Cooling system

Abstract

To provide a technology capable of efficiently warming up a battery.SOLUTION: In a cooling system 1, a heat exchanger 16 exchanges heat between a cooling liquid and a predetermined fluid. An arithmetic device 12 is supplied with the cooling liquid that has flowed out of the heat exchanger 16. A battery 10 is supplied with the cooling liquid that has flowed out from the arithmetic device 12. The coolant that has flowed out of battery 10 is supplied to the heat exchanger 16. The arithmetic device 12 executes a predetermined computation when a predetermined warm-up condition is satisfied.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cooling system.

Background Art

[0002] In a panel computer having a CPU, a hard disk, etc. in a housing, when the temperature of the hard disk or the like is equal to or lower than the lower limit set temperature, a warm-up operation for increasing the heat generation amount of the CPU is performed on the CPU, and the heat of the CPU is propagated into the housing by a fan to raise the temperature in the housing. A technique is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique of Patent Document 1, since the heat of the CPU is transferred by air, the air diffuses, and it is difficult to effectively warm the desired device. For example, in an electric vehicle, when the temperature of the battery for running is low, the voltage of the battery drops, and it is desired to warm up the battery.

[0005] An object of the present invention is to provide a technique capable of efficiently warming up a battery.

Means for Solving the Problems

[0006] To solve the above problems, a cooling system according to an aspect of the present invention includes a heat exchanger that exchanges heat between a coolant and a predetermined fluid, an arithmetic unit to which the coolant flowing out from the heat exchanger is supplied, and a battery to which the coolant flowing out from the arithmetic unit is supplied. The coolant flowing out from the battery is supplied to the heat exchanger. When a predetermined warm-up condition is satisfied, the arithmetic unit By executing the calculation load program, a dummy executes an operation shi , The dummy calculation increases the calculation load, causing the arithmetic unit to generate heat, and the heat generated by the dummy calculation is transferred to the battery through the coolant. When the warm-up condition is not satisfied, the arithmetic unit does not execute the dummy calculation.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a technique for efficiently warming up a battery.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0009] FIG. 1 schematically shows the configuration of a cooling system 1 according to an embodiment. The cooling system 1 is mounted on, for example, an electric vehicle (not shown) including a motor for traveling (not shown), a battery 10 that supplies power to the motor, and an arithmetic unit 12, and cools the battery 10 and the arithmetic unit 12. The arithmetic unit 12 operates with the power supplied from the battery 10 and controls the electric vehicle. The electric vehicle may be, for example, a hybrid electric vehicle (HEV), a battery electric vehicle (BEV), or a fuel cell electric vehicle (FCEV). In the embodiment, the electric vehicle is an autonomous driving vehicle, and an example will be described in which the arithmetic unit 12 mainly executes operations related to autonomous driving.

[0010] The cooling system 1 includes a cooling circuit 40 and a control device 42. The cooling circuit 40 has a battery 10, an arithmetic unit 12, an electric pump 14, a heat exchanger 16, a first flow path 20, a second flow path 22, a third flow path 24, a fourth flow path 26, a first temperature sensor 30, a second temperature sensor 32, and a third temperature sensor 34.

[0011] The cooling circuit 40 circulates the first coolant in the order of the electric pump 14, the first flow path 20, the heat exchanger 16, the second flow path 22, the arithmetic unit 12, the third flow path 24, the battery 10, the fourth flow path 26, and the electric pump 14. That is, the arithmetic unit 12 is disposed between the heat exchanger 16 and the battery 10 in the cooling circuit 40. In FIG. 1, the arrows of the first flow path 20, the second flow path 22, the third flow path 24, and the fourth flow path 26 indicate the direction in which the first coolant flows. The first coolant may be a known liquid, for example, a liquid having high electrical insulation. For example, the first coolant may be mineral oil, synthetic oil, silicone oil, fluorine oil, or the like.

