Fuel cell system

Abstract

To provide a fuel cell system that suppresses an increase in the power amount of an external power supply for starting a fuel cell.SOLUTION: A fuel cell system 1 includes: a fuel cell 8 which generates power by reacting hydrogen and oxygen, and can supply electric power to an electric load at the time of power reduction or loss of an external power supply; a hydrogen storage alloy tank 6 which stores hydrogen and can supply hydrogen to the fuel cell; a heater 7 which heats the hydrogen storage alloy tank 6; a storage battery 5 which can be charged by a system power supply 20 and can supply power to a load 30; and a control circuit 4. The control circuit 4 executes a first control process for supplying power from the storage battery 5 to the heater 7. In the fuel cell system 1, since the storage battery 5 can supply power to the heater 7, the hydrogen storage alloy tank 6 is not heated by the heater 7 during waiting in a normal state, but the hydrogen storage alloy tank 6 can be heated by supplying power from the storage battery 5 to the heater 7 after a power outage.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fuel cell system. [Background technology]

[0002] Patent Document 1 discloses an AC uninterruptible power supply system using a fuel cell. In this AC uninterruptible power supply system, a battery supplies power to a load for a specified time after a commercial AC power outage occurs, and if power is not restored thereafter, the fuel cell is started up to supply power to the load. Because hydrogen supplied to the fuel cell is stored in a hydrogen storage alloy, if the temperature of the hydrogen storage alloy tank falls below a certain level, sufficient hydrogen cannot be supplied to the fuel cell. In preparation for unpredictable power outages, the AC uninterruptible power supply system keeps the hydrogen storage alloy tank warm with a heater to maintain the tank temperature above a certain level. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-177576 Summary of the Invention [Problem to be solved by the invention]

[0004] The AC uninterruptible power supply system disclosed in Patent Document 1 had a problem in that when the ambient temperature is low, such as in winter, the heater must be operated for a longer period of time to maintain the temperature of the hydrogen storage alloy tank above a certain level, which can increase the amount of power required from the external power source.

[0005] An object of the present invention is to provide a fuel cell system that suppresses an increase in the amount of power required from an external power source to start up the fuel cell. [Means for solving the problem]

[0006] A fuel cell system according to a first aspect of the present invention includes a fuel cell that generates electricity by reacting hydrogen and oxygen and is capable of supplying power to an electrical load when power from an external power source drops or is lost, a hydrogen storage container that stores the hydrogen and is capable of supplying the hydrogen to the fuel cell, a heater that warms the hydrogen storage container, a power storage device that is chargeable by the external power source and is capable of supplying the power to the electrical load, and a control unit, wherein the control unit executes a first control process to supply the power from the power storage device to the heater. Because the fuel cell system is capable of supplying power to the heater from the power storage device, the hydrogen storage container can be heated by the power storage device after the external power source is lost. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an outline of the configuration of a fuel cell system 1. FIG. [Figure 2] FIG. 2 is a block diagram of a control circuit 4. [Figure 3] 10 is a flowchart showing a first main control process. [Figure 4] 10 is a flowchart showing a second main control process. [Figure 5] 10 is a flowchart showing a third main control process. [Figure 6] FIG. 10 is a diagram showing a load condition table 51. [Figure 7] FIG. 10 is a block diagram of a fuel cell system 1 according to a fourth embodiment. [Figure 8] FIG. 10 is a block diagram of a fuel cell system 1 according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the present invention will be described. The drawings are used to explain technical features that can be adopted by the present invention. In other words, the configurations, controls, etc. shown in the drawings are merely illustrative examples and are not intended to limit the present invention.

[0009] <Configuration of fuel cell system 1> The configuration of a fuel cell system 1 according to this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 shows the main components of the fuel cell system 1, and omits a circuit switching device, an interface circuit, a drive circuit, and other components, which are well known. The fuel cell system 1 supplies power to a load 30 during a power outage of a power grid 20. An example of the power grid 20 is a commercial power supply, e.g., 100 V AC. The fuel cell system 1 supplies power from the power grid 20 to the load 30 via a power supply line 21 when the power grid 20 is in a normal state, i.e., when no power outage occurs. In the following description, the "normal state" refers to a state in which power is supplied from the power grid 20. Furthermore, the "power outage" refers to a state in which power is not supplied from the power grid 20 and the power of the power grid 20 is lost. In the following embodiment, the operation of the fuel cell system 1 will be described using a "power outage" as an example. However, this is not limited to a "power outage." Even when the power of the power grid 20 drops, the fuel cell system 1 can supply power to the load 30, just as in a "power outage." An example of the load 30 is any electronic or electrical device that operates by receiving power.

