JP2011068233A - Fuel cell vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell vehicle accurately controlling temperature of a fuel cell. <P>SOLUTION: The fuel cell vehicle V is mounted with a cooling device 1 for the fuel cell including a coolant circulation passage circulating a coolant for cooling the fuel cell FC; and a radiator provided in the coolant circulation passage. The vehicle V includes a box 10 for storing the radiator; a flap device 12 taking-in outside air into the box 10; a flap control means adjusting opening of flap of the flap device 12; and an operation state detection means detecting the operation state of the fuel cell FC including a temperature of the fuel cell FC. The flap control means adjusts the opening of the flap of the flap device 12 based on information of the operation state of the fuel cell FC determined by the operation state detection means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell vehicle that controls the temperature of a fuel cell by circulating a refrigerant in the fuel cell.

  A fuel cell used as a power source for a fuel cell vehicle or the like generates heat as power is generated. Therefore, it is necessary to circulate a refrigerant in the fuel cell and cool the fuel cell appropriately. Piping that circulates refrigerant between the fuel cell and the radiator according to the temperature of the fuel cell, and bypasses the radiator if necessary as a cooling system for cooling the fuel cell by operating a refrigerant pump during power generation Generally, a refrigerant is circulated between the fuel cell and the fuel cell (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2008-4451 (FIG. 4)

  However, in the conventional cooling system as described in Patent Document 1, there is a problem that the heat dissipation control of the radiator is not sufficient, and the heat retaining property such as when the fuel cell is warmed up cannot be secured.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a fuel cell vehicle capable of accurately controlling the temperature of the fuel cell.

  The present invention provides a fuel cell vehicle equipped with a fuel cell cooling device including a refrigerant circulation path through which a refrigerant for cooling the fuel cell circulates, and a radiator provided in the refrigerant circulation path. An operating state of the fuel cell including at least a temperature of the fuel cell, a flap provided in the box and capable of taking outside air into the box, a flap control means capable of adjusting an opening of the flap Operating state detecting means for detecting the operating state, wherein the flap control means adjusts the opening of the flap based on information on the operating state of the fuel cell determined by the operating state detecting means. To do.

  According to this, the radiator and the refrigerant circulation pipe (refrigerant circulation path) are accommodated in the box, the flap that can take in the outside air is provided in the box, and the operation state (operation) of the fuel cell detected by the operation state detection means By adjusting the opening of the flap based on the mode), it becomes possible to control the fuel cell to a temperature suitable for each operating state. That is, by adjusting the opening degree of the flap, it becomes possible to finely control the heat dissipation performance of the radiator, and the temperature control of the fuel cell can be performed more accurately than before.

  The operation state of the fuel cell includes a plurality of operation modes, and the operation state detecting means determines the plurality of operation modes based on an ON / OFF signal state of an ignition switch and a temperature of the fuel cell. It is characterized by judging.

  According to this, the fuel cell is heated by the ON / OFF signal of the ignition switch depending on whether the fuel cell is activated or stopped, and the temperature of the fuel cell (refrigerant temperature, heat generation state, power generation amount, etc.). Easily determine multiple modes of operation, such as whether or not it is necessary to keep the fuel cell warm

  In addition, a target refrigerant temperature calculation unit that calculates a target refrigerant temperature from the temperature of the fuel cell is provided, and the flap control unit includes a target refrigerant temperature calculated by the target refrigerant temperature calculation unit, and an operating state detection unit The opening degree of the flap is adjusted based on the temperature of the fuel cell so that the temperature of the refrigerant of the cooling device of the fuel cell becomes a target refrigerant temperature.

  According to this, by comparing the target refrigerant temperature with the actual refrigerant temperature (actual refrigerant temperature of the present embodiment), it can be determined whether the current refrigerant temperature is too cold or too hot, and the temperature of the fuel cell Control can be performed with high accuracy.

  In addition, vehicle speed detection means for detecting the vehicle speed of the fuel cell vehicle is provided, and the flap control means corrects the opening of the flap based on the vehicle speed detected by the vehicle speed detection means.

  According to this, the temperature of the fuel cell can be controlled with higher accuracy by further feeding back the vehicle speed detected by the vehicle speed detecting means and controlling the flap (flap opening correction).

  In addition, when the outside air temperature detecting means for detecting the outside air temperature is provided, the flap control means determines that the operation mode of the fuel cell is a stop mode in which power generation of the fuel cell is stopped by the operating state detecting means. When the outside air temperature detected by the outside air temperature detecting means exceeds a predetermined temperature, the opening degree of the flap is opened and the cooling device for the fuel cell is stopped.

  According to this, when the outside air temperature exceeds the predetermined temperature, it is possible to prevent overheating when the fuel cell is started next time by closing the flap.

  A radiator fan for passing cooling air through the radiator; and a refrigerant pump for circulating the refrigerant of the cooling device, wherein the flap control means is configured such that the operation mode of the fuel cell is controlled by the operating state detection means. When it is determined that the fuel cell power generation is stopped, when the outside air temperature detected by the outside air temperature detecting means is equal to or lower than a predetermined temperature, the opening of the flap is opened and the refrigerant pump is turned on. The fuel cell rapid cooling process that operates and operates the radiator fan is performed.

