Cooling system for fuel cell vehicles

Abstract

To secure both mountability and cooling performance with a cooler of a fuel cell vehicle.SOLUTION: This invention is a cooler 1 of a fuel cell vehicle 2 comprising a cab 21 and a chassis frame 22 and driving a motor 24 with the power of the fuel cell 23. The cooler 1 comprises: a hydrogen gas storage part 3, installed outward in the vehicle width direction D2 of the chassis frame 22 behind the cab 21; a heat exchanging part 4, installed along the hydrogen gas storage part 3 outside in the vehicle width direction D2 of the hydrogen gas storage part 3; an outer air guiding part 5, provided between a heat exchange part 4 and the hydrogen gas storage part 3 to have a fan 7 capable of ventilating in two ways in a first direction directing inward from outside in the vehicle width direction D2 and a second direction directing outward from inside in the vehicle width direction D2; and a control part 20, which selects a first mode for guiding outer air in the first direction when the vehicle speed is less than a predetermined speed, and selects a second mode for guiding outer air in the second direction when the vehicle speed is more than a predetermined speed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a cooling device for a fuel cell vehicle including a cab and a chassis frame.

Background Art

[0002] Conventionally, a fuel cell system that generates electricity by utilizing a chemical reaction between hydrogen and oxygen (air) is known. In recent years, from the perspective of reducing the environmental load, development of fuel cell systems has also been carried out in the field of commercial vehicles such as trucks equipped with a cab and a chassis frame. Since a fuel cell system applied to a commercial vehicle is required to have a large output corresponding to the weight of the commercial vehicle, it tends to be large-sized. Along with this, a radiator for cooling the fuel cell also tends to be large-sized because high cooling performance is required. In contrast, Patent Document 1 discloses a technique for ensuring the cooling capacity for a fuel cell by using a plurality of radiators in a fuel cell truck. In this technique, a plurality of radiators are arranged below the cab together with the fuel cell.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, generally, in the space below the cab, in addition to the fuel cell, a steering device and the like are also arranged. Therefore, it is difficult to secure a large mounting space for the radiator, and it is particularly difficult to install a large radiator having sufficient cooling performance. Furthermore, in fuel cell vehicles, the components that need to be cooled include not only the fuel cell but also high-voltage batteries and electric motors. Therefore, it is necessary to determine the location of the cooling system so that it can provide sufficient cooling capacity for the fuel cell and other components that need to be cooled. When the cooling system is installed on the side of the fuel cell vehicle (outward in the vehicle width direction), it is easier to secure space compared to installing it below the cab. However, this installation location raises concerns that the high-temperature outside air discharged after heat exchange may affect people near the vehicle and the surrounding environment.

[0005] Therefore, the conventional technology disclosed in Patent Document 1 has room for improvement in ensuring both the mountability and cooling performance of the cooling device. [Means for solving the problem]

[0006] This project was undertaken to solve at least some of the above-mentioned problems and can be implemented in the following forms or applications.

[0007] The cooling system for a fuel cell vehicle according to this application example is a cooling system for a fuel cell vehicle that includes a cab and a chassis frame and drives a motor for traction with electricity from a fuel cell, and is installed behind the cab and outward in the vehicle width direction of the chassis frame, and stores hydrogen gas supplied to the fuel cell, and is installed outward in the vehicle width direction of the hydrogen gas storage unit and along the hydrogen gas storage unit, and performs heat exchange between at least the refrigerant that cools the fuel cell and the outside air, and the heat exchange unit and the hydrogen gas The fuel cell vehicle includes an outside air guide unit provided between the storage unit and the outside air guide unit, which has a fan capable of blowing air in both directions: a first direction from the outside in the vehicle width direction toward the inside in the vehicle width direction and a second direction from the inside in the vehicle width direction toward the outside in the vehicle width direction in order to guide the outside air to the heat exchange unit, and a control unit which selects a first mode in which the fan guides the outside air in the first direction when the vehicle speed of the fuel cell vehicle is less than a predetermined speed, and a second mode in which the fan guides the outside air in the second direction when the vehicle speed of the fuel cell vehicle is the predetermined speed or higher.

[0008] According to this application example, by installing the heat exchange unit along the hydrogen gas storage unit on the vehicle width side outward from the hydrogen gas storage unit, a large mounting space for the heat exchange unit can be secured, while also ensuring sufficient cooling performance. In a structure where a heat exchanger is installed on the outward side of the hydrogen gas storage section in the vehicle width direction, when the vehicle speed is below a predetermined speed, a first mode is selected in which the fan guides outside air in a first direction from the outward side in the vehicle width direction toward the inward side. As a result, outside air that has passed through the heat exchanger is discharged toward the inward side in the vehicle width direction, thus suppressing the impact of high-temperature outside air on the surrounding environment, such as people near the vehicle.

[0009] On the other hand, when the vehicle speed exceeds a predetermined speed, a second mode is selected in which the fan guides outside air in a second direction, from the inside to the outside in the vehicle width direction. As a result, outside air is discharged from the inside in the vehicle width direction, through the heat exchange section, and outwards in the vehicle width direction, so the high-temperature outside air that has passed through the heat exchanger does not come into contact with the hydrogen gas storage section. Therefore, it is possible to suppress the hydrogen gas storage section from becoming too hot. This contributes to ensuring cooling performance. [Effects of the Invention]

[0010] According to this invention, in a structure in which a heat exchange unit is installed on the outward side in the vehicle width direction of the hydrogen gas storage unit, it is possible to secure a large mounting space for the heat exchange unit, ensure sufficient cooling performance, and optimize the direction of outside air guidance (airflow direction) by the fan according to the vehicle speed. Therefore, it is possible to ensure both the ease of mounting the cooling device and the cooling performance. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic top view of a fuel cell vehicle to which the cooling system according to the first embodiment is applied. [Figure 2] Figure 1 is a schematic cross-sectional view showing the main components of the fuel cell vehicle, with the braces disassembled. [Figure 3] Figure 1 is a perspective view of a pedestrian guard installed on a fuel cell vehicle. [Figure 4] It is a cross-sectional view schematically showing a main part of the fuel cell vehicle in FIG. 1, and shows the flow of outside air along the first direction. [Figure 5] It is a cross-sectional view schematically showing a main part of the fuel cell vehicle in FIG. 1, and shows the flow of outside air along the second direction. [Figure 6] It is a block diagram for explaining a configuration example of a drive circuit of a fan. [Figure 7] It is a flowchart for explaining an example of control of the blowing direction. [Figure 8] It is a perspective view for explaining a fan of a cooling device according to the second embodiment, where the blades are set at the first angle. [Figure 9] It is a perspective view for explaining a fan of a cooling device according to the second embodiment, where the blades are set at the second angle. [Figure 10] It is an explanatory view of a louver attached to a pedestrian guard, and is a side view seen from the vehicle width direction. [Figure 11] It is a cross-sectional view of a louver in which the blade is in a downward inclined posture, seen from the line A-A in FIG. 10. [Figure 12] It is a cross-sectional view of a louver in which the blade is in an upward inclined posture, seen from the line A-A in FIG. 10. [Figure 13] It is a cross-sectional view for explaining a louver according to a modification example. [Figure 14] It is a flowchart for explaining an example of control of the blowing direction according to a modification example.

