Thermal management system and control method in a thermal management system

Abstract

A heat management system and a control method in a heat management system are provided. The heat management system includes a first cooler that cools a first heat source, a first circulation path that connects the first cooler and a first pump, a second cooler that cools a second heat source, a second circulation path that connects the second cooler and a second pump, a switching valve, and a controller. The switching valve is switchable between a first valve position and a second valve position. The first circulation path and the second circulation path are separated when the switching valve is in the first valve position. The controller causes both the first pump and the second pump to operate when a temperature difference between a cooling medium in the first circulation path and a cooling medium in the second circulation path exceeds a prescribed temperature difference threshold, with the switching valve set to the first valve position and one of the first pump and the second pump operating and the other stopped.

Description

Technical Field

[0001] The technology disclosed in this specification relates to thermal management systems and control methods within thermal management systems. Background Technology

[0002] Thermal management systems with multiple heat sources and corresponding coolers for each heat source are known. Japanese Patent Application Publication No. 2015-30289 discloses an example of such a thermal management system. The thermal management system of Japanese Patent Application Publication No. 2015-30289 has multiple flow paths connecting multiple coolers to multiple pumps, and includes a switching valve that switches the connection relationship of the flow paths according to the temperature of the cooling medium. Examples of the structure of the switching valve are disclosed in Japanese Patent Application Publication Nos. 2021-42809 and 2020-200943. Summary of the Invention

[0003] In switching valves that switch the connection relationships of multiple flow paths (e.g., switching valves according to Japanese Patent Application Publication No. 2021-42809 and 2020-200943), cooling medium leakage may occur. For example, there is a known switching valve that switches between a first valve position and a second valve position. In the first valve position, the first flow path is connected to the third flow path and the second flow path is connected to the fourth flow path. In the second valve position, the first flow path is connected to the fourth flow path and the second flow path is connected to the third flow path. When the first valve position is selected, the cooling medium flows to the first and third flow paths. When the cooling medium in the second and fourth flow paths stops, the valve position changes due to the pressure difference within the switching valve, and the cooling medium may leak from the first flow path to the second or fourth flow path. Alternatively, when the second valve position is selected, the cooling medium flows to the first and fourth flow paths. When the cooling medium in the second and third flow paths stops, the valve position moves due to the pressure difference within the switching valve, and the cooling medium may leak from the first flow path to the second or third flow path. When there is a large temperature difference between the cooling medium in the first flow path and the cooling medium in the second flow path, the movement of the cooling medium between the flow paths will lead to a decrease in cooling efficiency. This specification provides a technique for preventing the mixing of cooling media with temperature differences in a thermal management system with a switching valve that has a switching flow path connection.

[0004] The thermal management system of the first embodiment of the present invention includes a first cooler for cooling a first heat source, a first circulation path connecting the first cooler to a first pump, a second cooler for cooling a second heat source, a second circulation path connecting the second cooler to a second pump, a switching valve, and a controller. The switching valve is capable of switching between a first valve position and a second valve position. When the switching valve is set to the first valve position, the first circulation path and the second circulation path are separated. When the switching valve is set to the second valve position, and one of the first pump and the second pump is activated while the other is stopped, if the temperature difference between the cooling medium in the first circulation path and the cooling medium in the second circulation path exceeds a predetermined temperature difference threshold, the controller activates both the first pump and the second pump.

[0005] The controller typically sets the switching valve to the first position. If the temperature of the cooling medium in the first circulation path is high, the first pump is activated; if the temperature of the cooling medium in the first circulation path is low, the first pump is stopped. Similarly, if the temperature of the cooling medium in the second circulation path is high, the controller activates the second pump; if the temperature of the cooling medium in the second circulation path is low, the controller stops the second pump. When one pump is activated while the other is stopped, a pressure difference is created in the switching valve, potentially causing the cooling medium in the higher-pressure path to leak into the lower-pressure path.

[0006] If the temperature difference of the cooling medium in the two circulation paths is small, there is no problem even if the cooling medium leaks from one circulation path to the other. However, if the temperature difference of the cooling medium in the two circulation paths is large, the cooling efficiency may decrease if the cooling medium leaks from one circulation path to the other. Therefore, the controller activates both the first and second pumps when the temperature difference of the cooling medium in the two circulation paths exceeds a specified temperature difference threshold. By activating both pumps, the pressure difference in the switching valve is reduced, preventing cooling medium leakage.

