JP2006200564A - Liquid fuel supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid hydrogen consuming device for accurately seizing and warning the remaining amount of fuel in a system where liquid fuel and gas fuel exist. <P>SOLUTION: The liquid fuel consuming device to which the liquid fuel is supplied from the outside is constructed so that a gross remaining amount of fuel is computed in accordance with a total value for a remaining amount Q4 of the liquid fuel and a remaining amount Q6 of the gas fuel vaporizing from the liquid fuel. In the system using the gas fuel although the liquid fuel is supplied thereto, the remaining amount of fuel cannot be accurately seized for either the liquid fuel or the gas fuel. In this construction, the gross remaining amount of fuel Q6+Q7 are computed in accordance with the total value for the remaining amount of the liquid fuel and the remaining amount of the gas fuel, and so the gross amount of usable fuel is accurately seized and correct announcement is performed accordingly. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid fuel consuming apparatus using boil-off gas that is gaseous fuel.

  In liquid fuel storage devices that store liquid hydrogen, since the freezing point of liquid hydrogen is extremely low, boil-off in which the liquid fuel is vaporized no matter what adiabatic treatment is performed unless it is cooled to a very low temperature using a large cooling device Gas (gaseous fuel) is generated. In particular, when liquid hydrogen is stored in an automobile having a weight limit, it is practically impossible to provide sufficient cooling means. Therefore, it is necessary to configure the system on the assumption that boil-off gas is generated.

  Conventionally, the boil-off gas generated from liquid hydrogen is actively used as a gaseous fuel. As described in, for example, Japanese Patent Application Laid-Open No. 2003-56799, the boil-off gas generated from a liquid fuel tank is boosted by a booster. There has been a boil-off gas processing apparatus configured to increase the pressure and store the boosted boil-off gas in a high-pressure hydrogen tank connected to a fuel cell (Patent Document 1).

As another technology for issuing a warning when liquid fuel is insufficient, as described in Japanese Patent Laid-Open No. 2000-292195, refueling is performed based on the distance from the current location to the hydrogen station, which is the nearest liquid fuel filling facility. There was one that issued a warning when necessary (Patent Document 2). In addition, as described in Japanese Patent Application Laid-Open No. 2001-295996, there is a configuration in which a warning lamp is turned on when the supply of hydrogen from the last hydrogen storage tank is finished (Patent Document 3). Furthermore, as a technique for confirming the connection with the liquid fuel filling facility for filling the liquid fuel, as described in Japanese Patent Application Laid-Open No. 2003-104498, an abnormality is determined based on the connection state signal of the fuel connector. In some cases, the liquid fuel supply shut-off valve is controlled to be closed (Patent Document 4).
JP 2003-56799 A JP 2000-292195 A JP 2001-295996 A, JP 2002-106794 A

  However, in the liquid fuel storage device as described in Patent Document 1, since liquid fuel and boil-off gas coexist, there is a problem in correctly grasping the remaining amount of fuel and notifying the user.

  For example, in the apparatuses described in Patent Document 2 and Patent Document 3, since a warning is issued based on the remaining amount of gaseous hydrogen gas, liquid fuel as described in Patent Document 1 is supplied and boil-off gas is used. There was a possibility that the system could not give an accurate warning.

  Therefore, an object of the present invention is to provide a liquid hydrogen consuming apparatus capable of accurately grasping and warning the remaining amount of fuel in a system in which liquid fuel and gaseous fuel are present.

  The present invention for achieving the above object is a liquid fuel consumption apparatus in which liquid fuel is supplied from the outside, and is based on a total value of the remaining amount of liquid fuel and the remaining amount of gaseous fuel vaporized from the liquid fuel. The liquid fuel consuming apparatus is configured to calculate the total remaining fuel amount.

  In a system in which liquid fuel is supplied but gaseous fuel can be used, either the liquid fuel or the gaseous fuel cannot accurately grasp the remaining fuel amount. Since the total fuel remaining amount is calculated based on the total value with the remaining amount of fuel, the total amount of available fuel can be accurately grasped, and a notification based on it can also be performed correctly.

  Here, “liquid fuel” is liquid hydrogen or other boil-off gas that can be used as gaseous fuel, but includes cases where impurities (additives) are mixed with liquid hydrogen.

  Further, the “gaseous fuel” may include a gas fuel supplied from the beginning as well as a gas fuel vaporized. In such a case, the liquid fuel and the gaseous fuel may be different types of fuel.

  Here, as a specific system, it is conceivable to include a liquid fuel tank that stores liquid fuel and a gaseous fuel tank that stores gaseous fuel. In this case, the liquid fuel tank contains part of the gaseous fuel in addition to the liquid fuel. This is because when liquid fuel is stored in the liquid fuel tank, gaseous fuel vaporized from the liquid fuel may also exist. Of course, the number of liquid fuel tanks and the number of gaseous fuel tanks are not limited, and there are cases where there are a plurality of either or both. Also included is a system that includes only a liquid fuel tank and is configured to utilize boil-off gas that is inevitably generated from the liquid fuel in the liquid fuel tank.

  Here, based on the calculated total fuel remaining amount, a notification corresponding to the total fuel remaining amount may be made. This notification includes a notification when the total fuel remaining amount is sufficient and a notification when the total fuel remaining amount is low.

  In the latter case, it may be possible to notify when the total fuel remaining amount is equal to or less than a predetermined reference value. This is because less than the reference value indicates a shortage of fuel, that is, a so-called out-of-gas condition. Here, you may comprise so that this reference value may be changed based on the distance to the liquid fuel supply station which supplies liquid fuel. This is because the greater the distance that must be traveled before the liquid fuel can be refilled, the earlier it is necessary to warn of the need for refueling.