Embodiments for Carrying out the Invention

[0012] Referring to the drawings, embodiments of the present case will be described. The following embodiments are merely examples, and there is no intention to exclude various modifications and applications of technologies not explicitly stated in this embodiment. Each configuration of the following embodiments can be variously modified and implemented without departing from their gist. Also,取舍選択 can be made as necessary, or they can be appropriately combined.

[0013] [1. First Embodiment] [1-1. Configuration] <Fuel cell vehicle> As shown in Fig. 1, the cooling device 1 of the fuel cell vehicle according to the first embodiment is applied to a fuel cell vehicle 2 which is a truck. Hereinafter, the "cooling device 1 of the fuel cell vehicle" is also simply referred to as the "cooling device 1", and the "fuel cell vehicle 2" is also simply referred to as the "vehicle 2". The vehicle 2 includes a cab 21 and a chassis frame 22, and drives a motor 24 for running with the power of the fuel cell 23. The vehicle 2 of the present embodiment further includes a high-voltage battery 25 that stores the power of the fuel cell 23, and drives the motor 24 with the power stored in the high-voltage battery 25. In the drawings, both the cab 21 and the mounting 36 described later are shown by two-dot chain lines.

[0014] The chassis frame 22 of the present embodiment has a ladder frame structure. Specifically, the chassis frame 22 has a pair of side rails 26 that extend in the vehicle length direction (front-rear direction) D1 and are spaced apart from each other in the vehicle width direction (left-right direction) D2, and a plurality of cross members 27 (only two are shown in Fig. 1) that extend in the vehicle width direction D2 and connect the side rails 26, forming a ladder shape. The front part of the chassis frame 22 supports the cab 21 from below. On the other hand, the central part and the rear part of the chassis frame 22 in the vehicle length direction D1 support the mounting 36 arranged behind the cab 21 from below. The mounting 36 is, for example, a cargo box and is also called a body.

[0015] The fuel cell 23 is a device that generates electricity by the chemical reaction of hydrogen and oxygen (air). The fuel cell 23 is arranged, for example, between the pair of side rails 26 below the cab 21. Various auxiliary devices 28 (hereinafter, also referred to as FC auxiliary devices 28) such as valves and compressors related to the fuel cell 23 are attached to the fuel cell 23.

[0016] The high-voltage battery 25 is positioned, for example, behind the cab 21 and fuel cell 23, between a pair of side rails 26. Behind the fuel cell 23 and in front of the high-voltage battery 25, various electric auxiliary equipment 29 (hereinafter also referred to as E-auxiliary equipment 29), a heater 30, and a DC / DC converter 31 are positioned. Specifically, the E-auxiliary equipment 29 includes a water pump, compressor, and valves. The heater 30 is a device for warming the high-voltage battery 25. The DC / DC converter 31 is a device for raising and lowering the DC voltage. The E-auxiliary equipment 29, heater 30, and DC / DC converter 31 are all positioned between a pair of side rails 26.

[0017] The motor 24 is positioned, for example, behind the high-voltage battery 25, between a pair of side rails 26. The motor 24 is modularized with an inverter (not shown). Behind the motor 24 is an axle 32, which includes a reduction gear (not shown). An oil cooler 33 is positioned between the high-voltage battery 25 and the motor 24. The oil cooler 33 is a device that cools the oil used for cooling and lubricating the motor 24 and the axle 32. The oil cooler 33 in this embodiment is a water-cooled type that performs heat exchange between oil and cooling water. If the motor 24 and the axle 32 are cooled with cooling water instead of oil, the oil cooler 33 is omitted.

[0018] The VCU20 is an electronic control unit for comprehensively controlling various devices installed in the vehicle 2, such as between the high-voltage battery 25 and the oil cooler 33, and is configured as an LSI device or embedded electronic device that integrates a microprocessor, ROM, RAM, etc. The VCU20 is connected to multiple fans 7, which will be described later, via communication lines (shown as dotted lines in Figure 1).

[0019] <Cooling device> The cooling system 1 comprises a hydrogen gas storage unit 3 located behind the cab 21 and outside the chassis frame 22 in the vehicle width direction D2, and a heat exchange unit 4 located outside the hydrogen gas storage unit 3 in the vehicle width direction D2 and along the hydrogen gas storage unit 3. In this embodiment, the hydrogen gas storage unit 3 includes two tanks, a first tank 3A and a second tank 3B, as an example.

[0020] The first tank 3A is located on the outside of the vehicle width direction D2 of one of a pair of side rails 26 that extend in the vehicle length direction D1 in the chassis frame 22, which has a ladder frame structure (the left side rail in Figure 1). The second tank 3B is located on the outside of the vehicle width direction D2 of the other side rail 26 (the right side rail in Figure 1). Thus, in this embodiment, the first tank 3A is located to the left of the left side rail 26, and the second tank 3B is located to the right of the right side rail 26.

[0021] The hydrogen gas storage section 3 (each of the first tank 3A and the second tank 3B) is a container for storing hydrogen gas supplied to the fuel cell 23. For example, it has a shape such as a cylinder with both ends closed by hemispherical surfaces, and is mounted in a position where the axis of the cylinder extends along the vehicle length direction D1. In this embodiment, the first tank 3A and the second tank 3B, which have the same shape as each other, are given as examples. However, the shape of the hydrogen gas storage section 3 is not limited to the above example, and the two tanks 3A and 3B may have different shapes.

[0022] The hydrogen gas storage unit 3 is located in the space between the front wheels 34 and rear wheels 35 of the vehicle 2. Furthermore, from a safety standpoint, the hydrogen gas storage unit 3 is positioned at least a predetermined distance inward from the outer surface 37 of the vehicle 2 (for example, the outermost surface of the bodywork 36) in the vehicle width direction D2. Therefore, a space of at least a predetermined distance is provided outside the hydrogen gas storage unit 3 in the vehicle width direction D2.

[0023] As described above, the heat exchange unit 4 is located in a space of a predetermined size or larger, located outward in the vehicle width direction D2 from the hydrogen gas storage unit 3. In other words, the heat exchange unit 4 is mounted using the dead space located outward in the vehicle width direction D2 from the hydrogen gas storage unit 3. In this embodiment, the heat exchange unit 4 is located at a distance of D2 from the hydrogen gas storage unit 3 in the vehicle width direction D2.