[0007] In the thermal management system described above, one example of the first heat source could be a motor used for driving, and another example of the second heat source could be a power source supplying electricity to the motor. In this case, the controller can determine that the temperature difference exceeds a temperature difference threshold and activate the first and second pumps if the temperature of the cooling medium in the first circulation path exceeds a predetermined upper limit temperature. There may be a situation where the upper limit of the allowable temperature range of the motor is significantly higher than the upper limit of the allowable temperature range of the power source. In such a case, if the temperature of the cooling medium in the first circulation path cooling the motor exceeds the upper limit temperature, it can be determined that the temperature difference between the cooling media in the first and second circulation paths exceeds the temperature difference threshold.

[0008] Furthermore, in the thermal management system described above, the controller can stop the second pump when the temperature of the cooling medium in the second circulation path is below a predetermined temperature threshold while the switching valve is set to the first valve position. However, the controller can also operate both the first and second pumps regardless of the temperature of the cooling medium in the second circulation path if the temperature difference between the cooling medium in the first and second circulation paths exceeds a temperature difference threshold.

[0009] It should be noted that in the thermal management system of the above scheme, the controller can drive both the first pump and the second pump with the same output.

[0010] In the control method of the thermal management system of the second aspect of the present invention, the thermal management system includes: a first cooler for cooling a first heat source; a first circulation path connecting the first cooler to a first pump; a second cooler for cooling a second heat source; a second circulation path connecting the second cooler to a second pump; and a switching valve for switching between a first valve position separating the first circulation path and the second circulation path and a second valve position connecting the first circulation path and the second circulation path. In the control method, when the switching valve is set to the first valve position and one of the first pump and the second pump operates while the other stops, the temperature of the cooling medium in the first circulation path is compared with the temperature of the cooling medium in the second circulation path. If the temperature difference between the cooling medium in the first circulation path and the cooling medium in the second circulation path exceeds a predetermined temperature difference threshold, both the first pump and the second pump are activated.

[0011] Details of the technology disclosed in this specification and further improvements are described in the following "Detailed Description". Attached Figure Description

[0012] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals denote like parts, wherein:

[0013] Figure 1 This is the thermal loop diagram (first valve position) of the thermal management system of the first embodiment.

[0014] Figure 2 This is the thermal loop diagram (second valve position) of the thermal management system of the first embodiment.

[0015] Figure 3 This is a cross-sectional view showing an example of the construction of a switching valve (first valve position).

[0016] Figure 4 This is a cross-sectional view showing an example of the construction of a switching valve (second valve position).

[0017] Figure 5 This is a cross-sectional view showing an example of the construction of a switching valve (an example of the valve position in the middle).

[0018] Figure 6 This is a flowchart of the cooling control process.

[0019] Figure 7 This is a flowchart of the controller's processing in the first embodiment.

[0020] Figure 8 This is a flowchart of the controller's processing in the second embodiment. Detailed Implementation

[0021] (First Embodiment)

[0022] Referring to the accompanying drawings, the thermal management system 2 of the first embodiment will be described. Figure 1 The thermal loop diagram of thermal management system 2 is shown. In this specification, "thermal loop" refers to the loop of the flow path of the cooling medium.

[0023] The thermal management system 2 is installed in the electric vehicle and cools the power source 21 and the electric motor 11 used for driving. The electricity from the power source 21 is converted into AC power suitable for driving the electric motor 11 by a power converter (not shown) and supplied to the electric motor 11. The power source 21 is typically a lithium-ion battery or fuel cell, but can also be other types of power sources. Figure 1 The diagram of the power lines is omitted.

[0024] The thermal management system 2 includes a first circulation path 10 and a second circulation path 20 for supplying cooling medium, a first cooler 12 for cooling the motor 11, a second cooler 22 for cooling the power supply 21, a first heat exchanger 14 for cooling the cooling medium passing through the first circulation path 10, a second heat exchanger 24 for cooling the cooling medium passing through the second circulation path 20, a switching valve 30 for switching the flow path of the cooling medium, and a controller 40.

[0025] The first circulation path 10 is a pipe connecting the first cooler 12 and the first heat exchanger 14, allowing the cooling medium to circulate between the first cooler 12 and the first heat exchanger 14. A first pump 13 is provided on the first circulation path 10. The first pump 13 pressurizes and delivers the cooling medium in the first circulation path 10.

