JP6262481B2 - Fuel cell vehicle and control method of fuel cell vehicle - Google Patents

Description

  The present invention relates to a fuel cell vehicle and a fuel cell vehicle control method.

  A cooling system (fuel cell cooling circuit) for cooling the fuel cell of the fuel cell vehicle is moved to the air conditioning circuit to serve as a heat source for the air conditioning circuit (heating water circuit) and includes a heater core for heating the air conditioning air A fuel cell vehicle is known (for example, Patent Document 1). In this fuel cell vehicle, the heating capacity and fuel consumption can be improved by using the waste heat of the fuel cell vehicle as a heat source for heating.

JP2013-14268A

  In a fuel cell vehicle, the fuel cell is not warmed immediately after the fuel cell is started. In general, the higher the temperature, the better the efficiency of the fuel cell. Therefore, in order to warm up the fuel cell quickly, the cooling water of the fuel cell cooling circuit and the cooling water until the cooling water of the fuel cell cooling circuit reaches a predetermined temperature. Each circuit was operated separately so as not to mix the cooling water of the heating water circuit. When the temperature of the cooling water in the fuel cell cooling circuit reaches a predetermined temperature, the cooling water in the cooling circuit for the fuel cell is caused to flow through the heating water circuit, and the heat of the fuel cell is used as a heating heat source. Here, when there is a temperature difference between the cooling water for the fuel cell cooling circuit and the cooling water for the heating water circuit, the cooling water circuit flows when the cooling water flows from the fuel cell cooling circuit to the heating water circuit. The temperature of the cooling water varies greatly. Since the air-conditioning (air conditioner) blowing temperature is linked to the temperature of the cooling water in the heating water circuit, the air-conditioning blowing temperature also fluctuates greatly, which may cause the passengers to feel uncomfortable.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.
According to one aspect of the present invention, a fuel cell vehicle is provided. The fuel cell vehicle includes a fuel cell, a fuel cell cooling circuit for cooling the fuel cell, a heating water circuit used for heating the interior of the fuel cell vehicle, and the fuel cell. A valve that controls the supply of cooling water from the cooling circuit to the heating water circuit, and a control unit that controls the operation of the fuel cell vehicle, the control unit immediately after the start of the fuel cell, In response to turning on of the heating switch, the valve is opened to start the operation of circulating the cooling water flowing through the fuel cell cooling circuit to the heating water circuit. According to the fuel cell vehicle of this embodiment, when the fuel cell is in an unfrozen state, the valve is opened regardless of the temperature of the cooling water in response to turning on the heating after starting the fuel cell. Cooling water flowing through the cooling circuit is circulated to the heating water circuit. At this time, the temperature of the cooling water flowing through the cooling circuit for the fuel cell and the temperature of the cooling water flowing through the heating water circuit are substantially the same, and the temperature of the cooling water flowing through the heating water circuit is almost the same after the circulation. Fluctuates greatly, the heating temperature changes suddenly, and there is little risk of causing the passengers to feel uncomfortable.

(1) According to one aspect of the present invention, a fuel cell vehicle is provided. The fuel cell vehicle includes a fuel cell, a fuel cell cooling circuit for cooling the fuel cell, a heating water circuit used for heating the interior of the fuel cell vehicle, and the heating from the fuel cell cooling circuit. A valve for controlling the supply of cooling water to the irrigation circuit, and a control unit for controlling the operation of the fuel cell vehicle, wherein the control unit is configured so that the fuel cell vehicle is in a non-freezing state. In the case of heating, immediately after the start of the fuel cell, in response to turning on of the heating switch, the operation of opening the valve and circulating the cooling water flowing through the fuel cell cooling circuit to the heating water circuit is started. According to the fuel cell vehicle of this embodiment, the cooling water flowing through the fuel cell cooling circuit is circulated to the heating water circuit in response to turning on the heating switch after the fuel cell is started. At this time, the temperature of the cooling water flowing through the cooling circuit for the fuel cell and the temperature of the cooling water flowing through the heating water circuit are substantially the same, and the temperature of the cooling water flowing through the heating water circuit is almost the same after the circulation. Fluctuates greatly, the heating temperature changes suddenly, and there is little risk of causing the passengers to feel uncomfortable.

(2) In the fuel cell vehicle according to the above aspect, when the control unit circulates the cooling water flowing through the fuel cell cooling circuit to the heating water circuit, the control unit converts the efficiency of the fuel cell into that of the fuel cell vehicle. You may perform the low efficiency driving | running made lower than the efficiency at the time of driving | operation. When the cooling water flowing through the fuel cell cooling circuit is circulated to the heating water circuit after opening the valve after starting the fuel cell, the temperature of the cooling water flowing through the fuel cell cooling circuit is less likely to rise than when not flowing, By causing the fuel cell to generate heat and causing the temperature of the cooling water flowing through the cooling circuit for the fuel cell to rise quickly by executing a low-efficiency operation that lowers the efficiency of the fuel cell from that during normal operation of the fuel cell vehicle Is possible.

