Cooling control device, vehicle, cooling control method, and cooling control program

Abstract

To provide a cooling control device that can reduce the amount of energy used in controlling the temperature of the cooling water to maintain a constant temperature. [Solution] The cooling control device comprises a specification unit and a control unit. The specification unit identifies the amount of waste heat from the heat source into the cooling water flowing through the passage based on the operating status of the heat source mounted on the vehicle. The control unit controls at least one of the rotation speed of the fan that blows air to the radiator and the flow rate of the cooling water to the radiator in the passage based on the amount of waste heat identified by the specification unit.

Description

Technical Field

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[0001] The present invention relates to a cooling control device, a vehicle, a cooling control method, and a cooling control program.

Background Art

[0002] In vehicles such as electric vehicles, motors, batteries, etc. are mounted as heat sources that generate heat. A vehicle equipped with a heat source has a flow path through which the heat source and a radiator pass, and by driving a pump, cooling water circulates through the flow path. The heat generated by the heat source is dissipated as waste heat to the cooling water flowing through the flow path. Then, the cooling water from which heat has been dissipated from the heat source flows in the flow path toward the radiator. Further, in the radiator, the cooling water is cooled by the blowing air from the fan, and heat is radiated from the cooling water. And in the flow path, the cooling water cooled (radiated) in the radiator flows toward the heat source (see Patent Document 1).

[0003] In a vehicle equipped with a heat source and a radiator as described above, for example, control to keep the temperature of the cooling water flowing through the flow path constant over time, such as keeping the temperature of the cooling water constant over time at the outflow portion from the heat source, is performed by a cooling control device mounted on the vehicle. In the control to keep the temperature of the cooling water constant, the cooling control device controls, for example, the rotational speed of the fan that blows air to the radiator and the flow rate of the cooling water to the radiator in the flow path based on the temporal change in the temperature of the cooling water, thereby performing feedback control on the temperature of the cooling water.

Prior Art Documents

Patent Documents

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In vehicles equipped with heat sources and radiators, there is a need to reduce the amount of energy used in controlling the coolant temperature to maintain a constant temperature. Specifically, in controlling the coolant temperature to maintain a constant temperature, it is necessary to reduce the energy consumed by rotating the fan and the energy consumed by the pump that circulates the coolant.

[0006] The problem that this invention aims to solve is to provide a cooling control device, a vehicle, a cooling control method, and a cooling control program that can reduce the amount of energy used in controlling the temperature of the cooling water to maintain a constant temperature. [Means for solving the problem]

[0007] In one aspect of the present invention, the cooling control device comprises a specification unit and a control unit, the specification unit determines the amount of waste heat from the heat source to the cooling water flowing through the flow path based on the operating status of the heat source mounted on the vehicle. The control unit controls at least one of the rotational speed of a fan that blows air to the radiator and the flow rate of cooling water to the radiator through the flow path, based on the amount of waste heat determined by the specification unit. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a cooling control device, a vehicle, a cooling control method, and a cooling control program that can reduce the amount of energy used in controlling the temperature of the cooling water to maintain a constant temperature. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an example of a vehicle according to the embodiment. [Figure 2] This flowchart schematically shows an example of a process related to the cooling of a heat source, which is performed by the processing execution unit of the cooling control device in this embodiment. [Figure 3] This flowchart provides a schematic example of a process for determining the amount of waste heat based on the operating status of a heat source. [Figure 4] This flowchart provides a schematic example of a process for determining the amount of waste heat based on the operating status of a heat source. [Figure 5] This flowchart provides a schematic example of a process for determining the amount of waste heat based on the operating status of a heat source. [Figure 6] This flowchart schematically illustrates an example of control based on the identified amount of waste heat. [Figure 7] This flowchart schematically illustrates an example of control based on the time change of cooling water temperature. [Figure 8] This block diagram schematically illustrates an example of a process related to the cooling of a heat source, which is performed by the processing execution unit of the cooling control device in this embodiment, using functional blocks. [Figure 9] This schematic diagram shows an example of the time variation of the cooling water temperature and the amount of energy used for control, under conditions where the cooling water temperature is kept constant in the comparative example. [Figure 10] This schematic diagram shows an example of the time variation of the cooling water temperature and the amount of energy used for control, in an embodiment where the cooling water temperature is kept constant. [Modes for carrying out the invention]

[0010] The embodiments will be described below with reference to the drawings.

[0011] Figure 1 is a schematic diagram showing an example of a vehicle 1 according to an embodiment. Vehicle 1 is, for example, an electric vehicle. As shown in Figure 1, vehicle 1 is equipped with a motor 2 and a battery 3. Both the motor 2 and the battery 3 are heat sources that generate heat when in operation. In vehicle 1, the motor 2 is driven by the input of current to the motor 2, which generates the driving force that moves vehicle 1.

