JP6540575B2 - Fuel cell system control method - Google Patents

Description

  The present invention relates to a control method of a fuel cell system.

  In recent years, fuel cells that generate electricity by the electrochemical reaction of hydrogen and oxygen have attracted attention. Water is purified from the fuel cell by an electrochemical reaction, and this purified water is used to cool the inside of the fuel cell system or discharged from the water distribution pipe to the outside of the system.

  Conventionally, there exists Unexamined-Japanese-Patent No. 2006-155998 as a technique of such a field. The control method of the fuel cell system described in this publication describes controlling the output from the fuel cell stack when the hydrogen pump is locked due to freezing or the like.

Unexamined-Japanese-Patent No. 2006-155998

However, in the above-described conventional fuel cell system, even when the hydrogen pump is locked due to freezing, power generation is possible under a predetermined restriction, but in the case where the hydrogen pump is unlocked There is a problem that the normal operation can not be performed until the lock is naturally released. There is a demand for releasing the lock of the hydrogen pump in a short time and enabling the power generation by the normal operation.
The present invention provides a control method of a fuel cell system in which the time taken to unlock the hydrogen pump is shortened.

A control method of a fuel cell system according to the present invention includes a fuel cell stack, a hydrogen tank for supplying hydrogen to the fuel cell stack, and resupply of hydrogen discharged from the fuel cell stack to the fuel cell stack. A control method of a fuel cell system, comprising: a hydrogen pump to be circulated; a radiator for cooling a coolant to be circulated to cool the fuel cell stack; and a fan for sending air to the radiator. Determining at start-up whether or not the hydrogen pump is locked; and circulating the coolant between the fuel cell stack and the radiator when the hydrogen pump is locked, the hydrogen Supplying hydrogen from a tank to the fuel cell stack to generate electricity; The air runt is sent to the radiator circulating, and a step of warming said hydrogen pump.
Thereby, the release of the lock can be promoted by applying the air warmed by passing through the radiator to the hydrogen pump.

  As a result, the time taken to unlock the hydrogen pump can be shortened.

1 shows the configuration of a fuel cell system. It is a figure which shows arrangement | positioning of a fuel cell stack, a hydrogen pump, and a radiator. It is a figure showing the flow of the coolant in the state where the hydrogen pump was locked. It is a figure showing the flow of the coolant in the state where the hydrogen pump is not locked. It is a figure which shows the operation | movement flow of a fuel cell system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the fuel cell system 1 includes a fuel cell stack 11, a hydrogen tank 12 storing fuel gas (hydrogen), a hydrogen pump 13, and a radiator 14 for cooling a coolant used for the fuel cell stack 11. And a fan 15 for sending air to the radiator 14, an ion exchanger 16 for removing impurities from the coolant, and a rotary valve for switching whether the coolant is supplied to the path provided with the radiator 14 or to the path provided with the ion exchanger 16. And 17. Hereinafter, the fuel cell system 1 will be described as being used in an engine room of a car.

  The fuel cell stack 11 is an assembly of cells that generate electric power by an electrochemical reaction of hydrogen and oxygen. In the cell, a hydrogen electrode (anode) and an oxygen electrode (cathode) are disposed to sandwich an electrolyte membrane. The hydrogen stored in the hydrogen tank 12 is supplied to the anode as a fuel gas. Air as oxygen gas is supplied to the cathode.

  For example, the exhaust from the cathode is exhausted to the outside through an exhaust pipe and a muffler. In addition, water purified by the electrochemical reaction of hydrogen and oxygen is discharged to the outside through a drainage pipe. Each pipe is provided with a valve that is controlled to open and close.

  The hydrogen tank 12 stores hydrogen gas under high pressure. For example, the hydrogen tank 12 is provided with a plurality of regulators and valves, and the valve is opened after the pressure and supply amount of hydrogen gas sent from the hydrogen tank 12 to the fuel cell stack 11 are adjusted using the regulator As a result, hydrogen gas is supplied to the anode. That is, when the fuel cell system 1 is started in the environment below freezing, the hydrogen tank 12 supplies hydrogen gas to the anode by the injector, using the fact that the stored hydrogen gas is at high pressure.

