JP7505176B2 - Battery Temperature Management Device - Google Patents

Description

The present invention relates to a battery temperature management device installed in a vehicle.

As a technology related to the battery temperature management device configured as above, Patent Document 1 describes a battery temperature management device that includes a refrigerant flow path through which the refrigerant circulates, a pump, and a refrigerant heating device that can heat the refrigerant while the internal combustion engine is operating, and in warm-up mode, the refrigerant is heated by the refrigerant heating device to increase the temperature of the battery.

In addition, in Patent Document 1, a radiator, a refrigerant heating device, and a pump are arranged in series in a refrigerant flow path that circulates the refrigerant in the battery, and in warm-up mode, the refrigerant is heated by the refrigerant heating device, and when cooling of the refrigerant is required, the wind generated by the vehicle while it is moving can be supplied to the radiator.

Patent Document 1 also describes how, after the battery temperature reaches a specified temperature by supplying refrigerant in warm-up mode, the pump is rotated in reverse to cause the refrigerant to flow in the opposite direction, thereby suppressing the temperature difference between the multiple cells that make up the battery.

JP 2019-55649 A

When considering a vehicle that is configured to run on battery power, such as the hybrid vehicle described in Patent Document 1, the charge and discharge characteristics of the battery change depending on the temperature, and it is important to manage the battery temperature in order to obtain good charge and discharge characteristics.

Batteries used in hybrid vehicles (HVs), electric vehicles (EVs), plug-in hybrid vehicles (PHVs), etc. are composed of multiple modules, each of which is made up of multiple stacked cells, the smallest unit of the battery. Therefore, when managing the temperature of the battery, it was necessary to supply and discharge refrigerant to each of the multiple modules individually.

In addition, in Patent Document 1, the refrigerant is heated by the refrigerant heating device using heat generated when the internal combustion engine is operating and heat from an electric heater generated by electricity during operation, so the refrigerant temperature cannot be increased when the internal combustion engine is stopped.

For these reasons, there is a demand for a device that can properly control the temperature of a battery.

A characteristic configuration of a battery temperature management device according to the present invention includes a battery including a plurality of modules each having a plurality of cells as one module, the battery supplying current, a plurality of temperature sensors measuring the temperatures of the plurality of cells separately, a heat exchange flow path supplying a heat transfer fluid to the plurality of cells of the plurality of modules as cooling units, and a temperature control unit controlling the temperature of the heat transfer fluid, the heat exchange flow path having a main flow path and a radiator flow path, the main flow path including an electric pump for delivering the heat transfer fluid, and a temperature control unit for controlling the temperature of the heat transfer fluid. a heating section which heats the heat transfer fluid and a chiller section which cools the heat transfer fluid flowing through the heat exchange passage with a refrigerant capable of conditioning the air in the vehicle compartment , the radiator passage is provided with a radiator capable of dissipating heat of the heat transfer fluid that has flowed to the module, and is equipped with a switching valve which switches the flow direction of the heat transfer fluid flowing from the main passage to the module, and the temperature control unit controls the electric pump, the heating section, the chiller section, and the switching valve based on temperature information detected by the multiple temperature sensors.

According to this characteristic configuration, when the temperature of the battery is to be increased based on the temperature information detected by the temperature sensor, the temperature control unit drives the electric pump and increases the temperature of the heat transfer fluid in the heating section, thereby increasing the temperature of the battery. When the temperature of the battery is to be decreased, the temperature control unit drives the electric pump and decreases the temperature of the heat transfer fluid in the chiller section, thereby dissipating heat from the battery. In particular, the heat exchange passage supplies the heat transfer fluid to the multiple cells that constitute the battery module, thereby realizing the adjustment of the temperatures of the multiple cells .

In addition to the above configuration, the heat exchange flow path may include a main flow path in which the electric pump, the chiller unit, and the heating unit are arranged in series, and a temperature control flow path that flows the heat transfer fluid in a predetermined order through the multiple cells that make up the module, and the switching valve may be configured to be freely switched between a forward flow state in which the heat transfer fluid flows in a forward direction through the temperature control flow path, and a reverse flow state in which the heat transfer fluid flows in a direction opposite to the forward direction through the temperature control flow path.

The temperature of the heat transfer fluid is set by the chiller and heating units while the electric pump in the main flow path is driven, and the heat transfer fluid is supplied in a forward flow state (forward direction), making it possible to manage the temperature of multiple cells. Furthermore, if the heat transfer fluid is continuously supplied in a forward flow state, the temperature difference between the upstream and downstream sides of the flow direction of the heat transfer fluid among the multiple cells may increase. If this temperature difference increases, the switching valve can be operated to flow the heat transfer fluid in the reverse direction, making it possible to supply the heat transfer fluid in a reverse flow state and equalize the temperature of the multiple cells that make up the module.

In addition to the above configuration, the temperature control unit may control the switching valve to switch the flow direction of the heat transfer fluid when the difference between the maximum and minimum temperatures detected by the multiple temperature sensors exceeds a preset value.

