JP2013145689A - Battery pack for vehicle and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for raising the battery temperature efficiently by using a Peltier element.SOLUTION: The battery pack for vehicle includes a Peltier element, a battery, a heat exchanger plate for transferring heat radiated from the radiation surface of the Peltier element to the battery, and a first flow path for introducing the air warmed by the heat radiated from the battery to the heat absorption surface of the Peltier element. The Peltier element and the first flow path are disposed on the upstream side of the battery. Preferably, the first flow path has a part of restrictor shape for introducing the air warmed by the heat radiated from the battery and rising by natural convection to the heat absorption surface by Venturi effect.

Description

  The present invention relates to a technique for adjusting the temperature of a vehicle battery pack.

  In recent years, electric vehicles and hybrid vehicles equipped with electric motors for running vehicles have been attracting attention and put into practical use as vehicles that are conscious of the global environment. The electric motor is driven by electric power output from a chargeable / dischargeable battery pack.

  In addition, for example, a lithium ion battery has a high internal resistance in a low temperature environment and cannot output desired energy.

  Regarding battery temperature adjustment, when it is determined that the battery temperature is in a high temperature state, the battery temperature is lowered by flowing a current in a direction in which the outside of the Peltier element generates heat and the inside that is in close contact with the battery absorbs heat. When it is determined that the temperature is low, a temperature adjustment device is disclosed in which the outside of the Peltier element absorbs heat and current flows in a direction in which the inside that is in close contact with the battery generates heat to raise the battery temperature (see, for example, Patent Document 1). ).

Japanese Patent Laid-Open No. 08-147189

  In Patent Document 1, when it is determined that the battery temperature is in a low temperature state that does not reach an appropriate temperature, the battery is heated by heat dissipation from the Peltier element to increase the battery temperature. However, simply heating the battery using the Peltier element increases the power supplied to the Peltier element, resulting in poor temperature rise efficiency.

  An object of the present invention is to provide a technique for efficiently increasing the battery temperature using a Peltier element.

  In order to solve the above problems, a battery pack according to the present invention includes (1) a Peltier element, a battery, a heat transfer plate that transmits heat radiated from a heat radiation surface of the Peltier element to the battery, and the battery. A first flow path for guiding the air heated by the heat radiated from the heat to the heat absorbing surface of the Peltier element.

  (2) In the configuration of (1), the Peltier element and the first flow path are disposed above the battery, and the first flow path is warmed by heat radiated from the battery. And a throttle-shaped portion for guiding air rising by natural convection to the endothermic surface. According to the configuration of (2), since the venturi effect is generated by the throttle-shaped portion and the endothermic surface can be heated, a blower for forcibly blowing warmed air can be omitted.

  (3) In the configuration of (1) or (2), a heat sink is provided on the heat absorption surface of the Peltier element, and the air guided by the first flow path blows on the heat sink. It is done. According to the configuration of (3), more heat is absorbed by the heat sink, and the endothermic surface can be effectively warmed.

  (4) In the configuration of (3), the battery includes a pack case that houses the battery, and the battery includes a plurality of unit cells each having a straight tube shape, and the heat transfer plate includes the plurality of unit cells. Are arranged in a horizontal direction above the pack case, a first air passage in which the heat sink is located, and a slit for introducing air inside the pack case And the first air flow path can be configured to extend through a partition wall that partitions the first air flow path and the second air flow path.

  (5) In the configuration of (4), a blower, a first position for guiding air supplied by the operation of the blower to the first blower path, and a second position for guiding the air to the second blower path. A switching valve operating between the two positions.

  (6) In the configuration of (5), when raising the temperature of the battery, the blower is driven in a state where the switching valve is positioned at the first position, so that the air in the vehicle interior is You may have a controller which accept | permits the 1st operation | movement led to one ventilation path. According to the structure of (6), a heat sink can be heated using the air in a vehicle interior.

  (7) In the configuration of (6), the controller performs a second operation of energizing the Peltier element together with the first operation or after the first operation is executed for a predetermined time and stopped. It may be acceptable. According to the structure of (7), since a Peltier device can be driven in the state where the heat sink was warmed, a battery can be heated up earlier.

  (8) In the configuration of (6) or (7), when the controller cools the battery, the controller drives the blower with the switching valve positioned at the second position. A third operation for guiding the air in the passenger compartment to the second air passage may be allowed. According to the structure of (8), since the flow path used when raising the temperature of the battery and the flow path used when cooling the battery are partially shared, the structure of the vehicle battery pack is simplified. be able to.

