JP6222283B1 - Secondary battery temperature control device for vehicle - Google Patents

Abstract

To precisely control the temperature of a secondary battery mounted on a vehicle. A vehicle secondary battery temperature adjustment device includes a secondary battery (lithium ion battery 3), a temperature raising means (temperature raising device 6), and a temperature control means (controller 7). The temperature raising means includes a latent heat storage material 62, an electric heater 63 configured to heat the latent heat storage material, and a cooling unit 68 that cools the latent heat storage material. When the temperature of the latent heat storage material is lower than a predetermined temperature range, the temperature control means increases the temperature of the secondary battery through the latent heat storage material by energizing the electric heater, and the temperature of the latent heat storage material is predetermined. When the temperature zone is exceeded, the energization of the electric heater is stopped and the latent heat storage material is cooled by the cooling unit. [Selection] Figure 2

Description

  The technology disclosed herein relates to a secondary battery temperature adjustment device for a vehicle.

  Patent Document 1 describes a system that includes a heat storage body that covers a battery, a heat insulating material that covers the heat storage body, and an electric heater disposed in the heat storage body in an electric vehicle equipped with a battery for driving a motor. Has been. This system prevents the running performance from deteriorating due to a decrease in battery temperature and a decrease in battery electromotive force during cold weather.

Japanese Patent Laid-Open No. 10-32021

  The system described in Patent Document 1 increases the temperature of a battery through a heat storage material by energizing an electric heater. When the battery temperature rises, the electric heater is de-energized. However, even if energization of the electric heater is stopped when the temperature of the battery becomes too high, the temperature of the battery does not decrease immediately and the battery may be deteriorated.

  The technology disclosed herein has been made in view of such a point, and an object thereof is to precisely control the temperature of a secondary battery mounted on a vehicle.

  The technology disclosed herein relates to a secondary battery temperature adjustment device for a vehicle. The apparatus includes: a secondary battery mounted on a vehicle; a temperature raising unit configured to increase the temperature of the secondary battery; and a temperature control configured to adjust the temperature of the secondary battery through the temperature raising unit. And the temperature raising means covers the secondary battery and is configured to heat the latent heat storage material and the latent heat storage material configured to supply heat to the secondary battery. An electric heater, and a cooling unit configured to cool the latent heat storage material.

  And when the temperature of the latent heat storage material is lower than a predetermined temperature zone, the temperature control means increases the temperature of the secondary battery through the latent heat storage material by energizing the electric heater, and When the temperature of the latent heat storage material exceeds the predetermined temperature range, energization of the electric heater is stopped and the latent heat storage material is cooled by the cooling unit.

  Here, the vehicle may be an electric vehicle (EV) that travels when the motor is driven by the power of the secondary battery. Moreover, it is good also as what is called a hybrid vehicle (Hybrid Electric Vehicle: HEV) carrying both the motor and the engine which is an internal combustion engine. Among hybrid vehicles, a so-called plug-in hybrid electric vehicle (PHEV) that can charge a secondary battery with an external power source may be used. The vehicle is not limited to a four-wheeled vehicle.

  The “predetermined temperature range” may be a temperature range including a temperature at which the secondary battery can be charged. In other words, if the secondary battery and the latent heat storage material covering the secondary battery are substantially isothermal, when the temperature of the latent heat storage material is in a predetermined temperature range, the temperature of the secondary battery is also a predetermined temperature. Become a obi. The “temperature zone” may be defined as a temperature range having a predetermined width between a certain upper limit value and a certain lower limit value.

  According to the above configuration, the temperature control means increases the temperature of the secondary battery through the latent heat storage material by energizing the electric heater when the temperature of the latent heat storage material is lower than a predetermined temperature range.

  “When the temperature of the latent heat storage material is lower than a predetermined temperature range” may be defined as when the temperature of the latent heat storage material is lower than the lower limit value of the predetermined temperature range. As described above, if the secondary battery and the latent heat storage material covering the secondary battery are substantially isothermal, "when the temperature of the latent heat storage material is lower than a predetermined temperature range" When the temperature of the battery is lower than the predetermined temperature range, which makes it impossible to charge the secondary battery.

  According to the above configuration, the secondary battery can be charged if the temperature of the secondary battery is increased by energization of the electric heater. It becomes possible to charge the secondary battery with regenerative power when the vehicle is decelerated. As a result, fuel efficiency is improved.

  When the temperature of the latent heat storage material exceeds a predetermined temperature range, the temperature control means stops energization of the electric heater and cools the latent heat storage material by the cooling unit.

  “When the temperature of the latent heat storage material exceeds a predetermined temperature range” may be defined as when the temperature of the latent heat storage material is higher than the upper limit value of the predetermined temperature range. As described above, if the secondary battery and the latent heat storage material covering the secondary battery are substantially isothermal, "when the temperature of the latent heat storage material exceeds a predetermined temperature range" When the temperature of the battery becomes too high and there is a concern about deterioration of the secondary battery.

  In the above configuration, when the temperature of the latent heat storage material exceeds a predetermined temperature range, the cooling unit cools the latent heat storage material, so that the secondary battery temperature is prevented from becoming too high. In this way, it is possible to prevent the secondary battery from being deteriorated by precisely controlling the temperature of the secondary battery.

  In the above configuration, the secondary battery is covered with the latent heat storage material. The latent heat storage material may be configured to solidify in the predetermined temperature range. By doing so, the latent heat storage material heated by the electric heater stores heat in a predetermined temperature range. Therefore, after the energization of the electric heater is stopped, the temperature of the secondary battery can be maintained in a predetermined temperature range for a long period of time even in a low temperature environment by radiating the latent heat storage material.

The cooling unit cools the latent heat storage material by dissolving the water in the housing provided to transmit heat to the latent heat storage material and the water housed in the housing and supplied to the housing. that has a cryogen configured to.

  By doing so, the cooling unit can quickly cool the latent heat storage material when the temperature of the latent heat storage material exceeds a predetermined temperature range. Specifically, the cryogen may be ammonium thiocyanate or the like.