[0026] The first cooler 12 includes an oil cooler 91, an oil pump 92, and an oil flow path 93. A first circulation path 10 passes through the oil cooler 91. The oil flow path 93 passes through the oil cooler 91 and the electric motor 11. Oil flows in the oil flow path 93. The oil pump 92 is disposed in the oil flow path 93 to circulate the oil between the oil cooler 91 and the electric motor 11. The electric motor 11 is cooled by a cooling medium flowing in the first circulation path 10. More specifically, within the oil cooler 91, the cooling medium cools the oil, and the cooled oil cools the electric motor 11. The heat of the electric motor 11 is absorbed by the cooling medium via the oil.

[0027] The second circulation path 20 is a pipe connecting the second cooler 22 and the second heat exchanger 24, allowing the cooling medium to circulate between the second cooler 22 and the second heat exchanger 24. A second pump 23 is provided on the second circulation path 20. The second pump 23 pressurizes and delivers the cooling medium in the second circulation path 20. The cooling medium passing through the second cooler 22 cools the power supply 21. The cooling medium, which becomes high-temperature due to the heat from the power supply 21, is cooled by the second heat exchanger 24.

[0028] The thermal management system 2 includes temperature sensors 15 and 25. Temperature sensor 15 measures the temperature of the cooling medium in the first circulation path 10. Temperature sensor 25 measures the temperature of the cooling medium in the second circulation path 20. The thermal management system 2 also includes several other temperature sensors, but their descriptions are omitted.

[0029] The temperature sensors 15 and 25 transmit their measurements to the controller 40. The controller 40 controls the first pump 13 based on the temperature sensor 15 and the second pump 23 based on the temperature sensor 25. The controller 40 may be, for example, a processor, an ECU, etc.

[0030] Both the first circulation path 10 and the second circulation path 20 are connected to the switching valve 30. For ease of explanation, the first circulation path 10 is divided into flow path 10a and flow path 10b, and the second circulation path 20 is divided into flow path 20a and flow path 20b. Furthermore, a bypass flow path 19 is attached to the first circulation path 10. One end of each of flow paths 10a, 10b, 20a, 20b, and the bypass flow path 19 is connected to the switching valve 30. The switching valve 30 switches the connection relationship of these flow paths.

[0031] The other ends of flow paths 10a, 10b, 20a, 20b, and bypass flow path 19 are each connected by a plurality of three-way valves 95. A first pump 13, located in the first circulation path 10, and a second pump 23, located in the second circulation path 20, pressurize and supply cooling medium toward the switching valve 30. The path of the cooling medium is determined according to the state of the switching valve 30. Based on the path of the cooling medium, the direction of cooling medium flow at each of the plurality of three-way valves 95 is determined accordingly.

[0032] The switching valve 30 can select the first valve position and the second valve position. Figure 1 The arrows indicate the flow of cooling medium when the switching valve 30 selects the first valve position. When the switching valve 30 selects the first valve position, it connects flow path 10a to flow path 10b and flow path 20a to flow path 20b. As mentioned earlier, flow paths 10a and 10b constitute the first circulation path 10, and flow paths 20a and 20b constitute the second circulation path 20. The switching valve 30, when selecting the first valve position, separates the first circulation path 10 from the second circulation path 20. As mentioned earlier, the other ends of flow paths 10a, 10b, 20a, 20b, and the bypass flow path 19 are connected by several three-way valves 95. However, when the switching valve 30 selects the first valve position, the cooling medium flowing in the first circulation path 10 and the cooling medium flowing in the second circulation path 20 will not mix.

[0033] When the switching valve 30 selects the first valve position, the first circulation path 10 and the second circulation path are separated. At this time, the controller 40 controls the first pump 13 to maintain the temperature of the cooling medium in the first circulation path 10 (i.e., the temperature of the motor 11) below a predetermined first temperature threshold. When the temperature of the cooling medium in the first circulation path 10 exceeds the first temperature threshold, the controller 40 drives the first pump 13 to circulate the cooling medium between the first cooler 12 and the first heat exchanger 14. The temperature of the cooling medium in the first circulation path 10 is measured by the temperature sensor 15. The first heat exchanger 14 is a radiator that releases heat from the cooling medium in the first circulation path 10 to the outside air. The controller 40 stops the first pump 13 when the temperature of the cooling medium in the first circulation path 10 is below the first temperature threshold. It should be noted that, specifically, to prevent pulsation of the first pump 13, the controller 40 stops the first pump 13 when the temperature of the cooling medium in the first circulation path 10 is below the temperature obtained by subtracting the tolerance temperature from the first temperature threshold.