  (9) In the configuration of (5), the first lid member that opens and closes the slit and an opening formed in a lower wall portion that forms a lower end portion of the pack case, And a second lid member that opens and closes the opening that communicates with an exhaust duct for exhausting air used for cooling.

(10) In the configuration of (9), when raising the temperature of the battery, the blower is driven with the switching valve positioned at the first position, and the first and second lids are driven. After the first operation for guiding the air in the vehicle interior to the first air passage with the member positioned at the closed position and the first operation is performed for a predetermined time and stopped, the first and second A second operation that allows energization of the Peltier element in a state where only the first lid member of the lid members is moved to the open position; and when the battery is cooled, the switching valve is set to the second operation. A third operation for driving the blower in a state of being positioned, and for guiding air in the vehicle interior to the second air passage in a state of being in the open position of the first and second lid members; Can be provided. According to the configuration of (10), it is possible to prevent cold air from flowing from the exhaust duct into the pack case when the temperature of the battery is raised.

  According to the present invention, the battery temperature can be increased efficiently using the Peltier element.

It is a figure showing a part of hardware constitutions of vehicles. It is a figure which shows the battery unit of embodiment. It is a figure which shows the assembled battery of embodiment. It is a perspective view which shows the battery pack of 1st Embodiment, and is a figure which shows the internal structure of a ventilation duct. It is a figure which shows the plane of the ventilation duct of 1st Embodiment, and is the figure which illustrated the flow path W1. It is a figure which shows the plane of the ventilation duct of 1st Embodiment, and is the figure which illustrated the flow path W2. It is a figure which shows the battery pack of 1st Embodiment, and is the figure which illustrated the flow path W3 from the battery unit to 1st ventilation duct R1. It is a figure which shows the plane of the ventilation duct in the state in which the flow path was formed. It is a figure which shows the AA cross section of FIG. It is a flowchart which shows the control with respect to a battery pack. It is sectional drawing which shows an example of the battery pack in 2nd Embodiment.

  Hereinafter, aspects of the present embodiment will be described with reference to the drawings. FIG. 1 is a block diagram showing a hardware configuration of a part of a vehicle according to an embodiment of the present invention. In the figure, dotted arrows indicate the direction of signal flow. Vehicle 300 is a plug-in hybrid vehicle that has a drive path for driving a motor using the output from battery pack 1 and a drive path for the engine, and can charge battery pack 1 using an external power supply of vehicle 300. is there. However, vehicle 300 may be an electric vehicle that can be charged with a battery using an external power source outside the vehicle and that omits the engine. Vehicle 300 may be a hybrid vehicle in which battery pack 1 cannot be charged using an external power source outside the vehicle.

  The vehicle 300 includes a battery pack 1, a charger 22, smoothing capacitors C1 and C2, a voltage converter 32, an inverter 33, a motor generator MG1, a motor generator MG2, a power split planetary gear P1, and a reduction. Planetary gear P2, reduction gear D, engine 34, relay 31, DC / DC converter 41, auxiliary battery 42, intake fan (corresponding to a blower) 44, ECU 50, and monitoring unit 51 And inlet 62.

  Vehicle 300 further includes a power supply line PL1 and a ground line SL. The battery pack 1 is connected to a voltage converter 32 via system main relays SMR-G, SMR-B, and SMR-P constituting the relay 31. System main relay SMR-G is connected to the plus terminal of battery pack 1, and system main relay SMR-B is connected to the minus terminal of battery pack 1. The system main relay SMR-P and the precharge resistor 31A are connected in parallel to the system main relay SMR-B.

  These system main relays SMR-G, SMR-B, and SMR-P are relays that close contacts when the coil is energized. When SMR is on, it means an energized state, and when SMR is off, it means a non-energized state.

  The ECU 50 turns off all the system main relays SMR-G, SMR-B, and SMR-P when the current is interrupted, that is, when the ignition switch is in the OFF position. That is, the exciting current for the coils of the system main relays SMR-G, SMR-B, and SMR-P is turned off. The ignition switch is switched in the order of the OFF position and the ON position.

  An ECU (corresponding to a controller) 50 controls the entire vehicle 300. The ECU 50 may be a CPU, an MPU, or may include an ASIC circuit that executes at least a part of processing executed in these CPUs. Further, the number of CPUs or the like may be singular or plural. Therefore, for example, a CPU that controls the driving of the intake fan 44, a CPU that controls the driving of the Peltier element 12 described later, and a CPU that controls the driving of the damper 21 described later may be different. The ECU 50 is activated when electric power is supplied from the auxiliary battery 42.

  When the hybrid system is activated (when the main power supply is connected), that is, for example, when the driver depresses the brake pedal and pushes the push-type start switch, the ECU 50 first turns on the system main relay SMR-G. Next, the ECU 50 turns on the system main relay SMR-P to execute precharging.