  In such a system, for example, a position measuring device that measures the position of the liquid fuel consuming device is provided, and the liquid fuel supply is performed based on the measured position information of the liquid fuel consuming device and the position information of the liquid fuel supply station. It is conceivable to calculate the distance to the place. This is because the distance between the two points can be determined from the position information of the two points according to the above configuration. This distance may be based on a straight line distance, or may be based on an estimated travel distance obtained from route information provided by a position positioning device or the like.

  The present invention is a liquid fuel consumption device in which liquid fuel is supplied from the outside, and is configured to be able to limit the filling amount of the liquid fuel based on the remaining amount of gaseous fuel vaporized from the liquid fuel. Based on the amount of liquid fuel alone, there is a possibility that the amount of vaporized fuel that is excessively supplied and vaporized will increase too much. Since the filling amount of the liquid fuel is reduced according to the remaining amount, an appropriate amount of fuel can be filled.

  Here, it is preferable to permit filling of the liquid fuel based on at least one of the moving speed of the liquid fuel consuming device or the communication state with the liquid fuel filling machine. When filling with liquid fuel, the mobile body on which the liquid fuel consuming apparatus is mounted must be stopped or communication must be established so that information can be exchanged with the filling machine. In this regard, according to this configuration, when such a condition is satisfied, filling with liquid fuel is permitted. Here, “permission permission” refers to a case where, for example, a shutoff valve provided in a pipe from a liquid fuel filling port is opened.

  Moreover, it is preferable to prohibit the filling of the liquid fuel based on at least one of the remaining amount of the liquid fuel or the communication state with the liquid fuel filling machine. When the liquid fuel is sufficiently stored or when it becomes impossible to exchange information with the filling machine, it is not preferable to continue filling the liquid fuel further. In this regard, according to this configuration, in such a state, filling with liquid fuel is prohibited. Here, “prohibition of filling” is, for example, a case where a shutoff valve provided in a pipe from a filling port for liquid fuel is closed.

  According to the present invention, since the total fuel remaining amount is calculated based on the total value of the remaining amount of liquid fuel and the remaining amount of gaseous fuel vaporized from the liquid fuel, the total amount of available fuel can be accurately grasped. And you can make a correct announcement based on it.

  A preferred embodiment of the present invention will be described with reference to the drawings. The following embodiments are exemplifications of the present invention, and the present invention is not limited to the following embodiments and can be variously modified and implemented.

  FIG. 1 shows a system block diagram of a fuel cell system corresponding to the liquid fuel consuming apparatus of the present invention. The fuel cell system is mounted on an automobile as a moving body, and is configured to be able to use boil-off gas (hydrogen gas) generated from liquid hydrogen as liquid fuel and liquid hydrogen as gaseous fuel. The fuel cell system is configured to be able to grasp the remaining amount based on the total value of the remaining amount of liquid hydrogen and the remaining amount of boil-off gas.

  As shown in FIG. 1, the fuel cell system includes a hydrogen gas supply system 1 that supplies boil-off gas that is gaseous fuel, an air supply system 2 that supplies air that is oxidizing gas, and a fuel cell stack. A cooling system 3 for cooling 100, a power system 4 for charging / discharging the electric power generated by the fuel cell stack 100, a power supply control unit 5 for controlling the entire system, and a navigation for assisting the driver in driving by measuring the position of the vehicle A device 6 is provided.

  The hydrogen gas supply system 1 is mainly configured of a liquid fuel tank 10 that stores liquid hydrogen and gaseous fuel tanks 11 to 13 that store boil-off gas generated from the liquid hydrogen. The liquid fuel tank 10 has a vacuum double structure, can store liquid hydrogen having a very low boiling point (approximately 20K), and has a pressure resistant structure capable of storing boil-off gas to a certain high pressure. . Each of the liquid fuel tank 10 and the gaseous fuel tanks 11 to 13 is provided with a relief valve for lowering the internal pressure when the internal pressure becomes considerably high. Further, the liquid fuel tank 10 is provided with a level gauge LG for checking the amount of liquid fuel remaining in the liquid phase so as to be readable from the power supply control unit 5, and measures the liquid level position of the liquid fuel. Thus, it is possible to cause the power supply control unit 5 to grasp the amount of liquid fuel present as a liquid. The gaseous fuel tanks 11 to 13 all have a similar structure, and are configured to be able to store the boil-off gas from the liquid fuel tank 10 up to a certain high pressure.

  The piping / valve structure communicating between these tanks will be described. A liquid fuel pipe 16 is laid from the liquid fuel filling port FI to the liquid fuel tank 10, and a filling pipe 17 communicates from the liquid fuel tank 10 to the inlet side of the gaseous fuel tanks 11 to 13. Further, on the outlet side of the gaseous fuel tanks 11 to 13, supply pipes 18 for supplying boil-off gas from each tank in common communicate with each other and are connected to the main pipe 19.