  According to this, when the outside air temperature is equal to or lower than a predetermined temperature, the flap is opened to promote the heat radiation of the refrigerant by the radiator (cooling is promoted) so that the fuel cell is rapidly cooled. In other words, the fuel cell membrane (MEA) is prevented from being deteriorated by controlling the fuel cell so that it quickly passes through the temperature range (minus 1 ° C. to minus 5 ° C.) of the maximum ice crystal formation zone. It becomes possible.

  A radiator fan for passing cooling air through the radiator; and radiator fan control means for controlling a rotation speed of the radiator fan based on a difference between the target refrigerant temperature and the fuel cell temperature. Features.

  According to this, by controlling the rotational speed of the radiator fan, it is possible to accurately perform the heat radiation amount in the radiator.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell vehicle which can perform the temperature control of a fuel cell accurately can be provided.

1 is a schematic side view showing a system configuration of a fuel cell vehicle according to an embodiment. The external appearance perspective view which shows the box of the state in which all the flaps opened is shown, (a) is when it sees from diagonally forward, (b) is when it sees from diagonally back. The external appearance perspective view which shows the box of the state which all the flaps closed is shown, (a) is when it sees from diagonally forward, (b) is when it sees from diagonally back. It is a perspective view when the cooling device of the fuel cell in a box is seen from back. It is sectional drawing when cut | disconnecting by the AA line of FIG. It is a top view which shows arrangement | positioning of an ion exchanger and a refrigerant | coolant pump. It is a system diagram of a cooling system mounted on the fuel cell vehicle of the present embodiment. It is a flowchart which shows an example of the control in each operation mode of the fuel cell vehicle of this embodiment. It is a graph which shows an example of the temperature change in rapid cooling control. It is the figure which showed typically the state inside the film | membrane of a fuel cell, (a) is the state when rapidly cooled, (b) is the state when cooled slowly. It is a flowchart which shows flap control in driving | running | working mode. It is a map which calculates | requires the correction coefficient which correct | amends the opening degree of flap based on a vehicle speed. It is an external appearance perspective view which shows another control of a flap, (a) is when it sees from diagonally forward, (b) is when it sees from diagonally back.

Hereinafter, the fuel cell vehicle of this embodiment will be described with reference to FIGS. 1 to 13.
As shown in FIG. 1, a fuel cell vehicle V (hereinafter abbreviated as “vehicle V”) of this embodiment includes a box 10 in which a fuel cell cooling device 1 is housed, a fuel cell FC, an ECU (Electronic Control Unit). ) 100, temperature sensor 101, outside air temperature sensor 102 (outside air temperature detecting means), vehicle speed sensor 103 (vehicle speed detecting means), IG 104, temperature sensor 105 (see FIG. 7) and the like.

  The box 10 is located in the motor room MR at the front of the vehicle V, more specifically, in the motor room MR, behind the front grille (not shown) of the vehicle V. The box 10 is fixed to the vehicle body (bulkhead, frame, etc.) of the vehicle V with a bolt or the like. The detailed structure of the box 10 will be described later. A fuel cell FC is disposed behind the box 10.

  In the present embodiment, the installation position of the fuel cell FC is not particularly limited. Moreover, this embodiment is not limited to a four-wheeled vehicle, It can apply also to a two-wheeled vehicle, a train, etc.

  The fuel cell FC is, for example, a polymer electrolyte fuel cell (PEFC), and an MEA (Membrane Electrode Assembly) is sandwiched between conductive separators (not shown). A plurality of unit cells are stacked in the thickness direction, and each unit cell is electrically connected in series.

  Inside the fuel cell FC, a refrigerant flow path 6 is formed through which a refrigerant for cooling the fuel cell FC flows. A refrigerant | coolant consists of liquid mixture, such as ethylene glycol and water, for example.

  In such a fuel cell FC, hydrogen is supplied from a high-pressure hydrogen tank (not shown) to the anode, and air (oxygen) is supplied to the cathode, so that a chemical reaction occurs on the catalyst and the fuel cell FC can generate power. It becomes a state. Further, the fuel cell FC is electrically connected to an external load (such as a traveling motor), and the fuel cell FC generates power when current is taken out by the external load.

  As shown in FIGS. 2 (a), 2 (b) and FIGS. 3 (a), 3 (b), the box 10 includes a housing 11 formed in a substantially mountain shape in a side view and a flap device 12. ing.

  The front surface of the housing 11 is tilted backward in response to the tilt of the radiator 21 described later. On the other hand, the rear surface is formed to be inclined forward, and the dead space is set to be small in the internal space of the housing 11. The housing 11 has openings on the surfaces (front surface, upper surface, lower surface, and rear surface) to which the flap device 12 is attached, and the left side surface and the right side surface to which the flap device 12 is not attached are plate-like members. It is blocked.

  Further, the casing 11 of the box 10 is formed with through holes 11a and 11b through which a refrigerant circulation pipe 27 (see FIG. 4) extending from the refrigerant flow path 6 of the fuel cell FC is inserted at the lower end of the rear surface (see FIG. 4). (Refer FIG.2 (b) and FIG.3 (b)). An inlet 26a to which an end of a pipe 27a (see FIG. 1) of the refrigerant circulation pipe 27 is connected protrudes from the through hole 11a, and a pipe 27f (see FIG. 1) of the refrigerant circulation pipe 27 protrudes from the through hole 11b. The outlet port 24a to which the end portion is connected protrudes.