  A precharge resistor 31A is connected to the system main relay SMR-P. For this reason, even if the system main relay SMR-P is turned on, the input voltage to the inverter 33 rises gently, and the occurrence of an inrush current can be prevented.

  When the ignition switch is switched from the ON position to the OFF position, the ECU 50 first turns off the system main relay SMR-B, and then turns off the system main relay SMR-G. Thereby, the electrical connection between the battery pack 1 and the inverter 33 is cut off, and the power supply is cut off. System main relays SMR-B, SMR-G, and SMR-P are controlled to be in a conductive / non-conductive state in accordance with a control signal supplied from ECU 50.

  Capacitor C1 is connected between power supply line PL1 and ground line SL, and smoothes the voltage between the lines. A DC / DC converter 41 is connected between the power supply line PL1 and the ground line SL. The DC / DC converter 41 steps down the power supplied from the assembled battery 1 to charge the auxiliary battery 42 or supply power to the intake fan 44.

  The voltage converter 32 boosts the voltage between the terminals of the capacitor C1. Capacitor C <b> 2 smoothes the voltage boosted by voltage converter 32. Inverter 33 converts the DC voltage supplied from voltage converter 32 into a three-phase AC and outputs the same to motor generator MG2. Reduction planetary gear P <b> 2 transmits power obtained by motor generator MG <b> 2 to reduction gear D to drive vehicle 300. The power split planetary gear P1 splits the power obtained by the engine 34 into two paths, one of which is transmitted to the wheels via the speed reducer D, and the other drives the motor generator MG1 to generate power.

  The electric power generated by the motor generator MG1 is used to drive the motor generator MG2, thereby assisting the engine 34. Reduction planetary gear P2 transmits the power transmitted through speed reducer D to motor generator MG2 during vehicle deceleration, and drives motor generator MG2 as a generator. The electric power obtained by motor generator MG2 is converted from a three-phase AC to a DC voltage in inverter 33 and transmitted to voltage converter 32. At this time, the ECU 50 controls the voltage converter 32 to operate as a step-down circuit. The electric power stepped down by the voltage converter 32 is stored in the battery pack 1.

  The monitoring unit 51 acquires information regarding the voltage, current, and temperature of the battery pack 1. The monitoring unit 51 may be unitized together with the battery pack 1. The monitoring unit 51 outputs information acquired from the battery pack 1 to the ECU 50. The ECU 50 controls charging / discharging of the assembled battery 1 or driving of the intake fan 44 based on information acquired from the monitoring unit 51.

  Here, the intake fan 44 supplies air in the passenger compartment to the battery pack 1 in accordance with the rotation operation.

  The charger 22 is connected to the battery pack 1 via the relay 31. When the relay 31 is in an open state, the battery pack 1 is electrically disconnected from the voltage converter 32, the charger 22 and the like. When the relay 31 is in a closed state, the battery pack 1 is electrically connected to the voltage converter 32, the charger 22, and the like.

  The ECU 50 generates and outputs a drive signal for driving the charger 22 when the assembled battery 1 is charged from a commercial power supply outside the vehicle. The inlet 62 may be provided on a side portion of the vehicle 300. The inlet 62 is connected to a charging cable connector that connects the vehicle 300 and an external power source. The present invention can also be applied to non-contact charging in which the inlet 62 and the connector are not connected.

  Next, the battery pack 1 will be described with reference to FIGS. 2 and 3. Here, FIG. 2 is an exploded perspective view of the battery unit constituting a part of the battery pack, and FIG. 3 is a perspective view of the assembled battery housed in the battery pack. In addition, the X axis, Y axis, and Z axis shown in each figure after FIG. 2 are three axes that are orthogonal to each other. Yes.

  The battery pack 1 includes a battery unit 100. Battery unit 100 includes an assembled battery group A, a pack case 20 and a fixed plate 23. The assembled battery group A is configured by arranging a plurality of assembled batteries (corresponding to batteries) 10 in the X-axis direction. Adjacent battery packs 10 are electrically connected in series. However, some assembled batteries 10 may be electrically connected to each other in parallel.

  A flange portion 10a is formed on the end surface of the assembled battery group A in the X-axis direction. The flange portion 10a extends along the XY plane. An opening for fastening the fastening bolt 18 is formed in the flange portion 10a. The assembled battery group A is fixed to the fixed plate 23 by fastening the fastening bolts 18 to the openings formed in the flange portion 10a. The fixing plate 23 is fixed to the mounting position (for example, luggage room) of the battery pack 1. Here, the luggage room is a luggage room formed on the rear side of the rear seat of the vehicle.