[0010] The fuel cell system 1 includes a hydrogen storage alloy tank 6 and a fuel cell 8 that generates electricity using hydrogen supplied from the hydrogen storage alloy tank 6. The hydrogen storage alloy tank 6 contains a hydrogen storage alloy that releases hydrogen through an endothermic reaction. Therefore, the hydrogen storage alloy can achieve a much higher hydrogen filling density than gas. The supply temperature at which hydrogen can be released from the hydrogen storage alloy and supplied to the fuel cell 8 is designated X1. The hydrogen storage alloy tank 6 is provided with a pressure sensor 2 that detects the pressure of hydrogen in the hydrogen storage alloy tank 6 and a heater 7 that heats the hydrogen storage alloy tank 6. The fuel cell system 1 also includes a control circuit 4, a temperature sensor 3, the pressure sensor 2, a power detector 12, a storage battery 5, an AC / DC converter 10, a DC / AC inverter 11, and a DC / DC converter 9.

[0011] The control circuit 4 controls the fuel cell system 1. Specifically, the control circuit 4 controls the fuel cell 8, the storage battery 5, and the heater 7. As shown in FIG. 2, the control circuit 4 includes a CPU 41, a RAM 42, a ROM 43, a non-volatile memory 44, an input / output interface 45, and auxiliary circuits (not shown). The CPU 41 executes programs for the first to third main control processes described below. The RAM 42 temporarily stores data required for executing various processes. The ROM 43 stores various programs. The non-volatile memory 44 stores a load condition table 51 described below and various setting values ​​required for executing the programs. The input / output interface 45 mediates the input and output of signals between the CPU 41 and the temperature sensor 3, the pressure sensor 2, the heater 7, the power detector 12, the storage battery 5, and the fuel cell 8. The control circuit 4 may be configured with a dedicated circuit board for executing the first to third main control processes described below. Alternatively, the control circuit 4 may be configured with a dedicated ASIC.

[0012] The pressure sensor 2 is provided in the hydrogen storage alloy tank 6, detects the pressure of hydrogen in the hydrogen storage alloy tank 6, and outputs the detected value to the control circuit 4. The heater 7 heats the hydrogen storage alloy tank 6 under the control of the control circuit 4, heating the hydrogen storage alloy to a constant temperature. The power detector 12 detects the power supplied to the load 30 from the power supply line 21, and outputs the detected result to the control circuit 4. The control circuit 4 can obtain the power consumption of the load 30 from the output of the power detector 12. The temperature sensor 3 is provided in the housing of the fuel cell system 1, measures the ambient temperature, and outputs the measured result to the control circuit 4. The temperature sensor 3 may be provided outside the housing of the fuel cell system 1.

[0013] The AC-DC converter 10 converts the AC voltage of the system power supply 20 into a DC voltage and outputs it to a power supply line 22. An example of the output voltage of the AC-DC converter 10 is DC 48 V. Note that the output voltage of the AC-DC converter 10 is not limited to DC 48 V and may be any other voltage (for example, 24 V, 12 V, etc.). The AC-DC converter 10 supplies power to the control circuit 4, the storage battery 5, the DC-AC inverter 11, and the heater 7.

[0014] The storage battery 5 is charged with power supplied from the AC-DC converter 10 via a power supply line 22. An example of the output voltage of the storage battery 5 is DC 48V. The storage battery 5 is controlled by the control circuit 4, and during a power outage, supplies power to the DC-AC inverter 11 via power supply lines 24 and 22. The DC-AC inverter 11 converts DC voltage to AC voltage and supplies power to the load 30. An example of the output voltage of the DC-AC inverter 11 is AC 100V. The storage battery 5 also supplies power to the heater 7 via power supply line 24, power supply line 22, and power supply line 25. The storage battery 5 also supplies power to the control circuit 4 via power supply line 24, power supply line 22, and power supply line 23. The power supply line 22 and power supply line 25 are connected to each other.