(3) The fuel cell vehicle according to the above aspect includes a fuel gas circuit that supplies a fuel gas to the fuel cell, and an oxidant gas circuit that supplies an oxidant gas to the fuel cell, and the control unit includes the fuel cell. The low-efficiency operation may be performed by increasing the current of the fuel cell while maintaining the amounts of fuel gas and oxidizing gas supplied to the fuel cell. According to the fuel cell vehicle of this aspect, the low-efficiency operation that decreases the power generation efficiency of the fuel cell by increasing the current of the fuel cell while maintaining the amounts of the fuel gas and the oxidizing gas supplied to the fuel cell. Can be executed.

(4) In the fuel cell vehicle according to the above aspect, when the fuel cell is in a frozen state when the fuel cell vehicle is started, after the fuel cell is thawed, the control unit is configured for the fuel cell. The cooling water flowing through the cooling circuit may be circulated to the heating water circuit. According to the fuel cell vehicle of this embodiment, before the fuel cell is thawed, the cooling water flowing through the fuel cell cooling circuit is dedicated to thawing without flowing into the heating water circuit, and after the fuel cell is thawed, the fuel cell cooling is performed. Cooling water flowing through the circuit can be circulated to the heating water circuit.

(5) In the fuel cell vehicle according to the above aspect, the control unit further opens the valve after the temperature of the cooling water flowing through the fuel cell cooling circuit reaches a predetermined temperature to cool the fuel cell. Cooling water flowing through the circuit may be circulated to the heating water circuit. According to the fuel cell vehicle of this aspect, after the temperature of the cooling water flowing through the fuel cell cooling circuit reaches a predetermined temperature and the fuel cell can output and generate heat, the fuel cell cooling circuit The cooling water flowing through the heating water circuit is circulated to the heating water circuit, so that the cooling water flowing through the fuel cell cooling circuit and the heating water circuit can be quickly warmed.

  It should be noted that the present invention can be realized in various forms, for example, in the form of a control method in a fuel cell vehicle in addition to a fuel cell vehicle.

It is explanatory drawing which shows the structure of the fuel cell vehicle carrying a fuel cell system. It is explanatory drawing which shows the flow of the cooling water when a three-way valve is a non-cooperation mode state. It is explanatory drawing which shows the state of a three-way valve, and the flow of cooling water. It is explanatory drawing which shows the structure of an air conditioning duct. It is an example of the control flowchart of one Embodiment in this invention. It is explanatory drawing which shows IV characteristic at the time of normal driving | operating of a fuel cell, and IV characteristic at the time of low efficiency driving | operation. It is explanatory drawing which shows the cooling water exit temperature T245 in a comparative example, heater core entrance temperature T345, and blowing temperature T390. It is explanatory drawing which shows the cooling water exit temperature T245 in this embodiment, heater core entrance temperature T345, and blowing temperature T390.

  FIG. 1 is an explanatory diagram showing the configuration of a fuel cell vehicle 10 equipped with a fuel cell system. The fuel cell vehicle 10 includes a fuel cell 100, a fuel gas circuit 500, an oxidizing gas circuit 600, a fuel cell cooling circuit 200, a heating water circuit ("heating water circuit 300" or "air conditioning water circuit 300"). And a control unit 400 (Electronic control unit: ECU 400). The fuel cell 100 is a device that generates power using fuel gas and oxidizing gas. The fuel cell 100 has a large number of cells, and the large number of cells are stacked. In addition, a temperature sensor 110 that measures the temperature of the fuel cell 100 is attached to the fuel cell 100. The temperature sensor 110 may be arranged in either the cell near the center of the fuel cell 100 or the cell at the end.

  The fuel gas circuit 500 includes a fuel gas tank 510, a fuel gas supply pipe 520, fuel gas exhaust pipes 550 and 560, a fuel gas recirculation pipe 570, an on-off valve 530, a regulator 540, a hydrogen pump 580, and an exhaust valve. 590. The fuel gas tank 510 stores fuel gas. In this embodiment, hydrogen is used as the fuel gas. The fuel gas tank 510 and the fuel cell 100 are connected by a fuel gas supply pipe 520. On the fuel gas supply pipe 520, an open / close valve 530 for turning on / off the supply of the fuel gas from the fuel gas tank 510 and a regulator 540 for adjusting the pressure of the fuel gas supplied to the fuel cell 100 are provided. Yes.

  A fuel gas exhaust pipe 550 for discharging fuel exhaust gas is connected to the fuel cell 100. The fuel gas exhaust pipe 550 is also connected to the fuel gas exhaust pipe 560 and the fuel gas recirculation pipe 570. The fuel gas recirculation pipe 570 is connected to the fuel gas supply pipe 520. A hydrogen pump 580 is disposed on the fuel gas reflux pipe 570. The fuel exhaust gas exhausted to the fuel gas exhaust pipe 550 contains unreacted fuel gas. The unreacted fuel gas is recirculated by the fuel gas recirculation pipe 570 and the hydrogen pump 580, and is again fuel cell. 100.

