Cooling system

Abstract

To cool temperature of a battery and electric system components efficiently in a cooling system of an electric vehicle and moreover to enhance degree of freedom of installation layout of the components.SOLUTION: In a cooling system 100 of an electric vehicle comprising electric system components 1 which thermally generates by electrification, a battery 6 which electrically supplies to the electric system components, a heat pump 9 which performs heating or cooling of cooling water and a radiator 14 which cools the cooling water which adjusts temperature of the electric system components and the battery by the cooling water, it comprises a first selector valve 5 which flushes the cooling water, which is supplied from the heat pump or the radiator and passes through outer periphery of the electric system components, into either input for heating of the heat pump and the radiator and the outer periphery of the battery and a second selector valve 9 which flushes the cooling water, which passes through outer periphery of the battery, into either input for heating the heat pump and input for cooling it.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cooling system, and more particularly to a cooling system for an electric vehicle that cools a drive battery and electrical components. [Background technology]

[0002] An electric vehicle (EV) is equipped with a powertrain that consists of a motor for driving, a battery for driving that outputs direct current, and an inverter that converts the direct current from the battery into alternating current to drive the motor. The drive batteries installed in electric vehicles need to be kept at around room temperature (10℃ to 30℃). If the temperature is too low or too high, it will affect the battery's performance and durability. Therefore, it is necessary to control the battery temperature to keep it at around room temperature.

[0003] In addition, the motors, inverters, and other electrical components used in electric vehicles can be used at around 100°C, but from the viewpoint of reliability, it is preferable to cool them. While it is possible to enlarge the electrical components to improve the cooling effect, it is preferable to keep them small when considering the impact on cost and design, and a system that can effectively cool small electrical components is required.

[0004] As such, electric vehicles require thermal management of the temperatures of the drive battery, electrical components, and the like, but this thermal management is more complicated than when an internal combustion engine is used. Furthermore, if each component is cooled with coolant, many fluid paths are required to flow the coolant to the locations where the battery, electrical components, and the like are located, as well as valves to switch these flow paths.

[0005] Patent Document 1 discloses a multi-port valve that can accommodate multiple fluid paths for cooling water in an electric vehicle. The multi-port valve disclosed in Patent Document 1 has five ports for respectively flowing cooling water to a radiator, a battery, etc., and a valve body for switching the flow paths between the ports. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2018-536128 Summary of the Invention [Problem to be solved by the invention]

[0007] However, a multiport valve such as that disclosed in Patent Document 1 has a structure in which a single valve body switches between multiple ports, and since it is necessary to place this multiport valve in one place and then layout the battery and electrical components, there is an issue that the degree of freedom in the mounting layout of each of these components is reduced.

[0008] The present invention has been made in light of the above-mentioned points, and has an object to provide a cooling system for an electric vehicle that can efficiently cool the temperature of the battery and electrical components and improve the freedom of the mounting layout of these components. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the cooling system of the present invention is an electric vehicle cooling system that adjusts the temperature of the electrical system components and the battery using coolant in an electric vehicle that includes electrical system components that generate heat when electricity is passed through them, a battery that supplies power to the electrical system components, a heat pump that heats or cools coolant, and a radiator that cools the coolant, and is characterized in that it includes a first switching valve that causes the coolant that is supplied from the heat pump or the radiator and has passed around the periphery of the electrical system components to flow to either the heating input of the heat pump, the radiator, or the periphery of the battery, and a second switching valve that causes the coolant that has passed around the periphery of the battery to flow to either the heating input or the cooling input of the heat pump. Furthermore, it is desirable to provide a temperature sensor that detects the temperature of the cooling water that has passed around the outer periphery of the electrical system component, and a control unit that controls the switching operation of each of the first switching valve and the second switching valve based on the temperature detected by the temperature sensor.

[0010] With this configuration, the temperature of the electrical components and the battery can be adjusted efficiently by the coolant by controlling the switching of the first and second switching valves based on the temperature of the coolant. Furthermore, by disposing the switching valves separately in two, the method of connecting the piping can be simplified, and the degree of freedom in the mounting layout of each component can be improved compared to the conventional layout in which only one multi-port valve is disposed.