  The temperature control means may regenerate the cryogen by cooling the latent heat storage material and then energizing the electric heater to evaporate water in the housing and discharge the water from the housing. Good.

  By regenerating the cryogen in this way, the latent heat storage material can be repeatedly cooled.

  The temperature raising means includes a cooling water storage tank that is supplied with cooling water of an engine mounted on the vehicle and that transfers heat to the latent heat storage material, and the electric heater includes the cooling water It is good also as arrange | positioning in the storage tank.

  This configuration is suitable for HEV and PHEV. When the electric heater is energized, the temperature of the cooling water is raised in the cooling water storage tank. The latent heat storage material is heated through the cooling water. In this way, it is possible to perform engine warm-up and secondary battery temperature increase in parallel. This configuration is advantageous for an early temperature increase of the secondary battery and an early warm-up of the engine when starting the engine in a low temperature environment.

  Further, in the above configuration, after stopping the engine that has been warmed up, the temperature of the latent heat storage material is maintained in a predetermined temperature zone by supplying high-temperature cooling water to the cooling water storage tank, thereby providing a secondary This is also advantageous in maintaining the battery temperature in a predetermined temperature range.

  The electric heater may be disposed in the latent heat storage material. By doing so, the latent heat storage material is directly heated by the electric heater. This configuration is particularly suitable for EVs. However, you may apply to HEV and PHEV.

  The temperature raising means includes an evaporation tank provided adjacent to the latent heat storage material and configured to evaporate the supplied liquid in the predetermined temperature range, and the electric heater is disposed in the evaporation tank. It is good also as arrange | positioning.

  According to this configuration, the electric heater disposed in the evaporation tank heats the liquid supplied in the evaporation tank. The evaporation tank is configured to evaporate the liquid in a predetermined temperature range. For example, the inside of the evaporation tank may be configured to have a pressure at which water evaporates in a predetermined temperature range. In this way, the temperature of the evaporation tank can be maintained substantially constant within a predetermined temperature range, so that the temperature of the secondary battery can be maintained within a predetermined temperature range via the latent heat storage material. Become.

  As described above, in the configuration in which the latent heat storage material is directly heated by the electric heater, if the temperature of the electric heater is increased to quickly increase the temperature of the secondary battery, the latent heat storage material may be burnt. . In the configuration in which the latent heat storage material is directly heated by the electric heater, it is difficult to quickly increase the temperature of the secondary battery.

  On the other hand, the temperature of the electric heater can be increased by interposing an evaporation tank between the electric heater and the latent heat storage material. The evaporating tank can also transfer a large amount of heat at a time by boiling condensation type heat transfer. It becomes possible to raise the temperature of an evaporating tank rapidly, and to raise the temperature of a latent-heat storage material and a secondary battery rapidly.

  The secondary battery has a plurality of battery cells electrically connected to each other, and the latent heat storage material covers a portion of the plurality of battery cells excluding a portion electrically connected to each other, The temperature raising means includes: a heat insulating casing that covers the latent heat storage material; and a heat insulating lid that covers the electrically connected portions of the plurality of battery cells together with the heat insulating casing. Good.

  By doing so, the latent heat storage material, the battery cell, and the external environment are insulated by the heat insulating casing and the heat insulating lid. Thereby, after energization of the electric heater is stopped, the temperature of the battery cell can be maintained in a predetermined temperature range for a long period.

  As described above, according to the above-described secondary battery temperature adjusting device for a vehicle, it is possible to precisely control the temperature of the secondary battery mounted on the vehicle.

FIG. 1 is a diagram showing a configuration of a vehicle system equipped with a secondary battery temperature adjustment device. FIG. 2 is a diagram conceptually showing the configuration of the temperature raising device. FIG. 3 is a diagram illustrating characteristics of the latent heat storage material. FIG. 4 is a diagram conceptually illustrating a configuration example of a housing that stores the cryogen. FIG. 5 is a flowchart showing the heat retention control of the battery. FIG. 6 is a flowchart showing temperature increase control of the engine and the battery when starting the engine in a low temperature environment. FIG. 7 is a diagram exemplifying changes in the cooling water temperature and the battery temperature during the temperature increase control of the engine and the battery. FIG. 8 is a diagram showing a configuration of a vehicle system different from that shown in FIG. 1 in which the secondary battery temperature adjusting device is mounted. FIG. 9 is a diagram conceptually showing the configuration of the temperature raising device. FIG. 10 is a diagram conceptually showing the configuration of the temperature raising device different from FIG.

  Hereinafter, a secondary battery temperature adjusting device for a vehicle disclosed herein will be described in detail with reference to the drawings. In addition, the following description is an illustration. FIG. 1 shows a configuration of a vehicle system 1 equipped with a secondary battery temperature adjusting device. This vehicle is, for example, a four-wheel HEV or PHEV. In addition, the vehicle which can mount the secondary battery temperature control apparatus disclosed here is not limited to a four-wheeled vehicle.

  The vehicle system 1 includes an engine 11, a motor generator 2, and a lithium ion battery 3 that is a secondary battery. The engine 11 is, for example, a multi-cylinder internal combustion engine. The engine 11 is connected to the drive wheels 21 via the transmission 12. The lithium ion battery 3 is connected to the motor generator 2.

  The motor generator 2 is connected to the engine 11. Specifically, in this configuration example, the motor generator 2 is an ISG (Integrated Starter Generator) connected to the crankshaft of the engine 11 via a belt, for example. This vehicle is a so-called micro or mild hybrid vehicle. The capacity of the lithium ion battery 3 is relatively small. The vehicle travels when the engine 11 and / or the motor generator 2 drives the drive wheels 21.

