JP6139354B2 - 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.

  2. Description of the Related Art There is known a fuel cell vehicle including a heater core that heats air for air conditioning using cooling water of a cooling circuit that cools the fuel cell of the fuel cell vehicle as a heat source (for example, Patent Document 1).

JP2013-14268A

  In the fuel cell vehicle, the load of the fuel cell greatly varies depending on the traveling state. When a high load is applied to the fuel cell, the temperature of the fuel cell rises and the temperature of the cooling water rises. The heat of the cooling water is used to heat the heater core for heating. Excess heat is dissipated from the radiator. On the other hand, when the load of the fuel cell is reduced, the temperature of the fuel cell is lowered, the temperature of the cooling water is lowered, and the temperature of the heater core is lowered. Here, when sufficient air conditioning temperature cannot be maintained by heating from cooling water, heating is performed by an electric heater provided in the air conditioning system. As described above, since heat is thrown away at high loads and heat that is insufficient at low loads is heated by the electric heater, there is a problem that it is difficult to improve the efficiency of the fuel cell vehicle as a whole.

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 branches from the fuel cell, a fuel cell cooling circuit that cools the fuel cell using cooling water, and the fuel cell cooling circuit, and uses the heat of the cooling water. A cooling water circuit for heating the interior of the vehicle, a control unit for controlling the temperature of the cooling water in the cooling circuit for the fuel cell, an outside air temperature sensor, an in-vehicle temperature sensor, and an air conditioner setting unit. The control unit includes at least one of an outside air temperature measured by the outside air temperature sensor, an inside temperature measured by the in-vehicle temperature sensor, a set temperature of the air conditioner setting unit, and the cooling water of the cooling water circuit for heating. A target temperature of the cooling water in the heating cooling water circuit is set from at least one of the outside air temperature, the in-vehicle temperature, and the set temperature, using a map that defines a relationship with the target temperature of (a1), When the outside air temperature is equal to or higher than a predetermined temperature and the target temperature of the cooling water in the heating water circuit is less than a predetermined temperature, the cooling water A first control process is performed to set the coolant outlet water temperature at the outlet of the fuel cell to the first water temperature. (B1) When neither of the two conditions is satisfied, the coolant outlet water temperature is set to the first temperature. Temperature than water temperature Performing a second control process of the high second temperature. According to the fuel cell vehicle of this aspect, both of the two conditions that the outside air temperature is equal to or higher than the predetermined temperature and the target temperature of the cooling water of the heating cooling water circuit is lower than the predetermined temperature are satisfied. If not, heat is stored in the cooling water by increasing the temperature of the cooling water and used for heating. If the fuel cell generates less heat, the heat stored in the cooling water is used for heating. Therefore, less heat is discarded, and the overall thermal efficiency of the fuel cell vehicle can be increased.

(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 that cools the fuel cell using cooling water, and a heating coolant circuit that heats the interior of the fuel cell vehicle using heat of the cooling water. And a control unit for controlling the temperature of the cooling water in the fuel cell cooling circuit, and an outside air temperature sensor, wherein the control unit is (a1) an outside air temperature equal to or higher than a predetermined temperature, or (a2 ) When the target temperature of the cooling water in the heating cooling water circuit is lower than a predetermined temperature, a first control process is performed to set the cooling water outlet water temperature at the fuel cell outlet of the cooling water to the first water temperature. And (b1) when the outside air temperature is lower than the predetermined temperature and (b2) the target temperature is equal to or higher than the predetermined temperature, the cooling water outlet water temperature is set to the first temperature. The second water temperature is higher than the water temperature of the second To execute the control processing. According to the fuel cell vehicle of this aspect, when (b1) the outside air temperature is lower than the predetermined temperature and (b2) the target temperature is equal to or higher than the predetermined temperature, the cooling water When the temperature is increased, heat is stored in the cooling water and used for heating. When the fuel cell generates less heat, the heat stored in the cooling water is used for heating, so less heat is wasted. As a whole, it becomes possible to increase the thermal efficiency of the fuel cell vehicle.

(2) In the fuel cell vehicle according to the above aspect, the control unit is configured such that (a1) the outside air temperature is equal to or higher than the predetermined temperature, (a2) the target temperature is lower than a predetermined temperature, (a3) the fuel When the load of the battery satisfies at least one of the predetermined values, the first control process is executed, (b1) the outside air temperature is less than the predetermined temperature, and (B2) When the target temperature is equal to or higher than a predetermined temperature and (b3) the load of the fuel cell is equal to or higher than a predetermined value, the second control process is executed. Good. When the fuel cell is generating an output that is greater than or equal to a predetermined output, the amount of heat generated is also large, so that heat can be efficiently stored in the cooling water.