  The liquid fuel pipe 16 is a liquid fuel supply passage from the liquid fuel filling port FI to the liquid fuel tank 10 and is used when filling the liquid fuel. The liquid fuel pipe 16 is provided with check valves RV1, RV2, a manual valve H1, and a shut-off valve L1 in order from the liquid fuel filling port FI side. The liquid fuel filling port FI has a structure capable of connecting the supply nozzle of the liquid hydrogen filling machine with a liquid fuel stand or the like, so that the liquid hydrogen filling machine and the power supply control unit 5 of the fuel cell system can communicate with each other. A connector (not shown) is also provided. The check valves RV1 and RV2 have a double structure connected in series, and even if a valve failure such as a seal failure occurs in any of the valves, it is possible to prevent liquid hydrogen from flowing back. It has become. The pressure sensors p1 and p2 are provided for measuring the pressure in each section of the liquid fuel pipe 16 defined by the check valves RV1 and RV2. The manual valve H1 is a service valve that is manually opened and closed at the time of adjustment during manufacture and at the time of service, and is opened at a predetermined opening during normal use. The shut-off valve L1 is an electromagnetic valve that can be controlled to open and close by the power supply control unit 5, and is controlled to open when liquid fuel is supplied. The inlet side of the liquid fuel tank 10 is provided with a pressure sensor p3 for measuring the tank internal pressure, that is, the pressure of the boil-off gas generated by vaporization of liquid hydrogen, and the temperature sensor t1 for measuring the internal temperature of the boil-off gas. It has been.

  The filling pipe 17 communicates the liquid fuel tank 10 with the gaseous fuel tanks 11 to 13, and a manual valve H <b> 2 is provided in the vicinity of the outlet of the liquid fuel tank 10. In addition, check valves W1 to W3 and manual valves H3 to H5 corresponding to the gaseous fuel tanks are provided on the gaseous fuel tank inlet side after branching to the gaseous fuel tanks 11 to 13, respectively. In the present embodiment, the check valves W1 to W3 are configured to open and close based on the control of the power supply control unit 5, but are set to have a predetermined valve opening pressure mechanically, and the valve opening pressure is set to the valve opening pressure. More preferably, the valve is configured to automatically open when it reaches. This is because if the valve is configured to automatically open at a predetermined valve opening pressure, a control process is unnecessary and the structure can be simplified as long as the check valve is not broken. The manual valves H3 to H5 are service valves that are manually opened and closed at the time of adjustment during manufacture and during service, and are kept open at a predetermined opening during normal use. Pressure sensors p4 to p6 for measuring the boil-off gas pressure in the tank and temperature sensors t2 to t4 for measuring the internal temperature of each tank are provided at the inlets of the gaseous fuel tanks 11 to 13, respectively.

  The supply pipe 18 is for connecting the gaseous fuel tanks 11 to 13 to the main pipe 19. Regulating valves R1 to R3, manual valves H6 to H8, and shut-off valves G1 to G3 are provided in correspondence with branch pipe portions corresponding to the gaseous fuel tanks 11 to 13 in the supply pipe 18, respectively. The regulating valves R1 to R3 regulate the supply pressure from the gaseous fuel tanks 11 to 13 to the supply pipe 18, and are adjusted so as to output the boil-off gas at a predetermined differential pressure. The manual valves H6 to H8 are service valves that are manually opened and closed at the time of adjustment during manufacture and during service, and are kept open at a predetermined opening during normal use.

  The liquid fuel pipe 16 and the supply pipe 18 can be bypassed via the shutoff valve L2. This is because the boil-off gas remaining in the liquid fuel pipe 16 is quickly supplied to the supply pipe 18 via the shutoff valve L2 and consumed by the fuel cell stack 100.

  The configuration after the main pipe 19 will be described. From the upstream side of the main pipe 19, the gas-liquid separator 14, the shut-off valve SV 4, the hydrogen pump 15, and the purge shut-off valve L 5 pass through the pressure regulating valves R 4 and R 5, the shut-off valve L 3, and the flow path in the fuel cell stack 100. It is provided and constitutes a circulation path for hydrogen gas.

  The pressure regulating valves R4 and R5 are configured to regulate and output the boil-off gas from the supply pipe 18. The pressure regulating valves R4 and R5 are duplicated in order to cope with a seal failure. Each of the pressure regulating valves R4 and R5 is provided with a relief valve for reducing the pressure when the pressure in the pipe becomes a predetermined pressure or higher. The shut-off valve L3 is configured to open and close in accordance with the start / stop of power generation, and to control whether boil-off gas is supplied on the main pipe 19. The pressure sensor p10 is provided so as to be able to measure the pressure in the supply pipe 18 upstream of the main pipe 19, and the pressure sensor p11 is provided so as to be able to measure the internal pressure of the fuel cell stack 100.

The fuel cell stack 100 has a stack structure in which a plurality of power generation structures called single cells are stacked. Each unit cell is a power generating body called a MEA (M embrane E lectrode A ssembly ), a fuel gas (hydrogen gas, the boil-off gas), oxidizing gas (air), sandwiched by a pair of separators disposed flow path of the cooling liquid It has a structure. The MEA is configured by sandwiching a polymer electrolyte membrane between two electrodes, an anode and a cathode. The anode has an anode catalyst layer provided in the form of a porous support layer, and the cathode has a cathode catalyst layer provided on the porous support layer.

  The boil-off gas supplied to the anode of the fuel cell stack 100 is supplied to each single cell via the manifold, flows through the fuel gas flow path of the separator, and causes an electrochemical reaction at the anode of the MEA. The boil-off gas (hydrogen off-gas) discharged from the fuel cell stack 100 is supplied to the gas-liquid separator 14. The gas-liquid separator 14 is configured to remove moisture and other impurities generated by the electrochemical reaction of the fuel cell stack 100 during normal operation from the hydrogen off-gas and discharge them to the outside through the shutoff valve L4. The hydrogen pump 15 constitutes a circulation path by forcibly circulating the hydrogen off-gas and returning it to the main pipe 19. The purge shut-off valve L5 is opened at the time of purging, but is shut off at the time of normal operation state and pipe gas leak determination. The hydrogen off-gas purged from the purge shut-off valve SV5 is processed by an exhaust system including the diluter 25.

