Thermal management system, vehicle equipped with the same, and method for controlling a thermal management circuit

Abstract

To suppress deterioration in air-conditioning comfort when a circuit mode is switched during heating operation of a refrigeration cycle.SOLUTION: A thermal management system 1 comprises: a five-way valve 180 that switches between a first circuit mode in which a chiller 142 and a battery 163 are thermally connected, and a second circuit mode in which the chiller 142 and an LT radiator 122 are thermally connected; and an ECU 500 that controls a compressor 151 on the basis of a chiller temperature and a radiator temperature. In the case that switching is conducted between the first circuit mode and the second circuit mode according to control of a five-way valve 189 during heating operation of a refrigeration cycle 150, an ECU 100 controls the compressor 151 so that a temperature difference between the chiller temperature and the radiator temperature is small, prior to the switching.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a thermal management system, a vehicle equipped with the same, and a method for controlling a thermal management circuit. [Background technology]

[0002] The refrigeration cycle device disclosed in JP 2020-165604 A (Patent Document 1) includes a heat pump cycle, a high-temperature heat medium circuit, and a low-temperature heat medium circuit. The low-temperature heat medium circuit has multiple heat absorption devices that cause the low-temperature heat medium flowing out of the low-temperature heat medium-refrigerant heat exchanger to absorb heat, and a heat absorption amount adjustment unit that changes the amount of heat absorbed by the low-temperature heat medium in the heat absorption devices. When changing the amount of heat absorbed by the low-temperature heat medium in the multiple heat absorption devices, the heat absorption amount adjustment unit reduces the flow rate of refrigerant flowing into the heat exchanger (low-temperature heat medium-refrigerant heat exchanger) of the heat pump cycle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-165604 [Patent Document 2] Japanese Patent Application Publication No. 2018-98857 Summary of the Invention [Problem to be solved by the invention]

[0004] A thermal management system having the following configuration has been proposed. The thermal management system includes a battery through which a heat medium flows, a radiator through which the heat medium flows, a refrigeration cycle (heat pump circuit) through which a refrigerant flows, a chiller that exchanges heat between the heat medium and the refrigerant, and a switching valve. The switching valve is configured to switch between a first circuit mode in which the chiller and the battery are thermally connected, and a second circuit mode in which the chiller and the radiator are thermally connected.

[0005] In such a thermal management system, when the refrigeration cycle switches from the first circuit mode to the second circuit mode during heating operation, the temperature at the outlet of the heating air may change significantly, which may result in a deterioration in air conditioning comfort.

[0006] The present disclosure has been made to solve the above-mentioned problems, and one of the purposes of the present disclosure is to suppress deterioration in air conditioning comfort when switching from the first circuit mode to the second circuit mode during heating operation of the refrigeration cycle. [Means for solving the problem]

[0007] (1) A thermal management system according to a first aspect of the present disclosure includes a battery through which a heat medium flows, a radiator through which the heat medium flows, a refrigeration cycle through which a refrigerant flows, a chiller that exchanges heat between the heat medium and the refrigerant, and a switching valve that switches between a first circuit mode and a second circuit mode. The first circuit mode is a mode in which the chiller is thermally connected to the battery. The second circuit mode is a mode in which the chiller is thermally disconnected from the battery and thermally connected to the radiator. The thermal management system includes a first temperature sensor that detects a chiller temperature, which is the temperature of the refrigerant flowing through the chiller, a second temperature sensor that detects a radiator temperature, which is the temperature of the heat medium flowing through the radiator, a temperature adjustment device configured to adjust the temperature of one of the heat medium and the refrigerant, and a control device that controls the temperature adjustment device based on the chiller temperature and the radiator temperature. When switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve during heating operation of the refrigeration cycle, the control device controls the temperature adjustment device prior to the switching so that the temperature difference between the chiller temperature and the radiator temperature is reduced.

[0008] In the above configuration (1), the temperature adjustment device is controlled to reduce the temperature difference between the chiller temperature and the radiator temperature prior to switching the circuit mode. This prevents a sudden change in chiller temperature that accompanies switching the circuit mode. Therefore, the above configuration (1) prevents a deterioration in air conditioning comfort.

[0009] (2) When switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve during heating operation of the refrigeration cycle, prior to the switching, if the temperature difference between the chiller temperature and the radiator temperature is greater than a reference value, the control device controls the temperature adjustment device so that the temperature difference becomes smaller than the reference value, and the reference value is set to a predetermined value that suppresses deterioration of air conditioning comfort performance.

[0010] (3) The temperature adjustment device includes a compressor that compresses the refrigerant circulating through the refrigeration cycle. When the cooling of the battery by the chiller ends during heating operation of the refrigeration cycle and the mode is switched from the first circuit mode to the second circuit mode, the control device controls the rotation speed of the compressor so that the temperature difference becomes smaller than the reference value when the temperature difference is larger than the reference value in the first circuit mode.

[0011] (4) When the cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and the mode is switched from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is higher than the radiator temperature, the control device lowers the chiller temperature by increasing the compressor rotation speed in the first circuit mode when the temperature difference is greater than a reference value compared to when the temperature difference is smaller than the reference value.

[0012] (5) When the cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and the mode is switched from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is lower than the radiator temperature, the control device increases the chiller temperature by reducing the compressor rotation speed in the first circuit mode when the temperature difference is greater than a reference value compared to when the temperature difference is smaller than the reference value.

[0013] In the configurations (3) to (5) above, the temperature difference between the chiller temperature and the radiator temperature is controlled to be smaller than a reference value by adjusting the rotation speed of the compressor that compresses the refrigerant circulating through the refrigeration cycle. This also makes it possible to suppress a sudden change in the chiller temperature that occurs when switching from the first circuit mode to the second circuit mode. Therefore, the configurations (3) to (5) above make it possible to suppress a deterioration in air conditioning comfort.

[0014] (6) The temperature adjustment device includes an electric heater that heats the heat medium circulating through the radiator. When the cooling of the battery by the chiller is finished and the first circuit mode is switched to the second circuit mode, if the temperature difference in the first circuit mode is greater than a reference value, the control device controls the heat generation amount of the electric heater so that the temperature difference becomes smaller than the reference value.

[0015] (7) When the cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and the mode is switched from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is higher than the radiator temperature, the control device increases the heat output of the electric heater to raise the radiator temperature when the temperature difference is greater than a reference value in the first circuit mode, compared to when the temperature difference is smaller than the reference value.

[0016] (8) The temperature adjustment device includes a power conversion device through which the heat medium circulates through the radiator. When the cooling of the battery by the chiller is completed and switching from the first circuit mode to the second circuit mode is performed, the control device controls the heat loss of the power conversion device so that the temperature difference becomes smaller than the reference value when the temperature difference is larger than the reference value in the first circuit mode.

[0017] (9) When the cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and the mode is switched from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is higher than the radiator temperature, the control device increases the radiator temperature by increasing the heat loss of the power conversion device when the temperature difference is greater than a reference value in the first circuit mode, compared to when the temperature difference is smaller than the reference value.

[0018] In the configurations (6) to (9) above, the temperature difference between the chiller temperature and the radiator temperature is controlled to be smaller than a reference value by adjusting the heat output of the electric heater that heats the heat medium circulating in the radiator, or by adjusting the heat loss of the power converter through which the heat medium circulates in the radiator. This also prevents a sudden change in chiller temperature when the chiller stops cooling the battery and switches from the first circuit mode to the second circuit mode. Therefore, the configurations (6) to (9) above prevent a deterioration in air conditioning comfort.

[0019] (10) The temperature adjustment device includes an electric heater that heats the heat medium circulating through the radiator. When switching from the second circuit mode to the first circuit mode to start cooling the battery by the chiller, if the temperature difference in the second circuit mode is greater than a reference value, the control device controls the heat generation amount of the electric heater so that the temperature difference becomes smaller than the reference value.

[0020] (11) When switching from the second circuit mode to the first circuit mode is performed to start cooling the battery using the chiller, and the chiller temperature in the second circuit mode is higher than the radiator temperature, the control device increases the heat output of the electric heater to raise the radiator temperature when the temperature difference is greater than a reference value in the second circuit mode, compared to when the temperature difference is smaller than the reference value.

[0021] (12) The temperature adjustment device includes a power conversion device through which a heat medium circulates through a radiator. When switching from the second circuit mode to the first circuit mode to start cooling the battery by the chiller, if the temperature difference in the second circuit mode is greater than a reference value, the control device controls heat loss of the power conversion device so that the temperature difference becomes smaller than the reference value.

[0022] (13) When switching from the second circuit mode to the first circuit mode is performed to start cooling the battery using the chiller, and the chiller temperature in the second circuit mode is higher than the radiator temperature, the control device increases the radiator temperature by increasing the heat loss of the power conversion device when the temperature difference is greater than a reference value in the second circuit mode, compared to when the temperature difference is smaller than the reference value.

