
Further, the compressor and the fuel cell are connected to each other, and an oxidant gas supply passage for supplying the oxidant gas compressed by the compressor to the fuel cell; and an oxidant gas after reaction connected to the fuel cell. A shutoff valve provided in each of the oxidant gas exhaust passages that exhausts the fuel cell to the atmosphere,
The fuel cell stop means further closes each shut-off valve to stop the fuel cell;
A fuel cell system. A fuel cell that generates electricity by an electrochemical reaction between a fuel gas and an oxidant gas;
A compressor for compressing the oxidant gas;
An oxidant gas supply channel for connecting the compressor and the fuel cell, and supplying an oxidant gas compressed by the compressor to the fuel cell;
An oxidant gas exhaust passage connected to the fuel cell and exhausting the reacted oxidant gas from the fuel cell to the atmosphere;
A shut-off valve that is provided in each of the oxidant gas supply flow path and the oxidant gas exhaust flow path and is opened and closed by an open / close drive unit that uses the oxidant gas compressed by the compressor as an operating gas;
An operating gas supply channel connecting the compressor and the opening / closing drive unit;
Working gas supply adjusting means provided in the working gas supply flow path;
The oxidant gas supply channel and the oxidant gas exhaust channel are connected on the opposite side of the shutoff valve from the fuel cell, and the oxidant gas compressed by the compressor is supplied to the oxidant gas exhaust channel. A bypass flow path for bypassing,
A bypass valve provided in the bypass passage and adjustable in opening;
A control unit for performing start-stop control of the fuel cell;
A fuel cell system comprising:
The controller is
After the opening degree of the bypass valve is maintained at a predetermined opening degree, the operating gas supply adjusting means supplies the oxidant gas to the opening / closing drive unit to open the shutoff valve, and then fully opens the bypass valve. Fuel cell starting means,
A fuel cell system comprising: The fuel cell system according to claim 3, wherein
The control unit further includes a fuel cell stop means for stopping the fuel cell in a state where the opening degree of the bypass valve is a predetermined opening degree,
A fuel cell system comprising: The fuel cell system according to any one of claims 1 to 4,
The predetermined opening degree of the bypass valve is an opening degree such that the oxidant gas temperature compressed by the compressor is higher than the oxidant gas temperature during normal operation,
A fuel cell system. The fuel cell system according to any one of claims 1 to 4,
The predetermined opening of the bypass valve is a minimum holding opening of the bypass valve;
A fuel cell system.

Images