This makes it possible to reduce the temperature difference between multiple cells by switching the flow direction of the heat transfer fluid based on the temperature difference between the highest and lowest temperature values among the temperature information detected by multiple temperature sensors.

In addition to the above configuration, the temperature control unit may switch the flow direction of the heat transfer fluid when the difference between the maximum and minimum temperatures detected by the multiple temperature sensors that separately detect the temperatures of the multiple cells that make up one module exceeds a preset value.

By controlling the switching valve based on the maximum and minimum temperatures detected by a temperature sensor for the multiple cells that make up a single module, the temperature difference between the multiple cells in a single module is not allowed to increase.

As an additional configuration to any of the above configurations, the temperature control unit may operate the electric pump and heat the heat transfer fluid with the heating section when the temperature information detected by at least one of the multiple temperature sensors is less than the low temperature setting value, and operate the electric pump and cool the heat transfer fluid with the chiller section when the temperature information detected by at least one of the multiple temperature sensors exceeds the high temperature setting value.

According to this, when the temperature information detected by at least one of the multiple temperature sensors is below the low temperature setting value, the heating section heats the heat transfer fluid, and when the temperature information detected by at least one of the multiple temperature sensors exceeds the high temperature setting value, the chiller section dissipates heat from the heat transfer fluid, making it possible to maintain all of the cells that make up the battery in a temperature range from below the high temperature setting value to above the low temperature setting value.

FIG. 2 is a diagram showing a schematic diagram of a heat exchange passage etc. of a temperature management device. FIG. 2 is a block circuit diagram of a temperature control unit. FIG. 2 is a diagram showing the forward flow of heat transfer fluid in a battery module. FIG. 2 is a diagram showing the reverse flow of heat transfer fluid in a battery module. 4 is a flowchart showing a control mode of a temperature control unit. FIG. 13 is a diagram showing a schematic diagram of a temperature control device according to another embodiment (a). FIG. 13 is a diagram showing a schematic diagram of a temperature control device according to another embodiment (a). FIG. 11 is a diagram showing the forward flow of heat transfer fluid in a battery module of another embodiment (b). FIG. 11 is a diagram showing the flow of heat transfer fluid in the reverse direction in a battery module of another embodiment (b). 13 is a flowchart showing a control mode of a temperature control unit of another embodiment (c). FIG. 13 is a diagram showing a temperature control flow path in a module of another embodiment (d). FIG. 13 is a diagram showing a temperature control flow path in a module of another embodiment (e).

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
〔overall structure〕
Fig. 1 shows a heat exchange passage 10 of a battery temperature management device C (hereinafter referred to as temperature management device C) that manages the temperature of a battery B that supplies current to an electric traction motor 1 in a hybrid vehicle. Fig. 2 shows a temperature control unit 8 of the temperature management device C.

A hybrid vehicle is configured to be able to run using at least one of the driving forces of a running engine (not shown) and a running motor 1, and when obtaining driving force from the running motor 1, the current of the battery B is supplied to the running motor 1 via the inverter 2. The running motor 1 also functions as a generator, and for example, when the vehicle's running speed is reduced or the vehicle is going downhill, regenerative braking is performed, and the kinetic energy of the vehicle is converted into current by the running motor 1, and this current is charged to the battery B.

The charging and discharging performance of battery B changes depending on the temperature, so when battery B is at a temperature that is not suitable for charging or discharging, temperature management device C either increases or decreases the temperature of the heat transfer fluid, thereby maintaining the temperature of battery B at a temperature suitable for charging and discharging.

[Temperature control device: heat exchange channel]
As shown in Fig. 1, the heat exchange flow path of the temperature management device C includes a temperature control heat exchange flow path 10 that supplies a heat transfer fluid using cooling water to the battery B, and a refrigerant flow path 20 that supplies air conditioner refrigerant to a heat exchanger 23 for air conditioning of the vehicle body and a chiller section 12. The figure also shows a temperature control flow path 30 that supplies a heat transfer fluid using water that enables cooling of the travel motor 1 and the inverter 2 that controls the current supplied to the travel motor 1. The temperature control flow path 30 can also be used to warm up the battery B using heat obtained from the travel motor 1 and the inverter 2.

The heat exchange flow path 10 includes a main flow path 10a, a temperature control flow path 10b, a radiator flow path 10c, and a bypass flow path 10d. Since the heat exchange flow path 10 and the temperature control flow path 30 are formed as independent flow paths, the heat transfer fluids in the respective flow paths do not mix with each other.

In the main flow path 10a, a temperature control pump 11 (an example of an electric pump), a chiller section 12, and a heating section 13 consisting of an electric heater are arranged in series. The temperature control flow path 10b is configured to supply the heat transfer fluid supplied from the main flow path 10a to multiple cells 6 of the battery B (see the temperature control flow paths in Figures 3 and 4), and is configured to be able to switch the flow direction of the heat transfer fluid by including a switching valve 14 consisting of an electrically operated four-way valve. This switching valve 14 is arranged at the boundary between the main flow path 10a and the temperature control flow path 10b.