  The motor generator 2 functions as a prime mover upon receiving power from the lithium ion battery 3. The motor generator 2 cranks the engine 11 when the engine 11 is started. The motor generator 2 assists the engine 11 while the engine 11 is in operation. Furthermore, the motor generator 2 also functions as a generator. The motor generator 2 generates power when the vehicle is traveling at a reduced speed. The lithium ion battery 3 is regeneratively charged by the power generated by the motor generator 2.

  An inverter 22 is interposed between the motor generator 2 and the lithium ion battery 3. The inverter 22 controls driving of the motor generator 2 and power generation.

  A changeover switch 52 is interposed between the lithium ion battery 3 and the inverter 22. The changeover switch 52 is configured to switch the electric power from the lithium ion battery 3 between the motor generator 2 and a temperature raising device 6 described later.

  The temperature raising device 6 is configured to increase the temperature of the lithium ion battery 3 when the temperature of the lithium ion battery 3 is low. Although details will be described later, the temperature raising device 6 raises the temperature of the lithium ion battery 3 in a low temperature environment such as −30 ° C., for example.

  FIG. 2 shows the configuration of the temperature raising device 6. In FIG. 2, reference numeral 31 indicates a plurality of battery cells constituting the lithium ion battery 3. The plurality of battery cells 31 are electrically connected to each other. The temperature raising device 6 includes a heat insulating casing 61 and a heat insulating lid 611 provided so as to cover the battery cell 31, and a latent heat storage material provided so as to cover the battery cell 31 by being filled in the heat insulating casing 61. 62, a cooling water storage tank 670 configured to transfer heat to the latent heat storage material 62, and an electric heater 63 disposed in the cooling water storage tank 670.

  Each battery cell 31 is almost entirely covered with a heat insulating casing 61 and a latent heat storage material 62 except for portions that are electrically connected to each other. The portions of the battery cells 31 that are electrically connected to each other are covered with a heat insulating lid 611 and a heat insulating casing 61. By doing so, the heat transfer between each battery cell 31 and the latent heat storage material 62 becomes good, and the heat insulation between each battery cell 31 and the outside of the heat insulation housing 61 and the heat insulation lid 611 also becomes good. . FIG. 2 conceptually shows the configuration of the temperature raising device 6, and the specific configuration of the temperature raising device 6 is not limited to the configuration shown in FIG.

  The latent heat storage material 62 is configured to solidify in a predetermined temperature range. The predetermined temperature zone is a temperature zone set around 30 ° C. This temperature zone is a temperature zone in which the charging rate of the lithium ion battery 3 does not decrease. The latent heat storage material 62 that solidifies in a temperature range of about 30 ° C. can be, for example, a paraffin-based latent heat storage material. The latent heat storage material 62 stores heat in a temperature range around 30 ° C.

  FIG. 3 illustrates the characteristics of the latent heat storage material 62. The heat storage temperature zone changes according to the configuration of the paraffin-based latent heat storage material. The paraffin-based latent heat storage material shown in the figure has a characteristic that melting starts at a temperature T3 and completes at a temperature T4.

  The cooling water storage tank 670 is connected to a cooling water passage 67 through which the cooling water of the engine 11 flows. The cooling water passage 67 is provided independently of a cooling water circulation passage including a radiator (not shown in FIG. 1). The cooling water passage 67 has an outward path 671 from the engine 11 to the cooling water storage tank 670 and a return path 672 from the cooling water storage tank 670 to the engine 11. An open / close valve 673 and a pump 674 are interposed in the forward path 671. By opening the opening / closing valve 673 and driving the pump 674, the cooling water circulates between the engine 11 and the cooling water storage tank 670.

  The temperature raising device 6 increases the temperature of the battery cell 31 through the cooling water and the latent heat storage material 62 by energizing the electric heater 63 disposed in the cooling water storage tank 670. The temperature of the battery cell 31 is kept constant at the solidification temperature of the latent heat storage material 62. By heating the lithium ion battery 3 through the latent heat storage material 62, overheating of the lithium ion battery 3 is avoided.

  When energization of the electric heater 63 is stopped in a state where the temperature of the lithium ion battery 3 has reached a predetermined temperature range, the latent heat storage material 62 and the battery cell 31 and the external environment are separated by the heat insulating casing 61 and the heat insulating lid 611. Since it is insulated, the temperature drop of the battery cell 31 is suppressed. Even if the temperature of the battery cell 31 is lowered, the temperature of the battery cell 31 is maintained at the solidification temperature of the latent heat storage material 62 by the heat radiation of the latent heat storage material 62. Thus, the temperature raising device 6 maintains the temperature of the lithium ion battery 3 in a predetermined temperature range for a long time.

  The temperature raising device 6 also increases the temperature of the cooling water by energizing the electric heater 63, so that the engine 11 is also warmed up when the engine 11 is cold.

  Furthermore, when the temperature of the cooling water of the engine 11 is high, the temperature raising device 6 transmits heat from the cooling water in the cooling water storage tank 670 to the latent heat storage material 62 even when the electric heater 63 is not energized, thereby latent heat storage. It is possible to increase the temperature of the material 62 and the battery cell 31.

  As shown in FIG. 2, the temperature raising device 6 further includes a cooling unit 68. The cooling unit 68 cools the latent heat storage material 62 when the temperature of the latent heat storage material 62 becomes too high. Thereby, it is avoided beforehand that the temperature of the lithium ion battery 3 becomes too high and the lithium ion battery 3 deteriorates.

  The cooling unit 68 includes a housing 681 disposed in the latent heat storage material 62, a cryogen 682 (see FIG. 4) housed in the housing 681, and a circulation configured to supply water to the housing 681. And a path 683.

  The circulation path 683 is configured to supply water to the housing 681 and to discharge water vapor from the housing 681. A first opening / closing valve 684 is interposed on the water supply side in the circulation path 683. On the other hand, a second opening / closing valve 685 and a condenser 686 for condensing the water vapor into water are provided on the water circulation path 65 on the water vapor discharge side. The condenser 686 is configured by a heat exchanger disposed in the vehicle interior (more precisely, in an environment having the same temperature as the vehicle interior).