[0011] The vehicle also includes a first electric water pump for supplying cooling water cooled by the heat pump to the outer periphery of the battery, and a second electric water pump for supplying either or both of the cooling water heated by the heat pump and the cooling water supplied from the radiator to the outer periphery of the electrical system components, and it is desirable that the first electric water pump does not operate when cooling water is not supplied to the cooling input of the heat pump due to the switching operation of the second switching valve. With this configuration, low-temperature cooling water is not supplied to the battery when the battery is at a low temperature, and the battery can be effectively heated.

[0012] Moreover, it is preferable that the first and second changeover valves are motor-operated valves. By configuring the two changeover valves as motor-operated valves in this manner, the valves can be controlled to change over with high precision.

[0013] The first switching valve may be an electric valve, and the second switching valve may be a wax-type temperature control valve in which a wax element expands or contracts depending on the temperature of the cooling water to open and close the valve. By configuring in this way, the manufacturing costs can be further reduced. Effect of the Invention

[0014] According to the cooling system of the present invention, the temperature of the battery and electrical components can be efficiently cooled, and the degree of freedom in the mounting layout of these components can be improved. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a circuit diagram showing an example of the configuration of a cooling system according to an embodiment of the present invention, in a low-temperature mode. [Diagram 2] FIG. 2 is a circuit diagram showing an example of the configuration of a cooling system according to an embodiment of the present invention, in the intermediate mode. [Diagram 3] FIG. 3 is a circuit diagram showing an example of the configuration of a cooling system according to an embodiment of the present invention, in a high temperature mode. [Figure 4] FIG. 4 is a circuit diagram showing a modified example of the cooling system according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of a cooling system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to this embodiment. In addition, in the specification and drawings of the present application, elements that can be similarly described may be given the same reference numerals to avoid redundant description.

[0017] <Cooling system configuration> 1 to 3 are circuit diagrams showing an example of the configuration of a cooling system according to an embodiment, and show an example of a cooling system for an electric vehicle. In the circuit diagrams of Fig. 1 to 3, solid and dashed arrows indicate paths through which the cooling water flows, and the solid arrows indicate paths through which the cooling water does not flow, and the dashed arrows indicate paths through which the cooling water does not flow.

[0018] The electric vehicle equipped with the cooling system 100 includes an electrical system component 1 that generates heat when electricity is applied. The electrical system component 1 includes a charger 2, a PCM 3 that is a module that controls the output of the powertrain, and a motor 4 that constitutes the powertrain. This electric vehicle also includes a battery pack 6 (battery) that includes multiple batteries that serve as the driving source for the electric components 1 and power the electric vehicle, and a heat pump 9 that collects heat from the surrounding air and serves as a heat source for heating and cooling the interior of the vehicle, as well as being capable of heating or cooling the coolant.

[0019] This electric vehicle also has an air conditioning (A / C) cooler 10 that outputs air cooled by a heat pump 9, and an air conditioning (A / C) heater 11 that outputs air heated by the heat pump 9, and is configured so that cooling water (sometimes called cold water) cooled by the heat pump 9 flows around the periphery of the cooler 10, and cooling water (sometimes called hot water) heated by the heat pump 9 flows around the periphery of the heater 11. The electric vehicle also includes a radiator 14, which cools the hot coolant that passes through a cooling path for the coolant.

[0020] The cooling system 100 of the present invention includes a first electric water pump (EWP) 12 for circulating the cold water that has passed around the periphery of the cooler 10 throughout the system, a second electric water pump (EWP) 13 for circulating the hot water that has passed around the periphery of the heater 11 throughout the system, and a plurality of water temperature sensors for detecting the temperature of the coolant. In this embodiment, the water temperature sensor is provided at a position where it can detect the temperature of at least the coolant that has passed around the battery pack 6 and the temperature of the coolant that has passed around the electrical component 1.