[0024] The heat exchange unit 4 is a device that performs heat exchange between the refrigerant that cools the fuel cell 23 and the outside air. In this embodiment, the heat exchange unit 4 is illustrated by including three radiators: a first radiator 4A for cooling the fuel cell 23, a second radiator 4B for cooling the high-voltage battery 25, and a third radiator 4C for cooling the motor 24. Each of the three radiators 4A, 4B, and 4C is an air-cooled heat exchanger that cools the cooling water, which is the refrigerant, with the outside air. The radiators 4A, 4B, and 4C in this embodiment are all thin box-shaped, and are arranged so that the side with the largest area (the surface through which the outside air passes) is aligned at least along the vehicle length direction D1.

[0025] The first radiator 4A performs heat exchange between the first refrigerant (refrigerant) 41, which cools the fuel cell 23, and the outside air. In this embodiment, the first radiator 4A is a cooling device dedicated to the fuel cell 23. Therefore, the first refrigerant 41 circulates between the fuel cell 23 and the first radiator 4A, cools only the fuel cell 23, and is then cooled again by the first radiator 4A. The first radiator 4A is installed along the first tank 3A, outside the first tank 3A in the vehicle width direction D2. The dimension of the first radiator 4A in the vehicle length direction D1 is set to be approximately the same as, for example, the cylindrical portion of the first tank 3A.

[0026] The second radiator 4B is a refrigerant that cools the high-voltage battery 25 and exchanges heat between the second refrigerant (refrigerant) 42, which is different from the first refrigerant 41, and the outside air. In this embodiment, the second radiator 4B is a cooling device for the water-cooled section 40 that passes not only through the high-voltage battery 25 but also through the E auxiliary equipment 29, heater 30, and DC / DC converter 31. More specifically, the second refrigerant 42 circulates between the water-cooled section 40 and the second radiator 4B, cools the high-voltage battery 25, E auxiliary equipment 29, heater 30, and DC / DC converter 31 in the water-cooled section 40, and is then cooled again in the second radiator 4B. The second radiator 4B is installed along the second tank 3B, outside the vehicle width direction D2 of the second tank 3B.

[0027] The third radiator 4C is a refrigerant for cooling the motor 24 and exchanges heat between a third refrigerant (refrigerant) 43, which is different from the first refrigerant 41 and the second refrigerant 42, and the outside air. In this embodiment, the third radiator 4C is a cooling device for the oil that cools the FC auxiliary equipment 28 and the motor 24. Therefore, the third refrigerant 43 circulates between the FC auxiliary equipment 28, the oil cooler 33, and the third radiator 4C, cooling the FC auxiliary equipment 28, then cooling the oil for cooling the motor 24 in the oil cooler 33, and then being cooled again in the third radiator 4C. The third radiator 4C, together with the second radiator 4B, is installed along the second tank 3B, outside the vehicle width direction D2 of the second tank 3B.

[0028] Figure 1 shows an example in which the second radiator 4B is installed in front of the third radiator 4C. The dimensions D1 in the vehicle length direction of the second radiator 4B and the third radiator 4C are set to, for example, about half the length of the cylindrical portion of the second tank 3B. Figure 1 illustrates radiators 4A, 4B, and 4C in which both the refrigerant inlet and outlet are located on the same side (front or rear end). However, the layout of the refrigerant inlet and outlet in the heat exchange section 4 can be changed as appropriate. For example, in the first radiator 4A, the refrigerant inlet may be located at the front end and the refrigerant outlet at the rear end. By providing the refrigerant inlet and outlet on both sides of the heat exchange section 4 in the vehicle length direction D1, the dimensions of the heat exchange section 4 in the vehicle height direction (vertical direction) D3 (see Figure 2) can be reduced.

[0029] The cooling device 1 of this embodiment includes an outside air guide unit 5 that guides outside air to the heat exchange unit 4. This outside air guide unit 5 is provided inside the heat exchange unit 4 in the vehicle width direction D2 and includes a casing 6 (shown by a dashed line in Figure 1) that forms a passage for outside air between the heat exchange unit 4 and the hydrogen gas storage unit 3, and a fan 7 for generating the flow of outside air that passes through the heat exchange unit 4. In the outside air induction section 5 of this embodiment, two casings 6 are attached to two tanks 3A and 3B respectively, and a fan 7 is positioned in the space between the heat exchange section 4 and the hydrogen gas storage section 3.

[0030] Figure 1 shows an example in which three fans 7 are arranged in the vehicle length direction D1 in the space between the first radiator 4A and the first tank 3A, and three more fans 7 are arranged in the vehicle length direction D1 between the second radiator 4B and the third radiator 4C and the second tank 3B. However, the number of fans 7 is not limited to this. These fans 7 are installed facing directly towards the heat exchange section 4. This allows the fans 7 to generate an airflow of outside air perpendicular to the side surface with the largest surface area in the heat exchange section 4.

[0031] The following explanation will use Figures 2 and 3 as an example, referring to the casing 6 attached to the second tank 3B. As shown in Figure 2, the casing 6 of this embodiment is provided to cover the second tank 3B (hydrogen gas storage section 3) from the outside in the vehicle width direction D2, and is substantially box-shaped. On the sides of the casing 6 facing outward in the vehicle width direction D2, openings 61 and 62 are formed for fitting the second radiator 4B and the third radiator 4C, respectively.

[0032] The fan 7 is installed between the side of the casing 6 where the openings 61 and 62 are formed and the outer surface of the second tank 3B (hydrogen gas storage section 3). In other words, the fan 7 is installed inside the casing 6, inward in the vehicle width direction D2 of the second radiator 4B and the third radiator 4C (heat exchange section 4), and outward in the vehicle width direction D2 of the second tank 3B.

[0033] The casing 6, the second radiator 4B, and the third radiator 4C are supported by brackets 38 and 39 that fix the second tank 3B to the chassis frame 22. Furthermore, ventilation openings 64 are formed on the upper and lower surfaces of the casing 6, connecting the inside and outside of the casing 6. In addition, the casing 6 of this embodiment is attached to the outer surface of the second tank 3B without any gaps via a rubber material 51.

[0034] A pedestrian guard 10 is positioned outside the vehicle width direction D2 of the second radiator 4B and the third radiator 4C to protect pedestrians who may be struck from outside the vehicle width direction D2. The pedestrian guard 10 has a number of holes 11 that penetrate in the vehicle width direction D2 in order to allow outside air to flow into the second radiator 4B and the third radiator 4C.