[0012] The electric pump 14 sucks the first coolant from the suction port and discharges the first coolant from the discharge port. The electric pump 14 switches the output to large or small according to the control of the control device 42. When the output of the electric pump 14 is large, the discharge amount of the first coolant per unit time is a first value, and when the output is small, the discharge amount of the first coolant per unit time is a second value smaller than the first value. The first flow path 20 is connected to the discharge port of the electric pump 14. The first coolant discharged from the electric pump 14 to the first flow path 20 is pumped downstream of the cooling circuit 40 by the discharge pressure of the electric pump 14. The heat exchanger 16 is connected to the downstream side of the first flow path 20.

[0013] The first coolant is supplied from the first flow path 20 to the heat exchanger 16. The heat exchanger 16 exchanges heat between the supplied first coolant and a predetermined fluid, exhausts the heat of at least one of the battery 10 and the arithmetic unit 12, and allows the first coolant after heat exchange to flow out. The predetermined fluid is, for example, the second coolant 28 of a refrigeration cycle (not shown). The refrigeration cycle is included in, for example, the air conditioner of an electric vehicle. By using the second coolant 28 of the refrigeration cycle, the temperature of the first coolant can be reduced compared to the case of using air as the predetermined fluid. A second flow path 22 is connected to the downstream side of the heat exchanger 16. The arithmetic unit 12 is connected to the downstream side of the second flow path 22. The first coolant flowing out from the heat exchanger 16 passes through the second flow path 22 and is supplied to the arithmetic unit 12.

[0014] Although not shown, the arithmetic unit 12 has an arithmetic section that executes arithmetic operations and a housing case that houses the arithmetic section. The arithmetic unit 12 can also be called an electronic control unit (ECU: Electric Control Unit). The configuration of the arithmetic unit 12 can be realized by the cooperation of hardware resources and software resources. As hardware resources, analog elements, microcomputers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs can be used.

[0015] The downstream side of the second flow path 22 is connected to the inlet of the housing case of the arithmetic unit 12. When the first coolant flows from the second flow path 22 into the housing case of the arithmetic unit 12 and the temperature of the flowed-in first coolant is lower than the temperature of the arithmetic section, the heat of the arithmetic section moves to the first coolant, and the arithmetic section can be cooled by the first coolant. A third flow path 24 is connected to the outlet of the housing case of the arithmetic unit 12. The battery 10 is connected to the downstream side of the third flow path 24. The first coolant flowing out from the arithmetic unit 12 passes through the third flow path 24 and is supplied to the battery 10.

[0016] The battery 10 is a rechargeable power storage device. Although not shown, the battery 10 has a battery module and a battery case that houses the battery module. The battery 10 can also be called a battery pack. The downstream side of the third flow path 24 is connected to the inlet of the battery case of the battery 10. The first coolant flows into the interior of the battery case from the third flow path 24. When the temperature of the first coolant that has flowed in is lower than the temperature of the battery module, the heat of the battery module moves to the first coolant, and the battery module can be cooled by the first coolant.

[0017] As will be described later, in a situation where the temperature of the battery 10 is low in winter or the like when the air temperature is low, the heat of the arithmetic unit 12 moves to the first coolant passing through the arithmetic unit 12, and thus the temperature of the first coolant flowing into the battery 10 may be higher than the temperature of the battery module. When the temperature of the first coolant that has flowed in is higher than the temperature of the battery module, the heat of the first coolant moves to the battery module, and the battery module can be heated by the first coolant.

[0018] The fourth flow path 26 is connected to the outlet of the battery case. The downstream side of the fourth flow path 26 is connected to the suction port of the electric pump 14. The first coolant flowing out from the battery 10 is supplied to the suction port of the electric pump 14 through the fourth flow path 26.

[0019] The first temperature sensor 30 is disposed on the downstream side inside the battery case of the battery 10, detects the temperature Tbat of the battery 10, and outputs a signal indicating the detected value to the control device 42.

[0020] The second temperature sensor 32 is disposed on the downstream side in the third flow path 24 and near the inlet of the first coolant of the battery 10, detects the temperature Tcool of the first coolant passing through the third flow path 24, and outputs a signal indicating the detected value to the control device 42.

[0021] The third temperature sensor 34 is disposed in the housing case of the arithmetic unit 12, detects the temperature Tecu of the arithmetic unit 12, and outputs a signal indicating the detected value to the control device 42.