[0023] In the configurations (10) to (13) above, the temperature difference between the chiller temperature and the radiator temperature is controlled to be smaller than a reference value by adjusting the heat output of the electric heater that heats the heat medium circulating through the radiator, or by adjusting the heat loss of the power converter through which the heat medium circulates through the radiator. This also makes it possible to suppress a sudden change in the chiller temperature when switching from the first circuit mode to the second circuit mode to start cooling the battery by the chiller. Therefore, the configurations (10) to (13) above make it possible to suppress a deterioration in air conditioning comfort.

[0024] (14) A vehicle according to a second aspect of the present disclosure includes the above-described thermal management system.

[0025] (15) In a control method for a thermal management circuit according to a third aspect of the present disclosure, the thermal management circuit includes a battery through which a heat medium flows, a radiator through which the heat medium flows, a refrigeration cycle through which a refrigerant flows, a chiller that exchanges heat between the heat medium and the refrigerant, a switching valve that switches between a first circuit mode in which the chiller is thermally connected to the battery and a second circuit mode in which the chiller is thermally disconnected from the battery and thermally connected to the radiator, and a temperature adjustment device configured to adjust the temperature of one of the heat medium and the refrigerant. The control method includes the steps of detecting a chiller temperature, which is the temperature of the refrigerant flowing through the chiller, detecting a radiator temperature, which is the temperature of the heat medium flowing through the radiator, and controlling the temperature adjustment device based on the chiller temperature and the radiator temperature. The controlling step includes the step of controlling the temperature adjustment device so that a temperature difference between the chiller temperature and the radiator temperature is reduced prior to the switching between the first circuit mode and the second circuit mode by controlling the switching valve during heating operation of the refrigeration cycle.

[0026] According to the configuration (15) above, it is possible to suppress the deterioration of air conditioning comfort, similar to the configuration (1) above. Furthermore, according to the method (15) above, it is possible to suppress the deterioration of air conditioning comfort, similar to the configuration (1) above.

[0027] (16) The controlling step includes a step in which, when switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve during heating operation of the refrigeration cycle, the control device controls the temperature adjustment device prior to the switching so that the temperature difference between the chiller temperature and the radiator temperature becomes smaller than the reference value when the temperature difference is greater than the reference value, and the reference value is a predetermined value that is set to a value that suppresses deterioration of air conditioning comfort performance. [Effects of the Invention]

[0028] According to the present disclosure, it is possible to suppress deterioration of air conditioning comfort when switching from the first circuit mode to the second circuit mode during heating operation of the thermal management system. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a diagram illustrating an example of an overall configuration of a thermal management system according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a thermal management circuit. [Figure 3] FIG. 4 is a diagram for explaining an example of a first circuit mode in the first embodiment. [Figure 4] FIG. 4 is a diagram for explaining an example of a second circuit mode in the first embodiment. [Figure 5] 10 is a time chart illustrating an example of a sudden change in chiller water temperature when cooling of a battery is completed. [Figure 6] 4 is a time chart for explaining compressor control according to the first embodiment. [Figure 7] 4 is a flowchart showing a processing procedure for compressor control according to the first embodiment. [Figure 8] 10 is a time chart for explaining heater control according to the second embodiment. [Figure 9] 10 is a flowchart showing a procedure for heater control according to the second embodiment. [Figure 10] 10 is a time chart for explaining power train control according to a modification of the second embodiment. [Figure 11] 10 is a flowchart showing a processing procedure for power train control according to the second embodiment. [Figure 12] 10 is a time chart illustrating an example of a sudden change in chiller water temperature when cooling of a battery begins. [Figure 13] 10 is a time chart for explaining heater control according to the third embodiment. [Figure 14] 10 is a flowchart showing a procedure for heater control according to the third embodiment. [Figure 15] 10 is a flowchart showing a processing procedure for power train control according to a modification of the third embodiment. [Figure 16] FIG. 10 is a diagram showing a configuration of a thermal management circuit according to a fourth embodiment. [Figure 17] FIG. 13 is a diagram showing a configuration of a thermal management circuit according to a fifth embodiment. [Figure 18] FIG. 13 is a diagram for explaining a first circuit mode in the fifth embodiment. [Figure 19] FIG. 13 is a diagram for explaining a second circuit mode in the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0031] The following description will be given taking as an example a configuration in which a thermal management system according to the present disclosure is mounted on a vehicle. The vehicle is a vehicle equipped with a battery for driving, such as an electric vehicle (BEV: Battery Electric Vehicle). The vehicle may be a hybrid electric vehicle (HEV: Hybrid Electric Vehicle), a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle), or a fuel cell electric vehicle (FCEV: Fuel Cell Electric Vehicle). However, the use of the thermal management system according to the present disclosure is not limited to vehicles.

[0032] [Embodiment 1] <System configuration> 1 is a diagram illustrating an example of an overall configuration of a thermal management system according to a first embodiment of the present disclosure. The thermal management system 1 includes a thermal management circuit 100 and an electronic control unit (ECU) 500.

[0033] The thermal management circuit 100 is configured to allow a heat medium and a refrigerant to flow through it. The thermal management circuit 100 outputs various sensor values ​​to the ECU 500. The configuration of the thermal management circuit 100 will be described with reference to FIG.

[0034] The ECU 500 controls the thermal management circuit 100 by outputting control commands to the thermal management circuit 100 according to sensor values ​​from the thermal management circuit 100. The ECU 500 includes a processor 501, a memory 502, a storage 503, and an interface 504. The processor 501 is, for example, a central processing unit (CPU) or a microprocessing unit (MPU). The memory 502 is, for example, a random access memory (RAM). The storage 503 is a rewritable nonvolatile memory such as a hard disk drive (HDD), a solid state drive (SSD), or a flash memory. The storage 503 stores system programs including an operating system (OS) and control programs including computer-readable code required for control calculations. The processor 501 reads the system programs and control programs, loads them into the memory 502, and executes them to perform various processes. The interface 504 controls communication between the ECU 500 and the components of the thermal management circuit 100.

[0035] The ECU 500 corresponds to a "control device" according to the present disclosure. The ECU 500 may be divided into multiple ECUs for each function. Although FIG. 1 shows an example in which the ECU 500 includes one processor 501, the ECU 500 may include multiple processors. The same applies to the memory 502 and the storage 503.

[0036] In this specification, the term "processor" is not limited to a processor in the narrow sense that executes processing using a stored program, but may also include hardwired circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). Therefore, the term "processor" can also be interpreted as a processing circuitry whose processing is predefined by computer-readable code and / or hardwired circuitry.

[0037] <Circuit configuration> 2 is a diagram showing an example of the configuration of the thermal management circuit 100. The thermal management circuit 100 includes, for example, a high temperature (HT) circuit 110, a radiator 120, a low temperature (LT) circuit 130, a condenser 141, a chiller 142, a refrigeration cycle 150, a battery circuit 160, a reservoir tank (R / T) 170, a five-way valve 180, and temperature sensors 191-196.

[0038] The HT circuit 110 includes, for example, a water pump (W / P) 111, an electric heater 112, a three-way valve 113, a heater core 114, and a reservoir tank 115. The radiator 120 includes a high-temperature (HT) radiator 121 and a low-temperature (LT) radiator 122. The LT circuit 130 includes, for example, a water pump 131, a smart power unit (SPU) 132, a power control unit (PCU) 133, an oil cooler (O / C) 134, and a step-up / step-down converter 135. The refrigeration cycle 150 includes, for example, a compressor 151, an expansion valve 152, an evaporator 153, an evaporative pressure regulator (EPR) 154, and an expansion valve 155. The battery circuit 160 includes, for example, a water pump 161 , an electric heater 162 , a battery 163 , and a bypass path 164 .

[0039] The heat medium (usually hot water) circulating through the HT circuit 110 flows through one or both of a first path and a second path. The first path is the path of the water pump 111, condenser 141, electric heater 112, three-way valve 113, heater core 114, reservoir tank 115, and water pump 111. The second path is the path of the water pump 111, condenser 141, electric heater 112, three-way valve 113, HT radiator 121, reservoir tank 115, and water pump 111.

[0040] The water pump 111 circulates the heat medium within the HT circuit 110 in accordance with a control command from the ECU 500. The condenser 141 receives heat released from the heat medium circulating through the refrigeration cycle 150, thereby heating the heat medium circulating through the HT circuit 110. The electric heater 112 heats the heat medium in accordance with a control command from the ECU 500. The three-way valve 113 switches between a first path and a second path in accordance with a control command from the ECU 500. The heater core 114 heats the air by heat exchange between the heat medium circulating through the HT circuit 110 and the air blown into the vehicle cabin (heating operation). The reservoir tank 115 maintains the pressure and amount of the heat medium within the HT circuit 110 by storing a portion of the heat medium within the HT circuit 110 (the heat medium that overflows due to an increase in pressure).