  The flap device 12 has a front flap 12a on the front side of the box 10, an upper flap 12b on the upper side, a lower flap 12c (only a part of which is shown) on the lower side, and a rear flap 12d on the rear side. The front flap 12a is formed by dividing the rectangular frame portions 12a1 and 12a2 into left and right, and a plurality of blades 12a3 formed long in the horizontal direction in the frame portion 12a1 are freely rotatable at predetermined intervals in the vertical direction. Similarly, a plurality of blades 12a4 are supported in the frame portion 12a2 so as to be rotatable at predetermined intervals in the vertical direction. Similarly, the upper flap 12b has a plurality of blades 12b3 on the left side and a plurality of blades 12b4 on the right side. Similarly, the rear flap 12d is configured by arranging a plurality of blades 12d3 on the left side and a plurality of blades 12d4 on the right side. The lower flap 12c is similarly configured by arranging a plurality of blades (not shown) on the left side and a plurality of blades 12c4 on the right side.

  A motor (not shown) is connected to each of the front flap 12a, the upper flap 12b, the lower flap 12c, and the rear flap 12d via a reduction gear (not shown), and control of an ECU (Electronic Control Unit) 100 described later. Thus, each motor is driven to control opening and closing or its opening degree. 2A and 2B show a state in which all the flaps 12a to 12d of the flap device 12 are fully opened, and FIGS. 3A and 3B show that all the flaps 12a to 12d of the flap device 12 are fully closed. It is in the state.

  As shown in FIG. 4, the box 10 includes a radiator 21, radiator fans 22 and 22, refrigerant pumps 23 and 24, an ion exchanger 25, a thermostat valve 26, and a refrigerant circulation pipe 27 (part of the refrigerant circulation path). Contained. FIG. 4 illustrates a state in which the flap device 12 is removed from the box 10 and viewed from the rear and obliquely above.

  The radiator 21 takes in outside air and dissipates heat generated by power generation of the fuel cell FC through the refrigerant. The radiator 21 has a surface area that covers the entire back surface of the front flap 12a (see FIGS. 2 and 3).

  The radiator 21 is provided with a refrigerant inlet port 21a and a refrigerant outlet port 21b (see FIGS. 4 and 5). Further, the radiator 21 is disposed in a rearwardly inclined state along the front surface in the box 10 (see FIG. 5).

  The radiator fans 22, 22 are configured by an electric type controlled by the ECU 100, which will be described later, and are arranged side by side on the rear surface of the radiator 21 in order to force predetermined outside air to flow through the entire surface of the radiator 21.

  Further, an outlet port 21a of the radiator 21 is connected to an outlet of the refrigerant flow path 6 (see FIG. 1) of the fuel cell FC via a pipe 27c, a refrigerant pump 23, a pipe 27b, a thermostat valve 26, and a pipe 27a (see FIG. 1). Connected with.

  Further, the outlet port 21b of the radiator 21 is connected to the inlet of the refrigerant flow path 6 (see FIG. 1) of the fuel cell FC via the pipe 27d, the joint 28, the pipe 27e, the refrigerant pump 24, and the pipe 27f (see FIG. 1). It is connected. In addition, the thermostat valve 26 in this embodiment switches a flow path by electrical control. Note that if the vehicle V does not require the rapid cooling process described later, the thermostat valve may be configured such that the flow path is switched by changing the volume of wax inside depending on the temperature.

  The radiator 21 may be provided with a FC (Fuel Cell) radiator for cooling the fuel cell FC. However, the radiator 21 is not limited to this, and for the FC and the air conditioner (so-called air conditioner). And the motor (which cools the drive system including the traveling motor 3) may be stacked in the front-rear direction. For example, the air conditioner, motor, and FC are arranged in this order from the front side. Incidentally, the cooling requirements for FC, air conditioner, and motor are considered to be almost the same, so there is no problem even if the three sheets overlap in the thickness direction. Efficiency can be improved.

  The refrigerant pumps 23 and 24 are electrically operated to circulate the refrigerant, and the circulation flow rate is controlled by the ECU 100 described later. By the way, in this embodiment, by providing the two refrigerant pumps 23 and 24, each refrigerant pump 23 and 24 is small and consumes less power compared to the case where it is configured by a single refrigerant pump. Can do. The refrigerant pumps 23 and 24 are arranged on the bottom surface in the box 10 and are fixed to a support member (not shown) provided on the bottom surface of the casing 11 of the box 10 via bolts or the like.

  The ion exchanger 25 is filled with an ion exchange resin (a cation exchange resin, an anion exchange resin) in a cylindrical case made of polypropylene or the like, and is placed on the bottom surface of the box 10 along the vehicle width direction. It is arranged in a standing state. Both ends of the ion exchanger 25 in the axial direction are fixed via bolts or the like on a support member 10a (see FIG. 5) disposed on the bottom surface of the box 10 via a bracket (not shown).

  The ion exchanger 25 has one end of a bypass pipe 27g (pipe connecting member, refrigerant circulation path) connected to one end side in the axial direction, and the other end connected to a discharge port of the thermostat valve 26. The ion exchanger 25 has one end of a bypass pipe 27 h (pipe connecting member, refrigerant circulation path) connected to the other end side in the axial direction, and the other end connected to a return port of the joint 28.

