Battery cooling system

Abstract

The present application relates to a battery cooling system. The battery cooling system includes: a battery cooling circuit in which a heat medium that cools a battery circulates, the battery cooling circuit having a cooler path and a battery path; a cooler for cooling the heat medium; the battery; and a parallel cooling circuit; a switching valve that can switch communication and blockage between at least two paths of the cooler path, the battery path, and the parallel cooling circuit; a heat medium temperature sensor for detecting a heat medium temperature of the heat medium; an ambient temperature sensor for detecting an ambient temperature of an environment; a battery temperature sensor for acquiring a battery temperature of the battery; and a control device, wherein the control device discriminates an abnormality of the switching valve based on the heat medium temperature and a threshold temperature associated with a highest temperature of the ambient temperature and the battery temperature.

Description

Technical Field

[0001] The technology disclosed in this specification relates to systems for cooling batteries. Background Technology

[0002] Japanese Patent Application Publication No. 2020-4484 discloses a battery cooling system for vehicles. This battery cooling system has a battery cooling circuit for circulating a heat transfer medium to cool the battery. Summary of the Invention

[0003] There are also cases where the path of such a battery cooling system is connected to other cooling circuits, such as circuits used to cool heat-generating electrical equipment using power supplied from the battery. In this case, a switching valve is provided at the connection point between the battery cooling system and other cooling circuits, which can switch the connection and blockage of the mutual paths.

[0004] If the switching valve is damaged or deteriorates, its function will be reduced. Sometimes, heat transfer medium may unexpectedly flow into other cooling circuits or out of the battery cooling circuit via the switching valve. This reduced function of the switching valve will affect the battery's cooling performance.

[0005] However, identifying abnormalities such as damage or deterioration in switching valves is difficult because it requires specific procedures to independently verify or evaluate the valve's operation. Furthermore, rapid detection of switching valve abnormalities is required. This specification provides a technique that solves these problems.

[0006] The technology disclosed in this specification is specifically embodied in a battery cooling system. One aspect of the battery cooling system of the present invention includes: a battery cooling circuit in which a heat medium for cooling the battery circulates, the battery cooling circuit having a cooler path and a battery path for cooling the heat medium, the cooler path and the battery path being interconnected; a cooler for cooling the heat medium on the cooler path; a battery for cooling via the battery path; and a shared cooling circuit, a cooling circuit connected to the cooler path and the battery path at a connection point connecting them, the shared heat medium circulating in the shared cooling circuit; a switching valve capable of switching the connection and disconnection between the cooler path, the battery path, and at least two of the shared cooling circuits at the connection point between the cooler path and the battery path; a heat medium temperature sensor for detecting the temperature of the heat medium circulating in the battery cooling circuit; an ambient temperature sensor for detecting the ambient temperature of the environment in which the battery cooling system is located; a battery temperature sensor for acquiring the battery temperature; and a control device. The control device determines abnormalities in the switching valve based on the temperature of the heat medium and a threshold temperature associated with the highest of the ambient temperature and the battery temperature.

[0007] According to the inventors of the present invention, it has been found that, under normal operating conditions of the battery cooling system, the temperature of the heat transfer medium circulating in the battery cooling circuit of the battery cooling system remains constant relative to the ambient temperature and / or battery temperature of the environment in which the battery cooling system is located. Furthermore, it has been discovered that, in the event of an abnormality in the switching valve, the abnormality can be detected by setting a threshold temperature associated with the highest temperature of the ambient temperature and the battery temperature.

[0008] This battery cooling system allows for the detection of valve malfunctions directly within the system itself. In other words, it eliminates the need for verification or operational evaluation of the switching valve itself. Therefore, it avoids shutting down the battery cooling system to detect valve malfunctions, providing a simple and rapid method for assessment based on the temperature of the heat transfer medium and the threshold temperature.

[0009] There is no particular limitation on the threshold temperature associated with the highest ambient and battery temperatures. Although it also depends on the ambient and battery temperatures, it is acceptable as long as it is a value that can detect abnormalities in the switching valve, such as one that can be determined through experiments or simulations.

[0010] In the battery cooling system, the threshold temperature may also be a temperature that has increased by a predetermined temperature relative to the maximum temperature.

[0011] In the battery cooling system, the threshold temperature can also be set to a temperature that is 5°C higher than the maximum temperature but less than 15°C higher.

[0012] In the battery cooling system, the thermal medium temperature sensor may also be located downstream of the switching valve.

[0013] In the battery cooling system, the switching valve may also be located at the connection point between the downstream end of the cooler path and the upstream end of the battery path.

[0014] In the battery cooling system, the switching valve may also be a switching valve capable of switching the connection and disconnection between at least two of the paths of the cooler path, the battery path, and the path of the combined cooling circuit.

[0015] In the battery cooling system, the combined cooling circuit may also include: a heat-related device path, including heat-related devices that operate using the power of the battery; and a radiator path, including a radiator that facilitates heat exchange between the heat medium cooling the heat-related devices and the outside air, wherein the combined cooling circuit is a cooling circuit for circulating the heat medium.

