JP2007015419A - Battery cooling device for vehicle provided with hydrogen fuel tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent excessive cooling in a hybrid vehicle provided with a hydrogen fuel tank 40, while effectively cooling a battery 71. <P>SOLUTION: The battery cooling device is provided with: a hydrogen fuel pressure reducing means 3 intermediating in a hydrogen fuel supply system between the hydrogen fuel tank 40 and a hydrogen engine 1 for reducing the pressure of the hydrogen from the hydrogen fuel tank 40 and expanding the hydrogen; a temperature detecting means 76 for detecting the temperature of the battery 71; battery cooling means 72, 73 for cooling the battery 71 by using the cold generated in expansion of the hydrogen when reducing its pressure by the hydrogen fuel pressure reducing means 3; and a restricting means 77 for restricting the cooling of the battery 71 by the battery cooling means 72, 73 when the temperature of the battery 71 is lower than a prescribed temperature. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a battery cooling device for a vehicle including a hydrogen fuel tank.

  2. Description of the Related Art A hybrid vehicle (hereinafter also referred to as HEV: Hybrid Electric Vehicle) that includes a motor and an engine as drive sources and travels by combining these motor and engine is known. In such an HEV, a high voltage battery is mounted as a power source for a motor as a drive source. However, since a high voltage battery generates a large amount of heat when discharged (when the motor is driven), how to use the battery? The issue is whether to cool.

  For example, Patent Document 1 discloses a cooling fan for blowing air to a battery as a cooling device for a battery mounted on an HEV or the like. However, a high-voltage battery is sufficiently cooled only by blowing such a cooling fan. You may not be able to.

Further, for example, in Patent Document 2, although not a device for cooling a battery, in a fuel cell vehicle equipped with a hydrogen fuel tank, cold heat generated when the hydrogen supplied from the hydrogen fuel tank to the fuel cell is decompressed and expanded is shown. A structure that uses and cools the fuel cell is disclosed.
JP 2000-90976 A Japanese Patent Laying-Open No. 2005-71830

  By the way, when the engine in the hybrid vehicle is a hydrogen engine using hydrogen as a fuel, the vehicle is equipped with a hydrogen fuel tank. Therefore, as disclosed in Patent Document 2, the hydrogen is decompressed and expanded. It is conceivable to cool the battery, which is the power source of the drive motor, by using the cold heat generated during the operation.

  However, in the fuel cell vehicle, when the fuel cell is driven, in other words, when the fuel cell needs to be cooled, cold heat is generated as hydrogen is supplied to the fuel cell. Although it can be cooled effectively, in hybrid vehicles (particularly parallel type or parallel series type hybrid vehicles), cold energy is generated when the hydrogen engine is driven, in other words, when hydrogen is supplied to the engine. And the timing for driving the drive motor, in other words, the timing at which the battery needs to be cooled due to the discharge of the battery do not necessarily match. Therefore, if the battery is constantly cooled by the generated cold heat, the battery is overcooled, and the charge / discharge efficiency of the battery is reduced.

  The present invention has been made in view of such points, and an object of the present invention is to prevent overcooling of a hybrid vehicle including a hydrogen fuel tank while effectively cooling a battery. is there.

  The present invention relates to a hydrogen fuel tank that stores hydrogen, a hydrogen engine that generates a driving force of a vehicle using hydrogen supplied from the hydrogen fuel tank as a fuel, and a hydrogen fuel supply between the hydrogen fuel tank and the hydrogen engine. A hydrogen fuel decompressing means for decompressing and expanding hydrogen from the hydrogen fuel tank through a system; a battery; a drive motor for generating a driving force of the vehicle by electric power supplied from the battery; and a temperature of the battery A temperature detecting means for detecting the battery, a battery cooling means for cooling the battery using cold heat generated when the hydrogen is decompressed / expanded by the hydrogen fuel decompressing means, and the battery detected by the temperature detecting means. Based on the temperature, when the temperature of the battery is lower than a predetermined temperature, the cooling of the battery by the battery cooling means is limited. And limit means, a battery cooling device for the vehicle with an.

  According to this configuration, the vehicle is a hybrid vehicle that includes a hydrogen engine and a drive motor as drive sources, and the battery that is the power source of the drive motor supplies hydrogen supplied to the hydrogen engine by battery cooling means. It is cooled using the cold energy generated when decompressing and expanding. This effectively cools the battery.

