Heating system

Abstract

To provide a heating system suppressing a decrease in air-conditioning comfort in a cabin.SOLUTION: A heating system includes: flow paths FP1 to FP3; a battery 163; a chiller 142; an LT radiator 122; and a five-way valve 180. The battery 163 can exchange heat with a heat medium of the flow path FP1. The chiller 142 is provided in the flow path FP2. The LT radiator 122 is provided in the flow path FP3 and sucks heat from the outer air of a vehicle. The five-way valve 180 is configured to switch connection states among the flow paths FP1 to FP3. The connection states include a first state, a second state, and a third state. When one of the first state and the second state is switched to the other during heating operation, the five-way valve 180 first switches one of the states to the third state and then switches the third state to the other state of the two.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to heating systems. [Background technology]

[0002] JP 2020-165604 A (Patent Document 1) discloses an air conditioner mounted on a vehicle. The air conditioner includes a heat pump cycle (HPC: Heat Pump Cycle), a high-temperature side heat medium circuit (heating circuit), and a low-temperature side heat medium circuit. The HPC has a chiller and a condenser. The chiller absorbs heat from the low-temperature side heat medium circuit. The condenser transfers heat from the HPC to the high-temperature side heat medium circuit. The low-temperature side heat medium circuit has a battery, an outdoor air heat exchanger, and a three-way valve (switching device). Each of the battery and the outdoor air heat exchanger functions as a heat absorption device. The three-way valve is used to adjust the amount of heat transfer from the low-temperature side heat medium to the HPC. The modes of the air conditioner include a heating mode and a cooling / heating mode. In the heating mode, heat absorbed by the outdoor air heat exchanger is transferred to the high-temperature side heat medium circuit via the chiller and the HPC (outdoor air is used as a heating heat source). In the cooling / heating mode, the heat of the battery is transferred to the high-temperature side heat medium circuit via the chiller and HPC (the battery is used as a heating heat source). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-165604 A Summary of the Invention [Problem to be solved by the invention]

[0004] Whether outside air or a battery is used as the heating heat source, the HPC receives heat via the chiller device and transfers the heat to the vehicle's heating circuit (heating operation). When the heating heat source is changed during heating operation, the switching device switches the connection state between the flow paths of the heat medium. In this case, the temperature at the heating air outlet changes significantly, which may reduce the air conditioning comfort in the vehicle cabin.

[0005] The present disclosure has been made to solve the above problems, and has an object to provide a heating system that suppresses a decrease in air-conditioning comfort in a vehicle cabin. [Means for solving the problem]

[0006] The heating system of the present disclosure is mounted on a vehicle. The heating system includes a first flow path, a second flow path, and a third flow path, an electricity storage device, a chiller device, a heat absorption device, a heating circuit, a heat pump cycle, and a switching device. A heat medium can flow through the first flow path, the second flow path, and the third flow path. The electricity storage device is capable of heat exchange with the heat medium in the first flow path. The chiller device is provided in the second flow path. The heat absorption device is provided in the third flow path and configured to absorb heat from the outside air of the vehicle. The heating circuit heats the passenger compartment of the vehicle. The heat pump cycle performs a heating operation in which heat is received from the heat medium in the second flow path via the chiller device and the heat is transferred to the heating circuit. The switching device is configured to switch a connection state between the first flow path, the second flow path, and the third flow path. The connection states include a first state, a second state, and a third state. In the first state, the first flow path is disconnected from the second flow path and the third flow path, and the second flow path is connected to the third flow path. In the second state, the first flow path is connected to the second flow path and disconnected from the third flow path, and the second flow path is disconnected from the third flow path. In the third state, the first flow path is connected to the second and third flow paths, and the second flow path is connected to the third flow path. When switching the connection state from one of the first and second states to the other state during heating operation, the switching device performs an operation of switching the connection state from the one state to the third state and then switching the connection state from the third state to the other state. Effect of the Invention

[0007] According to the present disclosure, it is possible to suppress a decrease in air conditioning comfort inside the vehicle cabin. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of an overall configuration of a thermal management system (heating system) according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining control of a five-way valve by an ECU (Electronic Control Unit) in the embodiment. [Diagram 3] 10 is a diagram for explaining control of a five-way valve in a comparative example. FIG. [Figure 4] 11 is a time chart for explaining switching of the connection state between flow paths when cooling of the battery starts during heating operation. [Diagram 5] 10 is a flowchart showing a control process for switching the connection state between the flow paths using the five-way valve when cooling of the battery is started. [Figure 6] 5 is a time chart for explaining control of the five-way valve when cooling of the battery is completed during heating operation. [Figure 7] 10 is a flowchart showing a control process for switching the connection state between the flow paths using the five-way valve when cooling of the battery is completed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 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 characters and their description will not be repeated.