  As shown in FIG. 6, the ion exchanger 25 is placed horizontally on the bottom surface of the box 10 so that the left end (exit 25d) is positioned in front of the vehicle V in the front-rear direction from the right end (inlet 25c). It is arranged diagonally. Moreover, the ion exchanger 25 is arrange | positioned in the center of the left-right direction (vehicle width direction) of the bottom face in the box 10 (refer FIG. 4).

  In addition, the refrigerant pumps 23 and 24 intersect with the extension line S of the bypass pipes 27g and 27h connected to the inlet 25c and the outlet 25d of the ion exchanger 25 (with the bypass pipes 27g and 27h on the extension line S). The ion exchanger 25 is disposed so as to sandwich the ion exchanger 25 in the front-rear direction. The refrigerant pump 23 in front of the ion exchanger 25 is arranged on the right side with respect to the ion exchanger 25, and the refrigerant pump 24 behind the ion exchanger 25 is arranged on the left side with respect to the ion exchanger 25. Yes.

  Thus, since the main part of the cooling device 1 of the fuel cell FC is arranged on the bottom surface of the box 10 with the shape of the casing 11 of the box 10 being a mountain shape, the dead space in the box 10 is reduced, and the box 10 And the dead space in the motor room MR of the vehicle V is reduced.

  In the box 10, a reservoir tank 29 for temporarily storing excess refrigerant is provided. The reservoir tank 29 is located at the right end in the box 10 and is configured by a vertically long container 29a having a curved surface 29b that is curved so as not to overlap with the right radiator fan 22 in the front-rear direction. The reservoir tank 29 is connected to the radiator 21 through a pipe (not shown).

  Moreover, the vehicle V of this embodiment is provided with ECU100, the temperature sensor 101, the external temperature sensor 102, the temperature sensor 105 (refer FIG. 7), and IG (ignition switch) 104 as a control system (refer FIG. 1).

  Note that the temperature of the fuel cell FC is not limited to the temperature of the refrigerant, and may be determined based on the heat generation state of the fuel cell FC and the amount of power generated representing the heat generation state.

  As shown in FIG. 7, the ECU 100 controls the motors (not shown) of the flap device 12 to adjust the opening degree of the flaps 12 a to 12 d, and also controls the motors (not shown) of the radiator fans 22 and 22. The rotational speed is controlled, and the rotational speed of each motor (not shown) of the refrigerant pumps 23 and 24 is controlled to adjust the flow rate of the refrigerant. Further, the ECU 100 includes an operation state detection unit, a target refrigerant temperature determination unit, a flap control unit (a flap control device), and a radiator fan control unit.

  The operation state detection means has a function of determining the current operation mode of the fuel cell FC, and makes a determination based on, for example, the temperature of the fuel cell FC and the ON / OFF signal of the IG 104. The operation mode includes, for example, a warm-up mode from start (IG-ON) to warm-up of the fuel cell FC, a travel mode that is normal travel after completion of warm-up, and a stop mode when the IG 104 is turned off. . In this way, the current operation mode is determined, and the opening degree of each of the flaps 12a to 12d of the flap device 12 is controlled by the flap control means based on the information on the operation mode.

  The target refrigerant temperature determining means determines the target refrigerant temperature of the refrigerant from the power generation state, temperature, etc. of the fuel cell FC, and compares the target refrigerant temperature with the current refrigerant temperature (actual refrigerant temperature) obtained from the temperature sensor 101. Therefore, it is possible to determine whether it is necessary to raise the temperature of the refrigerant (required heat reception) or whether the refrigerant needs to be cooled (requires heat dissipation), and by comparing the target refrigerant temperature with the outside air temperature, the flap control means The opening degree of each flap 12a-12d of the flap apparatus 12 is set.

  A flap control means sets the opening degree of each flap 12a-12d based on the driving mode (vehicle state) judged by the driving | running state detection means.

  The radiator fan control means controls the rotational speeds of the radiator fans 22 and 22 based on the difference between the target refrigerant temperature determined by the target refrigerant temperature determination means and the temperature of the fuel cell FC (actual refrigerant temperature). For example, when the target refrigerant temperature is lower than the actual refrigerant temperature, the rotational speed of the radiator fans 22 and 22 is increased to increase the cooling capacity of the radiator 21. Conversely, when the target refrigerant temperature is higher than the actual refrigerant temperature. Lowers or stops the rotational speed of the radiator fans 22 and 22.

  Next, an example of the flap control in the vehicle V of the present embodiment will be described with reference to FIGS. 8 and 12. In step S1, the ECU 100 determines whether the vehicle state is the stop mode (IG-OFF) or the start mode (IG-ON). The stop mode is one of a plurality of operation modes, and is a state where power generation of the fuel cell FC is stopped. Whether or not it is in the stop mode can be determined by the ON / OFF signal of the IG 104. If the ECU 100 detects the IG-OFF signal (S1, Yes), the process proceeds to step S2.

  In step S <b> 2, the ECU 100 detects the outside air temperature T <b> 3 by the outside air temperature sensor 102. Then, in step S3, the ECU 100 determines whether or not the outside air temperature T3 is lower than the heat retention determination temperature (predetermined temperature, for example, 5 ° C.). Step S3 is a step of determining whether or not to keep the refrigerant in the box 10 in other words, whether it is a normal stop or a winter stop.