  The oxidizing gas circuit 600 includes a compressor 610, an oxidizing gas supply pipe 620, an oxidizing gas exhaust pipe 630, a humidifier 640, and a back pressure valve 650. In this embodiment, air is used as the oxidizing gas. The compressor 610 takes in air in the atmosphere and compresses it. The compressor 610 is connected to the fuel cell 100 by an oxidizing gas supply pipe 620. The fuel cell 100 is connected to an oxidizing gas exhaust pipe 630 for discharging oxidizing exhaust gas. Here, the oxidizing gas supply pipe 620 is provided with a humidifier 640 that uses the moisture in the oxidizing gas exhaust pipe 630. As described above, the fuel cell 100 according to the present embodiment generates power by reacting hydrogen and oxygen in the air to generate water. The generated water is discharged from the fuel cell 100 to the oxidizing gas exhaust pipe 630 together with the oxidizing exhaust gas. The humidifier 640 humidifies the oxidizing gas by moving the moisture contained in the oxidizing exhaust gas to the oxidizing gas supplied to the fuel cell 100. For example, the humidifier 640 may include an oxidizing gas channel and an oxidizing exhaust gas channel, and may include a humidifying film between the two channels (not shown). Thereby, it is possible to move the moisture in the oxidation exhaust gas in the oxidation exhaust gas channel to the oxidation gas in the oxidation gas channel via the humidifying film. A back pressure valve 650 is provided in the oxidizing gas exhaust pipe 630. The back pressure valve 650 is used to adjust the pressure of air in the fuel cell 100.

  In the present embodiment, a fuel gas exhaust pipe 560 is connected to the oxidizing gas exhaust pipe 630, and an exhaust valve 590 is provided in the fuel gas exhaust pipe 560. As described above, in this embodiment, the fuel gas exhaust pipe 550 is connected to the fuel gas supply pipe 520 via the fuel gas recirculation pipe 570, and recirculates and reuses the fuel gas (hydrogen). Here, when the fuel cell 100 is operated for a long time, nitrogen that does not contribute to the reaction increases in the fuel exhaust gas. The nitrogen is considered to be that the oxidizing gas (in the air) has permeated the electrolyte membrane (not shown) of the fuel cell 100. When nitrogen increases in the fuel exhaust gas, nitrogen also increases in the fuel gas, and the reactivity of the fuel cell 100 decreases. Therefore, in the present embodiment, when the amount of nitrogen in the fuel exhaust gas increases, the exhaust valve 590 is opened, the fuel exhaust gas is caused to flow through the oxidizing gas exhaust pipe 630, and the nitrogen in the fuel gas is exhausted. At this time, part of the hydrogen also flows into the oxidizing gas exhaust pipe 630. Hydrogen is diluted by the oxidizing exhaust gas in the oxidizing gas exhaust pipe 630 and released to the atmosphere.

  The fuel cell cooling circuit 200 includes a cooling water supply pipe 210, a cooling water discharge pipe 215, a three-way valve 245, a radiator pipe 220, a radiator 230, a bypass pipe 240, and a water pump 225. The cooling water supply pipe 210 is a pipe for supplying cooling water to the fuel cell 100, and a water pump 225 is disposed in the cooling water supply pipe 210. The cooling water discharge pipe 215 is a pipe for discharging cooling water from the fuel cell 100. A downstream portion of the cooling water discharge pipe 215 is connected to the radiator pipe 220 and the bypass pipe 240 via a three-way valve 245. A radiator 230 is provided in the radiator pipe 220. The radiator 230 is provided with a radiator fan 235. The radiator fan 235 sends wind to the radiator 230 and promotes heat dissipation from the radiator 230. The downstream part of the radiator pipe 220 and the downstream part of the bypass pipe 240 are connected to the cooling water supply pipe 210. Temperature sensors 250 and 255 are provided on the upstream side of the water pump 225 of the cooling water supply pipe 210 (downstream part of the radiator pipe 220) and the cooling water discharge pipe 215, respectively.

  The cooling water is supplied to the fuel cell 100 by the water pump 225 through the cooling water supply pipe 210 to cool the fuel cell 100. The cooling water is warmed by recovering heat from the fuel cell 100 and discharged from the cooling water discharge pipe 215. The warmed cooling water is distributed and fed to the radiator pipe 220 and the bypass pipe 240 by the three-way valve 245. The cooling water that has flowed to the radiator pipe 220 is cooled by the radiator 230, but the cooling water that has flowed to the bypass pipe 240 is not cooled. The temperature of the cooling water in the fuel cell cooling circuit 200 is controlled by the distribution ratio of the cooling water to the radiator pipe 220 and the bypass pipe 240 by the three-way valve 245, the outside air temperature, and the air volume from the radiator fan 235. For example, immediately after the fuel cell 100 is started, the temperature of the cooling water in the fuel cell cooling circuit 200 can be rapidly increased by flowing most of the cooling water through the bypass pipe 240.