[0010] Fig. 1 is a diagram showing an example of an overall configuration of a thermal management system (heating system) according to an embodiment. Referring to Fig. 1, the thermal management system 1 is mounted on a vehicle 5. The vehicle 5 is an electric vehicle such as an electric vehicle (BEV: Battery Electric Vehicle). The thermal management system 1 includes an ECU 50 and a thermal management circuit 100.

[0011] The ECU 50 includes a CPU (Central Processing Unit) 51 and a memory 52. ​​The CPU 51 executes various types of arithmetic processing. The memory 52 includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM stores programs executed by the CPU 51. The ECU 50 controls the thermal management circuit 100 by outputting a control command to the thermal management circuit 100 according to a sensor value from the thermal management circuit 100.

[0012] The thermal management circuit 100 is configured to allow a heat medium (refrigerant) to flow through it. The thermal management circuit 100 includes an HT (High Temperature) circuit 110, a radiator 120, an LT (Low Temperature) circuit 130, a water-cooled condenser 141, a chiller (chiller device) 142, a heat pump cycle (HPC) 150, a battery circuit 160, a five-way valve 180 having ports P1 to P5, and temperature sensors 192 to 195.

[0013] The HT circuit 110 includes a water pump (W / P) 111, a heater 112, a three-way valve 113, and a heater core 114. The radiator 120 includes a high temperature (HT) radiator 121 and a low temperature (LT) radiator 122. The LT circuit 130 includes a flow path FP3, a W / P 131, and a PCU (Power Control Unit) 133. The HPC 150 includes a compressor 151, expansion valves 152 and 155, an evaporator 153, and an EPR (Evaporative Pressure Regulator) 154. The battery circuit 160 includes flow paths FP1 and FP2, a W / P 161, a battery 163, a connection portion 165, and a flow path BP.

[0014] The heat medium can flow through each of the flow paths FP1 and FP2. The flow path FP1 is a flow path from the port P1 to the connection portion 165. The flow path FP2 is a flow path from the port P2 to the connection portion 165. The W / P 111 circulates the heat medium in the HT circuit 110. The water-cooled condenser 141 heats the heat medium in the HT circuit 110 by receiving heat released from the heat medium in the HPC 150. The heater 112 heats the heat medium in the HT circuit 110. The three-way valve 113 switches the destination of the heat medium between the heater core 114 and the HT radiator 121. The heater core 114 warms the air by heat exchange between the heat medium in the HT circuit 110 and the air blown into the vehicle cabin. This heats the vehicle cabin. The HT circuit 110 is a heating circuit that heats the vehicle cabin.

[0015] The LT radiator 122 is provided in the flow path FP3. The flow path FP3 is a flow path from port P3 to port P4, and allows the heat medium to flow through it. The LT radiator 122 functions as a heat absorption device that absorbs heat from the outside air when the temperature of the heat medium in the flow path FP3 is lower than the temperature of the outside air of the vehicle 5. The W / P 131 circulates the heat medium in the flow path FP3. The PCU 133 converts DC power from the battery 163 into AC power and supplies it to the driving motor of the vehicle 5.

[0016] The water-cooled condenser 141 releases heat from the heat medium of the HPC 150 to the heat medium of the HT circuit 110. The chiller 142 is provided in the flow path FP2, and exchanges heat between the heat medium of the HPC 150 and the heat medium of the battery circuit 160 (flow path FP2).

[0017] The heat medium (gas-phase refrigerant or liquid-phase refrigerant) of the HPC 150 circulates in a circuit passing through the evaporator 153 or a circuit passing through the water-cooled condenser 141. The HPC 150 is configured to perform a heating operation in which the HPC 150 receives heat from the heat medium of the flow path FP2 via the chiller 142 and transfers the heat to the HT circuit 110.

