Vehicle with a fuel cell system installed

Abstract

A vehicle having a fuel cell system (10) mounted therein, the fuel cell system (10) comprising: a fuel cell (100); a plurality of tanks (200) configured to store fuel gas to be used for power generation of the fuel cell (100), each tank having an opening / closing valve (210) for switching between executing and stopping the supply of the fuel gas; a plurality of supply flow paths (220) connected to the opening / closing valves (210) in the plurality of tanks (200) for supplying the fuel gas supplied from the plurality of tanks (200), respectively; a merging flow path (230) configured to merge the plurality of supply flow paths (220) to feed the fuel gas into the fuel cell (100) and fixed to a vehicle body of the vehicle at a fixing position with a fixing part (240); and a controller (300) configured to control the opening and closing of the opening / closing valves, wherein the controller (300) is designed to: to calculate a total flow path length as the total length of the merging flow path (230) and the supply flow path (220) which are within a range from the attachment part (240) to the opening / closing valve (210), and when the fuel cell system (10) is started, to open the opening / closing valve (210) for which the total flow path length from the fastening part (240) to the opening / closing valve (210) is the longest.

Description

BACKGROUND INVENTION AREA

[0001] The present disclosure relates to a vehicle having a fuel cell system mounted therein. RELATED TECHNOLOGY

[0002] Among fuel cell systems, there is one that includes: a fuel cell; a plurality of tanks that store fuel gas to be used for power generation by the fuel cell and that have opening / closing valves for switching between executing and stopping the fuel gas supply; a plurality of supply flow paths connected to the opening / closing valves for supplying the fuel gas; and a merging flow path for merging the plurality of supply flow paths to supply the fuel gas to the fuel cell.

[0003] However, in a vehicle incorporating the fuel cell system of JP 2006-120363 A, under the condition that the converging flow path is fixed to the vehicle body, there is a problem that, when the opening / closing valve of a tank is opened, vibrations due to the discharge of the fuel gas compressed in the tank are transmitted to the vehicle body via the converging flow path, causing the vehicle occupant to perceive the noise as a sound. When this noise is perceived by the occupant, it raises concerns that the occupant's perception of the vehicle may deteriorate. To address this and other problems, a technique capable of eliminating the possibility that noise due to vibrations caused by the discharge of the fuel gas compressed in the tanks may be perceived by the vehicle occupant is desired.Methods for situation-dependent opening of the fuel valves in a fuel cell system are also known from DE 10 2006 031 875 A1, DE 11 2007 002 802 T5 and JP 2015-69 910 A. SUMMARY

[0004] (1) In one aspect of the present disclosure, a vehicle with a fuel cell system mounted therein is provided. The fuel cell system includes: a fuel cell; a plurality of tanks for storing fuel gas to be used for power generation of the fuel cell, each tank having an opening / closing valve for switching between starting and stopping the supply of the fuel gas; a plurality of supply flow paths connected to the opening / closing valves in the plurality of tanks for respectively supplying the fuel gas supplied from the plurality of tanks; a merging flow path for merging the plurality of supply flow paths to supply the fuel gas to the fuel cell; and a controller for controlling the opening and closing of the opening / closing valves.wherein the converging flow path is attached to a vehicle body of the vehicle with a fastening part at a fastening position, and the controller is configured to: calculate a total flow path length as the total length of the converging flow path and the supply flow path that are within a range from the fastening part to the opening / closing valve, and, upon startup of the fuel cell system, open the one of the opening / closing valves whose total flow path length from the fastening part opening / closing valves in the plurality of tanks is the longest. Because the opening / closing valve whose total length of the converging flow path and the relevant supply flow path that are within a range from the fastening position to each opening / closing valve is the longest is opened upon startup of the fuel cell system,According to this aspect, the fuel gas is discharged from the tank having the largest pressure loss of the multiple tanks in a range up to the mounting position. As a result, compared to a mode in which the opening / closing valve with the longest overall length is not opened and another opening / closing valve is opened, the pressure of the fuel gas in the path from the tank to the mounting position can be greatly reduced, so that noise caused by vibrations due to the discharge of the fuel gas can be suppressed. Thus, it becomes possible to eliminate the possibility of the noise caused by vibrations due to the discharge of the fuel gas being perceived by a vehicle occupant.

[0005] (2) In the aforementioned aspect, the controller may exercise such control that includes: opening all the opening / closing valves in the plurality of tanks upon startup of the fuel cell system, provided that the startup is a first startup since the last fuel gas was refueled into the plurality of tanks; and opening an opening / closing valve whose total length is the longest among the plurality of opening / closing valves upon startup of the fuel cell system, provided that the startup is a second startup since the last fuel gas was refueled into the plurality of tanks. With this arrangement, damage to the opening / closing valves can be suppressed. This will be explained in more detail below.When a fuel cell system startup is the first time since the last fuel gas was refueled into the tanks, it is highly likely that the tanks have entered a high-pressure state due to the fuel gas refueling. In such a state, opening an opening / closing valve or valves of some of the multiple tanks increases the possibility that a closed opening / closing valve located between fuel gas discharged from inside a high-pressure tank and high-pressure fuel gas refueled into the closed tank may be damaged. Accordingly, such damage to the opening / closing valves can be suppressed by opening all opening / closing valves at a first startup.