[0016] In the battery cooling system, the cooling circuit may also include a bypass path that bypasses the radiator path.

[0017] The battery cooling system may also include a heat medium storage unit at another connection point between the cooler path and the battery path, wherein the battery cooling circuit and the concurrent cooling circuit are provided in such a manner that the battery cooling circuit and the concurrent cooling circuit are connected via the switching valve and the storage unit.

[0018] In the battery cooling system, the control device may determine the abnormality of the switching valve based on the temperature of the heat medium and the threshold temperature after a certain period of time has elapsed since the start of the circulation of the heat medium when the battery cooling circuit begins.

[0019] The battery cooling system may also include a first additional thermal circuit, which has a heat exchanger that cools the thermal medium by heat exchange with another thermal medium.

[0020] The battery cooling system may also include a second additional thermal circuit, which heats the other thermal medium through heat exchange with yet another thermal medium.

[0021] In the battery cooling system, the battery can also be a vehicle battery.

[0022] In the battery cooling system, the switching valve may be deemed to be malfunctioning when the temperature of the heat medium is compared with the threshold temperature, and the temperature of the heat medium is above or exceeds the threshold temperature.

[0023] In the battery cooling system, the switching valve may also be a switching valve capable of switching the connection and disconnection between the cooler path and the battery path and the concurrent cooling circuit. Attached Figure Description

[0024] 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, in which the same reference numerals show the same elements, and wherein:

[0025] Figure 1 This is a circuit diagram representing an example of a thermal management system that includes a battery cooling system.

[0026] Figure 2 This is a circuit diagram representing an example of the battery cooling operation mode in a thermal management system that includes a battery cooling system.

[0027] Figure 3 This diagram illustrates an example of anomaly detection and handling in a switching valve within a battery cooling system.

[0028] Figure 4 This is a loop diagram representing another example of the battery cooling operation mode in a thermal management system that includes a battery cooling system.

[0029] Figure 5 This is a loop diagram representing another example of the battery cooling operation mode in a thermal management system that includes a battery cooling system.

[0030] Figure 6 This is a loop diagram representing another example of a thermal management system that includes a battery cooling system. Detailed Implementation

[0031] In one embodiment of this technology, the threshold temperature can be set to a temperature that has increased by a predetermined temperature relative to the highest temperature. This allows for easy identification of any abnormalities in the switching valve.

[0032] In one embodiment of this technology, the threshold temperature can be set based on a temperature that is 5°C to 15°C higher than the maximum temperature. This allows for accurate detection of any abnormalities in the switching valve.

[0033] In one embodiment of this technology, a thermal medium temperature sensor can be provided on the downstream side of the switching valve. This allows for accurate detection of any abnormalities in the switching valve.

[0034] In one embodiment of this technology, a switching valve can be provided at the connection point between the downstream end of the cooler path and the upstream end of the battery path.

[0035] In one embodiment of this technology, the switching valve can be configured to switch between the connection and disconnection of at least two paths, including the cooler path, the battery path, and the combined cooling circuit. This allows for the design of both a battery cooling circuit and a combined cooling circuit with excellent thermal efficiency.

[0036] In one embodiment of this technology, a cooling circuit capable of circulating a heat transfer medium is used. This heat transfer medium circulation cooling circuit includes: a heat-related device path, including heat-related devices that operate using battery power; and a radiator path, including a radiator that exchanges heat between the heat transfer medium cooling the heat-related devices and the outside air. Thus, the circuit for cooling the interconnected battery and heat-related devices can be appropriately switched using a switching valve, thereby circulating the heat transfer medium.

[0037] In one embodiment of this technology, the cooling circuit can also have a bypass path that bypasses the radiator path. Therefore, temperature control of heat-related equipment within the cooling circuit can sometimes be performed efficiently.

[0038] In one embodiment of this technology, the battery cooling system can have a heat storage section at another connection point between the cooler path and the battery path, so that the battery cooling circuit and the shared cooling circuit are connected via a switching valve and the storage section. This allows for efficient temperature control of heat-related equipment in the shared cooling circuit.

[0039] In this embodiment of the technology, the control device can determine the abnormality of the switching valve based on the temperature of the thermal medium and a threshold temperature after a certain period of time has elapsed since the start of the circulation of the thermal medium in the battery cooling circuit. At the start of the circulation of the thermal medium in the battery cooling circuit, the temperature of the circulating thermal medium is uneven, making it difficult to detect the temperature of the thermal medium used for determination. This can sometimes lead to erroneous determination of the switching valve as normal or abnormal. By determining the abnormality based on the temperature of the thermal medium and the threshold temperature after a certain period of time has elapsed since the start of the circulation, high-precision determination is possible.

[0040] In embodiments of this technology, the battery cooling system may also include a first additional thermal circuit, which has a heat exchanger that cools the thermal medium through heat exchange with another thermal medium, and may also include a second additional thermal circuit that heats another thermal medium through heat exchange with yet another thermal medium. Thus, the heat absorbed by the thermal medium can be utilized efficiently.