  The inside of the housing 681 is kept at a low pressure so that water evaporates in a predetermined temperature zone (a temperature zone around 30 ° C. as described above). When the first opening / closing valve 684 is opened, condensed water is supplied into the housing 681 due to a pressure difference. The cryogen 682 in the housing 681 is made of ammonium thiocyanate or the like. When the cryogen 682 is dissolved in water, the temperature decreases by about 20 ° C. Since the housing 681 is configured to be able to transfer heat to the latent heat storage material 62, the latent heat storage material 62 is cooled by the temperature drop of the cryogen 682.

  As will be described in detail later, the cooling of the latent heat storage material 62 is performed when the temperature of the latent heat storage material 62 becomes too high when temperature rise control of the latent heat storage material 62 is performed. After the cooling of the latent heat storage material 62, the water supplied into the housing 681 is next energized to the electric heater 63 so that the temperature of the latent heat storage material 62 is controlled to increase the temperature of the latent heat storage material 62. As it rises to about 30 ° C, it evaporates. The water vapor is discharged from the inside of the housing 681 by opening the second opening / closing valve 685. The water vapor condenses in the condenser 686.

  Returning to FIG. 1, the vehicle system 1 includes a controller 7. The controller 7 controls the traveling of the vehicle through the control of the engine 11 and the inverter 22.

  The lithium ion battery 3 is provided with a temperature sensor 71 that detects the temperature of the battery. The temperature sensor 71 outputs a detection signal to the controller 7. The temperature raising device 6 is provided with a temperature sensor 72 that detects the temperature of the latent heat storage material 62. The temperature sensor 72 also outputs a detection signal to the controller 7. The vehicle system 1 also includes a water temperature sensor 73 that detects the cooling water temperature of the engine 11 and an outside air temperature sensor 74 that detects outside air temperature. The water temperature sensor 73 and the outside air temperature sensor 74 each output a detection signal to the controller 7.

  Based on these sensor signals, the controller 7 switches the switch 52, the electric heater 63 of the temperature raising device 6, the opening / closing valve 673 and the pump 674 of the cooling water passage 67, and the first opening / closing valve 684 and the second opening / closing of the cooling unit 68. Each of the valves 685 is controlled to adjust the temperature of the lithium ion battery 3.

  FIG. 5 is a flowchart showing a control procedure for temperature adjustment of the lithium ion battery 3 executed by the controller 7. This flow is control for suppressing a decrease in temperature of the lithium ion battery 3 and maintaining the temperature of the lithium ion battery 3 for a long time in a predetermined temperature range in a low temperature environment.

  First, in step S51 after the start, the controller 7 determines whether the vehicle is stopped or the engine is stopped. If the determination in step S51 is no, step S51 is repeated. When the determination is YES, the process proceeds to step S52.

  In step S52, the controller 7 determines whether or not the outside air temperature is equal to or lower than a predetermined value T1 based on the detection signal of the outside air temperature sensor 74. The predetermined value T1 may be appropriately set, for example, at a value of 0 ° C. or less. When the outside air temperature is equal to or lower than the predetermined value T1, the temperature of the lithium ion battery 3 gradually decreases, so that the temperature of the lithium ion battery 3 may fall below a predetermined temperature zone. When determination of step S52 is YES, it transfers to step S53. If the determination in step S52 is no, the process returns.

  In step S53, the controller 7 determines whether or not the coolant temperature exceeds a predetermined value T2 based on the detection signal of the coolant temperature sensor 73. If YES in step S53, the process proceeds to step S54, and if NO, the process proceeds to step S56. Here, for example, immediately after the warmed-up engine 11 is stopped, the description is continued assuming that the coolant temperature exceeds the predetermined value T2.

  In step S <b> 54, the controller 7 supplies cooling water to the temperature raising device 6. Specifically, the opening / closing valve 673 of the cooling water passage 67 is opened and the pump 674 is operated. As a result, high-temperature cooling water is circulated between the engine 11 and the cooling water storage tank 670. Heat is transferred from the cooling water storage tank 670 to the latent heat storage material 62, and the temperature of the latent heat storage material 62 increases. The temperature of the lithium ion battery 3 is also raised.

  In step S55 following step S54, the controller 7 determines whether or not the temperature of the latent heat storage material 62 is equal to or higher than a predetermined value T3. As shown in FIG. 3, the predetermined value T3 is a temperature at which the latent heat storage material 62 starts to melt. When the determination in step S55 is NO, the process returns to step S53 and the temperature increase of the latent heat storage material 62 is continued.

  Since the engine 11 is stopped, the temperature of the cooling water gradually decreases. If the temperature of the cooling water becomes equal to or lower than the predetermined value T2 in step S53, the flow moves to step S56.

  In step S56, the controller 7 determines whether or not the SOC of the lithium ion battery 3 exceeds a predetermined SOC. The SOC of the lithium ion battery 3 can be estimated or detected by an appropriate method. In step S <b> 56, it is determined whether or not the SOC of the lithium ion battery 3 is an SOC that can energize the electric heater 63. If the determination in step S56 is NO, the flow returns without energizing the electric heater 63. On the other hand, if determination of step S56 is NO, it will transfer to step S57.

  In step S <b> 57, the controller 7 energizes the electric heater 63. At this time, the controller 7 closes the opening / closing valve 673 of the cooling water passage 67 and stops the pump 674. Thereby, the temperature of the cooling water in the cooling water storage tank 670 is efficiently raised by the electric heater 63. The latent heat storage material 62 is heated through the cooling water, and the lithium ion battery 3 is also heated.

  If the temperature of the latent heat storage material 62 becomes equal to or higher than the predetermined temperature T3 in step S55, the flow moves to step S58. In step S58, the controller 7 stops the heating of the latent heat storage material 62 performed in step S54 or step S57. In subsequent step S59, the controller 7 determines whether or not the temperature of the latent heat storage material 62 is equal to or higher than a predetermined temperature T4. As shown in FIG. 3, the predetermined temperature T4 is a temperature at which the latent heat storage material 62 completes melting. That is, step S59 determines whether the temperature of the latent heat storage material 62 has become too high.