[0006] (3) In the aforementioned aspect, the controller may control to open an opening / closing valve having the longest total length, and then open, among the non-opening opening / closing valves, an opening / closing valve whose total length difference from that of the opening / closing valve having the longest total length is within a predetermined range. With such an arrangement, an opening / closing valve whose total length difference from that of the opening / closing valve having the longest total length is within a predetermined range can be opened, that is, an opening / closing valve of a tank having a pressure loss comparable to that of a tank having the largest pressure loss.Therefore, the noise caused by vibrations due to fuel gas discharge is suppressed, such as in the tank with the greatest pressure loss. This makes it possible to eliminate the possibility of the noise caused by vibrations due to fuel gas discharge being perceived by a vehicle occupant.

[0007] (4) In the aforementioned aspect, the fuel cell system may further include an auxiliary machine configured to make the fuel cell generate power, wherein, in a case where the vehicle is in an operation-activated state and an internal pressure of a tank with the opening / closing valve not opened is equal to or higher than a predetermined value and electric power still to be generated by the fuel cell is equal to or higher than a predetermined first electric power, the controller may exercise control to open the opening / closing valve of the tank with the opening / closing valve not opened.With such an arrangement, the opening / closing valve can be opened to counteract the operating noise of the auxiliary machine, which operates while generating a relatively loud operating noise, to enable the fuel cell to generate electric power of the predetermined first electric power or more. Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of fuel gas compressed in the tanks is perceived by a vehicle occupant.

[0008] (5) In the aforementioned aspect, in the case where the vehicle is in an operation-activated state and an internal pressure of a tank with the opening / closing valve not opened is equal to or higher than a predetermined value, and a vehicle speed of the vehicle is still equal to or higher than a predetermined first vehicle speed, the controller may exercise control to open the opening / closing valve of the tank with the opening / closing valve not opened. With such an arrangement, the opening / closing valves can be opened to counteract road noise and wind noise caused by the vehicle speed being equal to or higher than the predetermined first vehicle speed.This makes it possible to eliminate the possibility that the noise caused by vibrations due to the discharge of fuel gas compressed in the tanks is perceived by an occupant of the vehicle.

[0009] The present disclosure can be implemented in various modes other than fuel cell systems. For example, the disclosure can be implemented in modes such as a fuel gas supply method for supplying to a fuel cell in a fuel cell system to be mounted on a vehicle, a controller for executing this supply method, a computer program for implementing the supply method, a recording medium with the computer program recorded thereon, a movable body with a fuel cell system mounted therein, and the like. SHORT DESCRIPTION OF DRAWINGS Fig. 1 is a block diagram showing an embodiment of a fuel cell system; Fig. 2 is a flowchart showing a selective valve opening operation to be performed by a controller; Fig. 3 is a flowchart showing a selective valve opening operation to be performed by the controller; Fig. 4 is a flowchart showing a selective valve opening operation to be performed by the controller; Fig. 5 is a flowchart showing a fueling decision process to be executed by the controller; Fig. 6 is a flowchart showing a start valve opening selection process to be executed by the controller; and Fig. 7 is a flowchart showing a valve opening selection process in operation to be executed by the controller. DETAILED DESCRIPTION A. First embodiment:

[0010] The Fig. 1 is a block diagram showing a configuration of a fuel cell system 10 in a first embodiment of the present invention. The fuel cell system 10 is mounted in a motor vehicle as a power source of the vehicle. The fuel cell system 10 includes a fuel cell stack 100, tanks 200a, 200b, 200c, supply flow paths 220a, 220b, 220c, a merging flow path 230, a fixing part 240, and a controller 300. Hereinafter, when generally referred to, the three tanks are denoted using the reference numeral '200', and the three supply flow paths are denoted using the reference numeral '220'.

[0011] The fuel cell stack 100 has a stacked structure in which a plurality of unit cells are stacked in layers. Each of the unit cells is structured so that a membrane electrode assembly of a proton-conducting electrolyte membrane, constructed by joining an anode and a cathode on both sides, is held between two spacers. Hydrogen gas and air are supplied to the fuel cell stack 100 to perform power generation through electrochemical reactions of hydrogen and oxygen.

[0012] The tank 200a stores hydrogen gas as a fuel gas to be used for power generation of the fuel cell stack 100. The tank 200a has an opening / closing valve 210a. The opening / closing valve 210a switches between starting and stopping the supply of hydrogen gas from the tank 200a. The tanks 200b and 200c, which are structurally similar to the tank 200a, have corresponding opening / closing valves 210b and 210c, respectively. Hereinafter, the three opening / closing valves, when generally referred to, will be denoted using the reference numeral '210'.

[0013] The supply flow path 220a connects to the opening / closing valve 210a to supply hydrogen gas supplied from the tank 200a to the merging flow path 230. A pressure sensor 225a is provided on the supply flow path 220a. The pressure sensor 225a measures the internal pressure of the supply flow path 220a. The internal pressure of the supply flow path 220a, to be measured by the pressure sensor 225a in an open state of the opening / closing valve 210a, can be regarded as the hydrogen gas pressure in the tank 200a. The supply flow path 220b and the supply flow path 220c connect to the opening / closing valve 210b and the opening / closing valve 210c, respectively, to feed hydrogen gas supplied from the tank 200b and the tank 200c into the merging flow path 230. A pressure sensor 225b and a pressure sensor 225c are provided on the supply flow path 220b and the opening / closing valve 210c, respectively.provided accordingly on the supply flow path 220c. Hereinafter, the three pressure sensors, when referred to generally, will be designated using the reference numeral '225'.

[0014] The converging flow path 230 is a flow path in which the supply flow path 220a, the supply flow path 220b, and the supply flow path 220c are converged. The converging flow path 230 serves to feed hydrogen gas supplied via the supply flow path 220a, the supply flow path 220b, and the supply flow path 220c into the fuel cell stack 100.