[0041] The HT radiator 121 is connected to the HT circuit 110. The HT radiator 121 is disposed downstream of a grille shutter (not shown) and exchanges heat between the air outside the vehicle and the heat medium. The LT radiator 122 is connected to the LT circuit 130. The LT radiator 122 is disposed near the HT radiator 121 and exchanges heat with the HT radiator 121. The LT radiator 122 corresponds to the "radiator" according to the present disclosure.

[0042] The heat medium (coolant) circulating in the LT circuit 130 flows through the route of the water pump 131-SPU 132-PCU 133-oil cooler 134-boost / buck converter 135-five-way valve 180-LT radiator 122-reservoir tank 170-water pump 131.

[0043] Water pump 131 circulates the heat medium within LT circuit 130 in accordance with a control command from ECU 500. SPU 132 controls the charging and discharging of battery 163 in accordance with a control command from ECU 500. PCU 133 converts DC power supplied from battery 163 into AC power in accordance with a control command from ECU 500, and supplies the AC power to a motor (not shown) built into the transaxle. Oil cooler 134 circulates lubricating oil for the motor using an electric oil pump (EOP) (not shown). Oil cooler 134 cools the transaxle by heat exchange between the heat medium circulating through LT circuit 130 and the lubricating oil for the motor. Step-up / step-down converter 135 increases / decreases the voltage of battery 163 in accordance with a control command from ECU 500. The SPU 132 , the PCU 133 , the oil cooler 134 and the step-up / step-down converter 135 are cooled by a heat medium circulating through the LT circuit 130 .

[0044] The condenser 141 is connected to both the HT circuit 110 and the refrigeration cycle 150. The condenser 141 releases heat from the heat medium circulating through the refrigeration cycle 150. The chiller 142 is connected to both the refrigeration cycle 150 and the battery circuit 160. The chiller 142 exchanges heat between the heat medium circulating through the refrigeration cycle 150 and the heat medium circulating through the battery circuit 160.

[0045] The heat medium (gas-phase refrigerant or liquid-phase refrigerant) circulating through the refrigeration cycle 150 flows through one or both of a first path and a second path. The first path is a path of the compressor 151, condenser 141, expansion valve 152, evaporator 153, EPR 154, and compressor 151. The second path is a path of the compressor 151, condenser 141, expansion valve 155, chiller 142, and compressor 151.

[0046] Compressor 151 compresses the gas-phase refrigerant circulating through refrigeration cycle 150 in accordance with a control command from ECU 500. The rotation speed of compressor 151 is controlled according to the deviation between the target value and the current value of the blow-out temperature. Condenser 141 condenses the gas-phase refrigerant into liquid-phase refrigerant by releasing heat from the gas-phase refrigerant that has been compressed by compressor 151 and has become high-temperature and high-pressure. The high-temperature, high-pressure refrigerant compressed by compressor 151 releases heat to the heat medium (hot water) circulating through HT circuit 110 through heat exchange in condenser 141. Heat from the heated hot water is released by heater core 114, and heated air (heated air) is sent from the air outlet into the vehicle cabin (heating operation). Expansion valve 152 reduces the pressure of the liquid-phase refrigerant by expanding the high-pressure liquid-phase refrigerant compressed by condenser 141. The evaporator 153 cools the air blown onto the evaporator 153 by heat exchange between the air and the liquid-phase refrigerant (cooling operation). The EPR 154 adjusts the pressure inside the evaporator 153 to be approximately constant by controlling the flow rate of the refrigerant flowing in from the evaporator 153. Similar to the expansion valve 152, the expansion valve 155 reduces the pressure of the liquid-phase refrigerant by expanding the high-pressure liquid-phase refrigerant compressed by the condenser 141. The chiller 142 evaporates the liquid-phase refrigerant reduced in pressure by the expansion valve 155. As a result, heat is removed from the refrigerant circulating through the battery circuit 160, and the refrigerant is cooled.

[0047] The heat medium (coolant) circulating through the battery circuit 160 flows through one or both of a first path and a second path. The first path is the path of the water pump 161, chiller 142, five-way valve 180, electric heater 162, battery 163, reservoir tank 170, and water pump 161. The second path is the path of the water pump 161, chiller 142, five-way valve 180, bypass path 164, reservoir tank 170, and water pump 161.

[0048] The water pump 161 circulates the heat medium within the battery circuit 160 in accordance with a control command from the ECU 500. The chiller 142 cools the heat medium circulating through the battery circuit 160 by heat exchange between the heat medium circulating through the refrigeration cycle 150 and the heat medium circulating through the battery circuit 160. The electric heater 162 heats the heat medium in accordance with a control command from the ECU 500. The battery 163 supplies electric power for driving to a motor built into the transaxle. The battery 163 can be heated using the electric heater 162 or cooled using the chiller 142. The bypass path 164 is provided so that the heat medium bypasses the electric heater 162 and the battery 163. When the heat medium flows through the bypass path 164, a change in the temperature of the heat medium due to heat absorption / dissipation between the heat medium and the battery 163 can be suppressed.

[0049] In this example, the reservoir tank 170 is connected to both the LT circuit 130 and the battery circuit 160. The reservoir tank 170 stores a portion of the heat medium circulating through the LT circuit 130 and the battery circuit 160, thereby maintaining the pressure and amount of the heat medium.

[0050] The five-way valve 180 is connected to the LT circuit 130 and the battery circuit 160. The five-way valve 180 switches the paths of the heat medium in the LT circuit 130 and the battery circuit 160 in accordance with a control command from the ECU 500. The five-way valve 180 corresponds to the "switching valve" according to the present disclosure.

[0051] Temperature sensor 191 detects the temperature of the heat medium flowing through heater core 114 (heater core water temperature Th). Temperature sensor 192 detects the temperature of the heat medium flowing through LT radiator 122 (radiator water temperature Tr). Temperature sensor 193 detects the temperature (chiller water temperature Tc) of the refrigerant (which may be a heat medium instead of a refrigerant) flowing through chiller 142. Temperature sensor 194 detects the temperature of the heat medium flowing through battery 163 (battery water temperature Tb). Temperature sensor 195 detects the temperature of the heat medium flowing through PCU 133 (power train water temperature Tp). Temperature sensor 196 detects the temperature outside the vehicle (outside air temperature Ta). Each sensor outputs a sensor value indicating the detection result to ECU 500. Temperature sensor 193 corresponds to the "first temperature sensor" according to the present disclosure. Temperature sensor 192 corresponds to the "second temperature sensor" according to the present disclosure.

[0052] ECU 500 generates a control command based on the sensor values ​​obtained from temperature sensors 191 to 195 included in thermal management circuit 100, and outputs the generated control command to thermal management circuit 100.

[0053] <Circuit mode> The thermal management system 1 has a plurality of circuit modes that can be switched by controlling the five-way valve 180. Below, a first circuit mode and a second circuit mode among the plurality of circuit modes will be described.

[0054] Fig. 3 is a diagram for explaining an example of a first circuit mode in embodiment 1. Fig. 4 is a diagram for explaining a second circuit mode in embodiment 1. To facilitate understanding, Figs. 3 and 4 show only representative components of the thermal management system 1 described in Fig. 1.

[0055] 3, the first circuit mode is a mode in which the chiller 142 is thermally connected to the battery 163 (battery circuit 160). In the first circuit mode illustrated in FIG. 3, the five-way valve 180 is controlled so that port P1 and port P2 are in communication with each other and port P3 and port P5 are in communication with each other. This connects the LT circuit 130 and the battery circuit 160 in parallel (in other words, they are formed independently of each other). More specifically, a first path (LT circuit 130) is formed in which the heat medium flows in the following order: water pump 131, PCU 133, port P3, port P5, LT radiator 122, and water pump 131, and a second path (battery circuit 160) is formed in which the heat medium flows in the following order: water pump 161, chiller 142, port P1, port P2, battery 163, and water pump 161.

[0056] 4, the second circuit mode is a mode in which the chiller 142 is thermally connected to the LT radiator 122 (LT circuit 130). In the second circuit mode illustrated in FIG. 4, the five-way valve 180 is controlled so that port P1 and port P5 communicate with each other and port P3 and port P4 communicate with each other. This connects the LT circuit 130 and battery circuit 160 in series. More specifically, a single path is formed through which the heat medium flows in the following order: water pump 131-PCU 133-port P3-port P4-bypass path 164-water pump 161-chiller 142-port P1-port P5-LT radiator 122-water pump 131.

[0057] The first circuit mode is not limited to that shown in Fig. 3 as long as the chiller 142 is thermally connected to the battery 163. The second circuit mode is not limited to that shown in Fig. 4 as long as the chiller 142 is thermally connected to the LT radiator 122 and is not thermally connected to the battery 163.