The chiller section 12 functions as an evaporator to which refrigerant is supplied from the refrigerant flow path 20, and dissipates heat from the heat transfer fluid. The heating section 13 is configured as an electric heater having a heating element that generates heat when an electric current is supplied, and heats the heat transfer fluid by generating heat.

In particular, the flow direction of the heat transfer fluid supplied to battery B is switched by controlling the switching valve 14, thereby reducing the temperature difference between the multiple cells 6 that make up battery B (the control method will be described later).

The three-way valve 15 is configured to be able to select between a state in which the heat transfer fluid from the temperature control flow path 10b is supplied to the first radiator 16 via the radiator flow path 10c, and a state in which the heat transfer fluid from the temperature control flow path 10b is flowed to the bypass flow path 10d.

As a result, by controlling the three-way valve 15, the heat transfer fluid in the temperature control flow path 10b can be supplied to the first radiator 16 via the radiator flow path 10c to dissipate heat, and the heat transfer fluid after heat dissipation can be returned to the temperature control pump 11. In addition, by controlling the three-way valve 15, the heat transfer fluid in the temperature control flow path 10b can also be returned to the temperature control pump 11 via the bypass flow path 10d.

The refrigerant flow path 20 includes an electric compressor 21 that compresses the refrigerant, a condenser 22 that dissipates heat from the compressed refrigerant, a heat exchanger 23 that functions as an evaporator that conditions the air inside the vehicle, and an electromagnetic on-off valve 24 that allows the supply and cut-off of refrigerant to the chiller section 12, and an expansion valve 25 upstream of the heat exchanger 23.

In the refrigerant flow path 20, the refrigerant sent from the compressor 21 is supplied to the heat exchanger 23 via the condenser 22, enabling air conditioning in the vehicle cabin, and the opening/closing valve 24 is opened to supply the refrigerant to the chiller section 12, enabling the heat transfer fluid in the main flow path 10a to dissipate heat (cool).

The temperature control flow path 30 includes an electric heat dissipation pump 31 that supplies a heat transfer fluid using water to the inverter 2 and the traction motor 1 described above, and a second radiator 32 that dissipates heat from the heat transfer fluid.

In this temperature control flow path 30, the heat transfer fluid is circulated through the temperature control flow path 30 by driving the heat dissipation pump 31, thereby enabling heat dissipation between the inverter 2 and the traction motor 1. Note that the control of supplying the heat transfer fluid to this temperature control flow path 30 is not directly related to the temperature management of the battery B, and is not included in the configuration of the battery temperature management device C.

〔battery〕
3 and 4, the battery B has a plurality of modules 5, each of which includes a plurality of cells 6 arranged in a modularized form, and has a temperature control flow path 10b that supplies a heat transfer fluid individually to the plurality of modules 5. In this configuration, each of the plurality of modules 5 serves as a cooling unit.

A module 5 is a modularization of many cells 6, but Figures 3 and 4 show five cells 6 for one module 5, and in order to make it possible to identify the five cells 6, the cells 6 are numbered (1) to (5) in the stacking direction in the figures. In addition, the number of modules 5 is not limited to four, but Figure 4 shows four modules 5. Furthermore, the number of cells 5 is not limited to five, but Figure 4 shows five cells 5.

Although not shown in the drawings, the module 5 is housed in a casing, and a temperature control flow path 10b is formed in this casing so that a heat transfer fluid flows along the stacking direction of the multiple cells 6. This temperature control flow path 10b is connected to both ends of the casing in the stacking direction of the cells 6 (both upper and lower ends in Figures 3 and 4).

[Temperature control device: control configuration]
The temperature management device C includes a temperature control unit 8 shown in Fig. 2. This temperature control unit 8 receives detection information from temperature sensors 7 that individually detect the temperatures of the multiple cells 6, and outputs control information to a temperature control pump 11, an on-off valve 24, a heating section 13, a switching valve 14, a three-way valve 15, a compressor 21, and a heat dissipation pump 31. The temperature control unit 8 includes software that executes temperature management control shown as a flowchart in Fig. 5.

As shown in the flowchart of FIG. 5, when battery B is not being charged or discharged, there is no need to manage the temperature of battery B, so the temperature control pump 11 is stopped and the control returns (No in #101, step #102). Note that in step #102, if the temperature control pump 11 is already stopped, it remains stopped.

In response to this, if it is determined that battery B is being charged or discharged (Yes in step #101), and the detection results of the multiple temperature sensors 7 indicate that the temperature information from at least one of the temperature sensors 7 is below 0°C (an example of a low temperature setting) (Yes in step #103), the temperature control pump 11 is operated and a current is supplied to the heating unit 13 to increase the temperature of the heat transfer fluid (steps #103 to #105). When attempting to increase the temperature of the heat transfer fluid using the heating unit 13 in this manner, the on-off valve 24 is kept closed.