[0015] The fastening part 240 fastens the converging flow path 230 to the vehicle body of a vehicle in which the fuel cell system 10 is mounted. The fastening part 240 may, as an example, consist of a bracket and a bolt, and the bracket holding the converging flow path 230 may be fastened to the vehicle body with the bolt, so that the converging flow path 230 is fixed to the vehicle body.

[0016] The controller 300 receives signals output from various types of sensors (not shown) included in the fuel cell system 10 and controls the operations of individual parts of the fuel cell system 10. For example, the controller 300 receives signals from the pressure sensors 225 indicating measured values ​​measured by the pressure sensors 225. The controller 300 also controls, for example, the opening / closing of the opening / closing valve 210a, the opening / closing valve 210b, and the opening / closing valve 210c. The controller 300 may be implemented as an electronic control unit (ECU).

[0017] The Fig. 2, Fig. 3 and Fig. 4 are flowcharts showing a selective valve opening operation to be executed by the controller 300. The selective valve opening operation is started along with a start of the fuel cell system 10 and is repeatedly executed while the fuel cell system 10 is operating. The fuel cell system 10 is started when an ignition switch provided in the vehicle with the fuel cell system 10 mounted therein is turned on. Note that when the fuel cell system 10 is stopped, the opening / closing valve 210a, the opening / closing valve 210b, and the opening / closing valve 210c are closed.

[0018] As in the Fig. 2, the controller 300 reads sensor values ​​as well as signals measured by the various sensors provided in the fuel cell system 10 (step S110). The sensor values ​​and signals to be read in step S110 include a value indicating a current internal pressure of a tank 200, a value indicating electric power generated by the fuel cell stack 100, a value indicating a vehicle speed of the vehicle with the fuel cell system 10 mounted therein, a signal indicating a door lock state of the vehicle with the fuel cell system 10 mounted therein, a signal indicating whether or not a secondary battery provided in the vehicle with the fuel cell system 10 mounted therein is under charging, and the like.Here, the term "value" indicating a current internal pressure of a tank 200 refers to a value measured by the pressure sensor 225 in the tank 200 when the opening / closing valve 210 is open. In a tank 200 with the opening / closing valve 210 closed, the value differs depending on whether hydrogen gas refueling has been performed by communicative refueling with the opening / closing valve 210 closed. Here, the term "communicative refueling" refers to a refueling method in which hydrogen is refueled into a tank 200 while infrared communication is performed between the controller 300 and a hydrogen refueling station.For a tank 200 in which hydrogen gas refueling has been completed in a closed state of the opening / closing valve 210, the pressure value refers to a value indicative of an internal pressure of the tank 200 detected by the controller 300 during the communicative refueling process. For a tank 200 in which hydrogen gas refueling has not been completed in a closed state of the opening / closing valve 210, the pressure value refers to a value derived from a correction process in which a value measured by the pressure sensor 225 in the last open state of the opening / closing valve 210 is corrected based on conditions such as temperature, thermal expansion coefficient, compressibility factor of hydrogen, sensor accuracy of the pressure sensor 225, and the like.

[0019] After reading the sensor values ​​(after step S110), the controller 300 reads stored data values ​​stored in the controller 300 (step S120). The stored data values ​​to be read in step S120 include the startup history of the fuel cell system 10, the hydrogen gas refueling history, the internal pressure values ​​of the tanks 200, the valve opening count values ​​of the opening / closing valves 210, and the like.

[0020] After reading the stored data values ​​(after step S120), the controller 300 judges whether the fuel cell system 10 is at startup (step S130). In this embodiment, under the condition that the fuel cell stack 100 is not enabled to supply a predetermined electric power, the controller 300 judges that the fuel cell system 10 is at startup (YES in step S130). In this embodiment, under the condition that the fuel cell stack 100 is enabled to supply the predetermined electric power, the controller 300 judges that the fuel cell system 10 is not at startup. In addition, under the condition that the fuel cell system 10 is in a startup state (YES in step S130), the opening / closing valve 210a, the opening / closing valve 210b, and the opening / closing valve 210c are all in the closed state.

[0021] If it is determined that the fuel cell system 10 is starting (YES in step S130), the controller 300 performs a fueling decision process (step S140). In the fueling decision process, it is determined whether hydrogen gas refueling has been performed for the tanks 200 while the fuel cell system 10 is stopped. If it is determined that the fuel cell system 10 is starting (YES in step S130), the controller 300 updates a startup history of the fuel cell system 10 in this embodiment.

[0022] The Fig. 5 is a flowchart showing a fueling decision process to be executed by the controller 300. The controller 300 calculates a hydrogen fueling reference pressure PR indicating an internal pressure value of a tank 200 in a last-stopped state of the fuel cell system 10 (step S141). The term hydrogen fueling reference pressure PR refers to a value derived from a correction process in which a value measured by the pressure sensor 225 in the last-open state of the opening / closing valve 210 is corrected based on conditions such as temperature, thermal expansion coefficient, compressibility factor of hydrogen, sensor accuracy of the pressure sensor 225, and the like.