[0058] After a sufficient time has passed in the first circuit mode, the radiator water temperature Tr and the power train water temperature Tp become approximately equal. The chiller water temperature Tc and the battery water temperature Tb also become approximately equal. However, the chiller water temperature Tc and the radiator water temperature Tr may differ from each other. On the other hand, after a sufficient time has passed in the second circuit mode, the chiller water temperature Tc and the radiator water temperature Tr become approximately equal.

[0059] <Changes in chiller water temperature> During heating operation of the thermal management system 1 configured as described above, the temperature of the heat medium circulating through the chiller 142 (chiller water temperature Tc) may change suddenly as the circuit mode is switched. In the first embodiment, an example will be described in which the chiller water temperature Tc changes suddenly when cooling of the battery 163 is completed.

[0060] 5 is a time chart illustrating an example of a sudden change in chiller water temperature Tc when cooling of battery 163 is completed. The horizontal axis represents elapsed time. The vertical axis represents, from top to bottom, whether the cooling request for battery 163 is on or off, the circuit to which chiller 142 is connected (LT circuit 130 / battery circuit 160), chiller water temperature Tc, the amount of heat absorbed from the heat medium by chiller 142 (chiller heat absorption amount), heater core water temperature Th, compressor rotation speed, and the dryness fraction of the refrigerant at the inlet of compressor 151 (refrigerant dryness fraction).

[0061] At time tc, cooling of the battery 163 ends, and the cooling request for the battery 163 is switched from on to off. Accordingly, the thermal management system 1 is switched from the first circuit mode to the second circuit mode by control of the five-way valve 180. As a result, the heat medium circulating through the chiller 142 stops flowing through the battery 163 and instead flows through the LT radiator 122. This causes the chiller water temperature Tc to drop sharply. Accordingly, the amount of heat absorbed by the chiller decreases sharply, causing the heater core water temperature Th to drop sharply. This causes the temperature of the air (heated air) heated by the heater core 114 and blown into the vehicle cabin to drop. This may result in a deterioration in air conditioning comfort.

[0062] As mentioned above, the compressor speed is controlled based on the deviation between the target temperature and the current temperature at the heating air outlet. If the amount of heat absorption by the chiller suddenly decreases, the compressor speed increases only after the increase in the deviation is detected. In other words, the increase in the compressor speed is delayed relative to the timing of switching from the first circuit mode to the second circuit mode. Therefore, it is difficult to suppress the sudden decrease in the amount of change in the amount of heat absorption by the chiller by adjusting the compressor speed after switching from the first circuit mode to the second circuit mode.

[0063] In addition, if the heat absorption rate of the chiller decreases suddenly, the refrigerant quality may decrease, and the refrigerant may not be completely vaporized by chiller 142. That is, the refrigerant at the inlet of compressor 151 may become in a gas-liquid mixed phase state (a mixture of gas-phase refrigerant and liquid-phase refrigerant). As a result, compressor 151 may be damaged by the compression of the liquid-phase refrigerant.

[0064] As described above, in the thermal management system 1, when the refrigeration cycle 150 switches from the first circuit mode to the second circuit mode during heating operation, problems such as a deterioration in air conditioning comfort and damage to the compressor 151 may occur. Therefore, in the first embodiment, the compressor rotation speed is adjusted prior to switching from the first circuit mode to the second circuit mode to reduce the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr. Hereinafter, this process will be referred to as "compressor control."

[0065] 6 is a time chart for explaining compressor control according to embodiment 1. The horizontal axis represents elapsed time. The vertical axis represents, from top to bottom, the on / off status of the cooling request for battery 163, the circuit to which chiller 142 is connected (LT circuit 130 / battery circuit 160), chiller water temperature Tc, battery water temperature Tb, radiator water temperature Tr, power train water temperature Tp, and compressor rotation speed.

[0066] The solid lines indicate the time variations of each parameter in the compressor control according to embodiment 1. In addition, to clarify the characteristics of the compressor control according to embodiment 1, the dashed dotted lines indicate the time variations of each parameter in the comparative example.

[0067] In the example shown in FIG. 6, in the first circuit mode, the chiller water temperature Tc is higher than the radiator water temperature Tr, and the temperature difference ΔT (= Tc - Tr) between the chiller water temperature Tc and the radiator water temperature Tr is greater than the reference value REF1. In this case, the compressor rotation speed is set higher than when the temperature difference ΔT is smaller than the reference value REF1. When the compressor rotation speed is increased, the amount of heat absorbed by the chiller increases, causing the chiller water temperature Tc to decrease and approach the radiator water temperature Tr. By bringing the chiller water temperature Tc sufficiently close to the radiator water temperature Tr in advance, it is possible to suppress a sudden change in the chiller water temperature Tc that can occur after switching from the first circuit mode to the second circuit mode.

[0068] Although not shown, a situation may also occur in which the chiller water temperature Tc is lower than the radiator water temperature Tr and the temperature difference ΔT (= Tr - Tc) between the chiller water temperature Tc and the radiator water temperature Tr is greater than the reference value REF1. In this case, the compressor rotation speed is set lower than when the temperature difference ΔT is smaller than the reference value REF1. Lowering the compressor rotation speed reduces the amount of heat absorbed by the chiller, causing the chiller water temperature Tc to rise and approach the radiator water temperature Tr. This also helps to suppress sudden changes in the chiller water temperature Tc that can occur after switching from the first circuit mode to the second circuit mode.

[0069] 7 is a flowchart showing a processing procedure for compressor control according to the first embodiment. The processing shown in this flowchart is executed when a predetermined condition is met (for example, at every predetermined control period). Each step is realized by software processing by the ECU 500, but may also be realized by hardware (electrical circuitry) arranged within the ECU 500. Hereinafter, step will be abbreviated as S.

[0070] In S101, the ECU 500 acquires the chiller water temperature Tc from the temperature sensor 193. The ECU 500 also acquires the radiator water temperature Tr from the temperature sensor 192 (S102).

[0071] In S103, ECU 500 determines whether chiller water temperature Tc is higher than radiator water temperature Tr. If chiller water temperature Tc is higher than radiator water temperature Tr (YES in S103), ECU 500 calculates the heat medium / refrigerant temperature difference ΔT (ΔT=Tc−Tr) by subtracting radiator water temperature Tr from chiller water temperature Tc (S104).

[0072] In S105, ECU 500 determines whether the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than a reference value REF1. The reference value REF1 is a value that can be determined experimentally, and is such that the deterioration of air conditioning comfort is sufficiently small if the temperature difference ΔT is less than the reference value REF1. If the temperature difference ΔT is equal to or greater than the reference value REF1 (YES in S105), ECU 500 lowers the chiller target water temperature Tc(tag) compared to when the temperature difference ΔT is less than the reference value REF1 (S106).

[0073] In S107, ECU 500 increases the compressor rotation speed in accordance with the chiller target water temperature Tc(tag) set in S106. More specifically, memory 502 of ECU 500 stores a map that defines the correspondence between, for example, the chiller target water temperature Tc(tag), the outside air temperature Ta, and the compressor rotation speed. This map defines the correspondence such that the lower the chiller target water temperature, the higher the compressor rotation speed. By referring to this map, ECU 500 can calculate the compressor rotation speed from the chiller target water temperature Tc(tag) and the outside air temperature Ta (the detection result of temperature sensor 196).

[0074] On the other hand, if the chiller water temperature Tc(tag) is equal to or lower than the radiator water temperature Tr in S103 (NO in S103), the ECU 500 calculates the heat medium / refrigerant temperature difference ΔT (ΔT=Tr−Tc) by subtracting the chiller water temperature Tc from the radiator water temperature Tr (S108).

[0075] In S109, ECU 500 determines whether the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than a reference value REF1. The reference value REF1 may be different between the process of S105 and the process of S109. If the temperature difference ΔT is equal to or greater than the reference value REF1 (YES in S105), ECU 500 increases the chiller target water temperature Tc(tag) (S110) compared to when the temperature difference ΔT is less than the reference value REF1. Then, ECU 500 reduces the compressor rotation speed in accordance with the chiller target water temperature Tc(tag) (S111). Similar to the process of S107, this process may be implemented using a map, for example.

[0076] If the temperature difference ΔT between the heat medium and the refrigerant is less than the reference value REF1 in S105 (NO in S105), the compressor rotation speed does not need to be adjusted. The same applies to the case where the temperature difference ΔT is less than the reference value REF1 in S109 (NO in S109).

[0077] In the first circuit mode (see FIG. 3), the radiator water temperature Tr and the power train water temperature Tp are approximately equal. Therefore, instead of the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr, for example, the temperature difference between the chiller water temperature Tc and the power train water temperature Tp may be used.

[0078] As described above, in the first embodiment, prior to switching from the first circuit mode to the second circuit mode following completion of cooling of the battery 163, the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr is controlled to be smaller than the reference value REF1 by compressor control. In other words, the chiller water temperature Tc is adjusted to be sufficiently close to the radiator water temperature Tr. Therefore, according to the first embodiment, a sudden change in the chiller water temperature Tc that accompanies switching from the first circuit mode to the second circuit mode is suppressed. As a result, deterioration of air conditioning comfort can be suppressed, and damage to the compressor 151 can be prevented.