[0034] Additionally, the controller 40 controls the second pump 23 to maintain the temperature of the cooling medium in the second circulation path 20 (i.e., the temperature of the power supply 21) below a predetermined second temperature threshold. When the temperature of the cooling medium in the second circulation path 20 exceeds the second temperature threshold, the controller 40 drives the second pump 23, causing the cooling medium to circulate between the second cooler 22 and the second heat exchanger 24. The temperature of the cooling medium in the second circulation path 20 is measured by a temperature sensor 25. The second heat exchanger 24 is a vehicle air conditioner containing a radiator, which releases heat from the cooling medium in the second circulation path 20 to the outside air. The controller 40 stops the second pump 23 when the temperature of the cooling medium in the second circulation path 20 falls below the second temperature threshold. More specifically, to prevent pulsation of the second pump 23, the controller 40 stops the second pump 23 when the temperature of the cooling medium in the second circulation path 20 falls below the temperature obtained by subtracting a tolerance temperature from the second temperature threshold.

[0035] As mentioned earlier, the second heat exchanger 24 is a vehicle cabin air conditioner, which sometimes uses the heat from the power supply 21 to heat the vehicle cabin. Moreover, when the temperature of the power supply 21 is lower than the temperature of the outside air, the heat from the outside air is sometimes used for vehicle cabin heating. When the heat from the outside air is used for vehicle cabin heating, the controller 40 sets the switching valve 30 to the second valve position.

[0036] Figure 2 This indicates the thermal circuit when switching valve 30 selects the second valve position. Figure 2 The arrows indicate the flow of cooling medium when the switching valve 30 selects the second valve position. When the second valve position is selected, the switching valve 30 connects flow path 10b to flow path 20a and connects flow path 10a to bypass flow path 19. When the switching valve 30 selects the second valve position, a portion of the first circulation path 10 (flow path 10b) is connected to a portion of the second circulation path 20 (flow path 20a). In other words, when the second valve position is selected, the switching valve 30 connects the first circulation path 10 and the second circulation path 20.

[0037] Explain the construction of switching valve 30. Figure 3 and Figure 4 This is a cross-sectional view of the switching valve 30. The switching valve 30 includes a housing 31, a piston valve 32, a spring 33, a limiting element 34, and an electromagnetic actuator (not shown). Figure 3 This shows a cross-section of the piston valve 32 when it is in the first valve position. Figure 4 This shows a cross-section of the piston valve 32 when it is in the second valve position. Several paths are provided within the piston valve 32. Figure 3 and Figure 4 The arrows in the diagram indicate the flow of the cooling medium.

[0038] Spring 33 is a tension spring, applying upward force to piston valve 32. When controller 40 holds switching valve 30 in the first valve position, it stops energizing the solenoid (not shown). At this time, as... Figure 3 As shown, the piston valve 32 is held at its uppermost position by the tension of the spring 33. Inside the switching valve 30, flow path 10a and flow path 10b are connected to form a first circulation path 10, and flow path 20a and flow path 20b are connected to form a second circulation path 20. The bypass flow path 19 is isolated from the other flow paths.

[0039] When the controller 40 holds the switching valve 30 in the second valve position, it energizes a solenoid (not shown). The force of the solenoid overcomes the force of the spring 33, causing the piston valve 32 to descend. Figure 4As shown, piston valve 32 is held at its lowest position. Inside switching valve 30, flow path 10a is connected to bypass flow path 19, and flow path 20a is connected to flow path 10b. In other words, the first circulation path 10 and the second circulation path 20 are connected. When switching valve 30 is in the first valve position, the cooling medium in the first circulation path 10 and the cooling medium in the second circulation path 20 do not mix; however, when switching valve 30 is in the second valve position, the cooling medium in the first circulation path 10 and the cooling medium in the second circulation path 20 mix.