[0018] The compressor 151 compresses the gas-phase refrigerant circulating through the HPC 150. The rotation speed of the compressor 151 is controlled according to the deviation between the target value and the current value of the blowing temperature. The water-cooled condenser 141 condenses the gas-phase refrigerant into a liquid-phase refrigerant by releasing heat from the compressed high-temperature and high-pressure gas-phase refrigerant. The high-temperature and high-pressure refrigerant compressed by the compressor 151 releases heat to the heat medium (hot water) circulating through the HT circuit 110 by heat exchange in the water-cooled condenser 141. The heat of the heated hot water is released by the heater core 114, and the heated air (heated air) is sent from the blowing port into the vehicle cabin to heat the vehicle cabin. Each of the expansion valves 152 and 155 reduces the pressure of the liquid-phase refrigerant by expanding the high-pressure liquid-phase refrigerant. The EPR 154 adjusts the pressure in the evaporator 153 to be approximately constant by controlling the flow rate of the heat medium flowing in from the evaporator 153. The chiller 142 evaporates the liquid-phase refrigerant whose pressure has been reduced by the expansion valve 155. As a result, heat is removed from the heat medium circulating through the battery circuit 160, and the heat medium is cooled.

[0019] The heat medium circulating in the battery circuit 160 flows through one or both of a first circulation circuit and a second circulation circuit. The first circulation circuit is a path of W / P 161-chiller 142-five-way valve 180-battery 163-W / P 161. The second circulation circuit is a path of W / P 161-chiller 142-five-way valve 180-flow path BP-W / P 161.

[0020] The W / P 161 circulates the heat medium in the battery circuit 160. The chiller 142 cools the heat medium circulating through the battery circuit 160 by heat exchange between the heat medium circulating through the HPC 150 and the heat medium circulating through the battery circuit 160. The battery 163 is provided in the flow path FP1 and is capable of exchanging heat with the heat medium in the flow path FP1. The battery 163 stores electric power for running the vehicle 5. The battery 163 can be cooled by the heat medium in the flow path FP1.

[0021] Flow path BP is a flow path from port P5 to connection unit 165, and allows the heat medium to flow therethrough. Flow path BP is a bypass flow path that allows the heat medium to bypass battery 163. Flow path BP is connected to connection unit 165. Connection unit 165 is located in a portion of flow path FP1 downstream of battery 163 and in a portion of flow path FP2 upstream of chiller 142. Flow path BP is configured to be connectable to a portion of flow path FP3 downstream of LT radiator 122 via five-way valve 180.

[0022] The five-way valve 180 has ports P1 to P5. The port P1 is connectable to the flow path FP1. The port P2 is connectable to the flow path FP2. The ports P3 and P4 are connectable to the upstream and downstream portions of the flow path FP3 relative to the LT radiator 122, respectively. The port P5 is connectable to the flow path BP. The five-way valve 180 is a switching device that switches the connection state between the flow paths FP1 to FP3 and BP, and is controlled by the ECU 50.

[0023] Temperature sensor 192 detects radiator water temperature Tr as the temperature of the heat medium flowing through LT radiator 122 (temperature of the heat medium in flow path FP3). Radiator water temperature Tr corresponds to the temperature of the heat medium in the portion of flow path FP3 downstream of the LT radiator 122. Temperature sensor 193 detects the temperature of the heat medium in flow path FP2 (chiller water temperature Tc). In this example, chiller water temperature Tc corresponds to the temperature of the heat medium in the portion of flow path FP2 upstream of chiller 142. Temperature sensor 194 detects the temperature of the heat medium in flow path FP1 (battery water temperature Tb). Temperature sensor 195 detects the temperature of the heat medium flowing through PCU 133 (power train water temperature Tp). Power train water temperature Tp may be used as the temperature of the heat medium in flow path FP3.

[0024] Fig. 2 is a diagram for explaining the control of the five-way valve 180 by the ECU 50 in the embodiment. Referring to Fig. 2, the ECU 50 controls the five-way valve 180 so that the connection state between the flow paths FP1, FP2, FP3 and BP is in a first state, a second state or a third state.

[0025] The first state (upper part of FIG. 2) corresponds to a connection state between the flow paths when the outside air is used as a heating heat source. In the first state, the flow path FP1 is disconnected from the flow paths FP2, FP3, and BP, the flow path FP2 is connected to the flow paths FP3 and BP, and the flow path FP3 is connected to the flow path BP. The heat medium passing through the chiller 142 circulates in a closed circuit formed by the flow paths FP2, FP3, and BP. The ECU 50 achieves the first state by controlling the five-way valve 180 so that the port P1 is disconnected from the ports P2 to P5, the ports P2 and P3 are connected, and the ports P4 and P5 are connected. In the first state, the HPC 150 is performing a heating operation, and the battery 163 is not cooled.