[0012] In vehicle 1, for example, motor 2 is driven by power discharged from battery 3 being supplied to motor 2. In this case, the power from battery 3 is appropriately converted to power corresponding to motor 2 by DC / DC conversion or DC / AC conversion, etc., and supplied to motor 2. In another example, motor 2 also functions as a regenerative brake, and battery 3 is charged by the power generated by motor 2. In this case, the power from motor 2 is appropriately converted to power corresponding to battery 3 by DC / DC conversion or AC / DC conversion, etc., and supplied to battery 3.

[0013] Vehicle 1 has a cooling mechanism 5A used to cool the motor 2, and a cooling mechanism 5B used to cool the battery 3. Each of the cooling mechanisms 5A and 5B is equipped with a flow path 6, a radiator 7, a pump 8, and a fan 9. The configuration for cooling the motor 2 in cooling mechanism 5A will be described below. Note that the configuration for cooling the target of cooling mechanism 5B is the same as that of cooling mechanism 5A, except that the heat source to be cooled is the battery 3. Therefore, the configuration for cooling the battery 3 in cooling mechanism 5B will not be described.

[0014] The cooling mechanism 5A has a flow path 6 through which the motor 2, which is a heat source, and the radiator 7 passes. The flow path 6 is a circulating flow path that goes from the radiator 7, through the motor 2, and back to the radiator 7. The pump 8 is the drive source that moves the cooling fluid that is filled in the flow path 6. For example, the pump 8 is an electric water pump. In the cooling mechanism 5A, the cooling fluid, which is cooling water, circulates through the flow path 6 by driving the pump 8. The cooling water discharged from the pump 8 flows through the motor 2 and into the radiator 7. Then, the cooling water flows from the radiator 7 towards the pump 8.

[0015] In the cooling mechanism 5A, the heat generated by the motor 2 is dissipated as waste heat to the cooling water flowing through the flow path 6. Then, the cooling water from which heat has been dissipated from the motor 2 flows in the flow path 6 toward the radiator 7. In the cooling mechanism 5A, by driving the fan 9, air is blown from the fan 9 to the radiator 7. For this reason, in the radiator 7, the cooling water is cooled by the air blown from the fan 9, and heat is radiated from the cooling water. Then, in the flow path 6, the cooling water (from which heat has been radiated) cooled in the radiator 7 flows through the pump 8 and toward the motor 2. For this reason, the cooling water cooled in the radiator 7 is supplied to the motor 2.

[0016] In addition, in FIG. 1, the flow of the cooling water in each of the flow paths 6 of the cooling mechanisms 5A and 5B is indicated by an arrow F. Also, in the cooling mechanisms 5A and 5B, the temperature ranges of the cooling water flowing through the flow path 6 are different from each other. And the flow path 6 of the cooling mechanism 5A does not communicate with the flow path 6 of the cooling mechanism 5B and is independent of the flow path of the cooling mechanism 5B. Also, in the cooling mechanism 5A, the motor 2 can only dissipate waste heat to the cooling water flowing through the flow path 6, and in the cooling mechanism 5B, the motor 2 can only dissipate waste heat to the cooling water flowing through the flow path 6.

[0017] In the cooling mechanism 5A, corresponding to the rotation speed of the fan 9, the air volume from the fan 9 to the radiator 7 changes, and the air blowing state to the radiator 7 changes. In the cooling mechanism 5A, corresponding to an increase in the rotation speed of the fan 9, the amount of heat radiated from the cooling water in the radiator 7 increases. Also, in the cooling mechanism 5A, corresponding to the operation of the pump 8, the flow rate of the cooling water in the flow path 6 changes, and the flow rate of the cooling water to the radiator 7 changes. By changing the flow rate of the cooling water to the radiator 7, the time required for the cooling water to circulate once through the flow path 6 and the like change. For this reason, in the cooling mechanism 5A, corresponding to the rotation speed of the fan 9 and the flow rate of the cooling water to the radiator 7, the cooling state in the radiator 7 changes, and the amount of heat radiated from the cooling water in the radiator 7 changes. And corresponding to an increase in the flow rate of the cooling water to the radiator 7, the amount of heat radiated in the radiator 7 increases.

[0018] In each of the flow paths 6 of the cooling mechanisms 5A and 5B, a temperature sensor 11 for measuring the temperature of the cooling water flowing through the flow path 6 is arranged. In one example, in the flow path 6 of the cooling mechanism 5A, at the outflow portion (outlet portion) from the motor 2 which is a heat source, the temperature of the cooling water is measured by the temperature sensor 11. And in the flow path 6 of the cooling mechanism 5B, at the outflow portion (outlet portion) from the battery 3 which is a heat source, the temperature of the cooling water is measured by the temperature sensor 11.

[0019] The vehicle 1 further has an ammeter 12, a tachometer 13 such as a revolution meter, and a torque sensor 15 as measuring instruments for measuring parameters related to the operating state of the motor 2. The ammeter 12 measures the current input to the motor 2. The revolution meter 13 measures the rotational speed of the driving (rotationally driving) motor 2. The torque sensor 15 measures the torque acting on the driving motor 2. Also, the vehicle 1 has an ammeter 16 as a measuring instrument for measuring parameters related to the operating state of the battery 3. The ammeter 16 measures the current flowing through the battery 3. For this reason, when the battery 3 is in a charged state, the ammeter 16 measures the current input to the battery 3, and when the battery 3 is in a discharged state, the ammeter 16 measures the current output from the battery 3.