  The heating water circuit 300 includes a branch pipe 305, a three-way valve 340, a hot water supply pipe 310, a water pump 325, an electric heater 330, a heater core 320, a hot water discharge pipe 315, and a hot water reflux pipe 335. . The branch pipe 305 is connected to the cooling water discharge pipe 215 of the fuel cell cooling circuit 200, and distributes a part of the warmed cooling water discharged from the fuel cell 100 to the heating water circuit 300. The three-way valve 340 controls the inflow of cooling water from the fuel cell cooling circuit 200 to the heating water circuit 300. The electric heater 330 heats the cooling water flowing through the heating water circuit 300. The heater core 320 warms the air using the heat of the cooling water flowing through the heating water circuit 300. The warmed air is sent into the fuel cell vehicle 10 and used for heating the vehicle. The hot water discharge pipe 315 returns the waste water from the heater core 320 to the fuel cell cooling circuit 200. The warm water reflux pipe 335 connects between the warm water discharge pipe 315 and the three-way valve 340, and returns the waste water from the heater core 320 to the warm water supply pipe 310. A temperature sensor 345 is disposed between the electric heater 330 and the heater core 320.

  An air conditioner setting unit 410, an outside air temperature sensor 420, and an in-vehicle temperature sensor 430 are connected to the control unit 400. The control unit 400 sets the air conditioner setting unit 410, the outside air temperature, the vehicle interior temperature, and the water temperature upstream of the water pump 225 of the hot water supply pipe 310 of the fuel cell cooling circuit 200 (hereinafter, “water pump upstream water temperature T250”). ), The cooling water temperature at the outlet of the fuel cell 100 of the fuel cell cooling circuit 200 (hereinafter referred to as “cooling water outlet water temperature T255”), and the cooling at the inlet of the heater core 320 of the heating water circuit 300. Based on the water temperature (hereinafter referred to as “heater core inlet water temperature T345”), the operations of the three-way valves 245 and 340, the water pumps 225 and 325, the radiator fan 235, and the electric heater 330 are controlled. In the present embodiment, the fuel cell 100 is used as a power source for auxiliary equipment such as the water pumps 225 and 325 and the hydrogen pump 580. The air conditioner setting unit 410 includes a heating switch, a cooling switch (or an air conditioner switch). Further, a temperature setting button may be provided.

  2 and 3 are explanatory diagrams showing the state of the three-way valve 340 and the flow of cooling water. FIG. 2 shows the flow of cooling water when the three-way valve 340 is in the non-cooperative mode. In the present embodiment, the non-cooperative mode state means that the valve body connected to the branch pipe 305 among the three valve bodies of the three-way valve 340 is closed, and the valve body connected to the hot water supply pipe 310 and the hot water A state in which the valve body connected to the reflux pipe 335 is in an open state. In the non-cooperation mode state, the cooling water flowing through the fuel cell cooling circuit 200 is the cooling water supply pipe 210, the fuel cell 100, the cooling water discharge pipe 215, the three-way valve 245, the radiator pipe 220 (or the bypass pipe 240). ) And the water pump 225 is circulated. The cooling water of the heating water circuit 300 circulates through the hot water supply pipe 310, the water pump 325, the electric heater 330, the heater core 320, the hot water discharge pipe 315, the hot water return pipe 335, and the three-way valve 340. In the non-cooperation mode state, the cooling water does not circulate from the cooling water discharge pipe 215 of the fuel cell cooling circuit 200 to the heating water circuit 300, and is cooled from the heating water circuit 300 to the cooling water discharge pipe 215 of the fuel cell cooling circuit 200. Water does not flow out. The fuel cell cooling circuit 200 and the heating water circuit 300 are in an independent state, and the cooling water flowing through the fuel cell cooling circuit 200 does not circulate to the heating water circuit 300. For example, when the temperature of the fuel cell 100 is low, such as immediately after the start of the fuel cell 100, the temperature of the cooling water in the fuel cell cooling circuit 200 is low. Therefore, the control unit 400 uses the cooling water flowing in the fuel cell cooling circuit 200 and the heating water circuit rather than circulating the cooling water in the fuel cell cooling circuit 200 to the heating water circuit 300 and using it as a heating heat source. It is more efficient to make the cooling water flowing through 300 independent and to heat only the cooling water flowing through the heating water circuit 300 using the electric heater 330.