[0023] After executing the calculation of the hydrogen refueling reference pressure PR (after step S141), the controller 300 decides whether a current internal pressure of a tank 200 is higher than the hydrogen refueling reference pressure PR (step S142). The term "current internal pressure of a tank 200" here refers to a value indicating an internal pressure of a tank 200 read in step S110. In this embodiment, the pressure of a tank 200 to be compared with the hydrogen refueling reference pressure PR is a pressure of tank 200a among the tanks 200. Instead of the pressure of tank 200a or in addition to the pressure of tank 200a, at least one of the pressures of tank 200b and tank 200c may be adopted as the pressure of a tank 200 to be compared with the hydrogen refueling reference pressure PR for decision-making.

[0024] When it is judged that the current internal pressure of the tank 200 is not higher than the hydrogen refueling reference pressure PR (NO in step S142), the controller 300 judges whether there is a history of opening a tank cap (not shown) provided in the vehicle with the fuel cell system 10 mounted therein (step S143). Among the cases where it is judged that the current internal pressure of the tank 200 is not higher than the hydrogen refueling reference pressure PR, there is, for example, a case as follows. That is, provided that the current internal pressure of the tank 200 is a value of a tank 200 whose opening / closing valve 210 is closed and in which no refueling of hydrogen gas has been elapsed in a closed state of the opening / closing valve 210, the current internal pressure of the tank 200 and the hydrogen refueling reference pressure PR become equal to each other.

[0025] If it is judged that there is no history of opening the fuel cap (NO in step S143), the controller 300 judges whether or not there is a history of communicative refueling (step S144). If it is judged that there is no history of communicative refueling (NO in step S144), the controller 300 judges that no refueling of hydrogen gas into the tank 200 has been performed (step S145). Thereafter, the controller 300 terminates the refueling decision process.

[0026] If it is judged that the current internal pressure of the tank 200 is higher than the hydrogen refueling reference pressure PR (YES in step S142), or if it is judged that there is a history of opening the tank lid (YES in step S143), or if it is judged that there is a history of communicative refueling (YES in step S144), the controller 300 judges that there has been refueling of hydrogen gas into the tank 200 (step S146). In this case, the controller 300 updates the history of refueling with hydrogen gas. Thereafter, the controller 300 ends the refueling decision process.

[0027] Back to Fig. 2: After executing the refueling decision process (after step S140), the controller 300 executes a tank valve opening history decision to decide a valve opening count of an opening / closing valve 210 obtained since the last hydrogen gas refueling decision was made based on the history indicating the valve opening count of the opening / closing valve 210 read in step S120 (step S150).

[0028] After executing the tank valve opening history decision (after step S150), the controller 300 decides, based on the startup history of the fuel cell system 10 and the hydrogen gas refueling history, whether the startup of the fuel cell system 10 is a first startup since the last refueling of hydrogen gas into the tanks 200 or not (step S160).

[0029] If it is determined that the start-up of the fuel cell system 10 is the first time since the last refueling of hydrogen gas into the tanks 200 (YES in step S160), the controller 300 causes all the opening / closing valves in the fuel cell system 10 to open (step S170). In this embodiment, all the valves, the opening / closing valve 210a, the opening / closing valve 210b, and the opening / closing valve 210c, are opened. After that, the controller 300 ends the selective valve opening operation. Performing this operation makes it possible to suppress damage to the opening / closing valves. This will be explained in more detail below. If a start-up of the fuel cell system 10 is the first time since the last refueling of hydrogen gas into the tanks 200, it is highly likely that the tanks 200 have entered a high-pressure state due to the refueling of hydrogen gas.In such a state, opening an opening / closing valve 210 or opening / closing valves 210 of some of the tanks 200 increases a possibility that an opening / closing valve 210 located between hydrogen gas discharged from inside a high-pressure tank 200 and high-pressure hydrogen gas filled into the closed tank 200 may be damaged. Accordingly, such damage to the opening / closing valves 210 can be suppressed by opening all the opening / closing valves 210 at an initial startup.

[0030] If it is decided that the start of the fuel cell system 10 is not a first start since the last refueling of hydrogen gas into the tanks 200 (NO in step S160), the controller 300 executes a start valve opening selection process (step S180).

[0031] The Fig. 6 is a flowchart showing a start valve opening selection process to be executed by the controller 300. The controller 300 calculates a total length of the merging flow path 230 and the supply flow path 220 that exist within a range from the attachment part 240 to the opening / closing valve 210 (step S181). The term "total length" means a summed length of the merging flow path 230 and the supply flow path 220 that connects the attachment part 240 and an opening / closing valve 210. As shown in FIG. Fig. 1, in this embodiment, the total length to the opening / closing valve 210a is the longest, the total length to the opening / closing valve 210b is the second longest, and the total length to the opening / closing valve 210c is the third longest. In this embodiment, the values ​​of the total lengths for the three opening / closing valves 210 have been previously stored in the controller 300.

[0032] After calculating the total length (after step S181), the controller 300 opens the opening / closing valve having the longest total length (step S182).

[0033] After opening the opening / closing valve 210 having the longest total length (after step S182), the controller 300 decides whether there is an opening / closing valve 210 (hereinafter referred to as 'candidate opening / closing valve') whose total length difference from an opening / closing valve 210 having the longest total length among the non-opened opening / closing valves 210 is within 100 mm (step S183).

[0034] If an opening / closing candidate valve exists (YES in step S183), the controller 300 causes the opening / closing candidate valve to open. If it is judged in step S183 that multiple opening / closing candidate valves exist, an opening / closing candidate valve having the smaller valve opening count is opened (step S184). The decision on the valve opening count is made based on the valve opening counts of the opening / closing candidate valves since the last decision in step S150 that hydrogen gas refueling was performed. If there are opening / closing candidate valves with the same valve opening count, valve opening is performed in a predetermined order among the opening / closing candidate valves.For example, the valve opening occurs in a sequence starting with an opening / closing candidate valve that has the longer total length of the opening / closing candidate valves.