  When determination of step S59 is NO, it transfers to step S511. On the other hand, when the determination in step S59 is YES, the process proceeds to step S510.

  In step S510, the controller 7 cools the latent heat storage material 62. Specifically, the controller 7 supplies water into the housing 681 of the cooling unit 68, and the cryogen 682 dissolves in the water, thereby lowering the temperature of the latent heat storage material 62. Thereafter, the flow moves to step S511.

  In step S511, it is determined whether the temperature of the lithium ion battery 3 has fallen below a predetermined temperature TS. The predetermined temperature TS may be appropriately set as a temperature at which the lithium ion battery 3 cannot be charged, for example. When the flow of step S511 is NO, step S511 is repeated.

  Since the latent heat storage material 62 and the battery cell 31 and the external environment are thermally insulated by the heat insulation housing 61 and the heat insulation lid 611, the temperature drop of the battery cell 31 is suppressed. Moreover, even if the temperature of the battery cell 31 is going to decrease, the temperature of the battery cell 31 is kept at the solidification temperature of the latent heat storage material 62 because the latent heat storage material 62 that stores heat releases heat. Thus, the temperature raising device 6 maintains the temperature of the lithium ion battery 3 at or above the predetermined temperature TS for a long time even in a low temperature environment.

  If the temperature of the lithium ion battery 3 decreases and the determination in step S511 is YES, the flow returns to step S53. Thereby, the temperature of the latent heat storage material 62 and the lithium ion battery 3 is increased by the cooling water of the engine 11 or by the electric heater 63.

  The flow shown in FIG. 5 ends when the vehicle runs or the engine 11 starts.

  Like this control, it becomes possible to maintain the temperature of the lithium ion battery 3 in a predetermined temperature zone in a low temperature environment. Moreover, when the temperature of the latent heat storage material 62 becomes too high, the latent heat storage material 62 is cooled by the cooling unit 68 to prevent the temperature of the lithium ion battery 3 from becoming too high. As a result, deterioration of the lithium ion battery 3 is prevented.

  Further, by using the cryogen 682 as the cooling unit 68 that cools the latent heat storage material 62, the latent heat storage material 62 can be quickly cooled. Further, since the cryogen 682 can be regenerated, the latent heat storage material 62 can be repeatedly cooled.

  The controller 7 raises the temperature of the lithium ion battery 3 by energizing the electric heater 63 of the temperature raising device 6 when the temperature of the lithium ion battery 3 decreases while the vehicle is running. For example, when the frequency of deceleration regeneration is large, the controller 7 may supply a part of the regenerative power to the electric heater 63 and supply the rest to the lithium ion battery 3. When it is not necessary to raise the temperature of the lithium ion battery 3, all the regenerative power is supplied to the lithium ion battery 3 (however, charging is performed within the SOC limit of the lithium ion battery 3). When the frequency of deceleration regeneration is small (for example, when traveling at a high speed and a constant speed), a part of the electric power of the lithium ion battery 3 is supplied to the electric heater 63 of the temperature raising device 6, thereby What is necessary is just to raise the temperature of the battery 3. Further, when the temperature of the lithium ion battery 3 is raised during traveling of the vehicle, the cooling water of the engine 11 may be used.

  FIG. 6 is a flowchart showing a control procedure for temperature adjustment of the lithium ion battery 3 when the engine 11 is started at a low temperature. First, in step S61 after the start, the controller 7 determines whether or not the engine 11 has been started. If the determination in step S61 is no, step S61 is repeated. When the determination in step S61 is YES, the process proceeds to step S62.

  In step S <b> 62, the controller 7 circulates the cooling water between the engine 11 and the temperature raising device 6. Specifically, the controller 7 opens the opening / closing valve 673 of the cooling water passage 67 and drives the pump 674.

  In step S63, the controller 7 operates the engine 11 in the cooling water temperature increase mode. Specifically, the controller 7 increases the fuel injection amount of the engine 11, for example, and delays the combustion timing by retarding the ignition timing so that the cooling loss increases.

  In step S <b> 64, the controller 7 energizes the electric heater 63. Thus, the temperature of the cooling water is raised by the electric heater 63 in the cooling water storage tank 670. As the cooling water circulates through the cooling water passage 67, warming up of the engine 11 is promoted, and as described above, the latent heat storage material 62 is heated through the cooling water in the cooling water storage tank 670, The temperature of the lithium ion battery 3 also rises.

  In step S65, the controller 7 determines whether or not the temperature of the latent heat storage material 62 has exceeded a predetermined temperature T5. As shown in FIG. 3, the predetermined temperature T5 is higher than the temperature T3 at which melting of the latent heat storage material 62 starts and lower than the temperature T4 at which melting is completed. In this flow, the temperature of the cooling water of the engine 11 is increased by continuing the heating by the electric heater 63 as much as possible.

  When the determination in step S <b> 65 is NO, the process returns to step S <b> 62, and the controller 7 continues to raise the temperature of the coolant of the engine 11 and the temperature of the lithium ion battery 3 through the latent heat storage material 62. When determination of step S65 is YES, it transfers to step S66.

  In step S66, the controller 7 stops the circulation of the cooling water. Specifically, the controller 7 closes the opening / closing valve 673 and stops the pump 674. In step S67, the controller 7 stops energization of the electric heater 63.

  In subsequent step S68, the controller 7 determines whether or not the temperature of the latent heat storage material 62 has exceeded the predetermined temperature T4. As described above, it is determined whether or not the temperature of the latent heat storage material 62 has become too high. If the determination in step S68 is yes, the flow moves to step S69. As described above, the controller 7 supplies water into the housing 681 of the cooling unit 68. The cryogen 682 cools the latent heat storage material 62.