  FIG. 3 shows the flow of cooling water when the three-way valve 340 is in the cooperation mode state. The cooperation mode state includes a partial cooperation mode and a complete cooperation mode. 3A shows the partial cooperation mode state, and FIG. 3B shows the complete cooperation mode. In the present embodiment, the partial cooperation mode state refers to any of the valve body connected to the branch pipe 305, the valve body connected to the hot water supply pipe 310, and the valve body connected to the hot water reflux pipe 335. The state which becomes an open state. The complete cooperation mode is a state in which the valve body connected to the branch pipe 305 and the valve body connected to the hot water supply pipe 310 are opened, and the valve body connected to the hot water reflux pipe 335 is closed. say.

  When the three-way valve 340 is in the partial cooperation mode, a part of the warmed cooling water discharged from the fuel cell 100 is circulated to the hot water supply pipe 310 through the three-way valve 340. Further, a part of the cooling water flowing through the hot water discharge pipe 315 flows into the cooling water discharge pipe 215 of the fuel cell cooling circuit 200 (FIG. 1), and the remaining part passes through the hot water reflux pipe 335 and the three-way valve 340, It is refluxed to the supply pipe 310.

  In the full cooperation mode, the point that the part of the warmed cooling water discharged from the fuel cell 100 is supplied to the hot water supply pipe 310 through the three-way valve 340 is common to the partial cooperation mode. The total amount of the flowing cooling water is supplied to the cooling water discharge pipe 215 of the fuel cell cooling circuit 200.

  As described above, the control unit 400 controls the movement of cooling water and heat from the fuel cell cooling circuit 200 to the heating water circuit 300 by controlling the mode state of the three-way valve 340. In the cooperation mode, the waste heat of the fuel cell 100 can be used for heating in the vehicle. Note that only one of the partial cooperation mode and the complete cooperation mode may be adopted.

  FIG. 4 is an explanatory diagram showing the configuration of the air conditioning duct 350. The air conditioning duct 350 includes an in-vehicle air intake unit 355, an outside air intake unit 360, an in-vehicle circulation / outside air introduction switching door 365, a heating channel 370, a non-heating channel 375, a partition plate 380, and an air mix door 385. And an in-car blowing part 390. A heater core 320 (FIG. 1) is disposed in the heating channel 370. The in-vehicle circulation / outside air introduction switching door 365 switches between taking in air from the in-vehicle air intake unit 355 or taking in air from the outside air intake unit 360 into the air-conditioning duct 350 according to the setting of the air conditioner setting unit 410 (FIG. 1). . The partition plate 380 separates the heating channel 370 and the non-heating channel 375. The air mix door 385 distributes the taken-in air to the heating channel 370 and the non-heating channel 375. The air distributed to the heating channel 370 is warmed by the heater core 320, but the air distributed to the non-heating channel 375 is not warmed. The air distributed to the heating channel 370 and the non-heating channel 375 is blown into the vehicle from the vehicle blowing unit 390. The control unit 400 (FIG. 1) is based on the setting of the air conditioner setting unit 410 (FIG. 1), the temperature in the vehicle, and the temperature of the cooling water in the heating water circuit 300 (heater core inlet water temperature T345). The distribution ratio of the air to the heating flow path 370 and the non-heating flow path 375 in 385 is controlled, the temperature of the air blown out into the vehicle is controlled, and the vehicle interior temperature is controlled. For example, when the heater core inlet water temperature T345 is high, the temperature of the heater core 320 is also high, so the control unit 400 changes the opening of the air mix door 385 to reduce the amount of air flowing through the heating flow path 370. Make sure that the temperature inside the vehicle does not rise too much.

  FIG. 5 is an example of a control flowchart according to an embodiment of the present invention. Note that this flowchart is executed when the temperature is low, such as in winter. In step S100, when the start switch of the fuel cell vehicle 10 is turned on by an occupant (person), the control unit 400 starts the fuel cell 100. In step S110, the control unit 400 operates the fuel cell 100 normally (operation that is not low-efficiency operation), and sets the operation mode of the three-way valve 340 to the non-cooperation mode. In order to warm up the fuel cell 100 quickly, the control unit preferably sets the operation mode of the three-way valve 340 to the non-cooperation mode. From the viewpoint of fuel efficiency, the control unit 400 preferably operates the fuel cell 100 normally.

  In step S120, when it is detected that the heating switch is turned on by the occupant, control unit 400 shifts the processing to step S130 and turns on electric heater 300.

  In step S140, the control unit 400 determines whether or not the temperature of the fuel cell 140 is equal to or higher than a predetermined determination value. For example, the control unit 400 calculates the temperature of the fuel cell 100 using the water pump upstream water temperature T250, the cooling water outlet water temperature T255, and the rotation speed (cooling water supply amount) of the water pump 225. When the temperature of the fuel cell 100 is equal to or higher than a predetermined determination value, the control unit 400 proceeds to step S150. Considering the case where the fuel cell 100 is in a frozen state, after all the cells of the fuel cell 100 are thawed, the low-efficiency operation described later is performed. For example, the control unit 400 measures the temperature of the cell at the end of the fuel cell 100 with the temperature sensor 110 and determines that all the cells of the fuel cell 100 have been thawed when the temperature becomes 0 ° C. or higher. good. Note that the temperature of the cell near the center of the fuel cell 100 may be measured. The fuel cell 100 may be thawed by heat from the operation of the fuel cell, or may be thawed by being overheated by a fuel cell heater (not shown).