[0015] The fuel cell 8 reacts oxygen with hydrogen supplied from the hydrogen absorbing alloy tank 6 to generate DC voltage and supplies it to the DCDC converter 9. The DCDC converter 9 converts the DC voltage supplied from the fuel cell 8 to, for example, 48 V. The DCAC inverter 11 converts the DC voltage supplied from the fuel cell 8 via the DCDC converter 9 into AC voltage. For example, the DCAC inverter 11 converts 48 V DC to 100 V AC.

[0016] <First Example> Next, a first embodiment will be described. In the fuel cell system 1 of the first embodiment having the above configuration, when on standby in a normal state (non-power outage), the hydrogen storage alloy tank 6 containing the hydrogen storage alloy is not heated by the heater 7. After a power outage, power is supplied from the storage battery 5 to the heater 7 to heat the hydrogen storage alloy tank 6.

[0017] The first main control process of the fuel cell system 1 according to the first embodiment of the present invention will be described with reference to Fig. 3. When the power system 20 is turned on and power is supplied to the fuel cell system 1, 48V DC is supplied to the control circuit 4 from the AC / DC converter 10 connected to the power system 20. The CPU 41 of the control circuit 4 starts up and reads and executes a program for the first main control process from the ROM 43. The CPU 41 supplies power from the power system 20 to the load 30, and charges the storage battery 5 from the power system 20 via the AC / DC converter 10 (S1).

[0018] Next, the CPU 41 determines whether a power outage has occurred based on whether the voltage supplied from the power supply line 23 has dropped below a certain value (S2). The certain value is a predetermined reference value for determining a power outage. If the CPU 41 does not determine that a power outage has occurred (S2: NO), it performs the processes of S1 and S2. If the CPU 41 determines that a power outage has occurred (S2: YES), it supplies power from the storage battery 5 to the load 30 via the DCAC inverter 11 (S3). Therefore, the operation of the load 30 is maintained.

[0019] Next, the CPU 41 determines whether power has been restored (S4). Specifically, the CPU 41 determines whether the voltage supplied from the power supply line 23 has exceeded a certain value and the system power supply 20 has been restored, i.e., whether the power outage has been resolved and the system power supply 20 has returned to normal (S4). If the CPU 41 does not determine that power has been restored (S4: NO), it determines whether the pressure in the hydrogen storage alloy tank 6 is A1 or higher (S5). Specifically, the CPU 41 determines whether the output value of the pressure sensor 2 indicates a pressure of A1 or higher. If the hydrogen pressure is A1 or higher, the amount of hydrogen supplied from the hydrogen storage alloy tank 6 to the fuel cell 8 is sufficient for the fuel cell 8 to generate electricity. In other words, A1 is the supply pressure at which hydrogen can be supplied to the fuel cell 8. If the CPU 41 does not determine that the pressure in the hydrogen storage alloy tank 6 is A1 or higher (S5: NO), it uses the heater 7 with power from the storage battery 5 to heat the hydrogen storage alloy tank 6 and warm the hydrogen storage alloy (S6). Next, the CPU 41 performs the processes of S4 and S5.

[0020] When the CPU 41 determines that the pressure in the hydrogen storage alloy tank 6 is A1 or higher (S5: YES), it stops the heater 7 and starts power generation by the fuel cell 8 (S8). The power supplied from the fuel cell 8 is converted to 48 V DC by the DC-DC converter 9, supplied to the DC-AC inverter 11, and converted to 100 V AC. The 100 V AC is supplied from the DC-AC inverter 11 to the load 30 (S8). Therefore, even if the power outage lasts for a long time, power can be supplied to the load 30 regardless of the remaining amount of power stored in the storage battery 5.

[0021] Next, the CPU 41 determines whether power has been restored (S9). If the CPU 41 determines that power has been restored (S9: YES), it stops power generation by the fuel cell 8 (S10) and supplies 100V AC from the system power supply 20 to the load 30 (S1). If the CPU 41 does not determine that power has been restored (S9: NO), it repeats the determination of S9 and continues supplying power from the fuel cell 8 to the load 30.