  In step S610 after the energization of the electric heater 63 is stopped, the controller 7 continues to operate the engine 11 in the cooling water temperature increase mode. In subsequent step S611, the controller 7 determines whether or not the temperature of the cooling water has become equal to or higher than the target temperature TE. When the temperature is not equal to or higher than the target temperature TE, the controller 7 continues the engine coolant temperature raising mode.

  If the determination in step S611 is yes, the flow moves to step S612. Since the coolant of the engine 11 has reached the target temperature TE, the controller 7 operates the engine 11 in the normal mode.

  FIG. 7 shows the change in temperature of the lithium ion battery 3 (see the solid line in FIG. 7) and the change in the coolant temperature of the engine 11 (see FIG. 7) when the control shown in FIG. The change in temperature of the lithium ion battery 3 (see the two-dot chain line in FIG. 7) and the change in the coolant temperature of the engine 11 (see the broken line) and the case where the control shown in FIG. FIG. 7 shows a dash-dot line). Here, the change of the coolant temperature of the engine 11 as a comparative example shows an example of the change of the coolant temperature when the engine 11 is operated in the coolant temperature raising mode. Moreover, the change of the temperature of the lithium ion battery 3 as a comparative example is a configuration in which the temperature raising device 6 does not have the cooling water storage tank 670, that is, the temperature raising device 6 covers the latent heat storage material 62 covering the battery cell 31, When the electric heater 63 disposed in the latent heat storage material 62 and the heat insulating casing 61 and the heat insulating lid 611 that cover the battery cell 31 and the latent heat storage material 62 are provided (see, for example, FIG. 9). The temperature change of the lithium ion battery 3 is illustrated.

  First, in the comparative example, the configuration for raising the temperature of the cooling water of the engine 11 and the configuration for raising the temperature of the lithium ion battery 3 are independent of each other. Therefore, the temperature of the cooling water of the engine 11 and the temperature of the lithium ion battery 3 each rise with a predetermined inclination with respect to the passage of time. The temperature rise becomes relatively gradual. It takes a long time for the lithium ion battery 3 to reach the target battery temperature TS, and it takes a long time for the cooling water of the engine 11 to reach the target cooling water temperature TE.

  In contrast, in the embodiment, the configuration for raising the temperature of the cooling water of the engine 11 and the configuration for raising the temperature of the lithium ion battery 3 are combined. That is, the temperature of the lithium ion battery 3 is raised through the latent heat storage material 62 by the temperature rise of the cooling water in the cooling water temperature raising mode of the engine 11, and the cooling water is cooled by the electric heater 63 that raises the temperature of the lithium ion battery 3. Rises in temperature. As a result, in the embodiment, the temperature of the cooling water of the engine 11 and the temperature of the lithium ion battery 3 rise in the same manner, and the temperature rises more quickly than in the comparative example. Since the target battery temperature TS of the lithium ion battery 3 is lower than the target cooling water temperature TE of the cooling water, the temperature of the lithium ion battery 3 reaches the target battery temperature TS first (time t1). Here, as described above, in the flow shown in FIG. 6, the electric heater 63 is energized until the temperature of the latent heat storage material 62 becomes equal to or higher than the predetermined temperature T5. It is possible to continue for a long time. This is advantageous in quickly warming up the engine 11.

  The lithium ion battery 3 cannot be charged before the temperature of the lithium ion battery 3 reaches the target battery temperature TS. The controller 7 supplies regenerative electric power during deceleration traveling to the electric heater 63. By doing so, fuel efficiency is improved.

  If the temperature of the lithium ion battery 3 reaches the target battery temperature TS, the lithium ion battery 3 can be charged. The controller 7 supplies the regenerative electric power during deceleration traveling to the lithium ion battery 3 and charges the lithium ion battery 3. As described above, the temperature of the lithium ion battery 3 can be quickly increased, and charging of the lithium ion battery 3 can be started quickly. Therefore, it becomes advantageous for improvement of fuel consumption.

  In addition, instead of charging the lithium ion battery 3 or charging the lithium ion battery 3, the regenerative electric power at the time of decelerating driving may be supplied to other electric devices (for example, illustration is omitted, If the catalyst device of the engine 11 includes an EHC (Electrically Heated Catalyst), regenerative power may be supplied to the EHC).

  When the temperature of the lithium ion battery 3 reaches the target battery temperature TS, the energization of the electric heater 63 is stopped. For this reason, after time t1, the gradient of the temperature of the coolant of the engine 11 with respect to the passage of time becomes relatively small. When the cooling water of the engine 11 reaches the target cooling water temperature TE, the cooling water temperature raising mode ends (time t2).

  Thus, in the embodiment, the temperature of the lithium ion battery 3 quickly reaches the target battery temperature TS, and the temperature of the cooling water of the engine 11 also quickly reaches the target cooling water temperature TE.

  Similarly to the flow shown in FIG. 5, when the temperature of the latent heat storage material 62 becomes too high, the temperature of the lithium ion battery 3 becomes too high by cooling the latent heat storage material 62 by the cooling unit 68. However, it is avoided in advance. Deterioration of the lithium ion battery 3 is prevented.

  FIG. 8 shows a configuration of another vehicle system 10 equipped with a secondary battery temperature adjustment device. This vehicle is, for example, a four-wheel electric vehicle (EV). The vehicle on which the secondary battery temperature adjusting device disclosed herein can be mounted is not limited to four wheels. In the vehicle system 10, the description of the same configuration as the vehicle system 1 shown in FIG. 1 may be omitted.

  The vehicle system 10 includes a motor generator 2 and a lithium ion battery 3 that is a secondary battery. The motor generator 2 is connected to the drive wheels 21. The lithium ion battery 3 supplies power to the motor generator 2. The capacity of the lithium ion battery 3 is relatively large. The motor generator 2 that is supplied with power from the lithium ion battery 3 functions as a prime mover. The vehicle travels when the motor generator 2 drives the drive wheels 21. The motor generator 2 also functions as a generator. The motor generator 2 generates power when the vehicle is traveling at a reduced speed. The lithium ion battery 3 is regeneratively charged by the power generated by the motor generator 2.