  The air supply system 2 includes an air cleaner 21, a compressor 22, a humidifier 23, a gas-liquid separator 24, a diluter 25, and a silencer 26. The air cleaner 21 purifies the outside air and takes it into the fuel electric system. The compressor 22 compresses the taken-in air according to the control of the power supply control unit 5 and changes the amount of air supplied and the air pressure. The air supplied to the cathode of the fuel cell stack 100 is supplied to each single cell via the manifold in the same manner as the boil-off gas, flows through the air flow path of the separator, and causes an electrochemical reaction at the MEA cathode. The air (air off-gas) humidifier 23 discharged from the fuel cell stack 100 exchanges air off-gas and moisture with respect to the compressed air to add an appropriate humidity. The air supplied to the fuel cell stack 100 is supplied to each single cell via the manifold, flows through the air flow path of the separator, and causes an electrochemical reaction at the cathode of the MEA. Excess moisture is removed from the air off-gas discharged from the fuel cell stack 100 in the gas-liquid separator 24. The diluter 25 is configured to mix and dilute the hydrogen off-gas supplied from the purge shutoff valve L5 with air off-gas so as to uniformize it to a concentration at which no oxidation reaction can occur. The silencer 26 is configured to be able to discharge the mixed exhaust gas by reducing the noise level.

  The cooling system 3 includes a radiator 31, a fan 32, a cooling pump 33, a cooling device 34, and rotary valves C1 to C4. The radiator 31 includes a large number of pipes, and the divided coolant is forcibly air-cooled by the air blown by the fan 32. The cooling pump 33 circulates and supplies the coolant into the fuel cell stack 100. The coolant that has entered the fuel cell stack 100 is supplied to each single cell via the manifold, flows through the coolant flow path of the separator, and takes heat generated by power generation. The cooling device 34 includes a condenser and the like, has a cooling performance that exceeds air cooling, and can reduce the temperature of the coolant.

  The cooling system 3 can select any one of the cooling paths 35 to 37 by switching the rotary valve C1 or C2. The cooling path 35 is a path for supplying the coolant to the cooling pump 33 without air cooling by the radiator 31, and the cooling path 36 is a path for forced air cooling by the radiator 31. The cooling path 37 is a circulation path for cooling the gaseous fuel tanks 11 to 13 of the present invention. The rotary valve C1 switches the cooling path 37 for the gaseous fuel tanks 11 to 13 or the cooling paths 35 and 36, and the rotary valve C2 allows the coolant circulated from the gaseous fuel tanks 11 to 13 to It is switched between the cooling path 35 without air cooling or the cooling path 36 for air cooling. The cooling path 37 is provided with rotary valves C3 and C4. The rotary valve C3 is configured to select whether or not to supply the coolant to the gaseous fuel tank 11, and the rotary valve C4 is configured to select whether or not to supply the coolant to the gaseous fuel tank 12. The cooling path 37 is piped so that the vicinity of the boil-off gas input / output ports (near the check valves W1 to 3 and the pressure regulating valves R1 to R3) can be cooled in each of the gaseous fuel tanks 11 to 13, and controls the temperature of the boil-off gas. Thus, the pressure can be reduced.

  In particular, the rotary valves C1 and C2 are controlled so that the coolant circulates in the cooling path 35 at the time of activation. This is to prevent the coolant from flowing into the radiator 31 and the gaseous fuel tanks 11 to 13 at the time of startup, thereby suppressing the breakage due to the thermal shock generated when the coolant having a large temperature difference is supplied.

  The power system 4 includes a DC-DC converter 40, a battery 41, a traction inverter 42, a traction motor 43, an auxiliary inverter 44, a high-voltage auxiliary device 45, and the like. The fuel cell stack 100 is configured by connecting single cells in series, and a predetermined high voltage (for example, about 500 V) is generated between the anode A and the cathode C thereof. The DC-DC converter 40 performs bidirectional voltage conversion with a battery 41 having a terminal voltage different from the output voltage of the fuel cell stack 100, and uses the power of the battery 41 as an auxiliary power source of the fuel cell stack 100. Alternatively, it is possible to charge the battery 41 with surplus power from the fuel cell stack 100. The DC-DC converter 40 can set an inter-terminal voltage corresponding to the control of the power supply control unit 5. The battery 41 is configured such that battery cells are stacked and a constant high voltage is used as a terminal voltage, and surplus power can be charged or power can be supplementarily supplied under the control of a battery computer (not shown). The traction inverter 42 converts direct current into three-phase alternating current and supplies it to the traction motor 43. The traction motor 43 is, for example, a three-phase motor and is a main power source of an automobile on which the fuel cell system is mounted. The auxiliary machine inverter 44 is a DC-AC converting means for driving the high-voltage auxiliary machine 45. The high-pressure auxiliary machine 45 is various motors necessary for the operation of the fuel cell system such as the compressor 22, the hydrogen pump 15, the fan 32, and the cooling pump 33.

  The power supply control unit 5 includes a RAM, a ROM, an interface circuit, and the like as a general-purpose computer. The power supply control unit 5 controls the entire fuel cell system mainly including the hydrogen gas supply system 1, the air supply system 2, the cooling system 3, and the power system 4 by sequentially executing software programs stored in a built-in ROM or the like. In addition, the fuel cell system can be operated as the liquid fuel supply system of the present invention. The power supply control unit 5 is configured to be communicable with the navigation device 6, acquires a current position information of the vehicle by transmitting a command to the navigation device 6, or obtains the nearest liquid hydrogen supply station (stand ) Location information can be acquired.