[0022] Furthermore, if the CPU 41 determines in the determination process of S4 that power has been restored (S4: YES), it stops power generation by the fuel cell 8 and stops the heater 7 (S7). The CPU 41 supplies power from the system power supply 20 to the load 30 and charges the storage battery 5 from the system power supply 20 via the AC / DC converter 10 (S1). Thereafter, the processes of S1 to S10 are repeated in the same manner.

[0023] In the fuel cell system 1 of the first embodiment, power can be supplied to the heater 7 from the storage battery 5, so that during standby in a normal state (non-power outage), the heater 7 does not heat the hydrogen storage alloy tank 6, but after a power outage, power can be supplied from the storage battery 5 to the heater 7 to heat the hydrogen storage alloy tank 6. Since power can be supplied to the heater 7 from the storage battery 5, an increase in the amount of power consumed by the system power supply 20 to heat the hydrogen storage alloy tank 6 can be suppressed.

[0024] <Second Example> Next, a second embodiment will be described. In the second embodiment, the configuration of the fuel cell system 1 is the same as that of the first embodiment, so a description of the configuration will be omitted. In the fuel cell system 1 of the second embodiment, the hydrogen storage alloy tank 6 is kept warm by the heater 7 using power from the system power supply 20 so as to maintain the temperature of the hydrogen storage alloy tank 6 during standby in a normal state at a predetermined temperature (e.g., X2) lower than the hydrogen supply temperature X1, or to maintain the pressure inside the hydrogen storage alloy tank 6 at or above a predetermined pressure (e.g., A2) lower than the hydrogen supply pressure A1. Another feature is that after a power outage, power is supplied to the heater 7 from the storage battery 5 to heat the hydrogen storage alloy tank 6.

[0025] The second main control process of the fuel cell system 1 according to the second embodiment of the present invention will be described with reference to Fig. 4. In Fig. 4, the same controls as those in Fig. 3 will be described using the same step numbers as in Fig. 3. When the system power supply 20 is turned on and power is supplied to the fuel cell system 1, 48V DC is supplied to the control circuit 4 from the AC / DC converter 10 connected to the system power supply 20. The CPU 41 of the control circuit 4 starts up and reads and executes a program for the second main control process from the ROM 43. The CPU 41 supplies power from the system power supply 20 to the load 30 and charges the storage battery 5 from the system power supply 20 via the AC / DC converter 10 (S1).

[0026] Next, the CPU 41 determines whether the ambient temperature is less than X2 or the pressure in the hydrogen storage alloy tank 6 is less than A2 (S21). Specifically, if the output value from the temperature sensor 3 is a value indicating less than X2 or the output value from the pressure sensor 2 is a value indicating less than A2, the CPU 41 determines YES in the determination process of S21.

[0027] If the ambient temperature is below X2 or the pressure in the hydrogen storage alloy tank 6 is below A2 (S21: YES), the CPU 41 uses the heater 7 to heat the hydrogen storage alloy tank 6 to X2 or to A2 (S22). Next, the CPU 41 proceeds to S2. The CPU 41 also proceeds to S2 if the determination in S21 is NO. Therefore, in a normal state (non-power outage), the CPU 41 does not supply power to the heater 7 when the ambient temperature is equal to or higher than X2, and supplies power from the system power supply 20 to the heater 7 when the ambient temperature is below X2 to keep the hydrogen storage alloy tank 6 warm at X2. Since the processing of S2 to S10 in the second main control processing is the same as S2 to S10 in the first main control processing, the CPU 41 performs the processing of S2 to S10 in the same manner as the first main control processing. A description of the processing of S2 to S10 will be omitted.

[0028] In the fuel cell system 1 of the second embodiment, the temperature at which the heater 7 keeps the hydrogen storage alloy tank 6 warm using power from the power grid 20 or the pressure inside the hydrogen storage alloy tank 6 is lower than in conventional fuel cell systems during standby in normal conditions. After a power outage, power is supplied from the storage battery 5 to the heater 7 to heat the hydrogen storage alloy tank 6. Therefore, an increase in the amount of power consumed by the heater 7 on the power grid 20 during standby in normal conditions can be suppressed. Furthermore, because the hydrogen storage alloy tank 6 is kept warm using power from the power grid 20 during standby in normal conditions, the power required to heat the hydrogen storage alloy tank 6 by the heater 7 after a power outage can be reduced compared to when the hydrogen storage alloy tank 6 is not kept warm under normal conditions. Therefore, an increase in the power storage capacity of the storage battery 5 can be suppressed.