[0022] Based on the detected temperature Tbat of the battery 10 and the temperature Tecu of the arithmetic unit 12, the control device 42 controls the operation of the electric pump 14 and controls the circulation of the first coolant in the cooling circuit 40.

[0023] Based on the detected temperature Tbat of the battery 10 and the temperature Tcool of the first coolant, when a predetermined warm-up condition is satisfied, the control device 42 causes the arithmetic unit 12 to execute an arithmetic load program. When the warm-up condition is not satisfied, the control device 42 does not cause the arithmetic unit 12 to execute the arithmetic load program. The warm-up condition is that the temperature Tbat of the battery 10 is less than a third predetermined value and the temperature Tcool of the first coolant is less than a fourth predetermined value. The arithmetic load program is a program for causing the arithmetic unit 12 to execute dummy arithmetic. The arithmetic load increases due to the dummy arithmetic, so that the arithmetic unit 12 generates heat and the temperature of the arithmetic unit 12 rises.

[0024] The configuration of the control device 42 can be realized by the cooperation of hardware resources and software resources, or by hardware resources only. As hardware resources, analog elements, microcomputers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs can be used. As software resources, programs such as firmware can be used. The control device 42 may be included in the arithmetic unit 12.

[0025] FIG. 2 is a flowchart showing the first process of the control device 42 in FIG. 1. The process in FIG. 2 is periodically repeated by the control device 42.

[0026] When the temperature Tecu of the arithmetic unit 12 is not less than or equal to the first predetermined value Tp1 (N in S10), the control device 42 controls the output of the electric pump 14 to be large (S12) and returns to S10. Thereby, the arithmetic unit 12 that mainly generates heat can be cooled.

[0027] When the temperature Tecu of the arithmetic unit 12 is less than or equal to the first predetermined value Tp1 (Y in S10) and the temperature Tbat of the battery 10 is not less than or equal to the second predetermined value Tp2 (N in S14), the control device 42 proceeds to S12. Thereby, the battery 10 that mainly generates heat can be cooled.

[0028] When the temperature Tbat of the battery 10 is less than or equal to the second predetermined value Tp2 (Y in S14), the control device 42 controls the output of the electric pump 14 to be small (S16) and ends the process. Thereby, the cooling performance can be reduced and the power consumption can be reduced.

[0029] In this way, the control device 42 first determines regarding the temperature Tecu of the arithmetic unit 12 and then determines regarding the temperature Tbat of the battery 10.

[0030] The first predetermined value Tp1 and the second predetermined value Tp2 can be appropriately determined by experiments or simulations. For example, the first predetermined value Tp1 may be 45°C, and the second predetermined value Tp2 may be 35°C.

[0031] When the battery 10 is rapidly charged, there is no heat generation in the arithmetic unit 12, and the heat generation of the battery 10 is large. When the electric vehicle is traveling on a highway, the heat generation of the arithmetic unit 12 is small, and the heat generation of the battery 10 is large. When the electric vehicle is traveling in an urban area, the heat generation of the arithmetic unit 12 is large, and the heat generation of the battery 10 is small. The maximum heat generation amount of the battery 10 is smaller than the maximum heat generation amount of the arithmetic unit 12.

[0032] By cooling the arithmetic unit 12 with the first coolant cooled by the heat exchanger 16 before the battery 10, for example, when the battery 10 is rapidly charged or when the electric vehicle is traveling on a highway, the heat of the battery 10 with a large maximum heat generation amount can be prevented from being transmitted to the arithmetic unit 12 through the first coolant.

[0033] FIG. 3 is a flowchart showing the second process of the control device 42 in FIG. 1. The process in FIG. 3 is periodically repeated in parallel with the first process by the control device 42.

[0034] When the temperature Tbat of the battery 10 is not equal to or higher than the third predetermined value Tp3 (N in S20) and the temperature Tcool of the first coolant is not equal to or higher than the fourth predetermined value Tp4 (N in S22), the control device 42 causes the arithmetic unit 12 to execute an arithmetic load program (S24), and returns to S20. Thereby, the heat generated by the dummy arithmetic operation of the arithmetic unit 12 is transferred to the battery 10 via the first coolant, and the low-temperature battery 10 can be warmed up.