[0035] If no candidate opening / closing valves are present (NO in step S183), or after the candidate opening / closing valve has been opened (after step S184), the controller 300 judges whether the internal pressures of all tanks 200 having unopened opening / closing valves 210 are each less than a predetermined pressure value P4 (step S185). The term predetermined pressure value P4 herein refers to a value indicating an upper limit of the internal pressure of a tank 200 at which noise caused by vibrations due to the discharge of the fuel gas compressed in the tank 200 is not perceived by an occupant of the vehicle with the fuel cell system 10 mounted therein. The term internal pressure of a tank 200 to be used in step S185 refers here to a value indicating a current internal pressure of a tank 200 read in step S110.

[0036] When it is determined that the internal pressures of all tanks 200 each having non-opened opening / closing valves 210 are lower than the predetermined pressure value P4 (YES in step S185), the controller 300 opens all non-opened opening / closing valves 210 (step S186). Performing this operation makes it possible to reduce the pressure differences among the tanks 200. Thereafter, the controller 300 terminates the start valve opening selection process.

[0037] When it is decided that the internal pressure of at least one or more tanks 200 among the tanks 200 each having non-opened opening / closing valves 210 is not less than the predetermined pressure value P4 (NO in step S185), the controller 300 ends the start valve opening selection process.

[0038] Back to Fig. 2: After executing the start valve opening selection process (after step S180), the controller 300 ends the selective valve opening process.

[0039] The Fig. 3 is a flowchart showing a process to be executed by the controller 300 when it is decided that the fuel cell system 10 is not at startup (NO in step S130 in the Fig. 2). If it is judged that the fuel cell system 10 is not at startup (NO in step S130), the controller 300 judges whether the fuel cell system 10 is stopped or not (step S210). In this embodiment, when the ignition switch provided in the vehicle with the fuel cell system 10 mounted therein is turned off, the controller 300 judges that the fuel cell system 10 is stopped (YES in step S210).

[0040] If it is determined that the fuel cell system 10 is stopped (YES in step S210), the controller 300 deletes various types of histories (step S220). Among the histories to be deleted in step S220 are a fuel cap opening / closing history indicating whether or not the fuel cap has been opened, and a hydrogen communicative refueling history indicating whether or not there is a hydrogen communicative refueling history.

[0041] After deleting the various histories (after step S220), the controller 300 stores an internal pressure of a tank 200 determined when the fuel cell system 10 was stopped (step S230). In step S230, the controller 300 updates and stores the history of the internal pressure values ​​of the tank 200.

[0042] After storing the internal pressures of the tanks 200 (after step S230), the controller 300 stores histories indicating the valve opening counts of the opening / closing valves 210 (step S240). In step S240, the controller 300 updates and stores the histories indicating the valve opening counts of the opening / closing valves 210 by using the valve opening counts of the opening / closing valves 210 that have been opened since the fuel cell system 10 started up until its stop.

[0043] After storing histories indicating valve opening counts of the opening / closing valves 210 (after step S240), the controller 300 closes all opened opening / closing valves 210 (step S250). After closing all opened opening / closing valves 210, the controller 300 ends the selective valve opening process.

[0044] The Fig. Fig. 4 is a flowchart showing a process to be executed by the controller 300 when it is decided that the fuel cell system 10 is not stopped (NO in step S210 in the Fig. 3). If it is determined that the fuel cell system 10 is not stopped (NO in step S210), the controller 300 determines whether the vehicle with the fuel cell system 10 mounted therein is in an operation-activated state or not (step S310). In this embodiment, under the condition that the fuel cell stack 100 is activated to supply a predetermined electric power, the controller 300 determines that the vehicle with the fuel cell system 10 mounted therein is in an operation-activated state.

[0045] If it is determined that the vehicle with the fuel cell system 10 mounted therein is not in an operation-activated state (NO in step S310), the controller 300 terminates the selective valve opening process. In this case, the fuel cell system 10 is in a maintenance state.

[0046] When it is judged that the vehicle with the fuel cell system 10 mounted therein is in an operation enabled state (YES in step S310), the controller 300 performs an operation valve opening selection process (step S320).

[0047] The Fig. 7 is a flowchart showing an in-operation valve opening selection process to be executed by the controller 300. The controller 300 calculates a required electric power of the vehicle with the fuel cell system 10 mounted therein (step S321). The required electric power of the vehicle refers to, for example, supplying electric power to a drive motor (not shown), supplying electric power to auxiliary machinery, supplying electric power to an air-conditioning heater, and the like.

[0048] After the electric power required for the vehicle has been calculated (after step S321), the controller 300 calculates an electric power to be generated by the fuel cell stack 100 based on the required electric power of the vehicle (step S322).

[0049] After calculating the electric power to be generated by the fuel cell stack 100 (after step S322), the controller 300 decides whether or not the electric power generated by the fuel cell stack 100 is equal to or higher than a predetermined power value W1 (step S323). The term predetermined power value W1 here refers to a value indicating a lower limit of the power value that allows auxiliary machines to generate enough noise to counteract noise caused by vibrations due to fuel gas discharged from a tank 200 having a pressure value P4 or higher than an internal pressure of the tank 200. Such a power value W1 is preliminarily determined and established through experiments.The term "auxiliary machines" herein refers to those operated to allow the fuel cell stack 100 to generate electrical power, examples of which include an air compressor and the like. Increasing the electrical power generated by the fuel cell stack 100, involving an air compressor as one example, requires increasing the speed of the air compressor, thus increasing the operating noise of the air compressor.