[0021] The cooling system 100 also includes two switching valves for switching the cooling water path. In this embodiment, two motorized valves 5 and 7 are provided as the switching valves. Each of the motorized valves 5 and 7 has a control unit and switches the flow path of the cooling water according to the temperature detected by the water temperature sensor. The control unit may be an electronic control unit (ECU) of the vehicle and control the switching of the two motorized valves 5 and 7. The first electric valve 5 (first switching valve) is a four-way valve and has an input port 5a into which coolant that has passed through the outer periphery of the electrical system component 1 flows, an output port 5b for flowing coolant to the outer periphery of the battery pack 6, an output port 5c for flowing coolant to the heat pump 9, and an output port 5d for flowing coolant to the radiator 14.

[0022] In addition, the second electric valve 7 (second switching valve) is a three-way valve and has an input port 7a into which coolant that has passed around the outer periphery of the battery pack 6 flows in, an output port 7b for flowing coolant to the heating input 9a of the heat pump 9, and an output port 7c for flowing coolant to the cooling input 9b of the heat pump 9.

[0023] The cooling system 100 also includes a first flow path R1 for flowing the coolant heated by the heat pump 9 around the outer periphery of the heater 11, a second electric water pump (EWP) 13, and the outer periphery of the electrical components 1, in that order; a second flow path R2 for flowing the coolant from the first electric valve 5 to the outer periphery of the battery pack 6; a third flow path R3 for flowing the coolant from the first electric valve 5 to the heating input 9a of the heat pump 9; and a fourth flow path R4 for flowing the coolant from the first electric valve 5 to the radiator 14.

[0024] Furthermore, the cooling system 100 includes a fifth flow path R5 for flowing the cooling water cooled by the heat pump 9 from the outer periphery of the cooler 10 to the outer periphery of the battery pack 6, a sixth flow path R6 for flowing the cooling water that has flowed around the outer periphery of the battery pack 6 to the heating input 9a of the heat pump 9, and a seventh flow path R7 for flowing the cooling water that has flowed around the outer periphery of the battery pack 6 to the cooling input 9b of the heat pump 9.

[0025] In this embodiment, the temperature of the coolant is detected by a temperature sensor (not shown), and the detected temperature is supplied to the control units of the first motor-operated valve 5 and the second motor-operated valve 7 as described above. The control units perform valve switching control of the first motor-operated valve 5 and the second motor-operated valve 7 based on the detected temperature. An electronic control unit (ECU) of the vehicle (not shown) controls the first electric water pump (EWP) 12 and the second electric water pump (EWP) 13.

[0026] <Cooling system operation> Next, the operation of the cooling system 100 will be described with reference to Figures 1 to 3. The cooling system 100 shown in Figure 1 is in a low temperature mode, the cooling system 100 shown in Figure 2 is in an intermediate mode, and the cooling system 100 shown in Figure 3 is in a high temperature mode. The low temperature mode is an operation mode when the battery pack 6 is at a low temperature (the temperature T of the cooling water that has passed around the battery pack 6 is T<10°C). The intermediate mode is an operation mode when the battery pack 6 is at room temperature (the temperature T of the cooling water that has passed around the battery pack 6 is 10≦T<25°C). The high temperature mode is an operation mode when the temperature T of the cooling water that has passed around the electrical component 1 is high, specifically T>90°C. The temperature range of each mode can be changed as appropriate.

[0027] <Low temperature mode> When an electric vehicle starts operating, the battery pack 6 is at a low temperature and needs to be warmed up to room temperature. In the low temperature mode as shown in Fig. 1, the coolant (hot water) heated by the heat pump 9 is caused to flow around the heater 11, and the second electric water pump (EWP) 13 is turned on to cause the hot water to flow through the first flow path R1, and the hot water is supplied to the outside of the electrical system components 1. Note that the first electric water pump (EWP) 12 is turned off.

[0028] In the low-temperature mode, the control unit controls the first motor-operated valve 5 to cause the cooling water that has passed around the outer periphery of the electric system component 1 to flow around the outer periphery of the battery pack 6. This causes the cooling water to flow through the second flow path R2. Since the cooling water flowing around the outer periphery of the battery pack 6 is warm water, the battery pack 6, which has been at a low temperature, is quickly warmed up.