  The lithium ion battery 3 is configured such that it can be externally charged by the power of an external power supply (not shown). Although illustration is omitted, an inlet into which the charging plug is inserted may be provided in the vehicle. A non-contact charging system may be employed.

  Between the external power source and the lithium ion battery 3, a power converter 51 that performs AC-DC conversion and a changeover switch 52 are interposed. The changeover switch 52 is configured to switch the power supply destination of the external power source between the lithium ion battery 3 and a temperature raising device 6 described later.

  FIG. 9 illustrates the configuration of the temperature raising device 6. The temperature raising device 6 includes a heat insulating casing 61 and a heat insulating lid 611 provided so as to cover the battery cell 31, and a latent heat storage material provided so as to cover the battery cell 31 by being filled in the heat insulating casing 61. 62 and an electric heater 63 disposed in the heat insulating casing 61. A casing 681 of the cooling unit 68 is disposed in the latent heat storage material 62. The structure of the housing 681 is the same as that in FIG.

  When the electric heater 63 is energized, the temperature of the battery cell 31 is increased through the latent heat storage material 62. The temperature of the battery cell 31 is kept constant at the solidification temperature of the latent heat storage material 62. Even after the energization of the electric heater 63 is stopped, the temperature raising device 6 maintains the temperature of the lithium ion battery 3 in a predetermined temperature range for a long time.

  When the temperature of the latent heat storage material 62 becomes too high, the controller 7 supplies water into the housing 681 of the cooling unit 68 through the circulation path 683. The cryogen 682 stored in the housing 681 is dissolved in water, and the latent heat storage material 62 is cooled.

  Control of temperature adjustment of the lithium ion battery 3 is performed according to the flow shown in FIG. Specifically, in step S51 of the flow of FIG. 5, it is determined whether or not the vehicle is stopped. Further, both steps S53 and S54 are omitted. Therefore, the control of the temperature adjustment of the lithium ion battery 3 is performed by energizing the electric heater 63 when the SOC of the lithium ion battery 3 exceeds the predetermined SOC after the vehicle is stopped, and through the latent heat storage material 62. Increase the temperature of 3. When the temperature of the latent heat storage material 62 becomes equal to or higher than the predetermined temperature T3, energization of the electric heater 63 is stopped. When the temperature of the latent heat storage material 62 becomes equal to or higher than the predetermined temperature T4, the latent heat storage material 62 is cooled by the cryogen 682 by supplying water into the housing 681 of the cooling unit 68.

  Thus, the temperature of the lithium ion battery 3 is prevented from becoming too high while preventing the temperature drop of the lithium ion battery 3.

  Further, when the temperature of the lithium ion battery 3 is lowered even while the vehicle is traveling, the temperature of the lithium ion battery 3 is raised by the temperature raising device 6 as described above. When the deceleration regeneration frequency is high when the vehicle is traveling, the controller 7 may supply a part of the regenerative power to the electric heater 63 and supply the rest to the lithium ion battery 3 for charging. In addition, when the deceleration regeneration frequency is low, the controller 7 may supply the electric power from the lithium ion battery 3 to the electric heater 63. In addition, when the temperature of the lithium ion battery 3 is in a predetermined temperature range and the temperature rise of the lithium ion battery 3 is not required, all the regenerative power is charged in the lithium ion battery 3.

  Here, in the temperature raising device 6 shown in FIG. 9, the electric heater 63 is disposed in the latent heat storage material 62. The electric heater 63 heats the latent heat storage material 62 directly. In the temperature raising device 6 having this configuration, there is a risk of scorching the latent heat storage material 62 in contact with the electric heater 63 even if the temperature of the electric heater 63 is increased in order to increase the temperature of the lithium ion battery 3 at an early stage. Further, the configuration in which the electric heater 63 is disposed in the latent heat storage material 62 causes local deterioration of the latent heat storage material 62 when the electric heater 63 hits the latent heat storage material 62 or the like. There is also a fear.

  FIG. 10 shows a temperature raising device 6 configured to solve these problems. In addition to the heat insulating housing 61, the heat insulating lid 611, the latent heat storage material 62, and the electric heater 63, the temperature raising device 6 includes an evaporation tank 650 and a water circulation path 65 configured to supply water to the evaporation tank 650. ,have.

  The evaporation tank 650 is adjacent to the latent heat storage material 62. The evaporation tank 650 and the latent heat storage material 62 are in contact with each other so as to be able to transfer heat. In the example of FIG. 10, the evaporation tank 650 is disposed below the latent heat storage material 62, but the relative position between the evaporation tank 650 and the latent heat storage material 62 is not limited to the example of FIG. 10.

  The electric heater 63 is arranged not in the latent heat storage material 62 but in the evaporation tank 650 in the temperature raising device 6 having this configuration.

  The inside of the evaporation tank 650 is kept at a low pressure so that water evaporates in a predetermined temperature zone (a temperature zone around 30 ° C. as described above). The water supplied into the evaporation tank 650 is evaporated by being heated by the electric heater 63. The evaporation tank 650 is configured so that its temperature is maintained in a predetermined temperature range. By increasing the heat transfer area between the latent heat storage material 62 and the evaporation tank 650, the amount of heat transfer from the evaporation tank 650 to the latent heat storage material 62 increases, so the temperature of the latent heat storage material 62 and the lithium ion battery 3 is quickly increased. It becomes possible.

  The water circulation path 65 is configured to supply water to the evaporation tank 650 and to discharge water vapor from the evaporation tank 650. A water storage tank 651 for storing water and a pump 652 for controlling the supply of water from the water storage tank 651 to the evaporation tank 650 are interposed on the water supply side in the water circulation path 65. On the other hand, an opening / closing valve 653 for opening and closing the water circulation path 65 and a condenser 654 for condensing the water vapor into water are interposed on the water vapor discharge side of the water circulation path 65. The condenser 654 and the water storage tank 651 communicate with each other, and the water condensed by the condenser 654 is stored in the water storage tank 651.