[0035] As shown in Figure 3, the pedestrian guard 10 includes, for example, a number of hexagonal cylindrical sections 12, a grid-like frame 13 that supports the cylindrical sections 12, and a panel 14 connected to one end of the cylindrical sections 12. The panel 14 has a number of through holes that communicate with the hollow sections of the cylindrical sections 12. In this way, the communication between the hollow sections of the cylindrical sections 12 and the through holes in the panel 14 forms the aforementioned hole 11 that penetrates in the vehicle width direction D2. As shown in Figure 2, the pedestrian guard 10 is mounted on the vehicle 2 in a position where the panel 14 is located outward in the vehicle width direction D2 from the cylindrical sections 12.

[0036] As shown in Figures 1 and 2, fan 7 is a propeller fan having multiple blades (propellers) that rotate around a rotation axis. Fan 7 is installed with its rotation axis aligned with the vehicle width direction D2, and generates an airflow of outside air along the vehicle width direction D2. This fan 7 is configured as a bidirectional blower capable of blowing air in both directions: a first direction to draw outside air from the heat exchange unit 4 and a second direction to guide outside air to the heat exchange unit 4.

[0037] The first direction, as shown by the thick arrow F1 in Figure 1, is a blowing direction that guides outside air from the outside in the vehicle width direction D2 towards the inside (from the outside in the vehicle width direction D2 of the heat exchange section 4 towards the hydrogen gas storage section 3). The second direction, as shown by the thick arrow F2 in Figure 1, is a blowing direction that guides outside air from the inside to the outside in the vehicle width direction D2 (from the hydrogen gas storage section 3 to the outside in the vehicle width direction D2 of the heat exchange section 4).

[0038] Refer to Figure 4 to explain the flow of outside air along the first direction F1. As shown by the thick arrow F1 in Figure 4, outside air is guided from the outside to the inside in the vehicle width direction D2. As a result, outside air passes through the holes 11 in the pedestrian guard 10 to the second radiator 4B and the third radiator 4C. The outside air then flows upward and downward along the outer surface of the second tank 3B and is discharged inward in the vehicle width direction D2 through the vents 64 of the casing 6.

[0039] Refer to Figure 5 to explain the flow of outside air along the second direction F2. As shown by the thick arrow F2 in Figure 5, outside air is guided from the inside to the outside in the vehicle width direction D2. As a result, outside air flows into the casing 6 through the vent 64, flows upward and downward along the outer surface of the second tank 3B within the casing 6, and passes through the second radiator 4B and the third radiator 4C. The outside air is then discharged outwards in the vehicle width direction D2 through the holes 11 in the pedestrian guard 10.

[0040] The fan 7 in this embodiment is configured as a bidirectional fan capable of rotating in both forward and reverse directions, using a motor capable of forward and reverse rotation. By switching the rotation direction of the fan 7, the airflow direction of the fan 7 can be switched from one of the first direction F1 and the second direction F2 to the other. In this embodiment, when the fan 7 is rotating in the forward direction, outside air is guided in the first direction F1. When the fan 7 is rotating in the reverse direction, outside air is guided in the second direction F2.

[0041] Figure 6 is a block diagram of an example configuration of a motor drive circuit 70 for driving the fan 7 in both directions. A drive circuit 70 is built into each of the six fans 7 shown in Figure 1. The motor M is a three-phase brushless DC motor capable of rotating in both forward and reverse directions. The motor M is connected to the rotating shaft of the fan 7 (not shown in Figure 6).

[0042] The drive circuit 70 includes a control circuit 71 and an inverter circuit 72. The control circuit 71 includes a motor control unit 71A and three gate drivers 71B, and the motor control unit 71A receives a PWM signal as a control signal from the VCU20 (Figure 1). The inverter circuit 72 includes six switching elements 72A to 72F, which are connected to the three-phase windings of the motor M. The switching elements 72A to 72F are composed of, for example, MOSFETs.

[0043] The motor M is equipped with Hall sensors 73 on each phase of its windings to detect its rotational position. The detection signals from the Hall sensors 73 are input to the motor control unit 71A. The motor control unit 71A and gate driver 71B of the control circuit 71 generate control signals for the switching elements 72A to 72F based on the PWM signal supplied from the VCU 20 (Figure 1). The switching elements 72A to 72F generate drive power to the motor M according to the control signals. Drive power is applied to the windings of the motor M. As a result, the motor M is driven, and the fan 7 rotates in the forward or reverse direction. In the drive circuit 70 with the configuration described above, it is possible to control the rotation direction and rotation speed of the fan 7 according to the pattern of the PWM value (pulse time width) supplied as a PWM signal. Known technologies can be applied to such a drive circuit 70.

[0044] [1-2. Control] Next, we will explain how to control the airflow direction of fan 7. The airflow direction control involves controlling the direction in which the fan 7 guides outside air to either the first direction F1 or the second direction F2, and switching from one of the first direction F1 or the second direction F2 to the other when predetermined conditions are met.

[0045] Specifically, the VCU20 selects the first mode when the vehicle speed of vehicle 2 is below a predetermined speed. The first mode is the operating mode of the fan 7, in which the fan 7 guides outside air in the first direction F1. On the other hand, if the vehicle speed of vehicle 2 is above a predetermined speed, the VCU 20 selects the second mode. The second mode is the operating mode of the fan 7, in which the fan 7 guides outside air in the second direction F2.

[0046] The predetermined speed is set to a vehicle speed that serves as a threshold for determining whether vehicle 2 is traveling at a low speed or is stopped. Specifically, an example of a predetermined speed is 30 km / h. "Below the specified speed" includes the case where the vehicle speed is 0 km / h, i.e., when the vehicle is stopped. "Stopped" means that vehicle 2 is running (key on) and is stationary.

[0047] In the first mode, the VCU20 outputs a first control signal (PWM signal) to the drive circuit 70 of the fan 7, instructing it to direct outside air in the first direction F1. In the second mode, the VCU20 outputs a second control signal (PWM signal) to the drive circuit 70 of the fan 7, instructing it to direct outside air in the second direction. As described above, the fan 7 in this embodiment blows air in the first direction when rotating forward and in the second direction when rotating backward. Therefore, the first control signal is a PWM signal that instructs the fan 7 to rotate forward. The second control signal is a PWM signal that instructs the fan 7 to rotate backward.

[0048] Figure 7 is a flowchart showing an example of airflow direction control. The flow in Figure 7 starts when vehicle 2 is started (key on) and is executed repeatedly at predetermined intervals. The VCU20 determines whether the vehicle speed of vehicle 2 is below a predetermined speed (step S1). If the vehicle speed of vehicle 2 is below the predetermined speed (Yes in step S1), the VCU20 selects the first mode and outputs a first control signal to the drive circuit 70 of the fan 7 (step S2). As a result, fan 7 operates in the first mode when vehicle 2 is traveling at a speed below a predetermined speed. That is, fan 7 rotates in the forward direction to guide outside air along the first direction F1.