  Referring to FIG. 3, the assembled battery 10 includes a unit cell group B and a heat dissipation plate (corresponding to a heat transfer plate) 13. The unit cell group B has a plurality of unit cells 11. The unit cell 11 includes a straight tube-shaped case 11a containing a power generation element, a positive terminal 11b formed at one end in the longitudinal direction of the case 11a, and a negative terminal formed at the other end in the longitudinal direction of the case 11a. 11c. The plurality of unit cells 11 are arranged in the radial direction. The plurality of unit cells 11 may be electrically connected to each other in parallel. The unit cell 11 may be a secondary battery such as a nickel metal hydride battery or a lithium ion battery, or a capacitor. Further, the single battery 11 may be a battery cell constituted by a single power generation element or a battery module in which a plurality of power generation elements are connected.

  The heat dissipation plate 13 holds the cell group B from the radial direction of the cell 11. There may be an insulating layer between the heat dissipation plate 13 and each unit cell 11. The heat dissipating plate 13 may be a solid metal (for example, aluminum). Here, the solid metal is a metal body that is filled with metal and has no hollow inside. Since the heat dissipating plate 13 is made of a solid metal, heat generated from the unit cells 11 can be transferred to the other unit cells 11 through the heat dissipating plate 13. Thereby, the temperature variation between the single cells 11 is suppressed.

  A Peltier element 12 is provided on the end surface of the heat dissipation plate 13 in the Z-axis direction. The Peltier element 12 includes a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor, and a pair of copper electrodes that sandwich these semiconductors. The Peltier element 12 is a kind of heat exchanger, and by passing a current through the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor, the copper electrode (that is, corresponding to the heat absorption surface) to the other copper electrode (that is, the heat absorption surface) Move the heat toward the heat generation surface). A heat sink 14 is formed on the one copper electrode, and a heat dissipation plate 13 is in contact with the other copper electrode. Therefore, by passing an electric current through the Peltier element 12, heat is transferred from the heat sink 14 to the heat dissipating plate 13, and the temperature of each unit cell 11 can be increased via the heat dissipating plate 13. A plurality of Peltier elements 12 may be provided on the heat dissipation plate 13. In this case, the plurality of Peltier elements 12 constitute a Peltier module that performs heat exchange integrally.

  Note that the Peltier element 12 may be operated by electric power supplied from the auxiliary battery 42 in FIG.

  The heat sink 14 is formed of fins having a plurality of uneven structures. The heat sink 14 may be made of, for example, aluminum or copper having high thermal conductivity. By supplying warm air to the heat sink 14, the temperature of each unit cell 11 can be more reliably increased.

  Referring to FIG. 2 again, the assembled battery group A is housed in the pack case 20. The pack case 20 includes a first frame body 21 and a second frame body 22. The pack case 20 further includes a partition plate 10 b for forming an accommodation space for accommodating each assembled battery 10.

  A plurality of slits 21 a that allow air movement inside and outside the pack case 20 are formed in the upper wall portion of the first frame body 21. Each slit 21a extends in the longitudinal direction of the unit cell 11 (that is, the Y-axis direction). The plurality of slits 21 a are arranged in the horizontal direction (that is, the X-axis direction) orthogonal to the longitudinal direction of the unit cell 11. Each slit 21a communicates with the corresponding accommodating space of the battery pack 10. That is, the four slits 21a are made into one set and communicate with the accommodating space of the assembled battery 10 corresponding to each.

  A first notch 21 b is formed at the end of the upper wall portion of the first frame 21 in the Y-axis direction. A second notch 22b is formed at the end of the upper wall portion of the second frame 22 in the Y-axis direction. When the first frame body 21 and the second frame body 22 are integrated, at least a part of the heat sink 14 extends from the opening formed by the first cutout portion 21b and the second cutout portion 22b. Exposed outside the pack case 20. However, not only the heat sink 14 but also a part or all of the Peltier element 12 may be exposed to the outside of the pack case 20.

  Battery pack 1 further includes a blower duct 200. The air duct 200 will be described in detail with reference to FIGS. FIG. 4 is a schematic perspective view of the battery pack 1 and shows a part of the air duct 200 in a transparent manner. FIGS. 5 and 6 are plan views illustrating a part of the air duct 200. FIG. 5 corresponds to the time when the heat sink 14 is heated, and FIG. 6 corresponds to the time when each assembled battery 10 is cooled. ing. Arrows indicate the direction of air flow.