[0029] The control unit also controls the second motor-operated valve 7 to allow the cooling water that has passed around the outer periphery of the battery pack 6 to flow to the heating input 9a of the heat pump 9. This causes the cooling water to flow through the sixth flow path R6. The cooling water that has returned to the heat pump 9 is heated again, and the hot water that has passed around the outer periphery of the heater 11 is circulated by the second electric water pump (EWP) 13 through the outer periphery of the electrical system components 1, the outer periphery of the battery pack 6, and the heat pump 9, in that order.

[0030] <Intermediate mode> As the low-temperature mode continues, the temperature of the cooling water passing around the outer periphery of the electrical component 1 rises, and when it exceeds a predetermined temperature (for example, 10°C), the control unit determines that the battery pack 6 has reached room temperature, and controls the first motor-operated valve 5 so that the cooling water that has passed around the outer periphery of the electrical component 1 flows to the heating input 9a of the heat pump 9 (without flowing to the battery pack 6), as shown in Fig. 2. This causes the cooling water to flow into the third flow path R3.

[0031] 2, in the intermediate mode, similarly to the low temperature mode, the cooling water (hot water) heated by the heat pump 9 is caused to flow around the heater 11, and the second electric water pump (EWP) 13 is turned on to cause hot water to flow through the first flow path R1, and this hot water is supplied to the outer periphery of the electrical component 1. The first motor-operated valve 5 controlled by the control unit as described above causes the cooling water that has passed around the outer periphery of the electrical component 1 to flow through the third flow path R3 to the heating input 9a of the heat pump 9. The cooling water flowing through the heating input 9a of the heat pump 9 is heated again. That is, in the intermediate mode, the cooling water circulates through the heat pump 9 and the outer periphery of the electrical component 1 in turn.

[0032] On the other hand, in the intermediate mode, the first electric water pump (EWP) 12 is further turned on, and the cooling water cooled by the heat pump 9 passes through the outer periphery of the cooler 10, and is then supplied to the outer periphery of the battery pack 6 via the fifth flow path R5. The control unit controls the second motor-operated valve 7 to cause the cooling water that has passed through the battery pack 6 to flow to the cooling input 9b of the heat pump 9. The cooling water flows through the seventh flow path R7 and returns to the cooling input 9b of the heat pump 9. That is, in the intermediate mode, the cooling water cooled in the heat pump 9 circulates to keep the temperature of the battery pack 6 at room temperature.

[0033] <High temperature mode> If the intermediate mode continues and the temperature of the coolant that has passed around the outer periphery of the electric component 1 exceeds a predetermined temperature (e.g., 90°C), the control unit determines that it is necessary to cool the electric component 1 to prevent overheating. Specifically, the control unit controls the first motor-operated valve 5 to cause most of the coolant that has passed around the electric component 1 to flow through the fourth flow path R4 to the radiator 14, and to reduce the flow rate of the coolant that flows through the third flow path R3 to the heating input 9a of the heat pump 9, as shown in FIG.

[0034] In the high temperature mode, the first motor-operated valve 5 controlled as described above allows much of the coolant that has passed around the outer periphery of the electrical system component 1 to flow to the radiator 14, reducing the flow rate to the heating input 9a of the heat pump 9. The coolant flowing to the radiator 14 is cooled, and before flowing around the outer periphery of the heater 11, it merges with a smaller amount of coolant supplied from the heat pump 9. Here, the temperature of the coolant flowing through the first flow path R1 by the second electric water pump (EWP) 13 has been significantly reduced by the radiator 14, so that the electrical system component 1 that has become hot can be effectively cooled.

[0035] In addition, the first electric water pump (EWP) 12 is maintained in the ON state, and the second motor-operated valve 7, like in the intermediate mode, causes the cooling water that has passed through the outer periphery of the battery pack 6 to flow through the fifth flow path R5 to the cooling input 9b of the heat pump 9. That is, even in the high temperature mode, the cooling water cooled in the heat pump 9 circulates to keep the temperature of the battery pack 6 at room temperature.