[0041] In one embodiment of this technology, the battery can be configured as a vehicle battery. This allows for efficient utilization of heat generated within the vehicle.

[0042] The battery cooling system will now be described with reference to the accompanying drawings. The thermal management system 100 described below is installed in an electric vehicle and circulates a heat transfer medium such as antifreeze or refrigerant to heat and cool components of the electric vehicle and regulate the air inside the vehicle. The battery cooling system disclosed in this specification, as included in the thermal management system 100, includes at least a low-temperature radiator circuit 10, a first temperature sensor 44, a second temperature sensor 95, a third temperature sensor 97, and a control device 98. The thermal management system 100 can be called a battery cooling system as long as it includes these elements.

[0043] like Figure 1As shown, the thermal management system 100 includes a low-temperature radiator circuit 10 with a low-temperature radiator 42, a high-temperature radiator circuit 30 with a high-temperature radiator 94, a heat pump circuit 20 hot-connected between the two radiator circuits 10 and 30, and a control device 98. These circuits 10, 20, and 30 are thermally connected, but the paths of the heat transfer medium flow are independent of each other. Although not particularly limited, in the two radiator circuits 10 and 30, for example, a long-life antifreeze is used as the heat transfer medium. On the other hand, in the heat pump circuit 20, a refrigerant such as hydrofluorocarbon (HFC) (the heat transfer medium for the refrigeration cycle) is used as the heat transfer medium.

[0044] The low-temperature radiator circuit 10 and the heat pump circuit 20 are thermally connected via a cooler 70, and the heat pump circuit 20 and the high-temperature radiator circuit 30 are thermally connected via a capacitor 84. The cooler 70 and the capacitor 84 are both types of heat exchangers. The cooler 70 functions as an evaporator in the low-temperature radiator circuit 10, transferring heat from the heat medium of the low-temperature radiator circuit 10 to the heat medium of the heat pump circuit 20. The capacitor 84 functions as an evaporator in the heat pump circuit 20, transferring heat from the heat medium of the heat pump circuit 20 to the heat medium of the high-temperature radiator circuit 30.

[0045] The low-temperature radiator circuit 10 has a first circuit 12 for cooling a vehicle secondary battery (hereinafter referred to as the battery) 66 and a second circuit 16 for cooling thermally related equipment.

[0046] [First Circuit] The first circuit 12 is a circulation path that circulates the heat transfer medium between the cooler 70 and the battery 66. The first circuit 12 mainly includes a battery path 13 and a cooler path 14. The downstream end of the battery path 13 is connected to the upstream end of the cooler path 14, and the downstream end of the cooler path 14 is connected to the upstream end of the battery path 13. It should be noted that the first circuit 12 is an example of a battery cooling circuit disclosed in this specification, and the battery path 13 is an example of a battery path disclosed in this specification. In addition, the cooler 70 is an example of a cooler disclosed in this specification, and the cooler path 14 is an example of a cooler path disclosed in this specification.

[0047] Battery path 13 includes a heater 64, a battery 66, and a first temperature sensor 44 for detecting the temperature of the heat transfer medium at the outlet side of the battery 66, starting from the upstream side. The battery 66 supplies power to a motor integrated into the transmission drive axle 48 via the SPU 56 and PCU 58 (described later). The battery 66 is cooled by heat exchange with the heat transfer medium flowing in battery path 13. The heater 64 is an electric heater that heats the heat transfer medium in battery path 13 as needed, thereby heating the battery 66. The first temperature sensor 44 is connected to a control device 98, and the detected temperature (i.e., the temperature of the heat transfer medium flowing in the first loop 12) of the first temperature sensor 44 is taught to the control device 98.

[0048] The cooler path 14 includes a first pump 68 for circulating the heat medium and a cooler 70 from its upstream side. It should be noted that the location of the first pump 68 is not limited to the upstream side of the cooler 70, and can be appropriately set in the low-temperature radiator circuit 10.

[0049] The upstream end of battery path 13 and the downstream end of cooler path 14 are connected via a first switching valve 40. Additionally, the downstream end of battery path 13 and the upstream end of cooler path 14 are connected via a storage tank 69. The storage tank 69 has a heat medium storage section for removing air bubbles from the heat medium. The storage tank 69 is an example of a storage section disclosed in this specification.

[0050] The first switching valve 40 is a 5-way valve, connecting not only the two paths 13 and 14 of the first circuit 12, but also the three paths 17, 18, and 19 of the second circuit 16. Regarding the first circuit 12, the first switching valve 40 can circulate the hot medium within the first circuit 12, or switch the hot medium from the cooler path 14 to the low-temperature radiator path 17 of the second circuit 16, or adjust the flow rate ratio to each path. In other words, the hot medium in the first circuit 12 and the second circuit 16 is shared. The first switching valve 40 is connected to a control device 98, and its operation is controlled by the control device 98. The first switching valve 40 is one example of a switching valve disclosed in this specification.

