Fuel cell system for vehicle

Abstract

To execute scavenging processing at appropriate timing.SOLUTION: A fuel cell system for a vehicle comprises: a fuel cell; a gas supply unit for flowing purge gas through a gas passage inside the fuel cell; and a controlling unit for controlling the gas supply unit to execute scavenging processing on the fuel cell using purge gas for suppressing freezing of moisture in the gas passage. The controlling unit acquires an operation schedule of a vehicle. After receiving an instruction of stopping operation of the fuel cell, the controlling unit acquires, from the operation schedule, a stay time in which the vehicle stays at a present place, avoids execution of the scavenging processing (S18) when the stay time is within a predetermined time in which no execution of the scavenging processing is permitted at a current outdoor temperature (S14: No), and executes the scavenging processing (S16) when the stay time is not within the predetermined time (S14: Yes).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a fuel cell system for a vehicle equipped with a fuel cell, and more particularly to a fuel cell system that appropriately performs scavenging processing while the vehicle is parked. [Background technology]

[0002] It has been known that if moisture remains inside a fuel cell in a vehicle equipped with a fuel cell after the fuel cell is shut down, the moisture will freeze at low temperatures, causing a decrease in the start-up performance of the fuel cell. For this reason, it has been proposed to reduce the moisture remaining in the fuel cell by running a purge gas through the gas flow path inside the fuel cell after the fuel cell is shut down.

[0003] Patent Document 1 discloses a fuel cell system that determines whether or not white mist will be generated when exhaust gas flowing through an exhaust passage that discharges exhaust gas from a fuel cell is discharged into the outside air, and if it is determined that white mist will be generated, controls the flow rate or flow speed of the exhaust gas discharged into the outside air. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-37870 A Summary of the Invention [Problem to be solved by the invention]

[0005] In some vehicles that are driven by fuel cells, in order to prevent the water inside the fuel cell from freezing, the scavenging process is performed at the same time every time the ignition switch is turned off in winter. In this case, depending on the outside air temperature and the scavenging air temperature, the water coming out of the exhaust pipe may condense and generate white mist. This may make the vehicle look like it is emitting white smoke due to a malfunction, and if the white mist is blown by the wind, it may fall on people passing by the vehicle.

[0006] Although the white mist is harmless, there are concerns that it may affect the image of the company that operates and manages the commercial vehicle, for example. Therefore, it is desirable to be able to perform scavenging at an appropriate time.

[0007] An object of the present invention is to provide a fuel cell system for a vehicle that executes scavenging processing at an appropriate timing. [Means for solving the problem]

[0008] The fuel cell system for a vehicle according to the present invention is a fuel cell system mounted on a vehicle, and includes a fuel cell for driving the vehicle, a gas supply unit for supplying purge gas to a gas flow path inside the fuel cell, and a control unit for controlling the gas supply unit to perform a scavenging process of the fuel cell using the purge gas to suppress freezing of moisture in the gas flow path. The control unit obtains an operation schedule for the vehicle. After receiving an instruction to stop operation of the fuel cell, the control unit obtains from the operation schedule the stay time for which the vehicle will stay at its current location, and if the stay time is within a predetermined time for which it is permissible not to perform the scavenging process at the current outside air temperature, the control unit avoids performing the scavenging process, and otherwise performs the scavenging process.

[0009] Furthermore, in the vehicle fuel cell system of the present invention, the control unit may acquire the current location of the vehicle, and after receiving an instruction to stop operation of the fuel cell, if the current location is not within a predetermined scavenging-permitted area for the vehicle, avoid executing the scavenging process or execute the scavenging process in a limited manner even if the residence time exceeds the predetermined time. Effect of the Invention

[0010] According to the vehicle fuel cell system of the present invention, the execution of the scavenging process is suppressed as much as possible, and the scavenging process is executed at a timing when it is necessary. [Brief description of the drawings]

[0011] [Figure 1] 1 is a configuration diagram of a fuel cell system according to an embodiment of the present invention. [Diagram 2] FIG. 11 is an explanatory diagram for acquiring an operation schedule. [Diagram 3] FIG. 2 is a diagram showing an example of an operation schedule. [Figure 4] 5 is a flowchart showing execution control of a scavenging process. [Diagram 5] 10 is a flowchart showing another execution control of the scavenging process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described herein. In all drawings, the same reference numerals are used to designate equivalent elements, and duplicated explanations will be omitted.