[0020] The vehicle 1 also has a cooling control device 20. The cooling control device 20 includes a processing execution unit 21 and a storage unit 22, and the processing execution unit 21 includes a specifying unit 23 and a control unit 25. Programs and the like executed by the processing execution unit 21 are stored in the storage unit 22, and each of the specifying unit 23 and the control unit 25 executes at least a part of the processing by the processing execution unit 21. The processing execution unit 21 of the cooling control device 20 performs processing related to cooling of the motor 2 and the battery 3 which are heat sources. For example, the processing execution unit 21 performs operation control of each of the cooling mechanisms 5A and 5B. At this time, the processing execution unit 21 performs the processing by executing a cooling control program stored in the storage unit 22 and the like. Note that the processing execution unit 21 may download a program to be executed including the cooling control program via a network.

[0021] The cooling control device 20 is composed of an in-vehicle computer such as an in-vehicle server mounted in the vehicle. The processing execution unit 21 is composed of a processor or integrated circuit of the in-vehicle computer, and the processor etc. that constitutes the processing execution unit 21 includes any of the following electronic circuits: ECU (Electronic Control Unit), CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), microcontroller, FPGA (Field Programmable Gate Array), and DSP (Digital Signal Processor). The processing execution unit 21 may be composed of one processor etc. or may be composed of multiple processors etc. The storage unit 22 is composed of a storage medium and includes either a main storage medium including memory or an auxiliary storage medium.

[0022] The processing execution unit 21 of the cooling control device 20 periodically acquires the measurement results from the temperature sensors 11 of the cooling mechanisms 5A and 5B. Therefore, the processing execution unit 21 acquires the time change (time history) of the cooling water temperature in each of the cooling mechanisms 5A and 5B. In addition, the processing execution unit 21 periodically acquires the measurement results from the ammeter 12, tachometer 13, and torque sensor 15 as measurement results of parameters related to the operating status of the motor 2. Furthermore, the processing execution unit 21 periodically acquires the measurement results from the ammeter 16 as measurement results of parameters related to the operating status of the battery 3.

[0023] In the cooling process for the motor 2, which is a heat source, the control unit 25 of the processing execution unit 21 controls the operation of the pump 8 and fan 9 of the cooling mechanism 5A. As a result, in the cooling mechanism 5A, the rotation speed of the fan 9 and the flow rate of cooling water to the radiator 7 in the flow path 6 are controlled by the control unit 25, and the amount of heat dissipated by the radiator 7 is adjusted by the control unit 25, etc. In addition, in the cooling process for the battery 3, which is a heat source, the control unit 25 of the processing execution unit 21 controls the operation of the pump 8 and fan 9 of the cooling mechanism 5B. As a result, in the cooling mechanism 5B, the rotation speed of the fan 9 and the flow rate of cooling water to the radiator 7 in the flow path 6 are controlled by the control unit 25, and the amount of heat dissipated by the radiator 7 is adjusted by the control unit 25, etc.

[0024] Figure 2 is a flowchart schematically showing an example of a process related to the cooling of a heat source, performed by the processing execution unit 21 of the cooling control device 20 in this embodiment. The processing execution unit 21 repeatedly executes the process shown in Figure 2 as a process related to the cooling of the motor 2, which is a heat source, while the motor 2 is operating in the vehicle 1. Also, the processing execution unit 21 repeatedly executes the process shown in Figure 2 as a process related to the cooling of the battery 3, which is a heat source, while the battery 3 is operating in the vehicle 1. When the process shown in Figure 2 is started, the identification unit 23 of the processing execution unit 21 identifies the amount of waste heat from the heat source into the cooling water flowing through the flow path 6 based on the operating status of the heat source (S201). At this time, in the process related to the cooling of the motor 2, the amount of waste heat from the motor 2 into the cooling water flowing through the flow path 6 of the cooling mechanism 5A is identified. Then, in the process related to the cooling of the battery 3, the amount of waste heat from the battery 3 into the cooling water flowing through the flow path 6 of the cooling mechanism 5B is identified. Details of the process for identifying the amount of waste heat will be described later, but any of the multiple processes described later may be executed, or two or more processes may be combined.

[0025] Figure 3 is a flowchart illustrating an example of the process for determining the amount of waste heat (S201) based on the operating status of the heat source in Figure 2. Figure 3 is a flowchart showing the process for determining the amount of waste heat from the motor 2 to the cooling water when the motor 2, which is the heat source, is being driven to move the vehicle 1. When the determination process is started, the determination unit 23 acquires parameters indicating the operating status of the motor 2 (S301). The parameters indicating the operating status of the motor 2 are, for example, at least one of a plurality of parameters including the measurement results of the motor 2's current (input current), rotational speed, and torque. In this embodiment, the determination unit 23 acquires the measurement results of the motor 2's current (input current), rotational speed, and torque from the ammeter 12, tachometer 13, and torque sensor 15, respectively.