[0026] In the first state, the flow path FP1 is separated from the flow paths FP2, FP3, and BP. Therefore, the battery water temperature Tb may deviate from the chiller water temperature Tc or the radiator water temperature Tr (or the power train water temperature Tp). For example, when the outside air is used as a heating heat source in a low-temperature environment in winter, the radiator water temperature Tr is lower than the outside air temperature (e.g., 0°C). As a result, the battery water temperature Tb in the first state may be significantly higher than the radiator water temperature Tr. The deviation between the radiator water temperature Tr and the battery water temperature Tb becomes more noticeable when the cooling start temperature of the battery 163 is set high from the viewpoint of energy saving and the battery 163 is cooled less frequently.

[0027] The second state (lower part of FIG. 2) corresponds to a connection state between the flow paths when the battery 163 is used as a heating heat source. In the second state, the flow path FP1 is connected to the flow path FP2 and disconnected from the flow path FP3, the flow path FP2 is disconnected from the flow path FP3, and the flow path FP3 is disconnected from the flow path BP. The heat medium passing through the chiller 142 circulates in a closed circuit (dashed line) formed by the flow paths FP1 and FP2. The ECU 50 achieves the second state by controlling the five-way valve 180 so that the ports P1 and P2 communicate with each other, the ports P3 and P4 communicate with each other, and the port P5 is disconnected from the ports P1 to P4. In the second state, the heat of the battery 163 is supplied to the HT circuit 110 via the heat medium of the flow path FP1, the heat medium of the flow path FP2, the chiller 142, and the HPC 150 (FIG. 1) (the HPC 150 performs heating operation), and the battery 163 is cooled.

[0028] In the second state, the flow path FP3 is separated from the flow paths FP1, FP2, and BP. Therefore, the radiator water temperature Tr (or the power train water temperature Tp) may deviate from the battery water temperature Tb or the chiller water temperature Tc.

[0029] When cooling of the battery 163 starts or ends during heating operation, the ECU 50 controls the five-way valve 180 so that the connection state between the flow paths switches from one of the first state and the second state to the other state. For example, when cooling of the battery 163 starts, the ECU 50 controls the five-way valve 180 so that the connection state switches from the first state to the second state in order to change the heating heat source from the outside air to the battery 163. When cooling of the battery 163 ends, the ECU 50 controls the five-way valve 180 so that the connection state switches from the second state to the first state in order to change the heating heat source from the battery 163 to the outside air.

[0030] As described above, when ECU 50 switches the connection state from the first state to the second state, or from the second state to the first state, the chiller water temperature Tc may change suddenly, resulting in a decrease in air conditioning comfort (described in more detail below).

[0031] Therefore, when the connection state between the flow paths is switched from one of the first state and the second state to the other state during heating operation (when cooling of the battery 163 is started or ended), the ECU 50 controls the five-way valve 180 to execute a specific switching operation. This operation is an operation of switching the connection state from the one state to the third state (the middle part of FIG. 2), and then switching the connection state from the third state to the other state.

[0032] In the third state, the flow path FP1 is connected to the flow paths FP2, FP3, and BP, the flow path FP2 is connected to the flow paths FP3 and BP, and the flow path FP3 is connected to the flow path BP. The ECU 50 achieves the third state by controlling the five-way valve 180 so that the ports P1, P4, and P5 communicate with each other and the ports P2 and P3 communicate with each other.

[0033] In the third state, paths R1 and R2 are formed. The path R1 is a path through which the heat medium flows into the chiller 142 through the flow paths FP3 and BP and the connecting portion 165. The path R2 is a path through which the heat medium flows into the chiller 142 through the flow paths FP3 and FP1 and the connecting portion 165.

[0034] The specific switching operations described above include a first operation executed when cooling of the battery 163 starts, and a second operation executed when cooling of the battery 163 starts. The first operation is an operation of switching the connection state from the first state to the third state, and then from the third state to the second state (hatched arrow). The second operation is an operation of switching the connection state from the second state to the third state, and then from the third state to the first state (hollow arrow).

[0035] According to the first operation, when cooling of the battery 163 starts, the connection state is provisionally in the third state before being switched from the first state to the second state. In the third state, the closed circuit (chiller-battery circulation circuit) in which the heat medium passing through the chiller 142 and the battery 163 circulates is larger than the chiller-battery circulation circuit (dash line) in the second state in that it includes the flow path FP3. Therefore, the amount of heat medium in the chiller-battery circulation circuit in the third state is larger than the amount of heat medium in the chiller-battery circulation circuit in the second state. Therefore, the temperature change of the heat medium in the chiller-battery circulation circuit (temperature change associated with the connection of the flow paths FP1 and FP2) immediately after the first state is switched to the third state is smaller than the temperature change of the heat medium in the chiller-battery circulation circuit immediately after the first state is directly switched to the second state. This reduces the influence of the heat medium in the flow path FP2 from the heat of the battery 163 when cooling of the battery 163 starts. Therefore, the change in the chiller water temperature Tc can be reduced.