  On the other hand, when the temperature of the battery is lower than a predetermined temperature based on the temperature of the battery detected by the temperature detection means, the cooling of the battery by the battery cooling means is restricted by the restriction means. This prevents overcooling of the battery.

  Therefore, the present invention is effective in a hybrid vehicle equipped with a hydrogen engine and a drive motor in which the generation timing of cold heat due to the decompression and expansion of hydrogen fuel and the timing at which the battery needs to be cooled do not necessarily match. This is particularly effective in preventing overcooling while cooling the system.

  Here, the battery cooling means includes an outside air intake duct for introducing outside air, and a cooling fan for allowing outside air taken in by the outside air intake duct to flow into the periphery of the battery. The limiting means is provided in the outside air intake duct, and the limiting means controls the rotational driving of the cooling fan when the temperature of the battery detected by the temperature detecting means is lower than a predetermined temperature. The inflow of outside air around the battery through the outside air intake duct may be limited.

  By disposing the hydrogen fuel decompression means in the outside air intake duct, when the outside air taken in from the outside air intake duct is caused to flow around the battery by rotating the cooling fan, the hydrogen fuel decompression means flows in the duct. Cold heat transfer (heat transfer by convection) occurs to the outside air, and the low temperature outside air effectively cools the battery.

  When the temperature of the battery is lower than a predetermined temperature, the restricting unit controls the rotational drive of the cooling fan to restrict the inflow of outside air around the battery through the outside air intake duct. This restricts low-temperature outside air from flowing around the battery and suppresses cooling of the battery. As a result, overcooling of the battery is prevented.

  Further, since a high-voltage battery mounted on a hybrid vehicle or the like is usually provided with a cooling fan for cooling the battery, only hydrogen fuel decompression means is disposed in the outside air intake duct. This is advantageous in that the above hardware configuration is realized and it is not necessary to add a new structure.

  The restricting means may reduce the inflow amount of the outside air around the battery via the outside air intake duct by lowering the number of rotations of the cooling fan as the temperature of the battery is lower.

  By doing so, the lower the temperature of the battery, the lower the temperature of the outside air is suppressed from flowing around the battery, so that the battery is reliably prevented from overcooling.

  Further, the cooling fan is configured to be switchable between a forward rotation drive for flowing outside air around the battery via the outside air intake duct and a reverse rotation drive opposite thereto, and the limiting means is the temperature detecting means. When the temperature of the battery detected by the above is lower than a predetermined temperature, the cooling fan is driven to rotate in reverse, thereby prohibiting the inflow of outside air around the battery through the outside air intake duct.

  In this way, when the temperature of the battery is lower than the predetermined temperature, the cooling fan is driven in reverse rotation to prevent low-temperature outside air from flowing into the periphery of the battery, thus preventing the battery from overcooling more reliably. Is done.

  As described above, according to the battery cooling device for a vehicle of the present invention, the battery is effectively cooled by cooling the battery using the cold energy when the hydrogen fuel is decompressed and expanded by the battery cooling means. On the other hand, the battery can be prevented from being overcooled by restricting the cooling of the battery when the temperature of the battery is low by the limiting means.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration of a drive system of an automobile on which a battery cooling device according to Embodiment 1 of the present invention is mounted. This vehicle is a hybrid vehicle (hereinafter also referred to as HEV: Hybrid Electric Vehicle) that includes the engine 1 and the motor 21 as drive sources and travels by combining the engine 1 and the motor 21. This hybrid vehicle is a so-called series / parallel hybrid vehicle, and a crankshaft as an output shaft of the engine 1 is connected to a motor 21 and a generator 22 through a power split mechanism 4, and the motor 21 is also a differential mechanism (differential). Gear) 61 is connected to drive wheel 6. Thus, in this HEV, the power generated by the engine 1 is appropriately divided and transmitted to the generator 22 and the drive wheel 6 (motor 21) by the power split mechanism 4.

  The HEV is equipped with an engine control computer (ECU) 5, and the rotary engine 1, the motor 21 and the generator 22 are controlled by the ECU 5.