  (3) The fuel cell vehicle according to the above aspect further includes an impedance measurement unit that measures the impedance of the fuel cell, and the control unit is configured to execute the second control process according to claim 1 or 2. 3. The second control according to claim 1 or 2, wherein even if is established, if the magnitude of the resistance component of the impedance is equal to or greater than a predetermined value, the first control process is executed, If the condition for executing the control process is satisfied and the magnitude of the resistance component of the impedance is less than a predetermined value, the second control process may be executed. Fuel cells become less efficient when the electrolyte membrane is dried. The resistance component of impedance depends on the degree of drying of the electrolyte membrane, and increases in a dry state and decreases in a wet state. According to the fuel cell vehicle of this aspect, the control unit is configured such that when the resistance component of the impedance is equal to or smaller than a predetermined value (sufficiently wet, the temperature of the fuel cell is raised and the moisture of the electrolyte membrane is increased). If it is difficult to dry even if it evaporates), the second control process is executed to raise the temperature of the cooling water, and when the resistance component of the impedance exceeds a predetermined value (is sufficiently wet) In the case where the temperature of the fuel cell is raised and there is a risk of drying when the water content of the electrolyte membrane evaporates), the first control process is executed and the temperature of the cooling water is not raised. In other words, if the electrolyte membrane is difficult to dry even if the temperature of the fuel cell is raised, the heat of the fuel cell vehicle is increased because the heat is used for heating by increasing the temperature of the cooling water, so that this heat is used for heating. Can be increased.

  The present invention can be realized in various forms, for example, in the form of a control method in a fuel cell vehicle, a fuel cell cooling control method, and the like in addition to a fuel cell vehicle.

It is explanatory drawing which shows typically the cooling circuit for fuel cells of a fuel cell vehicle, and the cooling water circuit for heating. 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 flow of the cooling water when a three-way valve is a cooperation mode state. 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 the relationship between external temperature and the determination parameter J1. It is explanatory drawing which shows the relationship between the target temperature of heater core inlet water temperature, and the determination parameter J2. It is explanatory drawing which shows the relationship between an impedance and the target temperature of a cooling water exit water temperature. It is explanatory drawing which shows the relationship between a cooling water exit water temperature and the state of a three-way valve. It is explanatory drawing which shows the relationship between the heater core inlet water temperature T and the state of a three-way valve. It is explanatory drawing which shows the effect of this embodiment typically.

  FIG. 1 is an explanatory diagram schematically showing a fuel cell cooling circuit 200 and a heating coolant circuit 300 for a fuel cell vehicle. The fuel cell vehicle 10 includes a fuel cell 100, a fuel cell cooling circuit 200, a heating coolant circuit 300, and a control unit 400 (ECU: Electronic Control Unit).

  The fuel cell 100 is, for example, a power generation device that generates electricity by reacting hydrogen and oxygen. An impedance measuring unit 110 and a load 120 are connected to the fuel cell 100. The impedance measuring unit 110 measures a resistance component (hereinafter, also referred to as “internal resistance”) of the impedance of the fuel cell 100 using, for example, an AC impedance method. For example, according to Japanese Patent Laid-Open No. 2009-252706, when the frequency of the applied current is large (ω = ∞), the electrolyte membrane resistance can be acquired as the impedance, and when the frequency of the applied current is small (ω = 0), the electrolyte as the impedance Sum of membrane resistance and reaction resistance due to electrochemical reaction can be obtained. In the present embodiment, it is preferable that the impedance measurement unit 110 obtains an electrolyte membrane resistance as a resistance component of impedance. The load 120 includes a device that uses the electric energy of the fuel cell 100, such as an electric motor (not shown) that moves the fuel cell vehicle 10.

  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 pump 225. The cooling water supply pipe 210 is a pipe for supplying cooling water to the fuel cell 100, and a 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 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 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. The temperature of the cooling water 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 can be rapidly increased by flowing most of the cooling water through the bypass pipe 240.