[0079] [Embodiment 2] In the first embodiment, a configuration was described in which a sudden change in chiller water temperature Tc is suppressed by compressor control. In the second embodiment, a configuration will be described in which a sudden change in chiller water temperature Tc is suppressed by output control of electric heater 112. Hereinafter, this control will be referred to as "heater control."

[0080] Fig. 8 is a time chart for explaining heater control according to embodiment 2. The horizontal axis represents elapsed time. The vertical axis represents, from top to bottom, whether the cooling request for the battery 163 is on or off, the circuit to which the chiller 142 is connected (LT circuit 130 / battery circuit 160), the chiller water temperature Tc, the battery water temperature Tb, the radiator water temperature Tr, the power train water temperature Tp, and the heat generation amount per unit time of the electric heater 112 (heater heat generation amount). The same applies to Fig. 13, which will be described later.

[0081] In the first circuit mode, when the chiller water temperature Tc is higher than the radiator water temperature Tr and the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr is greater than a reference value REF1, the heater heat generation amount is set to be larger than when the temperature difference ΔT is smaller than the reference value REF1. When the temperature difference ΔT is smaller than the reference value REF1, the electric heater 112 may be stopped, whereas when the temperature difference ΔT is greater than the reference value REF1, the electric heater 112 may be operated.

[0082] Increasing the heater heat output increases the radiator water temperature Tr, thereby reducing the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr. By sufficiently reducing the temperature difference ΔT before switching from the first circuit mode to the second circuit mode, it is possible to suppress a sudden change in the chiller water temperature Tc after switching circuit modes.

[0083] Although not shown, a situation may also occur in which the chiller water temperature Tc is lower than the radiator water temperature Tr and the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr is greater than the reference value REF1. In this case, the heater heat generation amount is set to be smaller than when the temperature difference ΔT is smaller than the reference value REF1. When the temperature difference ΔT is smaller than the reference value REF1, the electric heater 112 may be operated, whereas when the temperature difference ΔT is greater than the reference value REF1, the electric heater 112 may be stopped.

[0084] Reducing the heater heat output lowers the radiator water temperature Tr, thereby reducing the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr. This also helps prevent a sudden change in the chiller water temperature Tc after switching from the first circuit mode to the second circuit mode.

[0085] 9 is a flowchart showing the heater control procedure according to embodiment 2. The processes of S201 to S205, S208, and S209 are the same as the processes of S101 to S105, S108, and S109 in embodiment 1 (see FIG. 7).

[0086] In S203, if chiller water temperature Tc is higher than radiator water temperature Tr (YES in S203), ECU 500 calculates the heat medium / refrigerant temperature difference ΔT (ΔT=Tc−Tr) by subtracting radiator water temperature Tr from chiller water temperature Tc (S204). On the other hand, if chiller water temperature Tc is equal to or lower than radiator water temperature Tr (NO in S203), ECU 500 calculates the temperature difference ΔT (ΔT=Tr−Tc) by subtracting chiller water temperature Tc from radiator water temperature Tr (S208).

[0087] In S205, ECU 500 determines whether the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than reference value REF2. If the temperature difference ΔT is equal to or greater than reference value REF2 (YES in S205), ECU 500 increases the radiator target water temperature Tr(tag) compared to when the temperature difference ΔT is less than reference value REF2 (S206).

[0088] In S207, ECU 500 increases the heater heat generation amount in accordance with the radiator target water temperature Tr(tag) set in S206. For example, ECU 500 can calculate the heater heat generation amount from the radiator target water temperature Tr(tag) and the outside air temperature Ta by referring to a map that defines the correspondence relationship between the radiator target water temperature Tr(tag), the outside air temperature Ta, and the heater heat generation amount.

[0089] In S209, ECU 500 determines whether the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than reference value REF2. If the temperature difference ΔT is equal to or greater than reference value REF2 (YES in S209), ECU 500 reduces the target radiator water temperature Tr(tag) (S210) compared to when the temperature difference ΔT is less than reference value REF2. Then, ECU 500 reduces the heater heat generation amount according to the target radiator water temperature Tr(tag) (S211). Similar to the process of S207, this process can be implemented using a map, for example.

[0090] As described above, in the second embodiment, prior to switching from the first circuit mode to the second circuit mode following completion of cooling of the battery 163, heater control is performed to control the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr to be smaller than the reference value REF2. In other words, the radiator water temperature Tr is adjusted to be sufficiently close to the chiller water temperature Tc. Therefore, according to the second embodiment, a sudden change in the chiller water temperature Tc that accompanies switching from the first circuit mode to the second circuit mode is suppressed. As a result, a deterioration in air conditioning comfort can be suppressed.

[0091] [Modification of the second embodiment] It is also possible to suppress a sudden change in chiller water temperature Tc by controlling the power train (PCU 133 and motor generator) instead of or in addition to controlling the output of electric heater 112. Hereinafter, this control will be referred to as "power train control."

[0092] Powertrain control is control that intentionally drives the powertrain in a state where heat loss is large. More specifically, field strengthening control / field weakening control of the motor generator may be performed so that the operating point of the motor generator expressed on the current advance angle-torque plane deviates from the optimal operating line where heat loss is minimized. For details of control that increases heat loss in the powertrain, see, for example, Japanese Patent Application Laid-Open No. 2018-98857 (Patent Document 2).

[0093] Fig. 10 is a time chart for explaining power train control according to a modification of embodiment 2. This time chart differs from the time chart of Fig. 8 in that the heat loss per unit time of the power train (power train heat loss) is shown at the bottom of the vertical axis instead of the amount of heat generated by the heater.

[0094] In the first circuit mode, when the chiller water temperature Tc is higher than the radiator water temperature Tr and the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr is greater than the reference value REF1, the power train heat loss is set to be larger than when the temperature difference ΔT is smaller than the reference value REF1. Increasing the power train heat loss increases the power train water temperature Tp, which in turn increases the radiator water temperature Tr. Therefore, the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr decreases. By sufficiently reducing the temperature difference ΔT before switching from the first circuit mode to the second circuit mode, a sudden change in the chiller water temperature Tc after switching from the first circuit mode to the second circuit mode can be suppressed.

[0095] Fig. 11 is a flowchart showing the processing procedure of power train control according to embodiment 2. This flowchart differs from the flowchart of Fig. 9 in that it includes the processes of S206A, S207A, S210A, and S211A instead of the processes of S206, S207, S210, and S211.

[0096] If the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than the reference value REF2 in S205 (YES in S205), ECU 500 increases the power train target water temperature Tp(tag) (S206A) compared to when the temperature difference ΔT is less than the reference value REF2. Then, ECU 500 increases the power train heat loss according to the power train target water temperature Tp(tag) set in S206A.

[0097] If the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than the reference value REF2 in S209 (YES in S209), ECU 500 lowers the power train target water temperature Tp(tag) compared to when the temperature difference ΔT is less than the reference value REF2 (S210A). Then, ECU 500 reduces the power train heat loss according to the power train target water temperature Tp(tag) (S211A). Note that, like the processes of S207 and S211, the processes of S207A and S211A may be implemented using a map, for example. If the operating point of the motor-generator is normally controlled on an optimal operating line that minimizes heat loss, the processes of S208 to S211A may be omitted.

[0098] [Embodiment 3] In the first and second embodiments, a situation has been described in which the chiller water temperature Tc changes suddenly when switching from the first circuit mode to the second circuit mode, in other words, when cooling of the battery 163 ends. Conversely, the chiller water temperature Tc can also change suddenly when switching from the second circuit mode to the first circuit mode, that is, when cooling of the battery 163 begins. In the third embodiment, such a situation will be described.

[0099] 12 is a time chart illustrating an example of a sudden change in chiller water temperature Tc when cooling of battery 163 begins. The horizontal axis represents elapsed time. The vertical axis represents, from top to bottom, whether the cooling request for battery 163 is on or off, the circuit to which chiller 142 is connected (LT circuit 130 / battery circuit 160), chiller water temperature Tc, the amount of heat absorbed from the heat medium by chiller 142 (chiller heat absorption amount), heater core water temperature Th, compressor rotation speed, and the pressure of the refrigerant at the outlet of compressor 151 (refrigerant pressure).

[0100] At time tc, the cooling request for battery 163 is switched from OFF to ON. Accordingly, thermal management system 1 is switched from the second circuit mode to the first circuit mode by control of five-way valve 180. As a result, the heat medium circulating through chiller 142 stops flowing through LT radiator 122 and begins to flow through battery 163. Therefore, chiller water temperature Tc approaches battery water temperature Tb. If there is a large temperature difference between chiller water temperature Tc and battery water temperature Tb before switching from the second circuit mode to the first circuit mode, chiller water temperature Tc may rise rapidly after the switch.