[0036] According to the second operation, when the cooling of the battery 163 is completed, the connection state is provisionally in the third state before being switched from the second state to the first state. In the third state, the closed circuit (chiller-radiator circulation circuit) in which the heat medium passing through the chiller 142 and the LT radiator 122 circulates is larger than the chiller-radiator circulation circuit (solid line) in the first state in that it includes the flow path FP1. Therefore, the amount of heat medium in the chiller-radiator circulation circuit in the third state is larger than the amount of heat medium in the chiller-radiator circulation circuit in the first state. Therefore, the temperature change of the heat medium in the chiller-battery circulation circuit (temperature change associated with the connection of the flow paths FP2 and FP3) immediately after the second state is switched to the third state is smaller than the temperature change of the heat medium in the chiller-battery circulation circuit immediately after the second state is directly switched to the first state. This reduces the influence of the heat medium in the flow path FP2 from the heat of the heat medium in the flow path FP3 at the end of the cooling of the battery 163. Therefore, the change in the chiller water temperature Tc can be reduced.

[0037] In this way, the first and second operations can reduce abrupt changes in the chiller water temperature Tc. As a result, the decrease in the comfort of the air conditioning in the vehicle cabin can be suppressed. Furthermore, there is no need to operate the heater 112 to compensate for the decrease in the comfort of the air conditioning caused by abrupt changes in the chiller water temperature Tc, and the highly efficient HPC 150 can be utilized. This can save power consumption when heating the vehicle cabin.

[0038] In the embodiment, in the third state, both the path R1 and the path R2 are formed. Therefore, the heat medium in the flow path FP3 flows into the chiller 142 through both the flow paths FP1 and FP2. In this case, the heat medium in the portion of the flow path FP1 downstream of the battery 163 and the heat medium in the flow path BP are mixed at the connection portion 165, and the mixed heat medium flows into the chiller 142. The temperature of the heat medium after mixing is closer to the chiller water temperature Tc before the connection state is switched than the temperature of the heat medium at the connection portion 165 in the case where the heat medium flows into the chiller 142 through only one of the paths R1 and R2. Therefore, the change in the chiller water temperature Tc can be reduced more effectively than in the above case.

[0039] For example, when cooling of the battery 163 starts (first state → third state), if the heat medium flows into the chiller 142 only through the path R1, only the relatively high-temperature heat medium that has passed through the battery 163 in the flow path FP1 flows into the chiller 142 through the connection part 165. On the other hand, in the embodiment, the relatively low-temperature heat medium supplied from the flow path FP3 through the flow path BP also flows into the connection part 165 and is mixed with the relatively high-temperature heat medium at the connection part 165. As a result, the medium-temperature heat medium after mixing flows into the chiller 142, so that a sudden change in the chiller water temperature Tc can be more effectively mitigated than in the above case where only the high-temperature heat medium flows into the chiller 142.

[0040] Similarly, when cooling of the battery 163 is completed (second state → third state), if the heat medium flows into the chiller 142 only through path R1, only the relatively low-temperature heat medium that has passed through the battery 163 in flow path FP1 flows into the chiller 142 through connection part 165. On the other hand, in the embodiment, the relatively high-temperature heat medium supplied from flow path FP3 through flow path BP also flows into connection part 165 and mixes with the relatively low-temperature heat medium at connection part 165. As a result, the medium-temperature heat medium flows into the chiller 142, and a sudden change in the chiller water temperature Tc can be effectively mitigated.

[0041] 3 is a diagram for explaining the control of the five-way valve 180 by the ECU in a comparative example. In this comparative example, when cooling of the battery 163 during heating operation starts or ends, the connection state between the flow paths is directly switched from one of the first state and the second state to the other state.