  The controller 7 controls the pump 652 and the opening / closing valve 653, respectively.

  When the temperature of the lithium ion battery 3 is raised by the temperature raising device 6 having this configuration, the controller 7 supplies power to the electric heater 63 and drives the pump 652 as described above to enter the evaporation tank 650. The water in the water storage tank 651 is supplied. The water supplied into the evaporation tank 650 is heated by the electric heater 63. Since the inside of the evaporation tank 650 is maintained at a predetermined low pressure state, water evaporates in a predetermined temperature range (that is, around 30 ° C.). Thereby, the temperature in the evaporation tank 650 becomes a predetermined temperature range, and the lithium ion battery 3 is heated through the latent heat storage material 62 and the latent heat storage material 62.

  As water evaporates in the evaporation tank 650, the evaporation temperature increases as the pressure in the evaporation tank 650 increases. Therefore, the controller 7 opens and closes the opening / closing valve 653 so that the pressure in the evaporation tank 650 maintains a low pressure state, and discharges the water vapor in the evaporation tank 650. The water vapor discharged from the evaporation tank 650 is condensed by the condenser 654, and the condensed water is stored in the water storage tank 651. Further, the controller 7 appropriately supplies water into the evaporation tank 650 so that the temperature in the evaporation tank 650 becomes a predetermined temperature range.

  Thus, the temperature state in the evaporation tank 650 is maintained in a predetermined temperature range by appropriately adjusting the supply of water to the evaporation tank 650 and the discharge of water vapor from the evaporation tank 650. The water circulation path 65 has a drain passage 655 that discharges excess water in the evaporation tank 650 and returns it to the water storage tank 651.

  In the temperature raising device 6 having this configuration, the electric heater 63 and the latent heat storage material 62 are not in direct contact with each other, so that it is possible to avoid local deterioration of the latent heat storage material 62 due to the contact of the electric heater 63 with each piece. .

  Further, even if the temperature of the electric heater 63 is increased, unlike the temperature raising device 6 shown in FIG. 9, the latent heat storage material 62 does not burn.

  The evaporation tank 650 can move a large amount of heat at a time by boiling condensation type heat transfer. As a result, the temperature of the lithium ion battery 3 can be rapidly increased.

  Moreover, since the temperature of the evaporation tank 650 is substantially constant, even if the temperature is rapidly increased, the latent heat storage material 62 and the battery cell 31 are prevented from being excessively heated.

  Further, when the temperature of the latent heat storage material 62 becomes too high, the cooling unit 68 cools the latent heat storage material 62, thereby preventing the temperature of the lithium ion battery 3 from becoming too high.

  Note that the temperature raising device 6 shown in FIGS. 9 and 10 is not necessarily mounted on an electric vehicle. The temperature raising device 6 shown in FIGS. 9 and 10 may be mounted on HEV or PHEV.

  Further, the secondary battery temperature adjusting device disclosed herein is not limited to application to a four-wheeled vehicle.

1, 10 Vehicle system 3 Lithium ion battery (secondary battery)
31 battery cell 6 temperature rising device (temperature rising means)
61 Heat insulation housing 611 Heat insulation lid 62 Latent heat storage material 63 Electric heater 650 Evaporation tank 670 Cooling water storage tank 68 Cooling part 681 Case 682 Cryogen 7 Controller (temperature control means)

Claims (6)

A secondary battery mounted on the vehicle;
A temperature raising means configured to increase the temperature of the secondary battery;
Temperature control means configured to adjust the temperature of the secondary battery through the temperature raising means, and
The temperature raising means includes a latent heat storage material configured to cover the secondary battery and supply heat to the secondary battery, an electric heater configured to heat the latent heat storage material, and the latent heat A cooling section configured to cool the heat storage material,
The cooling unit cools the latent heat storage material by dissolving the water in the housing provided to transmit heat to the latent heat storage material and the water housed in the housing and supplied to the housing. And a cryogen configured to
When the temperature of the latent heat storage material is lower than a predetermined temperature range, the temperature control means increases the temperature of the secondary battery through the latent heat storage material by energizing the electric heater, and the latent heat storage material. When the temperature of the material exceeds the predetermined temperature range, the vehicle secondary battery temperature adjusting device stops the energization of the electric heater and cools the latent heat storage material by the cooling unit. The secondary battery temperature adjusting device for a vehicle according to claim 1 ,
The temperature control means cools the latent heat storage material, and then energizes the electric heater to evaporate water in the casing and discharge it from the casing, thereby regenerating the cryogen. Secondary battery temperature control device. In the vehicle secondary battery temperature regulating device according to claim 1 or 2 ,
The temperature raising means includes a cooling water storage tank configured to be supplied with cooling water of an engine mounted on the vehicle and to transfer heat to the latent heat storage material,
The electric heater is a secondary battery temperature adjusting device for a vehicle disposed in the cooling water storage tank. In the vehicle secondary battery temperature regulating device according to claim 1 or 2 ,
The electric heater is a secondary battery temperature adjusting device for a vehicle disposed in the latent heat storage material. In the vehicle secondary battery temperature regulating device according to claim 1 or 2 ,
The temperature raising means includes an evaporation tank provided to transfer heat to the latent heat storage material and configured to evaporate the supplied liquid in the predetermined temperature range,
The electric heater is a secondary battery temperature adjustment device for a vehicle disposed in the evaporation tank. In the secondary battery temperature regulating device for vehicles according to any one of claims 1 to 5 ,
The secondary battery has a plurality of battery cells electrically connected to each other,
The latent heat storage material covers a portion of the plurality of battery cells excluding portions electrically connected to each other,
The temperature raising means includes a heat insulating housing that covers the latent heat storage material, and a heat insulating lid that covers the electrically connected portions of the plurality of battery cells together with the heat insulating housing. Battery temperature adjustment device.

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