[0101] A sudden rise in chiller water temperature Tc causes a sudden increase in the amount of heat absorbed by the chiller, which in turn causes a sudden rise in heater core water temperature Th. This causes the temperature of the air (heated air) heated by heater core 114 and blown into the vehicle cabin to rise. As a result, air conditioning comfort may deteriorate. The compressor rotation speed decreases with a delay relative to the timing of switching from the first circuit mode to the second circuit mode.

[0102] In addition, if the heat absorption rate of the chiller increases suddenly, all of the refrigerant in the chiller 142 becomes gaseous refrigerant, and the pressure of the gaseous refrigerant increases. This can cause the pressure of the refrigerant at the outlet of the compressor 151 to become excessively high. As a result, the components of the refrigeration cycle 150 (compressor 151, expansion valves 152 and 155, etc.) may be damaged.

[0103] As described above, in the thermal management system 1, even when the refrigeration cycle 150 is switched from the second circuit mode to the first circuit mode during heating operation, problems such as a deterioration in air conditioning comfort and damage to the components of the refrigeration cycle 150 may occur. Therefore, in the third embodiment, heater control is executed before switching from the second circuit mode to the first circuit mode. Power train control may be executed instead of or in addition to the heater control.

[0104] 13 is a time chart for explaining heater control according to Embodiment 3. In the second circuit mode, when the chiller water temperature Tc is higher than the radiator water temperature Tr and the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr is larger than a reference value REF3, the heater heat generation amount is set to be larger than when the temperature difference ΔT is smaller than the reference value REF3.

[0105] Increasing the heater heat generation amount in the second circuit mode not only increases the radiator water temperature Tr and power train water temperature Tp, but also the chiller water temperature Tc. This causes the chiller water temperature Tc to approach the battery water temperature Tb before switching from the second circuit mode to the first circuit mode (i.e., before cooling). By making the temperature difference between the chiller water temperature Tc and the battery water temperature Tb sufficiently small before switching the circuit mode, a sudden rise in the chiller water temperature Tc after switching the circuit mode can be suppressed.

[0106] Although not shown, a situation may also occur in which the chiller water temperature Tc is lower than the radiator water temperature Tr and the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr is greater than the reference value REF1. In this case, the heater heat generation amount is set smaller than when the temperature difference ΔT is smaller than the reference value REF1. Reducing the heater heat generation amount lowers the radiator water temperature Tr, thereby reducing the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr. This also makes it possible to suppress a sudden change in the chiller water temperature Tc after switching from the second circuit mode to the first circuit mode.

[0107] 14 is a flowchart showing the heater control procedure according to embodiment 3. The processes of S301 to S304, S308, and S309 are the same as the processes of S201 to S204, S208, and S209 in embodiment 2 (see FIG. 9).

[0108] In S305, ECU 500 determines whether the temperature difference ΔT (=Tc−Tr) between the heat medium and the refrigerant is equal to or greater than reference value REF3. If the temperature difference ΔT is equal to or greater than reference value REF3 (YES in S305), ECU 500 increases chiller target water temperature Tc(tag) compared to when the temperature difference ΔT is less than reference value REF3 (S306).

[0109] In S307, ECU 500 increases the heater heat generation amount in accordance with the chiller target water temperature Tc(tag) set in S306. For example, ECU 500 can calculate the heater heat generation amount from the chiller target water temperature Tc(tag) and the outside air temperature Ta by referring to a map that defines the correspondence relationship between the chiller target water temperature Tc(tag), the outside air temperature Ta, and the heater heat generation amount.

[0110] In S309, ECU 500 determines whether the temperature difference ΔT (=Tr−Tc) between the heat medium and the refrigerant is equal to or greater than reference value REF3. If the temperature difference ΔT is equal to or greater than reference value REF3 (YES in S309), ECU 500 reduces the chiller target water temperature Tc(tag) compared to when the temperature difference ΔT is less than reference value REF3 (S310). Then, ECU 500 reduces the heater heat generation amount in accordance with the chiller target water temperature Tc(tag) (S311). Similar to the process of S307, this process can be implemented using a map, for example.

[0111] After a sufficient amount of time has passed in the second circuit mode, the battery water temperature Tb, the radiator water temperature Tr, and the power train water temperature Tp become approximately equal. Therefore, instead of the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr, the temperature difference between the chiller water temperature Tc and the battery water temperature Tb may be used, or the temperature difference between the chiller water temperature Tc and the power train water temperature Tp may be used.

[0112] As described above, in the third embodiment, prior to switching from the second circuit mode to the first circuit mode in response to the start of cooling of the battery 163, heater control is performed to control the temperature difference ΔT between the chiller water temperature Tc and the radiator water temperature Tr to be smaller than the reference value REF3. In other words, the radiator water temperature Tr is adjusted to be sufficiently close to the chiller water temperature Tc. Therefore, according to the third embodiment, a sudden change in the chiller water temperature Tc that occurs when switching from the second circuit mode to the first circuit mode can be suppressed. As a result, a deterioration in air conditioning comfort can be suppressed. Furthermore, because a sudden increase in the amount of heat absorbed by the chiller is suppressed, damage to the components of the refrigeration cycle 150 can be prevented.

[0113] [Modification of the third embodiment] Fig. 15 is a flowchart showing the processing procedure for power train control according to a modification of embodiment 3. This flowchart differs from the flowchart of Fig. 14 in that it includes processes of S306A, S307A, S310A, and S311A instead of the processes of S306, S307, S310, and S311.

[0114] If the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than the reference value REF3 in S305 (YES in S305), ECU 500 increases the chiller target water temperature Tc(tag) compared to when the temperature difference ΔT is less than the reference value REF3 (S306A). Then, ECU 500 increases the power train heat loss in accordance with the chiller target water temperature Tc(tag) set in S306A (S307A).

[0115] If the temperature difference ΔT between the heat medium and the refrigerant is equal to or greater than the reference value REF3 in S309 (YES in S309), ECU 500 lowers the chiller target water temperature Tc(tag) compared to when the temperature difference ΔT is less than the reference value REF3 (S310A). Then, ECU 500 reduces the power train heat loss according to the chiller target water temperature Tc(tag) (S311A). Note that, like the processes of S307 and S311, the processes of S307A and S311A can be implemented using a map, for example. As with the modification of the second embodiment, the processes of S308 to S311A can be omitted.

[0116] [Embodiment 4] In the fourth and fifth embodiments, a thermal management circuit will be described that has a different configuration from that described in the first to third embodiments. The overall configuration of the thermal management system is the same as the configuration shown in FIG.

[0117] Fig. 16 is a diagram showing the configuration of a thermal management circuit in embodiment 4. The thermal management circuit 100A shown in Fig. 16 differs from the thermal management circuit 100 shown in Fig. 2 in that it does not include the HT circuit 110 (water pump 111, electric heater 112, three-way valve 113, heater core 114, and reservoir tank 115) and the temperature sensor 191, and in that it includes a refrigeration cycle 150A instead of the refrigeration cycle 150. The refrigeration cycle 150A differs from the refrigeration cycle 150 in that it further includes an accumulator 156, an indoor condenser 157, expansion valves 158BA and 158B, and a check valve 159.

[0118] The accumulator 156 is connected upstream (refrigerant input side) of the compressor 151. The accumulator 156 separates the liquid-phase refrigerant from the gas-phase refrigerant, and causes the compressor 151 to suck only the gas-phase refrigerant.

[0119] The indoor condenser 157 is connected downstream (refrigerant output side) of the compressor 151. The indoor condenser 157 heats the air by exchanging heat between the refrigerant flowing inside the indoor condenser 157 and the air.

[0120] Expansion valve 158A is connected to a pipe that branches off from the upstream of accumulator 156 and leads to the upstream of check valve 159. Expansion valve 158A reduces the pressure of the refrigerant that has passed through chiller 142 and / or EPR 154, expands it, and outputs it to check valve 159.

[0121] Expansion valve 158B is connected to a pipe that branches off from the downstream of indoor condenser 157 and leads to the downstream of check valve 159. Expansion valve 158B expands the high-pressure liquid-phase refrigerant that has passed through indoor condenser 157, changing it into wet vapor in a low-temperature, low-pressure gas-liquid mixed state.

[0122] Check valve 159 is connected between HT radiator 121 and expansion valve 152 (between HT radiator 121 and expansion valve 155). Check valve 159 allows the refrigerant output from HT radiator 121 to flow while prohibiting a flow in the reverse direction.

[0123] In a system configuration in which thermal management circuit 100A is employed, ECU 500 may execute the compressor control (see FIG. 7) described in the first embodiment, or may execute the power train control (see FIG. 11) in the modified example of the second embodiment. ECU 500 may execute the compressor control (see FIG. 15) described in the modified example of the third embodiment. These controls have already been described in detail, and therefore will not be described again here.