  In the above configuration, when the liquid fuel tank 10 is filled with liquid hydrogen, the liquid hydrogen is vaporized by external heat to generate boil-off gas, which fills the liquid phase of liquid hydrogen. At this time, since the liquid fuel tank 10 communicates with the gaseous fuel tanks 11 to 13 through the filling pipe 17, the valve opening pressures in which the boil-off gas pressure in the liquid fuel tank 10 is set to each of the check valves W1 to W3. , The check valve is opened in order under the control of the power supply control unit 5, and the gas fuel tank 11, the gas fuel tank 12, and the gas fuel tank 13 are filled in this order. The remaining amount of fuel in this system can be grasped from the remaining amount of liquid hydrogen in the liquid fuel tank 10 and the remaining amount of boil-off gas in the gaseous fuel tanks 11 to 13. This remaining amount grasping process will be specifically described later with reference to the flowchart of FIG.

  FIG. 2 shows a block diagram of the navigation device. As shown in FIG. 2, the navigation device 6 includes a position information control unit 60, an angular velocity sensor 61, an acceleration sensor 62, a wheel speed sensor 63, a DPS reception unit 64, a display control unit 65, a display 66, a disk drive 67, and an input / output. The apparatus 68 is provided.

  The position information control unit 60 is a central control unit of the navigation device, and includes an input / output device, a CPU (central processing unit), a ROM, a RAM, and the like. The angular velocity sensor 61 can detect the angular velocity of the automobile. The acceleration sensor 62 can detect the acceleration of the automobile. The wheel speed sensor 63 obtains the wheel rotation speed of the automobile, and can calculate the travel distance by the integration process of the position information control unit 60. The GPS receiving unit 64 can receive and decode radio waves from GPS satellites conforming to a specific GPS standard, and can decode radio waves from a plurality of GPS satellites. The display control unit 65 controls image display on the display 66, and can display an image based on the image information from the position information control unit 60 on the display 66. The disk drive 67 detachably stores a DVD-ROM or CD-ROM storing map information and can read the information. The input / output device 68 can communicate commands and information with the power supply display unit 5 in accordance with a predetermined standard. The DVD-ROM or CD-ROM supplied to the disk drive 67 includes position information of a liquid fuel supply station (stand) where a filling machine capable of filling liquid hydrogen is provided as part of the map information. It shall be.

  With the above configuration, the position information control unit 60 detects the current position information grasped from the GPS satellite from the GPS receiver 64, the angular velocity grasped from the angular velocity sensor 61, the acceleration grasped from the acceleration sensor 62, and the wheel speed sensor 63. The current position is measured by correcting based on the calculated travel distance. Then, map information, route information merge data or difference update data corresponding to the current position is read from the disk drive 67 and stored in a memory such as a RAM. Then, a marker image indicating the current position information is synthesized with the map image obtained from the map information on the memory, and stored in the image memory so that it can be read out by the display control unit 65.

  When the position information control unit 60 receives a predetermined command for obtaining the current position from the power supply control unit 5, the position information control unit 60 transmits the current position information and can transmit the position information of the nearest liquid fuel supply station. Yes.

  The liquid fuel consumption method in the present embodiment will be described with reference to the flowcharts of FIGS. These flowcharts are periodically performed regardless of whether the vehicle is traveling or liquid fuel is being charged. The main modules in steps S1 to S13 relate to permission / prohibition processing for liquid fuel filling according to the present invention. Further, the sub-modules in steps S20 to S29 relate to the total fuel remaining amount calculation and warning processing based thereon based on the present invention. The submodule of steps S30 to 39 relates to a capacity changing process in which the capacity (quantity) of the gaseous fuel tank is changed according to the amount of boil-off gas that is gaseous fuel. As a precondition for these processes, the shutoff valve L1 of the liquid fuel pipe 16 is closed.

  In the main module, steps S1 to S11 are processes during filling with liquid fuel, and steps S12 and S13 are processes that are periodically performed during operation. First, it is checked whether or not the fuel cover covering the liquid fuel filling port FI for supplying liquid fuel has been opened (S1). This is because it is premised on that it is instructed to first open the fuel lid for supplying liquid fuel. If the fuel cover has been opened (S1: YES), it is next determined whether or not it was performed while the vehicle was stopped (S2). If the vehicle is not stopped (S2: NO), nothing is done because it can be determined that the vehicle has been erroneously operated while traveling. On the other hand, when the vehicle is stopped (S2: YES), it can be determined that the liquid fuel supply process is actually requested, and the process proceeds to a process for connecting to the liquid fuel filling machine at the liquid fuel stand.

  Next, it is inspected whether the fuel cell system is in operation, that is, whether the fuel cell stack 100 is generating power (S3). When the fuel cell system is in operation (S3: YES), the operation of the fuel cell system is stopped. For example, the high pressure auxiliary machine 45 is stopped and each shut-off valve is closed so that air and hydrogen gas are not supplied to the fuel cell stack 100.

  Next, it is inspected whether communication with a filling machine for filling liquid hydrogen has been established (S5). If communication cannot be established (S5: NO), the process is left as it is.