[0026] The specific unit 23 calculates the input energy to the motor 2 based on the measurement result of the motor 2's current (S302). The specific unit 23 calculates the input energy to the motor 2 as electrical energy. Furthermore, the input energy of the motor 2 becomes larger as the current of the motor 2 increases.

[0027] The specific unit 23 calculates the output energy from motor 2 based on the measured rotational speed and torque of motor 2 (S303). The specific unit 23 calculates the output energy from motor 2 as kinetic energy. The output energy of motor 2 is larger the higher the rotational speed of motor 2. The output energy of motor 2 is larger the higher the torque of motor 2.

[0028] The identification unit 23 determines the amount of waste heat from the motor 2 to the cooling water based on the input energy and output energy (S304). Specifically, the identification unit 23 determines the amount of waste heat from the motor 2 to the cooling water based on the value obtained by subtracting the output energy from the input energy. That is, the energy corresponding to the loss in the conversion from electrical energy to kinetic energy in the motor 2 is wasted as thermal energy from the motor 2 to the cooling water. The input energy to the motor 2, the output energy from the motor 2, and the amount of waste heat from the motor 2 are each expressed in units of watts (W), for example. Alternatively, the value obtained by subtracting the output energy from the input energy may be used as the determined amount of waste heat, or the value obtained by multiplying the value obtained by the subtraction by the transfer rate to the cooling water as a coefficient may be used as the determined amount of waste heat.

[0029] Figure 4 is a flowchart illustrating another example of the process for determining the amount of waste heat based on the operating status of the heat source (S201). Figure 4 is a flowchart showing the process for determining the amount of waste heat from the motor 2 to the cooling water when the motor 2, which is the heat source, is performing regenerative operation in the vehicle 1 and generating electricity. When the determination process in Figure 4 is started, the determination unit 23 acquires the measurement results of the motor 2's current (output current), rotational speed, and torque from the ammeter 12, tachometer 13, and torque sensor 15, respectively (S401). The motor 2's current, rotational speed, and torque are acquired as parameters indicating the operating status of the motor 2.

[0030] The specific unit 23 calculates the input energy (regenerative energy) to the motor 2 based on the measurement results of the rotational speed and torque of the motor 2 (S402). The specific unit 23 calculates the input energy to the motor 2 as kinetic energy. The input energy to the motor 2 is larger the higher the rotational speed of the motor 2. The input energy to the motor 2 is larger the higher the torque of the motor 2.

[0031] The specific unit 23 calculates the output energy of motor 2 based on the measurement result of the motor 2's current (S403). The output energy of motor 2 is calculated as electrical energy. Furthermore, the output energy of motor 2 is larger as the current of motor 2 increases.

[0032] The identification unit 23 determines the amount of waste heat from the motor 2 to the cooling water based on the input energy and output energy (S404). Specifically, the identification unit 23 determines the amount of waste heat from the motor 2 to the cooling water based on the value obtained by subtracting the output energy from the input energy. That is, the energy corresponding to the loss when kinetic energy is converted to electrical energy by the regenerative operation of the motor 2 is wasted as thermal energy from the motor 2 to the cooling water. The input energy to the motor 2, the output energy from the motor 2, and the amount of waste heat from the motor 2 are each expressed in units of watts (W), for example. Alternatively, the loss energy obtained by subtracting the output energy from the input energy may be used as the determined amount of waste heat, or the value obtained by multiplying the loss energy by the transfer rate to the cooling water as a coefficient may be used as the determined amount of waste heat.

[0033] Figure 5 is a flowchart illustrating another example of the waste heat quantity determination process (S201) based on the operating status of the heat source in Figure 2. Figure 5 is a flowchart showing the process of determining the amount of waste heat from the battery 3 to the cooling water when the battery 3, which is the heat source, is operating by charging or discharging. When the determination process in Figure 5 is started, the determination unit 23 acquires the measurement result of the battery 3 current (input current or output current) from the ammeter 16 (S501). The battery 3 current is acquired as a parameter indicating the operating status of the battery 3.

[0034] Then, the identification unit 23 calculates the Joule heat generated in the battery 3 based on the measurement result of the battery 3's current (S502). The storage unit 22 stores information regarding the internal resistance of the battery 3. In the process of S502, the identification unit 23 calculates the Joule heat in the battery 3 using the measurement result of the battery 3's current and the information regarding the internal resistance of the battery 3. Based on the calculation result of the Joule heat, the identification unit 23 identifies the amount of waste heat from the battery 3 to the cooling water (S503). That is, the energy corresponding to the Joule heat is wasted as thermal energy from the battery 3 to the cooling water. The amount of waste heat from the battery 3 is expressed, for example, in units of W (watts). Alternatively, the value obtained as Joule heat may be used as the identified amount of waste heat, or the value obtained as Joule heat may be multiplied by the transfer rate to the cooling water as a coefficient and used as the identified amount of waste heat.