[0049] If the vehicle speed of vehicle 2 is equal to or greater than a predetermined speed (No. in step S1), the VCU 20 selects the second mode and outputs a second control signal to the drive circuit 70 of fan 7 (step S3). As a result, fan 7 operates in the second mode when vehicle 2 is traveling at a speed above a predetermined speed. That is, fan 7 rotates in the reverse direction to guide outside air along the second direction F2.

[0050] [1-3. Action and Effects] According to the cooling system 1 of this invention, the heat exchange unit 4 is installed along the hydrogen gas storage unit 3 on the outside in the vehicle width direction D2. Therefore, the heat exchange unit 4 can be mounted using the dead space located on the outside in the vehicle width direction D2 of the hydrogen gas storage unit 3. As a result, compared to the conventional case where the heat exchange unit (radiator) is installed below the cab, a larger mounting space for the heat exchange unit 4 can be secured, making it possible to install a large heat exchange unit 4 with sufficient cooling performance.

[0051] However, if the fan 7 is not provided, the following concerns arise with the structure of the cooling device 1 in which the heat exchange unit 4 is installed outside the hydrogen gas storage unit 3 in the vehicle width direction D2. When outside air is guided from the outside in the vehicle width direction D2, the high-temperature outside air that has passed through the heat exchange unit 4 will come into contact with the hydrogen gas storage unit 3. As a result, the hydrogen gas storage unit 3 may become hot. Also, when outside air is guided from the inside out in the vehicle width direction D2, the high-temperature outside air that has passed through the heat exchange unit 4 will be discharged outside in the vehicle width direction D2. As a result, there is a risk of affecting people such as workers or pedestrians in the vicinity of the vehicle 2.

[0052] In relation to the above, the cooling device 1 of this embodiment is provided with an outside air induction unit 5 having a fan 7 capable of blowing air in both directions, a first direction F1 and a second direction F2. The operating mode of the fan 7 is switched according to the vehicle speed between a first mode in which outside air is guided along the first direction F1, which is from the outside to the inside of the vehicle width direction D2, and a second mode in which outside air is guided along the second direction, which is from the inside to the outside of the vehicle width direction D2. Therefore, the following advantages are available.

[0053] If the vehicle speed of vehicle 2 is below the predetermined speed, the first mode is selected. When the vehicle is traveling at a low speed below the predetermined speed or is stopped, there is a high probability that people such as workers or pedestrians are present in the vicinity of vehicle 2. In this respect, in the first mode, the outside air that has passed through the heat exchange section 4 is discharged inward in the vehicle width direction D2 (see Figure 4). Therefore, the impact of the high-temperature outside air on the surrounding environment, such as people near the vehicle 2, is suppressed. In addition, because the temperature of the outside air after passing through the heat exchange section 4 is relatively low, sufficient cooling performance can be ensured even if the outside air comes into contact with the hydrogen gas storage section 3.

[0054] The second mode is selected when the vehicle speed of vehicle 2 is above a predetermined speed. When vehicle 2 is traveling at a high speed above a predetermined speed, the cooling requirement is generally high. In this regard, in the second mode, outside air passes through the heat exchange section 4 from the inside in the vehicle width direction D2, so the high-temperature outside air that has passed through the heat exchange section 4 does not come into contact with the hydrogen gas storage section 3. Therefore, it is possible to suppress the hydrogen gas storage section 3 from becoming hot. This contributes to ensuring cooling performance. Furthermore, when the vehicle speed is above a predetermined speed, the likelihood of people such as workers or pedestrians being present near vehicle 2 is low, and vehicle 2 is moving at high speed. Therefore, even if the high-temperature outside air that has passed through the heat exchange section 4 is discharged outwards in the vehicle width direction D2 (see Figure 5), the impact on people near vehicle 2 and the surrounding environment is suppressed.

[0055] Based on the above, the cooling device 1 of the present invention, in a structure in which the heat exchange unit 4 is installed outside the hydrogen gas storage unit 3 in the vehicle width direction D2, allows for a large mounting space for the heat exchange unit 4 and ensures sufficient cooling performance. Furthermore, the direction in which outside air is guided by the fan 7 (airflow direction) can be optimized according to the vehicle speed. In addition, in a structure in which the heat exchange unit 4 is installed outside the hydrogen gas storage unit 3 in the vehicle width direction D2, it is easier to ensure cooling performance for equipment to be cooled, such as the fuel cell 23, as well as the high-voltage battery 25 and the electric motor 24. Therefore, it is possible to ensure both the mountability and cooling performance of the cooling device 1.

[0056] [2. Second Embodiment] [2-1. Structure] The cooling device according to the second embodiment differs from the cooling device 1 of the first embodiment in the configuration of the fan 7'. The fan 7' of this embodiment is configured to blow air in both directions, a first direction F1 and a second direction F2, even if the rotation axis of the fan 7' rotates in the same direction. Specifically, as shown in Figures 8 and 9, the fan 7' is provided with a plurality of blades 7A on the outer circumference of the hub 7C, and has a built-in angle adjustment mechanism 7B for adjusting the mounting angle of the blades 7A. The angle adjustment mechanism 7B is a mechanism that switches the mounting angle of the blades 7A to either the first angle shown in Figure 8 or the second angle shown in Figure 9. Note that some of the plurality of blades 7A are omitted in Figures 8 and 9. Note that some of the plurality of blades 7A are omitted in Figures 8 and 9.

[0057] The first angle is set as the mounting angle at which outside air is guided along the first direction F1 by the rotation of the fan 7', as shown in Figure 8. The second angle is set as the mounting angle at which outside air is guided along the second direction F2 by the rotation of the fan 7', as shown in Figure 9. It should be noted that the structure of a fan capable of bidirectional airflow by adjusting the mounting angle of the blades is a well-known technology.

[0058] [2-2. Control] In the second embodiment, the VCU20 differs from the first embodiment in that it outputs an angle control signal to the angle adjustment mechanism 7B as a control signal, which instructs the switching of the mounting angle of the blade 7A. The angle control signal is a signal that instructs either the first angle shown in Figure 8 or the second angle shown in Figure 9. In other words, the fan 7' rotates in only one direction, and the airflow direction is switched from one of the first and second directions to the other by changing the mounting angle of the blades 7A.

[0059] If the vehicle speed is below a predetermined speed, the VCU20 outputs an angle control signal to the angle adjustment mechanism 7B indicating the first angle. Based on the angle control signal, the angle adjustment mechanism 7B sets the angle of attack of the blade 7A to the first angle. In this case, outside air is guided along the first direction F1 by the action of the fan 7'. When the vehicle speed is above a predetermined speed, the angle of the blade 7A is set to the second angle, and outside air is guided along the second direction F2 by the rotational action of the fan 7'. In this case, the same effects as those of the first embodiment described above can be obtained.