  The heating coolant circuit 300 includes a branch pipe 305, a three-way valve 340, a hot water supply pipe 310, a pump 325, an electric heater 330, a heater core 320, a hot water discharge pipe 315, and a hot water reflux pipe 335. Prepare. The branch pipe 305 is connected to the coolant discharge pipe 215 of the fuel cell cooling circuit 200, and distributes a part of the warmed coolant discharged from the fuel cell 100 to the heating coolant circuit 300. The three-way valve 340 controls the inflow of coolant from the fuel cell cooling circuit 200 to the heating coolant circuit 300. The electric heater 330 heats the coolant flowing through the heating coolant circuit 300. The heater core 320 warms the air using the heat of the cooling water flowing through the heating cooling 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, the water temperature upstream of the pump 225 of the hot water supply pipe 310 of the fuel cell cooling circuit 200, and the fuel of the fuel cell cooling circuit 200. The temperature of the cooling water at the outlet of the battery 100 (hereinafter referred to as “cooling water outlet water temperature T255”) and the temperature of the cooling water at the inlet of the heater core 320 of the heating cooling water circuit 300 (hereinafter referred to as “heater core inlet water temperature T345”). )), The operations of the three-way valves 245 and 340, the pumps 225 and 325, the radiator fan 235, and the electric heater 330 are controlled.

  FIG. 2 is an explanatory diagram showing the flow of cooling water when the three-way valve 340 is in the non-cooperation mode state. 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 pump 225 is circulated. The cooling water of the heating cooling water circuit 300 circulates through the hot water supply pipe 310, the 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 flow from the cooling water discharge pipe 215 of the fuel cell cooling circuit 200 into the heating cooling water circuit 300, and the cooling water discharge of the fuel cell cooling circuit 200 from the heating cooling water circuit 300 occurs. The cooling water does not flow out to the pipe 215. The cooling circuit for fuel cell 200 and the cooling water circuit for heating 300 are in an independent state, and the cooling water flowing through the cooling circuit for fuel cell 200 and the cooling water flowing through the cooling water circuit for heating 300 are not mixed. 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 distributes the cooling water in the fuel cell cooling circuit 200 to the heating cooling water circuit 300 and uses it as a heating heat source, It is more efficient to make the cooling water flowing through the cooling water circuit 300 independent and to heat only the cooling water flowing through the heating cooling water circuit 300 using the electric heater 330.

  FIG. 3 is an explanatory diagram showing 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 state, a 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. 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 flows 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 cooling 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 merges at the in-vehicle outlet 390 and is blown into the vehicle. The control unit 400 (FIG. 1) determines the air temperature 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 coolant 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 the mix door 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. In step S100, control unit 400 determines whether or not the load of fuel cell 100 is equal to or greater than a predetermined value. The controller 400 can calculate the load using the voltage and current of the fuel cell 100. When the load is less than the predetermined value, the control unit 400 proceeds to step S110, and sets the target temperature of the cooling water of the fuel cell cooling circuit 200 to a predetermined value (TL described later). Set. On the other hand, when the load is greater than or equal to a predetermined value, control unit 400 proceeds to step S120.

  In step S120, control unit 400 acquires the outside air temperature and determines determination parameter J1 based on the outside air temperature. FIG. 6 is an explanatory diagram showing the relationship between the outside air temperature and the determination parameter J1. When the outside air temperature is equal to or higher than T2, which is a predetermined temperature, control unit 400 sets determination parameter J1 to zero. On the other hand, when the outside air temperature is equal to or lower than T1, which is a predetermined temperature (T1 <T2), the control unit 400 sets the determination parameter J1 to 1. When the outside air temperature is between T1 and T2, it depends on the change in the outside air temperature and the previous value of the determination parameter J1. When the outside air temperature falls and the judgment parameter J1 is 0, even if the outside air temperature is less than T2, the judgment parameter J1 remains 0 until the temperature falls to T1, and it is judged that the outside air temperature reaches T1. The parameter J1 becomes 1. If the outside air temperature changes from the decreasing direction to the increasing direction before the outside temperature reaches T1, the determination parameter J1 remains zero. When the outside air temperature rises and the judgment parameter J1 is 1, even if the outside air temperature exceeds T1, the judgment parameter J1 is 1 until it rises to T2, and when the outside air temperature reaches T2, the judgment parameter J1 Becomes 0. If the outside air temperature changes from the rising direction to the decreasing direction before the outside temperature reaches T2, the determination parameter J1 remains at 1. For example, when the determination parameter J1 is determined based on whether the outside air temperature is higher or lower than T2 so as not to have hysteresis between the outside air temperature and the determination parameter J1, a change in which the outside air temperature rises across T2, T2 The determination parameter J1 fluctuates in any of the changes that fall across. On the other hand, in this embodiment, since the relationship between the outside air temperature and the judgment parameter J1 is provided with hysteresis, the judgment parameter J1 changes when the outside air temperature changes across T2, but the outside air temperature changes. In the case of a change that falls across T2, the determination parameter J1 does not change. Therefore, frequent fluctuations in the determination parameter J1 can be suppressed. In this embodiment, for example, 20 ° C. is adopted as the temperature T1, and 25 ° C. is adopted as the T2. The reason why T2 is set to 25 ° C. is that in the case of an air conditioner for automobiles, it is often set to 25 ° C. throughout the season, and when the outside temperature is higher than this temperature (25 ° C.), the possibility of heating is low. So there is little need to store heat. Moreover, it is because the effect of heat storage is also small. The reason why T1 is set to 20 ° C. is that if T1 = T2 or the temperature difference between T1 and T2 is small, the determination parameter J1 frequently fluctuates as described above. It is a thing. The temperatures at T1 and T2 do not have to be 20 ° C. and 25 ° C., respectively.