  In step S3, if the outside air temperature T3 is not lower than the heat retention determination temperature (No), the ECU 100 determines that the refrigerant in the box 10 is not warmed, proceeds to step S4, and the outside air temperature T3 is determined to be warm. When it is lower than the temperature (Yes), it is determined that the refrigerant in the box 10 needs to be kept warm, and the process proceeds to step S5.

  In step S4, the ECU 100 performs control to open the flap. For example, when the outside air temperature T3 is high, such as in summer, a normal heat dissipation state is established with respect to the outside air by opening the flap. Specifically, all the flaps 12a to 12d of the flap device 12 are opened, and the radiator fans 22 and 22 and the refrigerant pumps 23 and 24 are stopped (stop mode).

  In step S3, when the ECU 100 determines that the outside air temperature T3 is equal to or higher than the heat retention determination temperature (Yes), the ECU 100 determines that the refrigerant in the box 10 needs to be warmed, proceeds to step S5, and proceeds to the fuel cell FC. The temperature (refrigerant temperature: hereinafter referred to as FC refrigerant temperature) T2 is detected. In step S6, the ECU 100 determines whether the FC refrigerant temperature T2 is lower than the rapid cooling preparation start temperature (for example, 1 ° C.). In addition, it is not limited to 1 degreeC, 0 degreeC, 2 degreeC, etc. may be sufficient.

  In step S6, when the ECU 100 determines that the FC refrigerant temperature T2 is equal to or higher than the rapid cooling preparation start temperature (No), the ECU 100 determines that heat retention is necessary or is in progress and proceeds to step S12. Control to close the flap. Specifically, control is performed to close all the flaps 12 a to 12 d of the flap device 12. In step S6, if the ECU 100 determines that the FC refrigerant temperature T2 is lower than the rapid cooling preparation start temperature (Yes), the ECU 100 determines that preparation for rapid cooling is necessary, and proceeds to step S7. Control to open the flap. The rapid cooling preparation start temperature set here is set to a temperature higher than the temperature range of the maximum ice crystal formation zone (minus 1 ° C. to minus 5 ° C.).

  In step S8, the ECU 100 proceeds to a quick cooling preparation process before the rapid cooling is executed. In the rapid cooling preparation process, for example, all the flaps 12a to 12d of the flap device 12 are opened, and the radiator fans 22 and 22 are operated. The refrigerant pumps 23 and 24 are stopped.

  Thereby, by forcing outside air into the box 10, the inside of the box 10 is cooled and the refrigerant in the box 10 is cooled. That is, when the outside air passes between the fins of the radiator 21, the refrigerant in the radiator 21 is cooled, and when the outside air is taken into the box 10, the refrigerant in the pipes 27 b to 27 e and the bypass pipes 27 g and 27 h To be cooled.

  Since the process in step S8 is a process for cooling only the refrigerant in the box 10, for example, only the rear flap 12d is closed so that the cooling air is not applied to the fuel cell FC located behind the box 10. May be.

  In step S9, the ECU 100 detects the refrigerant temperature T4 (see FIG. 7) in the box 10. In step S10, the ECU 100 determines whether the refrigerant temperature T4 is lower than the FC refrigerant temperature T2. Step S10 is a process of determining whether or not the refrigerant temperature T4 in the box 10 has decreased below the FC refrigerant temperature T2. In step S10, when the ECU 100 determines that the refrigerant temperature T4 in the box 10 is not lower than the FC refrigerant temperature T2 (No), the ECU 100 returns without executing the rapid cooling, and the refrigerant temperature T4 becomes the FC refrigerant temperature. If it is determined that it is lower than T2 (Yes), the process proceeds to step S11. Note that the determination in step S10 is not limited to the refrigerant temperature T4, and may be determined based on elapsed time using a timer.

  In step S11, the ECU 100 executes a process for rapidly cooling the fuel cell FC (fuel cell rapid cooling process). That is, the ECU 100 opens all the flaps 12a to 12 of the flap device 12, operates the refrigerant pumps 23 and 24, and electrically controls the thermostat valve 26 so that the entire amount of refrigerant flows to the radiator 21 side.

  As shown in the graph of FIG. 10, when the FC refrigerant temperature T2 becomes lower than the rapid cooling preparation start temperature (S6, Yes), by opening the flap and starting the rapid cooling preparation, Since the refrigerant is released from the heat retaining state, the refrigerant temperature T4 in the box 10 rapidly decreases from the middle (S7, S8) as shown by the dashed line graph. Since the refrigerant pumps 23 and 24 are not operated, the FC refrigerant temperature T2 gradually decreases without changing the temperature decrease rate as shown by the solid line graph. Then, when the refrigerant temperature T4 in the box 10 becomes lower than the FC refrigerant temperature T2, rapid cooling of the fuel cell FC is started. When the rapid cooling is started, the refrigerant cooled in the box 10 is supplied to the fuel cell FC, and the refrigerant circulates between the fuel cell FC and the radiator 21, whereby the fuel cell FC is rapidly cooled.

  As a result, the time required for the fuel cell FC to pass through the temperature range of the maximum ice crystal formation zone (minus 1 ° C to minus 5 ° C) is shortened (shorter than when the fuel cell rapid cooling process is not performed). The fuel cell FC is rapidly cooled.