  In the above series of processes, the shut-off valve L1 is used when the fuel cover is open (S1: NO), when the vehicle is not stopped (S2: NO), and when communication with the filling machine cannot be established (S5: NO). Is not opened, the supply of liquid fuel is prohibited, and only the remaining fuel amount calculation process (S12) and the capacity change process (S13) described later with reference to FIGS. 4 and 5 are performed.

  Now, when the communication with the filling machine is correctly connected and communication is synchronized according to a predetermined protocol and data can be correctly transmitted and received (S5: YES), the shutoff valve L1 is set to permit the supply of liquid fuel. It is opened (S6). When liquid hydrogen from the liquid fuel filling port FI can be filled into the liquid fuel tank 10 via the liquid fuel pipe 16, a liquid hydrogen request signal is transmitted to the filling machine (S7).

  Upon receiving the liquid hydrogen request signal, the filling machine starts injecting liquid hydrogen from the liquid fuel filling port FI. However, the remaining fuel amount calculation process is performed not only during the filling of the liquid fuel but also during the driving of the automobile, that is, during the consumption of the fuel. During the liquid fuel filling, the remaining fuel amount calculation process (S8) and the capacity change process (S9) are continued. These will be described later with reference to FIGS.

  If liquid hydrogen is filled in the liquid fuel tank 10 in order and a full filling signal indicating that the liquid fuel tank 10 is in a fully filled state is output (S10: YES), supply of liquid hydrogen to the filling machine A liquid hydrogen stop request signal for requesting to stop is output, all the valves related to filling, that is, the shut-off valves L1 and the check valves W1 to W3 are closed, and the process ends (S11).

  When the above processing is completed, the filling machine is disconnected, the fuel cover is closed, and the fuel cell system can be operated again. The power supply control unit 5 may open the shutoff valves G1 to G3 as necessary to supply the boil-off gas to the fuel cell stack 100 via the supply pipe 18 and the main pipe 19.

  Thereafter, liquid hydrogen or boil-off gas filled as required is used. That is, when the use conditions are met, the shutoff valves G1 to G3 are opened according to the pressure, and the boil-off gas is sequentially released from the gaseous fuel tank 13 to 12, and further used.

  FIG. 4 shows a flowchart of the remaining fuel amount calculation process according to the present invention. This processing is performed in the main module of FIG. 3 both when filling liquid fuel (S8) and during normal operation (S12).

  In FIG. 4, first, the remaining amount of boil-off gas in each tank is calculated. For each of the gaseous fuel tanks 11 to 13, the internal pressure is obtained based on the measured values of the pressure sensors p4 to p6, the tank internal temperature is obtained based on the measured values of the temperature sensors t2 to t4, and the obtained tank internal pressure and Based on the temperature in the tank, the amounts Q1 to Q3 of the boil-off gas filled in or remaining in each of the gaseous fuel tanks 11 to 13 are calculated (S20).

  As for the liquid fuel tank 10, the level gauge LG provided in the liquid fuel tank 10 is referred to, the liquid level position of the liquid hydrogen in the liquid fuel tank 10 is measured, and the remaining amount of liquid hydrogen in the liquid phase is based on the measured level. Q4 is calculated. The remaining space of the remaining amount Q4 of liquid hydrogen can be grasped as the volume of the boil-off gas that is a gas phase. Therefore, the internal pressure and temperature of the gas phase boil-off gas are calculated based on the pressure sensor p3 and the temperature sensor t1 provided in the liquid fuel tank 10, and the remaining amount Q5 of the boil-off gas inside the liquid fuel tank 10 is calculated. (S21).

  Then, the boil-off gas remaining amount Q1 to Q3 in the gaseous fuel tanks 11 to 13 obtained in step S20 and the boil-off gas remaining amount Q5 in the gas phase portion of the liquid fuel tank 10 obtained in step S21 are totaled to obtain the gaseous fuel. Is calculated (S22). Next, the total amount Q7 of boil-off gas obtained when the liquid hydrogen is vaporized is converted from the remaining amount Q4 of liquid hydrogen in the liquid fuel tank 10 obtained in step S21 (S23). This conversion is calculated as the remaining amount when the conditions of temperature and pressure are matched in order to handle the amount equivalent to the remaining amount of boil-off gas in steps S20 and S21. The total value of the vapor phase boil-off gas total remaining amount Q6 and the conversion amount Q7 of liquid-phase liquid hydrogen converted into boil-off gas is the total remaining fuel amount that can be used. In this case, the amount of liquid fuel was converted to the volume of boil-off gas, which is gaseous fuel. Conversely, the volume of boil-off gas was converted to the amount of liquid liquid fuel, and the total remaining fuel amount was determined. May be.

  Next, the necessity of warning is determined based on the calculated total fuel remaining amount. First, a travelable distance D1 is calculated which indicates how much the vehicle can travel with the total amount of fuel Q6 + Q7 (S24). This can be calculated on the basis of information such as fuel economy that is averaged for the vehicle.

  Next, a command for inquiring about the current position is transmitted to the navigation device 6, and the current position Pc is obtained from the returned current position information (S25). Similarly, an inquiry command is transmitted to the navigation device 6 for the position Ps of the liquid fuel supply station nearest to the acquired current position Pc, and the position Ps of the liquid fuel supply station is obtained (S26). Then, based on the current position Pc and the position Ps of the liquid fuel supply station, a distance D2 between them is calculated (S27). In this calculation, the straight line distance between the current position Pc and the position Ps of the liquid fuel supply station may be simply obtained, or it may be obtained by inquiring the route length connecting the road connecting the two positions to the navigation device 6. May be.