[0051] [Second Circuit] The second circuit 16 is a circulation path that circulates the heat transfer medium between the cryogenic radiator 42 and several heat-related devices. The second circuit 16 mainly comprises a cryogenic radiator path 17 and a heat-related device path 18. The upstream end of the cryogenic radiator path 17 and the downstream end of the heat-related device path 18 are connected via a first switching valve 40 shared with the first circuit 12. The downstream end of the cryogenic radiator path 17 and the upstream end of the heat-related device path 18 are connected via a storage tank 69 shared with the first circuit 12. The second circuit 16 is an example of a shared cooling circuit disclosed in this specification. The cryogenic radiator 42 is shared between the first circuit 12 and the second circuit 16. Thus, the cryogenic radiator circuit 10 can be constructed efficiently.

[0052] The low-temperature radiator path 17 includes a low-temperature radiator 42. The heat-related equipment path 18 includes a second pump 60 for circulating the heat transfer medium. The heat-related equipment included in the heat-related equipment path 18 includes, for example, an oil cooler 54, a variable speed drive axle 48, and a power conversion device. As an example, the power conversion device in this embodiment includes an SPU56 (Smart Power Unit) containing a DC-DC converter and a PCU58 (Power Control Unit) containing an inverter.

[0053] The oil cooler 54 is a type of heat exchanger, thermally connected to the transmission drive axle 48 via an oil circulation path 50. The transmission drive axle 48 includes a drive motor for driving the wheels, a speed reducer between the drive motor and the wheels, etc. The oil circulation path 50 includes an oil pump 52, which circulates oil as a heat medium between the oil cooler 54 and the transmission drive axle 48. Thus, heat from the transmission drive axle 48 is transferred to the oil cooler 54, and then from the oil cooler 54 to the heat medium in the second circuit 16. Here, the transmission drive axle 48, oil cooler 54, power conversion device, etc., in this embodiment are examples of heat-related equipment provided in the second circuit 16.

[0054] The second circuit 16 also has a bypass path 19. The bypass path 19 bypasses the cryogenic radiator 42. The bypass path 19 branches at the first switching valve 40 at the connection point between the cryogenic radiator path 17 and the heat-related equipment path 18, bypasses the cryogenic radiator 42, and merges at the storage tank 69 at the downstream end of the cryogenic radiator path 17.

[0055] Using the first switching valve 40, in addition to the flow path and flow control already described, flow path control is also performed to form a circulation path for the second circuit 16 that allows the hot medium from the heat-related equipment path 18 to flow into the low-temperature radiator path 17 and circulate within the second circuit 16, or allows the hot medium from the heat-related equipment path 18 to flow into the bypass path 19 and bypass the low-temperature radiator 42, and flow path control is also performed on these paths.

[0056] The heat pump circuit 20 mainly comprises a main circuit 22 and a refrigeration path 24. The main circuit 22 is a circulation path that circulates the heat transfer medium (refrigerant) between the cooler 70 and the capacitor 84. The main circuit 22 also includes an expansion valve 72 and a compressor 82, forming a so-called refrigeration cycle. It should be noted that the expansion valve 72 is located upstream of the cooler 70, and the compressor 82 is located upstream of the capacitor 84. That is, in the main circuit 22, the heat transfer medium... Figure 1 The heat pump circuit operates in a counter-clockwise direction. The main circuit 22 transfers heat from the low-temperature radiator circuit 10, connected to the cooler 70, to the high-temperature radiator circuit 30, connected to the capacitor 84. The expansion valve 72 and the compressor 82 are connected to the control device 98, and their operation is controlled by the control device 98. It should be noted that the heat pump circuit 20 is one example of the first other heat circuit disclosed in this specification.

[0057] The refrigeration path 24 is arranged parallel to the cooler 70, bypassing the cooler 70. An expansion valve 78, a refrigeration evaporator 76, and an EPR 74 (evaporator pressure regulator) are provided in the refrigeration path 24. The refrigeration path 24 branches from the main circuit 22 upstream of the cooler 70 and merges back into the main circuit 22 downstream of the cooler 70. A second switching valve 80 is provided at the upstream end of the refrigeration path 24 (i.e., the branch point from the main circuit 22). The second switching valve 80 can switch the flow of the heat medium in the heat pump circuit 20 between the cooler 70 and the evaporator 76, or adjust the proportion of flow to them. The second switching valve 80 is connected to a control device 98, and its operation is controlled by the control device 98. As described above, in the cooler 70, heat is absorbed from the heat medium of the low-temperature radiator circuit 10 and transferred to the heat medium of the heat pump circuit 20. In contrast, in the evaporator 76 used for cooling, heat is absorbed from the air inside the vehicle (including air introduced from outside) and transferred to the heat medium of the heat pump circuit 20, thereby cooling the vehicle interior. The heat absorbed by the evaporator 76 is transferred from the capacitor 84 to the high-temperature radiator circuit 30.