[0035] Returning to the explanation of the flowchart in Figure 2, after the processing in S201, the control unit 25 performs cooling control processing for the heat source based on the result of identifying the amount of waste heat from the heat source (S202). In the processing related to the cooling of motor 2, in S202, the operation of the cooling mechanism 5A is controlled based on the amount of waste heat identified for motor 2, and the operation of the pump 8 and fan 9 of the cooling mechanism 5A is controlled. Then, in the processing related to the cooling of battery 3, in S102, the operation of the cooling mechanism 5B is controlled based on the amount of waste heat identified for battery 3, and the operation of the pump 8 and fan 9 of the cooling mechanism 5B is controlled.

[0036] Figure 6 is a flowchart illustrating an example of the cooling control process (S202) based on the heat output determination result in Figure 2. The cooling control process in Figure 6 controls the operation of the cooling mechanism 5A based on the heat output determination result from the motor 2, which is the heat source. The cooling control process in Figure 6 also controls the operation of the cooling mechanism 5B based on the heat output determination result from the battery 3, which is the heat source. When the control in Figure 6 is started, the control unit 25 acquires the determined amount of waste heat (heat output determination result) from the heat source (motor 2 or battery 3) to the cooling water (S601).

[0037] The control unit 25 then determines the rotation speed of the fan 9 and the flow rate of the coolant in the cooling mechanism (5A or 5B) so that the amount of heat dissipated by the radiator 7 matches the result of identifying the amount of waste heat from the heat source (S602). The storage unit 22 stores relationship data (correlation map) for each of the cooling mechanisms 5A and 5B, showing the relationship between the rotation speed of the fan 9 and the flow rate of the coolant, and the amount of heat dissipated by the radiator 7. The control unit 25 uses the identified amount of waste heat and the aforementioned relationship data to determine the rotation speed of the fan 9 and the flow rate of the coolant so that the amount of heat dissipated by the radiator 7 matches the result of identifying the amount of waste heat from the heat source. The form of the correlation map is not limited to the above. For example, the correlation map may include settings for multiple conditions in which either the temperature of the coolant or the temperature of the outside air blown onto the radiator 7 by the fan 9 differs from each other, specifying the rotation speed of the fan 9 and the flow rate of the coolant so that the amount of heat dissipated by the radiator 7 matches the result of identifying the amount of waste heat from the heat source. In this case, the control unit 25 determines the rotation speed of the fan 9 and the flow rate of the cooling water based on the results of the waste heat amount determination, the temperature of the cooling water obtained from the temperature sensor 11, the ambient temperature obtained from an ambient temperature sensor (not shown), and the correlation map. Although a correlation map has been illustrated, it is also possible to use relational expressions for each parameter that have been determined experimentally or theoretically in advance, rather than using a map.

[0038] Then, the control unit 25 controls the fan 9 and the pump 8 to achieve the determined rotational speed of the fan 9 and the flow rate of the coolant to the radiator 7 (S603). As a result of the processing shown in Figure 6, the cooling mechanism (5A or 5B) controls at least one of the rotational speed of the fan 9 and the flow rate of the coolant to the radiator 7, based on the result of determining the amount of waste heat from the heat source and relational data showing the relationship between the rotational speed of the fan 9 and the amount of heat dissipated by the radiator 7, so that the difference between the determined amount of waste heat and the amount of heat dissipated by the radiator 7 is within a predetermined range. In one example, the control unit 25 controls the rotational speed of the fan 9 and the flow rate of the coolant to the radiator 7 so that the determined amount of waste heat and the amount of heat dissipated by the radiator 7 are in agreement.

[0039] Let's return to the explanation of the flowchart in Figure 2. The control unit 25 determines whether or not the temperature of the cooling water in the cooling mechanism (5A or 5B) has changed (S203). While the cooling control process is being executed, the control unit 25 obtains information indicating the temperature of the cooling water flowing through the flow path 6 of the cooling mechanism (5A or 5B) from the temperature sensors 11 of each cooling mechanism. When the cooling mechanisms 5A and 5B are adjusted to the rotation speed of the fan 9 and the flow rate of the cooling water to the radiator 7 determined based on the results of the waste heat amount determination, the control unit 25 sequentially obtains the measurement results of the cooling water temperature from the temperature sensors 11 of the cooling mechanism (5A or 5B). Here, the process in Figure 2 is repeated periodically while the heat source is operating. Therefore, the control unit 25 periodically obtains the measurement results of the cooling water temperature. The control unit 25 determines that the temperature of the cooling water has changed if the measurement result of the cooling water temperature has changed compared to the measurement result obtained last time. Furthermore, whether or not the coolant temperature has changed may be determined if the difference from the previous measurement result is greater than or equal to a predetermined value (for example, 1°C). Alternatively, a change may be determined if the rate of change of the time-averaged value of the measured coolant temperature over a predetermined period exceeds a predetermined threshold.