[0050] When the electric power generated by the fuel cell stack 100 is equal to or higher than the predetermined power value W1 (YES in step S323), the controller 300 opens all the non-opening opening / closing valves 210 (step S330). After that, the controller 300 terminates the valve opening selection process in operation. Opening the opening / closing valves 210 simultaneously with the operating noise of the auxiliary machines in step S330 makes it possible to counteract the noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200. Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by a passenger of the vehicle.

[0051] If the electric power generated by the fuel cell stack 100 is other than equal to or higher than the predetermined power value W1 (NO in step S323), the controller 300 judges whether a vehicle speed of the vehicle with the fuel cell stack 100 mounted therein is equal to or higher than a predetermined vehicle speed value V1 (step S324). The term "predetermined vehicle speed value V1" here refers to a value indicating a lower limit of the vehicle speed value that enables the generation of noise, such as road noise and wind noise, that can counteract the noise caused by vibration due to hydrogen gas discharged from a tank 200 having a pressure value P4 or higher than an internal pressure of the tank 200.The term road noise here refers to a noise caused by friction between a road surface and the tire of the vehicle with the fuel cell system 10 mounted therein. Such a vehicle speed value V1 is preliminarily determined and established through experiments.

[0052] When the vehicle speed of the vehicle with the fuel cell stack 100 mounted therein is equal to or higher than the predetermined vehicle speed value V1 (YES in step S324), the aforementioned step S330 is executed. Thereafter, the controller 300 terminates the valve opening selection process in operation. Opening the opening / closing valves 210 simultaneously with the road noise or wind noise generated by the vehicle speed value V1 makes it possible to counteract the noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200. Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by a passenger of the vehicle.

[0053] When the vehicle speed of the vehicle with the fuel cell stack 100 mounted therein is other than equal to or higher than the predetermined vehicle speed value V1 (NO in step S324), the controller 300 judges whether the electric power generated by the fuel cell stack 100 is equal to or higher than a predetermined power value W2 and, at the same time, the vehicle speed of the vehicle with the fuel cell stack 100 mounted therein is equal to or higher than a predetermined vehicle speed value V2 (step S325).Here, the terms predetermined power value W2 and vehicle speed value V2 refer to values ​​indicating lower limits of the power value and the vehicle speed value in such a combination that a noise that can counteract the noise caused by vibration due to hydrogen gas discharged from a tank 200 having a pressure value P4 or higher than an internal pressure of the tank 200 can be generated by combining the operating noise of the auxiliary machinery with the road noise and the wind noise. Such a power value W2 and a vehicle speed value V2 are preliminarily determined and established through experiments.

[0054] When the electric power generated by the fuel cell stack 100 is equal to or higher than the predetermined power value W2 and, at the same time, the vehicle speed of the vehicle with the fuel cell stack 100 mounted therein is equal to or higher than the predetermined vehicle speed value V2 (YES in step S325), the above-described step S330 is executed. Thereafter, the controller 300 terminates the valve opening selection process in operation. Noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200 can be counteracted by opening the opening / closing valves 210 simultaneously with the operating noise of the auxiliary machines operating at the power value W2, as well as with road noise and wind noise generated by the vehicle speed value V2.Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by an occupant of the vehicle.

[0055] When the electric power generated by the fuel cell stack 100 is equal to or higher than the predetermined power value W2, and furthermore, the vehicle speed of the vehicle with the fuel cell stack 100 mounted therein is other than equal to or higher than the predetermined vehicle speed value V2 (NO in step S325), the controller 300 judges whether or not a vehicle speed sensing door lock capable of automatically locking the door in conjunction with the vehicle speed is turned on (step S326). The phrase "vehicle speed sensing door lock is turned on" means that the door is locked when the vehicle with the fuel cell system 10 mounted therein has exceeded a predetermined vehicle speed. In this embodiment, the predetermined vehicle speed is a speed per hour of 15 km / h.

[0056] If the vehicle speed detecting door lock is turned on (YES in step S326), the above-described step S330 is executed. Thereafter, the controller 300 terminates the valve opening selection process in operation. Opening the opening / closing valves 210 simultaneously with the noise caused by turning on the vehicle speed detecting door lock makes it possible to counteract the noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200. Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by a passenger of the vehicle.

[0057] If the vehicle speed detecting door lock is not turned on (NO in step S326), the controller 300 judges whether a door lock is turned on or not (step S327). Here, the phrase "a door lock is turned on" means that the door is locked by a door locking operation performed by an occupant of the vehicle with the fuel cell system 10 mounted therein.

[0058] If the door lock is turned on (YES in step S327), the above-described step S330 is executed. Thereafter, the controller 300 terminates the valve opening selection process in operation. As in the above-described case where the vehicle speed sensing door lock is turned on, opening the opening / closing valves 210 simultaneously with the noise caused by turning on the door lock by a vehicle occupant makes it possible to counteract the noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200. Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by a vehicle occupant.

[0059] If the door lock is not turned on (NO in step S327), the controller 300 decides whether or not an internal pressure difference between a tank 200 with an open opening / closing valve 210 and a tank 200 with a non-opening opening / closing valve 210 is equal to or higher than a predetermined pressure value P1 (step S328). The term "predetermined pressure value P1" here refers to a value indicating a lower limit of the pressure difference at which, when a tank 200 with a non-opening opening / closing valve 210 is opened, noise may be caused by a shock due to an internal pressure difference between the tank 200 and another tank 200 with an already open opening / closing valve 210.