[0036] <Effects, etc.> As described above, according to this embodiment, in an electric vehicle including an electrical system component 1 that generates heat when current is applied, a battery pack 6 that supplies power to the electrical system component 1, a heat pump 9 that heats or cools the coolant, and a radiator 14 that cools the coolant, the cooling system 100 adjusts the temperatures of the electrical system component 1 and the battery pack 6 using the coolant. That is, the cooling system 100 includes a first electric valve 5 that directs cooling water supplied from a heat pump 9 or a radiator 14 and passing around the outer periphery of an electrical component 1 to either the heating input 9a of the heat pump 9, the radiator 14, or the outer periphery of a battery pack 6, and a second electric valve 7 that directs cooling water that has passed around the outer periphery of the battery pack 6 to either the heating input 9a or the cooling input 9b of the heat pump 9. In this configuration, the control unit controls the switching of the first motor-operated valve 5 and the second motor-operated valve 7 based on the temperature of the cooling water, thereby making it possible to efficiently adjust the temperatures of the electrical system components 1 and the battery pack 6 using the cooling water. Furthermore, by dividing the switching valve into two, the method of connecting the piping is simplified, and the degree of freedom in the mounting layout of each component can be improved compared to the conventional layout in which each component is laid out by arranging only one multi-port valve. In addition, when switching the flow path by controlling the first electric valve 5 and the second electric valve 7, the rotation of the first electric water pump (EWP) 12 and the second electric water pump (EWP) 13 can be slowed down or stopped, thereby reducing the load on the first electric valve 5 and the second electric valve 7, making it possible to make the valves smaller.

[0037] In this embodiment, the second motor-operated valve 7 is used as a switching valve having three-way ports, but the present invention is not limited to this. For example, as shown in Fig. 4, a wax-type temperature control valve 20, which opens and closes the valve by expanding or contracting a wax element depending on the temperature of the cooling water, may be used instead of the second motor-operated valve 7. In this way, the manufacturing cost can be further reduced.

[0038] Moreover, although the preferred embodiment of the present invention has been described in detail, modifications, variations and changes can be made without departing from the scope of the appended claims. [Explanation of symbols]

[0039] 1 Electrical components 2 charger 3 PCM 4 Motor 5. First motor-operated valve (first switching valve) 6 Battery pack (battery) 7 Second motor-operated valve (second switching valve) 9. Heat Pump 9a Heating input 9b Cooling input 10. Cooler 11 Heater 12 First electric water pump 13 Second electric water pump 14 Radiator 20 Wax type temperature control valve (switching valve) 100 Cooling System

Claims

1. A cooling system for an electric vehicle including electrical components that generate heat when current is applied, a battery that supplies power to the electrical components, a heat pump that heats or cools a coolant, and a radiator that cools the coolant, the cooling system adjusting temperatures of the electrical components and the battery using coolant, a first switching valve for causing the cooling water supplied from the heat pump or the radiator and passing through an outer periphery of the electrical system components to flow to one of the heating input of the heat pump, the radiator, and the outer periphery of the battery; a second switching valve that causes the cooling water that has passed around the outer periphery of the battery to flow to either the heating input or the cooling input of the heat pump; A cooling system comprising:

2. a temperature sensor for detecting a temperature of the cooling water that has passed around the outer periphery of the electrical system component; a control unit that controls a switching operation of each of the first switching valve and the second switching valve based on the temperature detected by the temperature sensor; 2. The cooling system of claim 1, further comprising:

3. a first electric water pump for supplying the cooling water cooled by the heat pump to an outer periphery of the battery; a second electric water pump for supplying either or both of the cooling water heated by the heat pump and the cooling water supplied from the radiator to an outer periphery of the electrical system components; Equipped with 2. The cooling system according to claim 1, wherein the first electric water pump does not operate when cooling water is not supplied to the cooling input of the heat pump due to the switching operation of the second switching valve.

4. 2. The cooling system according to claim 1, wherein the first changeover valve and the second changeover valve are motor-operated valves.

5. 2. The cooling system according to claim 1, wherein the first switching valve is an electric valve, and the second switching valve is a wax-type temperature control valve in which a wax element expands or contracts depending on the temperature of the cooling water to open and close the valve.

Images