  In the rapid cooling in step S11, the front flap 12a, the upper flap 12b, and the rear flap 12d may be opened, the lower flap 12c may be closed, and the refrigerant pumps 23 and 24 may be operated. As a result, the exhaust air (cooling air) sucked from the front flap 12a and discharged from the rear surface of the radiator 21 is discharged from the upper flap 12b and the rear flap 12d, and the center tunnel ST (see FIG. 1) located behind the box 10. (See) The fuel cell FC in the center tunnel ST is cooled by passing through the inside. At this time, closing the lower flap 12c makes it easy for the exhaust air from the radiator fans 22 and 22 to flow toward the fuel cell FC. That is, the exhaust air from the radiator fan 22 is prevented from leaking from the bottom surface of the box 10 to the ground side. Thereby, the fuel cell FC is rapidly cooled by the circulation of the refrigerant and the exhaust air.

  Such rapid cooling control increases the cooling rate when passing through the maximum ice crystal formation zone as shown in FIG. 9, and as shown in FIG. Even if there are nuclei (circles in the figure), the antifreeze water (supercooled water) in the electrolyte membrane is not attracted to the ice nuclei, but freezes in the electrolyte membrane and ice crystals grow. It is suppressed. On the other hand, as shown in FIG. 10 (b), when the cooling rate in the maximum ice crystal formation zone is slow (slow cooling) (comparative example), the ice nuclei generated in the electrode are not in the electrolyte membrane. Frozen water (supercooled water) is sucked and solidified to grow ice crystals. At this time, an ice crystal grows across the electrode and the electrolyte membrane, thereby causing an event that the electrolyte membrane is damaged by the ice crystal. Therefore, by rapidly cooling the fuel cell FC in the maximum ice crystal production zone, the growth of ice crystals can be suppressed, so that deterioration of the fuel cell FC can be suppressed.

  Note that the ECU 100 determines that the rapid cooling control is completed when the FC refrigerant temperature (actual refrigerant temperature T2) falls below the temperature range of the maximum ice crystal generation zone. Note that the completion condition of the rapid cooling control is not limited to the FC refrigerant temperature T2, but may be determined based on a time determined by a prior experiment or simulation.

  In addition, when performing rapid cooling control, it is preferable to discharge the generated water remaining in the fuel cell FC to the outside in advance. The generated water can be discharged by operating an air compressor (not shown) and sending air as a scavenging gas to the anode side and the cathode side of the fuel cell FC. The air of the air compressor can be sent to the anode side, for example, by connecting the cathode side pipe and the anode side pipe upstream of the fuel cell FC.

  In step S1, when ECU 100 determines that the ignition is IG-ON (not in the stop mode), the ECU 100 proceeds to step S13 and detects the FC refrigerant temperature T2. In step S14, the ECU 100 determines whether or not the FC refrigerant temperature T2 is lower than the warm-up completion temperature. Note that the warm-up is warm-up of the fuel cell FC, and is a process executed in a low-temperature environment (for example, below freezing point) and a normal temperature environment. For example, it is executed when the outside air temperature T3 and the FC refrigerant temperature T2 are not more than a predetermined temperature (for example, 10 ° C.). The warm-up completion condition (warm-up completion temperature) is when the FC refrigerant temperature T2 is equal to or higher than a predetermined temperature (a temperature at which power generation can be performed efficiently, for example, 30 ° C.).

  In step S14, when the ECU 100 determines that the FC refrigerant temperature T2 is lower than the warm-up completion temperature (Yes), the ECU 100 proceeds to step S15 and performs control to close the flap. Specifically, control is performed to close all the flaps 12 a to 12 d of the flap device 12. Further, the thermostat valve 26 is electrically controlled (see FIGS. 4 and 7) so that the entire amount of the refrigerant flows toward the bypass pipes 27g and 27h, and the refrigerant pump 24 is operated. Thereby, warm-up is promoted. In step S15, the flaps 12a to 12c may be closed and the rear flap 12d may be opened so that the heat of the components in the motor room MR is taken into the box 10.

  In step S14, when the ECU 100 determines that the FC refrigerant temperature T2 is equal to or higher than the warm-up completion temperature (No), the ECU 100 proceeds to step S16 and executes the control in the traveling mode shown in FIG. That is, in step S21, the ECU 100 calculates the target refrigerant temperature T1 of the refrigerant from the temperature of the fuel cell FC, the current calorific value of the fuel cell FC, and the like. In the traveling mode, the flow of the thermostat valve 26 is switched to the radiator 21 side and the bypass pipes 27g and 27h side according to the temperature of the refrigerant under the control of the ECU 100.

  In step S22, the ECU 100 determines whether the target refrigerant temperature T1 is higher than the actual refrigerant temperature T2 (current refrigerant temperature, FC refrigerant temperature), and the target refrigerant temperature T1 is higher than the actual refrigerant temperature T2. If it is determined that the temperature is high (Yes), that is, the current temperature of the refrigerant is too low, the process proceeds to step S23, and control is performed so that the opening of the flap is reduced (heat reception required). If it is determined in step S22 that the target refrigerant temperature T1 is not higher than the actual refrigerant temperature T2 (No), that is, the current refrigerant temperature is too high, the process proceeds to step S24, where the flap opening degree is large. Control is performed as follows (heat dissipation required).