In addition, if it is determined that battery B is being charged or discharged (Yes in step #101), the temperature information of any one of the temperature sensors 7 is not below 0°C (No in step #103), and it is determined from the detection results of the multiple temperature sensors 7 that the temperature information of any one of the temperature sensors 7 exceeds 40°C (an example of a high temperature setting value) (Yes in step #106), the temperature control pump 11 is operated, the compressor 21 is operated, and the opening/closing valve 24 is opened to remove heat from the heat transfer fluid in the chiller section 12 and lower the temperature of the heat transfer fluid (steps #106 to #108). Note that when the temperature of the heat transfer fluid is lowered in the chiller section 12 in this way, the state in which the supply of current to the heating section 13 is cut off is maintained.

If it is determined in step #106 that the temperature information from all of the detection results of the temperature sensor 7 does not exceed 40°C (No in step #106), this control is returned. This allows the temperature of battery B to be maintained at an appropriate level even when battery B is being charged or discharged.

Furthermore, after the heat transfer fluid has been heated and released, the temperature difference between the temperature information of the most upstream cell 6 (cell 6 (1) in Figures 3 and 4) to which the heat transfer fluid is supplied and the temperature information of the most downstream cell 6 (cell 6 (5) in Figures 3 and 4) among the multiple temperature sensors 7 constituting one of the multiple modules 5 of battery B is obtained (step #109). This temperature difference is obtained for all of the multiple modules 5, and temperature difference information is obtained for each module 5.

In other words, if the direction of flow of the heat transfer fluid is determined as the forward flow state as shown in FIG. 3 and the direction of flow of the heat transfer fluid is determined as the reverse flow state as shown in FIG. 4, in step #109 when it is determined that the temperature information of even one of the temperature sensors 7 is less than 0°C (Yes in step #103), if the heat transfer fluid flows in the forward flow state, the temperature information of the most upstream cell 6 (cell 6 (1) in FIG. 3 and FIG. 4) will be the maximum temperature value, and the temperature information of the most downstream cell 6 (cell 6 (5) in FIG. 3 and FIG. 4) will be the minimum temperature value, and the temperature difference will be the absolute value of the difference between the maximum temperature value and the minimum temperature value. For this reason, if the absolute value of even one of the acquired multiple temperature differences is greater than 2°C (an example of a set value) (Yes in step #110), the flow direction of the heat transfer fluid is switched (reversed) to the reverse flow state by controlling the switching valve 14 (steps #110 and #111), and this control is returned. Also. If the absolute value of the temperature difference is less than 2°C in #110 (No in step #110), the flow direction of the heat transfer fluid is not changed (the flow direction is maintained) and the control returns.

In other words, in the control of steps #110 and #111, for example, in a situation where the heating unit 13 is attempting to increase the temperature of the heat transfer fluid, if the heat transfer fluid flows through the multiple cells 6 of the multiple modules 5 shown in FIG. 3 in the order (forward flow state) of each of the cells 6 (1) to (5) shown in the same figure, the temperature of the most downstream cell 6 (cell 6 (5) in the same figure) will be lower than the temperature of the most upstream cell 6 (cell 6 (1) in the same figure), causing the performance of the multiple cells 6 to become uneven, which may result in a deterioration of the charge/discharge characteristics of battery B.

For this reason, when the absolute value of the temperature difference with the information exceeds 2°C, the flow direction of the heat transfer fluid is reversed as shown in Figure 4, and the heat transfer fluid is made to flow in the order (5) to (1) (reverse flow state) for the multiple cells 6 of the multiple modules 5. This prevents the temperature difference between the cells 6 from increasing, eliminates the inconvenience of uneven performance of the cells 6, and maintains the charge and discharge characteristics of battery B in good condition.

Although not shown in the flowchart, the inverter 2 and the driving motor 1 are equipped with sensors that measure temperature. When the temperature detected by the sensors rises, the heat dissipation pump 31 is driven and the heat transfer fluid is cooled by the second radiator 32, thereby suppressing the temperature rise of the inverter 2 and the driving motor 1 and maintaining them at an appropriate temperature.

[Additional explanation of control mode]
5, the temperature control is performed by setting 0°C as the low temperature setting value and 40°C as the high temperature setting value, but the minimum temperature value and the maximum temperature value are not limited to the values shown in the flowchart and may be values different from those shown in the flowchart. Also, in #103 and #106, the control is determined based on the temperature information of any one of the multiple temperature sensors 7, but the control form may be set so that the control is performed, for example, when the temperature information (e.g., average value) detected by the multiple temperature sensors 7 is less than the above-mentioned maximum temperature value or when the temperature information (e.g., average value) detected by the multiple temperature sensors 7 exceeds the maximum temperature value.

In addition, in step #109, the maximum and minimum temperature values were obtained for each of the multiple modules 5. Alternatively, it is also possible to obtain the maximum and minimum temperature values from the detection results of all temperature sensors 7, obtain the temperature difference of the cells 6 from this, and set the control form to switch the flow direction.