  In step S120 of FIG. 5, when determination parameter J1 is 0, control unit 400 proceeds to step S110, and when determination parameter J1 is 1, control unit 400 proceeds to step S130. Since the possibility of a heating request is low when the outside air temperature is high, the control unit 400 sets the determination parameter J1 to 0 and sets the target temperature of the cooling water of the fuel cell cooling circuit 200 to a predetermined value (described later). TL).

  In step S130, the control unit 400 determines the next processing step using the target temperature of the heater core inlet water temperature T345. The heater core inlet water temperature T345 refers to the temperature of the cooling water immediately before entering the heater core 320. The heater core inlet water temperature T345 can be measured by the temperature sensor 345. The controller 400 may set the target temperature of the heater core inlet water temperature T345 according to a predetermined map using at least one of the outside air temperature, the in-vehicle temperature, and the set temperature in the air conditioner setting unit 410.

FIG. 7 is an explanatory diagram showing the relationship between the target temperature of the heater core inlet water temperature T345 and the determination parameter J2. When the target temperature of the heater core inlet water temperature T345 is equal to or higher than T4, the control unit 400 sets the determination parameter J2 to 1. On the other hand, when the target temperature of the heater core inlet coolant temperature T345 is T3 following (T3 <T4), the control unit 400, a determination parameter J2 to 0. Incidentally, when the target temperature of the heater core inlet water temperature T345 is between T3 and T4, as in the graph of FIG. 6, the relationship between the target temperature of the heater core inlet water temperature T345 and the determination parameter J2 is provided with hysteresis. In the present embodiment, for example, 35 ° C. (T3 = T1 + 15 ° C.) is adopted as the temperature T3, and 40 ° C. (T4 = T2 + 15 ° C.) is adopted as the T4. When heating the interior of the vehicle, air is heated from the heater core 320. Here, the heater core inlet water temperature T345 has poor heating efficiency unless the temperature is somewhat higher than the air conditioner set temperature (for example, 25 ° C.). Therefore, T4 is set to 40 ° C which is 15 ° C higher than 25 ° C, and T3 is set to 35 ° C which is 5 ° C lower than T4 in order to provide hysteresis. Note that the temperatures of T3 and T4 may not be 35 ° C. and 40 ° C., respectively. Note that the target temperature of the heater core inlet water temperature T345 is also a parameter for determining whether it is cooling or heating. Therefore, in step S130, the control unit 400 may determine the determination parameter J2 by a cooling / heating switching switch in the air conditioner setting unit 410 instead of the target temperature of the heater core inlet water temperature T345.

  In step S130 of FIG. 5, when determination parameter J2 is 0, control unit 400 proceeds to step S110, and when determination parameter J2 is 1, control unit 400 proceeds to step S140. In the case of cooling, since it is not necessary to warm the cooling water, the control unit 400 sets the determination parameter J2 to 0 and sets the target temperature of the cooling water of the fuel cell cooling circuit 200 to a predetermined value (described later). TL).