[0040] If the cooling water temperature has not changed (S203-No), the processing unit 21 terminates the process shown in Figure 2 without performing the process in S204. Note that the process shown in Figure 2 is repeated while the heat source is operating. Therefore, as long as the heat source is operating, the process shown in Figure 2 is restarted, and the process of determining the amount of waste heat based on the operating status of the heat source (S201) is performed. If the cooling water temperature has not changed from the previous measurement result, the control unit 25 controls the fan 9 and the pump 8 to maintain the rotation speed of the fan 9 and the flow rate of cooling water to the radiator 7 determined based on the result of determining the amount of waste heat. In one example, the processing unit 21 determines that the actual amount of waste heat from the heat source (motor 2 or battery 3) to the cooling water matches the amount of heat dissipated by the radiator 7, and that the result of determining the amount of waste heat from the heat source to the cooling water matches the actual amount of waste heat.

[0041] On the other hand, if the temperature of the cooling water is changing (S203-Yes), the control unit 25 executes a control process to control the operation related to the cooling of the heat source based on the time change in the temperature of the cooling water (S204). In the process related to the cooling of the motor 2, in S204, the operation of the cooling mechanism 5A is controlled based on the time change in the temperature of the cooling water in the cooling mechanism 5A, and the operation of the pump 8 and fan 9 of the cooling mechanism 5A is controlled. Then, in the process related to the cooling of the battery 3, in S204, the operation of the cooling mechanism 5B is controlled based on the time change in the temperature of the cooling water in the cooling mechanism 5B, and the operation of the pump 8 and fan 9 of the cooling mechanism 5B is controlled.

[0042] Figure 7 is a flowchart illustrating an example of the control process (S204) based on the time change of the cooling water temperature in Figure 2. The process in Figure 7 is performed for each of the cooling mechanisms 5A and 5B as control of operation based on the time change of the cooling water temperature. When the control in Figure 7 is started, the control unit 25 determines whether or not the temperature of the cooling water in the cooling mechanism (5A or 5B) has risen (S141). In this embodiment, the control unit 25 determines that the temperature of the cooling water has risen if the measured temperature of the cooling water has risen compared to the previous measurement result, and determines that the temperature of the cooling water has fallen if the measured temperature of the cooling water has fallen compared to the previous measurement result.

[0043] If the coolant temperature is rising (S701-Yes), the control unit 25 controls the fan 9 and pump 8 by increasing at least one of the parameters of the fan 9 rotation speed and the coolant flow rate to the radiator 7, which are determined based on the results of the heat dissipation determination (S702). The control unit 25 determines the amount of increase for at least one of the fan 9 rotation speed and the coolant flow rate in accordance with the amount of rise in the coolant temperature. For example, the greater the rise in the coolant temperature compared to the previous measurement result, the larger the increase in the fan 9 rotation speed and the coolant flow rate, which are determined based on the heat dissipation determination result. In one example, if the coolant temperature has risen compared to the previous measurement result, the processing execution unit 21 determines that the actual amount of heat dissipated from the heat source (motor 2 or battery 3) to the coolant is greater than the amount of heat dissipated by the radiator 7, and that the actual amount of heat dissipated from the heat source to the coolant is greater than the results of the heat dissipation determination.

[0044] On the other hand, if the coolant temperature has decreased (S701-No), the control unit 25 reduces at least one of the parameters of the fan speed 9 and the coolant flow rate to the radiator 7, which are determined based on the results of the heat waste amount determination (S703). The control unit 25 determines the amount of reduction for at least one of the fan speed 9 and the coolant flow rate in accordance with the amount of decrease in the coolant temperature. For example, the greater the decrease in the coolant temperature compared to the previous measurement result, the greater the reduction in the fan speed 9 and the coolant flow rate, which are determined based on the heat waste amount determination. In one example, if the coolant temperature has decreased compared to the previous measurement result, the processing execution unit 21 determines that the actual amount of heat waste from the heat source to the coolant is less than the amount of heat dissipated by the radiator 7, and that the actual amount of heat waste from the heat source to the coolant is less than the results of the heat waste amount determination.

[0045] Figure 8 is a block diagram illustrating an example of a heat source cooling process performed by the processing execution unit 21 of the cooling control device 20 in an embodiment, using functional blocks. In this embodiment, as described above, the heat source cooling process is performed, and as shown in Figure 8, the amount of waste heat from the heat source into the cooling water flowing through the flow path 6 is determined based on the operating status of the heat source. Based on the determination of the amount of waste heat from the heat source, the rotation speed of the fan 9 that blows air to the radiator 7 and the flow rate of the cooling water to the radiator 7 in the flow path 6 are controlled. The temperature of the cooling water is adjusted by controlling the rotation speed of the fan 9 and the flow rate of the cooling water to the radiator 7.