[0029] <Third Example> Next, a third embodiment will be described. In the third embodiment, the configuration of the fuel cell system 1 is the same as in the first and second embodiments, so a description of the configuration will be omitted. The fuel cell system 1 of the third embodiment is characterized in that, in the configuration of the fuel cell system 1 of the second embodiment, if the power consumption of the load 30 before the power outage is less than the rated output of the load 30, the power consumption of the load 30 after the power outage is estimated to be about the same, and the power capacity supplied from the storage battery 5 to the load 30 from the power outage until the fuel cell 8 starts generating power is reduced.

[0030] The third main control process of the fuel cell system 1 according to the third embodiment of the present invention will be described with reference to Figure 5. In Figure 5, the same controls as those in Figure 3 will be described using the same step numbers as in Figure 3. When the system power supply 20 is turned on and power is supplied to the fuel cell system 1, 48V DC is supplied to the control circuit 4 from the AC / DC converter 10 connected to the system power supply 20. The CPU 41 of the control circuit 4 starts up and reads and executes a program for the third main control process from the ROM 43. The CPU 41 supplies power from the system power supply 20 to the load 30 and charges the storage battery 5 from the system power supply 20 via the AC / DC converter 10 (S1).

[0031] Next, the CPU 41 acquires the conditions for heating the hydrogen storage alloy tank 6 with the heater 7 (S31). Specifically, the CPU 41 acquires the power consumption of the load 30 from the value detected by the power detector 12. Next, the CPU 41 refers to a load condition table 51 shown in FIG. 6 to acquire the conditions for heating the hydrogen storage alloy tank 6 corresponding to the power consumption of the load 30 detected by the power detector 12 (S31). The load condition table 51 will be described with reference to FIG. 6. The load condition table 51 is stored in the non-volatile memory 44 shown in FIG. 2 and is referenced by the CPU 41. The load condition table 51 stores three power consumption values ​​of the load 30 and the conditions for heating the hydrogen storage alloy tank 6 with the heater 7 corresponding to each value. The power consumption value of the load 30 can be greater than P1, less than or equal to P1, greater than P2, or less than P2, where P1 > P2 and P1 is the rated value of the load 30. Therefore, power consumption is greatest when it exceeds P1 and is lowest when it is less than or equal to P2.

[0032] If the temperature exceeds P1, and the ambient temperature is less than X2 (or the pressure in the hydrogen storage alloy tank 6 is A2), the hydrogen storage alloy tank 6 is heated to X2 (or the pressure in the hydrogen storage alloy tank 6 is A2). If the temperature is less than P1 but exceeds P2, and the ambient temperature is less than X3 (or the pressure in the hydrogen storage alloy tank 6 is A3), the hydrogen storage alloy tank 6 is heated to X3 (or the pressure in the hydrogen storage alloy tank 6 is A3). If the temperature is less than P2, and the ambient temperature is less than X4 (or the pressure in the hydrogen storage alloy tank 6 is A4), the hydrogen storage alloy tank 6 is heated to X4 (or the pressure in the hydrogen storage alloy tank 6 is A4). The ambient temperature condition is X1>X2>X3>X4. The pressure condition in the hydrogen storage alloy tank 6 is A1>A2>A3>A4.

[0033] Next, the CPU 41 determines whether the condition acquired in S31 is met (S32). If the CPU 41 determines that the condition acquired in S31 is met (S32: YES), it heats the hydrogen storage alloy tank 6 under the met condition (S33). For example, when the CPU 41 determines that the power consumption of the load 30 is P2 or less based on the detected value of the power detector 12, and if the environmental temperature detected by the temperature sensor 3 is X4 or less (or the pressure in the hydrogen storage alloy tank 6 detected by the pressure sensor 2 is A4) or less, the CPU 41 heats the hydrogen storage alloy tank 6 by the heater 7 to X4 (or the pressure in the hydrogen storage alloy tank 6 is A4) (S33). When the CPU 41 determines that the power consumption of the load 30 is below P1 and above P2 based on the detection value of the power detector 12, and if the environmental temperature detected by the temperature sensor 3 is below X3 (or the pressure in the hydrogen storage alloy tank 6 detected by the pressure sensor 2 is below A3), the CPU 41 causes the heater 7 to heat the hydrogen storage alloy tank 6 to X3 (or the pressure in the hydrogen storage alloy tank 6 is A3) (S33). Also, when the CPU 41 determines that the power consumption of the load 30 is above P1 based on the detection value of the power detector 12, and if the environmental temperature detected by the temperature sensor 3 is below X2 (or the pressure in the hydrogen storage alloy tank 6 detected by the pressure sensor 2 is below A2), the CPU 41 causes the heater 7 to heat the hydrogen storage alloy tank 6 to X2 (or the pressure in the hydrogen storage alloy tank 6 is A2) (S33).