[0058] The high-temperature radiator circuit 30 mainly comprises a main circuit 32 and a heating path 34. The main circuit 32 of the high-temperature radiator circuit 30 is a circulation path for circulating the heat transfer medium between the capacitor 84 and the high-temperature radiator 94. A third pump 88 for circulating the heat transfer medium is provided in the main circuit 32. The third pump 88 is located upstream of the capacitor 84. By circulating the heat transfer medium, the main circuit 32 releases heat transferred from the heat pump circuit 20 from the high-temperature radiator 94 to the outside air. It should be noted that a heater 86 is also provided in the main circuit 32. The heater 86 is an electric heater capable of heating the heat transfer medium as needed. The heater 86 is connected to a control device 98, and its operation is controlled by the control device 98. It should be noted that the high-temperature radiator circuit 30 is yet another example of a second other heat circuit disclosed in this specification.

[0059] A heating path 34 is arranged parallel to the high-temperature radiator 94, bypassing it. A heater core 92 is provided in the heating path 34. The heating path 34 branches from the main circuit 32 upstream of the high-temperature radiator 94 and merges back into the main circuit 32 downstream of the high-temperature radiator 94. A third switching valve 90 is provided at the upstream end of the heating path 34 (i.e., the branch point from the main circuit 32). The third switching valve 90 can switch the flow of the heat medium in the high-temperature radiator circuit 30 between the high-temperature radiator 94 and the heater core 92, or adjust the proportion of flow to them. The third switching valve 90 is connected to a control device 98, and its operation is controlled by the control device 98. In the heater core 92, heat is dissipated from the heat medium flowing in the heating path 34 to the air inside the vehicle (including air introduced from outside air), thereby heating the vehicle interior.

[0060] The thermal management system 100 also includes a second temperature sensor 95 for detecting the ambient temperature at which the thermal management system 100 is configured, and a third temperature sensor 97 for detecting the temperature of the battery 66. Here, the ambient temperature at which the thermal management system 100 is configured is, for example, the external air temperature of the housing containing the thermal management system (in this case, the vehicle). The second temperature sensor 95 can also be installed in the vehicle equipped with the thermal management system 100. For example, it can be installed near the front grille for introducing external air into the vehicle. The second temperature sensor 95 can also be a device that obtains the air temperature at the vehicle's location from a data center connected via a suitable communication network based on the vehicle's location information. This device can be a standalone device capable of communication or part of the control device 98. The second temperature sensor 95 is connected to the control device 98, and the ambient temperature detected by the second temperature sensor 95 is taught to the control device 98.

[0061] The third temperature sensor 97 is, for example, located inside the battery 66, and the battery temperature detected by the third temperature sensor 97 is, for example, the temperature of the battery cell of the battery 66. If the battery 66 has multiple battery cells, the third temperature sensor 97 can also be located in multiple places. The battery temperature detected by the third temperature sensor 97 is taught to the control device 98.

[0062] The thermal management system 100 has independent low-temperature radiator circuit 10, heat pump circuit 20, and high-temperature radiator circuit 30. In each circuit 10, 20, and 30, the control device 98 can switch the flow path of the heat medium in various ways. The thermal management system 100 can, for example, selectively or in appropriate combinations, execute various modes such as heating operation mode, cooling operation mode, heat-related equipment cooling mode, and battery cooling mode. These operation modes will be described later.

[0063] The control device 98 of the thermal management system 100 is configured as a so-called computer, equipped with at least one processor and memory. The memory stores a program executed when the first circuit 12 for cooling the battery 66 is operating. This program is used to detect abnormalities in the first switching valve 40 when the first circuit 12 is operating. The control device 98 is capable of performing a series of processes to detect abnormalities in the first switching valve 40 based on the temperatures obtained from the first temperature sensor 44, the second temperature sensor 95, and the third temperature sensor 97.

[0064] When the processor is operating in the first loop 12, it performs a series of processes to determine the abnormality of the switching valve through the switching valve abnormality detection program. In the control device 98, when the processor is operating in the first loop 12, it can obtain the temperature of the thermal medium, the ambient temperature, and the battery temperature from the first temperature sensor 44, the second temperature sensor 95, and the third temperature sensor 97 at a predetermined timing.

[0065] In the switching valve anomaly detection procedure, the processor determines whether the temperature of the heat transfer medium is above or exceeds a threshold temperature based on the highest temperature between the ambient temperature and the battery temperature. Here, the highest temperature is defined as either the higher of the two (ambient temperature and battery temperature) or the same of the two (equal temperatures). The processor can determine the highest temperature based on the ambient temperature and the battery temperature, and then determine the threshold temperature based on that highest temperature.