[0060] [3. Variant] As shown in Figures 10-12, louvers 46 may be attached to the pedestrian guard 10. As shown in Figure 10, the louver 46 of this embodiment is incorporated into the pedestrian guard 10 on the surface facing outward in the vehicle width direction D2. The louver 46 is provided with a frame 46A that forms the outer frame of the louver 46, and a plurality of vanes 46B within the opening surrounded by the frame 46A. The plurality of vanes 46B are arranged parallel to each other along the vehicle height direction D3, with a gap that connects the outward and inward sides in the vehicle width direction D2. The louver 46 can control the direction of outside air discharged outward in the vehicle width direction D2 along the second direction F2, either upward or downward, by the inclination of the vanes 46B.

[0061] Figures 11 and 12 are cross-sectional views of Figure 10 as seen from line AA, with elements other than the louvers 46 omitted. The louver 46 shown in Figure 11 has a slanted vane 46B in which the outer edge in the vehicle width direction D2 is positioned lower in the vehicle height direction D3 than the inner edge (downward slanted position). In this case, as shown by the thick arrow in Figure 11, the outside air guided along the second direction F2 is discharged from the louver 46 outward and diagonally downward in the vehicle width direction D2.

[0062] The louver 46' shown in Figure 12 has a slat 46B' that is in an inclined position (upward inclined position) where the outer edge in the vehicle width direction D2 is positioned higher in the vehicle height direction D3 than the inner edge. In this case, as shown by the thick arrow in Figure 12, the outside air guided along the second direction F2 is discharged from the louver 46' outward and diagonally upward in the vehicle width direction D2. The louvers 46, 46' direct the exhaust air outward in the vehicle width direction D2 to be discharged diagonally downward or upward, further reducing the impact on people near vehicle 2 and the surrounding environment.

[0063] In addition, as an example of a condition for selecting the first or second mode in controlling the airflow direction of the VCU20, the condition of whether the vehicle speed is below a predetermined speed was given. This condition can also be said to be a condition that allows for the determination of two points: whether the cooling demand is high, and whether the situation may affect people in the vicinity of vehicle 2. Therefore, as a condition for selecting the first or second mode, in addition to or instead of the condition of whether the vehicle speed is below a predetermined speed, conditions such as whether there is a high cooling requirement or whether there is a person (such as a pedestrian) in the vicinity of vehicle 2 can be used.

[0064] As a variation of the control of the airflow direction, in addition to the speed condition of "whether or not the vehicle speed is below a predetermined speed" as described above in the first embodiment, a predetermined temperature condition may be used to select one of the first mode, second mode, and third mode. The following modified examples of airflow direction control are given as examples of applications to a cooling device 1 using a bidirectional fan 7 according to the first embodiment. However, the airflow direction control according to this modified example may also be applied to a cooling device 1 using a fan 7' according to the second embodiment (i.e., a fan in which the mounting angle of the blades 7A can be adjusted).

[0065] In the control of the airflow direction according to this modified example, the VCU20 (Figure 1) selects the first mode when the vehicle speed of the vehicle 2 is less than a predetermined speed and both a predetermined first temperature condition and a predetermined second temperature condition are satisfied, selects the second mode when the vehicle speed of the vehicle 2 is at or above a predetermined speed, and selects the third mode when the vehicle speed of the vehicle 2 is less than a predetermined speed and neither the predetermined first temperature condition nor the predetermined second temperature condition is satisfied. Here, the first mode and the second mode are the same as those in the first embodiment described above. That is, the first mode is a mode in which outside air is guided along the first direction F1, and the second mode is a mode in which outside air is guided along the second direction F2.

[0066] The second mode, which guides outside air along the second direction, tends to ensure better cooling performance (higher cooling performance) compared to the first mode, which guides outside air along the first direction F1. Focusing on this difference in cooling performance, the third mode has been established. In other words, the third mode is a mode in which outside air is guided along the second direction F2 in order to ensure cooling performance when the vehicle speed of vehicle 2 is below a predetermined speed but the cooling requirement is high.

[0067] When the vehicle speed of vehicle 2 is below a predetermined speed, the VCU20 (Figure 1) selects either the first mode or the third mode based on the predetermined first temperature condition and the predetermined second temperature condition described below. The predetermined first temperature condition and the predetermined second temperature condition are set to determine, based on temperature, whether or not the cooling requirement by the heat exchange unit 4 (Figure 1) is high.

[0068] The predetermined first temperature condition is that the temperature of the object to be cooled by the heat exchange unit 4 is below a predetermined maximum allowable temperature. Specifically, the objects to be cooled include the fuel cell 23 (Figure 1), as well as other equipment such as the high-voltage battery 25 (Figure 1) and the electric motor 24 (Figure 1). Each device is equipped with a temperature sensor (not shown in the diagram). Each temperature sensor is connected to the input side of VCU20 (Figure 1), and VCU20 (Figure 1) constantly monitors the temperature of each device.

[0069] The VCU20 (Figure 1) can determine whether the temperature of the object to be cooled is below a predetermined maximum allowable temperature based on temperature data acquired from the temperature sensor. The predetermined maximum allowable temperature is a temperature set in advance as a criterion for determining whether the temperature of the object to be cooled is in a state of high cooling demand. A higher temperature indicates a higher cooling demand, and a lower temperature indicates a lower cooling demand. The value used as this maximum allowable temperature is set appropriately based on the results of simulations, experiments, etc.

[0070] The predetermined second temperature condition is that the rate of temperature change per unit time of the refrigerant in the heat exchange unit 4 (Figure 1) is less than a predetermined threshold. The refrigerant is a medium used to cool each of the components to be cooled in the heat exchange unit 4, and specifically refers to the first refrigerant 41, the second refrigerant 42, and the third refrigerant 43 shown in Figure 1. The rate of temperature change of the refrigerant is the rate of change of the temperature of each of the refrigerants 41, 42, and 43 per unit of time. Temperature sensors (not shown) are provided in the circulation paths of each refrigerant 41, 42, and 43 (Figure 1). Each temperature sensor is connected to the input side of VCU20 (Figure 1), and VCU20 (Figure 1) constantly monitors the temperature of each refrigerant 41, 42, and 43.

[0071] The VCU20 can calculate the rate of temperature change based on the temperatures of each refrigerant 41, 42, and 43, and can determine whether the calculated rate of temperature change is below a predetermined threshold. The temperature change rate threshold is a pre-set value used as a criterion for determining whether or not a state of high cooling demand exists, based on the temperature change rate of the refrigerant. A larger temperature change rate indicates a higher cooling demand, while a smaller value indicates a lower cooling demand. The value used as the temperature change rate threshold is set appropriately based on the results of simulations, experiments, etc.