The flowchart does not explain how the temperature control pump 11 sets the flow rate of the heat transfer fluid, or how the current value supplied to the heating unit 13 is set when attempting to increase the temperature of the heat transfer fluid, but it is also possible to configure the system so that, for example, the drive speed of the temperature control pump 11 is set based on the deviation between a target value and the value detected by the sensor, and the current value supplied to the heating unit 13 is set.

[Effects of the embodiment]
In this way, the temperature management device C (an example of a battery temperature management device C) is configured to include the heat exchange flow path 10, the refrigerant flow path 20, and the temperature control unit 8, so that if any one of the multiple cells 6 constituting the battery B drops below 0° C., a current is supplied to the heating unit 13 to raise the temperature of the heat transfer fluid, thereby raising the temperatures of all the cells 6 to an appropriate temperature and suppressing a performance degradation of the battery B. Also, if any one of the multiple cells 6 constituting the battery B exceeds 40° C., a refrigerant is supplied to the chiller unit 12 to lower the temperature of the heat transfer fluid, thereby lowering the temperatures of all the cells 6 to an appropriate temperature and suppressing a performance degradation of the battery B.

In addition, in this control, since the heating unit 13 is configured as an electric heater, it is possible to increase the temperature of the cell 6 even when the engine is not running, compared to, for example, a system that uses exhaust heat from an engine to raise the temperature. Moreover, since the chiller unit 12 is supplied with refrigerant from the electric compressor 21, it is possible to reduce the temperature even when the engine is not running, compared to, for example, a system that sends refrigerant using a compressor driven by the engine. In particular, it is possible to reduce the temperature more reliably, compared to a system that dissipates heat by supplying outside air.

This control in the main flow path 10a sets the temperature of the heat transfer fluid, and heating and dissipation are performed based on the highest and lowest temperature information of all cells 6, so the temperatures of all cells 6 are maintained within an appropriate range.

In particular, as shown in Figures 3 and 4, even if a temperature difference occurs between the most upstream cell 6 and the most downstream cell 6 in each module 5 due to the configuration in which the heat transfer fluid flows in the direction in which the multiple cells 6 are stacked in each of the multiple modules 5 that make up battery B, the temperature difference between the multiple cells 6 is reduced by reversing the flow direction of the heat transfer fluid, and the performance of each cell 6 is maintained at a high level.

When controlling the change in the flow direction of the heat transfer fluid in this manner, if the absolute value of the temperature difference between the cells 6 constituting any one of the multiple modules 5 exceeds 2°C, the flow direction of the heat transfer fluid is changed to the opposite direction, thereby reducing the temperature difference between the multiple cells 6 constituting all of the modules 5 (equal to all of the cells 6 of battery B).

In addition, this temperature control device C can also maintain the inverter 2 and the traction motor 1 at appropriate temperatures.

[Another embodiment]
The present invention may be configured as follows in addition to the above-described embodiment (common numbers and symbols as in the embodiment are used to designate components having the same functions as in the embodiment).

(a) As shown in FIG. 6, the heat exchange flow path 10 is configured so that the heat transfer fluid can be radiated and heated in the main flow path 10a in which the temperature control pump 11, the chiller section 12, and the heating section 13 consisting of an electric heater are arranged in series, and a switching valve 14 is provided to switch the flow direction of the heat transfer fluid supplied from the main flow path 10a to the temperature control flow path 10b. In this alternative embodiment (a), a composite radiator 33 is provided instead of the first radiator 16 and the second radiator 32 described in the embodiment, and the heat transfer fluid of the heat exchange flow path 10 and the heat transfer fluid of the temperature control flow path 30 are used in common.

In other words, in this alternative embodiment (a), the heat exchange flow path 10 includes a main flow path 10a having a configuration common to the above-mentioned embodiment, a temperature control flow path 10b having a switching valve 14, and a bypass flow path 10d. Also, the refrigerant flow path 20 includes a compressor 21, a condenser 22, a heat exchanger 23, and an on-off valve 24 having a configuration common to the above-mentioned embodiment.

In contrast, the temperature control flow path 30 has a flow path structure common to the embodiment for supplying the inverter 2 and the driving motor 1 with the heat transfer fluid, but has a heat dissipation pump 31 in a different position from the above embodiment, and has a flow path switching valve 34 consisting of an electrically operated four-way valve for controlling the flow of fluid between the heat exchange flow path 10 and the temperature control flow path 30. The temperature control flow path 30 has a composite radiator 33 for dissipating heat from the heat transfer fluid, and has a flow path control valve 36 consisting of a three-way valve and a heat dissipation bypass flow path 35 for returning the heat transfer fluid flowing in the temperature control flow path 30 without flowing it to the composite radiator 33.

In accordance with this configuration, in the temperature management device C of another embodiment (a) (one example of a battery temperature management device), when the flow path switching valve 34 is set to the position shown in FIG. 6, the heat transfer fluid is circulated through the main flow path 10a, the temperature control flow path 10b, and the bypass flow path 10d of the heat exchange flow path 10 by driving the temperature control pump 11, making it possible to control the temperature of the heat transfer fluid in the chiller section 12 and the heating section 13. Furthermore, when performing temperature management of the battery B in this manner, the flow direction of the heat transfer fluid can also be switched by controlling the switching valve 14.