[0060] If the pressure difference is equal to or higher than the predetermined pressure value P1 (YES in step S328), the above-described step S330 is executed. Thereafter, the controller 300 terminates the valve opening selection process in operation. If the pressure difference is higher than the pressure value P1, there is a possibility that noise may be caused by a shock due to the opening of a tank 200 with a non-opening opening / closing valve 210. Therefore, opening all non-opening opening / closing valves 210 makes it possible to reduce the pressure difference so that the noise caused by a shock does not increase and is audible to a passenger of the vehicle.

[0061] When the pressure difference is other than equal to or higher than the predetermined pressure value P1 (NO in step S328), the controller 300 decides whether the secondary battery in the vehicle with the fuel cell system 10 mounted therein is under charging or not (step S329).

[0062] When the secondary battery in the vehicle with the fuel cell system 10 mounted therein is under charging (YES in step S329), the above-described step S330 is executed. Thereafter, the controller 300 terminates the valve opening selection process during operation. Opening the opening / closing valves 210 simultaneously with the operating noise of the auxiliary machines operated to charge the secondary battery makes it possible to counteract the noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200. Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by a passenger of the vehicle.

[0063] When the secondary battery in the vehicle with the fuel cell system 10 mounted therein is not under charging (NO in step S329), the controller 300 terminates the valve opening operation in operation.

[0064] Back to Fig. 4: After the valve opening operation has been performed in operation (after step S320), the controller 300 ends the selective valve opening operation.

[0065] According to the first embodiment described above, when the fuel cell system 10 is started, the opening / closing valve 210 having the longest total length of the merging flow path 230 and the supply flow path 220, ranging from the attachment part 240 to the opening / closing valve 210, is opened, so that hydrogen gas is discharged from the tank 200 having the largest pressure loss in the area up to the attachment part 240 among the tanks 200. As a result, compared with a mode in which the opening / closing valve 210 having the longest total length is not opened and another opening / closing valve 210 is opened, the pressure of the hydrogen gas passing from the tank 200 to the attachment part 240 can be greatly reduced, so that noise caused by vibration due to the discharge of the hydrogen gas can be suppressed.Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by an occupant of the vehicle.

[0066] Also according to the first embodiment, when the fuel cell system 10 is started for the first time since the last refueling of hydrogen gas into the tanks 200, all of the opening / closing valves 210 are opened; otherwise, when the fuel cell system 10 is started for the second or subsequent time since the last refueling of hydrogen gas into the tanks 200, the opening / closing valve 210 with the longest total length is opened. Therefore, damage to the opening / closing valves 210 can be suppressed. This will be described in detail below. In the case of a first start of the fuel cell system 10 since the last refueling of hydrogen gas into the tanks 200, it is highly likely that the tanks 200 were in a high-pressure state due to the refueling of hydrogen gas.By opening only one opening / closing valve or opening / closing valves 210 of some of the tanks 200, a closed opening / closing valve 210 may be located between hydrogen gas discharged from inside a high-pressure tank 200 and high-pressure hydrogen gas filled into the tank 200 with the closed valve, and may be damaged. Therefore, all opening / closing valves 210 are opened at the initial startup, whereby such damage to the opening / closing valves 210 can be suppressed.

[0067] Also according to the first embodiment, to open the opening / closing valve 210 with the longest total length under the condition that an opening / closing valve 210 with a total length difference of 100 mm or less from that of the opening / closing valve 210 with the longest total length exists among the non-opening opening / closing valves 210, the controller 300 opens the opening / closing valve 210 with a total length difference of 100 mm or less. As a result, an opening / closing valve 210 whose total length difference from that of the opening / closing valve 210 having the longest total length is within a predetermined range can be opened, that is, an opening / closing valve 210 of a tank 200 having a pressure loss comparable to that of a tank 200 having the largest pressure loss.Therefore, the noise caused by vibrations due to the discharge of hydrogen gas is suppressed, such as in the tank 200 that has the largest pressure loss. Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas may be perceived by a passenger of the vehicle.

[0068] Also according to the first embodiment, in the case where the vehicle with the fuel cell system 10 mounted therein is in an operation-activated state, and where at least one or more tanks 200, among the tanks 200 each having non-opening opening / closing valves 210, have an internal pressure of pressure value P4 or higher, and yet the electric power generated by the fuel cell stack 100 is equal to or higher than power value W1, the controller 300 opens the opening / closing valve 210 of a tank 200 having a non-opening opening / closing valve 210. Therefore, the opening / closing valve 210 can be opened to counteract the operating noise of the auxiliary machines that operate while generating a relatively loud operating noise, to enable the fuel cell system 10 to generate electric power of power value W1 or more.Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200 is perceived by an occupant of the vehicle.