[0040] As previously described, when the first valve position is selected, the switching valve 30 separates the first circulation path 10 from the second circulation path 20. At this time, the controller 40 controls the first pump 13 based on the temperature of the cooling medium in the first circulation path 10, and independently controls the second pump 23 based on the temperature of the cooling medium in the second circulation path 20. When the first pump 13 is activated and the second pump 23 is stopped, or when the first pump 13 is stopped and the second pump 23 is activated, a state arises within the switching valve 30 where cooling medium flows in one path and not in the other. Within the switching valve 30, a pressure difference in the cooling medium occurs. There exists a situation where this pressure difference overcomes the force of the spring 33, causing the piston valve 32 to move.

[0041] Figure 5 A cross-sectional view of the switching valve 30 is shown when the valve is in the intermediate position. Figure 5 The example illustrates a state where cooling medium flows in path P1, connecting flow paths 10a and 10b of the first circulation path 10, and does not flow in path P2, connecting flow paths 20a and 20b of the second circulation path 20. Because the first pump 13 is activated and the second pump 23 is stopped, the pressure in path P1 is higher than the pressure in path P2. Inside the switching valve 30, the pressure difference becomes a force F that overcomes the force of the spring 33 holding the piston valve 32 at its uppermost position, causing the piston valve 32 to be pressed down. Due to the force F generated by the pressure difference, there is a possibility that the piston valve 32 may move to a midway position, causing cooling medium to leak from the first circulation path 10 to the second circulation path 20. Figure 5 The dashed arrow symbolically represents the leaking cooling medium.

[0042] If the temperature difference of the cooling medium in the two circulation paths (first circulation path 10 and second circulation path 20) is small, there is no problem even if the cooling medium leaks from one circulation path to the other. However, if the temperature difference of the cooling medium in the two circulation paths is large, the cooling efficiency may decrease if the cooling medium leaks from one circulation path to the other. Therefore, when the temperature difference of the cooling medium in the two circulation paths exceeds a predetermined temperature difference threshold, the controller 40 activates both the first pump 13 and the second pump 23. By activating both pumps, the pressure difference in the switching valve 30 is reduced, preventing cooling medium leakage.

[0043] Figure 6 A flowchart of the cooling control is shown. Figure 6 This is a flowchart for controlling the cooling medium to maintain its temperature within an appropriate range. The controller 40 repeats this process at predetermined time intervals during the period when the switching valve 30 selects the first valve position. Figure 6 The processing.

[0044] The controller 40 compares the temperature of the cooling medium in the first circulation path 10 with a first temperature threshold (step S2). If the temperature of the cooling medium exceeds the first temperature threshold, the controller 40 drives the first pump 13 (step S2 is "Yes", S3). If the temperature of the cooling medium is below the first temperature threshold, the controller 40 stops the first pump 13 (step S2 is "No", S4 is "Yes", S5). It should be noted that, as mentioned above, strictly speaking, the controller 40 stops the first pump 13 when the temperature of the cooling medium is lower than the value obtained by subtracting the tolerance temperature from the first temperature threshold.

[0045] Next, the controller 40 compares the temperature of the cooling medium in the second circulation path 20 with a second temperature threshold (step S6). If the temperature of the cooling medium in the second circulation path 20 exceeds the second temperature threshold, the controller 40 drives the second pump 23 (step S6 is "Yes", S7). If the temperature of the cooling medium is below the second temperature threshold, the controller 40 stops the second pump 23 (step S6 is "No", S8 is "Yes", S9). It should be noted that, as mentioned above, strictly speaking, the controller 40 stops the second pump 23 when the temperature of the cooling medium is lower than the value obtained by subtracting the tolerance temperature from the second temperature threshold.

[0046] like Figure 6 As shown, the controller 40 controls the first pump 13 based on the temperature of the cooling medium in the first circulation path 10, and controls the second pump 23 independently based on the temperature of the cooling medium in the second circulation path 20.

[0047] Figure 7A flowchart illustrating the process for preventing coolant leakage is shown. The controller 40 repeatedly executes this process at a constant cycle while the switching valve 30 is set to the first valve position. Figure 6 The processing. Controller 40 and Figure 6 The processing is performed independently and repeatedly. Figure 7 The controller 40 checks whether either the first pump 13 or the second pump 23 is in operation (step S12). If both the first pump 13 and the second pump 23 are in operation or both are stopped, the controller 40 does nothing and ends the process (step S12 is "No", return).