[0072] Incidentally, as mentioned above, if the speed of vehicle 2 is below the predetermined speed, there is a high probability that there are people such as workers or pedestrians in the vicinity of vehicle 2. In this regard, the cooling device 1 according to this modified example is configured such that when the third mode is selected, outside air is discharged along the second direction F2 and either upward or downward, depending on the mounting angle (tilt) of the vane 46B'' of the louver 46'' shown in Figure 13.

[0073] In other words, in the modified cooling device 1, the louver 46'' shown in Figure 13 is attached to the pedestrian guard 10. The louver 46'' in Figure 13 differs from the louvers 46 in Figures 10 to 12 in that multiple fins 46B'' are configured to allow the mounting angle (tilt) to be changed. Specifically, each wing plate 46B'' can be deformed and adjusted to either the horizontal mode shown by the solid line in Figure 13, or the inclined mode shown by the dashed line in Figure 13, with respect to its respective inclination.

[0074] The horizontal mode is a mode in which the vane 46B'' is positioned to discharge outside air approximately horizontally along the vehicle width direction D2 (second direction F2). The inclined mode is a mode in which the vane 46B'' is positioned to discharge outside air upward along the vehicle width direction D2 (second direction F2) and in an upward inclined position. The louvers 46'' incorporate a tilt adjustment mechanism (not shown), and the output side of the VCU20 (see Figure 1) is connected to this tilt adjustment mechanism (not shown). Based on the control signal from the VCU20 (see Figure 1), the tilt of each slat 46B'' can be switched between horizontal mode and tilt mode.

[0075] Figure 14 is a flowchart showing an example of airflow direction control according to the modified example described above. The flow in Figure 14 starts when vehicle 2 is started (key on) and is executed repeatedly at predetermined intervals. The VCU20 determines whether the vehicle speed of vehicle 2 is below a predetermined speed (step S10). If the vehicle speed of vehicle 2 is below the predetermined speed (Yes in step S10), the VCU20 determines whether the temperature of the object to be cooled is below the maximum allowable temperature (step S11). If the temperature of the object to be cooled is below the maximum allowable temperature (Yes in step S11), the VCU20 determines whether the rate of temperature change of the refrigerant is below a predetermined threshold (step S12).

[0076] If the rate of temperature change of the refrigerant is below a predetermined threshold (Yes in step S12), the VCU20 selects the first mode (step S13). In this case, the VCU20 outputs a first control signal to the drive circuit 70 of the fan 7, causing the fan 7 to rotate in the forward direction and guide outside air along the first direction F1. The VCU20 also outputs a control signal indicating the horizontal mode to the tilt adjustment mechanism of the louvers 46'' (not shown in Figure 13), setting the multiple vanes 46B'' to the horizontal mode (shown by solid lines in Figure 13).

[0077] On the other hand, if the vehicle speed of vehicle 2 is above a predetermined speed (No. in step S10), the VCU 20 selects the second mode (step S14). In this case, the VCU 20 outputs a second control signal to the drive circuit 70 of the fan 7, causing the fan 7 to rotate in the reverse direction and guide outside air along the second direction F2. The VCU 20 also outputs a control signal indicating the horizontal mode to the tilt adjustment mechanism of the louvers 46'' (not shown in Figure 13), setting the multiple vanes 46B'' to the horizontal mode (shown by solid lines in Figure 13).

[0078] Furthermore, if the vehicle speed of vehicle 2 is below a predetermined speed (Yes in step S10) and the temperature of the object to be cooled is above the maximum allowable temperature (No in step S11), or if the temperature of the object to be cooled is below the maximum allowable temperature (Yes in step S11) and the rate of temperature change of the refrigerant is above a predetermined threshold (No in step S12), the VCU 20 selects the third mode (step S15). In this case, the VCU 20 outputs a second control signal to the drive circuit 70 of the fan 7, causing the fan 7 to rotate in the reverse direction and guide outside air along the second direction F2. The VCU 20 also outputs a control signal indicating the tilt mode to the tilt adjustment mechanism of the louver 46'' (not shown in Figure 13), setting the multiple vanes 46B'' to the tilt mode (shown by dashed lines in Figure 13).

[0079] According to the control of the airflow direction in the modified example described above, if the vehicle speed is slow or if the first or second temperature condition is not met even when the vehicle is stopped, the third mode is selected to reverse the rotation of the fan 7, and the inclination of the multiple blades 46B′′ is set to the tilt mode, so that outside air is guided in the second direction F2 and upward. As a result, even when the vehicle speed is slow or when the vehicle is stopped, outside air is guided along the second direction F2, making it easier to ensure cooling performance compared to when the first mode, which guides outside air along the first direction F1, is selected. In addition, since the outside air is guided upward along the second direction F2 by the multiple vanes 46B′′, the impact on people near the vehicle 2 and the surrounding environment is suppressed.

[0080] When the first mode is selected, and when the second mode is selected, the same effects and advantages as those of the first embodiment described above can be obtained, respectively. Furthermore, the tilt mode of the vane 46B'' is not limited to the upward tilt position described above, but may also be a downward tilt position in which the vane 46B'' is aligned with the vehicle width direction D2 (second direction F2) and can expel outside air downward. In this case, when the third mode is selected, the multiple vanes 46B'' guide outside air downward along the second direction F2, thereby suppressing the impact on people near the vehicle 2 and the surrounding environment.