  FIG. 8 is an explanatory diagram showing the relationship between the impedance and the target temperature of the coolant outlet water temperature T255. In step S140 of FIG. 5, the control unit 400 sets a target temperature of the coolant outlet water temperature T255 for the coolant of the fuel cell cooling circuit 200 based on the resistance component (internal resistance) of the impedance of the fuel cell 100. When the resistance component of the impedance is equal to or greater than R2 that is a predetermined value, the control unit 400 sets the target value of the coolant temperature of the fuel cell cooling circuit 200 to the initial value TL. On the other hand, when the resistance component of the impedance is equal to or less than a predetermined value R1 (R1 <R2), the control unit 400 sets the target value of the coolant temperature of the fuel cell cooling circuit 200 to TH (TH> TL). Set to. The resistance component of the impedance of the fuel cell 100 depends on the moisture content (wet state) of the electrolyte membrane (not shown) of the fuel cell 100 as disclosed in JP-A-2009-252706. That is, when the impedance is small, the electrolyte membrane is sufficiently wet. In such a case, even if the temperature of the fuel cell 100 rises slightly from TL to TH and moisture is evaporated from the electrolyte membrane, the electrolyte membrane is difficult to dry. The value of R1 can be experimentally determined from the amount of water in the electrolyte membrane and the degree of progress of drying of the electrolyte membrane depending on the temperature. Note that hysteresis may be set between the resistance component of the impedance of the fuel cell 100 and the target temperature of the cooling water by setting R2 having a resistance value larger than R1. Further, the temperatures TL and TH may be appropriate operating temperature ranges of the fuel cell 100, and the temperature TH may be close to the upper limit of the appropriate operating temperature range.

  When the outside air temperature is equal to or higher than T1 and the target temperature of the heater core inlet water temperature T345 is lower than T4, the target temperature of the cooling water outlet water temperature T255 is set to the first water temperature (TL) lower than the second water temperature (TH). ). Since the outside air temperature is high (T1 or higher), the possibility of heating the inside of the vehicle is low. Therefore, it is not necessary to increase the temperature of the coolant outlet water temperature T255 to the second temperature (TH) and store the heat for heating the inside of the vehicle. Further, since the outside air temperature is high, the amount of decrease in the coolant temperature is low even when the fuel cell 100 is stopped (during idling). Therefore, it is less necessary to store heat in the cooling water in advance when heat for heating the vehicle is required.

  In step S150, the control unit 400 controls the temperature of the cooling water in the fuel cell cooling circuit 200 (the temperature of the cooling water discharged from the fuel cell 100 (cooling water outlet water temperature T255)) and the cooling in the cooling water circuit 300 for heating. Based on the temperature of the water (heater core inlet water temperature T345), the state of the three-way valve 340 is controlled, and the first control process in the claims is a process in which the processes in steps S140 and S150 are combined.

  FIG. 9 is an explanatory diagram showing the relationship between the coolant outlet water temperature and the state of the three-way valve 340. There are three states of the three-way valve 340: a value 0 (the above-described non-cooperation mode), a value 1 (the above-described partial cooperation mode), and a value 2 (the above-described complete cooperation mode). When the cooling water outlet water temperature T255 is equal to or lower than T7, the three-way valve 340 is in the non-cooperative mode (the state shown in FIG. 2), and when the cooling water outlet water temperature T255 is equal to or higher than T10, the three-way valve 340 is in the complete cooperative mode (see FIG. B)). The graph of FIG. 9 has hysteresis. When the three-way valve 340 is in the non-cooperation mode and the cooling water outlet water temperature T255 is increased, the three-way valve 340 is in the partial cooperation mode (the state shown in FIG. 3A) when the cooling water outlet water temperature T255 is T9. It becomes cooperation mode. Conversely, when the three-way valve 340 is in the complete cooperation mode and the cooling water outlet water temperature T255 is lowered, the three-way valve 340 is in the partial cooperation mode when the cooling water outlet water temperature T255 is T8, and is in the non-cooperation mode when T7 is reached.

  FIG. 10 is an explanatory diagram showing the relationship between the heater core inlet water temperature T345 and the state of the three-way valve 340. When the heater core inlet water temperature T345 is equal to or lower than T11, the three-way valve 340 is in the non-cooperative mode (the state shown in FIG. 2). State). Note that FIG. 10 also has hysteresis.