In contrast, when the flow path switching valve 34 is set to the position shown in FIG. 7, the heat dissipation pump 31 is driven to supply the heat transfer fluid sent to the inverter 2 and the traction motor 1 to the combined radiator 33, enabling heat dissipation. Also, when the heat dissipation pump 31 is driven in this manner, the flow path control valve 36 can be controlled to flow the heat transfer fluid in the temperature control flow path 30 into the heat dissipation bypass flow path 35, thereby suppressing excessive heat dissipation.

In particular, in this alternative embodiment (a), by driving the temperature control pump 11 and the heat dissipation pump 31 simultaneously or independently with the flow path switching valve 34 set to the position shown in FIG. 7, it becomes possible to circulate the heat transfer fluid that has flowed through the heat exchange flow path 10 by sending it to the temperature control flow path 30 via the flow path switching valve 34 and returning it to the heat dissipation pump 31 via the composite radiator 33 or the heat dissipation bypass flow path 35.

By configuring the heat transfer fluid to circulate in this way, not only is it possible to dissipate heat using a single composite radiator 33, but the flow path is simplified, allowing the device to be made more compact.

(b) As shown in Figures 8 and 9, the temperature control flow paths 10b formed in the multiple modules 5 of battery B are configured with a vertical flow path 10y for flowing heat transfer fluid in the direction in which the cells 6 are stacked in each of the multiple cells 6, and a branch flow path 10x branching from the center of this vertical flow path 10y. In this configuration, the same number of branch flow paths 10x as the number of multiple modules 5 are formed, but a single branch flow path 10x is shown so that the heat transfer fluid flowing in these branch flow paths 10x is merged and flows.

Although the module 5 is made up of a large number of stacked cells 6, Figures 8 and 9 show one module 5 having five cells 6, and in order to make it possible to identify the five cells 6, the figures are labeled (1) to (5) along the stacking direction. Therefore, in this alternative embodiment (b), the branch flow path 10x branches off from the vertical flow path 10y at the position of the cell 6 labeled (3).

In this alternative embodiment (b), when heat transfer fluid is supplied to the vertical flow passage 10y from both ends of the stacking direction of the cells 6 as shown in FIG. 8, the heat transfer fluid is sent out from the branch flow passage 10x. In contrast, when heat transfer fluid is supplied from the branch flow passage 10x as shown in FIG. 9, the heat transfer fluid supplied from this branch flow passage 10x flows through the vertical flow passage 10y toward both ends of the stacking direction of the cells 6.

In this way, in another embodiment (b), by switching between a state in which a heat transfer fluid is supplied as shown in FIG. 8 and a state in which a heat transfer fluid is supplied as shown in FIG. 9, it is possible to reduce the temperature difference between the cells 6 at both ends and the cell 6 in the center.

(c) In a vehicle equipped with a battery B having a flow path formed as in the above-mentioned alternative embodiment (b), it is possible to set the control mode of the temperature management device C as shown in the flowchart of FIG. 10. Also, this alternative embodiment (c) describes the control mode of the temperature management device C having the configuration shown in FIG. 1 of the embodiment.

In other words, as shown in the flowchart of FIG. 10, when battery B is not being charged or discharged, there is no need to adjust the temperature of battery B, so the temperature control pump 11 is stopped and the control returns (No in #201, step #202). Note that in step #202, if the temperature control pump 11 is already stopped, it remains stopped.

In response to this, if it is determined that battery B is being charged or discharged (Yes in step #201), and the detection results of the multiple temperature sensors 7 indicate that the temperature information from at least one of the temperature sensors 7 is below 0°C (an example of a low temperature setting) (Yes in step #203), the temperature control pump 11 is operated and a current is supplied to the heating unit 13 to increase the temperature of the heat transfer fluid (steps #203 to #205). When attempting to increase the temperature of the heat transfer fluid using the heating unit 13 in this manner, the on-off valve 24 is kept closed.

In addition, if it is determined that battery B is being charged or discharged (Yes in step #201), the temperature information of any one of the temperature sensors 7 is not below 0°C (No in step #203), and it is determined from the detection results of the multiple temperature sensors 7 that the temperature information of any one of the temperature sensors 7 exceeds 40°C (an example of a high temperature setting value) (Yes in step #206), the temperature control pump 11 is operated, the compressor 21 is operated, and the opening/closing valve 24 is opened to remove heat from the heat transfer fluid in the chiller section 12 and lower the temperature of the heat transfer fluid (steps #206 to #208). Note that when the temperature of the heat transfer fluid is lowered in the chiller section 12 in this way, the state in which the supply of current to the heating section 13 is cut off is maintained.

If it is determined in step #206 that the temperature information from all of the temperature sensors 7 does not exceed 40°C (No in step #206), the temperature information from all of the temperature sensors 7 is acquired, and the inter-cell temperature difference between the cells 6 at the start and end where the heat transfer fluid flows is acquired individually. If the acquired inter-cell temperature difference (strictly speaking, the absolute value of the temperature difference) exceeds 2°C (an example of a set value), the temperature control pump 11 is operated but no heating or heat dissipation is performed (steps #209 and #210).