[0042] 3, when cooling of the battery 163 starts, the ECU of the comparative example controls the five-way valve 180 so that the connection state between the flow paths is switched directly from the first state to the second state (hatched arrows). This connects flow path FP2 to flow path FP1 and disconnects it from flow path FP3. As a result, the heat medium flowing through the chiller 142 stops flowing through the LT radiator 122 and instead flows through the battery 163 (it circulates through the closed circuit formed by the flow paths FP1 and FP2). Therefore, if the battery water temperature Tb deviates from the chiller water temperature Tc when cooling of the battery 163 starts, there is a possibility that the chiller water temperature Tc will change suddenly due to the influence of the battery water temperature Tb immediately after switching from the first state to the second state.

[0043] When cooling of the battery 163 is completed, the ECU controls the five-way valve 180 so that the connection state between the flow paths is switched directly from the second state to the first state (white arrow). This disconnects flow path FP2 from flow path FP1 and connects it to flow path FP3. As a result, the heat medium flowing through the chiller 142 stops flowing through the battery 163 and instead flows through the LT radiator 122 (circulating through the closed circuit formed by the flow paths FP2, FP3, and BP). Therefore, if the radiator water temperature Tr (power train water temperature Tp) deviates from the chiller water temperature Tc when cooling of the battery 163 is completed, there is a possibility that the chiller water temperature Tc will change suddenly due to the influence of the radiator water temperature Tr immediately after switching from the second state to the first state.

[0044] A sudden change in the chiller water temperature Tc affects the HT circuit 110 via the HPC 150, leading to a large change in temperature at the outlet of the heated air. As a result, the air conditioning comfort in the vehicle cabin may decrease. To compensate for the decrease in air conditioning comfort, the heater 112 can be operated, but this increases power consumption compared to high-efficiency heating using the HPC 150.

[0045] As described above, the compressor rotation speed is controlled according to the deviation between the target value and the current value of the temperature at the heating air outlet, but if the chiller heat absorption amount changes suddenly, the compressor rotation speed increases after the increase in this deviation is detected. In other words, the increase in the compressor rotation speed is delayed with respect to the timing of switching between the first state and the second state. Therefore, it is difficult to suppress a sudden change in the chiller heat absorption amount (chiller water temperature Tc) by adjusting the compressor rotation speed after switching from the first state to the second state or from the second state to the first state.

[0046] In addition, if the amount of heat absorbed by the chiller changes suddenly, the refrigerant dryness may change, and the heat medium may not be completely vaporized by the chiller 142. That is, the heat medium at the inlet of the compressor 151 may become in a gas-liquid mixed phase state (a state in which the gas-phase refrigerant and the liquid-phase refrigerant are mixed). This is not preferable from the viewpoint of protecting the compressor 151.

[0047] Thus, in the comparative example, problems such as a decrease in air conditioning comfort, an increase in power consumption, and gas-liquid mixed phase of the heat medium at the inlet of the compressor 151 may occur when cooling of the battery 163 starts or ends. On the other hand, in the embodiment (FIG. 2), such problems can be suppressed.

[0048] Fig. 4 is a time chart for explaining the switching of the connection state between the flow paths FP1-FP3 and BP when cooling of the battery 163 starts during heating operation. With reference to Fig. 4, the horizontal axis represents elapsed time. The vertical axis represents, from top to bottom, whether there is a request to cool the battery 163, 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 connection state between each flow path.

[0049] The changes over time of each parameter in the embodiment and the comparative example are indicated by a solid line and a dashed dotted line, respectively. In this comparative example, the connection state is directly switched from the first state to the second state.

[0050] In a period TP1 before time ta, the connection state is the first state. At time ta, the battery water temperature Tb rises to the cooling start temperature TS, and a cooling request for the battery 163 is generated. In the embodiment, the ECU 50 controls the five-way valve 180 to execute the first operation in response to the cooling request. Specifically, the ECU 50 switches the connection state between the flow paths from the first state to the third state at time ta, and then maintains the third state during a period TP2. The period TP2 continues until the chiller water temperature Tc rises by the reference temperature ΔPT1 (until time tb). At time tb, the ECU 50 switches the connection state from the third state to the second state, and maintains the connection state in the second state during a period TP3.

[0051] The temperature difference between the battery water temperature Tb and the chiller water temperature Tc or the radiator water temperature Tr (power train water temperature Tp) is also expressed as the temperature difference ΔT1 (=|Tb-Tc|, |Tb-Tr|, or |Tb-Tp|). The temperature difference ΔT1 is related to the change in the chiller water temperature Tc when cooling of the battery 163 starts. For example, if the temperature difference ΔT1 is large enough to be equal to or greater than the threshold value TH1 in the first state before cooling of the battery 163 starts, it is predicted that the chiller water temperature Tc will change rapidly if the connection state is directly switched from the first state to the second state when cooling of the battery 163 starts. If this is not the case, the temperature difference ΔT1 is small, and therefore it is predicted that the chiller water temperature Tc will not change rapidly at the time of switching.