[0066] The threshold temperature can be preset based on evaluation and experimentation of the first switching valve 40. For example, it can be set to a temperature a certain degree higher than the maximum temperature. While not specifically limited, the lower limit of the sum of the temperatures added to the maximum temperature is, for example, 3°C, 4°C, 5°C, or 7°C. The upper limit of the sum of the temperatures is, for example, 15°C, 13°C, 12°C, or 10°C. The sum of the temperatures can be arbitrarily set based on these lower and upper limits, for example, 5°C to 15°C, or 7°C to 12°C, etc. By setting such a sum of temperatures relative to the maximum temperature as the threshold temperature, abnormalities of the first switching valve 40 can be easily and accurately identified.

[0067] Furthermore, as another example, the temperature added to the highest temperature could also include a temperature that varies depending on the height of the determined highest temperature. Additionally, for example, different temperatures could be appropriately added depending on whether the determined highest temperature originates from ambient temperature or battery temperature. For example, different temperatures could be appropriately added depending on whether the temperature is detected by the second temperature sensor 95 or the third temperature sensor 97. A table for setting such threshold temperatures could also be stored in the first memory.

[0068] Below, in Figure 2 The example illustrates the cooling operation mode of the battery 66 performed by the thermal management system 100. As an example of the processing performed by the thermal management system 100, in... Figure 3 The process of handling an anomaly in the first switching valve 40 between the first circuit 12 and the second circuit 16 in the battery cooling operation mode is illustrated below.

[0069] (Battery cooling operation mode) Figure 2 The circuit represents the battery cooling operation mode that the thermal management system 100 can perform. Figure 2 This refers to the battery cooling operation mode within the cooling operation mode. In the battery cooling operation mode, the control device 98, for example... Figure 2 The diagram shows the various parts of the thermal management system 100. In the high-temperature radiator circuit 30, the third switching valve 90 and the third pump 88 are controlled to circulate the heat medium in the main circuit 32. In the heat pump circuit 20, the second switching valve 80 and the compressor 82 are controlled to circulate the heat medium in the main circuit 22. In the low-temperature radiator circuit 10, the first pump 68 and the first switching valve 40 are controlled to allow the heat medium to flow in the first circuit 12, which is formed by the cooler path 14 and the battery path 13, via the first switching valve 40.

[0070] Therefore, in the main circuit 22 of the heat pump circuit 20, the heat medium cooled by the capacitor 84 flows into the cooler 70. In the cooler 70, the heat medium in the cooler path 14 is cooled, and the cooled heat medium flows into the battery path 13 to perform cooling of the battery 66.

[0071] (Switching valve anomaly detection and handling) Figure 3 The illustrated process is an example of a procedure performed by control device 98 based on a battery cooling requirement generated by detecting a temperature above a reference temperature of battery 66. Control device 98 initiates battery cooling processing based on the battery cooling requirement and performs processing based on the following switching valve anomaly detection procedure. Control device 98 first controls the first switching valve 40 and the first pump 68 based on the battery cooling requirement to circulate the heat transfer medium in the first circuit 12.

[0072] When the first pump 68 starts operating according to the battery cooling requirements and its output reaches a level sufficient to supply heat transfer medium to the first circuit 12, the processor executes processing based on the switching valve anomaly detection procedure. While not specifically limited, processing is executed, for example, when the duty cycle indication rate relative to the output voltage of the first pump 68 is 30% or higher.

[0073] If the valve malfunction detection process is initiated, the processor uses a built-in timer to measure the elapsed time from the start of the process and determines whether a certain amount of time has elapsed (step S100). According to step S100, by setting a standby time after the first pump 68 starts working, false detections caused by uneven temperature distribution of the heat transfer medium in the first circuit 12 can be avoided. This is because, when a vehicle equipped with the thermal management system 100 is parked with the motor of the transmission drive axle 48 or similar components stopped, the battery path 13 and cooler path 14 of the first circuit 12 are sometimes heated inside the vehicle, causing a localized rise in the temperature of the heat transfer medium.

[0074] The aforementioned time, i.e. the time required to eliminate the uneven distribution of the heat medium temperature immediately after the first pump 68 starts working, can be preset through evaluation experiments under various conditions. There is no particular limitation, and it can vary depending on the length of the path of the first loop 12, the setting range, etc. For example, it can be set in the range of tens of seconds to several minutes, which can be within 1 minute or within 3 minutes.

[0075] When the processor determines in step S100 that a certain amount of time has elapsed since the start of processing, it executes an anomaly judgment step (step S110) to determine whether the thermal medium temperature is above a threshold temperature by comparing the thermal medium temperature of the first circuit 12 with a threshold temperature based on the highest temperature of the ambient temperature and the battery temperature. The thermal medium temperature is obtained by the first temperature sensor 44, the ambient temperature is obtained by the second temperature sensor 95, and the battery temperature is obtained by the third temperature sensor 97.

[0076] When the temperature of the heat transfer medium is lower than or below a preset threshold temperature, the processor assumes that the first switching valve 40 has not malfunctioned and generates detection data (detection date and time, elapsed time since the start of the process, heat transfer medium temperature, ambient temperature, battery temperature, and threshold temperature, etc.) as switching valve information, and executes the step stored in the memory (step S120). The process ends.