[0081] [4. Addendum] Further details regarding the above embodiments are disclosed. [Note 1] A cooling system for a fuel cell vehicle that includes a cab and chassis frame and drives a motor for propulsion using electricity from a fuel cell, A hydrogen gas storage unit is installed behind the cab and outward in the vehicle width direction of the chassis frame, and stores hydrogen gas supplied to the fuel cell. A heat exchange unit is installed along the hydrogen gas storage unit on the outward side in the vehicle width direction of the hydrogen gas storage unit, and performs heat exchange between at least the refrigerant that cools the fuel cell and the outside air, An outside air guide unit is provided between the heat exchange unit and the hydrogen gas storage unit, and has a fan capable of blowing air in both directions: a first direction from the outside in the vehicle width direction toward the inside in the vehicle width direction and a second direction from the inside in the vehicle width direction toward the outside in the vehicle width direction, in order to guide the outside air to the heat exchange unit. The fuel cell vehicle includes a control unit that, when the vehicle speed of the fuel cell vehicle is below a predetermined speed, selects a first mode in which the fan guides the outside air in the first direction, and when the vehicle speed of the fuel cell vehicle is above the predetermined speed, selects a second mode in which the fan guides the outside air in the second direction. A cooling system for a fuel cell vehicle, characterized by the following features. [Note 2] The control unit selects the first mode if the vehicle speed of the fuel cell vehicle is less than the predetermined speed and both the first temperature condition, where the temperature of the object to be cooled in the heat exchange unit is less than a predetermined maximum allowable temperature, and the second temperature condition, where the rate of temperature change of the refrigerant in the heat exchange unit per unit time is less than a predetermined threshold, are satisfied. If the vehicle speed of the fuel cell vehicle is equal to or greater than the predetermined speed, the control unit selects the second mode. If the vehicle speed of the fuel cell vehicle is less than the predetermined speed and neither the first nor the second temperature condition is satisfied, the control unit selects the third mode, in which the fan guides the outside air in the second direction. A cooling device for a fuel cell vehicle as described in Appendix 1, characterized by the features described herein. [Note 3] The heat exchange section is provided with a frame installed on the outer side in the vehicle width direction, and a louver having a plurality of vanes provided within an opening surrounded by the frame, which can be transformed into a horizontal mode that discharges the outside air substantially horizontally along the second direction, or an inclined mode that discharges the outside air along the second direction upward or downward, The control unit sets the vane to the horizontal mode in the first and second modes, and sets the vane to the inclined mode in the third mode. A cooling device for a fuel cell vehicle as described in Appendix 2, characterized by the features described herein. [Note 4] The aforementioned fan is configured as a bidirectional fan capable of rotating in both forward and reverse directions by a motor capable of forward and reverse rotation. The control unit outputs to the fan a first control signal that rotates the fan forward to guide the outside air in the first direction, or a second control signal that rotates the fan backward to guide the outside air in the second direction. A cooling system for a fuel cell vehicle, characterized by any one of the features described in Appendix 1 to 3. [Note 5] The fan has blades whose mounting angle can be adjusted to a first angle that guides the outside air in the first direction for rotation in the same direction, or a second angle that guides the outside air in the second direction for rotation in the same direction. The control unit outputs a first angle control signal indicating the first angle or a second angle control signal indicating the second angle to the fan. A cooling device for a fuel cell vehicle as described in any one of the appendices 1 to 3, characterized by the above. [Explanation of Symbols]

[0082] 1. Cooling system (cooling system for fuel cell vehicles) 2 vehicles (fuel cell vehicles) 3. Hydrogen gas storage section 3A First Tank 3B Second Tank 4 Heat exchange section 4A First Radiator 4B Second Radiator 4C Third Radiator 5. Outside air induction section 6. Casing 7 Fans 7A blade 7B Angle adjustment mechanism 10 Pedestrian guardrail 11 Hole 12 Cylinder part 13 frames 14 panels 20 VCU (Control Unit) 21 Cab 22 Chassis Frame 23 Fuel Cell 24 motors 25 High-voltage batteries 26 Side Rails 27 Crossmember 28 FC Auxiliary Equipment 29 E Auxiliary Locomotive 30 Heater 31 DC / DC Converters 32 Axle 33 Oil cooler 34 Front Wheel 35 Rear wheel 36 Bodywork 37 Exterior 38 Mount 39 Stay 40 Water cooling section 41 First refrigerant 42 Second refrigerant 43 Third refrigerant 44 Side Guard 46 louvers 46A Frame 46B Feather board 51 Rubber material 61 Aperture 62 Aperture 63 Inlet 64 Ventilation holes 70 Drive Circuit 71 Control circuits 71A Motor Control Unit 71B Gate Driver 72 Inverter Circuit 72A~72F Switching Component 73 Hall Sensor F1 first direction F2 Second direction D1 Vehicle length direction (front / rear direction) D2 Vehicle width direction (left-right direction) D3 Vehicle height direction (vertical direction)

Claims

1. A cooling system for a fuel cell vehicle that includes a cab and chassis frame and drives a motor for propulsion using electricity from a fuel cell, A hydrogen gas storage unit is installed behind the cab and outward in the vehicle width direction of the chassis frame, and stores hydrogen gas supplied to the fuel cell. A heat exchange unit is installed along the hydrogen gas storage unit on the outward side in the vehicle width direction of the hydrogen gas storage unit, and performs heat exchange between at least the refrigerant that cools the fuel cell and the outside air, An outside air guide unit is provided between the heat exchange unit and the hydrogen gas storage unit, and has a fan capable of blowing air in both directions: a first direction from the outside in the vehicle width direction toward the inside in the vehicle width direction and a second direction from the inside in the vehicle width direction toward the outside in the vehicle width direction, in order to guide the outside air to the heat exchange unit. The fuel cell vehicle includes a control unit that, when the vehicle speed of the fuel cell vehicle is below a predetermined speed, selects a first mode in which the fan guides the outside air in the first direction, and when the vehicle speed of the fuel cell vehicle is above the predetermined speed, selects a second mode in which the fan guides the outside air in the second direction. A cooling system for a fuel cell vehicle, characterized by the following features.

2. The control unit selects the first mode if the vehicle speed of the fuel cell vehicle is less than the predetermined speed and both the first temperature condition, where the temperature of the object to be cooled in the heat exchange unit is less than a predetermined maximum allowable temperature, and the second temperature condition, where the rate of temperature change of the refrigerant in the heat exchange unit per unit time is less than a predetermined threshold, are satisfied. If the vehicle speed of the fuel cell vehicle is equal to or greater than the predetermined speed, the control unit selects the second mode. If the vehicle speed of the fuel cell vehicle is less than the predetermined speed and neither the first nor the second temperature condition is satisfied, the control unit selects the third mode, in which the fan guides the outside air in the second direction. A cooling device for a fuel cell vehicle according to claim 1, characterized in that...

3. The heat exchange section is provided with a frame installed on the outer side in the vehicle width direction, and a louver having a plurality of vanes provided within an opening surrounded by the frame, which can be transformed into a horizontal mode that discharges the outside air substantially horizontally along the second direction, or an inclined mode that discharges the outside air along the second direction upward or downward, The control unit sets the vane to the horizontal mode in the first and second modes, and sets the vane to the inclined mode in the third mode. A cooling device for a fuel cell vehicle according to claim 2, characterized in that

4. The aforementioned fan is configured as a bidirectional fan capable of rotating in both forward and reverse directions by a motor capable of forward and reverse rotation. The control unit outputs to the fan a first control signal that rotates the fan forward to guide the outside air in the first direction, or a second control signal that rotates the fan backward to guide the outside air in the second direction. A cooling device for a fuel cell vehicle according to claim 1 or 2, characterized in that

5. The fan has blades whose mounting angle can be adjusted to a first angle that guides the outside air in the first direction for rotation in the same direction, or a second angle that guides the outside air in the second direction for rotation in the same direction. The control unit outputs a first angle control signal indicating the first angle or a second angle control signal indicating the second angle to the fan. A cooling device for a fuel cell vehicle according to claim 1 or 2, characterized in that

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