[0013] <System configuration> 1 is a configuration diagram of a vehicle fuel cell system 10 according to an embodiment. The vehicle fuel cell system 10 is mounted on a fuel cell vehicle, and includes a fuel cell 12, a control unit 20, a cathode gas supply and discharge unit 30, an anode gas supply and discharge unit 40, a refrigerant circulation cooling unit 50, and an external circuit 60. The vehicle fuel cell system 10 also includes an outside air temperature sensor 22 that detects the temperature of the outside air, and a fuel cell temperature sensor 80. Hereinafter, the vehicle fuel cell system 10 will be referred to as the fuel cell system 10.

[0014] The fuel cell 12 includes a cell stack formed by stacking a plurality of fuel cells, which are power generating bodies. In the fuel cell 12, a current collector plate and an end plate are stacked on both ends of the cell stack in the stacking direction. An insulating plate may be provided between the current collector plate and the end plate.

[0015] Each fuel cell includes, for example, a membrane electrode assembly formed by sandwiching an electrolyte membrane between an anode electrode and a cathode electrode, and separators arranged on both sides of the assembly. Hydrogen gas is supplied to the anode electrode as an anode gas, and air is supplied to the cathode electrode as a cathode gas. Hydrogen ions generated at the anode electrode move to the cathode electrode through the electrolyte membrane, and undergo an electrochemical reaction with oxygen at the cathode electrode, producing water. Electrons move from the anode electrode to the cathode electrode through an external circuit 60, generating an electromotive force. The power generated by the fuel cell 12 is supplied to a secondary battery 61, which is charged.

[0016] The control unit 20 includes a processor 20a (see FIG. 2) such as a central processing unit (CPU) and a storage device 20b such as a memory. The control unit 20 may include a microcomputer. The control unit 20 functions as a power generation control unit that causes the fuel cell 12 (see FIG. 1) to generate power in response to an output request for the fuel cell 12.

[0017] After the operation of the fuel cell 12 is stopped, the control unit 20 controls the operation of the components of the fuel cell system 10, such as the air compressor 31 and the hydrogen circulation pump 41, during the scavenging process. This causes the purge gas, which is a gas for scavenging, to flow through the gas flow path inside the fuel cell 12 and the flow path formed by the piping connected to the fuel cell 12. As a result, the control unit 20 executes the scavenging process of the fuel cell 12 using the purge gas.

[0018] The cathode gas supply and discharge unit 30 is used to supply air to the cathode electrode of the fuel cell 12 and discharge the cathode off-gas after being subjected to an electrochemical reaction at the cathode electrode. Specifically, the cathode gas supply and discharge unit 30 includes a cathode gas supply passage 32, an air cleaner 33, an air compressor 31, a cathode off-gas discharge passage 34, and a back pressure valve 35 which is an opening and closing valve. The cathode gas supply passage 32 is connected to the cathode side inlet of the fuel cell 12 in order to supply air to the cathode side gas flow passage of the fuel cell 12. The air compressor 31 and the air cleaner 33 are connected to the upstream side of the cathode gas supply passage 32. The air compressor 31 is driven to send air as outside air to the air cleaner 33. The air from which foreign matter such as dust has been removed by passing through a filter in the air cleaner 33 is sent to the air compressor 31, pressurized, and supplied to the fuel cell 12. The air compressor 31 is driven by a motor (not shown), which is controlled by the control unit 20 .

[0019] The cathode off-gas discharge path 34 is connected to the cathode-side outlet of the fuel cell 12 in order to discharge the cathode-side off-gas after being subjected to an electrochemical reaction in each fuel cell of the fuel cell 12. The back pressure valve 35 is connected to an intermediate portion of the cathode off-gas discharge path 34, and opening and closing thereof is controlled by the control unit 20. When the back pressure valve 35 is opened, the cathode-side off-gas is discharged to the outside.