  When the distance between the two points is obtained, the distance D1 that can be traveled with the current remaining fuel amount calculated in step S24 is compared with the distance D2 to the nearest liquid fuel supply station (S28). If the two distances are simply compared at this time, there is a possibility that the fuel will run out if the vehicle has passed through the latest liquid fuel supply station or if it has lost its way, resulting in a so-called out-of-gas condition. For this reason, a constant margin β is provided, and the comparison is performed so that the remaining fuel warning can be given with a margin.

  If the travelable distance D1 is greater than the sum of the distance D2 to the nearest liquid fuel supply station and the margin β (S28: NO), the process is terminated assuming that there is still sufficient fuel remaining. On the other hand, when the travelable distance D1 becomes equal to or less than the sum of the distance D2 to the nearest liquid fuel supply station and the margin β (S28: YES), it is necessary to inform the driver that it is time to go to the liquid fuel supply station. is there. Therefore, an appropriate fuel shortage warning is issued (S29). As this fuel shortage warning, for example, a fuel out lamp may be turned on.

  FIG. 5 shows a flowchart of the volume changing process. This volume changing process is a process of changing the number of gas fuel tanks to be used (filling volume) in accordance with the remaining amount of boil-off gas. In the main module of FIG. 3, at the time of liquid fuel filling (S9). Are also carried out during normal operation (S13).

  First, when the remaining boil-off gas amount Q5 of the liquid fuel tank 10 obtained in the remaining fuel amount calculation process (FIG. 4) is equal to or greater than a predetermined value Qa (S30: YES), all the check valves W1 to W3 are opened. (S31). The predetermined value Qa is the amount of boil-off gas in a state where the inside of the liquid fuel tank 10 is at a considerably high pressure, and the boil-off gas is dispersed and filled not only in the liquid fuel tank 10 but also in the gas fuel tank 11. This is the threshold value for the amount of boil-off gas to be passed.

  When it is not necessary to open all the check valves W1 to W3, that is, when the boil-off gas amount Q5 of the liquid fuel tank 10 is smaller than the predetermined value Qa (S30: NO), the process proceeds to the main body of the capacity changing process. First, it is determined whether the remaining boil-off gas amount Q1 for the gaseous fuel tank 11 is equal to or less than a predetermined value Qb. When the boil-off gas remaining amount Q1 is equal to or less than the predetermined value Qb (S32: YES), the check valve W1 is opened (S33). Based on this process, the boil-off gas is preferentially filled into the gaseous fuel tank 11 via the filling pipe 17 at the time of filling, and the boil-off gas is used from the gaseous fuel tank 11 at the time of consumption. The predetermined value Qb is a threshold value of the boil-off gas amount when the gaseous fuel tank 12 should be filled with the boil-off gas.

  When the remaining amount B1 of the boil-off gas in the gaseous fuel tank 11 is larger than the predetermined amount Qb and smaller than the predetermined value Qc (S34: YES), the check valve W1 of the gaseous fuel tank 11 is closed and the check valve is closed. W2 is released (S35). This process enables preferential filling of the gaseous fuel tank 12 with the boil-off gas and preferential use of the boil-off gas from the gaseous fuel tank 12. The predetermined value Qc is a threshold value of the boil-off gas amount when the gaseous fuel tank 13 should be filled with the boil-off gas.

  Further, when the remaining amount B2 of the boil-off gas in the gaseous fuel tank 12 is larger than the predetermined amount Qc and smaller than the predetermined amount Qd (S36: YES), the check valve W2 of the gaseous fuel tank 12 is closed, and the check valve W3 is released (S37). By this processing, it becomes possible to preferentially fill the gas fuel tank 13 with the boil-off gas and to preferentially use the boil-off gas from the gas fuel tank 13. Here, the predetermined value Qd is a threshold value of the boil-off gas amount indicating that all the gaseous fuel tanks 11 to 13 including the gaseous fuel tank 13 have been fully filled.

  When the remaining boil-off gas amount Q3 in the gaseous fuel tank 13 exceeds the predetermined amount Qd (S38: YES), the check valve W3 is closed. In this state, all the gaseous fuel tanks 11 to 13 are filled.

  As described above, according to the present embodiment, when the liquid fuel is filled, the total fuel remaining amount is calculated based on the total value of the remaining amount Q4 (Q7) of the liquid fuel and the remaining amount Q6 of the gaseous fuel. The total amount can be accurately grasped, and the announcement based on it can be performed correctly.

  Further, according to the present embodiment, since it is possible to notify that the total fuel remaining amount is insufficient based on the total fuel remaining amount, it is possible to prevent a gas shortage state in advance.

  Further, according to the present embodiment, the presence or absence of a warning is determined based on a comparison between the distance D2 to the liquid fuel supply station and the distance D1 that can be traveled based on the total fuel remaining amount. More accurate and flexible warnings are possible than when warnings are uniform.

  Furthermore, according to the present embodiment, the amount of liquid fuel is limited according to the remaining amount of the gaseous fuel on the assumption that the gaseous fuel is also used, so that an appropriate amount of fuel can be filled.

  Furthermore, according to the present embodiment, the opening / closing of the shutoff valve L1 that permits filling is controlled based on whether the vehicle is stopped and the communication state with the liquid fuel filling machine is established. It is possible to determine.

  Moreover, according to this embodiment, the validity of the gaseous fuel tanks 11-13 is controlled according to the amount of boil-off gas, and the volume for filling the boil-off gas which is gaseous fuel is changed. By this series of processing, the volume is changed so that the boil-off gas is filled at a small volume when the amount of the boil-off gas is relatively small and as the boil-off gas is relatively large. Therefore, the supply pressure at the inlet of the fuel cell stack 100 can be maintained at a certain level or higher.