[0035] When the temperature Tbat of the battery 10 is equal to or higher than the third predetermined value Tp3 (Y in S20), the control device 42 does not cause the arithmetic unit 12 to execute the arithmetic load program (S26), and ends the process.

[0036] When the temperature Tcool of the first coolant is equal to or higher than the fourth predetermined value Tp4 (Y in S22), the control device 42 moves to S26. In this case, the battery 10 can be warmed up by the first coolant having a temperature equal to or higher than the fourth predetermined value Tp4 without causing the arithmetic unit 12 to execute a dummy arithmetic operation, the power consumption of the arithmetic unit 12 can be reduced, and the arithmetic ability of the arithmetic unit 12 can be effectively used for arithmetic operations other than the dummy arithmetic operation.

[0037] The third predetermined value Tp3 is lower than the fourth predetermined value Tp4. The third predetermined value Tp3 and the fourth predetermined value Tp4 can be appropriately determined by experiments and simulations so that the warm-up of the battery 10 can be appropriately performed. For example, the third predetermined value Tp3 may be 0°C, and the fourth predetermined value Tp4 may be 25°C.

[0038] According to the embodiment, when the warm-up condition is satisfied, the heat generated by the arithmetic operation of the arithmetic unit 12 is transferred to the downstream battery 10 via the first coolant, so that the battery 10 can be warmed up with high heat transfer efficiency. Therefore, when the temperature Tbat of the battery 10 is lower than the third predetermined value Tp3 in winter when the temperature is low, the battery 10 can be efficiently warmed up.

[0039] As a result, it is not necessary to install a heater for heating the battery modules of the battery 10 inside the battery case of the battery 10, so that the pressure loss of the cooling circuit 40 can be reduced and the cost can also be reduced.

[0040] In addition, when the arithmetic unit 12 executes arithmetic operations related to autonomous driving, the amount of heat generated is likely to be larger than that of an arithmetic unit that does not execute arithmetic operations related to autonomous driving. However, since the heat exchanger 16 cools the first coolant using the second coolant 28 of the refrigeration cycle, the arithmetic unit 12 can be cooled more effectively.

[0041] As described above, the present invention has been described based on the embodiments. It should be understood by those skilled in the art that the embodiments are merely examples, and various modifications are possible for the combination of each component and each processing process, and such modifications are also within the scope of the present invention.

[0042] For example, in S16 of FIG. 2, the control device 42 may stop the electric pump 14. In this case, in S24 of FIG. 3, the control device 42 may cause the arithmetic unit 12 to execute an arithmetic load program and control the output of the electric pump 14 to be small.

Explanation of Reference Numerals

[0043] 1... Cooling system, 10... Battery, 12... Arithmetic unit, 14... Electric pump, 16... Heat exchanger, 20... First flow path, 22... Second flow path, 24... Third flow path, 26... Fourth flow path, 30... First temperature sensor, 32... Second temperature sensor, 34... Third temperature sensor, 40... Cooling circuit, 42... Control device.

Claims

1. A heat exchanger that exchanges heat between a coolant and a predetermined fluid, An arithmetic unit to which the coolant flowing out of the heat exchanger is supplied, A battery to which the coolant flowing out of the arithmetic unit is supplied, comprising: The coolant flowing out of the battery is supplied to the heat exchanger, When a predetermined warm-up condition is satisfied, the arithmetic unit executes a dummy operation by executing an arithmetic load program, and the arithmetic unit generates heat due to an increase in the arithmetic load by the dummy operation, and the heat generated by the dummy operation is transferred to the battery via the coolant. When the warm-up condition is not satisfied, the arithmetic unit does not execute a dummy operation. A cooling system characterized by the above.

2. The warm-up condition is that the temperature of the battery is less than a predetermined value and the temperature of the coolant is less than another predetermined value, The predetermined value is lower than the other predetermined value. The cooling system according to claim 1, characterized by the above.

3. The cooling system is mounted on a vehicle, The arithmetic unit executes an arithmetic operation related to the autonomous driving of the vehicle. The cooling system according to claim 1 or 2, characterized by the above.

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