[0124] According to the fourth embodiment, similarly to the first to third embodiments (or their modifications), abrupt changes in the chiller water temperature Tc are suppressed, and as a result, deterioration in air conditioning comfort can be suppressed.

[0125] [Embodiment 5] 17 is a diagram showing the configuration of a thermal management circuit in embodiment 5. Thermal management circuit 200 includes, for example, a chiller circuit 210, a chiller 220, a radiator circuit 230, a refrigeration cycle 240, a condenser 250, a drive unit circuit 260, a battery circuit 270, an eight-way valve 280, and temperature sensors 291-295.

[0126] The chiller circuit 210 includes a water pump (W / P) 211. The chiller 220 is connected to (shared with) both the chiller circuit 210 and the refrigeration cycle 240. The radiator circuit 230 includes a radiator 231. The refrigeration cycle 240 includes, for example, a compressor 241, a solenoid valve 242, an expansion valve 243, solenoid valves 244A, 244B, 245, and 246, an evaporator 247, an orifice (expansion valve) 248, and an accumulator 249. The condenser 250 includes a water-cooled condenser 251 and an air-cooled condenser 252, and is connected to both the refrigeration cycle 240 and the drive unit circuit 260. The drive unit circuit 260 includes, for example, a water pump 261, an SPU 262, a PCU 263, an oil cooler 264, and a reservoir tank 265. The battery circuit 270 includes, for example, an advanced driver-assistance system (ADAS) 271 and a battery 272.

[0127] The heat medium circulating through the chiller circuit 210 flows through the path of the eight-way valve 280 (port P3), the water pump 211, the chiller 220, and the eight-way valve 280 (port P5).

[0128] Water pump 211 circulates the heat medium within chiller circuit 210 in accordance with a control command from ECU 500. Chiller 220 exchanges heat between the heat medium circulating through chiller circuit 210 and the heat medium circulating through refrigeration cycle 240. Eight-way valve 280 switches the path to which chiller circuit 210 is connected in accordance with a control command from ECU 500. The path switching by eight-way valve 280 will be described in detail later.

[0129] The heat medium circulating in the radiator circuit 230 flows between the radiator 231 and the eight-way valve 280 (ports P6, P7). The radiator 231 is disposed downstream of a grille shutter (not shown) and exchanges heat between the outside air of the vehicle and the heat medium.

[0130] The heat medium (gas-phase refrigerant or liquid-phase refrigerant) circulating through the refrigeration cycle 240 flows through any one of a first path to a third path. The first path is the path of the compressor 241, expansion valve 243, solenoid valve 244 (244A, 244B), air-cooled condenser 252, solenoid valve 245, evaporator 247, orifice 248, accumulator 249, and compressor 241. The second path is the path of the compressor 241, air-cooled condenser 252, solenoid valve 246, chiller 220, accumulator 249, and compressor 241. The third path is the path of the compressor 241, expansion valve 243, solenoid valve 244 (244A, 244B), air-cooled condenser 252, solenoid valve 246, chiller 220, accumulator 249, and compressor 241.

[0131] The compressor 241 compresses the gas-phase refrigerant circulating through the refrigeration cycle 240 in accordance with a control command from the ECU 500. The solenoid valve 242 is connected in parallel to the compressor 241 and adjusts the amount of gas-phase refrigerant that flows into the compressor 241 in accordance with a control command from the ECU 500. The expansion valve 243 reduces the pressure of the liquid-phase refrigerant by expanding the high-pressure liquid-phase refrigerant compressed by the compressor 241. The solenoid valves 244 (244A, 244B) switch on / off the flow of liquid-phase refrigerant between the expansion valve 243 and the air-cooled condenser 252 in accordance with a control command from the ECU 500. The air-cooled condenser 252 exchanges heat with the water-cooled condenser 251 of the drive unit circuit 260. The solenoid valve 245 limits the flow of liquid-phase refrigerant into the evaporator 247 in accordance with a control command from the ECU 500. The solenoid valve 246 limits the inflow of liquid-phase refrigerant into the chiller 220 in accordance with a control command from the ECU 500. The orifice 248 reduces the pressure of the refrigerant from the evaporator 247. The accumulator 249 prevents the liquid-phase refrigerant from being drawn into the compressor 241 if the refrigerant is not completely vaporized by the evaporator 247.

[0132] The heat medium (coolant) circulating through the drive unit circuit 260 flows through the route of the eight-way valve 280 (port P8), the water pump 261, the SPU 262, the PCU 263, the oil cooler 264, the water-cooled condenser 251, the reservoir tank 265, and the eight-way valve 280 (port P2).

[0133] Water pump 261 circulates a heat medium within drive unit circuit 260 in accordance with a control command from ECU 500. SPU 262 controls charging and discharging of battery 272 in accordance with a control command from ECU 500. PCU 263 converts DC power supplied from battery 272 into AC power in accordance with a control command from ECU 500, and supplies the AC power to a motor (not shown) built into the transaxle. Oil cooler 264 cools the transaxle by heat exchange between the heat medium circulating through drive unit circuit 260 and lubricating oil for the motor. SPU 262, PCU 263, and oil cooler 264 are cooled by the heat medium circulating through drive unit circuit 260. Water-cooled condenser 251 exchanges heat with air-cooled condenser 252 of refrigeration cycle 240. The reservoir tank 265 stores a portion of the heat medium in the drive unit circuit 260 (the heat medium that overflows due to an increase in pressure), thereby maintaining the pressure and amount of the heat medium in the drive unit circuit 260. The water-cooled condenser 251 corresponds to the "radiator" according to the present disclosure.

[0134] The heat medium (coolant) circulating in the battery circuit 270 flows through the path of the eight-way valve 280 (port P1)-ADAS 271-battery 272-eight-way valve 280 (port P4).

[0135] The ADAS 271 includes, for example, an adaptive cruise control (ACC), an auto speed limiter (ASL), a lane keeping assist (LKA), a pre-crash safety (PCS), and a lane departure alert (LDA). The battery circuit 270 may include an autonomous driving system (ADS) in addition to the ADAS 271. The battery 272 supplies power for driving to a motor generator built into the transaxle.

[0136] Eight-way valve 280 includes ports P1 to P8 (see FIGS. 18 and 19), and is connected to chiller circuit 210, radiator circuit 230, drive unit circuit 260, and battery circuit 270. Eight-way valve 280 corresponds to the "switching valve" according to the present disclosure.

[0137] Temperature sensor 291 detects the temperature of the heat medium flowing through radiator 231 (radiator water temperature Tr). Temperature sensor 292 detects the temperature (chiller water temperature Tc) of the refrigerant (which may be a heat medium instead of a refrigerant) flowing through chiller 220. Temperature sensor 293 detects the temperature of the heat medium flowing through battery 272 (battery water temperature Tb). Temperature sensor 294 detects the temperature of the heat medium flowing through PCU 263 (power train water temperature Tp). Temperature sensor 295 detects the temperature outside the vehicle (outside air temperature Ta). Each sensor outputs a sensor value indicating the detection result to ECU 500. Temperature sensor 292 corresponds to the "first temperature sensor" according to the present disclosure. Temperature sensor 291 corresponds to the "second temperature sensor" according to the present disclosure.

[0138] 18 is a diagram illustrating the first circuit mode in the fifth embodiment. In the first circuit mode, the eight-way valve 280 connects, for example, the battery circuit 270 and the chiller circuit 210 in series, and also connects the drive unit circuit 260 and the radiator circuit 230 in series. More specifically, a first path is formed in which the heat medium flows in the following order: port P1, battery 272, port P4, port P3, water pump 211, chiller 220, port P5, and port P1. Also, a second path is formed in which the heat medium flows in the following order: port P8, water pump 261, PCU 263, water-cooled condenser 251, reservoir tank 265, port P2, port P6, radiator 231, port P7, and port P8. The first path and the second path are connected in parallel.

[0139] 19 is a diagram illustrating the second circuit mode in the fifth embodiment. In the second circuit mode, for example, the battery circuit 270, the drive unit circuit 260, the radiator circuit 230, and the chiller circuit 210 are all connected in series by the eight-way valve 280. More specifically, a path is formed through which the heat medium flows in the following order: port P1, battery 272, port P4, port P8, water pump 261, PCU 263, water-cooled condenser 251, reservoir tank 265, port P2, port P6, radiator 231, port P7, port P3, water pump 211, chiller 220, port P5, and port P1.

[0140] In a system configuration in which thermal management circuit 200 is employed, ECU 500 may execute the compressor control (see FIG. 7) described in the first embodiment, or may execute the power train control (see FIG. 11) described in the modified example of the second embodiment. ECU 500 may execute the power train control (see FIG. 15) described in the modified example of the third embodiment. These controls have already been described in detail, and therefore will not be described again here.