[0069] In the case where the vehicle with the fuel cell system 10 mounted therein is in an operation-activated state, and at least one or more tanks 200 of the tanks 200 each having non-opening opening / closing valves 210 have an internal pressure of the pressure value P4 or higher, and the vehicle speed of the vehicle is still equal to or higher than the vehicle speed value V1, the controller 300 also according to the first embodiment opens the opening / closing valves 210 of all the tanks 200 each having non-opening opening / closing valves 210. Therefore, the opening / closing valves 210 can be opened to counteract road noise and wind noise caused by the vehicle speed of the vehicle speed value V1 or higher.Thus, it becomes possible to eliminate the possibility that the noise caused by vibrations due to the discharge of hydrogen gas compressed in the tanks 200 is perceived by an occupant of the vehicle. B. Modifications:B1. Modification 1:

[0070] In the fuel cell system 10 of the first embodiment, whether the fuel cell system 10 is at startup is decided depending on whether the fuel cell stack 100 is enabled to supply a predetermined electric power. However, the present disclosure is not limited to this. For example, the fuel cell system 10 may also be arranged to decide whether the fuel cell system 10 is at startup depending on whether a predetermined time has elapsed after the ignition switch provided in the vehicle with the fuel cell system 10 mounted therein is turned on. B2. Modification 2:

[0071] In the fuel cell system 10 of the first embodiment, all the opening / closing valves 210 are opened when the fuel cell system 10 is started for the first time since the last refueling of hydrogen gas into the tanks 200. However, the present disclosure is not limited to this. For example, the fuel cell system 10 may be arranged such that not all the opening / closing valves 210 are opened, but only the opening / closing valve 210 with the longest total length is opened when the fuel cell system 10 is started for the first time since the last refueling of hydrogen gas into the tanks 200. B3. Modification 3:

[0072] In the fuel cell system 10 of the first embodiment, candidate opening / closing valves are opened to open the opening / closing valve 210 with the longest overall length. However, the present disclosure is not limited to this. For example, the fuel cell system 10 may also be arranged such that, even if an opening / closing candidate valve is present, the opening / closing candidate valves do not necessarily need to be opened to open the opening / closing valve 210 with the longest overall length.

Claims

[1] A vehicle having a fuel cell system (10) mounted therein, the fuel cell system (10) comprising: a fuel cell (100); a plurality of tanks (200) configured to store fuel gas to be used for power generation of the fuel cell (100), each tank having an opening / closing valve (210) for switching between executing and stopping the supply of the fuel gas; a plurality of supply flow paths (220) connected to the opening / closing valves (210) in the plurality of tanks (200) for supplying the fuel gas supplied from the plurality of tanks (200), respectively; a merging flow path (230) configured to merge the plurality of supply flow paths (220) to feed the fuel gas into the fuel cell (100) and fixed to a vehicle body of the vehicle at a fixing position with a fixing part (240); and a controller (300) configured to control the opening and closing of the opening / closing valves, wherein the controller (300) is designed to: to calculate a total flow path length as the total length of the merging flow path (230) and the supply flow path (220) which are within a range from the attachment part (240) to the opening / closing valve (210), and when the fuel cell system (10) is started, to open the opening / closing valve (210) for which the total flow path length from the fastening part (240) to the opening / closing valve (210) is the longest. [2] The vehicle of claim 1, wherein the controller (300) is configured to exercise such control comprising: upon start-up of the fuel cell system (10), to open all opening / closing valves (210) in the plurality of tanks (200), provided that the start-up is a first start-up since the last refueling with fuel gas into the plurality of tanks (200); and upon a start of the fuel cell system (10), provided that the start is a second start since the last refueling with fuel gas into the plurality of tanks (200), to open the opening / closing valve (210) of the plurality of opening / closing valves (210) for which the total flow path length is the longest. [3] The vehicle according to claim 1 or 2, wherein the controller (300) is configured to exercise such control to open an opening / closing valve (210) of the plurality of opening / closing valves (210) in which the total flow path length is the longest, and thereafter to open an opening / closing valve (210) of the non-opened opening / closing valves (210) in which the total flow path length difference from the opening / closing valve (210) in which the total flow path length is the longest is within a predetermined range. [4] Vehicle according to one of claims 1 to 3, wherein the fuel cell system (10) further comprises: an auxiliary machine configured to allow the fuel cell (100) to generate power, wherein the controller (300) is designed to exercise such a control, in the event that the vehicle is in an operation-activated state and that an internal pressure of a tank (200) with the opening / closing valve (210) not opened is equal to or higher than a predetermined value and that electrical power still to be generated by the fuel cell (100) is equal to or higher than a predetermined first electrical power, to open the opening / closing valve (210) of the tank (200) with the opening / closing valve (210) not opened. [5] The vehicle according to any one of claims 1 to 4, wherein, in the event that the vehicle is in an operation-activated state and that an internal pressure of a tank (200) with the opening / closing valve (210) not opened is equal to or higher than a predetermined value and that a vehicle speed of the vehicle is still equal to or higher than a predetermined first vehicle speed, the controller (300) is adapted to exercise such control to open the opening / closing valve (210) of the tank (200) with the opening / closing valve (210) not opened. [6] A fuel gas supply method for supplying fuel gas to a fuel cell (100) in a fuel cell system (10) to be mounted in a vehicle, the fuel cell system (10) comprising: the fuel cell (100); and a plurality of tanks (200) for storing therein the fuel gas to be used for power generation of the fuel cell (100), and each having opening / closing valves (210) for switching between executing and stopping the supply of fuel gas, the fuel gas supply method comprising: to feed the fuel gas supplied from the tanks (200) to the fuel cell (100) using a merging flow path (230) which serves to merge a plurality of supply flow paths (220) connected to the opening / closing valves (210) of the plurality of tanks (200) and which is fixed to a vehicle body of the vehicle with a fixing part (240) at a fixing position, a total flow path length is calculated as the total length of the merging flow path (230) and the supply flow path (220) which are within a range from the attachment part (240) to the opening / closing valve (210), wherein feeding the fuel gas comprises, upon start-up of the fuel cell system (10), opening that one of the opening / closing valves (210) in which the total flow path length from the fastening part (240) to the opening / closing valve (210) is the longest.

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