[0034] Next, the CPU 41 proceeds to S2. The CPU 41 also proceeds to S2 if it determines NO in the determination process of S32. Since the processes of S2 to S10 of the third main control process are the same as S2 to S10 of the first main control process, the CPU 41 performs the processes of S2 to S10 in the same way as the first main control process. A description of the processes of S2 to S10 will be omitted.

[0035] In the fuel cell system 1 of the third embodiment, if the power consumption of the load 30 before the power outage is less than the rated output (threshold), the load power is estimated to be approximately the same after the power outage, and the amount of power supplied from the storage battery 5 to the load 30 during the time from the power outage until the fuel cell 8 starts generating electricity is reduced. Because the power capacity of the storage battery 5 increases the amount of power available to the heater 7, the standby temperature of the hydrogen storage alloy tank 6 can be lowered compared to the second embodiment. Therefore, when the load 30 is under a light load, the standby power consumption during standby can be reduced compared to the second embodiment. Furthermore, when the power consumption of the load 30 is low, the amount of power supplied from the storage battery 5 to the heater 7 can be increased while the predetermined temperature is lowered, thereby further suppressing an increase in the amount of power supplied from the grid power supply 20. The CPU 41 controls the temperature at which the hydrogen storage alloy tank 6 is heated according to the power consumption of the load 30, and can control the heater 7 so that the temperature of the hydrogen storage alloy tank 6 is maintained at a predetermined temperature according to the power consumption of the load 30. Therefore, the amount of power supplied from the grid power supply 20 can be adjusted according to the power of the load 30.

[0036] <Fourth Example> Next, a fourth embodiment will be described with reference to FIG. 7. In the fourth embodiment, the configuration of the fuel cell system 1 differs from the first to third embodiments in that it includes a solar panel 40 and a DC-DC converter 13. Since the other configurations are the same as those of the first to third embodiments, a description of the other configurations will be omitted. The output of the solar panel 40 is input to the DC-DC converter 13, converted to 48V DC, and fed to the power feeder 25. Therefore, charging power for the storage battery 5 and power for the heater 7 can be supplied from sunlight. This makes it possible to reduce the power consumption of the system power supply 20 during normal standby. Furthermore, power may be supplied to at least one of the storage battery 5 and the heater 7 from the solar panel 40. The power consumption of the system power supply 20 for heating the hydrogen storage alloy tank 6 can be reduced.

[0037] <Fifth Example> Next, a fifth embodiment will be described with reference to FIG. 8. The configuration of the fuel cell system 1 in the fifth embodiment differs from the first to third embodiments in that it includes a small wind power generator 50 and a DC-DC converter 13. The output of the small wind power generator 50 is converted to 48V DC by the DC-DC converter 13 and supplied to the power supply line 25. Therefore, charging power for the storage battery 5 and power for the heater 7 can be supplied from the small wind power generator 50. This reduces the power consumption of the grid power supply 20 during normal standby. Even in winter, at night, or at other times when the temperature is low and the hydrogen storage alloy tank 6 needs to be kept warm, the small wind power generator 50 can generate power if there is wind. Furthermore, power may be supplied to at least one of the storage battery 5 and the heater 7 from the small wind power generator 50. This reduces the power consumption of the grid power supply 20 for heating the hydrogen storage alloy tank 6.