  When the same amount of heat is desired, it is preferable to correct the flap opening degree to the large side at low vehicle speeds and to correct the flap opening degree to a small side at high vehicle speeds. For example, as shown in FIG. 12, when the reference vehicle speed is set to 50 km / hour, for example, when the vehicle speed is lower than the reference vehicle speed, the correction coefficient is set larger than 1, and the flap opening degree is corrected to the larger side. To do. When the vehicle speed is higher than the reference vehicle speed, the correction coefficient is made smaller than 1 and the flap opening degree is corrected to the small side. When the same heat radiation amount is desired, it is preferable to correct the flap opening degree to the large side at low vehicle speeds and to the small side at high vehicle speeds as described in FIG.

  When the fuel cell FC is in the warm-up mode (S15), the warm-up mode time can be shortened due to the heat retention effect, so that fuel efficiency, power generation performance, and durability of the fuel cell FC can be improved. Further, when the fuel cell FC is in the travel mode (S16), by making the flap of the flap device 12 variable, fine temperature control of the refrigerant becomes possible, so that fuel consumption, power generation performance, and fuel cell FC can be controlled. Durability can be improved. In addition, when the fuel cell FC is in the stop mode (stop → heat retention) (S12), it is possible to shorten the startup time when the fuel cell FC is started next time, so that the power generation performance can be improved. Since the fuel cell FC can be prevented from being exposed to a low temperature environment, the durability of the fuel cell FC can be improved. In addition, when the fuel cell FC is in the stop mode (heat retention → rapid cooling preparation, rapid cooling) (S8, S11), the fuel cell FC is rapidly cooled in the temperature region of the maximum ice crystal generation zone, The growth of the fuel cell FC can be suppressed and the durability of the fuel cell FC can be improved.

  As described above, in the vehicle V of the present embodiment, the main components (the radiator 21, the refrigerant pumps 23 and 24, and the ion exchanger 25) of the cooling device 1 of the fuel cell FC are centrally arranged in the box 10, Compared with the case where the main parts are dispersedly arranged, the pipe length of the refrigerant circulation pipe 27 can be shortened. Since the pipe length can be shortened in this way, the pressure loss when the refrigerant flows in the pipe is reduced, and the pipe diameter can be reduced. As a result, the amount of refrigerant retained in the pipe can be reduced, and the weight and cost of the pipe can be reduced. Furthermore, since the amount of refrigerant held can be reduced, it is possible to shorten the warm-up time (temperature rise time) when the fuel cell FC is warmed up when used in a low-temperature environment. Furthermore, since only the inlet 26a and the outlet 24a are out of the box 10, the vehicle V of the cooling device 1 can be obtained by compactly storing the cooling device 1 of the fuel cell FC in the box 10 and unitizing it. It is possible to reduce the number of work steps and work time when attaching to the heat exchanger and replacing the cooling device 1. Furthermore, it is possible to reduce the number of brackets and connection points for fixing the pipe, and to improve versatility such as mounting on other vehicle types.

  Further, in the vehicle V of the present embodiment, since the flap device 12 that arbitrarily adjusts the outside air inflow amount into the box 10 according to the vehicle state (warm-up mode, travel mode, and each stop mode) is provided, the radiator 21 Therefore, it is possible to accurately control the heat dissipation performance (temperature adjustment control of the fuel cell FC).

  Further, in the vehicle V of the present embodiment, the flap device 12 is provided on the front surface, rear surface, top surface, and bottom surface of the box 10, so that the flaps 12 a to 12 f of the flap device 12 are in accordance with the vehicle state, the environment outside the vehicle, and the like. By adjusting 12d, the temperature of the refrigerant can be controlled with higher accuracy.

  Further, by arranging devices other than the radiator 21 (ion exchanger 25, refrigerant pumps 23, 24) on the bottom surface (same surface) of the box 10, the mounting structure of the devices can be simplified and reduced in weight. .

  Further, in the vehicle V of the present embodiment, the radiator 21 and the refrigerant circulation pipe 27 are accommodated in the box 10, and the flap device 12 capable of taking outside air is provided in the box 10, which is detected by the operating state detection means. By adjusting the flap opening degree of the flap device 12 based on the operation state (operation mode) of the fuel cell FC, the fuel cell FC can be accurately adjusted to a temperature suitable for each operation state (vehicle state). It becomes possible.

  In the vehicle V of the present embodiment, a plurality of operation modes (warm-up mode, stop mode, travel mode, etc.) are determined by determining a plurality of operation modes from the ON / OFF signal state of the IG 104 and the temperature of the fuel cell FC. Can be easily determined.

  Further, in the vehicle V of the present embodiment, by comparing the target refrigerant temperature T1 calculated based on the temperature of the fuel cell FC, the amount of heat generation, and the like with the temperature of the fuel cell FC (actual refrigerant temperature T2), the heat reception requires heat. It can be judged whether there is heat dissipation or not. Furthermore, by controlling the flap opening degree of the flap device 12, the temperature control of the fuel cell FC can be performed with high accuracy.

  In the vehicle V of the present embodiment, the temperature control of the fuel cell FC can be performed with higher accuracy by correcting the flap device 12 based on the vehicle speed detected by the vehicle speed sensor 103.

  Further, in the vehicle V of the present embodiment, when the outside air temperature T3 is detected by the outside air temperature sensor 102 in the stop mode (IG-OFF) and the outside air temperature T3 is equal to or higher than a predetermined temperature (heat retention determination temperature), Since the cooling device 1 of the fuel cell FC is stopped by opening the flaps 12a to 12d, the heat radiation to the outside of the box 10 is promoted, and the refrigerant is efficiently cooled. As a result, it is possible to prevent overheating when the fuel cell FC is started next time.