[0020] On the other hand, the anode gas supply and discharge unit 40 is used to supply hydrogen gas to the anode electrode of the fuel cell 12 and discharge the anode off-gas after being subjected to an electrochemical reaction at the anode electrode. Specifically, the anode gas supply and discharge unit 40 includes an anode gas supply path 42, a hydrogen tank 43, a hydrogen circulation pump 41, an anode off-gas discharge path 44, a gas-liquid separator 45, a circulation path 46, a drainage path 47, and a purge valve 48. The anode gas supply path 42 is connected between the outlet of the hydrogen tank 43 and the anode inlet of the fuel cell 12. A shutoff valve 42a and a regulator 42b are connected to the anode gas supply path 42. The shutoff valve 42a is controlled to open and close by the control unit 20. The regulator 42b is a pressure reducing valve for adjusting the pressure of hydrogen gas on the upstream side of the anode gas supply path 42, and the opening degree thereof is controlled by the control unit 20. When the shutoff valve 42 a opens, the hydrogen gas is sent to the regulator 42 b, where it is depressurized and flows through the anode gas supply passage 42 toward the fuel cell 12 , and is then supplied to the fuel cell 12 .

[0021] The anode off-gas discharge path 44 is connected to the anode-side outlet of the fuel cell 12 in order to discharge the anode-side off-gas after being subjected to the electrochemical reaction in each fuel cell of the fuel cell 12. The circulation path 46 is connected between the downstream side of the anode off-gas discharge path 44 and the downstream side of the anode gas supply path 42.

[0022] The gas-liquid separation unit 45 is connected between the anode off-gas discharge path 44 and the circulation path 46. The gas-liquid separation unit 45 separates the gas components and moisture contained in the anode-side off-gas. A hydrogen circulation pump 41 is connected to the middle of the circulation path 46, and the gas components separated by the gas-liquid separation unit 45 and sent to the circulation path 46 are returned to the anode gas supply path 42 by the hydrogen circulation pump 41. The drive of the hydrogen circulation pump 41 is controlled by the control unit 20. Since the anode-side off-gas may contain unreacted hydrogen that was not used in the power generation reaction, the hydrogen circulation pump 41 returns the unreacted hydrogen to the anode gas supply path 42. The unreacted hydrogen is merged with hydrogen gas sent from the upstream side of the anode gas supply path 42 and then sent again to the fuel cell 12.

[0023] The gas-liquid separation unit 45 guides moisture contained in the anode-side off-gas to a drainage channel 47. The purge valve 48 is connected to an intermediate portion of the drainage channel 47, and its opening and closing is controlled by the control unit 20. By opening the purge valve 48, gas containing impurities (nitrogen, water, etc.) can be discharged from the anode-off-gas discharge channel 44. During operation of the fuel cell 12, the control unit 20 normally closes the purge valve and opens the purge valve at a predetermined drainage timing or at a timing for discharging inert gas in the anode-side off-gas.

[0024] The coolant circulation cooling unit 50 adjusts the temperature of the fuel cell 12 by circulating the coolant through the fuel cell 12. Specifically, the coolant circulation cooling unit 50 includes a radiator 51, a coolant discharge path 52, a coolant supply path 53, a coolant circulation pump 54, and a temperature sensor 80 that is a coolant temperature sensor. The radiator 51 is connected between the coolant discharge path 52 and the coolant supply path 53. The radiator 51 has a heat transfer tube (not shown) and cools the coolant by exchanging heat between the coolant sent from the coolant discharge path 52 and flowing inside the heat transfer tube and air passing outside the heat transfer tube. The cooled coolant is sent to the coolant supply path 53. The coolant circulation pump 54 is connected to an intermediate portion of the coolant supply path 53 and is driven to flow the coolant through the coolant supply path 53 toward an internal coolant flow path (not shown) of the fuel cell 12. The coolant that has flowed through the internal coolant flow path is discharged to the coolant discharge path 52. The fuel cell 12 is cooled by the coolant flowing through the internal coolant flow path. Furthermore, the temperature of the fuel cell 12 is adjusted by adjusting the amount of coolant flowing through the internal coolant flow passage by the coolant circulation pump 54 .

[0025] The temperature sensor 80 is disposed in the coolant discharge path 52 near the fuel cell 12. The temperature sensor 80 measures the temperature of the coolant, and a signal representing the measured value is sent to the control unit 20. The measured value of the temperature sensor 80 is approximately the same as the temperature of the fuel cell 12, and is therefore treated as the temperature of the fuel cell 12. The temperature sensor 80 is constituted by a thermistor or the like.

[0026] The external circuit 60 supplies power output from the fuel cell 12 or the secondary battery 61 to a driving motor 62. The external circuit 60 includes the driving motor 62, an inverter 63, a DC / DC converter 64, and the secondary battery 61. The driving motor 62 is connected to the positive and negative current collecting plates of the fuel cell 12 via the inverter 63. The inverter 63 is connected in parallel with the fuel cell 12 and the secondary battery 61, and converts the direct current supplied from the fuel cell 12 or the secondary battery 61 into alternating current and supplies it to the driving motor 62.