  When the three-way valve 340 is in the fully linked mode or the partially fully linked mode, the cooling water of the fuel cell cooling circuit 200 flows into the heating cooling water circuit 300. Therefore, the movement of the cooling water outlet water temperature T255 and the heater core inlet water temperature T345 is linked. When the cooling water outlet water temperature T255 increases, the heater core inlet water temperature T345 increases. When the cooling water outlet water temperature T255 decreases, the heater core inlet water temperature T345 also decreases. In this embodiment, when the state of the three-way valve obtained by FIGS. 9 and 10 contradicts, the state of the three-way valve is determined as follows. When the cooling water outlet water temperature T255 is lowered, the control unit 400 sets the priority in the order of complete cooperation mode, partial cooperation mode, and non-cooperation mode. In other words, if one of the determinations is in the complete cooperation mode, the full cooperation mode is set even if the other determination is in the partial cooperation mode or the non-cooperation mode. On the other hand, when the coolant outlet water temperature T255 increases, the priority is set in the order of the non-cooperation mode, the partial cooperation mode, and the complete cooperation mode. That is, if any one of the determinations indicates the non-cooperation mode, the non-cooperation mode is set even if the other determination is the partial cooperation mode or the complete cooperation mode. Note that the controller 400 may determine the state of the three-way valve 340 based only on the coolant outlet water temperature T255.

  In step S <b> 160, the control unit 400 opens and closes the air mix door 385 and controls the vehicle interior temperature to approach the target temperature set by the air conditioner setting unit 410. For example, when the heater core inlet water temperature T345 is high and the temperature of the heater core 320 is high, the amount of air passing through the heating channel 370 is reduced compared to when the heater core inlet water temperature T345 is low, and the amount of air passing through the non-heating channel 375 is reduced. By reducing the amount, it is possible to blow out air at the same temperature from the in-vehicle blowing unit 390.

  FIG. 11 is an explanatory diagram schematically showing the effect of the present embodiment. As the output (load) of the fuel cell 100 increases, the heat generation of the fuel cell 100 increases and the coolant outlet water temperature T255 increases. When the coolant outlet water temperature T255 reaches T10, the control unit 400 sets the three-way valve 340 to the complete linkage mode, and stops heating the coolant in the heating coolant circuit 300 by the electric heater 330. In the case of the comparative example, the coolant outlet water temperature T255 is controlled so as not to exceed TL, and excess heat is radiated from the radiator 230. On the other hand, in the present embodiment, when the impedance is small, the cooling water outlet water temperature T255 is controlled so as not to exceed TH, and excess heat is radiated from the radiator 230. In this embodiment, as compared with the comparative example, the amount of heat corresponding to the hatching X can be accumulated in the cooling water.

  Thereafter, for example, when the fuel cell 100 is in an idling state and the output decreases, the heat generation of the fuel cell 100 decreases, and the coolant outlet water temperature T255 decreases. In the fuel cell vehicle 10, the idling state means that the fuel cell vehicle 10 is stopped and the fuel cell 100 is not subjected to a load for traveling, but power from the fuel cell 100 to an auxiliary device such as an air conditioner is electric power. Says the state that is being supplied. When the fuel cell vehicle 10 is in an idling state, at the same time, the coolant outlet water temperature T255 of the present embodiment is higher than the coolant outlet water temperature T255 of the comparative example. When the cooling water outlet water temperature T255 falls to T7, the three-way valve 340 is set to the non-cooperation mode, and the electric heater 330 is turned on. In the comparative example, the time when the coolant outlet water temperature T255 falls to T7 and the electric heater 330 is turned on is t1, but in this embodiment, it is t2. Therefore, in this embodiment, the time when the electric heater 330 is turned on can be delayed from t1 to t2. That is, in this embodiment, the heat energy is used for heating by increasing the cooling water outlet water temperature T255, and this heat energy is used for heating. When the cooling water outlet water temperature T255 is lowered, the time when the cooling water outlet water temperature T255 falls to T7 is later than that of the comparative example, so that the time when the electric heater 330 is turned on can be delayed. Since it is not necessary to use the electric heater 330 by the amount, electric energy can be saved.

  In the present embodiment, the case where the temperature of the fuel cell 100 is changed to an idling state in which the temperature of the fuel cell 100 is likely to decrease has been described as an example, but the load of the fuel cell 100 may be reduced.