  Further, in the vehicle V of the present embodiment, when the outside air temperature T3 is lower than the heat retention determination temperature and the FC refrigerant temperature T2 is lower than the rapid cooling preparation start temperature in the stop mode (IG-OFF), the flap device 12 is used. And the radiator fans 22 and 22 are operated to cool the refrigerant in the box 10, and when the refrigerant temperature T4 in the box 10 becomes lower than the FC refrigerant temperature T2, the radiator fan 22 and 22 22 and the refrigerant pumps 23 and 24 are operated to rapidly cool the fuel cell FC so as to quickly pass through the temperature range (−1 ° C. to −5 ° C.) of the maximum ice crystal formation zone. Crystal growth is suppressed, and deterioration of the fuel cell electrolyte membrane and the like can be suppressed.

  In the vehicle V of the present embodiment, the fuel cell FC is controlled by controlling the rotation speed of the radiator fans 22 and 22 together with the flap control of the flap device 12 based on the difference between the target refrigerant temperature T1 and the FC refrigerant temperature T2. The temperature control can be performed with higher accuracy.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, as shown in FIG. 13, only one of the left and right flap devices 12A (or the flap device 12B) may be opened to control the temperature of the fuel cell FC. Thus, by operating only the radiator fan 22 of the left and right flap devices 12A (or 12B), power consumption can be reduced. Furthermore, in addition to opening and closing the left and right flap devices 12A and 12B, the temperature control of the fuel cell FC may be performed by adjusting the opening degree of the flaps 12a to 12d of the respective flap devices 12A and 12B.

1 Fuel Cell Cooling Device 10 Box 12 Flap Device 12a Front Flap (Flap)
12b Upper flap (flap)
12c Lower flap (Flap)
12d rear flap (flap)
21 Radiator 22 Radiator fan 23, 24 Refrigerant pump 24a Outlet port 25 Ion exchanger 25c Inlet 25d Outlet 26a Inlet port 27g, 27h Bypass piping (pipe connecting member)
27a to 27f Piping (refrigerant circuit)
100 ECU (operating state detection means, target refrigerant temperature determination means, flap control means, radiator fan control means)
101, 105 Temperature sensor 102 Outside air temperature sensor (outside air temperature detecting means)
103 Vehicle speed sensor (vehicle speed detection means)
104 IG
FC fuel cell V fuel cell vehicle

Claims (7)

A refrigerant circulation path through which a refrigerant for cooling the fuel cell circulates;
A radiator provided in the refrigerant circulation path;
In a fuel cell vehicle equipped with a fuel cell cooling device comprising:
A box containing the radiator;
A flap provided in the box and capable of taking outside air into the box;
Flap control means capable of adjusting the opening of the flap;
An operation state detection means for detecting an operation state of the fuel cell including at least the temperature of the fuel cell, and
The fuel cell vehicle characterized in that the flap control means adjusts the opening degree of the flap based on information on the fuel cell operation state determined by the operation state detection means. The operation state of the fuel cell includes a plurality of operation modes,
2. The fuel cell vehicle according to claim 1, wherein the operation state detection unit determines the plurality of operation modes based on an ON / OFF signal state of an ignition switch and a temperature of the fuel cell. 3. A target refrigerant temperature calculating means for calculating a target refrigerant temperature from the temperature of the fuel cell;
The flap control means sets the temperature of the refrigerant of the fuel cell cooling device as a target based on the target refrigerant temperature calculated by the target refrigerant temperature calculation means and the temperature of the fuel cell from the operating state detection means. 3. The fuel cell vehicle according to claim 1, wherein the opening degree of the flap is adjusted so as to reach a refrigerant temperature. 4. Vehicle speed detecting means for detecting the vehicle speed of the fuel cell vehicle;
The fuel cell vehicle according to claim 3, wherein the flap control means corrects the opening degree of the flap based on a vehicle speed detected by the vehicle speed detection means. An outside temperature detecting means for detecting outside temperature is provided,
When the operation state detection unit determines that the operation mode of the fuel cell is a stop mode in which power generation of the fuel cell is stopped, the flap control unit has a predetermined outside air temperature detected by the outside air temperature detection unit. 3. The fuel cell vehicle according to claim 2, wherein when the temperature exceeds, the opening degree of the flap is opened and the cooling device for the fuel cell is stopped. 4. A radiator fan for passing cooling air through the radiator;
A refrigerant pump for circulating the refrigerant of the cooling device,
When the operation state detection unit determines that the operation mode of the fuel cell is a stop mode in which power generation of the fuel cell is stopped, the flap control unit has a predetermined outside air temperature detected by the outside air temperature detection unit. 6. The fuel cell according to claim 5, wherein when the temperature is equal to or lower than the temperature, the opening degree of the flap is opened, the refrigerant pump is operated, and the fuel cell rapid cooling process for operating the radiator fan is performed. vehicle. A radiator fan for passing cooling air through the radiator;
5. The fuel cell vehicle according to claim 3, further comprising a radiator fan control unit configured to control a rotational speed of the radiator fan based on a difference between the target refrigerant temperature and the temperature of the fuel cell. .

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