  The engine 1 is a hydrogen engine 1 that generates driving force of a vehicle using hydrogen as a fuel. In the present embodiment, although not shown in the drawings, a saddle-shaped rotor housing having a trochoid inner peripheral surface and a side housing are provided. The hydrogen rotary engine 1 includes a substantially triangular rotor that is housed in an enclosed rotor housing chamber (cylinder) and supported so as to perform planetary rotational movement with respect to the crankshaft. In other words, the rotor rotates around the eccentric wheel of the crankshaft while the seal portions respectively disposed on the three tops of the outer periphery thereof are in contact with the trochoid inner peripheral surface of the rotor housing. It revolves around the shaft center, and while the rotor makes one rotation, the working chamber formed between the tops of the rotor moves in the circumferential direction, and intake, compression, expansion (combustion) And each process of exhaust is performed, and the rotational force generated by this is output from the crankshaft via the rotor.

  The hydrogen rotary engine 1 is of a two-rotor type in which two rotor housings are integrated so as to be sandwiched between three side housings, and the rotors are housed in two cylinders formed therebetween. In addition, two electronically controlled fuel injection valves 19 and 19 (injectors) for directly injecting fuel into the cylinder are provided for each cylinder. The hydrogen engine 1 is not limited to a rotary engine but may be a reciprocating engine.

  Each injector 19 is connected to a hydrogen fuel tank 40, and hydrogen as a fuel is supplied to each injector 19 from the hydrogen fuel tank 40. Here, the hydrogen fuel tank 40 in the present embodiment is a high-pressure container that stores gaseous hydrogen. The hydrogen fuel tank 40 is provided with a pressure sensor 42 for detecting the pressure in the tank (the remaining amount of hydrogen in the tank), and the detected value of the pressure sensor 42 is input to the ECU 5.

  The hydrogen fuel supply system between the hydrogen fuel tank 40 (upstream side) and each injector 19 (downstream side) includes a main valve 41 that opens and closes a hydrogen gas supply passage from the upstream side toward the downstream side, and A regulator 3 is provided for reducing the high-pressure hydrogen gas to a predetermined pressure.

  The original valve 41 is an on-off valve, and its opening and closing is controlled by the ECU 5. That is, the ECU 5 is based on the target fuel injection amount of each cylinder of the hydrogen engine 1 set according to the running state of the vehicle and the pressure in the hydrogen fuel tank 40 which is a detection value of the pressure sensor 42. The opening time of the valve 41 is controlled so that a predetermined amount of hydrogen is supplied to each injector 19.

  As shown in FIG. 2, the regulator 3 communicates with the atmosphere through an inflow chamber 31 connected to the hydrogen fuel tank 40 side, a decompression chamber 32 connected to the engine 1 (injector 19) side, and an air hole 33a. The atmospheric chamber 33 is provided.

  The inflow chamber 31 and the decompression chamber 32 communicate with each other via a throttle valve 34, while the decompression chamber 32 and the atmospheric chamber 33 are partitioned by a diaphragm 35. A throttle valve 34 is connected to the diaphragm 35. The atmospheric chamber 33 has a compression spring 36 disposed therein, and the compression spring 36 urges the diaphragm 35 downward in FIG.

  The high-pressure hydrogen gas that has flowed into the inflow chamber 31 from the hydrogen fuel tank 40 flows into the decompression chamber 32 through the throttle valve 34. When the pressure of the hydrogen flowing in is higher than a predetermined pressure, the diaphragm 35 is pushed down in FIG. 2, and accordingly, the throttle valve 34 connected to the diaphragm 35 is pulled up in FIG. As a result, since the opening degree of the throttle valve 34 is reduced, the flow rate of hydrogen flowing into the decompression chamber 32 is reduced, and the pressure of hydrogen output from the decompression chamber 32 to the engine 1 side is reduced. Conversely, when the pressure of the hydrogen flowing in is lower than the predetermined pressure, the diaphragm 35 is pushed downward by the urging force of the compression spring 36 and atmospheric pressure, and the opening of the throttle valve 34 is increased accordingly. Become. Therefore, the flow rate of hydrogen flowing into the decompression chamber 32 increases, and the pressure of hydrogen output to the engine 1 side increases. In this manner, the regulator 3 decompresses and expands the high-pressure hydrogen gas from the hydrogen fuel tank 40 by the throttle valve 34, and at a predetermined pressure by balancing the compression spring 36 and the biasing force due to the atmospheric pressure with the pressure of the flowing hydrogen. Of hydrogen gas is supplied to each injector 19.