[0046] In addition, in the example shown in Figure 8, the temperature of the coolant is measured. Based on the measured coolant temperature in addition to the identified amount of waste heat, the rotation speed of the fan 9 and the flow rate of coolant to the radiator 7 are controlled. Therefore, while the control unit 25 is controlling the rotation speed of the fan 9 and the flow rate of coolant based on the identified amount of waste heat from the heat source, it provides feedback control for the coolant temperature. Furthermore, while the control unit 25 is controlling the rotation speed of the fan 9 and the flow rate of coolant based on the identified amount of waste heat from the heat source, if the coolant temperature changes, it controls the rotation speed of the fan 9 and the flow rate of coolant based on the change in the coolant temperature over time.

[0047] Here, as a comparative example, we consider a case where the amount of waste heat from the heat source to the coolant is not identified, nor is control performed based on the result of identifying the amount of waste heat from the heat source. Instead, the coolant temperature is maintained at a constant level solely by feedback control of the coolant temperature. In the comparative example, the rotation speed of the fan 9 and the flow rate of coolant to the radiator 7 are controlled only based on the time change in the coolant temperature.

[0048] Figure 9 is a schematic diagram showing an example of the time variation of the cooling water temperature and the amount of energy used for control, in a comparative example where the cooling water temperature is kept constant. Figure 10 is a schematic diagram showing an example of the time variation of the cooling water temperature and the amount of energy used for control, in an embodiment where the cooling water temperature is kept constant. Figures 9 and 10 each show graphs, where the horizontal axis, the left vertical axis, and the right vertical axis represent time, cooling water temperature, and the amount of energy used for control, respectively. In Figures 9 and 10, the time variation of the cooling water temperature is shown by a dashed line, and the time variation of the amount of energy used for control is shown by a solid line. The amount of energy used for control includes the energy consumed to rotate the fan 9 and the energy consumed by the pump 8 that circulates the cooling water, and is shown, for example, in units of W (watts).

[0049] As shown in Figure 9, the control method of the comparative example is prone to rapid increases and decreases in the coolant temperature. Furthermore, when attempting to maintain the coolant temperature at a constant reference temperature, overshoot (coolant temperature significantly above the reference temperature) and undershoot (coolant temperature significantly below the reference temperature) are more likely to occur. In addition, because rapid increases and decreases in the coolant temperature are more likely to occur in the control method of the comparative example, the amount of energy used in the control tends to increase.

[0050] In contrast, in the control of this embodiment, the operation related to the cooling of the heat source is controlled based on the result of determining the amount of waste heat from the heat source to the cooling water. As a result, as shown in Figure 10, in the control of this embodiment, rapid increases and decreases in the temperature of the cooling water are less likely to occur. Furthermore, when controlling to maintain the temperature of the cooling water at a constant reference temperature, the aforementioned overshoot and undershoot are less likely to occur. In addition, since rapid increases and decreases in the temperature of the cooling water are less likely to occur in the control of this embodiment, the amount of energy used in the control is reduced.

[0051] As described above, in this embodiment, the amount of waste heat from the heat source, such as the motor 2 or battery 3, into the cooling water flowing through the flow path 6 is determined based on the operating status of the heat source. Based on the determined amount of waste heat, at least one of the rotation speed of the fan 9 that blows air to the radiator 7 and the flow rate of the cooling water to the radiator 7 in the flow path 6 is controlled. Therefore, by controlling the cooling water temperature to be kept constant based on the determination (prediction) of the amount of waste heat from the heat source, it is possible to keep the cooling water temperature constant or nearly constant over time without, or with little to no, rapid increases or decreases in the cooling water temperature. Furthermore, in the control that keeps the cooling water temperature constant based on the determined amount of waste heat, the amount of energy used can be appropriately reduced.

[0052] Furthermore, in this embodiment, based on the results of identifying the amount of waste heat from the heat source and information showing the relationship between the rotational speed of the fan 9 and the amount of heat dissipated by the radiator 7, at least one of the rotational speed of the fan 9 and the amount of heat dissipated by the radiator 7 is controlled so that the difference between the identified amount of waste heat and the amount of heat dissipated by the radiator 7 is within a predetermined range. As a result, the operation of the cooling mechanism (5A or 5B) is appropriately controlled so that the amount of heat dissipated by the radiator 7 is the same as or approximately the same as the identified amount of waste heat from the heat source.

[0053] Furthermore, in one embodiment, when the rotation speed of the fan 9 and the flow rate of the coolant to the radiator 7 are controlled based on the determination of the amount of waste heat from the heat source, if the temperature of the coolant changes, the rotation speed of the fan 9 and the flow rate of the coolant are controlled based on the time change in the temperature of the coolant. Therefore, even if the determination of the amount of waste heat to the coolant from the heat source deviates from the actual amount of waste heat, the temperature change caused by the discrepancy between the determined amount of waste heat and the actual amount of waste heat is appropriately corrected. In other words, appropriate control is performed to keep the temperature of the coolant constant over time, taking into account the effect of the discrepancy between the determined amount of waste heat and the actual amount of waste heat.