  The air duct 200 includes a first air duct (corresponding to a first air passage) R1 extending along the direction in which the assembled batteries 10 are arranged (that is, the X-axis direction), and a second air duct (second air duct). R2 corresponding to the air flow path). The first air duct R1 and the second air duct R2 are juxtaposed in the horizontal direction via the partition wall WL1. A heat sink 14 is located inside the first air duct R1. The lower end portion of the second air duct R2 also serves as the outer wall of the pack case 20, and a plurality of slits 21a are formed in the outer wall portion. When the intake fan 44 is activated, a flow path W1 indicated by an arrow is formed inside the first air duct R1, and a flow path W2 indicated by an arrow is formed inside the second air duct R2.

  As for 1st ventilation duct R1, the edge part of an upstream is connected with the vehicle interior. Therefore, when the intake fan 44 is operated, warm air in the passenger compartment is sucked into the first air duct R1, and the heat sink 14 can be warmed by the sucked air. That is, the first air duct R1 is used as a temperature raising path when the temperature of the cryogenic assembled battery 10 is raised.

  As for 2nd ventilation duct R2, the terminal part is obstruct | occluded by the side wall WL2. Therefore, when the intake fan 44 is operated, the air in the passenger compartment is sucked into the second blower duct R2, and the sucked air flows into the pack case 20 through the slit 21a. Thereby, each assembled battery 10 can be cooled. That is, the second air duct R2 is used as a cooling path when cooling each assembled battery 10 that has generated heat.

  The first air duct R1 and the second air duct R2 communicate with each other via a gradually decreasing duct (corresponding to the first flow path) 15. The gradually decreasing duct 15 extends through the partition wall WL1. The gradually decreasing duct 15 is provided corresponding to each assembled battery 10. The gradually decreasing duct 15 has a start end located inside the second air duct R2 and a terminal end located inside the first air duct R1. The gradually decreasing duct 15 is formed in a throttle shape whose inner diameter gradually decreases from the start end to the end. The effect of the gradual reduction duct 15 will be described later.

  A damper (corresponding to a switching valve) 21 is provided on the upstream side of the air duct 200. The damper 21 rotates around an axis extending in the Z-axis direction. FIG. 4 shows a state where the damper 21 is located at a position where the second air duct R2 is blocked. In this case, the air sucked by the intake fan 44 is prohibited from flowing into the second air duct R2 by the damper 21, and flows into the first air duct R1. When the damper 21 rotates around the axis and moves to a position that closes the first air duct R1, the air sucked by the intake fan 44 is prohibited from flowing into the first air duct R1 by the damper 21, Flows into the second air duct R2. The damper 21 can be rotated by power transmitted from a motor (not shown). The ECU 50 may control driving of the motor.

When the vehicle is left in an extremely low temperature environment, the temperature of each assembled battery 10 is cooled by cool air from the ground or the like, and becomes relatively lower than the temperature in the passenger compartment. Here, leaving the vehicle means that the IG switch of the vehicle is turned off and the air conditioner in the vehicle interior is stopped.
In this case, as shown in FIG. 5, by positioning the damper 21 at a position where the second air duct R <b> 2 is blocked, the air in the passenger compartment is sucked into the first air duct R <b> 1, and the heat absorption surface of the Peltier element 12 is changed. Can be heated.

  On the other hand, when each assembled battery 10 is generating heat by charging and discharging, the temperature of each assembled battery 10 becomes high due to a chemical reaction accompanying charging and discharging. In this case, as shown in FIG. 6, the damper 21 is positioned at a position where the first air duct R <b> 1 is closed, so that air in the vehicle compartment is sucked into the second air duct R <b> 2. The air sucked into the second blower duct R2 flows into the pack case 20 through the slit 21a. The air that has flowed into the pack case 20 moves through the gaps formed between the unit cells 11 to cool each unit cell 11.

  Here, it is preferable that the minimum sectional area of the gradually decreasing duct 15 (that is, the opening area on the first air duct R1 side) is smaller than the total area of the slits 21a (the total area of the four slits 21a). Thereby, the pressure loss of the flow path from the second air duct R2 toward the gradually decreasing duct 15 becomes larger than the pressure loss of the flow path from the second air duct R2 to the inside of the pack case 20 through the slit 21a. . As a result, when the battery pack 1 is cooled, it is possible to suppress a part of the air that goes toward the inside of the pack case 20 from flowing out to the first air duct R1 via the gradually decreasing duct 15. In addition, when the battery pack 1 is cooled, air gradually flows out into the first air duct R1 by arranging the taper duct 15 obliquely or vertically with respect to the moving direction of the air flowing through the second air duct R2. This can be more effectively suppressed.