  When the hydrogen gas is decompressed and expanded by the throttle valve 34 of the regulator 3, cold heat is generated by the Joule-Thompson effect. The generated cold heat is used for cooling the battery 71 as will be described later, and a heat radiating plate 37 is attached to the outer peripheral portion of the regulator 3, and the heat transfer from the regulator 3 to the outside air by the heat radiating plate 37. The efficiency of heat transfer by convection is increased.

  The crankshaft of the rotary engine 1 is connected to two motor / generators 21 and 22 via a power split mechanism 4. Both of these motor generators 21 and 22 are designed so that their functions are switched between the electric motor and the generator depending on the situation. In a normal driving situation, the motor / generator 21 is an auxiliary engine. The motor / generator 22 is mainly responsible for a function as an electric motor that generates power, and serves mainly as a generator that generates power using the power of the engine 1. Therefore, in the following description, the motor / generator 21 is referred to as a motor (drive motor), and the motor / generator 22 is referred to as a generator.

  The power split mechanism 4 is a planetary gear having a sun gear, a ring gear, and a planetary carrier. The sun gear is connected to the generator 22, the ring gear is connected to the motor 21, and the planetary carrier is connected to the rotary engine 1.

  The motor 21 and the generator 22 are connected to the battery 71 via the inverter 25.

  As shown in FIG. 3, the battery 71 is a part of the battery module 7, and the battery module 7 is an outside air intake duct 72 for taking in outside air and a cooling unit disposed on the downstream side of the duct 72. A fan 73, a case 74 in which the battery 71 is accommodated, a discharge duct 75 that is provided in the case 74 and discharges outside air supplied into the case 74, and a plurality of (three in the illustrated example) that detect the temperature of the battery 71. ) A temperature sensor 76, and a battery controller 77 that receives information on the detected value of the temperature sensor 76 (that is, the temperature of the battery 71), battery current, and voltage.

  The outside air intake duct 72, the cooling fan 73, the case 74, and the discharge duct 75 constitute a cooling path that supplies and discharges the outside air around the battery 71 as the cooling fan 73 is driven (see FIG. (See the white arrow). The regulator 3 is disposed at a position upstream of the cooling fan 73 in the outside air intake duct 72. As a result, when the outside air is supplied around the battery 71 by driving the cooling fan 73, the cold heat generated when the hydrogen gas is decompressed and expanded in the regulator 3 moves to the outside air, and the low temperature outside air becomes the case 74. Flows in. Thereby, the battery 71 can be cooled effectively.

  As will be described later, the battery controller 77 transmits information on the battery temperature, battery current, and voltage to the ECU 5 and controls the rotational drive of the cooling fan 73. Details of the control of the cooling fan 73 by the battery controller 77 will be described later.

  As shown in FIG. 1, the ECU 5 receives output signals from the pressure sensor 42 and various sensors 24 of the hydrogen fuel tank 40 and battery temperature, battery current and voltage information from the battery controller 77. The ECU 5 determines the traveling state of the vehicle based on the output signals, and controls the rotary engine 1, the motor 21, and the generator 22 according to the traveling state. That is, the rotary engine 1 is controlled by controlling the fuel injection amount and ignition timing of each cylinder according to the running state, and the current flowing between the motor 21 and the battery 71 by the control of the inverter 25 and the generator The current flowing between the battery 22 and the battery 71 is adjusted to control the output and rotation speed of the motor 21 and the power generation amount and rotation speed of the generator 22.

  Specifically, in a region where the rotation of the drive wheels 6 is low speed and high load and the operating efficiency of the rotary engine 1 is reduced, such as when starting or running at a low speed, the operation of the rotary engine 1 is stopped and the motor 21 is stopped. The drive wheel 6 is driven only by the power of On the other hand, during normal travel, the rotary engine 1 is operated and its power is transmitted to the drive wheels 6 via the power split mechanism 4, and the power is also transmitted to the generator 22 via the power split mechanism 4 to generate power. Done. Then, the electric power generated by the generator 22 is supplied to the motor 21, and the motor 21 is used as auxiliary power for the rotary engine 1. Depending on the running state during the normal running, the power generation amount of the generator 22 is decreased to reduce or stop the power assist by the motor 21, or the power generation amount of the generator 22 is increased to improve the power assist by the motor 21. To do.