  In this embodiment, the operation state of the three-way valve 340 is set to three modes (non-cooperation mode, partial cooperation mode, and complete cooperation mode). However, only one of the partial cooperation mode and the complete cooperation mode may be adopted. . In this case, the three-way valve 340 is assumed to have two mode states (open / closed state), that is, a non-cooperation mode and a cooperation mode. Further, in the present embodiment, the three-way valve 340 is used, but instead of the three-way valve 340, another type of valve (for example, an on-off valve or an on-off valve) is provided between the fuel cell cooling circuit 200 and the heating coolant circuit 300. A flow control valve) may be provided, and the hot water reflux pipe 335 may not be provided. 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 the present embodiment, the three-way valve 340 is provided. However, the cooling circuit 200 for the fuel cell and the cooling water circuit 300 for heating are integrated without providing a valve such as the three-way valve 340. The structure provided with a water circuit may be sufficient.

  In the present embodiment, the temperature of the coolant outlet temperature T255 in the fuel cell cooling circuit 200 is configured as a control target. However, the control target is measured by measuring the temperature of the coolant in other locations of the fuel cell cooling circuit 200. May be used as

  Some of the three determinations of steps S100, S120, and S130 in FIG. 5 may be omitted.

  In the present embodiment, the temperature of the cooling water is controlled by the amount of heat released from the radiator, but the temperature control of the cooling water may be performed by other methods. For example, the controller 400 may increase or decrease the amount of cooling water that flows into the fuel cell 100. For example, if the amount of cooling water flowing into the fuel cell 100 is decreased, the temperature of the cooling water can be increased. Further, the controller 400 may increase or decrease the amount of heat generated by the fuel cell 100 by changing the operating point of the fuel cell 100. Also in this case, the temperature of the cooling water can be raised or lowered.

  In the present embodiment, the control unit 400 sets the target temperature of the coolant outlet water temperature T255 for the coolant of the fuel cell cooling circuit 200 based on the magnitude of the impedance resistance component. As described above, the resistance component of the impedance depends on the degree of drying of the electrolyte membrane of the fuel cell 100. That is, in the present embodiment, the reason why the control unit 400 considers the magnitude of the resistance component of the impedance is to prevent the electrolyte membrane of the fuel cell 100 from being dried too much. The control unit 400 does not consider the drying of the electrolyte membrane, that is, the magnitude of the resistance component of the impedance, and cools the cooling water of the fuel cell cooling circuit 200 based on the outside air temperature and the target temperature of the heater core inlet water temperature T345. A target temperature of the water outlet water temperature T255 may be set. Specifically, in step S140 of FIG. 5, when J2 = 1, the target temperature of the coolant outlet water temperature T255 may be set to TH.

  In the above embodiment, the control unit 400 determines whether or not the load of the fuel cell 100 is equal to or greater than a predetermined value in step S100, and the load of the fuel cell 100 is equal to or greater than a predetermined value. When the target temperature of the heater core inlet water temperature T345 is equal to or higher than a predetermined temperature, the target temperature of the cooling water outlet water temperature T255 is set high (TH). This is because the greater the load on the fuel cell 100, the more easily the fuel cell 100 generates heat, and the heat is easily stored in the cooling water. The controller 400 may set the target temperature of the coolant outlet water temperature T255 based on the outside air temperature and the target temperature of the heater core inlet water temperature T345 without determining the load of the fuel cell 100.

  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 ... Impedance measuring part 120 ... Load 200 ... Cooling circuit for fuel cells 210 ... Cooling water supply pipe 215 ... Cooling water discharge pipe 220 ... Radiator pipe 225 ... Pump 230 ... Radiator 235 ... Radiator fan 240 ... Bypass pipe 245 ... Three-way valve 250 ... Temperature sensor 300 ... Heating cooling water circuit 305 ... Branch pipe 310 ... Hot water supply pipe 315 ... Hot water discharge pipe 320 ... Heater core 325 ... Pump 330 ... Electric heater 335 ... Hot water reflux pipe 340 ... Three-way valve 345 ... Temperature sensor 350 ... Air conditioning duct 355 ... Vehicle air intake section 360 ... Outside air intake section 365 ... Outside air introduction switching door 370 ... Heating channel 375 ... Non-heating channel 380 ... Partition plate 385 ... Air mix door 390 ... Vehicle interior Air outlet 400 ... Control unit 410 ... Air conditioner installation Fixed portion 420 ... Outside air temperature sensor 430 ... In-vehicle temperature sensor

Claims (6)