  Next, the effect of the gradual reduction duct 15 that guides the air heated by the heat radiated from each unit cell 11 to the heat sink 14 will be described in detail with reference to FIGS. 7 to 9. FIG. 7 is a perspective view corresponding to FIG. FIG. 8 is a plan view corresponding to FIGS. FIG. 9 is a cross-sectional view of the battery pack taken along the plane AA of FIG. The arrows in FIGS. 7 to 9 indicate the flow path W3 of the air warmed by each assembled battery 10.

  Referring to FIG. 9, when a current is passed through Peltier element 12, heat moves from the heat absorbing surface of Peltier element 12 toward the heat generating surface, and the heat generating surface is warmed. Since the heat generating surface of the Peltier element 12 is in contact with the heat dissipating plate 13, the heat of the heat generating surface is transferred to the heat dissipating plate 13. Thereby, each cell 11 hold | maintained at the heat-spreading plate 13 can be heated up.

  Part of the heat transferred to the unit cell 11 is radiated from the outer surface of the unit cell 11, and the air inside the pack case 20 is warmed. The warmed air rises by natural convection and flows out from the slit 21a provided in the pack case 20 to the second air duct R2. The warm air that has flowed out into the second air duct R2 is drawn into the gradually decreasing duct 15 due to the venturi effect of the gradually decreasing duct 15, and is blown to the heat sink 14 located inside the first air duct R1. Note that an opening 21 c communicating with the exhaust duct 19 for exhausting air used for cooling each assembled battery 10 is formed at the lower end of the pack case 20.

  Here, the Peltier element 12 has a characteristic that the coefficient of performance (COP) is lowered by increasing the temperature difference between the heat generating surface and the heat absorbing surface. The coefficient of performance is a coefficient for checking the energy consumption efficiency of the heating appliance, and is calculated by dividing the heating capacity (W) by the heating power consumption (W). In this embodiment, since the gradually decreasing duct 15 is provided, warm air is blown onto the heat sink 14 to heat the endothermic surface, so that an increase in the temperature difference between the exothermic surface and the endothermic surface is suppressed. Thereby, the assembled battery 10 can be heated efficiently. That is, normally, when the Peltier element 12 is driven, the temperature difference between the endothermic surface and the heat generating surface gradually increases, but in this embodiment, the endothermic surface is heated, and thus the expansion of the temperature difference is suppressed. be able to.

  Furthermore, since the air heated by the heat radiated from each unit cell 11 is blown to the heat sink 14, an independent heat source for heating the air can be omitted. Thereby, energy consumption and cost can be reduced.

  Further, since the warm air blown to the heat sink 14 is naturally supplied to the heat sink 14 by the natural convection of air and the venturi effect of the gradual reduction duct 15, a blower for blowing air becomes unnecessary. Thereby, energy consumption and cost can be reduced.

  Referring to FIG. 8, when each assembled battery 10 is heated using the Peltier element 12, the damper 21 is located at a position that closes the second air duct R <b> 2. Thereby, it can suppress that the warm air which flowed in into 2nd ventilation duct R2 from the pack case 20 moves to the upstream side of 2nd ventilation duct R2, and flows out. As a result, the air heated by each unit cell 11 can be intensively blown against the heat sink 14.

  Thus, the damper 21 of the present embodiment has a function of forming a cooling path for cooling the assembled battery 10, a function of forming a heating path for heating the heat sink 14 using air in the vehicle interior, Since the air warmed by the unit cell 11 is provided with a function for directing more air toward the gradually decreasing duct 15, the configuration of the battery pack 1 can be simplified by integrating the functions.

  Next, processing performed by the ECU 50 will be described with reference to the flowchart of FIG. In step S101, the ECU 50 determines whether or not the IG switch is turned on. When the IG switch is turned on (step S101, Yes), the ECU 50 acquires the temperature inside the pack case 20 via the monitoring unit 51 in step S102. In step S103, the ECU 50 determines whether the temperature inside the pack case 20 is equal to or lower than a first threshold value that is a threshold value indicating a low temperature. The first threshold value can be appropriately set based on the characteristics of the battery whose input / output characteristics decrease as the temperature decreases.

  When the temperature inside the pack case 20 is equal to or lower than the first threshold (step S103, Yes), the ECU 50 moves the damper 21 to a position where the second air duct R2 is closed in step S104, and in step S105, the intake fan 44 is activated. As a result, the air in the passenger compartment is drawn into the first air duct R1, and the heat sink 14 is warmed.

  In step S106, the ECU 50 determines whether or not the operating time of the intake fan 44 has reached a predetermined time. If the predetermined time has elapsed (step S106, Yes), the ECU 50 determines that the heat sink 14 has been warmed to some extent, and stops the intake fan 44 and allows the Peltier element 12 to be energized in step S107.