  Thus, in this HEV, the rotary engine 1 is always operated in an efficient operation region by appropriately controlling the sharing of the two power sources of the rotary engine 1 and the motor 21 according to the situation. The timing for driving the rotary engine 1 and the timing for driving the motor 21 do not necessarily match. That is, there is a timing when only the rotary engine 1 is driven and the motor 21 is not driven.

  Next, the cooling control of the battery 71 will be described with reference to the flowchart shown in FIG. The battery controller 77 executes the cooling control of the battery 71.

  First, in step S11, the detected value (in-battery temperature T) of the temperature sensor 76 is read. Here, the temperature T in the battery is an average value of detection values of the three temperature sensors 76.

  In a succeeding step S12, it is determined whether or not a difference between the calculated battery internal temperature T and a preset reference battery internal temperature Tr is larger than 0 (T−Tr> 0). When YES is greater than 0, the process proceeds to step S13. When NO is less than 0, the process proceeds to step S15. Here, the reference battery internal temperature Tr may be set as appropriate. An example is 20 ° C.

  In step S13, the rotational speed of the cooling fan 73 is determined according to a preset map based on the difference between the battery internal temperature T and the reference battery internal temperature Tr.

  FIG. 5 shows an example of a map for determining the number of rotations of the cooling fan 73, and the difference between the battery internal temperature T and the reference battery internal temperature Tr is higher than 0 and equal to or less than a predetermined value A. Sometimes, the larger the value is, the higher the rotational speed of the cooling fan 73 is set. On the other hand, when the value of T-Tr is larger than the predetermined value A, the rotational speed of the cooling fan 73 is set to a constant rotational speed RA. .

  In step S14, an operation command is output to the cooling fan 73 based on the rotational speed of the cooling fan 73 determined in step S13, and the process returns.

  On the other hand, in step S15, a stop command is output to the cooling fan 73 and the process returns.

  With this control flow, the rotational speed of the cooling fan 73 with respect to the battery internal temperature T has a relationship as shown in FIG. 5, and when the battery internal temperature T is higher than the reference battery internal temperature Tr (T−Tr> 0). The cooling fan 73 is driven to rotate, and the battery 71 is actively cooled using the cold generated by the decompression and expansion of the hydrogen gas. In particular, when the battery internal temperature T is higher than a predetermined temperature (A + Tr) (that is, when A <T−Tr), the rotation speed of the cooling fan 73 is set to the predetermined rotation speed RA, but is lower than that. When 0 <T−Tr ≦ A, the rotation speed of the cooling fan 73 decreases as the battery temperature T decreases, so that the battery 71 is cooled according to the temperature of the battery 71. When the battery internal temperature T is equal to or lower than the reference battery internal temperature Tr, the cooling fan 73 is stopped, so that the flow of low-temperature outside air into the case 74 is suppressed, and the cooling of the battery 71 is suppressed. . That is, overcooling of the battery 71 is prevented. Thus, in the HEV in which the generation timing of the cold due to the decompression / expansion of hydrogen and the timing at which the battery 71 needs to be cooled do not necessarily match, while the battery 71 is effectively cooled using the cold, the battery 71 Is prevented from overcooling.

  Further, since the battery module 7 (the outside air intake duct 72, the cooling fan 73, the case 74, and the discharge duct 75) has the configuration of the normal battery module 7 mounted on the HEV, the regulator 3 is connected to the outside air intake duct 72. The hardware configuration of the first embodiment can be realized only by arranging it inside. Therefore, it is advantageous in that it is not necessary to add a new structure.

(Embodiment 2)
The second embodiment is different from the first embodiment in that the cooling fan 73 is configured to be able to switch between forward rotation drive and reverse rotation drive according to a control command from the battery controller 77.