  In step S150, the control unit 400 determines whether or not the fuel cell 100 can output an output equal to or higher than a predetermined determination value. When the fuel cell 100 can output more than the determination value, the control unit 400 proceeds to step S160. When the fuel cell 100 can generate an output that is equal to or higher than the determination value, the control unit 400 causes the fuel cell 100 to perform a low-efficiency operation described later to warm the fuel cell 100. For example, the predetermined output may be an output necessary for normal traveling, and may be 60 kW or 70 kW, for example. The control unit 400 may determine whether or not the fuel cell 100 can output an output equal to or higher than a determination value using the temperature of the fuel cell 100. If the temperature of the fuel cell 100 is 30 ° C. to 40 ° C. or higher, it can be determined that an output higher than the determination value can be output.

  In step S160, the control unit 400 sets the three-way valve 340 to the cooperation mode, and causes the fuel cell 100 to operate with low efficiency. As a result, the cooling water outlet water temperature T255 and the heater core inlet water temperature T345 increase in temperature in the same manner, and the temperature difference between the cooling water outlet water temperature T255 and the heater core inlet water temperature T345 can be reduced.

  FIG. 6 is an explanatory diagram showing IV characteristics during normal operation and IV characteristics during low-efficiency operation of the fuel cell. The voltage of the fuel cell 100 is highest when the current density (current) is zero (OCV (Open Circuit Voltage)) and decreases as the current density (current) increases. Here, if the current is increased while the supply amounts of the fuel gas (hydrogen) and the oxidizing gas (air) are maintained, the voltage of the fuel cell 100 rapidly decreases and the operating point moves to a point P1 in FIG. . At this time, the fuel cell 100 generates heat, and this heat increases the temperature of the fuel cell 100. The energy generated by the chemical reaction of the fuel cell 100 is divided into electric energy and thermal energy. When the control unit 400 performs control to increase the current while maintaining the supply amount of the oxidizing gas, the ratio of electrical energy decreases and the ratio of thermal energy increases. Since the fuel cell vehicle 10 operates using electric energy, reducing the ratio of electric energy and increasing the ratio of thermal energy lowers the efficiency of the fuel cell vehicle 10 (or the fuel cell 100) (lower efficiency). Is equivalent to) In the present embodiment, an operation in which the ratio of electrical energy is reduced and the ratio of thermal energy is increased as compared with a normal operation is referred to as “low efficiency operation”. In the low-efficiency operation, since the ratio of thermal energy increases, the amount of heat generated by the fuel cell 100 increases, and the temperature of the cooling water in the fuel cell cooling circuit 200 and the temperature of the cooling water in the heating water circuit 300 increases.

  In FIG. 6, the control unit 400 may increase the loss (auxiliary loss) of the hydrogen pump 580 by driving the hydrogen pump 580 more strongly. At this time, as the current consumption of the hydrogen pump 580 increases, the amount of current of the fuel cell 100 also increases, so that the operating point moves from the point P1 to the point P2. In addition, when the hydrogen to be recirculated increases, the energy generated by the chemical reaction of the fuel cell 100 increases, and there is an effect that the thermal energy increases. As a result, the temperature of the fuel cell 100 is increased, and the temperature of the cooling water is increased quickly.

  In FIG. 6, the control unit 400 may drive the water pump 225 more strongly to increase the loss of the water pump 225 (auxiliary machine loss). At this time, as the current consumption of the water pump 225 increases, the amount of current of the fuel cell 100 also increases, so that the operating point moves from the point P2 to the point P3. In addition, since the water pump 225 generates heat when operating, and the water pump 225 itself is in contact with the cooling water, there is an effect that heat generated in the water pump 225 can be directly transferred to the cooling water. As a result, the temperature of the cooling water can be increased quickly. Note that either the hydrogen pump 580 or the water pump 225 may be operated more strongly first.

  In step S <b> 170 of FIG. 5, the control unit 400 causes warm air to be blown out from the in-vehicle blowing unit 390. In step S180, control unit 400 determines whether or not cooling water outlet temperature T245 is equal to or higher than a predetermined determination value. When the cooling water outlet temperature T245 becomes equal to or higher than the predetermined determination value, the control unit 400 shifts the process to step S190 and stops the low-efficiency operation of the fuel cell 100. If the fuel cell 100 is warmed up, it is not necessary to generate a large amount of heat by low-efficiency operation. For example, this determination value may be 50 ° C., for example. In this process, the control unit 400 may measure the temperature of the fuel cell 100 using the temperature sensor 110 and make a determination.