[0048] When only one of the first pump 13 and the second pump 23 is operating, the controller 40 compares the temperature difference between the cooling medium in the first circulation path 10 and the cooling medium in the second circulation path 20 with a predetermined temperature difference threshold (step S12 is "Yes", S13). If the temperature difference is lower than the temperature difference threshold (step S13 is "No"), the controller 40 directly terminates the process. On the other hand, if the temperature difference exceeds the temperature difference threshold (step S13 is "Yes"), the controller 40 activates both the first pump 13 and the second pump 23 (step S14). At this time, the controller 40 drives the first pump 13 and the second pump 23 with the same output. When the temperature difference of the cooling medium is large and one pump is operating while the other pump is stopped, the controller 40 drives both pumps with the same output. Through this process, the pressure difference in the switching valve 30 is reduced, thus preventing leakage of the cooling medium in the switching valve 30.

[0049] It should be noted that if step S14 is executed, skipping it... Figure 6 Step S5 or S9. That is, when the temperature difference between the cooling medium in the first circulation path 10 and the cooling medium in the second circulation path 20 exceeds the temperature difference threshold, the controller 40 will activate both the first pump 13 and the second pump 23, regardless of the temperature of the cooling medium in the first circulation path 10 and the second circulation path 20.

[0050] (Second Embodiment)

[0051] The thermal management system of the second embodiment will be described. The hardware structure of the thermal management system of the second embodiment is the same as that of the thermal management system 2 of the first embodiment (refer to...). Figure 1 , Figure 2 )same. Figure 8 A flowchart illustrating the processing performed by the controller 40 of the thermal management system according to the second embodiment is shown. The controller 40 repeatedly executes this process at a constant cycle when the switching valve 30 selects the first valve position. Figure 8 The processing. Controller 40 and Figure 6 The processing is performed in parallel. Figure 8 The processing.

[0052] The controller 40 confirms whether either the first pump 13 or the second pump 23 is in operation (step S22). If both the first pump 13 and the second pump 23 are in operation or both are stopped, the controller 40 does nothing and ends the process (step S22 is "No", return).

[0053] When only one of the first pump 13 and the second pump 23 is operating, the controller 40 compares the temperature of the cooling medium in the first circulation path 10 with a predetermined upper limit temperature (step S22 is "Yes", S23). If the temperature of the cooling medium in the first circulation path 10 is lower than the predetermined upper limit temperature (step S23 is "No"), the controller 40 directly terminates the process. On the other hand, if the temperature of the cooling medium in the first circulation path 10 exceeds the upper limit temperature (step S23 is "Yes"), the controller 40 activates both the first pump 13 and the second pump 23 (step S24). The first circulation path 10 (first cooler 12) cools the motor 11, thus the temperature of the cooling medium becomes high. On the other hand, the second circulation path 20 (second cooler 22) cools the power supply 21. The upper limit temperature of the motor 11 is significantly higher than the upper limit temperature of the power supply 21. That is, if the temperature of the cooling medium in the first circulation path 10 exceeds the upper limit temperature, there is a high probability that the temperature difference between the cooling medium in the first circulation path 10 and the cooling medium in the second circulation path 20 exceeds the temperature difference threshold. In this situation, the controller 40 drives both the first pump 13 and the second pump 23 (step S23 is "Yes", S24). In this case, the internal pressure difference of the switching valve 30 also decreases, thus preventing leakage of the cooling medium inside the switching valve 30.

[0054] It should be noted that in the second embodiment, step S24 is also executed, but skipped. Figure 6 Step S5 or S9. That is, if the temperature of the cooling medium in the first circulation path 10 exceeds the upper limit temperature, the controller 40 will activate both the first pump 13 and the second pump 23, regardless of the temperature of the cooling medium in the first circulation path 10 and the second circulation path 20.

[0055] As described above, the thermal management system 2 can prevent cooling medium leakage when the temperature difference of the cooling medium in the switching valve 30 that switches multiple flow paths is large.

[0056] It should be noted that when the temperature difference of the cooling medium is small, it is possible for one pump to operate while the other pump remains inactive.

[0057] Note the points to note regarding the techniques described in the embodiments. The motor 11 for driving is an example of a first heat source. The power supply 21 is an example of a second heat source.