  The hydrogen pump 13 circulates the hydrogen discharged from the fuel cell stack 11 so as to be resupplied to the fuel cell stack 11. The hydrogen pump 13 is a pump device that compresses and discharges gas using the power of a rotating mechanism such as a scroll pump, a vane pump, a roots pump, or a diaphragm pump. The hydrogen pump 13 is provided with a sensor such as a temperature sensor for measuring a frozen state, and a rotation number sensor for measuring the rotation number. As shown in FIG. 2, the hydrogen pump 13 is disposed in the engine room near the hydrogen tank 12 and is disposed so that the air warmed by the radiator 14 is blown when blown by the fan 15. ing. In FIG. 2, the left side of the drawing is the front.

  The radiator 14 dissipates the heat that cools the fuel cell stack 11. As shown in FIG. 3, a plurality of sub-radiators may be arranged in the vicinity of the radiator 14.

  The fan 15 is provided in the vicinity of the radiator 14. The air warmed by the heat radiation of the radiator 14 is blown to the hydrogen pump 13 by the operation of the fan 15.

  Here, as shown in FIG. 3, in the fuel cell system 1, there are a first pipe 21 connected to the fuel cell stack 11 for letting the coolant flow out, and a second pipe 22 and a second pipe 22 branched from the first pipe 21. A third piping 23 and a second piping 22 and a third piping 23 are joined together and connected, and a fourth piping 24 for allowing coolant to flow into the fuel cell stack 11 is provided.

  A thermometer 25 that measures the temperature of the coolant is disposed in the first pipe 21. Further, a rotary valve 17 is disposed at a branch point of the second pipe 22 and the third pipe 23 downstream of the first pipe. The rotary valve 17 controls the flow direction of the coolant according to the locked state of the hydrogen pump 13. For example, when the rotary valve 17 determines that the hydrogen pump 13 is locked by the control unit (not shown) based on the output of a sensor provided in the hydrogen pump 13, the second pipe 22 Pour the coolant into the Further, the rotary valve 17 causes the coolant to flow through the third pipe 23 when it is determined by the control unit that the hydrogen pump 13 is not locked. Note that, for example, the control unit is configured by an arithmetic device provided with a CPU (Central Processing Unit) and a memory.

  The second pipe is a pipe passing through the front side of the engine room. A radiator 14 is disposed in the second pipe. In the second pipe, a thermometer 26 for measuring the temperature of the coolant is disposed.

  The third pipe 23 is disposed on the rear side of the engine compartment as compared to the second pipe 22. In other words, the third pipe 23 is disposed to bypass between the first pipe 21 and the fourth pipe 24. An ion exchanger 16 is disposed in the third pipe 23.

  The ion exchanger 16 performs ion exchange of the coolant flowing through the third pipe 23. Thereby, the ion exchanger 16 removes ions in the coolant.

  Next, an operation of driving the fuel cell system 1 under freezing point will be described with reference to FIG.

  Driving of the fuel cell system 1 is started below freezing (S11). That is, the temperature of the coolant measured by the thermometer 25 is lower than 0 ° C.

  The control unit uses the information acquired from the sensor disposed in the hydrogen pump 13 and determines whether or not the rotational speed is in a locked state in which abnormality occurs in the rotational speed due to freezing of condensed water and purified water inside the rotor chamber of the hydrogen pump 13 Is determined (S12). In addition, the determination of the lock state of the hydrogen pump 13 is information on whether or not a torque loss has occurred in addition to the abnormality in the deviation of the rotational speed, and whether an abnormality on the driver operating the hydrogen pump 13 has occurred. May be obtained using these information. When the control unit determines that the hydrogen pump 13 is locked, the process proceeds to S13, and when it is determined that the hydrogen pump 13 is not locked, the process proceeds to S21.

  The valve for exhausting and draining the fuel cell stack 11 is opened (S13). Further, hydrogen is supplied from the hydrogen tank 12 to the fuel cell stack 11 by the injector.

  The control unit controls the rotary valve 17 so that the coolant discharged from the fuel cell stack 11 flows from the first pipe 21 to the second pipe 22 (S14). The coolant is dissipated by the radiator 14 in the second pipe 22 and circulates so as to return to the fuel cell stack 11 through the fourth pipe.

  The fuel cell stack 11 performs power generation in a state where predetermined output limitation is performed (S15). For example, the fuel cell stack 11 operates with output limitation such that the output is 35% of the maximum output. Alternatively, when the temperature of the fuel cell stack 11 is low, the operating state is likely to deteriorate, so the output power limit may be determined according to the temperature of the fuel cell stack 11. In addition, the electric power which is insufficient for output restriction may be supplied from a secondary battery (not shown).