[0054] Furthermore, the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. The embodiments may also be combined as appropriate as possible, and the combined effects can be obtained in such cases. Moreover, the embodiments described above include inventions at various stages, and various inventions can be extracted by appropriate combinations of the multiple disclosed constituent elements. [Explanation of symbols]

[0055] 1...Vehicle, 2...Motor, 3...Battery, 5A, 5B...Cooling mechanism, 6...Flow path, 7...Radiator, 8...Pump, 9...Fan, 11...Temperature sensor, 12...Ammeter, 13...Tachometer, 15...Torque sensor, 16...Ammeter, 20...Cooling control device, 21...Processing execution unit, 22...Storage unit, 23...Specification unit, 25...Control unit.

Claims

1. A unit that identifies the amount of waste heat from the heat source into the cooling water flowing through the passage, based on the operating status of the heat source mounted on the vehicle, A control unit that controls at least one of the rotation speed of a fan that blows air to the radiator and the flow rate of the cooling water to the radiator in the flow path, based on the amount of waste heat identified by the specified unit, A cooling control device equipped with the following:

2. The cooling control device according to claim 1, wherein the control unit controls at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator based on the identified amount of waste heat, and when the temperature of the cooling water changes, the control unit controls at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator based on the time change of the temperature of the cooling water.

3. The cooling control device according to claim 2, wherein the control unit controls the fan to increase at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator when the temperature of the cooling water increases.

4. The cooling control device according to claim 2, wherein the control unit controls the fan to reduce at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator when the temperature of the cooling water decreases.

5. The cooling control device according to claim 1, wherein the control unit controls at least one of the fan's rotation speed and the cooling water flow rate so that the difference between the identified waste heat amount and the amount of heat dissipated by the radiator is within a predetermined range, based on the identified waste heat amount and information showing the relationship between the fan's rotation speed and the cooling water flow rate and the amount of heat dissipated by the radiator.

6. The heat source is a motor for driving the vehicle, The specified unit determines the amount of waste heat to be added to the cooling water based on a value obtained by subtracting the output energy from the motor from the input energy to the motor. A cooling control device according to claim 1.

7. The heat source is a battery that supplies power to the motor for driving the vehicle. The specified unit determines the amount of waste heat to be supplied to the cooling water by calculating the Joule heat generated by the battery. A cooling control device according to claim 1.

8. A cooling control device according to any one of claims 1 to 7, The flow path through which the cooling water flows, The heat source, whose amount of waste heat to be added to the cooling water is determined by the specified unit of the cooling control device, The radiator, in which the flow rate of the cooling water supplied through the flow path is controlled by the control unit of the cooling control device, The fan blows air to the radiator, and its rotational speed is controlled by the control unit of the cooling control device, A vehicle equipped with [a certain feature].

9. Based on the operating status of the heat source installed in the vehicle, the amount of waste heat from the heat source into the cooling water flowing through the channel is determined, Based on the identified amount of waste heat, the rotation speed of the fan that blows air to the radiator and at least one of the flow rate of the coolant to the radiator in the flow path are controlled. A cooling control method comprising the following:

10. The cooling control method according to claim 9, further comprising controlling at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator based on the identified amount of waste heat, when the temperature of the cooling water changes, controlling at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator based on the time change of the temperature of the cooling water.

11. The cooling control method according to claim 10, wherein, in the control based on the time change of the temperature of the cooling water, if the temperature of the cooling water increases, at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator is increased.

12. The cooling control method of claim 10, in which, in the control based on the time change of the temperature of the cooling water, if the temperature of the cooling water decreases, at least one of the rotational speed of the fan and the flow rate of the cooling water to the radiator is reduced.

13. The cooling control method according to claim 9, wherein, in the control based on the specified amount of waste heat, at least one of the fan's rotation speed and the flow rate of the cooling water is controlled based on the specified amount of waste heat and information showing the relationship between the fan's rotation speed and the flow rate of the cooling water and the amount of heat dissipated by the radiator, so that the difference between the specified amount of waste heat and the amount of heat dissipated by the radiator is within a predetermined range.

14. The heat source is a motor for driving the vehicle, In determining the amount of waste heat, the amount of waste heat to be added to the cooling water is determined based on the value obtained by subtracting the output energy from the motor from the input energy to the motor. The cooling control method according to claim 9.

15. The heat source is a battery that supplies power to the motor for driving the vehicle. In determining the amount of waste heat, the amount of waste heat to be added to the cooling water is determined by calculating the Joule heat generated by the battery. The cooling control method according to claim 9.

16. On the computer, Based on the operating status of the heat source installed in the vehicle, the amount of waste heat from the heat source into the cooling water flowing through the channel is determined. Based on the identified amount of waste heat, the rotation speed of the fan that blows air to the radiator and at least one of the flow rate of the coolant to the radiator in the flow path are controlled. A cooling control program equipped with the following features.

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