[0027] The DC / DC converter 64 boosts the output voltage of the secondary battery 61 and supplies it to the inverter 63. The DC / DC converter 64 can step down the output voltage of the fuel cell 12 and supply it to the secondary battery 61 in order to store surplus power generated by the fuel cell 12. This allows at least a portion of the power generated by the fuel cell 12 to be stored in the secondary battery 61. The secondary battery 61 is, for example, a nickel-metal hydride secondary battery, a lithium-ion secondary battery, or the like.

[0028] The traction motor 62 is a three-phase AC motor and is used as a drive source for a drive shaft (not shown) for driving the wheels (not shown) of the vehicle. The fuel cell 12 and the secondary battery 61 can also supply power to auxiliary equipment for generating electricity for the fuel cell 12, such as the air compressor 31 and the hydrogen circulation pump 41.

[0029] The control unit 20 controls the power generation operation of the fuel cell 12. The control unit 20 calculates the system required power based on signals from an accelerator sensor (not shown) that detects the amount of operation (depression amount) of the accelerator pedal of the vehicle, a vehicle speed sensor (not shown) that detects the vehicle speed, and the like, and signals that indicate the operating state of accessories such as the air compressor 31. The control unit 20 determines the share of the system required power between the fuel cell 12 and the secondary battery 61, and controls the operation of accessories such as the air compressor 31, the shutoff valve 42a, and the hydrogen circulation pump 41 so as to generate the determined required power generation amount of the fuel cell 12.

[0030] The control unit 20 receives the vehicle's outside air temperature, which is the detection value of the outside air temperature sensor 22. The outside air temperature sensor 22 is composed of a thermistor or the like. The control unit 20 determines whether or not to execute the scavenging process based on the input outside air temperature. The control unit 20 may determine whether or not to execute the scavenging process based on the temperature of the fuel cell 12, which is the detection value of the temperature sensor 80, in addition to or instead of the outside air temperature.

[0031] When an instruction to stop the operation of the fuel cell 12 is received, the control unit 20 stops the operation of the fuel cell 12. Then, the control unit 20 executes a scavenging process. As will be described later, the scavenging process is not executed every time the operation of the fuel cell 12 is stopped, but is executed when a predetermined condition is met.

[0032] The scavenging process is a process that is executed by the control unit 20 upon receiving an instruction to stop the operation of the fuel cell 12 by turning off a start instruction unit such as an ignition switch while the driver has stopped driving the vehicle. The scavenging process is intended to prevent moisture remaining in the gas flow path from freezing when the temperature of the fuel cell 12 falls below 0°C due to leaving the vehicle in a low-temperature environment, etc. The scavenging process is executed on both the anode side and the cathode side, or on either one of them.

[0033] The scavenging process on the anode side is performed as follows. First, the hydrogen circulation pump 41 is driven to circulate the gas containing hydrogen remaining in the fuel cell 12 as a purge gas. Then, the purge valve 48 is opened at a preset timing to drain the moisture separated in the gas-liquid separator 45. This allows the purge gas to flow through the inside of the fuel cell 12 and the anode-side gas flow path in the flow path connected to the fuel cell 12 when the operation of the fuel cell 12 is stopped, and the gas flow path is scavenged to discharge the water remaining in the gas flow path. At this time, the hydrogen circulation pump 41 and the purge valve 48 driven by the power of the secondary battery 61 function as a gas supply unit that flows the purge gas into the gas flow path.

[0034] In the scavenging process on the anode side, the purge valve 48 and the shutoff valve 42a may be opened, the regulator 42b may be opened to a larger degree, and the hydrogen circulation pump 41 may be driven. This also causes the purge gas to flow through the gas flow passage in the fuel cell 12 and in the flow passage connected to the fuel cell 12. At this time, the shutoff valve 42a, the regulator 42b, the hydrogen circulation pump 41, and the purge valve 48, which are driven by power from the secondary battery 61, function as a gas supply unit that causes the purge gas to flow through the gas flow passage.