A fuel cell vehicle,
A fuel cell;
A fuel cell cooling circuit for cooling the fuel cell using cooling water;
A cooling water circuit for heating that branches from the cooling circuit for the fuel cell and heats the interior of the fuel cell vehicle using heat of the cooling water;
A control unit for controlling the temperature of the cooling water of the fuel cell cooling circuit,
An outside temperature sensor,
An in-vehicle temperature sensor;
An air conditioner setting unit;
With
The controller is
At least one of the outside air temperature measured by the outside air temperature sensor, the inside temperature measured by the inside temperature sensor, and the set temperature of the air conditioner setting unit, and the target of the cooling water of the cooling water circuit for heating Using a map that defines a relationship with temperature, setting a target temperature of the cooling water of the heating cooling water circuit from at least one of the outside air temperature, the vehicle interior temperature, and the set temperature,
(A1) the outside air temperature is the predetermined temperature or higher, and, if it meets any of the below target temperature of the cooling water reaches a predetermined temperature, two conditions that the heating cooling water circuit, said Performing a first control process of setting a coolant outlet water temperature at the outlet of the fuel cell of the coolant to a first water temperature;
(B1) When neither of the two conditions is satisfied , a second control process is performed in which the cooling water outlet water temperature is set to a second water temperature higher than the first water temperature.
Fuel cell vehicle. The fuel cell vehicle according to claim 1,
The controller is
(A 2 ) When satisfying any one of three conditions obtained by adding a condition that the load of the fuel cell is less than a predetermined value to the two conditions , the first control process is executed,
If (b 2) satisfies none of the three conditions, it executes the second control process,
Fuel cell vehicle. The fuel cell vehicle according to claim 1 or 2, further comprising:
An impedance measuring unit for measuring the impedance of the fuel cell;
The controller is
Even if the conditions for executing the pre-Symbol second control process is established, in the case of more than magnitude predetermined value of the resistance component of the impedance may execute the first control process,
Condition for executing the pre-Symbol second control process is established, and, in the case of less than the magnitude of the resistance component of the impedance is predetermined value, executes the second control process,
Fuel cell vehicle. A cooling circuit for a fuel cell that collects heat from the fuel cell by flowing cooling water, and cooling for heating that branches from the cooling circuit for the fuel cell and that uses the heat of the cooling water for heating in the air conditioning of the interior of the fuel cell vehicle A water circuit and a method for controlling a fuel cell vehicle comprising:
Measuring the outside air temperature,
Measuring the temperature inside the vehicle;
Acquiring the set temperature of the air conditioner setting unit;
Using a map that defines a relationship between at least one of the outside air temperature, the in-vehicle temperature, and a set temperature of the air conditioner setting unit and a target temperature of the cooling water in the heating cooling water circuit, Setting a target temperature of the cooling water in the heating cooling water circuit from at least one of an air temperature, an in-vehicle temperature, and the set temperature;
Controlling the cooling water outlet water temperature at the outlet of the fuel cell of the cooling water,
In the step of controlling the cooling water outlet water temperature,
(A1) the outside air temperature is the predetermined temperature or higher, and, if it meets any of the below target temperature of the cooling water reaches a predetermined temperature, two conditions that the heating cooling water circuit, said first control processing is executed for the cooling water outlet temperature at the outlet of the fuel cell cooling water to the first water temperature,
(B1) When neither of the two conditions is satisfied , a second control process is performed in which the cooling water outlet water temperature is set to a second water temperature higher than the first water temperature.
Fuel cell vehicle control method. In the control method of the fuel cell vehicle according to claim 4,
Obtaining a load of the fuel cell,
In the step of controlling the cooling water outlet water temperature,
(A 2 ) When satisfying any one of the three conditions including the condition that the load of the fuel cell is less than a predetermined value in addition to the two conditions , the first control process is executed,
If (b 2) satisfies none of the three conditions, the second control process is executed,
Fuel cell vehicle control method. In the control method of the fuel cell vehicle according to claim 4 or 5,
Measuring the impedance of the fuel cell,
It satisfied the conditions before Symbol second control process is executed, and, if less than the size reaches a predetermined value of the resistive component of the impedance, the second control process is executed,
Even when the condition before Symbol second control processing is executed it is satisfied, when the size of the resistance component of the impedance is greater than or equal to a predetermined, the first control process is executed The
Fuel cell vehicle control method.

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