[0052] Therefore, when switching the connection state from the first state to the second state, the ECU 50 may control the five-way valve 180 to execute the first operation when the temperature difference ΔT1 is equal to or greater than the threshold value TH1. On the other hand, when the temperature difference ΔT1 is less than the threshold value TH1, the ECU 50 may control the five-way valve 180 to switch the connection state directly to the second state without switching the connection state from the first state to the third state.

[0053] According to this control, if it is predicted that there will be no sudden change in the chiller water temperature Tc, heating of the vehicle interior using the battery 163 as a heating heat source can be started immediately.

[0054] 5 is a flowchart showing a control process procedure for switching the connection state between the flow paths using the five-way valve 180 when starting to cool the battery 163. The process shown in this flowchart is started in response to a request to cool the battery 163. Hereinafter, step is abbreviated as S.

[0055] 5, in S105, ECU 50 determines whether or not temperature difference ΔT1 is equal to or greater than threshold value TH1 (S105).

[0056] If the temperature difference ΔT1 is less than the threshold value TH1 (NO in S105), the ECU 50 controls the five-way valve 180 to switch the connection state of the flow paths FP1-FP3, BP directly to the second state without switching it from the first state to the third state (S120). If not (YES in S105), the ECU 50 controls the five-way valve 180 to switch the connection state of the flow paths FP1-FP3, BP from the first state to the third connection state (S110). After that, the ECU 50 controls the five-way valve 180 to switch the connection state of the flow paths FP1-FP3, BP from the third state to the second connection state (S115).

[0057] 6 is a time chart for explaining the control of five-way valve 180 at the end of cooling of battery 163 during heating operation. Referring to FIG. 6, the parameters of the horizontal and vertical axes are the same as those shown in FIG.

[0058] The changes over time of each parameter in the embodiment and the comparative example are indicated by a solid line and a dashed dotted line, respectively. In this comparative example, the connection state is directly switched from the second state to the first state.

[0059] In a period TP1a before time tc, the connection state is the second state. At time tc, the request to cool the battery 163 disappears. As a result, the ECU 50 of the embodiment controls the five-way valve 180 to execute the second operation. Specifically, the ECU 50 switches each connection state from the second state to the third state at time tc, and then maintains the third state during a period TP2a. The period TP2a continues until the chiller water temperature Tc drops by the reference temperature ΔPT2 (until time td). At time td, the ECU 50 switches the connection state from the third state to the first state, and maintains it in the first state during a period TP3a.

[0060] In this example, the chiller water temperature Tc at the end of battery cooling is lower than that at the start of battery cooling (Figure 4), but even if this is not the case, the second action can suppress sudden changes in the chiller water temperature Tc.

[0061] The temperature difference between the radiator water temperature Tr (power train water temperature Tp) and the battery water temperature Tb or the chiller water temperature Tc is also expressed as the temperature difference ΔT2 (=|Tr-Tb|, |Tr-Tc|, |Tp-Tb| or |Tp-Tc|). The temperature difference ΔT2 is related to the change in the chiller water temperature Tc at the end of cooling the battery 163. For example, if the temperature difference ΔT2 is large enough to be equal to or greater than the threshold value TH2 in the second state before the end of cooling the battery 163, it is predicted that the chiller water temperature Tc will change rapidly if the connection state is directly switched from the second state to the first state at the end of cooling the battery 163. If this is not the case, it is predicted that the temperature difference ΔT2 is small and the chiller water temperature Tc will not change rapidly.

[0062] Therefore, when switching the connection state from the second state to the first state, the ECU 50 may control the five-way valve 180 to execute the second operation when the temperature difference ΔT2 is equal to or greater than the threshold value TH2. On the other hand, when the temperature difference ΔT2 is less than the threshold value TH2, the ECU 50 may control the five-way valve 180 to switch the connection state directly to the first state without switching the connection state from the second state to the third state.

[0063] According to such control, when it is predicted that there will be no sudden change in the chiller water temperature Tc, the heating heat source can be switched from the battery 163 to the outside air early.

[0064] 7 is a flowchart showing a control process for switching the connection state between the flow paths using the five-way valve 180 when cooling of the battery 163 is completed. The process shown in this flowchart is started in response to the disappearance of the request to cool the battery 163.