  By energizing the Peltier element 12, the heat of the heat sink 14 moves from the heat absorption surface of the Peltier element 12 to the heat generation surface, and each unit cell 11 can be heated via the heat dissipation plate 13. Further, when the intake fan 44 is stopped, it is possible to suppress the warm air that has flowed into the first air duct R1 from the gradually decreasing duct 15 from being exhausted from the first air duct R1 without being blown to the heat sink 14. Furthermore, power consumption can be reduced by stopping the intake fan 44.

  In step S108, the ECU 50 determines whether or not the temperature inside the pack case 20 has exceeded a first threshold value. When the temperature inside the pack case 20 exceeds the first threshold (step S108, Yes), the ECU 50 stops energization of the Peltier element 12 in step S109. Thereby, since supply of the electric power with respect to the Peltier device 12 is cut off, power consumption can be reduced. When the temperature inside the pack case 20 does not exceed the first threshold value (No at Step S108), the ECU 50 returns to Step S107 and continues energizing the Peltier element 12.

  On the other hand, when the internal temperature of the pack case 20 acquired in step S102 exceeds the first threshold value (No in step S103), the ECU 50 uses the internal temperature of the pack case 20 and a threshold value indicating a high temperature. A certain second threshold value is compared (step S110). The second threshold value can be appropriately set based on the characteristics of the unit cell 11 that deteriorates as the temperature increases. Here, when the temperature inside the pack case 20 is equal to or higher than the second threshold (step S110, Yes), the ECU 50 moves the damper 21 to a position where the first air duct R1 is closed in step S111. In step S112, the intake fan 44 is driven. Thereby, each assembled battery 10 can be cooled using the air suck | inhaled by 2nd ventilation duct R2.

  When the temperature inside the pack case 20 acquired in step S102 is lower than the second threshold (No in step S110), the temperature of each assembled battery 10 is within the allowable temperature, and the process ends as it is.

(Modification 1)
In the above-described embodiment, the venturi effect by the gradual reduction duct 15 is used as a method of blowing the air heated by the unit cells 11 to the heat sink 14, but the present invention is not limited to this, and other methods may be used. . The other method may be, for example, a method of providing a duct (for example, a duct having a constant cross-sectional area) that is not a gradually decreasing shape that connects the slit 21a and the first air duct R1. In this case, the battery pack 1 may include a blower for forcibly blowing the air heated by the unit cells 11 to the heat sink 14.

(Modification 2)
In the flowchart described above, the temperature control of each assembled battery 10 is performed based on the temperature inside the pack case 20. However, the temperature control of each assembled battery 10 is performed based on the temperature detected by the temperature sensor provided in the unit cell 11. May be performed.

(Modification 3)
In the above flow chart, preheating is performed in which air in the passenger compartment is sucked and the heat sink 14 is heated before energizing the Peltier element 12, but the present invention is not limited to this, and preheating is omitted. You can also. Even in this method, the heat sink 14 is heated using the heat radiated from the unit cells 11.

(Modification 4)
In the flowchart described above, energization to the Peltier element 12 is permitted after the preheating is stopped. However, the present invention is not limited to this, and for example, energization to the Peltier element 12 may be performed together with the preheating. That is, energization of the Peltier element 12 may be allowed simultaneously with the start of the preheating, or energization of the Peltier element 12 may be allowed during the preheating.

(Modification 5)
In the above-described embodiment, the heat sink 14 is brought into contact with the heat absorbing surface of the Peltier element 12, but the present invention is not limited to this, and the heat sink 14 is omitted and warm air is directly applied to the heat absorbing surface of the Peltier element 12. The structure which sprays may be sufficient.

(Second Embodiment)
Referring to FIG. 11, in addition to the configuration of the first embodiment, the present embodiment includes a lid body (corresponding to a first lid body) 17a that opens and closes the slit 21a. The lid body 17a rotates around a rotation shaft 171a extending in the X-axis direction. The lid 17a may be driven by a motor (not shown). The ECU 50 controls driving of the motor.

  The present embodiment further includes a lid (corresponding to a second lid) 17b that opens and closes the opening 21c. The lid body 17b rotates around a rotation shaft 171b extending in the X-axis direction. The lid 17b may be driven by a motor (not shown). The ECU 50 controls driving of the motor.