[0058] The construction of switching valves that may leak cooling medium is not limited to... Figures 3-5 The construction of the valve is well known. It is also known that liquid (cooling medium) may leak from the switching valve. The switching valves with such constructions illustrated in Japanese Patent Application Laid-Open Nos. 2021-42809 and 2020-200943 are applicable to the technology disclosed in this specification.

[0059] The specific examples of the present invention have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes structures with various modifications and alterations to the specific examples described above. The technical elements illustrated in this specification or drawings are elements that exert technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of application. Moreover, the technology illustrated in this specification or drawings is capable of achieving multiple objectives simultaneously, and achieving one of these objectives is itself technically useful.

Claims

1. A thermal management system, characterized by, comprises: a first cooler that cools a first heat source; a first circulation passage that connects the first cooler and a first pump; a second cooler that cools a second heat source; a second circulation passage that connects the second cooler and a second pump; a switching valve that switches between a first valve position in which the first circulation passage and the second circulation passage are separated and a second valve position in which the first circulation passage and the second circulation passage are communicated; and a controller that, when the switching valve is set to the first valve position and one of the first pump and the second pump is operated while the other is stopped, operates both the first pump and the second pump when a temperature difference between a cooling medium in the first circulation passage and a cooling medium in the second circulation passage exceeds a prescribed temperature difference threshold value in the state in which the switching valve is set to the first valve position, the controller drives both the first pump and the second pump at the same output.

2. The thermal management system according to claim 1, wherein the first heat source is an electric motor for running, and the second heat source is a power supply that supplies electric power to the electric motor; the controller stops the second pump during a period in which the temperature of the cooling medium in the second circulation passage is lower than a prescribed temperature threshold value during the period in which the switching valve selects the first valve position, the controller operates both the first pump and the second pump regardless of the temperature of the cooling medium in the second circulation passage when the temperature difference exceeds the temperature difference threshold value. comprises:

3. A thermal management system, characterized by, a first cooler that cools a first heat source; a first circulation passage that connects the first cooler and a first pump; a second cooler that cools a second heat source; a second circulation passage that connects the second cooler and a second pump; a switching valve that switches between a first valve position in which the first circulation passage and the second circulation passage are separated and a second valve position in which the first circulation passage and the second circulation passage are communicated; and a controller that, when the switching valve is set to the first valve position and one of the first pump and the second pump is operated while the other is stopped, operates both the first pump and the second pump when the temperature of a cooling medium in the first circulation passage exceeds a prescribed upper limit temperature, the first heat source is an electric motor for running, and the second heat source is a power supply that supplies electric power to the electric motor, the controller drives both the first pump and the second pump at the same output.

4. A control method in a thermal management system, a first cooler that cools a first heat source; a first circulation passage that connects the first cooler and a first pump; a second cooler that cools a second heat source; The thermal management system comprises: a second circulation passage that connects the second cooler and a second pump; a switching valve that switches between a first valve position in which the first circulation passage and the second circulation passage are separated and a second valve position in which the first circulation passage and the second circulation passage are communicated, the control method is characterized in that, when the switching valve is set to the first valve position and one of the first pump and the second pump is operated while the other is stopped, ​ ​ comparing a temperature of the cooling medium in the first circulation passage with a temperature of the cooling medium in the second circulation passage, in a case where a difference between the temperature of the cooling medium in the first circulation passage and the temperature of the cooling medium in the second circulation passage exceeds a prescribed temperature difference threshold value, causing both the first pump and the second pump to operate in a state where the switching valve is set to the first valve position, driving both the first pump and the second pump at the same output.

5. A control method in a thermal management system, The thermal management system comprises: a first cooler that cools a first heat source; a first circulation passage that connects the first cooler and a first pump; a second cooler that cools a second heat source; a second circulation passage that connects the second cooler and a second pump; and a switching valve that switches between a first valve position in which the first circulation passage and the second circulation passage are separated and a second valve position in which the first circulation passage and the second circulation passage are communicated, the control method being characterized in that, in a case where the switching valve is set to the first valve position and one of the first pump and the second pump is operating while the other is stopped, in a case where the temperature of the cooling medium in the first circulation passage exceeds a prescribed upper limit temperature, causing both the first pump and the second pump to operate, the first heat source is an electric motor for running, and the second heat source is a power supply that supplies power to the electric motor, driving both the first pump and the second pump at the same output.

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