In other words, in FIG. 8, the starting (most upstream) cell 6 is cell 6 (1) and (5), and the end (most downstream) cell 6 is cell 6 (3). Also, in FIG. 9, the starting (most upstream) cell 6 is cell 6 (3), and the end (most downstream) cell 6 is cell 6 (1) and (5) in FIG. 8. In particular, when acquiring the inter-cell temperature difference, it is not necessary to acquire it on a module basis, and the temperature difference between the starting cell 6 and the end cell 6 of battery B may be acquired as the inter-cell temperature difference.

In particular, in the flowchart of FIG. 10, after step #209, the temperature control pump 11 may be operated and the control mode may be set to heat or dissipate heat from the heat transfer fluid so as to reduce the temperature difference between the cells.

If the inter-cell temperature difference does not exceed 2°C in step #209 (No in step #209), this control is returned. This allows the temperature of battery B to be maintained at an appropriate level even when battery B is being charged or discharged.

After the heat transfer fluid has been heated and released, the temperature difference between the temperature information of the most upstream cell 6 (cell 6 (1) and (5) in FIG. 8, cell 6 (3) in FIG. 9) to which the heat transfer fluid is supplied and the temperature information of the most downstream cell 6 (cell 6 (3) in FIG. 8, cell 6 (1) and (5) in FIG. 9) among the multiple temperature sensors 7 constituting one of the multiple modules 5 of battery B is obtained (step #211). This temperature difference is obtained for all of the multiple modules 5, and temperature difference information is obtained for each module 5.

If the absolute value of any one of the acquired temperature differences is greater than 2°C (Yes in step #212), the flow direction of the heat transfer fluid is switched (reversed) by controlling the switching valve 14 (steps #212 and #213), and the control returns. Also, if the absolute value of the temperature difference in #110 is less than 2°C (No in step #212), the flow direction of the heat transfer fluid is not changed (the flow direction is maintained), and the control returns.

In the control of this alternative embodiment (c), the temperature value when performing temperature adjustment control is not limited to the value shown in the flowchart, and may be a different value. Also, in #203 and #206, control was determined based on one piece of temperature information from temperature sensor 7, but the control form may be set to perform control, for example, when the temperature information (e.g., average value) detected by multiple temperature sensors 7 is less than the maximum temperature value described above, or when the temperature information (e.g., average value) detected by multiple temperature sensors 7 exceeds the maximum temperature value.

The flowchart shown in FIG. 10 does not explain how the temperature control pump 11 sets the flow rate of the heat transfer fluid, or how the current value supplied to the heating unit 13 is set when attempting to increase the temperature of the heat transfer fluid. However, it is also possible to configure the system so that, for example, the drive speed of the temperature control pump 11 is set based on the deviation between a target value and a value detected by a sensor, and the current value supplied to the heating unit 13 is set.

(d) The main flow path 10a shown in Figure 11 is a modified example of the temperature control flow path shown in Figures 3 and 4 of the embodiment, and the temperature control flow path 10b is configured so that the heat transfer fluid supplied from outside the battery B flows an equal distance before being discharged from the battery B, regardless of which of the multiple modules 5 it is supplied to.

In this alternative embodiment (d), similar to the embodiment, a temperature control pump 11 (an example of an electric pump), a chiller section 12, and a heating section 13 consisting of an electric heater are arranged in series in the main flow path 10a, and a switching valve 14 is provided that switches the flow direction of the heat transfer fluid and supplies it to the temperature control flow path 10b of battery B. Note that in the temperature control flow path shown in FIG. 11, the flow direction of the heat transfer fluid can also be switched to a reverse flow state by controlling the switching valve 14.

By configuring the temperature control flow path 10b as shown in FIG. 11, the flow path resistance acting on the heat transfer fluid flowing through each of the multiple modules 5 is equalized regardless of the direction of flow of the heat transfer fluid set by the control of the switching valve 14, which results in the amount of heat transfer fluid flowing through the multiple modules 5 being made uniform, making it possible to uniformize the temperature in the multiple modules 5.

(e) The main flow path 10a shown in FIG. 12 is a modified example of the temperature control flow path shown in FIG. 8 and FIG. 9 of another embodiment (b), and is configured to equalize the pressure acting on both ends in the stacking direction in each of the multiple modules 5 when the heat transfer fluid supplied from outside the battery B flows through the vertical flow path 10y.

In this alternative embodiment (e), similar to alternative embodiment (b), a temperature control pump 11 (an example of an electric pump), a chiller section 12, and a heating section 13 consisting of an electric heater are arranged in series in the main flow path 10a, and a switching valve 14 is provided that switches the flow direction of the heat transfer fluid to supply it to the temperature control flow path 10b of battery B. Note that in the temperature control flow path shown in FIG. 12, the switching valve 14 can be controlled to switch the direction of the heat transfer fluid from the vertical flow path 10y to the branch flow path 10x, or vice versa.