[0035] On the other hand, the scavenging process on the cathode side is performed by opening the back pressure valve 35 and supplying a predetermined amount of air as purge gas to the fuel cell 12 by the air compressor 31. This allows the purge gas to flow through the inside of the fuel cell and the cathode side gas flow path in the flow path connected to the fuel cell when the operation of the fuel cell 12 is stopped, and the gas flow path can be scavenged and water remaining in the gas flow path can be discharged. At this time, the air compressor 31 driven by the power of the secondary battery 61 and the back pressure valve 35 function as a gas supply unit that flows the purge gas into the gas flow path. Note that an opening and closing valve may be provided in the cathode gas supply path 32 of the cathode gas supply and discharge unit 30. At this time, when the scavenging process is performed, this opening and closing valve is also opened as a gas supply unit.

[0036] <Execution control of scavenging process> Next, the execution control of the scavenging process will be described. The vehicle in this embodiment is a moving body such as an automobile that moves according to a driving schedule. The vehicle may be, for example, a commercial vehicle such as a truck or van that transports goods, or a bus that transports people. FIG. 3 is a diagram showing an example of a driving schedule 90, which shows the driving schedule of a vehicle that delivers goods to each of a plurality of convenience stores in turn. The driving schedule 90 exists as electronic data.

[0037] 2, the operation schedule 90 is stored in a management server 100. The management server 100 is, for example, a computer used by a company that manages multiple vehicles. The management server 100 may be constructed as a single computer, or as a system consisting of multiple computers that cooperate with each other, such as a cloud service. The management server 100 includes a processor 100a such as a CPU, and a storage device 100b such as a hard disk.

[0038] The storage device 100b of the management server 100 stores an operation schedule 90 linked to the identification information of each vehicle. The vehicle acquires its own vehicle operation schedule 90 from the management server 100 via a network such as wireless communication or the Internet. The vehicle acquires its own vehicle operation schedule 90 at a predetermined timing, such as when the driver turns on or off the ignition switch, and stores it in the storage device 20b of the control unit 20.

[0039] As shown in FIG. 3, the operation schedule 90 is a table that links the location and time of the vehicle's location on a day, for example. In the example of FIG. 3, it is shown that the vehicle leaves the head office parking lot at 8:00, travels between 8:00 and 8:59, and is at convenience store A between 9:00 and 9:19. It is also shown that the vehicle leaves convenience store A at 9:20, travels between 9:20 and 9:59, and is at convenience store B between 10:00 and 10:14. Subsequent rows (items) of the operation schedule 90 have the same meaning. It is shown that the vehicle is at the head office parking lot after 18:00, the last day of the day.

[0040] The scavenging process of the fuel cell 12 may cause white mist, and if the scavenging process is performed in a customer parking lot such as a convenience store, it may cause inconvenience to others. On the other hand, in the parking lot of the company that manages the vehicle (hereinafter referred to as the company), the scavenging process is unlikely to cause problems. Therefore, in this embodiment, the scavenging process is permitted in the company's parking lot, while the scavenging process is suppressed in the customer parking lots such as convenience stores. In the operation schedule of FIG. 3, the row (item) for the company's parking lot is filled in gray.

[0041] FIG. 4 is a flowchart showing the execution control of the scavenging process. The control flow in FIG. 4 is executed when the driver turns off the ignition switch of the vehicle and instructs the fuel cell to stop operating. In step S10, the control unit 20 of the vehicle checks whether or not there is a provisional scavenging request. Specifically, if the outside air temperature detected by the outside air temperature sensor 22 is a temperature at which moisture in the gas flow path of the fuel cell 12 may freeze, there is a provisional scavenging request (S10: Yes). On the other hand, if not, there is no provisional scavenging request (S10: No). For example, if the outside air temperature is 5° C. or higher, there is no provisional scavenging request (S10: No). If step S10 is No, in step S18, the control unit 20 avoids the execution of the scavenging process.

[0042] On the other hand, if step S10 is Yes, in step S12, the control unit 20 refers to the operation schedule 90 to confirm the stop time (stay time) at the current location (present position). The control unit 20 checks the current time against the time of each line in the operation schedule 90 to confirm the current location and its stay time. For example, if the current time is 9:01, it is understood from the operation schedule 90 in Fig. 3 that the current location is "Convenience Store A" and that the vehicle will stay there for approximately 20 minutes (09:00 to 09:19).

[0043] Next, in step S14, the control unit 20 checks whether the residence time acquired in step S12 exceeds a predetermined time for which it is permitted not to execute the scavenging process at the current outside air temperature. The outside air temperature is a detection value of the outside air temperature sensor 22.