  Further, according to the embodiment, since the valve opening pressures of the check valves W1 to W3 are set to be different from each other, from the gaseous fuel tank 11 associated with the check valve W1 with the valve opening pressure set low. The boil-off gas is filled in order, and the volume of the entire gaseous fuel tank can be changed according to the amount of the boil-off gas.

  Furthermore, according to the embodiment, when the initial amount B5 of the boil-off gas is larger than the predetermined value Qa, the boil-off gas can be filled in the plurality of gaseous fuel tanks 11 to 13 at the same time. In the case of a large amount, a large filling volume can be ensured, and the boil-off gas can be filled without extremely increasing the filling pressure.

  Furthermore, according to the embodiment, since the shutoff valve L2 for connecting the liquid fuel pipe 16 to the main pipe 19 communicating with the fuel cell stack 100 is provided, the boil-off gas in the liquid fuel pipe 16 is preferentially used for the fuel cell stack 100. The utilization efficiency of liquid hydrogen can be improved.

(Modification)
The present invention is not limited to the above-described embodiment, and can be variously modified and applied.
For example, in the above embodiment, the liquid fuel is allowed to be charged when all the conditions that the fuel cover is open, the vehicle is stopped, and the communication with the filling machine can be satisfied. Filling may be permitted under any one of the conditions.

  In the above embodiment, the lack of gas is determined using the information of the navigation device 6. However, the relationship between the current total remaining fuel amount and the amount of fuel necessary to the nearest liquid fuel supply station is shown. Since it is sufficient to be able to grasp, the assistance of the navigation device is not necessarily required. For example, it is possible to use position information regarding fuel supply given from the outside.

  In the above embodiment, liquid hydrogen is described as an example of the liquid fuel to be handled. However, the same idea can be applied to any fuel that has a relatively low boiling point and is expected to generate boil-off gas. .

  Furthermore, the present invention can be applied not only to a moving body such as a vehicle, a ship, and an aircraft equipped with a fuel cell system, but also to a fuel cell system placed in a closed space such as a building or a house.

Block configuration diagram of a fuel cell system equipped with the liquid fuel consuming apparatus of the present invention Block diagram of the navigation device of the present embodiment Flowchart explaining the main module of the present embodiment Flowchart for explaining fuel remaining amount calculation processing of the present embodiment Flow chart for explaining the capacity changing process of the present embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen gas supply system, 2 Air supply system, 3 Cooling system, 4 Electric power system, 5 Control part, 6 Navigation apparatus, 100 Fuel cell stack, 10 Liquid fuel tank, 11-13 Gas fuel tank, 14, 24 Gas-liquid separation 15 Hydrogen pump, 21 Air cleaner, 22 Compressor, 23 Humidifier, 25 Diluter, 26 Silencer, 31 Radiator, 32 Fan, 33 Cooling pump, 34 Cooling device, 40 DC-DC converter, 41 Battery, 42 Traction inverter , 43 Traction motor, 44 Auxiliary machine inverter, 45 High voltage auxiliary machine, 60 Position information controller, 61 Angular velocity sensor, 62 Acceleration sensor, 63 Wheel speed sensor, 64 DPS receiver, 65 Display controller, 66 Display, 67 Disk drive 68 Input / output (I / O) devices, FI liquid fuel filling port, RV1, RV2, W1 to W3 check valve, L1 to 5, G1 to G3 shutoff valve, R1 to 5 pressure regulating valve, C1 to C4 rotary valve, p1 to p6, p10, p11 pressure sensor, t1 ~ T6 Temperature sensor

Claims (9)

A liquid fuel consuming device in which liquid fuel is supplied from the outside,
A liquid fuel consuming apparatus configured to be able to calculate a total fuel remaining amount based on a total value of a remaining amount of liquid fuel and a remaining amount of gaseous fuel vaporized from the liquid fuel. A liquid fuel tank for storing the liquid fuel;
A gaseous fuel tank for storing the gaseous fuel,
The liquid fuel consuming apparatus according to claim 1, wherein the liquid fuel tank includes a part of the gaseous fuel in addition to the liquid fuel.   The liquid fuel consuming apparatus according to claim 1, wherein a notification corresponding to the total fuel remaining amount is made based on the calculated total fuel remaining amount.   The liquid fuel consuming apparatus according to claim 3, wherein the notification is performed when the total fuel remaining amount is equal to or less than a predetermined reference value.   The liquid fuel consuming apparatus according to claim 4, wherein the reference value is changed based on a distance to a liquid fuel supply station that supplies the liquid fuel. A position positioning device for positioning the position of the liquid fuel consumption device;
The liquid fuel consumption device according to claim 5, wherein a distance to the liquid fuel supply station is calculated based on the measured position information of the liquid fuel consumption device and the position information of the liquid fuel supply station. A liquid fuel consuming device in which liquid fuel is supplied from the outside,
A liquid fuel consumption device configured to be able to limit a filling amount of the liquid fuel based on a remaining amount of gaseous fuel vaporized from the liquid fuel.   The liquid fuel consumption device according to claim 1, wherein filling of the liquid fuel is permitted based on at least one of a moving speed of the liquid fuel consumption device or a communication state with the liquid fuel filling machine.   The liquid fuel consumption device according to claim 1, wherein charging of the liquid fuel is prohibited based on at least one of a remaining amount of the liquid fuel or a communication state with the liquid fuel filling machine.

Images