  The thermometers 25 and 26 confirm that the temperature of the coolant rises due to the operation of the fuel cell stack 11, and the temperature of the coolant becomes higher than 0 ° C. (S16). When the temperature of the coolant is lower than 0 ° C., power generation is continued in a state where the output is limited, and the operation waits until the temperature becomes higher than 0 ° C.

  The air blowing by the fan 15 is started (S17). Thus, when cooling the coolant passing through the second pipe 22, the air warmed by the heat radiation generated by the radiator 14 is sent to the hydrogen pump 13.

  As a result, the temperature of the hydrogen pump 13 rises, and stable rotation of the rotor becomes possible (S18). As a result, the hydrogen pump 13 can operate normally, so the process proceeds to S21, and the control shifts to normal control.

  Next, when it is determined in S12 that the hydrogen pump 13 is not locked, or after it is determined that the hydrogen pump 13 is locked, the process proceeds to S18 and an operation at the time of normal control will be described.

  Hydrogen is supplied from the hydrogen tank 12 to the fuel cell stack 11 by the injector (S21).

  The control unit controls the rotary valve 17 so that the coolant flows from the first pipe 21 to the third pipe 23 (bypass side) (S22). The ion exchange of the coolant is performed by the ion exchanger 16 provided in the third pipe 23.

  The fuel cell stack 11 performs power generation in a state where predetermined output limitation is performed (S23). Similarly to S15, the power limit may be determined as a predetermined ratio to the maximum power, or the limit may be changed according to the temperature of the fuel cell stack 11.

  The thermometer 25 checks that the temperature of the coolant rises due to the operation of the fuel cell stack 11, and the temperature of the coolant becomes higher than 50 ° C. (S24). In addition, when the temperature of the coolant is lower than 50 ° C., the process waits in a state where power generation in the output limited state is continued until the temperature becomes higher than 50 ° C.

  The fuel cell stack 11 starts normal power generation (S25). At this time, the hydrogen pump 13 starts normal operation. That is, the hydrogen pump 13 circulates the hydrogen discharged from the fuel cell stack 11 so as to be resupplied to the fuel cell stack 11 as a normal operation.

  Thereby, the lock state of the hydrogen pump 13 is determined, and when the hydrogen pump 13 is in the lock state, the air warmed by passing through the radiator 14 is applied to the hydrogen pump 13 by the fan 15 to lock it. It can facilitate the cancellation. Thereby, even when the operation of the fuel cell system is started in the environment below freezing, the hydrogen pump 13 can be put into a normal operable state in a short time, and the normal power generation in the fuel cell stack 11 is performed It can be done.

  The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the scope of the present invention. For example, in S16 of the description of the operation of the fuel cell system 1, after confirming that the temperature of the coolant is higher than 0 ° C., the process proceeds to S17. However, the reference temperature needs to be 0 ° C. For example, any temperature higher than 0 ° C. may be used. Similarly, the reference temperature in S24 does not necessarily have to be 50 ° C., and can be set to any temperature suitable for normal operation of the fuel cell system 1.

DESCRIPTION OF SYMBOLS 1 Fuel cell system 11 Fuel cell stack 12 Hydrogen tank 13 Hydrogen pump 14 Radiator 15 Fan 16 Ion exchanger 17 Rotary valve 21 1st piping 22 2nd piping 23 3rd piping 24 4th piping 25 Thermometer 26 Thermometer

Claims (1)

A fuel cell stack,
A hydrogen tank for supplying hydrogen to the fuel cell stack;
A hydrogen pump that circulates hydrogen discharged from the fuel cell stack to be resupplied to the fuel cell stack;
A radiator for cooling a coolant circulated to cool the fuel cell stack;
A control method of a fuel cell system, comprising: a fan for sending air to the radiator;
Determining whether the hydrogen pump is locked due to freezing ;
Circulating the coolant between the fuel cell stack and the radiator when the hydrogen pump is locked due to freezing, and supplying hydrogen from the hydrogen tank to the fuel cell stack to generate electricity;
Warming the hydrogen pump with air sent to the radiator in which the coolant is circulating.
Control method of fuel cell system.

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