[0077] On the other hand, when the temperature of the heat medium is above or exceeds the threshold temperature, the processor treats the first switching valve 40 as an anomaly and generates anomaly detection content (anomaly occurrence date and time, elapsed time since the start of processing, heat medium temperature, ambient temperature, battery temperature, and threshold temperature, etc.) as anomaly occurrence information, and executes the steps stored in the memory (step S130).

[0078] Furthermore, when the processor detects an abnormality in the first switching valve 40, it notifies the control device 98 of this situation and displays the abnormality of the first switching valve 40 on the thermal management system 100 or an appropriate display device provided by the vehicle, thus ending the process.

[0079] Through the above series of processes, the thermal management system 100 can detect any abnormality in the first switching valve 40 during the cooling process of the battery 66. It can easily and accurately detect any abnormality in the first switching valve 40, thus enabling rapid response to the abnormality and suppressing or preventing performance degradation of the battery 66. Furthermore, it can detect any abnormality in the first switching valve 40 at the start of the cooling process of the battery 66, allowing for rapid response.

[0080] It should be noted that the above process describes the execution of the switching valve anomaly detection process after the battery cooling operation has begun, but the execution period of the switching valve anomaly detection process is not limited to this. For example, the switching valve anomaly detection process can also be implemented at any time after the aforementioned certain period has elapsed since the start of the battery cooling operation, and until the end of the battery cooling operation. For example, it can be set to repeatedly execute the above process at a predetermined time interval starting from the start of the cooling operation of battery 66.

[0081] Furthermore, in the above processing, to avoid misjudgment while the vehicle is stationary, the switching valve malfunction detection step is not performed for a certain period of time after the battery cooling operation begins, but this is not a limitation. For example, the thermal management system 100 sometimes includes temperature sensors that detect the temperature of the thermal medium in the first circuit 12 at multiple locations within the first circuit 12. In this case, the processor can perform a step of detecting the temperature of the thermal medium from multiple different locations in the first circuit 12 from these temperature sensors and detecting that their temperature difference is below a certain value. Through this step, the switching valve malfunction detection step can also be performed when the temperature difference is below a certain value. Thus, without specifically setting a detection standby time from the start of the battery cooling operation, the malfunction of the first switching valve 40 can be accurately detected.

[0082] It should be noted that in the above process, the thermal management system 100 executes the battery cooling operation mode simultaneously with the cooling operation mode, but it is not limited to this. The battery cooling operation mode can also be executed independently, such as... Figure 4 As shown, the thermal management system 100 can also be executed simultaneously in the heating operation mode. That is, by operating the heat transfer medium in the high-temperature radiator circuit 30 in a manner that circulates in the heating path 34, and by operating the heat pump circuit 20 in the same manner as in the cooling operation mode, the heating operation can be performed.

[0083] In addition, such as Figure 5 As shown, the battery cooling operation mode can also be selectively or simultaneously executed with the heat-related equipment cooling operation mode, which circulates the heat transfer medium in the second circuit 16 of the cryogenic radiator circuit 10. For example, in order to simultaneously execute the battery cooling operation and the heat-related equipment cooling operation, the control device 98 controls the first switching valve 40, the first pump 68, and the second pump 60 so that the heat transfer medium circulates independently in the first circuit 12 and the second circuit 16. By using the cryogenic radiator 42 to cool the heat transfer medium in the cryogenic radiator path 17, it flows into the heat-related equipment path 18, thereby performing cooling of the heat-related equipment and the transmission drive axle 48 (motor).

[0084] Moreover, such as Figure 5 As shown, in the thermal management system 100, the battery cooling operation mode can also be selectively or simultaneously executed with the bypass loop operation mode, which circulates the thermal medium in the bypass loop 19a formed by the bypass path 19 of the second loop 16 and the thermally related equipment path 18. For example, in order to execute the battery cooling operation mode and the bypass loop operation mode simultaneously, the control device 98 controls the first switching valve 40, the first pump 68, and the second pump 60 to make the thermal medium circulate independently in the first loop 12 and the bypass loop 19a.

[0085] In the thermal management system 100, the first temperature sensor 44 is provided on the outlet side (downstream side) of the battery 66, but it is not limited to this. For example, the first temperature sensor 44 may also be provided on the inlet side (upstream side) of the battery 66, which is downstream of the first switching valve 40 and closer to the first switching valve 40. In this way, the temperature of the heat medium that has not passed through the battery 66 can be detected.

[0086] The thermal management system 100 includes a cooler 70 as a cooler, but is not limited to this. In addition to various known coolers, a heat exchanger can also be used.

[0087] The thermal management system 100 is designed to be installed in electric vehicles, but is not limited to this. It can also be used as a stationary thermal management system 100. In addition, the thermal management system 100 is provided with a battery cooling circuit (battery cooling system) for cooling the battery 66, but it can also be used as a cooling system for other batteries such as fuel cells.

[0088] The thermal management system 100 is configured to include a heat pump circuit 20 and a high-temperature radiator circuit 30, but these circuits are not required. Any system that includes the purpose of battery cooling is acceptable.