  The ECU 50 moves the lids 17a and 17b to the closed position when performing the preheating (see step S104) of the first embodiment. By positioning the lid body 17a at the closed position, it is possible to suppress the warm air supplied to the first air duct R1 from flowing into the second air duct R2 via the gradually decreasing duct 15. As a result, since warm air is intensively supplied to the first air duct R1, the heat sink 14 can be warmed up early. Moreover, it can suppress that cold air | gas enters into the inside of the pack case 20 from the exhaust duct 19 because the cover body 17b is located in an open position.

  On the other hand, when the preheating is finished (see step S107), the ECU 50 moves only the lid body 17a from the closed position to the open position among the lid body 17a and the lid body 17b. Thereby, since the slit 21a is opened, the air warmed by each unit cell 11 can be introduced into the second blower duct R2. As a result, as described in the first embodiment, warm air is blown to the heat sink 14, and each unit cell 11 is efficiently warmed while suppressing an increase in temperature difference between the heat absorption surface and the heat generation surface of the Peltier element 12. Can do. In addition, since the lid body 17b is located at the closed position, it is possible to prevent cold air from entering the inside of the pack case 20 from the exhaust duct 19. As a result, the expansion of the temperature difference between each unit cell 11 and the air around them (that is, the air inside the pack case 20) is suppressed, and the heat radiation amount of each unit cell 11 can be reduced.

  On the other hand, when the assembled battery 10 needs to be cooled, the ECU 50 moves the lid body 17a and the lid body 17b to the open position. Thereby, air is introduced into the inside of the pack case 20 from the slit 21a, and each unit cell 11 can be cooled.

DESCRIPTION OF SYMBOLS 10 Assembly battery 11 Cell 12 Peltier element 13 Heat dissipation plate 14 Heat sink 15 Gradually decreasing duct 21 Damper 21a Slit 20 Pack case 44 Intake fan 50 ECU
100 battery unit 200 air duct 300 vehicle

Claims (11)

Peltier element,
Battery,
A heat transfer plate that transfers heat radiated from the heat dissipation surface of the Peltier element to the battery;
A first flow path for guiding air heated by heat radiated from the battery to the heat absorbing surface of the Peltier element;
A vehicle battery pack having The Peltier element and the first flow path are arranged above the battery,
The said 1st flow path is warmed by the heat radiated from the said battery, and has an aperture shape part for guiding the air which rises by natural convection to the said heat absorption surface. Battery pack for vehicles. A heat sink is provided on the heat absorbing surface of the Peltier element,
The vehicle battery pack according to claim 1, wherein the air guided by the first flow path is blown to the heat sink. A pack case containing the battery;
The battery includes a plurality of unit cells each having a straight tube shape,
The heat transfer plate holds the plurality of single cells from the radial direction,
Above the pack case, a first air passage in which the heat sink is located and a second air passage in which a slit for introducing air inside the pack case is formed in parallel with each other in the horizontal direction. And are formed,
The vehicle battery pack according to claim 3, wherein the first flow path extends through a partition wall that partitions the first and second air passages. A blower,
A switching valve that operates between a first position that guides the air supplied by the operation of the blower to the first air passage and a second position that guides the air to the second air passage;
The vehicle battery pack according to claim 4, comprising:   When raising the temperature of the battery, the air blower is driven in a state where the switching valve is positioned at the first position, whereby a first operation for guiding the air in the passenger compartment to the first air passage is performed. The vehicle battery pack according to claim 5, further comprising an allowable controller.   7. The controller according to claim 6, wherein the controller allows a second operation to energize the Peltier element together with the first operation or after the first operation is executed for a predetermined time and stopped. The battery pack for vehicles as described.   When the controller cools the battery, the controller drives the blower in a state where the switching valve is positioned at the second position, thereby guiding the air in the vehicle interior to the second blow passage. The vehicle battery pack according to claim 6 or 7, wherein the operation is allowed. A first lid member for opening and closing the slit;
An opening formed in a lower wall portion forming a lower end portion of the pack case, and opening and closing the opening communicating with an exhaust duct for exhausting air used for cooling each unit cell. The vehicle battery pack according to claim 5, comprising two lid members. When the battery is heated, the blower is driven with the switching valve positioned at the first position, and the vehicle is operated with the first and second lid members positioned at the closed position. Only the first lid member of the first and second lid members after the first operation for guiding indoor air to the first air passage and the first operation is stopped for a predetermined time. A second operation for allowing energization of the Peltier element in a state where is moved to the open position;
When cooling the battery, the blower is driven with the switching valve positioned at the second position, and the vehicle interior is driven with the first and second lid members positioned at the open position. The vehicle battery pack according to claim 9, further comprising a controller that permits a third operation for guiding the air to the second air passage.   A vehicle equipped with the vehicle battery pack according to any one of claims 1 to 10.

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