  FIG. 7 is an explanatory diagram showing the cooling water outlet temperature T245, the heater core inlet temperature T345, and the temperature T390 of the air blown out from the in-vehicle blowing section 390 (hereinafter referred to as “blowing temperature T390”) in the comparative example. is there. In the comparative example, the heater core inlet temperature T345 and the blowout temperature T390 rise in temperature separately, so both rise in temperature, but the rate of rise is different. In the comparative example, the heater core inlet temperature T345 has a higher temperature increase rate. When the heater core inlet temperature T345 reaches a predetermined temperature, it starts to rise, and thereafter, the temperature rises at substantially the same speed as the heater core inlet temperature T345. Here, when the three-way valve 340 enters the cooperation mode, the high-temperature cooling water flowing through the fuel cell cooling circuit 200 is supplied into the heating water circuit 300, so that the heater core inlet temperature T345 rapidly increases. As a result, the blowing temperature T390 suddenly rises, causing discomfort to the occupant.

  FIG. 8 is an explanatory diagram showing the cooling water outlet temperature T245, the heater core inlet temperature T345, and the blowing temperature T390 in the present embodiment. In the present embodiment, since the three-way valve 340 is in the cooperation mode, the cooling water flowing through the fuel cell cooling circuit 200 is supplied to the heating water circuit 300. As a result, the cooling water outlet temperature T245 and the heater core inlet temperature T345 increase in temperature at substantially the same rate. Here, the blow-out temperature T390 starts to rise when the heater core inlet temperature T345 reaches a predetermined temperature, and thereafter rises at substantially the same speed as the heater core inlet temperature T345. In this embodiment, since the cooling water outlet temperature T245 and the heater core inlet temperature T345 are both in a low temperature state, the three-way valve 340 is in the cooperation mode, and the heater core inlet temperature T345 has a speed substantially the same as the cooling water outlet temperature T245. The temperature rises. Therefore, the heater core inlet temperature T345 does not increase suddenly. On the other hand, in the comparative example, since the heater core inlet temperature T345 and the blowout temperature T390 rise separately, the cooling water outlet temperature T245 when the three-way valve 340 shifts from the non-cooperation mode to the cooperation mode, The temperature difference from the heater core inlet temperature T345 is relatively large. Therefore, when the three-way valve 340 shifts to the cooperation mode, the warm cooling water flowing through the fuel cell cooling circuit 200 is supplied to the heating water circuit 300, so that the heater core inlet temperature T345 greatly fluctuates and the blowing temperature T390 is also It fluctuates greatly. As a result, the passenger is uncomfortable.

  In the present embodiment, the fuel cell 100 is operated with low efficiency, and in the comparative example, the fuel cell 100 is not operated with low efficiency. As a result, the fuel cell 100 generates more heat in the present embodiment than in the comparative example, and the coolant outlet water temperature T255 increases faster in the present embodiment than in the comparative example. In the present embodiment, since the three-way valve 340 is set to the cooperation mode, the heater core inlet water temperature T345 rises in conjunction with the cooling water outlet water temperature T255. On the other hand, in the comparative example, the cooling water of the heating water circuit 300 is heated by the electric heater 330, but the three-way valve 340 is not in the cooperation mode, so that the heat of the fuel cell 100 can be transmitted to the cooling water of the heating water circuit 300. I can't. Therefore, the heater core inlet water temperature T345 rises only slowly. Even if the heat of the fuel cell 100 can be transferred to the cooling water of the heating water circuit 300, since the fuel cell 100 is operated efficiently and generates little heat, the heater core inlet water temperature T345 only rises slowly.

  In the present embodiment, the three-way valve 340 is used in the present embodiment. However, instead of the three-way valve 340, another type of valve (for example, an on-off valve) is provided between the fuel cell cooling circuit 200 and the heating water circuit 300. Or a flow control valve) and a configuration without the hot water reflux pipe 335 may be used. Also in this case, the operating state of the on-off valve (flow control valve) is either the non-cooperation mode or the cooperation mode (complete cooperation mode).

  In this embodiment, the temperature and output of the fuel cell 100 are determined in steps S140 and S150. However, these determinations may be omitted. When these determinations are not performed, immediately after the start of the fuel cell, the three-way valve 340 is in the cooperation mode in response to the heating switch being turned on, and the fuel cell 100 is operated at a low efficiency.