[0044] Here, the storage device 20b of the control unit 20 stores an outside air temperature table in advance. The outside air temperature table associates, for each outside air temperature range, a predetermined time during which the scavenging process is not executed. As an example, the outside air temperature table associates outside air temperature ≧0° C. with 0.75 hours (predetermined time, the same applies below), 0° C.>outside air temperature ≧-2° C. with 0.5 hours, -2° C.>outside air temperature ≧-4° C. with 0.4 hours, and outside air temperature <-4° C. with 0.3 hours. Note that this outside air temperature table is merely an example, and the association between the outside air temperature range and the predetermined time set in the outside air temperature table changes depending on the specifications of the fuel cell 12, etc. When the outside air temperature is low, the moisture in the gas flow path of the fuel cell 12 is more likely to freeze in a shorter time. Therefore, as in the example of the outside air temperature table described above, when the outside air temperature is low, the predetermined time during which the scavenging process is not executed is also shorter.

[0045] The control unit 20 obtains a predetermined time corresponding to the current outside air temperature from the outside air temperature table. For example, if the current outside air temperature is 0°C, 0.75 hours is obtained as the predetermined time in the above-mentioned example of the outside air temperature table. Then, the control unit 20 checks whether the stay time obtained in step S12 exceeds the predetermined time obtained from the outside air temperature table (step S14). If step S14 is Yes, that is, if the stay time exceeds the predetermined time, the control unit 20 executes a scavenging process in step S16. On the other hand, if step S10 is No, that is, if the stay time is within the predetermined time, the control unit 20 avoids the execution of the scavenging process in step S18.

[0046] In the case of "Convenience Store A" in the operation schedule 90 of FIG. 3, when the stay time there is short, such as about 20 minutes (about 0.33 hours), step 14 will be No (stay time ≦ predetermined time) in relatively many cases, and the execution of the scavenging process will be avoided. Therefore, it is possible to prevent a situation in which the scavenging process is performed in a customer parking lot of a convenience store or the like, causing inconvenience to people around the vehicle. It is also possible to prevent a situation in which the image of the company that manages the vehicle is damaged due to the generation of white mist caused by the scavenging process.

[0047] On the other hand, when the vehicle returns to the company's parking lot (head office parking lot in FIG. 3) and parks there for a long time, as shown in the last line of the operation schedule 90 in FIG. 3, step 14 becomes Yes (stay time>predetermined time), and the scavenging process is executed. Therefore, the water inside the fuel cell 12 can be prevented from freezing.

[0048] According to the fuel cell system 10 described above, the execution of the scavenging process is suppressed as much as possible, and the scavenging process is executed at a timing when it is necessary.

[0049] Next, another execution control of the scavenging process will be described. Fig. 5 is a flowchart showing another execution control of the scavenging process. The flowchart in Fig. 5 is obtained by adding the processes of S115 and S117 to the flowchart in Fig. 4. S110, S112, S114, S116, and S118 in Fig. 5 are the same processes as S10, S12, S14, S16, and S18 in Fig. 4, respectively.

[0050] In the execution control of this other scavenging process (FIG. 5), the control unit 20 acquires the current location of the vehicle. For example, the fuel cell system 10 is equipped with a GNSS sensor, and the current location (position information) of the vehicle is acquired using the GNSS sensor. The current location may also be acquired by comparing the current time with the times of each line of the operation schedule 90.

[0051] Then, in step S114, if the vehicle's stay time at the current location acquired from the operation schedule exceeds a predetermined time that is permitted for not executing the scavenging process at the current outside air temperature (S114: Yes), step S115 is executed. That is, in step S115, the control unit 20 judges whether the vehicle's current location is in a scavenging permission area that is predetermined for the vehicle. The scavenging permission area is an area in which the scavenging process is permitted to be executed, and is stored in advance in the storage device 20b of the control unit 20. The scavenging permission area is an area in which the scavenging process does not cause inconvenience to people around the vehicle, and is, for example, a parking lot (company parking lot) of the company that manages the vehicle, such as "head office parking lot" and "branch office A parking lot" in the operation schedule 90 of FIG. 3.

[0052] If step S115 is Yes, i.e., if the vehicle is in the scavenging permission area (for example, if the vehicle is in the company's parking lot), then in step S116, the control unit 20 executes the scavenging process. On the other hand, if step S115 is No, i.e., if the vehicle is not in the scavenging permission area (for example, if the vehicle is in a customer's parking lot such as a convenience store), then in step S117, the control unit 20 avoids the execution of the scavenging process or executes the scavenging process in a limited manner. Note that "executing the scavenging process in a limited manner" means, for example, that the scavenging process is executed with the output of the gas supply unit (air compressor 31, hydrogen circulation pump 41, etc.) lowered compared to the scavenging process in step S116, and means that the scavenging process is executed with the generation of white mist suppressed.