[0089] In the thermal management system 100, the first switching valve 40 is configured as a 5-way valve located at the connection point between the first circuit 12 and the second circuit 16, but it is not limited to this. For example, the first circuit 12 and the second circuit 16 may also be connected via a connecting circuit. For example, in Figure 6 In the thermal management system 200 shown, the first loop 12 and the second loop 16 are connected via connection path 210 and connection path 212. Furthermore, a first switching valve 220 is provided at the connection point between the first loop 12 and connection path 210. Additionally, a switching valve 240 is provided at a branch of the bypass path 19 of the second loop 16. If a high-temperature heat medium from the second loop 16 flows into connection paths 210 and 212, and the first switching valve 220 malfunctions, the temperature of the heat medium in the first loop 12 may rise. The switching valve malfunction detection processing disclosed in this specification can also be applied to the first loop 12 of the thermal management system 200.

[0090] The embodiments have been described in detail above, but these are merely illustrative and do not limit the scope of this disclosure. The technology disclosed includes various modifications and variations of the specific examples described above. The technical elements described in this specification or drawings exert their technical usefulness individually or in various combinations, and are not limited to the combinations described in the specific examples. Furthermore, the technology illustrated in this specification or drawings is a technology that simultaneously achieves multiple objectives, and achieving one of these objectives is itself technically useful.

Claims

1. A battery cooling system, characterized in that, include: A battery cooling circuit in which a heat medium for cooling the battery circulates, the battery cooling circuit having a cooler path and a battery path for cooling the heat medium, the cooler path and the battery path for cooling the heat medium being interconnected. A cooler that cools the heat medium along the cooler path; The battery is cooled using the battery path. The shared cooling circuit is a cooling circuit that connects the cooler path and the battery path to each other at a connection point, and the shared heat medium circulates in the shared cooling circuit. A switching valve, at one connection point between the cooler path and the battery path, is capable of switching the connection and disconnection between the cooler path, the battery path, and at least two paths in the combined cooling circuit; A thermal medium temperature sensor is used to detect the temperature of the thermal medium circulating in the battery cooling circuit; An ambient temperature sensor is used to detect the ambient temperature of an environment equipped with a battery cooling system. A battery temperature sensor is used to obtain the battery temperature of the battery; as well as Control device, wherein The control device determines a maximum temperature based on the ambient temperature and the battery temperature, determines a threshold temperature based on the maximum temperature, compares the heat medium temperature with the threshold temperature, and determines that the switching valve is malfunctioning when the heat medium temperature is above the threshold temperature.

2. The battery cooling system according to claim 1, characterized in that, The threshold temperature is the temperature after a predetermined increase relative to the maximum temperature.

3. The battery cooling system according to claim 1 or 2, characterized in that, The threshold temperature is set to a temperature that is 5°C higher than the maximum temperature but less than 15°C higher.

4. The battery cooling system according to claim 1 or 2, characterized in that, The thermal medium temperature sensor is located on the downstream side of the switching valve.

5. The battery cooling system according to claim 1 or 2, characterized in that, The switching valve is provided at the connection point between the downstream end of the cooler path and the upstream end of the battery path.

6. The battery cooling system according to claim 1 or 2, characterized in that, The switching valve is a switching valve capable of switching the connection and disconnection between at least two of the paths of the cooler path, the battery path, and the path of the combined cooling circuit.

7. The battery cooling system according to claim 1 or 2, characterized in that, The combined cooling circuit includes: a heat-related device path, including heat-related devices that operate using power from the battery; and a heat sink path, including a heat sink for heat exchange between the heat medium cooling the heat-related devices and the outside air. The combined cooling circuit is a cooling circuit for circulating the heat medium.

8. The battery cooling system according to claim 7, characterized in that, The combined cooling circuit also includes a bypass path that bypasses the radiator path.

9. The battery cooling system according to claim 1 or 2, characterized in that, The battery cooling system also includes a heat storage section for the heat transfer medium at another connection point between the cooler path and the battery path. The battery cooling circuit and the concurrent cooling circuit are provided in such a way that the battery cooling circuit and the concurrent cooling circuit are connected via the switching valve and the storage unit.

10. The battery cooling system according to claim 1 or 2, characterized in that, When the heat medium begins to circulate the battery cooling circuit, after a certain period of time has elapsed since the start of the circulation of the heat medium, the control device determines the abnormality of the switching valve based on the temperature of the heat medium and the threshold temperature.

11. The battery cooling system according to claim 1 or 2, characterized in that, The battery cooling system also includes a first additional thermal circuit, which has a heat exchanger that cools the thermal medium by heat exchange with another thermal medium.

12. The battery cooling system according to claim 11, characterized in that, The battery cooling system also includes a second additional thermal circuit, which heats the other thermal medium through heat exchange with yet another thermal medium.

13. The battery cooling system according to claim 1 or 2, characterized in that, The battery in question is a vehicle battery.

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