[0065] 7, in S205, ECU 50 determines whether or not temperature difference ΔT2 is equal to or greater than threshold value TH2 (S205).

[0066] If the temperature difference ΔT2 is less than the threshold value TH2 (NO in S205), the ECU 50 controls the five-way valve 180 to switch the connection state of the flow paths FP1-FP3, BP directly to the first state without switching it from the second state to the third state (S220). If not (YES in S205), the ECU 50 controls the five-way valve 180 to switch the connection state of the flow paths FP1-FP3, BP from the second state to the third connection state (S210). After that, the ECU 50 controls the five-way valve 180 to switch the connection state of the flow paths FP1-FP3, BP from the third state to the first connection state (S215).

[0067] As described above, according to the embodiment, it is possible to suppress a decrease in the air conditioning comfort in the vehicle cabin.

[0068] <Other Modifications> When the thermal management circuit 100 includes an interior condenser, the heat of the heat medium in the battery circuit 160 may be dissipated to the vehicle interior via the chiller 142 and the interior condenser to heat the vehicle interior.

[0069] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0070] 1 Thermal management system, 5 Vehicle, 50 ECU, 100 Thermal management circuit, 122 LT radiator, 142 Chiller, 163 Battery, 180 Five-way valve, BP, FP1, FP2, FP3 flow path.

Claims

1. A heating system installed in a vehicle, a first flow path, a second flow path, and a third flow path through which a heat transfer medium can flow; an electricity storage device capable of exchanging heat with the heat medium in the first flow path; A chiller device provided in the second flow path; a heat absorbing device provided in the third flow path and configured to absorb heat from air outside the vehicle; a heating circuit for heating a passenger compartment of the vehicle; a heat pump cycle that performs a heating operation by receiving heat from the heat medium in the second flow path via the chiller device and transferring the heat to the heating circuit; a switching device configured to switch a connection state between the first flow path, the second flow path, and the third flow path, The connection state is a first state in which the first flow path is separated from the second flow path and the third flow path and the second flow path is connected to the third flow path; a second state in which the first flow path is connected to the second flow path and is separated from the third flow path, and the second flow path is separated from the third flow path; a third state in which the first flow path is connected to the second flow path and the third flow path, and the second flow path is connected to the third flow path; A heating system in which, when switching the connection state from one of the first state and the second state to the other state during the heating operation, the switching device performs an operation of switching the connection state from the one state to the third state, and then switching the connection state from the third state to the other state.

2. When a temperature difference between the temperature of the heat medium in the second flow path or the temperature of the heat medium in the third flow path and the temperature of the heat medium in the first flow path is defined as a first temperature difference, When switching the connection state from the first state to the second state, the switching device performing the action when the first temperature difference is equal to or greater than a first threshold; The heating system of claim 1 , wherein when the first temperature difference is less than the first threshold value, the connection state is switched to the second state without switching from the first state to the third state.

3. When a temperature difference between the temperature of the heat medium in the first flow path or the temperature of the heat medium in the second flow path and the temperature of the heat medium in the third flow path is defined as a second temperature difference, When switching the connection state from the second state to the first state, the switching device performing the action when the second temperature difference is equal to or greater than a second threshold; The heating system of claim 1 , wherein when the second temperature difference is less than the second threshold value, the connection state is switched to the first state without switching from the second state to the third state.

4. Further comprising a bypass flow path; the bypass flow path is connected to a connection portion located in a downstream portion of the power storage device in the first flow path and in an upstream portion of the chiller device in the second flow path, and is configured to be connectable to a downstream portion of the heat absorption device in the third flow path, 4. The heating system according to claim 1, wherein the third state includes a state in which a first path is formed through which the heat medium flows into the chiller device through the third flow path, the bypass flow path, and the connection portion, and a second path is formed through which the heat medium flows into the chiller device through the third flow path, the first flow path, and the connection portion.

5. The switching device is A first port connectable to the first flow path; A second port connectable to the second flow path; a third port connectable to a portion of the third flow path upstream of the heat absorption device; a fourth port connectable to a portion of the third flow path downstream of the heat absorption device; a fifth port connectable to the bypass flow path, the first state includes a state in which the first port is disconnected from the second to fifth ports, the second port is in communication with the third port, and the fourth port is in communication with the fifth port; the second state includes a state in which the first port is in communication with the second port, the third port is in communication with the fourth port, and the fifth port is separated from the first to fourth ports; The heating system according to claim 4 , wherein the third state includes a state in which the first port is in communication with the fourth and fifth ports, and the second port is in communication with the third port.

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