By configuring the temperature control flow path 10b as shown in FIG. 12, the switching valve 14 is controlled as shown in the figure, and when the heat transfer fluid flows from the vertical flow path 10y to the branch flow path 10x, the pressure acting on both ends of the multiple modules 5 can be made uniform. In addition, when the heat transfer fluid flows from the branch flow path 10x to the vertical flow path 10y by controlling the switching valve 14, the flow path resistance acting on the vertical flow path 10y of the multiple modules 5 can be made uniform. As a result, it is possible to suppress the variation in the flow rate of the heat transfer fluid flowing through each of the multiple modules 5.

(f) In order to enable switching of the flow direction of the heat transfer fluid to battery B, instead of the single switching valve 14 consisting of a four-way valve described in the embodiment, for example, a combination of multiple on-off valves or three-way valves, etc., is configured to enable switching of the flow direction of the heat transfer fluid by selectively controlling these.

(g) For example, in order to enable temperature management of battery B even in a situation where battery B is not being charged or discharged, the control form may be set so that control by the temperature control unit 8 is performed in a situation where the temperature-managed battery B is not being charged or discharged, for example, at a timing such as when the vehicle's main switch is turned ON.

By setting the control mode as in this alternative embodiment (g), for example, when the vehicle starts to move, it is possible to instantly supply the required current to the driving motor 1 without degrading the driving performance.

This invention can be used in battery temperature management devices installed in vehicles.

1 Travel motor 5 Module 6 Cell 7 Temperature sensor 8 Temperature control unit 10 Heat exchange flow path 10a Main flow path 10b Temperature control flow path 11 Temperature control pump (electric pump)
12 Chiller section 13 Heater section 14 Switching valve B Battery C Temperature management device (battery temperature management device)

Claims (8)

a battery including a plurality of modules each having a plurality of cells as one module, the battery supplying a current;
A plurality of temperature sensors for measuring the temperatures of the plurality of cells respectively;
a heat exchange passage for supplying a heat transfer fluid to a plurality of cells of the plurality of modules as cooling units;
A temperature control unit for controlling the temperature of the heat transfer fluid,
The heat exchange passage includes a main passage and a radiator passage,
an electric pump that pumps out the heat transfer fluid, a heating unit that heats the heat transfer fluid flowing through the heat exchange flow path, and a chiller unit that cools the heat transfer fluid flowing through the heat exchange flow path with a refrigerant capable of air conditioning a vehicle interior ,
The radiator flow path includes a radiator that is capable of radiating heat of the heat transfer fluid that has flowed through the module.
a switching valve that switches a flow direction of the heat transfer fluid flowing from the main flow path to the module ,
The temperature control unit is a battery temperature management device that controls the electric pump, the heating section, the chiller section, and the switching valve based on temperature information detected by the multiple temperature sensors. The heat exchange passage further includes a temperature control passage through which the heat transfer fluid flows in the module,
the temperature control flow path connects a plurality of the modules in parallel,
2. The battery temperature management device according to claim 1, wherein the switching valve is configured to be freely switched between a forward flow state in which the heat transfer fluid flows in a forward direction relative to the temperature control flow path, and a reverse flow state in which the heat transfer fluid flows in a direction opposite to the forward direction relative to the temperature control flow path. 3. The battery temperature management device according to claim 2, wherein the temperature control flow path is composed of a vertical flow path through which the heat transfer fluid flows in a stacking direction of the plurality of cells, and a branch flow path branching off from a center of the vertical flow path . The heat exchange passage further includes a bypass passage connected to a position for returning the heat transfer fluid to the electric pump,
4. The battery temperature management device according to claim 2, further comprising a three-way valve that selectively directs the heat transfer fluid flowing in the temperature adjustment flow path to either the bypass flow path or the radiator flow path . The battery temperature management device according to any one of claims 1 to 4, further comprising a condenser that dissipates heat from the refrigerant, and the chiller section is supplied with the refrigerant discharged from the condenser . The battery temperature management device according to any one of claims 1 to 5, wherein the temperature control unit controls the switching valve to switch the flow direction of the heat transfer fluid when a difference between a maximum temperature value and a minimum temperature value among the temperatures detected by the plurality of temperature sensors exceeds a preset value. The battery temperature management device according to any one of claims 1 to 5, wherein the temperature control unit switches the flow direction of the heat transfer fluid when a difference between a maximum temperature value and a minimum temperature value among temperatures detected by a plurality of temperature sensors that separately detect the temperatures of a plurality of cells that constitute one module exceeds a preset value. The battery temperature management device according to any one of claims 1 to 7, wherein the temperature control unit operates the electric pump and heats the heat transfer fluid in the heating section when temperature information detected by at least one of the plurality of temperature sensors is less than a low temperature setting value, and operates the electric pump and cools the heat transfer fluid in the chiller section when temperature information detected by at least one of the plurality of temperature sensors exceeds a high temperature setting value.

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