[0038] In the above embodiment, the hydrogen storage alloy tank 6 is an example of a "hydrogen storage container" of the present invention. The storage battery 5 is an example of a "power storage device" of the present invention. The control circuit 4 or the CPU 41 is an example of a "control unit" of the present invention. The system power supply 20 is an example of an "external power supply" of the present invention. The load 30 is an example of an "electrical load" of the present invention. The solar panel 40 is an example of a "photovoltaic power generation device" of the present invention. The small wind power generator 50 is an example of a "wind power generation device" of the present invention. The processing of S6 is an example of a "first control process" and a "second control process" of the present invention. The processing of S22 is an example of a "third control process" of the present invention. The processing of S33 is an example of a "fourth control process" and a "fifth control process" of the present invention.

[0039] The present invention is not limited to the above embodiment and various modifications are possible. A temperature sensor may be provided on or inside the hydrogen storage alloy tank 6 to detect the temperature of the hydrogen storage alloy tank 6 or the hydrogen storage alloy contained therein and output the temperature to the control circuit 4. Since the temperature of the hydrogen storage alloy tank 6 is proportional to the hydrogen pressure in the hydrogen storage alloy tank 6, the CPU 41 may determine the temperature of the hydrogen storage alloy tank 6 based on the hydrogen pressure in the hydrogen storage alloy tank 6 detected by the pressure sensor 2. In this case, the temperature of the hydrogen storage alloy tank 6 can be determined from the hydrogen pressure in the hydrogen storage alloy tank 6 without using a temperature sensor. The pressure value in the hydrogen storage alloy tank 6 used in the determination in S5 may be determined based on the characteristics of the fuel cell 8. The storage battery 5 may be an all-solid-state battery or the like. The values ​​of the power consumption of the load 30, the ambient temperature, the temperature of the hydrogen storage alloy tank 6, and the hydrogen pressure in the hydrogen storage alloy tank 6 in the load condition table 51 are not limited to the values ​​listed in the load condition table 51 and may be determined appropriately depending on the power consumption of the load 30, the characteristics of the hydrogen storage alloy, and the characteristics of the hydrogen storage alloy tank 6. [Explanation of symbols]

[0040] 1: Fuel cell system 2: Pressure sensor 3: Temperature sensor 4: Control circuit 5: Storage battery 6: Hydrogen storage alloy tank 7: Heater 8: Fuel cell 12: Power detector 13: DC / DC converter 20: Grid power supply 30: Load 40: Solar panels 41:CPU 50: Small wind turbine 51: Load condition table

Claims

1. a fuel cell that generates electricity by reacting hydrogen and oxygen and is capable of supplying power to an electrical load when the power of an external power source decreases or is lost; a hydrogen storage container that stores the hydrogen and is capable of supplying the hydrogen to the fuel cell; a heater for heating the hydrogen storage container; an electric storage device that can be charged by the external power supply and can supply the electric power to the electric load; Control unit and Equipped with The fuel cell system is characterized in that the control unit executes a first control process for supplying the electric power from the power storage device to the heater.

2. The power can be supplied to the heater from the external power source, 2. The fuel cell system according to claim 1, wherein the control unit executes a second control process to supply the electric power from the power storage device to the heater when the electric power of the external power supply drops or is lost.

3. 3. The fuel cell system according to claim 1, wherein the control unit, when receiving the electric power from the external power source, executes a third control process to control the heater so that the temperature of the hydrogen storage container becomes a predetermined temperature that is lower than the supply temperature of the hydrogen and higher than the ambient temperature.

4. 3. The fuel cell system according to claim 1, wherein the hydrogen storage container contains a hydrogen absorbing alloy that releases the hydrogen through an endothermic reaction.

5. 4. The fuel cell system according to claim 3, wherein the control unit performs a fourth control process in which, when the power consumption of the electrical load is equal to or less than a threshold, the predetermined temperature is made lower than when the power consumption of the electrical load exceeds the threshold.

6. 4. The fuel cell system according to claim 3, wherein the control unit executes a fifth control process for controlling the predetermined temperature in accordance with the power consumption of the electric load.

7. 3. The fuel cell system according to claim 1, further comprising a solar power generation device capable of supplying power to at least one of the heater and the power storage device.

8. 3. The fuel cell system according to claim 1, further comprising a wind power generator capable of supplying power to at least one of the heater and the power storage device.

9. 3. The fuel cell system according to claim 1, wherein the control unit determines the temperature of the hydrogen storage container based on the pressure of the hydrogen in the hydrogen storage container.

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