[0141] According to the fifth embodiment, similarly to the first to third embodiments (or their modifications), abrupt changes in the chiller water temperature Tc are suppressed, and as a result, deterioration in air conditioning comfort can be suppressed.

[0142] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0143] 1 Thermal management system, 100 Thermal management circuit, 110 HT circuit, 111 Water pump, 112 Electric heater, 113 Three-way valve, 114 Heater core, 115 Reservoir tank, 120 Radiator, 121 HT radiator, 122 LT radiator, 130 LT circuit, 131 Water pump, 132 SPU, 133 PCU, 134 Oil cooler, 135 Boost / Buck converter, 141 Condenser, 142 Chiller, 150 Refrigeration cycle, 151 Compressor, 152 Expansion valve, 153 Evaporator, 154 EPR, 155 Expansion valve, 100A Thermal management circuit, 150A Refrigeration cycle, 156 Accumulator, 157 Indoor condenser, 157A, 158B Expansion valve, 159 Check valve, 160 Battery circuit, 161 Water pump, 162 Electric heater, 163 Battery, 164 Bypass path, 170 Reservoir tank, 180 Five-way valve, 191-196 Temperature sensor, 200 Thermal management circuit, 210 Chiller circuit, 211 Water pump, 220 Chiller, 230 Radiator circuit, 231 Radiator, 240 Refrigeration cycle, 241 Compressor, 242 Solenoid valve, 243 Expansion valve, 244 (244A, 244B), 245, 246 Solenoid valve, 247 Evaporator, 248 Orifice, 249 Accumulator, 250 Condenser, 251 Water-cooled condenser, 252 Air-cooled condenser, 260 Drive unit circuit, 261 Water pump, 262 SPU, 263 PCU, 264 oil cooler, 265 reservoir tank, 270 battery circuit, 272 battery, 280 eight-way valve, P1~P8 ports, 291~295 temperature sensor, 500 ECU, 501 processor, 502 memory, 503 storage, 504 interface.

Claims

1. a battery through which a heat transfer medium flows; a radiator through which the heat medium flows; a refrigeration cycle in which a refrigerant circulates; a chiller that exchanges heat between the heat medium and the refrigerant; a switching valve for switching between the first circuit mode and the second circuit mode, the first circuit mode is a mode in which the chiller is thermally connected to the battery; the second circuit mode is a mode in which the chiller is thermally disconnected from the battery and the chiller is thermally connected to the radiator; and a first temperature sensor for detecting a chiller temperature, which is the temperature of the refrigerant flowing through the chiller; a second temperature sensor that detects a radiator temperature, which is the temperature of the heat medium flowing through the radiator; a temperature adjusting device configured to adjust the temperature of one of the heat medium and the refrigerant; a control device that controls the temperature adjustment device based on the chiller temperature and the radiator temperature, A thermal management system in which, when switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve during heating operation of the refrigeration cycle, the control device controls the temperature adjustment device so as to reduce the temperature difference between the chiller temperature and the radiator temperature prior to the switching.

2. When switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve during heating operation of the refrigeration cycle, if a temperature difference between the chiller temperature and the radiator temperature is greater than a reference value, the control device controls the temperature adjustment device so that the temperature difference becomes smaller than the reference value prior to the switching; The thermal management system according to claim 1 , wherein the reference value is a predetermined value that is set to a value that suppresses deterioration of air conditioning comfort performance.

3. the temperature adjustment device includes a compressor that compresses the refrigerant circulating through the refrigeration cycle, 3. The thermal management system of claim 2, wherein when cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and switching is performed from the first circuit mode to the second circuit mode, if the temperature difference is greater than the reference value in the first circuit mode, the control device controls the rotation speed of the compressor so that the temperature difference becomes smaller than the reference value.

4. 4. The thermal management system of claim 3, wherein when cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and switching is performed from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is higher than the radiator temperature, when the temperature difference in the first circuit mode is greater than the reference value, the control device lowers the chiller temperature by increasing the rotation speed of the compressor in the first circuit mode compared to when the temperature difference is smaller than the reference value.

5. 4. The thermal management system of claim 3, wherein when cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and switching is performed from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is lower than the radiator temperature, when the temperature difference is greater than the reference value, the control device increases the chiller temperature by reducing the rotation speed of the compressor in the first circuit mode compared to when the temperature difference is smaller than the reference value.

6. the temperature adjustment device includes an electric heater that heats the heat medium flowing through the radiator, 3. The thermal management system of claim 2, wherein when the cooling of the battery by the chiller is completed and switching from the first circuit mode to the second circuit mode is performed, if the temperature difference is greater than the reference value in the first circuit mode, the control device controls the heat generation amount of the electric heater so that the temperature difference becomes smaller than the reference value.

7. 7. The thermal management system of claim 6, wherein when cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and switching is performed from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is higher than the radiator temperature, the control device increases the heat generation amount of the electric heater to raise the radiator temperature when the temperature difference is greater than the reference value in the first circuit mode, compared to when the temperature difference is smaller than the reference value.

8. the temperature adjustment device includes a power conversion device through which the heat medium circulates in the radiator, 3. The thermal management system of claim 2, wherein when the cooling of the battery by the chiller is completed and switching from the first circuit mode to the second circuit mode is performed, if the temperature difference is greater than the reference value in the first circuit mode, the control device controls the heat loss of the power conversion device so that the temperature difference becomes smaller than the reference value.

9. 9. The thermal management system of claim 8, wherein when cooling of the battery by the chiller is completed during heating operation of the refrigeration cycle and switching is performed from the first circuit mode to the second circuit mode, and the chiller temperature in the first circuit mode is higher than the radiator temperature, the control device increases the radiator temperature by increasing heat loss of the power conversion device when the temperature difference is greater than the reference value in the first circuit mode, compared to when the temperature difference is smaller than the reference value.

10. the temperature adjustment device includes an electric heater that heats the heat medium flowing through the radiator, 3. The thermal management system of claim 2, wherein when switching from the second circuit mode to the first circuit mode is performed to start cooling the battery by the chiller, if the temperature difference is greater than the reference value in the second circuit mode, the control device controls the heat generation amount of the electric heater so that the temperature difference becomes smaller than the reference value.

11. 11. The thermal management system of claim 10, wherein when switching from the second circuit mode to the first circuit mode is performed to start cooling the battery by the chiller, and the chiller temperature in the second circuit mode is higher than the radiator temperature, the control device increases the heat output of the electric heater to raise the radiator temperature when the temperature difference is greater than the reference value in the second circuit mode, compared to when the temperature difference is smaller than the reference value.

12. the temperature adjustment device includes a power conversion device through which the heat medium circulates in the radiator, 3. The thermal management system of claim 2, wherein when switching from the second circuit mode to the first circuit mode is performed to start cooling the battery by the chiller, if the temperature difference is greater than the reference value in the second circuit mode, the control device controls the heat loss of the power conversion device so that the temperature difference becomes smaller than the reference value.

13. 13. The thermal management system of claim 12, wherein when switching from the second circuit mode to the first circuit mode is performed to start cooling the battery by the chiller, and the chiller temperature in the second circuit mode is higher than the radiator temperature, the control device increases the radiator temperature by increasing heat loss of the power conversion device when the temperature difference is greater than the reference value in the second circuit mode, compared to when the temperature difference is smaller than the reference value.

14. A vehicle comprising the thermal management system according to any one of claims 1 to 13.

15. 1. A method for controlling a thermal management circuit, comprising: The thermal management circuit includes: a battery through which a heat transfer medium flows; a radiator through which the heat medium flows; a refrigeration cycle in which a refrigerant circulates; a chiller that exchanges heat between the heat medium and the refrigerant; a switching valve that switches between the first circuit mode and the second circuit mode; a temperature adjusting device configured to adjust a temperature of one of the heat medium and the refrigerant, the first circuit mode is a mode in which the chiller is thermally connected to the battery; the second circuit mode is a mode in which the chiller is thermally disconnected from the battery and the chiller is thermally connected to the radiator; The control method includes: detecting a chiller temperature, which is the temperature of the refrigerant flowing through the chiller; detecting a radiator temperature, which is the temperature of the heat medium flowing through the radiator; and controlling the temperature adjustment device based on the chiller temperature and the radiator temperature, The control method for a thermal management circuit includes a step of controlling the temperature adjustment device so that a temperature difference between the chiller temperature and the radiator temperature is reduced prior to switching between the first circuit mode and the second circuit mode by controlling the switching valve during heating operation of the refrigeration cycle.

16. the controlling step includes, when switching between the first circuit mode and the second circuit mode is performed by controlling the switching valve during heating operation of the refrigeration cycle, if a temperature difference between the chiller temperature and the radiator temperature is greater than a reference value, controlling the temperature adjustment device so that the temperature difference becomes smaller than the reference value prior to the switching; 16. The method of controlling a thermal management circuit according to claim 15, wherein the reference value is a predetermined value that is set to a value that suppresses deterioration of air conditioning comfort performance.

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