  In the above-described embodiment, the control unit 400 sets the three-way valve 340 in the cooperation mode from the start of the fuel cell 100. However, for example, before the warm air is blown from the in-vehicle blowing unit 390, the three-way valve 340 may be set in the cooperation mode. Good. When the three-way valve 340 is changed from the non-cooperation mode to the cooperation mode after the hot air is blown out from the in-car blowing unit 390, the heater core inlet water temperature T345 greatly fluctuates, and the blowout temperature T390 also fluctuates greatly. If the control unit 400 has previously changed the three-way valve 340 from the non-cooperation mode to the cooperation mode, even if the heater core inlet water temperature T345 fluctuates greatly, the warm air from the in-vehicle outlet 390 is not blown out. As a result, the blowing temperature T390 does not fluctuate greatly after the warm air from the in-vehicle blowing unit 390 is blown out.

  The embodiments of the present invention have been described above based on some embodiments. However, the embodiments of the present invention described above are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell vehicle 100 ... Fuel cell 110 ... Temperature sensor 200 ... Cooling circuit for fuel cells 210 ... Cooling water supply pipe 215 ... Cooling water discharge pipe 220 ... Radiator pipe 225 ... Water pump 230 ... Radiator 235 ... Radiator fan 240 ... Bypass Pipe 245 ... Three-way valve 250 ... Temperature sensor 300 ... Water circuit for heating (cooling water circuit for air conditioning)
305 ... Branch pipe 310 ... Warm water supply pipe 315 ... Warm water discharge pipe 320 ... Heater core 325 ... Water pump 330 ... Electric heater 335 ... Warm water return pipe 340 ... Three-way valve 345 ... Temperature sensor 350 ... Air conditioning duct 355 ... Car air intake section 360 ... Outside air intake part 365 ... Outside air introduction switching door 370 ... Heating flow path 375 ... Non-heating flow path 380 ... Partition plate 385 ... Air mix door 390 ... Car interior blowing part 400 ... Control part (ECU)
410: Air conditioner setting unit 420 ... Outside air temperature sensor 430 ... Inside temperature sensor 500 ... Fuel gas circuit 510 ... Fuel gas tank 520 ... Fuel gas supply pipe 530 ... Open / close valve 540 ... Regulator 550 ... Fuel gas exhaust pipe 560 ... Fuel gas exhaust pipe 570 ... fuel gas recirculation pipe 580 ... hydrogen pump 590 ... exhaust valve 600 ... oxidizing gas circuit 610 ... compressor 620 ... oxidizing gas supply pipe 630 ... oxidizing gas exhaust pipe 640 ... humidifier 650 ... back pressure valve T255 ... cooling water outlet water temperature T345 ... heater core Inlet water temperature

Claims (6)

A fuel cell vehicle,
A fuel cell;
A fuel cell cooling circuit for cooling the fuel cell;
A heating water circuit used to heat the interior of the fuel cell vehicle;
A valve for controlling the supply of cooling water from the fuel cell cooling circuit to the heating water circuit;
A control unit for controlling the operation of the fuel cell vehicle;
With
When the fuel cell is in an unfrozen state, the control unit opens the valve regardless of the temperature of the cooling water immediately after the start of the fuel cell, according to the heating switch being turned on. A fuel cell vehicle that starts an operation of circulating cooling water flowing through the circuit to the heating water circuit. The fuel cell vehicle according to claim 1,
The control unit is configured to reduce the efficiency of the fuel cell to be lower than the efficiency during normal operation of the fuel cell vehicle when circulating the cooling water flowing through the cooling circuit for the fuel cell to the heating water circuit. Run the fuel cell vehicle. The fuel cell vehicle according to claim 2, wherein
A fuel gas circuit for supplying fuel gas to the fuel cell;
An oxidizing gas circuit for supplying an oxidizing gas to the fuel cell;
With
The said control part is a fuel cell vehicle which performs the said low efficiency driving | operation by increasing the electric current of the said fuel cell, maintaining the quantity of the fuel gas and oxidizing gas which are supplied to the said fuel cell. A cooling circuit for a fuel cell that collects heat from the fuel cell by flowing cooling water, and a heating water circuit that is connected to the cooling circuit for the fuel cell and uses the heat for heating in the air conditioning of the interior of the fuel cell vehicle. A control method for a fuel cell vehicle comprising: a valve that controls supply of the cooling water from the fuel cell cooling circuit to the heating water circuit,
Immediately after starting the fuel cell, in response to turning on the heating switch, if the fuel cell is in an unfrozen state, the cooling water flows through the fuel cell cooling circuit by opening the valve regardless of the temperature of the cooling water. A control method for a fuel cell vehicle, in which an operation for circulating the water in the heating water circuit is started. In the control method of the fuel cell vehicle according to claim 4 ,
When the cooling water flowing through the fuel cell cooling circuit is circulated to the heating water circuit, a low-efficiency operation is performed in which the efficiency of the fuel cell is lower than that during normal operation of the fuel cell vehicle. Fuel cell vehicle control method. In the control method of the fuel cell vehicle according to claim 5 ,
A control method for a fuel cell vehicle, wherein the low-efficiency operation is executed by increasing the current of the fuel cell while maintaining the amounts of fuel gas and oxidizing gas supplied to the fuel cell.

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