  FIG. 6 is a flowchart of the cooling control of the battery 71 by the battery controller 77 according to the second embodiment. First, in step S21, the detection value (battery temperature T) of the temperature sensor 76 is read, and in the subsequent step S22, the reading is performed. Whether the difference between the battery internal temperature T and the reference battery internal temperature Tr is greater than 0 (T-Tr> 0) is determined. When YES is greater than 0, the process proceeds to step S23, and when NO is 0 or less, the process proceeds to step S26. The reference battery internal temperature Tr here may be set as appropriate similarly to the first embodiment, and an example is 20 ° C.

  In step S23, it is determined whether or not the battery internal temperature T is higher than a predetermined temperature (C + Tr), that is, whether or not T−Tr> C. If YES, the process proceeds to step S24, and if NO, step S24 is performed. The process proceeds to S25.

  In step S24, the cooling fan 73 is driven to rotate forward at a predetermined rotational speed RC and returned. In step S25, the cooling fan 73 is stopped.

  On the other hand, in step S26, it is determined whether or not the battery internal temperature T is higher than a predetermined temperature (B + Tr), that is, whether or not T−Tr> B. If YES, the process proceeds to step S25. While cooling fan 73 is stopped, when it is NO, it shifts to Step S27.

  In step S27, the cooling fan 73 is reversely driven at a predetermined rotational speed RB and the process returns.

  With this control flow, the rotational speed of the cooling fan 73 with respect to the battery internal temperature T has a relationship as shown in FIG. 7, and when the battery internal temperature T is higher than the first predetermined temperature (Tr + C), the cooling fan 73 is predetermined. The battery 71 is actively cooled by being rotated forward at the rotational speed RC.

  On the other hand, when the battery internal temperature T is equal to or lower than the first predetermined temperature (Tr + C) and higher than the second predetermined temperature (Tr + B), the cooling fan 73 is stopped and the cooling of the battery 71 is suppressed. On the other hand, when the battery internal temperature T is equal to or lower than the second predetermined temperature (Tr + B), the cooling fan 73 is reversely driven at a predetermined rotational speed RB, thereby preventing the outside air from flowing into the battery 71. As a result, overcooling of the battery 71 is more reliably prevented.

(Embodiment 3)
In the third embodiment, unlike the first and second embodiments, the battery module 7 does not have the cooling fan 73, and instead, an open / close damper 78 is provided in the outside air intake duct 72.

  Specifically, FIG. 8 shows the configuration of the battery cooling device according to the third embodiment. As described above, the open / close damper 78 is disposed at a position downstream of the regulator 3 in the outside air intake duct 72. The open / close damper 78 opens and closes the outside air intake duct 72. In this embodiment, the outside air intake duct 72 is provided so that traveling air can be taken in, and when the open / close damper 78 is open, the traveling air (traveling air that has become low temperature due to cold heat transfer from the regulator 3) is the case. It flows into 74 and the battery 71 is cooled. On the other hand, when the open / close damper 78 is closed, the traveling wind does not flow into the case 74 and cooling of the battery 71 is suppressed. The open / close damper is opened / closed by the battery controller 77 controlling an actuator (not shown). In addition, since the other structure of the battery module 7 which concerns on Embodiment 3 is the same as the battery module 7 shown in FIG. 3, the same code | symbol is attached | subjected about the same member and the detailed description is abbreviate | omitted.

  Next, the cooling control of the battery 71 by the battery controller 77 according to the third embodiment will be described with reference to the flowchart shown in FIG.

  First, in step S31, the detected value (in-battery temperature T) of the temperature sensor 76 is read. In the following step S32, whether or not the read-in battery temperature T is higher than the reference battery temperature Tr (T> Tr). Determine. When T is higher than Tr, the process proceeds to step S33. When T is equal to or lower than Tr, the process proceeds to step S36. The reference battery internal temperature Tr here may be set as appropriate similarly to the first embodiment, and an example is 20 ° C.

  In step S33, it is determined whether or not the open / close damper 78 is in an open state. When the open state is YES, the process proceeds to step S34. When the open state is not open (that is, in the closed state), step S35 is performed. Migrate to

  In step S34, the open / close damper 78 is maintained open and the process returns. In step S35, an open command is output to the open / close damper 78 and the open / close damper 78 is returned to return.

  On the other hand, in step S36, it is determined whether or not the open / close damper 78 is in the closed state. When the open / close damper 78 is in the closed state, the process proceeds to step S37. In this case, the process proceeds to step S38.