[0053] According to this different scavenging process execution control (Figure 5), even if the current location of the vehicle is not in a scavenging-permitted area, for example, if the current location of the vehicle is a customer parking lot such as a convenience store and the stay time there exceeds a predetermined time (S114: Yes), the scavenging process is avoided or is executed in a limited manner, thereby accurately preventing a situation in which the scavenging process causes inconvenience to people around the vehicle.

[0054] In addition, in a form in which the execution of the scavenging process is avoided (S115: No, S117) when the residence time exceeds a predetermined time (S114: Yes), it is preferable to execute an alternative process (such as a process of restarting the operation of the fuel cell, or a process of repeating the operation and stopping of the fuel cell at predetermined time intervals) to suppress freezing of water in the gas flow path of the fuel cell 12.

[0055] Next, a modified example will be described. In the embodiment described above, the operation schedule 90 is stored in the control unit 20 of the vehicle, and the execution of the scavenging process is controlled using the operation schedule 90. However, instead of storing the operation schedule 90 in the control unit 20 of the vehicle, the control unit 20 of the vehicle may access the management server 100 (see FIG. 2) and refer to the operation schedule 90 of its own vehicle stored in the management server 100 to control the execution of the scavenging process.

[0056] Alternatively, the vehicle control unit 20 may inquire of the management server 100 as to whether or not scavenging processing should be performed, and the management server 100 may respond to the inquiry by transmitting an instruction to perform or not perform scavenging processing to the vehicle, and the vehicle control unit 20 may operate according to the instruction. In this case, when an inquiry is received from the vehicle control unit 20, the management server 100 acquires the current time and the duration of time that the vehicle will stay at the current location from the vehicle's operation schedule 90, compares the duration of time with the predetermined time in the above-mentioned outside air temperature table (prestored in advance in the management server 100), and determines whether or not to perform scavenging processing based on the above-mentioned condition judgment. [Explanation of symbols]

[0057] 10 Vehicle fuel cell system (fuel cell system), 12 fuel cell, 20 control unit, 20a processor, 20b storage device, 22 outside air temperature sensor, 30 cathode gas supply and discharge unit, 31 air compressor, 32 cathode gas supply channel, 33 air cleaner, 34 cathode off-gas discharge channel, 35 back pressure valve, 40 anode gas supply and discharge unit, 41 hydrogen circulation pump, 42 anode gas supply channel, 42a shutoff valve, 42b regulator, 43 hydrogen tank, 44 anode off-gas discharge channel, 45 gas-liquid separation unit, 46 circulation channel, 47 drain channel, 48 purge valve, 50 refrigerant circulation cooling unit, 51 radiator, 52 refrigerant discharge channel, 53 refrigerant supply channel, 54 refrigerant circulation pump, 60 external circuit, 61 secondary battery, 62 driving motor, 63 inverter, 64 DC / DC converter, 80 temperature sensor, 90 Operation schedule, 100 management server, 100a processor, 100b storage device.

Claims

1. A fuel cell system mounted on a vehicle, a fuel cell for driving the vehicle; a gas supply unit that supplies a purge gas to a gas flow path inside the fuel cell; a control unit that controls the gas supply unit to perform a scavenging process of the fuel cell with the purge gas in order to suppress freezing of moisture in the gas flow path; The control unit is Obtaining an operation schedule of the vehicle; After receiving an instruction to stop the operation of the fuel cell, a stay time during which the vehicle will stay at the current location is obtained from the operation schedule, and if the stay time is within a predetermined time within which it is permissible not to execute the scavenging process at the current outside air temperature, execution of the scavenging process is avoided, and if not, the scavenging process is executed. Fuel cell systems for vehicles.

2. 2. The vehicle fuel cell system according to claim 1, The control unit is Obtaining the current location of the vehicle; after receiving an instruction to stop the operation of the fuel cell, if the current location is not in a scavenging permission area that is predetermined for the vehicle, even if the stay time exceeds the predetermined time, execution of the scavenging process is avoided or the scavenging process is executed in a limited manner. Fuel cell systems for vehicles.

Images