  In step S37, the open / close damper 78 is kept closed and the process returns, and in step S38, a close command is output to the open / close damper 78 and the open damper 78 is returned to return.

  With this control flow, when the battery internal temperature T is higher than the reference battery internal temperature Tr, the open / close damper 78 is opened, whereby low-temperature outside air is supplied to the battery 71 and the battery is cooled. On the other hand, when the battery internal temperature T is equal to or lower than the reference battery internal temperature Tr, the open / close damper 78 is closed to prevent low temperature outside air from being supplied to the battery 71 and to suppress cooling thereof. Thus, overcooling of the battery 71 is prevented.

  The hybrid vehicle on which the battery cooling device according to the present invention is mounted is not limited to the series / parallel system as in the above embodiment.

  As described above, since the present invention can effectively cool a high voltage battery and prevent overcooling of the high voltage battery, for example, a battery cooling device for a vehicle including a hydrogen fuel tank such as a hybrid vehicle. Useful for.

It is a block diagram which shows the structure of the drive system of the hybrid vehicle which concerns on embodiment of this invention. It is sectional drawing which shows the structure of a regulator. It is the schematic which shows the structure of the battery cooling device which concerns on Embodiment 1. FIG. 3 is a control flow of the battery cooling device according to the first embodiment. It is a figure which shows the relationship (control map) of the rotation speed of the cooling fan with respect to battery temperature in the battery cooling device which concerns on Embodiment 1. FIG. It is a control flow of the battery cooling device which concerns on Embodiment 2. FIG. It is a figure which shows the relationship of the rotation speed of the cooling fan with respect to battery temperature in the battery cooling device which concerns on Embodiment 2. FIG. It is the schematic which shows the structure of the battery cooling device which concerns on Embodiment 3. It is a control flow of the battery cooling device which concerns on Embodiment 3. FIG.

Explanation of symbols

1 Hydrogen rotary engine (hydrogen engine)
3 Regulator (hydrogen fuel decompression means)
20 Hydrogen fuel tank 21 Motor generator (drive motor)
71 Battery 72 Outside air intake duct (battery cooling means)
73 Cooling fan (battery cooling means)
76 Temperature sensor (temperature detection means)
77 Battery controller (battery cooling means, limiting means)
78 Opening and closing damper (limitation means)

Claims (4)

A hydrogen fuel tank for storing hydrogen;
A hydrogen engine that generates the driving force of the vehicle using hydrogen supplied from the hydrogen fuel tank as fuel;
Hydrogen fuel decompression means for decompressing and expanding hydrogen from the hydrogen fuel tank interposed in a hydrogen fuel supply system between the hydrogen fuel tank and the hydrogen engine;
Battery,
A driving motor for generating a driving force of the vehicle by electric power supplied from the battery;
Temperature detecting means for detecting the temperature of the battery;
Battery cooling means for cooling the battery using cold heat generated when the hydrogen is decompressed and expanded by the hydrogen fuel decompressing means;
And a limiting unit that limits cooling of the battery by the battery cooling unit when the temperature of the battery is lower than a predetermined temperature based on the temperature of the battery detected by the temperature detection unit. Battery cooling device. The battery cooling device according to claim 1,
The battery cooling means includes an outside air intake duct for guiding outside air, and a cooling fan for allowing outside air taken in by the outside air intake duct to flow into the periphery of the battery,
The hydrogen fuel decompression means is provided in the outside air intake duct,
When the temperature of the battery detected by the temperature detection means is lower than a predetermined temperature, the limiting means controls the rotational drive of the cooling fan, so that the outside air around the battery via the outside air intake duct is controlled. Battery cooling device that restricts inflow of water. The battery cooling device according to claim 2,
The battery cooling device, wherein the limiting means reduces the amount of outside air flowing into the periphery of the battery via the outside air intake duct by lowering the number of revolutions of the cooling fan as the temperature of the battery is lower. The battery cooling device according to claim 2,
The cooling fan is configured to be able to switch between a forward rotation drive for flowing outside air around the battery through the outside air intake duct and a reverse rotation drive opposite to the drive.
When the temperature of the battery detected by the temperature detecting means is lower than a predetermined temperature, the restricting means drives the cooling fan to rotate in the reverse direction so that the outside air around the battery is passed through the outside air intake duct. Battery cooling device that prohibits inflow.